| 1 | /* |
| 2 | * Copyright (C) 2007 Oracle. All rights reserved. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public |
| 6 | * License v2 as published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 11 | * General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public |
| 14 | * License along with this program; if not, write to the |
| 15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| 16 | * Boston, MA 021110-1307, USA. |
| 17 | */ |
| 18 | |
| 19 | #include <linux/fs.h> |
| 20 | #include <linux/pagemap.h> |
| 21 | #include <linux/highmem.h> |
| 22 | #include <linux/time.h> |
| 23 | #include <linux/init.h> |
| 24 | #include <linux/string.h> |
| 25 | #include <linux/backing-dev.h> |
| 26 | #include <linux/mpage.h> |
| 27 | #include <linux/aio.h> |
| 28 | #include <linux/falloc.h> |
| 29 | #include <linux/swap.h> |
| 30 | #include <linux/writeback.h> |
| 31 | #include <linux/statfs.h> |
| 32 | #include <linux/compat.h> |
| 33 | #include <linux/slab.h> |
| 34 | #include <linux/btrfs.h> |
| 35 | #include "ctree.h" |
| 36 | #include "disk-io.h" |
| 37 | #include "transaction.h" |
| 38 | #include "btrfs_inode.h" |
| 39 | #include "print-tree.h" |
| 40 | #include "tree-log.h" |
| 41 | #include "locking.h" |
| 42 | #include "volumes.h" |
| 43 | |
| 44 | static struct kmem_cache *btrfs_inode_defrag_cachep; |
| 45 | /* |
| 46 | * when auto defrag is enabled we |
| 47 | * queue up these defrag structs to remember which |
| 48 | * inodes need defragging passes |
| 49 | */ |
| 50 | struct inode_defrag { |
| 51 | struct rb_node rb_node; |
| 52 | /* objectid */ |
| 53 | u64 ino; |
| 54 | /* |
| 55 | * transid where the defrag was added, we search for |
| 56 | * extents newer than this |
| 57 | */ |
| 58 | u64 transid; |
| 59 | |
| 60 | /* root objectid */ |
| 61 | u64 root; |
| 62 | |
| 63 | /* last offset we were able to defrag */ |
| 64 | u64 last_offset; |
| 65 | |
| 66 | /* if we've wrapped around back to zero once already */ |
| 67 | int cycled; |
| 68 | }; |
| 69 | |
| 70 | static int __compare_inode_defrag(struct inode_defrag *defrag1, |
| 71 | struct inode_defrag *defrag2) |
| 72 | { |
| 73 | if (defrag1->root > defrag2->root) |
| 74 | return 1; |
| 75 | else if (defrag1->root < defrag2->root) |
| 76 | return -1; |
| 77 | else if (defrag1->ino > defrag2->ino) |
| 78 | return 1; |
| 79 | else if (defrag1->ino < defrag2->ino) |
| 80 | return -1; |
| 81 | else |
| 82 | return 0; |
| 83 | } |
| 84 | |
| 85 | /* pop a record for an inode into the defrag tree. The lock |
| 86 | * must be held already |
| 87 | * |
| 88 | * If you're inserting a record for an older transid than an |
| 89 | * existing record, the transid already in the tree is lowered |
| 90 | * |
| 91 | * If an existing record is found the defrag item you |
| 92 | * pass in is freed |
| 93 | */ |
| 94 | static int __btrfs_add_inode_defrag(struct inode *inode, |
| 95 | struct inode_defrag *defrag) |
| 96 | { |
| 97 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 98 | struct inode_defrag *entry; |
| 99 | struct rb_node **p; |
| 100 | struct rb_node *parent = NULL; |
| 101 | int ret; |
| 102 | |
| 103 | p = &root->fs_info->defrag_inodes.rb_node; |
| 104 | while (*p) { |
| 105 | parent = *p; |
| 106 | entry = rb_entry(parent, struct inode_defrag, rb_node); |
| 107 | |
| 108 | ret = __compare_inode_defrag(defrag, entry); |
| 109 | if (ret < 0) |
| 110 | p = &parent->rb_left; |
| 111 | else if (ret > 0) |
| 112 | p = &parent->rb_right; |
| 113 | else { |
| 114 | /* if we're reinserting an entry for |
| 115 | * an old defrag run, make sure to |
| 116 | * lower the transid of our existing record |
| 117 | */ |
| 118 | if (defrag->transid < entry->transid) |
| 119 | entry->transid = defrag->transid; |
| 120 | if (defrag->last_offset > entry->last_offset) |
| 121 | entry->last_offset = defrag->last_offset; |
| 122 | return -EEXIST; |
| 123 | } |
| 124 | } |
| 125 | set_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags); |
| 126 | rb_link_node(&defrag->rb_node, parent, p); |
| 127 | rb_insert_color(&defrag->rb_node, &root->fs_info->defrag_inodes); |
| 128 | return 0; |
| 129 | } |
| 130 | |
| 131 | static inline int __need_auto_defrag(struct btrfs_root *root) |
| 132 | { |
| 133 | if (!btrfs_test_opt(root, AUTO_DEFRAG)) |
| 134 | return 0; |
| 135 | |
| 136 | if (btrfs_fs_closing(root->fs_info)) |
| 137 | return 0; |
| 138 | |
| 139 | return 1; |
| 140 | } |
| 141 | |
| 142 | /* |
| 143 | * insert a defrag record for this inode if auto defrag is |
| 144 | * enabled |
| 145 | */ |
| 146 | int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans, |
| 147 | struct inode *inode) |
| 148 | { |
| 149 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 150 | struct inode_defrag *defrag; |
| 151 | u64 transid; |
| 152 | int ret; |
| 153 | |
| 154 | if (!__need_auto_defrag(root)) |
| 155 | return 0; |
| 156 | |
| 157 | if (test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags)) |
| 158 | return 0; |
| 159 | |
| 160 | if (trans) |
| 161 | transid = trans->transid; |
| 162 | else |
| 163 | transid = BTRFS_I(inode)->root->last_trans; |
| 164 | |
| 165 | defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS); |
| 166 | if (!defrag) |
| 167 | return -ENOMEM; |
| 168 | |
| 169 | defrag->ino = btrfs_ino(inode); |
| 170 | defrag->transid = transid; |
| 171 | defrag->root = root->root_key.objectid; |
| 172 | |
| 173 | spin_lock(&root->fs_info->defrag_inodes_lock); |
| 174 | if (!test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags)) { |
| 175 | /* |
| 176 | * If we set IN_DEFRAG flag and evict the inode from memory, |
| 177 | * and then re-read this inode, this new inode doesn't have |
| 178 | * IN_DEFRAG flag. At the case, we may find the existed defrag. |
| 179 | */ |
| 180 | ret = __btrfs_add_inode_defrag(inode, defrag); |
| 181 | if (ret) |
| 182 | kmem_cache_free(btrfs_inode_defrag_cachep, defrag); |
| 183 | } else { |
| 184 | kmem_cache_free(btrfs_inode_defrag_cachep, defrag); |
| 185 | } |
| 186 | spin_unlock(&root->fs_info->defrag_inodes_lock); |
| 187 | return 0; |
| 188 | } |
| 189 | |
| 190 | /* |
| 191 | * Requeue the defrag object. If there is a defrag object that points to |
| 192 | * the same inode in the tree, we will merge them together (by |
| 193 | * __btrfs_add_inode_defrag()) and free the one that we want to requeue. |
| 194 | */ |
| 195 | static void btrfs_requeue_inode_defrag(struct inode *inode, |
| 196 | struct inode_defrag *defrag) |
| 197 | { |
| 198 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 199 | int ret; |
| 200 | |
| 201 | if (!__need_auto_defrag(root)) |
| 202 | goto out; |
| 203 | |
| 204 | /* |
| 205 | * Here we don't check the IN_DEFRAG flag, because we need merge |
| 206 | * them together. |
| 207 | */ |
| 208 | spin_lock(&root->fs_info->defrag_inodes_lock); |
| 209 | ret = __btrfs_add_inode_defrag(inode, defrag); |
| 210 | spin_unlock(&root->fs_info->defrag_inodes_lock); |
| 211 | if (ret) |
| 212 | goto out; |
| 213 | return; |
| 214 | out: |
| 215 | kmem_cache_free(btrfs_inode_defrag_cachep, defrag); |
| 216 | } |
| 217 | |
| 218 | /* |
| 219 | * pick the defragable inode that we want, if it doesn't exist, we will get |
| 220 | * the next one. |
| 221 | */ |
| 222 | static struct inode_defrag * |
| 223 | btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino) |
| 224 | { |
| 225 | struct inode_defrag *entry = NULL; |
| 226 | struct inode_defrag tmp; |
| 227 | struct rb_node *p; |
| 228 | struct rb_node *parent = NULL; |
| 229 | int ret; |
| 230 | |
| 231 | tmp.ino = ino; |
| 232 | tmp.root = root; |
| 233 | |
| 234 | spin_lock(&fs_info->defrag_inodes_lock); |
| 235 | p = fs_info->defrag_inodes.rb_node; |
| 236 | while (p) { |
| 237 | parent = p; |
| 238 | entry = rb_entry(parent, struct inode_defrag, rb_node); |
| 239 | |
| 240 | ret = __compare_inode_defrag(&tmp, entry); |
| 241 | if (ret < 0) |
| 242 | p = parent->rb_left; |
| 243 | else if (ret > 0) |
| 244 | p = parent->rb_right; |
| 245 | else |
| 246 | goto out; |
| 247 | } |
| 248 | |
| 249 | if (parent && __compare_inode_defrag(&tmp, entry) > 0) { |
| 250 | parent = rb_next(parent); |
| 251 | if (parent) |
| 252 | entry = rb_entry(parent, struct inode_defrag, rb_node); |
| 253 | else |
| 254 | entry = NULL; |
| 255 | } |
| 256 | out: |
| 257 | if (entry) |
| 258 | rb_erase(parent, &fs_info->defrag_inodes); |
| 259 | spin_unlock(&fs_info->defrag_inodes_lock); |
| 260 | return entry; |
| 261 | } |
| 262 | |
| 263 | void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info) |
| 264 | { |
| 265 | struct inode_defrag *defrag; |
| 266 | struct rb_node *node; |
| 267 | |
| 268 | spin_lock(&fs_info->defrag_inodes_lock); |
| 269 | node = rb_first(&fs_info->defrag_inodes); |
| 270 | while (node) { |
| 271 | rb_erase(node, &fs_info->defrag_inodes); |
| 272 | defrag = rb_entry(node, struct inode_defrag, rb_node); |
| 273 | kmem_cache_free(btrfs_inode_defrag_cachep, defrag); |
| 274 | |
| 275 | if (need_resched()) { |
| 276 | spin_unlock(&fs_info->defrag_inodes_lock); |
| 277 | cond_resched(); |
| 278 | spin_lock(&fs_info->defrag_inodes_lock); |
| 279 | } |
| 280 | |
| 281 | node = rb_first(&fs_info->defrag_inodes); |
| 282 | } |
| 283 | spin_unlock(&fs_info->defrag_inodes_lock); |
| 284 | } |
| 285 | |
| 286 | #define BTRFS_DEFRAG_BATCH 1024 |
| 287 | |
| 288 | static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info, |
| 289 | struct inode_defrag *defrag) |
| 290 | { |
| 291 | struct btrfs_root *inode_root; |
| 292 | struct inode *inode; |
| 293 | struct btrfs_key key; |
| 294 | struct btrfs_ioctl_defrag_range_args range; |
| 295 | int num_defrag; |
| 296 | int index; |
| 297 | int ret; |
| 298 | |
| 299 | /* get the inode */ |
| 300 | key.objectid = defrag->root; |
| 301 | btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); |
| 302 | key.offset = (u64)-1; |
| 303 | |
| 304 | index = srcu_read_lock(&fs_info->subvol_srcu); |
| 305 | |
| 306 | inode_root = btrfs_read_fs_root_no_name(fs_info, &key); |
| 307 | if (IS_ERR(inode_root)) { |
| 308 | ret = PTR_ERR(inode_root); |
| 309 | goto cleanup; |
| 310 | } |
| 311 | |
| 312 | key.objectid = defrag->ino; |
| 313 | btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY); |
| 314 | key.offset = 0; |
| 315 | inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL); |
| 316 | if (IS_ERR(inode)) { |
| 317 | ret = PTR_ERR(inode); |
| 318 | goto cleanup; |
| 319 | } |
| 320 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
| 321 | |
| 322 | /* do a chunk of defrag */ |
| 323 | clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags); |
| 324 | memset(&range, 0, sizeof(range)); |
| 325 | range.len = (u64)-1; |
| 326 | range.start = defrag->last_offset; |
| 327 | |
| 328 | sb_start_write(fs_info->sb); |
| 329 | num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid, |
| 330 | BTRFS_DEFRAG_BATCH); |
| 331 | sb_end_write(fs_info->sb); |
| 332 | /* |
| 333 | * if we filled the whole defrag batch, there |
| 334 | * must be more work to do. Queue this defrag |
| 335 | * again |
| 336 | */ |
| 337 | if (num_defrag == BTRFS_DEFRAG_BATCH) { |
| 338 | defrag->last_offset = range.start; |
| 339 | btrfs_requeue_inode_defrag(inode, defrag); |
| 340 | } else if (defrag->last_offset && !defrag->cycled) { |
| 341 | /* |
| 342 | * we didn't fill our defrag batch, but |
| 343 | * we didn't start at zero. Make sure we loop |
| 344 | * around to the start of the file. |
| 345 | */ |
| 346 | defrag->last_offset = 0; |
| 347 | defrag->cycled = 1; |
