2 * linux/fs/ext4/inode.c
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)
11 * linux/fs/minix/inode.c
13 * Copyright (C) 1991, 1992 Linus Torvalds
15 * 64-bit file support on 64-bit platforms by Jakub Jelinek
16 * (jj@sunsite.ms.mff.cuni.cz)
18 * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000
22 #include <linux/time.h>
23 #include <linux/jbd2.h>
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>
30 #include <linux/pagevec.h>
31 #include <linux/mpage.h>
32 #include <linux/namei.h>
33 #include <linux/uio.h>
34 #include <linux/bio.h>
35 #include <linux/workqueue.h>
36 #include <linux/kernel.h>
37 #include <linux/printk.h>
38 #include <linux/slab.h>
39 #include <linux/ratelimit.h>
40 #include <linux/aio.h>
41 #include <linux/bitops.h>
43 #include "ext4_jbd2.h"
48 #include <trace/events/ext4.h>
50 #define MPAGE_DA_EXTENT_TAIL 0x01
52 static __u32 ext4_inode_csum(struct inode *inode, struct ext4_inode *raw,
53 struct ext4_inode_info *ei)
55 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
60 csum_lo = le16_to_cpu(raw->i_checksum_lo);
61 raw->i_checksum_lo = 0;
62 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
63 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) {
64 csum_hi = le16_to_cpu(raw->i_checksum_hi);
65 raw->i_checksum_hi = 0;
68 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)raw,
69 EXT4_INODE_SIZE(inode->i_sb));
71 raw->i_checksum_lo = cpu_to_le16(csum_lo);
72 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
73 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
74 raw->i_checksum_hi = cpu_to_le16(csum_hi);
79 static int ext4_inode_csum_verify(struct inode *inode, struct ext4_inode *raw,
80 struct ext4_inode_info *ei)
82 __u32 provided, calculated;
84 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
85 cpu_to_le32(EXT4_OS_LINUX) ||
86 !EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
87 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
90 provided = le16_to_cpu(raw->i_checksum_lo);
91 calculated = ext4_inode_csum(inode, raw, ei);
92 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
93 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
94 provided |= ((__u32)le16_to_cpu(raw->i_checksum_hi)) << 16;
98 return provided == calculated;
101 static void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw,
102 struct ext4_inode_info *ei)
106 if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
107 cpu_to_le32(EXT4_OS_LINUX) ||
108 !EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
109 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
112 csum = ext4_inode_csum(inode, raw, ei);
113 raw->i_checksum_lo = cpu_to_le16(csum & 0xFFFF);
114 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
115 EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
116 raw->i_checksum_hi = cpu_to_le16(csum >> 16);
119 static inline int ext4_begin_ordered_truncate(struct inode *inode,
122 trace_ext4_begin_ordered_truncate(inode, new_size);
124 * If jinode is zero, then we never opened the file for
125 * writing, so there's no need to call
126 * jbd2_journal_begin_ordered_truncate() since there's no
127 * outstanding writes we need to flush.
129 if (!EXT4_I(inode)->jinode)
131 return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode),
132 EXT4_I(inode)->jinode,
136 static void ext4_invalidatepage(struct page *page, unsigned int offset,
137 unsigned int length);
138 static int __ext4_journalled_writepage(struct page *page, unsigned int len);
139 static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);
140 static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,
144 * Test whether an inode is a fast symlink.
146 static int ext4_inode_is_fast_symlink(struct inode *inode)
148 int ea_blocks = EXT4_I(inode)->i_file_acl ?
149 EXT4_CLUSTER_SIZE(inode->i_sb) >> 9 : 0;
151 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
155 * Restart the transaction associated with *handle. This does a commit,
156 * so before we call here everything must be consistently dirtied against
159 int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
165 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
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.
170 BUG_ON(EXT4_JOURNAL(inode) == NULL);
171 jbd_debug(2, "restarting handle %p\n", handle);
172 up_write(&EXT4_I(inode)->i_data_sem);
173 ret = ext4_journal_restart(handle, nblocks);
174 down_write(&EXT4_I(inode)->i_data_sem);
175 ext4_discard_preallocations(inode);
181 * Called at the last iput() if i_nlink is zero.
183 void ext4_evict_inode(struct inode *inode)
188 trace_ext4_evict_inode(inode);
190 if (inode->i_nlink) {
192 * When journalling data dirty buffers are tracked only in the
193 * journal. So although mm thinks everything is clean and
194 * ready for reaping the inode might still have some pages to
195 * write in the running transaction or waiting to be
196 * checkpointed. Thus calling jbd2_journal_invalidatepage()
197 * (via truncate_inode_pages()) to discard these buffers can
198 * cause data loss. Also even if we did not discard these
199 * buffers, we would have no way to find them after the inode
200 * is reaped and thus user could see stale data if he tries to
201 * read them before the transaction is checkpointed. So be
202 * careful and force everything to disk here... We use
203 * ei->i_datasync_tid to store the newest transaction
204 * containing inode's data.
206 * Note that directories do not have this problem because they
207 * don't use page cache.
209 if (ext4_should_journal_data(inode) &&
210 (S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode)) &&
211 inode->i_ino != EXT4_JOURNAL_INO) {
212 journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
213 tid_t commit_tid = EXT4_I(inode)->i_datasync_tid;
215 jbd2_complete_transaction(journal, commit_tid);
216 filemap_write_and_wait(&inode->i_data);
218 truncate_inode_pages_final(&inode->i_data);
220 WARN_ON(atomic_read(&EXT4_I(inode)->i_ioend_count));
224 if (!is_bad_inode(inode))
225 dquot_initialize(inode);
227 if (ext4_should_order_data(inode))
228 ext4_begin_ordered_truncate(inode, 0);
229 truncate_inode_pages_final(&inode->i_data);
231 WARN_ON(atomic_read(&EXT4_I(inode)->i_ioend_count));
232 if (is_bad_inode(inode))
236 * Protect us against freezing - iput() caller didn't have to have any
237 * protection against it
239 sb_start_intwrite(inode->i_sb);
240 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE,
241 ext4_blocks_for_truncate(inode)+3);
242 if (IS_ERR(handle)) {
243 ext4_std_error(inode->i_sb, PTR_ERR(handle));
245 * If we're going to skip the normal cleanup, we still need to
246 * make sure that the in-core orphan linked list is properly
249 ext4_orphan_del(NULL, inode);
250 sb_end_intwrite(inode->i_sb);
255 ext4_handle_sync(handle);
257 err = ext4_mark_inode_dirty(handle, inode);
259 ext4_warning(inode->i_sb,
260 "couldn't mark inode dirty (err %d)", err);
264 ext4_truncate(inode);
267 * ext4_ext_truncate() doesn't reserve any slop when it
268 * restarts journal transactions; therefore there may not be
269 * enough credits left in the handle to remove the inode from
270 * the orphan list and set the dtime field.
272 if (!ext4_handle_has_enough_credits(handle, 3)) {
273 err = ext4_journal_extend(handle, 3);
275 err = ext4_journal_restart(handle, 3);
277 ext4_warning(inode->i_sb,
278 "couldn't extend journal (err %d)", err);
280 ext4_journal_stop(handle);
281 ext4_orphan_del(NULL, inode);
282 sb_end_intwrite(inode->i_sb);
288 * Kill off the orphan record which ext4_truncate created.
289 * AKPM: I think this can be inside the above `if'.
290 * Note that ext4_orphan_del() has to be able to cope with the
291 * deletion of a non-existent orphan - this is because we don't
292 * know if ext4_truncate() actually created an orphan record.
293 * (Well, we could do this if we need to, but heck - it works)
295 ext4_orphan_del(handle, inode);
296 EXT4_I(inode)->i_dtime = get_seconds();
299 * One subtle ordering requirement: if anything has gone wrong
300 * (transaction abort, IO errors, whatever), then we can still
301 * do these next steps (the fs will already have been marked as
302 * having errors), but we can't free the inode if the mark_dirty
305 if (ext4_mark_inode_dirty(handle, inode))
306 /* If that failed, just do the required in-core inode clear. */
307 ext4_clear_inode(inode);
309 ext4_free_inode(handle, inode);
310 ext4_journal_stop(handle);
311 sb_end_intwrite(inode->i_sb);
314 ext4_clear_inode(inode); /* We must guarantee clearing of inode... */
318 qsize_t *ext4_get_reserved_space(struct inode *inode)
320 return &EXT4_I(inode)->i_reserved_quota;
325 * Calculate the number of metadata blocks need to reserve
326 * to allocate a block located at @lblock
328 static int ext4_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
330 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
331 return ext4_ext_calc_metadata_amount(inode, lblock);
333 return ext4_ind_calc_metadata_amount(inode, lblock);
337 * Called with i_data_sem down, which is important since we can call
338 * ext4_discard_preallocations() from here.
340 void ext4_da_update_reserve_space(struct inode *inode,
341 int used, int quota_claim)
343 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
344 struct ext4_inode_info *ei = EXT4_I(inode);
346 spin_lock(&ei->i_block_reservation_lock);
347 trace_ext4_da_update_reserve_space(inode, used, quota_claim);
348 if (unlikely(used > ei->i_reserved_data_blocks)) {
349 ext4_warning(inode->i_sb, "%s: ino %lu, used %d "
350 "with only %d reserved data blocks",
351 __func__, inode->i_ino, used,
352 ei->i_reserved_data_blocks);
354 used = ei->i_reserved_data_blocks;
357 if (unlikely(ei->i_allocated_meta_blocks > ei->i_reserved_meta_blocks)) {
358 ext4_warning(inode->i_sb, "ino %lu, allocated %d "
359 "with only %d reserved metadata blocks "
360 "(releasing %d blocks with reserved %d data blocks)",
361 inode->i_ino, ei->i_allocated_meta_blocks,
362 ei->i_reserved_meta_blocks, used,
363 ei->i_reserved_data_blocks);
365 ei->i_allocated_meta_blocks = ei->i_reserved_meta_blocks;
368 /* Update per-inode reservations */
369 ei->i_reserved_data_blocks -= used;
370 ei->i_reserved_meta_blocks -= ei->i_allocated_meta_blocks;
371 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
372 used + ei->i_allocated_meta_blocks);
373 ei->i_allocated_meta_blocks = 0;
375 if (ei->i_reserved_data_blocks == 0) {
377 * We can release all of the reserved metadata blocks
378 * only when we have written all of the delayed
381 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
382 ei->i_reserved_meta_blocks);
383 ei->i_reserved_meta_blocks = 0;
384 ei->i_da_metadata_calc_len = 0;
386 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
388 /* Update quota subsystem for data blocks */
390 dquot_claim_block(inode, EXT4_C2B(sbi, used));
393 * We did fallocate with an offset that is already delayed
394 * allocated. So on delayed allocated writeback we should
395 * not re-claim the quota for fallocated blocks.
397 dquot_release_reservation_block(inode, EXT4_C2B(sbi, used));
401 * If we have done all the pending block allocations and if
402 * there aren't any writers on the inode, we can discard the
403 * inode's preallocations.
405 if ((ei->i_reserved_data_blocks == 0) &&
406 (atomic_read(&inode->i_writecount) == 0))
407 ext4_discard_preallocations(inode);
410 static int __check_block_validity(struct inode *inode, const char *func,
412 struct ext4_map_blocks *map)
414 if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk,
416 ext4_error_inode(inode, func, line, map->m_pblk,
417 "lblock %lu mapped to illegal pblock "
418 "(length %d)", (unsigned long) map->m_lblk,
425 #define check_block_validity(inode, map) \
426 __check_block_validity((inode), __func__, __LINE__, (map))
428 #ifdef ES_AGGRESSIVE_TEST
429 static void ext4_map_blocks_es_recheck(handle_t *handle,
431 struct ext4_map_blocks *es_map,
432 struct ext4_map_blocks *map,
439 * There is a race window that the result is not the same.
440 * e.g. xfstests #223 when dioread_nolock enables. The reason
441 * is that we lookup a block mapping in extent status tree with
442 * out taking i_data_sem. So at the time the unwritten extent
443 * could be converted.
445 if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
446 down_read((&EXT4_I(inode)->i_data_sem));
447 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
448 retval = ext4_ext_map_blocks(handle, inode, map, flags &
449 EXT4_GET_BLOCKS_KEEP_SIZE);
451 retval = ext4_ind_map_blocks(handle, inode, map, flags &
452 EXT4_GET_BLOCKS_KEEP_SIZE);
454 if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
455 up_read((&EXT4_I(inode)->i_data_sem));
457 * Clear EXT4_MAP_FROM_CLUSTER and EXT4_MAP_BOUNDARY flag
458 * because it shouldn't be marked in es_map->m_flags.
460 map->m_flags &= ~(EXT4_MAP_FROM_CLUSTER | EXT4_MAP_BOUNDARY);
463 * We don't check m_len because extent will be collpased in status
464 * tree. So the m_len might not equal.
466 if (es_map->m_lblk != map->m_lblk ||
467 es_map->m_flags != map->m_flags ||
468 es_map->m_pblk != map->m_pblk) {
469 printk("ES cache assertion failed for inode: %lu "
470 "es_cached ex [%d/%d/%llu/%x] != "
471 "found ex [%d/%d/%llu/%x] retval %d flags %x\n",
472 inode->i_ino, es_map->m_lblk, es_map->m_len,
473 es_map->m_pblk, es_map->m_flags, map->m_lblk,
474 map->m_len, map->m_pblk, map->m_flags,
478 #endif /* ES_AGGRESSIVE_TEST */
481 * The ext4_map_blocks() function tries to look up the requested blocks,
482 * and returns if the blocks are already mapped.
484 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
485 * and store the allocated blocks in the result buffer head and mark it
488 * If file type is extents based, it will call ext4_ext_map_blocks(),
489 * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
492 * On success, it returns the number of blocks being mapped or allocate.
493 * if create==0 and the blocks are pre-allocated and uninitialized block,
494 * the result buffer head is unmapped. If the create ==1, it will make sure
495 * the buffer head is mapped.
497 * It returns 0 if plain look up failed (blocks have not been allocated), in
498 * that case, buffer head is unmapped
500 * It returns the error in case of allocation failure.
502 int ext4_map_blocks(handle_t *handle, struct inode *inode,
503 struct ext4_map_blocks *map, int flags)
505 struct extent_status es;
508 #ifdef ES_AGGRESSIVE_TEST
509 struct ext4_map_blocks orig_map;
511 memcpy(&orig_map, map, sizeof(*map));
515 ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
516 "logical block %lu\n", inode->i_ino, flags, map->m_len,
517 (unsigned long) map->m_lblk);
520 * ext4_map_blocks returns an int, and m_len is an unsigned int
522 if (unlikely(map->m_len > INT_MAX))
523 map->m_len = INT_MAX;
525 /* We can handle the block number less than EXT_MAX_BLOCKS */
526 if (unlikely(map->m_lblk >= EXT_MAX_BLOCKS))
529 /* Lookup extent status tree firstly */
530 if (ext4_es_lookup_extent(inode, map->m_lblk, &es)) {
531 ext4_es_lru_add(inode);
532 if (ext4_es_is_written(&es) || ext4_es_is_unwritten(&es)) {
533 map->m_pblk = ext4_es_pblock(&es) +
534 map->m_lblk - es.es_lblk;
535 map->m_flags |= ext4_es_is_written(&es) ?
536 EXT4_MAP_MAPPED : EXT4_MAP_UNWRITTEN;
537 retval = es.es_len - (map->m_lblk - es.es_lblk);
538 if (retval > map->m_len)
541 } else if (ext4_es_is_delayed(&es) || ext4_es_is_hole(&es)) {
546 #ifdef ES_AGGRESSIVE_TEST
547 ext4_map_blocks_es_recheck(handle, inode, map,
554 * Try to see if we can get the block without requesting a new
557 if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
558 down_read((&EXT4_I(inode)->i_data_sem));
559 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
560 retval = ext4_ext_map_blocks(handle, inode, map, flags &
561 EXT4_GET_BLOCKS_KEEP_SIZE);
563 retval = ext4_ind_map_blocks(handle, inode, map, flags &
564 EXT4_GET_BLOCKS_KEEP_SIZE);
569 if (unlikely(retval != map->m_len)) {
570 ext4_warning(inode->i_sb,
571 "ES len assertion failed for inode "
572 "%lu: retval %d != map->m_len %d",
573 inode->i_ino, retval, map->m_len);
577 status = map->m_flags & EXT4_MAP_UNWRITTEN ?
578 EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
579 if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
580 ext4_find_delalloc_range(inode, map->m_lblk,
581 map->m_lblk + map->m_len - 1))
582 status |= EXTENT_STATUS_DELAYED;
583 ret = ext4_es_insert_extent(inode, map->m_lblk,
584 map->m_len, map->m_pblk, status);
588 if (!(flags & EXT4_GET_BLOCKS_NO_LOCK))
589 up_read((&EXT4_I(inode)->i_data_sem));
592 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
593 ret = check_block_validity(inode, map);
598 /* If it is only a block(s) look up */
599 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
603 * Returns if the blocks have already allocated
605 * Note that if blocks have been preallocated
606 * ext4_ext_get_block() returns the create = 0
607 * with buffer head unmapped.
609 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
611 * If we need to convert extent to unwritten
612 * we continue and do the actual work in
613 * ext4_ext_map_blocks()
615 if (!(flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN))
619 * Here we clear m_flags because after allocating an new extent,
620 * it will be set again.
622 map->m_flags &= ~EXT4_MAP_FLAGS;
625 * New blocks allocate and/or writing to uninitialized extent
626 * will possibly result in updating i_data, so we take
627 * the write lock of i_data_sem, and call get_blocks()
628 * with create == 1 flag.
630 down_write((&EXT4_I(inode)->i_data_sem));
633 * if the caller is from delayed allocation writeout path
634 * we have already reserved fs blocks for allocation
635 * let the underlying get_block() function know to
636 * avoid double accounting
638 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
639 ext4_set_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
641 * We need to check for EXT4 here because migrate
642 * could have changed the inode type in between
644 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
645 retval = ext4_ext_map_blocks(handle, inode, map, flags);
647 retval = ext4_ind_map_blocks(handle, inode, map, flags);
649 if (retval > 0 && map->m_flags & EXT4_MAP_NEW) {
651 * We allocated new blocks which will result in
652 * i_data's format changing. Force the migrate
653 * to fail by clearing migrate flags
655 ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
659 * Update reserved blocks/metadata blocks after successful
660 * block allocation which had been deferred till now. We don't
661 * support fallocate for non extent files. So we can update
662 * reserve space here.
