ext4: simplify list handling in ext4_do_flush_completed_IO()
[deliverable/linux.git] / fs / ext4 / inode.c
CommitLineData
ac27a0ec 1/*
617ba13b 2 * linux/fs/ext4/inode.c
ac27a0ec
DK
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/inode.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
ac27a0ec
DK
15 * 64-bit file support on 64-bit platforms by Jakub Jelinek
16 * (jj@sunsite.ms.mff.cuni.cz)
17 *
617ba13b 18 * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000
ac27a0ec
DK
19 */
20
ac27a0ec
DK
21#include <linux/fs.h>
22#include <linux/time.h>
dab291af 23#include <linux/jbd2.h>
ac27a0ec
DK
24#include <linux/highuid.h>
25#include <linux/pagemap.h>
26#include <linux/quotaops.h>
27#include <linux/string.h>
28#include <linux/buffer_head.h>
29#include <linux/writeback.h>
64769240 30#include <linux/pagevec.h>
ac27a0ec 31#include <linux/mpage.h>
e83c1397 32#include <linux/namei.h>
ac27a0ec
DK
33#include <linux/uio.h>
34#include <linux/bio.h>
4c0425ff 35#include <linux/workqueue.h>
744692dc 36#include <linux/kernel.h>
6db26ffc 37#include <linux/printk.h>
5a0e3ad6 38#include <linux/slab.h>
a8901d34 39#include <linux/ratelimit.h>
9bffad1e 40
3dcf5451 41#include "ext4_jbd2.h"
ac27a0ec
DK
42#include "xattr.h"
43#include "acl.h"
9f125d64 44#include "truncate.h"
ac27a0ec 45
9bffad1e
TT
46#include <trace/events/ext4.h>
47
a1d6cc56
AK
48#define MPAGE_DA_EXTENT_TAIL 0x01
49
814525f4
DW
50static __u32 ext4_inode_csum(struct inode *inode, struct ext4_inode *raw,
51 struct ext4_inode_info *ei)
52{
53 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
54 __u16 csum_lo;
55 __u16 csum_hi = 0;
56 __u32 csum;
57
58 csum_lo = raw->i_checksum_lo;
59 raw->i_checksum_lo = 0;
60 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
61 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) {
62 csum_hi = raw->i_checksum_hi;
63 raw->i_checksum_hi = 0;
64 }
65
66 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)raw,
67 EXT4_INODE_SIZE(inode->i_sb));
68
69 raw->i_checksum_lo = csum_lo;
70 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
71 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
72 raw->i_checksum_hi = csum_hi;
73
74 return csum;
75}
76
77static int ext4_inode_csum_verify(struct inode *inode, struct ext4_inode *raw,
78 struct ext4_inode_info *ei)
79{
80 __u32 provided, calculated;
81
82 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
83 cpu_to_le32(EXT4_OS_LINUX) ||
84 !EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
85 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
86 return 1;
87
88 provided = le16_to_cpu(raw->i_checksum_lo);
89 calculated = ext4_inode_csum(inode, raw, ei);
90 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
91 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
92 provided |= ((__u32)le16_to_cpu(raw->i_checksum_hi)) << 16;
93 else
94 calculated &= 0xFFFF;
95
96 return provided == calculated;
97}
98
99static void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw,
100 struct ext4_inode_info *ei)
101{
102 __u32 csum;
103
104 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
105 cpu_to_le32(EXT4_OS_LINUX) ||
106 !EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
107 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
108 return;
109
110 csum = ext4_inode_csum(inode, raw, ei);
111 raw->i_checksum_lo = cpu_to_le16(csum & 0xFFFF);
112 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
113 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
114 raw->i_checksum_hi = cpu_to_le16(csum >> 16);
115}
116
678aaf48
JK
117static inline int ext4_begin_ordered_truncate(struct inode *inode,
118 loff_t new_size)
119{
7ff9c073 120 trace_ext4_begin_ordered_truncate(inode, new_size);
8aefcd55
TT
121 /*
122 * If jinode is zero, then we never opened the file for
123 * writing, so there's no need to call
124 * jbd2_journal_begin_ordered_truncate() since there's no
125 * outstanding writes we need to flush.
126 */
127 if (!EXT4_I(inode)->jinode)
128 return 0;
129 return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode),
130 EXT4_I(inode)->jinode,
131 new_size);
678aaf48
JK
132}
133
64769240 134static void ext4_invalidatepage(struct page *page, unsigned long offset);
cb20d518
TT
135static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
136 struct buffer_head *bh_result, int create);
cb20d518
TT
137static int __ext4_journalled_writepage(struct page *page, unsigned int len);
138static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);
5f163cc7
ES
139static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
140 struct inode *inode, struct page *page, loff_t from,
141 loff_t length, int flags);
64769240 142
ac27a0ec
DK
143/*
144 * Test whether an inode is a fast symlink.
145 */
617ba13b 146static int ext4_inode_is_fast_symlink(struct inode *inode)
ac27a0ec 147{
617ba13b 148 int ea_blocks = EXT4_I(inode)->i_file_acl ?
ac27a0ec
DK
149 (inode->i_sb->s_blocksize >> 9) : 0;
150
151 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
152}
153
ac27a0ec
DK
154/*
155 * Restart the transaction associated with *handle. This does a commit,
156 * so before we call here everything must be consistently dirtied against
157 * this transaction.
158 */
fa5d1113 159int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
487caeef 160 int nblocks)
ac27a0ec 161{
487caeef
JK
162 int ret;
163
164 /*
e35fd660 165 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
487caeef
JK
166 * moment, get_block can be called only for blocks inside i_size since
167 * page cache has been already dropped and writes are blocked by
168 * i_mutex. So we can safely drop the i_data_sem here.
169 */
0390131b 170 BUG_ON(EXT4_JOURNAL(inode) == NULL);
ac27a0ec 171 jbd_debug(2, "restarting handle %p\n", handle);
487caeef 172 up_write(&EXT4_I(inode)->i_data_sem);
8e8eaabe 173 ret = ext4_journal_restart(handle, nblocks);
487caeef 174 down_write(&EXT4_I(inode)->i_data_sem);
fa5d1113 175 ext4_discard_preallocations(inode);
487caeef
JK
176
177 return ret;
ac27a0ec
DK
178}
179
180/*
181 * Called at the last iput() if i_nlink is zero.
182 */
0930fcc1 183void ext4_evict_inode(struct inode *inode)
ac27a0ec
DK
184{
185 handle_t *handle;
bc965ab3 186 int err;
ac27a0ec 187
7ff9c073 188 trace_ext4_evict_inode(inode);
2581fdc8 189
2581fdc8
JZ
190 ext4_ioend_wait(inode);
191
0930fcc1 192 if (inode->i_nlink) {
2d859db3
JK
193 /*
194 * When journalling data dirty buffers are tracked only in the
195 * journal. So although mm thinks everything is clean and
196 * ready for reaping the inode might still have some pages to
197 * write in the running transaction or waiting to be
198 * checkpointed. Thus calling jbd2_journal_invalidatepage()
199 * (via truncate_inode_pages()) to discard these buffers can
200 * cause data loss. Also even if we did not discard these
201 * buffers, we would have no way to find them after the inode
202 * is reaped and thus user could see stale data if he tries to
203 * read them before the transaction is checkpointed. So be
204 * careful and force everything to disk here... We use
205 * ei->i_datasync_tid to store the newest transaction
206 * containing inode's data.
207 *
208 * Note that directories do not have this problem because they
209 * don't use page cache.
210 */
211 if (ext4_should_journal_data(inode) &&
212 (S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode))) {
213 journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
214 tid_t commit_tid = EXT4_I(inode)->i_datasync_tid;
215
216 jbd2_log_start_commit(journal, commit_tid);
217 jbd2_log_wait_commit(journal, commit_tid);
218 filemap_write_and_wait(&inode->i_data);
219 }
0930fcc1
AV
220 truncate_inode_pages(&inode->i_data, 0);
221 goto no_delete;
222 }
223
907f4554 224 if (!is_bad_inode(inode))
871a2931 225 dquot_initialize(inode);
907f4554 226
678aaf48
JK
227 if (ext4_should_order_data(inode))
228 ext4_begin_ordered_truncate(inode, 0);
ac27a0ec
DK
229 truncate_inode_pages(&inode->i_data, 0);
230
231 if (is_bad_inode(inode))
232 goto no_delete;
233
8e8ad8a5
JK
234 /*
235 * Protect us against freezing - iput() caller didn't have to have any
236 * protection against it
237 */
238 sb_start_intwrite(inode->i_sb);
9f125d64 239 handle = ext4_journal_start(inode, ext4_blocks_for_truncate(inode)+3);
ac27a0ec 240 if (IS_ERR(handle)) {
bc965ab3 241 ext4_std_error(inode->i_sb, PTR_ERR(handle));
ac27a0ec
DK
242 /*
243 * If we're going to skip the normal cleanup, we still need to
244 * make sure that the in-core orphan linked list is properly
245 * cleaned up.
246 */
617ba13b 247 ext4_orphan_del(NULL, inode);
8e8ad8a5 248 sb_end_intwrite(inode->i_sb);
ac27a0ec
DK
249 goto no_delete;
250 }
251
252 if (IS_SYNC(inode))
0390131b 253 ext4_handle_sync(handle);
ac27a0ec 254 inode->i_size = 0;
bc965ab3
TT
255 err = ext4_mark_inode_dirty(handle, inode);
256 if (err) {
12062ddd 257 ext4_warning(inode->i_sb,
bc965ab3
TT
258 "couldn't mark inode dirty (err %d)", err);
259 goto stop_handle;
260 }
ac27a0ec 261 if (inode->i_blocks)
617ba13b 262 ext4_truncate(inode);
bc965ab3
TT
263
264 /*
265 * ext4_ext_truncate() doesn't reserve any slop when it
266 * restarts journal transactions; therefore there may not be
267 * enough credits left in the handle to remove the inode from
268 * the orphan list and set the dtime field.
269 */
0390131b 270 if (!ext4_handle_has_enough_credits(handle, 3)) {
bc965ab3
TT
271 err = ext4_journal_extend(handle, 3);
272 if (err > 0)
273 err = ext4_journal_restart(handle, 3);
274 if (err != 0) {
12062ddd 275 ext4_warning(inode->i_sb,
bc965ab3
TT
276 "couldn't extend journal (err %d)", err);
277 stop_handle:
278 ext4_journal_stop(handle);
45388219 279 ext4_orphan_del(NULL, inode);
8e8ad8a5 280 sb_end_intwrite(inode->i_sb);
bc965ab3
TT
281 goto no_delete;
282 }
283 }
284
ac27a0ec 285 /*
617ba13b 286 * Kill off the orphan record which ext4_truncate created.
ac27a0ec 287 * AKPM: I think this can be inside the above `if'.
617ba13b 288 * Note that ext4_orphan_del() has to be able to cope with the
ac27a0ec 289 * deletion of a non-existent orphan - this is because we don't
617ba13b 290 * know if ext4_truncate() actually created an orphan record.
ac27a0ec
DK
291 * (Well, we could do this if we need to, but heck - it works)
292 */
617ba13b
MC
293 ext4_orphan_del(handle, inode);
294 EXT4_I(inode)->i_dtime = get_seconds();
ac27a0ec
DK
295
296 /*
297 * One subtle ordering requirement: if anything has gone wrong
298 * (transaction abort, IO errors, whatever), then we can still
299 * do these next steps (the fs will already have been marked as
300 * having errors), but we can't free the inode if the mark_dirty
301 * fails.
302 */
617ba13b 303 if (ext4_mark_inode_dirty(handle, inode))
ac27a0ec 304 /* If that failed, just do the required in-core inode clear. */
0930fcc1 305 ext4_clear_inode(inode);
ac27a0ec 306 else
617ba13b
MC
307 ext4_free_inode(handle, inode);
308 ext4_journal_stop(handle);
8e8ad8a5 309 sb_end_intwrite(inode->i_sb);
ac27a0ec
DK
310 return;
311no_delete:
0930fcc1 312 ext4_clear_inode(inode); /* We must guarantee clearing of inode... */
ac27a0ec
DK
313}
314
a9e7f447
DM
315#ifdef CONFIG_QUOTA
316qsize_t *ext4_get_reserved_space(struct inode *inode)
60e58e0f 317{
a9e7f447 318 return &EXT4_I(inode)->i_reserved_quota;
60e58e0f 319}
a9e7f447 320#endif
9d0be502 321
12219aea
AK
322/*
323 * Calculate the number of metadata blocks need to reserve
9d0be502 324 * to allocate a block located at @lblock
12219aea 325 */
01f49d0b 326static int ext4_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
12219aea 327{
12e9b892 328 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
9d0be502 329 return ext4_ext_calc_metadata_amount(inode, lblock);
12219aea 330
8bb2b247 331 return ext4_ind_calc_metadata_amount(inode, lblock);
12219aea
AK
332}
333
0637c6f4
TT
334/*
335 * Called with i_data_sem down, which is important since we can call
336 * ext4_discard_preallocations() from here.
337 */
5f634d06
AK
338void ext4_da_update_reserve_space(struct inode *inode,
339 int used, int quota_claim)
12219aea
AK
340{
341 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
0637c6f4 342 struct ext4_inode_info *ei = EXT4_I(inode);
0637c6f4
TT
343
344 spin_lock(&ei->i_block_reservation_lock);
d8990240 345 trace_ext4_da_update_reserve_space(inode, used, quota_claim);
0637c6f4
TT
346 if (unlikely(used > ei->i_reserved_data_blocks)) {
347 ext4_msg(inode->i_sb, KERN_NOTICE, "%s: ino %lu, used %d "
1084f252 348 "with only %d reserved data blocks",
0637c6f4
TT
349 __func__, inode->i_ino, used,
350 ei->i_reserved_data_blocks);
351 WARN_ON(1);
352 used = ei->i_reserved_data_blocks;
353 }
12219aea 354
97795d2a
BF
355 if (unlikely(ei->i_allocated_meta_blocks > ei->i_reserved_meta_blocks)) {
356 ext4_msg(inode->i_sb, KERN_NOTICE, "%s: ino %lu, allocated %d "
357 "with only %d reserved metadata blocks\n", __func__,
358 inode->i_ino, ei->i_allocated_meta_blocks,
359 ei->i_reserved_meta_blocks);
360 WARN_ON(1);
361 ei->i_allocated_meta_blocks = ei->i_reserved_meta_blocks;
362 }
363
0637c6f4
TT
364 /* Update per-inode reservations */
365 ei->i_reserved_data_blocks -= used;
0637c6f4 366 ei->i_reserved_meta_blocks -= ei->i_allocated_meta_blocks;
57042651 367 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
72b8ab9d 368 used + ei->i_allocated_meta_blocks);
0637c6f4 369 ei->i_allocated_meta_blocks = 0;
6bc6e63f 370
0637c6f4
TT
371 if (ei->i_reserved_data_blocks == 0) {
372 /*
373 * We can release all of the reserved metadata blocks
374 * only when we have written all of the delayed
375 * allocation blocks.
376 */
57042651 377 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
72b8ab9d 378 ei->i_reserved_meta_blocks);
ee5f4d9c 379 ei->i_reserved_meta_blocks = 0;
9d0be502 380 ei->i_da_metadata_calc_len = 0;
6bc6e63f 381 }
12219aea 382 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
60e58e0f 383
72b8ab9d
ES
384 /* Update quota subsystem for data blocks */
385 if (quota_claim)
7b415bf6 386 dquot_claim_block(inode, EXT4_C2B(sbi, used));
72b8ab9d 387 else {
5f634d06
AK
388 /*
389 * We did fallocate with an offset that is already delayed
390 * allocated. So on delayed allocated writeback we should
72b8ab9d 391 * not re-claim the quota for fallocated blocks.
5f634d06 392 */
7b415bf6 393 dquot_release_reservation_block(inode, EXT4_C2B(sbi, used));
5f634d06 394 }
d6014301
AK
395
396 /*
397 * If we have done all the pending block allocations and if
398 * there aren't any writers on the inode, we can discard the
399 * inode's preallocations.
400 */
0637c6f4
TT
401 if ((ei->i_reserved_data_blocks == 0) &&
402 (atomic_read(&inode->i_writecount) == 0))
d6014301 403 ext4_discard_preallocations(inode);
12219aea
AK
404}
405
e29136f8 406static int __check_block_validity(struct inode *inode, const char *func,
c398eda0
TT
407 unsigned int line,
408 struct ext4_map_blocks *map)
6fd058f7 409{
24676da4
TT
410 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk,
411 map->m_len)) {
c398eda0
TT
412 ext4_error_inode(inode, func, line, map->m_pblk,
413 "lblock %lu mapped to illegal pblock "
414 "(length %d)", (unsigned long) map->m_lblk,
415 map->m_len);
6fd058f7
TT
416 return -EIO;
417 }
418 return 0;
419}
420
e29136f8 421#define check_block_validity(inode, map) \
c398eda0 422 __check_block_validity((inode), __func__, __LINE__, (map))
e29136f8 423
55138e0b 424/*
1f94533d
TT
425 * Return the number of contiguous dirty pages in a given inode
426 * starting at page frame idx.
55138e0b
TT
427 */
428static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx,
429 unsigned int max_pages)
430{
431 struct address_space *mapping = inode->i_mapping;
432 pgoff_t index;
433 struct pagevec pvec;
434 pgoff_t num = 0;
435 int i, nr_pages, done = 0;
436
437 if (max_pages == 0)
438 return 0;
439 pagevec_init(&pvec, 0);
440 while (!done) {
441 index = idx;
442 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index,
443 PAGECACHE_TAG_DIRTY,
444 (pgoff_t)PAGEVEC_SIZE);
445 if (nr_pages == 0)
446 break;
447 for (i = 0; i < nr_pages; i++) {
448 struct page *page = pvec.pages[i];
449 struct buffer_head *bh, *head;
450
451 lock_page(page);
452 if (unlikely(page->mapping != mapping) ||
453 !PageDirty(page) ||
454 PageWriteback(page) ||
455 page->index != idx) {
456 done = 1;
457 unlock_page(page);
458 break;
459 }
1f94533d
TT
460 if (page_has_buffers(page)) {
461 bh = head = page_buffers(page);
462 do {
463 if (!buffer_delay(bh) &&
464 !buffer_unwritten(bh))
465 done = 1;
466 bh = bh->b_this_page;
467 } while (!done && (bh != head));
468 }
55138e0b
TT
469 unlock_page(page);
470 if (done)
471 break;
472 idx++;
473 num++;
659c6009
ES
474 if (num >= max_pages) {
475 done = 1;
55138e0b 476 break;
659c6009 477 }
55138e0b
TT
478 }
479 pagevec_release(&pvec);
480 }
481 return num;
482}
483
f5ab0d1f 484/*
e35fd660 485 * The ext4_map_blocks() function tries to look up the requested blocks,
2b2d6d01 486 * and returns if the blocks are already mapped.
f5ab0d1f 487 *
f5ab0d1f
MC
488 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
489 * and store the allocated blocks in the result buffer head and mark it
490 * mapped.
491 *
e35fd660
TT
492 * If file type is extents based, it will call ext4_ext_map_blocks(),
493 * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
f5ab0d1f
MC
494 * based files
495 *
496 * On success, it returns the number of blocks being mapped or allocate.
497 * if create==0 and the blocks are pre-allocated and uninitialized block,
498 * the result buffer head is unmapped. If the create ==1, it will make sure
499 * the buffer head is mapped.
500 *
501 * It returns 0 if plain look up failed (blocks have not been allocated), in
df3ab170 502 * that case, buffer head is unmapped
f5ab0d1f
MC
503 *
504 * It returns the error in case of allocation failure.
505 */
e35fd660
TT
506int ext4_map_blocks(handle_t *handle, struct inode *inode,
507 struct ext4_map_blocks *map, int flags)
0e855ac8
AK
508{
509 int retval;
f5ab0d1f 510
e35fd660
TT
511 map->m_flags = 0;
512 ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
513 "logical block %lu\n", inode->i_ino, flags, map->m_len,
514 (unsigned long) map->m_lblk);
4df3d265 515 /*
b920c755
TT
516 * Try to see if we can get the block without requesting a new
517 * file system block.
4df3d265 518 */
729f52c6
ZL
519 if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
520 down_read((&EXT4_I(inode)->i_data_sem));
12e9b892 521 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
a4e5d88b
DM
522 retval = ext4_ext_map_blocks(handle, inode, map, flags &
523 EXT4_GET_BLOCKS_KEEP_SIZE);
0e855ac8 524 } else {
a4e5d88b
DM
525 retval = ext4_ind_map_blocks(handle, inode, map, flags &
526 EXT4_GET_BLOCKS_KEEP_SIZE);
0e855ac8 527 }
729f52c6
ZL
528 if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
529 up_read((&EXT4_I(inode)->i_data_sem));
f5ab0d1f 530
e35fd660 531 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
51865fda
ZL
532 int ret;
533 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
534 /* delayed alloc may be allocated by fallocate and
535 * coverted to initialized by directIO.
536 * we need to handle delayed extent here.
537 */
538 down_write((&EXT4_I(inode)->i_data_sem));
539 goto delayed_mapped;
540 }
541 ret = check_block_validity(inode, map);
6fd058f7
TT
542 if (ret != 0)
543 return ret;
544 }
545
f5ab0d1f 546 /* If it is only a block(s) look up */
c2177057 547 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
f5ab0d1f
MC
548 return retval;
549
550 /*
551 * Returns if the blocks have already allocated
552 *
553 * Note that if blocks have been preallocated
df3ab170 554 * ext4_ext_get_block() returns the create = 0
f5ab0d1f
MC
555 * with buffer head unmapped.
556 */
e35fd660 557 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
4df3d265
AK
558 return retval;
559
2a8964d6
AK
560 /*
561 * When we call get_blocks without the create flag, the
562 * BH_Unwritten flag could have gotten set if the blocks
563 * requested were part of a uninitialized extent. We need to
564 * clear this flag now that we are committed to convert all or
565 * part of the uninitialized extent to be an initialized
566 * extent. This is because we need to avoid the combination
567 * of BH_Unwritten and BH_Mapped flags being simultaneously
568 * set on the buffer_head.
569 */
e35fd660 570 map->m_flags &= ~EXT4_MAP_UNWRITTEN;
2a8964d6 571
4df3d265 572 /*
f5ab0d1f
MC
573 * New blocks allocate and/or writing to uninitialized extent
574 * will possibly result in updating i_data, so we take
575 * the write lock of i_data_sem, and call get_blocks()
576 * with create == 1 flag.
4df3d265
AK
577 */
578 down_write((&EXT4_I(inode)->i_data_sem));
d2a17637
MC
579
580 /*
581 * if the caller is from delayed allocation writeout path
582 * we have already reserved fs blocks for allocation
583 * let the underlying get_block() function know to
584 * avoid double accounting
585 */
c2177057 586 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
f2321097 587 ext4_set_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
4df3d265
AK
588 /*
589 * We need to check for EXT4 here because migrate
590 * could have changed the inode type in between
591 */
12e9b892 592 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
e35fd660 593 retval = ext4_ext_map_blocks(handle, inode, map, flags);
0e855ac8 594 } else {
e35fd660 595 retval = ext4_ind_map_blocks(handle, inode, map, flags);
267e4db9 596
e35fd660 597 if (retval > 0 && map->m_flags & EXT4_MAP_NEW) {
267e4db9
AK
598 /*
599 * We allocated new blocks which will result in
600 * i_data's format changing. Force the migrate
601 * to fail by clearing migrate flags
602 */
19f5fb7a 603 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
267e4db9 604 }
d2a17637 605
5f634d06
AK
606 /*
607 * Update reserved blocks/metadata blocks after successful
608 * block allocation which had been deferred till now. We don't
609 * support fallocate for non extent files. So we can update
610 * reserve space here.