| 348 | btrfs_requeue_inode_defrag(inode, defrag); |
| 349 | } else { |
| 350 | kmem_cache_free(btrfs_inode_defrag_cachep, defrag); |
| 351 | } |
| 352 | |
| 353 | iput(inode); |
| 354 | return 0; |
| 355 | cleanup: |
| 356 | srcu_read_unlock(&fs_info->subvol_srcu, index); |
| 357 | kmem_cache_free(btrfs_inode_defrag_cachep, defrag); |
| 358 | return ret; |
| 359 | } |
| 360 | |
| 361 | /* |
| 362 | * run through the list of inodes in the FS that need |
| 363 | * defragging |
| 364 | */ |
| 365 | int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info) |
| 366 | { |
| 367 | struct inode_defrag *defrag; |
| 368 | u64 first_ino = 0; |
| 369 | u64 root_objectid = 0; |
| 370 | |
| 371 | atomic_inc(&fs_info->defrag_running); |
| 372 | while (1) { |
| 373 | /* Pause the auto defragger. */ |
| 374 | if (test_bit(BTRFS_FS_STATE_REMOUNTING, |
| 375 | &fs_info->fs_state)) |
| 376 | break; |
| 377 | |
| 378 | if (!__need_auto_defrag(fs_info->tree_root)) |
| 379 | break; |
| 380 | |
| 381 | /* find an inode to defrag */ |
| 382 | defrag = btrfs_pick_defrag_inode(fs_info, root_objectid, |
| 383 | first_ino); |
| 384 | if (!defrag) { |
| 385 | if (root_objectid || first_ino) { |
| 386 | root_objectid = 0; |
| 387 | first_ino = 0; |
| 388 | continue; |
| 389 | } else { |
| 390 | break; |
| 391 | } |
| 392 | } |
| 393 | |
| 394 | first_ino = defrag->ino + 1; |
| 395 | root_objectid = defrag->root; |
| 396 | |
| 397 | __btrfs_run_defrag_inode(fs_info, defrag); |
| 398 | } |
| 399 | atomic_dec(&fs_info->defrag_running); |
| 400 | |
| 401 | /* |
| 402 | * during unmount, we use the transaction_wait queue to |
| 403 | * wait for the defragger to stop |
| 404 | */ |
| 405 | wake_up(&fs_info->transaction_wait); |
| 406 | return 0; |
| 407 | } |
| 408 | |
| 409 | /* simple helper to fault in pages and copy. This should go away |
| 410 | * and be replaced with calls into generic code. |
| 411 | */ |
| 412 | static noinline int btrfs_copy_from_user(loff_t pos, int num_pages, |
| 413 | size_t write_bytes, |
| 414 | struct page **prepared_pages, |
| 415 | struct iov_iter *i) |
| 416 | { |
| 417 | size_t copied = 0; |
| 418 | size_t total_copied = 0; |
| 419 | int pg = 0; |
| 420 | int offset = pos & (PAGE_CACHE_SIZE - 1); |
| 421 | |
| 422 | while (write_bytes > 0) { |
| 423 | size_t count = min_t(size_t, |
| 424 | PAGE_CACHE_SIZE - offset, write_bytes); |
| 425 | struct page *page = prepared_pages[pg]; |
| 426 | /* |
| 427 | * Copy data from userspace to the current page |
| 428 | */ |
| 429 | copied = iov_iter_copy_from_user_atomic(page, i, offset, count); |
| 430 | |
| 431 | /* Flush processor's dcache for this page */ |
| 432 | flush_dcache_page(page); |
| 433 | |
| 434 | /* |
| 435 | * if we get a partial write, we can end up with |
| 436 | * partially up to date pages. These add |
| 437 | * a lot of complexity, so make sure they don't |
| 438 | * happen by forcing this copy to be retried. |
| 439 | * |
| 440 | * The rest of the btrfs_file_write code will fall |
| 441 | * back to page at a time copies after we return 0. |
| 442 | */ |
| 443 | if (!PageUptodate(page) && copied < count) |
| 444 | copied = 0; |
| 445 | |
| 446 | iov_iter_advance(i, copied); |
| 447 | write_bytes -= copied; |
| 448 | total_copied += copied; |
| 449 | |
| 450 | /* Return to btrfs_file_aio_write to fault page */ |
| 451 | if (unlikely(copied == 0)) |
| 452 | break; |
| 453 | |
| 454 | if (unlikely(copied < PAGE_CACHE_SIZE - offset)) { |
| 455 | offset += copied; |
| 456 | } else { |
| 457 | pg++; |
| 458 | offset = 0; |
| 459 | } |
| 460 | } |
| 461 | return total_copied; |
| 462 | } |
| 463 | |
| 464 | /* |
| 465 | * unlocks pages after btrfs_file_write is done with them |
| 466 | */ |
| 467 | static void btrfs_drop_pages(struct page **pages, size_t num_pages) |
| 468 | { |
| 469 | size_t i; |
| 470 | for (i = 0; i < num_pages; i++) { |
| 471 | /* page checked is some magic around finding pages that |
| 472 | * have been modified without going through btrfs_set_page_dirty |
| 473 | * clear it here |
| 474 | */ |
| 475 | ClearPageChecked(pages[i]); |
| 476 | unlock_page(pages[i]); |
| 477 | mark_page_accessed(pages[i]); |
| 478 | page_cache_release(pages[i]); |
| 479 | } |
| 480 | } |
| 481 | |
| 482 | /* |
| 483 | * after copy_from_user, pages need to be dirtied and we need to make |
| 484 | * sure holes are created between the current EOF and the start of |
| 485 | * any next extents (if required). |
| 486 | * |
| 487 | * this also makes the decision about creating an inline extent vs |
| 488 | * doing real data extents, marking pages dirty and delalloc as required. |
| 489 | */ |
| 490 | int btrfs_dirty_pages(struct btrfs_root *root, struct inode *inode, |
| 491 | struct page **pages, size_t num_pages, |
| 492 | loff_t pos, size_t write_bytes, |
| 493 | struct extent_state **cached) |
| 494 | { |
| 495 | int err = 0; |
| 496 | int i; |
| 497 | u64 num_bytes; |
| 498 | u64 start_pos; |
| 499 | u64 end_of_last_block; |
| 500 | u64 end_pos = pos + write_bytes; |
| 501 | loff_t isize = i_size_read(inode); |
| 502 | |
| 503 | start_pos = pos & ~((u64)root->sectorsize - 1); |
| 504 | num_bytes = ALIGN(write_bytes + pos - start_pos, root->sectorsize); |
| 505 | |
| 506 | end_of_last_block = start_pos + num_bytes - 1; |
| 507 | err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block, |
| 508 | cached); |
| 509 | if (err) |
| 510 | return err; |
| 511 | |
| 512 | for (i = 0; i < num_pages; i++) { |
| 513 | struct page *p = pages[i]; |
| 514 | SetPageUptodate(p); |
| 515 | ClearPageChecked(p); |
| 516 | set_page_dirty(p); |
| 517 | } |
| 518 | |
| 519 | /* |
| 520 | * we've only changed i_size in ram, and we haven't updated |
| 521 | * the disk i_size. There is no need to log the inode |
| 522 | * at this time. |
| 523 | */ |
| 524 | if (end_pos > isize) |
| 525 | i_size_write(inode, end_pos); |
| 526 | return 0; |
| 527 | } |
| 528 | |
| 529 | /* |
| 530 | * this drops all the extents in the cache that intersect the range |
| 531 | * [start, end]. Existing extents are split as required. |
| 532 | */ |
| 533 | void btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end, |
| 534 | int skip_pinned) |
| 535 | { |
| 536 | struct extent_map *em; |
| 537 | struct extent_map *split = NULL; |
| 538 | struct extent_map *split2 = NULL; |
| 539 | struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; |
| 540 | u64 len = end - start + 1; |
| 541 | u64 gen; |
| 542 | int ret; |
| 543 | int testend = 1; |
| 544 | unsigned long flags; |
| 545 | int compressed = 0; |
| 546 | bool modified; |
| 547 | |
| 548 | WARN_ON(end < start); |
| 549 | if (end == (u64)-1) { |
| 550 | len = (u64)-1; |
| 551 | testend = 0; |
| 552 | } |
| 553 | while (1) { |
| 554 | int no_splits = 0; |
| 555 | |
| 556 | modified = false; |
| 557 | if (!split) |
| 558 | split = alloc_extent_map(); |
| 559 | if (!split2) |
| 560 | split2 = alloc_extent_map(); |
| 561 | if (!split || !split2) |
| 562 | no_splits = 1; |
| 563 | |
| 564 | write_lock(&em_tree->lock); |
| 565 | em = lookup_extent_mapping(em_tree, start, len); |
| 566 | if (!em) { |
| 567 | write_unlock(&em_tree->lock); |
| 568 | break; |
| 569 | } |
| 570 | flags = em->flags; |
| 571 | gen = em->generation; |
| 572 | if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) { |
| 573 | if (testend && em->start + em->len >= start + len) { |
| 574 | free_extent_map(em); |
| 575 | write_unlock(&em_tree->lock); |
| 576 | break; |
| 577 | } |
| 578 | start = em->start + em->len; |
| 579 | if (testend) |
| 580 | len = start + len - (em->start + em->len); |
| 581 | free_extent_map(em); |
| 582 | write_unlock(&em_tree->lock); |
| 583 | continue; |
| 584 | } |
| 585 | compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags); |
| 586 | clear_bit(EXTENT_FLAG_PINNED, &em->flags); |
| 587 | clear_bit(EXTENT_FLAG_LOGGING, &flags); |
| 588 | modified = !list_empty(&em->list); |
| 589 | if (no_splits) |
| 590 | goto next; |
| 591 | |
| 592 | if (em->start < start) { |
| 593 | split->start = em->start; |
| 594 | split->len = start - em->start; |
| 595 | |
| 596 | if (em->block_start < EXTENT_MAP_LAST_BYTE) { |
| 597 | split->orig_start = em->orig_start; |
| 598 | split->block_start = em->block_start; |
| 599 | |
| 600 | if (compressed) |
| 601 | split->block_len = em->block_len; |
| 602 | else |
| 603 | split->block_len = split->len; |
| 604 | split->orig_block_len = max(split->block_len, |
| 605 | em->orig_block_len); |
| 606 | split->ram_bytes = em->ram_bytes; |
| 607 | } else { |
| 608 | split->orig_start = split->start; |
| 609 | split->block_len = 0; |
| 610 | split->block_start = em->block_start; |
| 611 | split->orig_block_len = 0; |
| 612 | split->ram_bytes = split->len; |
| 613 | } |
| 614 | |
| 615 | split->generation = gen; |
| 616 | split->bdev = em->bdev; |
| 617 | split->flags = flags; |
| 618 | split->compress_type = em->compress_type; |
| 619 | replace_extent_mapping(em_tree, em, split, modified); |
| 620 | free_extent_map(split); |
| 621 | split = split2; |
| 622 | split2 = NULL; |
| 623 | } |
| 624 | if (testend && em->start + em->len > start + len) { |
| 625 | u64 diff = start + len - em->start; |
| 626 | |
| 627 | split->start = start + len; |
| 628 | split->len = em->start + em->len - (start + len); |
| 629 | split->bdev = em->bdev; |
| 630 | split->flags = flags; |
| 631 | split->compress_type = em->compress_type; |
| 632 | split->generation = gen; |
| 633 | |
| 634 | if (em->block_start < EXTENT_MAP_LAST_BYTE) { |
| 635 | split->orig_block_len = max(em->block_len, |
| 636 | em->orig_block_len); |
| 637 | |
| 638 | split->ram_bytes = em->ram_bytes; |
| 639 | if (compressed) { |
| 640 | split->block_len = em->block_len; |
| 641 | split->block_start = em->block_start; |
| 642 | split->orig_start = em->orig_start; |
| 643 | } else { |
| 644 | split->block_len = split->len; |
| 645 | split->block_start = em->block_start |
| 646 | + diff; |
| 647 | split->orig_start = em->orig_start; |
| 648 | } |
| 649 | } else { |
| 650 | split->ram_bytes = split->len; |
| 651 | split->orig_start = split->start; |
| 652 | split->block_len = 0; |
| 653 | split->block_start = em->block_start; |
| 654 | split->orig_block_len = 0; |
| 655 | } |
| 656 | |
| 657 | if (extent_map_in_tree(em)) { |
| 658 | replace_extent_mapping(em_tree, em, split, |
| 659 | modified); |
| 660 | } else { |
| 661 | ret = add_extent_mapping(em_tree, split, |
| 662 | modified); |
| 663 | ASSERT(ret == 0); /* Logic error */ |
| 664 | } |
| 665 | free_extent_map(split); |
| 666 | split = NULL; |
| 667 | } |
| 668 | next: |
| 669 | if (extent_map_in_tree(em)) |
| 670 | remove_extent_mapping(em_tree, em); |
| 671 | write_unlock(&em_tree->lock); |
| 672 | |
| 673 | /* once for us */ |
| 674 | free_extent_map(em); |
| 675 | /* once for the tree*/ |
| 676 | free_extent_map(em); |
| 677 | } |
| 678 | if (split) |
| 679 | free_extent_map(split); |
| 680 | if (split2) |
| 681 | free_extent_map(split2); |
| 682 | } |
| 683 | |
| 684 | /* |
| 685 | * this is very complex, but the basic idea is to drop all extents |
| 686 | * in the range start - end. hint_block is filled in with a block number |
| 687 | * that would be a good hint to the block allocator for this file. |
| 688 | * |
| 689 | * If an extent intersects the range but is not entirely inside the range |
| 690 | * it is either truncated or split. Anything entirely inside the range |
| 691 | * is deleted from the tree. |
| 692 | */ |
| 693 | int __btrfs_drop_extents(struct btrfs_trans_handle *trans, |