665 (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE))
666 ext4_da_update_reserve_space(inode, retval, 1);
668 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
669 ext4_clear_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED);
674 if (unlikely(retval != map->m_len)) {
675 ext4_warning(inode->i_sb,
676 "ES len assertion failed for inode "
677 "%lu: retval %d != map->m_len %d",
678 inode->i_ino, retval, map->m_len);
683 * If the extent has been zeroed out, we don't need to update
684 * extent status tree.
686 if ((flags & EXT4_GET_BLOCKS_PRE_IO) &&
687 ext4_es_lookup_extent(inode, map->m_lblk, &es)) {
688 if (ext4_es_is_written(&es))
691 status = map->m_flags & EXT4_MAP_UNWRITTEN ?
692 EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
693 if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
694 ext4_find_delalloc_range(inode, map->m_lblk,
695 map->m_lblk + map->m_len - 1))
696 status |= EXTENT_STATUS_DELAYED;
697 ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
698 map->m_pblk, status);
704 up_write((&EXT4_I(inode)->i_data_sem));
705 if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
706 ret = check_block_validity(inode, map);
713 /* Maximum number of blocks we map for direct IO at once. */
714 #define DIO_MAX_BLOCKS 4096
716 static int _ext4_get_block(struct inode *inode, sector_t iblock,
717 struct buffer_head *bh, int flags)
719 handle_t *handle = ext4_journal_current_handle();
720 struct ext4_map_blocks map;
721 int ret = 0, started = 0;
724 if (ext4_has_inline_data(inode))
728 map.m_len = bh->b_size >> inode->i_blkbits;
730 if (flags && !(flags & EXT4_GET_BLOCKS_NO_LOCK) && !handle) {
731 /* Direct IO write... */
732 if (map.m_len > DIO_MAX_BLOCKS)
733 map.m_len = DIO_MAX_BLOCKS;
734 dio_credits = ext4_chunk_trans_blocks(inode, map.m_len);
735 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
737 if (IS_ERR(handle)) {
738 ret = PTR_ERR(handle);
744 ret = ext4_map_blocks(handle, inode, &map, flags);
746 ext4_io_end_t *io_end = ext4_inode_aio(inode);
748 map_bh(bh, inode->i_sb, map.m_pblk);
749 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
750 if (io_end && io_end->flag & EXT4_IO_END_UNWRITTEN)
751 set_buffer_defer_completion(bh);
752 bh->b_size = inode->i_sb->s_blocksize * map.m_len;
756 ext4_journal_stop(handle);
760 int ext4_get_block(struct inode *inode, sector_t iblock,
761 struct buffer_head *bh, int create)
763 return _ext4_get_block(inode, iblock, bh,
764 create ? EXT4_GET_BLOCKS_CREATE : 0);
768 * `handle' can be NULL if create is zero
770 struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
771 ext4_lblk_t block, int create, int *errp)
773 struct ext4_map_blocks map;
774 struct buffer_head *bh;
777 J_ASSERT(handle != NULL || create == 0);
781 err = ext4_map_blocks(handle, inode, &map,
782 create ? EXT4_GET_BLOCKS_CREATE : 0);
784 /* ensure we send some value back into *errp */
787 if (create && err == 0)
788 err = -ENOSPC; /* should never happen */
794 bh = sb_getblk(inode->i_sb, map.m_pblk);
799 if (map.m_flags & EXT4_MAP_NEW) {
800 J_ASSERT(create != 0);
801 J_ASSERT(handle != NULL);
804 * Now that we do not always journal data, we should
805 * keep in mind whether this should always journal the
806 * new buffer as metadata. For now, regular file
807 * writes use ext4_get_block instead, so it's not a
811 BUFFER_TRACE(bh, "call get_create_access");
812 fatal = ext4_journal_get_create_access(handle, bh);
813 if (!fatal && !buffer_uptodate(bh)) {
814 memset(bh->b_data, 0, inode->i_sb->s_blocksize);
815 set_buffer_uptodate(bh);
818 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
819 err = ext4_handle_dirty_metadata(handle, inode, bh);
823 BUFFER_TRACE(bh, "not a new buffer");
833 struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
834 ext4_lblk_t block, int create, int *err)
836 struct buffer_head *bh;
838 bh = ext4_getblk(handle, inode, block, create, err);
841 if (buffer_uptodate(bh))
843 ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh);
845 if (buffer_uptodate(bh))
852 int ext4_walk_page_buffers(handle_t *handle,
853 struct buffer_head *head,
857 int (*fn)(handle_t *handle,
858 struct buffer_head *bh))
860 struct buffer_head *bh;
861 unsigned block_start, block_end;
862 unsigned blocksize = head->b_size;
864 struct buffer_head *next;
866 for (bh = head, block_start = 0;
867 ret == 0 && (bh != head || !block_start);
868 block_start = block_end, bh = next) {
869 next = bh->b_this_page;
870 block_end = block_start + blocksize;
871 if (block_end <= from || block_start >= to) {
872 if (partial && !buffer_uptodate(bh))
876 err = (*fn)(handle, bh);
884 * To preserve ordering, it is essential that the hole instantiation and
885 * the data write be encapsulated in a single transaction. We cannot
886 * close off a transaction and start a new one between the ext4_get_block()
887 * and the commit_write(). So doing the jbd2_journal_start at the start of
888 * prepare_write() is the right place.
890 * Also, this function can nest inside ext4_writepage(). In that case, we
891 * *know* that ext4_writepage() has generated enough buffer credits to do the
892 * whole page. So we won't block on the journal in that case, which is good,
893 * because the caller may be PF_MEMALLOC.
895 * By accident, ext4 can be reentered when a transaction is open via
896 * quota file writes. If we were to commit the transaction while thus
897 * reentered, there can be a deadlock - we would be holding a quota
898 * lock, and the commit would never complete if another thread had a
899 * transaction open and was blocking on the quota lock - a ranking
902 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
903 * will _not_ run commit under these circumstances because handle->h_ref
904 * is elevated. We'll still have enough credits for the tiny quotafile
907 int do_journal_get_write_access(handle_t *handle,
908 struct buffer_head *bh)
910 int dirty = buffer_dirty(bh);
913 if (!buffer_mapped(bh) || buffer_freed(bh))
916 * __block_write_begin() could have dirtied some buffers. Clean
917 * the dirty bit as jbd2_journal_get_write_access() could complain
918 * otherwise about fs integrity issues. Setting of the dirty bit
919 * by __block_write_begin() isn't a real problem here as we clear
920 * the bit before releasing a page lock and thus writeback cannot
921 * ever write the buffer.
924 clear_buffer_dirty(bh);
925 ret = ext4_journal_get_write_access(handle, bh);
927 ret = ext4_handle_dirty_metadata(handle, NULL, bh);
931 static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock,
932 struct buffer_head *bh_result, int create);
933 static int ext4_write_begin(struct file *file, struct address_space *mapping,
934 loff_t pos, unsigned len, unsigned flags,
935 struct page **pagep, void **fsdata)
937 struct inode *inode = mapping->host;
938 int ret, needed_blocks;
945 trace_ext4_write_begin(inode, pos, len, flags);
947 * Reserve one block more for addition to orphan list in case
948 * we allocate blocks but write fails for some reason
950 needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
951 index = pos >> PAGE_CACHE_SHIFT;
952 from = pos & (PAGE_CACHE_SIZE - 1);
955 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
956 ret = ext4_try_to_write_inline_data(mapping, inode, pos, len,
965 * grab_cache_page_write_begin() can take a long time if the
966 * system is thrashing due to memory pressure, or if the page
967 * is being written back. So grab it first before we start
968 * the transaction handle. This also allows us to allocate
969 * the page (if needed) without using GFP_NOFS.
972 page = grab_cache_page_write_begin(mapping, index, flags);
978 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, needed_blocks);
979 if (IS_ERR(handle)) {
980 page_cache_release(page);
981 return PTR_ERR(handle);
985 if (page->mapping != mapping) {
986 /* The page got truncated from under us */
988 page_cache_release(page);
989 ext4_journal_stop(handle);
992 /* In case writeback began while the page was unlocked */
993 wait_for_stable_page(page);
995 if (ext4_should_dioread_nolock(inode))
996 ret = __block_write_begin(page, pos, len, ext4_get_block_write);
998 ret = __block_write_begin(page, pos, len, ext4_get_block);
1000 if (!ret && ext4_should_journal_data(inode)) {
1001 ret = ext4_walk_page_buffers(handle, page_buffers(page),
1003 do_journal_get_write_access);
1009 * __block_write_begin may have instantiated a few blocks
1010 * outside i_size. Trim these off again. Don't need
1011 * i_size_read because we hold i_mutex.
1013 * Add inode to orphan list in case we crash before
1016 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1017 ext4_orphan_add(handle, inode);
1019 ext4_journal_stop(handle);
1020 if (pos + len > inode->i_size) {
1021 ext4_truncate_failed_write(inode);
1023 * If truncate failed early the inode might
1024 * still be on the orphan list; we need to
1025 * make sure the inode is removed from the
1026 * orphan list in that case.
1029 ext4_orphan_del(NULL, inode);
1032 if (ret == -ENOSPC &&
1033 ext4_should_retry_alloc(inode->i_sb, &retries))
1035 page_cache_release(page);
1042 /* For write_end() in data=journal mode */
1043 static int write_end_fn(handle_t *handle, struct buffer_head *bh)
1046 if (!buffer_mapped(bh) || buffer_freed(bh))
1048 set_buffer_uptodate(bh);
1049 ret = ext4_handle_dirty_metadata(handle, NULL, bh);
1050 clear_buffer_meta(bh);
1051 clear_buffer_prio(bh);
1056 * We need to pick up the new inode size which generic_commit_write gave us
1057 * `file' can be NULL - eg, when called from page_symlink().
1059 * ext4 never places buffers on inode->i_mapping->private_list. metadata
1060 * buffers are managed internally.
1062 static int ext4_write_end(struct file *file,
1063 struct address_space *mapping,
1064 loff_t pos, unsigned len, unsigned copied,
1065 struct page *page, void *fsdata)
1067 handle_t *handle = ext4_journal_current_handle();
1068 struct inode *inode = mapping->host;
1070 int i_size_changed = 0;
1072 trace_ext4_write_end(inode, pos, len, copied);
1073 if (ext4_test_inode_state(inode, EXT4_STATE_ORDERED_MODE)) {
1074 ret = ext4_jbd2_file_inode(handle, inode);
1077 page_cache_release(page);
1082 if (ext4_has_inline_data(inode)) {
1083 ret = ext4_write_inline_data_end(inode, pos, len,
1089 copied = block_write_end(file, mapping, pos,
1090 len, copied, page, fsdata);
1093 * No need to use i_size_read() here, the i_size
1094 * cannot change under us because we hole i_mutex.
1096 * But it's important to update i_size while still holding page lock:
1097 * page writeout could otherwise come in and zero beyond i_size.
1099 if (pos + copied > inode->i_size) {
1100 i_size_write(inode, pos + copied);
1104 if (pos + copied > EXT4_I(inode)->i_disksize) {
1105 /* We need to mark inode dirty even if
1106 * new_i_size is less that inode->i_size
1107 * but greater than i_disksize. (hint delalloc)
1109 ext4_update_i_disksize(inode, (pos + copied));
1113 page_cache_release(page);
1116 * Don't mark the inode dirty under page lock. First, it unnecessarily
1117 * makes the holding time of page lock longer. Second, it forces lock
1118 * ordering of page lock and transaction start for journaling
1122 ext4_mark_inode_dirty(handle, inode);
1124 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1125 /* if we have allocated more blocks and copied
1126 * less. We will have blocks allocated outside
1127 * inode->i_size. So truncate them
1129 ext4_orphan_add(handle, inode);
1131 ret2 = ext4_journal_stop(handle);
1135 if (pos + len > inode->i_size) {
1136 ext4_truncate_failed_write(inode);
1138 * If truncate failed early the inode might still be
1139 * on the orphan list; we need to make sure the inode
1140 * is removed from the orphan list in that case.
1143 ext4_orphan_del(NULL, inode);
1146 return ret ? ret : copied;
1149 static int ext4_journalled_write_end(struct file *file,
1150 struct address_space *mapping,
1151 loff_t pos, unsigned len, unsigned copied,
1152 struct page *page, void *fsdata)
1154 handle_t *handle = ext4_journal_current_handle();
1155 struct inode *inode = mapping->host;
1161 trace_ext4_journalled_write_end(inode, pos, len, copied);
1162 from = pos & (PAGE_CACHE_SIZE - 1);
1165 BUG_ON(!ext4_handle_valid(handle));
1167 if (ext4_has_inline_data(inode))
1168 copied = ext4_write_inline_data_end(inode, pos, len,
1172 if (!PageUptodate(page))
1174 page_zero_new_buffers(page, from+copied, to);
1177 ret = ext4_walk_page_buffers(handle, page_buffers(page), from,
1178 to, &partial, write_end_fn);
1180 SetPageUptodate(page);
1182 new_i_size = pos + copied;
1183 if (new_i_size > inode->i_size)
1184 i_size_write(inode, pos+copied);
1185 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
1186 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
1187 if (new_i_size > EXT4_I(inode)->i_disksize) {
1188 ext4_update_i_disksize(inode, new_i_size);
1189 ret2 = ext4_mark_inode_dirty(handle, inode);
1195 page_cache_release(page);
1196 if (pos + len > inode->i_size && ext4_can_truncate(inode))
1197 /* if we have allocated more blocks and copied
1198 * less. We will have blocks allocated outside
1199 * inode->i_size. So truncate them
1201 ext4_orphan_add(handle, inode);
1203 ret2 = ext4_journal_stop(handle);
1206 if (pos + len > inode->i_size) {
1207 ext4_truncate_failed_write(inode);
1209 * If truncate failed early the inode might still be
1210 * on the orphan list; we need to make sure the inode
1211 * is removed from the orphan list in that case.
1214 ext4_orphan_del(NULL, inode);
1217 return ret ? ret : copied;
1221 * Reserve a metadata for a single block located at lblock
1223 static int ext4_da_reserve_metadata(struct inode *inode, ext4_lblk_t lblock)
1225 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1226 struct ext4_inode_info *ei = EXT4_I(inode);
1227 unsigned int md_needed;
1228 ext4_lblk_t save_last_lblock;
1232 * recalculate the amount of metadata blocks to reserve
1233 * in order to allocate nrblocks
1234 * worse case is one extent per block
1236 spin_lock(&ei->i_block_reservation_lock);
1238 * ext4_calc_metadata_amount() has side effects, which we have
1239 * to be prepared undo if we fail to claim space.
1241 save_len = ei->i_da_metadata_calc_len;
1242 save_last_lblock = ei->i_da_metadata_calc_last_lblock;
1243 md_needed = EXT4_NUM_B2C(sbi,
1244 ext4_calc_metadata_amount(inode, lblock));
1245 trace_ext4_da_reserve_space(inode, md_needed);
1248 * We do still charge estimated metadata to the sb though;
1249 * we cannot afford to run out of free blocks.
1251 if (ext4_claim_free_clusters(sbi, md_needed, 0)) {
1252 ei->i_da_metadata_calc_len = save_len;
1253 ei->i_da_metadata_calc_last_lblock = save_last_lblock;
1254 spin_unlock(&ei->i_block_reservation_lock);
1257 ei->i_reserved_meta_blocks += md_needed;
1258 spin_unlock(&ei->i_block_reservation_lock);
1260 return 0; /* success */
1264 * Reserve a single cluster located at lblock
1266 static int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock)
1268 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1269 struct ext4_inode_info *ei = EXT4_I(inode);
1270 unsigned int md_needed;
1272 ext4_lblk_t save_last_lblock;
1276 * We will charge metadata quota at writeout time; this saves
1277 * us from metadata over-estimation, though we may go over by
1278 * a small amount in the end. Here we just reserve for data.
1280 ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1));
1285 * recalculate the amount of metadata blocks to reserve
1286 * in order to allocate nrblocks
1287 * worse case is one extent per block
1289 spin_lock(&ei->i_block_reservation_lock);
1291 * ext4_calc_metadata_amount() has side effects, which we have
1292 * to be prepared undo if we fail to claim space.
1294 save_len = ei->i_da_metadata_calc_len;
1295 save_last_lblock = ei->i_da_metadata_calc_last_lblock;
1296 md_needed = EXT4_NUM_B2C(sbi,
1297 ext4_calc_metadata_amount(inode, lblock));
1298 trace_ext4_da_reserve_space(inode, md_needed);
1301 * We do still charge estimated metadata to the sb though;
1302 * we cannot afford to run out of free blocks.
1304 if (ext4_claim_free_clusters(sbi, md_needed + 1, 0)) {
1305 ei->i_da_metadata_calc_len = save_len;
1306 ei->i_da_metadata_calc_last_lblock = save_last_lblock;
1307 spin_unlock(&ei->i_block_reservation_lock);
1308 dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1));
1311 ei->i_reserved_data_blocks++;
1312 ei->i_reserved_meta_blocks += md_needed;
1313 spin_unlock(&ei->i_block_reservation_lock);
1315 return 0; /* success */
1318 static void ext4_da_release_space(struct inode *inode, int to_free)
1320 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1321 struct ext4_inode_info *ei = EXT4_I(inode);
1324 return; /* Nothing to release, exit */
1326 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1328 trace_ext4_da_release_space(inode, to_free);
1329 if (unlikely(to_free > ei->i_reserved_data_blocks)) {
1331 * if there aren't enough reserved blocks, then the
1332 * counter is messed up somewhere. Since this
1333 * function is called from invalidate page, it's
1334 * harmless to return without any action.
1336 ext4_warning(inode->i_sb, "ext4_da_release_space: "
1337 "ino %lu, to_free %d with only %d reserved "
1338 "data blocks", inode->i_ino, to_free,
1339 ei->i_reserved_data_blocks);
1341 to_free = ei->i_reserved_data_blocks;
1343 ei->i_reserved_data_blocks -= to_free;
1345 if (ei->i_reserved_data_blocks == 0) {
1347 * We can release all of the reserved metadata blocks
1348 * only when we have written all of the delayed
1349 * allocation blocks.
1350 * Note that in case of bigalloc, i_reserved_meta_blocks,
1351 * i_reserved_data_blocks, etc. refer to number of clusters.