611 */
612 if ((retval > 0) &&
1296cc85 613 (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE))
5f634d06
AK
614 ext4_da_update_reserve_space(inode, retval, 1);
615 }
5356f261 616 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
f2321097 617 ext4_clear_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
2ac3b6e0 618
51865fda
ZL
619 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
620 int ret;
51865fda
ZL
621delayed_mapped:
622 /* delayed allocation blocks has been allocated */
623 ret = ext4_es_remove_extent(inode, map->m_lblk,
624 map->m_len);
625 if (ret < 0)
626 retval = ret;
627 }
5356f261
AK
628 }
629
4df3d265 630 up_write((&EXT4_I(inode)->i_data_sem));
e35fd660 631 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
e29136f8 632 int ret = check_block_validity(inode, map);
6fd058f7
TT
633 if (ret != 0)
634 return ret;
635 }
0e855ac8
AK
636 return retval;
637}
638
f3bd1f3f
MC
639/* Maximum number of blocks we map for direct IO at once. */
640#define DIO_MAX_BLOCKS 4096
641
2ed88685
TT
642static int _ext4_get_block(struct inode *inode, sector_t iblock,
643 struct buffer_head *bh, int flags)
ac27a0ec 644{
3e4fdaf8 645 handle_t *handle = ext4_journal_current_handle();
2ed88685 646 struct ext4_map_blocks map;
7fb5409d 647 int ret = 0, started = 0;
f3bd1f3f 648 int dio_credits;
ac27a0ec 649
46c7f254
TM
650 if (ext4_has_inline_data(inode))
651 return -ERANGE;
652
2ed88685
TT
653 map.m_lblk = iblock;
654 map.m_len = bh->b_size >> inode->i_blkbits;
655
8b0f165f 656 if (flags && !(flags & EXT4_GET_BLOCKS_NO_LOCK) && !handle) {
7fb5409d 657 /* Direct IO write... */
2ed88685
TT
658 if (map.m_len > DIO_MAX_BLOCKS)
659 map.m_len = DIO_MAX_BLOCKS;
660 dio_credits = ext4_chunk_trans_blocks(inode, map.m_len);
f3bd1f3f 661 handle = ext4_journal_start(inode, dio_credits);
7fb5409d 662 if (IS_ERR(handle)) {
ac27a0ec 663 ret = PTR_ERR(handle);
2ed88685 664 return ret;
ac27a0ec 665 }
7fb5409d 666 started = 1;
ac27a0ec
DK
667 }
668
2ed88685 669 ret = ext4_map_blocks(handle, inode, &map, flags);
7fb5409d 670 if (ret > 0) {
2ed88685
TT
671 map_bh(bh, inode->i_sb, map.m_pblk);
672 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
673 bh->b_size = inode->i_sb->s_blocksize * map.m_len;
7fb5409d 674 ret = 0;
ac27a0ec 675 }
7fb5409d
JK
676 if (started)
677 ext4_journal_stop(handle);
ac27a0ec
DK
678 return ret;
679}
680
2ed88685
TT
681int ext4_get_block(struct inode *inode, sector_t iblock,
682 struct buffer_head *bh, int create)
683{
684 return _ext4_get_block(inode, iblock, bh,
685 create ? EXT4_GET_BLOCKS_CREATE : 0);
686}
687
ac27a0ec
DK
688/*
689 * `handle' can be NULL if create is zero
690 */
617ba13b 691struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
725d26d3 692 ext4_lblk_t block, int create, int *errp)
ac27a0ec 693{
2ed88685
TT
694 struct ext4_map_blocks map;
695 struct buffer_head *bh;
ac27a0ec
DK
696 int fatal = 0, err;
697
698 J_ASSERT(handle != NULL || create == 0);
699
2ed88685
TT
700 map.m_lblk = block;
701 map.m_len = 1;
702 err = ext4_map_blocks(handle, inode, &map,
703 create ? EXT4_GET_BLOCKS_CREATE : 0);
ac27a0ec 704
90b0a973
CM
705 /* ensure we send some value back into *errp */
706 *errp = 0;
707
2ed88685
TT
708 if (err < 0)
709 *errp = err;
710 if (err <= 0)
711 return NULL;
2ed88685
TT
712
713 bh = sb_getblk(inode->i_sb, map.m_pblk);
aebf0243 714 if (unlikely(!bh)) {
860d21e2 715 *errp = -ENOMEM;
2ed88685 716 return NULL;
ac27a0ec 717 }
2ed88685
TT
718 if (map.m_flags & EXT4_MAP_NEW) {
719 J_ASSERT(create != 0);
720 J_ASSERT(handle != NULL);
ac27a0ec 721
2ed88685
TT
722 /*
723 * Now that we do not always journal data, we should
724 * keep in mind whether this should always journal the
725 * new buffer as metadata. For now, regular file
726 * writes use ext4_get_block instead, so it's not a
727 * problem.
728 */
729 lock_buffer(bh);
730 BUFFER_TRACE(bh, "call get_create_access");
731 fatal = ext4_journal_get_create_access(handle, bh);
732 if (!fatal && !buffer_uptodate(bh)) {
733 memset(bh->b_data, 0, inode->i_sb->s_blocksize);
734 set_buffer_uptodate(bh);
ac27a0ec 735 }
2ed88685
TT
736 unlock_buffer(bh);
737 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
738 err = ext4_handle_dirty_metadata(handle, inode, bh);
739 if (!fatal)
740 fatal = err;
741 } else {
742 BUFFER_TRACE(bh, "not a new buffer");
ac27a0ec 743 }
2ed88685
TT
744 if (fatal) {
745 *errp = fatal;
746 brelse(bh);
747 bh = NULL;
748 }
749 return bh;
ac27a0ec
DK
750}
751
617ba13b 752struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
725d26d3 753 ext4_lblk_t block, int create, int *err)
ac27a0ec 754{
af5bc92d 755 struct buffer_head *bh;
ac27a0ec 756
617ba13b 757 bh = ext4_getblk(handle, inode, block, create, err);
ac27a0ec
DK
758 if (!bh)
759 return bh;
760 if (buffer_uptodate(bh))
761 return bh;
65299a3b 762 ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh);
ac27a0ec
DK
763 wait_on_buffer(bh);
764 if (buffer_uptodate(bh))
765 return bh;
766 put_bh(bh);
767 *err = -EIO;
768 return NULL;
769}
770
f19d5870
TM
771int ext4_walk_page_buffers(handle_t *handle,
772 struct buffer_head *head,
773 unsigned from,
774 unsigned to,
775 int *partial,
776 int (*fn)(handle_t *handle,
777 struct buffer_head *bh))
ac27a0ec
DK
778{
779 struct buffer_head *bh;
780 unsigned block_start, block_end;
781 unsigned blocksize = head->b_size;
782 int err, ret = 0;
783 struct buffer_head *next;
784
af5bc92d
TT
785 for (bh = head, block_start = 0;
786 ret == 0 && (bh != head || !block_start);
de9a55b8 787 block_start = block_end, bh = next) {
ac27a0ec
DK
788 next = bh->b_this_page;
789 block_end = block_start + blocksize;
790 if (block_end <= from || block_start >= to) {
791 if (partial && !buffer_uptodate(bh))
792 *partial = 1;
793 continue;
794 }
795 err = (*fn)(handle, bh);
796 if (!ret)
797 ret = err;
798 }
799 return ret;
800}
801
802/*
803 * To preserve ordering, it is essential that the hole instantiation and
804 * the data write be encapsulated in a single transaction. We cannot
617ba13b 805 * close off a transaction and start a new one between the ext4_get_block()
dab291af 806 * and the commit_write(). So doing the jbd2_journal_start at the start of
ac27a0ec
DK
807 * prepare_write() is the right place.
808 *
36ade451
JK
809 * Also, this function can nest inside ext4_writepage(). In that case, we
810 * *know* that ext4_writepage() has generated enough buffer credits to do the
811 * whole page. So we won't block on the journal in that case, which is good,
812 * because the caller may be PF_MEMALLOC.
ac27a0ec 813 *
617ba13b 814 * By accident, ext4 can be reentered when a transaction is open via
ac27a0ec
DK
815 * quota file writes. If we were to commit the transaction while thus
816 * reentered, there can be a deadlock - we would be holding a quota
817 * lock, and the commit would never complete if another thread had a
818 * transaction open and was blocking on the quota lock - a ranking
819 * violation.
820 *
dab291af 821 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
ac27a0ec
DK
822 * will _not_ run commit under these circumstances because handle->h_ref
823 * is elevated. We'll still have enough credits for the tiny quotafile
824 * write.
825 */
f19d5870
TM
826int do_journal_get_write_access(handle_t *handle,
827 struct buffer_head *bh)
ac27a0ec 828{
56d35a4c
JK
829 int dirty = buffer_dirty(bh);
830 int ret;
831
ac27a0ec
DK
832 if (!buffer_mapped(bh) || buffer_freed(bh))
833 return 0;
56d35a4c 834 /*
ebdec241 835 * __block_write_begin() could have dirtied some buffers. Clean
56d35a4c
JK
836 * the dirty bit as jbd2_journal_get_write_access() could complain
837 * otherwise about fs integrity issues. Setting of the dirty bit
ebdec241 838 * by __block_write_begin() isn't a real problem here as we clear
56d35a4c
JK
839 * the bit before releasing a page lock and thus writeback cannot
840 * ever write the buffer.
841 */
842 if (dirty)
843 clear_buffer_dirty(bh);
844 ret = ext4_journal_get_write_access(handle, bh);
845 if (!ret && dirty)
846 ret = ext4_handle_dirty_metadata(handle, NULL, bh);
847 return ret;
ac27a0ec
DK
848}
849
8b0f165f
AP
850static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock,
851 struct buffer_head *bh_result, int create);
bfc1af65 852static int ext4_write_begin(struct file *file, struct address_space *mapping,
de9a55b8
TT
853 loff_t pos, unsigned len, unsigned flags,
854 struct page **pagep, void **fsdata)
ac27a0ec 855{
af5bc92d 856 struct inode *inode = mapping->host;
1938a150 857 int ret, needed_blocks;
ac27a0ec
DK
858 handle_t *handle;
859 int retries = 0;
af5bc92d 860 struct page *page;
de9a55b8 861 pgoff_t index;
af5bc92d 862 unsigned from, to;
bfc1af65 863
9bffad1e 864 trace_ext4_write_begin(inode, pos, len, flags);
1938a150
AK
865 /*
866 * Reserve one block more for addition to orphan list in case
867 * we allocate blocks but write fails for some reason
868 */
869 needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
de9a55b8 870 index = pos >> PAGE_CACHE_SHIFT;
af5bc92d
TT
871 from = pos & (PAGE_CACHE_SIZE - 1);
872 to = from + len;
ac27a0ec 873
f19d5870
TM
874 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
875 ret = ext4_try_to_write_inline_data(mapping, inode, pos, len,
876 flags, pagep);
877 if (ret < 0)
878 goto out;
879 if (ret == 1) {
880 ret = 0;
881 goto out;
882 }
883 }
884
ac27a0ec 885retry:
af5bc92d
TT
886 handle = ext4_journal_start(inode, needed_blocks);
887 if (IS_ERR(handle)) {
888 ret = PTR_ERR(handle);
889 goto out;
7479d2b9 890 }
ac27a0ec 891
ebd3610b
JK
892 /* We cannot recurse into the filesystem as the transaction is already
893 * started */
894 flags |= AOP_FLAG_NOFS;
895
54566b2c 896 page = grab_cache_page_write_begin(mapping, index, flags);
cf108bca
JK
897 if (!page) {
898 ext4_journal_stop(handle);
899 ret = -ENOMEM;
900 goto out;
901 }
f19d5870 902
cf108bca
JK
903 *pagep = page;
904
744692dc 905 if (ext4_should_dioread_nolock(inode))
6e1db88d 906 ret = __block_write_begin(page, pos, len, ext4_get_block_write);
744692dc 907 else
6e1db88d 908 ret = __block_write_begin(page, pos, len, ext4_get_block);
bfc1af65
NP
909
910 if (!ret && ext4_should_journal_data(inode)) {
f19d5870
TM
911 ret = ext4_walk_page_buffers(handle, page_buffers(page),
912 from, to, NULL,
913 do_journal_get_write_access);
ac27a0ec 914 }
bfc1af65
NP
915
916 if (ret) {
af5bc92d 917 unlock_page(page);
af5bc92d 918 page_cache_release(page);
ae4d5372 919 /*
6e1db88d 920 * __block_write_begin may have instantiated a few blocks
ae4d5372
AK
921 * outside i_size. Trim these off again. Don't need
922 * i_size_read because we hold i_mutex.
1938a150
AK
923 *
924 * Add inode to orphan list in case we crash before
925 * truncate finishes
ae4d5372 926 */
ffacfa7a 927 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1938a150
AK
928 ext4_orphan_add(handle, inode);
929
930 ext4_journal_stop(handle);
931 if (pos + len > inode->i_size) {
b9a4207d 932 ext4_truncate_failed_write(inode);
de9a55b8 933 /*
ffacfa7a 934 * If truncate failed early the inode might
1938a150
AK
935 * still be on the orphan list; we need to
936 * make sure the inode is removed from the
937 * orphan list in that case.
938 */
939 if (inode->i_nlink)
940 ext4_orphan_del(NULL, inode);
941 }
bfc1af65
NP
942 }
943
617ba13b 944 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
ac27a0ec 945 goto retry;
7479d2b9 946out:
ac27a0ec
DK
947 return ret;
948}
949
bfc1af65
NP
950/* For write_end() in data=journal mode */
951static int write_end_fn(handle_t *handle, struct buffer_head *bh)
ac27a0ec
DK
952{
953 if (!buffer_mapped(bh) || buffer_freed(bh))
954 return 0;
955 set_buffer_uptodate(bh);
0390131b 956 return ext4_handle_dirty_metadata(handle, NULL, bh);
ac27a0ec
DK
957}
958
f8514083 959static int ext4_generic_write_end(struct file *file,
de9a55b8
TT
960 struct address_space *mapping,
961 loff_t pos, unsigned len, unsigned copied,
962 struct page *page, void *fsdata)
f8514083
AK
963{
964 int i_size_changed = 0;
965 struct inode *inode = mapping->host;
966 handle_t *handle = ext4_journal_current_handle();
967
f19d5870
TM
968 if (ext4_has_inline_data(inode))
969 copied = ext4_write_inline_data_end(inode, pos, len,
970 copied, page);
971 else
972 copied = block_write_end(file, mapping, pos,
973 len, copied, page, fsdata);
f8514083
AK
974
975 /*
976 * No need to use i_size_read() here, the i_size
977 * cannot change under us because we hold i_mutex.
978 *
979 * But it's important to update i_size while still holding page lock:
980 * page writeout could otherwise come in and zero beyond i_size.
981 */
982 if (pos + copied > inode->i_size) {
983 i_size_write(inode, pos + copied);
984 i_size_changed = 1;
985 }
986
987 if (pos + copied > EXT4_I(inode)->i_disksize) {
988 /* We need to mark inode dirty even if
989 * new_i_size is less that inode->i_size
990 * bu greater than i_disksize.(hint delalloc)
991 */
992 ext4_update_i_disksize(inode, (pos + copied));
993 i_size_changed = 1;
994 }
995 unlock_page(page);
996 page_cache_release(page);
997
998 /*
999 * Don't mark the inode dirty under page lock. First, it unnecessarily
1000 * makes the holding time of page lock longer. Second, it forces lock
1001 * ordering of page lock and transaction start for journaling
1002 * filesystems.
1003 */
1004 if (i_size_changed)
1005 ext4_mark_inode_dirty(handle, inode);
1006
1007 return copied;
1008}
1009
ac27a0ec
DK
1010/*
1011 * We need to pick up the new inode size which generic_commit_write gave us
1012 * `file' can be NULL - eg, when called from page_symlink().
1013 *
617ba13b 1014 * ext4 never places buffers on inode->i_mapping->private_list. metadata
ac27a0ec
DK
1015 * buffers are managed internally.
1016 */
bfc1af65 1017static int ext4_ordered_write_end(struct file *file,
de9a55b8
TT
1018 struct address_space *mapping,
1019 loff_t pos, unsigned len, unsigned copied,
1020 struct page *page, void *fsdata)
ac27a0ec 1021{
617ba13b 1022 handle_t *handle = ext4_journal_current_handle();
cf108bca 1023 struct inode *inode = mapping->host;
ac27a0ec
DK
1024 int ret = 0, ret2;
1025
9bffad1e 1026 trace_ext4_ordered_write_end(inode, pos, len, copied);
678aaf48 1027 ret = ext4_jbd2_file_inode(handle, inode);
ac27a0ec
DK
1028
1029 if (ret == 0) {
f8514083 1030 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
bfc1af65 1031 page, fsdata);
f8a87d89 1032 copied = ret2;
ffacfa7a 1033 if (pos + len > inode->i_size && ext4_can_truncate(inode))
f8514083
AK
1034 /* if we have allocated more blocks and copied
1035 * less. We will have blocks allocated outside
1036 * inode->i_size. So truncate them
1037 */
1038 ext4_orphan_add(handle, inode);
f8a87d89
RK
1039 if (ret2 < 0)
1040 ret = ret2;
09e0834f
AF
1041 } else {
1042 unlock_page(page);
1043 page_cache_release(page);
ac27a0ec 1044 }
09e0834f 1045
617ba13b 1046 ret2 = ext4_journal_stop(handle);
ac27a0ec
DK
1047 if (!ret)
1048 ret = ret2;
bfc1af65 1049
f8514083 1050 if (pos + len > inode->i_size) {
b9a4207d 1051 ext4_truncate_failed_write(inode);
de9a55b8 1052 /*
ffacfa7a 1053 * If truncate failed early the inode might still be
f8514083
AK
1054 * on the orphan list; we need to make sure the inode
1055 * is removed from the orphan list in that case.
1056 */
1057 if (inode->i_nlink)
1058 ext4_orphan_del(NULL, inode);
1059 }
1060
1061
bfc1af65 1062 return ret ? ret : copied;
ac27a0ec
DK
1063}
1064
bfc1af65 1065static int ext4_writeback_write_end(struct file *file,
de9a55b8
TT
1066 struct address_space *mapping,
1067 loff_t pos, unsigned len, unsigned copied,
1068 struct page *page, void *fsdata)
ac27a0ec 1069{
617ba13b 1070 handle_t *handle = ext4_journal_current_handle();
cf108bca 1071 struct inode *inode = mapping->host;
ac27a0ec 1072 int ret = 0, ret2;
ac27a0ec 1073
9bffad1e 1074 trace_ext4_writeback_write_end(inode, pos, len, copied);
f8514083 1075 ret2 = ext4_generic_write_end(file, mapping, pos, len, copied,
bfc1af65 1076 page, fsdata);
f8a87d89 1077 copied = ret2;
ffacfa7a 1078 if (pos + len > inode->i_size && ext4_can_truncate(inode))
f8514083
AK
1079 /* if we have allocated more blocks and copied
1080 * less. We will have blocks allocated outside
1081 * inode->i_size. So truncate them
1082 */
1083 ext4_orphan_add(handle, inode);
1084
f8a87d89
RK
1085 if (ret2 < 0)
1086 ret = ret2;
ac27a0ec 1087
617ba13b 1088 ret2 = ext4_journal_stop(handle);
ac27a0ec
DK
1089 if (!ret)
1090 ret = ret2;
bfc1af65 1091
f8514083 1092 if (pos + len > inode->i_size) {
b9a4207d 1093 ext4_truncate_failed_write(inode);
de9a55b8 1094 /*
ffacfa7a 1095 * If truncate failed early the inode might still be
f8514083
AK
1096 * on the orphan list; we need to make sure the inode
1097 * is removed from the orphan list in that case.
1098 */
1099 if (inode->i_nlink)
1100 ext4_orphan_del(NULL, inode);
1101 }
1102
bfc1af65 1103 return ret ? ret : copied;
ac27a0ec
DK
1104}
1105
bfc1af65 1106static int ext4_journalled_write_end(struct file *file,
de9a55b8
TT
1107 struct address_space *mapping,
1108 loff_t pos, unsigned len, unsigned copied,
1109 struct page *page, void *fsdata)
ac27a0ec 1110{
617ba13b 1111 handle_t *handle = ext4_journal_current_handle();
bfc1af65 1112 struct inode *inode = mapping->host;
ac27a0ec
DK
1113 int ret = 0, ret2;
1114 int partial = 0;
bfc1af65 1115 unsigned from, to;
cf17fea6 1116 loff_t new_i_size;
ac27a0ec 1117
9bffad1e 1118 trace_ext4_journalled_write_end(inode, pos, len, copied);
bfc1af65
NP
1119 from = pos & (PAGE_CACHE_SIZE - 1);
1120 to = from + len;
1121
441c8508
CW
1122 BUG_ON(!ext4_handle_valid(handle));
1123
3fdcfb66
TM
1124 if (ext4_has_inline_data(inode))
1125 copied = ext4_write_inline_data_end(inode, pos, len,
1126 copied, page);
1127 else {
1128 if (copied < len) {
1129 if (!PageUptodate(page))
1130 copied = 0;
1131 page_zero_new_buffers(page, from+copied, to);
1132 }
ac27a0ec 1133
3fdcfb66
TM
1134 ret = ext4_walk_page_buffers(handle, page_buffers(page), from,
1135 to, &partial, write_end_fn);
1136 if (!partial)
1137 SetPageUptodate(page);
1138 }
cf17fea6
AK
1139 new_i_size = pos + copied;
1140 if (new_i_size > inode->i_size)
bfc1af65 1141 i_size_write(inode, pos+copied);
19f5fb7a 1142 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
2d859db3 1143 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
cf17fea6
AK
1144 if (new_i_size > EXT4_I(inode)->i_disksize) {
1145 ext4_update_i_disksize(inode, new_i_size);
617ba13b 1146 ret2 = ext4_mark_inode_dirty(handle, inode);
ac27a0ec
DK
1147 if (!ret)
1148 ret = ret2;
1149 }
bfc1af65 1150
cf108bca 1151 unlock_page(page);
f8514083 1152 page_cache_release(page);
ffacfa7a 1153 if (pos + len > inode->i_size && ext4_can_truncate(inode))
f8514083
AK
1154 /* if we have allocated more blocks and copied
1155 * less. We will have blocks allocated outside
1156 * inode->i_size. So truncate them
1157 */
1158 ext4_orphan_add(handle, inode);
1159
617ba13b 1160 ret2 = ext4_journal_stop(handle);
ac27a0ec
DK
1161 if (!ret)
1162 ret = ret2;
f8514083 1163 if (pos + len > inode->i_size) {
b9a4207d 1164 ext4_truncate_failed_write(inode);
de9a55b8 1165 /*
ffacfa7a 1166 * If truncate failed early the inode might still be
f8514083
AK
1167 * on the orphan list; we need to make sure the inode
1168 * is removed from the orphan list in that case.
1169 */
1170 if (inode->i_nlink)
1171 ext4_orphan_del(NULL, inode);
1172 }
bfc1af65
NP
1173
1174 return ret ? ret : copied;
ac27a0ec 1175}
d2a17637 1176
9d0be502 1177/*
7b415bf6 1178 * Reserve a single cluster located at lblock
9d0be502 1179 */
01f49d0b 1180static int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock)
d2a17637 1181{
030ba6bc 1182 int retries = 0;
60e58e0f 1183 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
0637c6f4 1184 struct ext4_inode_info *ei = EXT4_I(inode);
7b415bf6 1185 unsigned int md_needed;
5dd4056d 1186 int ret;
03179fe9
TT
1187 ext4_lblk_t save_last_lblock;
1188 int save_len;
1189
1190 /*
1191 * We will charge metadata quota at writeout time; this saves
1192 * us from metadata over-estimation, though we may go over by
1193 * a small amount in the end. Here we just reserve for data.
1194 */
1195 ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1));
1196 if (ret)
1197 return ret;
d2a17637
MC
1198
1199 /*
1200 * recalculate the amount of metadata blocks to reserve
1201 * in order to allocate nrblocks
1202 * worse case is one extent per block
1203 */
030ba6bc 1204repeat:
0637c6f4 1205 spin_lock(&ei->i_block_reservation_lock);
03179fe9
TT
1206 /*
1207 * ext4_calc_metadata_amount() has side effects, which we have
1208 * to be prepared undo if we fail to claim space.
1209 */
1210 save_len = ei->i_da_metadata_calc_len;
1211 save_last_lblock = ei->i_da_metadata_calc_last_lblock;
7b415bf6
AK
1212 md_needed = EXT4_NUM_B2C(sbi,
1213 ext4_calc_metadata_amount(inode, lblock));
f8ec9d68 1214 trace_ext4_da_reserve_space(inode, md_needed);
d2a17637 1215
72b8ab9d
ES
1216 /*
1217 * We do still charge estimated metadata to the sb though;
1218 * we cannot afford to run out of free blocks.
1219 */
e7d5f315 1220 if (ext4_claim_free_clusters(sbi, md_needed + 1, 0)) {
03179fe9
TT
1221 ei->i_da_metadata_calc_len = save_len;
1222 ei->i_da_metadata_calc_last_lblock = save_last_lblock;
1223 spin_unlock(&ei->i_block_reservation_lock);
030ba6bc
AK
1224 if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
1225 yield();
1226 goto repeat;
1227 }
03179fe9 1228 dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1));
d2a17637
MC
1229 return -ENOSPC;
1230 }
9d0be502 1231 ei->i_reserved_data_blocks++;
0637c6f4
TT
1232 ei->i_reserved_meta_blocks += md_needed;
1233 spin_unlock(&ei->i_block_reservation_lock);
39bc680a 1234
d2a17637
MC
1235 return 0; /* success */
1236}
1237
12219aea 1238static void ext4_da_release_space(struct inode *inode, int to_free)
d2a17637
MC
1239{
1240 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
0637c6f4 1241 struct ext4_inode_info *ei = EXT4_I(inode);
d2a17637 1242
cd213226
MC
1243 if (!to_free)
1244 return; /* Nothing to release, exit */
1245
d2a17637 1246 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
cd213226 1247
5a58ec87 1248 trace_ext4_da_release_space(inode, to_free);
0637c6f4 1249 if (unlikely(to_free > ei->i_reserved_data_blocks)) {
cd213226 1250 /*
0637c6f4
TT
1251 * if there aren't enough reserved blocks, then the
1252 * counter is messed up somewhere. Since this
1253 * function is called from invalidate page, it's
1254 * harmless to return without any action.
cd213226 1255 */
0637c6f4
TT
1256 ext4_msg(inode->i_sb, KERN_NOTICE, "ext4_da_release_space: "
1257 "ino %lu, to_free %d with only %d reserved "
1084f252 1258 "data blocks", inode->i_ino, to_free,
0637c6f4
TT
1259 ei->i_reserved_data_blocks);
1260 WARN_ON(1);
1261 to_free = ei->i_reserved_data_blocks;
cd213226 1262 }
0637c6f4 1263 ei->i_reserved_data_blocks -= to_free;
cd213226 1264
0637c6f4
TT
1265 if (ei->i_reserved_data_blocks == 0) {
1266 /*
1267 * We can release all of the reserved metadata blocks
1268 * only when we have written all of the delayed
1269 * allocation blocks.