| 694 | struct btrfs_root *root, struct inode *inode, |
| 695 | struct btrfs_path *path, u64 start, u64 end, |
| 696 | u64 *drop_end, int drop_cache, |
| 697 | int replace_extent, |
| 698 | u32 extent_item_size, |
| 699 | int *key_inserted) |
| 700 | { |
| 701 | struct extent_buffer *leaf; |
| 702 | struct btrfs_file_extent_item *fi; |
| 703 | struct btrfs_key key; |
| 704 | struct btrfs_key new_key; |
| 705 | u64 ino = btrfs_ino(inode); |
| 706 | u64 search_start = start; |
| 707 | u64 disk_bytenr = 0; |
| 708 | u64 num_bytes = 0; |
| 709 | u64 extent_offset = 0; |
| 710 | u64 extent_end = 0; |
| 711 | int del_nr = 0; |
| 712 | int del_slot = 0; |
| 713 | int extent_type; |
| 714 | int recow; |
| 715 | int ret; |
| 716 | int modify_tree = -1; |
| 717 | int update_refs = (root->ref_cows || root == root->fs_info->tree_root); |
| 718 | int found = 0; |
| 719 | int leafs_visited = 0; |
| 720 | |
| 721 | if (drop_cache) |
| 722 | btrfs_drop_extent_cache(inode, start, end - 1, 0); |
| 723 | |
| 724 | if (start >= BTRFS_I(inode)->disk_i_size && !replace_extent) |
| 725 | modify_tree = 0; |
| 726 | |
| 727 | while (1) { |
| 728 | recow = 0; |
| 729 | ret = btrfs_lookup_file_extent(trans, root, path, ino, |
| 730 | search_start, modify_tree); |
| 731 | if (ret < 0) |
| 732 | break; |
| 733 | if (ret > 0 && path->slots[0] > 0 && search_start == start) { |
| 734 | leaf = path->nodes[0]; |
| 735 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1); |
| 736 | if (key.objectid == ino && |
| 737 | key.type == BTRFS_EXTENT_DATA_KEY) |
| 738 | path->slots[0]--; |
| 739 | } |
| 740 | ret = 0; |
| 741 | leafs_visited++; |
| 742 | next_slot: |
| 743 | leaf = path->nodes[0]; |
| 744 | if (path->slots[0] >= btrfs_header_nritems(leaf)) { |
| 745 | BUG_ON(del_nr > 0); |
| 746 | ret = btrfs_next_leaf(root, path); |
| 747 | if (ret < 0) |
| 748 | break; |
| 749 | if (ret > 0) { |
| 750 | ret = 0; |
| 751 | break; |
| 752 | } |
| 753 | leafs_visited++; |
| 754 | leaf = path->nodes[0]; |
| 755 | recow = 1; |
| 756 | } |
| 757 | |
| 758 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| 759 | if (key.objectid > ino || |
| 760 | key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end) |
| 761 | break; |
| 762 | |
| 763 | fi = btrfs_item_ptr(leaf, path->slots[0], |
| 764 | struct btrfs_file_extent_item); |
| 765 | extent_type = btrfs_file_extent_type(leaf, fi); |
| 766 | |
| 767 | if (extent_type == BTRFS_FILE_EXTENT_REG || |
| 768 | extent_type == BTRFS_FILE_EXTENT_PREALLOC) { |
| 769 | disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); |
| 770 | num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); |
| 771 | extent_offset = btrfs_file_extent_offset(leaf, fi); |
| 772 | extent_end = key.offset + |
| 773 | btrfs_file_extent_num_bytes(leaf, fi); |
| 774 | } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| 775 | extent_end = key.offset + |
| 776 | btrfs_file_extent_inline_len(leaf, |
| 777 | path->slots[0], fi); |
| 778 | } else { |
| 779 | WARN_ON(1); |
| 780 | extent_end = search_start; |
| 781 | } |
| 782 | |
| 783 | if (extent_end <= search_start) { |
| 784 | path->slots[0]++; |
| 785 | goto next_slot; |
| 786 | } |
| 787 | |
| 788 | found = 1; |
| 789 | search_start = max(key.offset, start); |
| 790 | if (recow || !modify_tree) { |
| 791 | modify_tree = -1; |
| 792 | btrfs_release_path(path); |
| 793 | continue; |
| 794 | } |
| 795 | |
| 796 | /* |
| 797 | * | - range to drop - | |
| 798 | * | -------- extent -------- | |
| 799 | */ |
| 800 | if (start > key.offset && end < extent_end) { |
| 801 | BUG_ON(del_nr > 0); |
| 802 | if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| 803 | ret = -EOPNOTSUPP; |
| 804 | break; |
| 805 | } |
| 806 | |
| 807 | memcpy(&new_key, &key, sizeof(new_key)); |
| 808 | new_key.offset = start; |
| 809 | ret = btrfs_duplicate_item(trans, root, path, |
| 810 | &new_key); |
| 811 | if (ret == -EAGAIN) { |
| 812 | btrfs_release_path(path); |
| 813 | continue; |
| 814 | } |
| 815 | if (ret < 0) |
| 816 | break; |
| 817 | |
| 818 | leaf = path->nodes[0]; |
| 819 | fi = btrfs_item_ptr(leaf, path->slots[0] - 1, |
| 820 | struct btrfs_file_extent_item); |
| 821 | btrfs_set_file_extent_num_bytes(leaf, fi, |
| 822 | start - key.offset); |
| 823 | |
| 824 | fi = btrfs_item_ptr(leaf, path->slots[0], |
| 825 | struct btrfs_file_extent_item); |
| 826 | |
| 827 | extent_offset += start - key.offset; |
| 828 | btrfs_set_file_extent_offset(leaf, fi, extent_offset); |
| 829 | btrfs_set_file_extent_num_bytes(leaf, fi, |
| 830 | extent_end - start); |
| 831 | btrfs_mark_buffer_dirty(leaf); |
| 832 | |
| 833 | if (update_refs && disk_bytenr > 0) { |
| 834 | ret = btrfs_inc_extent_ref(trans, root, |
| 835 | disk_bytenr, num_bytes, 0, |
| 836 | root->root_key.objectid, |
| 837 | new_key.objectid, |
| 838 | start - extent_offset, 0); |
| 839 | BUG_ON(ret); /* -ENOMEM */ |
| 840 | } |
| 841 | key.offset = start; |
| 842 | } |
| 843 | /* |
| 844 | * | ---- range to drop ----- | |
| 845 | * | -------- extent -------- | |
| 846 | */ |
| 847 | if (start <= key.offset && end < extent_end) { |
| 848 | if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| 849 | ret = -EOPNOTSUPP; |
| 850 | break; |
| 851 | } |
| 852 | |
| 853 | memcpy(&new_key, &key, sizeof(new_key)); |
| 854 | new_key.offset = end; |
| 855 | btrfs_set_item_key_safe(root, path, &new_key); |
| 856 | |
| 857 | extent_offset += end - key.offset; |
| 858 | btrfs_set_file_extent_offset(leaf, fi, extent_offset); |
| 859 | btrfs_set_file_extent_num_bytes(leaf, fi, |
| 860 | extent_end - end); |
| 861 | btrfs_mark_buffer_dirty(leaf); |
| 862 | if (update_refs && disk_bytenr > 0) |
| 863 | inode_sub_bytes(inode, end - key.offset); |
| 864 | break; |
| 865 | } |
| 866 | |
| 867 | search_start = extent_end; |
| 868 | /* |
| 869 | * | ---- range to drop ----- | |
| 870 | * | -------- extent -------- | |
| 871 | */ |
| 872 | if (start > key.offset && end >= extent_end) { |
| 873 | BUG_ON(del_nr > 0); |
| 874 | if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| 875 | ret = -EOPNOTSUPP; |
| 876 | break; |
| 877 | } |
| 878 | |
| 879 | btrfs_set_file_extent_num_bytes(leaf, fi, |
| 880 | start - key.offset); |
| 881 | btrfs_mark_buffer_dirty(leaf); |
| 882 | if (update_refs && disk_bytenr > 0) |
| 883 | inode_sub_bytes(inode, extent_end - start); |
| 884 | if (end == extent_end) |
| 885 | break; |
| 886 | |
| 887 | path->slots[0]++; |
| 888 | goto next_slot; |
| 889 | } |
| 890 | |
| 891 | /* |
| 892 | * | ---- range to drop ----- | |
| 893 | * | ------ extent ------ | |
| 894 | */ |
| 895 | if (start <= key.offset && end >= extent_end) { |
| 896 | if (del_nr == 0) { |
| 897 | del_slot = path->slots[0]; |
| 898 | del_nr = 1; |
| 899 | } else { |
| 900 | BUG_ON(del_slot + del_nr != path->slots[0]); |
| 901 | del_nr++; |
| 902 | } |
| 903 | |
| 904 | if (update_refs && |
| 905 | extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| 906 | inode_sub_bytes(inode, |
| 907 | extent_end - key.offset); |
| 908 | extent_end = ALIGN(extent_end, |
| 909 | root->sectorsize); |
| 910 | } else if (update_refs && disk_bytenr > 0) { |
| 911 | ret = btrfs_free_extent(trans, root, |
| 912 | disk_bytenr, num_bytes, 0, |
| 913 | root->root_key.objectid, |
| 914 | key.objectid, key.offset - |
| 915 | extent_offset, 0); |
| 916 | BUG_ON(ret); /* -ENOMEM */ |
| 917 | inode_sub_bytes(inode, |
| 918 | extent_end - key.offset); |
| 919 | } |
| 920 | |
| 921 | if (end == extent_end) |
| 922 | break; |
| 923 | |
| 924 | if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) { |
| 925 | path->slots[0]++; |
| 926 | goto next_slot; |
| 927 | } |
| 928 | |
| 929 | ret = btrfs_del_items(trans, root, path, del_slot, |
| 930 | del_nr); |
| 931 | if (ret) { |
| 932 | btrfs_abort_transaction(trans, root, ret); |
| 933 | break; |
| 934 | } |
| 935 | |
| 936 | del_nr = 0; |
| 937 | del_slot = 0; |
| 938 | |
| 939 | btrfs_release_path(path); |
| 940 | continue; |
| 941 | } |
| 942 | |
| 943 | BUG_ON(1); |
| 944 | } |
| 945 | |
| 946 | if (!ret && del_nr > 0) { |
| 947 | /* |
| 948 | * Set path->slots[0] to first slot, so that after the delete |
| 949 | * if items are move off from our leaf to its immediate left or |
| 950 | * right neighbor leafs, we end up with a correct and adjusted |
| 951 | * path->slots[0] for our insertion (if replace_extent != 0). |
| 952 | */ |
| 953 | path->slots[0] = del_slot; |
| 954 | ret = btrfs_del_items(trans, root, path, del_slot, del_nr); |
| 955 | if (ret) |
| 956 | btrfs_abort_transaction(trans, root, ret); |
| 957 | } |
| 958 | |
| 959 | leaf = path->nodes[0]; |
| 960 | /* |
| 961 | * If btrfs_del_items() was called, it might have deleted a leaf, in |
| 962 | * which case it unlocked our path, so check path->locks[0] matches a |
| 963 | * write lock. |
| 964 | */ |
| 965 | if (!ret && replace_extent && leafs_visited == 1 && |
| 966 | (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING || |
| 967 | path->locks[0] == BTRFS_WRITE_LOCK) && |
| 968 | btrfs_leaf_free_space(root, leaf) >= |
| 969 | sizeof(struct btrfs_item) + extent_item_size) { |
| 970 | |
| 971 | key.objectid = ino; |
| 972 | key.type = BTRFS_EXTENT_DATA_KEY; |
| 973 | key.offset = start; |
| 974 | if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) { |
| 975 | struct btrfs_key slot_key; |
| 976 | |
| 977 | btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]); |
| 978 | if (btrfs_comp_cpu_keys(&key, &slot_key) > 0) |
| 979 | path->slots[0]++; |
| 980 | } |
| 981 | setup_items_for_insert(root, path, &key, |
| 982 | &extent_item_size, |
| 983 | extent_item_size, |
| 984 | sizeof(struct btrfs_item) + |
| 985 | extent_item_size, 1); |
| 986 | *key_inserted = 1; |
| 987 | } |
| 988 | |
| 989 | if (!replace_extent || !(*key_inserted)) |
| 990 | btrfs_release_path(path); |
| 991 | if (drop_end) |
| 992 | *drop_end = found ? min(end, extent_end) : end; |
| 993 | return ret; |
| 994 | } |
| 995 | |
| 996 | int btrfs_drop_extents(struct btrfs_trans_handle *trans, |
| 997 | struct btrfs_root *root, struct inode *inode, u64 start, |
| 998 | u64 end, int drop_cache) |
| 999 | { |
| 1000 | struct btrfs_path *path; |
| 1001 | int ret; |
| 1002 | |
| 1003 | path = btrfs_alloc_path(); |
| 1004 | if (!path) |
| 1005 | return -ENOMEM; |
| 1006 | ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL, |
| 1007 | drop_cache, 0, 0, NULL); |
| 1008 | btrfs_free_path(path); |
| 1009 | return ret; |
| 1010 | } |
| 1011 | |
| 1012 | static int extent_mergeable(struct extent_buffer *leaf, int slot, |
| 1013 | u64 objectid, u64 bytenr, u64 orig_offset, |
| 1014 | u64 *start, u64 *end) |
| 1015 | { |
| 1016 | struct btrfs_file_extent_item *fi; |
| 1017 | struct btrfs_key key; |
| 1018 | u64 extent_end; |
| 1019 | |
| 1020 | if (slot < 0 || slot >= btrfs_header_nritems(leaf)) |
| 1021 | return 0; |
| 1022 | |
| 1023 | btrfs_item_key_to_cpu(leaf, &key, slot); |
| 1024 | if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY) |
| 1025 | return 0; |
| 1026 | |
| 1027 | fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); |
| 1028 | if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG || |
| 1029 | btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr || |
| 1030 | btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset || |
| 1031 | btrfs_file_extent_compression(leaf, fi) || |
| 1032 | btrfs_file_extent_encryption(leaf, fi) || |
| 1033 | btrfs_file_extent_other_encoding(leaf, fi)) |
| 1034 | return 0; |
| 1035 | |
