| 1 | /* |
| 2 | * linux/fs/ext4/inode.c |
| 3 | * |
| 4 | * Copyright (C) 1992, 1993, 1994, 1995 |
| 5 | * Remy Card (card@masi.ibp.fr) |
| 6 | * Laboratoire MASI - Institut Blaise Pascal |
| 7 | * Universite Pierre et Marie Curie (Paris VI) |
| 8 | * |
| 9 | * from |
| 10 | * |
| 11 | * linux/fs/minix/inode.c |
| 12 | * |
| 13 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 14 | * |
| 15 | * Goal-directed block allocation by Stephen Tweedie |
| 16 | * (sct@redhat.com), 1993, 1998 |
| 17 | * Big-endian to little-endian byte-swapping/bitmaps by |
| 18 | * David S. Miller (davem@caip.rutgers.edu), 1995 |
| 19 | * 64-bit file support on 64-bit platforms by Jakub Jelinek |
| 20 | * (jj@sunsite.ms.mff.cuni.cz) |
| 21 | * |
| 22 | * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000 |
| 23 | */ |
| 24 | |
| 25 | #include <linux/module.h> |
| 26 | #include <linux/fs.h> |
| 27 | #include <linux/time.h> |
| 28 | #include <linux/jbd2.h> |
| 29 | #include <linux/highuid.h> |
| 30 | #include <linux/pagemap.h> |
| 31 | #include <linux/quotaops.h> |
| 32 | #include <linux/string.h> |
| 33 | #include <linux/buffer_head.h> |
| 34 | #include <linux/writeback.h> |
| 35 | #include <linux/pagevec.h> |
| 36 | #include <linux/mpage.h> |
| 37 | #include <linux/namei.h> |
| 38 | #include <linux/uio.h> |
| 39 | #include <linux/bio.h> |
| 40 | #include <linux/workqueue.h> |
| 41 | #include <linux/kernel.h> |
| 42 | #include <linux/printk.h> |
| 43 | #include <linux/slab.h> |
| 44 | #include <linux/ratelimit.h> |
| 45 | |
| 46 | #include "ext4_jbd2.h" |
| 47 | #include "xattr.h" |
| 48 | #include "acl.h" |
| 49 | #include "ext4_extents.h" |
| 50 | |
| 51 | #include <trace/events/ext4.h> |
| 52 | |
| 53 | #define MPAGE_DA_EXTENT_TAIL 0x01 |
| 54 | |
| 55 | static inline int ext4_begin_ordered_truncate(struct inode *inode, |
| 56 | loff_t new_size) |
| 57 | { |
| 58 | trace_ext4_begin_ordered_truncate(inode, new_size); |
| 59 | /* |
| 60 | * If jinode is zero, then we never opened the file for |
| 61 | * writing, so there's no need to call |
| 62 | * jbd2_journal_begin_ordered_truncate() since there's no |
| 63 | * outstanding writes we need to flush. |
| 64 | */ |
| 65 | if (!EXT4_I(inode)->jinode) |
| 66 | return 0; |
| 67 | return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode), |
| 68 | EXT4_I(inode)->jinode, |
| 69 | new_size); |
| 70 | } |
| 71 | |
| 72 | static void ext4_invalidatepage(struct page *page, unsigned long offset); |
| 73 | static int noalloc_get_block_write(struct inode *inode, sector_t iblock, |
| 74 | struct buffer_head *bh_result, int create); |
| 75 | static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode); |
| 76 | static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate); |
| 77 | static int __ext4_journalled_writepage(struct page *page, unsigned int len); |
| 78 | static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh); |
| 79 | |
| 80 | /* |
| 81 | * Test whether an inode is a fast symlink. |
| 82 | */ |
| 83 | static int ext4_inode_is_fast_symlink(struct inode *inode) |
| 84 | { |
| 85 | int ea_blocks = EXT4_I(inode)->i_file_acl ? |
| 86 | (inode->i_sb->s_blocksize >> 9) : 0; |
| 87 | |
| 88 | return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0); |
| 89 | } |
| 90 | |
| 91 | /* |
| 92 | * Work out how many blocks we need to proceed with the next chunk of a |
| 93 | * truncate transaction. |
| 94 | */ |
| 95 | static unsigned long blocks_for_truncate(struct inode *inode) |
| 96 | { |
| 97 | ext4_lblk_t needed; |
| 98 | |
| 99 | needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9); |
| 100 | |
| 101 | /* Give ourselves just enough room to cope with inodes in which |
| 102 | * i_blocks is corrupt: we've seen disk corruptions in the past |
| 103 | * which resulted in random data in an inode which looked enough |
| 104 | * like a regular file for ext4 to try to delete it. Things |
| 105 | * will go a bit crazy if that happens, but at least we should |
| 106 | * try not to panic the whole kernel. */ |
| 107 | if (needed < 2) |
| 108 | needed = 2; |
| 109 | |
| 110 | /* But we need to bound the transaction so we don't overflow the |
| 111 | * journal. */ |
| 112 | if (needed > EXT4_MAX_TRANS_DATA) |
| 113 | needed = EXT4_MAX_TRANS_DATA; |
| 114 | |
| 115 | return EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + needed; |
| 116 | } |
| 117 | |
| 118 | /* |
| 119 | * Truncate transactions can be complex and absolutely huge. So we need to |
| 120 | * be able to restart the transaction at a conventient checkpoint to make |
| 121 | * sure we don't overflow the journal. |
| 122 | * |
| 123 | * start_transaction gets us a new handle for a truncate transaction, |
| 124 | * and extend_transaction tries to extend the existing one a bit. If |
| 125 | * extend fails, we need to propagate the failure up and restart the |
| 126 | * transaction in the top-level truncate loop. --sct |
| 127 | */ |
| 128 | static handle_t *start_transaction(struct inode *inode) |
| 129 | { |
| 130 | handle_t *result; |
| 131 | |
| 132 | result = ext4_journal_start(inode, blocks_for_truncate(inode)); |
| 133 | if (!IS_ERR(result)) |
| 134 | return result; |
| 135 | |
| 136 | ext4_std_error(inode->i_sb, PTR_ERR(result)); |
| 137 | return result; |
| 138 | } |
| 139 | |
| 140 | /* |
| 141 | * Try to extend this transaction for the purposes of truncation. |
| 142 | * |
| 143 | * Returns 0 if we managed to create more room. If we can't create more |
| 144 | * room, and the transaction must be restarted we return 1. |
| 145 | */ |
| 146 | static int try_to_extend_transaction(handle_t *handle, struct inode *inode) |
| 147 | { |
| 148 | if (!ext4_handle_valid(handle)) |
| 149 | return 0; |
| 150 | if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1)) |
| 151 | return 0; |
| 152 | if (!ext4_journal_extend(handle, blocks_for_truncate(inode))) |
| 153 | return 0; |
| 154 | return 1; |
| 155 | } |
| 156 | |
| 157 | /* |
| 158 | * Restart the transaction associated with *handle. This does a commit, |
| 159 | * so before we call here everything must be consistently dirtied against |
| 160 | * this transaction. |
| 161 | */ |
| 162 | int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode, |
| 163 | int nblocks) |
| 164 | { |
| 165 | int ret; |
| 166 | |
| 167 | /* |
| 168 | * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this |
| 169 | * moment, get_block can be called only for blocks inside i_size since |
| 170 | * page cache has been already dropped and writes are blocked by |
| 171 | * i_mutex. So we can safely drop the i_data_sem here. |
| 172 | */ |
| 173 | BUG_ON(EXT4_JOURNAL(inode) == NULL); |
| 174 | jbd_debug(2, "restarting handle %p\n", handle); |
| 175 | up_write(&EXT4_I(inode)->i_data_sem); |
| 176 | ret = ext4_journal_restart(handle, nblocks); |
| 177 | down_write(&EXT4_I(inode)->i_data_sem); |
| 178 | ext4_discard_preallocations(inode); |
| 179 | |
| 180 | return ret; |
| 181 | } |
| 182 | |
| 183 | /* |
| 184 | * Called at the last iput() if i_nlink is zero. |
| 185 | */ |
| 186 | void ext4_evict_inode(struct inode *inode) |
| 187 | { |
| 188 | handle_t *handle; |
| 189 | int err; |
| 190 | |
| 191 | trace_ext4_evict_inode(inode); |
| 192 | if (inode->i_nlink) { |
| 193 | truncate_inode_pages(&inode->i_data, 0); |
| 194 | goto no_delete; |
| 195 | } |
| 196 | |
| 197 | if (!is_bad_inode(inode)) |
| 198 | dquot_initialize(inode); |
| 199 | |
| 200 | if (ext4_should_order_data(inode)) |
| 201 | ext4_begin_ordered_truncate(inode, 0); |
| 202 | truncate_inode_pages(&inode->i_data, 0); |
| 203 | |
| 204 | if (is_bad_inode(inode)) |
| 205 | goto no_delete; |
| 206 | |
| 207 | handle = ext4_journal_start(inode, blocks_for_truncate(inode)+3); |
| 208 | if (IS_ERR(handle)) { |
| 209 | ext4_std_error(inode->i_sb, PTR_ERR(handle)); |
| 210 | /* |
| 211 | * If we're going to skip the normal cleanup, we still need to |
| 212 | * make sure that the in-core orphan linked list is properly |
| 213 | * cleaned up. |
| 214 | */ |
| 215 | ext4_orphan_del(NULL, inode); |
| 216 | goto no_delete; |
| 217 | } |
| 218 | |
| 219 | if (IS_SYNC(inode)) |
| 220 | ext4_handle_sync(handle); |
| 221 | inode->i_size = 0; |
| 222 | err = ext4_mark_inode_dirty(handle, inode); |
| 223 | if (err) { |
| 224 | ext4_warning(inode->i_sb, |
| 225 | "couldn't mark inode dirty (err %d)", err); |
| 226 | goto stop_handle; |
| 227 | } |
| 228 | if (inode->i_blocks) |
| 229 | ext4_truncate(inode); |
| 230 | |
| 231 | /* |
| 232 | * ext4_ext_truncate() doesn't reserve any slop when it |
| 233 | * restarts journal transactions; therefore there may not be |
| 234 | * enough credits left in the handle to remove the inode from |
| 235 | * the orphan list and set the dtime field. |
| 236 | */ |
| 237 | if (!ext4_handle_has_enough_credits(handle, 3)) { |
| 238 | err = ext4_journal_extend(handle, 3); |
| 239 | if (err > 0) |
| 240 | err = ext4_journal_restart(handle, 3); |
| 241 | if (err != 0) { |
| 242 | ext4_warning(inode->i_sb, |
| 243 | "couldn't extend journal (err %d)", err); |
| 244 | stop_handle: |
| 245 | ext4_journal_stop(handle); |
| 246 | ext4_orphan_del(NULL, inode); |
| 247 | goto no_delete; |
| 248 | } |
| 249 | } |
| 250 | |
| 251 | /* |
| 252 | * Kill off the orphan record which ext4_truncate created. |
| 253 | * AKPM: I think this can be inside the above `if'. |
| 254 | * Note that ext4_orphan_del() has to be able to cope with the |
| 255 | * deletion of a non-existent orphan - this is because we don't |
| 256 | * know if ext4_truncate() actually created an orphan record. |
| 257 | * (Well, we could do this if we need to, but heck - it works) |
| 258 | */ |
| 259 | ext4_orphan_del(handle, inode); |
| 260 | EXT4_I(inode)->i_dtime = get_seconds(); |
| 261 | |
| 262 | /* |
| 263 | * One subtle ordering requirement: if anything has gone wrong |
| 264 | * (transaction abort, IO errors, whatever), then we can still |
| 265 | * do these next steps (the fs will already have been marked as |
| 266 | * having errors), but we can't free the inode if the mark_dirty |
| 267 | * fails. |
| 268 | */ |
| 269 | if (ext4_mark_inode_dirty(handle, inode)) |
| 270 | /* If that failed, just do the required in-core inode clear. */ |
| 271 | ext4_clear_inode(inode); |
| 272 | else |
| 273 | ext4_free_inode(handle, inode); |
| 274 | ext4_journal_stop(handle); |
| 275 | return; |
| 276 | no_delete: |
| 277 | ext4_clear_inode(inode); /* We must guarantee clearing of inode... */ |
| 278 | } |
| 279 | |
| 280 | typedef struct { |
| 281 | __le32 *p; |
| 282 | __le32 key; |
| 283 | struct buffer_head *bh; |
| 284 | } Indirect; |
| 285 | |
| 286 | static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) |
| 287 | { |
| 288 | p->key = *(p->p = v); |
| 289 | p->bh = bh; |
| 290 | } |
| 291 | |
| 292 | /** |
| 293 | * ext4_block_to_path - parse the block number into array of offsets |
| 294 | * @inode: inode in question (we are only interested in its superblock) |
| 295 | * @i_block: block number to be parsed |
| 296 | * @offsets: array to store the offsets in |
| 297 | * @boundary: set this non-zero if the referred-to block is likely to be |
| 298 | * followed (on disk) by an indirect block. |
| 299 | * |
| 300 | * To store the locations of file's data ext4 uses a data structure common |
| 301 | * for UNIX filesystems - tree of pointers anchored in the inode, with |
| 302 | * data blocks at leaves and indirect blocks in intermediate nodes. |
| 303 | * This function translates the block number into path in that tree - |
| 304 | * return value is the path length and @offsets[n] is the offset of |
| 305 | * pointer to (n+1)th node in the nth one. If @block is out of range |
| 306 | * (negative or too large) warning is printed and zero returned. |
| 307 | * |
| 308 | * Note: function doesn't find node addresses, so no IO is needed. All |
| 309 | * we need to know is the capacity of indirect blocks (taken from the |
| 310 | * inode->i_sb). |
| 311 | */ |
| 312 | |
| 313 | /* |
| 314 | * Portability note: the last comparison (check that we fit into triple |
| 315 | * indirect block) is spelled differently, because otherwise on an |
| 316 | * architecture with 32-bit longs and 8Kb pages we might get into trouble |
| 317 | * if our filesystem had 8Kb blocks. We might use long long, but that would |
| 318 | * kill us on x86. Oh, well, at least the sign propagation does not matter - |
| 319 | * i_block would have to be negative in the very beginning, so we would not |
| 320 | * get there at all. |
| 321 | */ |
| 322 | |
| 323 | static int ext4_block_to_path(struct inode *inode, |
| 324 | ext4_lblk_t i_block, |
| 325 | ext4_lblk_t offsets[4], int *boundary) |
| 326 | { |
| 327 | int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb); |
| 328 | int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb); |
| 329 | const long direct_blocks = EXT4_NDIR_BLOCKS, |
| 330 | indirect_blocks = ptrs, |
| 331 | double_blocks = (1 << (ptrs_bits * 2)); |
| 332 | int n = 0; |
| 333 | int final = 0; |
| 334 | |
| 335 | if (i_block < direct_blocks) { |
| 336 | offsets[n++] = i_block; |
| 337 | final = direct_blocks; |
| 338 | } else if ((i_block -= direct_blocks) < indirect_blocks) { |
| 339 | offsets[n++] = EXT4_IND_BLOCK; |
| 340 | offsets[n++] = i_block; |
| 341 | final = ptrs; |
| 342 | } else if ((i_block -= indirect_blocks) < double_blocks) { |
| 343 | offsets[n++] = EXT4_DIND_BLOCK; |
| 344 | offsets[n++] = i_block >> ptrs_bits; |
| 345 | offsets[n++] = i_block & (ptrs - 1); |
| 346 | final = ptrs; |
| 347 | } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { |
| 348 | offsets[n++] = EXT4_TIND_BLOCK; |
| 349 | offsets[n++] = i_block >> (ptrs_bits * 2); |
| 350 | offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); |
| 351 | offsets[n++] = i_block & (ptrs - 1); |
| 352 | final = ptrs; |
| 353 | } else { |
| 354 | ext4_warning(inode->i_sb, "block %lu > max in inode %lu", |
| 355 | i_block + direct_blocks + |
| 356 | indirect_blocks + double_blocks, inode->i_ino); |
| 357 | } |
| 358 | if (boundary) |
| 359 | *boundary = final - 1 - (i_block & (ptrs - 1)); |
| 360 | return n; |
| 361 | } |
| 362 | |
| 363 | static int __ext4_check_blockref(const char *function, unsigned int line, |
| 364 | struct inode *inode, |
| 365 | __le32 *p, unsigned int max) |
| 366 | { |
| 367 | struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es; |
| 368 | __le32 *bref = p; |
| 369 | unsigned int blk; |
| 370 | |
| 371 | while (bref < p+max) { |
| 372 | blk = le32_to_cpu(*bref++); |
| 373 | if (blk && |
| 374 | unlikely(!ext4_data_block_valid(EXT4_SB(inode->i_sb), |
| 375 | blk, 1))) { |
| 376 | es->s_last_error_block = cpu_to_le64(blk); |
| 377 | ext4_error_inode(inode, function, line, blk, |
| 378 | "invalid block"); |
| 379 | return -EIO; |
| 380 | } |
| 381 | } |
| 382 | return 0; |
| 383 | } |
| 384 | |
| 385 | |
| 386 | #define ext4_check_indirect_blockref(inode, bh) \ |
| 387 | __ext4_check_blockref(__func__, __LINE__, inode, \ |
| 388 | (__le32 *)(bh)->b_data, \ |
| 389 | EXT4_ADDR_PER_BLOCK((inode)->i_sb)) |
| 390 | |
| 391 | #define ext4_check_inode_blockref(inode) \ |
| 392 | __ext4_check_blockref(__func__, __LINE__, inode, \ |
| 393 | EXT4_I(inode)->i_data, \ |
| 394 | EXT4_NDIR_BLOCKS) |
| 395 | |
| 396 | /** |
| 397 | * ext4_get_branch - read the chain of indirect blocks leading to data |
| 398 | * @inode: inode in question |
| 399 | * @depth: depth of the chain (1 - direct pointer, etc.) |
| 400 | * @offsets: offsets of pointers in inode/indirect blocks |
| 401 | * @chain: place to store the result |
| 402 | * @err: here we store the error value |
| 403 | * |
| 404 | * Function fills the array of triples <key, p, bh> and returns %NULL |
| 405 | * if everything went OK or the pointer to the last filled triple |
| 406 | * (incomplete one) otherwise. Upon the return chain[i].key contains |
| 407 | * the number of (i+1)-th block in the chain (as it is stored in memory, |
| 408 | * i.e. little-endian 32-bit), chain[i].p contains the address of that |
| 409 | * number (it points into struct inode for i==0 and into the bh->b_data |
| 410 | * for i>0) and chain[i].bh points to the buffer_head of i-th indirect |
| 411 | * block for i>0 and NULL for i==0. In other words, it holds the block |
| 412 | * numbers of the chain, addresses they were taken from (and where we can |
| 413 | * verify that chain did not change) and buffer_heads hosting these |
| 414 | * numbers. |
| 415 | * |
| 416 | * Function stops when it stumbles upon zero pointer (absent block) |
| 417 | * (pointer to last triple returned, *@err == 0) |
| 418 | * or when it gets an IO error reading an indirect block |
| 419 | * (ditto, *@err == -EIO) |
| 420 | * or when it reads all @depth-1 indirect blocks successfully and finds |
| 421 | * the whole chain, all way to the data (returns %NULL, *err == 0). |
| 422 | * |
| 423 | * Need to be called with |
| 424 | * down_read(&EXT4_I(inode)->i_data_sem) |
| 425 | */ |
| 426 | static Indirect *ext4_get_branch(struct inode *inode, int depth, |
| 427 | ext4_lblk_t *offsets, |
| 428 | Indirect chain[4], int *err) |
| 429 | { |
| 430 | struct super_block *sb = inode->i_sb; |
| 431 | Indirect *p = chain; |
| 432 | struct buffer_head *bh; |
| 433 | |
| 434 | *err = 0; |
| 435 | /* i_data is not going away, no lock needed */ |
| 436 | add_chain(chain, NULL, EXT4_I(inode)->i_data + *offsets); |
| 437 | if (!p->key) |
| 438 | goto no_block; |
| 439 | while (--depth) { |
| 440 | bh = sb_getblk(sb, le32_to_cpu(p->key)); |
| 441 | if (unlikely(!bh)) |
| 442 | goto failure; |
| 443 | |
| 444 | if (!bh_uptodate_or_lock(bh)) { |
| 445 | if (bh_submit_read(bh) < 0) { |
| 446 | put_bh(bh); |
| 447 | goto failure; |
| 448 | } |
| 449 | /* validate block references */ |
| 450 | if (ext4_check_indirect_blockref(inode, bh)) { |
| 451 | put_bh(bh); |
| 452 | goto failure; |
| 453 | } |
| 454 | } |
| 455 | |
| 456 | add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets); |
| 457 | /* Reader: end */ |
| 458 | if (!p->key) |
| 459 | goto no_block; |
| 460 | } |
| 461 | return NULL; |
| 462 | |
| 463 | failure: |
| 464 | *err = -EIO; |
| 465 | no_block: |
| 466 | return p; |
| 467 | } |
| 468 | |
| 469 | /** |
| 470 | * ext4_find_near - find a place for allocation with sufficient locality |
| 471 | * @inode: owner |
| 472 | * @ind: descriptor of indirect block. |
| 473 | * |
| 474 | * This function returns the preferred place for block allocation. |
| 475 | * It is used when heuristic for sequential allocation fails. |
| 476 | * Rules are: |
| 477 | * + if there is a block to the left of our position - allocate near it. |
| 478 | * + if pointer will live in indirect block - allocate near that block. |
| 479 | * + if pointer will live in inode - allocate in the same |
| 480 | * cylinder group. |
| 481 | * |
| 482 | * In the latter case we colour the starting block by the callers PID to |
| 483 | * prevent it from clashing with concurrent allocations for a different inode |
| 484 | * in the same block group. The PID is used here so that functionally related |
| 485 | * files will be close-by on-disk. |
| 486 | * |
| 487 | * Caller must make sure that @ind is valid and will stay that way. |
| 488 | */ |
| 489 | static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind) |
| 490 | { |
| 491 | struct ext4_inode_info *ei = EXT4_I(inode); |
| 492 | __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; |
| 493 | __le32 *p; |
| 494 | ext4_fsblk_t bg_start; |
| 495 | ext4_fsblk_t last_block; |
| 496 | ext4_grpblk_t colour; |
| 497 | ext4_group_t block_group; |
| 498 | int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb)); |
| 499 | |
| 500 | /* Try to find previous block */ |
| 501 | for (p = ind->p - 1; p >= start; p--) { |
| 502 | if (*p) |
| 503 | return le32_to_cpu(*p); |
| 504 | } |
| 505 | |
| 506 | /* No such thing, so let's try location of indirect block */ |
| 507 | if (ind->bh) |
| 508 | return ind->bh->b_blocknr; |
| 509 | |
| 510 | /* |
| 511 | * It is going to be referred to from the inode itself? OK, just put it |
| 512 | * into the same cylinder group then. |
| 513 | */ |
| 514 | block_group = ei->i_block_group; |
| 515 | if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) { |
| 516 | block_group &= ~(flex_size-1); |
| 517 | if (S_ISREG(inode->i_mode)) |
| 518 | block_group++; |
| 519 | } |
| 520 | bg_start = ext4_group_first_block_no(inode->i_sb, block_group); |
| 521 | last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1; |
| 522 | |
| 523 | /* |
| 524 | * If we are doing delayed allocation, we don't need take |
| 525 | * colour into account. |
| 526 | */ |
| 527 | if (test_opt(inode->i_sb, DELALLOC)) |
| 528 | return bg_start; |
| 529 | |
| 530 | if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block) |
| 531 | colour = (current->pid % 16) * |
| 532 | (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16); |
| 533 | else |
| 534 | colour = (current->pid % 16) * ((last_block - bg_start) / 16); |
| 535 | return bg_start + colour; |
| 536 | } |
| 537 | |
| 538 | /** |
| 539 | * ext4_find_goal - find a preferred place for allocation. |
| 540 | * @inode: owner |
| 541 | * @block: block we want |
| 542 | * @partial: pointer to the last triple within a chain |
| 543 | * |
| 544 | * Normally this function find the preferred place for block allocation, |
| 545 | * returns it. |
| 546 | * Because this is only used for non-extent files, we limit the block nr |
| 547 | * to 32 bits. |
| 548 | */ |
| 549 | static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block, |
| 550 | Indirect *partial) |
| 551 | { |
| 552 | ext4_fsblk_t goal; |
| 553 | |
| 554 | /* |
| 555 | * XXX need to get goal block from mballoc's data structures |
| 556 | */ |
| 557 | |
| 558 | goal = ext4_find_near(inode, partial); |
| 559 | goal = goal & EXT4_MAX_BLOCK_FILE_PHYS; |
| 560 | return goal; |
| 561 | } |
| 562 | |
| 563 | /** |
| 564 | * ext4_blks_to_allocate - Look up the block map and count the number |
| 565 | * of direct blocks need to be allocated for the given branch. |
| 566 | * |
| 567 | * @branch: chain of indirect blocks |
| 568 | * @k: number of blocks need for indirect blocks |
| 569 | * @blks: number of data blocks to be mapped. |
| 570 | * @blocks_to_boundary: the offset in the indirect block |
| 571 | * |
| 572 | * return the total number of blocks to be allocate, including the |
| 573 | * direct and indirect blocks. |
| 574 | */ |
| 575 | static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned int blks, |
| 576 | int blocks_to_boundary) |
| 577 | { |
| 578 | unsigned int count = 0; |
| 579 | |
| 580 | /* |
| 581 | * Simple case, [t,d]Indirect block(s) has not allocated yet |
| 582 | * then it's clear blocks on that path have not allocated |
| 583 | */ |
| 584 | if (k > 0) { |
| 585 | /* right now we don't handle cross boundary allocation */ |
| 586 | if (blks < blocks_to_boundary + 1) |
| 587 | count += blks; |
| 588 | else |
| 589 | count += blocks_to_boundary + 1; |
| 590 | return count; |
| 591 | } |
| 592 | |
| 593 | count++; |
| 594 | while (count < blks && count <= blocks_to_boundary && |
| 595 | le32_to_cpu(*(branch[0].p + count)) == 0) { |
| 596 | count++; |
| 597 | } |
| 598 | return count; |
| 599 | } |
| 600 | |
| 601 | /** |
| 602 | * ext4_alloc_blocks: multiple allocate blocks needed for a branch |
| 603 | * @handle: handle for this transaction |
| 604 | * @inode: inode which needs allocated blocks |
| 605 | * @iblock: the logical block to start allocated at |
| 606 | * @goal: preferred physical block of allocation |
| 607 | * @indirect_blks: the number of blocks need to allocate for indirect |
| 608 | * blocks |
| 609 | * @blks: number of desired blocks |
| 610 | * @new_blocks: on return it will store the new block numbers for |
| 611 | * the indirect blocks(if needed) and the first direct block, |
| 612 | * @err: on return it will store the error code |
| 613 | * |
| 614 | * This function will return the number of blocks allocated as |
| 615 | * requested by the passed-in parameters. |
| 616 | */ |
| 617 | static int ext4_alloc_blocks(handle_t *handle, struct inode *inode, |
| 618 | ext4_lblk_t iblock, ext4_fsblk_t goal, |
| 619 | int indirect_blks, int blks, |
| 620 | ext4_fsblk_t new_blocks[4], int *err) |
| 621 | { |
| 622 | struct ext4_allocation_request ar; |
| 623 | int target, i; |
| 624 | unsigned long count = 0, blk_allocated = 0; |
| 625 | int index = 0; |
| 626 | ext4_fsblk_t current_block = 0; |
| 627 | int ret = 0; |
| 628 | |
| 629 | /* |
| 630 | * Here we try to allocate the requested multiple blocks at once, |
| 631 | * on a best-effort basis. |
| 632 | * To build a branch, we should allocate blocks for |
| 633 | * the indirect blocks(if not allocated yet), and at least |
| 634 | * the first direct block of this branch. That's the |
| 635 | * minimum number of blocks need to allocate(required) |
| 636 | */ |
| 637 | /* first we try to allocate the indirect blocks */ |
| 638 | target = indirect_blks; |
| 639 | while (target > 0) { |
| 640 | count = target; |
| 641 | /* allocating blocks for indirect blocks and direct blocks */ |
| 642 | current_block = ext4_new_meta_blocks(handle, inode, goal, |
| 643 | 0, &count, err); |
| 644 | if (*err) |
| 645 | goto failed_out; |
| 646 | |
| 647 | if (unlikely(current_block + count > EXT4_MAX_BLOCK_FILE_PHYS)) { |
| 648 | EXT4_ERROR_INODE(inode, |
| 649 | "current_block %llu + count %lu > %d!", |
| 650 | current_block, count, |
| 651 | EXT4_MAX_BLOCK_FILE_PHYS); |
| 652 | *err = -EIO; |
| 653 | goto failed_out; |
| 654 | } |
| 655 | |
| 656 | target -= count; |
| 657 | /* allocate blocks for indirect blocks */ |
| 658 | while (index < indirect_blks && count) { |
| 659 | new_blocks[index++] = current_block++; |
| 660 | count--; |
| 661 | } |
| 662 | if (count > 0) { |
| 663 | /* |
| 664 | * save the new block number |
| 665 | * for the first direct block |
| 666 | */ |
| 667 | new_blocks[index] = current_block; |
| 668 | printk(KERN_INFO "%s returned more blocks than " |
| 669 | "requested\n", __func__); |
| 670 | WARN_ON(1); |
| 671 | break; |
| 672 | } |
| 673 | } |
| 674 | |
| 675 | target = blks - count ; |
| 676 | blk_allocated = count; |
| 677 | if (!target) |
| 678 | goto allocated; |
| 679 | /* Now allocate data blocks */ |
| 680 | memset(&ar, 0, sizeof(ar)); |
| 681 | ar.inode = inode; |
| 682 | ar.goal = goal; |
| 683 | ar.len = target; |
| 684 | ar.logical = iblock; |
| 685 | if (S_ISREG(inode->i_mode)) |
| 686 | /* enable in-core preallocation only for regular files */ |
| 687 | ar.flags = EXT4_MB_HINT_DATA; |
| 688 | |
| 689 | current_block = ext4_mb_new_blocks(handle, &ar, err); |
| 690 | if (unlikely(current_block + ar.len > EXT4_MAX_BLOCK_FILE_PHYS)) { |
| 691 | EXT4_ERROR_INODE(inode, |
| 692 | "current_block %llu + ar.len %d > %d!", |
| 693 | current_block, ar.len, |
| 694 | EXT4_MAX_BLOCK_FILE_PHYS); |
| 695 | *err = -EIO; |
| 696 | goto failed_out; |
| 697 | } |
| 698 | |
| 699 | if (*err && (target == blks)) { |
| 700 | /* |
| 701 | * if the allocation failed and we didn't allocate |
| 702 | * any blocks before |
| 703 | */ |
| 704 | goto failed_out; |
| 705 | } |
| 706 | if (!*err) { |
| 707 | if (target == blks) { |
| 708 | /* |
| 709 | * save the new block number |
| 710 | * for the first direct block |
| 711 | */ |
| 712 | new_blocks[index] = current_block; |
| 713 | } |
| 714 | blk_allocated += ar.len; |
| 715 | } |
| 716 | allocated: |
| 717 | /* total number of blocks allocated for direct blocks */ |
| 718 | ret = blk_allocated; |
| 719 | *err = 0; |
| 720 | return ret; |
| 721 | failed_out: |
| 722 | for (i = 0; i < index; i++) |
| 723 | ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1, 0); |
| 724 | return ret; |
| 725 | } |
| 726 | |
| 727 | /** |
| 728 | * ext4_alloc_branch - allocate and set up a chain of blocks. |
| 729 | * @handle: handle for this transaction |
| 730 | * @inode: owner |
| 731 | * @indirect_blks: number of allocated indirect blocks |
| 732 | * @blks: number of allocated direct blocks |
| 733 | * @goal: preferred place for allocation |
| 734 | * @offsets: offsets (in the blocks) to store the pointers to next. |
| 735 | * @branch: place to store the chain in. |
| 736 | * |
| 737 | * This function allocates blocks, zeroes out all but the last one, |
| 738 | * links them into chain and (if we are synchronous) writes them to disk. |
| 739 | * In other words, it prepares a branch that can be spliced onto the |
| 740 | * inode. It stores the information about that chain in the branch[], in |
| 741 | * the same format as ext4_get_branch() would do. We are calling it after |