7b415bf6
AK
1270 * Note that in case of bigalloc, i_reserved_meta_blocks,
1271 * i_reserved_data_blocks, etc. refer to number of clusters.
0637c6f4 1272 */
57042651 1273 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
72b8ab9d 1274 ei->i_reserved_meta_blocks);
ee5f4d9c 1275 ei->i_reserved_meta_blocks = 0;
9d0be502 1276 ei->i_da_metadata_calc_len = 0;
0637c6f4 1277 }
d2a17637 1278
72b8ab9d 1279 /* update fs dirty data blocks counter */
57042651 1280 percpu_counter_sub(&sbi->s_dirtyclusters_counter, to_free);
d2a17637 1281
d2a17637 1282 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
60e58e0f 1283
7b415bf6 1284 dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free));
d2a17637
MC
1285}
1286
1287static void ext4_da_page_release_reservation(struct page *page,
de9a55b8 1288 unsigned long offset)
d2a17637
MC
1289{
1290 int to_release = 0;
1291 struct buffer_head *head, *bh;
1292 unsigned int curr_off = 0;
7b415bf6
AK
1293 struct inode *inode = page->mapping->host;
1294 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1295 int num_clusters;
51865fda 1296 ext4_fsblk_t lblk;
d2a17637
MC
1297
1298 head = page_buffers(page);
1299 bh = head;
1300 do {
1301 unsigned int next_off = curr_off + bh->b_size;
1302
1303 if ((offset <= curr_off) && (buffer_delay(bh))) {
1304 to_release++;
1305 clear_buffer_delay(bh);
1306 }
1307 curr_off = next_off;
1308 } while ((bh = bh->b_this_page) != head);
7b415bf6 1309
51865fda
ZL
1310 if (to_release) {
1311 lblk = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1312 ext4_es_remove_extent(inode, lblk, to_release);
1313 }
1314
7b415bf6
AK
1315 /* If we have released all the blocks belonging to a cluster, then we
1316 * need to release the reserved space for that cluster. */
1317 num_clusters = EXT4_NUM_B2C(sbi, to_release);
1318 while (num_clusters > 0) {
7b415bf6
AK
1319 lblk = (page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits)) +
1320 ((num_clusters - 1) << sbi->s_cluster_bits);
1321 if (sbi->s_cluster_ratio == 1 ||
7d1b1fbc 1322 !ext4_find_delalloc_cluster(inode, lblk))
7b415bf6
AK
1323 ext4_da_release_space(inode, 1);
1324
1325 num_clusters--;
1326 }
d2a17637 1327}
ac27a0ec 1328
64769240
AT
1329/*
1330 * Delayed allocation stuff
1331 */
1332
64769240
AT
1333/*
1334 * mpage_da_submit_io - walks through extent of pages and try to write
a1d6cc56 1335 * them with writepage() call back
64769240
AT
1336 *
1337 * @mpd->inode: inode
1338 * @mpd->first_page: first page of the extent
1339 * @mpd->next_page: page after the last page of the extent
64769240
AT
1340 *
1341 * By the time mpage_da_submit_io() is called we expect all blocks
1342 * to be allocated. this may be wrong if allocation failed.
1343 *
1344 * As pages are already locked by write_cache_pages(), we can't use it
1345 */
1de3e3df
TT
1346static int mpage_da_submit_io(struct mpage_da_data *mpd,
1347 struct ext4_map_blocks *map)
64769240 1348{
791b7f08
AK
1349 struct pagevec pvec;
1350 unsigned long index, end;
1351 int ret = 0, err, nr_pages, i;
1352 struct inode *inode = mpd->inode;
1353 struct address_space *mapping = inode->i_mapping;
cb20d518 1354 loff_t size = i_size_read(inode);
3ecdb3a1
TT
1355 unsigned int len, block_start;
1356 struct buffer_head *bh, *page_bufs = NULL;
1de3e3df 1357 sector_t pblock = 0, cur_logical = 0;
bd2d0210 1358 struct ext4_io_submit io_submit;
64769240
AT
1359
1360 BUG_ON(mpd->next_page <= mpd->first_page);
bd2d0210 1361 memset(&io_submit, 0, sizeof(io_submit));
791b7f08
AK
1362 /*
1363 * We need to start from the first_page to the next_page - 1
1364 * to make sure we also write the mapped dirty buffer_heads.
8dc207c0 1365 * If we look at mpd->b_blocknr we would only be looking
791b7f08
AK
1366 * at the currently mapped buffer_heads.
1367 */
64769240
AT
1368 index = mpd->first_page;
1369 end = mpd->next_page - 1;
1370
791b7f08 1371 pagevec_init(&pvec, 0);
64769240 1372 while (index <= end) {
791b7f08 1373 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
64769240
AT
1374 if (nr_pages == 0)
1375 break;
1376 for (i = 0; i < nr_pages; i++) {
97498956 1377 int commit_write = 0, skip_page = 0;
64769240
AT
1378 struct page *page = pvec.pages[i];
1379
791b7f08
AK
1380 index = page->index;
1381 if (index > end)
1382 break;
cb20d518
TT
1383
1384 if (index == size >> PAGE_CACHE_SHIFT)
1385 len = size & ~PAGE_CACHE_MASK;
1386 else
1387 len = PAGE_CACHE_SIZE;
1de3e3df
TT
1388 if (map) {
1389 cur_logical = index << (PAGE_CACHE_SHIFT -
1390 inode->i_blkbits);
1391 pblock = map->m_pblk + (cur_logical -
1392 map->m_lblk);
1393 }
791b7f08
AK
1394 index++;
1395
1396 BUG_ON(!PageLocked(page));
1397 BUG_ON(PageWriteback(page));
1398
64769240 1399 /*
cb20d518
TT
1400 * If the page does not have buffers (for
1401 * whatever reason), try to create them using
a107e5a3 1402 * __block_write_begin. If this fails,
97498956 1403 * skip the page and move on.
64769240 1404 */
cb20d518 1405 if (!page_has_buffers(page)) {
a107e5a3 1406 if (__block_write_begin(page, 0, len,
cb20d518 1407 noalloc_get_block_write)) {
97498956 1408 skip_page:
cb20d518
TT
1409 unlock_page(page);
1410 continue;
1411 }
1412 commit_write = 1;
1413 }
64769240 1414
3ecdb3a1
TT
1415 bh = page_bufs = page_buffers(page);
1416 block_start = 0;
64769240 1417 do {
1de3e3df 1418 if (!bh)
97498956 1419 goto skip_page;
1de3e3df
TT
1420 if (map && (cur_logical >= map->m_lblk) &&
1421 (cur_logical <= (map->m_lblk +
1422 (map->m_len - 1)))) {
29fa89d0
AK
1423 if (buffer_delay(bh)) {
1424 clear_buffer_delay(bh);
1425 bh->b_blocknr = pblock;
29fa89d0 1426 }
1de3e3df
TT
1427 if (buffer_unwritten(bh) ||
1428 buffer_mapped(bh))
1429 BUG_ON(bh->b_blocknr != pblock);
1430 if (map->m_flags & EXT4_MAP_UNINIT)
1431 set_buffer_uninit(bh);
1432 clear_buffer_unwritten(bh);
1433 }
29fa89d0 1434
13a79a47
YY
1435 /*
1436 * skip page if block allocation undone and
1437 * block is dirty
1438 */
1439 if (ext4_bh_delay_or_unwritten(NULL, bh))
97498956 1440 skip_page = 1;
3ecdb3a1
TT
1441 bh = bh->b_this_page;
1442 block_start += bh->b_size;
64769240
AT
1443 cur_logical++;
1444 pblock++;
1de3e3df
TT
1445 } while (bh != page_bufs);
1446
97498956
TT
1447 if (skip_page)
1448 goto skip_page;
cb20d518
TT
1449
1450 if (commit_write)
1451 /* mark the buffer_heads as dirty & uptodate */
1452 block_commit_write(page, 0, len);
1453
97498956 1454 clear_page_dirty_for_io(page);
fe089c77
JK
1455 err = ext4_bio_write_page(&io_submit, page, len,
1456 mpd->wbc);
cb20d518 1457 if (!err)
a1d6cc56 1458 mpd->pages_written++;
64769240
AT
1459 /*
1460 * In error case, we have to continue because
1461 * remaining pages are still locked
64769240
AT
1462 */
1463 if (ret == 0)
1464 ret = err;
64769240
AT
1465 }
1466 pagevec_release(&pvec);
1467 }
bd2d0210 1468 ext4_io_submit(&io_submit);
64769240 1469 return ret;
64769240
AT
1470}
1471
c7f5938a 1472static void ext4_da_block_invalidatepages(struct mpage_da_data *mpd)
c4a0c46e
AK
1473{
1474 int nr_pages, i;
1475 pgoff_t index, end;
1476 struct pagevec pvec;
1477 struct inode *inode = mpd->inode;
1478 struct address_space *mapping = inode->i_mapping;
51865fda 1479 ext4_lblk_t start, last;
c4a0c46e 1480
c7f5938a
CW
1481 index = mpd->first_page;
1482 end = mpd->next_page - 1;
51865fda
ZL
1483
1484 start = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1485 last = end << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1486 ext4_es_remove_extent(inode, start, last - start + 1);
1487
66bea92c 1488 pagevec_init(&pvec, 0);
c4a0c46e
AK
1489 while (index <= end) {
1490 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
1491 if (nr_pages == 0)
1492 break;
1493 for (i = 0; i < nr_pages; i++) {
1494 struct page *page = pvec.pages[i];
9b1d0998 1495 if (page->index > end)
c4a0c46e 1496 break;
c4a0c46e
AK
1497 BUG_ON(!PageLocked(page));
1498 BUG_ON(PageWriteback(page));
1499 block_invalidatepage(page, 0);
1500 ClearPageUptodate(page);
1501 unlock_page(page);
1502 }
9b1d0998
JK
1503 index = pvec.pages[nr_pages - 1]->index + 1;
1504 pagevec_release(&pvec);
c4a0c46e
AK
1505 }
1506 return;
1507}
1508
df22291f
AK
1509static void ext4_print_free_blocks(struct inode *inode)
1510{
1511 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
92b97816
TT
1512 struct super_block *sb = inode->i_sb;
1513
1514 ext4_msg(sb, KERN_CRIT, "Total free blocks count %lld",
5dee5437
TT
1515 EXT4_C2B(EXT4_SB(inode->i_sb),
1516 ext4_count_free_clusters(inode->i_sb)));
92b97816
TT
1517 ext4_msg(sb, KERN_CRIT, "Free/Dirty block details");
1518 ext4_msg(sb, KERN_CRIT, "free_blocks=%lld",
57042651
TT
1519 (long long) EXT4_C2B(EXT4_SB(inode->i_sb),
1520 percpu_counter_sum(&sbi->s_freeclusters_counter)));
92b97816 1521 ext4_msg(sb, KERN_CRIT, "dirty_blocks=%lld",
7b415bf6
AK
1522 (long long) EXT4_C2B(EXT4_SB(inode->i_sb),
1523 percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
92b97816
TT
1524 ext4_msg(sb, KERN_CRIT, "Block reservation details");
1525 ext4_msg(sb, KERN_CRIT, "i_reserved_data_blocks=%u",
1526 EXT4_I(inode)->i_reserved_data_blocks);
1527 ext4_msg(sb, KERN_CRIT, "i_reserved_meta_blocks=%u",
1693918e 1528 EXT4_I(inode)->i_reserved_meta_blocks);
df22291f
AK
1529 return;
1530}
1531
64769240 1532/*
5a87b7a5
TT
1533 * mpage_da_map_and_submit - go through given space, map them
1534 * if necessary, and then submit them for I/O
64769240 1535 *
8dc207c0 1536 * @mpd - bh describing space
64769240
AT
1537 *
1538 * The function skips space we know is already mapped to disk blocks.
1539 *
64769240 1540 */
5a87b7a5 1541static void mpage_da_map_and_submit(struct mpage_da_data *mpd)
64769240 1542{
2ac3b6e0 1543 int err, blks, get_blocks_flags;
1de3e3df 1544 struct ext4_map_blocks map, *mapp = NULL;
2fa3cdfb
TT
1545 sector_t next = mpd->b_blocknr;
1546 unsigned max_blocks = mpd->b_size >> mpd->inode->i_blkbits;
1547 loff_t disksize = EXT4_I(mpd->inode)->i_disksize;
1548 handle_t *handle = NULL;
64769240
AT
1549
1550 /*
5a87b7a5
TT
1551 * If the blocks are mapped already, or we couldn't accumulate
1552 * any blocks, then proceed immediately to the submission stage.
2fa3cdfb 1553 */
5a87b7a5
TT
1554 if ((mpd->b_size == 0) ||
1555 ((mpd->b_state & (1 << BH_Mapped)) &&
1556 !(mpd->b_state & (1 << BH_Delay)) &&
1557 !(mpd->b_state & (1 << BH_Unwritten))))
1558 goto submit_io;
2fa3cdfb
TT
1559
1560 handle = ext4_journal_current_handle();
1561 BUG_ON(!handle);
1562
79ffab34 1563 /*
79e83036 1564 * Call ext4_map_blocks() to allocate any delayed allocation
2ac3b6e0
TT
1565 * blocks, or to convert an uninitialized extent to be
1566 * initialized (in the case where we have written into
1567 * one or more preallocated blocks).
1568 *
1569 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE to
1570 * indicate that we are on the delayed allocation path. This
1571 * affects functions in many different parts of the allocation
1572 * call path. This flag exists primarily because we don't
79e83036 1573 * want to change *many* call functions, so ext4_map_blocks()
f2321097 1574 * will set the EXT4_STATE_DELALLOC_RESERVED flag once the
2ac3b6e0
TT
1575 * inode's allocation semaphore is taken.
1576 *
1577 * If the blocks in questions were delalloc blocks, set
1578 * EXT4_GET_BLOCKS_DELALLOC_RESERVE so the delalloc accounting
1579 * variables are updated after the blocks have been allocated.
79ffab34 1580 */
2ed88685
TT
1581 map.m_lblk = next;
1582 map.m_len = max_blocks;
1296cc85 1583 get_blocks_flags = EXT4_GET_BLOCKS_CREATE;
744692dc
JZ
1584 if (ext4_should_dioread_nolock(mpd->inode))
1585 get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
2ac3b6e0 1586 if (mpd->b_state & (1 << BH_Delay))
1296cc85
AK
1587 get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
1588
2ed88685 1589 blks = ext4_map_blocks(handle, mpd->inode, &map, get_blocks_flags);
2fa3cdfb 1590 if (blks < 0) {
e3570639
ES
1591 struct super_block *sb = mpd->inode->i_sb;
1592
2fa3cdfb 1593 err = blks;
ed5bde0b 1594 /*
5a87b7a5 1595 * If get block returns EAGAIN or ENOSPC and there
97498956
TT
1596 * appears to be free blocks we will just let
1597 * mpage_da_submit_io() unlock all of the pages.
c4a0c46e
AK
1598 */
1599 if (err == -EAGAIN)
5a87b7a5 1600 goto submit_io;
df22291f 1601
5dee5437 1602 if (err == -ENOSPC && ext4_count_free_clusters(sb)) {
df22291f 1603 mpd->retval = err;
5a87b7a5 1604 goto submit_io;
df22291f
AK
1605 }
1606
c4a0c46e 1607 /*
ed5bde0b
TT
1608 * get block failure will cause us to loop in
1609 * writepages, because a_ops->writepage won't be able
1610 * to make progress. The page will be redirtied by
1611 * writepage and writepages will again try to write
1612 * the same.
c4a0c46e 1613 */
e3570639
ES
1614 if (!(EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) {
1615 ext4_msg(sb, KERN_CRIT,
1616 "delayed block allocation failed for inode %lu "
1617 "at logical offset %llu with max blocks %zd "
1618 "with error %d", mpd->inode->i_ino,
1619 (unsigned long long) next,
1620 mpd->b_size >> mpd->inode->i_blkbits, err);
1621 ext4_msg(sb, KERN_CRIT,
1622 "This should not happen!! Data will be lost\n");
1623 if (err == -ENOSPC)
1624 ext4_print_free_blocks(mpd->inode);
030ba6bc 1625 }
2fa3cdfb 1626 /* invalidate all the pages */
c7f5938a 1627 ext4_da_block_invalidatepages(mpd);
e0fd9b90
CW
1628
1629 /* Mark this page range as having been completed */
1630 mpd->io_done = 1;
5a87b7a5 1631 return;
c4a0c46e 1632 }
2fa3cdfb
TT
1633 BUG_ON(blks == 0);
1634
1de3e3df 1635 mapp = &map;
2ed88685
TT
1636 if (map.m_flags & EXT4_MAP_NEW) {
1637 struct block_device *bdev = mpd->inode->i_sb->s_bdev;
1638 int i;
64769240 1639
2ed88685
TT
1640 for (i = 0; i < map.m_len; i++)
1641 unmap_underlying_metadata(bdev, map.m_pblk + i);
2fa3cdfb
TT
1642 }
1643
1644 /*
03f5d8bc 1645 * Update on-disk size along with block allocation.
2fa3cdfb
TT
1646 */
1647 disksize = ((loff_t) next + blks) << mpd->inode->i_blkbits;
1648 if (disksize > i_size_read(mpd->inode))
1649 disksize = i_size_read(mpd->inode);
1650 if (disksize > EXT4_I(mpd->inode)->i_disksize) {
1651 ext4_update_i_disksize(mpd->inode, disksize);
5a87b7a5
TT
1652 err = ext4_mark_inode_dirty(handle, mpd->inode);
1653 if (err)
1654 ext4_error(mpd->inode->i_sb,
1655 "Failed to mark inode %lu dirty",
1656 mpd->inode->i_ino);
2fa3cdfb
TT
1657 }
1658
5a87b7a5 1659submit_io:
1de3e3df 1660 mpage_da_submit_io(mpd, mapp);
5a87b7a5 1661 mpd->io_done = 1;
64769240
AT
1662}
1663
bf068ee2
AK
1664#define BH_FLAGS ((1 << BH_Uptodate) | (1 << BH_Mapped) | \
1665 (1 << BH_Delay) | (1 << BH_Unwritten))
64769240
AT
1666
1667/*
1668 * mpage_add_bh_to_extent - try to add one more block to extent of blocks
1669 *
1670 * @mpd->lbh - extent of blocks
1671 * @logical - logical number of the block in the file
1672 * @bh - bh of the block (used to access block's state)
1673 *
1674 * the function is used to collect contig. blocks in same state
1675 */
1676static void mpage_add_bh_to_extent(struct mpage_da_data *mpd,
8dc207c0
TT
1677 sector_t logical, size_t b_size,
1678 unsigned long b_state)
64769240 1679{
64769240 1680 sector_t next;
8dc207c0 1681 int nrblocks = mpd->b_size >> mpd->inode->i_blkbits;
64769240 1682
c445e3e0
ES
1683 /*
1684 * XXX Don't go larger than mballoc is willing to allocate
1685 * This is a stopgap solution. We eventually need to fold
1686 * mpage_da_submit_io() into this function and then call
79e83036 1687 * ext4_map_blocks() multiple times in a loop
c445e3e0
ES
1688 */
1689 if (nrblocks >= 8*1024*1024/mpd->inode->i_sb->s_blocksize)
1690 goto flush_it;
1691
525f4ed8 1692 /* check if thereserved journal credits might overflow */
12e9b892 1693 if (!(ext4_test_inode_flag(mpd->inode, EXT4_INODE_EXTENTS))) {
525f4ed8
MC
1694 if (nrblocks >= EXT4_MAX_TRANS_DATA) {
1695 /*
1696 * With non-extent format we are limited by the journal
1697 * credit available. Total credit needed to insert
1698 * nrblocks contiguous blocks is dependent on the
1699 * nrblocks. So limit nrblocks.
1700 */
1701 goto flush_it;
1702 } else if ((nrblocks + (b_size >> mpd->inode->i_blkbits)) >
1703 EXT4_MAX_TRANS_DATA) {
1704 /*
1705 * Adding the new buffer_head would make it cross the
1706 * allowed limit for which we have journal credit
1707 * reserved. So limit the new bh->b_size
1708 */
1709 b_size = (EXT4_MAX_TRANS_DATA - nrblocks) <<
1710 mpd->inode->i_blkbits;
1711 /* we will do mpage_da_submit_io in the next loop */
1712 }
1713 }
64769240
AT
1714 /*
1715 * First block in the extent
1716 */
8dc207c0
TT
1717 if (mpd->b_size == 0) {
1718 mpd->b_blocknr = logical;
1719 mpd->b_size = b_size;
1720 mpd->b_state = b_state & BH_FLAGS;
64769240
AT
1721 return;
1722 }
1723
8dc207c0 1724 next = mpd->b_blocknr + nrblocks;
64769240
AT
1725 /*
1726 * Can we merge the block to our big extent?
1727 */
8dc207c0
TT
1728 if (logical == next && (b_state & BH_FLAGS) == mpd->b_state) {
1729 mpd->b_size += b_size;
64769240
AT
1730 return;
1731 }
1732
525f4ed8 1733flush_it:
64769240
AT
1734 /*
1735 * We couldn't merge the block to our extent, so we
1736 * need to flush current extent and start new one
1737 */
5a87b7a5 1738 mpage_da_map_and_submit(mpd);
a1d6cc56 1739 return;
64769240
AT
1740}
1741
c364b22c 1742static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
29fa89d0 1743{
c364b22c 1744 return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
29fa89d0
AK
1745}
1746
5356f261
AK
1747/*
1748 * This function is grabs code from the very beginning of
1749 * ext4_map_blocks, but assumes that the caller is from delayed write
1750 * time. This function looks up the requested blocks and sets the
1751 * buffer delay bit under the protection of i_data_sem.
1752 */
1753static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
1754 struct ext4_map_blocks *map,
1755 struct buffer_head *bh)
1756{
1757 int retval;
1758 sector_t invalid_block = ~((sector_t) 0xffff);
1759
1760 if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
1761 invalid_block = ~0;
1762
1763 map->m_flags = 0;
1764 ext_debug("ext4_da_map_blocks(): inode %lu, max_blocks %u,"
1765 "logical block %lu\n", inode->i_ino, map->m_len,
1766 (unsigned long) map->m_lblk);
1767 /*
1768 * Try to see if we can get the block without requesting a new
1769 * file system block.
1770 */
1771 down_read((&EXT4_I(inode)->i_data_sem));
9c3569b5
TM
1772 if (ext4_has_inline_data(inode)) {
1773 /*
1774 * We will soon create blocks for this page, and let
1775 * us pretend as if the blocks aren't allocated yet.
1776 * In case of clusters, we have to handle the work
1777 * of mapping from cluster so that the reserved space
1778 * is calculated properly.
1779 */
1780 if ((EXT4_SB(inode->i_sb)->s_cluster_ratio > 1) &&
1781 ext4_find_delalloc_cluster(inode, map->m_lblk))
1782 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
1783 retval = 0;
1784 } else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5356f261
AK
1785 retval = ext4_ext_map_blocks(NULL, inode, map, 0);
1786 else
1787 retval = ext4_ind_map_blocks(NULL, inode, map, 0);
1788
1789 if (retval == 0) {
1790 /*
1791 * XXX: __block_prepare_write() unmaps passed block,
1792 * is it OK?
1793 */
1794 /* If the block was allocated from previously allocated cluster,
1795 * then we dont need to reserve it again. */
1796 if (!(map->m_flags & EXT4_MAP_FROM_CLUSTER)) {
1797 retval = ext4_da_reserve_space(inode, iblock);
1798 if (retval)
1799 /* not enough space to reserve */
1800 goto out_unlock;
1801 }
1802
51865fda
ZL
1803 retval = ext4_es_insert_extent(inode, map->m_lblk, map->m_len);
1804 if (retval)
1805 goto out_unlock;
1806
5356f261
AK
1807 /* Clear EXT4_MAP_FROM_CLUSTER flag since its purpose is served
1808 * and it should not appear on the bh->b_state.
1809 */
1810 map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
1811
1812 map_bh(bh, inode->i_sb, invalid_block);
1813 set_buffer_new(bh);
1814 set_buffer_delay(bh);
1815 }
1816
1817out_unlock:
1818 up_read((&EXT4_I(inode)->i_data_sem));
1819
1820 return retval;
1821}
1822
64769240 1823/*
b920c755
TT
1824 * This is a special get_blocks_t callback which is used by
1825 * ext4_da_write_begin(). It will either return mapped block or
1826 * reserve space for a single block.
29fa89d0
AK
1827 *
1828 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
1829 * We also have b_blocknr = -1 and b_bdev initialized properly
1830 *
1831 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
1832 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
1833 * initialized properly.
64769240 1834 */
9c3569b5
TM
1835int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
1836 struct buffer_head *bh, int create)
64769240 1837{
2ed88685 1838 struct ext4_map_blocks map;
64769240
AT
1839 int ret = 0;
1840
1841 BUG_ON(create == 0);
2ed88685
TT
1842 BUG_ON(bh->b_size != inode->i_sb->s_blocksize);
1843
1844 map.m_lblk = iblock;
1845 map.m_len = 1;
64769240
AT
1846
1847 /*
1848 * first, we need to know whether the block is allocated already
1849 * preallocated blocks are unmapped but should treated
1850 * the same as allocated blocks.