| 1036 | extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); |
| 1037 | if ((*start && *start != key.offset) || (*end && *end != extent_end)) |
| 1038 | return 0; |
| 1039 | |
| 1040 | *start = key.offset; |
| 1041 | *end = extent_end; |
| 1042 | return 1; |
| 1043 | } |
| 1044 | |
| 1045 | /* |
| 1046 | * Mark extent in the range start - end as written. |
| 1047 | * |
| 1048 | * This changes extent type from 'pre-allocated' to 'regular'. If only |
| 1049 | * part of extent is marked as written, the extent will be split into |
| 1050 | * two or three. |
| 1051 | */ |
| 1052 | int btrfs_mark_extent_written(struct btrfs_trans_handle *trans, |
| 1053 | struct inode *inode, u64 start, u64 end) |
| 1054 | { |
| 1055 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 1056 | struct extent_buffer *leaf; |
| 1057 | struct btrfs_path *path; |
| 1058 | struct btrfs_file_extent_item *fi; |
| 1059 | struct btrfs_key key; |
| 1060 | struct btrfs_key new_key; |
| 1061 | u64 bytenr; |
| 1062 | u64 num_bytes; |
| 1063 | u64 extent_end; |
| 1064 | u64 orig_offset; |
| 1065 | u64 other_start; |
| 1066 | u64 other_end; |
| 1067 | u64 split; |
| 1068 | int del_nr = 0; |
| 1069 | int del_slot = 0; |
| 1070 | int recow; |
| 1071 | int ret; |
| 1072 | u64 ino = btrfs_ino(inode); |
| 1073 | |
| 1074 | path = btrfs_alloc_path(); |
| 1075 | if (!path) |
| 1076 | return -ENOMEM; |
| 1077 | again: |
| 1078 | recow = 0; |
| 1079 | split = start; |
| 1080 | key.objectid = ino; |
| 1081 | key.type = BTRFS_EXTENT_DATA_KEY; |
| 1082 | key.offset = split; |
| 1083 | |
| 1084 | ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| 1085 | if (ret < 0) |
| 1086 | goto out; |
| 1087 | if (ret > 0 && path->slots[0] > 0) |
| 1088 | path->slots[0]--; |
| 1089 | |
| 1090 | leaf = path->nodes[0]; |
| 1091 | btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| 1092 | BUG_ON(key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY); |
| 1093 | fi = btrfs_item_ptr(leaf, path->slots[0], |
| 1094 | struct btrfs_file_extent_item); |
| 1095 | BUG_ON(btrfs_file_extent_type(leaf, fi) != |
| 1096 | BTRFS_FILE_EXTENT_PREALLOC); |
| 1097 | extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); |
| 1098 | BUG_ON(key.offset > start || extent_end < end); |
| 1099 | |
| 1100 | bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); |
| 1101 | num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); |
| 1102 | orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi); |
| 1103 | memcpy(&new_key, &key, sizeof(new_key)); |
| 1104 | |
| 1105 | if (start == key.offset && end < extent_end) { |
| 1106 | other_start = 0; |
| 1107 | other_end = start; |
| 1108 | if (extent_mergeable(leaf, path->slots[0] - 1, |
| 1109 | ino, bytenr, orig_offset, |
| 1110 | &other_start, &other_end)) { |
| 1111 | new_key.offset = end; |
| 1112 | btrfs_set_item_key_safe(root, path, &new_key); |
| 1113 | fi = btrfs_item_ptr(leaf, path->slots[0], |
| 1114 | struct btrfs_file_extent_item); |
| 1115 | btrfs_set_file_extent_generation(leaf, fi, |
| 1116 | trans->transid); |
| 1117 | btrfs_set_file_extent_num_bytes(leaf, fi, |
| 1118 | extent_end - end); |
| 1119 | btrfs_set_file_extent_offset(leaf, fi, |
| 1120 | end - orig_offset); |
| 1121 | fi = btrfs_item_ptr(leaf, path->slots[0] - 1, |
| 1122 | struct btrfs_file_extent_item); |
| 1123 | btrfs_set_file_extent_generation(leaf, fi, |
| 1124 | trans->transid); |
| 1125 | btrfs_set_file_extent_num_bytes(leaf, fi, |
| 1126 | end - other_start); |
| 1127 | btrfs_mark_buffer_dirty(leaf); |
| 1128 | goto out; |
| 1129 | } |
| 1130 | } |
| 1131 | |
| 1132 | if (start > key.offset && end == extent_end) { |
| 1133 | other_start = end; |
| 1134 | other_end = 0; |
| 1135 | if (extent_mergeable(leaf, path->slots[0] + 1, |
| 1136 | ino, bytenr, orig_offset, |
| 1137 | &other_start, &other_end)) { |
| 1138 | fi = btrfs_item_ptr(leaf, path->slots[0], |
| 1139 | struct btrfs_file_extent_item); |
| 1140 | btrfs_set_file_extent_num_bytes(leaf, fi, |
| 1141 | start - key.offset); |
| 1142 | btrfs_set_file_extent_generation(leaf, fi, |
| 1143 | trans->transid); |
| 1144 | path->slots[0]++; |
| 1145 | new_key.offset = start; |
| 1146 | btrfs_set_item_key_safe(root, path, &new_key); |
| 1147 | |
| 1148 | fi = btrfs_item_ptr(leaf, path->slots[0], |
| 1149 | struct btrfs_file_extent_item); |
| 1150 | btrfs_set_file_extent_generation(leaf, fi, |
| 1151 | trans->transid); |
| 1152 | btrfs_set_file_extent_num_bytes(leaf, fi, |
| 1153 | other_end - start); |
| 1154 | btrfs_set_file_extent_offset(leaf, fi, |
| 1155 | start - orig_offset); |
| 1156 | btrfs_mark_buffer_dirty(leaf); |
| 1157 | goto out; |
| 1158 | } |
| 1159 | } |
| 1160 | |
| 1161 | while (start > key.offset || end < extent_end) { |
| 1162 | if (key.offset == start) |
| 1163 | split = end; |
| 1164 | |
| 1165 | new_key.offset = split; |
| 1166 | ret = btrfs_duplicate_item(trans, root, path, &new_key); |
| 1167 | if (ret == -EAGAIN) { |
| 1168 | btrfs_release_path(path); |
| 1169 | goto again; |
| 1170 | } |
| 1171 | if (ret < 0) { |
| 1172 | btrfs_abort_transaction(trans, root, ret); |
| 1173 | goto out; |
| 1174 | } |
| 1175 | |
| 1176 | leaf = path->nodes[0]; |
| 1177 | fi = btrfs_item_ptr(leaf, path->slots[0] - 1, |
| 1178 | struct btrfs_file_extent_item); |
| 1179 | btrfs_set_file_extent_generation(leaf, fi, trans->transid); |
| 1180 | btrfs_set_file_extent_num_bytes(leaf, fi, |
| 1181 | split - key.offset); |
| 1182 | |
| 1183 | fi = btrfs_item_ptr(leaf, path->slots[0], |
| 1184 | struct btrfs_file_extent_item); |
| 1185 | |
| 1186 | btrfs_set_file_extent_generation(leaf, fi, trans->transid); |
| 1187 | btrfs_set_file_extent_offset(leaf, fi, split - orig_offset); |
| 1188 | btrfs_set_file_extent_num_bytes(leaf, fi, |
| 1189 | extent_end - split); |
| 1190 | btrfs_mark_buffer_dirty(leaf); |
| 1191 | |
| 1192 | ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0, |
| 1193 | root->root_key.objectid, |
| 1194 | ino, orig_offset, 0); |
| 1195 | BUG_ON(ret); /* -ENOMEM */ |
| 1196 | |
| 1197 | if (split == start) { |
| 1198 | key.offset = start; |
| 1199 | } else { |
| 1200 | BUG_ON(start != key.offset); |
| 1201 | path->slots[0]--; |
| 1202 | extent_end = end; |
| 1203 | } |
| 1204 | recow = 1; |
| 1205 | } |
| 1206 | |
| 1207 | other_start = end; |
| 1208 | other_end = 0; |
| 1209 | if (extent_mergeable(leaf, path->slots[0] + 1, |
| 1210 | ino, bytenr, orig_offset, |
| 1211 | &other_start, &other_end)) { |
| 1212 | if (recow) { |
| 1213 | btrfs_release_path(path); |
| 1214 | goto again; |
| 1215 | } |
| 1216 | extent_end = other_end; |
| 1217 | del_slot = path->slots[0] + 1; |
| 1218 | del_nr++; |
| 1219 | ret = btrfs_free_extent(trans, root, bytenr, num_bytes, |
| 1220 | 0, root->root_key.objectid, |
| 1221 | ino, orig_offset, 0); |
| 1222 | BUG_ON(ret); /* -ENOMEM */ |
| 1223 | } |
| 1224 | other_start = 0; |
| 1225 | other_end = start; |
| 1226 | if (extent_mergeable(leaf, path->slots[0] - 1, |
| 1227 | ino, bytenr, orig_offset, |
| 1228 | &other_start, &other_end)) { |
| 1229 | if (recow) { |
| 1230 | btrfs_release_path(path); |
| 1231 | goto again; |
| 1232 | } |
| 1233 | key.offset = other_start; |
| 1234 | del_slot = path->slots[0]; |
| 1235 | del_nr++; |
| 1236 | ret = btrfs_free_extent(trans, root, bytenr, num_bytes, |
| 1237 | 0, root->root_key.objectid, |
| 1238 | ino, orig_offset, 0); |
| 1239 | BUG_ON(ret); /* -ENOMEM */ |
| 1240 | } |
| 1241 | if (del_nr == 0) { |
| 1242 | fi = btrfs_item_ptr(leaf, path->slots[0], |
| 1243 | struct btrfs_file_extent_item); |
| 1244 | btrfs_set_file_extent_type(leaf, fi, |
| 1245 | BTRFS_FILE_EXTENT_REG); |
| 1246 | btrfs_set_file_extent_generation(leaf, fi, trans->transid); |
| 1247 | btrfs_mark_buffer_dirty(leaf); |
| 1248 | } else { |
| 1249 | fi = btrfs_item_ptr(leaf, del_slot - 1, |
| 1250 | struct btrfs_file_extent_item); |
| 1251 | btrfs_set_file_extent_type(leaf, fi, |
| 1252 | BTRFS_FILE_EXTENT_REG); |
| 1253 | btrfs_set_file_extent_generation(leaf, fi, trans->transid); |
| 1254 | btrfs_set_file_extent_num_bytes(leaf, fi, |
| 1255 | extent_end - key.offset); |
| 1256 | btrfs_mark_buffer_dirty(leaf); |
| 1257 | |
| 1258 | ret = btrfs_del_items(trans, root, path, del_slot, del_nr); |
| 1259 | if (ret < 0) { |
| 1260 | btrfs_abort_transaction(trans, root, ret); |
| 1261 | goto out; |
| 1262 | } |
| 1263 | } |
| 1264 | out: |
| 1265 | btrfs_free_path(path); |
| 1266 | return 0; |
| 1267 | } |
| 1268 | |
| 1269 | /* |
| 1270 | * on error we return an unlocked page and the error value |
| 1271 | * on success we return a locked page and 0 |
| 1272 | */ |
| 1273 | static int prepare_uptodate_page(struct page *page, u64 pos, |
| 1274 | bool force_uptodate) |
| 1275 | { |
| 1276 | int ret = 0; |
| 1277 | |
| 1278 | if (((pos & (PAGE_CACHE_SIZE - 1)) || force_uptodate) && |
| 1279 | !PageUptodate(page)) { |
| 1280 | ret = btrfs_readpage(NULL, page); |
| 1281 | if (ret) |
| 1282 | return ret; |
| 1283 | lock_page(page); |
| 1284 | if (!PageUptodate(page)) { |
| 1285 | unlock_page(page); |
| 1286 | return -EIO; |
| 1287 | } |
| 1288 | } |
| 1289 | return 0; |
| 1290 | } |
| 1291 | |
| 1292 | /* |
| 1293 | * this just gets pages into the page cache and locks them down. |
| 1294 | */ |
| 1295 | static noinline int prepare_pages(struct inode *inode, struct page **pages, |
| 1296 | size_t num_pages, loff_t pos, |
| 1297 | size_t write_bytes, bool force_uptodate) |
| 1298 | { |
| 1299 | int i; |
| 1300 | unsigned long index = pos >> PAGE_CACHE_SHIFT; |
| 1301 | gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping); |
| 1302 | int err = 0; |
| 1303 | int faili; |
| 1304 | |
| 1305 | for (i = 0; i < num_pages; i++) { |
| 1306 | pages[i] = find_or_create_page(inode->i_mapping, index + i, |
| 1307 | mask | __GFP_WRITE); |
| 1308 | if (!pages[i]) { |
| 1309 | faili = i - 1; |
| 1310 | err = -ENOMEM; |
| 1311 | goto fail; |
| 1312 | } |
| 1313 | |
| 1314 | if (i == 0) |
| 1315 | err = prepare_uptodate_page(pages[i], pos, |
| 1316 | force_uptodate); |
| 1317 | if (i == num_pages - 1) |
| 1318 | err = prepare_uptodate_page(pages[i], |
| 1319 | pos + write_bytes, false); |
| 1320 | if (err) { |
| 1321 | page_cache_release(pages[i]); |
| 1322 | faili = i - 1; |
| 1323 | goto fail; |
| 1324 | } |
| 1325 | wait_on_page_writeback(pages[i]); |
| 1326 | } |
| 1327 | |
| 1328 | return 0; |
| 1329 | fail: |
| 1330 | while (faili >= 0) { |
| 1331 | unlock_page(pages[faili]); |
| 1332 | page_cache_release(pages[faili]); |
| 1333 | faili--; |
| 1334 | } |
| 1335 | return err; |
| 1336 | |
| 1337 | } |
| 1338 | |
| 1339 | /* |
| 1340 | * This function locks the extent and properly waits for data=ordered extents |
| 1341 | * to finish before allowing the pages to be modified if need. |
| 1342 | * |
| 1343 | * The return value: |
| 1344 | * 1 - the extent is locked |
| 1345 | * 0 - the extent is not locked, and everything is OK |
| 1346 | * -EAGAIN - need re-prepare the pages |
| 1347 | * the other < 0 number - Something wrong happens |
| 1348 | */ |
| 1349 | static noinline int |
| 1350 | lock_and_cleanup_extent_if_need(struct inode *inode, struct page **pages, |
| 1351 | size_t num_pages, loff_t pos, |
| 1352 | u64 *lockstart, u64 *lockend, |
| 1353 | struct extent_state **cached_state) |
| 1354 | { |
| 1355 | u64 start_pos; |
| 1356 | u64 last_pos; |
| 1357 | int i; |
| 1358 | int ret = 0; |
| 1359 | |
| 1360 | start_pos = pos & ~((u64)PAGE_CACHE_SIZE - 1); |
| 1361 | last_pos = start_pos + ((u64)num_pages << PAGE_CACHE_SHIFT) - 1; |