| 742 | * we had read the existing part of chain and partial points to the last |
| 743 | * triple of that (one with zero ->key). Upon the exit we have the same |
| 744 | * picture as after the successful ext4_get_block(), except that in one |
| 745 | * place chain is disconnected - *branch->p is still zero (we did not |
| 746 | * set the last link), but branch->key contains the number that should |
| 747 | * be placed into *branch->p to fill that gap. |
| 748 | * |
| 749 | * If allocation fails we free all blocks we've allocated (and forget |
| 750 | * their buffer_heads) and return the error value the from failed |
| 751 | * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain |
| 752 | * as described above and return 0. |
| 753 | */ |
| 754 | static int ext4_alloc_branch(handle_t *handle, struct inode *inode, |
| 755 | ext4_lblk_t iblock, int indirect_blks, |
| 756 | int *blks, ext4_fsblk_t goal, |
| 757 | ext4_lblk_t *offsets, Indirect *branch) |
| 758 | { |
| 759 | int blocksize = inode->i_sb->s_blocksize; |
| 760 | int i, n = 0; |
| 761 | int err = 0; |
| 762 | struct buffer_head *bh; |
| 763 | int num; |
| 764 | ext4_fsblk_t new_blocks[4]; |
| 765 | ext4_fsblk_t current_block; |
| 766 | |
| 767 | num = ext4_alloc_blocks(handle, inode, iblock, goal, indirect_blks, |
| 768 | *blks, new_blocks, &err); |
| 769 | if (err) |
| 770 | return err; |
| 771 | |
| 772 | branch[0].key = cpu_to_le32(new_blocks[0]); |
| 773 | /* |
| 774 | * metadata blocks and data blocks are allocated. |
| 775 | */ |
| 776 | for (n = 1; n <= indirect_blks; n++) { |
| 777 | /* |
| 778 | * Get buffer_head for parent block, zero it out |
| 779 | * and set the pointer to new one, then send |
| 780 | * parent to disk. |
| 781 | */ |
| 782 | bh = sb_getblk(inode->i_sb, new_blocks[n-1]); |
| 783 | if (unlikely(!bh)) { |
| 784 | err = -EIO; |
| 785 | goto failed; |
| 786 | } |
| 787 | |
| 788 | branch[n].bh = bh; |
| 789 | lock_buffer(bh); |
| 790 | BUFFER_TRACE(bh, "call get_create_access"); |
| 791 | err = ext4_journal_get_create_access(handle, bh); |
| 792 | if (err) { |
| 793 | /* Don't brelse(bh) here; it's done in |
| 794 | * ext4_journal_forget() below */ |
| 795 | unlock_buffer(bh); |
| 796 | goto failed; |
| 797 | } |
| 798 | |
| 799 | memset(bh->b_data, 0, blocksize); |
| 800 | branch[n].p = (__le32 *) bh->b_data + offsets[n]; |
| 801 | branch[n].key = cpu_to_le32(new_blocks[n]); |
| 802 | *branch[n].p = branch[n].key; |
| 803 | if (n == indirect_blks) { |
| 804 | current_block = new_blocks[n]; |
| 805 | /* |
| 806 | * End of chain, update the last new metablock of |
| 807 | * the chain to point to the new allocated |
| 808 | * data blocks numbers |
| 809 | */ |
| 810 | for (i = 1; i < num; i++) |
| 811 | *(branch[n].p + i) = cpu_to_le32(++current_block); |
| 812 | } |
| 813 | BUFFER_TRACE(bh, "marking uptodate"); |
| 814 | set_buffer_uptodate(bh); |
| 815 | unlock_buffer(bh); |
| 816 | |
| 817 | BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); |
| 818 | err = ext4_handle_dirty_metadata(handle, inode, bh); |
| 819 | if (err) |
| 820 | goto failed; |
| 821 | } |
| 822 | *blks = num; |
| 823 | return err; |
| 824 | failed: |
| 825 | /* Allocation failed, free what we already allocated */ |
| 826 | ext4_free_blocks(handle, inode, NULL, new_blocks[0], 1, 0); |
| 827 | for (i = 1; i <= n ; i++) { |
| 828 | /* |
| 829 | * branch[i].bh is newly allocated, so there is no |
| 830 | * need to revoke the block, which is why we don't |
| 831 | * need to set EXT4_FREE_BLOCKS_METADATA. |
| 832 | */ |
| 833 | ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1, |
| 834 | EXT4_FREE_BLOCKS_FORGET); |
| 835 | } |
| 836 | for (i = n+1; i < indirect_blks; i++) |
| 837 | ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1, 0); |
| 838 | |
| 839 | ext4_free_blocks(handle, inode, NULL, new_blocks[i], num, 0); |
| 840 | |
| 841 | return err; |
| 842 | } |
| 843 | |
| 844 | /** |
| 845 | * ext4_splice_branch - splice the allocated branch onto inode. |
| 846 | * @handle: handle for this transaction |
| 847 | * @inode: owner |
| 848 | * @block: (logical) number of block we are adding |
| 849 | * @chain: chain of indirect blocks (with a missing link - see |
| 850 | * ext4_alloc_branch) |
| 851 | * @where: location of missing link |
| 852 | * @num: number of indirect blocks we are adding |
| 853 | * @blks: number of direct blocks we are adding |
| 854 | * |
| 855 | * This function fills the missing link and does all housekeeping needed in |
| 856 | * inode (->i_blocks, etc.). In case of success we end up with the full |
| 857 | * chain to new block and return 0. |
| 858 | */ |
| 859 | static int ext4_splice_branch(handle_t *handle, struct inode *inode, |
| 860 | ext4_lblk_t block, Indirect *where, int num, |
| 861 | int blks) |
| 862 | { |
| 863 | int i; |
| 864 | int err = 0; |
| 865 | ext4_fsblk_t current_block; |
| 866 | |
| 867 | /* |
| 868 | * If we're splicing into a [td]indirect block (as opposed to the |
| 869 | * inode) then we need to get write access to the [td]indirect block |
| 870 | * before the splice. |
| 871 | */ |
| 872 | if (where->bh) { |
| 873 | BUFFER_TRACE(where->bh, "get_write_access"); |
| 874 | err = ext4_journal_get_write_access(handle, where->bh); |
| 875 | if (err) |
| 876 | goto err_out; |
| 877 | } |
| 878 | /* That's it */ |
| 879 | |
| 880 | *where->p = where->key; |
| 881 | |
| 882 | /* |
| 883 | * Update the host buffer_head or inode to point to more just allocated |
| 884 | * direct blocks blocks |
| 885 | */ |
| 886 | if (num == 0 && blks > 1) { |
| 887 | current_block = le32_to_cpu(where->key) + 1; |
| 888 | for (i = 1; i < blks; i++) |
| 889 | *(where->p + i) = cpu_to_le32(current_block++); |
| 890 | } |
| 891 | |
| 892 | /* We are done with atomic stuff, now do the rest of housekeeping */ |
| 893 | /* had we spliced it onto indirect block? */ |
| 894 | if (where->bh) { |
| 895 | /* |
| 896 | * If we spliced it onto an indirect block, we haven't |
| 897 | * altered the inode. Note however that if it is being spliced |
| 898 | * onto an indirect block at the very end of the file (the |
| 899 | * file is growing) then we *will* alter the inode to reflect |
| 900 | * the new i_size. But that is not done here - it is done in |
| 901 | * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode. |
| 902 | */ |
| 903 | jbd_debug(5, "splicing indirect only\n"); |
| 904 | BUFFER_TRACE(where->bh, "call ext4_handle_dirty_metadata"); |
| 905 | err = ext4_handle_dirty_metadata(handle, inode, where->bh); |
| 906 | if (err) |
| 907 | goto err_out; |
| 908 | } else { |
| 909 | /* |
| 910 | * OK, we spliced it into the inode itself on a direct block. |
| 911 | */ |
| 912 | ext4_mark_inode_dirty(handle, inode); |
| 913 | jbd_debug(5, "splicing direct\n"); |
| 914 | } |
| 915 | return err; |
| 916 | |
| 917 | err_out: |
| 918 | for (i = 1; i <= num; i++) { |
| 919 | /* |
| 920 | * branch[i].bh is newly allocated, so there is no |
| 921 | * need to revoke the block, which is why we don't |
| 922 | * need to set EXT4_FREE_BLOCKS_METADATA. |
| 923 | */ |
| 924 | ext4_free_blocks(handle, inode, where[i].bh, 0, 1, |
| 925 | EXT4_FREE_BLOCKS_FORGET); |
| 926 | } |
| 927 | ext4_free_blocks(handle, inode, NULL, le32_to_cpu(where[num].key), |
| 928 | blks, 0); |
| 929 | |
| 930 | return err; |
| 931 | } |
| 932 | |
| 933 | /* |
| 934 | * The ext4_ind_map_blocks() function handles non-extents inodes |
| 935 | * (i.e., using the traditional indirect/double-indirect i_blocks |
| 936 | * scheme) for ext4_map_blocks(). |
| 937 | * |
| 938 | * Allocation strategy is simple: if we have to allocate something, we will |
| 939 | * have to go the whole way to leaf. So let's do it before attaching anything |
| 940 | * to tree, set linkage between the newborn blocks, write them if sync is |
| 941 | * required, recheck the path, free and repeat if check fails, otherwise |
| 942 | * set the last missing link (that will protect us from any truncate-generated |
| 943 | * removals - all blocks on the path are immune now) and possibly force the |
| 944 | * write on the parent block. |
| 945 | * That has a nice additional property: no special recovery from the failed |
| 946 | * allocations is needed - we simply release blocks and do not touch anything |
| 947 | * reachable from inode. |
| 948 | * |
| 949 | * `handle' can be NULL if create == 0. |
| 950 | * |
| 951 | * return > 0, # of blocks mapped or allocated. |
| 952 | * return = 0, if plain lookup failed. |
| 953 | * return < 0, error case. |
| 954 | * |
| 955 | * The ext4_ind_get_blocks() function should be called with |
| 956 | * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem |
| 957 | * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or |
| 958 | * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system |
| 959 | * blocks. |
| 960 | */ |
| 961 | static int ext4_ind_map_blocks(handle_t *handle, struct inode *inode, |
| 962 | struct ext4_map_blocks *map, |
| 963 | int flags) |
| 964 | { |
| 965 | int err = -EIO; |
| 966 | ext4_lblk_t offsets[4]; |
| 967 | Indirect chain[4]; |
| 968 | Indirect *partial; |
| 969 | ext4_fsblk_t goal; |
| 970 | int indirect_blks; |
| 971 | int blocks_to_boundary = 0; |
| 972 | int depth; |
| 973 | int count = 0; |
| 974 | ext4_fsblk_t first_block = 0; |
| 975 | |
| 976 | trace_ext4_ind_map_blocks_enter(inode, map->m_lblk, map->m_len, flags); |
| 977 | J_ASSERT(!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))); |
| 978 | J_ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0); |
| 979 | depth = ext4_block_to_path(inode, map->m_lblk, offsets, |
| 980 | &blocks_to_boundary); |
| 981 | |
| 982 | if (depth == 0) |
| 983 | goto out; |
| 984 | |
| 985 | partial = ext4_get_branch(inode, depth, offsets, chain, &err); |
| 986 | |
| 987 | /* Simplest case - block found, no allocation needed */ |
| 988 | if (!partial) { |
| 989 | first_block = le32_to_cpu(chain[depth - 1].key); |
| 990 | count++; |
| 991 | /*map more blocks*/ |
| 992 | while (count < map->m_len && count <= blocks_to_boundary) { |
| 993 | ext4_fsblk_t blk; |
| 994 | |
| 995 | blk = le32_to_cpu(*(chain[depth-1].p + count)); |
| 996 | |
| 997 | if (blk == first_block + count) |
| 998 | count++; |
| 999 | else |
| 1000 | break; |
| 1001 | } |
| 1002 | goto got_it; |
| 1003 | } |
| 1004 | |
| 1005 | /* Next simple case - plain lookup or failed read of indirect block */ |
| 1006 | if ((flags & EXT4_GET_BLOCKS_CREATE) == 0 || err == -EIO) |
| 1007 | goto cleanup; |
| 1008 | |
| 1009 | /* |
| 1010 | * Okay, we need to do block allocation. |
| 1011 | */ |
| 1012 | goal = ext4_find_goal(inode, map->m_lblk, partial); |
| 1013 | |
| 1014 | /* the number of blocks need to allocate for [d,t]indirect blocks */ |
| 1015 | indirect_blks = (chain + depth) - partial - 1; |
| 1016 | |
| 1017 | /* |
| 1018 | * Next look up the indirect map to count the totoal number of |
| 1019 | * direct blocks to allocate for this branch. |
| 1020 | */ |
| 1021 | count = ext4_blks_to_allocate(partial, indirect_blks, |
| 1022 | map->m_len, blocks_to_boundary); |
| 1023 | /* |
| 1024 | * Block out ext4_truncate while we alter the tree |
| 1025 | */ |
| 1026 | err = ext4_alloc_branch(handle, inode, map->m_lblk, indirect_blks, |
| 1027 | &count, goal, |
| 1028 | offsets + (partial - chain), partial); |
| 1029 | |
| 1030 | /* |
| 1031 | * The ext4_splice_branch call will free and forget any buffers |
| 1032 | * on the new chain if there is a failure, but that risks using |
| 1033 | * up transaction credits, especially for bitmaps where the |
| 1034 | * credits cannot be returned. Can we handle this somehow? We |
| 1035 | * may need to return -EAGAIN upwards in the worst case. --sct |
| 1036 | */ |
| 1037 | if (!err) |
| 1038 | err = ext4_splice_branch(handle, inode, map->m_lblk, |
| 1039 | partial, indirect_blks, count); |
| 1040 | if (err) |
| 1041 | goto cleanup; |
| 1042 | |
| 1043 | map->m_flags |= EXT4_MAP_NEW; |
| 1044 | |
| 1045 | ext4_update_inode_fsync_trans(handle, inode, 1); |
| 1046 | got_it: |
| 1047 | map->m_flags |= EXT4_MAP_MAPPED; |
| 1048 | map->m_pblk = le32_to_cpu(chain[depth-1].key); |
| 1049 | map->m_len = count; |
| 1050 | if (count > blocks_to_boundary) |
| 1051 | map->m_flags |= EXT4_MAP_BOUNDARY; |
| 1052 | err = count; |
| 1053 | /* Clean up and exit */ |
| 1054 | partial = chain + depth - 1; /* the whole chain */ |
| 1055 | cleanup: |
| 1056 | while (partial > chain) { |
| 1057 | BUFFER_TRACE(partial->bh, "call brelse"); |
| 1058 | brelse(partial->bh); |
| 1059 | partial--; |
| 1060 | } |
| 1061 | out: |
| 1062 | trace_ext4_ind_map_blocks_exit(inode, map->m_lblk, |
| 1063 | map->m_pblk, map->m_len, err); |
| 1064 | return err; |
| 1065 | } |
| 1066 | |
| 1067 | #ifdef CONFIG_QUOTA |
| 1068 | qsize_t *ext4_get_reserved_space(struct inode *inode) |
| 1069 | { |
| 1070 | return &EXT4_I(inode)->i_reserved_quota; |
| 1071 | } |
| 1072 | #endif |
| 1073 | |
| 1074 | /* |
| 1075 | * Calculate the number of metadata blocks need to reserve |
| 1076 | * to allocate a new block at @lblocks for non extent file based file |
| 1077 | */ |
| 1078 | static int ext4_indirect_calc_metadata_amount(struct inode *inode, |
| 1079 | sector_t lblock) |
| 1080 | { |
| 1081 | struct ext4_inode_info *ei = EXT4_I(inode); |
| 1082 | sector_t dind_mask = ~((sector_t)EXT4_ADDR_PER_BLOCK(inode->i_sb) - 1); |
| 1083 | int blk_bits; |
| 1084 | |
| 1085 | if (lblock < EXT4_NDIR_BLOCKS) |
| 1086 | return 0; |
| 1087 | |
| 1088 | lblock -= EXT4_NDIR_BLOCKS; |
| 1089 | |
| 1090 | if (ei->i_da_metadata_calc_len && |
| 1091 | (lblock & dind_mask) == ei->i_da_metadata_calc_last_lblock) { |
| 1092 | ei->i_da_metadata_calc_len++; |
| 1093 | return 0; |
| 1094 | } |
| 1095 | ei->i_da_metadata_calc_last_lblock = lblock & dind_mask; |
| 1096 | ei->i_da_metadata_calc_len = 1; |
| 1097 | blk_bits = order_base_2(lblock); |
| 1098 | return (blk_bits / EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb)) + 1; |
| 1099 | } |
| 1100 | |
| 1101 | /* |
| 1102 | * Calculate the number of metadata blocks need to reserve |
| 1103 | * to allocate a block located at @lblock |
| 1104 | */ |
| 1105 | static int ext4_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock) |
| 1106 | { |
| 1107 | if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) |
| 1108 | return ext4_ext_calc_metadata_amount(inode, lblock); |
| 1109 | |
| 1110 | return ext4_indirect_calc_metadata_amount(inode, lblock); |
| 1111 | } |
| 1112 | |
| 1113 | /* |
| 1114 | * Called with i_data_sem down, which is important since we can call |
| 1115 | * ext4_discard_preallocations() from here. |
| 1116 | */ |
| 1117 | void ext4_da_update_reserve_space(struct inode *inode, |
| 1118 | int used, int quota_claim) |
| 1119 | { |
| 1120 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| 1121 | struct ext4_inode_info *ei = EXT4_I(inode); |
| 1122 | |
| 1123 | spin_lock(&ei->i_block_reservation_lock); |
| 1124 | trace_ext4_da_update_reserve_space(inode, used); |
| 1125 | if (unlikely(used > ei->i_reserved_data_blocks)) { |
| 1126 | ext4_msg(inode->i_sb, KERN_NOTICE, "%s: ino %lu, used %d " |
| 1127 | "with only %d reserved data blocks\n", |
| 1128 | __func__, inode->i_ino, used, |
| 1129 | ei->i_reserved_data_blocks); |
| 1130 | WARN_ON(1); |
| 1131 | used = ei->i_reserved_data_blocks; |
| 1132 | } |
| 1133 | |
| 1134 | /* Update per-inode reservations */ |
| 1135 | ei->i_reserved_data_blocks -= used; |
| 1136 | ei->i_reserved_meta_blocks -= ei->i_allocated_meta_blocks; |
| 1137 | percpu_counter_sub(&sbi->s_dirtyblocks_counter, |
| 1138 | used + ei->i_allocated_meta_blocks); |
| 1139 | ei->i_allocated_meta_blocks = 0; |
| 1140 | |
| 1141 | if (ei->i_reserved_data_blocks == 0) { |
| 1142 | /* |
| 1143 | * We can release all of the reserved metadata blocks |
| 1144 | * only when we have written all of the delayed |
| 1145 | * allocation blocks. |
| 1146 | */ |
| 1147 | percpu_counter_sub(&sbi->s_dirtyblocks_counter, |
| 1148 | ei->i_reserved_meta_blocks); |
| 1149 | ei->i_reserved_meta_blocks = 0; |
| 1150 | ei->i_da_metadata_calc_len = 0; |
| 1151 | } |
| 1152 | spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); |
| 1153 | |
| 1154 | /* Update quota subsystem for data blocks */ |
| 1155 | if (quota_claim) |
| 1156 | dquot_claim_block(inode, used); |
| 1157 | else { |
| 1158 | /* |
| 1159 | * We did fallocate with an offset that is already delayed |
| 1160 | * allocated. So on delayed allocated writeback we should |
| 1161 | * not re-claim the quota for fallocated blocks. |
| 1162 | */ |
| 1163 | dquot_release_reservation_block(inode, used); |
| 1164 | } |
| 1165 | |
| 1166 | /* |
| 1167 | * If we have done all the pending block allocations and if |
| 1168 | * there aren't any writers on the inode, we can discard the |
| 1169 | * inode's preallocations. |
| 1170 | */ |
| 1171 | if ((ei->i_reserved_data_blocks == 0) && |
| 1172 | (atomic_read(&inode->i_writecount) == 0)) |
| 1173 | ext4_discard_preallocations(inode); |
| 1174 | } |
| 1175 | |
| 1176 | static int __check_block_validity(struct inode *inode, const char *func, |
| 1177 | unsigned int line, |
| 1178 | struct ext4_map_blocks *map) |
| 1179 | { |
| 1180 | if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk, |
| 1181 | map->m_len)) { |
| 1182 | ext4_error_inode(inode, func, line, map->m_pblk, |
| 1183 | "lblock %lu mapped to illegal pblock " |
| 1184 | "(length %d)", (unsigned long) map->m_lblk, |
| 1185 | map->m_len); |
| 1186 | return -EIO; |
| 1187 | } |
| 1188 | return 0; |
| 1189 | } |
| 1190 | |
| 1191 | #define check_block_validity(inode, map) \ |
| 1192 | __check_block_validity((inode), __func__, __LINE__, (map)) |
| 1193 | |
| 1194 | /* |
| 1195 | * Return the number of contiguous dirty pages in a given inode |
| 1196 | * starting at page frame idx. |
| 1197 | */ |
| 1198 | static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx, |
| 1199 | unsigned int max_pages) |
| 1200 | { |
| 1201 | struct address_space *mapping = inode->i_mapping; |
| 1202 | pgoff_t index; |
| 1203 | struct pagevec pvec; |
| 1204 | pgoff_t num = 0; |
| 1205 | int i, nr_pages, done = 0; |
| 1206 | |
| 1207 | if (max_pages == 0) |
| 1208 | return 0; |
| 1209 | pagevec_init(&pvec, 0); |
| 1210 | while (!done) { |
| 1211 | index = idx; |
| 1212 | nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, |
| 1213 | PAGECACHE_TAG_DIRTY, |
| 1214 | (pgoff_t)PAGEVEC_SIZE); |
| 1215 | if (nr_pages == 0) |
| 1216 | break; |
| 1217 | for (i = 0; i < nr_pages; i++) { |
| 1218 | struct page *page = pvec.pages[i]; |
| 1219 | struct buffer_head *bh, *head; |
| 1220 | |
| 1221 | lock_page(page); |
| 1222 | if (unlikely(page->mapping != mapping) || |
| 1223 | !PageDirty(page) || |
| 1224 | PageWriteback(page) || |
| 1225 | page->index != idx) { |
| 1226 | done = 1; |
| 1227 | unlock_page(page); |
| 1228 | break; |
| 1229 | } |
| 1230 | if (page_has_buffers(page)) { |
| 1231 | bh = head = page_buffers(page); |
| 1232 | do { |
| 1233 | if (!buffer_delay(bh) && |
| 1234 | !buffer_unwritten(bh)) |
| 1235 | done = 1; |
| 1236 | bh = bh->b_this_page; |
| 1237 | } while (!done && (bh != head)); |
| 1238 | } |
| 1239 | unlock_page(page); |
| 1240 | if (done) |
| 1241 | break; |
| 1242 | idx++; |
| 1243 | num++; |
| 1244 | if (num >= max_pages) { |
| 1245 | done = 1; |
| 1246 | break; |
| 1247 | } |
| 1248 | } |
| 1249 | pagevec_release(&pvec); |
| 1250 | } |
| 1251 | return num; |
| 1252 | } |
| 1253 | |
| 1254 | /* |
| 1255 | * The ext4_map_blocks() function tries to look up the requested blocks, |
| 1256 | * and returns if the blocks are already mapped. |
| 1257 | * |
| 1258 | * Otherwise it takes the write lock of the i_data_sem and allocate blocks |
| 1259 | * and store the allocated blocks in the result buffer head and mark it |
| 1260 | * mapped. |
| 1261 | * |
| 1262 | * If file type is extents based, it will call ext4_ext_map_blocks(), |
| 1263 | * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping |
| 1264 | * based files |
| 1265 | * |
| 1266 | * On success, it returns the number of blocks being mapped or allocate. |
| 1267 | * if create==0 and the blocks are pre-allocated and uninitialized block, |
| 1268 | * the result buffer head is unmapped. If the create ==1, it will make sure |
| 1269 | * the buffer head is mapped. |
| 1270 | * |
| 1271 | * It returns 0 if plain look up failed (blocks have not been allocated), in |
| 1272 | * that casem, buffer head is unmapped |
| 1273 | * |
| 1274 | * It returns the error in case of allocation failure. |
| 1275 | */ |
| 1276 | int ext4_map_blocks(handle_t *handle, struct inode *inode, |
| 1277 | struct ext4_map_blocks *map, int flags) |
| 1278 | { |
| 1279 | int retval; |
| 1280 | |
| 1281 | map->m_flags = 0; |
| 1282 | ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u," |
| 1283 | "logical block %lu\n", inode->i_ino, flags, map->m_len, |
| 1284 | (unsigned long) map->m_lblk); |
| 1285 | /* |
| 1286 | * Try to see if we can get the block without requesting a new |
| 1287 | * file system block. |
| 1288 | */ |
| 1289 | down_read((&EXT4_I(inode)->i_data_sem)); |
| 1290 | if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { |
| 1291 | retval = ext4_ext_map_blocks(handle, inode, map, 0); |
| 1292 | } else { |
| 1293 | retval = ext4_ind_map_blocks(handle, inode, map, 0); |
| 1294 | } |
| 1295 | up_read((&EXT4_I(inode)->i_data_sem)); |
| 1296 | |
| 1297 | if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) { |
| 1298 | int ret = check_block_validity(inode, map); |
| 1299 | if (ret != 0) |
| 1300 | return ret; |
| 1301 | } |
| 1302 | |
| 1303 | /* If it is only a block(s) look up */ |
| 1304 | if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) |
| 1305 | return retval; |
| 1306 | |
| 1307 | /* |
| 1308 | * Returns if the blocks have already allocated |
| 1309 | * |
| 1310 | * Note that if blocks have been preallocated |
| 1311 | * ext4_ext_get_block() returns th create = 0 |
| 1312 | * with buffer head unmapped. |
| 1313 | */ |
| 1314 | if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) |
| 1315 | return retval; |
| 1316 | |
| 1317 | /* |
| 1318 | * When we call get_blocks without the create flag, the |
| 1319 | * BH_Unwritten flag could have gotten set if the blocks |
| 1320 | * requested were part of a uninitialized extent. We need to |
| 1321 | * clear this flag now that we are committed to convert all or |
| 1322 | * part of the uninitialized extent to be an initialized |
| 1323 | * extent. This is because we need to avoid the combination |
| 1324 | * of BH_Unwritten and BH_Mapped flags being simultaneously |
| 1325 | * set on the buffer_head. |
| 1326 | */ |
| 1327 | map->m_flags &= ~EXT4_MAP_UNWRITTEN; |
| 1328 | |
| 1329 | /* |
| 1330 | * New blocks allocate and/or writing to uninitialized extent |
| 1331 | * will possibly result in updating i_data, so we take |
| 1332 | * the write lock of i_data_sem, and call get_blocks() |
| 1333 | * with create == 1 flag. |
| 1334 | */ |
| 1335 | down_write((&EXT4_I(inode)->i_data_sem)); |
| 1336 | |
| 1337 | /* |
| 1338 | * if the caller is from delayed allocation writeout path |
| 1339 | * we have already reserved fs blocks for allocation |
| 1340 | * let the underlying get_block() function know to |
| 1341 | * avoid double accounting |
| 1342 | */ |
| 1343 | if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) |
| 1344 | ext4_set_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED); |
| 1345 | /* |
| 1346 | * We need to check for EXT4 here because migrate |
| 1347 | * could have changed the inode type in between |
| 1348 | */ |
| 1349 | if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { |
| 1350 | retval = ext4_ext_map_blocks(handle, inode, map, flags); |
| 1351 | } else { |
| 1352 | retval = ext4_ind_map_blocks(handle, inode, map, flags); |
| 1353 | |
| 1354 | if (retval > 0 && map->m_flags & EXT4_MAP_NEW) { |
| 1355 | /* |
| 1356 | * We allocated new blocks which will result in |
| 1357 | * i_data's format changing. Force the migrate |
| 1358 | * to fail by clearing migrate flags |
| 1359 | */ |
| 1360 | ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE); |
| 1361 | } |
| 1362 | |
| 1363 | /* |
| 1364 | * Update reserved blocks/metadata blocks after successful |
| 1365 | * block allocation which had been deferred till now. We don't |
| 1366 | * support fallocate for non extent files. So we can update |
| 1367 | * reserve space here. |
| 1368 | */ |
| 1369 | if ((retval > 0) && |
| 1370 | (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)) |
| 1371 | ext4_da_update_reserve_space(inode, retval, 1); |
| 1372 | } |
| 1373 | if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) |
| 1374 | ext4_clear_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED); |
| 1375 | |
| 1376 | up_write((&EXT4_I(inode)->i_data_sem)); |
| 1377 | if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) { |
| 1378 | int ret = check_block_validity(inode, map); |
| 1379 | if (ret != 0) |
| 1380 | return ret; |
| 1381 | } |
| 1382 | return retval; |
| 1383 | } |
| 1384 | |
| 1385 | /* Maximum number of blocks we map for direct IO at once. */ |
| 1386 | #define DIO_MAX_BLOCKS 4096 |
| 1387 | |
| 1388 | static int _ext4_get_block(struct inode *inode, sector_t iblock, |
| 1389 | struct buffer_head *bh, int flags) |
| 1390 | { |
| 1391 | handle_t *handle = ext4_journal_current_handle(); |
| 1392 | struct ext4_map_blocks map; |
| 1393 | int ret = 0, started = 0; |
| 1394 | int dio_credits; |
| 1395 | |
| 1396 | map.m_lblk = iblock; |
| 1397 | map.m_len = bh->b_size >> inode->i_blkbits; |
| 1398 | |
| 1399 | if (flags && !handle) { |
| 1400 | /* Direct IO write... */ |
| 1401 | if (map.m_len > DIO_MAX_BLOCKS) |
| 1402 | map.m_len = DIO_MAX_BLOCKS; |
| 1403 | dio_credits = ext4_chunk_trans_blocks(inode, map.m_len); |
| 1404 | handle = ext4_journal_start(inode, dio_credits); |
| 1405 | if (IS_ERR(handle)) { |
| 1406 | ret = PTR_ERR(handle); |
| 1407 | return ret; |
| 1408 | } |
| 1409 | started = 1; |
| 1410 | } |
| 1411 | |
| 1412 | ret = ext4_map_blocks(handle, inode, &map, flags); |
| 1413 | if (ret > 0) { |
| 1414 | map_bh(bh, inode->i_sb, map.m_pblk); |
| 1415 | bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags; |
| 1416 | bh->b_size = inode->i_sb->s_blocksize * map.m_len; |
| 1417 | ret = 0; |
| 1418 | } |
| 1419 | if (started) |
| 1420 | ext4_journal_stop(handle); |
| 1421 | return ret; |
| 1422 | } |
| 1423 | |
| 1424 | int ext4_get_block(struct inode *inode, sector_t iblock, |
| 1425 | struct buffer_head *bh, int create) |
| 1426 | { |
| 1427 | return _ext4_get_block(inode, iblock, bh, |
| 1428 | create ? EXT4_GET_BLOCKS_CREATE : 0); |
| 1429 | } |
| 1430 | |
| 1431 | /* |
| 1432 | * `handle' can be NULL if create is zero |
| 1433 | */ |
| 1434 | struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode, |
| 1435 | ext4_lblk_t block, int create, int *errp) |
| 1436 | { |
| 1437 | struct ext4_map_blocks map; |
| 1438 | struct buffer_head *bh; |
| 1439 | int fatal = 0, err; |
| 1440 | |
| 1441 | J_ASSERT(handle != NULL || create == 0); |
| 1442 | |
| 1443 | map.m_lblk = block; |
| 1444 | map.m_len = 1; |
| 1445 | err = ext4_map_blocks(handle, inode, &map, |
| 1446 | create ? EXT4_GET_BLOCKS_CREATE : 0); |
| 1447 | |
| 1448 | if (err < 0) |
| 1449 | *errp = err; |
| 1450 | if (err <= 0) |
| 1451 | return NULL; |
| 1452 | *errp = 0; |
| 1453 | |
| 1454 | bh = sb_getblk(inode->i_sb, map.m_pblk); |
| 1455 | if (!bh) { |
| 1456 | *errp = -EIO; |
| 1457 | return NULL; |
| 1458 | } |
| 1459 | if (map.m_flags & EXT4_MAP_NEW) { |
| 1460 | J_ASSERT(create != 0); |
| 1461 | J_ASSERT(handle != NULL); |
| 1462 | |
| 1463 | /* |
| 1464 | * Now that we do not always journal data, we should |
| 1465 | * keep in mind whether this should always journal the |
| 1466 | * new buffer as metadata. For now, regular file |
| 1467 | * writes use ext4_get_block instead, so it's not a |
| 1468 | * problem. |
| 1469 | */ |
| 1470 | lock_buffer(bh); |
| 1471 | BUFFER_TRACE(bh, "call get_create_access"); |
| 1472 | fatal = ext4_journal_get_create_access(handle, bh); |
| 1473 | if (!fatal && !buffer_uptodate(bh)) { |
| 1474 | memset(bh->b_data, 0, inode->i_sb->s_blocksize); |
| 1475 | set_buffer_uptodate(bh); |
| 1476 | } |
| 1477 | unlock_buffer(bh); |
| 1478 | BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); |
| 1479 | err = ext4_handle_dirty_metadata(handle, inode, bh); |
| 1480 | if (!fatal) |
| 1481 | fatal = err; |
| 1482 | } else { |
| 1483 | BUFFER_TRACE(bh, "not a new buffer"); |
| 1484 | } |
| 1485 | if (fatal) { |
| 1486 | *errp = fatal; |
| 1487 | brelse(bh); |