1851 */
5356f261
AK
1852 ret = ext4_da_map_blocks(inode, iblock, &map, bh);
1853 if (ret <= 0)
2ed88685 1854 return ret;
64769240 1855
2ed88685
TT
1856 map_bh(bh, inode->i_sb, map.m_pblk);
1857 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
1858
1859 if (buffer_unwritten(bh)) {
1860 /* A delayed write to unwritten bh should be marked
1861 * new and mapped. Mapped ensures that we don't do
1862 * get_block multiple times when we write to the same
1863 * offset and new ensures that we do proper zero out
1864 * for partial write.
1865 */
1866 set_buffer_new(bh);
c8205636 1867 set_buffer_mapped(bh);
2ed88685
TT
1868 }
1869 return 0;
64769240 1870}
61628a3f 1871
b920c755 1872/*
36ade451
JK
1873 * This function is used as a standard get_block_t calback function when there
1874 * is no desire to allocate any blocks. It is used as a callback function for
1875 * block_write_begin(). These functions should only try to map a single block
1876 * at a time.
b920c755
TT
1877 *
1878 * Since this function doesn't do block allocations even if the caller
1879 * requests it by passing in create=1, it is critically important that
1880 * any caller checks to make sure that any buffer heads are returned
1881 * by this function are either all already mapped or marked for
36ade451 1882 * delayed allocation before calling ext4_bio_write_page(). Otherwise,
206f7ab4
CH
1883 * b_blocknr could be left unitialized, and the page write functions will
1884 * be taken by surprise.
b920c755
TT
1885 */
1886static int noalloc_get_block_write(struct inode *inode, sector_t iblock,
f0e6c985
AK
1887 struct buffer_head *bh_result, int create)
1888{
a2dc52b5 1889 BUG_ON(bh_result->b_size != inode->i_sb->s_blocksize);
2ed88685 1890 return _ext4_get_block(inode, iblock, bh_result, 0);
61628a3f
MC
1891}
1892
62e086be
AK
1893static int bget_one(handle_t *handle, struct buffer_head *bh)
1894{
1895 get_bh(bh);
1896 return 0;
1897}
1898
1899static int bput_one(handle_t *handle, struct buffer_head *bh)
1900{
1901 put_bh(bh);
1902 return 0;
1903}
1904
1905static int __ext4_journalled_writepage(struct page *page,
62e086be
AK
1906 unsigned int len)
1907{
1908 struct address_space *mapping = page->mapping;
1909 struct inode *inode = mapping->host;
3fdcfb66 1910 struct buffer_head *page_bufs = NULL;
62e086be 1911 handle_t *handle = NULL;
3fdcfb66
TM
1912 int ret = 0, err = 0;
1913 int inline_data = ext4_has_inline_data(inode);
1914 struct buffer_head *inode_bh = NULL;
62e086be 1915
cb20d518 1916 ClearPageChecked(page);
3fdcfb66
TM
1917
1918 if (inline_data) {
1919 BUG_ON(page->index != 0);
1920 BUG_ON(len > ext4_get_max_inline_size(inode));
1921 inode_bh = ext4_journalled_write_inline_data(inode, len, page);
1922 if (inode_bh == NULL)
1923 goto out;
1924 } else {
1925 page_bufs = page_buffers(page);
1926 if (!page_bufs) {
1927 BUG();
1928 goto out;
1929 }
1930 ext4_walk_page_buffers(handle, page_bufs, 0, len,
1931 NULL, bget_one);
1932 }
62e086be
AK
1933 /* As soon as we unlock the page, it can go away, but we have
1934 * references to buffers so we are safe */
1935 unlock_page(page);
1936
1937 handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
1938 if (IS_ERR(handle)) {
1939 ret = PTR_ERR(handle);
1940 goto out;
1941 }
1942
441c8508
CW
1943 BUG_ON(!ext4_handle_valid(handle));
1944
3fdcfb66
TM
1945 if (inline_data) {
1946 ret = ext4_journal_get_write_access(handle, inode_bh);
62e086be 1947
3fdcfb66
TM
1948 err = ext4_handle_dirty_metadata(handle, inode, inode_bh);
1949
1950 } else {
1951 ret = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
1952 do_journal_get_write_access);
1953
1954 err = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
1955 write_end_fn);
1956 }
62e086be
AK
1957 if (ret == 0)
1958 ret = err;
2d859db3 1959 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
62e086be
AK
1960 err = ext4_journal_stop(handle);
1961 if (!ret)
1962 ret = err;
1963
3fdcfb66
TM
1964 if (!ext4_has_inline_data(inode))
1965 ext4_walk_page_buffers(handle, page_bufs, 0, len,
1966 NULL, bput_one);
19f5fb7a 1967 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
62e086be 1968out:
3fdcfb66 1969 brelse(inode_bh);
62e086be
AK
1970 return ret;
1971}
1972
61628a3f 1973/*
43ce1d23
AK
1974 * Note that we don't need to start a transaction unless we're journaling data
1975 * because we should have holes filled from ext4_page_mkwrite(). We even don't
1976 * need to file the inode to the transaction's list in ordered mode because if
1977 * we are writing back data added by write(), the inode is already there and if
25985edc 1978 * we are writing back data modified via mmap(), no one guarantees in which
43ce1d23
AK
1979 * transaction the data will hit the disk. In case we are journaling data, we
1980 * cannot start transaction directly because transaction start ranks above page
1981 * lock so we have to do some magic.
1982 *
b920c755
TT
1983 * This function can get called via...
1984 * - ext4_da_writepages after taking page lock (have journal handle)
1985 * - journal_submit_inode_data_buffers (no journal handle)
f6463b0d 1986 * - shrink_page_list via the kswapd/direct reclaim (no journal handle)
b920c755 1987 * - grab_page_cache when doing write_begin (have journal handle)
43ce1d23
AK
1988 *
1989 * We don't do any block allocation in this function. If we have page with
1990 * multiple blocks we need to write those buffer_heads that are mapped. This
1991 * is important for mmaped based write. So if we do with blocksize 1K
1992 * truncate(f, 1024);
1993 * a = mmap(f, 0, 4096);
1994 * a[0] = 'a';
1995 * truncate(f, 4096);
1996 * we have in the page first buffer_head mapped via page_mkwrite call back
90802ed9 1997 * but other buffer_heads would be unmapped but dirty (dirty done via the
43ce1d23
AK
1998 * do_wp_page). So writepage should write the first block. If we modify
1999 * the mmap area beyond 1024 we will again get a page_fault and the
2000 * page_mkwrite callback will do the block allocation and mark the
2001 * buffer_heads mapped.
2002 *
2003 * We redirty the page if we have any buffer_heads that is either delay or
2004 * unwritten in the page.
2005 *
2006 * We can get recursively called as show below.
2007 *
2008 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
2009 * ext4_writepage()
2010 *
2011 * But since we don't do any block allocation we should not deadlock.
2012 * Page also have the dirty flag cleared so we don't get recurive page_lock.
61628a3f 2013 */
43ce1d23 2014static int ext4_writepage(struct page *page,
62e086be 2015 struct writeback_control *wbc)
64769240 2016{
a42afc5f 2017 int ret = 0, commit_write = 0;
61628a3f 2018 loff_t size;
498e5f24 2019 unsigned int len;
744692dc 2020 struct buffer_head *page_bufs = NULL;
61628a3f 2021 struct inode *inode = page->mapping->host;
36ade451 2022 struct ext4_io_submit io_submit;
61628a3f 2023
a9c667f8 2024 trace_ext4_writepage(page);
f0e6c985
AK
2025 size = i_size_read(inode);
2026 if (page->index == size >> PAGE_CACHE_SHIFT)
2027 len = size & ~PAGE_CACHE_MASK;
2028 else
2029 len = PAGE_CACHE_SIZE;
64769240 2030
a42afc5f
TT
2031 /*
2032 * If the page does not have buffers (for whatever reason),
a107e5a3 2033 * try to create them using __block_write_begin. If this
a42afc5f
TT
2034 * fails, redirty the page and move on.
2035 */
b1142e8f 2036 if (!page_has_buffers(page)) {
a107e5a3 2037 if (__block_write_begin(page, 0, len,
a42afc5f
TT
2038 noalloc_get_block_write)) {
2039 redirty_page:
f0e6c985
AK
2040 redirty_page_for_writepage(wbc, page);
2041 unlock_page(page);
2042 return 0;
2043 }
a42afc5f
TT
2044 commit_write = 1;
2045 }
2046 page_bufs = page_buffers(page);
f19d5870
TM
2047 if (ext4_walk_page_buffers(NULL, page_bufs, 0, len, NULL,
2048 ext4_bh_delay_or_unwritten)) {
f0e6c985 2049 /*
b1142e8f
TT
2050 * We don't want to do block allocation, so redirty
2051 * the page and return. We may reach here when we do
2052 * a journal commit via journal_submit_inode_data_buffers.
966dbde2
MG
2053 * We can also reach here via shrink_page_list but it
2054 * should never be for direct reclaim so warn if that
2055 * happens
f0e6c985 2056 */
966dbde2
MG
2057 WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) ==
2058 PF_MEMALLOC);
a42afc5f
TT
2059 goto redirty_page;
2060 }
2061 if (commit_write)
ed9b3e33 2062 /* now mark the buffer_heads as dirty and uptodate */
b767e78a 2063 block_commit_write(page, 0, len);
64769240 2064
cb20d518 2065 if (PageChecked(page) && ext4_should_journal_data(inode))
43ce1d23
AK
2066 /*
2067 * It's mmapped pagecache. Add buffers and journal it. There
2068 * doesn't seem much point in redirtying the page here.
2069 */
3f0ca309 2070 return __ext4_journalled_writepage(page, len);
43ce1d23 2071
36ade451
JK
2072 memset(&io_submit, 0, sizeof(io_submit));
2073 ret = ext4_bio_write_page(&io_submit, page, len, wbc);
2074 ext4_io_submit(&io_submit);
64769240
AT
2075 return ret;
2076}
2077
61628a3f 2078/*
525f4ed8 2079 * This is called via ext4_da_writepages() to
25985edc 2080 * calculate the total number of credits to reserve to fit
525f4ed8
MC
2081 * a single extent allocation into a single transaction,
2082 * ext4_da_writpeages() will loop calling this before
2083 * the block allocation.
61628a3f 2084 */
525f4ed8
MC
2085
2086static int ext4_da_writepages_trans_blocks(struct inode *inode)
2087{
2088 int max_blocks = EXT4_I(inode)->i_reserved_data_blocks;
2089
2090 /*
2091 * With non-extent format the journal credit needed to
2092 * insert nrblocks contiguous block is dependent on
2093 * number of contiguous block. So we will limit
2094 * number of contiguous block to a sane value
2095 */
12e9b892 2096 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) &&
525f4ed8
MC
2097 (max_blocks > EXT4_MAX_TRANS_DATA))
2098 max_blocks = EXT4_MAX_TRANS_DATA;
2099
2100 return ext4_chunk_trans_blocks(inode, max_blocks);
2101}
61628a3f 2102
8e48dcfb
TT
2103/*
2104 * write_cache_pages_da - walk the list of dirty pages of the given
8eb9e5ce 2105 * address space and accumulate pages that need writing, and call
168fc022
TT
2106 * mpage_da_map_and_submit to map a single contiguous memory region
2107 * and then write them.
8e48dcfb 2108 */
9c3569b5
TM
2109static int write_cache_pages_da(handle_t *handle,
2110 struct address_space *mapping,
8e48dcfb 2111 struct writeback_control *wbc,
72f84e65
ES
2112 struct mpage_da_data *mpd,
2113 pgoff_t *done_index)
8e48dcfb 2114{
4f01b02c 2115 struct buffer_head *bh, *head;
168fc022 2116 struct inode *inode = mapping->host;
4f01b02c
TT
2117 struct pagevec pvec;
2118 unsigned int nr_pages;
2119 sector_t logical;
2120 pgoff_t index, end;
2121 long nr_to_write = wbc->nr_to_write;
2122 int i, tag, ret = 0;
8e48dcfb 2123
168fc022
TT
2124 memset(mpd, 0, sizeof(struct mpage_da_data));
2125 mpd->wbc = wbc;
2126 mpd->inode = inode;
8e48dcfb
TT
2127 pagevec_init(&pvec, 0);
2128 index = wbc->range_start >> PAGE_CACHE_SHIFT;
2129 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2130
6e6938b6 2131 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
5b41d924
ES
2132 tag = PAGECACHE_TAG_TOWRITE;
2133 else
2134 tag = PAGECACHE_TAG_DIRTY;
2135
72f84e65 2136 *done_index = index;
4f01b02c 2137 while (index <= end) {
5b41d924 2138 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
8e48dcfb
TT
2139 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
2140 if (nr_pages == 0)
4f01b02c 2141 return 0;
8e48dcfb
TT
2142
2143 for (i = 0; i < nr_pages; i++) {
2144 struct page *page = pvec.pages[i];
2145
2146 /*
2147 * At this point, the page may be truncated or
2148 * invalidated (changing page->mapping to NULL), or
2149 * even swizzled back from swapper_space to tmpfs file
2150 * mapping. However, page->index will not change
2151 * because we have a reference on the page.
2152 */
4f01b02c
TT
2153 if (page->index > end)
2154 goto out;
8e48dcfb 2155
72f84e65
ES
2156 *done_index = page->index + 1;
2157
78aaced3
TT
2158 /*
2159 * If we can't merge this page, and we have
2160 * accumulated an contiguous region, write it
2161 */
2162 if ((mpd->next_page != page->index) &&
2163 (mpd->next_page != mpd->first_page)) {
2164 mpage_da_map_and_submit(mpd);
2165 goto ret_extent_tail;
2166 }
2167
8e48dcfb
TT
2168 lock_page(page);
2169
2170 /*
4f01b02c
TT
2171 * If the page is no longer dirty, or its
2172 * mapping no longer corresponds to inode we
2173 * are writing (which means it has been
2174 * truncated or invalidated), or the page is
2175 * already under writeback and we are not
2176 * doing a data integrity writeback, skip the page
8e48dcfb 2177 */
4f01b02c
TT
2178 if (!PageDirty(page) ||
2179 (PageWriteback(page) &&
2180 (wbc->sync_mode == WB_SYNC_NONE)) ||
2181 unlikely(page->mapping != mapping)) {
8e48dcfb
TT
2182 unlock_page(page);
2183 continue;
2184 }
2185
7cb1a535 2186 wait_on_page_writeback(page);
8e48dcfb 2187 BUG_ON(PageWriteback(page));
8e48dcfb 2188
9c3569b5
TM
2189 /*
2190 * If we have inline data and arrive here, it means that
2191 * we will soon create the block for the 1st page, so
2192 * we'd better clear the inline data here.
2193 */
2194 if (ext4_has_inline_data(inode)) {
2195 BUG_ON(ext4_test_inode_state(inode,
2196 EXT4_STATE_MAY_INLINE_DATA));
2197 ext4_destroy_inline_data(handle, inode);
2198 }
2199
168fc022 2200 if (mpd->next_page != page->index)
8eb9e5ce 2201 mpd->first_page = page->index;
8eb9e5ce
TT
2202 mpd->next_page = page->index + 1;
2203 logical = (sector_t) page->index <<
2204 (PAGE_CACHE_SHIFT - inode->i_blkbits);
2205
2206 if (!page_has_buffers(page)) {
4f01b02c
TT
2207 mpage_add_bh_to_extent(mpd, logical,
2208 PAGE_CACHE_SIZE,
8eb9e5ce 2209 (1 << BH_Dirty) | (1 << BH_Uptodate));
4f01b02c
TT
2210 if (mpd->io_done)
2211 goto ret_extent_tail;
8eb9e5ce
TT
2212 } else {
2213 /*
4f01b02c
TT
2214 * Page with regular buffer heads,
2215 * just add all dirty ones
8eb9e5ce
TT
2216 */
2217 head = page_buffers(page);
2218 bh = head;
2219 do {
2220 BUG_ON(buffer_locked(bh));
2221 /*
2222 * We need to try to allocate
2223 * unmapped blocks in the same page.
2224 * Otherwise we won't make progress
2225 * with the page in ext4_writepage
2226 */
2227 if (ext4_bh_delay_or_unwritten(NULL, bh)) {
2228 mpage_add_bh_to_extent(mpd, logical,
2229 bh->b_size,
2230 bh->b_state);
4f01b02c
TT
2231 if (mpd->io_done)
2232 goto ret_extent_tail;
8eb9e5ce
TT
2233 } else if (buffer_dirty(bh) && (buffer_mapped(bh))) {
2234 /*
4f01b02c
TT
2235 * mapped dirty buffer. We need
2236 * to update the b_state
2237 * because we look at b_state
2238 * in mpage_da_map_blocks. We
2239 * don't update b_size because
2240 * if we find an unmapped
2241 * buffer_head later we need to
2242 * use the b_state flag of that
2243 * buffer_head.
8eb9e5ce
TT
2244 */
2245 if (mpd->b_size == 0)
2246 mpd->b_state = bh->b_state & BH_FLAGS;
2247 }
2248 logical++;
2249 } while ((bh = bh->b_this_page) != head);
8e48dcfb
TT
2250 }
2251
2252 if (nr_to_write > 0) {
2253 nr_to_write--;
2254 if (nr_to_write == 0 &&
4f01b02c 2255 wbc->sync_mode == WB_SYNC_NONE)
8e48dcfb
TT
2256 /*
2257 * We stop writing back only if we are
2258 * not doing integrity sync. In case of
2259 * integrity sync we have to keep going
2260 * because someone may be concurrently
2261 * dirtying pages, and we might have
2262 * synced a lot of newly appeared dirty
2263 * pages, but have not synced all of the
2264 * old dirty pages.
2265 */
4f01b02c 2266 goto out;
8e48dcfb
TT
2267 }
2268 }
2269 pagevec_release(&pvec);
2270 cond_resched();
2271 }
4f01b02c
TT
2272 return 0;
2273ret_extent_tail:
2274 ret = MPAGE_DA_EXTENT_TAIL;
8eb9e5ce
TT
2275out:
2276 pagevec_release(&pvec);
2277 cond_resched();
8e48dcfb
TT
2278 return ret;
2279}
2280
2281
64769240 2282static int ext4_da_writepages(struct address_space *mapping,
a1d6cc56 2283 struct writeback_control *wbc)
64769240 2284{
22208ded
AK
2285 pgoff_t index;
2286 int range_whole = 0;
61628a3f 2287 handle_t *handle = NULL;
df22291f 2288 struct mpage_da_data mpd;
5e745b04 2289 struct inode *inode = mapping->host;
498e5f24 2290 int pages_written = 0;
55138e0b 2291 unsigned int max_pages;
2acf2c26 2292 int range_cyclic, cycled = 1, io_done = 0;
55138e0b
TT
2293 int needed_blocks, ret = 0;
2294 long desired_nr_to_write, nr_to_writebump = 0;
de89de6e 2295 loff_t range_start = wbc->range_start;
5e745b04 2296 struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
72f84e65 2297 pgoff_t done_index = 0;
5b41d924 2298 pgoff_t end;
1bce63d1 2299 struct blk_plug plug;
61628a3f 2300
9bffad1e 2301 trace_ext4_da_writepages(inode, wbc);
ba80b101 2302
61628a3f
MC
2303 /*
2304 * No pages to write? This is mainly a kludge to avoid starting
2305 * a transaction for special inodes like journal inode on last iput()
2306 * because that could violate lock ordering on umount
2307 */
a1d6cc56 2308 if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
61628a3f 2309 return 0;
2a21e37e
TT
2310
2311 /*
2312 * If the filesystem has aborted, it is read-only, so return
2313 * right away instead of dumping stack traces later on that
2314 * will obscure the real source of the problem. We test
4ab2f15b 2315 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2a21e37e
TT
2316 * the latter could be true if the filesystem is mounted
2317 * read-only, and in that case, ext4_da_writepages should
2318 * *never* be called, so if that ever happens, we would want
2319 * the stack trace.
2320 */
4ab2f15b 2321 if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED))
2a21e37e
TT
2322 return -EROFS;
2323
22208ded
AK
2324 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2325 range_whole = 1;
61628a3f 2326
2acf2c26
AK
2327 range_cyclic = wbc->range_cyclic;
2328 if (wbc->range_cyclic) {
22208ded 2329 index = mapping->writeback_index;
2acf2c26
AK
2330 if (index)
2331 cycled = 0;
2332 wbc->range_start = index << PAGE_CACHE_SHIFT;
2333 wbc->range_end = LLONG_MAX;
2334 wbc->range_cyclic = 0;
5b41d924
ES
2335 end = -1;
2336 } else {
22208ded 2337 index = wbc->range_start >> PAGE_CACHE_SHIFT;
5b41d924
ES
2338 end = wbc->range_end >> PAGE_CACHE_SHIFT;
2339 }
a1d6cc56 2340
55138e0b
TT
2341 /*
2342 * This works around two forms of stupidity. The first is in
2343 * the writeback code, which caps the maximum number of pages
2344 * written to be 1024 pages. This is wrong on multiple
2345 * levels; different architectues have a different page size,
2346 * which changes the maximum amount of data which gets
2347 * written. Secondly, 4 megabytes is way too small. XFS
2348 * forces this value to be 16 megabytes by multiplying
2349 * nr_to_write parameter by four, and then relies on its
2350 * allocator to allocate larger extents to make them
2351 * contiguous. Unfortunately this brings us to the second
2352 * stupidity, which is that ext4's mballoc code only allocates
2353 * at most 2048 blocks. So we force contiguous writes up to
2354 * the number of dirty blocks in the inode, or
2355 * sbi->max_writeback_mb_bump whichever is smaller.
2356 */
2357 max_pages = sbi->s_max_writeback_mb_bump << (20 - PAGE_CACHE_SHIFT);
b443e733
ES
2358 if (!range_cyclic && range_whole) {
2359 if (wbc->nr_to_write == LONG_MAX)
2360 desired_nr_to_write = wbc->nr_to_write;
2361 else
2362 desired_nr_to_write = wbc->nr_to_write * 8;
2363 } else
55138e0b
TT
2364 desired_nr_to_write = ext4_num_dirty_pages(inode, index,
2365 max_pages);
2366 if (desired_nr_to_write > max_pages)
2367 desired_nr_to_write = max_pages;
2368
2369 if (wbc->nr_to_write < desired_nr_to_write) {
2370 nr_to_writebump = desired_nr_to_write - wbc->nr_to_write;
2371 wbc->nr_to_write = desired_nr_to_write;
2372 }
2373
2acf2c26 2374retry:
6e6938b6 2375 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
5b41d924
ES
2376 tag_pages_for_writeback(mapping, index, end);
2377
1bce63d1 2378 blk_start_plug(&plug);
22208ded 2379 while (!ret && wbc->nr_to_write > 0) {
a1d6cc56
AK
2380
2381 /*
2382 * we insert one extent at a time. So we need
2383 * credit needed for single extent allocation.
2384 * journalled mode is currently not supported
2385 * by delalloc
2386 */
2387 BUG_ON(ext4_should_journal_data(inode));
525f4ed8 2388 needed_blocks = ext4_da_writepages_trans_blocks(inode);
a1d6cc56 2389
61628a3f
MC
2390 /* start a new transaction*/
2391 handle = ext4_journal_start(inode, needed_blocks);
2392 if (IS_ERR(handle)) {
2393 ret = PTR_ERR(handle);
1693918e 2394 ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
fbe845dd 2395 "%ld pages, ino %lu; err %d", __func__,
a1d6cc56 2396 wbc->nr_to_write, inode->i_ino, ret);
3c1fcb2c 2397 blk_finish_plug(&plug);
61628a3f
MC
2398 goto out_writepages;
2399 }
f63e6005
TT
2400
2401 /*
8eb9e5ce 2402 * Now call write_cache_pages_da() to find the next
f63e6005 2403 * contiguous region of logical blocks that need
8eb9e5ce 2404 * blocks to be allocated by ext4 and submit them.
f63e6005 2405 */
9c3569b5
TM
2406 ret = write_cache_pages_da(handle, mapping,
2407 wbc, &mpd, &done_index);
f63e6005 2408 /*
af901ca1 2409 * If we have a contiguous extent of pages and we
f63e6005
TT
2410 * haven't done the I/O yet, map the blocks and submit
2411 * them for I/O.
2412 */
2413 if (!mpd.io_done && mpd.next_page != mpd.first_page) {
5a87b7a5 2414 mpage_da_map_and_submit(&mpd);
f63e6005
TT
2415 ret = MPAGE_DA_EXTENT_TAIL;
2416 }
b3a3ca8c 2417 trace_ext4_da_write_pages(inode, &mpd);
f63e6005 2418 wbc->nr_to_write -= mpd.pages_written;
df22291f 2419
61628a3f 2420 ext4_journal_stop(handle);
df22291f 2421
8f64b32e 2422 if ((mpd.retval == -ENOSPC) && sbi->s_journal) {
22208ded
AK
2423 /* commit the transaction which would
2424 * free blocks released in the transaction
2425 * and try again
2426 */
df22291f 2427 jbd2_journal_force_commit_nested(sbi->s_journal);
22208ded
AK
2428 ret = 0;
2429 } else if (ret == MPAGE_DA_EXTENT_TAIL) {
a1d6cc56 2430 /*
8de49e67
KM
2431 * Got one extent now try with rest of the pages.