| 1362 | |
| 1363 | if (start_pos < inode->i_size) { |
| 1364 | struct btrfs_ordered_extent *ordered; |
| 1365 | lock_extent_bits(&BTRFS_I(inode)->io_tree, |
| 1366 | start_pos, last_pos, 0, cached_state); |
| 1367 | ordered = btrfs_lookup_ordered_range(inode, start_pos, |
| 1368 | last_pos - start_pos + 1); |
| 1369 | if (ordered && |
| 1370 | ordered->file_offset + ordered->len > start_pos && |
| 1371 | ordered->file_offset <= last_pos) { |
| 1372 | unlock_extent_cached(&BTRFS_I(inode)->io_tree, |
| 1373 | start_pos, last_pos, |
| 1374 | cached_state, GFP_NOFS); |
| 1375 | for (i = 0; i < num_pages; i++) { |
| 1376 | unlock_page(pages[i]); |
| 1377 | page_cache_release(pages[i]); |
| 1378 | } |
| 1379 | btrfs_start_ordered_extent(inode, ordered, 1); |
| 1380 | btrfs_put_ordered_extent(ordered); |
| 1381 | return -EAGAIN; |
| 1382 | } |
| 1383 | if (ordered) |
| 1384 | btrfs_put_ordered_extent(ordered); |
| 1385 | |
| 1386 | clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos, |
| 1387 | last_pos, EXTENT_DIRTY | EXTENT_DELALLOC | |
| 1388 | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, |
| 1389 | 0, 0, cached_state, GFP_NOFS); |
| 1390 | *lockstart = start_pos; |
| 1391 | *lockend = last_pos; |
| 1392 | ret = 1; |
| 1393 | } |
| 1394 | |
| 1395 | for (i = 0; i < num_pages; i++) { |
| 1396 | if (clear_page_dirty_for_io(pages[i])) |
| 1397 | account_page_redirty(pages[i]); |
| 1398 | set_page_extent_mapped(pages[i]); |
| 1399 | WARN_ON(!PageLocked(pages[i])); |
| 1400 | } |
| 1401 | |
| 1402 | return ret; |
| 1403 | } |
| 1404 | |
| 1405 | static noinline int check_can_nocow(struct inode *inode, loff_t pos, |
| 1406 | size_t *write_bytes) |
| 1407 | { |
| 1408 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 1409 | struct btrfs_ordered_extent *ordered; |
| 1410 | u64 lockstart, lockend; |
| 1411 | u64 num_bytes; |
| 1412 | int ret; |
| 1413 | |
| 1414 | ret = btrfs_start_nocow_write(root); |
| 1415 | if (!ret) |
| 1416 | return -ENOSPC; |
| 1417 | |
| 1418 | lockstart = round_down(pos, root->sectorsize); |
| 1419 | lockend = round_up(pos + *write_bytes, root->sectorsize) - 1; |
| 1420 | |
| 1421 | while (1) { |
| 1422 | lock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend); |
| 1423 | ordered = btrfs_lookup_ordered_range(inode, lockstart, |
| 1424 | lockend - lockstart + 1); |
| 1425 | if (!ordered) { |
| 1426 | break; |
| 1427 | } |
| 1428 | unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend); |
| 1429 | btrfs_start_ordered_extent(inode, ordered, 1); |
| 1430 | btrfs_put_ordered_extent(ordered); |
| 1431 | } |
| 1432 | |
| 1433 | num_bytes = lockend - lockstart + 1; |
| 1434 | ret = can_nocow_extent(inode, lockstart, &num_bytes, NULL, NULL, NULL); |
| 1435 | if (ret <= 0) { |
| 1436 | ret = 0; |
| 1437 | btrfs_end_nocow_write(root); |
| 1438 | } else { |
| 1439 | *write_bytes = min_t(size_t, *write_bytes , |
| 1440 | num_bytes - pos + lockstart); |
| 1441 | } |
| 1442 | |
| 1443 | unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend); |
| 1444 | |
| 1445 | return ret; |
| 1446 | } |
| 1447 | |
| 1448 | static noinline ssize_t __btrfs_buffered_write(struct file *file, |
| 1449 | struct iov_iter *i, |
| 1450 | loff_t pos) |
| 1451 | { |
| 1452 | struct inode *inode = file_inode(file); |
| 1453 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 1454 | struct page **pages = NULL; |
| 1455 | struct extent_state *cached_state = NULL; |
| 1456 | u64 release_bytes = 0; |
| 1457 | u64 lockstart; |
| 1458 | u64 lockend; |
| 1459 | unsigned long first_index; |
| 1460 | size_t num_written = 0; |
| 1461 | int nrptrs; |
| 1462 | int ret = 0; |
| 1463 | bool only_release_metadata = false; |
| 1464 | bool force_page_uptodate = false; |
| 1465 | bool need_unlock; |
| 1466 | |
| 1467 | nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) / |
| 1468 | PAGE_CACHE_SIZE, PAGE_CACHE_SIZE / |
| 1469 | (sizeof(struct page *))); |
| 1470 | nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied); |
| 1471 | nrptrs = max(nrptrs, 8); |
| 1472 | pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL); |
| 1473 | if (!pages) |
| 1474 | return -ENOMEM; |
| 1475 | |
| 1476 | first_index = pos >> PAGE_CACHE_SHIFT; |
| 1477 | |
| 1478 | while (iov_iter_count(i) > 0) { |
| 1479 | size_t offset = pos & (PAGE_CACHE_SIZE - 1); |
| 1480 | size_t write_bytes = min(iov_iter_count(i), |
| 1481 | nrptrs * (size_t)PAGE_CACHE_SIZE - |
| 1482 | offset); |
| 1483 | size_t num_pages = (write_bytes + offset + |
| 1484 | PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT; |
| 1485 | size_t reserve_bytes; |
| 1486 | size_t dirty_pages; |
| 1487 | size_t copied; |
| 1488 | |
| 1489 | WARN_ON(num_pages > nrptrs); |
| 1490 | |
| 1491 | /* |
| 1492 | * Fault pages before locking them in prepare_pages |
| 1493 | * to avoid recursive lock |
| 1494 | */ |
| 1495 | if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) { |
| 1496 | ret = -EFAULT; |
| 1497 | break; |
| 1498 | } |
| 1499 | |
| 1500 | reserve_bytes = num_pages << PAGE_CACHE_SHIFT; |
| 1501 | ret = btrfs_check_data_free_space(inode, reserve_bytes); |
| 1502 | if (ret == -ENOSPC && |
| 1503 | (BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW | |
| 1504 | BTRFS_INODE_PREALLOC))) { |
| 1505 | ret = check_can_nocow(inode, pos, &write_bytes); |
| 1506 | if (ret > 0) { |
| 1507 | only_release_metadata = true; |
| 1508 | /* |
| 1509 | * our prealloc extent may be smaller than |
| 1510 | * write_bytes, so scale down. |
| 1511 | */ |
| 1512 | num_pages = (write_bytes + offset + |
| 1513 | PAGE_CACHE_SIZE - 1) >> |
| 1514 | PAGE_CACHE_SHIFT; |
| 1515 | reserve_bytes = num_pages << PAGE_CACHE_SHIFT; |
| 1516 | ret = 0; |
| 1517 | } else { |
| 1518 | ret = -ENOSPC; |
| 1519 | } |
| 1520 | } |
| 1521 | |
| 1522 | if (ret) |
| 1523 | break; |
| 1524 | |
| 1525 | ret = btrfs_delalloc_reserve_metadata(inode, reserve_bytes); |
| 1526 | if (ret) { |
| 1527 | if (!only_release_metadata) |
| 1528 | btrfs_free_reserved_data_space(inode, |
| 1529 | reserve_bytes); |
| 1530 | else |
| 1531 | btrfs_end_nocow_write(root); |
| 1532 | break; |
| 1533 | } |
| 1534 | |
| 1535 | release_bytes = reserve_bytes; |
| 1536 | need_unlock = false; |
| 1537 | again: |
| 1538 | /* |
| 1539 | * This is going to setup the pages array with the number of |
| 1540 | * pages we want, so we don't really need to worry about the |
| 1541 | * contents of pages from loop to loop |
| 1542 | */ |
| 1543 | ret = prepare_pages(inode, pages, num_pages, |
| 1544 | pos, write_bytes, |
| 1545 | force_page_uptodate); |
| 1546 | if (ret) |
| 1547 | break; |
| 1548 | |
| 1549 | ret = lock_and_cleanup_extent_if_need(inode, pages, num_pages, |
| 1550 | pos, &lockstart, &lockend, |
| 1551 | &cached_state); |
| 1552 | if (ret < 0) { |
| 1553 | if (ret == -EAGAIN) |
| 1554 | goto again; |
| 1555 | break; |
| 1556 | } else if (ret > 0) { |
| 1557 | need_unlock = true; |
| 1558 | ret = 0; |
| 1559 | } |
| 1560 | |
| 1561 | copied = btrfs_copy_from_user(pos, num_pages, |
| 1562 | write_bytes, pages, i); |
| 1563 | |
| 1564 | /* |
| 1565 | * if we have trouble faulting in the pages, fall |
| 1566 | * back to one page at a time |
| 1567 | */ |
| 1568 | if (copied < write_bytes) |
| 1569 | nrptrs = 1; |
| 1570 | |
| 1571 | if (copied == 0) { |
| 1572 | force_page_uptodate = true; |
| 1573 | dirty_pages = 0; |
| 1574 | } else { |
| 1575 | force_page_uptodate = false; |
| 1576 | dirty_pages = (copied + offset + |
| 1577 | PAGE_CACHE_SIZE - 1) >> |
| 1578 | PAGE_CACHE_SHIFT; |
| 1579 | } |
| 1580 | |
| 1581 | /* |
| 1582 | * If we had a short copy we need to release the excess delaloc |
| 1583 | * bytes we reserved. We need to increment outstanding_extents |
| 1584 | * because btrfs_delalloc_release_space will decrement it, but |
| 1585 | * we still have an outstanding extent for the chunk we actually |
| 1586 | * managed to copy. |
| 1587 | */ |
| 1588 | if (num_pages > dirty_pages) { |
| 1589 | release_bytes = (num_pages - dirty_pages) << |
| 1590 | PAGE_CACHE_SHIFT; |
| 1591 | if (copied > 0) { |
| 1592 | spin_lock(&BTRFS_I(inode)->lock); |
| 1593 | BTRFS_I(inode)->outstanding_extents++; |
| 1594 | spin_unlock(&BTRFS_I(inode)->lock); |
| 1595 | } |
| 1596 | if (only_release_metadata) |
| 1597 | btrfs_delalloc_release_metadata(inode, |
| 1598 | release_bytes); |
| 1599 | else |
| 1600 | btrfs_delalloc_release_space(inode, |
| 1601 | release_bytes); |
| 1602 | } |
| 1603 | |
| 1604 | release_bytes = dirty_pages << PAGE_CACHE_SHIFT; |
| 1605 | |
| 1606 | if (copied > 0) |
| 1607 | ret = btrfs_dirty_pages(root, inode, pages, |
| 1608 | dirty_pages, pos, copied, |
| 1609 | NULL); |
| 1610 | if (need_unlock) |
| 1611 | unlock_extent_cached(&BTRFS_I(inode)->io_tree, |
| 1612 | lockstart, lockend, &cached_state, |
| 1613 | GFP_NOFS); |
| 1614 | if (ret) { |
| 1615 | btrfs_drop_pages(pages, num_pages); |
| 1616 | break; |
| 1617 | } |
| 1618 | |
| 1619 | release_bytes = 0; |
| 1620 | if (only_release_metadata) |
| 1621 | btrfs_end_nocow_write(root); |
| 1622 | |
| 1623 | if (only_release_metadata && copied > 0) { |
| 1624 | u64 lockstart = round_down(pos, root->sectorsize); |
| 1625 | u64 lockend = lockstart + |
| 1626 | (dirty_pages << PAGE_CACHE_SHIFT) - 1; |
| 1627 | |
| 1628 | set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, |
| 1629 | lockend, EXTENT_NORESERVE, NULL, |
| 1630 | NULL, GFP_NOFS); |
| 1631 | only_release_metadata = false; |
| 1632 | } |
| 1633 | |
| 1634 | btrfs_drop_pages(pages, num_pages); |
| 1635 | |
| 1636 | cond_resched(); |
| 1637 | |
| 1638 | balance_dirty_pages_ratelimited(inode->i_mapping); |
| 1639 | if (dirty_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1) |
| 1640 | btrfs_btree_balance_dirty(root); |
| 1641 | |
| 1642 | pos += copied; |
| 1643 | num_written += copied; |
| 1644 | } |
| 1645 | |
| 1646 | kfree(pages); |
| 1647 | |
| 1648 | if (release_bytes) { |
| 1649 | if (only_release_metadata) { |
| 1650 | btrfs_end_nocow_write(root); |
| 1651 | btrfs_delalloc_release_metadata(inode, release_bytes); |
| 1652 | } else { |
| 1653 | btrfs_delalloc_release_space(inode, release_bytes); |
| 1654 | } |
| 1655 | } |
| 1656 | |
| 1657 | return num_written ? num_written : ret; |
| 1658 | } |
| 1659 | |
| 1660 | static ssize_t __btrfs_direct_write(struct kiocb *iocb, |
| 1661 | struct iov_iter *from, |
| 1662 | loff_t pos, |
| 1663 | size_t count, size_t ocount) |
| 1664 | { |
| 1665 | struct file *file = iocb->ki_filp; |
| 1666 | ssize_t written; |
| 1667 | ssize_t written_buffered; |
| 1668 | loff_t endbyte; |
| 1669 | int err; |
| 1670 | |
| 1671 | written = generic_file_direct_write(iocb, from, pos, count, ocount); |
| 1672 | |
| 1673 | if (written < 0 || written == count) |
| 1674 | return written; |
| 1675 | |
| 1676 | pos += written; |
| 1677 | written_buffered = __btrfs_buffered_write(file, from, pos); |
| 1678 | if (written_buffered < 0) { |
| 1679 | err = written_buffered; |
| 1680 | goto out; |
| 1681 | } |
| 1682 | endbyte = pos + written_buffered - 1; |
| 1683 | err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte); |
| 1684 | if (err) |
| 1685 | goto out; |
| 1686 | written += written_buffered; |
| 1687 | iocb->ki_pos = pos + written_buffered; |
| 1688 | invalidate_mapping_pages(file->f_mapping, pos >> PAGE_CACHE_SHIFT, |
| 1689 | endbyte >> PAGE_CACHE_SHIFT); |
| 1690 | out: |
| 1691 | return written ? written : err; |
| 1692 | } |
| 1693 | |
| 1694 | static void update_time_for_write(struct inode *inode) |