| 1488 | bh = NULL; |
| 1489 | } |
| 1490 | return bh; |
| 1491 | } |
| 1492 | |
| 1493 | struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode, |
| 1494 | ext4_lblk_t block, int create, int *err) |
| 1495 | { |
| 1496 | struct buffer_head *bh; |
| 1497 | |
| 1498 | bh = ext4_getblk(handle, inode, block, create, err); |
| 1499 | if (!bh) |
| 1500 | return bh; |
| 1501 | if (buffer_uptodate(bh)) |
| 1502 | return bh; |
| 1503 | ll_rw_block(READ_META, 1, &bh); |
| 1504 | wait_on_buffer(bh); |
| 1505 | if (buffer_uptodate(bh)) |
| 1506 | return bh; |
| 1507 | put_bh(bh); |
| 1508 | *err = -EIO; |
| 1509 | return NULL; |
| 1510 | } |
| 1511 | |
| 1512 | static int walk_page_buffers(handle_t *handle, |
| 1513 | struct buffer_head *head, |
| 1514 | unsigned from, |
| 1515 | unsigned to, |
| 1516 | int *partial, |
| 1517 | int (*fn)(handle_t *handle, |
| 1518 | struct buffer_head *bh)) |
| 1519 | { |
| 1520 | struct buffer_head *bh; |
| 1521 | unsigned block_start, block_end; |
| 1522 | unsigned blocksize = head->b_size; |
| 1523 | int err, ret = 0; |
| 1524 | struct buffer_head *next; |
| 1525 | |
| 1526 | for (bh = head, block_start = 0; |
| 1527 | ret == 0 && (bh != head || !block_start); |
| 1528 | block_start = block_end, bh = next) { |
| 1529 | next = bh->b_this_page; |
| 1530 | block_end = block_start + blocksize; |
| 1531 | if (block_end <= from || block_start >= to) { |
| 1532 | if (partial && !buffer_uptodate(bh)) |
| 1533 | *partial = 1; |
| 1534 | continue; |
| 1535 | } |
| 1536 | err = (*fn)(handle, bh); |
| 1537 | if (!ret) |
| 1538 | ret = err; |
| 1539 | } |
| 1540 | return ret; |
| 1541 | } |
| 1542 | |
| 1543 | /* |
| 1544 | * To preserve ordering, it is essential that the hole instantiation and |
| 1545 | * the data write be encapsulated in a single transaction. We cannot |
| 1546 | * close off a transaction and start a new one between the ext4_get_block() |
| 1547 | * and the commit_write(). So doing the jbd2_journal_start at the start of |
| 1548 | * prepare_write() is the right place. |
| 1549 | * |
| 1550 | * Also, this function can nest inside ext4_writepage() -> |
| 1551 | * block_write_full_page(). In that case, we *know* that ext4_writepage() |
| 1552 | * has generated enough buffer credits to do the whole page. So we won't |
| 1553 | * block on the journal in that case, which is good, because the caller may |
| 1554 | * be PF_MEMALLOC. |
| 1555 | * |
| 1556 | * By accident, ext4 can be reentered when a transaction is open via |
| 1557 | * quota file writes. If we were to commit the transaction while thus |
| 1558 | * reentered, there can be a deadlock - we would be holding a quota |
| 1559 | * lock, and the commit would never complete if another thread had a |
| 1560 | * transaction open and was blocking on the quota lock - a ranking |
| 1561 | * violation. |
| 1562 | * |
| 1563 | * So what we do is to rely on the fact that jbd2_journal_stop/journal_start |
| 1564 | * will _not_ run commit under these circumstances because handle->h_ref |
| 1565 | * is elevated. We'll still have enough credits for the tiny quotafile |
| 1566 | * write. |
| 1567 | */ |
| 1568 | static int do_journal_get_write_access(handle_t *handle, |
| 1569 | struct buffer_head *bh) |
| 1570 | { |
| 1571 | int dirty = buffer_dirty(bh); |
| 1572 | int ret; |
| 1573 | |
| 1574 | if (!buffer_mapped(bh) || buffer_freed(bh)) |
| 1575 | return 0; |
| 1576 | /* |
| 1577 | * __block_write_begin() could have dirtied some buffers. Clean |
| 1578 | * the dirty bit as jbd2_journal_get_write_access() could complain |
| 1579 | * otherwise about fs integrity issues. Setting of the dirty bit |
| 1580 | * by __block_write_begin() isn't a real problem here as we clear |
| 1581 | * the bit before releasing a page lock and thus writeback cannot |
| 1582 | * ever write the buffer. |
| 1583 | */ |
| 1584 | if (dirty) |
| 1585 | clear_buffer_dirty(bh); |
| 1586 | ret = ext4_journal_get_write_access(handle, bh); |
| 1587 | if (!ret && dirty) |
| 1588 | ret = ext4_handle_dirty_metadata(handle, NULL, bh); |
| 1589 | return ret; |
| 1590 | } |
| 1591 | |
| 1592 | /* |
| 1593 | * Truncate blocks that were not used by write. We have to truncate the |
| 1594 | * pagecache as well so that corresponding buffers get properly unmapped. |
| 1595 | */ |
| 1596 | static void ext4_truncate_failed_write(struct inode *inode) |
| 1597 | { |
| 1598 | truncate_inode_pages(inode->i_mapping, inode->i_size); |
| 1599 | ext4_truncate(inode); |
| 1600 | } |
| 1601 | |
| 1602 | static int ext4_get_block_write(struct inode *inode, sector_t iblock, |
| 1603 | struct buffer_head *bh_result, int create); |
| 1604 | static int ext4_write_begin(struct file *file, struct address_space *mapping, |
| 1605 | loff_t pos, unsigned len, unsigned flags, |
| 1606 | struct page **pagep, void **fsdata) |
| 1607 | { |
| 1608 | struct inode *inode = mapping->host; |
| 1609 | int ret, needed_blocks; |
| 1610 | handle_t *handle; |
| 1611 | int retries = 0; |
| 1612 | struct page *page; |
| 1613 | pgoff_t index; |
| 1614 | unsigned from, to; |
| 1615 | |
| 1616 | trace_ext4_write_begin(inode, pos, len, flags); |
| 1617 | /* |
| 1618 | * Reserve one block more for addition to orphan list in case |
| 1619 | * we allocate blocks but write fails for some reason |
| 1620 | */ |
| 1621 | needed_blocks = ext4_writepage_trans_blocks(inode) + 1; |
| 1622 | index = pos >> PAGE_CACHE_SHIFT; |
| 1623 | from = pos & (PAGE_CACHE_SIZE - 1); |
| 1624 | to = from + len; |
| 1625 | |
| 1626 | retry: |
| 1627 | handle = ext4_journal_start(inode, needed_blocks); |
| 1628 | if (IS_ERR(handle)) { |
| 1629 | ret = PTR_ERR(handle); |
| 1630 | goto out; |
| 1631 | } |
| 1632 | |
| 1633 | /* We cannot recurse into the filesystem as the transaction is already |
| 1634 | * started */ |
| 1635 | flags |= AOP_FLAG_NOFS; |
| 1636 | |
| 1637 | page = grab_cache_page_write_begin(mapping, index, flags); |
| 1638 | if (!page) { |
| 1639 | ext4_journal_stop(handle); |
| 1640 | ret = -ENOMEM; |
| 1641 | goto out; |
| 1642 | } |
| 1643 | *pagep = page; |
| 1644 | |
| 1645 | if (ext4_should_dioread_nolock(inode)) |
| 1646 | ret = __block_write_begin(page, pos, len, ext4_get_block_write); |
| 1647 | else |
| 1648 | ret = __block_write_begin(page, pos, len, ext4_get_block); |
| 1649 | |
| 1650 | if (!ret && ext4_should_journal_data(inode)) { |
| 1651 | ret = walk_page_buffers(handle, page_buffers(page), |
| 1652 | from, to, NULL, do_journal_get_write_access); |
| 1653 | } |
| 1654 | |
| 1655 | if (ret) { |
| 1656 | unlock_page(page); |
| 1657 | page_cache_release(page); |
| 1658 | /* |
| 1659 | * __block_write_begin may have instantiated a few blocks |
| 1660 | * outside i_size. Trim these off again. Don't need |
| 1661 | * i_size_read because we hold i_mutex. |
| 1662 | * |
| 1663 | * Add inode to orphan list in case we crash before |
| 1664 | * truncate finishes |
| 1665 | */ |
| 1666 | if (pos + len > inode->i_size && ext4_can_truncate(inode)) |
| 1667 | ext4_orphan_add(handle, inode); |
| 1668 | |
| 1669 | ext4_journal_stop(handle); |
| 1670 | if (pos + len > inode->i_size) { |
| 1671 | ext4_truncate_failed_write(inode); |
| 1672 | /* |
| 1673 | * If truncate failed early the inode might |
| 1674 | * still be on the orphan list; we need to |
| 1675 | * make sure the inode is removed from the |
| 1676 | * orphan list in that case. |
| 1677 | */ |
| 1678 | if (inode->i_nlink) |
| 1679 | ext4_orphan_del(NULL, inode); |
| 1680 | } |
| 1681 | } |
| 1682 | |
| 1683 | if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) |
| 1684 | goto retry; |
| 1685 | out: |
| 1686 | return ret; |
| 1687 | } |
| 1688 | |
| 1689 | /* For write_end() in data=journal mode */ |
| 1690 | static int write_end_fn(handle_t *handle, struct buffer_head *bh) |
| 1691 | { |
| 1692 | if (!buffer_mapped(bh) || buffer_freed(bh)) |
| 1693 | return 0; |
| 1694 | set_buffer_uptodate(bh); |
| 1695 | return ext4_handle_dirty_metadata(handle, NULL, bh); |
| 1696 | } |
| 1697 | |
| 1698 | static int ext4_generic_write_end(struct file *file, |
| 1699 | struct address_space *mapping, |
| 1700 | loff_t pos, unsigned len, unsigned copied, |
| 1701 | struct page *page, void *fsdata) |
| 1702 | { |
| 1703 | int i_size_changed = 0; |
| 1704 | struct inode *inode = mapping->host; |
| 1705 | handle_t *handle = ext4_journal_current_handle(); |
| 1706 | |
| 1707 | copied = block_write_end(file, mapping, pos, len, copied, page, fsdata); |
| 1708 | |
| 1709 | /* |
| 1710 | * No need to use i_size_read() here, the i_size |
| 1711 | * cannot change under us because we hold i_mutex. |
| 1712 | * |
| 1713 | * But it's important to update i_size while still holding page lock: |
| 1714 | * page writeout could otherwise come in and zero beyond i_size. |
| 1715 | */ |
| 1716 | if (pos + copied > inode->i_size) { |
| 1717 | i_size_write(inode, pos + copied); |
| 1718 | i_size_changed = 1; |
| 1719 | } |
| 1720 | |
| 1721 | if (pos + copied > EXT4_I(inode)->i_disksize) { |
| 1722 | /* We need to mark inode dirty even if |
| 1723 | * new_i_size is less that inode->i_size |
| 1724 | * bu greater than i_disksize.(hint delalloc) |
| 1725 | */ |
| 1726 | ext4_update_i_disksize(inode, (pos + copied)); |
| 1727 | i_size_changed = 1; |
| 1728 | } |
| 1729 | unlock_page(page); |
| 1730 | page_cache_release(page); |
| 1731 | |
| 1732 | /* |
| 1733 | * Don't mark the inode dirty under page lock. First, it unnecessarily |
| 1734 | * makes the holding time of page lock longer. Second, it forces lock |
| 1735 | * ordering of page lock and transaction start for journaling |
| 1736 | * filesystems. |
| 1737 | */ |
| 1738 | if (i_size_changed) |
| 1739 | ext4_mark_inode_dirty(handle, inode); |
| 1740 | |
| 1741 | return copied; |
| 1742 | } |
| 1743 | |
| 1744 | /* |
| 1745 | * We need to pick up the new inode size which generic_commit_write gave us |
| 1746 | * `file' can be NULL - eg, when called from page_symlink(). |
| 1747 | * |
| 1748 | * ext4 never places buffers on inode->i_mapping->private_list. metadata |
| 1749 | * buffers are managed internally. |
| 1750 | */ |
| 1751 | static int ext4_ordered_write_end(struct file *file, |
| 1752 | struct address_space *mapping, |
| 1753 | loff_t pos, unsigned len, unsigned copied, |
| 1754 | struct page *page, void *fsdata) |
| 1755 | { |
| 1756 | handle_t *handle = ext4_journal_current_handle(); |
| 1757 | struct inode *inode = mapping->host; |
| 1758 | int ret = 0, ret2; |
| 1759 | |
| 1760 | trace_ext4_ordered_write_end(inode, pos, len, copied); |
| 1761 | ret = ext4_jbd2_file_inode(handle, inode); |
| 1762 | |
| 1763 | if (ret == 0) { |
| 1764 | ret2 = ext4_generic_write_end(file, mapping, pos, len, copied, |
| 1765 | page, fsdata); |
| 1766 | copied = ret2; |
| 1767 | if (pos + len > inode->i_size && ext4_can_truncate(inode)) |
| 1768 | /* if we have allocated more blocks and copied |
| 1769 | * less. We will have blocks allocated outside |
| 1770 | * inode->i_size. So truncate them |
| 1771 | */ |
| 1772 | ext4_orphan_add(handle, inode); |
| 1773 | if (ret2 < 0) |
| 1774 | ret = ret2; |
| 1775 | } |
| 1776 | ret2 = ext4_journal_stop(handle); |
| 1777 | if (!ret) |
| 1778 | ret = ret2; |
| 1779 | |
| 1780 | if (pos + len > inode->i_size) { |
| 1781 | ext4_truncate_failed_write(inode); |
| 1782 | /* |
| 1783 | * If truncate failed early the inode might still be |
| 1784 | * on the orphan list; we need to make sure the inode |
| 1785 | * is removed from the orphan list in that case. |
| 1786 | */ |
| 1787 | if (inode->i_nlink) |
| 1788 | ext4_orphan_del(NULL, inode); |
| 1789 | } |
| 1790 | |
| 1791 | |
| 1792 | return ret ? ret : copied; |
| 1793 | } |
| 1794 | |
| 1795 | static int ext4_writeback_write_end(struct file *file, |
| 1796 | struct address_space *mapping, |
| 1797 | loff_t pos, unsigned len, unsigned copied, |
| 1798 | struct page *page, void *fsdata) |
| 1799 | { |
| 1800 | handle_t *handle = ext4_journal_current_handle(); |
| 1801 | struct inode *inode = mapping->host; |
| 1802 | int ret = 0, ret2; |
| 1803 | |
| 1804 | trace_ext4_writeback_write_end(inode, pos, len, copied); |
| 1805 | ret2 = ext4_generic_write_end(file, mapping, pos, len, copied, |
| 1806 | page, fsdata); |
| 1807 | copied = ret2; |
| 1808 | if (pos + len > inode->i_size && ext4_can_truncate(inode)) |
| 1809 | /* if we have allocated more blocks and copied |
| 1810 | * less. We will have blocks allocated outside |
| 1811 | * inode->i_size. So truncate them |
| 1812 | */ |
| 1813 | ext4_orphan_add(handle, inode); |
| 1814 | |
| 1815 | if (ret2 < 0) |
| 1816 | ret = ret2; |
| 1817 | |
| 1818 | ret2 = ext4_journal_stop(handle); |
| 1819 | if (!ret) |
| 1820 | ret = ret2; |
| 1821 | |
| 1822 | if (pos + len > inode->i_size) { |
| 1823 | ext4_truncate_failed_write(inode); |
| 1824 | /* |
| 1825 | * If truncate failed early the inode might still be |
| 1826 | * on the orphan list; we need to make sure the inode |
| 1827 | * is removed from the orphan list in that case. |
| 1828 | */ |
| 1829 | if (inode->i_nlink) |
| 1830 | ext4_orphan_del(NULL, inode); |
| 1831 | } |
| 1832 | |
| 1833 | return ret ? ret : copied; |
| 1834 | } |
| 1835 | |
| 1836 | static int ext4_journalled_write_end(struct file *file, |
| 1837 | struct address_space *mapping, |
| 1838 | loff_t pos, unsigned len, unsigned copied, |
| 1839 | struct page *page, void *fsdata) |
| 1840 | { |
| 1841 | handle_t *handle = ext4_journal_current_handle(); |
| 1842 | struct inode *inode = mapping->host; |
| 1843 | int ret = 0, ret2; |
| 1844 | int partial = 0; |
| 1845 | unsigned from, to; |
| 1846 | loff_t new_i_size; |
| 1847 | |
| 1848 | trace_ext4_journalled_write_end(inode, pos, len, copied); |
| 1849 | from = pos & (PAGE_CACHE_SIZE - 1); |
| 1850 | to = from + len; |
| 1851 | |
| 1852 | if (copied < len) { |
| 1853 | if (!PageUptodate(page)) |
| 1854 | copied = 0; |
| 1855 | page_zero_new_buffers(page, from+copied, to); |
| 1856 | } |
| 1857 | |
| 1858 | ret = walk_page_buffers(handle, page_buffers(page), from, |
| 1859 | to, &partial, write_end_fn); |
| 1860 | if (!partial) |
| 1861 | SetPageUptodate(page); |
| 1862 | new_i_size = pos + copied; |
| 1863 | if (new_i_size > inode->i_size) |
| 1864 | i_size_write(inode, pos+copied); |
| 1865 | ext4_set_inode_state(inode, EXT4_STATE_JDATA); |
| 1866 | if (new_i_size > EXT4_I(inode)->i_disksize) { |
| 1867 | ext4_update_i_disksize(inode, new_i_size); |
| 1868 | ret2 = ext4_mark_inode_dirty(handle, inode); |
| 1869 | if (!ret) |
| 1870 | ret = ret2; |
| 1871 | } |
| 1872 | |
| 1873 | unlock_page(page); |
| 1874 | page_cache_release(page); |
| 1875 | if (pos + len > inode->i_size && ext4_can_truncate(inode)) |
| 1876 | /* if we have allocated more blocks and copied |
| 1877 | * less. We will have blocks allocated outside |
| 1878 | * inode->i_size. So truncate them |
| 1879 | */ |
| 1880 | ext4_orphan_add(handle, inode); |
| 1881 | |
| 1882 | ret2 = ext4_journal_stop(handle); |
| 1883 | if (!ret) |
| 1884 | ret = ret2; |
| 1885 | if (pos + len > inode->i_size) { |
| 1886 | ext4_truncate_failed_write(inode); |
| 1887 | /* |
| 1888 | * If truncate failed early the inode might still be |
| 1889 | * on the orphan list; we need to make sure the inode |
| 1890 | * is removed from the orphan list in that case. |
| 1891 | */ |
| 1892 | if (inode->i_nlink) |
| 1893 | ext4_orphan_del(NULL, inode); |
| 1894 | } |
| 1895 | |
| 1896 | return ret ? ret : copied; |
| 1897 | } |
| 1898 | |
| 1899 | /* |
| 1900 | * Reserve a single block located at lblock |
| 1901 | */ |
| 1902 | static int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock) |
| 1903 | { |
| 1904 | int retries = 0; |
| 1905 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| 1906 | struct ext4_inode_info *ei = EXT4_I(inode); |
| 1907 | unsigned long md_needed; |
| 1908 | int ret; |
| 1909 | |
| 1910 | /* |
| 1911 | * recalculate the amount of metadata blocks to reserve |
| 1912 | * in order to allocate nrblocks |
| 1913 | * worse case is one extent per block |
| 1914 | */ |
| 1915 | repeat: |
| 1916 | spin_lock(&ei->i_block_reservation_lock); |
| 1917 | md_needed = ext4_calc_metadata_amount(inode, lblock); |
| 1918 | trace_ext4_da_reserve_space(inode, md_needed); |
| 1919 | spin_unlock(&ei->i_block_reservation_lock); |
| 1920 | |
| 1921 | /* |
| 1922 | * We will charge metadata quota at writeout time; this saves |
| 1923 | * us from metadata over-estimation, though we may go over by |
| 1924 | * a small amount in the end. Here we just reserve for data. |
| 1925 | */ |
| 1926 | ret = dquot_reserve_block(inode, 1); |
| 1927 | if (ret) |
| 1928 | return ret; |
| 1929 | /* |
| 1930 | * We do still charge estimated metadata to the sb though; |
| 1931 | * we cannot afford to run out of free blocks. |
| 1932 | */ |
| 1933 | if (ext4_claim_free_blocks(sbi, md_needed + 1, 0)) { |
| 1934 | dquot_release_reservation_block(inode, 1); |
| 1935 | if (ext4_should_retry_alloc(inode->i_sb, &retries)) { |
| 1936 | yield(); |
| 1937 | goto repeat; |
| 1938 | } |
| 1939 | return -ENOSPC; |
| 1940 | } |
| 1941 | spin_lock(&ei->i_block_reservation_lock); |
| 1942 | ei->i_reserved_data_blocks++; |
| 1943 | ei->i_reserved_meta_blocks += md_needed; |
| 1944 | spin_unlock(&ei->i_block_reservation_lock); |
| 1945 | |
| 1946 | return 0; /* success */ |
| 1947 | } |
| 1948 | |
| 1949 | static void ext4_da_release_space(struct inode *inode, int to_free) |
| 1950 | { |
| 1951 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| 1952 | struct ext4_inode_info *ei = EXT4_I(inode); |
| 1953 | |
| 1954 | if (!to_free) |
| 1955 | return; /* Nothing to release, exit */ |
| 1956 | |
| 1957 | spin_lock(&EXT4_I(inode)->i_block_reservation_lock); |
| 1958 | |
| 1959 | trace_ext4_da_release_space(inode, to_free); |
| 1960 | if (unlikely(to_free > ei->i_reserved_data_blocks)) { |
| 1961 | /* |
| 1962 | * if there aren't enough reserved blocks, then the |
| 1963 | * counter is messed up somewhere. Since this |
| 1964 | * function is called from invalidate page, it's |
| 1965 | * harmless to return without any action. |
| 1966 | */ |
| 1967 | ext4_msg(inode->i_sb, KERN_NOTICE, "ext4_da_release_space: " |
| 1968 | "ino %lu, to_free %d with only %d reserved " |
| 1969 | "data blocks\n", inode->i_ino, to_free, |
| 1970 | ei->i_reserved_data_blocks); |
| 1971 | WARN_ON(1); |
| 1972 | to_free = ei->i_reserved_data_blocks; |
| 1973 | } |
| 1974 | ei->i_reserved_data_blocks -= to_free; |
| 1975 | |
| 1976 | if (ei->i_reserved_data_blocks == 0) { |
| 1977 | /* |
| 1978 | * We can release all of the reserved metadata blocks |
| 1979 | * only when we have written all of the delayed |
| 1980 | * allocation blocks. |
| 1981 | */ |
| 1982 | percpu_counter_sub(&sbi->s_dirtyblocks_counter, |
| 1983 | ei->i_reserved_meta_blocks); |
| 1984 | ei->i_reserved_meta_blocks = 0; |
| 1985 | ei->i_da_metadata_calc_len = 0; |
| 1986 | } |
| 1987 | |
| 1988 | /* update fs dirty data blocks counter */ |
| 1989 | percpu_counter_sub(&sbi->s_dirtyblocks_counter, to_free); |
| 1990 | |
| 1991 | spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); |
| 1992 | |
| 1993 | dquot_release_reservation_block(inode, to_free); |
| 1994 | } |
| 1995 | |
| 1996 | static void ext4_da_page_release_reservation(struct page *page, |
| 1997 | unsigned long offset) |
| 1998 | { |
| 1999 | int to_release = 0; |
| 2000 | struct buffer_head *head, *bh; |
| 2001 | unsigned int curr_off = 0; |
| 2002 | |
| 2003 | head = page_buffers(page); |
| 2004 | bh = head; |
| 2005 | do { |
| 2006 | unsigned int next_off = curr_off + bh->b_size; |
| 2007 | |
| 2008 | if ((offset <= curr_off) && (buffer_delay(bh))) { |
| 2009 | to_release++; |
| 2010 | clear_buffer_delay(bh); |
| 2011 | } |
| 2012 | curr_off = next_off; |
| 2013 | } while ((bh = bh->b_this_page) != head); |
| 2014 | ext4_da_release_space(page->mapping->host, to_release); |
| 2015 | } |
| 2016 | |
| 2017 | /* |
| 2018 | * Delayed allocation stuff |
| 2019 | */ |
| 2020 | |
| 2021 | /* |
| 2022 | * mpage_da_submit_io - walks through extent of pages and try to write |
| 2023 | * them with writepage() call back |
| 2024 | * |
| 2025 | * @mpd->inode: inode |
| 2026 | * @mpd->first_page: first page of the extent |
| 2027 | * @mpd->next_page: page after the last page of the extent |
| 2028 | * |
| 2029 | * By the time mpage_da_submit_io() is called we expect all blocks |
| 2030 | * to be allocated. this may be wrong if allocation failed. |
| 2031 | * |
| 2032 | * As pages are already locked by write_cache_pages(), we can't use it |
| 2033 | */ |
| 2034 | static int mpage_da_submit_io(struct mpage_da_data *mpd, |
| 2035 | struct ext4_map_blocks *map) |
| 2036 | { |
| 2037 | struct pagevec pvec; |
| 2038 | unsigned long index, end; |
| 2039 | int ret = 0, err, nr_pages, i; |
| 2040 | struct inode *inode = mpd->inode; |
| 2041 | struct address_space *mapping = inode->i_mapping; |
| 2042 | loff_t size = i_size_read(inode); |
| 2043 | unsigned int len, block_start; |
| 2044 | struct buffer_head *bh, *page_bufs = NULL; |
| 2045 | int journal_data = ext4_should_journal_data(inode); |
| 2046 | sector_t pblock = 0, cur_logical = 0; |
| 2047 | struct ext4_io_submit io_submit; |
| 2048 | |
| 2049 | BUG_ON(mpd->next_page <= mpd->first_page); |
| 2050 | memset(&io_submit, 0, sizeof(io_submit)); |
| 2051 | /* |
| 2052 | * We need to start from the first_page to the next_page - 1 |
| 2053 | * to make sure we also write the mapped dirty buffer_heads. |
| 2054 | * If we look at mpd->b_blocknr we would only be looking |
| 2055 | * at the currently mapped buffer_heads. |
| 2056 | */ |
| 2057 | index = mpd->first_page; |
| 2058 | end = mpd->next_page - 1; |
| 2059 | |
| 2060 | pagevec_init(&pvec, 0); |
| 2061 | while (index <= end) { |
| 2062 | nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE); |
| 2063 | if (nr_pages == 0) |
| 2064 | break; |
| 2065 | for (i = 0; i < nr_pages; i++) { |
| 2066 | int commit_write = 0, skip_page = 0; |
| 2067 | struct page *page = pvec.pages[i]; |
| 2068 | |
| 2069 | index = page->index; |
| 2070 | if (index > end) |
| 2071 | break; |
| 2072 | |
| 2073 | if (index == size >> PAGE_CACHE_SHIFT) |
| 2074 | len = size & ~PAGE_CACHE_MASK; |
| 2075 | else |
| 2076 | len = PAGE_CACHE_SIZE; |
| 2077 | if (map) { |
| 2078 | cur_logical = index << (PAGE_CACHE_SHIFT - |
| 2079 | inode->i_blkbits); |
| 2080 | pblock = map->m_pblk + (cur_logical - |
| 2081 | map->m_lblk); |
| 2082 | } |
| 2083 | index++; |
| 2084 | |
| 2085 | BUG_ON(!PageLocked(page)); |
| 2086 | BUG_ON(PageWriteback(page)); |
| 2087 | |
| 2088 | /* |
| 2089 | * If the page does not have buffers (for |
| 2090 | * whatever reason), try to create them using |
| 2091 | * __block_write_begin. If this fails, |
| 2092 | * skip the page and move on. |
| 2093 | */ |
| 2094 | if (!page_has_buffers(page)) { |
| 2095 | if (__block_write_begin(page, 0, len, |
| 2096 | noalloc_get_block_write)) { |
| 2097 | skip_page: |
| 2098 | unlock_page(page); |
| 2099 | continue; |
| 2100 | } |
| 2101 | commit_write = 1; |
| 2102 | } |
| 2103 | |
| 2104 | bh = page_bufs = page_buffers(page); |
| 2105 | block_start = 0; |
| 2106 | do { |
| 2107 | if (!bh) |
| 2108 | goto skip_page; |
| 2109 | if (map && (cur_logical >= map->m_lblk) && |
| 2110 | (cur_logical <= (map->m_lblk + |
| 2111 | (map->m_len - 1)))) { |
| 2112 | if (buffer_delay(bh)) { |
| 2113 | clear_buffer_delay(bh); |
| 2114 | bh->b_blocknr = pblock; |
| 2115 | } |
| 2116 | if (buffer_unwritten(bh) || |
| 2117 | buffer_mapped(bh)) |
| 2118 | BUG_ON(bh->b_blocknr != pblock); |
| 2119 | if (map->m_flags & EXT4_MAP_UNINIT) |
| 2120 | set_buffer_uninit(bh); |
| 2121 | clear_buffer_unwritten(bh); |
| 2122 | } |
| 2123 | |
| 2124 | /* skip page if block allocation undone */ |
| 2125 | if (buffer_delay(bh) || buffer_unwritten(bh)) |
| 2126 | skip_page = 1; |
| 2127 | bh = bh->b_this_page; |
| 2128 | block_start += bh->b_size; |
| 2129 | cur_logical++; |
| 2130 | pblock++; |
| 2131 | } while (bh != page_bufs); |
| 2132 | |
| 2133 | if (skip_page) |
| 2134 | goto skip_page; |
| 2135 | |
| 2136 | if (commit_write) |
| 2137 | /* mark the buffer_heads as dirty & uptodate */ |
| 2138 | block_commit_write(page, 0, len); |
| 2139 | |
| 2140 | clear_page_dirty_for_io(page); |
| 2141 | /* |
| 2142 | * Delalloc doesn't support data journalling, |
| 2143 | * but eventually maybe we'll lift this |
| 2144 | * restriction. |
| 2145 | */ |
| 2146 | if (unlikely(journal_data && PageChecked(page))) |
| 2147 | err = __ext4_journalled_writepage(page, len); |
| 2148 | else if (test_opt(inode->i_sb, MBLK_IO_SUBMIT)) |
| 2149 | err = ext4_bio_write_page(&io_submit, page, |
| 2150 | len, mpd->wbc); |
| 2151 | else |
| 2152 | err = block_write_full_page(page, |
| 2153 | noalloc_get_block_write, mpd->wbc); |
| 2154 | |
| 2155 | if (!err) |
| 2156 | mpd->pages_written++; |
| 2157 | /* |
| 2158 | * In error case, we have to continue because |
| 2159 | * remaining pages are still locked |
| 2160 | */ |
| 2161 | if (ret == 0) |
| 2162 | ret = err; |
| 2163 | } |
| 2164 | pagevec_release(&pvec); |
| 2165 | } |
| 2166 | ext4_io_submit(&io_submit); |
| 2167 | return ret; |
| 2168 | } |
| 2169 | |
| 2170 | static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd) |
| 2171 | { |
| 2172 | int nr_pages, i; |
| 2173 | pgoff_t index, end; |
| 2174 | struct pagevec pvec; |
| 2175 | struct inode *inode = mpd->inode; |
| 2176 | struct address_space *mapping = inode->i_mapping; |
| 2177 | |
| 2178 | index = mpd->first_page; |
| 2179 | end = mpd->next_page - 1; |
| 2180 | while (index <= end) { |
| 2181 | nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE); |
| 2182 | if (nr_pages == 0) |
| 2183 | break; |
| 2184 | for (i = 0; i < nr_pages; i++) { |
| 2185 | struct page *page = pvec.pages[i]; |
| 2186 | if (page->index > end) |
| 2187 | break; |
| 2188 | BUG_ON(!PageLocked(page)); |
| 2189 | BUG_ON(PageWriteback(page)); |
| 2190 | block_invalidatepage(page, 0); |
| 2191 | ClearPageUptodate(page); |
| 2192 | unlock_page(page); |
| 2193 | } |
| 2194 | index = pvec.pages[nr_pages - 1]->index + 1; |
| 2195 | pagevec_release(&pvec); |
| 2196 | } |
| 2197 | return; |
| 2198 | } |
| 2199 | |
| 2200 | static void ext4_print_free_blocks(struct inode *inode) |
| 2201 | { |
| 2202 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| 2203 | printk(KERN_CRIT "Total free blocks count %lld\n", |
| 2204 | ext4_count_free_blocks(inode->i_sb)); |
| 2205 | printk(KERN_CRIT "Free/Dirty block details\n"); |
| 2206 | printk(KERN_CRIT "free_blocks=%lld\n", |
| 2207 | (long long) percpu_counter_sum(&sbi->s_freeblocks_counter)); |
| 2208 | printk(KERN_CRIT "dirty_blocks=%lld\n", |
| 2209 | (long long) percpu_counter_sum(&sbi->s_dirtyblocks_counter)); |
| 2210 | printk(KERN_CRIT "Block reservation details\n"); |
| 2211 | printk(KERN_CRIT "i_reserved_data_blocks=%u\n", |
| 2212 | EXT4_I(inode)->i_reserved_data_blocks); |
| 2213 | printk(KERN_CRIT "i_reserved_meta_blocks=%u\n", |
| 2214 | EXT4_I(inode)->i_reserved_meta_blocks); |
| 2215 | return; |
| 2216 | } |
| 2217 | |
| 2218 | /* |
| 2219 | * mpage_da_map_and_submit - go through given space, map them |
| 2220 | * if necessary, and then submit them for I/O |
| 2221 | * |
| 2222 | * @mpd - bh describing space |
| 2223 | * |
| 2224 | * The function skips space we know is already mapped to disk blocks. |
| 2225 | * |
| 2226 | */ |
| 2227 | static void mpage_da_map_and_submit(struct mpage_da_data *mpd) |
| 2228 | { |
| 2229 | int err, blks, get_blocks_flags; |
| 2230 | struct ext4_map_blocks map, *mapp = NULL; |
| 2231 | sector_t next = mpd->b_blocknr; |
| 2232 | unsigned max_blocks = mpd->b_size >> mpd->inode->i_blkbits; |
| 2233 | loff_t disksize = EXT4_I(mpd->inode)->i_disksize; |
| 2234 | handle_t *handle = NULL; |
| 2235 | |
| 2236 | /* |
| 2237 | * If the blocks are mapped already, or we couldn't accumulate |
| 2238 | * any blocks, then proceed immediately to the submission stage. |
| 2239 | */ |
| 2240 | if ((mpd->b_size == 0) || |
| 2241 | ((mpd->b_state & (1 << BH_Mapped)) && |
| 2242 | !(mpd->b_state & (1 << BH_Delay)) && |
| 2243 | !(mpd->b_state & (1 << BH_Unwritten)))) |
| 2244 | goto submit_io; |
| 2245 | |
| 2246 | handle = ext4_journal_current_handle(); |
| 2247 | BUG_ON(!handle); |
| 2248 | |
| 2249 | /* |
| 2250 | * Call ext4_map_blocks() to allocate any delayed allocation |
| 2251 | * blocks, or to convert an uninitialized extent to be |
| 2252 | * initialized (in the case where we have written into |
| 2253 | * one or more preallocated blocks). |
| 2254 | * |
| 2255 | * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to |
| 2256 | * indicate that we are on the delayed allocation path. This |