2432 * If mpd.retval is set -EIO, journal is aborted.
2433 * So we don't need to write any more.
a1d6cc56 2434 */
22208ded 2435 pages_written += mpd.pages_written;
8de49e67 2436 ret = mpd.retval;
2acf2c26 2437 io_done = 1;
22208ded 2438 } else if (wbc->nr_to_write)
61628a3f
MC
2439 /*
2440 * There is no more writeout needed
2441 * or we requested for a noblocking writeout
2442 * and we found the device congested
2443 */
61628a3f 2444 break;
a1d6cc56 2445 }
1bce63d1 2446 blk_finish_plug(&plug);
2acf2c26
AK
2447 if (!io_done && !cycled) {
2448 cycled = 1;
2449 index = 0;
2450 wbc->range_start = index << PAGE_CACHE_SHIFT;
2451 wbc->range_end = mapping->writeback_index - 1;
2452 goto retry;
2453 }
22208ded
AK
2454
2455 /* Update index */
2acf2c26 2456 wbc->range_cyclic = range_cyclic;
22208ded
AK
2457 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2458 /*
2459 * set the writeback_index so that range_cyclic
2460 * mode will write it back later
2461 */
72f84e65 2462 mapping->writeback_index = done_index;
a1d6cc56 2463
61628a3f 2464out_writepages:
2faf2e19 2465 wbc->nr_to_write -= nr_to_writebump;
de89de6e 2466 wbc->range_start = range_start;
9bffad1e 2467 trace_ext4_da_writepages_result(inode, wbc, ret, pages_written);
61628a3f 2468 return ret;
64769240
AT
2469}
2470
79f0be8d
AK
2471static int ext4_nonda_switch(struct super_block *sb)
2472{
2473 s64 free_blocks, dirty_blocks;
2474 struct ext4_sb_info *sbi = EXT4_SB(sb);
2475
2476 /*
2477 * switch to non delalloc mode if we are running low
2478 * on free block. The free block accounting via percpu
179f7ebf 2479 * counters can get slightly wrong with percpu_counter_batch getting
79f0be8d
AK
2480 * accumulated on each CPU without updating global counters
2481 * Delalloc need an accurate free block accounting. So switch
2482 * to non delalloc when we are near to error range.
2483 */
57042651
TT
2484 free_blocks = EXT4_C2B(sbi,
2485 percpu_counter_read_positive(&sbi->s_freeclusters_counter));
2486 dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyclusters_counter);
00d4e736
TT
2487 /*
2488 * Start pushing delalloc when 1/2 of free blocks are dirty.
2489 */
2490 if (dirty_blocks && (free_blocks < 2 * dirty_blocks) &&
2491 !writeback_in_progress(sb->s_bdi) &&
2492 down_read_trylock(&sb->s_umount)) {
2493 writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE);
2494 up_read(&sb->s_umount);
2495 }
2496
79f0be8d 2497 if (2 * free_blocks < 3 * dirty_blocks ||
df55c99d 2498 free_blocks < (dirty_blocks + EXT4_FREECLUSTERS_WATERMARK)) {
79f0be8d 2499 /*
c8afb446
ES
2500 * free block count is less than 150% of dirty blocks
2501 * or free blocks is less than watermark
79f0be8d
AK
2502 */
2503 return 1;
2504 }
2505 return 0;
2506}
2507
64769240 2508static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
de9a55b8
TT
2509 loff_t pos, unsigned len, unsigned flags,
2510 struct page **pagep, void **fsdata)
64769240 2511{
72b8ab9d 2512 int ret, retries = 0;
64769240
AT
2513 struct page *page;
2514 pgoff_t index;
64769240
AT
2515 struct inode *inode = mapping->host;
2516 handle_t *handle;
2517
2518 index = pos >> PAGE_CACHE_SHIFT;
79f0be8d
AK
2519
2520 if (ext4_nonda_switch(inode->i_sb)) {
2521 *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
2522 return ext4_write_begin(file, mapping, pos,
2523 len, flags, pagep, fsdata);
2524 }
2525 *fsdata = (void *)0;
9bffad1e 2526 trace_ext4_da_write_begin(inode, pos, len, flags);
9c3569b5
TM
2527
2528 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2529 ret = ext4_da_write_inline_data_begin(mapping, inode,
2530 pos, len, flags,
2531 pagep, fsdata);
2532 if (ret < 0)
2533 goto out;
2534 if (ret == 1) {
2535 ret = 0;
2536 goto out;
2537 }
2538 }
2539
d2a17637 2540retry:
64769240
AT
2541 /*
2542 * With delayed allocation, we don't log the i_disksize update
2543 * if there is delayed block allocation. But we still need
2544 * to journalling the i_disksize update if writes to the end
2545 * of file which has an already mapped buffer.
2546 */
2547 handle = ext4_journal_start(inode, 1);
2548 if (IS_ERR(handle)) {
2549 ret = PTR_ERR(handle);
2550 goto out;
2551 }
ebd3610b
JK
2552 /* We cannot recurse into the filesystem as the transaction is already
2553 * started */
2554 flags |= AOP_FLAG_NOFS;
64769240 2555
54566b2c 2556 page = grab_cache_page_write_begin(mapping, index, flags);
d5a0d4f7
ES
2557 if (!page) {
2558 ext4_journal_stop(handle);
2559 ret = -ENOMEM;
2560 goto out;
2561 }
64769240
AT
2562 *pagep = page;
2563
6e1db88d 2564 ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep);
64769240
AT
2565 if (ret < 0) {
2566 unlock_page(page);
2567 ext4_journal_stop(handle);
2568 page_cache_release(page);
ae4d5372
AK
2569 /*
2570 * block_write_begin may have instantiated a few blocks
2571 * outside i_size. Trim these off again. Don't need
2572 * i_size_read because we hold i_mutex.
2573 */
2574 if (pos + len > inode->i_size)
b9a4207d 2575 ext4_truncate_failed_write(inode);
64769240
AT
2576 }
2577
d2a17637
MC
2578 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
2579 goto retry;
64769240
AT
2580out:
2581 return ret;
2582}
2583
632eaeab
MC
2584/*
2585 * Check if we should update i_disksize
2586 * when write to the end of file but not require block allocation
2587 */
2588static int ext4_da_should_update_i_disksize(struct page *page,
de9a55b8 2589 unsigned long offset)
632eaeab
MC
2590{
2591 struct buffer_head *bh;
2592 struct inode *inode = page->mapping->host;
2593 unsigned int idx;
2594 int i;
2595
2596 bh = page_buffers(page);
2597 idx = offset >> inode->i_blkbits;
2598
af5bc92d 2599 for (i = 0; i < idx; i++)
632eaeab
MC
2600 bh = bh->b_this_page;
2601
29fa89d0 2602 if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
632eaeab
MC
2603 return 0;
2604 return 1;
2605}
2606
64769240 2607static int ext4_da_write_end(struct file *file,
de9a55b8
TT
2608 struct address_space *mapping,
2609 loff_t pos, unsigned len, unsigned copied,
2610 struct page *page, void *fsdata)
64769240
AT
2611{
2612 struct inode *inode = mapping->host;
2613 int ret = 0, ret2;
2614 handle_t *handle = ext4_journal_current_handle();
2615 loff_t new_i_size;
632eaeab 2616 unsigned long start, end;
79f0be8d
AK
2617 int write_mode = (int)(unsigned long)fsdata;
2618
2619 if (write_mode == FALL_BACK_TO_NONDELALLOC) {
3d2b1582
LC
2620 switch (ext4_inode_journal_mode(inode)) {
2621 case EXT4_INODE_ORDERED_DATA_MODE:
79f0be8d
AK
2622 return ext4_ordered_write_end(file, mapping, pos,
2623 len, copied, page, fsdata);
3d2b1582 2624 case EXT4_INODE_WRITEBACK_DATA_MODE:
79f0be8d
AK
2625 return ext4_writeback_write_end(file, mapping, pos,
2626 len, copied, page, fsdata);
3d2b1582 2627 default:
79f0be8d
AK
2628 BUG();
2629 }
2630 }
632eaeab 2631
9bffad1e 2632 trace_ext4_da_write_end(inode, pos, len, copied);
632eaeab 2633 start = pos & (PAGE_CACHE_SIZE - 1);
af5bc92d 2634 end = start + copied - 1;
64769240
AT
2635
2636 /*
2637 * generic_write_end() will run mark_inode_dirty() if i_size
2638 * changes. So let's piggyback the i_disksize mark_inode_dirty
2639 * into that.
2640 */
64769240 2641 new_i_size = pos + copied;
ea51d132 2642 if (copied && new_i_size > EXT4_I(inode)->i_disksize) {
9c3569b5
TM
2643 if (ext4_has_inline_data(inode) ||
2644 ext4_da_should_update_i_disksize(page, end)) {
632eaeab 2645 down_write(&EXT4_I(inode)->i_data_sem);
f3b59291 2646 if (new_i_size > EXT4_I(inode)->i_disksize)
632eaeab 2647 EXT4_I(inode)->i_disksize = new_i_size;
632eaeab 2648 up_write(&EXT4_I(inode)->i_data_sem);
cf17fea6
AK
2649 /* We need to mark inode dirty even if
2650 * new_i_size is less that inode->i_size
2651 * bu greater than i_disksize.(hint delalloc)
2652 */
2653 ext4_mark_inode_dirty(handle, inode);
64769240 2654 }
632eaeab 2655 }
9c3569b5
TM
2656
2657 if (write_mode != CONVERT_INLINE_DATA &&
2658 ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) &&
2659 ext4_has_inline_data(inode))
2660 ret2 = ext4_da_write_inline_data_end(inode, pos, len, copied,
2661 page);
2662 else
2663 ret2 = generic_write_end(file, mapping, pos, len, copied,
64769240 2664 page, fsdata);
9c3569b5 2665
64769240
AT
2666 copied = ret2;
2667 if (ret2 < 0)
2668 ret = ret2;
2669 ret2 = ext4_journal_stop(handle);
2670 if (!ret)
2671 ret = ret2;
2672
2673 return ret ? ret : copied;
2674}
2675
2676static void ext4_da_invalidatepage(struct page *page, unsigned long offset)
2677{
64769240
AT
2678 /*
2679 * Drop reserved blocks
2680 */
2681 BUG_ON(!PageLocked(page));
2682 if (!page_has_buffers(page))
2683 goto out;
2684
d2a17637 2685 ext4_da_page_release_reservation(page, offset);
64769240
AT
2686
2687out:
2688 ext4_invalidatepage(page, offset);
2689
2690 return;
2691}
2692
ccd2506b
TT
2693/*
2694 * Force all delayed allocation blocks to be allocated for a given inode.
2695 */
2696int ext4_alloc_da_blocks(struct inode *inode)
2697{
fb40ba0d
TT
2698 trace_ext4_alloc_da_blocks(inode);
2699
ccd2506b
TT
2700 if (!EXT4_I(inode)->i_reserved_data_blocks &&
2701 !EXT4_I(inode)->i_reserved_meta_blocks)
2702 return 0;
2703
2704 /*
2705 * We do something simple for now. The filemap_flush() will
2706 * also start triggering a write of the data blocks, which is
2707 * not strictly speaking necessary (and for users of
2708 * laptop_mode, not even desirable). However, to do otherwise
2709 * would require replicating code paths in:
de9a55b8 2710 *
ccd2506b
TT
2711 * ext4_da_writepages() ->
2712 * write_cache_pages() ---> (via passed in callback function)
2713 * __mpage_da_writepage() -->
2714 * mpage_add_bh_to_extent()
2715 * mpage_da_map_blocks()
2716 *
2717 * The problem is that write_cache_pages(), located in
2718 * mm/page-writeback.c, marks pages clean in preparation for
2719 * doing I/O, which is not desirable if we're not planning on
2720 * doing I/O at all.
2721 *
2722 * We could call write_cache_pages(), and then redirty all of
380cf090 2723 * the pages by calling redirty_page_for_writepage() but that
ccd2506b
TT
2724 * would be ugly in the extreme. So instead we would need to
2725 * replicate parts of the code in the above functions,
25985edc 2726 * simplifying them because we wouldn't actually intend to
ccd2506b
TT
2727 * write out the pages, but rather only collect contiguous
2728 * logical block extents, call the multi-block allocator, and
2729 * then update the buffer heads with the block allocations.
de9a55b8 2730 *
ccd2506b
TT
2731 * For now, though, we'll cheat by calling filemap_flush(),
2732 * which will map the blocks, and start the I/O, but not
2733 * actually wait for the I/O to complete.
2734 */
2735 return filemap_flush(inode->i_mapping);
2736}
64769240 2737
ac27a0ec
DK
2738/*
2739 * bmap() is special. It gets used by applications such as lilo and by
2740 * the swapper to find the on-disk block of a specific piece of data.
2741 *
2742 * Naturally, this is dangerous if the block concerned is still in the
617ba13b 2743 * journal. If somebody makes a swapfile on an ext4 data-journaling
ac27a0ec
DK
2744 * filesystem and enables swap, then they may get a nasty shock when the
2745 * data getting swapped to that swapfile suddenly gets overwritten by
2746 * the original zero's written out previously to the journal and
2747 * awaiting writeback in the kernel's buffer cache.
2748 *
2749 * So, if we see any bmap calls here on a modified, data-journaled file,
2750 * take extra steps to flush any blocks which might be in the cache.
2751 */
617ba13b 2752static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
ac27a0ec
DK
2753{
2754 struct inode *inode = mapping->host;
2755 journal_t *journal;
2756 int err;
2757
46c7f254
TM
2758 /*
2759 * We can get here for an inline file via the FIBMAP ioctl
2760 */
2761 if (ext4_has_inline_data(inode))
2762 return 0;
2763
64769240
AT
2764 if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
2765 test_opt(inode->i_sb, DELALLOC)) {
2766 /*
2767 * With delalloc we want to sync the file
2768 * so that we can make sure we allocate
2769 * blocks for file
2770 */
2771 filemap_write_and_wait(mapping);
2772 }
2773
19f5fb7a
TT
2774 if (EXT4_JOURNAL(inode) &&
2775 ext4_test_inode_state(inode, EXT4_STATE_JDATA)) {
ac27a0ec
DK
2776 /*
2777 * This is a REALLY heavyweight approach, but the use of
2778 * bmap on dirty files is expected to be extremely rare:
2779 * only if we run lilo or swapon on a freshly made file
2780 * do we expect this to happen.
2781 *
2782 * (bmap requires CAP_SYS_RAWIO so this does not
2783 * represent an unprivileged user DOS attack --- we'd be
2784 * in trouble if mortal users could trigger this path at
2785 * will.)
2786 *
617ba13b 2787 * NB. EXT4_STATE_JDATA is not set on files other than
ac27a0ec
DK
2788 * regular files. If somebody wants to bmap a directory
2789 * or symlink and gets confused because the buffer
2790 * hasn't yet been flushed to disk, they deserve
2791 * everything they get.
2792 */
2793
19f5fb7a 2794 ext4_clear_inode_state(inode, EXT4_STATE_JDATA);
617ba13b 2795 journal = EXT4_JOURNAL(inode);
dab291af
MC
2796 jbd2_journal_lock_updates(journal);
2797 err = jbd2_journal_flush(journal);
2798 jbd2_journal_unlock_updates(journal);
ac27a0ec
DK
2799
2800 if (err)
2801 return 0;
2802 }
2803
af5bc92d 2804 return generic_block_bmap(mapping, block, ext4_get_block);
ac27a0ec
DK
2805}
2806
617ba13b 2807static int ext4_readpage(struct file *file, struct page *page)
ac27a0ec 2808{
46c7f254
TM
2809 int ret = -EAGAIN;
2810 struct inode *inode = page->mapping->host;
2811
0562e0ba 2812 trace_ext4_readpage(page);
46c7f254
TM
2813
2814 if (ext4_has_inline_data(inode))
2815 ret = ext4_readpage_inline(inode, page);
2816
2817 if (ret == -EAGAIN)
2818 return mpage_readpage(page, ext4_get_block);
2819
2820 return ret;
ac27a0ec
DK
2821}
2822
2823static int
617ba13b 2824ext4_readpages(struct file *file, struct address_space *mapping,
ac27a0ec
DK
2825 struct list_head *pages, unsigned nr_pages)
2826{
46c7f254
TM
2827 struct inode *inode = mapping->host;
2828
2829 /* If the file has inline data, no need to do readpages. */
2830 if (ext4_has_inline_data(inode))
2831 return 0;
2832
617ba13b 2833 return mpage_readpages(mapping, pages, nr_pages, ext4_get_block);
ac27a0ec
DK
2834}
2835
617ba13b 2836static void ext4_invalidatepage(struct page *page, unsigned long offset)
ac27a0ec 2837{
0562e0ba
JZ
2838 trace_ext4_invalidatepage(page, offset);
2839
4520fb3c
JK
2840 /* No journalling happens on data buffers when this function is used */
2841 WARN_ON(page_has_buffers(page) && buffer_jbd(page_buffers(page)));
2842
2843 block_invalidatepage(page, offset);
2844}
2845
53e87268
JK
2846static int __ext4_journalled_invalidatepage(struct page *page,
2847 unsigned long offset)
4520fb3c
JK
2848{
2849 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
2850
2851 trace_ext4_journalled_invalidatepage(page, offset);
2852
ac27a0ec
DK
2853 /*
2854 * If it's a full truncate we just forget about the pending dirtying
2855 */
2856 if (offset == 0)
2857 ClearPageChecked(page);
2858
53e87268
JK
2859 return jbd2_journal_invalidatepage(journal, page, offset);
2860}
2861
2862/* Wrapper for aops... */
2863static void ext4_journalled_invalidatepage(struct page *page,
2864 unsigned long offset)
2865{
2866 WARN_ON(__ext4_journalled_invalidatepage(page, offset) < 0);
ac27a0ec
DK
2867}
2868
617ba13b 2869static int ext4_releasepage(struct page *page, gfp_t wait)
ac27a0ec 2870{
617ba13b 2871 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
ac27a0ec 2872
0562e0ba
JZ
2873 trace_ext4_releasepage(page);
2874
ac27a0ec
DK
2875 WARN_ON(PageChecked(page));
2876 if (!page_has_buffers(page))
2877 return 0;
0390131b
FM
2878 if (journal)
2879 return jbd2_journal_try_to_free_buffers(journal, page, wait);
2880 else
2881 return try_to_free_buffers(page);
ac27a0ec
DK
2882}
2883
2ed88685
TT
2884/*
2885 * ext4_get_block used when preparing for a DIO write or buffer write.
2886 * We allocate an uinitialized extent if blocks haven't been allocated.
2887 * The extent will be converted to initialized after the IO is complete.
2888 */
f19d5870 2889int ext4_get_block_write(struct inode *inode, sector_t iblock,
4c0425ff
MC
2890 struct buffer_head *bh_result, int create)
2891{
c7064ef1 2892 ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n",
8d5d02e6 2893 inode->i_ino, create);
2ed88685
TT
2894 return _ext4_get_block(inode, iblock, bh_result,
2895 EXT4_GET_BLOCKS_IO_CREATE_EXT);
4c0425ff
MC
2896}
2897
729f52c6 2898static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock,
8b0f165f 2899 struct buffer_head *bh_result, int create)
729f52c6 2900{
8b0f165f
AP
2901 ext4_debug("ext4_get_block_write_nolock: inode %lu, create flag %d\n",
2902 inode->i_ino, create);
2903 return _ext4_get_block(inode, iblock, bh_result,
2904 EXT4_GET_BLOCKS_NO_LOCK);
729f52c6
ZL
2905}
2906
4c0425ff 2907static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
552ef802
CH
2908 ssize_t size, void *private, int ret,
2909 bool is_async)
4c0425ff 2910{
72c5052d 2911 struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
4c0425ff 2912 ext4_io_end_t *io_end = iocb->private;
4c0425ff 2913
4b70df18
M
2914 /* if not async direct IO or dio with 0 bytes write, just return */
2915 if (!io_end || !size)
552ef802 2916 goto out;
4b70df18 2917
88635ca2 2918 ext_debug("ext4_end_io_dio(): io_end 0x%p "
ace36ad4 2919 "for inode %lu, iocb 0x%p, offset %llu, size %zd\n",
8d5d02e6
MC
2920 iocb->private, io_end->inode->i_ino, iocb, offset,
2921 size);
8d5d02e6 2922
b5a7e970
TT
2923 iocb->private = NULL;
2924
8d5d02e6 2925 /* if not aio dio with unwritten extents, just free io and return */
bd2d0210 2926 if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
8d5d02e6 2927 ext4_free_io_end(io_end);
5b3ff237
JZ
2928out:
2929 if (is_async)
2930 aio_complete(iocb, ret, 0);
72c5052d 2931 inode_dio_done(inode);
5b3ff237 2932 return;
8d5d02e6
MC
2933 }
2934
4c0425ff
MC
2935 io_end->offset = offset;
2936 io_end->size = size;
5b3ff237
JZ
2937 if (is_async) {
2938 io_end->iocb = iocb;
2939 io_end->result = ret;
2940 }
4c0425ff 2941
28a535f9 2942 ext4_add_complete_io(io_end);
4c0425ff 2943}
c7064ef1 2944
4c0425ff
MC
2945/*
2946 * For ext4 extent files, ext4 will do direct-io write to holes,
2947 * preallocated extents, and those write extend the file, no need to
2948 * fall back to buffered IO.
2949 *
b595076a 2950 * For holes, we fallocate those blocks, mark them as uninitialized
69c499d1 2951 * If those blocks were preallocated, we mark sure they are split, but
b595076a 2952 * still keep the range to write as uninitialized.
4c0425ff 2953 *
69c499d1 2954 * The unwritten extents will be converted to written when DIO is completed.
8d5d02e6 2955 * For async direct IO, since the IO may still pending when return, we
25985edc 2956 * set up an end_io call back function, which will do the conversion
8d5d02e6 2957 * when async direct IO completed.
4c0425ff
MC
2958 *
2959 * If the O_DIRECT write will extend the file then add this inode to the
2960 * orphan list. So recovery will truncate it back to the original size
2961 * if the machine crashes during the write.
2962 *
2963 */
2964static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
2965 const struct iovec *iov, loff_t offset,
2966 unsigned long nr_segs)
2967{
2968 struct file *file = iocb->ki_filp;
2969 struct inode *inode = file->f_mapping->host;
2970 ssize_t ret;
2971 size_t count = iov_length(iov, nr_segs);
69c499d1
TT
2972 int overwrite = 0;
2973 get_block_t *get_block_func = NULL;
2974 int dio_flags = 0;
4c0425ff 2975 loff_t final_size = offset + count;
729f52c6 2976
69c499d1
TT
2977 /* Use the old path for reads and writes beyond i_size. */
2978 if (rw != WRITE || final_size > inode->i_size)
2979 return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
4bd809db 2980
69c499d1 2981 BUG_ON(iocb->private == NULL);
4bd809db 2982
69c499d1
TT
2983 /* If we do a overwrite dio, i_mutex locking can be released */
2984 overwrite = *((int *)iocb->private);
4bd809db 2985
69c499d1
TT
2986 if (overwrite) {
2987 atomic_inc(&inode->i_dio_count);
2988 down_read(&EXT4_I(inode)->i_data_sem);
2989 mutex_unlock(&inode->i_mutex);
2990 }
8d5d02e6 2991
69c499d1
TT
2992 /*
2993 * We could direct write to holes and fallocate.
2994 *
2995 * Allocated blocks to fill the hole are marked as
2996 * uninitialized to prevent parallel buffered read to expose
2997 * the stale data before DIO complete the data IO.
2998 *
2999 * As to previously fallocated extents, ext4 get_block will
3000 * just simply mark the buffer mapped but still keep the
3001 * extents uninitialized.
3002 *
3003 * For non AIO case, we will convert those unwritten extents
3004 * to written after return back from blockdev_direct_IO.
3005 *
3006 * For async DIO, the conversion needs to be deferred when the
3007 * IO is completed. The ext4 end_io callback function will be
3008 * called to take care of the conversion work. Here for async
3009 * case, we allocate an io_end structure to hook to the iocb.
3010 */
3011 iocb->private = NULL;
3012 ext4_inode_aio_set(inode, NULL);
3013 if (!is_sync_kiocb(iocb)) {
3014 ext4_io_end_t *io_end = ext4_init_io_end(inode, GFP_NOFS);
3015 if (!io_end) {
3016 ret = -ENOMEM;
3017 goto retake_lock;
8b0f165f 3018 }
69c499d1
TT
3019 io_end->flag |= EXT4_IO_END_DIRECT;
3020 iocb->private = io_end;
8d5d02e6 3021 /*
69c499d1
TT
3022 * we save the io structure for current async direct
3023 * IO, so that later ext4_map_blocks() could flag the
3024 * io structure whether there is a unwritten extents
3025 * needs to be converted when IO is completed.
8d5d02e6 3026 */
69c499d1
TT
3027 ext4_inode_aio_set(inode, io_end);
3028 }
4bd809db 3029
69c499d1
TT
3030 if (overwrite) {
3031 get_block_func = ext4_get_block_write_nolock;
3032 } else {
3033 get_block_func = ext4_get_block_write;
3034 dio_flags = DIO_LOCKING;
3035 }
3036 ret = __blockdev_direct_IO(rw, iocb, inode,
3037 inode->i_sb->s_bdev, iov,
3038 offset, nr_segs,
3039 get_block_func,
3040 ext4_end_io_dio,
3041 NULL,
3042 dio_flags);
3043
3044 if (iocb->private)
3045 ext4_inode_aio_set(inode, NULL);
3046 /*
3047 * The io_end structure takes a reference to the inode, that
3048 * structure needs to be destroyed and the reference to the
3049 * inode need to be dropped, when IO is complete, even with 0
3050 * byte write, or failed.