| 1695 | { |
| 1696 | struct timespec now; |
| 1697 | |
| 1698 | if (IS_NOCMTIME(inode)) |
| 1699 | return; |
| 1700 | |
| 1701 | now = current_fs_time(inode->i_sb); |
| 1702 | if (!timespec_equal(&inode->i_mtime, &now)) |
| 1703 | inode->i_mtime = now; |
| 1704 | |
| 1705 | if (!timespec_equal(&inode->i_ctime, &now)) |
| 1706 | inode->i_ctime = now; |
| 1707 | |
| 1708 | if (IS_I_VERSION(inode)) |
| 1709 | inode_inc_iversion(inode); |
| 1710 | } |
| 1711 | |
| 1712 | static ssize_t btrfs_file_aio_write(struct kiocb *iocb, |
| 1713 | const struct iovec *iov, |
| 1714 | unsigned long nr_segs, loff_t pos) |
| 1715 | { |
| 1716 | struct file *file = iocb->ki_filp; |
| 1717 | struct inode *inode = file_inode(file); |
| 1718 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 1719 | u64 start_pos; |
| 1720 | u64 end_pos; |
| 1721 | ssize_t num_written = 0; |
| 1722 | ssize_t err = 0; |
| 1723 | size_t count, ocount; |
| 1724 | bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host); |
| 1725 | struct iov_iter i; |
| 1726 | |
| 1727 | mutex_lock(&inode->i_mutex); |
| 1728 | |
| 1729 | count = ocount = iov_length(iov, nr_segs); |
| 1730 | |
| 1731 | current->backing_dev_info = inode->i_mapping->backing_dev_info; |
| 1732 | err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); |
| 1733 | if (err) { |
| 1734 | mutex_unlock(&inode->i_mutex); |
| 1735 | goto out; |
| 1736 | } |
| 1737 | |
| 1738 | if (count == 0) { |
| 1739 | mutex_unlock(&inode->i_mutex); |
| 1740 | goto out; |
| 1741 | } |
| 1742 | |
| 1743 | iov_iter_init(&i, WRITE, iov, nr_segs, count); |
| 1744 | |
| 1745 | err = file_remove_suid(file); |
| 1746 | if (err) { |
| 1747 | mutex_unlock(&inode->i_mutex); |
| 1748 | goto out; |
| 1749 | } |
| 1750 | |
| 1751 | /* |
| 1752 | * If BTRFS flips readonly due to some impossible error |
| 1753 | * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR), |
| 1754 | * although we have opened a file as writable, we have |
| 1755 | * to stop this write operation to ensure FS consistency. |
| 1756 | */ |
| 1757 | if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) { |
| 1758 | mutex_unlock(&inode->i_mutex); |
| 1759 | err = -EROFS; |
| 1760 | goto out; |
| 1761 | } |
| 1762 | |
| 1763 | /* |
| 1764 | * We reserve space for updating the inode when we reserve space for the |
| 1765 | * extent we are going to write, so we will enospc out there. We don't |
| 1766 | * need to start yet another transaction to update the inode as we will |
| 1767 | * update the inode when we finish writing whatever data we write. |
| 1768 | */ |
| 1769 | update_time_for_write(inode); |
| 1770 | |
| 1771 | start_pos = round_down(pos, root->sectorsize); |
| 1772 | if (start_pos > i_size_read(inode)) { |
| 1773 | /* Expand hole size to cover write data, preventing empty gap */ |
| 1774 | end_pos = round_up(pos + count, root->sectorsize); |
| 1775 | err = btrfs_cont_expand(inode, i_size_read(inode), end_pos); |
| 1776 | if (err) { |
| 1777 | mutex_unlock(&inode->i_mutex); |
| 1778 | goto out; |
| 1779 | } |
| 1780 | } |
| 1781 | |
| 1782 | if (sync) |
| 1783 | atomic_inc(&BTRFS_I(inode)->sync_writers); |
| 1784 | |
| 1785 | if (unlikely(file->f_flags & O_DIRECT)) { |
| 1786 | num_written = __btrfs_direct_write(iocb, &i, |
| 1787 | pos, count, ocount); |
| 1788 | } else { |
| 1789 | num_written = __btrfs_buffered_write(file, &i, pos); |
| 1790 | if (num_written > 0) |
| 1791 | iocb->ki_pos = pos + num_written; |
| 1792 | } |
| 1793 | |
| 1794 | mutex_unlock(&inode->i_mutex); |
| 1795 | |
| 1796 | /* |
| 1797 | * we want to make sure fsync finds this change |
| 1798 | * but we haven't joined a transaction running right now. |
| 1799 | * |
| 1800 | * Later on, someone is sure to update the inode and get the |
| 1801 | * real transid recorded. |
| 1802 | * |
| 1803 | * We set last_trans now to the fs_info generation + 1, |
| 1804 | * this will either be one more than the running transaction |
| 1805 | * or the generation used for the next transaction if there isn't |
| 1806 | * one running right now. |
| 1807 | * |
| 1808 | * We also have to set last_sub_trans to the current log transid, |
| 1809 | * otherwise subsequent syncs to a file that's been synced in this |
| 1810 | * transaction will appear to have already occured. |
| 1811 | */ |
| 1812 | BTRFS_I(inode)->last_trans = root->fs_info->generation + 1; |
| 1813 | BTRFS_I(inode)->last_sub_trans = root->log_transid; |
| 1814 | if (num_written > 0) { |
| 1815 | err = generic_write_sync(file, pos, num_written); |
| 1816 | if (err < 0) |
| 1817 | num_written = err; |
| 1818 | } |
| 1819 | |
| 1820 | if (sync) |
| 1821 | atomic_dec(&BTRFS_I(inode)->sync_writers); |
| 1822 | out: |
| 1823 | current->backing_dev_info = NULL; |
| 1824 | return num_written ? num_written : err; |
| 1825 | } |
| 1826 | |
| 1827 | int btrfs_release_file(struct inode *inode, struct file *filp) |
| 1828 | { |
| 1829 | /* |
| 1830 | * ordered_data_close is set by settattr when we are about to truncate |
| 1831 | * a file from a non-zero size to a zero size. This tries to |
| 1832 | * flush down new bytes that may have been written if the |
| 1833 | * application were using truncate to replace a file in place. |
| 1834 | */ |
| 1835 | if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE, |
| 1836 | &BTRFS_I(inode)->runtime_flags)) { |
| 1837 | struct btrfs_trans_handle *trans; |
| 1838 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 1839 | |
| 1840 | /* |
| 1841 | * We need to block on a committing transaction to keep us from |
| 1842 | * throwing a ordered operation on to the list and causing |
| 1843 | * something like sync to deadlock trying to flush out this |
| 1844 | * inode. |
| 1845 | */ |
| 1846 | trans = btrfs_start_transaction(root, 0); |
| 1847 | if (IS_ERR(trans)) |
| 1848 | return PTR_ERR(trans); |
| 1849 | btrfs_add_ordered_operation(trans, BTRFS_I(inode)->root, inode); |
| 1850 | btrfs_end_transaction(trans, root); |
| 1851 | if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT) |
| 1852 | filemap_flush(inode->i_mapping); |
| 1853 | } |
| 1854 | if (filp->private_data) |
| 1855 | btrfs_ioctl_trans_end(filp); |
| 1856 | return 0; |
| 1857 | } |
| 1858 | |
| 1859 | /* |
| 1860 | * fsync call for both files and directories. This logs the inode into |
| 1861 | * the tree log instead of forcing full commits whenever possible. |
| 1862 | * |
| 1863 | * It needs to call filemap_fdatawait so that all ordered extent updates are |
| 1864 | * in the metadata btree are up to date for copying to the log. |
| 1865 | * |
| 1866 | * It drops the inode mutex before doing the tree log commit. This is an |
| 1867 | * important optimization for directories because holding the mutex prevents |
| 1868 | * new operations on the dir while we write to disk. |
| 1869 | */ |
| 1870 | int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) |
| 1871 | { |
| 1872 | struct dentry *dentry = file->f_path.dentry; |
| 1873 | struct inode *inode = dentry->d_inode; |
| 1874 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 1875 | struct btrfs_trans_handle *trans; |
| 1876 | struct btrfs_log_ctx ctx; |
| 1877 | int ret = 0; |
| 1878 | bool full_sync = 0; |
| 1879 | |
| 1880 | trace_btrfs_sync_file(file, datasync); |
| 1881 | |
| 1882 | /* |
| 1883 | * We write the dirty pages in the range and wait until they complete |
| 1884 | * out of the ->i_mutex. If so, we can flush the dirty pages by |
| 1885 | * multi-task, and make the performance up. See |
| 1886 | * btrfs_wait_ordered_range for an explanation of the ASYNC check. |
| 1887 | */ |
| 1888 | atomic_inc(&BTRFS_I(inode)->sync_writers); |
| 1889 | ret = filemap_fdatawrite_range(inode->i_mapping, start, end); |
| 1890 | if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT, |
| 1891 | &BTRFS_I(inode)->runtime_flags)) |
| 1892 | ret = filemap_fdatawrite_range(inode->i_mapping, start, end); |
| 1893 | atomic_dec(&BTRFS_I(inode)->sync_writers); |
| 1894 | if (ret) |
| 1895 | return ret; |
| 1896 | |
| 1897 | mutex_lock(&inode->i_mutex); |
| 1898 | |
| 1899 | /* |
| 1900 | * We flush the dirty pages again to avoid some dirty pages in the |
| 1901 | * range being left. |
| 1902 | */ |
| 1903 | atomic_inc(&root->log_batch); |
| 1904 | full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, |
| 1905 | &BTRFS_I(inode)->runtime_flags); |
| 1906 | if (full_sync) { |
| 1907 | ret = btrfs_wait_ordered_range(inode, start, end - start + 1); |
| 1908 | if (ret) { |
| 1909 | mutex_unlock(&inode->i_mutex); |
| 1910 | goto out; |
| 1911 | } |
| 1912 | } |
| 1913 | atomic_inc(&root->log_batch); |
| 1914 | |
| 1915 | /* |
| 1916 | * check the transaction that last modified this inode |
| 1917 | * and see if its already been committed |
| 1918 | */ |
| 1919 | if (!BTRFS_I(inode)->last_trans) { |
| 1920 | mutex_unlock(&inode->i_mutex); |
| 1921 | goto out; |
| 1922 | } |
| 1923 | |
| 1924 | /* |
| 1925 | * if the last transaction that changed this file was before |
| 1926 | * the current transaction, we can bail out now without any |
| 1927 | * syncing |
| 1928 | */ |
| 1929 | smp_mb(); |
| 1930 | if (btrfs_inode_in_log(inode, root->fs_info->generation) || |
| 1931 | BTRFS_I(inode)->last_trans <= |
| 1932 | root->fs_info->last_trans_committed) { |
| 1933 | BTRFS_I(inode)->last_trans = 0; |
| 1934 | |
| 1935 | /* |
| 1936 | * We'v had everything committed since the last time we were |
| 1937 | * modified so clear this flag in case it was set for whatever |
| 1938 | * reason, it's no longer relevant. |
| 1939 | */ |
| 1940 | clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC, |
| 1941 | &BTRFS_I(inode)->runtime_flags); |
| 1942 | mutex_unlock(&inode->i_mutex); |
| 1943 | goto out; |
| 1944 | } |
| 1945 | |
| 1946 | /* |
| 1947 | * ok we haven't committed the transaction yet, lets do a commit |
| 1948 | */ |
| 1949 | if (file->private_data) |
| 1950 | btrfs_ioctl_trans_end(file); |
| 1951 | |
| 1952 | /* |
| 1953 | * We use start here because we will need to wait on the IO to complete |
| 1954 | * in btrfs_sync_log, which could require joining a transaction (for |
| 1955 | * example checking cross references in the nocow path). If we use join |
| 1956 | * here we could get into a situation where we're waiting on IO to |
| 1957 | * happen that is blocked on a transaction trying to commit. With start |
| 1958 | * we inc the extwriter counter, so we wait for all extwriters to exit |
| 1959 | * before we start blocking join'ers. This comment is to keep somebody |
| 1960 | * from thinking they are super smart and changing this to |
| 1961 | * btrfs_join_transaction *cough*Josef*cough*. |
| 1962 | */ |
| 1963 | trans = btrfs_start_transaction(root, 0); |
| 1964 | if (IS_ERR(trans)) { |
| 1965 | ret = PTR_ERR(trans); |
| 1966 | mutex_unlock(&inode->i_mutex); |
| 1967 | goto out; |
| 1968 | } |
| 1969 | trans->sync = true; |
| 1970 | |
| 1971 | btrfs_init_log_ctx(&ctx); |
| 1972 | |
| 1973 | ret = btrfs_log_dentry_safe(trans, root, dentry, &ctx); |
| 1974 | if (ret < 0) { |
| 1975 | /* Fallthrough and commit/free transaction. */ |
| 1976 | ret = 1; |
| 1977 | } |
| 1978 | |
| 1979 | /* we've logged all the items and now have a consistent |
| 1980 | * version of the file in the log. It is possible that |
| 1981 | * someone will come in and modify the file, but that's |
| 1982 | * fine because the log is consistent on disk, and we |
| 1983 | * have references to all of the file's extents |
| 1984 | * |
| 1985 | * It is possible that someone will come in and log the |