| 2257 | * affects functions in many different parts of the allocation |
| 2258 | * call path. This flag exists primarily because we don't |
| 2259 | * want to change *many* call functions, so ext4_map_blocks() |
| 2260 | * will set the EXT4_STATE_DELALLOC_RESERVED flag once the |
| 2261 | * inode's allocation semaphore is taken. |
| 2262 | * |
| 2263 | * If the blocks in questions were delalloc blocks, set |
| 2264 | * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting |
| 2265 | * variables are updated after the blocks have been allocated. |
| 2266 | */ |
| 2267 | map.m_lblk = next; |
| 2268 | map.m_len = max_blocks; |
| 2269 | get_blocks_flags = EXT4_GET_BLOCKS_CREATE; |
| 2270 | if (ext4_should_dioread_nolock(mpd->inode)) |
| 2271 | get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT; |
| 2272 | if (mpd->b_state & (1 << BH_Delay)) |
| 2273 | get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE; |
| 2274 | |
| 2275 | blks = ext4_map_blocks(handle, mpd->inode, &map, get_blocks_flags); |
| 2276 | if (blks < 0) { |
| 2277 | struct super_block *sb = mpd->inode->i_sb; |
| 2278 | |
| 2279 | err = blks; |
| 2280 | /* |
| 2281 | * If get block returns EAGAIN or ENOSPC and there |
| 2282 | * appears to be free blocks we will just let |
| 2283 | * mpage_da_submit_io() unlock all of the pages. |
| 2284 | */ |
| 2285 | if (err == -EAGAIN) |
| 2286 | goto submit_io; |
| 2287 | |
| 2288 | if (err == -ENOSPC && |
| 2289 | ext4_count_free_blocks(sb)) { |
| 2290 | mpd->retval = err; |
| 2291 | goto submit_io; |
| 2292 | } |
| 2293 | |
| 2294 | /* |
| 2295 | * get block failure will cause us to loop in |
| 2296 | * writepages, because a_ops->writepage won't be able |
| 2297 | * to make progress. The page will be redirtied by |
| 2298 | * writepage and writepages will again try to write |
| 2299 | * the same. |
| 2300 | */ |
| 2301 | if (!(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) { |
| 2302 | ext4_msg(sb, KERN_CRIT, |
| 2303 | "delayed block allocation failed for inode %lu " |
| 2304 | "at logical offset %llu with max blocks %zd " |
| 2305 | "with error %d", mpd->inode->i_ino, |
| 2306 | (unsigned long long) next, |
| 2307 | mpd->b_size >> mpd->inode->i_blkbits, err); |
| 2308 | ext4_msg(sb, KERN_CRIT, |
| 2309 | "This should not happen!! Data will be lost\n"); |
| 2310 | if (err == -ENOSPC) |
| 2311 | ext4_print_free_blocks(mpd->inode); |
| 2312 | } |
| 2313 | /* invalidate all the pages */ |
| 2314 | ext4_da_block_invalidatepages(mpd); |
| 2315 | |
| 2316 | /* Mark this page range as having been completed */ |
| 2317 | mpd->io_done = 1; |
| 2318 | return; |
| 2319 | } |
| 2320 | BUG_ON(blks == 0); |
| 2321 | |
| 2322 | mapp = ↦ |
| 2323 | if (map.m_flags & EXT4_MAP_NEW) { |
| 2324 | struct block_device *bdev = mpd->inode->i_sb->s_bdev; |
| 2325 | int i; |
| 2326 | |
| 2327 | for (i = 0; i < map.m_len; i++) |
| 2328 | unmap_underlying_metadata(bdev, map.m_pblk + i); |
| 2329 | } |
| 2330 | |
| 2331 | if (ext4_should_order_data(mpd->inode)) { |
| 2332 | err = ext4_jbd2_file_inode(handle, mpd->inode); |
| 2333 | if (err) |
| 2334 | /* This only happens if the journal is aborted */ |
| 2335 | return; |
| 2336 | } |
| 2337 | |
| 2338 | /* |
| 2339 | * Update on-disk size along with block allocation. |
| 2340 | */ |
| 2341 | disksize = ((loff_t) next + blks) << mpd->inode->i_blkbits; |
| 2342 | if (disksize > i_size_read(mpd->inode)) |
| 2343 | disksize = i_size_read(mpd->inode); |
| 2344 | if (disksize > EXT4_I(mpd->inode)->i_disksize) { |
| 2345 | ext4_update_i_disksize(mpd->inode, disksize); |
| 2346 | err = ext4_mark_inode_dirty(handle, mpd->inode); |
| 2347 | if (err) |
| 2348 | ext4_error(mpd->inode->i_sb, |
| 2349 | "Failed to mark inode %lu dirty", |
| 2350 | mpd->inode->i_ino); |
| 2351 | } |
| 2352 | |
| 2353 | submit_io: |
| 2354 | mpage_da_submit_io(mpd, mapp); |
| 2355 | mpd->io_done = 1; |
| 2356 | } |
| 2357 | |
| 2358 | #define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \ |
| 2359 | (1 << BH_Delay) | (1 << BH_Unwritten)) |
| 2360 | |
| 2361 | /* |
| 2362 | * mpage_add_bh_to_extent - try to add one more block to extent of blocks |
| 2363 | * |
| 2364 | * @mpd->lbh - extent of blocks |
| 2365 | * @logical - logical number of the block in the file |
| 2366 | * @bh - bh of the block (used to access block's state) |
| 2367 | * |
| 2368 | * the function is used to collect contig. blocks in same state |
| 2369 | */ |
| 2370 | static void mpage_add_bh_to_extent(struct mpage_da_data *mpd, |
| 2371 | sector_t logical, size_t b_size, |
| 2372 | unsigned long b_state) |
| 2373 | { |
| 2374 | sector_t next; |
| 2375 | int nrblocks = mpd->b_size >> mpd->inode->i_blkbits; |
| 2376 | |
| 2377 | /* |
| 2378 | * XXX Don't go larger than mballoc is willing to allocate |
| 2379 | * This is a stopgap solution. We eventually need to fold |
| 2380 | * mpage_da_submit_io() into this function and then call |
| 2381 | * ext4_map_blocks() multiple times in a loop |
| 2382 | */ |
| 2383 | if (nrblocks >= 8*1024*1024/mpd->inode->i_sb->s_blocksize) |
| 2384 | goto flush_it; |
| 2385 | |
| 2386 | /* check if thereserved journal credits might overflow */ |
| 2387 | if (!(ext4_test_inode_flag(mpd->inode, EXT4_INODE_EXTENTS))) { |
| 2388 | if (nrblocks >= EXT4_MAX_TRANS_DATA) { |
| 2389 | /* |
| 2390 | * With non-extent format we are limited by the journal |
| 2391 | * credit available. Total credit needed to insert |
| 2392 | * nrblocks contiguous blocks is dependent on the |
| 2393 | * nrblocks. So limit nrblocks. |
| 2394 | */ |
| 2395 | goto flush_it; |
| 2396 | } else if ((nrblocks + (b_size >> mpd->inode->i_blkbits)) > |
| 2397 | EXT4_MAX_TRANS_DATA) { |
| 2398 | /* |
| 2399 | * Adding the new buffer_head would make it cross the |
| 2400 | * allowed limit for which we have journal credit |
| 2401 | * reserved. So limit the new bh->b_size |
| 2402 | */ |
| 2403 | b_size = (EXT4_MAX_TRANS_DATA - nrblocks) << |
| 2404 | mpd->inode->i_blkbits; |
| 2405 | /* we will do mpage_da_submit_io in the next loop */ |
| 2406 | } |
| 2407 | } |
| 2408 | /* |
| 2409 | * First block in the extent |
| 2410 | */ |
| 2411 | if (mpd->b_size == 0) { |
| 2412 | mpd->b_blocknr = logical; |
| 2413 | mpd->b_size = b_size; |
| 2414 | mpd->b_state = b_state & BH_FLAGS; |
| 2415 | return; |
| 2416 | } |
| 2417 | |
| 2418 | next = mpd->b_blocknr + nrblocks; |
| 2419 | /* |
| 2420 | * Can we merge the block to our big extent? |
| 2421 | */ |
| 2422 | if (logical == next && (b_state & BH_FLAGS) == mpd->b_state) { |
| 2423 | mpd->b_size += b_size; |
| 2424 | return; |
| 2425 | } |
| 2426 | |
| 2427 | flush_it: |
| 2428 | /* |
| 2429 | * We couldn't merge the block to our extent, so we |
| 2430 | * need to flush current extent and start new one |
| 2431 | */ |
| 2432 | mpage_da_map_and_submit(mpd); |
| 2433 | return; |
| 2434 | } |
| 2435 | |
| 2436 | static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh) |
| 2437 | { |
| 2438 | return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh); |
| 2439 | } |
| 2440 | |
| 2441 | /* |
| 2442 | * This is a special get_blocks_t callback which is used by |
| 2443 | * ext4_da_write_begin(). It will either return mapped block or |
| 2444 | * reserve space for a single block. |
| 2445 | * |
| 2446 | * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set. |
| 2447 | * We also have b_blocknr = -1 and b_bdev initialized properly |
| 2448 | * |
| 2449 | * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set. |
| 2450 | * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev |
| 2451 | * initialized properly. |
| 2452 | */ |
| 2453 | static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock, |
| 2454 | struct buffer_head *bh, int create) |
| 2455 | { |
| 2456 | struct ext4_map_blocks map; |
| 2457 | int ret = 0; |
| 2458 | sector_t invalid_block = ~((sector_t) 0xffff); |
| 2459 | |
| 2460 | if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es)) |
| 2461 | invalid_block = ~0; |
| 2462 | |
| 2463 | BUG_ON(create == 0); |
| 2464 | BUG_ON(bh->b_size != inode->i_sb->s_blocksize); |
| 2465 | |
| 2466 | map.m_lblk = iblock; |
| 2467 | map.m_len = 1; |
| 2468 | |
| 2469 | /* |
| 2470 | * first, we need to know whether the block is allocated already |
| 2471 | * preallocated blocks are unmapped but should treated |
| 2472 | * the same as allocated blocks. |
| 2473 | */ |
| 2474 | ret = ext4_map_blocks(NULL, inode, &map, 0); |
| 2475 | if (ret < 0) |
| 2476 | return ret; |
| 2477 | if (ret == 0) { |
| 2478 | if (buffer_delay(bh)) |
| 2479 | return 0; /* Not sure this could or should happen */ |
| 2480 | /* |
| 2481 | * XXX: __block_write_begin() unmaps passed block, is it OK? |
| 2482 | */ |
| 2483 | ret = ext4_da_reserve_space(inode, iblock); |
| 2484 | if (ret) |
| 2485 | /* not enough space to reserve */ |
| 2486 | return ret; |
| 2487 | |
| 2488 | map_bh(bh, inode->i_sb, invalid_block); |
| 2489 | set_buffer_new(bh); |
| 2490 | set_buffer_delay(bh); |
| 2491 | return 0; |
| 2492 | } |
| 2493 | |
| 2494 | map_bh(bh, inode->i_sb, map.m_pblk); |
| 2495 | bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags; |
| 2496 | |
| 2497 | if (buffer_unwritten(bh)) { |
| 2498 | /* A delayed write to unwritten bh should be marked |
| 2499 | * new and mapped. Mapped ensures that we don't do |
| 2500 | * get_block multiple times when we write to the same |
| 2501 | * offset and new ensures that we do proper zero out |
| 2502 | * for partial write. |
| 2503 | */ |
| 2504 | set_buffer_new(bh); |
| 2505 | set_buffer_mapped(bh); |
| 2506 | } |
| 2507 | return 0; |
| 2508 | } |
| 2509 | |
| 2510 | /* |
| 2511 | * This function is used as a standard get_block_t calback function |
| 2512 | * when there is no desire to allocate any blocks. It is used as a |
| 2513 | * callback function for block_write_begin() and block_write_full_page(). |
| 2514 | * These functions should only try to map a single block at a time. |
| 2515 | * |
| 2516 | * Since this function doesn't do block allocations even if the caller |
| 2517 | * requests it by passing in create=1, it is critically important that |
| 2518 | * any caller checks to make sure that any buffer heads are returned |
| 2519 | * by this function are either all already mapped or marked for |
| 2520 | * delayed allocation before calling block_write_full_page(). Otherwise, |
| 2521 | * b_blocknr could be left unitialized, and the page write functions will |
| 2522 | * be taken by surprise. |
| 2523 | */ |
| 2524 | static int noalloc_get_block_write(struct inode *inode, sector_t iblock, |
| 2525 | struct buffer_head *bh_result, int create) |
| 2526 | { |
| 2527 | BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize); |
| 2528 | return _ext4_get_block(inode, iblock, bh_result, 0); |
| 2529 | } |
| 2530 | |
| 2531 | static int bget_one(handle_t *handle, struct buffer_head *bh) |
| 2532 | { |
| 2533 | get_bh(bh); |
| 2534 | return 0; |
| 2535 | } |
| 2536 | |
| 2537 | static int bput_one(handle_t *handle, struct buffer_head *bh) |
| 2538 | { |
| 2539 | put_bh(bh); |
| 2540 | return 0; |
| 2541 | } |
| 2542 | |
| 2543 | static int __ext4_journalled_writepage(struct page *page, |
| 2544 | unsigned int len) |
| 2545 | { |
| 2546 | struct address_space *mapping = page->mapping; |
| 2547 | struct inode *inode = mapping->host; |
| 2548 | struct buffer_head *page_bufs; |
| 2549 | handle_t *handle = NULL; |
| 2550 | int ret = 0; |
| 2551 | int err; |
| 2552 | |
| 2553 | ClearPageChecked(page); |
| 2554 | page_bufs = page_buffers(page); |
| 2555 | BUG_ON(!page_bufs); |
| 2556 | walk_page_buffers(handle, page_bufs, 0, len, NULL, bget_one); |
| 2557 | /* As soon as we unlock the page, it can go away, but we have |
| 2558 | * references to buffers so we are safe */ |
| 2559 | unlock_page(page); |
| 2560 | |
| 2561 | handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode)); |
| 2562 | if (IS_ERR(handle)) { |
| 2563 | ret = PTR_ERR(handle); |
| 2564 | goto out; |
| 2565 | } |
| 2566 | |
| 2567 | ret = walk_page_buffers(handle, page_bufs, 0, len, NULL, |
| 2568 | do_journal_get_write_access); |
| 2569 | |
| 2570 | err = walk_page_buffers(handle, page_bufs, 0, len, NULL, |
| 2571 | write_end_fn); |
| 2572 | if (ret == 0) |
| 2573 | ret = err; |
| 2574 | err = ext4_journal_stop(handle); |
| 2575 | if (!ret) |
| 2576 | ret = err; |
| 2577 | |
| 2578 | walk_page_buffers(handle, page_bufs, 0, len, NULL, bput_one); |
| 2579 | ext4_set_inode_state(inode, EXT4_STATE_JDATA); |
| 2580 | out: |
| 2581 | return ret; |
| 2582 | } |
| 2583 | |
| 2584 | static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode); |
| 2585 | static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate); |
| 2586 | |
| 2587 | /* |
| 2588 | * Note that we don't need to start a transaction unless we're journaling data |
| 2589 | * because we should have holes filled from ext4_page_mkwrite(). We even don't |
| 2590 | * need to file the inode to the transaction's list in ordered mode because if |
| 2591 | * we are writing back data added by write(), the inode is already there and if |
| 2592 | * we are writing back data modified via mmap(), no one guarantees in which |
| 2593 | * transaction the data will hit the disk. In case we are journaling data, we |
| 2594 | * cannot start transaction directly because transaction start ranks above page |
| 2595 | * lock so we have to do some magic. |
| 2596 | * |
| 2597 | * This function can get called via... |
| 2598 | * - ext4_da_writepages after taking page lock (have journal handle) |
| 2599 | * - journal_submit_inode_data_buffers (no journal handle) |
| 2600 | * - shrink_page_list via pdflush (no journal handle) |
| 2601 | * - grab_page_cache when doing write_begin (have journal handle) |
| 2602 | * |
| 2603 | * We don't do any block allocation in this function. If we have page with |
| 2604 | * multiple blocks we need to write those buffer_heads that are mapped. This |
| 2605 | * is important for mmaped based write. So if we do with blocksize 1K |
| 2606 | * truncate(f, 1024); |
| 2607 | * a = mmap(f, 0, 4096); |
| 2608 | * a[0] = 'a'; |
| 2609 | * truncate(f, 4096); |
| 2610 | * we have in the page first buffer_head mapped via page_mkwrite call back |
| 2611 | * but other bufer_heads would be unmapped but dirty(dirty done via the |
| 2612 | * do_wp_page). So writepage should write the first block. If we modify |
| 2613 | * the mmap area beyond 1024 we will again get a page_fault and the |
| 2614 | * page_mkwrite callback will do the block allocation and mark the |
| 2615 | * buffer_heads mapped. |
| 2616 | * |
| 2617 | * We redirty the page if we have any buffer_heads that is either delay or |
| 2618 | * unwritten in the page. |
| 2619 | * |
| 2620 | * We can get recursively called as show below. |
| 2621 | * |
| 2622 | * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() -> |
| 2623 | * ext4_writepage() |
| 2624 | * |
| 2625 | * But since we don't do any block allocation we should not deadlock. |
| 2626 | * Page also have the dirty flag cleared so we don't get recurive page_lock. |
| 2627 | */ |
| 2628 | static int ext4_writepage(struct page *page, |
| 2629 | struct writeback_control *wbc) |
| 2630 | { |
| 2631 | int ret = 0, commit_write = 0; |
| 2632 | loff_t size; |
| 2633 | unsigned int len; |
| 2634 | struct buffer_head *page_bufs = NULL; |
| 2635 | struct inode *inode = page->mapping->host; |
| 2636 | |
| 2637 | trace_ext4_writepage(page); |
| 2638 | size = i_size_read(inode); |
| 2639 | if (page->index == size >> PAGE_CACHE_SHIFT) |
| 2640 | len = size & ~PAGE_CACHE_MASK; |
| 2641 | else |
| 2642 | len = PAGE_CACHE_SIZE; |
| 2643 | |
| 2644 | /* |
| 2645 | * If the page does not have buffers (for whatever reason), |
| 2646 | * try to create them using __block_write_begin. If this |
| 2647 | * fails, redirty the page and move on. |
| 2648 | */ |
| 2649 | if (!page_has_buffers(page)) { |
| 2650 | if (__block_write_begin(page, 0, len, |
| 2651 | noalloc_get_block_write)) { |
| 2652 | redirty_page: |
| 2653 | redirty_page_for_writepage(wbc, page); |
| 2654 | unlock_page(page); |
| 2655 | return 0; |
| 2656 | } |
| 2657 | commit_write = 1; |
| 2658 | } |
| 2659 | page_bufs = page_buffers(page); |
| 2660 | if (walk_page_buffers(NULL, page_bufs, 0, len, NULL, |
| 2661 | ext4_bh_delay_or_unwritten)) { |
| 2662 | /* |
| 2663 | * We don't want to do block allocation, so redirty |
| 2664 | * the page and return. We may reach here when we do |
| 2665 | * a journal commit via journal_submit_inode_data_buffers. |
| 2666 | * We can also reach here via shrink_page_list |
| 2667 | */ |
| 2668 | goto redirty_page; |
| 2669 | } |
| 2670 | if (commit_write) |
| 2671 | /* now mark the buffer_heads as dirty and uptodate */ |
| 2672 | block_commit_write(page, 0, len); |
| 2673 | |
| 2674 | if (PageChecked(page) && ext4_should_journal_data(inode)) |
| 2675 | /* |
| 2676 | * It's mmapped pagecache. Add buffers and journal it. There |
| 2677 | * doesn't seem much point in redirtying the page here. |
| 2678 | */ |
| 2679 | return __ext4_journalled_writepage(page, len); |
| 2680 | |
| 2681 | if (buffer_uninit(page_bufs)) { |
| 2682 | ext4_set_bh_endio(page_bufs, inode); |
| 2683 | ret = block_write_full_page_endio(page, noalloc_get_block_write, |
| 2684 | wbc, ext4_end_io_buffer_write); |
| 2685 | } else |
| 2686 | ret = block_write_full_page(page, noalloc_get_block_write, |
| 2687 | wbc); |
| 2688 | |
| 2689 | return ret; |
| 2690 | } |
| 2691 | |
| 2692 | /* |
| 2693 | * This is called via ext4_da_writepages() to |
| 2694 | * calculate the total number of credits to reserve to fit |
| 2695 | * a single extent allocation into a single transaction, |
| 2696 | * ext4_da_writpeages() will loop calling this before |
| 2697 | * the block allocation. |
| 2698 | */ |
| 2699 | |
| 2700 | static int ext4_da_writepages_trans_blocks(struct inode *inode) |
| 2701 | { |
| 2702 | int max_blocks = EXT4_I(inode)->i_reserved_data_blocks; |
| 2703 | |
| 2704 | /* |
| 2705 | * With non-extent format the journal credit needed to |
| 2706 | * insert nrblocks contiguous block is dependent on |
| 2707 | * number of contiguous block. So we will limit |
| 2708 | * number of contiguous block to a sane value |
| 2709 | */ |
| 2710 | if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) && |
| 2711 | (max_blocks > EXT4_MAX_TRANS_DATA)) |
| 2712 | max_blocks = EXT4_MAX_TRANS_DATA; |
| 2713 | |
| 2714 | return ext4_chunk_trans_blocks(inode, max_blocks); |
| 2715 | } |
| 2716 | |
| 2717 | /* |
| 2718 | * write_cache_pages_da - walk the list of dirty pages of the given |
| 2719 | * address space and accumulate pages that need writing, and call |
| 2720 | * mpage_da_map_and_submit to map a single contiguous memory region |
| 2721 | * and then write them. |
| 2722 | */ |
| 2723 | static int write_cache_pages_da(struct address_space *mapping, |
| 2724 | struct writeback_control *wbc, |
| 2725 | struct mpage_da_data *mpd, |
| 2726 | pgoff_t *done_index) |
| 2727 | { |
| 2728 | struct buffer_head *bh, *head; |
| 2729 | struct inode *inode = mapping->host; |
| 2730 | struct pagevec pvec; |
| 2731 | unsigned int nr_pages; |
| 2732 | sector_t logical; |
| 2733 | pgoff_t index, end; |
| 2734 | long nr_to_write = wbc->nr_to_write; |
| 2735 | int i, tag, ret = 0; |
| 2736 | |
| 2737 | memset(mpd, 0, sizeof(struct mpage_da_data)); |
| 2738 | mpd->wbc = wbc; |
| 2739 | mpd->inode = inode; |
| 2740 | pagevec_init(&pvec, 0); |
| 2741 | index = wbc->range_start >> PAGE_CACHE_SHIFT; |
| 2742 | end = wbc->range_end >> PAGE_CACHE_SHIFT; |
| 2743 | |
| 2744 | if (wbc->sync_mode == WB_SYNC_ALL) |
| 2745 | tag = PAGECACHE_TAG_TOWRITE; |
| 2746 | else |
| 2747 | tag = PAGECACHE_TAG_DIRTY; |
| 2748 | |
| 2749 | *done_index = index; |
| 2750 | while (index <= end) { |
| 2751 | nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag, |
| 2752 | min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1); |
| 2753 | if (nr_pages == 0) |
| 2754 | return 0; |
| 2755 | |
| 2756 | for (i = 0; i < nr_pages; i++) { |
| 2757 | struct page *page = pvec.pages[i]; |
| 2758 | |
| 2759 | /* |
| 2760 | * At this point, the page may be truncated or |
| 2761 | * invalidated (changing page->mapping to NULL), or |
| 2762 | * even swizzled back from swapper_space to tmpfs file |
| 2763 | * mapping. However, page->index will not change |
| 2764 | * because we have a reference on the page. |
| 2765 | */ |
| 2766 | if (page->index > end) |
| 2767 | goto out; |
| 2768 | |
| 2769 | *done_index = page->index + 1; |
| 2770 | |
| 2771 | /* |
| 2772 | * If we can't merge this page, and we have |
| 2773 | * accumulated an contiguous region, write it |
| 2774 | */ |
| 2775 | if ((mpd->next_page != page->index) && |
| 2776 | (mpd->next_page != mpd->first_page)) { |
| 2777 | mpage_da_map_and_submit(mpd); |
| 2778 | goto ret_extent_tail; |
| 2779 | } |
| 2780 | |
| 2781 | lock_page(page); |
| 2782 | |
| 2783 | /* |
| 2784 | * If the page is no longer dirty, or its |
| 2785 | * mapping no longer corresponds to inode we |
| 2786 | * are writing (which means it has been |
| 2787 | * truncated or invalidated), or the page is |
| 2788 | * already under writeback and we are not |
| 2789 | * doing a data integrity writeback, skip the page |
| 2790 | */ |
| 2791 | if (!PageDirty(page) || |
| 2792 | (PageWriteback(page) && |
| 2793 | (wbc->sync_mode == WB_SYNC_NONE)) || |
| 2794 | unlikely(page->mapping != mapping)) { |
| 2795 | unlock_page(page); |
| 2796 | continue; |
| 2797 | } |
| 2798 | |
| 2799 | wait_on_page_writeback(page); |
| 2800 | BUG_ON(PageWriteback(page)); |
| 2801 | |
| 2802 | if (mpd->next_page != page->index) |
| 2803 | mpd->first_page = page->index; |
| 2804 | mpd->next_page = page->index + 1; |
| 2805 | logical = (sector_t) page->index << |
| 2806 | (PAGE_CACHE_SHIFT - inode->i_blkbits); |
| 2807 | |
| 2808 | if (!page_has_buffers(page)) { |
| 2809 | mpage_add_bh_to_extent(mpd, logical, |
| 2810 | PAGE_CACHE_SIZE, |
| 2811 | (1 << BH_Dirty) | (1 << BH_Uptodate)); |
| 2812 | if (mpd->io_done) |
| 2813 | goto ret_extent_tail; |
| 2814 | } else { |
| 2815 | /* |
| 2816 | * Page with regular buffer heads, |
| 2817 | * just add all dirty ones |
| 2818 | */ |
| 2819 | head = page_buffers(page); |
| 2820 | bh = head; |
| 2821 | do { |
| 2822 | BUG_ON(buffer_locked(bh)); |
| 2823 | /* |
| 2824 | * We need to try to allocate |
| 2825 | * unmapped blocks in the same page. |
| 2826 | * Otherwise we won't make progress |
| 2827 | * with the page in ext4_writepage |
| 2828 | */ |
| 2829 | if (ext4_bh_delay_or_unwritten(NULL, bh)) { |
| 2830 | mpage_add_bh_to_extent(mpd, logical, |
| 2831 | bh->b_size, |
| 2832 | bh->b_state); |
| 2833 | if (mpd->io_done) |
| 2834 | goto ret_extent_tail; |
| 2835 | } else if (buffer_dirty(bh) && (buffer_mapped(bh))) { |
| 2836 | /* |
| 2837 | * mapped dirty buffer. We need |
| 2838 | * to update the b_state |
| 2839 | * because we look at b_state |
| 2840 | * in mpage_da_map_blocks. We |
| 2841 | * don't update b_size because |
| 2842 | * if we find an unmapped |
| 2843 | * buffer_head later we need to |
| 2844 | * use the b_state flag of that |
| 2845 | * buffer_head. |
| 2846 | */ |
| 2847 | if (mpd->b_size == 0) |
| 2848 | mpd->b_state = bh->b_state & BH_FLAGS; |
| 2849 | } |
| 2850 | logical++; |
| 2851 | } while ((bh = bh->b_this_page) != head); |
| 2852 | } |
| 2853 | |
| 2854 | if (nr_to_write > 0) { |
| 2855 | nr_to_write--; |
| 2856 | if (nr_to_write == 0 && |
| 2857 | wbc->sync_mode == WB_SYNC_NONE) |
| 2858 | /* |
| 2859 | * We stop writing back only if we are |
| 2860 | * not doing integrity sync. In case of |
| 2861 | * integrity sync we have to keep going |
| 2862 | * because someone may be concurrently |
| 2863 | * dirtying pages, and we might have |
| 2864 | * synced a lot of newly appeared dirty |
| 2865 | * pages, but have not synced all of the |
| 2866 | * old dirty pages. |
| 2867 | */ |
| 2868 | goto out; |
| 2869 | } |
| 2870 | } |
| 2871 | pagevec_release(&pvec); |
| 2872 | cond_resched(); |
| 2873 | } |
| 2874 | return 0; |
| 2875 | ret_extent_tail: |
| 2876 | ret = MPAGE_DA_EXTENT_TAIL; |
| 2877 | out: |
| 2878 | pagevec_release(&pvec); |
| 2879 | cond_resched(); |
| 2880 | return ret; |
| 2881 | } |
| 2882 | |
| 2883 | |
| 2884 | static int ext4_da_writepages(struct address_space *mapping, |
| 2885 | struct writeback_control *wbc) |
| 2886 | { |
| 2887 | pgoff_t index; |
| 2888 | int range_whole = 0; |
| 2889 | handle_t *handle = NULL; |
| 2890 | struct mpage_da_data mpd; |
| 2891 | struct inode *inode = mapping->host; |
| 2892 | int pages_written = 0; |
| 2893 | unsigned int max_pages; |
| 2894 | int range_cyclic, cycled = 1, io_done = 0; |
| 2895 | int needed_blocks, ret = 0; |
| 2896 | long desired_nr_to_write, nr_to_writebump = 0; |
| 2897 | loff_t range_start = wbc->range_start; |
| 2898 | struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb); |
| 2899 | pgoff_t done_index = 0; |
| 2900 | pgoff_t end; |
| 2901 | |
| 2902 | trace_ext4_da_writepages(inode, wbc); |
| 2903 | |
| 2904 | /* |
| 2905 | * No pages to write? This is mainly a kludge to avoid starting |
| 2906 | * a transaction for special inodes like journal inode on last iput() |
| 2907 | * because that could violate lock ordering on umount |
| 2908 | */ |
| 2909 | if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) |
| 2910 | return 0; |
| 2911 | |
| 2912 | /* |
| 2913 | * If the filesystem has aborted, it is read-only, so return |
| 2914 | * right away instead of dumping stack traces later on that |
| 2915 | * will obscure the real source of the problem. We test |
| 2916 | * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because |
| 2917 | * the latter could be true if the filesystem is mounted |
| 2918 | * read-only, and in that case, ext4_da_writepages should |
| 2919 | * *never* be called, so if that ever happens, we would want |
| 2920 | * the stack trace. |
| 2921 | */ |
| 2922 | if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED)) |
| 2923 | return -EROFS; |
| 2924 | |
| 2925 | if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) |
| 2926 | range_whole = 1; |
| 2927 | |
| 2928 | range_cyclic = wbc->range_cyclic; |
| 2929 | if (wbc->range_cyclic) { |
| 2930 | index = mapping->writeback_index; |
| 2931 | if (index) |
| 2932 | cycled = 0; |
| 2933 | wbc->range_start = index << PAGE_CACHE_SHIFT; |
| 2934 | wbc->range_end = LLONG_MAX; |
| 2935 | wbc->range_cyclic = 0; |
| 2936 | end = -1; |
| 2937 | } else { |
| 2938 | index = wbc->range_start >> PAGE_CACHE_SHIFT; |
| 2939 | end = wbc->range_end >> PAGE_CACHE_SHIFT; |
| 2940 | } |
| 2941 | |
| 2942 | /* |
| 2943 | * This works around two forms of stupidity. The first is in |
| 2944 | * the writeback code, which caps the maximum number of pages |
| 2945 | * written to be 1024 pages. This is wrong on multiple |
| 2946 | * levels; different architectues have a different page size, |
| 2947 | * which changes the maximum amount of data which gets |
| 2948 | * written. Secondly, 4 megabytes is way too small. XFS |
| 2949 | * forces this value to be 16 megabytes by multiplying |
| 2950 | * nr_to_write parameter by four, and then relies on its |
| 2951 | * allocator to allocate larger extents to make them |
| 2952 | * contiguous. Unfortunately this brings us to the second |
| 2953 | * stupidity, which is that ext4's mballoc code only allocates |
| 2954 | * at most 2048 blocks. So we force contiguous writes up to |
| 2955 | * the number of dirty blocks in the inode, or |
| 2956 | * sbi->max_writeback_mb_bump whichever is smaller. |
| 2957 | */ |
| 2958 | max_pages = sbi->s_max_writeback_mb_bump << (20 - PAGE_CACHE_SHIFT); |
| 2959 | if (!range_cyclic && range_whole) { |
| 2960 | if (wbc->nr_to_write == LONG_MAX) |
| 2961 | desired_nr_to_write = wbc->nr_to_write; |
| 2962 | else |
| 2963 | desired_nr_to_write = wbc->nr_to_write * 8; |
| 2964 | } else |
| 2965 | desired_nr_to_write = ext4_num_dirty_pages(inode, index, |
| 2966 | max_pages); |
| 2967 | if (desired_nr_to_write > max_pages) |
| 2968 | desired_nr_to_write = max_pages; |
| 2969 | |
| 2970 | if (wbc->nr_to_write < desired_nr_to_write) { |
| 2971 | nr_to_writebump = desired_nr_to_write - wbc->nr_to_write; |
| 2972 | wbc->nr_to_write = desired_nr_to_write; |
| 2973 | } |
| 2974 | |
| 2975 | retry: |
| 2976 | if (wbc->sync_mode == WB_SYNC_ALL) |
| 2977 | tag_pages_for_writeback(mapping, index, end); |
| 2978 | |
| 2979 | while (!ret && wbc->nr_to_write > 0) { |
| 2980 | |
| 2981 | /* |
| 2982 | * we insert one extent at a time. So we need |
| 2983 | * credit needed for single extent allocation. |
| 2984 | * journalled mode is currently not supported |