1353 percpu_counter_sub(&sbi->s_dirtyclusters_counter,
1354 ei->i_reserved_meta_blocks);
1355 ei->i_reserved_meta_blocks = 0;
1356 ei->i_da_metadata_calc_len = 0;
1359 /* update fs dirty data blocks counter */
1360 percpu_counter_sub(&sbi->s_dirtyclusters_counter, to_free);
1362 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1364 dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free));
1367 static void ext4_da_page_release_reservation(struct page *page,
1368 unsigned int offset,
1369 unsigned int length)
1372 struct buffer_head *head, *bh;
1373 unsigned int curr_off = 0;
1374 struct inode *inode = page->mapping->host;
1375 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1376 unsigned int stop = offset + length;
1380 BUG_ON(stop > PAGE_CACHE_SIZE || stop < length);
1382 head = page_buffers(page);
1385 unsigned int next_off = curr_off + bh->b_size;
1387 if (next_off > stop)
1390 if ((offset <= curr_off) && (buffer_delay(bh))) {
1392 clear_buffer_delay(bh);
1394 curr_off = next_off;
1395 } while ((bh = bh->b_this_page) != head);
1398 lblk = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1399 ext4_es_remove_extent(inode, lblk, to_release);
1402 /* If we have released all the blocks belonging to a cluster, then we
1403 * need to release the reserved space for that cluster. */
1404 num_clusters = EXT4_NUM_B2C(sbi, to_release);
1405 while (num_clusters > 0) {
1406 lblk = (page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits)) +
1407 ((num_clusters - 1) << sbi->s_cluster_bits);
1408 if (sbi->s_cluster_ratio == 1 ||
1409 !ext4_find_delalloc_cluster(inode, lblk))
1410 ext4_da_release_space(inode, 1);
1417 * Delayed allocation stuff
1420 struct mpage_da_data {
1421 struct inode *inode;
1422 struct writeback_control *wbc;
1424 pgoff_t first_page; /* The first page to write */
1425 pgoff_t next_page; /* Current page to examine */
1426 pgoff_t last_page; /* Last page to examine */
1428 * Extent to map - this can be after first_page because that can be
1429 * fully mapped. We somewhat abuse m_flags to store whether the extent
1430 * is delalloc or unwritten.
1432 struct ext4_map_blocks map;
1433 struct ext4_io_submit io_submit; /* IO submission data */
1436 static void mpage_release_unused_pages(struct mpage_da_data *mpd,
1441 struct pagevec pvec;
1442 struct inode *inode = mpd->inode;
1443 struct address_space *mapping = inode->i_mapping;
1445 /* This is necessary when next_page == 0. */
1446 if (mpd->first_page >= mpd->next_page)
1449 index = mpd->first_page;
1450 end = mpd->next_page - 1;
1452 ext4_lblk_t start, last;
1453 start = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1454 last = end << (PAGE_CACHE_SHIFT - inode->i_blkbits);
1455 ext4_es_remove_extent(inode, start, last - start + 1);
1458 pagevec_init(&pvec, 0);
1459 while (index <= end) {
1460 nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE);
1463 for (i = 0; i < nr_pages; i++) {
1464 struct page *page = pvec.pages[i];
1465 if (page->index > end)
1467 BUG_ON(!PageLocked(page));
1468 BUG_ON(PageWriteback(page));
1470 block_invalidatepage(page, 0, PAGE_CACHE_SIZE);
1471 ClearPageUptodate(page);
1475 index = pvec.pages[nr_pages - 1]->index + 1;
1476 pagevec_release(&pvec);
1480 static void ext4_print_free_blocks(struct inode *inode)
1482 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1483 struct super_block *sb = inode->i_sb;
1484 struct ext4_inode_info *ei = EXT4_I(inode);
1486 ext4_msg(sb, KERN_CRIT, "Total free blocks count %lld",
1487 EXT4_C2B(EXT4_SB(inode->i_sb),
1488 ext4_count_free_clusters(sb)));
1489 ext4_msg(sb, KERN_CRIT, "Free/Dirty block details");
1490 ext4_msg(sb, KERN_CRIT, "free_blocks=%lld",
1491 (long long) EXT4_C2B(EXT4_SB(sb),
1492 percpu_counter_sum(&sbi->s_freeclusters_counter)));
1493 ext4_msg(sb, KERN_CRIT, "dirty_blocks=%lld",
1494 (long long) EXT4_C2B(EXT4_SB(sb),
1495 percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
1496 ext4_msg(sb, KERN_CRIT, "Block reservation details");
1497 ext4_msg(sb, KERN_CRIT, "i_reserved_data_blocks=%u",
1498 ei->i_reserved_data_blocks);
1499 ext4_msg(sb, KERN_CRIT, "i_reserved_meta_blocks=%u",
1500 ei->i_reserved_meta_blocks);
1501 ext4_msg(sb, KERN_CRIT, "i_allocated_meta_blocks=%u",
1502 ei->i_allocated_meta_blocks);
1506 static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
1508 return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
1512 * This function is grabs code from the very beginning of
1513 * ext4_map_blocks, but assumes that the caller is from delayed write
1514 * time. This function looks up the requested blocks and sets the
1515 * buffer delay bit under the protection of i_data_sem.
1517 static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
1518 struct ext4_map_blocks *map,
1519 struct buffer_head *bh)
1521 struct extent_status es;
1523 sector_t invalid_block = ~((sector_t) 0xffff);
1524 #ifdef ES_AGGRESSIVE_TEST
1525 struct ext4_map_blocks orig_map;
1527 memcpy(&orig_map, map, sizeof(*map));
1530 if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
1534 ext_debug("ext4_da_map_blocks(): inode %lu, max_blocks %u,"
1535 "logical block %lu\n", inode->i_ino, map->m_len,
1536 (unsigned long) map->m_lblk);
1538 /* Lookup extent status tree firstly */
1539 if (ext4_es_lookup_extent(inode, iblock, &es)) {
1540 ext4_es_lru_add(inode);
1541 if (ext4_es_is_hole(&es)) {
1543 down_read((&EXT4_I(inode)->i_data_sem));
1548 * Delayed extent could be allocated by fallocate.
1549 * So we need to check it.
1551 if (ext4_es_is_delayed(&es) && !ext4_es_is_unwritten(&es)) {
1552 map_bh(bh, inode->i_sb, invalid_block);
1554 set_buffer_delay(bh);
1558 map->m_pblk = ext4_es_pblock(&es) + iblock - es.es_lblk;
1559 retval = es.es_len - (iblock - es.es_lblk);
1560 if (retval > map->m_len)
1561 retval = map->m_len;
1562 map->m_len = retval;
1563 if (ext4_es_is_written(&es))
1564 map->m_flags |= EXT4_MAP_MAPPED;
1565 else if (ext4_es_is_unwritten(&es))
1566 map->m_flags |= EXT4_MAP_UNWRITTEN;
1570 #ifdef ES_AGGRESSIVE_TEST
1571 ext4_map_blocks_es_recheck(NULL, inode, map, &orig_map, 0);
1577 * Try to see if we can get the block without requesting a new
1578 * file system block.
1580 down_read((&EXT4_I(inode)->i_data_sem));
1581 if (ext4_has_inline_data(inode)) {
1583 * We will soon create blocks for this page, and let
1584 * us pretend as if the blocks aren't allocated yet.
1585 * In case of clusters, we have to handle the work
1586 * of mapping from cluster so that the reserved space
1587 * is calculated properly.
1589 if ((EXT4_SB(inode->i_sb)->s_cluster_ratio > 1) &&
1590 ext4_find_delalloc_cluster(inode, map->m_lblk))
1591 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
1593 } else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
1594 retval = ext4_ext_map_blocks(NULL, inode, map,
1595 EXT4_GET_BLOCKS_NO_PUT_HOLE);
1597 retval = ext4_ind_map_blocks(NULL, inode, map,
1598 EXT4_GET_BLOCKS_NO_PUT_HOLE);
1604 * XXX: __block_prepare_write() unmaps passed block,
1608 * If the block was allocated from previously allocated cluster,
1609 * then we don't need to reserve it again. However we still need
1610 * to reserve metadata for every block we're going to write.
1612 if (!(map->m_flags & EXT4_MAP_FROM_CLUSTER)) {
1613 ret = ext4_da_reserve_space(inode, iblock);
1615 /* not enough space to reserve */
1620 ret = ext4_da_reserve_metadata(inode, iblock);
1622 /* not enough space to reserve */
1628 ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
1629 ~0, EXTENT_STATUS_DELAYED);
1635 /* Clear EXT4_MAP_FROM_CLUSTER flag since its purpose is served
1636 * and it should not appear on the bh->b_state.
1638 map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
1640 map_bh(bh, inode->i_sb, invalid_block);
1642 set_buffer_delay(bh);
1643 } else if (retval > 0) {
1645 unsigned int status;
1647 if (unlikely(retval != map->m_len)) {
1648 ext4_warning(inode->i_sb,
1649 "ES len assertion failed for inode "
1650 "%lu: retval %d != map->m_len %d",
1651 inode->i_ino, retval, map->m_len);
1655 status = map->m_flags & EXT4_MAP_UNWRITTEN ?
1656 EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
1657 ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
1658 map->m_pblk, status);
1664 up_read((&EXT4_I(inode)->i_data_sem));
1670 * This is a special get_blocks_t callback which is used by
1671 * ext4_da_write_begin(). It will either return mapped block or
1672 * reserve space for a single block.
1674 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
1675 * We also have b_blocknr = -1 and b_bdev initialized properly
1677 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
1678 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
1679 * initialized properly.
1681 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
1682 struct buffer_head *bh, int create)
1684 struct ext4_map_blocks map;
1687 BUG_ON(create == 0);
1688 BUG_ON(bh->b_size != inode->i_sb->s_blocksize);
1690 map.m_lblk = iblock;
1694 * first, we need to know whether the block is allocated already
1695 * preallocated blocks are unmapped but should treated
1696 * the same as allocated blocks.
1698 ret = ext4_da_map_blocks(inode, iblock, &map, bh);
1702 map_bh(bh, inode->i_sb, map.m_pblk);
1703 bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags;
1705 if (buffer_unwritten(bh)) {
1706 /* A delayed write to unwritten bh should be marked
1707 * new and mapped. Mapped ensures that we don't do
1708 * get_block multiple times when we write to the same
1709 * offset and new ensures that we do proper zero out
1710 * for partial write.
1713 set_buffer_mapped(bh);
1718 static int bget_one(handle_t *handle, struct buffer_head *bh)
1724 static int bput_one(handle_t *handle, struct buffer_head *bh)
1730 static int __ext4_journalled_writepage(struct page *page,
1733 struct address_space *mapping = page->mapping;
1734 struct inode *inode = mapping->host;
1735 struct buffer_head *page_bufs = NULL;
1736 handle_t *handle = NULL;
1737 int ret = 0, err = 0;
1738 int inline_data = ext4_has_inline_data(inode);
1739 struct buffer_head *inode_bh = NULL;
1741 ClearPageChecked(page);
1744 BUG_ON(page->index != 0);
1745 BUG_ON(len > ext4_get_max_inline_size(inode));
1746 inode_bh = ext4_journalled_write_inline_data(inode, len, page);
1747 if (inode_bh == NULL)
1750 page_bufs = page_buffers(page);
1755 ext4_walk_page_buffers(handle, page_bufs, 0, len,
1758 /* As soon as we unlock the page, it can go away, but we have
1759 * references to buffers so we are safe */
1762 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
1763 ext4_writepage_trans_blocks(inode));
1764 if (IS_ERR(handle)) {
1765 ret = PTR_ERR(handle);
1769 BUG_ON(!ext4_handle_valid(handle));
1772 ret = ext4_journal_get_write_access(handle, inode_bh);
1774 err = ext4_handle_dirty_metadata(handle, inode, inode_bh);
1777 ret = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
1778 do_journal_get_write_access);
1780 err = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
1785 EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
1786 err = ext4_journal_stop(handle);
1790 if (!ext4_has_inline_data(inode))
1791 ext4_walk_page_buffers(NULL, page_bufs, 0, len,
1793 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
1800 * Note that we don't need to start a transaction unless we're journaling data
1801 * because we should have holes filled from ext4_page_mkwrite(). We even don't
1802 * need to file the inode to the transaction's list in ordered mode because if
1803 * we are writing back data added by write(), the inode is already there and if
1804 * we are writing back data modified via mmap(), no one guarantees in which
1805 * transaction the data will hit the disk. In case we are journaling data, we
1806 * cannot start transaction directly because transaction start ranks above page
1807 * lock so we have to do some magic.
1809 * This function can get called via...
1810 * - ext4_writepages after taking page lock (have journal handle)
1811 * - journal_submit_inode_data_buffers (no journal handle)
1812 * - shrink_page_list via the kswapd/direct reclaim (no journal handle)
1813 * - grab_page_cache when doing write_begin (have journal handle)
1815 * We don't do any block allocation in this function. If we have page with
1816 * multiple blocks we need to write those buffer_heads that are mapped. This
1817 * is important for mmaped based write. So if we do with blocksize 1K
1818 * truncate(f, 1024);
1819 * a = mmap(f, 0, 4096);
1821 * truncate(f, 4096);
1822 * we have in the page first buffer_head mapped via page_mkwrite call back
1823 * but other buffer_heads would be unmapped but dirty (dirty done via the
1824 * do_wp_page). So writepage should write the first block. If we modify
1825 * the mmap area beyond 1024 we will again get a page_fault and the
1826 * page_mkwrite callback will do the block allocation and mark the
1827 * buffer_heads mapped.
1829 * We redirty the page if we have any buffer_heads that is either delay or
1830 * unwritten in the page.
1832 * We can get recursively called as show below.
1834 * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1837 * But since we don't do any block allocation we should not deadlock.
1838 * Page also have the dirty flag cleared so we don't get recurive page_lock.
1840 static int ext4_writepage(struct page *page,
1841 struct writeback_control *wbc)
1846 struct buffer_head *page_bufs = NULL;
1847 struct inode *inode = page->mapping->host;
1848 struct ext4_io_submit io_submit;
1850 trace_ext4_writepage(page);
1851 size = i_size_read(inode);
1852 if (page->index == size >> PAGE_CACHE_SHIFT)
1853 len = size & ~PAGE_CACHE_MASK;
1855 len = PAGE_CACHE_SIZE;
1857 page_bufs = page_buffers(page);
1859 * We cannot do block allocation or other extent handling in this
1860 * function. If there are buffers needing that, we have to redirty
1861 * the page. But we may reach here when we do a journal commit via
1862 * journal_submit_inode_data_buffers() and in that case we must write
1863 * allocated buffers to achieve data=ordered mode guarantees.
1865 if (ext4_walk_page_buffers(NULL, page_bufs, 0, len, NULL,
1866 ext4_bh_delay_or_unwritten)) {
1867 redirty_page_for_writepage(wbc, page);
1868 if (current->flags & PF_MEMALLOC) {
1870 * For memory cleaning there's no point in writing only
1871 * some buffers. So just bail out. Warn if we came here
1872 * from direct reclaim.
1874 WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD))
1881 if (PageChecked(page) && ext4_should_journal_data(inode))
1883 * It's mmapped pagecache. Add buffers and journal it. There
1884 * doesn't seem much point in redirtying the page here.
1886 return __ext4_journalled_writepage(page, len);
1888 ext4_io_submit_init(&io_submit, wbc);
1889 io_submit.io_end = ext4_init_io_end(inode, GFP_NOFS);
1890 if (!io_submit.io_end) {
1891 redirty_page_for_writepage(wbc, page);
1895 ret = ext4_bio_write_page(&io_submit, page, len, wbc);
1896 ext4_io_submit(&io_submit);
1897 /* Drop io_end reference we got from init */
1898 ext4_put_io_end_defer(io_submit.io_end);
1902 static int mpage_submit_page(struct mpage_da_data *mpd, struct page *page)
1905 loff_t size = i_size_read(mpd->inode);
1908 BUG_ON(page->index != mpd->first_page);
1909 if (page->index == size >> PAGE_CACHE_SHIFT)
1910 len = size & ~PAGE_CACHE_MASK;
1912 len = PAGE_CACHE_SIZE;
1913 clear_page_dirty_for_io(page);
1914 err = ext4_bio_write_page(&mpd->io_submit, page, len, mpd->wbc);
1916 mpd->wbc->nr_to_write--;
1922 #define BH_FLAGS ((1 << BH_Unwritten) | (1 << BH_Delay))
1925 * mballoc gives us at most this number of blocks...
1926 * XXX: That seems to be only a limitation of ext4_mb_normalize_request().
1927 * The rest of mballoc seems to handle chunks up to full group size.
1929 #define MAX_WRITEPAGES_EXTENT_LEN 2048
1932 * mpage_add_bh_to_extent - try to add bh to extent of blocks to map
1934 * @mpd - extent of blocks
1935 * @lblk - logical number of the block in the file
1936 * @bh - buffer head we want to add to the extent
1938 * The function is used to collect contig. blocks in the same state. If the
1939 * buffer doesn't require mapping for writeback and we haven't started the
1940 * extent of buffers to map yet, the function returns 'true' immediately - the
1941 * caller can write the buffer right away. Otherwise the function returns true
1942 * if the block has been added to the extent, false if the block couldn't be
1945 static bool mpage_add_bh_to_extent(struct mpage_da_data *mpd, ext4_lblk_t lblk,
1946 struct buffer_head *bh)
1948 struct ext4_map_blocks *map = &mpd->map;
1950 /* Buffer that doesn't need mapping for writeback? */
1951 if (!buffer_dirty(bh) || !buffer_mapped(bh) ||
1952 (!buffer_delay(bh) && !buffer_unwritten(bh))) {
1953 /* So far no extent to map => we write the buffer right away */
1954 if (map->m_len == 0)
1959 /* First block in the extent? */
1960 if (map->m_len == 0) {
1963 map->m_flags = bh->b_state & BH_FLAGS;
1967 /* Don't go larger than mballoc is willing to allocate */
1968 if (map->m_len >= MAX_WRITEPAGES_EXTENT_LEN)
1971 /* Can we merge the block to our big extent? */
1972 if (lblk == map->m_lblk + map->m_len &&
1973 (bh->b_state & BH_FLAGS) == map->m_flags) {
1981 * mpage_process_page_bufs - submit page buffers for IO or add them to extent
1983 * @mpd - extent of blocks for mapping
1984 * @head - the first buffer in the page
1985 * @bh - buffer we should start processing from
1986 * @lblk - logical number of the block in the file corresponding to @bh
1988 * Walk through page buffers from @bh upto @head (exclusive) and either submit
1989 * the page for IO if all buffers in this page were mapped and there's no
1990 * accumulated extent of buffers to map or add buffers in the page to the
1991 * extent of buffers to map. The function returns 1 if the caller can continue
1992 * by processing the next page, 0 if it should stop adding buffers to the
1993 * extent to map because we cannot extend it anymore. It can also return value
1994 * < 0 in case of error during IO submission.