3051 *
3052 * In the successful AIO DIO case, the io_end structure will
3053 * be destroyed and the reference to the inode will be dropped
3054 * after the end_io call back function is called.
3055 *
3056 * In the case there is 0 byte write, or error case, since VFS
3057 * direct IO won't invoke the end_io call back function, we
3058 * need to free the end_io structure here.
3059 */
3060 if (ret != -EIOCBQUEUED && ret <= 0 && iocb->private) {
3061 ext4_free_io_end(iocb->private);
3062 iocb->private = NULL;
3063 } else if (ret > 0 && !overwrite && ext4_test_inode_state(inode,
3064 EXT4_STATE_DIO_UNWRITTEN)) {
3065 int err;
3066 /*
3067 * for non AIO case, since the IO is already
3068 * completed, we could do the conversion right here
3069 */
3070 err = ext4_convert_unwritten_extents(inode,
3071 offset, ret);
3072 if (err < 0)
3073 ret = err;
3074 ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
3075 }
4bd809db 3076
69c499d1
TT
3077retake_lock:
3078 /* take i_mutex locking again if we do a ovewrite dio */
3079 if (overwrite) {
3080 inode_dio_done(inode);
3081 up_read(&EXT4_I(inode)->i_data_sem);
3082 mutex_lock(&inode->i_mutex);
4c0425ff 3083 }
8d5d02e6 3084
69c499d1 3085 return ret;
4c0425ff
MC
3086}
3087
3088static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
3089 const struct iovec *iov, loff_t offset,
3090 unsigned long nr_segs)
3091{
3092 struct file *file = iocb->ki_filp;
3093 struct inode *inode = file->f_mapping->host;
0562e0ba 3094 ssize_t ret;
4c0425ff 3095
84ebd795
TT
3096 /*
3097 * If we are doing data journalling we don't support O_DIRECT
3098 */
3099 if (ext4_should_journal_data(inode))
3100 return 0;
3101
46c7f254
TM
3102 /* Let buffer I/O handle the inline data case. */
3103 if (ext4_has_inline_data(inode))
3104 return 0;
3105
0562e0ba 3106 trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw);
12e9b892 3107 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
0562e0ba
JZ
3108 ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs);
3109 else
3110 ret = ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
3111 trace_ext4_direct_IO_exit(inode, offset,
3112 iov_length(iov, nr_segs), rw, ret);
3113 return ret;
4c0425ff
MC
3114}
3115
ac27a0ec 3116/*
617ba13b 3117 * Pages can be marked dirty completely asynchronously from ext4's journalling
ac27a0ec
DK
3118 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3119 * much here because ->set_page_dirty is called under VFS locks. The page is
3120 * not necessarily locked.
3121 *
3122 * We cannot just dirty the page and leave attached buffers clean, because the
3123 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3124 * or jbddirty because all the journalling code will explode.
3125 *
3126 * So what we do is to mark the page "pending dirty" and next time writepage
3127 * is called, propagate that into the buffers appropriately.
3128 */
617ba13b 3129static int ext4_journalled_set_page_dirty(struct page *page)
ac27a0ec
DK
3130{
3131 SetPageChecked(page);
3132 return __set_page_dirty_nobuffers(page);
3133}
3134
617ba13b 3135static const struct address_space_operations ext4_ordered_aops = {
8ab22b9a
HH
3136 .readpage = ext4_readpage,
3137 .readpages = ext4_readpages,
43ce1d23 3138 .writepage = ext4_writepage,
8ab22b9a
HH
3139 .write_begin = ext4_write_begin,
3140 .write_end = ext4_ordered_write_end,
3141 .bmap = ext4_bmap,
3142 .invalidatepage = ext4_invalidatepage,
3143 .releasepage = ext4_releasepage,
3144 .direct_IO = ext4_direct_IO,
3145 .migratepage = buffer_migrate_page,
3146 .is_partially_uptodate = block_is_partially_uptodate,
aa261f54 3147 .error_remove_page = generic_error_remove_page,
ac27a0ec
DK
3148};
3149
617ba13b 3150static const struct address_space_operations ext4_writeback_aops = {
8ab22b9a
HH
3151 .readpage = ext4_readpage,
3152 .readpages = ext4_readpages,
43ce1d23 3153 .writepage = ext4_writepage,
8ab22b9a
HH
3154 .write_begin = ext4_write_begin,
3155 .write_end = ext4_writeback_write_end,
3156 .bmap = ext4_bmap,
3157 .invalidatepage = ext4_invalidatepage,
3158 .releasepage = ext4_releasepage,
3159 .direct_IO = ext4_direct_IO,
3160 .migratepage = buffer_migrate_page,
3161 .is_partially_uptodate = block_is_partially_uptodate,
aa261f54 3162 .error_remove_page = generic_error_remove_page,
ac27a0ec
DK
3163};
3164
617ba13b 3165static const struct address_space_operations ext4_journalled_aops = {
8ab22b9a
HH
3166 .readpage = ext4_readpage,
3167 .readpages = ext4_readpages,
43ce1d23 3168 .writepage = ext4_writepage,
8ab22b9a
HH
3169 .write_begin = ext4_write_begin,
3170 .write_end = ext4_journalled_write_end,
3171 .set_page_dirty = ext4_journalled_set_page_dirty,
3172 .bmap = ext4_bmap,
4520fb3c 3173 .invalidatepage = ext4_journalled_invalidatepage,
8ab22b9a 3174 .releasepage = ext4_releasepage,
84ebd795 3175 .direct_IO = ext4_direct_IO,
8ab22b9a 3176 .is_partially_uptodate = block_is_partially_uptodate,
aa261f54 3177 .error_remove_page = generic_error_remove_page,
ac27a0ec
DK
3178};
3179
64769240 3180static const struct address_space_operations ext4_da_aops = {
8ab22b9a
HH
3181 .readpage = ext4_readpage,
3182 .readpages = ext4_readpages,
43ce1d23 3183 .writepage = ext4_writepage,
8ab22b9a 3184 .writepages = ext4_da_writepages,
8ab22b9a
HH
3185 .write_begin = ext4_da_write_begin,
3186 .write_end = ext4_da_write_end,
3187 .bmap = ext4_bmap,
3188 .invalidatepage = ext4_da_invalidatepage,
3189 .releasepage = ext4_releasepage,
3190 .direct_IO = ext4_direct_IO,
3191 .migratepage = buffer_migrate_page,
3192 .is_partially_uptodate = block_is_partially_uptodate,
aa261f54 3193 .error_remove_page = generic_error_remove_page,
64769240
AT
3194};
3195
617ba13b 3196void ext4_set_aops(struct inode *inode)
ac27a0ec 3197{
3d2b1582
LC
3198 switch (ext4_inode_journal_mode(inode)) {
3199 case EXT4_INODE_ORDERED_DATA_MODE:
3200 if (test_opt(inode->i_sb, DELALLOC))
3201 inode->i_mapping->a_ops = &ext4_da_aops;
3202 else
3203 inode->i_mapping->a_ops = &ext4_ordered_aops;
3204 break;
3205 case EXT4_INODE_WRITEBACK_DATA_MODE:
3206 if (test_opt(inode->i_sb, DELALLOC))
3207 inode->i_mapping->a_ops = &ext4_da_aops;
3208 else
3209 inode->i_mapping->a_ops = &ext4_writeback_aops;
3210 break;
3211 case EXT4_INODE_JOURNAL_DATA_MODE:
617ba13b 3212 inode->i_mapping->a_ops = &ext4_journalled_aops;
3d2b1582
LC
3213 break;
3214 default:
3215 BUG();
3216 }
ac27a0ec
DK
3217}
3218
4e96b2db
AH
3219
3220/*
3221 * ext4_discard_partial_page_buffers()
3222 * Wrapper function for ext4_discard_partial_page_buffers_no_lock.
3223 * This function finds and locks the page containing the offset
3224 * "from" and passes it to ext4_discard_partial_page_buffers_no_lock.
3225 * Calling functions that already have the page locked should call
3226 * ext4_discard_partial_page_buffers_no_lock directly.
3227 */
3228int ext4_discard_partial_page_buffers(handle_t *handle,
3229 struct address_space *mapping, loff_t from,
3230 loff_t length, int flags)
3231{
3232 struct inode *inode = mapping->host;
3233 struct page *page;
3234 int err = 0;
3235
3236 page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT,
3237 mapping_gfp_mask(mapping) & ~__GFP_FS);
3238 if (!page)
5129d05f 3239 return -ENOMEM;
4e96b2db
AH
3240
3241 err = ext4_discard_partial_page_buffers_no_lock(handle, inode, page,
3242 from, length, flags);
3243
3244 unlock_page(page);
3245 page_cache_release(page);
3246 return err;
3247}
3248
3249/*
3250 * ext4_discard_partial_page_buffers_no_lock()
3251 * Zeros a page range of length 'length' starting from offset 'from'.
3252 * Buffer heads that correspond to the block aligned regions of the
3253 * zeroed range will be unmapped. Unblock aligned regions
3254 * will have the corresponding buffer head mapped if needed so that
3255 * that region of the page can be updated with the partial zero out.
3256 *
3257 * This function assumes that the page has already been locked. The
3258 * The range to be discarded must be contained with in the given page.
3259 * If the specified range exceeds the end of the page it will be shortened
3260 * to the end of the page that corresponds to 'from'. This function is
3261 * appropriate for updating a page and it buffer heads to be unmapped and
3262 * zeroed for blocks that have been either released, or are going to be
3263 * released.
3264 *
3265 * handle: The journal handle
3266 * inode: The files inode
3267 * page: A locked page that contains the offset "from"
4907cb7b 3268 * from: The starting byte offset (from the beginning of the file)
4e96b2db
AH
3269 * to begin discarding
3270 * len: The length of bytes to discard
3271 * flags: Optional flags that may be used:
3272 *
3273 * EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED
3274 * Only zero the regions of the page whose buffer heads
3275 * have already been unmapped. This flag is appropriate
4907cb7b 3276 * for updating the contents of a page whose blocks may
4e96b2db
AH
3277 * have already been released, and we only want to zero
3278 * out the regions that correspond to those released blocks.
3279 *
4907cb7b 3280 * Returns zero on success or negative on failure.
4e96b2db 3281 */
5f163cc7 3282static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
4e96b2db
AH
3283 struct inode *inode, struct page *page, loff_t from,
3284 loff_t length, int flags)
3285{
3286 ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
3287 unsigned int offset = from & (PAGE_CACHE_SIZE-1);
3288 unsigned int blocksize, max, pos;
4e96b2db
AH
3289 ext4_lblk_t iblock;
3290 struct buffer_head *bh;
3291 int err = 0;
3292
3293 blocksize = inode->i_sb->s_blocksize;
3294 max = PAGE_CACHE_SIZE - offset;
3295
3296 if (index != page->index)
3297 return -EINVAL;
3298
3299 /*
3300 * correct length if it does not fall between
3301 * 'from' and the end of the page
3302 */
3303 if (length > max || length < 0)
3304 length = max;
3305
3306 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
3307
093e6e36
YY
3308 if (!page_has_buffers(page))
3309 create_empty_buffers(page, blocksize, 0);
4e96b2db
AH
3310
3311 /* Find the buffer that contains "offset" */
3312 bh = page_buffers(page);
3313 pos = blocksize;
3314 while (offset >= pos) {
3315 bh = bh->b_this_page;
3316 iblock++;
3317 pos += blocksize;
3318 }
3319
3320 pos = offset;
3321 while (pos < offset + length) {
e260daf2
YY
3322 unsigned int end_of_block, range_to_discard;
3323
4e96b2db
AH
3324 err = 0;
3325
3326 /* The length of space left to zero and unmap */
3327 range_to_discard = offset + length - pos;
3328
3329 /* The length of space until the end of the block */
3330 end_of_block = blocksize - (pos & (blocksize-1));
3331
3332 /*
3333 * Do not unmap or zero past end of block
3334 * for this buffer head
3335 */
3336 if (range_to_discard > end_of_block)
3337 range_to_discard = end_of_block;
3338
3339
3340 /*
3341 * Skip this buffer head if we are only zeroing unampped
3342 * regions of the page
3343 */
3344 if (flags & EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED &&
3345 buffer_mapped(bh))
3346 goto next;
3347
3348 /* If the range is block aligned, unmap */
3349 if (range_to_discard == blocksize) {
3350 clear_buffer_dirty(bh);
3351 bh->b_bdev = NULL;
3352 clear_buffer_mapped(bh);
3353 clear_buffer_req(bh);
3354 clear_buffer_new(bh);
3355 clear_buffer_delay(bh);
3356 clear_buffer_unwritten(bh);
3357 clear_buffer_uptodate(bh);
3358 zero_user(page, pos, range_to_discard);
3359 BUFFER_TRACE(bh, "Buffer discarded");
3360 goto next;
3361 }
3362
3363 /*
3364 * If this block is not completely contained in the range
3365 * to be discarded, then it is not going to be released. Because
3366 * we need to keep this block, we need to make sure this part
3367 * of the page is uptodate before we modify it by writeing
3368 * partial zeros on it.
3369 */
3370 if (!buffer_mapped(bh)) {
3371 /*
3372 * Buffer head must be mapped before we can read
3373 * from the block
3374 */
3375 BUFFER_TRACE(bh, "unmapped");
3376 ext4_get_block(inode, iblock, bh, 0);
3377 /* unmapped? It's a hole - nothing to do */
3378 if (!buffer_mapped(bh)) {
3379 BUFFER_TRACE(bh, "still unmapped");
3380 goto next;
3381 }
3382 }
3383
3384 /* Ok, it's mapped. Make sure it's up-to-date */
3385 if (PageUptodate(page))
3386 set_buffer_uptodate(bh);
3387
3388 if (!buffer_uptodate(bh)) {
3389 err = -EIO;
3390 ll_rw_block(READ, 1, &bh);
3391 wait_on_buffer(bh);
3392 /* Uhhuh. Read error. Complain and punt.*/
3393 if (!buffer_uptodate(bh))
3394 goto next;
3395 }
3396
3397 if (ext4_should_journal_data(inode)) {
3398 BUFFER_TRACE(bh, "get write access");
3399 err = ext4_journal_get_write_access(handle, bh);
3400 if (err)
3401 goto next;
3402 }
3403
3404 zero_user(page, pos, range_to_discard);
3405
3406 err = 0;
3407 if (ext4_should_journal_data(inode)) {
3408 err = ext4_handle_dirty_metadata(handle, inode, bh);
decbd919 3409 } else
4e96b2db 3410 mark_buffer_dirty(bh);
4e96b2db
AH
3411
3412 BUFFER_TRACE(bh, "Partial buffer zeroed");
3413next:
3414 bh = bh->b_this_page;
3415 iblock++;
3416 pos += range_to_discard;
3417 }
3418
3419 return err;
3420}
3421
91ef4caf
DG
3422int ext4_can_truncate(struct inode *inode)
3423{
91ef4caf
DG
3424 if (S_ISREG(inode->i_mode))
3425 return 1;
3426 if (S_ISDIR(inode->i_mode))
3427 return 1;
3428 if (S_ISLNK(inode->i_mode))
3429 return !ext4_inode_is_fast_symlink(inode);
3430 return 0;
3431}
3432
a4bb6b64
AH
3433/*
3434 * ext4_punch_hole: punches a hole in a file by releaseing the blocks
3435 * associated with the given offset and length
3436 *
3437 * @inode: File inode
3438 * @offset: The offset where the hole will begin
3439 * @len: The length of the hole
3440 *
4907cb7b 3441 * Returns: 0 on success or negative on failure
a4bb6b64
AH
3442 */
3443
3444int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
3445{
3446 struct inode *inode = file->f_path.dentry->d_inode;
3447 if (!S_ISREG(inode->i_mode))
73355192 3448 return -EOPNOTSUPP;
a4bb6b64 3449
8bad6fc8
ZL
3450 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3451 return ext4_ind_punch_hole(file, offset, length);
a4bb6b64 3452
bab08ab9
TT
3453 if (EXT4_SB(inode->i_sb)->s_cluster_ratio > 1) {
3454 /* TODO: Add support for bigalloc file systems */
73355192 3455 return -EOPNOTSUPP;
bab08ab9
TT
3456 }
3457
aaddea81
ZL
3458 trace_ext4_punch_hole(inode, offset, length);
3459
a4bb6b64
AH
3460 return ext4_ext_punch_hole(file, offset, length);
3461}
3462
ac27a0ec 3463/*
617ba13b 3464 * ext4_truncate()
ac27a0ec 3465 *
617ba13b
MC
3466 * We block out ext4_get_block() block instantiations across the entire
3467 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
ac27a0ec
DK
3468 * simultaneously on behalf of the same inode.
3469 *
42b2aa86 3470 * As we work through the truncate and commit bits of it to the journal there
ac27a0ec
DK
3471 * is one core, guiding principle: the file's tree must always be consistent on
3472 * disk. We must be able to restart the truncate after a crash.
3473 *
3474 * The file's tree may be transiently inconsistent in memory (although it
3475 * probably isn't), but whenever we close off and commit a journal transaction,
3476 * the contents of (the filesystem + the journal) must be consistent and
3477 * restartable. It's pretty simple, really: bottom up, right to left (although
3478 * left-to-right works OK too).
3479 *
3480 * Note that at recovery time, journal replay occurs *before* the restart of
3481 * truncate against the orphan inode list.
3482 *
3483 * The committed inode has the new, desired i_size (which is the same as
617ba13b 3484 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
ac27a0ec 3485 * that this inode's truncate did not complete and it will again call
617ba13b
MC
3486 * ext4_truncate() to have another go. So there will be instantiated blocks
3487 * to the right of the truncation point in a crashed ext4 filesystem. But
ac27a0ec 3488 * that's fine - as long as they are linked from the inode, the post-crash
617ba13b 3489 * ext4_truncate() run will find them and release them.
ac27a0ec 3490 */
617ba13b 3491void ext4_truncate(struct inode *inode)
ac27a0ec 3492{
0562e0ba
JZ
3493 trace_ext4_truncate_enter(inode);
3494
91ef4caf 3495 if (!ext4_can_truncate(inode))
ac27a0ec
DK
3496 return;
3497
12e9b892 3498 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
c8d46e41 3499
5534fb5b 3500 if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
19f5fb7a 3501 ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
7d8f9f7d 3502
aef1c851
TM
3503 if (ext4_has_inline_data(inode)) {
3504 int has_inline = 1;
3505
3506 ext4_inline_data_truncate(inode, &has_inline);
3507 if (has_inline)
3508 return;
3509 }
3510
ff9893dc 3511 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
cf108bca 3512 ext4_ext_truncate(inode);
ff9893dc
AG
3513 else
3514 ext4_ind_truncate(inode);
ac27a0ec 3515
0562e0ba 3516 trace_ext4_truncate_exit(inode);
ac27a0ec
DK
3517}
3518
ac27a0ec 3519/*
617ba13b 3520 * ext4_get_inode_loc returns with an extra refcount against the inode's
ac27a0ec
DK
3521 * underlying buffer_head on success. If 'in_mem' is true, we have all
3522 * data in memory that is needed to recreate the on-disk version of this
3523 * inode.
3524 */
617ba13b
MC
3525static int __ext4_get_inode_loc(struct inode *inode,
3526 struct ext4_iloc *iloc, int in_mem)
ac27a0ec 3527{
240799cd
TT
3528 struct ext4_group_desc *gdp;
3529 struct buffer_head *bh;
3530 struct super_block *sb = inode->i_sb;
3531 ext4_fsblk_t block;
3532 int inodes_per_block, inode_offset;
3533
3a06d778 3534 iloc->bh = NULL;
240799cd
TT
3535 if (!ext4_valid_inum(sb, inode->i_ino))
3536 return -EIO;
ac27a0ec 3537
240799cd
TT
3538 iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb);
3539 gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
3540 if (!gdp)
ac27a0ec
DK
3541 return -EIO;
3542
240799cd
TT
3543 /*
3544 * Figure out the offset within the block group inode table
3545 */
00d09882 3546 inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
240799cd
TT
3547 inode_offset = ((inode->i_ino - 1) %
3548 EXT4_INODES_PER_GROUP(sb));
3549 block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
3550 iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
3551
3552 bh = sb_getblk(sb, block);
aebf0243 3553 if (unlikely(!bh))
860d21e2 3554 return -ENOMEM;
ac27a0ec
DK
3555 if (!buffer_uptodate(bh)) {
3556 lock_buffer(bh);
9c83a923
HK
3557
3558 /*
3559 * If the buffer has the write error flag, we have failed
3560 * to write out another inode in the same block. In this
3561 * case, we don't have to read the block because we may
3562 * read the old inode data successfully.
3563 */
3564 if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
3565 set_buffer_uptodate(bh);
3566
ac27a0ec
DK
3567 if (buffer_uptodate(bh)) {
3568 /* someone brought it uptodate while we waited */
3569 unlock_buffer(bh);
3570 goto has_buffer;
3571 }
3572
3573 /*
3574 * If we have all information of the inode in memory and this
3575 * is the only valid inode in the block, we need not read the
3576 * block.
3577 */
3578 if (in_mem) {
3579 struct buffer_head *bitmap_bh;
240799cd 3580 int i, start;
ac27a0ec 3581
240799cd 3582 start = inode_offset & ~(inodes_per_block - 1);
ac27a0ec 3583
240799cd
TT
3584 /* Is the inode bitmap in cache? */
3585 bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp));
aebf0243 3586 if (unlikely(!bitmap_bh))
ac27a0ec
DK
3587 goto make_io;
3588
3589 /*
3590 * If the inode bitmap isn't in cache then the
3591 * optimisation may end up performing two reads instead
3592 * of one, so skip it.
3593 */
3594 if (!buffer_uptodate(bitmap_bh)) {
3595 brelse(bitmap_bh);
3596 goto make_io;
3597 }
240799cd 3598 for (i = start; i < start + inodes_per_block; i++) {
ac27a0ec
DK
3599 if (i == inode_offset)
3600 continue;
617ba13b 3601 if (ext4_test_bit(i, bitmap_bh->b_data))
ac27a0ec
DK
3602 break;
3603 }
3604 brelse(bitmap_bh);
240799cd 3605 if (i == start + inodes_per_block) {
ac27a0ec
DK
3606 /* all other inodes are free, so skip I/O */
3607 memset(bh->b_data, 0, bh->b_size);
3608 set_buffer_uptodate(bh);
3609 unlock_buffer(bh);
3610 goto has_buffer;
3611 }
3612 }
3613
3614make_io:
240799cd
TT
3615 /*
3616 * If we need to do any I/O, try to pre-readahead extra
3617 * blocks from the inode table.
3618 */
3619 if (EXT4_SB(sb)->s_inode_readahead_blks) {
3620 ext4_fsblk_t b, end, table;
3621 unsigned num;
3622
3623 table = ext4_inode_table(sb, gdp);
b713a5ec 3624 /* s_inode_readahead_blks is always a power of 2 */
240799cd
TT
3625 b = block & ~(EXT4_SB(sb)->s_inode_readahead_blks-1);
3626 if (table > b)
3627 b = table;
3628 end = b + EXT4_SB(sb)->s_inode_readahead_blks;
3629 num = EXT4_INODES_PER_GROUP(sb);
feb0ab32 3630 if (ext4_has_group_desc_csum(sb))
560671a0 3631 num -= ext4_itable_unused_count(sb, gdp);
240799cd
TT
3632 table += num / inodes_per_block;
3633 if (end > table)
3634 end = table;
3635 while (b <= end)
3636 sb_breadahead(sb, b++);
3637 }
3638
ac27a0ec
DK
3639 /*
3640 * There are other valid inodes in the buffer, this inode
3641 * has in-inode xattrs, or we don't have this inode in memory.
3642 * Read the block from disk.