| 2985 | * by delalloc |
| 2986 | */ |
| 2987 | BUG_ON(ext4_should_journal_data(inode)); |
| 2988 | needed_blocks = ext4_da_writepages_trans_blocks(inode); |
| 2989 | |
| 2990 | /* start a new transaction*/ |
| 2991 | handle = ext4_journal_start(inode, needed_blocks); |
| 2992 | if (IS_ERR(handle)) { |
| 2993 | ret = PTR_ERR(handle); |
| 2994 | ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: " |
| 2995 | "%ld pages, ino %lu; err %d", __func__, |
| 2996 | wbc->nr_to_write, inode->i_ino, ret); |
| 2997 | goto out_writepages; |
| 2998 | } |
| 2999 | |
| 3000 | /* |
| 3001 | * Now call write_cache_pages_da() to find the next |
| 3002 | * contiguous region of logical blocks that need |
| 3003 | * blocks to be allocated by ext4 and submit them. |
| 3004 | */ |
| 3005 | ret = write_cache_pages_da(mapping, wbc, &mpd, &done_index); |
| 3006 | /* |
| 3007 | * If we have a contiguous extent of pages and we |
| 3008 | * haven't done the I/O yet, map the blocks and submit |
| 3009 | * them for I/O. |
| 3010 | */ |
| 3011 | if (!mpd.io_done && mpd.next_page != mpd.first_page) { |
| 3012 | mpage_da_map_and_submit(&mpd); |
| 3013 | ret = MPAGE_DA_EXTENT_TAIL; |
| 3014 | } |
| 3015 | trace_ext4_da_write_pages(inode, &mpd); |
| 3016 | wbc->nr_to_write -= mpd.pages_written; |
| 3017 | |
| 3018 | ext4_journal_stop(handle); |
| 3019 | |
| 3020 | if ((mpd.retval == -ENOSPC) && sbi->s_journal) { |
| 3021 | /* commit the transaction which would |
| 3022 | * free blocks released in the transaction |
| 3023 | * and try again |
| 3024 | */ |
| 3025 | jbd2_journal_force_commit_nested(sbi->s_journal); |
| 3026 | ret = 0; |
| 3027 | } else if (ret == MPAGE_DA_EXTENT_TAIL) { |
| 3028 | /* |
| 3029 | * got one extent now try with |
| 3030 | * rest of the pages |
| 3031 | */ |
| 3032 | pages_written += mpd.pages_written; |
| 3033 | ret = 0; |
| 3034 | io_done = 1; |
| 3035 | } else if (wbc->nr_to_write) |
| 3036 | /* |
| 3037 | * There is no more writeout needed |
| 3038 | * or we requested for a noblocking writeout |
| 3039 | * and we found the device congested |
| 3040 | */ |
| 3041 | break; |
| 3042 | } |
| 3043 | if (!io_done && !cycled) { |
| 3044 | cycled = 1; |
| 3045 | index = 0; |
| 3046 | wbc->range_start = index << PAGE_CACHE_SHIFT; |
| 3047 | wbc->range_end = mapping->writeback_index - 1; |
| 3048 | goto retry; |
| 3049 | } |
| 3050 | |
| 3051 | /* Update index */ |
| 3052 | wbc->range_cyclic = range_cyclic; |
| 3053 | if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) |
| 3054 | /* |
| 3055 | * set the writeback_index so that range_cyclic |
| 3056 | * mode will write it back later |
| 3057 | */ |
| 3058 | mapping->writeback_index = done_index; |
| 3059 | |
| 3060 | out_writepages: |
| 3061 | wbc->nr_to_write -= nr_to_writebump; |
| 3062 | wbc->range_start = range_start; |
| 3063 | trace_ext4_da_writepages_result(inode, wbc, ret, pages_written); |
| 3064 | return ret; |
| 3065 | } |
| 3066 | |
| 3067 | #define FALL_BACK_TO_NONDELALLOC 1 |
| 3068 | static int ext4_nonda_switch(struct super_block *sb) |
| 3069 | { |
| 3070 | s64 free_blocks, dirty_blocks; |
| 3071 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
| 3072 | |
| 3073 | /* |
| 3074 | * switch to non delalloc mode if we are running low |
| 3075 | * on free block. The free block accounting via percpu |
| 3076 | * counters can get slightly wrong with percpu_counter_batch getting |
| 3077 | * accumulated on each CPU without updating global counters |
| 3078 | * Delalloc need an accurate free block accounting. So switch |
| 3079 | * to non delalloc when we are near to error range. |
| 3080 | */ |
| 3081 | free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); |
| 3082 | dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyblocks_counter); |
| 3083 | if (2 * free_blocks < 3 * dirty_blocks || |
| 3084 | free_blocks < (dirty_blocks + EXT4_FREEBLOCKS_WATERMARK)) { |
| 3085 | /* |
| 3086 | * free block count is less than 150% of dirty blocks |
| 3087 | * or free blocks is less than watermark |
| 3088 | */ |
| 3089 | return 1; |
| 3090 | } |
| 3091 | /* |
| 3092 | * Even if we don't switch but are nearing capacity, |
| 3093 | * start pushing delalloc when 1/2 of free blocks are dirty. |
| 3094 | */ |
| 3095 | if (free_blocks < 2 * dirty_blocks) |
| 3096 | writeback_inodes_sb_if_idle(sb); |
| 3097 | |
| 3098 | return 0; |
| 3099 | } |
| 3100 | |
| 3101 | static int ext4_da_write_begin(struct file *file, struct address_space *mapping, |
| 3102 | loff_t pos, unsigned len, unsigned flags, |
| 3103 | struct page **pagep, void **fsdata) |
| 3104 | { |
| 3105 | int ret, retries = 0; |
| 3106 | struct page *page; |
| 3107 | pgoff_t index; |
| 3108 | struct inode *inode = mapping->host; |
| 3109 | handle_t *handle; |
| 3110 | |
| 3111 | index = pos >> PAGE_CACHE_SHIFT; |
| 3112 | |
| 3113 | if (ext4_nonda_switch(inode->i_sb)) { |
| 3114 | *fsdata = (void *)FALL_BACK_TO_NONDELALLOC; |
| 3115 | return ext4_write_begin(file, mapping, pos, |
| 3116 | len, flags, pagep, fsdata); |
| 3117 | } |
| 3118 | *fsdata = (void *)0; |
| 3119 | trace_ext4_da_write_begin(inode, pos, len, flags); |
| 3120 | retry: |
| 3121 | /* |
| 3122 | * With delayed allocation, we don't log the i_disksize update |
| 3123 | * if there is delayed block allocation. But we still need |
| 3124 | * to journalling the i_disksize update if writes to the end |
| 3125 | * of file which has an already mapped buffer. |
| 3126 | */ |
| 3127 | handle = ext4_journal_start(inode, 1); |
| 3128 | if (IS_ERR(handle)) { |
| 3129 | ret = PTR_ERR(handle); |
| 3130 | goto out; |
| 3131 | } |
| 3132 | /* We cannot recurse into the filesystem as the transaction is already |
| 3133 | * started */ |
| 3134 | flags |= AOP_FLAG_NOFS; |
| 3135 | |
| 3136 | page = grab_cache_page_write_begin(mapping, index, flags); |
| 3137 | if (!page) { |
| 3138 | ext4_journal_stop(handle); |
| 3139 | ret = -ENOMEM; |
| 3140 | goto out; |
| 3141 | } |
| 3142 | *pagep = page; |
| 3143 | |
| 3144 | ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep); |
| 3145 | if (ret < 0) { |
| 3146 | unlock_page(page); |
| 3147 | ext4_journal_stop(handle); |
| 3148 | page_cache_release(page); |
| 3149 | /* |
| 3150 | * block_write_begin may have instantiated a few blocks |
| 3151 | * outside i_size. Trim these off again. Don't need |
| 3152 | * i_size_read because we hold i_mutex. |
| 3153 | */ |
| 3154 | if (pos + len > inode->i_size) |
| 3155 | ext4_truncate_failed_write(inode); |
| 3156 | } |
| 3157 | |
| 3158 | if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) |
| 3159 | goto retry; |
| 3160 | out: |
| 3161 | return ret; |
| 3162 | } |
| 3163 | |
| 3164 | /* |
| 3165 | * Check if we should update i_disksize |
| 3166 | * when write to the end of file but not require block allocation |
| 3167 | */ |
| 3168 | static int ext4_da_should_update_i_disksize(struct page *page, |
| 3169 | unsigned long offset) |
| 3170 | { |
| 3171 | struct buffer_head *bh; |
| 3172 | struct inode *inode = page->mapping->host; |
| 3173 | unsigned int idx; |
| 3174 | int i; |
| 3175 | |
| 3176 | bh = page_buffers(page); |
| 3177 | idx = offset >> inode->i_blkbits; |
| 3178 | |
| 3179 | for (i = 0; i < idx; i++) |
| 3180 | bh = bh->b_this_page; |
| 3181 | |
| 3182 | if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh)) |
| 3183 | return 0; |
| 3184 | return 1; |
| 3185 | } |
| 3186 | |
| 3187 | static int ext4_da_write_end(struct file *file, |
| 3188 | struct address_space *mapping, |
| 3189 | loff_t pos, unsigned len, unsigned copied, |
| 3190 | struct page *page, void *fsdata) |
| 3191 | { |
| 3192 | struct inode *inode = mapping->host; |
| 3193 | int ret = 0, ret2; |
| 3194 | handle_t *handle = ext4_journal_current_handle(); |
| 3195 | loff_t new_i_size; |
| 3196 | unsigned long start, end; |
| 3197 | int write_mode = (int)(unsigned long)fsdata; |
| 3198 | |
| 3199 | if (write_mode == FALL_BACK_TO_NONDELALLOC) { |
| 3200 | if (ext4_should_order_data(inode)) { |
| 3201 | return ext4_ordered_write_end(file, mapping, pos, |
| 3202 | len, copied, page, fsdata); |
| 3203 | } else if (ext4_should_writeback_data(inode)) { |
| 3204 | return ext4_writeback_write_end(file, mapping, pos, |
| 3205 | len, copied, page, fsdata); |
| 3206 | } else { |
| 3207 | BUG(); |
| 3208 | } |
| 3209 | } |
| 3210 | |
| 3211 | trace_ext4_da_write_end(inode, pos, len, copied); |
| 3212 | start = pos & (PAGE_CACHE_SIZE - 1); |
| 3213 | end = start + copied - 1; |
| 3214 | |
| 3215 | /* |
| 3216 | * generic_write_end() will run mark_inode_dirty() if i_size |
| 3217 | * changes. So let's piggyback the i_disksize mark_inode_dirty |
| 3218 | * into that. |
| 3219 | */ |
| 3220 | |
| 3221 | new_i_size = pos + copied; |
| 3222 | if (new_i_size > EXT4_I(inode)->i_disksize) { |
| 3223 | if (ext4_da_should_update_i_disksize(page, end)) { |
| 3224 | down_write(&EXT4_I(inode)->i_data_sem); |
| 3225 | if (new_i_size > EXT4_I(inode)->i_disksize) { |
| 3226 | /* |
| 3227 | * Updating i_disksize when extending file |
| 3228 | * without needing block allocation |
| 3229 | */ |
| 3230 | if (ext4_should_order_data(inode)) |
| 3231 | ret = ext4_jbd2_file_inode(handle, |
| 3232 | inode); |
| 3233 | |
| 3234 | EXT4_I(inode)->i_disksize = new_i_size; |
| 3235 | } |
| 3236 | up_write(&EXT4_I(inode)->i_data_sem); |
| 3237 | /* We need to mark inode dirty even if |
| 3238 | * new_i_size is less that inode->i_size |
| 3239 | * bu greater than i_disksize.(hint delalloc) |
| 3240 | */ |
| 3241 | ext4_mark_inode_dirty(handle, inode); |
| 3242 | } |
| 3243 | } |
| 3244 | ret2 = generic_write_end(file, mapping, pos, len, copied, |
| 3245 | page, fsdata); |
| 3246 | copied = ret2; |
| 3247 | if (ret2 < 0) |
| 3248 | ret = ret2; |
| 3249 | ret2 = ext4_journal_stop(handle); |
| 3250 | if (!ret) |
| 3251 | ret = ret2; |
| 3252 | |
| 3253 | return ret ? ret : copied; |
| 3254 | } |
| 3255 | |
| 3256 | static void ext4_da_invalidatepage(struct page *page, unsigned long offset) |
| 3257 | { |
| 3258 | /* |
| 3259 | * Drop reserved blocks |
| 3260 | */ |
| 3261 | BUG_ON(!PageLocked(page)); |
| 3262 | if (!page_has_buffers(page)) |
| 3263 | goto out; |
| 3264 | |
| 3265 | ext4_da_page_release_reservation(page, offset); |
| 3266 | |
| 3267 | out: |
| 3268 | ext4_invalidatepage(page, offset); |
| 3269 | |
| 3270 | return; |
| 3271 | } |
| 3272 | |
| 3273 | /* |
| 3274 | * Force all delayed allocation blocks to be allocated for a given inode. |
| 3275 | */ |
| 3276 | int ext4_alloc_da_blocks(struct inode *inode) |
| 3277 | { |
| 3278 | trace_ext4_alloc_da_blocks(inode); |
| 3279 | |
| 3280 | if (!EXT4_I(inode)->i_reserved_data_blocks && |
| 3281 | !EXT4_I(inode)->i_reserved_meta_blocks) |
| 3282 | return 0; |
| 3283 | |
| 3284 | /* |
| 3285 | * We do something simple for now. The filemap_flush() will |
| 3286 | * also start triggering a write of the data blocks, which is |
| 3287 | * not strictly speaking necessary (and for users of |
| 3288 | * laptop_mode, not even desirable). However, to do otherwise |
| 3289 | * would require replicating code paths in: |
| 3290 | * |
| 3291 | * ext4_da_writepages() -> |
| 3292 | * write_cache_pages() ---> (via passed in callback function) |
| 3293 | * __mpage_da_writepage() --> |
| 3294 | * mpage_add_bh_to_extent() |
| 3295 | * mpage_da_map_blocks() |
| 3296 | * |
| 3297 | * The problem is that write_cache_pages(), located in |
| 3298 | * mm/page-writeback.c, marks pages clean in preparation for |
| 3299 | * doing I/O, which is not desirable if we're not planning on |
| 3300 | * doing I/O at all. |
| 3301 | * |
| 3302 | * We could call write_cache_pages(), and then redirty all of |
| 3303 | * the pages by calling redirty_page_for_writepage() but that |
| 3304 | * would be ugly in the extreme. So instead we would need to |
| 3305 | * replicate parts of the code in the above functions, |
| 3306 | * simplifying them because we wouldn't actually intend to |
| 3307 | * write out the pages, but rather only collect contiguous |
| 3308 | * logical block extents, call the multi-block allocator, and |
| 3309 | * then update the buffer heads with the block allocations. |
| 3310 | * |
| 3311 | * For now, though, we'll cheat by calling filemap_flush(), |
| 3312 | * which will map the blocks, and start the I/O, but not |
| 3313 | * actually wait for the I/O to complete. |
| 3314 | */ |
| 3315 | return filemap_flush(inode->i_mapping); |
| 3316 | } |
| 3317 | |
| 3318 | /* |
| 3319 | * bmap() is special. It gets used by applications such as lilo and by |
| 3320 | * the swapper to find the on-disk block of a specific piece of data. |
| 3321 | * |
| 3322 | * Naturally, this is dangerous if the block concerned is still in the |
| 3323 | * journal. If somebody makes a swapfile on an ext4 data-journaling |
| 3324 | * filesystem and enables swap, then they may get a nasty shock when the |
| 3325 | * data getting swapped to that swapfile suddenly gets overwritten by |
| 3326 | * the original zero's written out previously to the journal and |
| 3327 | * awaiting writeback in the kernel's buffer cache. |
| 3328 | * |
| 3329 | * So, if we see any bmap calls here on a modified, data-journaled file, |
| 3330 | * take extra steps to flush any blocks which might be in the cache. |
| 3331 | */ |
| 3332 | static sector_t ext4_bmap(struct address_space *mapping, sector_t block) |
| 3333 | { |
| 3334 | struct inode *inode = mapping->host; |
| 3335 | journal_t *journal; |
| 3336 | int err; |
| 3337 | |
| 3338 | if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) && |
| 3339 | test_opt(inode->i_sb, DELALLOC)) { |
| 3340 | /* |
| 3341 | * With delalloc we want to sync the file |
| 3342 | * so that we can make sure we allocate |
| 3343 | * blocks for file |
| 3344 | */ |
| 3345 | filemap_write_and_wait(mapping); |
| 3346 | } |
| 3347 | |
| 3348 | if (EXT4_JOURNAL(inode) && |
| 3349 | ext4_test_inode_state(inode, EXT4_STATE_JDATA)) { |
| 3350 | /* |
| 3351 | * This is a REALLY heavyweight approach, but the use of |
| 3352 | * bmap on dirty files is expected to be extremely rare: |
| 3353 | * only if we run lilo or swapon on a freshly made file |
| 3354 | * do we expect this to happen. |
| 3355 | * |
| 3356 | * (bmap requires CAP_SYS_RAWIO so this does not |
| 3357 | * represent an unprivileged user DOS attack --- we'd be |
| 3358 | * in trouble if mortal users could trigger this path at |
| 3359 | * will.) |
| 3360 | * |
| 3361 | * NB. EXT4_STATE_JDATA is not set on files other than |
| 3362 | * regular files. If somebody wants to bmap a directory |
| 3363 | * or symlink and gets confused because the buffer |
| 3364 | * hasn't yet been flushed to disk, they deserve |
| 3365 | * everything they get. |
| 3366 | */ |
| 3367 | |
| 3368 | ext4_clear_inode_state(inode, EXT4_STATE_JDATA); |
| 3369 | journal = EXT4_JOURNAL(inode); |
| 3370 | jbd2_journal_lock_updates(journal); |
| 3371 | err = jbd2_journal_flush(journal); |
| 3372 | jbd2_journal_unlock_updates(journal); |
| 3373 | |
| 3374 | if (err) |
| 3375 | return 0; |
| 3376 | } |
| 3377 | |
| 3378 | return generic_block_bmap(mapping, block, ext4_get_block); |
| 3379 | } |
| 3380 | |
| 3381 | static int ext4_readpage(struct file *file, struct page *page) |
| 3382 | { |
| 3383 | trace_ext4_readpage(page); |
| 3384 | return mpage_readpage(page, ext4_get_block); |
| 3385 | } |
| 3386 | |
| 3387 | static int |
| 3388 | ext4_readpages(struct file *file, struct address_space *mapping, |
| 3389 | struct list_head *pages, unsigned nr_pages) |
| 3390 | { |
| 3391 | return mpage_readpages(mapping, pages, nr_pages, ext4_get_block); |
| 3392 | } |
| 3393 | |
| 3394 | static void ext4_invalidatepage_free_endio(struct page *page, unsigned long offset) |
| 3395 | { |
| 3396 | struct buffer_head *head, *bh; |
| 3397 | unsigned int curr_off = 0; |
| 3398 | |
| 3399 | if (!page_has_buffers(page)) |
| 3400 | return; |
| 3401 | head = bh = page_buffers(page); |
| 3402 | do { |
| 3403 | if (offset <= curr_off && test_clear_buffer_uninit(bh) |
| 3404 | && bh->b_private) { |
| 3405 | ext4_free_io_end(bh->b_private); |
| 3406 | bh->b_private = NULL; |
| 3407 | bh->b_end_io = NULL; |
| 3408 | } |
| 3409 | curr_off = curr_off + bh->b_size; |
| 3410 | bh = bh->b_this_page; |
| 3411 | } while (bh != head); |
| 3412 | } |
| 3413 | |
| 3414 | static void ext4_invalidatepage(struct page *page, unsigned long offset) |
| 3415 | { |
| 3416 | journal_t *journal = EXT4_JOURNAL(page->mapping->host); |
| 3417 | |
| 3418 | trace_ext4_invalidatepage(page, offset); |
| 3419 | |
| 3420 | /* |
| 3421 | * free any io_end structure allocated for buffers to be discarded |
| 3422 | */ |
| 3423 | if (ext4_should_dioread_nolock(page->mapping->host)) |
| 3424 | ext4_invalidatepage_free_endio(page, offset); |
| 3425 | /* |
| 3426 | * If it's a full truncate we just forget about the pending dirtying |
| 3427 | */ |
| 3428 | if (offset == 0) |
| 3429 | ClearPageChecked(page); |
| 3430 | |
| 3431 | if (journal) |
| 3432 | jbd2_journal_invalidatepage(journal, page, offset); |
| 3433 | else |
| 3434 | block_invalidatepage(page, offset); |
| 3435 | } |
| 3436 | |
| 3437 | static int ext4_releasepage(struct page *page, gfp_t wait) |
| 3438 | { |
| 3439 | journal_t *journal = EXT4_JOURNAL(page->mapping->host); |
| 3440 | |
| 3441 | trace_ext4_releasepage(page); |
| 3442 | |
| 3443 | WARN_ON(PageChecked(page)); |
| 3444 | if (!page_has_buffers(page)) |
| 3445 | return 0; |
| 3446 | if (journal) |
| 3447 | return jbd2_journal_try_to_free_buffers(journal, page, wait); |
| 3448 | else |
| 3449 | return try_to_free_buffers(page); |
| 3450 | } |
| 3451 | |
| 3452 | /* |
| 3453 | * O_DIRECT for ext3 (or indirect map) based files |
| 3454 | * |
| 3455 | * If the O_DIRECT write will extend the file then add this inode to the |
| 3456 | * orphan list. So recovery will truncate it back to the original size |
| 3457 | * if the machine crashes during the write. |
| 3458 | * |
| 3459 | * If the O_DIRECT write is intantiating holes inside i_size and the machine |
| 3460 | * crashes then stale disk data _may_ be exposed inside the file. But current |
| 3461 | * VFS code falls back into buffered path in that case so we are safe. |
| 3462 | */ |
| 3463 | static ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb, |
| 3464 | const struct iovec *iov, loff_t offset, |
| 3465 | unsigned long nr_segs) |
| 3466 | { |
| 3467 | struct file *file = iocb->ki_filp; |
| 3468 | struct inode *inode = file->f_mapping->host; |
| 3469 | struct ext4_inode_info *ei = EXT4_I(inode); |
| 3470 | handle_t *handle; |
| 3471 | ssize_t ret; |
| 3472 | int orphan = 0; |
| 3473 | size_t count = iov_length(iov, nr_segs); |
| 3474 | int retries = 0; |
| 3475 | |
| 3476 | if (rw == WRITE) { |
| 3477 | loff_t final_size = offset + count; |
| 3478 | |
| 3479 | if (final_size > inode->i_size) { |
| 3480 | /* Credits for sb + inode write */ |
| 3481 | handle = ext4_journal_start(inode, 2); |
| 3482 | if (IS_ERR(handle)) { |
| 3483 | ret = PTR_ERR(handle); |
| 3484 | goto out; |
| 3485 | } |
| 3486 | ret = ext4_orphan_add(handle, inode); |
| 3487 | if (ret) { |
| 3488 | ext4_journal_stop(handle); |
| 3489 | goto out; |
| 3490 | } |
| 3491 | orphan = 1; |
| 3492 | ei->i_disksize = inode->i_size; |
| 3493 | ext4_journal_stop(handle); |
| 3494 | } |
| 3495 | } |
| 3496 | |
| 3497 | retry: |
| 3498 | if (rw == READ && ext4_should_dioread_nolock(inode)) |
| 3499 | ret = __blockdev_direct_IO(rw, iocb, inode, |
| 3500 | inode->i_sb->s_bdev, iov, |
| 3501 | offset, nr_segs, |
| 3502 | ext4_get_block, NULL, NULL, 0); |
| 3503 | else { |
| 3504 | ret = blockdev_direct_IO(rw, iocb, inode, |
| 3505 | inode->i_sb->s_bdev, iov, |
| 3506 | offset, nr_segs, |
| 3507 | ext4_get_block, NULL); |
| 3508 | |
| 3509 | if (unlikely((rw & WRITE) && ret < 0)) { |
| 3510 | loff_t isize = i_size_read(inode); |
| 3511 | loff_t end = offset + iov_length(iov, nr_segs); |
| 3512 | |
| 3513 | if (end > isize) |
| 3514 | ext4_truncate_failed_write(inode); |
| 3515 | } |
| 3516 | } |
| 3517 | if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) |
| 3518 | goto retry; |
| 3519 | |
| 3520 | if (orphan) { |
| 3521 | int err; |
| 3522 | |
| 3523 | /* Credits for sb + inode write */ |
| 3524 | handle = ext4_journal_start(inode, 2); |
| 3525 | if (IS_ERR(handle)) { |
| 3526 | /* This is really bad luck. We've written the data |
| 3527 | * but cannot extend i_size. Bail out and pretend |
| 3528 | * the write failed... */ |
| 3529 | ret = PTR_ERR(handle); |
| 3530 | if (inode->i_nlink) |
| 3531 | ext4_orphan_del(NULL, inode); |
| 3532 | |
| 3533 | goto out; |
| 3534 | } |
| 3535 | if (inode->i_nlink) |
| 3536 | ext4_orphan_del(handle, inode); |
| 3537 | if (ret > 0) { |
| 3538 | loff_t end = offset + ret; |
| 3539 | if (end > inode->i_size) { |
| 3540 | ei->i_disksize = end; |
| 3541 | i_size_write(inode, end); |
| 3542 | /* |
| 3543 | * We're going to return a positive `ret' |
| 3544 | * here due to non-zero-length I/O, so there's |
| 3545 | * no way of reporting error returns from |
| 3546 | * ext4_mark_inode_dirty() to userspace. So |
| 3547 | * ignore it. |
| 3548 | */ |
| 3549 | ext4_mark_inode_dirty(handle, inode); |
| 3550 | } |
| 3551 | } |
| 3552 | err = ext4_journal_stop(handle); |
| 3553 | if (ret == 0) |
| 3554 | ret = err; |
| 3555 | } |
| 3556 | out: |
| 3557 | return ret; |
| 3558 | } |
| 3559 | |
| 3560 | /* |
| 3561 | * ext4_get_block used when preparing for a DIO write or buffer write. |
| 3562 | * We allocate an uinitialized extent if blocks haven't been allocated. |
| 3563 | * The extent will be converted to initialized after the IO is complete. |
| 3564 | */ |
| 3565 | static int ext4_get_block_write(struct inode *inode, sector_t iblock, |
| 3566 | struct buffer_head *bh_result, int create) |
| 3567 | { |
| 3568 | ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n", |
| 3569 | inode->i_ino, create); |
| 3570 | return _ext4_get_block(inode, iblock, bh_result, |
| 3571 | EXT4_GET_BLOCKS_IO_CREATE_EXT); |
| 3572 | } |
| 3573 | |
| 3574 | static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset, |
| 3575 | ssize_t size, void *private, int ret, |
| 3576 | bool is_async) |
| 3577 | { |
| 3578 | ext4_io_end_t *io_end = iocb->private; |
| 3579 | struct workqueue_struct *wq; |
| 3580 | unsigned long flags; |
| 3581 | struct ext4_inode_info *ei; |
| 3582 | |
| 3583 | /* if not async direct IO or dio with 0 bytes write, just return */ |
| 3584 | if (!io_end || !size) |
| 3585 | goto out; |
| 3586 | |
| 3587 | ext_debug("ext4_end_io_dio(): io_end 0x%p" |
| 3588 | "for inode %lu, iocb 0x%p, offset %llu, size %llu\n", |
| 3589 | iocb->private, io_end->inode->i_ino, iocb, offset, |
| 3590 | size); |
| 3591 | |
| 3592 | /* if not aio dio with unwritten extents, just free io and return */ |
| 3593 | if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) { |
| 3594 | ext4_free_io_end(io_end); |
| 3595 | iocb->private = NULL; |
| 3596 | out: |
| 3597 | if (is_async) |
| 3598 | aio_complete(iocb, ret, 0); |
| 3599 | return; |
| 3600 | } |
| 3601 | |
| 3602 | io_end->offset = offset; |
| 3603 | io_end->size = size; |
| 3604 | if (is_async) { |
| 3605 | io_end->iocb = iocb; |
| 3606 | io_end->result = ret; |
| 3607 | } |
| 3608 | wq = EXT4_SB(io_end->inode->i_sb)->dio_unwritten_wq; |
| 3609 | |
| 3610 | /* Add the io_end to per-inode completed aio dio list*/ |
| 3611 | ei = EXT4_I(io_end->inode); |
| 3612 | spin_lock_irqsave(&ei->i_completed_io_lock, flags); |
| 3613 | list_add_tail(&io_end->list, &ei->i_completed_io_list); |
| 3614 | spin_unlock_irqrestore(&ei->i_completed_io_lock, flags); |
| 3615 | |
| 3616 | /* queue the work to convert unwritten extents to written */ |
| 3617 | queue_work(wq, &io_end->work); |
| 3618 | iocb->private = NULL; |
| 3619 | } |
| 3620 | |
| 3621 | static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate) |
| 3622 | { |
| 3623 | ext4_io_end_t *io_end = bh->b_private; |
| 3624 | struct workqueue_struct *wq; |
| 3625 | struct inode *inode; |
| 3626 | unsigned long flags; |
| 3627 | |
| 3628 | if (!test_clear_buffer_uninit(bh) || !io_end) |
| 3629 | goto out; |
| 3630 | |
| 3631 | if (!(io_end->inode->i_sb->s_flags & MS_ACTIVE)) { |
| 3632 | printk("sb umounted, discard end_io request for inode %lu\n", |
| 3633 | io_end->inode->i_ino); |
| 3634 | ext4_free_io_end(io_end); |
| 3635 | goto out; |
| 3636 | } |
| 3637 | |
| 3638 | io_end->flag = EXT4_IO_END_UNWRITTEN; |
| 3639 | inode = io_end->inode; |
| 3640 | |
| 3641 | /* Add the io_end to per-inode completed io list*/ |
| 3642 | spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags); |
| 3643 | list_add_tail(&io_end->list, &EXT4_I(inode)->i_completed_io_list); |
| 3644 | spin_unlock_irqrestore(&EXT4_I(inode)->i_completed_io_lock, flags); |
| 3645 | |
| 3646 | wq = EXT4_SB(inode->i_sb)->dio_unwritten_wq; |
| 3647 | /* queue the work to convert unwritten extents to written */ |
| 3648 | queue_work(wq, &io_end->work); |
| 3649 | out: |
| 3650 | bh->b_private = NULL; |
| 3651 | bh->b_end_io = NULL; |
| 3652 | clear_buffer_uninit(bh); |
| 3653 | end_buffer_async_write(bh, uptodate); |
| 3654 | } |
| 3655 | |
| 3656 | static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode) |
| 3657 | { |
| 3658 | ext4_io_end_t *io_end; |
| 3659 | struct page *page = bh->b_page; |
| 3660 | loff_t offset = (sector_t)page->index << PAGE_CACHE_SHIFT; |
| 3661 | size_t size = bh->b_size; |
| 3662 | |
| 3663 | retry: |
| 3664 | io_end = ext4_init_io_end(inode, GFP_ATOMIC); |
| 3665 | if (!io_end) { |
| 3666 | pr_warn_ratelimited("%s: allocation fail\n", __func__); |
| 3667 | schedule(); |
| 3668 | goto retry; |
| 3669 | } |
| 3670 | io_end->offset = offset; |
| 3671 | io_end->size = size; |
| 3672 | /* |
| 3673 | * We need to hold a reference to the page to make sure it |
| 3674 | * doesn't get evicted before ext4_end_io_work() has a chance |
| 3675 | * to convert the extent from written to unwritten. |
| 3676 | */ |
| 3677 | io_end->page = page; |
| 3678 | get_page(io_end->page); |
| 3679 | |
| 3680 | bh->b_private = io_end; |
| 3681 | bh->b_end_io = ext4_end_io_buffer_write; |
| 3682 | return 0; |
| 3683 | } |
| 3684 | |
| 3685 | /* |
| 3686 | * For ext4 extent files, ext4 will do direct-io write to holes, |
| 3687 | * preallocated extents, and those write extend the file, no need to |
| 3688 | * fall back to buffered IO. |
| 3689 | * |
| 3690 | * For holes, we fallocate those blocks, mark them as uninitialized |
| 3691 | * If those blocks were preallocated, we mark sure they are splited, but |
| 3692 | * still keep the range to write as uninitialized. |
| 3693 | * |
| 3694 | * The unwrritten extents will be converted to written when DIO is completed. |
| 3695 | * For async direct IO, since the IO may still pending when return, we |
| 3696 | * set up an end_io call back function, which will do the conversion |
| 3697 | * when async direct IO completed. |
| 3698 | * |
| 3699 | * If the O_DIRECT write will extend the file then add this inode to the |
| 3700 | * orphan list. So recovery will truncate it back to the original size |
| 3701 | * if the machine crashes during the write. |
| 3702 | * |
| 3703 | */ |
| 3704 | static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb, |
| 3705 | const struct iovec *iov, loff_t offset, |
| 3706 | unsigned long nr_segs) |
| 3707 | { |
| 3708 | struct file *file = iocb->ki_filp; |
| 3709 | struct inode *inode = file->f_mapping->host; |
| 3710 | ssize_t ret; |
| 3711 | size_t count = iov_length(iov, nr_segs); |
| 3712 | |
| 3713 | loff_t final_size = offset + count; |
| 3714 | if (rw == WRITE && final_size <= inode->i_size) { |
| 3715 | /* |
| 3716 | * We could direct write to holes and fallocate. |
| 3717 | * |
| 3718 | * Allocated blocks to fill the hole are marked as uninitialized |
| 3719 | * to prevent parallel buffered read to expose the stale data |
| 3720 | * before DIO complete the data IO. |
| 3721 | * |
| 3722 | * As to previously fallocated extents, ext4 get_block |
| 3723 | * will just simply mark the buffer mapped but still |
| 3724 | * keep the extents uninitialized. |
| 3725 | * |
| 3726 | * for non AIO case, we will convert those unwritten extents |
| 3727 | * to written after return back from blockdev_direct_IO. |
| 3728 | * |
| 3729 | * for async DIO, the conversion needs to be defered when |
| 3730 | * the IO is completed. The ext4 end_io callback function |
| 3731 | * will be called to take care of the conversion work. |
| 3732 | * Here for async case, we allocate an io_end structure to |
| 3733 | * hook to the iocb. |
| 3734 | */ |
| 3735 | iocb->private = NULL; |
| 3736 | EXT4_I(inode)->cur_aio_dio = NULL; |