1996 static int mpage_process_page_bufs(struct mpage_da_data *mpd,
1997 struct buffer_head *head,
1998 struct buffer_head *bh,
2001 struct inode *inode = mpd->inode;
2003 ext4_lblk_t blocks = (i_size_read(inode) + (1 << inode->i_blkbits) - 1)
2004 >> inode->i_blkbits;
2007 BUG_ON(buffer_locked(bh));
2009 if (lblk >= blocks || !mpage_add_bh_to_extent(mpd, lblk, bh)) {
2010 /* Found extent to map? */
2013 /* Everything mapped so far and we hit EOF */
2016 } while (lblk++, (bh = bh->b_this_page) != head);
2017 /* So far everything mapped? Submit the page for IO. */
2018 if (mpd->map.m_len == 0) {
2019 err = mpage_submit_page(mpd, head->b_page);
2023 return lblk < blocks;
2027 * mpage_map_buffers - update buffers corresponding to changed extent and
2028 * submit fully mapped pages for IO
2030 * @mpd - description of extent to map, on return next extent to map
2032 * Scan buffers corresponding to changed extent (we expect corresponding pages
2033 * to be already locked) and update buffer state according to new extent state.
2034 * We map delalloc buffers to their physical location, clear unwritten bits,
2035 * and mark buffers as uninit when we perform writes to uninitialized extents
2036 * and do extent conversion after IO is finished. If the last page is not fully
2037 * mapped, we update @map to the next extent in the last page that needs
2038 * mapping. Otherwise we submit the page for IO.
2040 static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd)
2042 struct pagevec pvec;
2044 struct inode *inode = mpd->inode;
2045 struct buffer_head *head, *bh;
2046 int bpp_bits = PAGE_CACHE_SHIFT - inode->i_blkbits;
2052 start = mpd->map.m_lblk >> bpp_bits;
2053 end = (mpd->map.m_lblk + mpd->map.m_len - 1) >> bpp_bits;
2054 lblk = start << bpp_bits;
2055 pblock = mpd->map.m_pblk;
2057 pagevec_init(&pvec, 0);
2058 while (start <= end) {
2059 nr_pages = pagevec_lookup(&pvec, inode->i_mapping, start,
2063 for (i = 0; i < nr_pages; i++) {
2064 struct page *page = pvec.pages[i];
2066 if (page->index > end)
2068 /* Up to 'end' pages must be contiguous */
2069 BUG_ON(page->index != start);
2070 bh = head = page_buffers(page);
2072 if (lblk < mpd->map.m_lblk)
2074 if (lblk >= mpd->map.m_lblk + mpd->map.m_len) {
2076 * Buffer after end of mapped extent.
2077 * Find next buffer in the page to map.
2080 mpd->map.m_flags = 0;
2082 * FIXME: If dioread_nolock supports
2083 * blocksize < pagesize, we need to make
2084 * sure we add size mapped so far to
2085 * io_end->size as the following call
2086 * can submit the page for IO.
2088 err = mpage_process_page_bufs(mpd, head,
2090 pagevec_release(&pvec);
2095 if (buffer_delay(bh)) {
2096 clear_buffer_delay(bh);
2097 bh->b_blocknr = pblock++;
2099 clear_buffer_unwritten(bh);
2100 } while (lblk++, (bh = bh->b_this_page) != head);
2103 * FIXME: This is going to break if dioread_nolock
2104 * supports blocksize < pagesize as we will try to
2105 * convert potentially unmapped parts of inode.
2107 mpd->io_submit.io_end->size += PAGE_CACHE_SIZE;
2108 /* Page fully mapped - let IO run! */
2109 err = mpage_submit_page(mpd, page);
2111 pagevec_release(&pvec);
2116 pagevec_release(&pvec);
2118 /* Extent fully mapped and matches with page boundary. We are done. */
2120 mpd->map.m_flags = 0;
2124 static int mpage_map_one_extent(handle_t *handle, struct mpage_da_data *mpd)
2126 struct inode *inode = mpd->inode;
2127 struct ext4_map_blocks *map = &mpd->map;
2128 int get_blocks_flags;
2131 trace_ext4_da_write_pages_extent(inode, map);
2133 * Call ext4_map_blocks() to allocate any delayed allocation blocks, or
2134 * to convert an uninitialized extent to be initialized (in the case
2135 * where we have written into one or more preallocated blocks). It is
2136 * possible that we're going to need more metadata blocks than
2137 * previously reserved. However we must not fail because we're in
2138 * writeback and there is nothing we can do about it so it might result
2139 * in data loss. So use reserved blocks to allocate metadata if
2142 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE if the blocks
2143 * in question are delalloc blocks. This affects functions in many
2144 * different parts of the allocation call path. This flag exists
2145 * primarily because we don't want to change *many* call functions, so
2146 * ext4_map_blocks() will set the EXT4_STATE_DELALLOC_RESERVED flag
2147 * once the inode's allocation semaphore is taken.
2149 get_blocks_flags = EXT4_GET_BLOCKS_CREATE |
2150 EXT4_GET_BLOCKS_METADATA_NOFAIL;
2151 if (ext4_should_dioread_nolock(inode))
2152 get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
2153 if (map->m_flags & (1 << BH_Delay))
2154 get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;
2156 err = ext4_map_blocks(handle, inode, map, get_blocks_flags);
2159 if (map->m_flags & EXT4_MAP_UNINIT) {
2160 if (!mpd->io_submit.io_end->handle &&
2161 ext4_handle_valid(handle)) {
2162 mpd->io_submit.io_end->handle = handle->h_rsv_handle;
2163 handle->h_rsv_handle = NULL;
2165 ext4_set_io_unwritten_flag(inode, mpd->io_submit.io_end);
2168 BUG_ON(map->m_len == 0);
2169 if (map->m_flags & EXT4_MAP_NEW) {
2170 struct block_device *bdev = inode->i_sb->s_bdev;
2173 for (i = 0; i < map->m_len; i++)
2174 unmap_underlying_metadata(bdev, map->m_pblk + i);
2180 * mpage_map_and_submit_extent - map extent starting at mpd->lblk of length
2181 * mpd->len and submit pages underlying it for IO
2183 * @handle - handle for journal operations
2184 * @mpd - extent to map
2185 * @give_up_on_write - we set this to true iff there is a fatal error and there
2186 * is no hope of writing the data. The caller should discard
2187 * dirty pages to avoid infinite loops.
2189 * The function maps extent starting at mpd->lblk of length mpd->len. If it is
2190 * delayed, blocks are allocated, if it is unwritten, we may need to convert
2191 * them to initialized or split the described range from larger unwritten
2192 * extent. Note that we need not map all the described range since allocation
2193 * can return less blocks or the range is covered by more unwritten extents. We
2194 * cannot map more because we are limited by reserved transaction credits. On
2195 * the other hand we always make sure that the last touched page is fully
2196 * mapped so that it can be written out (and thus forward progress is
2197 * guaranteed). After mapping we submit all mapped pages for IO.
2199 static int mpage_map_and_submit_extent(handle_t *handle,
2200 struct mpage_da_data *mpd,
2201 bool *give_up_on_write)
2203 struct inode *inode = mpd->inode;
2204 struct ext4_map_blocks *map = &mpd->map;
2208 mpd->io_submit.io_end->offset =
2209 ((loff_t)map->m_lblk) << inode->i_blkbits;
2211 err = mpage_map_one_extent(handle, mpd);
2213 struct super_block *sb = inode->i_sb;
2215 if (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
2216 goto invalidate_dirty_pages;
2218 * Let the uper layers retry transient errors.
2219 * In the case of ENOSPC, if ext4_count_free_blocks()
2220 * is non-zero, a commit should free up blocks.
2222 if ((err == -ENOMEM) ||
2223 (err == -ENOSPC && ext4_count_free_clusters(sb)))
2225 ext4_msg(sb, KERN_CRIT,
2226 "Delayed block allocation failed for "
2227 "inode %lu at logical offset %llu with"
2228 " max blocks %u with error %d",
2230 (unsigned long long)map->m_lblk,
2231 (unsigned)map->m_len, -err);
2232 ext4_msg(sb, KERN_CRIT,
2233 "This should not happen!! Data will "
2236 ext4_print_free_blocks(inode);
2237 invalidate_dirty_pages:
2238 *give_up_on_write = true;
2242 * Update buffer state, submit mapped pages, and get us new
2245 err = mpage_map_and_submit_buffers(mpd);
2248 } while (map->m_len);
2251 * Update on-disk size after IO is submitted. Races with
2252 * truncate are avoided by checking i_size under i_data_sem.
2254 disksize = ((loff_t)mpd->first_page) << PAGE_CACHE_SHIFT;
2255 if (disksize > EXT4_I(inode)->i_disksize) {
2259 down_write(&EXT4_I(inode)->i_data_sem);
2260 i_size = i_size_read(inode);
2261 if (disksize > i_size)
2263 if (disksize > EXT4_I(inode)->i_disksize)
2264 EXT4_I(inode)->i_disksize = disksize;
2265 err2 = ext4_mark_inode_dirty(handle, inode);
2266 up_write(&EXT4_I(inode)->i_data_sem);
2268 ext4_error(inode->i_sb,
2269 "Failed to mark inode %lu dirty",
2278 * Calculate the total number of credits to reserve for one writepages
2279 * iteration. This is called from ext4_writepages(). We map an extent of
2280 * up to MAX_WRITEPAGES_EXTENT_LEN blocks and then we go on and finish mapping
2281 * the last partial page. So in total we can map MAX_WRITEPAGES_EXTENT_LEN +
2282 * bpp - 1 blocks in bpp different extents.
2284 static int ext4_da_writepages_trans_blocks(struct inode *inode)
2286 int bpp = ext4_journal_blocks_per_page(inode);
2288 return ext4_meta_trans_blocks(inode,
2289 MAX_WRITEPAGES_EXTENT_LEN + bpp - 1, bpp);
2293 * mpage_prepare_extent_to_map - find & lock contiguous range of dirty pages
2294 * and underlying extent to map
2296 * @mpd - where to look for pages
2298 * Walk dirty pages in the mapping. If they are fully mapped, submit them for
2299 * IO immediately. When we find a page which isn't mapped we start accumulating
2300 * extent of buffers underlying these pages that needs mapping (formed by
2301 * either delayed or unwritten buffers). We also lock the pages containing
2302 * these buffers. The extent found is returned in @mpd structure (starting at
2303 * mpd->lblk with length mpd->len blocks).
2305 * Note that this function can attach bios to one io_end structure which are
2306 * neither logically nor physically contiguous. Although it may seem as an
2307 * unnecessary complication, it is actually inevitable in blocksize < pagesize
2308 * case as we need to track IO to all buffers underlying a page in one io_end.
2310 static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
2312 struct address_space *mapping = mpd->inode->i_mapping;
2313 struct pagevec pvec;
2314 unsigned int nr_pages;
2315 long left = mpd->wbc->nr_to_write;
2316 pgoff_t index = mpd->first_page;
2317 pgoff_t end = mpd->last_page;
2320 int blkbits = mpd->inode->i_blkbits;
2322 struct buffer_head *head;
2324 if (mpd->wbc->sync_mode == WB_SYNC_ALL || mpd->wbc->tagged_writepages)
2325 tag = PAGECACHE_TAG_TOWRITE;
2327 tag = PAGECACHE_TAG_DIRTY;
2329 pagevec_init(&pvec, 0);
2331 mpd->next_page = index;
2332 while (index <= end) {
2333 nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag,
2334 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
2338 for (i = 0; i < nr_pages; i++) {
2339 struct page *page = pvec.pages[i];
2342 * At this point, the page may be truncated or
2343 * invalidated (changing page->mapping to NULL), or
2344 * even swizzled back from swapper_space to tmpfs file
2345 * mapping. However, page->index will not change
2346 * because we have a reference on the page.
2348 if (page->index > end)
2352 * Accumulated enough dirty pages? This doesn't apply
2353 * to WB_SYNC_ALL mode. For integrity sync we have to
2354 * keep going because someone may be concurrently
2355 * dirtying pages, and we might have synced a lot of
2356 * newly appeared dirty pages, but have not synced all
2357 * of the old dirty pages.
2359 if (mpd->wbc->sync_mode == WB_SYNC_NONE && left <= 0)
2362 /* If we can't merge this page, we are done. */
2363 if (mpd->map.m_len > 0 && mpd->next_page != page->index)
2368 * If the page is no longer dirty, or its mapping no
2369 * longer corresponds to inode we are writing (which
2370 * means it has been truncated or invalidated), or the
2371 * page is already under writeback and we are not doing
2372 * a data integrity writeback, skip the page
2374 if (!PageDirty(page) ||
2375 (PageWriteback(page) &&
2376 (mpd->wbc->sync_mode == WB_SYNC_NONE)) ||
2377 unlikely(page->mapping != mapping)) {
2382 wait_on_page_writeback(page);
2383 BUG_ON(PageWriteback(page));
2385 if (mpd->map.m_len == 0)
2386 mpd->first_page = page->index;
2387 mpd->next_page = page->index + 1;
2388 /* Add all dirty buffers to mpd */
2389 lblk = ((ext4_lblk_t)page->index) <<
2390 (PAGE_CACHE_SHIFT - blkbits);
2391 head = page_buffers(page);
2392 err = mpage_process_page_bufs(mpd, head, head, lblk);
2398 pagevec_release(&pvec);
2403 pagevec_release(&pvec);
2407 static int __writepage(struct page *page, struct writeback_control *wbc,
2410 struct address_space *mapping = data;
2411 int ret = ext4_writepage(page, wbc);
2412 mapping_set_error(mapping, ret);
2416 static int ext4_writepages(struct address_space *mapping,
2417 struct writeback_control *wbc)
2419 pgoff_t writeback_index = 0;
2420 long nr_to_write = wbc->nr_to_write;
2421 int range_whole = 0;
2423 handle_t *handle = NULL;
2424 struct mpage_da_data mpd;
2425 struct inode *inode = mapping->host;
2426 int needed_blocks, rsv_blocks = 0, ret = 0;
2427 struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
2429 struct blk_plug plug;
2430 bool give_up_on_write = false;
2432 trace_ext4_writepages(inode, wbc);
2435 * No pages to write? This is mainly a kludge to avoid starting
2436 * a transaction for special inodes like journal inode on last iput()
2437 * because that could violate lock ordering on umount
2439 if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
2440 goto out_writepages;
2442 if (ext4_should_journal_data(inode)) {
2443 struct blk_plug plug;
2445 blk_start_plug(&plug);
2446 ret = write_cache_pages(mapping, wbc, __writepage, mapping);
2447 blk_finish_plug(&plug);
2448 goto out_writepages;
2452 * If the filesystem has aborted, it is read-only, so return
2453 * right away instead of dumping stack traces later on that
2454 * will obscure the real source of the problem. We test
2455 * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because
2456 * the latter could be true if the filesystem is mounted
2457 * read-only, and in that case, ext4_writepages should
2458 * *never* be called, so if that ever happens, we would want
2461 if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED)) {
2463 goto out_writepages;
2466 if (ext4_should_dioread_nolock(inode)) {
2468 * We may need to convert up to one extent per block in
2469 * the page and we may dirty the inode.
2471 rsv_blocks = 1 + (PAGE_CACHE_SIZE >> inode->i_blkbits);
2475 * If we have inline data and arrive here, it means that
2476 * we will soon create the block for the 1st page, so
2477 * we'd better clear the inline data here.
2479 if (ext4_has_inline_data(inode)) {
2480 /* Just inode will be modified... */
2481 handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
2482 if (IS_ERR(handle)) {
2483 ret = PTR_ERR(handle);
2484 goto out_writepages;
2486 BUG_ON(ext4_test_inode_state(inode,
2487 EXT4_STATE_MAY_INLINE_DATA));
2488 ext4_destroy_inline_data(handle, inode);
2489 ext4_journal_stop(handle);
2492 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
2495 if (wbc->range_cyclic) {
2496 writeback_index = mapping->writeback_index;
2497 if (writeback_index)
2499 mpd.first_page = writeback_index;
2502 mpd.first_page = wbc->range_start >> PAGE_CACHE_SHIFT;
2503 mpd.last_page = wbc->range_end >> PAGE_CACHE_SHIFT;
2508 ext4_io_submit_init(&mpd.io_submit, wbc);
2510 if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
2511 tag_pages_for_writeback(mapping, mpd.first_page, mpd.last_page);
2513 blk_start_plug(&plug);
2514 while (!done && mpd.first_page <= mpd.last_page) {
2515 /* For each extent of pages we use new io_end */
2516 mpd.io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL);
2517 if (!mpd.io_submit.io_end) {
2523 * We have two constraints: We find one extent to map and we
2524 * must always write out whole page (makes a difference when
2525 * blocksize < pagesize) so that we don't block on IO when we
2526 * try to write out the rest of the page. Journalled mode is
2527 * not supported by delalloc.
