2 * linux/fs/ext3/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 * Goal-directed block allocation by Stephen Tweedie
16 * (sct@redhat.com), 1993, 1998
17 * Big-endian to little-endian byte-swapping/bitmaps by
18 * David S. Miller (davem@caip.rutgers.edu), 1995
19 * 64-bit file support on 64-bit platforms by Jakub Jelinek
20 * (jj@sunsite.ms.mff.cuni.cz)
22 * Assorted race fixes, rewrite of ext3_get_block() by Al Viro, 2000
25 #include <linux/module.h>
27 #include <linux/time.h>
28 #include <linux/ext3_jbd.h>
29 #include <linux/jbd.h>
30 #include <linux/smp_lock.h>
31 #include <linux/highuid.h>
32 #include <linux/pagemap.h>
33 #include <linux/quotaops.h>
34 #include <linux/string.h>
35 #include <linux/buffer_head.h>
36 #include <linux/writeback.h>
37 #include <linux/mpage.h>
38 #include <linux/uio.h>
39 #include <linux/vserver/xid.h>
44 * Test whether an inode is a fast symlink.
46 static inline int ext3_inode_is_fast_symlink(struct inode *inode)
48 int ea_blocks = EXT3_I(inode)->i_file_acl ?
49 (inode->i_sb->s_blocksize >> 9) : 0;
51 return (S_ISLNK(inode->i_mode) &&
52 inode->i_blocks - ea_blocks == 0);
55 /* The ext3 forget function must perform a revoke if we are freeing data
56 * which has been journaled. Metadata (eg. indirect blocks) must be
57 * revoked in all cases.
59 * "bh" may be NULL: a metadata block may have been freed from memory
60 * but there may still be a record of it in the journal, and that record
61 * still needs to be revoked.
64 int ext3_forget(handle_t *handle, int is_metadata,
65 struct inode *inode, struct buffer_head *bh,
70 BUFFER_TRACE(bh, "enter");
72 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
74 bh, is_metadata, inode->i_mode,
75 test_opt(inode->i_sb, DATA_FLAGS));
77 /* Never use the revoke function if we are doing full data
78 * journaling: there is no need to, and a V1 superblock won't
79 * support it. Otherwise, only skip the revoke on un-journaled
82 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ||
83 (!is_metadata && !ext3_should_journal_data(inode))) {
85 BUFFER_TRACE(bh, "call journal_forget");
86 ext3_journal_forget(handle, bh);
92 * data!=journal && (is_metadata || should_journal_data(inode))
94 BUFFER_TRACE(bh, "call ext3_journal_revoke");
95 err = ext3_journal_revoke(handle, blocknr, bh);
97 ext3_abort(inode->i_sb, __FUNCTION__,
98 "error %d when attempting revoke", err);
99 BUFFER_TRACE(bh, "exit");
104 * Work out how many blocks we need to progress with the next chunk of a
105 * truncate transaction.
108 static unsigned long blocks_for_truncate(struct inode *inode)
110 unsigned long needed;
112 needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
114 /* Give ourselves just enough room to cope with inodes in which
115 * i_blocks is corrupt: we've seen disk corruptions in the past
116 * which resulted in random data in an inode which looked enough
117 * like a regular file for ext3 to try to delete it. Things
118 * will go a bit crazy if that happens, but at least we should
119 * try not to panic the whole kernel. */
123 /* But we need to bound the transaction so we don't overflow the
125 if (needed > EXT3_MAX_TRANS_DATA)
126 needed = EXT3_MAX_TRANS_DATA;
128 return EXT3_DATA_TRANS_BLOCKS + needed;
132 * Truncate transactions can be complex and absolutely huge. So we need to
133 * be able to restart the transaction at a conventient checkpoint to make
134 * sure we don't overflow the journal.
136 * start_transaction gets us a new handle for a truncate transaction,
137 * and extend_transaction tries to extend the existing one a bit. If
138 * extend fails, we need to propagate the failure up and restart the
139 * transaction in the top-level truncate loop. --sct
142 static handle_t *start_transaction(struct inode *inode)
146 result = ext3_journal_start(inode, blocks_for_truncate(inode));
150 ext3_std_error(inode->i_sb, PTR_ERR(result));
155 * Try to extend this transaction for the purposes of truncation.
157 * Returns 0 if we managed to create more room. If we can't create more
158 * room, and the transaction must be restarted we return 1.