| 3737 | if (!is_sync_kiocb(iocb)) { |
| 3738 | iocb->private = ext4_init_io_end(inode, GFP_NOFS); |
| 3739 | if (!iocb->private) |
| 3740 | return -ENOMEM; |
| 3741 | /* |
| 3742 | * we save the io structure for current async |
| 3743 | * direct IO, so that later ext4_map_blocks() |
| 3744 | * could flag the io structure whether there |
| 3745 | * is a unwritten extents needs to be converted |
| 3746 | * when IO is completed. |
| 3747 | */ |
| 3748 | EXT4_I(inode)->cur_aio_dio = iocb->private; |
| 3749 | } |
| 3750 | |
| 3751 | ret = blockdev_direct_IO(rw, iocb, inode, |
| 3752 | inode->i_sb->s_bdev, iov, |
| 3753 | offset, nr_segs, |
| 3754 | ext4_get_block_write, |
| 3755 | ext4_end_io_dio); |
| 3756 | if (iocb->private) |
| 3757 | EXT4_I(inode)->cur_aio_dio = NULL; |
| 3758 | /* |
| 3759 | * The io_end structure takes a reference to the inode, |
| 3760 | * that structure needs to be destroyed and the |
| 3761 | * reference to the inode need to be dropped, when IO is |
| 3762 | * complete, even with 0 byte write, or failed. |
| 3763 | * |
| 3764 | * In the successful AIO DIO case, the io_end structure will be |
| 3765 | * desctroyed and the reference to the inode will be dropped |
| 3766 | * after the end_io call back function is called. |
| 3767 | * |
| 3768 | * In the case there is 0 byte write, or error case, since |
| 3769 | * VFS direct IO won't invoke the end_io call back function, |
| 3770 | * we need to free the end_io structure here. |
| 3771 | */ |
| 3772 | if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) { |
| 3773 | ext4_free_io_end(iocb->private); |
| 3774 | iocb->private = NULL; |
| 3775 | } else if (ret > 0 && ext4_test_inode_state(inode, |
| 3776 | EXT4_STATE_DIO_UNWRITTEN)) { |
| 3777 | int err; |
| 3778 | /* |
| 3779 | * for non AIO case, since the IO is already |
| 3780 | * completed, we could do the conversion right here |
| 3781 | */ |
| 3782 | err = ext4_convert_unwritten_extents(inode, |
| 3783 | offset, ret); |
| 3784 | if (err < 0) |
| 3785 | ret = err; |
| 3786 | ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); |
| 3787 | } |
| 3788 | return ret; |
| 3789 | } |
| 3790 | |
| 3791 | /* for write the the end of file case, we fall back to old way */ |
| 3792 | return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs); |
| 3793 | } |
| 3794 | |
| 3795 | static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb, |
| 3796 | const struct iovec *iov, loff_t offset, |
| 3797 | unsigned long nr_segs) |
| 3798 | { |
| 3799 | struct file *file = iocb->ki_filp; |
| 3800 | struct inode *inode = file->f_mapping->host; |
| 3801 | ssize_t ret; |
| 3802 | |
| 3803 | trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw); |
| 3804 | if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) |
| 3805 | ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs); |
| 3806 | else |
| 3807 | ret = ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs); |
| 3808 | trace_ext4_direct_IO_exit(inode, offset, |
| 3809 | iov_length(iov, nr_segs), rw, ret); |
| 3810 | return ret; |
| 3811 | } |
| 3812 | |
| 3813 | /* |
| 3814 | * Pages can be marked dirty completely asynchronously from ext4's journalling |
| 3815 | * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do |
| 3816 | * much here because ->set_page_dirty is called under VFS locks. The page is |
| 3817 | * not necessarily locked. |
| 3818 | * |
| 3819 | * We cannot just dirty the page and leave attached buffers clean, because the |
| 3820 | * buffers' dirty state is "definitive". We cannot just set the buffers dirty |
| 3821 | * or jbddirty because all the journalling code will explode. |
| 3822 | * |
| 3823 | * So what we do is to mark the page "pending dirty" and next time writepage |
| 3824 | * is called, propagate that into the buffers appropriately. |
| 3825 | */ |
| 3826 | static int ext4_journalled_set_page_dirty(struct page *page) |
| 3827 | { |
| 3828 | SetPageChecked(page); |
| 3829 | return __set_page_dirty_nobuffers(page); |
| 3830 | } |
| 3831 | |
| 3832 | static const struct address_space_operations ext4_ordered_aops = { |
| 3833 | .readpage = ext4_readpage, |
| 3834 | .readpages = ext4_readpages, |
| 3835 | .writepage = ext4_writepage, |
| 3836 | .write_begin = ext4_write_begin, |
| 3837 | .write_end = ext4_ordered_write_end, |
| 3838 | .bmap = ext4_bmap, |
| 3839 | .invalidatepage = ext4_invalidatepage, |
| 3840 | .releasepage = ext4_releasepage, |
| 3841 | .direct_IO = ext4_direct_IO, |
| 3842 | .migratepage = buffer_migrate_page, |
| 3843 | .is_partially_uptodate = block_is_partially_uptodate, |
| 3844 | .error_remove_page = generic_error_remove_page, |
| 3845 | }; |
| 3846 | |
| 3847 | static const struct address_space_operations ext4_writeback_aops = { |
| 3848 | .readpage = ext4_readpage, |
| 3849 | .readpages = ext4_readpages, |
| 3850 | .writepage = ext4_writepage, |
| 3851 | .write_begin = ext4_write_begin, |
| 3852 | .write_end = ext4_writeback_write_end, |
| 3853 | .bmap = ext4_bmap, |
| 3854 | .invalidatepage = ext4_invalidatepage, |
| 3855 | .releasepage = ext4_releasepage, |
| 3856 | .direct_IO = ext4_direct_IO, |
| 3857 | .migratepage = buffer_migrate_page, |
| 3858 | .is_partially_uptodate = block_is_partially_uptodate, |
| 3859 | .error_remove_page = generic_error_remove_page, |
| 3860 | }; |
| 3861 | |
| 3862 | static const struct address_space_operations ext4_journalled_aops = { |
| 3863 | .readpage = ext4_readpage, |
| 3864 | .readpages = ext4_readpages, |
| 3865 | .writepage = ext4_writepage, |
| 3866 | .write_begin = ext4_write_begin, |
| 3867 | .write_end = ext4_journalled_write_end, |
| 3868 | .set_page_dirty = ext4_journalled_set_page_dirty, |
| 3869 | .bmap = ext4_bmap, |
| 3870 | .invalidatepage = ext4_invalidatepage, |
| 3871 | .releasepage = ext4_releasepage, |
| 3872 | .is_partially_uptodate = block_is_partially_uptodate, |
| 3873 | .error_remove_page = generic_error_remove_page, |
| 3874 | }; |
| 3875 | |
| 3876 | static const struct address_space_operations ext4_da_aops = { |
| 3877 | .readpage = ext4_readpage, |
| 3878 | .readpages = ext4_readpages, |
| 3879 | .writepage = ext4_writepage, |
| 3880 | .writepages = ext4_da_writepages, |
| 3881 | .write_begin = ext4_da_write_begin, |
| 3882 | .write_end = ext4_da_write_end, |
| 3883 | .bmap = ext4_bmap, |
| 3884 | .invalidatepage = ext4_da_invalidatepage, |
| 3885 | .releasepage = ext4_releasepage, |
| 3886 | .direct_IO = ext4_direct_IO, |
| 3887 | .migratepage = buffer_migrate_page, |
| 3888 | .is_partially_uptodate = block_is_partially_uptodate, |
| 3889 | .error_remove_page = generic_error_remove_page, |
| 3890 | }; |
| 3891 | |
| 3892 | void ext4_set_aops(struct inode *inode) |
| 3893 | { |
| 3894 | if (ext4_should_order_data(inode) && |
| 3895 | test_opt(inode->i_sb, DELALLOC)) |
| 3896 | inode->i_mapping->a_ops = &ext4_da_aops; |
| 3897 | else if (ext4_should_order_data(inode)) |
| 3898 | inode->i_mapping->a_ops = &ext4_ordered_aops; |
| 3899 | else if (ext4_should_writeback_data(inode) && |
| 3900 | test_opt(inode->i_sb, DELALLOC)) |
| 3901 | inode->i_mapping->a_ops = &ext4_da_aops; |
| 3902 | else if (ext4_should_writeback_data(inode)) |
| 3903 | inode->i_mapping->a_ops = &ext4_writeback_aops; |
| 3904 | else |
| 3905 | inode->i_mapping->a_ops = &ext4_journalled_aops; |
| 3906 | } |
| 3907 | |
| 3908 | /* |
| 3909 | * ext4_block_truncate_page() zeroes out a mapping from file offset `from' |
| 3910 | * up to the end of the block which corresponds to `from'. |
| 3911 | * This required during truncate. We need to physically zero the tail end |
| 3912 | * of that block so it doesn't yield old data if the file is later grown. |
| 3913 | */ |
| 3914 | int ext4_block_truncate_page(handle_t *handle, |
| 3915 | struct address_space *mapping, loff_t from) |
| 3916 | { |
| 3917 | unsigned offset = from & (PAGE_CACHE_SIZE-1); |
| 3918 | unsigned length; |
| 3919 | unsigned blocksize; |
| 3920 | struct inode *inode = mapping->host; |
| 3921 | |
| 3922 | blocksize = inode->i_sb->s_blocksize; |
| 3923 | length = blocksize - (offset & (blocksize - 1)); |
| 3924 | |
| 3925 | return ext4_block_zero_page_range(handle, mapping, from, length); |
| 3926 | } |
| 3927 | |
| 3928 | /* |
| 3929 | * ext4_block_zero_page_range() zeros out a mapping of length 'length' |
| 3930 | * starting from file offset 'from'. The range to be zero'd must |
| 3931 | * be contained with in one block. If the specified range exceeds |
| 3932 | * the end of the block it will be shortened to end of the block |
| 3933 | * that cooresponds to 'from' |
| 3934 | */ |
| 3935 | int ext4_block_zero_page_range(handle_t *handle, |
| 3936 | struct address_space *mapping, loff_t from, loff_t length) |
| 3937 | { |
| 3938 | ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT; |
| 3939 | unsigned offset = from & (PAGE_CACHE_SIZE-1); |
| 3940 | unsigned blocksize, max, pos; |
| 3941 | ext4_lblk_t iblock; |
| 3942 | struct inode *inode = mapping->host; |
| 3943 | struct buffer_head *bh; |
| 3944 | struct page *page; |
| 3945 | int err = 0; |
| 3946 | |
| 3947 | page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT, |
| 3948 | mapping_gfp_mask(mapping) & ~__GFP_FS); |
| 3949 | if (!page) |
| 3950 | return -EINVAL; |
| 3951 | |
| 3952 | blocksize = inode->i_sb->s_blocksize; |
| 3953 | max = blocksize - (offset & (blocksize - 1)); |
| 3954 | |
| 3955 | /* |
| 3956 | * correct length if it does not fall between |
| 3957 | * 'from' and the end of the block |
| 3958 | */ |
| 3959 | if (length > max || length < 0) |
| 3960 | length = max; |
| 3961 | |
| 3962 | iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); |
| 3963 | |
| 3964 | if (!page_has_buffers(page)) |
| 3965 | create_empty_buffers(page, blocksize, 0); |
| 3966 | |
| 3967 | /* Find the buffer that contains "offset" */ |
| 3968 | bh = page_buffers(page); |
| 3969 | pos = blocksize; |
| 3970 | while (offset >= pos) { |
| 3971 | bh = bh->b_this_page; |
| 3972 | iblock++; |
| 3973 | pos += blocksize; |
| 3974 | } |
| 3975 | |
| 3976 | err = 0; |
| 3977 | if (buffer_freed(bh)) { |
| 3978 | BUFFER_TRACE(bh, "freed: skip"); |
| 3979 | goto unlock; |
| 3980 | } |
| 3981 | |
| 3982 | if (!buffer_mapped(bh)) { |
| 3983 | BUFFER_TRACE(bh, "unmapped"); |
| 3984 | ext4_get_block(inode, iblock, bh, 0); |
| 3985 | /* unmapped? It's a hole - nothing to do */ |
| 3986 | if (!buffer_mapped(bh)) { |
| 3987 | BUFFER_TRACE(bh, "still unmapped"); |
| 3988 | goto unlock; |
| 3989 | } |
| 3990 | } |
| 3991 | |
| 3992 | /* Ok, it's mapped. Make sure it's up-to-date */ |
| 3993 | if (PageUptodate(page)) |
| 3994 | set_buffer_uptodate(bh); |
| 3995 | |
| 3996 | if (!buffer_uptodate(bh)) { |
| 3997 | err = -EIO; |
| 3998 | ll_rw_block(READ, 1, &bh); |
| 3999 | wait_on_buffer(bh); |
| 4000 | /* Uhhuh. Read error. Complain and punt. */ |
| 4001 | if (!buffer_uptodate(bh)) |
| 4002 | goto unlock; |
| 4003 | } |
| 4004 | |
| 4005 | if (ext4_should_journal_data(inode)) { |
| 4006 | BUFFER_TRACE(bh, "get write access"); |
| 4007 | err = ext4_journal_get_write_access(handle, bh); |
| 4008 | if (err) |
| 4009 | goto unlock; |
| 4010 | } |
| 4011 | |
| 4012 | zero_user(page, offset, length); |
| 4013 | |
| 4014 | BUFFER_TRACE(bh, "zeroed end of block"); |
| 4015 | |
| 4016 | err = 0; |
| 4017 | if (ext4_should_journal_data(inode)) { |
| 4018 | err = ext4_handle_dirty_metadata(handle, inode, bh); |
| 4019 | } else { |
| 4020 | if (ext4_should_order_data(inode) && EXT4_I(inode)->jinode) |
| 4021 | err = ext4_jbd2_file_inode(handle, inode); |
| 4022 | mark_buffer_dirty(bh); |
| 4023 | } |
| 4024 | |
| 4025 | unlock: |
| 4026 | unlock_page(page); |
| 4027 | page_cache_release(page); |
| 4028 | return err; |
| 4029 | } |
| 4030 | |
| 4031 | /* |
| 4032 | * Probably it should be a library function... search for first non-zero word |
| 4033 | * or memcmp with zero_page, whatever is better for particular architecture. |
| 4034 | * Linus? |
| 4035 | */ |
| 4036 | static inline int all_zeroes(__le32 *p, __le32 *q) |
| 4037 | { |
| 4038 | while (p < q) |
| 4039 | if (*p++) |
| 4040 | return 0; |
| 4041 | return 1; |
| 4042 | } |
| 4043 | |
| 4044 | /** |
| 4045 | * ext4_find_shared - find the indirect blocks for partial truncation. |
| 4046 | * @inode: inode in question |
| 4047 | * @depth: depth of the affected branch |
| 4048 | * @offsets: offsets of pointers in that branch (see ext4_block_to_path) |
| 4049 | * @chain: place to store the pointers to partial indirect blocks |
| 4050 | * @top: place to the (detached) top of branch |
| 4051 | * |
| 4052 | * This is a helper function used by ext4_truncate(). |
| 4053 | * |
| 4054 | * When we do truncate() we may have to clean the ends of several |
| 4055 | * indirect blocks but leave the blocks themselves alive. Block is |
| 4056 | * partially truncated if some data below the new i_size is referred |
| 4057 | * from it (and it is on the path to the first completely truncated |
| 4058 | * data block, indeed). We have to free the top of that path along |
| 4059 | * with everything to the right of the path. Since no allocation |
| 4060 | * past the truncation point is possible until ext4_truncate() |
| 4061 | * finishes, we may safely do the latter, but top of branch may |
| 4062 | * require special attention - pageout below the truncation point |
| 4063 | * might try to populate it. |
| 4064 | * |
| 4065 | * We atomically detach the top of branch from the tree, store the |
| 4066 | * block number of its root in *@top, pointers to buffer_heads of |
| 4067 | * partially truncated blocks - in @chain[].bh and pointers to |
| 4068 | * their last elements that should not be removed - in |
| 4069 | * @chain[].p. Return value is the pointer to last filled element |
| 4070 | * of @chain. |
| 4071 | * |
| 4072 | * The work left to caller to do the actual freeing of subtrees: |
| 4073 | * a) free the subtree starting from *@top |
| 4074 | * b) free the subtrees whose roots are stored in |
| 4075 | * (@chain[i].p+1 .. end of @chain[i].bh->b_data) |
| 4076 | * c) free the subtrees growing from the inode past the @chain[0]. |
| 4077 | * (no partially truncated stuff there). */ |
| 4078 | |
| 4079 | static Indirect *ext4_find_shared(struct inode *inode, int depth, |
| 4080 | ext4_lblk_t offsets[4], Indirect chain[4], |
| 4081 | __le32 *top) |
| 4082 | { |
| 4083 | Indirect *partial, *p; |
| 4084 | int k, err; |
| 4085 | |
| 4086 | *top = 0; |
| 4087 | /* Make k index the deepest non-null offset + 1 */ |
| 4088 | for (k = depth; k > 1 && !offsets[k-1]; k--) |
| 4089 | ; |
| 4090 | partial = ext4_get_branch(inode, k, offsets, chain, &err); |
| 4091 | /* Writer: pointers */ |
| 4092 | if (!partial) |
| 4093 | partial = chain + k-1; |
| 4094 | /* |
| 4095 | * If the branch acquired continuation since we've looked at it - |
| 4096 | * fine, it should all survive and (new) top doesn't belong to us. |
| 4097 | */ |
| 4098 | if (!partial->key && *partial->p) |
| 4099 | /* Writer: end */ |
| 4100 | goto no_top; |
| 4101 | for (p = partial; (p > chain) && all_zeroes((__le32 *) p->bh->b_data, p->p); p--) |
| 4102 | ; |
| 4103 | /* |
| 4104 | * OK, we've found the last block that must survive. The rest of our |
| 4105 | * branch should be detached before unlocking. However, if that rest |
| 4106 | * of branch is all ours and does not grow immediately from the inode |
| 4107 | * it's easier to cheat and just decrement partial->p. |
| 4108 | */ |
| 4109 | if (p == chain + k - 1 && p > chain) { |
| 4110 | p->p--; |
| 4111 | } else { |
| 4112 | *top = *p->p; |
| 4113 | /* Nope, don't do this in ext4. Must leave the tree intact */ |
| 4114 | #if 0 |
| 4115 | *p->p = 0; |
| 4116 | #endif |
| 4117 | } |
| 4118 | /* Writer: end */ |
| 4119 | |
| 4120 | while (partial > p) { |
| 4121 | brelse(partial->bh); |
| 4122 | partial--; |
| 4123 | } |
| 4124 | no_top: |
| 4125 | return partial; |
| 4126 | } |
| 4127 | |
| 4128 | /* |
| 4129 | * Zero a number of block pointers in either an inode or an indirect block. |
| 4130 | * If we restart the transaction we must again get write access to the |
| 4131 | * indirect block for further modification. |
| 4132 | * |
| 4133 | * We release `count' blocks on disk, but (last - first) may be greater |
| 4134 | * than `count' because there can be holes in there. |
| 4135 | * |
| 4136 | * Return 0 on success, 1 on invalid block range |
| 4137 | * and < 0 on fatal error. |
| 4138 | */ |
| 4139 | static int ext4_clear_blocks(handle_t *handle, struct inode *inode, |
| 4140 | struct buffer_head *bh, |
| 4141 | ext4_fsblk_t block_to_free, |
| 4142 | unsigned long count, __le32 *first, |
| 4143 | __le32 *last) |
| 4144 | { |
| 4145 | __le32 *p; |
| 4146 | int flags = EXT4_FREE_BLOCKS_FORGET | EXT4_FREE_BLOCKS_VALIDATED; |
| 4147 | int err; |
| 4148 | |
| 4149 | if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) |
| 4150 | flags |= EXT4_FREE_BLOCKS_METADATA; |
| 4151 | |
| 4152 | if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), block_to_free, |
| 4153 | count)) { |
| 4154 | EXT4_ERROR_INODE(inode, "attempt to clear invalid " |
| 4155 | "blocks %llu len %lu", |
| 4156 | (unsigned long long) block_to_free, count); |
| 4157 | return 1; |
| 4158 | } |
| 4159 | |
| 4160 | if (try_to_extend_transaction(handle, inode)) { |
| 4161 | if (bh) { |
| 4162 | BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); |
| 4163 | err = ext4_handle_dirty_metadata(handle, inode, bh); |
| 4164 | if (unlikely(err)) |
| 4165 | goto out_err; |
| 4166 | } |
| 4167 | err = ext4_mark_inode_dirty(handle, inode); |
| 4168 | if (unlikely(err)) |
| 4169 | goto out_err; |
| 4170 | err = ext4_truncate_restart_trans(handle, inode, |
| 4171 | blocks_for_truncate(inode)); |
| 4172 | if (unlikely(err)) |
| 4173 | goto out_err; |
| 4174 | if (bh) { |
| 4175 | BUFFER_TRACE(bh, "retaking write access"); |
| 4176 | err = ext4_journal_get_write_access(handle, bh); |
| 4177 | if (unlikely(err)) |
| 4178 | goto out_err; |
| 4179 | } |
| 4180 | } |
| 4181 | |
| 4182 | for (p = first; p < last; p++) |
| 4183 | *p = 0; |
| 4184 | |
| 4185 | ext4_free_blocks(handle, inode, NULL, block_to_free, count, flags); |
| 4186 | return 0; |
| 4187 | out_err: |
| 4188 | ext4_std_error(inode->i_sb, err); |
| 4189 | return err; |
| 4190 | } |
| 4191 | |
| 4192 | /** |
| 4193 | * ext4_free_data - free a list of data blocks |
| 4194 | * @handle: handle for this transaction |
| 4195 | * @inode: inode we are dealing with |
| 4196 | * @this_bh: indirect buffer_head which contains *@first and *@last |
| 4197 | * @first: array of block numbers |
| 4198 | * @last: points immediately past the end of array |
| 4199 | * |
| 4200 | * We are freeing all blocks referred from that array (numbers are stored as |
| 4201 | * little-endian 32-bit) and updating @inode->i_blocks appropriately. |
| 4202 | * |
| 4203 | * We accumulate contiguous runs of blocks to free. Conveniently, if these |
| 4204 | * blocks are contiguous then releasing them at one time will only affect one |
| 4205 | * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't |
| 4206 | * actually use a lot of journal space. |
| 4207 | * |
| 4208 | * @this_bh will be %NULL if @first and @last point into the inode's direct |
| 4209 | * block pointers. |
| 4210 | */ |
| 4211 | static void ext4_free_data(handle_t *handle, struct inode *inode, |
| 4212 | struct buffer_head *this_bh, |
| 4213 | __le32 *first, __le32 *last) |
| 4214 | { |
| 4215 | ext4_fsblk_t block_to_free = 0; /* Starting block # of a run */ |
| 4216 | unsigned long count = 0; /* Number of blocks in the run */ |
| 4217 | __le32 *block_to_free_p = NULL; /* Pointer into inode/ind |
| 4218 | corresponding to |
| 4219 | block_to_free */ |
| 4220 | ext4_fsblk_t nr; /* Current block # */ |
| 4221 | __le32 *p; /* Pointer into inode/ind |
| 4222 | for current block */ |
| 4223 | int err = 0; |
| 4224 | |
| 4225 | if (this_bh) { /* For indirect block */ |
| 4226 | BUFFER_TRACE(this_bh, "get_write_access"); |
| 4227 | err = ext4_journal_get_write_access(handle, this_bh); |
| 4228 | /* Important: if we can't update the indirect pointers |
| 4229 | * to the blocks, we can't free them. */ |
| 4230 | if (err) |
| 4231 | return; |
| 4232 | } |
| 4233 | |
| 4234 | for (p = first; p < last; p++) { |
| 4235 | nr = le32_to_cpu(*p); |
| 4236 | if (nr) { |
| 4237 | /* accumulate blocks to free if they're contiguous */ |
| 4238 | if (count == 0) { |
| 4239 | block_to_free = nr; |
| 4240 | block_to_free_p = p; |
| 4241 | count = 1; |
| 4242 | } else if (nr == block_to_free + count) { |
| 4243 | count++; |
| 4244 | } else { |
| 4245 | err = ext4_clear_blocks(handle, inode, this_bh, |
| 4246 | block_to_free, count, |
| 4247 | block_to_free_p, p); |
| 4248 | if (err) |
| 4249 | break; |
| 4250 | block_to_free = nr; |
| 4251 | block_to_free_p = p; |
| 4252 | count = 1; |
| 4253 | } |
| 4254 | } |
| 4255 | } |
| 4256 | |
| 4257 | if (!err && count > 0) |
| 4258 | err = ext4_clear_blocks(handle, inode, this_bh, block_to_free, |
| 4259 | count, block_to_free_p, p); |
| 4260 | if (err < 0) |
| 4261 | /* fatal error */ |
| 4262 | return; |
| 4263 | |
| 4264 | if (this_bh) { |
| 4265 | BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata"); |
| 4266 | |
| 4267 | /* |
| 4268 | * The buffer head should have an attached journal head at this |
| 4269 | * point. However, if the data is corrupted and an indirect |
| 4270 | * block pointed to itself, it would have been detached when |
| 4271 | * the block was cleared. Check for this instead of OOPSing. |
| 4272 | */ |
| 4273 | if ((EXT4_JOURNAL(inode) == NULL) || bh2jh(this_bh)) |
| 4274 | ext4_handle_dirty_metadata(handle, inode, this_bh); |
| 4275 | else |
| 4276 | EXT4_ERROR_INODE(inode, |
| 4277 | "circular indirect block detected at " |
| 4278 | "block %llu", |
| 4279 | (unsigned long long) this_bh->b_blocknr); |
| 4280 | } |
| 4281 | } |
| 4282 | |
| 4283 | /** |
| 4284 | * ext4_free_branches - free an array of branches |
| 4285 | * @handle: JBD handle for this transaction |
| 4286 | * @inode: inode we are dealing with |
| 4287 | * @parent_bh: the buffer_head which contains *@first and *@last |
| 4288 | * @first: array of block numbers |
| 4289 | * @last: pointer immediately past the end of array |
| 4290 | * @depth: depth of the branches to free |
| 4291 | * |
| 4292 | * We are freeing all blocks referred from these branches (numbers are |
| 4293 | * stored as little-endian 32-bit) and updating @inode->i_blocks |
| 4294 | * appropriately. |
| 4295 | */ |
| 4296 | static void ext4_free_branches(handle_t *handle, struct inode *inode, |
| 4297 | struct buffer_head *parent_bh, |
| 4298 | __le32 *first, __le32 *last, int depth) |
| 4299 | { |
| 4300 | ext4_fsblk_t nr; |
| 4301 | __le32 *p; |
| 4302 | |
| 4303 | if (ext4_handle_is_aborted(handle)) |
| 4304 | return; |
| 4305 | |
| 4306 | if (depth--) { |
| 4307 | struct buffer_head *bh; |
| 4308 | int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb); |
| 4309 | p = last; |
| 4310 | while (--p >= first) { |
| 4311 | nr = le32_to_cpu(*p); |
| 4312 | if (!nr) |
| 4313 | continue; /* A hole */ |
| 4314 | |
| 4315 | if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), |
| 4316 | nr, 1)) { |
| 4317 | EXT4_ERROR_INODE(inode, |
| 4318 | "invalid indirect mapped " |
| 4319 | "block %lu (level %d)", |
| 4320 | (unsigned long) nr, depth); |
| 4321 | break; |
| 4322 | } |
| 4323 | |
| 4324 | /* Go read the buffer for the next level down */ |
| 4325 | bh = sb_bread(inode->i_sb, nr); |
| 4326 | |
| 4327 | /* |
| 4328 | * A read failure? Report error and clear slot |
| 4329 | * (should be rare). |
| 4330 | */ |
| 4331 | if (!bh) { |
| 4332 | EXT4_ERROR_INODE_BLOCK(inode, nr, |
| 4333 | "Read failure"); |
| 4334 | continue; |
| 4335 | } |
| 4336 | |
| 4337 | /* This zaps the entire block. Bottom up. */ |
| 4338 | BUFFER_TRACE(bh, "free child branches"); |
| 4339 | ext4_free_branches(handle, inode, bh, |
| 4340 | (__le32 *) bh->b_data, |
| 4341 | (__le32 *) bh->b_data + addr_per_block, |
| 4342 | depth); |
| 4343 | brelse(bh); |
| 4344 | |
| 4345 | /* |
| 4346 | * Everything below this this pointer has been |
| 4347 | * released. Now let this top-of-subtree go. |
| 4348 | * |
| 4349 | * We want the freeing of this indirect block to be |
| 4350 | * atomic in the journal with the updating of the |
| 4351 | * bitmap block which owns it. So make some room in |
| 4352 | * the journal. |
| 4353 | * |
| 4354 | * We zero the parent pointer *after* freeing its |
| 4355 | * pointee in the bitmaps, so if extend_transaction() |
| 4356 | * for some reason fails to put the bitmap changes and |
| 4357 | * the release into the same transaction, recovery |
| 4358 | * will merely complain about releasing a free block, |
| 4359 | * rather than leaking blocks. |
| 4360 | */ |
| 4361 | if (ext4_handle_is_aborted(handle)) |
| 4362 | return; |
| 4363 | if (try_to_extend_transaction(handle, inode)) { |
| 4364 | ext4_mark_inode_dirty(handle, inode); |
| 4365 | ext4_truncate_restart_trans(handle, inode, |
| 4366 | blocks_for_truncate(inode)); |
| 4367 | } |
| 4368 | |
| 4369 | /* |
| 4370 | * The forget flag here is critical because if |
| 4371 | * we are journaling (and not doing data |
| 4372 | * journaling), we have to make sure a revoke |
| 4373 | * record is written to prevent the journal |
| 4374 | * replay from overwriting the (former) |
| 4375 | * indirect block if it gets reallocated as a |
| 4376 | * data block. This must happen in the same |
| 4377 | * transaction where the data blocks are |
| 4378 | * actually freed. |
| 4379 | */ |
| 4380 | ext4_free_blocks(handle, inode, NULL, nr, 1, |
| 4381 | EXT4_FREE_BLOCKS_METADATA| |
| 4382 | EXT4_FREE_BLOCKS_FORGET); |
| 4383 | |
| 4384 | if (parent_bh) { |
| 4385 | /* |
| 4386 | * The block which we have just freed is |
| 4387 | * pointed to by an indirect block: journal it |
| 4388 | */ |
| 4389 | BUFFER_TRACE(parent_bh, "get_write_access"); |
| 4390 | if (!ext4_journal_get_write_access(handle, |
| 4391 | parent_bh)){ |
| 4392 | *p = 0; |
| 4393 | BUFFER_TRACE(parent_bh, |
| 4394 | "call ext4_handle_dirty_metadata"); |
| 4395 | ext4_handle_dirty_metadata(handle, |
| 4396 | inode, |
| 4397 | parent_bh); |
| 4398 | } |
| 4399 | } |
| 4400 | } |
| 4401 | } else { |
| 4402 | /* We have reached the bottom of the tree. */ |
| 4403 | BUFFER_TRACE(parent_bh, "free data blocks"); |
| 4404 | ext4_free_data(handle, inode, parent_bh, first, last); |
| 4405 | } |
| 4406 | } |
| 4407 | |
| 4408 | int ext4_can_truncate(struct inode *inode) |
| 4409 | { |
| 4410 | if (S_ISREG(inode->i_mode)) |
| 4411 | return 1; |
| 4412 | if (S_ISDIR(inode->i_mode)) |
| 4413 | return 1; |
| 4414 | if (S_ISLNK(inode->i_mode)) |
| 4415 | return !ext4_inode_is_fast_symlink(inode); |
| 4416 | return 0; |
| 4417 | } |
| 4418 | |
| 4419 | /* |
| 4420 | * ext4_punch_hole: punches a hole in a file by releaseing the blocks |
| 4421 | * associated with the given offset and length |
| 4422 | * |
| 4423 | * @inode: File inode |
| 4424 | * @offset: The offset where the hole will begin |
| 4425 | * @len: The length of the hole |
| 4426 | * |
| 4427 | * Returns: 0 on sucess or negative on failure |
| 4428 | */ |
| 4429 | |
| 4430 | int ext4_punch_hole(struct file *file, loff_t offset, loff_t length) |
| 4431 | { |
| 4432 | struct inode *inode = file->f_path.dentry->d_inode; |
| 4433 | if (!S_ISREG(inode->i_mode)) |
| 4434 | return -ENOTSUPP; |
| 4435 | |
| 4436 | if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { |
| 4437 | /* TODO: Add support for non extent hole punching */ |
| 4438 | return -ENOTSUPP; |
| 4439 | } |
| 4440 | |
| 4441 | return ext4_ext_punch_hole(file, offset, length); |
| 4442 | } |
| 4443 | |
| 4444 | /* |
| 4445 | * ext4_truncate() |
| 4446 | * |
| 4447 | * We block out ext4_get_block() block instantiations across the entire |
| 4448 | * transaction, and VFS/VM ensures that ext4_truncate() cannot run |
| 4449 | * simultaneously on behalf of the same inode. |
| 4450 | * |
| 4451 | * As we work through the truncate and commmit bits of it to the journal there |
| 4452 | * is one core, guiding principle: the file's tree must always be consistent on |
| 4453 | * disk. We must be able to restart the truncate after a crash. |
| 4454 | * |
| 4455 | * The file's tree may be transiently inconsistent in memory (although it |
| 4456 | * probably isn't), but whenever we close off and commit a journal transaction, |
| 4457 | * the contents of (the filesystem + the journal) must be consistent and |
| 4458 | * restartable. It's pretty simple, really: bottom up, right to left (although |
| 4459 | * left-to-right works OK too). |
| 4460 | * |