| 1986 | * file again, but that will end up using the synchronization |
| 1987 | * inside btrfs_sync_log to keep things safe. |
| 1988 | */ |
| 1989 | mutex_unlock(&inode->i_mutex); |
| 1990 | |
| 1991 | if (ret != BTRFS_NO_LOG_SYNC) { |
| 1992 | if (!ret) { |
| 1993 | ret = btrfs_sync_log(trans, root, &ctx); |
| 1994 | if (!ret) { |
| 1995 | ret = btrfs_end_transaction(trans, root); |
| 1996 | goto out; |
| 1997 | } |
| 1998 | } |
| 1999 | if (!full_sync) { |
| 2000 | ret = btrfs_wait_ordered_range(inode, start, |
| 2001 | end - start + 1); |
| 2002 | if (ret) |
| 2003 | goto out; |
| 2004 | } |
| 2005 | ret = btrfs_commit_transaction(trans, root); |
| 2006 | } else { |
| 2007 | ret = btrfs_end_transaction(trans, root); |
| 2008 | } |
| 2009 | out: |
| 2010 | return ret > 0 ? -EIO : ret; |
| 2011 | } |
| 2012 | |
| 2013 | static const struct vm_operations_struct btrfs_file_vm_ops = { |
| 2014 | .fault = filemap_fault, |
| 2015 | .map_pages = filemap_map_pages, |
| 2016 | .page_mkwrite = btrfs_page_mkwrite, |
| 2017 | .remap_pages = generic_file_remap_pages, |
| 2018 | }; |
| 2019 | |
| 2020 | static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma) |
| 2021 | { |
| 2022 | struct address_space *mapping = filp->f_mapping; |
| 2023 | |
| 2024 | if (!mapping->a_ops->readpage) |
| 2025 | return -ENOEXEC; |
| 2026 | |
| 2027 | file_accessed(filp); |
| 2028 | vma->vm_ops = &btrfs_file_vm_ops; |
| 2029 | |
| 2030 | return 0; |
| 2031 | } |
| 2032 | |
| 2033 | static int hole_mergeable(struct inode *inode, struct extent_buffer *leaf, |
| 2034 | int slot, u64 start, u64 end) |
| 2035 | { |
| 2036 | struct btrfs_file_extent_item *fi; |
| 2037 | struct btrfs_key key; |
| 2038 | |
| 2039 | if (slot < 0 || slot >= btrfs_header_nritems(leaf)) |
| 2040 | return 0; |
| 2041 | |
| 2042 | btrfs_item_key_to_cpu(leaf, &key, slot); |
| 2043 | if (key.objectid != btrfs_ino(inode) || |
| 2044 | key.type != BTRFS_EXTENT_DATA_KEY) |
| 2045 | return 0; |
| 2046 | |
| 2047 | fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); |
| 2048 | |
| 2049 | if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) |
| 2050 | return 0; |
| 2051 | |
| 2052 | if (btrfs_file_extent_disk_bytenr(leaf, fi)) |
| 2053 | return 0; |
| 2054 | |
| 2055 | if (key.offset == end) |
| 2056 | return 1; |
| 2057 | if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start) |
| 2058 | return 1; |
| 2059 | return 0; |
| 2060 | } |
| 2061 | |
| 2062 | static int fill_holes(struct btrfs_trans_handle *trans, struct inode *inode, |
| 2063 | struct btrfs_path *path, u64 offset, u64 end) |
| 2064 | { |
| 2065 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 2066 | struct extent_buffer *leaf; |
| 2067 | struct btrfs_file_extent_item *fi; |
| 2068 | struct extent_map *hole_em; |
| 2069 | struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; |
| 2070 | struct btrfs_key key; |
| 2071 | int ret; |
| 2072 | |
| 2073 | if (btrfs_fs_incompat(root->fs_info, NO_HOLES)) |
| 2074 | goto out; |
| 2075 | |
| 2076 | key.objectid = btrfs_ino(inode); |
| 2077 | key.type = BTRFS_EXTENT_DATA_KEY; |
| 2078 | key.offset = offset; |
| 2079 | |
| 2080 | ret = btrfs_search_slot(trans, root, &key, path, 0, 1); |
| 2081 | if (ret < 0) |
| 2082 | return ret; |
| 2083 | BUG_ON(!ret); |
| 2084 | |
| 2085 | leaf = path->nodes[0]; |
| 2086 | if (hole_mergeable(inode, leaf, path->slots[0]-1, offset, end)) { |
| 2087 | u64 num_bytes; |
| 2088 | |
| 2089 | path->slots[0]--; |
| 2090 | fi = btrfs_item_ptr(leaf, path->slots[0], |
| 2091 | struct btrfs_file_extent_item); |
| 2092 | num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + |
| 2093 | end - offset; |
| 2094 | btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); |
| 2095 | btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes); |
| 2096 | btrfs_set_file_extent_offset(leaf, fi, 0); |
| 2097 | btrfs_mark_buffer_dirty(leaf); |
| 2098 | goto out; |
| 2099 | } |
| 2100 | |
| 2101 | if (hole_mergeable(inode, leaf, path->slots[0]+1, offset, end)) { |
| 2102 | u64 num_bytes; |
| 2103 | |
| 2104 | path->slots[0]++; |
| 2105 | key.offset = offset; |
| 2106 | btrfs_set_item_key_safe(root, path, &key); |
| 2107 | fi = btrfs_item_ptr(leaf, path->slots[0], |
| 2108 | struct btrfs_file_extent_item); |
| 2109 | num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end - |
| 2110 | offset; |
| 2111 | btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); |
| 2112 | btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes); |
| 2113 | btrfs_set_file_extent_offset(leaf, fi, 0); |
| 2114 | btrfs_mark_buffer_dirty(leaf); |
| 2115 | goto out; |
| 2116 | } |
| 2117 | btrfs_release_path(path); |
| 2118 | |
| 2119 | ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset, |
| 2120 | 0, 0, end - offset, 0, end - offset, |
| 2121 | 0, 0, 0); |
| 2122 | if (ret) |
| 2123 | return ret; |
| 2124 | |
| 2125 | out: |
| 2126 | btrfs_release_path(path); |
| 2127 | |
| 2128 | hole_em = alloc_extent_map(); |
| 2129 | if (!hole_em) { |
| 2130 | btrfs_drop_extent_cache(inode, offset, end - 1, 0); |
| 2131 | set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, |
| 2132 | &BTRFS_I(inode)->runtime_flags); |
| 2133 | } else { |
| 2134 | hole_em->start = offset; |
| 2135 | hole_em->len = end - offset; |
| 2136 | hole_em->ram_bytes = hole_em->len; |
| 2137 | hole_em->orig_start = offset; |
| 2138 | |
| 2139 | hole_em->block_start = EXTENT_MAP_HOLE; |
| 2140 | hole_em->block_len = 0; |
| 2141 | hole_em->orig_block_len = 0; |
| 2142 | hole_em->bdev = root->fs_info->fs_devices->latest_bdev; |
| 2143 | hole_em->compress_type = BTRFS_COMPRESS_NONE; |
| 2144 | hole_em->generation = trans->transid; |
| 2145 | |
| 2146 | do { |
| 2147 | btrfs_drop_extent_cache(inode, offset, end - 1, 0); |
| 2148 | write_lock(&em_tree->lock); |
| 2149 | ret = add_extent_mapping(em_tree, hole_em, 1); |
| 2150 | write_unlock(&em_tree->lock); |
| 2151 | } while (ret == -EEXIST); |
| 2152 | free_extent_map(hole_em); |
| 2153 | if (ret) |
| 2154 | set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, |
| 2155 | &BTRFS_I(inode)->runtime_flags); |
| 2156 | } |
| 2157 | |
| 2158 | return 0; |
| 2159 | } |
| 2160 | |
| 2161 | static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len) |
| 2162 | { |
| 2163 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 2164 | struct extent_state *cached_state = NULL; |
| 2165 | struct btrfs_path *path; |
| 2166 | struct btrfs_block_rsv *rsv; |
| 2167 | struct btrfs_trans_handle *trans; |
| 2168 | u64 lockstart = round_up(offset, BTRFS_I(inode)->root->sectorsize); |
| 2169 | u64 lockend = round_down(offset + len, |
| 2170 | BTRFS_I(inode)->root->sectorsize) - 1; |
| 2171 | u64 cur_offset = lockstart; |
| 2172 | u64 min_size = btrfs_calc_trunc_metadata_size(root, 1); |
| 2173 | u64 drop_end; |
| 2174 | int ret = 0; |
| 2175 | int err = 0; |
| 2176 | int rsv_count; |
| 2177 | bool same_page = ((offset >> PAGE_CACHE_SHIFT) == |
| 2178 | ((offset + len - 1) >> PAGE_CACHE_SHIFT)); |
| 2179 | bool no_holes = btrfs_fs_incompat(root->fs_info, NO_HOLES); |
| 2180 | u64 ino_size = round_up(inode->i_size, PAGE_CACHE_SIZE); |
| 2181 | |
| 2182 | ret = btrfs_wait_ordered_range(inode, offset, len); |
| 2183 | if (ret) |
| 2184 | return ret; |
| 2185 | |
| 2186 | mutex_lock(&inode->i_mutex); |
| 2187 | /* |
| 2188 | * We needn't truncate any page which is beyond the end of the file |
| 2189 | * because we are sure there is no data there. |
| 2190 | */ |
| 2191 | /* |
| 2192 | * Only do this if we are in the same page and we aren't doing the |
| 2193 | * entire page. |
| 2194 | */ |
| 2195 | if (same_page && len < PAGE_CACHE_SIZE) { |
| 2196 | if (offset < ino_size) |
| 2197 | ret = btrfs_truncate_page(inode, offset, len, 0); |
| 2198 | mutex_unlock(&inode->i_mutex); |
| 2199 | return ret; |
| 2200 | } |
| 2201 | |
| 2202 | /* zero back part of the first page */ |
| 2203 | if (offset < ino_size) { |
| 2204 | ret = btrfs_truncate_page(inode, offset, 0, 0); |
| 2205 | if (ret) { |
| 2206 | mutex_unlock(&inode->i_mutex); |
| 2207 | return ret; |
| 2208 | } |
| 2209 | } |
| 2210 | |
| 2211 | /* zero the front end of the last page */ |
| 2212 | if (offset + len < ino_size) { |
| 2213 | ret = btrfs_truncate_page(inode, offset + len, 0, 1); |
| 2214 | if (ret) { |
| 2215 | mutex_unlock(&inode->i_mutex); |
| 2216 | return ret; |
| 2217 | } |
| 2218 | } |
| 2219 | |
| 2220 | if (lockend < lockstart) { |
| 2221 | mutex_unlock(&inode->i_mutex); |
| 2222 | return 0; |
| 2223 | } |
| 2224 | |
| 2225 | while (1) { |
| 2226 | struct btrfs_ordered_extent *ordered; |
| 2227 | |
| 2228 | truncate_pagecache_range(inode, lockstart, lockend); |
| 2229 | |
| 2230 | lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, |
| 2231 | 0, &cached_state); |
| 2232 | ordered = btrfs_lookup_first_ordered_extent(inode, lockend); |
| 2233 | |
| 2234 | /* |
| 2235 | * We need to make sure we have no ordered extents in this range |
| 2236 | * and nobody raced in and read a page in this range, if we did |
| 2237 | * we need to try again. |
| 2238 | */ |
| 2239 | if ((!ordered || |
| 2240 | (ordered->file_offset + ordered->len <= lockstart || |
| 2241 | ordered->file_offset > lockend)) && |
| 2242 | !test_range_bit(&BTRFS_I(inode)->io_tree, lockstart, |
| 2243 | lockend, EXTENT_UPTODATE, 0, |
| 2244 | cached_state)) { |
| 2245 | if (ordered) |
| 2246 | btrfs_put_ordered_extent(ordered); |
| 2247 | break; |
| 2248 | } |
| 2249 | if (ordered) |
| 2250 | btrfs_put_ordered_extent(ordered); |
| 2251 | unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, |
| 2252 | lockend, &cached_state, GFP_NOFS); |
| 2253 | ret = btrfs_wait_ordered_range(inode, lockstart, |
| 2254 | lockend - lockstart + 1); |
| 2255 | if (ret) { |
| 2256 | mutex_unlock(&inode->i_mutex); |
| 2257 | return ret; |
| 2258 | } |
| 2259 | } |
| 2260 | |
| 2261 | path = btrfs_alloc_path(); |
| 2262 | if (!path) { |
| 2263 | ret = -ENOMEM; |
| 2264 | goto out; |
| 2265 | } |
| 2266 | |
| 2267 | rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP); |
| 2268 | if (!rsv) { |
| 2269 | ret = -ENOMEM; |
| 2270 | goto out_free; |
| 2271 | } |
| 2272 | rsv->size = btrfs_calc_trunc_metadata_size(root, 1); |
| 2273 | rsv->failfast = 1; |
| 2274 | |
| 2275 | /* |
| 2276 | * 1 - update the inode |
| 2277 | * 1 - removing the extents in the range |
| 2278 | * 1 - adding the hole extent if no_holes isn't set |
| 2279 | */ |
| 2280 | rsv_count = no_holes ? 2 : 3; |
| 2281 | trans = btrfs_start_transaction(root, rsv_count); |
| 2282 | if (IS_ERR(trans)) { |
| 2283 | err = PTR_ERR(trans); |
| 2284 | goto out_free; |
| 2285 | } |
| 2286 | |
| 2287 | ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv, |
| 2288 | min_size); |
| 2289 | BUG_ON(ret); |
| 2290 | trans->block_rsv = rsv; |
| 2291 | |
| 2292 | while (cur_offset < lockend) { |
| 2293 | ret = __btrfs_drop_extents(trans, root, inode, path, |
| 2294 | cur_offset, lockend + 1, |
| 2295 | &drop_end, 1, 0, 0, NULL); |
| 2296 | if (ret != -ENOSPC) |
| 2297 | break; |
| 2298 | |
| 2299 | trans->block_rsv = &root->fs_info->trans_block_rsv; |
| 2300 | |
| 2301 | if (cur_offset < ino_size) { |
| 2302 | ret = fill_holes(trans, inode, path, cur_offset, |
| 2303 | drop_end); |
| 2304 | if (ret) { |
| 2305 | err = ret; |
| 2306 | break; |
| 2307 | } |
| 2308 | } |
| 2309 | |
| 2310 | cur_offset = drop_end; |
| 2311 | |
| 2312 | ret = btrfs_update_inode(trans, root, inode); |
| 2313 | if (ret) { |
| 2314 | err = ret; |
| 2315 | break; |