2529 BUG_ON(ext4_should_journal_data(inode));
2530 needed_blocks = ext4_da_writepages_trans_blocks(inode);
2532 /* start a new transaction */
2533 handle = ext4_journal_start_with_reserve(inode,
2534 EXT4_HT_WRITE_PAGE, needed_blocks, rsv_blocks);
2535 if (IS_ERR(handle)) {
2536 ret = PTR_ERR(handle);
2537 ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
2538 "%ld pages, ino %lu; err %d", __func__,
2539 wbc->nr_to_write, inode->i_ino, ret);
2540 /* Release allocated io_end */
2541 ext4_put_io_end(mpd.io_submit.io_end);
2545 trace_ext4_da_write_pages(inode, mpd.first_page, mpd.wbc);
2546 ret = mpage_prepare_extent_to_map(&mpd);
2549 ret = mpage_map_and_submit_extent(handle, &mpd,
2553 * We scanned the whole range (or exhausted
2554 * nr_to_write), submitted what was mapped and
2555 * didn't find anything needing mapping. We are
2561 ext4_journal_stop(handle);
2562 /* Submit prepared bio */
2563 ext4_io_submit(&mpd.io_submit);
2564 /* Unlock pages we didn't use */
2565 mpage_release_unused_pages(&mpd, give_up_on_write);
2566 /* Drop our io_end reference we got from init */
2567 ext4_put_io_end(mpd.io_submit.io_end);
2569 if (ret == -ENOSPC && sbi->s_journal) {
2571 * Commit the transaction which would
2572 * free blocks released in the transaction
2575 jbd2_journal_force_commit_nested(sbi->s_journal);
2579 /* Fatal error - ENOMEM, EIO... */
2583 blk_finish_plug(&plug);
2584 if (!ret && !cycled && wbc->nr_to_write > 0) {
2586 mpd.last_page = writeback_index - 1;
2592 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
2594 * Set the writeback_index so that range_cyclic
2595 * mode will write it back later
2597 mapping->writeback_index = mpd.first_page;
2600 trace_ext4_writepages_result(inode, wbc, ret,
2601 nr_to_write - wbc->nr_to_write);
2605 static int ext4_nonda_switch(struct super_block *sb)
2607 s64 free_clusters, dirty_clusters;
2608 struct ext4_sb_info *sbi = EXT4_SB(sb);
2611 * switch to non delalloc mode if we are running low
2612 * on free block. The free block accounting via percpu
2613 * counters can get slightly wrong with percpu_counter_batch getting
2614 * accumulated on each CPU without updating global counters
2615 * Delalloc need an accurate free block accounting. So switch
2616 * to non delalloc when we are near to error range.
2619 percpu_counter_read_positive(&sbi->s_freeclusters_counter);
2621 percpu_counter_read_positive(&sbi->s_dirtyclusters_counter);
2623 * Start pushing delalloc when 1/2 of free blocks are dirty.
2625 if (dirty_clusters && (free_clusters < 2 * dirty_clusters))
2626 try_to_writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE);
2628 if (2 * free_clusters < 3 * dirty_clusters ||
2629 free_clusters < (dirty_clusters + EXT4_FREECLUSTERS_WATERMARK)) {
2631 * free block count is less than 150% of dirty blocks
2632 * or free blocks is less than watermark
2639 static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
2640 loff_t pos, unsigned len, unsigned flags,
2641 struct page **pagep, void **fsdata)
2643 int ret, retries = 0;
2646 struct inode *inode = mapping->host;
2649 index = pos >> PAGE_CACHE_SHIFT;
2651 if (ext4_nonda_switch(inode->i_sb)) {
2652 *fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
2653 return ext4_write_begin(file, mapping, pos,
2654 len, flags, pagep, fsdata);
2656 *fsdata = (void *)0;
2657 trace_ext4_da_write_begin(inode, pos, len, flags);
2659 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
2660 ret = ext4_da_write_inline_data_begin(mapping, inode,
2670 * grab_cache_page_write_begin() can take a long time if the
2671 * system is thrashing due to memory pressure, or if the page
2672 * is being written back. So grab it first before we start
2673 * the transaction handle. This also allows us to allocate
2674 * the page (if needed) without using GFP_NOFS.
2677 page = grab_cache_page_write_begin(mapping, index, flags);
2683 * With delayed allocation, we don't log the i_disksize update
2684 * if there is delayed block allocation. But we still need
2685 * to journalling the i_disksize update if writes to the end
2686 * of file which has an already mapped buffer.
2689 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, 1);
2690 if (IS_ERR(handle)) {
2691 page_cache_release(page);
2692 return PTR_ERR(handle);
2696 if (page->mapping != mapping) {
2697 /* The page got truncated from under us */
2699 page_cache_release(page);
2700 ext4_journal_stop(handle);
2703 /* In case writeback began while the page was unlocked */
2704 wait_for_stable_page(page);
2706 ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep);
2709 ext4_journal_stop(handle);
2711 * block_write_begin may have instantiated a few blocks
2712 * outside i_size. Trim these off again. Don't need
2713 * i_size_read because we hold i_mutex.
2715 if (pos + len > inode->i_size)
2716 ext4_truncate_failed_write(inode);
2718 if (ret == -ENOSPC &&
2719 ext4_should_retry_alloc(inode->i_sb, &retries))
2722 page_cache_release(page);
2731 * Check if we should update i_disksize
2732 * when write to the end of file but not require block allocation
2734 static int ext4_da_should_update_i_disksize(struct page *page,
2735 unsigned long offset)
2737 struct buffer_head *bh;
2738 struct inode *inode = page->mapping->host;
2742 bh = page_buffers(page);
2743 idx = offset >> inode->i_blkbits;
2745 for (i = 0; i < idx; i++)
2746 bh = bh->b_this_page;
2748 if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
2753 static int ext4_da_write_end(struct file *file,
2754 struct address_space *mapping,
2755 loff_t pos, unsigned len, unsigned copied,
2756 struct page *page, void *fsdata)
2758 struct inode *inode = mapping->host;
2760 handle_t *handle = ext4_journal_current_handle();
2762 unsigned long start, end;
2763 int write_mode = (int)(unsigned long)fsdata;
2765 if (write_mode == FALL_BACK_TO_NONDELALLOC)
2766 return ext4_write_end(file, mapping, pos,
2767 len, copied, page, fsdata);
2769 trace_ext4_da_write_end(inode, pos, len, copied);
2770 start = pos & (PAGE_CACHE_SIZE - 1);
2771 end = start + copied - 1;
2774 * generic_write_end() will run mark_inode_dirty() if i_size
2775 * changes. So let's piggyback the i_disksize mark_inode_dirty
2778 new_i_size = pos + copied;
2779 if (copied && new_i_size > EXT4_I(inode)->i_disksize) {
2780 if (ext4_has_inline_data(inode) ||
2781 ext4_da_should_update_i_disksize(page, end)) {
2782 down_write(&EXT4_I(inode)->i_data_sem);
2783 if (new_i_size > EXT4_I(inode)->i_disksize)
2784 EXT4_I(inode)->i_disksize = new_i_size;
2785 up_write(&EXT4_I(inode)->i_data_sem);
2786 /* We need to mark inode dirty even if
2787 * new_i_size is less that inode->i_size
2788 * bu greater than i_disksize.(hint delalloc)
2790 ext4_mark_inode_dirty(handle, inode);
2794 if (write_mode != CONVERT_INLINE_DATA &&
2795 ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) &&
2796 ext4_has_inline_data(inode))
2797 ret2 = ext4_da_write_inline_data_end(inode, pos, len, copied,
2800 ret2 = generic_write_end(file, mapping, pos, len, copied,
2806 ret2 = ext4_journal_stop(handle);
2810 return ret ? ret : copied;
2813 static void ext4_da_invalidatepage(struct page *page, unsigned int offset,
2814 unsigned int length)
2817 * Drop reserved blocks
2819 BUG_ON(!PageLocked(page));
2820 if (!page_has_buffers(page))
2823 ext4_da_page_release_reservation(page, offset, length);
2826 ext4_invalidatepage(page, offset, length);
2832 * Force all delayed allocation blocks to be allocated for a given inode.
2834 int ext4_alloc_da_blocks(struct inode *inode)
2836 trace_ext4_alloc_da_blocks(inode);
2838 if (!EXT4_I(inode)->i_reserved_data_blocks &&
2839 !EXT4_I(inode)->i_reserved_meta_blocks)
2843 * We do something simple for now. The filemap_flush() will
2844 * also start triggering a write of the data blocks, which is
2845 * not strictly speaking necessary (and for users of
2846 * laptop_mode, not even desirable). However, to do otherwise
2847 * would require replicating code paths in:
2849 * ext4_writepages() ->
2850 * write_cache_pages() ---> (via passed in callback function)
2851 * __mpage_da_writepage() -->
2852 * mpage_add_bh_to_extent()
2853 * mpage_da_map_blocks()
2855 * The problem is that write_cache_pages(), located in
2856 * mm/page-writeback.c, marks pages clean in preparation for
2857 * doing I/O, which is not desirable if we're not planning on
2860 * We could call write_cache_pages(), and then redirty all of
2861 * the pages by calling redirty_page_for_writepage() but that
2862 * would be ugly in the extreme. So instead we would need to
2863 * replicate parts of the code in the above functions,
2864 * simplifying them because we wouldn't actually intend to
2865 * write out the pages, but rather only collect contiguous
2866 * logical block extents, call the multi-block allocator, and
2867 * then update the buffer heads with the block allocations.
2869 * For now, though, we'll cheat by calling filemap_flush(),
2870 * which will map the blocks, and start the I/O, but not
2871 * actually wait for the I/O to complete.
2873 return filemap_flush(inode->i_mapping);
2877 * bmap() is special. It gets used by applications such as lilo and by
2878 * the swapper to find the on-disk block of a specific piece of data.
2880 * Naturally, this is dangerous if the block concerned is still in the
2881 * journal. If somebody makes a swapfile on an ext4 data-journaling
2882 * filesystem and enables swap, then they may get a nasty shock when the
2883 * data getting swapped to that swapfile suddenly gets overwritten by
2884 * the original zero's written out previously to the journal and
2885 * awaiting writeback in the kernel's buffer cache.
2887 * So, if we see any bmap calls here on a modified, data-journaled file,
2888 * take extra steps to flush any blocks which might be in the cache.
2890 static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
2892 struct inode *inode = mapping->host;
2897 * We can get here for an inline file via the FIBMAP ioctl
2899 if (ext4_has_inline_data(inode))
2902 if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
2903 test_opt(inode->i_sb, DELALLOC)) {
2905 * With delalloc we want to sync the file
2906 * so that we can make sure we allocate
2909 filemap_write_and_wait(mapping);
2912 if (EXT4_JOURNAL(inode) &&
2913 ext4_test_inode_state(inode, EXT4_STATE_JDATA)) {
2915 * This is a REALLY heavyweight approach, but the use of
2916 * bmap on dirty files is expected to be extremely rare:
2917 * only if we run lilo or swapon on a freshly made file
2918 * do we expect this to happen.
2920 * (bmap requires CAP_SYS_RAWIO so this does not
2921 * represent an unprivileged user DOS attack --- we'd be
2922 * in trouble if mortal users could trigger this path at
2925 * NB. EXT4_STATE_JDATA is not set on files other than
2926 * regular files. If somebody wants to bmap a directory
2927 * or symlink and gets confused because the buffer
2928 * hasn't yet been flushed to disk, they deserve
2929 * everything they get.
2932 ext4_clear_inode_state(inode, EXT4_STATE_JDATA);
2933 journal = EXT4_JOURNAL(inode);
2934 jbd2_journal_lock_updates(journal);
2935 err = jbd2_journal_flush(journal);
2936 jbd2_journal_unlock_updates(journal);
2942 return generic_block_bmap(mapping, block, ext4_get_block);
2945 static int ext4_readpage(struct file *file, struct page *page)
2948 struct inode *inode = page->mapping->host;
2950 trace_ext4_readpage(page);
2952 if (ext4_has_inline_data(inode))
2953 ret = ext4_readpage_inline(inode, page);
2956 return mpage_readpage(page, ext4_get_block);
2962 ext4_readpages(struct file *file, struct address_space *mapping,
2963 struct list_head *pages, unsigned nr_pages)
2965 struct inode *inode = mapping->host;
2967 /* If the file has inline data, no need to do readpages. */
2968 if (ext4_has_inline_data(inode))
2971 return mpage_readpages(mapping, pages, nr_pages, ext4_get_block);
2974 static void ext4_invalidatepage(struct page *page, unsigned int offset,
2975 unsigned int length)
2977 trace_ext4_invalidatepage(page, offset, length);
2979 /* No journalling happens on data buffers when this function is used */
2980 WARN_ON(page_has_buffers(page) && buffer_jbd(page_buffers(page)));
2982 block_invalidatepage(page, offset, length);
2985 static int __ext4_journalled_invalidatepage(struct page *page,
2986 unsigned int offset,
2987 unsigned int length)
2989 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
2991 trace_ext4_journalled_invalidatepage(page, offset, length);
2994 * If it's a full truncate we just forget about the pending dirtying
2996 if (offset == 0 && length == PAGE_CACHE_SIZE)
2997 ClearPageChecked(page);
2999 return jbd2_journal_invalidatepage(journal, page, offset, length);
3002 /* Wrapper for aops... */
3003 static void ext4_journalled_invalidatepage(struct page *page,
3004 unsigned int offset,
3005 unsigned int length)
3007 WARN_ON(__ext4_journalled_invalidatepage(page, offset, length) < 0);
3010 static int ext4_releasepage(struct page *page, gfp_t wait)
3012 journal_t *journal = EXT4_JOURNAL(page->mapping->host);
3014 trace_ext4_releasepage(page);
3016 /* Page has dirty journalled data -> cannot release */
3017 if (PageChecked(page))
3020 return jbd2_journal_try_to_free_buffers(journal, page, wait);
3022 return try_to_free_buffers(page);
3026 * ext4_get_block used when preparing for a DIO write or buffer write.
3027 * We allocate an uinitialized extent if blocks haven't been allocated.
3028 * The extent will be converted to initialized after the IO is complete.
3030 int ext4_get_block_write(struct inode *inode, sector_t iblock,
3031 struct buffer_head *bh_result, int create)
3033 ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n",
3034 inode->i_ino, create);
3035 return _ext4_get_block(inode, iblock, bh_result,
3036 EXT4_GET_BLOCKS_IO_CREATE_EXT);
3039 static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock,
3040 struct buffer_head *bh_result, int create)
3042 ext4_debug("ext4_get_block_write_nolock: inode %lu, create flag %d\n",
3043 inode->i_ino, create);
3044 return _ext4_get_block(inode, iblock, bh_result,
3045 EXT4_GET_BLOCKS_NO_LOCK);
3048 static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
3049 ssize_t size, void *private)
3051 ext4_io_end_t *io_end = iocb->private;
3053 /* if not async direct IO just return */
3057 ext_debug("ext4_end_io_dio(): io_end 0x%p "
3058 "for inode %lu, iocb 0x%p, offset %llu, size %zd\n",
3059 iocb->private, io_end->inode->i_ino, iocb, offset,
3062 iocb->private = NULL;
3063 io_end->offset = offset;
3064 io_end->size = size;
3065 ext4_put_io_end(io_end);
3069 * For ext4 extent files, ext4 will do direct-io write to holes,
3070 * preallocated extents, and those write extend the file, no need to
3071 * fall back to buffered IO.
3073 * For holes, we fallocate those blocks, mark them as uninitialized
3074 * If those blocks were preallocated, we mark sure they are split, but
3075 * still keep the range to write as uninitialized.
3077 * The unwritten extents will be converted to written when DIO is completed.
3078 * For async direct IO, since the IO may still pending when return, we
3079 * set up an end_io call back function, which will do the conversion
3080 * when async direct IO completed.
3082 * If the O_DIRECT write will extend the file then add this inode to the
3083 * orphan list. So recovery will truncate it back to the original size
3084 * if the machine crashes during the write.
3087 static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
3088 const struct iovec *iov, loff_t offset,
3089 unsigned long nr_segs)
3091 struct file *file = iocb->ki_filp;
3092 struct inode *inode = file->f_mapping->host;
3094 size_t count = iov_length(iov, nr_segs);
3096 get_block_t *get_block_func = NULL;
3098 loff_t final_size = offset + count;
3099 ext4_io_end_t *io_end = NULL;
3101 /* Use the old path for reads and writes beyond i_size. */
3102 if (rw != WRITE || final_size > inode->i_size)
3103 return ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
3105 BUG_ON(iocb->private == NULL);
3108 * Make all waiters for direct IO properly wait also for extent
3109 * conversion. This also disallows race between truncate() and
3110 * overwrite DIO as i_dio_count needs to be incremented under i_mutex.
3113 atomic_inc(&inode->i_dio_count);
3115 /* If we do a overwrite dio, i_mutex locking can be released */
3116 overwrite = *((int *)iocb->private);
3119 down_read(&EXT4_I(inode)->i_data_sem);
3120 mutex_unlock(&inode->i_mutex);
3124 * We could direct write to holes and fallocate.
3126 * Allocated blocks to fill the hole are marked as
3127 * uninitialized to prevent parallel buffered read to expose
3128 * the stale data before DIO complete the data IO.
3130 * As to previously fallocated extents, ext4 get_block will
3131 * just simply mark the buffer mapped but still keep the
3132 * extents uninitialized.
3134 * For non AIO case, we will convert those unwritten extents
3135 * to written after return back from blockdev_direct_IO.
3137 * For async DIO, the conversion needs to be deferred when the
3138 * IO is completed. The ext4 end_io callback function will be
3139 * called to take care of the conversion work. Here for async
3140 * case, we allocate an io_end structure to hook to the iocb.
3142 iocb->private = NULL;
3143 ext4_inode_aio_set(inode, NULL);
3144 if (!is_sync_kiocb(iocb)) {
3145 io_end = ext4_init_io_end(inode, GFP_NOFS);
3151 * Grab reference for DIO. Will be dropped in ext4_end_io_dio()
3153 iocb->private = ext4_get_io_end(io_end);
3155 * we save the io structure for current async direct
3156 * IO, so that later ext4_map_blocks() could flag the
3157 * io structure whether there is a unwritten extents
3158 * needs to be converted when IO is completed.
3160 ext4_inode_aio_set(inode, io_end);
3164 get_block_func = ext4_get_block_write_nolock;
3166 get_block_func = ext4_get_block_write;
3167 dio_flags = DIO_LOCKING;
3169 ret = __blockdev_direct_IO(rw, iocb, inode,
3170 inode->i_sb->s_bdev, iov,
3178 * Put our reference to io_end. This can free the io_end structure e.g.
3179 * in sync IO case or in case of error. It can even perform extent
3180 * conversion if all bios we submitted finished before we got here.
3181 * Note that in that case iocb->private can be already set to NULL
3185 ext4_inode_aio_set(inode, NULL);
3186 ext4_put_io_end(io_end);
3188 * When no IO was submitted ext4_end_io_dio() was not
3189 * called so we have to put iocb's reference.