| 4461 | * Note that at recovery time, journal replay occurs *before* the restart of |
| 4462 | * truncate against the orphan inode list. |
| 4463 | * |
| 4464 | * The committed inode has the new, desired i_size (which is the same as |
| 4465 | * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see |
| 4466 | * that this inode's truncate did not complete and it will again call |
| 4467 | * ext4_truncate() to have another go. So there will be instantiated blocks |
| 4468 | * to the right of the truncation point in a crashed ext4 filesystem. But |
| 4469 | * that's fine - as long as they are linked from the inode, the post-crash |
| 4470 | * ext4_truncate() run will find them and release them. |
| 4471 | */ |
| 4472 | void ext4_truncate(struct inode *inode) |
| 4473 | { |
| 4474 | handle_t *handle; |
| 4475 | struct ext4_inode_info *ei = EXT4_I(inode); |
| 4476 | __le32 *i_data = ei->i_data; |
| 4477 | int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb); |
| 4478 | struct address_space *mapping = inode->i_mapping; |
| 4479 | ext4_lblk_t offsets[4]; |
| 4480 | Indirect chain[4]; |
| 4481 | Indirect *partial; |
| 4482 | __le32 nr = 0; |
| 4483 | int n = 0; |
| 4484 | ext4_lblk_t last_block, max_block; |
| 4485 | unsigned blocksize = inode->i_sb->s_blocksize; |
| 4486 | |
| 4487 | trace_ext4_truncate_enter(inode); |
| 4488 | |
| 4489 | if (!ext4_can_truncate(inode)) |
| 4490 | return; |
| 4491 | |
| 4492 | ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS); |
| 4493 | |
| 4494 | if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC)) |
| 4495 | ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE); |
| 4496 | |
| 4497 | if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { |
| 4498 | ext4_ext_truncate(inode); |
| 4499 | trace_ext4_truncate_exit(inode); |
| 4500 | return; |
| 4501 | } |
| 4502 | |
| 4503 | handle = start_transaction(inode); |
| 4504 | if (IS_ERR(handle)) |
| 4505 | return; /* AKPM: return what? */ |
| 4506 | |
| 4507 | last_block = (inode->i_size + blocksize-1) |
| 4508 | >> EXT4_BLOCK_SIZE_BITS(inode->i_sb); |
| 4509 | max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1) |
| 4510 | >> EXT4_BLOCK_SIZE_BITS(inode->i_sb); |
| 4511 | |
| 4512 | if (inode->i_size & (blocksize - 1)) |
| 4513 | if (ext4_block_truncate_page(handle, mapping, inode->i_size)) |
| 4514 | goto out_stop; |
| 4515 | |
| 4516 | if (last_block != max_block) { |
| 4517 | n = ext4_block_to_path(inode, last_block, offsets, NULL); |
| 4518 | if (n == 0) |
| 4519 | goto out_stop; /* error */ |
| 4520 | } |
| 4521 | |
| 4522 | /* |
| 4523 | * OK. This truncate is going to happen. We add the inode to the |
| 4524 | * orphan list, so that if this truncate spans multiple transactions, |
| 4525 | * and we crash, we will resume the truncate when the filesystem |
| 4526 | * recovers. It also marks the inode dirty, to catch the new size. |
| 4527 | * |
| 4528 | * Implication: the file must always be in a sane, consistent |
| 4529 | * truncatable state while each transaction commits. |
| 4530 | */ |
| 4531 | if (ext4_orphan_add(handle, inode)) |
| 4532 | goto out_stop; |
| 4533 | |
| 4534 | /* |
| 4535 | * From here we block out all ext4_get_block() callers who want to |
| 4536 | * modify the block allocation tree. |
| 4537 | */ |
| 4538 | down_write(&ei->i_data_sem); |
| 4539 | |
| 4540 | ext4_discard_preallocations(inode); |
| 4541 | |
| 4542 | /* |
| 4543 | * The orphan list entry will now protect us from any crash which |
| 4544 | * occurs before the truncate completes, so it is now safe to propagate |
| 4545 | * the new, shorter inode size (held for now in i_size) into the |
| 4546 | * on-disk inode. We do this via i_disksize, which is the value which |
| 4547 | * ext4 *really* writes onto the disk inode. |
| 4548 | */ |
| 4549 | ei->i_disksize = inode->i_size; |
| 4550 | |
| 4551 | if (last_block == max_block) { |
| 4552 | /* |
| 4553 | * It is unnecessary to free any data blocks if last_block is |
| 4554 | * equal to the indirect block limit. |
| 4555 | */ |
| 4556 | goto out_unlock; |
| 4557 | } else if (n == 1) { /* direct blocks */ |
| 4558 | ext4_free_data(handle, inode, NULL, i_data+offsets[0], |
| 4559 | i_data + EXT4_NDIR_BLOCKS); |
| 4560 | goto do_indirects; |
| 4561 | } |
| 4562 | |
| 4563 | partial = ext4_find_shared(inode, n, offsets, chain, &nr); |
| 4564 | /* Kill the top of shared branch (not detached) */ |
| 4565 | if (nr) { |
| 4566 | if (partial == chain) { |
| 4567 | /* Shared branch grows from the inode */ |
| 4568 | ext4_free_branches(handle, inode, NULL, |
| 4569 | &nr, &nr+1, (chain+n-1) - partial); |
| 4570 | *partial->p = 0; |
| 4571 | /* |
| 4572 | * We mark the inode dirty prior to restart, |
| 4573 | * and prior to stop. No need for it here. |
| 4574 | */ |
| 4575 | } else { |
| 4576 | /* Shared branch grows from an indirect block */ |
| 4577 | BUFFER_TRACE(partial->bh, "get_write_access"); |
| 4578 | ext4_free_branches(handle, inode, partial->bh, |
| 4579 | partial->p, |
| 4580 | partial->p+1, (chain+n-1) - partial); |
| 4581 | } |
| 4582 | } |
| 4583 | /* Clear the ends of indirect blocks on the shared branch */ |
| 4584 | while (partial > chain) { |
| 4585 | ext4_free_branches(handle, inode, partial->bh, partial->p + 1, |
| 4586 | (__le32*)partial->bh->b_data+addr_per_block, |
| 4587 | (chain+n-1) - partial); |
| 4588 | BUFFER_TRACE(partial->bh, "call brelse"); |
| 4589 | brelse(partial->bh); |
| 4590 | partial--; |
| 4591 | } |
| 4592 | do_indirects: |
| 4593 | /* Kill the remaining (whole) subtrees */ |
| 4594 | switch (offsets[0]) { |
| 4595 | default: |
| 4596 | nr = i_data[EXT4_IND_BLOCK]; |
| 4597 | if (nr) { |
| 4598 | ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1); |
| 4599 | i_data[EXT4_IND_BLOCK] = 0; |
| 4600 | } |
| 4601 | case EXT4_IND_BLOCK: |
| 4602 | nr = i_data[EXT4_DIND_BLOCK]; |
| 4603 | if (nr) { |
| 4604 | ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2); |
| 4605 | i_data[EXT4_DIND_BLOCK] = 0; |
| 4606 | } |
| 4607 | case EXT4_DIND_BLOCK: |
| 4608 | nr = i_data[EXT4_TIND_BLOCK]; |
| 4609 | if (nr) { |
| 4610 | ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3); |
| 4611 | i_data[EXT4_TIND_BLOCK] = 0; |
| 4612 | } |
| 4613 | case EXT4_TIND_BLOCK: |
| 4614 | ; |
| 4615 | } |
| 4616 | |
| 4617 | out_unlock: |
| 4618 | up_write(&ei->i_data_sem); |
| 4619 | inode->i_mtime = inode->i_ctime = ext4_current_time(inode); |
| 4620 | ext4_mark_inode_dirty(handle, inode); |
| 4621 | |
| 4622 | /* |
| 4623 | * In a multi-transaction truncate, we only make the final transaction |
| 4624 | * synchronous |
| 4625 | */ |
| 4626 | if (IS_SYNC(inode)) |
| 4627 | ext4_handle_sync(handle); |
| 4628 | out_stop: |
| 4629 | /* |
| 4630 | * If this was a simple ftruncate(), and the file will remain alive |
| 4631 | * then we need to clear up the orphan record which we created above. |
| 4632 | * However, if this was a real unlink then we were called by |
| 4633 | * ext4_delete_inode(), and we allow that function to clean up the |
| 4634 | * orphan info for us. |
| 4635 | */ |
| 4636 | if (inode->i_nlink) |
| 4637 | ext4_orphan_del(handle, inode); |
| 4638 | |
| 4639 | ext4_journal_stop(handle); |
| 4640 | trace_ext4_truncate_exit(inode); |
| 4641 | } |
| 4642 | |
| 4643 | /* |
| 4644 | * ext4_get_inode_loc returns with an extra refcount against the inode's |
| 4645 | * underlying buffer_head on success. If 'in_mem' is true, we have all |
| 4646 | * data in memory that is needed to recreate the on-disk version of this |
| 4647 | * inode. |
| 4648 | */ |
| 4649 | static int __ext4_get_inode_loc(struct inode *inode, |
| 4650 | struct ext4_iloc *iloc, int in_mem) |
| 4651 | { |
| 4652 | struct ext4_group_desc *gdp; |
| 4653 | struct buffer_head *bh; |
| 4654 | struct super_block *sb = inode->i_sb; |
| 4655 | ext4_fsblk_t block; |
| 4656 | int inodes_per_block, inode_offset; |
| 4657 | |
| 4658 | iloc->bh = NULL; |
| 4659 | if (!ext4_valid_inum(sb, inode->i_ino)) |
| 4660 | return -EIO; |
| 4661 | |
| 4662 | iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb); |
| 4663 | gdp = ext4_get_group_desc(sb, iloc->block_group, NULL); |
| 4664 | if (!gdp) |
| 4665 | return -EIO; |
| 4666 | |
| 4667 | /* |
| 4668 | * Figure out the offset within the block group inode table |
| 4669 | */ |
| 4670 | inodes_per_block = EXT4_SB(sb)->s_inodes_per_block; |
| 4671 | inode_offset = ((inode->i_ino - 1) % |
| 4672 | EXT4_INODES_PER_GROUP(sb)); |
| 4673 | block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block); |
| 4674 | iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb); |
| 4675 | |
| 4676 | bh = sb_getblk(sb, block); |
| 4677 | if (!bh) { |
| 4678 | EXT4_ERROR_INODE_BLOCK(inode, block, |
| 4679 | "unable to read itable block"); |
| 4680 | return -EIO; |
| 4681 | } |
| 4682 | if (!buffer_uptodate(bh)) { |
| 4683 | lock_buffer(bh); |
| 4684 | |
| 4685 | /* |
| 4686 | * If the buffer has the write error flag, we have failed |
| 4687 | * to write out another inode in the same block. In this |
| 4688 | * case, we don't have to read the block because we may |
| 4689 | * read the old inode data successfully. |
| 4690 | */ |
| 4691 | if (buffer_write_io_error(bh) && !buffer_uptodate(bh)) |
| 4692 | set_buffer_uptodate(bh); |
| 4693 | |
| 4694 | if (buffer_uptodate(bh)) { |
| 4695 | /* someone brought it uptodate while we waited */ |
| 4696 | unlock_buffer(bh); |
| 4697 | goto has_buffer; |
| 4698 | } |
| 4699 | |
| 4700 | /* |
| 4701 | * If we have all information of the inode in memory and this |
| 4702 | * is the only valid inode in the block, we need not read the |
| 4703 | * block. |
| 4704 | */ |
| 4705 | if (in_mem) { |
| 4706 | struct buffer_head *bitmap_bh; |
| 4707 | int i, start; |
| 4708 | |
| 4709 | start = inode_offset & ~(inodes_per_block - 1); |
| 4710 | |
| 4711 | /* Is the inode bitmap in cache? */ |
| 4712 | bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp)); |
| 4713 | if (!bitmap_bh) |
| 4714 | goto make_io; |
| 4715 | |
| 4716 | /* |
| 4717 | * If the inode bitmap isn't in cache then the |
| 4718 | * optimisation may end up performing two reads instead |
| 4719 | * of one, so skip it. |
| 4720 | */ |
| 4721 | if (!buffer_uptodate(bitmap_bh)) { |
| 4722 | brelse(bitmap_bh); |
| 4723 | goto make_io; |
| 4724 | } |
| 4725 | for (i = start; i < start + inodes_per_block; i++) { |
| 4726 | if (i == inode_offset) |
| 4727 | continue; |
| 4728 | if (ext4_test_bit(i, bitmap_bh->b_data)) |
| 4729 | break; |
| 4730 | } |
| 4731 | brelse(bitmap_bh); |
| 4732 | if (i == start + inodes_per_block) { |
| 4733 | /* all other inodes are free, so skip I/O */ |
| 4734 | memset(bh->b_data, 0, bh->b_size); |
| 4735 | set_buffer_uptodate(bh); |
| 4736 | unlock_buffer(bh); |
| 4737 | goto has_buffer; |
| 4738 | } |
| 4739 | } |
| 4740 | |
| 4741 | make_io: |
| 4742 | /* |
| 4743 | * If we need to do any I/O, try to pre-readahead extra |
| 4744 | * blocks from the inode table. |
| 4745 | */ |
| 4746 | if (EXT4_SB(sb)->s_inode_readahead_blks) { |
| 4747 | ext4_fsblk_t b, end, table; |
| 4748 | unsigned num; |
| 4749 | |
| 4750 | table = ext4_inode_table(sb, gdp); |
| 4751 | /* s_inode_readahead_blks is always a power of 2 */ |
| 4752 | b = block & ~(EXT4_SB(sb)->s_inode_readahead_blks-1); |
| 4753 | if (table > b) |
| 4754 | b = table; |
| 4755 | end = b + EXT4_SB(sb)->s_inode_readahead_blks; |
| 4756 | num = EXT4_INODES_PER_GROUP(sb); |
| 4757 | if (EXT4_HAS_RO_COMPAT_FEATURE(sb, |
| 4758 | EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) |
| 4759 | num -= ext4_itable_unused_count(sb, gdp); |
| 4760 | table += num / inodes_per_block; |
| 4761 | if (end > table) |
| 4762 | end = table; |
| 4763 | while (b <= end) |
| 4764 | sb_breadahead(sb, b++); |
| 4765 | } |
| 4766 | |
| 4767 | /* |
| 4768 | * There are other valid inodes in the buffer, this inode |
| 4769 | * has in-inode xattrs, or we don't have this inode in memory. |
| 4770 | * Read the block from disk. |
| 4771 | */ |
| 4772 | trace_ext4_load_inode(inode); |
| 4773 | get_bh(bh); |
| 4774 | bh->b_end_io = end_buffer_read_sync; |
| 4775 | submit_bh(READ_META, bh); |
| 4776 | wait_on_buffer(bh); |
| 4777 | if (!buffer_uptodate(bh)) { |
| 4778 | EXT4_ERROR_INODE_BLOCK(inode, block, |
| 4779 | "unable to read itable block"); |
| 4780 | brelse(bh); |
| 4781 | return -EIO; |
| 4782 | } |
| 4783 | } |
| 4784 | has_buffer: |
| 4785 | iloc->bh = bh; |
| 4786 | return 0; |
| 4787 | } |
| 4788 | |
| 4789 | int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc) |
| 4790 | { |
| 4791 | /* We have all inode data except xattrs in memory here. */ |
| 4792 | return __ext4_get_inode_loc(inode, iloc, |
| 4793 | !ext4_test_inode_state(inode, EXT4_STATE_XATTR)); |
| 4794 | } |
| 4795 | |
| 4796 | void ext4_set_inode_flags(struct inode *inode) |
| 4797 | { |
| 4798 | unsigned int flags = EXT4_I(inode)->i_flags; |
| 4799 | |
| 4800 | inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); |
| 4801 | if (flags & EXT4_SYNC_FL) |
| 4802 | inode->i_flags |= S_SYNC; |
| 4803 | if (flags & EXT4_APPEND_FL) |
| 4804 | inode->i_flags |= S_APPEND; |
| 4805 | if (flags & EXT4_IMMUTABLE_FL) |
| 4806 | inode->i_flags |= S_IMMUTABLE; |
| 4807 | if (flags & EXT4_NOATIME_FL) |
| 4808 | inode->i_flags |= S_NOATIME; |
| 4809 | if (flags & EXT4_DIRSYNC_FL) |
| 4810 | inode->i_flags |= S_DIRSYNC; |
| 4811 | } |
| 4812 | |
| 4813 | /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */ |
| 4814 | void ext4_get_inode_flags(struct ext4_inode_info *ei) |
| 4815 | { |
| 4816 | unsigned int vfs_fl; |
| 4817 | unsigned long old_fl, new_fl; |
| 4818 | |
| 4819 | do { |
| 4820 | vfs_fl = ei->vfs_inode.i_flags; |
| 4821 | old_fl = ei->i_flags; |
| 4822 | new_fl = old_fl & ~(EXT4_SYNC_FL|EXT4_APPEND_FL| |
| 4823 | EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL| |
| 4824 | EXT4_DIRSYNC_FL); |
| 4825 | if (vfs_fl & S_SYNC) |
| 4826 | new_fl |= EXT4_SYNC_FL; |
| 4827 | if (vfs_fl & S_APPEND) |
| 4828 | new_fl |= EXT4_APPEND_FL; |
| 4829 | if (vfs_fl & S_IMMUTABLE) |
| 4830 | new_fl |= EXT4_IMMUTABLE_FL; |
| 4831 | if (vfs_fl & S_NOATIME) |
| 4832 | new_fl |= EXT4_NOATIME_FL; |
| 4833 | if (vfs_fl & S_DIRSYNC) |
| 4834 | new_fl |= EXT4_DIRSYNC_FL; |
| 4835 | } while (cmpxchg(&ei->i_flags, old_fl, new_fl) != old_fl); |
| 4836 | } |
| 4837 | |
| 4838 | static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode, |
| 4839 | struct ext4_inode_info *ei) |
| 4840 | { |
| 4841 | blkcnt_t i_blocks ; |
| 4842 | struct inode *inode = &(ei->vfs_inode); |
| 4843 | struct super_block *sb = inode->i_sb; |
| 4844 | |
| 4845 | if (EXT4_HAS_RO_COMPAT_FEATURE(sb, |
| 4846 | EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) { |
| 4847 | /* we are using combined 48 bit field */ |
| 4848 | i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 | |
| 4849 | le32_to_cpu(raw_inode->i_blocks_lo); |
| 4850 | if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) { |
| 4851 | /* i_blocks represent file system block size */ |
| 4852 | return i_blocks << (inode->i_blkbits - 9); |
| 4853 | } else { |
| 4854 | return i_blocks; |
| 4855 | } |
| 4856 | } else { |
| 4857 | return le32_to_cpu(raw_inode->i_blocks_lo); |
| 4858 | } |
| 4859 | } |
| 4860 | |
| 4861 | struct inode *ext4_iget(struct super_block *sb, unsigned long ino) |
| 4862 | { |
| 4863 | struct ext4_iloc iloc; |
| 4864 | struct ext4_inode *raw_inode; |
| 4865 | struct ext4_inode_info *ei; |
| 4866 | struct inode *inode; |
| 4867 | journal_t *journal = EXT4_SB(sb)->s_journal; |
| 4868 | long ret; |
| 4869 | int block; |
| 4870 | |
| 4871 | inode = iget_locked(sb, ino); |
| 4872 | if (!inode) |
| 4873 | return ERR_PTR(-ENOMEM); |
| 4874 | if (!(inode->i_state & I_NEW)) |
| 4875 | return inode; |
| 4876 | |
| 4877 | ei = EXT4_I(inode); |
| 4878 | iloc.bh = NULL; |
| 4879 | |
| 4880 | ret = __ext4_get_inode_loc(inode, &iloc, 0); |
| 4881 | if (ret < 0) |
| 4882 | goto bad_inode; |
| 4883 | raw_inode = ext4_raw_inode(&iloc); |
| 4884 | inode->i_mode = le16_to_cpu(raw_inode->i_mode); |
| 4885 | inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); |
| 4886 | inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); |
| 4887 | if (!(test_opt(inode->i_sb, NO_UID32))) { |
| 4888 | inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; |
| 4889 | inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; |
| 4890 | } |
| 4891 | inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); |
| 4892 | |
| 4893 | ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */ |
| 4894 | ei->i_dir_start_lookup = 0; |
| 4895 | ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); |
| 4896 | /* We now have enough fields to check if the inode was active or not. |
| 4897 | * This is needed because nfsd might try to access dead inodes |
| 4898 | * the test is that same one that e2fsck uses |
| 4899 | * NeilBrown 1999oct15 |
| 4900 | */ |
| 4901 | if (inode->i_nlink == 0) { |
| 4902 | if (inode->i_mode == 0 || |
| 4903 | !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) { |
| 4904 | /* this inode is deleted */ |
| 4905 | ret = -ESTALE; |
| 4906 | goto bad_inode; |
| 4907 | } |
| 4908 | /* The only unlinked inodes we let through here have |
| 4909 | * valid i_mode and are being read by the orphan |
| 4910 | * recovery code: that's fine, we're about to complete |
| 4911 | * the process of deleting those. */ |
| 4912 | } |
| 4913 | ei->i_flags = le32_to_cpu(raw_inode->i_flags); |
| 4914 | inode->i_blocks = ext4_inode_blocks(raw_inode, ei); |
| 4915 | ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo); |
| 4916 | if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) |
| 4917 | ei->i_file_acl |= |
| 4918 | ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32; |
| 4919 | inode->i_size = ext4_isize(raw_inode); |
| 4920 | ei->i_disksize = inode->i_size; |
| 4921 | #ifdef CONFIG_QUOTA |
| 4922 | ei->i_reserved_quota = 0; |
| 4923 | #endif |
| 4924 | inode->i_generation = le32_to_cpu(raw_inode->i_generation); |
| 4925 | ei->i_block_group = iloc.block_group; |
| 4926 | ei->i_last_alloc_group = ~0; |
| 4927 | /* |
| 4928 | * NOTE! The in-memory inode i_data array is in little-endian order |
| 4929 | * even on big-endian machines: we do NOT byteswap the block numbers! |
| 4930 | */ |
| 4931 | for (block = 0; block < EXT4_N_BLOCKS; block++) |
| 4932 | ei->i_data[block] = raw_inode->i_block[block]; |
| 4933 | INIT_LIST_HEAD(&ei->i_orphan); |
| 4934 | |
| 4935 | /* |
| 4936 | * Set transaction id's of transactions that have to be committed |
| 4937 | * to finish f[data]sync. We set them to currently running transaction |
| 4938 | * as we cannot be sure that the inode or some of its metadata isn't |
| 4939 | * part of the transaction - the inode could have been reclaimed and |
| 4940 | * now it is reread from disk. |
| 4941 | */ |
| 4942 | if (journal) { |
| 4943 | transaction_t *transaction; |
| 4944 | tid_t tid; |
| 4945 | |
| 4946 | read_lock(&journal->j_state_lock); |
| 4947 | if (journal->j_running_transaction) |
| 4948 | transaction = journal->j_running_transaction; |
| 4949 | else |
| 4950 | transaction = journal->j_committing_transaction; |
| 4951 | if (transaction) |
| 4952 | tid = transaction->t_tid; |
| 4953 | else |
| 4954 | tid = journal->j_commit_sequence; |
| 4955 | read_unlock(&journal->j_state_lock); |
| 4956 | ei->i_sync_tid = tid; |
| 4957 | ei->i_datasync_tid = tid; |
| 4958 | } |
| 4959 | |
| 4960 | if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { |
| 4961 | ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize); |
| 4962 | if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > |
| 4963 | EXT4_INODE_SIZE(inode->i_sb)) { |
| 4964 | ret = -EIO; |
| 4965 | goto bad_inode; |
| 4966 | } |
| 4967 | if (ei->i_extra_isize == 0) { |
| 4968 | /* The extra space is currently unused. Use it. */ |
| 4969 | ei->i_extra_isize = sizeof(struct ext4_inode) - |
| 4970 | EXT4_GOOD_OLD_INODE_SIZE; |
| 4971 | } else { |
| 4972 | __le32 *magic = (void *)raw_inode + |
| 4973 | EXT4_GOOD_OLD_INODE_SIZE + |
| 4974 | ei->i_extra_isize; |
| 4975 | if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC)) |
| 4976 | ext4_set_inode_state(inode, EXT4_STATE_XATTR); |
| 4977 | } |
| 4978 | } else |
| 4979 | ei->i_extra_isize = 0; |
| 4980 | |
| 4981 | EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode); |
| 4982 | EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode); |
| 4983 | EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode); |
| 4984 | EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode); |
| 4985 | |
| 4986 | inode->i_version = le32_to_cpu(raw_inode->i_disk_version); |
| 4987 | if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { |
| 4988 | if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi)) |
| 4989 | inode->i_version |= |
| 4990 | (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32; |
| 4991 | } |
| 4992 | |
| 4993 | ret = 0; |
| 4994 | if (ei->i_file_acl && |
| 4995 | !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) { |
| 4996 | EXT4_ERROR_INODE(inode, "bad extended attribute block %llu", |
| 4997 | ei->i_file_acl); |
| 4998 | ret = -EIO; |
| 4999 | goto bad_inode; |
| 5000 | } else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { |
| 5001 | if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || |
| 5002 | (S_ISLNK(inode->i_mode) && |
| 5003 | !ext4_inode_is_fast_symlink(inode))) |
| 5004 | /* Validate extent which is part of inode */ |
| 5005 | ret = ext4_ext_check_inode(inode); |
| 5006 | } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || |
| 5007 | (S_ISLNK(inode->i_mode) && |
| 5008 | !ext4_inode_is_fast_symlink(inode))) { |
| 5009 | /* Validate block references which are part of inode */ |
| 5010 | ret = ext4_check_inode_blockref(inode); |
| 5011 | } |
| 5012 | if (ret) |
| 5013 | goto bad_inode; |
| 5014 | |
| 5015 | if (S_ISREG(inode->i_mode)) { |
| 5016 | inode->i_op = &ext4_file_inode_operations; |
| 5017 | inode->i_fop = &ext4_file_operations; |
| 5018 | ext4_set_aops(inode); |
| 5019 | } else if (S_ISDIR(inode->i_mode)) { |
| 5020 | inode->i_op = &ext4_dir_inode_operations; |
| 5021 | inode->i_fop = &ext4_dir_operations; |
| 5022 | } else if (S_ISLNK(inode->i_mode)) { |
| 5023 | if (ext4_inode_is_fast_symlink(inode)) { |
| 5024 | inode->i_op = &ext4_fast_symlink_inode_operations; |
| 5025 | nd_terminate_link(ei->i_data, inode->i_size, |
| 5026 | sizeof(ei->i_data) - 1); |
| 5027 | } else { |
| 5028 | inode->i_op = &ext4_symlink_inode_operations; |
| 5029 | ext4_set_aops(inode); |
| 5030 | } |
| 5031 | } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || |
| 5032 | S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { |
| 5033 | inode->i_op = &ext4_special_inode_operations; |
| 5034 | if (raw_inode->i_block[0]) |
| 5035 | init_special_inode(inode, inode->i_mode, |
| 5036 | old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); |
| 5037 | else |
| 5038 | init_special_inode(inode, inode->i_mode, |
| 5039 | new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); |
| 5040 | } else { |
| 5041 | ret = -EIO; |
| 5042 | EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode); |
| 5043 | goto bad_inode; |
| 5044 | } |
| 5045 | brelse(iloc.bh); |
| 5046 | ext4_set_inode_flags(inode); |
| 5047 | unlock_new_inode(inode); |
| 5048 | return inode; |
| 5049 | |
| 5050 | bad_inode: |
| 5051 | brelse(iloc.bh); |
| 5052 | iget_failed(inode); |
| 5053 | return ERR_PTR(ret); |
| 5054 | } |
| 5055 | |
| 5056 | static int ext4_inode_blocks_set(handle_t *handle, |
| 5057 | struct ext4_inode *raw_inode, |
| 5058 | struct ext4_inode_info *ei) |
| 5059 | { |
| 5060 | struct inode *inode = &(ei->vfs_inode); |
| 5061 | u64 i_blocks = inode->i_blocks; |
| 5062 | struct super_block *sb = inode->i_sb; |
| 5063 | |
| 5064 | if (i_blocks <= ~0U) { |
| 5065 | /* |
| 5066 | * i_blocks can be represnted in a 32 bit variable |
| 5067 | * as multiple of 512 bytes |
| 5068 | */ |
| 5069 | raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); |
| 5070 | raw_inode->i_blocks_high = 0; |
| 5071 | ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE); |
| 5072 | return 0; |
| 5073 | } |
| 5074 | if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) |
| 5075 | return -EFBIG; |
| 5076 | |
| 5077 | if (i_blocks <= 0xffffffffffffULL) { |
| 5078 | /* |
| 5079 | * i_blocks can be represented in a 48 bit variable |
| 5080 | * as multiple of 512 bytes |
| 5081 | */ |
| 5082 | raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); |
| 5083 | raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32); |
| 5084 | ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE); |
| 5085 | } else { |
| 5086 | ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE); |
| 5087 | /* i_block is stored in file system block size */ |
| 5088 | i_blocks = i_blocks >> (inode->i_blkbits - 9); |
| 5089 | raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); |
| 5090 | raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32); |
| 5091 | } |
| 5092 | return 0; |
| 5093 | } |
| 5094 | |
| 5095 | /* |
| 5096 | * Post the struct inode info into an on-disk inode location in the |
| 5097 | * buffer-cache. This gobbles the caller's reference to the |
| 5098 | * buffer_head in the inode location struct. |
| 5099 | * |
| 5100 | * The caller must have write access to iloc->bh. |
| 5101 | */ |
| 5102 | static int ext4_do_update_inode(handle_t *handle, |
| 5103 | struct inode *inode, |
| 5104 | struct ext4_iloc *iloc) |
| 5105 | { |
| 5106 | struct ext4_inode *raw_inode = ext4_raw_inode(iloc); |
| 5107 | struct ext4_inode_info *ei = EXT4_I(inode); |
| 5108 | struct buffer_head *bh = iloc->bh; |
| 5109 | int err = 0, rc, block; |
| 5110 | |
| 5111 | /* For fields not not tracking in the in-memory inode, |
| 5112 | * initialise them to zero for new inodes. */ |
| 5113 | if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) |
| 5114 | memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); |
| 5115 | |
| 5116 | ext4_get_inode_flags(ei); |
| 5117 | raw_inode->i_mode = cpu_to_le16(inode->i_mode); |
| 5118 | if (!(test_opt(inode->i_sb, NO_UID32))) { |
| 5119 | raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid)); |
| 5120 | raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid)); |
| 5121 | /* |
| 5122 | * Fix up interoperability with old kernels. Otherwise, old inodes get |
| 5123 | * re-used with the upper 16 bits of the uid/gid intact |
| 5124 | */ |
| 5125 | if (!ei->i_dtime) { |
| 5126 | raw_inode->i_uid_high = |
| 5127 | cpu_to_le16(high_16_bits(inode->i_uid)); |
| 5128 | raw_inode->i_gid_high = |
| 5129 | cpu_to_le16(high_16_bits(inode->i_gid)); |
| 5130 | } else { |
| 5131 | raw_inode->i_uid_high = 0; |
| 5132 | raw_inode->i_gid_high = 0; |
| 5133 | } |
| 5134 | } else { |
| 5135 | raw_inode->i_uid_low = |
| 5136 | cpu_to_le16(fs_high2lowuid(inode->i_uid)); |
| 5137 | raw_inode->i_gid_low = |
| 5138 | cpu_to_le16(fs_high2lowgid(inode->i_gid)); |
| 5139 | raw_inode->i_uid_high = 0; |
| 5140 | raw_inode->i_gid_high = 0; |
| 5141 | } |
| 5142 | raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); |
| 5143 | |
| 5144 | EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode); |
| 5145 | EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode); |
| 5146 | EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode); |
| 5147 | EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode); |
| 5148 | |
| 5149 | if (ext4_inode_blocks_set(handle, raw_inode, ei)) |
| 5150 | goto out_brelse; |
| 5151 | raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); |
| 5152 | raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF); |
| 5153 | if (EXT4_SB(inode->i_sb)->s_es->s_creator_os != |
| 5154 | cpu_to_le32(EXT4_OS_HURD)) |
| 5155 | raw_inode->i_file_acl_high = |
| 5156 | cpu_to_le16(ei->i_file_acl >> 32); |
| 5157 | raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl); |
| 5158 | ext4_isize_set(raw_inode, ei->i_disksize); |
| 5159 | if (ei->i_disksize > 0x7fffffffULL) { |
| 5160 | struct super_block *sb = inode->i_sb; |
| 5161 | if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, |
| 5162 | EXT4_FEATURE_RO_COMPAT_LARGE_FILE) || |
| 5163 | EXT4_SB(sb)->s_es->s_rev_level == |
| 5164 | cpu_to_le32(EXT4_GOOD_OLD_REV)) { |
| 5165 | /* If this is the first large file |
| 5166 | * created, add a flag to the superblock. |
| 5167 | */ |
| 5168 | err = ext4_journal_get_write_access(handle, |
| 5169 | EXT4_SB(sb)->s_sbh); |
| 5170 | if (err) |
| 5171 | goto out_brelse; |
| 5172 | ext4_update_dynamic_rev(sb); |
| 5173 | EXT4_SET_RO_COMPAT_FEATURE(sb, |
| 5174 | EXT4_FEATURE_RO_COMPAT_LARGE_FILE); |
| 5175 | sb->s_dirt = 1; |