| 2316 | } |
| 2317 | |
| 2318 | btrfs_end_transaction(trans, root); |
| 2319 | btrfs_btree_balance_dirty(root); |
| 2320 | |
| 2321 | trans = btrfs_start_transaction(root, rsv_count); |
| 2322 | if (IS_ERR(trans)) { |
| 2323 | ret = PTR_ERR(trans); |
| 2324 | trans = NULL; |
| 2325 | break; |
| 2326 | } |
| 2327 | |
| 2328 | ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, |
| 2329 | rsv, min_size); |
| 2330 | BUG_ON(ret); /* shouldn't happen */ |
| 2331 | trans->block_rsv = rsv; |
| 2332 | } |
| 2333 | |
| 2334 | if (ret) { |
| 2335 | err = ret; |
| 2336 | goto out_trans; |
| 2337 | } |
| 2338 | |
| 2339 | trans->block_rsv = &root->fs_info->trans_block_rsv; |
| 2340 | if (cur_offset < ino_size) { |
| 2341 | ret = fill_holes(trans, inode, path, cur_offset, drop_end); |
| 2342 | if (ret) { |
| 2343 | err = ret; |
| 2344 | goto out_trans; |
| 2345 | } |
| 2346 | } |
| 2347 | |
| 2348 | out_trans: |
| 2349 | if (!trans) |
| 2350 | goto out_free; |
| 2351 | |
| 2352 | inode_inc_iversion(inode); |
| 2353 | inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| 2354 | |
| 2355 | trans->block_rsv = &root->fs_info->trans_block_rsv; |
| 2356 | ret = btrfs_update_inode(trans, root, inode); |
| 2357 | btrfs_end_transaction(trans, root); |
| 2358 | btrfs_btree_balance_dirty(root); |
| 2359 | out_free: |
| 2360 | btrfs_free_path(path); |
| 2361 | btrfs_free_block_rsv(root, rsv); |
| 2362 | out: |
| 2363 | unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, |
| 2364 | &cached_state, GFP_NOFS); |
| 2365 | mutex_unlock(&inode->i_mutex); |
| 2366 | if (ret && !err) |
| 2367 | err = ret; |
| 2368 | return err; |
| 2369 | } |
| 2370 | |
| 2371 | static long btrfs_fallocate(struct file *file, int mode, |
| 2372 | loff_t offset, loff_t len) |
| 2373 | { |
| 2374 | struct inode *inode = file_inode(file); |
| 2375 | struct extent_state *cached_state = NULL; |
| 2376 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 2377 | u64 cur_offset; |
| 2378 | u64 last_byte; |
| 2379 | u64 alloc_start; |
| 2380 | u64 alloc_end; |
| 2381 | u64 alloc_hint = 0; |
| 2382 | u64 locked_end; |
| 2383 | struct extent_map *em; |
| 2384 | int blocksize = BTRFS_I(inode)->root->sectorsize; |
| 2385 | int ret; |
| 2386 | |
| 2387 | alloc_start = round_down(offset, blocksize); |
| 2388 | alloc_end = round_up(offset + len, blocksize); |
| 2389 | |
| 2390 | /* Make sure we aren't being give some crap mode */ |
| 2391 | if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)) |
| 2392 | return -EOPNOTSUPP; |
| 2393 | |
| 2394 | if (mode & FALLOC_FL_PUNCH_HOLE) |
| 2395 | return btrfs_punch_hole(inode, offset, len); |
| 2396 | |
| 2397 | /* |
| 2398 | * Make sure we have enough space before we do the |
| 2399 | * allocation. |
| 2400 | */ |
| 2401 | ret = btrfs_check_data_free_space(inode, alloc_end - alloc_start); |
| 2402 | if (ret) |
| 2403 | return ret; |
| 2404 | if (root->fs_info->quota_enabled) { |
| 2405 | ret = btrfs_qgroup_reserve(root, alloc_end - alloc_start); |
| 2406 | if (ret) |
| 2407 | goto out_reserve_fail; |
| 2408 | } |
| 2409 | |
| 2410 | mutex_lock(&inode->i_mutex); |
| 2411 | ret = inode_newsize_ok(inode, alloc_end); |
| 2412 | if (ret) |
| 2413 | goto out; |
| 2414 | |
| 2415 | if (alloc_start > inode->i_size) { |
| 2416 | ret = btrfs_cont_expand(inode, i_size_read(inode), |
| 2417 | alloc_start); |
| 2418 | if (ret) |
| 2419 | goto out; |
| 2420 | } else { |
| 2421 | /* |
| 2422 | * If we are fallocating from the end of the file onward we |
| 2423 | * need to zero out the end of the page if i_size lands in the |
| 2424 | * middle of a page. |
| 2425 | */ |
| 2426 | ret = btrfs_truncate_page(inode, inode->i_size, 0, 0); |
| 2427 | if (ret) |
| 2428 | goto out; |
| 2429 | } |
| 2430 | |
| 2431 | /* |
| 2432 | * wait for ordered IO before we have any locks. We'll loop again |
| 2433 | * below with the locks held. |
| 2434 | */ |
| 2435 | ret = btrfs_wait_ordered_range(inode, alloc_start, |
| 2436 | alloc_end - alloc_start); |
| 2437 | if (ret) |
| 2438 | goto out; |
| 2439 | |
| 2440 | locked_end = alloc_end - 1; |
| 2441 | while (1) { |
| 2442 | struct btrfs_ordered_extent *ordered; |
| 2443 | |
| 2444 | /* the extent lock is ordered inside the running |
| 2445 | * transaction |
| 2446 | */ |
| 2447 | lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start, |
| 2448 | locked_end, 0, &cached_state); |
| 2449 | ordered = btrfs_lookup_first_ordered_extent(inode, |
| 2450 | alloc_end - 1); |
| 2451 | if (ordered && |
| 2452 | ordered->file_offset + ordered->len > alloc_start && |
| 2453 | ordered->file_offset < alloc_end) { |
| 2454 | btrfs_put_ordered_extent(ordered); |
| 2455 | unlock_extent_cached(&BTRFS_I(inode)->io_tree, |
| 2456 | alloc_start, locked_end, |
| 2457 | &cached_state, GFP_NOFS); |
| 2458 | /* |
| 2459 | * we can't wait on the range with the transaction |
| 2460 | * running or with the extent lock held |
| 2461 | */ |
| 2462 | ret = btrfs_wait_ordered_range(inode, alloc_start, |
| 2463 | alloc_end - alloc_start); |
| 2464 | if (ret) |
| 2465 | goto out; |
| 2466 | } else { |
| 2467 | if (ordered) |
| 2468 | btrfs_put_ordered_extent(ordered); |
| 2469 | break; |
| 2470 | } |
| 2471 | } |
| 2472 | |
| 2473 | cur_offset = alloc_start; |
| 2474 | while (1) { |
| 2475 | u64 actual_end; |
| 2476 | |
| 2477 | em = btrfs_get_extent(inode, NULL, 0, cur_offset, |
| 2478 | alloc_end - cur_offset, 0); |
| 2479 | if (IS_ERR_OR_NULL(em)) { |
| 2480 | if (!em) |
| 2481 | ret = -ENOMEM; |
| 2482 | else |
| 2483 | ret = PTR_ERR(em); |
| 2484 | break; |
| 2485 | } |
| 2486 | last_byte = min(extent_map_end(em), alloc_end); |
| 2487 | actual_end = min_t(u64, extent_map_end(em), offset + len); |
| 2488 | last_byte = ALIGN(last_byte, blocksize); |
| 2489 | |
| 2490 | if (em->block_start == EXTENT_MAP_HOLE || |
| 2491 | (cur_offset >= inode->i_size && |
| 2492 | !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) { |
| 2493 | ret = btrfs_prealloc_file_range(inode, mode, cur_offset, |
| 2494 | last_byte - cur_offset, |
| 2495 | 1 << inode->i_blkbits, |
| 2496 | offset + len, |
| 2497 | &alloc_hint); |
| 2498 | |
| 2499 | if (ret < 0) { |
| 2500 | free_extent_map(em); |
| 2501 | break; |
| 2502 | } |
| 2503 | } else if (actual_end > inode->i_size && |
| 2504 | !(mode & FALLOC_FL_KEEP_SIZE)) { |
| 2505 | /* |
| 2506 | * We didn't need to allocate any more space, but we |
| 2507 | * still extended the size of the file so we need to |
| 2508 | * update i_size. |
| 2509 | */ |
| 2510 | inode->i_ctime = CURRENT_TIME; |
| 2511 | i_size_write(inode, actual_end); |
| 2512 | btrfs_ordered_update_i_size(inode, actual_end, NULL); |
| 2513 | } |
| 2514 | free_extent_map(em); |
| 2515 | |
| 2516 | cur_offset = last_byte; |
| 2517 | if (cur_offset >= alloc_end) { |
| 2518 | ret = 0; |
| 2519 | break; |
| 2520 | } |
| 2521 | } |
| 2522 | unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end, |
| 2523 | &cached_state, GFP_NOFS); |
| 2524 | out: |
| 2525 | mutex_unlock(&inode->i_mutex); |
| 2526 | if (root->fs_info->quota_enabled) |
| 2527 | btrfs_qgroup_free(root, alloc_end - alloc_start); |
| 2528 | out_reserve_fail: |
| 2529 | /* Let go of our reservation. */ |
| 2530 | btrfs_free_reserved_data_space(inode, alloc_end - alloc_start); |
| 2531 | return ret; |
| 2532 | } |
| 2533 | |
| 2534 | static int find_desired_extent(struct inode *inode, loff_t *offset, int whence) |
| 2535 | { |
| 2536 | struct btrfs_root *root = BTRFS_I(inode)->root; |
| 2537 | struct extent_map *em = NULL; |
| 2538 | struct extent_state *cached_state = NULL; |
| 2539 | u64 lockstart = *offset; |
| 2540 | u64 lockend = i_size_read(inode); |
| 2541 | u64 start = *offset; |
| 2542 | u64 len = i_size_read(inode); |
| 2543 | int ret = 0; |
| 2544 | |
| 2545 | lockend = max_t(u64, root->sectorsize, lockend); |
| 2546 | if (lockend <= lockstart) |
| 2547 | lockend = lockstart + root->sectorsize; |
| 2548 | |
| 2549 | lockend--; |
| 2550 | len = lockend - lockstart + 1; |
| 2551 | |
| 2552 | len = max_t(u64, len, root->sectorsize); |
| 2553 | if (inode->i_size == 0) |
| 2554 | return -ENXIO; |
| 2555 | |
| 2556 | lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 0, |
| 2557 | &cached_state); |
| 2558 | |
| 2559 | while (start < inode->i_size) { |
| 2560 | em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0); |
| 2561 | if (IS_ERR(em)) { |
| 2562 | ret = PTR_ERR(em); |
| 2563 | em = NULL; |
| 2564 | break; |
| 2565 | } |
| 2566 | |
| 2567 | if (whence == SEEK_HOLE && |
| 2568 | (em->block_start == EXTENT_MAP_HOLE || |
| 2569 | test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) |
| 2570 | break; |
| 2571 | else if (whence == SEEK_DATA && |
| 2572 | (em->block_start != EXTENT_MAP_HOLE && |
| 2573 | !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) |
| 2574 | break; |
| 2575 | |
| 2576 | start = em->start + em->len; |
| 2577 | free_extent_map(em); |
| 2578 | em = NULL; |
| 2579 | cond_resched(); |
| 2580 | } |
| 2581 | free_extent_map(em); |
| 2582 | if (!ret) { |
| 2583 | if (whence == SEEK_DATA && start >= inode->i_size) |
| 2584 | ret = -ENXIO; |
| 2585 | else |
| 2586 | *offset = min_t(loff_t, start, inode->i_size); |
| 2587 | } |
| 2588 | unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend, |
| 2589 | &cached_state, GFP_NOFS); |
| 2590 | return ret; |
| 2591 | } |
| 2592 | |
| 2593 | static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence) |
| 2594 | { |
| 2595 | struct inode *inode = file->f_mapping->host; |
| 2596 | int ret; |
| 2597 | |
| 2598 | mutex_lock(&inode->i_mutex); |
| 2599 | switch (whence) { |
| 2600 | case SEEK_END: |
| 2601 | case SEEK_CUR: |
| 2602 | offset = generic_file_llseek(file, offset, whence); |
| 2603 | goto out; |
| 2604 | case SEEK_DATA: |
| 2605 | case SEEK_HOLE: |
| 2606 | if (offset >= i_size_read(inode)) { |
| 2607 | mutex_unlock(&inode->i_mutex); |
| 2608 | return -ENXIO; |
| 2609 | } |
| 2610 | |
| 2611 | ret = find_desired_extent(inode, &offset, whence); |
| 2612 | if (ret) { |
| 2613 | mutex_unlock(&inode->i_mutex); |
| 2614 | return ret; |
| 2615 | } |
| 2616 | } |
| 2617 | |
| 2618 | offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes); |
| 2619 | out: |
| 2620 | mutex_unlock(&inode->i_mutex); |
| 2621 | return offset; |
| 2622 | } |
| 2623 | |
| 2624 | const struct file_operations btrfs_file_operations = { |
| 2625 | .llseek = btrfs_file_llseek, |
| 2626 | .read = do_sync_read, |
| 2627 | .write = do_sync_write, |
| 2628 | .aio_read = generic_file_aio_read, |
| 2629 | .splice_read = generic_file_splice_read, |
| 2630 | .aio_write = btrfs_file_aio_write, |
| 2631 | .mmap = btrfs_file_mmap, |
| 2632 | .open = generic_file_open, |
| 2633 | .release = btrfs_release_file, |
| 2634 | .fsync = btrfs_sync_file, |
| 2635 | .fallocate = btrfs_fallocate, |
| 2636 | .unlocked_ioctl = btrfs_ioctl, |
| 2637 | #ifdef CONFIG_COMPAT |
| 2638 | .compat_ioctl = btrfs_ioctl, |
| 2639 | #endif |
| 2640 | }; |
| 2641 | |
| 2642 | void btrfs_auto_defrag_exit(void) |
| 2643 | { |
| 2644 | if (btrfs_inode_defrag_cachep) |
| 2645 | kmem_cache_destroy(btrfs_inode_defrag_cachep); |
| 2646 | } |
| 2647 | |
| 2648 | int btrfs_auto_defrag_init(void) |
| 2649 | { |
| 2650 | btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag", |
| 2651 | sizeof(struct inode_defrag), 0, |
| 2652 | SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, |
| 2653 | NULL); |
| 2654 | if (!btrfs_inode_defrag_cachep) |
| 2655 | return -ENOMEM; |
| 2656 | |
| 2657 | return 0; |
| 2658 | } |