3643 */
0562e0ba 3644 trace_ext4_load_inode(inode);
ac27a0ec
DK
3645 get_bh(bh);
3646 bh->b_end_io = end_buffer_read_sync;
65299a3b 3647 submit_bh(READ | REQ_META | REQ_PRIO, bh);
ac27a0ec
DK
3648 wait_on_buffer(bh);
3649 if (!buffer_uptodate(bh)) {
c398eda0
TT
3650 EXT4_ERROR_INODE_BLOCK(inode, block,
3651 "unable to read itable block");
ac27a0ec
DK
3652 brelse(bh);
3653 return -EIO;
3654 }
3655 }
3656has_buffer:
3657 iloc->bh = bh;
3658 return 0;
3659}
3660
617ba13b 3661int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
ac27a0ec
DK
3662{
3663 /* We have all inode data except xattrs in memory here. */
617ba13b 3664 return __ext4_get_inode_loc(inode, iloc,
19f5fb7a 3665 !ext4_test_inode_state(inode, EXT4_STATE_XATTR));
ac27a0ec
DK
3666}
3667
617ba13b 3668void ext4_set_inode_flags(struct inode *inode)
ac27a0ec 3669{
617ba13b 3670 unsigned int flags = EXT4_I(inode)->i_flags;
ac27a0ec
DK
3671
3672 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
617ba13b 3673 if (flags & EXT4_SYNC_FL)
ac27a0ec 3674 inode->i_flags |= S_SYNC;
617ba13b 3675 if (flags & EXT4_APPEND_FL)
ac27a0ec 3676 inode->i_flags |= S_APPEND;
617ba13b 3677 if (flags & EXT4_IMMUTABLE_FL)
ac27a0ec 3678 inode->i_flags |= S_IMMUTABLE;
617ba13b 3679 if (flags & EXT4_NOATIME_FL)
ac27a0ec 3680 inode->i_flags |= S_NOATIME;
617ba13b 3681 if (flags & EXT4_DIRSYNC_FL)
ac27a0ec
DK
3682 inode->i_flags |= S_DIRSYNC;
3683}
3684
ff9ddf7e
JK
3685/* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
3686void ext4_get_inode_flags(struct ext4_inode_info *ei)
3687{
84a8dce2
DM
3688 unsigned int vfs_fl;
3689 unsigned long old_fl, new_fl;
3690
3691 do {
3692 vfs_fl = ei->vfs_inode.i_flags;
3693 old_fl = ei->i_flags;
3694 new_fl = old_fl & ~(EXT4_SYNC_FL|EXT4_APPEND_FL|
3695 EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|
3696 EXT4_DIRSYNC_FL);
3697 if (vfs_fl & S_SYNC)
3698 new_fl |= EXT4_SYNC_FL;
3699 if (vfs_fl & S_APPEND)
3700 new_fl |= EXT4_APPEND_FL;
3701 if (vfs_fl & S_IMMUTABLE)
3702 new_fl |= EXT4_IMMUTABLE_FL;
3703 if (vfs_fl & S_NOATIME)
3704 new_fl |= EXT4_NOATIME_FL;
3705 if (vfs_fl & S_DIRSYNC)
3706 new_fl |= EXT4_DIRSYNC_FL;
3707 } while (cmpxchg(&ei->i_flags, old_fl, new_fl) != old_fl);
ff9ddf7e 3708}
de9a55b8 3709
0fc1b451 3710static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
de9a55b8 3711 struct ext4_inode_info *ei)
0fc1b451
AK
3712{
3713 blkcnt_t i_blocks ;
8180a562
AK
3714 struct inode *inode = &(ei->vfs_inode);
3715 struct super_block *sb = inode->i_sb;
0fc1b451
AK
3716
3717 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3718 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
3719 /* we are using combined 48 bit field */
3720 i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
3721 le32_to_cpu(raw_inode->i_blocks_lo);
07a03824 3722 if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) {
8180a562
AK
3723 /* i_blocks represent file system block size */
3724 return i_blocks << (inode->i_blkbits - 9);
3725 } else {
3726 return i_blocks;
3727 }
0fc1b451
AK
3728 } else {
3729 return le32_to_cpu(raw_inode->i_blocks_lo);
3730 }
3731}
ff9ddf7e 3732
152a7b0a
TM
3733static inline void ext4_iget_extra_inode(struct inode *inode,
3734 struct ext4_inode *raw_inode,
3735 struct ext4_inode_info *ei)
3736{
3737 __le32 *magic = (void *)raw_inode +
3738 EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize;
67cf5b09 3739 if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC)) {
152a7b0a 3740 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
67cf5b09 3741 ext4_find_inline_data_nolock(inode);
f19d5870
TM
3742 } else
3743 EXT4_I(inode)->i_inline_off = 0;
152a7b0a
TM
3744}
3745
1d1fe1ee 3746struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
ac27a0ec 3747{
617ba13b
MC
3748 struct ext4_iloc iloc;
3749 struct ext4_inode *raw_inode;
1d1fe1ee 3750 struct ext4_inode_info *ei;
1d1fe1ee 3751 struct inode *inode;
b436b9be 3752 journal_t *journal = EXT4_SB(sb)->s_journal;
1d1fe1ee 3753 long ret;
ac27a0ec 3754 int block;
08cefc7a
EB
3755 uid_t i_uid;
3756 gid_t i_gid;
ac27a0ec 3757
1d1fe1ee
DH
3758 inode = iget_locked(sb, ino);
3759 if (!inode)
3760 return ERR_PTR(-ENOMEM);
3761 if (!(inode->i_state & I_NEW))
3762 return inode;
3763
3764 ei = EXT4_I(inode);
7dc57615 3765 iloc.bh = NULL;
ac27a0ec 3766
1d1fe1ee
DH
3767 ret = __ext4_get_inode_loc(inode, &iloc, 0);
3768 if (ret < 0)
ac27a0ec 3769 goto bad_inode;
617ba13b 3770 raw_inode = ext4_raw_inode(&iloc);
814525f4
DW
3771
3772 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
3773 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
3774 if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
3775 EXT4_INODE_SIZE(inode->i_sb)) {
3776 EXT4_ERROR_INODE(inode, "bad extra_isize (%u != %u)",
3777 EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize,
3778 EXT4_INODE_SIZE(inode->i_sb));
3779 ret = -EIO;
3780 goto bad_inode;
3781 }
3782 } else
3783 ei->i_extra_isize = 0;
3784
3785 /* Precompute checksum seed for inode metadata */
3786 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3787 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
3788 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3789 __u32 csum;
3790 __le32 inum = cpu_to_le32(inode->i_ino);
3791 __le32 gen = raw_inode->i_generation;
3792 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
3793 sizeof(inum));
3794 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
3795 sizeof(gen));
3796 }
3797
3798 if (!ext4_inode_csum_verify(inode, raw_inode, ei)) {
3799 EXT4_ERROR_INODE(inode, "checksum invalid");
3800 ret = -EIO;
3801 goto bad_inode;
3802 }
3803
ac27a0ec 3804 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
08cefc7a
EB
3805 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
3806 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
af5bc92d 3807 if (!(test_opt(inode->i_sb, NO_UID32))) {
08cefc7a
EB
3808 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
3809 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
ac27a0ec 3810 }
08cefc7a
EB
3811 i_uid_write(inode, i_uid);
3812 i_gid_write(inode, i_gid);
bfe86848 3813 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
ac27a0ec 3814
353eb83c 3815 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
67cf5b09 3816 ei->i_inline_off = 0;
ac27a0ec
DK
3817 ei->i_dir_start_lookup = 0;
3818 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
3819 /* We now have enough fields to check if the inode was active or not.
3820 * This is needed because nfsd might try to access dead inodes
3821 * the test is that same one that e2fsck uses
3822 * NeilBrown 1999oct15
3823 */
3824 if (inode->i_nlink == 0) {
3825 if (inode->i_mode == 0 ||
617ba13b 3826 !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) {
ac27a0ec 3827 /* this inode is deleted */
1d1fe1ee 3828 ret = -ESTALE;
ac27a0ec
DK
3829 goto bad_inode;
3830 }
3831 /* The only unlinked inodes we let through here have
3832 * valid i_mode and are being read by the orphan
3833 * recovery code: that's fine, we're about to complete
3834 * the process of deleting those. */
3835 }
ac27a0ec 3836 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
0fc1b451 3837 inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
7973c0c1 3838 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
a9e81742 3839 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT))
a1ddeb7e
BP
3840 ei->i_file_acl |=
3841 ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
a48380f7 3842 inode->i_size = ext4_isize(raw_inode);
ac27a0ec 3843 ei->i_disksize = inode->i_size;
a9e7f447
DM
3844#ifdef CONFIG_QUOTA
3845 ei->i_reserved_quota = 0;
3846#endif
ac27a0ec
DK
3847 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
3848 ei->i_block_group = iloc.block_group;
a4912123 3849 ei->i_last_alloc_group = ~0;
ac27a0ec
DK
3850 /*
3851 * NOTE! The in-memory inode i_data array is in little-endian order
3852 * even on big-endian machines: we do NOT byteswap the block numbers!
3853 */
617ba13b 3854 for (block = 0; block < EXT4_N_BLOCKS; block++)
ac27a0ec
DK
3855 ei->i_data[block] = raw_inode->i_block[block];
3856 INIT_LIST_HEAD(&ei->i_orphan);
3857
b436b9be
JK
3858 /*
3859 * Set transaction id's of transactions that have to be committed
3860 * to finish f[data]sync. We set them to currently running transaction
3861 * as we cannot be sure that the inode or some of its metadata isn't
3862 * part of the transaction - the inode could have been reclaimed and
3863 * now it is reread from disk.
3864 */
3865 if (journal) {
3866 transaction_t *transaction;
3867 tid_t tid;
3868
a931da6a 3869 read_lock(&journal->j_state_lock);
b436b9be
JK
3870 if (journal->j_running_transaction)
3871 transaction = journal->j_running_transaction;
3872 else
3873 transaction = journal->j_committing_transaction;
3874 if (transaction)
3875 tid = transaction->t_tid;
3876 else
3877 tid = journal->j_commit_sequence;
a931da6a 3878 read_unlock(&journal->j_state_lock);
b436b9be
JK
3879 ei->i_sync_tid = tid;
3880 ei->i_datasync_tid = tid;
3881 }
3882
0040d987 3883 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
ac27a0ec
DK
3884 if (ei->i_extra_isize == 0) {
3885 /* The extra space is currently unused. Use it. */
617ba13b
MC
3886 ei->i_extra_isize = sizeof(struct ext4_inode) -
3887 EXT4_GOOD_OLD_INODE_SIZE;
ac27a0ec 3888 } else {
152a7b0a 3889 ext4_iget_extra_inode(inode, raw_inode, ei);
ac27a0ec 3890 }
814525f4 3891 }
ac27a0ec 3892
ef7f3835
KS
3893 EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
3894 EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
3895 EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
3896 EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
3897
25ec56b5
JNC
3898 inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
3899 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
3900 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
3901 inode->i_version |=
3902 (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
3903 }
3904
c4b5a614 3905 ret = 0;
485c26ec 3906 if (ei->i_file_acl &&
1032988c 3907 !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) {
24676da4
TT
3908 EXT4_ERROR_INODE(inode, "bad extended attribute block %llu",
3909 ei->i_file_acl);
485c26ec
TT
3910 ret = -EIO;
3911 goto bad_inode;
f19d5870
TM
3912 } else if (!ext4_has_inline_data(inode)) {
3913 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
3914 if ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
3915 (S_ISLNK(inode->i_mode) &&
3916 !ext4_inode_is_fast_symlink(inode))))
3917 /* Validate extent which is part of inode */
3918 ret = ext4_ext_check_inode(inode);
3919 } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
3920 (S_ISLNK(inode->i_mode) &&
3921 !ext4_inode_is_fast_symlink(inode))) {
3922 /* Validate block references which are part of inode */
3923 ret = ext4_ind_check_inode(inode);
3924 }
fe2c8191 3925 }
567f3e9a 3926 if (ret)
de9a55b8 3927 goto bad_inode;
7a262f7c 3928
ac27a0ec 3929 if (S_ISREG(inode->i_mode)) {
617ba13b
MC
3930 inode->i_op = &ext4_file_inode_operations;
3931 inode->i_fop = &ext4_file_operations;
3932 ext4_set_aops(inode);
ac27a0ec 3933 } else if (S_ISDIR(inode->i_mode)) {
617ba13b
MC
3934 inode->i_op = &ext4_dir_inode_operations;
3935 inode->i_fop = &ext4_dir_operations;
ac27a0ec 3936 } else if (S_ISLNK(inode->i_mode)) {
e83c1397 3937 if (ext4_inode_is_fast_symlink(inode)) {
617ba13b 3938 inode->i_op = &ext4_fast_symlink_inode_operations;
e83c1397
DG
3939 nd_terminate_link(ei->i_data, inode->i_size,
3940 sizeof(ei->i_data) - 1);
3941 } else {
617ba13b
MC
3942 inode->i_op = &ext4_symlink_inode_operations;
3943 ext4_set_aops(inode);
ac27a0ec 3944 }
563bdd61
TT
3945 } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
3946 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
617ba13b 3947 inode->i_op = &ext4_special_inode_operations;
ac27a0ec
DK
3948 if (raw_inode->i_block[0])
3949 init_special_inode(inode, inode->i_mode,
3950 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
3951 else
3952 init_special_inode(inode, inode->i_mode,
3953 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
563bdd61 3954 } else {
563bdd61 3955 ret = -EIO;
24676da4 3956 EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode);
563bdd61 3957 goto bad_inode;
ac27a0ec 3958 }
af5bc92d 3959 brelse(iloc.bh);
617ba13b 3960 ext4_set_inode_flags(inode);
1d1fe1ee
DH
3961 unlock_new_inode(inode);
3962 return inode;
ac27a0ec
DK
3963
3964bad_inode:
567f3e9a 3965 brelse(iloc.bh);
1d1fe1ee
DH
3966 iget_failed(inode);
3967 return ERR_PTR(ret);
ac27a0ec
DK
3968}
3969
0fc1b451
AK
3970static int ext4_inode_blocks_set(handle_t *handle,
3971 struct ext4_inode *raw_inode,
3972 struct ext4_inode_info *ei)
3973{
3974 struct inode *inode = &(ei->vfs_inode);
3975 u64 i_blocks = inode->i_blocks;
3976 struct super_block *sb = inode->i_sb;
0fc1b451
AK
3977
3978 if (i_blocks <= ~0U) {
3979 /*
4907cb7b 3980 * i_blocks can be represented in a 32 bit variable
0fc1b451
AK
3981 * as multiple of 512 bytes
3982 */
8180a562 3983 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
0fc1b451 3984 raw_inode->i_blocks_high = 0;
84a8dce2 3985 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
f287a1a5
TT
3986 return 0;
3987 }
3988 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE))
3989 return -EFBIG;
3990
3991 if (i_blocks <= 0xffffffffffffULL) {
0fc1b451
AK
3992 /*
3993 * i_blocks can be represented in a 48 bit variable
3994 * as multiple of 512 bytes
3995 */
8180a562 3996 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
0fc1b451 3997 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
84a8dce2 3998 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
0fc1b451 3999 } else {
84a8dce2 4000 ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE);
8180a562
AK
4001 /* i_block is stored in file system block size */
4002 i_blocks = i_blocks >> (inode->i_blkbits - 9);
4003 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4004 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
0fc1b451 4005 }
f287a1a5 4006 return 0;
0fc1b451
AK
4007}
4008
ac27a0ec
DK
4009/*
4010 * Post the struct inode info into an on-disk inode location in the
4011 * buffer-cache. This gobbles the caller's reference to the
4012 * buffer_head in the inode location struct.
4013 *
4014 * The caller must have write access to iloc->bh.
4015 */
617ba13b 4016static int ext4_do_update_inode(handle_t *handle,
ac27a0ec 4017 struct inode *inode,
830156c7 4018 struct ext4_iloc *iloc)
ac27a0ec 4019{
617ba13b
MC
4020 struct ext4_inode *raw_inode = ext4_raw_inode(iloc);
4021 struct ext4_inode_info *ei = EXT4_I(inode);
ac27a0ec
DK
4022 struct buffer_head *bh = iloc->bh;
4023 int err = 0, rc, block;
b71fc079 4024 int need_datasync = 0;
08cefc7a
EB
4025 uid_t i_uid;
4026 gid_t i_gid;
ac27a0ec
DK
4027
4028 /* For fields not not tracking in the in-memory inode,
4029 * initialise them to zero for new inodes. */
19f5fb7a 4030 if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
617ba13b 4031 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
ac27a0ec 4032
ff9ddf7e 4033 ext4_get_inode_flags(ei);
ac27a0ec 4034 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
08cefc7a
EB
4035 i_uid = i_uid_read(inode);
4036 i_gid = i_gid_read(inode);
af5bc92d 4037 if (!(test_opt(inode->i_sb, NO_UID32))) {
08cefc7a
EB
4038 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid));
4039 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid));
ac27a0ec
DK
4040/*
4041 * Fix up interoperability with old kernels. Otherwise, old inodes get
4042 * re-used with the upper 16 bits of the uid/gid intact
4043 */
af5bc92d 4044 if (!ei->i_dtime) {
ac27a0ec 4045 raw_inode->i_uid_high =
08cefc7a 4046 cpu_to_le16(high_16_bits(i_uid));
ac27a0ec 4047 raw_inode->i_gid_high =
08cefc7a 4048 cpu_to_le16(high_16_bits(i_gid));
ac27a0ec
DK
4049 } else {
4050 raw_inode->i_uid_high = 0;
4051 raw_inode->i_gid_high = 0;
4052 }
4053 } else {
08cefc7a
EB
4054 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid));
4055 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(i_gid));
ac27a0ec
DK
4056 raw_inode->i_uid_high = 0;
4057 raw_inode->i_gid_high = 0;
4058 }
4059 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
ef7f3835
KS
4060
4061 EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
4062 EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode);
4063 EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
4064 EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
4065
0fc1b451
AK
4066 if (ext4_inode_blocks_set(handle, raw_inode, ei))
4067 goto out_brelse;
ac27a0ec 4068 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
353eb83c 4069 raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF);
9b8f1f01
MC
4070 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
4071 cpu_to_le32(EXT4_OS_HURD))
a1ddeb7e
BP
4072 raw_inode->i_file_acl_high =
4073 cpu_to_le16(ei->i_file_acl >> 32);
7973c0c1 4074 raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
b71fc079
JK
4075 if (ei->i_disksize != ext4_isize(raw_inode)) {
4076 ext4_isize_set(raw_inode, ei->i_disksize);
4077 need_datasync = 1;
4078 }
a48380f7
AK
4079 if (ei->i_disksize > 0x7fffffffULL) {
4080 struct super_block *sb = inode->i_sb;
4081 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
4082 EXT4_FEATURE_RO_COMPAT_LARGE_FILE) ||
4083 EXT4_SB(sb)->s_es->s_rev_level ==
4084 cpu_to_le32(EXT4_GOOD_OLD_REV)) {
4085 /* If this is the first large file
4086 * created, add a flag to the superblock.
4087 */
4088 err = ext4_journal_get_write_access(handle,
4089 EXT4_SB(sb)->s_sbh);
4090 if (err)
4091 goto out_brelse;
4092 ext4_update_dynamic_rev(sb);
4093 EXT4_SET_RO_COMPAT_FEATURE(sb,
617ba13b 4094 EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
0390131b 4095 ext4_handle_sync(handle);
b50924c2 4096 err = ext4_handle_dirty_super(handle, sb);
ac27a0ec
DK
4097 }
4098 }
4099 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
4100 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
4101 if (old_valid_dev(inode->i_rdev)) {
4102 raw_inode->i_block[0] =
4103 cpu_to_le32(old_encode_dev(inode->i_rdev));
4104 raw_inode->i_block[1] = 0;
4105 } else {
4106 raw_inode->i_block[0] = 0;
4107 raw_inode->i_block[1] =
4108 cpu_to_le32(new_encode_dev(inode->i_rdev));
4109 raw_inode->i_block[2] = 0;
4110 }
f19d5870 4111 } else if (!ext4_has_inline_data(inode)) {
de9a55b8
TT
4112 for (block = 0; block < EXT4_N_BLOCKS; block++)
4113 raw_inode->i_block[block] = ei->i_data[block];
f19d5870 4114 }
ac27a0ec 4115
25ec56b5
JNC
4116 raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
4117 if (ei->i_extra_isize) {
4118 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4119 raw_inode->i_version_hi =
4120 cpu_to_le32(inode->i_version >> 32);
ac27a0ec 4121 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
25ec56b5
JNC
4122 }
4123
814525f4
DW
4124 ext4_inode_csum_set(inode, raw_inode, ei);
4125
830156c7 4126 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
73b50c1c 4127 rc = ext4_handle_dirty_metadata(handle, NULL, bh);
830156c7
FM
4128 if (!err)
4129 err = rc;
19f5fb7a 4130 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
ac27a0ec 4131
b71fc079 4132 ext4_update_inode_fsync_trans(handle, inode, need_datasync);
ac27a0ec 4133out_brelse:
af5bc92d 4134 brelse(bh);
617ba13b 4135 ext4_std_error(inode->i_sb, err);
ac27a0ec
DK
4136 return err;
4137}
4138
4139/*
617ba13b 4140 * ext4_write_inode()
ac27a0ec
DK
4141 *
4142 * We are called from a few places:
4143 *
4144 * - Within generic_file_write() for O_SYNC files.
4145 * Here, there will be no transaction running. We wait for any running
4907cb7b 4146 * transaction to commit.
ac27a0ec
DK
4147 *
4148 * - Within sys_sync(), kupdate and such.
4149 * We wait on commit, if tol to.
4150 *
4151 * - Within prune_icache() (PF_MEMALLOC == true)
4152 * Here we simply return. We can't afford to block kswapd on the
4153 * journal commit.
4154 *
4155 * In all cases it is actually safe for us to return without doing anything,
4156 * because the inode has been copied into a raw inode buffer in
617ba13b 4157 * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
ac27a0ec
DK
4158 * knfsd.
4159 *
4160 * Note that we are absolutely dependent upon all inode dirtiers doing the
4161 * right thing: they *must* call mark_inode_dirty() after dirtying info in
4162 * which we are interested.
4163 *
4164 * It would be a bug for them to not do this. The code:
4165 *
4166 * mark_inode_dirty(inode)
4167 * stuff();
4168 * inode->i_size = expr;
4169 *
4170 * is in error because a kswapd-driven write_inode() could occur while
4171 * `stuff()' is running, and the new i_size will be lost. Plus the inode
4172 * will no longer be on the superblock's dirty inode list.
4173 */
a9185b41 4174int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
ac27a0ec 4175{
91ac6f43
FM
4176 int err;
4177
ac27a0ec
DK
4178 if (current->flags & PF_MEMALLOC)
4179 return 0;
4180
91ac6f43
FM
4181 if (EXT4_SB(inode->i_sb)->s_journal) {
4182 if (ext4_journal_current_handle()) {
4183 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
4184 dump_stack();
4185 return -EIO;
4186 }
ac27a0ec 4187
a9185b41 4188 if (wbc->sync_mode != WB_SYNC_ALL)
91ac6f43
FM
4189 return 0;
4190
4191 err = ext4_force_commit(inode->i_sb);
4192 } else {
4193 struct ext4_iloc iloc;
ac27a0ec 4194
8b472d73 4195 err = __ext4_get_inode_loc(inode, &iloc, 0);
91ac6f43
FM
4196 if (err)
4197 return err;
a9185b41 4198 if (wbc->sync_mode == WB_SYNC_ALL)
830156c7
FM
4199 sync_dirty_buffer(iloc.bh);
4200 if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) {
c398eda0
TT
4201 EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr,
4202 "IO error syncing inode");
830156c7
FM
4203 err = -EIO;
4204 }
fd2dd9fb 4205 brelse(iloc.bh);
91ac6f43
FM
4206 }
4207 return err;
ac27a0ec
DK
4208}
4209
53e87268
JK
4210/*
4211 * In data=journal mode ext4_journalled_invalidatepage() may fail to invalidate
4212 * buffers that are attached to a page stradding i_size and are undergoing
4213 * commit. In that case we have to wait for commit to finish and try again.
4214 */
4215static void ext4_wait_for_tail_page_commit(struct inode *inode)
4216{
4217 struct page *page;
4218 unsigned offset;
4219 journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
4220 tid_t commit_tid = 0;
4221 int ret;
4222
4223 offset = inode->i_size & (PAGE_CACHE_SIZE - 1);
4224 /*
4225 * All buffers in the last page remain valid? Then there's nothing to
4226 * do. We do the check mainly to optimize the common PAGE_CACHE_SIZE ==
4227 * blocksize case
4228 */
4229 if (offset > PAGE_CACHE_SIZE - (1 << inode->i_blkbits))
4230 return;
4231 while (1) {
4232 page = find_lock_page(inode->i_mapping,
4233 inode->i_size >> PAGE_CACHE_SHIFT);
4234 if (!page)
4235 return;
4236 ret = __ext4_journalled_invalidatepage(page, offset);
4237 unlock_page(page);
4238 page_cache_release(page);
4239 if (ret != -EBUSY)
4240 return;
4241 commit_tid = 0;
4242 read_lock(&journal->j_state_lock);
4243 if (journal->j_committing_transaction)
4244 commit_tid = journal->j_committing_transaction->t_tid;
4245 read_unlock(&journal->j_state_lock);
4246 if (commit_tid)
4247 jbd2_log_wait_commit(journal, commit_tid);
4248 }
4249}
4250
ac27a0ec 4251/*
617ba13b 4252 * ext4_setattr()
ac27a0ec
DK
4253 *
4254 * Called from notify_change.
4255 *
4256 * We want to trap VFS attempts to truncate the file as soon as
4257 * possible. In particular, we want to make sure that when the VFS
4258 * shrinks i_size, we put the inode on the orphan list and modify
4259 * i_disksize immediately, so that during the subsequent flushing of
4260 * dirty pages and freeing of disk blocks, we can guarantee that any
4261 * commit will leave the blocks being flushed in an unused state on
4262 * disk. (On recovery, the inode will get truncated and the blocks will
4263 * be freed, so we have a strong guarantee that no future commit will
4264 * leave these blocks visible to the user.)
4265 *
678aaf48
JK
4266 * Another thing we have to assure is that if we are in ordered mode
4267 * and inode is still attached to the committing transaction, we must
4268 * we start writeout of all the dirty pages which are being truncated.
4269 * This way we are sure that all the data written in the previous
4270 * transaction are already on disk (truncate waits for pages under
4271 * writeback).