| 5176 | ext4_handle_sync(handle); |
| 5177 | err = ext4_handle_dirty_metadata(handle, NULL, |
| 5178 | EXT4_SB(sb)->s_sbh); |
| 5179 | } |
| 5180 | } |
| 5181 | raw_inode->i_generation = cpu_to_le32(inode->i_generation); |
| 5182 | if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { |
| 5183 | if (old_valid_dev(inode->i_rdev)) { |
| 5184 | raw_inode->i_block[0] = |
| 5185 | cpu_to_le32(old_encode_dev(inode->i_rdev)); |
| 5186 | raw_inode->i_block[1] = 0; |
| 5187 | } else { |
| 5188 | raw_inode->i_block[0] = 0; |
| 5189 | raw_inode->i_block[1] = |
| 5190 | cpu_to_le32(new_encode_dev(inode->i_rdev)); |
| 5191 | raw_inode->i_block[2] = 0; |
| 5192 | } |
| 5193 | } else |
| 5194 | for (block = 0; block < EXT4_N_BLOCKS; block++) |
| 5195 | raw_inode->i_block[block] = ei->i_data[block]; |
| 5196 | |
| 5197 | raw_inode->i_disk_version = cpu_to_le32(inode->i_version); |
| 5198 | if (ei->i_extra_isize) { |
| 5199 | if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi)) |
| 5200 | raw_inode->i_version_hi = |
| 5201 | cpu_to_le32(inode->i_version >> 32); |
| 5202 | raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize); |
| 5203 | } |
| 5204 | |
| 5205 | BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); |
| 5206 | rc = ext4_handle_dirty_metadata(handle, NULL, bh); |
| 5207 | if (!err) |
| 5208 | err = rc; |
| 5209 | ext4_clear_inode_state(inode, EXT4_STATE_NEW); |
| 5210 | |
| 5211 | ext4_update_inode_fsync_trans(handle, inode, 0); |
| 5212 | out_brelse: |
| 5213 | brelse(bh); |
| 5214 | ext4_std_error(inode->i_sb, err); |
| 5215 | return err; |
| 5216 | } |
| 5217 | |
| 5218 | /* |
| 5219 | * ext4_write_inode() |
| 5220 | * |
| 5221 | * We are called from a few places: |
| 5222 | * |
| 5223 | * - Within generic_file_write() for O_SYNC files. |
| 5224 | * Here, there will be no transaction running. We wait for any running |
| 5225 | * trasnaction to commit. |
| 5226 | * |
| 5227 | * - Within sys_sync(), kupdate and such. |
| 5228 | * We wait on commit, if tol to. |
| 5229 | * |
| 5230 | * - Within prune_icache() (PF_MEMALLOC == true) |
| 5231 | * Here we simply return. We can't afford to block kswapd on the |
| 5232 | * journal commit. |
| 5233 | * |
| 5234 | * In all cases it is actually safe for us to return without doing anything, |
| 5235 | * because the inode has been copied into a raw inode buffer in |
| 5236 | * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for |
| 5237 | * knfsd. |
| 5238 | * |
| 5239 | * Note that we are absolutely dependent upon all inode dirtiers doing the |
| 5240 | * right thing: they *must* call mark_inode_dirty() after dirtying info in |
| 5241 | * which we are interested. |
| 5242 | * |
| 5243 | * It would be a bug for them to not do this. The code: |
| 5244 | * |
| 5245 | * mark_inode_dirty(inode) |
| 5246 | * stuff(); |
| 5247 | * inode->i_size = expr; |
| 5248 | * |
| 5249 | * is in error because a kswapd-driven write_inode() could occur while |
| 5250 | * `stuff()' is running, and the new i_size will be lost. Plus the inode |
| 5251 | * will no longer be on the superblock's dirty inode list. |
| 5252 | */ |
| 5253 | int ext4_write_inode(struct inode *inode, struct writeback_control *wbc) |
| 5254 | { |
| 5255 | int err; |
| 5256 | |
| 5257 | if (current->flags & PF_MEMALLOC) |
| 5258 | return 0; |
| 5259 | |
| 5260 | if (EXT4_SB(inode->i_sb)->s_journal) { |
| 5261 | if (ext4_journal_current_handle()) { |
| 5262 | jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n"); |
| 5263 | dump_stack(); |
| 5264 | return -EIO; |
| 5265 | } |
| 5266 | |
| 5267 | if (wbc->sync_mode != WB_SYNC_ALL) |
| 5268 | return 0; |
| 5269 | |
| 5270 | err = ext4_force_commit(inode->i_sb); |
| 5271 | } else { |
| 5272 | struct ext4_iloc iloc; |
| 5273 | |
| 5274 | err = __ext4_get_inode_loc(inode, &iloc, 0); |
| 5275 | if (err) |
| 5276 | return err; |
| 5277 | if (wbc->sync_mode == WB_SYNC_ALL) |
| 5278 | sync_dirty_buffer(iloc.bh); |
| 5279 | if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) { |
| 5280 | EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr, |
| 5281 | "IO error syncing inode"); |
| 5282 | err = -EIO; |
| 5283 | } |
| 5284 | brelse(iloc.bh); |
| 5285 | } |
| 5286 | return err; |
| 5287 | } |
| 5288 | |
| 5289 | /* |
| 5290 | * ext4_setattr() |
| 5291 | * |
| 5292 | * Called from notify_change. |
| 5293 | * |
| 5294 | * We want to trap VFS attempts to truncate the file as soon as |
| 5295 | * possible. In particular, we want to make sure that when the VFS |
| 5296 | * shrinks i_size, we put the inode on the orphan list and modify |
| 5297 | * i_disksize immediately, so that during the subsequent flushing of |
| 5298 | * dirty pages and freeing of disk blocks, we can guarantee that any |
| 5299 | * commit will leave the blocks being flushed in an unused state on |
| 5300 | * disk. (On recovery, the inode will get truncated and the blocks will |
| 5301 | * be freed, so we have a strong guarantee that no future commit will |
| 5302 | * leave these blocks visible to the user.) |
| 5303 | * |
| 5304 | * Another thing we have to assure is that if we are in ordered mode |
| 5305 | * and inode is still attached to the committing transaction, we must |
| 5306 | * we start writeout of all the dirty pages which are being truncated. |
| 5307 | * This way we are sure that all the data written in the previous |
| 5308 | * transaction are already on disk (truncate waits for pages under |
| 5309 | * writeback). |
| 5310 | * |
| 5311 | * Called with inode->i_mutex down. |
| 5312 | */ |
| 5313 | int ext4_setattr(struct dentry *dentry, struct iattr *attr) |
| 5314 | { |
| 5315 | struct inode *inode = dentry->d_inode; |
| 5316 | int error, rc = 0; |
| 5317 | int orphan = 0; |
| 5318 | const unsigned int ia_valid = attr->ia_valid; |
| 5319 | |
| 5320 | error = inode_change_ok(inode, attr); |
| 5321 | if (error) |
| 5322 | return error; |
| 5323 | |
| 5324 | if (is_quota_modification(inode, attr)) |
| 5325 | dquot_initialize(inode); |
| 5326 | if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) || |
| 5327 | (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) { |
| 5328 | handle_t *handle; |
| 5329 | |
| 5330 | /* (user+group)*(old+new) structure, inode write (sb, |
| 5331 | * inode block, ? - but truncate inode update has it) */ |
| 5332 | handle = ext4_journal_start(inode, (EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)+ |
| 5333 | EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb))+3); |
| 5334 | if (IS_ERR(handle)) { |
| 5335 | error = PTR_ERR(handle); |
| 5336 | goto err_out; |
| 5337 | } |
| 5338 | error = dquot_transfer(inode, attr); |
| 5339 | if (error) { |
| 5340 | ext4_journal_stop(handle); |
| 5341 | return error; |
| 5342 | } |
| 5343 | /* Update corresponding info in inode so that everything is in |
| 5344 | * one transaction */ |
| 5345 | if (attr->ia_valid & ATTR_UID) |
| 5346 | inode->i_uid = attr->ia_uid; |
| 5347 | if (attr->ia_valid & ATTR_GID) |
| 5348 | inode->i_gid = attr->ia_gid; |
| 5349 | error = ext4_mark_inode_dirty(handle, inode); |
| 5350 | ext4_journal_stop(handle); |
| 5351 | } |
| 5352 | |
| 5353 | if (attr->ia_valid & ATTR_SIZE) { |
| 5354 | inode_dio_wait(inode); |
| 5355 | |
| 5356 | if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { |
| 5357 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| 5358 | |
| 5359 | if (attr->ia_size > sbi->s_bitmap_maxbytes) |
| 5360 | return -EFBIG; |
| 5361 | } |
| 5362 | } |
| 5363 | |
| 5364 | if (S_ISREG(inode->i_mode) && |
| 5365 | attr->ia_valid & ATTR_SIZE && |
| 5366 | (attr->ia_size < inode->i_size)) { |
| 5367 | handle_t *handle; |
| 5368 | |
| 5369 | handle = ext4_journal_start(inode, 3); |
| 5370 | if (IS_ERR(handle)) { |
| 5371 | error = PTR_ERR(handle); |
| 5372 | goto err_out; |
| 5373 | } |
| 5374 | if (ext4_handle_valid(handle)) { |
| 5375 | error = ext4_orphan_add(handle, inode); |
| 5376 | orphan = 1; |
| 5377 | } |
| 5378 | EXT4_I(inode)->i_disksize = attr->ia_size; |
| 5379 | rc = ext4_mark_inode_dirty(handle, inode); |
| 5380 | if (!error) |
| 5381 | error = rc; |
| 5382 | ext4_journal_stop(handle); |
| 5383 | |
| 5384 | if (ext4_should_order_data(inode)) { |
| 5385 | error = ext4_begin_ordered_truncate(inode, |
| 5386 | attr->ia_size); |
| 5387 | if (error) { |
| 5388 | /* Do as much error cleanup as possible */ |
| 5389 | handle = ext4_journal_start(inode, 3); |
| 5390 | if (IS_ERR(handle)) { |
| 5391 | ext4_orphan_del(NULL, inode); |
| 5392 | goto err_out; |
| 5393 | } |
| 5394 | ext4_orphan_del(handle, inode); |
| 5395 | orphan = 0; |
| 5396 | ext4_journal_stop(handle); |
| 5397 | goto err_out; |
| 5398 | } |
| 5399 | } |
| 5400 | } |
| 5401 | |
| 5402 | if (attr->ia_valid & ATTR_SIZE) { |
| 5403 | if (attr->ia_size != i_size_read(inode)) { |
| 5404 | truncate_setsize(inode, attr->ia_size); |
| 5405 | ext4_truncate(inode); |
| 5406 | } else if (ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)) |
| 5407 | ext4_truncate(inode); |
| 5408 | } |
| 5409 | |
| 5410 | if (!rc) { |
| 5411 | setattr_copy(inode, attr); |
| 5412 | mark_inode_dirty(inode); |
| 5413 | } |
| 5414 | |
| 5415 | /* |
| 5416 | * If the call to ext4_truncate failed to get a transaction handle at |
| 5417 | * all, we need to clean up the in-core orphan list manually. |
| 5418 | */ |
| 5419 | if (orphan && inode->i_nlink) |
| 5420 | ext4_orphan_del(NULL, inode); |
| 5421 | |
| 5422 | if (!rc && (ia_valid & ATTR_MODE)) |
| 5423 | rc = ext4_acl_chmod(inode); |
| 5424 | |
| 5425 | err_out: |
| 5426 | ext4_std_error(inode->i_sb, error); |
| 5427 | if (!error) |
| 5428 | error = rc; |
| 5429 | return error; |
| 5430 | } |
| 5431 | |
| 5432 | int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry, |
| 5433 | struct kstat *stat) |
| 5434 | { |
| 5435 | struct inode *inode; |
| 5436 | unsigned long delalloc_blocks; |
| 5437 | |
| 5438 | inode = dentry->d_inode; |
| 5439 | generic_fillattr(inode, stat); |
| 5440 | |
| 5441 | /* |
| 5442 | * We can't update i_blocks if the block allocation is delayed |
| 5443 | * otherwise in the case of system crash before the real block |
| 5444 | * allocation is done, we will have i_blocks inconsistent with |
| 5445 | * on-disk file blocks. |
| 5446 | * We always keep i_blocks updated together with real |
| 5447 | * allocation. But to not confuse with user, stat |
| 5448 | * will return the blocks that include the delayed allocation |
| 5449 | * blocks for this file. |
| 5450 | */ |
| 5451 | delalloc_blocks = EXT4_I(inode)->i_reserved_data_blocks; |
| 5452 | |
| 5453 | stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9; |
| 5454 | return 0; |
| 5455 | } |
| 5456 | |
| 5457 | static int ext4_indirect_trans_blocks(struct inode *inode, int nrblocks, |
| 5458 | int chunk) |
| 5459 | { |
| 5460 | int indirects; |
| 5461 | |
| 5462 | /* if nrblocks are contiguous */ |
| 5463 | if (chunk) { |
| 5464 | /* |
| 5465 | * With N contiguous data blocks, we need at most |
| 5466 | * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks, |
| 5467 | * 2 dindirect blocks, and 1 tindirect block |
| 5468 | */ |
| 5469 | return DIV_ROUND_UP(nrblocks, |
| 5470 | EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4; |
| 5471 | } |
| 5472 | /* |
| 5473 | * if nrblocks are not contiguous, worse case, each block touch |
| 5474 | * a indirect block, and each indirect block touch a double indirect |
| 5475 | * block, plus a triple indirect block |
| 5476 | */ |
| 5477 | indirects = nrblocks * 2 + 1; |
| 5478 | return indirects; |
| 5479 | } |
| 5480 | |
| 5481 | static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk) |
| 5482 | { |
| 5483 | if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) |
| 5484 | return ext4_indirect_trans_blocks(inode, nrblocks, chunk); |
| 5485 | return ext4_ext_index_trans_blocks(inode, nrblocks, chunk); |
| 5486 | } |
| 5487 | |
| 5488 | /* |
| 5489 | * Account for index blocks, block groups bitmaps and block group |
| 5490 | * descriptor blocks if modify datablocks and index blocks |
| 5491 | * worse case, the indexs blocks spread over different block groups |
| 5492 | * |
| 5493 | * If datablocks are discontiguous, they are possible to spread over |
| 5494 | * different block groups too. If they are contiuguous, with flexbg, |
| 5495 | * they could still across block group boundary. |
| 5496 | * |
| 5497 | * Also account for superblock, inode, quota and xattr blocks |
| 5498 | */ |
| 5499 | static int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk) |
| 5500 | { |
| 5501 | ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb); |
| 5502 | int gdpblocks; |
| 5503 | int idxblocks; |
| 5504 | int ret = 0; |
| 5505 | |
| 5506 | /* |
| 5507 | * How many index blocks need to touch to modify nrblocks? |
| 5508 | * The "Chunk" flag indicating whether the nrblocks is |
| 5509 | * physically contiguous on disk |
| 5510 | * |
| 5511 | * For Direct IO and fallocate, they calls get_block to allocate |
| 5512 | * one single extent at a time, so they could set the "Chunk" flag |
| 5513 | */ |
| 5514 | idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk); |
| 5515 | |
| 5516 | ret = idxblocks; |
| 5517 | |
| 5518 | /* |
| 5519 | * Now let's see how many group bitmaps and group descriptors need |
| 5520 | * to account |
| 5521 | */ |
| 5522 | groups = idxblocks; |
| 5523 | if (chunk) |
| 5524 | groups += 1; |
| 5525 | else |
| 5526 | groups += nrblocks; |
| 5527 | |
| 5528 | gdpblocks = groups; |
| 5529 | if (groups > ngroups) |
| 5530 | groups = ngroups; |
| 5531 | if (groups > EXT4_SB(inode->i_sb)->s_gdb_count) |
| 5532 | gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count; |
| 5533 | |
| 5534 | /* bitmaps and block group descriptor blocks */ |
| 5535 | ret += groups + gdpblocks; |
| 5536 | |
| 5537 | /* Blocks for super block, inode, quota and xattr blocks */ |
| 5538 | ret += EXT4_META_TRANS_BLOCKS(inode->i_sb); |
| 5539 | |
| 5540 | return ret; |
| 5541 | } |
| 5542 | |
| 5543 | /* |
| 5544 | * Calculate the total number of credits to reserve to fit |
| 5545 | * the modification of a single pages into a single transaction, |
| 5546 | * which may include multiple chunks of block allocations. |
| 5547 | * |
| 5548 | * This could be called via ext4_write_begin() |
| 5549 | * |
| 5550 | * We need to consider the worse case, when |
| 5551 | * one new block per extent. |
| 5552 | */ |
| 5553 | int ext4_writepage_trans_blocks(struct inode *inode) |
| 5554 | { |
| 5555 | int bpp = ext4_journal_blocks_per_page(inode); |
| 5556 | int ret; |
| 5557 | |
| 5558 | ret = ext4_meta_trans_blocks(inode, bpp, 0); |
| 5559 | |
| 5560 | /* Account for data blocks for journalled mode */ |
| 5561 | if (ext4_should_journal_data(inode)) |
| 5562 | ret += bpp; |
| 5563 | return ret; |
| 5564 | } |
| 5565 | |
| 5566 | /* |
| 5567 | * Calculate the journal credits for a chunk of data modification. |
| 5568 | * |
| 5569 | * This is called from DIO, fallocate or whoever calling |
| 5570 | * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks. |
| 5571 | * |
| 5572 | * journal buffers for data blocks are not included here, as DIO |
| 5573 | * and fallocate do no need to journal data buffers. |
| 5574 | */ |
| 5575 | int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks) |
| 5576 | { |
| 5577 | return ext4_meta_trans_blocks(inode, nrblocks, 1); |
| 5578 | } |
| 5579 | |
| 5580 | /* |
| 5581 | * The caller must have previously called ext4_reserve_inode_write(). |
| 5582 | * Give this, we know that the caller already has write access to iloc->bh. |
| 5583 | */ |
| 5584 | int ext4_mark_iloc_dirty(handle_t *handle, |
| 5585 | struct inode *inode, struct ext4_iloc *iloc) |
| 5586 | { |
| 5587 | int err = 0; |
| 5588 | |
| 5589 | if (test_opt(inode->i_sb, I_VERSION)) |
| 5590 | inode_inc_iversion(inode); |
| 5591 | |
| 5592 | /* the do_update_inode consumes one bh->b_count */ |
| 5593 | get_bh(iloc->bh); |
| 5594 | |
| 5595 | /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */ |
| 5596 | err = ext4_do_update_inode(handle, inode, iloc); |
| 5597 | put_bh(iloc->bh); |
| 5598 | return err; |
| 5599 | } |
| 5600 | |
| 5601 | /* |
| 5602 | * On success, We end up with an outstanding reference count against |
| 5603 | * iloc->bh. This _must_ be cleaned up later. |
| 5604 | */ |
| 5605 | |
| 5606 | int |
| 5607 | ext4_reserve_inode_write(handle_t *handle, struct inode *inode, |
| 5608 | struct ext4_iloc *iloc) |
| 5609 | { |
| 5610 | int err; |
| 5611 | |
| 5612 | err = ext4_get_inode_loc(inode, iloc); |
| 5613 | if (!err) { |
| 5614 | BUFFER_TRACE(iloc->bh, "get_write_access"); |
| 5615 | err = ext4_journal_get_write_access(handle, iloc->bh); |
| 5616 | if (err) { |
| 5617 | brelse(iloc->bh); |
| 5618 | iloc->bh = NULL; |
| 5619 | } |
| 5620 | } |
| 5621 | ext4_std_error(inode->i_sb, err); |
| 5622 | return err; |
| 5623 | } |
| 5624 | |
| 5625 | /* |
| 5626 | * Expand an inode by new_extra_isize bytes. |
| 5627 | * Returns 0 on success or negative error number on failure. |
| 5628 | */ |
| 5629 | static int ext4_expand_extra_isize(struct inode *inode, |
| 5630 | unsigned int new_extra_isize, |
| 5631 | struct ext4_iloc iloc, |
| 5632 | handle_t *handle) |
| 5633 | { |
| 5634 | struct ext4_inode *raw_inode; |
| 5635 | struct ext4_xattr_ibody_header *header; |
| 5636 | |
| 5637 | if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) |
| 5638 | return 0; |
| 5639 | |
| 5640 | raw_inode = ext4_raw_inode(&iloc); |
| 5641 | |
| 5642 | header = IHDR(inode, raw_inode); |
| 5643 | |
| 5644 | /* No extended attributes present */ |
| 5645 | if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) || |
| 5646 | header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) { |
| 5647 | memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0, |
| 5648 | new_extra_isize); |
| 5649 | EXT4_I(inode)->i_extra_isize = new_extra_isize; |
| 5650 | return 0; |
| 5651 | } |
| 5652 | |
| 5653 | /* try to expand with EAs present */ |
| 5654 | return ext4_expand_extra_isize_ea(inode, new_extra_isize, |
| 5655 | raw_inode, handle); |
| 5656 | } |
| 5657 | |
| 5658 | /* |
| 5659 | * What we do here is to mark the in-core inode as clean with respect to inode |
| 5660 | * dirtiness (it may still be data-dirty). |
| 5661 | * This means that the in-core inode may be reaped by prune_icache |
| 5662 | * without having to perform any I/O. This is a very good thing, |
| 5663 | * because *any* task may call prune_icache - even ones which |
| 5664 | * have a transaction open against a different journal. |
| 5665 | * |
| 5666 | * Is this cheating? Not really. Sure, we haven't written the |
| 5667 | * inode out, but prune_icache isn't a user-visible syncing function. |
| 5668 | * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync) |
| 5669 | * we start and wait on commits. |
| 5670 | * |
| 5671 | * Is this efficient/effective? Well, we're being nice to the system |
| 5672 | * by cleaning up our inodes proactively so they can be reaped |
| 5673 | * without I/O. But we are potentially leaving up to five seconds' |
| 5674 | * worth of inodes floating about which prune_icache wants us to |
| 5675 | * write out. One way to fix that would be to get prune_icache() |
| 5676 | * to do a write_super() to free up some memory. It has the desired |
| 5677 | * effect. |
| 5678 | */ |
| 5679 | int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode) |
| 5680 | { |
| 5681 | struct ext4_iloc iloc; |
| 5682 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| 5683 | static unsigned int mnt_count; |
| 5684 | int err, ret; |
| 5685 | |
| 5686 | might_sleep(); |
| 5687 | trace_ext4_mark_inode_dirty(inode, _RET_IP_); |
| 5688 | err = ext4_reserve_inode_write(handle, inode, &iloc); |
| 5689 | if (ext4_handle_valid(handle) && |
| 5690 | EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize && |
| 5691 | !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) { |
| 5692 | /* |
| 5693 | * We need extra buffer credits since we may write into EA block |
| 5694 | * with this same handle. If journal_extend fails, then it will |
| 5695 | * only result in a minor loss of functionality for that inode. |
| 5696 | * If this is felt to be critical, then e2fsck should be run to |
| 5697 | * force a large enough s_min_extra_isize. |
| 5698 | */ |
| 5699 | if ((jbd2_journal_extend(handle, |
| 5700 | EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) { |
| 5701 | ret = ext4_expand_extra_isize(inode, |
| 5702 | sbi->s_want_extra_isize, |
| 5703 | iloc, handle); |
| 5704 | if (ret) { |
| 5705 | ext4_set_inode_state(inode, |
| 5706 | EXT4_STATE_NO_EXPAND); |
| 5707 | if (mnt_count != |
| 5708 | le16_to_cpu(sbi->s_es->s_mnt_count)) { |
| 5709 | ext4_warning(inode->i_sb, |
| 5710 | "Unable to expand inode %lu. Delete" |
| 5711 | " some EAs or run e2fsck.", |
| 5712 | inode->i_ino); |
| 5713 | mnt_count = |
| 5714 | le16_to_cpu(sbi->s_es->s_mnt_count); |
| 5715 | } |
| 5716 | } |
| 5717 | } |
| 5718 | } |
| 5719 | if (!err) |
| 5720 | err = ext4_mark_iloc_dirty(handle, inode, &iloc); |
| 5721 | return err; |
| 5722 | } |
| 5723 | |
| 5724 | /* |
| 5725 | * ext4_dirty_inode() is called from __mark_inode_dirty() |
| 5726 | * |
| 5727 | * We're really interested in the case where a file is being extended. |
| 5728 | * i_size has been changed by generic_commit_write() and we thus need |
| 5729 | * to include the updated inode in the current transaction. |
| 5730 | * |
| 5731 | * Also, dquot_alloc_block() will always dirty the inode when blocks |
| 5732 | * are allocated to the file. |
| 5733 | * |
| 5734 | * If the inode is marked synchronous, we don't honour that here - doing |
| 5735 | * so would cause a commit on atime updates, which we don't bother doing. |
| 5736 | * We handle synchronous inodes at the highest possible level. |
| 5737 | */ |
| 5738 | void ext4_dirty_inode(struct inode *inode, int flags) |
| 5739 | { |
| 5740 | handle_t *handle; |
| 5741 | |
| 5742 | handle = ext4_journal_start(inode, 2); |
| 5743 | if (IS_ERR(handle)) |
| 5744 | goto out; |
| 5745 | |
| 5746 | ext4_mark_inode_dirty(handle, inode); |
| 5747 | |
| 5748 | ext4_journal_stop(handle); |
| 5749 | out: |
| 5750 | return; |
| 5751 | } |
| 5752 | |
| 5753 | #if 0 |
| 5754 | /* |
| 5755 | * Bind an inode's backing buffer_head into this transaction, to prevent |
| 5756 | * it from being flushed to disk early. Unlike |
| 5757 | * ext4_reserve_inode_write, this leaves behind no bh reference and |
| 5758 | * returns no iloc structure, so the caller needs to repeat the iloc |
| 5759 | * lookup to mark the inode dirty later. |
| 5760 | */ |
| 5761 | static int ext4_pin_inode(handle_t *handle, struct inode *inode) |
| 5762 | { |
| 5763 | struct ext4_iloc iloc; |
| 5764 | |
| 5765 | int err = 0; |
| 5766 | if (handle) { |
| 5767 | err = ext4_get_inode_loc(inode, &iloc); |
| 5768 | if (!err) { |
| 5769 | BUFFER_TRACE(iloc.bh, "get_write_access"); |
| 5770 | err = jbd2_journal_get_write_access(handle, iloc.bh); |
| 5771 | if (!err) |
| 5772 | err = ext4_handle_dirty_metadata(handle, |
| 5773 | NULL, |
| 5774 | iloc.bh); |
| 5775 | brelse(iloc.bh); |
| 5776 | } |
| 5777 | } |
| 5778 | ext4_std_error(inode->i_sb, err); |
| 5779 | return err; |
| 5780 | } |
| 5781 | #endif |
| 5782 | |
| 5783 | int ext4_change_inode_journal_flag(struct inode *inode, int val) |
| 5784 | { |
| 5785 | journal_t *journal; |
| 5786 | handle_t *handle; |
| 5787 | int err; |
| 5788 | |
| 5789 | /* |
| 5790 | * We have to be very careful here: changing a data block's |
| 5791 | * journaling status dynamically is dangerous. If we write a |
| 5792 | * data block to the journal, change the status and then delete |
| 5793 | * that block, we risk forgetting to revoke the old log record |
| 5794 | * from the journal and so a subsequent replay can corrupt data. |
| 5795 | * So, first we make sure that the journal is empty and that |
| 5796 | * nobody is changing anything. |
| 5797 | */ |
| 5798 | |
| 5799 | journal = EXT4_JOURNAL(inode); |
| 5800 | if (!journal) |
| 5801 | return 0; |
| 5802 | if (is_journal_aborted(journal)) |
| 5803 | return -EROFS; |
| 5804 | |
| 5805 | jbd2_journal_lock_updates(journal); |
| 5806 | jbd2_journal_flush(journal); |
| 5807 | |
| 5808 | /* |
| 5809 | * OK, there are no updates running now, and all cached data is |
| 5810 | * synced to disk. We are now in a completely consistent state |
| 5811 | * which doesn't have anything in the journal, and we know that |
| 5812 | * no filesystem updates are running, so it is safe to modify |
| 5813 | * the inode's in-core data-journaling state flag now. |
| 5814 | */ |
| 5815 | |
| 5816 | if (val) |
| 5817 | ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA); |
| 5818 | else |
| 5819 | ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA); |
| 5820 | ext4_set_aops(inode); |
| 5821 | |
| 5822 | jbd2_journal_unlock_updates(journal); |
| 5823 | |
| 5824 | /* Finally we can mark the inode as dirty. */ |
| 5825 | |
| 5826 | handle = ext4_journal_start(inode, 1); |
| 5827 | if (IS_ERR(handle)) |
| 5828 | return PTR_ERR(handle); |
| 5829 | |
| 5830 | err = ext4_mark_inode_dirty(handle, inode); |
| 5831 | ext4_handle_sync(handle); |
| 5832 | ext4_journal_stop(handle); |
| 5833 | ext4_std_error(inode->i_sb, err); |
| 5834 | |
| 5835 | return err; |
| 5836 | } |
| 5837 | |
| 5838 | static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh) |
| 5839 | { |
| 5840 | return !buffer_mapped(bh); |
| 5841 | } |
| 5842 | |
| 5843 | int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) |
| 5844 | { |
| 5845 | struct page *page = vmf->page; |
| 5846 | loff_t size; |
| 5847 | unsigned long len; |
| 5848 | int ret; |
| 5849 | struct file *file = vma->vm_file; |
| 5850 | struct inode *inode = file->f_path.dentry->d_inode; |
| 5851 | struct address_space *mapping = inode->i_mapping; |
| 5852 | handle_t *handle; |
| 5853 | get_block_t *get_block; |
| 5854 | int retries = 0; |
| 5855 | |
| 5856 | /* |
| 5857 | * This check is racy but catches the common case. We rely on |
| 5858 | * __block_page_mkwrite() to do a reliable check. |
| 5859 | */ |
| 5860 | vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE); |
| 5861 | /* Delalloc case is easy... */ |
| 5862 | if (test_opt(inode->i_sb, DELALLOC) && |
| 5863 | !ext4_should_journal_data(inode) && |
| 5864 | !ext4_nonda_switch(inode->i_sb)) { |
| 5865 | do { |
| 5866 | ret = __block_page_mkwrite(vma, vmf, |
| 5867 | ext4_da_get_block_prep); |
| 5868 | } while (ret == -ENOSPC && |
| 5869 | ext4_should_retry_alloc(inode->i_sb, &retries)); |
| 5870 | goto out_ret; |
| 5871 | } |
| 5872 | |
| 5873 | lock_page(page); |
| 5874 | size = i_size_read(inode); |
| 5875 | /* Page got truncated from under us? */ |
| 5876 | if (page->mapping != mapping || page_offset(page) > size) { |
| 5877 | unlock_page(page); |
| 5878 | ret = VM_FAULT_NOPAGE; |
| 5879 | goto out; |
| 5880 | } |
| 5881 | |
| 5882 | if (page->index == size >> PAGE_CACHE_SHIFT) |
| 5883 | len = size & ~PAGE_CACHE_MASK; |
| 5884 | else |
| 5885 | len = PAGE_CACHE_SIZE; |
| 5886 | /* |
| 5887 | * Return if we have all the buffers mapped. This avoids the need to do |
| 5888 | * journal_start/journal_stop which can block and take a long time |
| 5889 | */ |
| 5890 | if (page_has_buffers(page)) { |
| 5891 | if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL, |
| 5892 | ext4_bh_unmapped)) { |
| 5893 | /* Wait so that we don't change page under IO */ |
| 5894 | wait_on_page_writeback(page); |
| 5895 | ret = VM_FAULT_LOCKED; |
| 5896 | goto out; |
| 5897 | } |
| 5898 | } |
| 5899 | unlock_page(page); |
| 5900 | /* OK, we need to fill the hole... */ |
| 5901 | if (ext4_should_dioread_nolock(inode)) |
| 5902 | get_block = ext4_get_block_write; |
| 5903 | else |
| 5904 | get_block = ext4_get_block; |
| 5905 | retry_alloc: |
| 5906 | handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode)); |
| 5907 | if (IS_ERR(handle)) { |
| 5908 | ret = VM_FAULT_SIGBUS; |
| 5909 | goto out; |
| 5910 | } |
| 5911 | ret = __block_page_mkwrite(vma, vmf, get_block); |
| 5912 | if (!ret && ext4_should_journal_data(inode)) { |
| 5913 | if (walk_page_buffers(handle, page_buffers(page), 0, |
| 5914 | PAGE_CACHE_SIZE, NULL, do_journal_get_write_access)) { |
| 5915 | unlock_page(page); |
| 5916 | ret = VM_FAULT_SIGBUS; |
| 5917 | goto out; |
| 5918 | } |
| 5919 | ext4_set_inode_state(inode, EXT4_STATE_JDATA); |
| 5920 | } |
| 5921 | ext4_journal_stop(handle); |
| 5922 | if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) |
| 5923 | goto retry_alloc; |
| 5924 | out_ret: |
| 5925 | ret = block_page_mkwrite_return(ret); |
| 5926 | out: |
| 5927 | return ret; |
| 5928 | } |