3191 if (ret <= 0 && ret != -EIOCBQUEUED && iocb->private) {
3192 WARN_ON(iocb->private != io_end);
3193 WARN_ON(io_end->flag & EXT4_IO_END_UNWRITTEN);
3194 ext4_put_io_end(io_end);
3195 iocb->private = NULL;
3198 if (ret > 0 && !overwrite && ext4_test_inode_state(inode,
3199 EXT4_STATE_DIO_UNWRITTEN)) {
3202 * for non AIO case, since the IO is already
3203 * completed, we could do the conversion right here
3205 err = ext4_convert_unwritten_extents(NULL, inode,
3209 ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
3214 inode_dio_done(inode);
3215 /* take i_mutex locking again if we do a ovewrite dio */
3217 up_read(&EXT4_I(inode)->i_data_sem);
3218 mutex_lock(&inode->i_mutex);
3224 static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
3225 const struct iovec *iov, loff_t offset,
3226 unsigned long nr_segs)
3228 struct file *file = iocb->ki_filp;
3229 struct inode *inode = file->f_mapping->host;
3233 * If we are doing data journalling we don't support O_DIRECT
3235 if (ext4_should_journal_data(inode))
3238 /* Let buffer I/O handle the inline data case. */
3239 if (ext4_has_inline_data(inode))
3242 trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw);
3243 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3244 ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs);
3246 ret = ext4_ind_direct_IO(rw, iocb, iov, offset, nr_segs);
3247 trace_ext4_direct_IO_exit(inode, offset,
3248 iov_length(iov, nr_segs), rw, ret);
3253 * Pages can be marked dirty completely asynchronously from ext4's journalling
3254 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
3255 * much here because ->set_page_dirty is called under VFS locks. The page is
3256 * not necessarily locked.
3258 * We cannot just dirty the page and leave attached buffers clean, because the
3259 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
3260 * or jbddirty because all the journalling code will explode.
3262 * So what we do is to mark the page "pending dirty" and next time writepage
3263 * is called, propagate that into the buffers appropriately.
3265 static int ext4_journalled_set_page_dirty(struct page *page)
3267 SetPageChecked(page);
3268 return __set_page_dirty_nobuffers(page);
3271 static const struct address_space_operations ext4_aops = {
3272 .readpage = ext4_readpage,
3273 .readpages = ext4_readpages,
3274 .writepage = ext4_writepage,
3275 .writepages = ext4_writepages,
3276 .write_begin = ext4_write_begin,
3277 .write_end = ext4_write_end,
3279 .invalidatepage = ext4_invalidatepage,
3280 .releasepage = ext4_releasepage,
3281 .direct_IO = ext4_direct_IO,
3282 .migratepage = buffer_migrate_page,
3283 .is_partially_uptodate = block_is_partially_uptodate,
3284 .error_remove_page = generic_error_remove_page,
3287 static const struct address_space_operations ext4_journalled_aops = {
3288 .readpage = ext4_readpage,
3289 .readpages = ext4_readpages,
3290 .writepage = ext4_writepage,
3291 .writepages = ext4_writepages,
3292 .write_begin = ext4_write_begin,
3293 .write_end = ext4_journalled_write_end,
3294 .set_page_dirty = ext4_journalled_set_page_dirty,
3296 .invalidatepage = ext4_journalled_invalidatepage,
3297 .releasepage = ext4_releasepage,
3298 .direct_IO = ext4_direct_IO,
3299 .is_partially_uptodate = block_is_partially_uptodate,
3300 .error_remove_page = generic_error_remove_page,
3303 static const struct address_space_operations ext4_da_aops = {
3304 .readpage = ext4_readpage,
3305 .readpages = ext4_readpages,
3306 .writepage = ext4_writepage,
3307 .writepages = ext4_writepages,
3308 .write_begin = ext4_da_write_begin,
3309 .write_end = ext4_da_write_end,
3311 .invalidatepage = ext4_da_invalidatepage,
3312 .releasepage = ext4_releasepage,
3313 .direct_IO = ext4_direct_IO,
3314 .migratepage = buffer_migrate_page,
3315 .is_partially_uptodate = block_is_partially_uptodate,
3316 .error_remove_page = generic_error_remove_page,
3319 void ext4_set_aops(struct inode *inode)
3321 switch (ext4_inode_journal_mode(inode)) {
3322 case EXT4_INODE_ORDERED_DATA_MODE:
3323 ext4_set_inode_state(inode, EXT4_STATE_ORDERED_MODE);
3325 case EXT4_INODE_WRITEBACK_DATA_MODE:
3326 ext4_clear_inode_state(inode, EXT4_STATE_ORDERED_MODE);
3328 case EXT4_INODE_JOURNAL_DATA_MODE:
3329 inode->i_mapping->a_ops = &ext4_journalled_aops;
3334 if (test_opt(inode->i_sb, DELALLOC))
3335 inode->i_mapping->a_ops = &ext4_da_aops;
3337 inode->i_mapping->a_ops = &ext4_aops;
3341 * ext4_block_zero_page_range() zeros out a mapping of length 'length'
3342 * starting from file offset 'from'. The range to be zero'd must
3343 * be contained with in one block. If the specified range exceeds
3344 * the end of the block it will be shortened to end of the block
3345 * that cooresponds to 'from'
3347 static int ext4_block_zero_page_range(handle_t *handle,
3348 struct address_space *mapping, loff_t from, loff_t length)
3350 ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
3351 unsigned offset = from & (PAGE_CACHE_SIZE-1);
3352 unsigned blocksize, max, pos;
3354 struct inode *inode = mapping->host;
3355 struct buffer_head *bh;
3359 page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT,
3360 mapping_gfp_mask(mapping) & ~__GFP_FS);
3364 blocksize = inode->i_sb->s_blocksize;
3365 max = blocksize - (offset & (blocksize - 1));
3368 * correct length if it does not fall between
3369 * 'from' and the end of the block
3371 if (length > max || length < 0)
3374 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
3376 if (!page_has_buffers(page))
3377 create_empty_buffers(page, blocksize, 0);
3379 /* Find the buffer that contains "offset" */
3380 bh = page_buffers(page);
3382 while (offset >= pos) {
3383 bh = bh->b_this_page;
3387 if (buffer_freed(bh)) {
3388 BUFFER_TRACE(bh, "freed: skip");
3391 if (!buffer_mapped(bh)) {
3392 BUFFER_TRACE(bh, "unmapped");
3393 ext4_get_block(inode, iblock, bh, 0);
3394 /* unmapped? It's a hole - nothing to do */
3395 if (!buffer_mapped(bh)) {
3396 BUFFER_TRACE(bh, "still unmapped");
3401 /* Ok, it's mapped. Make sure it's up-to-date */
3402 if (PageUptodate(page))
3403 set_buffer_uptodate(bh);
3405 if (!buffer_uptodate(bh)) {
3407 ll_rw_block(READ, 1, &bh);
3409 /* Uhhuh. Read error. Complain and punt. */
3410 if (!buffer_uptodate(bh))
3413 if (ext4_should_journal_data(inode)) {
3414 BUFFER_TRACE(bh, "get write access");
3415 err = ext4_journal_get_write_access(handle, bh);
3419 zero_user(page, offset, length);
3420 BUFFER_TRACE(bh, "zeroed end of block");
3422 if (ext4_should_journal_data(inode)) {
3423 err = ext4_handle_dirty_metadata(handle, inode, bh);
3426 mark_buffer_dirty(bh);
3427 if (ext4_test_inode_state(inode, EXT4_STATE_ORDERED_MODE))
3428 err = ext4_jbd2_file_inode(handle, inode);
3433 page_cache_release(page);
3438 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
3439 * up to the end of the block which corresponds to `from'.
3440 * This required during truncate. We need to physically zero the tail end
3441 * of that block so it doesn't yield old data if the file is later grown.
3443 int ext4_block_truncate_page(handle_t *handle,
3444 struct address_space *mapping, loff_t from)
3446 unsigned offset = from & (PAGE_CACHE_SIZE-1);
3449 struct inode *inode = mapping->host;
3451 blocksize = inode->i_sb->s_blocksize;
3452 length = blocksize - (offset & (blocksize - 1));
3454 return ext4_block_zero_page_range(handle, mapping, from, length);
3457 int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
3458 loff_t lstart, loff_t length)
3460 struct super_block *sb = inode->i_sb;
3461 struct address_space *mapping = inode->i_mapping;
3462 unsigned partial_start, partial_end;
3463 ext4_fsblk_t start, end;
3464 loff_t byte_end = (lstart + length - 1);
3467 partial_start = lstart & (sb->s_blocksize - 1);
3468 partial_end = byte_end & (sb->s_blocksize - 1);
3470 start = lstart >> sb->s_blocksize_bits;
3471 end = byte_end >> sb->s_blocksize_bits;
3473 /* Handle partial zero within the single block */
3475 (partial_start || (partial_end != sb->s_blocksize - 1))) {
3476 err = ext4_block_zero_page_range(handle, mapping,
3480 /* Handle partial zero out on the start of the range */
3481 if (partial_start) {
3482 err = ext4_block_zero_page_range(handle, mapping,
3483 lstart, sb->s_blocksize);
3487 /* Handle partial zero out on the end of the range */
3488 if (partial_end != sb->s_blocksize - 1)
3489 err = ext4_block_zero_page_range(handle, mapping,
3490 byte_end - partial_end,
3495 int ext4_can_truncate(struct inode *inode)
3497 if (S_ISREG(inode->i_mode))
3499 if (S_ISDIR(inode->i_mode))
3501 if (S_ISLNK(inode->i_mode))
3502 return !ext4_inode_is_fast_symlink(inode);
3507 * ext4_punch_hole: punches a hole in a file by releaseing the blocks
3508 * associated with the given offset and length
3510 * @inode: File inode
3511 * @offset: The offset where the hole will begin
3512 * @len: The length of the hole
3514 * Returns: 0 on success or negative on failure
3517 int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length)
3519 struct super_block *sb = inode->i_sb;
3520 ext4_lblk_t first_block, stop_block;
3521 struct address_space *mapping = inode->i_mapping;
3522 loff_t first_block_offset, last_block_offset;
3524 unsigned int credits;
3527 if (!S_ISREG(inode->i_mode))
3530 trace_ext4_punch_hole(inode, offset, length, 0);
3533 * Write out all dirty pages to avoid race conditions
3534 * Then release them.
3536 if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
3537 ret = filemap_write_and_wait_range(mapping, offset,
3538 offset + length - 1);
3543 mutex_lock(&inode->i_mutex);
3545 /* No need to punch hole beyond i_size */
3546 if (offset >= inode->i_size)
3550 * If the hole extends beyond i_size, set the hole
3551 * to end after the page that contains i_size
3553 if (offset + length > inode->i_size) {
3554 length = inode->i_size +
3555 PAGE_CACHE_SIZE - (inode->i_size & (PAGE_CACHE_SIZE - 1)) -
3559 if (offset & (sb->s_blocksize - 1) ||
3560 (offset + length) & (sb->s_blocksize - 1)) {
3562 * Attach jinode to inode for jbd2 if we do any zeroing of
3565 ret = ext4_inode_attach_jinode(inode);
3571 first_block_offset = round_up(offset, sb->s_blocksize);
3572 last_block_offset = round_down((offset + length), sb->s_blocksize) - 1;
3574 /* Now release the pages and zero block aligned part of pages*/
3575 if (last_block_offset > first_block_offset)
3576 truncate_pagecache_range(inode, first_block_offset,
3579 /* Wait all existing dio workers, newcomers will block on i_mutex */
3580 ext4_inode_block_unlocked_dio(inode);
3581 inode_dio_wait(inode);
3583 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3584 credits = ext4_writepage_trans_blocks(inode);
3586 credits = ext4_blocks_for_truncate(inode);
3587 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
3588 if (IS_ERR(handle)) {
3589 ret = PTR_ERR(handle);
3590 ext4_std_error(sb, ret);
3594 ret = ext4_zero_partial_blocks(handle, inode, offset,
3599 first_block = (offset + sb->s_blocksize - 1) >>
3600 EXT4_BLOCK_SIZE_BITS(sb);
3601 stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);
3603 /* If there are no blocks to remove, return now */
3604 if (first_block >= stop_block)
3607 down_write(&EXT4_I(inode)->i_data_sem);
3608 ext4_discard_preallocations(inode);
3610 ret = ext4_es_remove_extent(inode, first_block,
3611 stop_block - first_block);
3613 up_write(&EXT4_I(inode)->i_data_sem);
3617 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3618 ret = ext4_ext_remove_space(inode, first_block,
3621 ret = ext4_free_hole_blocks(handle, inode, first_block,
3624 ext4_discard_preallocations(inode);
3625 up_write(&EXT4_I(inode)->i_data_sem);
3627 ext4_handle_sync(handle);
3629 /* Now release the pages again to reduce race window */
3630 if (last_block_offset > first_block_offset)
3631 truncate_pagecache_range(inode, first_block_offset,
3634 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
3635 ext4_mark_inode_dirty(handle, inode);
3637 ext4_journal_stop(handle);
3639 ext4_inode_resume_unlocked_dio(inode);
3641 mutex_unlock(&inode->i_mutex);
3645 int ext4_inode_attach_jinode(struct inode *inode)
3647 struct ext4_inode_info *ei = EXT4_I(inode);
3648 struct jbd2_inode *jinode;
3650 if (ei->jinode || !EXT4_SB(inode->i_sb)->s_journal)
3653 jinode = jbd2_alloc_inode(GFP_KERNEL);
3654 spin_lock(&inode->i_lock);
3657 spin_unlock(&inode->i_lock);
3660 ei->jinode = jinode;
3661 jbd2_journal_init_jbd_inode(ei->jinode, inode);
3664 spin_unlock(&inode->i_lock);
3665 if (unlikely(jinode != NULL))
3666 jbd2_free_inode(jinode);
3673 * We block out ext4_get_block() block instantiations across the entire
3674 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
3675 * simultaneously on behalf of the same inode.
3677 * As we work through the truncate and commit bits of it to the journal there
3678 * is one core, guiding principle: the file's tree must always be consistent on
3679 * disk. We must be able to restart the truncate after a crash.
3681 * The file's tree may be transiently inconsistent in memory (although it
3682 * probably isn't), but whenever we close off and commit a journal transaction,
3683 * the contents of (the filesystem + the journal) must be consistent and
3684 * restartable. It's pretty simple, really: bottom up, right to left (although
3685 * left-to-right works OK too).
3687 * Note that at recovery time, journal replay occurs *before* the restart of
3688 * truncate against the orphan inode list.
3690 * The committed inode has the new, desired i_size (which is the same as
3691 * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see
3692 * that this inode's truncate did not complete and it will again call
3693 * ext4_truncate() to have another go. So there will be instantiated blocks
3694 * to the right of the truncation point in a crashed ext4 filesystem. But
3695 * that's fine - as long as they are linked from the inode, the post-crash
3696 * ext4_truncate() run will find them and release them.
3698 void ext4_truncate(struct inode *inode)
3700 struct ext4_inode_info *ei = EXT4_I(inode);
3701 unsigned int credits;
3703 struct address_space *mapping = inode->i_mapping;
3706 * There is a possibility that we're either freeing the inode
3707 * or it's a completely new inode. In those cases we might not
3708 * have i_mutex locked because it's not necessary.
3710 if (!(inode->i_state & (I_NEW|I_FREEING)))
3711 WARN_ON(!mutex_is_locked(&inode->i_mutex));
3712 trace_ext4_truncate_enter(inode);
3714 if (!ext4_can_truncate(inode))
3717 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3719 if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
3720 ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
3722 if (ext4_has_inline_data(inode)) {
3725 ext4_inline_data_truncate(inode, &has_inline);
3730 /* If we zero-out tail of the page, we have to create jinode for jbd2 */
3731 if (inode->i_size & (inode->i_sb->s_blocksize - 1)) {
3732 if (ext4_inode_attach_jinode(inode) < 0)
3736 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3737 credits = ext4_writepage_trans_blocks(inode);
3739 credits = ext4_blocks_for_truncate(inode);
3741 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
3742 if (IS_ERR(handle)) {
3743 ext4_std_error(inode->i_sb, PTR_ERR(handle));
3747 if (inode->i_size & (inode->i_sb->s_blocksize - 1))
3748 ext4_block_truncate_page(handle, mapping, inode->i_size);
3751 * We add the inode to the orphan list, so that if this
3752 * truncate spans multiple transactions, and we crash, we will
3753 * resume the truncate when the filesystem recovers. It also
3754 * marks the inode dirty, to catch the new size.
3756 * Implication: the file must always be in a sane, consistent
3757 * truncatable state while each transaction commits.
3759 if (ext4_orphan_add(handle, inode))
3762 down_write(&EXT4_I(inode)->i_data_sem);
3764 ext4_discard_preallocations(inode);
3766 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
3767 ext4_ext_truncate(handle, inode);
3769 ext4_ind_truncate(handle, inode);
3771 up_write(&ei->i_data_sem);
3774 ext4_handle_sync(handle);
3778 * If this was a simple ftruncate() and the file will remain alive,
3779 * then we need to clear up the orphan record which we created above.
3780 * However, if this was a real unlink then we were called by
3781 * ext4_delete_inode(), and we allow that function to clean up the
3782 * orphan info for us.
3785 ext4_orphan_del(handle, inode);
3787 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
3788 ext4_mark_inode_dirty(handle, inode);
3789 ext4_journal_stop(handle);
3791 trace_ext4_truncate_exit(inode);
3795 * ext4_get_inode_loc returns with an extra refcount against the inode's
3796 * underlying buffer_head on success. If 'in_mem' is true, we have all
3797 * data in memory that is needed to recreate the on-disk version of this
3800 static int __ext4_get_inode_loc(struct inode *inode,
3801 struct ext4_iloc *iloc, int in_mem)
3803 struct ext4_group_desc *gdp;
3804 struct buffer_head *bh;
3805 struct super_block *sb = inode->i_sb;
3807 int inodes_per_block, inode_offset;
3810 if (!ext4_valid_inum(sb, inode->i_ino))
3813 iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb);
3814 gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
3819 * Figure out the offset within the block group inode table
3821 inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
3822 inode_offset = ((inode->i_ino - 1) %
3823 EXT4_INODES_PER_GROUP(sb));
3824 block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
3825 iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);
3827 bh = sb_getblk(sb, block);
3830 if (!buffer_uptodate(bh)) {
3834 * If the buffer has the write error flag, we have failed
3835 * to write out another inode in the same block. In this
3836 * case, we don't have to read the block because we may
3837 * read the old inode data successfully.
3839 if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
3840 set_buffer_uptodate(bh);
3842 if (buffer_uptodate(bh)) {
3843 /* someone brought it uptodate while we waited */
3849 * If we have all information of the inode in memory and this
3850 * is the only valid inode in the block, we need not read the
3854 struct buffer_head *bitmap_bh;
3857 start = inode_offset & ~(inodes_per_block - 1);
3859 /* Is the inode bitmap in cache? */
3860 bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp));
3861 if (unlikely(!bitmap_bh))
3865 * If the inode bitmap isn't in cache then the
3866 * optimisation may end up performing two reads instead
3867 * of one, so skip it.