4272 *
4273 * Called with inode->i_mutex down.
ac27a0ec 4274 */
617ba13b 4275int ext4_setattr(struct dentry *dentry, struct iattr *attr)
ac27a0ec
DK
4276{
4277 struct inode *inode = dentry->d_inode;
4278 int error, rc = 0;
3d287de3 4279 int orphan = 0;
ac27a0ec
DK
4280 const unsigned int ia_valid = attr->ia_valid;
4281
4282 error = inode_change_ok(inode, attr);
4283 if (error)
4284 return error;
4285
12755627 4286 if (is_quota_modification(inode, attr))
871a2931 4287 dquot_initialize(inode);
08cefc7a
EB
4288 if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, inode->i_uid)) ||
4289 (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, inode->i_gid))) {
ac27a0ec
DK
4290 handle_t *handle;
4291
4292 /* (user+group)*(old+new) structure, inode write (sb,
4293 * inode block, ? - but truncate inode update has it) */
5aca07eb 4294 handle = ext4_journal_start(inode, (EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)+
194074ac 4295 EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb))+3);
ac27a0ec
DK
4296 if (IS_ERR(handle)) {
4297 error = PTR_ERR(handle);
4298 goto err_out;
4299 }
b43fa828 4300 error = dquot_transfer(inode, attr);
ac27a0ec 4301 if (error) {
617ba13b 4302 ext4_journal_stop(handle);
ac27a0ec
DK
4303 return error;
4304 }
4305 /* Update corresponding info in inode so that everything is in
4306 * one transaction */
4307 if (attr->ia_valid & ATTR_UID)
4308 inode->i_uid = attr->ia_uid;
4309 if (attr->ia_valid & ATTR_GID)
4310 inode->i_gid = attr->ia_gid;
617ba13b
MC
4311 error = ext4_mark_inode_dirty(handle, inode);
4312 ext4_journal_stop(handle);
ac27a0ec
DK
4313 }
4314
e2b46574 4315 if (attr->ia_valid & ATTR_SIZE) {
562c72aa 4316
12e9b892 4317 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
e2b46574
ES
4318 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4319
0c095c7f
TT
4320 if (attr->ia_size > sbi->s_bitmap_maxbytes)
4321 return -EFBIG;
e2b46574
ES
4322 }
4323 }
4324
ac27a0ec 4325 if (S_ISREG(inode->i_mode) &&
c8d46e41 4326 attr->ia_valid & ATTR_SIZE &&
072bd7ea 4327 (attr->ia_size < inode->i_size)) {
ac27a0ec
DK
4328 handle_t *handle;
4329
617ba13b 4330 handle = ext4_journal_start(inode, 3);
ac27a0ec
DK
4331 if (IS_ERR(handle)) {
4332 error = PTR_ERR(handle);
4333 goto err_out;
4334 }
3d287de3
DM
4335 if (ext4_handle_valid(handle)) {
4336 error = ext4_orphan_add(handle, inode);
4337 orphan = 1;
4338 }
617ba13b
MC
4339 EXT4_I(inode)->i_disksize = attr->ia_size;
4340 rc = ext4_mark_inode_dirty(handle, inode);
ac27a0ec
DK
4341 if (!error)
4342 error = rc;
617ba13b 4343 ext4_journal_stop(handle);
678aaf48
JK
4344
4345 if (ext4_should_order_data(inode)) {
4346 error = ext4_begin_ordered_truncate(inode,
4347 attr->ia_size);
4348 if (error) {
4349 /* Do as much error cleanup as possible */
4350 handle = ext4_journal_start(inode, 3);
4351 if (IS_ERR(handle)) {
4352 ext4_orphan_del(NULL, inode);
4353 goto err_out;
4354 }
4355 ext4_orphan_del(handle, inode);
3d287de3 4356 orphan = 0;
678aaf48
JK
4357 ext4_journal_stop(handle);
4358 goto err_out;
4359 }
4360 }
ac27a0ec
DK
4361 }
4362
072bd7ea 4363 if (attr->ia_valid & ATTR_SIZE) {
53e87268
JK
4364 if (attr->ia_size != inode->i_size) {
4365 loff_t oldsize = inode->i_size;
4366
4367 i_size_write(inode, attr->ia_size);
4368 /*
4369 * Blocks are going to be removed from the inode. Wait
4370 * for dio in flight. Temporarily disable
4371 * dioread_nolock to prevent livelock.
4372 */
1b65007e 4373 if (orphan) {
53e87268
JK
4374 if (!ext4_should_journal_data(inode)) {
4375 ext4_inode_block_unlocked_dio(inode);
4376 inode_dio_wait(inode);
4377 ext4_inode_resume_unlocked_dio(inode);
4378 } else
4379 ext4_wait_for_tail_page_commit(inode);
1b65007e 4380 }
53e87268
JK
4381 /*
4382 * Truncate pagecache after we've waited for commit
4383 * in data=journal mode to make pages freeable.
4384 */
4385 truncate_pagecache(inode, oldsize, inode->i_size);
1c9114f9 4386 }
afcff5d8 4387 ext4_truncate(inode);
072bd7ea 4388 }
ac27a0ec 4389
1025774c
CH
4390 if (!rc) {
4391 setattr_copy(inode, attr);
4392 mark_inode_dirty(inode);
4393 }
4394
4395 /*
4396 * If the call to ext4_truncate failed to get a transaction handle at
4397 * all, we need to clean up the in-core orphan list manually.
4398 */
3d287de3 4399 if (orphan && inode->i_nlink)
617ba13b 4400 ext4_orphan_del(NULL, inode);
ac27a0ec
DK
4401
4402 if (!rc && (ia_valid & ATTR_MODE))
617ba13b 4403 rc = ext4_acl_chmod(inode);
ac27a0ec
DK
4404
4405err_out:
617ba13b 4406 ext4_std_error(inode->i_sb, error);
ac27a0ec
DK
4407 if (!error)
4408 error = rc;
4409 return error;
4410}
4411
3e3398a0
MC
4412int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
4413 struct kstat *stat)
4414{
4415 struct inode *inode;
4416 unsigned long delalloc_blocks;
4417
4418 inode = dentry->d_inode;
4419 generic_fillattr(inode, stat);
4420
4421 /*
4422 * We can't update i_blocks if the block allocation is delayed
4423 * otherwise in the case of system crash before the real block
4424 * allocation is done, we will have i_blocks inconsistent with
4425 * on-disk file blocks.
4426 * We always keep i_blocks updated together with real
4427 * allocation. But to not confuse with user, stat
4428 * will return the blocks that include the delayed allocation
4429 * blocks for this file.
4430 */
96607551
TM
4431 delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb),
4432 EXT4_I(inode)->i_reserved_data_blocks);
3e3398a0
MC
4433
4434 stat->blocks += (delalloc_blocks << inode->i_sb->s_blocksize_bits)>>9;
4435 return 0;
4436}
ac27a0ec 4437
a02908f1
MC
4438static int ext4_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
4439{
12e9b892 4440 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
8bb2b247 4441 return ext4_ind_trans_blocks(inode, nrblocks, chunk);
ac51d837 4442 return ext4_ext_index_trans_blocks(inode, nrblocks, chunk);
a02908f1 4443}
ac51d837 4444
ac27a0ec 4445/*
a02908f1
MC
4446 * Account for index blocks, block groups bitmaps and block group
4447 * descriptor blocks if modify datablocks and index blocks
4448 * worse case, the indexs blocks spread over different block groups
ac27a0ec 4449 *
a02908f1 4450 * If datablocks are discontiguous, they are possible to spread over
4907cb7b 4451 * different block groups too. If they are contiguous, with flexbg,
a02908f1 4452 * they could still across block group boundary.
ac27a0ec 4453 *
a02908f1
MC
4454 * Also account for superblock, inode, quota and xattr blocks
4455 */
1f109d5a 4456static int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
a02908f1 4457{
8df9675f
TT
4458 ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
4459 int gdpblocks;
a02908f1
MC
4460 int idxblocks;
4461 int ret = 0;
4462
4463 /*
4464 * How many index blocks need to touch to modify nrblocks?
4465 * The "Chunk" flag indicating whether the nrblocks is
4466 * physically contiguous on disk
4467 *
4468 * For Direct IO and fallocate, they calls get_block to allocate
4469 * one single extent at a time, so they could set the "Chunk" flag
4470 */
4471 idxblocks = ext4_index_trans_blocks(inode, nrblocks, chunk);
4472
4473 ret = idxblocks;
4474
4475 /*
4476 * Now let's see how many group bitmaps and group descriptors need
4477 * to account
4478 */
4479 groups = idxblocks;
4480 if (chunk)
4481 groups += 1;
4482 else
4483 groups += nrblocks;
4484
4485 gdpblocks = groups;
8df9675f
TT
4486 if (groups > ngroups)
4487 groups = ngroups;
a02908f1
MC
4488 if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
4489 gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
4490
4491 /* bitmaps and block group descriptor blocks */
4492 ret += groups + gdpblocks;
4493
4494 /* Blocks for super block, inode, quota and xattr blocks */
4495 ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
4496
4497 return ret;
4498}
4499
4500/*
25985edc 4501 * Calculate the total number of credits to reserve to fit
f3bd1f3f
MC
4502 * the modification of a single pages into a single transaction,
4503 * which may include multiple chunks of block allocations.
ac27a0ec 4504 *
525f4ed8 4505 * This could be called via ext4_write_begin()
ac27a0ec 4506 *
525f4ed8 4507 * We need to consider the worse case, when
a02908f1 4508 * one new block per extent.
ac27a0ec 4509 */
a86c6181 4510int ext4_writepage_trans_blocks(struct inode *inode)
ac27a0ec 4511{
617ba13b 4512 int bpp = ext4_journal_blocks_per_page(inode);
ac27a0ec
DK
4513 int ret;
4514
a02908f1 4515 ret = ext4_meta_trans_blocks(inode, bpp, 0);
a86c6181 4516
a02908f1 4517 /* Account for data blocks for journalled mode */
617ba13b 4518 if (ext4_should_journal_data(inode))
a02908f1 4519 ret += bpp;
ac27a0ec
DK
4520 return ret;
4521}
f3bd1f3f
MC
4522
4523/*
4524 * Calculate the journal credits for a chunk of data modification.
4525 *
4526 * This is called from DIO, fallocate or whoever calling
79e83036 4527 * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
f3bd1f3f
MC
4528 *
4529 * journal buffers for data blocks are not included here, as DIO
4530 * and fallocate do no need to journal data buffers.
4531 */
4532int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
4533{
4534 return ext4_meta_trans_blocks(inode, nrblocks, 1);
4535}
4536
ac27a0ec 4537/*
617ba13b 4538 * The caller must have previously called ext4_reserve_inode_write().
ac27a0ec
DK
4539 * Give this, we know that the caller already has write access to iloc->bh.
4540 */
617ba13b 4541int ext4_mark_iloc_dirty(handle_t *handle,
de9a55b8 4542 struct inode *inode, struct ext4_iloc *iloc)
ac27a0ec
DK
4543{
4544 int err = 0;
4545
c64db50e 4546 if (IS_I_VERSION(inode))
25ec56b5
JNC
4547 inode_inc_iversion(inode);
4548
ac27a0ec
DK
4549 /* the do_update_inode consumes one bh->b_count */
4550 get_bh(iloc->bh);
4551
dab291af 4552 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
830156c7 4553 err = ext4_do_update_inode(handle, inode, iloc);
ac27a0ec
DK
4554 put_bh(iloc->bh);
4555 return err;
4556}
4557
4558/*
4559 * On success, We end up with an outstanding reference count against
4560 * iloc->bh. This _must_ be cleaned up later.
4561 */
4562
4563int
617ba13b
MC
4564ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
4565 struct ext4_iloc *iloc)
ac27a0ec 4566{
0390131b
FM
4567 int err;
4568
4569 err = ext4_get_inode_loc(inode, iloc);
4570 if (!err) {
4571 BUFFER_TRACE(iloc->bh, "get_write_access");
4572 err = ext4_journal_get_write_access(handle, iloc->bh);
4573 if (err) {
4574 brelse(iloc->bh);
4575 iloc->bh = NULL;
ac27a0ec
DK
4576 }
4577 }
617ba13b 4578 ext4_std_error(inode->i_sb, err);
ac27a0ec
DK
4579 return err;
4580}
4581
6dd4ee7c
KS
4582/*
4583 * Expand an inode by new_extra_isize bytes.
4584 * Returns 0 on success or negative error number on failure.
4585 */
1d03ec98
AK
4586static int ext4_expand_extra_isize(struct inode *inode,
4587 unsigned int new_extra_isize,
4588 struct ext4_iloc iloc,
4589 handle_t *handle)
6dd4ee7c
KS
4590{
4591 struct ext4_inode *raw_inode;
4592 struct ext4_xattr_ibody_header *header;
6dd4ee7c
KS
4593
4594 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
4595 return 0;
4596
4597 raw_inode = ext4_raw_inode(&iloc);
4598
4599 header = IHDR(inode, raw_inode);
6dd4ee7c
KS
4600
4601 /* No extended attributes present */
19f5fb7a
TT
4602 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
4603 header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
6dd4ee7c
KS
4604 memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
4605 new_extra_isize);
4606 EXT4_I(inode)->i_extra_isize = new_extra_isize;
4607 return 0;
4608 }
4609
4610 /* try to expand with EAs present */
4611 return ext4_expand_extra_isize_ea(inode, new_extra_isize,
4612 raw_inode, handle);
4613}
4614
ac27a0ec
DK
4615/*
4616 * What we do here is to mark the in-core inode as clean with respect to inode
4617 * dirtiness (it may still be data-dirty).
4618 * This means that the in-core inode may be reaped by prune_icache
4619 * without having to perform any I/O. This is a very good thing,
4620 * because *any* task may call prune_icache - even ones which
4621 * have a transaction open against a different journal.
4622 *
4623 * Is this cheating? Not really. Sure, we haven't written the
4624 * inode out, but prune_icache isn't a user-visible syncing function.
4625 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
4626 * we start and wait on commits.
ac27a0ec 4627 */
617ba13b 4628int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
ac27a0ec 4629{
617ba13b 4630 struct ext4_iloc iloc;
6dd4ee7c
KS
4631 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4632 static unsigned int mnt_count;
4633 int err, ret;
ac27a0ec
DK
4634
4635 might_sleep();
7ff9c073 4636 trace_ext4_mark_inode_dirty(inode, _RET_IP_);
617ba13b 4637 err = ext4_reserve_inode_write(handle, inode, &iloc);
0390131b
FM
4638 if (ext4_handle_valid(handle) &&
4639 EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
19f5fb7a 4640 !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {
6dd4ee7c
KS
4641 /*
4642 * We need extra buffer credits since we may write into EA block
4643 * with this same handle. If journal_extend fails, then it will
4644 * only result in a minor loss of functionality for that inode.
4645 * If this is felt to be critical, then e2fsck should be run to
4646 * force a large enough s_min_extra_isize.
4647 */
4648 if ((jbd2_journal_extend(handle,
4649 EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) {
4650 ret = ext4_expand_extra_isize(inode,
4651 sbi->s_want_extra_isize,
4652 iloc, handle);
4653 if (ret) {
19f5fb7a
TT
4654 ext4_set_inode_state(inode,
4655 EXT4_STATE_NO_EXPAND);
c1bddad9
AK
4656 if (mnt_count !=
4657 le16_to_cpu(sbi->s_es->s_mnt_count)) {
12062ddd 4658 ext4_warning(inode->i_sb,
6dd4ee7c
KS
4659 "Unable to expand inode %lu. Delete"
4660 " some EAs or run e2fsck.",
4661 inode->i_ino);
c1bddad9
AK
4662 mnt_count =
4663 le16_to_cpu(sbi->s_es->s_mnt_count);
6dd4ee7c
KS
4664 }
4665 }
4666 }
4667 }
ac27a0ec 4668 if (!err)
617ba13b 4669 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
ac27a0ec
DK
4670 return err;
4671}
4672
4673/*
617ba13b 4674 * ext4_dirty_inode() is called from __mark_inode_dirty()
ac27a0ec
DK
4675 *
4676 * We're really interested in the case where a file is being extended.
4677 * i_size has been changed by generic_commit_write() and we thus need
4678 * to include the updated inode in the current transaction.
4679 *
5dd4056d 4680 * Also, dquot_alloc_block() will always dirty the inode when blocks
ac27a0ec
DK
4681 * are allocated to the file.
4682 *
4683 * If the inode is marked synchronous, we don't honour that here - doing
4684 * so would cause a commit on atime updates, which we don't bother doing.
4685 * We handle synchronous inodes at the highest possible level.
4686 */
aa385729 4687void ext4_dirty_inode(struct inode *inode, int flags)
ac27a0ec 4688{
ac27a0ec
DK
4689 handle_t *handle;
4690
617ba13b 4691 handle = ext4_journal_start(inode, 2);
ac27a0ec
DK
4692 if (IS_ERR(handle))
4693 goto out;
f3dc272f 4694
f3dc272f
CW
4695 ext4_mark_inode_dirty(handle, inode);
4696
617ba13b 4697 ext4_journal_stop(handle);
ac27a0ec
DK
4698out:
4699 return;
4700}
4701
4702#if 0
4703/*
4704 * Bind an inode's backing buffer_head into this transaction, to prevent
4705 * it from being flushed to disk early. Unlike
617ba13b 4706 * ext4_reserve_inode_write, this leaves behind no bh reference and
ac27a0ec
DK
4707 * returns no iloc structure, so the caller needs to repeat the iloc
4708 * lookup to mark the inode dirty later.
4709 */
617ba13b 4710static int ext4_pin_inode(handle_t *handle, struct inode *inode)
ac27a0ec 4711{
617ba13b 4712 struct ext4_iloc iloc;
ac27a0ec
DK
4713
4714 int err = 0;
4715 if (handle) {
617ba13b 4716 err = ext4_get_inode_loc(inode, &iloc);
ac27a0ec
DK
4717 if (!err) {
4718 BUFFER_TRACE(iloc.bh, "get_write_access");
dab291af 4719 err = jbd2_journal_get_write_access(handle, iloc.bh);
ac27a0ec 4720 if (!err)
0390131b 4721 err = ext4_handle_dirty_metadata(handle,
73b50c1c 4722 NULL,
0390131b 4723 iloc.bh);
ac27a0ec
DK
4724 brelse(iloc.bh);
4725 }
4726 }
617ba13b 4727 ext4_std_error(inode->i_sb, err);
ac27a0ec
DK
4728 return err;
4729}
4730#endif
4731
617ba13b 4732int ext4_change_inode_journal_flag(struct inode *inode, int val)
ac27a0ec
DK
4733{
4734 journal_t *journal;
4735 handle_t *handle;
4736 int err;
4737
4738 /*
4739 * We have to be very careful here: changing a data block's
4740 * journaling status dynamically is dangerous. If we write a
4741 * data block to the journal, change the status and then delete
4742 * that block, we risk forgetting to revoke the old log record
4743 * from the journal and so a subsequent replay can corrupt data.
4744 * So, first we make sure that the journal is empty and that
4745 * nobody is changing anything.
4746 */
4747
617ba13b 4748 journal = EXT4_JOURNAL(inode);
0390131b
FM
4749 if (!journal)
4750 return 0;
d699594d 4751 if (is_journal_aborted(journal))
ac27a0ec 4752 return -EROFS;
2aff57b0
YY
4753 /* We have to allocate physical blocks for delalloc blocks
4754 * before flushing journal. otherwise delalloc blocks can not
4755 * be allocated any more. even more truncate on delalloc blocks
4756 * could trigger BUG by flushing delalloc blocks in journal.
4757 * There is no delalloc block in non-journal data mode.
4758 */
4759 if (val && test_opt(inode->i_sb, DELALLOC)) {
4760 err = ext4_alloc_da_blocks(inode);
4761 if (err < 0)
4762 return err;
4763 }
ac27a0ec 4764
17335dcc
DM
4765 /* Wait for all existing dio workers */
4766 ext4_inode_block_unlocked_dio(inode);
4767 inode_dio_wait(inode);
4768
dab291af 4769 jbd2_journal_lock_updates(journal);
ac27a0ec
DK
4770
4771 /*
4772 * OK, there are no updates running now, and all cached data is
4773 * synced to disk. We are now in a completely consistent state
4774 * which doesn't have anything in the journal, and we know that
4775 * no filesystem updates are running, so it is safe to modify
4776 * the inode's in-core data-journaling state flag now.
4777 */
4778
4779 if (val)
12e9b892 4780 ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
5872ddaa
YY
4781 else {
4782 jbd2_journal_flush(journal);
12e9b892 4783 ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
5872ddaa 4784 }
617ba13b 4785 ext4_set_aops(inode);
ac27a0ec 4786
dab291af 4787 jbd2_journal_unlock_updates(journal);
17335dcc 4788 ext4_inode_resume_unlocked_dio(inode);
ac27a0ec
DK
4789
4790 /* Finally we can mark the inode as dirty. */
4791
617ba13b 4792 handle = ext4_journal_start(inode, 1);
ac27a0ec
DK
4793 if (IS_ERR(handle))
4794 return PTR_ERR(handle);
4795
617ba13b 4796 err = ext4_mark_inode_dirty(handle, inode);
0390131b 4797 ext4_handle_sync(handle);
617ba13b
MC
4798 ext4_journal_stop(handle);
4799 ext4_std_error(inode->i_sb, err);
ac27a0ec
DK
4800
4801 return err;
4802}
2e9ee850
AK
4803
4804static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
4805{
4806 return !buffer_mapped(bh);
4807}
4808
c2ec175c 4809int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
2e9ee850 4810{
c2ec175c 4811 struct page *page = vmf->page;
2e9ee850
AK
4812 loff_t size;
4813 unsigned long len;
9ea7df53 4814 int ret;
2e9ee850
AK
4815 struct file *file = vma->vm_file;
4816 struct inode *inode = file->f_path.dentry->d_inode;
4817 struct address_space *mapping = inode->i_mapping;
9ea7df53
JK
4818 handle_t *handle;
4819 get_block_t *get_block;
4820 int retries = 0;
2e9ee850 4821
8e8ad8a5 4822 sb_start_pagefault(inode->i_sb);
041bbb6d 4823 file_update_time(vma->vm_file);
9ea7df53
JK
4824 /* Delalloc case is easy... */
4825 if (test_opt(inode->i_sb, DELALLOC) &&
4826 !ext4_should_journal_data(inode) &&
4827 !ext4_nonda_switch(inode->i_sb)) {
4828 do {
4829 ret = __block_page_mkwrite(vma, vmf,
4830 ext4_da_get_block_prep);
4831 } while (ret == -ENOSPC &&
4832 ext4_should_retry_alloc(inode->i_sb, &retries));
4833 goto out_ret;
2e9ee850 4834 }
0e499890
DW
4835
4836 lock_page(page);
9ea7df53
JK
4837 size = i_size_read(inode);
4838 /* Page got truncated from under us? */
4839 if (page->mapping != mapping || page_offset(page) > size) {
4840 unlock_page(page);
4841 ret = VM_FAULT_NOPAGE;
4842 goto out;
0e499890 4843 }
2e9ee850
AK
4844
4845 if (page->index == size >> PAGE_CACHE_SHIFT)
4846 len = size & ~PAGE_CACHE_MASK;
4847 else
4848 len = PAGE_CACHE_SIZE;
a827eaff 4849 /*
9ea7df53
JK
4850 * Return if we have all the buffers mapped. This avoids the need to do
4851 * journal_start/journal_stop which can block and take a long time
a827eaff 4852 */
2e9ee850 4853 if (page_has_buffers(page)) {
f19d5870
TM
4854 if (!ext4_walk_page_buffers(NULL, page_buffers(page),
4855 0, len, NULL,
4856 ext4_bh_unmapped)) {
9ea7df53
JK
4857 /* Wait so that we don't change page under IO */
4858 wait_on_page_writeback(page);
4859 ret = VM_FAULT_LOCKED;
4860 goto out;
a827eaff 4861 }
2e9ee850 4862 }
a827eaff 4863 unlock_page(page);
9ea7df53
JK
4864 /* OK, we need to fill the hole... */
4865 if (ext4_should_dioread_nolock(inode))
4866 get_block = ext4_get_block_write;
4867 else
4868 get_block = ext4_get_block;
4869retry_alloc:
4870 handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode));
4871 if (IS_ERR(handle)) {
c2ec175c 4872 ret = VM_FAULT_SIGBUS;
9ea7df53
JK
4873 goto out;
4874 }
4875 ret = __block_page_mkwrite(vma, vmf, get_block);
4876 if (!ret && ext4_should_journal_data(inode)) {
f19d5870 4877 if (ext4_walk_page_buffers(handle, page_buffers(page), 0,
9ea7df53
JK
4878 PAGE_CACHE_SIZE, NULL, do_journal_get_write_access)) {
4879 unlock_page(page);
4880 ret = VM_FAULT_SIGBUS;
fcbb5515 4881 ext4_journal_stop(handle);
9ea7df53
JK
4882 goto out;
4883 }
4884 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
4885 }
4886 ext4_journal_stop(handle);
4887 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
4888 goto retry_alloc;
4889out_ret:
4890 ret = block_page_mkwrite_return(ret);
4891out:
8e8ad8a5 4892 sb_end_pagefault(inode->i_sb);
2e9ee850
AK
4893 return ret;
4894}
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