3869 if (!buffer_uptodate(bitmap_bh)) {
3873 for (i = start; i < start + inodes_per_block; i++) {
3874 if (i == inode_offset)
3876 if (ext4_test_bit(i, bitmap_bh->b_data))
3880 if (i == start + inodes_per_block) {
3881 /* all other inodes are free, so skip I/O */
3882 memset(bh->b_data, 0, bh->b_size);
3883 set_buffer_uptodate(bh);
3891 * If we need to do any I/O, try to pre-readahead extra
3892 * blocks from the inode table.
3894 if (EXT4_SB(sb)->s_inode_readahead_blks) {
3895 ext4_fsblk_t b, end, table;
3897 __u32 ra_blks = EXT4_SB(sb)->s_inode_readahead_blks;
3899 table = ext4_inode_table(sb, gdp);
3900 /* s_inode_readahead_blks is always a power of 2 */
3901 b = block & ~((ext4_fsblk_t) ra_blks - 1);
3905 num = EXT4_INODES_PER_GROUP(sb);
3906 if (ext4_has_group_desc_csum(sb))
3907 num -= ext4_itable_unused_count(sb, gdp);
3908 table += num / inodes_per_block;
3912 sb_breadahead(sb, b++);
3916 * There are other valid inodes in the buffer, this inode
3917 * has in-inode xattrs, or we don't have this inode in memory.
3918 * Read the block from disk.
3920 trace_ext4_load_inode(inode);
3922 bh->b_end_io = end_buffer_read_sync;
3923 submit_bh(READ | REQ_META | REQ_PRIO, bh);
3925 if (!buffer_uptodate(bh)) {
3926 EXT4_ERROR_INODE_BLOCK(inode, block,
3927 "unable to read itable block");
3937 int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
3939 /* We have all inode data except xattrs in memory here. */
3940 return __ext4_get_inode_loc(inode, iloc,
3941 !ext4_test_inode_state(inode, EXT4_STATE_XATTR));
3944 void ext4_set_inode_flags(struct inode *inode)
3946 unsigned int flags = EXT4_I(inode)->i_flags;
3947 unsigned int new_fl = 0;
3949 if (flags & EXT4_SYNC_FL)
3951 if (flags & EXT4_APPEND_FL)
3953 if (flags & EXT4_IMMUTABLE_FL)
3954 new_fl |= S_IMMUTABLE;
3955 if (flags & EXT4_NOATIME_FL)
3956 new_fl |= S_NOATIME;
3957 if (flags & EXT4_DIRSYNC_FL)
3958 new_fl |= S_DIRSYNC;
3959 inode_set_flags(inode, new_fl,
3960 S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
3963 /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */
3964 void ext4_get_inode_flags(struct ext4_inode_info *ei)
3966 unsigned int vfs_fl;
3967 unsigned long old_fl, new_fl;
3970 vfs_fl = ei->vfs_inode.i_flags;
3971 old_fl = ei->i_flags;
3972 new_fl = old_fl & ~(EXT4_SYNC_FL|EXT4_APPEND_FL|
3973 EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|
3975 if (vfs_fl & S_SYNC)
3976 new_fl |= EXT4_SYNC_FL;
3977 if (vfs_fl & S_APPEND)
3978 new_fl |= EXT4_APPEND_FL;
3979 if (vfs_fl & S_IMMUTABLE)
3980 new_fl |= EXT4_IMMUTABLE_FL;
3981 if (vfs_fl & S_NOATIME)
3982 new_fl |= EXT4_NOATIME_FL;
3983 if (vfs_fl & S_DIRSYNC)
3984 new_fl |= EXT4_DIRSYNC_FL;
3985 } while (cmpxchg(&ei->i_flags, old_fl, new_fl) != old_fl);
3988 static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
3989 struct ext4_inode_info *ei)
3992 struct inode *inode = &(ei->vfs_inode);
3993 struct super_block *sb = inode->i_sb;
3995 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3996 EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
3997 /* we are using combined 48 bit field */
3998 i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
3999 le32_to_cpu(raw_inode->i_blocks_lo);
4000 if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) {
4001 /* i_blocks represent file system block size */
4002 return i_blocks << (inode->i_blkbits - 9);
4007 return le32_to_cpu(raw_inode->i_blocks_lo);
4011 static inline void ext4_iget_extra_inode(struct inode *inode,
4012 struct ext4_inode *raw_inode,
4013 struct ext4_inode_info *ei)
4015 __le32 *magic = (void *)raw_inode +
4016 EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize;
4017 if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC)) {
4018 ext4_set_inode_state(inode, EXT4_STATE_XATTR);
4019 ext4_find_inline_data_nolock(inode);
4021 EXT4_I(inode)->i_inline_off = 0;
4024 struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
4026 struct ext4_iloc iloc;
4027 struct ext4_inode *raw_inode;
4028 struct ext4_inode_info *ei;
4029 struct inode *inode;
4030 journal_t *journal = EXT4_SB(sb)->s_journal;
4036 inode = iget_locked(sb, ino);
4038 return ERR_PTR(-ENOMEM);
4039 if (!(inode->i_state & I_NEW))
4045 ret = __ext4_get_inode_loc(inode, &iloc, 0);
4048 raw_inode = ext4_raw_inode(&iloc);
4050 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4051 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
4052 if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
4053 EXT4_INODE_SIZE(inode->i_sb)) {
4054 EXT4_ERROR_INODE(inode, "bad extra_isize (%u != %u)",
4055 EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize,
4056 EXT4_INODE_SIZE(inode->i_sb));
4061 ei->i_extra_isize = 0;
4063 /* Precompute checksum seed for inode metadata */
4064 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
4065 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
4066 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4068 __le32 inum = cpu_to_le32(inode->i_ino);
4069 __le32 gen = raw_inode->i_generation;
4070 csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
4072 ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
4076 if (!ext4_inode_csum_verify(inode, raw_inode, ei)) {
4077 EXT4_ERROR_INODE(inode, "checksum invalid");
4082 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
4083 i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
4084 i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
4085 if (!(test_opt(inode->i_sb, NO_UID32))) {
4086 i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
4087 i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
4089 i_uid_write(inode, i_uid);
4090 i_gid_write(inode, i_gid);
4091 set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
4093 ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */
4094 ei->i_inline_off = 0;
4095 ei->i_dir_start_lookup = 0;
4096 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
4097 /* We now have enough fields to check if the inode was active or not.
4098 * This is needed because nfsd might try to access dead inodes
4099 * the test is that same one that e2fsck uses
4100 * NeilBrown 1999oct15
4102 if (inode->i_nlink == 0) {
4103 if ((inode->i_mode == 0 ||
4104 !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) &&
4105 ino != EXT4_BOOT_LOADER_INO) {
4106 /* this inode is deleted */
4110 /* The only unlinked inodes we let through here have
4111 * valid i_mode and are being read by the orphan
4112 * recovery code: that's fine, we're about to complete
4113 * the process of deleting those.
4114 * OR it is the EXT4_BOOT_LOADER_INO which is
4115 * not initialized on a new filesystem. */
4117 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
4118 inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
4119 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
4120 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT))
4122 ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
4123 inode->i_size = ext4_isize(raw_inode);
4124 ei->i_disksize = inode->i_size;
4126 ei->i_reserved_quota = 0;
4128 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
4129 ei->i_block_group = iloc.block_group;
4130 ei->i_last_alloc_group = ~0;
4132 * NOTE! The in-memory inode i_data array is in little-endian order
4133 * even on big-endian machines: we do NOT byteswap the block numbers!
4135 for (block = 0; block < EXT4_N_BLOCKS; block++)
4136 ei->i_data[block] = raw_inode->i_block[block];
4137 INIT_LIST_HEAD(&ei->i_orphan);
4140 * Set transaction id's of transactions that have to be committed
4141 * to finish f[data]sync. We set them to currently running transaction
4142 * as we cannot be sure that the inode or some of its metadata isn't
4143 * part of the transaction - the inode could have been reclaimed and
4144 * now it is reread from disk.
4147 transaction_t *transaction;
4150 read_lock(&journal->j_state_lock);
4151 if (journal->j_running_transaction)
4152 transaction = journal->j_running_transaction;
4154 transaction = journal->j_committing_transaction;
4156 tid = transaction->t_tid;
4158 tid = journal->j_commit_sequence;
4159 read_unlock(&journal->j_state_lock);
4160 ei->i_sync_tid = tid;
4161 ei->i_datasync_tid = tid;
4164 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4165 if (ei->i_extra_isize == 0) {
4166 /* The extra space is currently unused. Use it. */
4167 ei->i_extra_isize = sizeof(struct ext4_inode) -
4168 EXT4_GOOD_OLD_INODE_SIZE;
4170 ext4_iget_extra_inode(inode, raw_inode, ei);
4174 EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
4175 EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
4176 EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
4177 EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
4179 if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) {
4180 inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
4181 if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4182 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4184 (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
4189 if (ei->i_file_acl &&
4190 !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) {
4191 EXT4_ERROR_INODE(inode, "bad extended attribute block %llu",
4195 } else if (!ext4_has_inline_data(inode)) {
4196 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
4197 if ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
4198 (S_ISLNK(inode->i_mode) &&
4199 !ext4_inode_is_fast_symlink(inode))))
4200 /* Validate extent which is part of inode */
4201 ret = ext4_ext_check_inode(inode);
4202 } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
4203 (S_ISLNK(inode->i_mode) &&
4204 !ext4_inode_is_fast_symlink(inode))) {
4205 /* Validate block references which are part of inode */
4206 ret = ext4_ind_check_inode(inode);
4212 if (S_ISREG(inode->i_mode)) {
4213 inode->i_op = &ext4_file_inode_operations;
4214 inode->i_fop = &ext4_file_operations;
4215 ext4_set_aops(inode);
4216 } else if (S_ISDIR(inode->i_mode)) {
4217 inode->i_op = &ext4_dir_inode_operations;
4218 inode->i_fop = &ext4_dir_operations;
4219 } else if (S_ISLNK(inode->i_mode)) {
4220 if (ext4_inode_is_fast_symlink(inode)) {
4221 inode->i_op = &ext4_fast_symlink_inode_operations;
4222 nd_terminate_link(ei->i_data, inode->i_size,
4223 sizeof(ei->i_data) - 1);
4225 inode->i_op = &ext4_symlink_inode_operations;
4226 ext4_set_aops(inode);
4228 } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
4229 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
4230 inode->i_op = &ext4_special_inode_operations;
4231 if (raw_inode->i_block[0])
4232 init_special_inode(inode, inode->i_mode,
4233 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
4235 init_special_inode(inode, inode->i_mode,
4236 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
4237 } else if (ino == EXT4_BOOT_LOADER_INO) {
4238 make_bad_inode(inode);
4241 EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode);
4245 ext4_set_inode_flags(inode);
4246 unlock_new_inode(inode);
4252 return ERR_PTR(ret);
4255 static int ext4_inode_blocks_set(handle_t *handle,
4256 struct ext4_inode *raw_inode,
4257 struct ext4_inode_info *ei)
4259 struct inode *inode = &(ei->vfs_inode);
4260 u64 i_blocks = inode->i_blocks;
4261 struct super_block *sb = inode->i_sb;
4263 if (i_blocks <= ~0U) {
4265 * i_blocks can be represented in a 32 bit variable
4266 * as multiple of 512 bytes
4268 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4269 raw_inode->i_blocks_high = 0;
4270 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4273 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE))
4276 if (i_blocks <= 0xffffffffffffULL) {
4278 * i_blocks can be represented in a 48 bit variable
4279 * as multiple of 512 bytes
4281 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4282 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
4283 ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4285 ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4286 /* i_block is stored in file system block size */
4287 i_blocks = i_blocks >> (inode->i_blkbits - 9);
4288 raw_inode->i_blocks_lo = cpu_to_le32(i_blocks);
4289 raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
4295 * Post the struct inode info into an on-disk inode location in the
4296 * buffer-cache. This gobbles the caller's reference to the
4297 * buffer_head in the inode location struct.
4299 * The caller must have write access to iloc->bh.
4301 static int ext4_do_update_inode(handle_t *handle,
4302 struct inode *inode,
4303 struct ext4_iloc *iloc)
4305 struct ext4_inode *raw_inode = ext4_raw_inode(iloc);
4306 struct ext4_inode_info *ei = EXT4_I(inode);
4307 struct buffer_head *bh = iloc->bh;
4308 int err = 0, rc, block;
4309 int need_datasync = 0;
4313 /* For fields not not tracking in the in-memory inode,
4314 * initialise them to zero for new inodes. */
4315 if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
4316 memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
4318 ext4_get_inode_flags(ei);
4319 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
4320 i_uid = i_uid_read(inode);
4321 i_gid = i_gid_read(inode);
4322 if (!(test_opt(inode->i_sb, NO_UID32))) {
4323 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid));
4324 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid));
4326 * Fix up interoperability with old kernels. Otherwise, old inodes get
4327 * re-used with the upper 16 bits of the uid/gid intact
4330 raw_inode->i_uid_high =
4331 cpu_to_le16(high_16_bits(i_uid));
4332 raw_inode->i_gid_high =
4333 cpu_to_le16(high_16_bits(i_gid));
4335 raw_inode->i_uid_high = 0;
4336 raw_inode->i_gid_high = 0;
4339 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid));
4340 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(i_gid));
4341 raw_inode->i_uid_high = 0;
4342 raw_inode->i_gid_high = 0;
4344 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
4346 EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
4347 EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode);
4348 EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
4349 EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
4351 if (ext4_inode_blocks_set(handle, raw_inode, ei))
4353 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
4354 raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF);
4355 if (likely(!test_opt2(inode->i_sb, HURD_COMPAT)))
4356 raw_inode->i_file_acl_high =
4357 cpu_to_le16(ei->i_file_acl >> 32);
4358 raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
4359 if (ei->i_disksize != ext4_isize(raw_inode)) {
4360 ext4_isize_set(raw_inode, ei->i_disksize);
4363 if (ei->i_disksize > 0x7fffffffULL) {
4364 struct super_block *sb = inode->i_sb;
4365 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
4366 EXT4_FEATURE_RO_COMPAT_LARGE_FILE) ||
4367 EXT4_SB(sb)->s_es->s_rev_level ==
4368 cpu_to_le32(EXT4_GOOD_OLD_REV)) {
4369 /* If this is the first large file
4370 * created, add a flag to the superblock.
4372 err = ext4_journal_get_write_access(handle,
4373 EXT4_SB(sb)->s_sbh);
4376 ext4_update_dynamic_rev(sb);
4377 EXT4_SET_RO_COMPAT_FEATURE(sb,
4378 EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
4379 ext4_handle_sync(handle);
4380 err = ext4_handle_dirty_super(handle, sb);
4383 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
4384 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
4385 if (old_valid_dev(inode->i_rdev)) {
4386 raw_inode->i_block[0] =
4387 cpu_to_le32(old_encode_dev(inode->i_rdev));
4388 raw_inode->i_block[1] = 0;
4390 raw_inode->i_block[0] = 0;
4391 raw_inode->i_block[1] =
4392 cpu_to_le32(new_encode_dev(inode->i_rdev));
4393 raw_inode->i_block[2] = 0;
4395 } else if (!ext4_has_inline_data(inode)) {
4396 for (block = 0; block < EXT4_N_BLOCKS; block++)
4397 raw_inode->i_block[block] = ei->i_data[block];
4400 if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) {
4401 raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
4402 if (ei->i_extra_isize) {
4403 if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
4404 raw_inode->i_version_hi =
4405 cpu_to_le32(inode->i_version >> 32);
4406 raw_inode->i_extra_isize =
4407 cpu_to_le16(ei->i_extra_isize);
4411 ext4_inode_csum_set(inode, raw_inode, ei);
4413 BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
4414 rc = ext4_handle_dirty_metadata(handle, NULL, bh);
4417 ext4_clear_inode_state(inode, EXT4_STATE_NEW);
4419 ext4_update_inode_fsync_trans(handle, inode, need_datasync);
4422 ext4_std_error(inode->i_sb, err);
4427 * ext4_write_inode()
4429 * We are called from a few places:
4431 * - Within generic_file_aio_write() -> generic_write_sync() for O_SYNC files.
4432 * Here, there will be no transaction running. We wait for any running
4433 * transaction to commit.
4435 * - Within flush work (sys_sync(), kupdate and such).
4436 * We wait on commit, if told to.
4438 * - Within iput_final() -> write_inode_now()
4439 * We wait on commit, if told to.
4441 * In all cases it is actually safe for us to return without doing anything,
4442 * because the inode has been copied into a raw inode buffer in
4443 * ext4_mark_inode_dirty(). This is a correctness thing for WB_SYNC_ALL
4446 * Note that we are absolutely dependent upon all inode dirtiers doing the
4447 * right thing: they *must* call mark_inode_dirty() after dirtying info in
4448 * which we are interested.
4450 * It would be a bug for them to not do this. The code:
4452 * mark_inode_dirty(inode)
4454 * inode->i_size = expr;
4456 * is in error because write_inode() could occur while `stuff()' is running,
4457 * and the new i_size will be lost. Plus the inode will no longer be on the
4458 * superblock's dirty inode list.
4460 int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
4464 if (WARN_ON_ONCE(current->flags & PF_MEMALLOC))
4467 if (EXT4_SB(inode->i_sb)->s_journal) {
4468 if (ext4_journal_current_handle()) {
4469 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
4475 * No need to force transaction in WB_SYNC_NONE mode. Also
4476 * ext4_sync_fs() will force the commit after everything is
4479 if (wbc->sync_mode != WB_SYNC_ALL || wbc->for_sync)
4482 err = ext4_force_commit(inode->i_sb);
4484 struct ext4_iloc iloc;
4486 err = __ext4_get_inode_loc(inode, &iloc, 0);
4490 * sync(2) will flush the whole buffer cache. No need to do
4491 * it here separately for each inode.
4493 if (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync)
4494 sync_dirty_buffer(iloc.bh);
4495 if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) {
4496 EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr,
4497 "IO error syncing inode");
4506 * In data=journal mode ext4_journalled_invalidatepage() may fail to invalidate
4507 * buffers that are attached to a page stradding i_size and are undergoing
4508 * commit. In that case we have to wait for commit to finish and try again.
4510 static void ext4_wait_for_tail_page_commit(struct inode *inode)
4514 journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
4515 tid_t commit_tid = 0;
4518 offset = inode->i_size & (PAGE_CACHE_SIZE - 1);
4520 * All buffers in the last page remain valid? Then there's nothing to
4521 * do. We do the check mainly to optimize the common PAGE_CACHE_SIZE ==
4524 if (offset > PAGE_CACHE_SIZE - (1 << inode->i_blkbits))
4527 page = find_lock_page(inode->i_mapping,
4528 inode->i_size >> PAGE_CACHE_SHIFT);
4531 ret = __ext4_journalled_invalidatepage(page, offset,
4532 PAGE_CACHE_SIZE - offset);
4534 page_cache_release(page);
4538 read_lock(&journal->j_state_lock);
4539 if (journal->j_committing_transaction)
4540 commit_tid = journal->j_committing_transaction->t_tid;
4541 read_unlock(&journal->j_state_lock);
4543 jbd2_log_wait_commit(journal, commit_tid);
4550 * Called from notify_change.
4552 * We want to trap VFS attempts to truncate the file as soon as
4553 * possible. In particular, we want to make sure that when the VFS
4554 * shrinks i_size, we put the inode on the orphan list and modify
4555 * i_disksize immediately, so that during the subsequent flushing of
4556 * dirty pages and freeing of disk blocks, we can guarantee that any
4557 * commit will leave the blocks being flushed in an unused state on
4558 * disk. (On recovery, the inode will get truncated and the blocks will
4559 * be freed, so we have a strong guarantee that no future commit will
4560 * leave these blocks visible to the user.)
4562 * Another thing we have to assure is that if we are in ordered mode
4563 * and inode is still attached to the committing transaction, we must
4564 * we start writeout of all the dirty pages which are being truncated.
4565 * This way we are sure that all the data written in the previous
4566 * transaction are already on disk (truncate waits for pages under
4569 * Called with inode->i_mutex down.
4571 int ext4_setattr(struct dentry *dentry, struct iattr *attr)
4573 struct inode *inode = dentry->d_inode;
4576 const unsigned int ia_valid = attr->ia_valid;
4578 error = inode_change_ok(inode, attr);
4582 if (is_quota_modification(inode, attr))
4583 dquot_initialize(inode);
4584 if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, inode->i_uid)) ||
4585 (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, inode->i_gid))) {
4588 /* (user+group)*(old+new) structure, inode write (sb,
4589 * inode block, ? - but truncate inode update has it) */
4590 handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
4591 (EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb) +
4592 EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb)) + 3);
4593 if (IS_ERR(handle)) {
4594 error = PTR_ERR(handle);
4597 error = dquot_transfer(inode, attr);
4599 ext4_journal_stop(handle);
4602 /* Update corresponding info in inode so that everything is in
4603 * one transaction */
4604 if (attr->ia_valid & ATTR_UID)
4605 inode->i_uid = attr->ia_uid;
4606 if (attr->ia_valid & ATTR_GID)
4607 inode->i_gid = attr->ia_gid;
4608 error = ext4_mark_inode_dirty(handle, inode);
4609 ext4_journal_stop(handle);
4612 if (attr->ia_valid & ATTR_SIZE && attr->ia_size != inode->i_size) {
4615 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4616 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4618 if (attr->ia_size > sbi->s_bitmap_maxbytes)
4622 if (IS_I_VERSION(inode) && attr->ia_size != inode->i_size)
4623 inode_inc_iversion(inode);
4625 if (S_ISREG(inode->i_mode) &&
4626 (attr->ia_size < inode->i_size)) {
4627 if (ext4_should_order_data(inode)) {
4628 error = ext4_begin_ordered_truncate(inode,
4633 handle = ext4_journal_start(inode, EXT4_HT_INODE, 3);
4634 if (IS_ERR(handle)) {
4635 error = PTR_ERR(handle);
4638 if (ext4_handle_valid(handle)) {
4639 error = ext4_orphan_add(handle, inode);
4642 down_write(&EXT4_I(inode)->i_data_sem);
4643 EXT4_I(inode)->i_disksize = attr->ia_size;
4644 rc = ext4_mark_inode_dirty(handle, inode);
4648 * We have to update i_size under i_data_sem together
4649 * with i_disksize to avoid races with writeback code
4650 * running ext4_wb_update_i_disksize().
4653 i_size_write(inode, attr->ia_size);
4654 up_write(&EXT4_I(inode)->i_data_sem);
4655 ext4_journal_stop(handle);
4657 ext4_orphan_del(NULL, inode);
4661 i_size_write(inode, attr->ia_size);
4664 * Blocks are going to be removed from the inode. Wait
4665 * for dio in flight. Temporarily disable
4666 * dioread_nolock to prevent livelock.
4669 if (!ext4_should_journal_data(inode)) {
4670 ext4_inode_block_unlocked_dio(inode);
4671 inode_dio_wait(inode);
4672 ext4_inode_resume_unlocked_dio(inode);
4674 ext4_wait_for_tail_page_commit(inode);
4677 * Truncate pagecache after we've waited for commit
4678 * in data=journal mode to make pages freeable.
4680 truncate_pagecache(inode, inode->i_size);
4683 * We want to call ext4_truncate() even if attr->ia_size ==
4684 * inode->i_size for cases like truncation of fallocated space
4686 if (attr->ia_valid & ATTR_SIZE)
4687 ext4_truncate(inode);
4690 setattr_copy(inode, attr);
4691 mark_inode_dirty(inode);
4695 * If the call to ext4_truncate failed to get a transaction handle at
4696 * all, we need to clean up the in-core orphan list manually.
4698 if (orphan && inode->i_nlink)
4699 ext4_orphan_del(NULL, inode);
4701 if (!rc && (ia_valid & ATTR_MODE))
4702 rc = posix_acl_chmod(inode, inode->i_mode);
4705 ext4_std_error(inode->i_sb, error);
4711 int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry,
4714 struct inode *inode;
4715 unsigned long long delalloc_blocks;
4717 inode = dentry->d_inode;
4718 generic_fillattr(inode, stat);
4721 * If there is inline data in the inode, the inode will normally not
4722 * have data blocks allocated (it may have an external xattr block).
4723 * Report at least one sector for such files, so tools like tar, rsync,
4724 * others doen't incorrectly think the file is completely sparse.
4726 if (unlikely(ext4_has_inline_data(inode)))
4727 stat->blocks += (stat->size + 511) >> 9;
4730 * We can't update i_blocks if the block allocation is delayed
4731 * otherwise in the case of system crash before the real block
4732 * allocation is done, we will have i_blocks inconsistent with
4733 * on-disk file blocks.
4734 * We always keep i_blocks updated together with real
4735 * allocation. But to not confuse with user, stat
4736 * will return the blocks that include the delayed allocation
4737 * blocks for this file.
4739 delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb),
4740 EXT4_I(inode)->i_reserved_data_blocks);
4741 stat->blocks += delalloc_blocks << (inode->i_sb->s_blocksize_bits - 9);
4745 static int ext4_index_trans_blocks(struct inode *inode, int lblocks,
4748 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4749 return ext4_ind_trans_blocks(inode, lblocks);
4750 return ext4_ext_index_trans_blocks(inode, pextents);
4754 * Account for index blocks, block groups bitmaps and block group
4755 * descriptor blocks if modify datablocks and index blocks
4756 * worse case, the indexs blocks spread over different block groups
4758 * If datablocks are discontiguous, they are possible to spread over
4759 * different block groups too. If they are contiguous, with flexbg,
4760 * they could still across block group boundary.
4762 * Also account for superblock, inode, quota and xattr blocks
4764 static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,
4767 ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
4773 * How many index blocks need to touch to map @lblocks logical blocks
4774 * to @pextents physical extents?
4776 idxblocks = ext4_index_trans_blocks(inode, lblocks, pextents);
4781 * Now let's see how many group bitmaps and group descriptors need
4784 groups = idxblocks + pextents;
4786 if (groups > ngroups)
4788 if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
4789 gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;
4791 /* bitmaps and block group descriptor blocks */
4792 ret += groups + gdpblocks;
4794 /* Blocks for super block, inode, quota and xattr blocks */
4795 ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);
4801 * Calculate the total number of credits to reserve to fit
4802 * the modification of a single pages into a single transaction,
4803 * which may include multiple chunks of block allocations.
4805 * This could be called via ext4_write_begin()
4807 * We need to consider the worse case, when
4808 * one new block per extent.
4810 int ext4_writepage_trans_blocks(struct inode *inode)
4812 int bpp = ext4_journal_blocks_per_page(inode);
4815 ret = ext4_meta_trans_blocks(inode, bpp, bpp);
4817 /* Account for data blocks for journalled mode */
4818 if (ext4_should_journal_data(inode))
4824 * Calculate the journal credits for a chunk of data modification.
4826 * This is called from DIO, fallocate or whoever calling
4827 * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
4829 * journal buffers for data blocks are not included here, as DIO
4830 * and fallocate do no need to journal data buffers.
4832 int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
4834 return ext4_meta_trans_blocks(inode, nrblocks, 1);
4838 * The caller must have previously called ext4_reserve_inode_write().
4839 * Give this, we know that the caller already has write access to iloc->bh.
4841 int ext4_mark_iloc_dirty(handle_t *handle,
4842 struct inode *inode, struct ext4_iloc *iloc)
4846 if (IS_I_VERSION(inode))
4847 inode_inc_iversion(inode);
4849 /* the do_update_inode consumes one bh->b_count */
4852 /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
4853 err = ext4_do_update_inode(handle, inode, iloc);
4859 * On success, We end up with an outstanding reference count against
4860 * iloc->bh. This _must_ be cleaned up later.
4864 ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
4865 struct ext4_iloc *iloc)
4869 err = ext4_get_inode_loc(inode, iloc);
4871 BUFFER_TRACE(iloc->bh, "get_write_access");
4872 err = ext4_journal_get_write_access(handle, iloc->bh);
4878 ext4_std_error(inode->i_sb, err);
4883 * Expand an inode by new_extra_isize bytes.
4884 * Returns 0 on success or negative error number on failure.
4886 static int ext4_expand_extra_isize(struct inode *inode,
4887 unsigned int new_extra_isize,
4888 struct ext4_iloc iloc,
4891 struct ext4_inode *raw_inode;
4892 struct ext4_xattr_ibody_header *header;
4894 if (EXT4_I(inode)->i_extra_isize >= new_extra_isize)
4897 raw_inode = ext4_raw_inode(&iloc);
4899 header = IHDR(inode, raw_inode);
4901 /* No extended attributes present */
4902 if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
4903 header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
4904 memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
4906 EXT4_I(inode)->i_extra_isize = new_extra_isize;
4910 /* try to expand with EAs present */
4911 return ext4_expand_extra_isize_ea(inode, new_extra_isize,
4916 * What we do here is to mark the in-core inode as clean with respect to inode
4917 * dirtiness (it may still be data-dirty).
4918 * This means that the in-core inode may be reaped by prune_icache
4919 * without having to perform any I/O. This is a very good thing,
4920 * because *any* task may call prune_icache - even ones which
4921 * have a transaction open against a different journal.
4923 * Is this cheating? Not really. Sure, we haven't written the
4924 * inode out, but prune_icache isn't a user-visible syncing function.
4925 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
4926 * we start and wait on commits.
4928 int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
4930 struct ext4_iloc iloc;
4931 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4932 static unsigned int mnt_count;
4936 trace_ext4_mark_inode_dirty(inode, _RET_IP_);
4937 err = ext4_reserve_inode_write(handle, inode, &iloc);
4938 if (ext4_handle_valid(handle) &&
4939 EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize &&
4940 !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {
4942 * We need extra buffer credits since we may write into EA block
4943 * with this same handle. If journal_extend fails, then it will
4944 * only result in a minor loss of functionality for that inode.
4945 * If this is felt to be critical, then e2fsck should be run to
4946 * force a large enough s_min_extra_isize.
4948 if ((jbd2_journal_extend(handle,
4949 EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) {
4950 ret = ext4_expand_extra_isize(inode,
4951 sbi->s_want_extra_isize,
4954 ext4_set_inode_state(inode,
4955 EXT4_STATE_NO_EXPAND);
4957 le16_to_cpu(sbi->s_es->s_mnt_count)) {
4958 ext4_warning(inode->i_sb,
4959 "Unable to expand inode %lu. Delete"
4960 " some EAs or run e2fsck.",
4963 le16_to_cpu(sbi->s_es->s_mnt_count);
4969 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
4974 * ext4_dirty_inode() is called from __mark_inode_dirty()
4976 * We're really interested in the case where a file is being extended.
4977 * i_size has been changed by generic_commit_write() and we thus need
4978 * to include the updated inode in the current transaction.
4980 * Also, dquot_alloc_block() will always dirty the inode when blocks
4981 * are allocated to the file.
4983 * If the inode is marked synchronous, we don't honour that here - doing
4984 * so would cause a commit on atime updates, which we don't bother doing.
4985 * We handle synchronous inodes at the highest possible level.
4987 void ext4_dirty_inode(struct inode *inode, int flags)
4991 handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
4995 ext4_mark_inode_dirty(handle, inode);
4997 ext4_journal_stop(handle);
5004 * Bind an inode's backing buffer_head into this transaction, to prevent
5005 * it from being flushed to disk early. Unlike
5006 * ext4_reserve_inode_write, this leaves behind no bh reference and
5007 * returns no iloc structure, so the caller needs to repeat the iloc
5008 * lookup to mark the inode dirty later.
5010 static int ext4_pin_inode(handle_t *handle, struct inode *inode)
5012 struct ext4_iloc iloc;
5016 err = ext4_get_inode_loc(inode, &iloc);
5018 BUFFER_TRACE(iloc.bh, "get_write_access");
5019 err = jbd2_journal_get_write_access(handle, iloc.bh);
5021 err = ext4_handle_dirty_metadata(handle,
5027 ext4_std_error(inode->i_sb, err);
5032 int ext4_change_inode_journal_flag(struct inode *inode, int val)
5039 * We have to be very careful here: changing a data block's
5040 * journaling status dynamically is dangerous. If we write a
5041 * data block to the journal, change the status and then delete
5042 * that block, we risk forgetting to revoke the old log record
5043 * from the journal and so a subsequent replay can corrupt data.
5044 * So, first we make sure that the journal is empty and that
5045 * nobody is changing anything.
5048 journal = EXT4_JOURNAL(inode);
5051 if (is_journal_aborted(journal))
5053 /* We have to allocate physical blocks for delalloc blocks
5054 * before flushing journal. otherwise delalloc blocks can not
5055 * be allocated any more. even more truncate on delalloc blocks
5056 * could trigger BUG by flushing delalloc blocks in journal.
5057 * There is no delalloc block in non-journal data mode.
5059 if (val && test_opt(inode->i_sb, DELALLOC)) {
5060 err = ext4_alloc_da_blocks(inode);
5065 /* Wait for all existing dio workers */
5066 ext4_inode_block_unlocked_dio(inode);
5067 inode_dio_wait(inode);
5069 jbd2_journal_lock_updates(journal);
5072 * OK, there are no updates running now, and all cached data is
5073 * synced to disk. We are now in a completely consistent state
5074 * which doesn't have anything in the journal, and we know that
5075 * no filesystem updates are running, so it is safe to modify
5076 * the inode's in-core data-journaling state flag now.
5080 ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
5082 jbd2_journal_flush(journal);
5083 ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
5085 ext4_set_aops(inode);
5087 jbd2_journal_unlock_updates(journal);
5088 ext4_inode_resume_unlocked_dio(inode);
5090 /* Finally we can mark the inode as dirty. */
5092 handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
5094 return PTR_ERR(handle);
5096 err = ext4_mark_inode_dirty(handle, inode);
5097 ext4_handle_sync(handle);
5098 ext4_journal_stop(handle);
5099 ext4_std_error(inode->i_sb, err);
5104 static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
5106 return !buffer_mapped(bh);
5109 int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
5111 struct page *page = vmf->page;
5115 struct file *file = vma->vm_file;
5116 struct inode *inode = file_inode(file);
5117 struct address_space *mapping = inode->i_mapping;
5119 get_block_t *get_block;
5122 sb_start_pagefault(inode->i_sb);
5123 file_update_time(vma->vm_file);
5124 /* Delalloc case is easy... */
5125 if (test_opt(inode->i_sb, DELALLOC) &&
5126 !ext4_should_journal_data(inode) &&
5127 !ext4_nonda_switch(inode->i_sb)) {
5129 ret = __block_page_mkwrite(vma, vmf,
5130 ext4_da_get_block_prep);
5131 } while (ret == -ENOSPC &&
5132 ext4_should_retry_alloc(inode->i_sb, &retries));
5137 size = i_size_read(inode);
5138 /* Page got truncated from under us? */
5139 if (page->mapping != mapping || page_offset(page) > size) {
5141 ret = VM_FAULT_NOPAGE;
5145 if (page->index == size >> PAGE_CACHE_SHIFT)
5146 len = size & ~PAGE_CACHE_MASK;
5148 len = PAGE_CACHE_SIZE;
5150 * Return if we have all the buffers mapped. This avoids the need to do
5151 * journal_start/journal_stop which can block and take a long time
5153 if (page_has_buffers(page)) {
5154 if (!ext4_walk_page_buffers(NULL, page_buffers(page),
5156 ext4_bh_unmapped)) {
5157 /* Wait so that we don't change page under IO */
5158 wait_for_stable_page(page);
5159 ret = VM_FAULT_LOCKED;
5164 /* OK, we need to fill the hole... */
5165 if (ext4_should_dioread_nolock(inode))
5166 get_block = ext4_get_block_write;
5168 get_block = ext4_get_block;
5170 handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
5171 ext4_writepage_trans_blocks(inode));
5172 if (IS_ERR(handle)) {
5173 ret = VM_FAULT_SIGBUS;
5176 ret = __block_page_mkwrite(vma, vmf, get_block);
5177 if (!ret && ext4_should_journal_data(inode)) {
5178 if (ext4_walk_page_buffers(handle, page_buffers(page), 0,
5179 PAGE_CACHE_SIZE, NULL, do_journal_get_write_access)) {
5181 ret = VM_FAULT_SIGBUS;
5182 ext4_journal_stop(handle);
5185 ext4_set_inode_state(inode, EXT4_STATE_JDATA);
5187 ext4_journal_stop(handle);
5188 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
5191 ret = block_page_mkwrite_return(ret);
5193 sb_end_pagefault(inode->i_sb);