160 static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
162 if (handle->h_buffer_credits > EXT3_RESERVE_TRANS_BLOCKS)
164 if (!ext3_journal_extend(handle, blocks_for_truncate(inode)))
170 * Restart the transaction associated with *handle. This does a commit,
171 * so before we call here everything must be consistently dirtied against
174 static int ext3_journal_test_restart(handle_t *handle, struct inode *inode)
176 jbd_debug(2, "restarting handle %p\n", handle);
177 return ext3_journal_restart(handle, blocks_for_truncate(inode));
181 * Called at each iput()
183 * The inode may be "bad" if ext3_read_inode() saw an error from
184 * ext3_get_inode(), so we need to check that to avoid freeing random disk
187 void ext3_put_inode(struct inode *inode)
189 if (!is_bad_inode(inode))
190 ext3_discard_prealloc(inode);
193 static void ext3_truncate_nocheck (struct inode *inode);
196 * Called at the last iput() if i_nlink is zero.
198 void ext3_delete_inode (struct inode * inode)
202 if (is_bad_inode(inode))
205 handle = start_transaction(inode);
206 if (IS_ERR(handle)) {
207 /* If we're going to skip the normal cleanup, we still
208 * need to make sure that the in-core orphan linked list
209 * is properly cleaned up. */
210 ext3_orphan_del(NULL, inode);
212 ext3_std_error(inode->i_sb, PTR_ERR(handle));
220 ext3_truncate_nocheck(inode);
222 * Kill off the orphan record which ext3_truncate created.
223 * AKPM: I think this can be inside the above `if'.
224 * Note that ext3_orphan_del() has to be able to cope with the
225 * deletion of a non-existent orphan - this is because we don't
226 * know if ext3_truncate() actually created an orphan record.
227 * (Well, we could do this if we need to, but heck - it works)
229 ext3_orphan_del(handle, inode);
230 EXT3_I(inode)->i_dtime = get_seconds();
233 * One subtle ordering requirement: if anything has gone wrong
234 * (transaction abort, IO errors, whatever), then we can still
235 * do these next steps (the fs will already have been marked as
236 * having errors), but we can't free the inode if the mark_dirty
239 if (ext3_mark_inode_dirty(handle, inode))
240 /* If that failed, just do the required in-core inode clear. */
243 ext3_free_inode(handle, inode);
244 ext3_journal_stop(handle);
247 clear_inode(inode); /* We must guarantee clearing of inode... */
250 void ext3_discard_prealloc (struct inode * inode)
252 #ifdef EXT3_PREALLOCATE
253 struct ext3_inode_info *ei = EXT3_I(inode);
254 /* Writer: ->i_prealloc* */
255 if (ei->i_prealloc_count) {
256 unsigned short total = ei->i_prealloc_count;
257 unsigned long block = ei->i_prealloc_block;
258 ei->i_prealloc_count = 0;
259 ei->i_prealloc_block = 0;
261 ext3_free_blocks (inode, block, total);
266 static int ext3_alloc_block (handle_t *handle,
267 struct inode * inode, unsigned long goal, int *err)
269 unsigned long result;
271 #ifdef EXT3_PREALLOCATE
273 static unsigned long alloc_hits, alloc_attempts;
275 struct ext3_inode_info *ei = EXT3_I(inode);
276 /* Writer: ->i_prealloc* */
277 if (ei->i_prealloc_count &&
278 (goal == ei->i_prealloc_block ||
279 goal + 1 == ei->i_prealloc_block))
281 result = ei->i_prealloc_block++;
282 ei->i_prealloc_count--;
284 ext3_debug ("preallocation hit (%lu/%lu).\n",
285 ++alloc_hits, ++alloc_attempts);
287 ext3_discard_prealloc (inode);
288 ext3_debug ("preallocation miss (%lu/%lu).\n",
289 alloc_hits, ++alloc_attempts);
290 if (S_ISREG(inode->i_mode))
291 result = ext3_new_block (inode, goal,
292 &ei->i_prealloc_count,
293 &ei->i_prealloc_block, err);
295 result = ext3_new_block (inode, goal, 0, 0, err);
297 * AKPM: this is somewhat sticky. I'm not surprised it was
298 * disabled in 2.2's ext3. Need to integrate b_committed_data
299 * guarding with preallocation, if indeed preallocation is
304 result = ext3_new_block (handle, inode, goal, 0, 0, err);
313 struct buffer_head *bh;
316 static inline void add_chain(Indirect *p, struct buffer_head *bh, u32 *v)
318 p->key = *(p->p = v);
322 static inline int verify_chain(Indirect *from, Indirect *to)
324 while (from <= to && from->key == *from->p)
330 * ext3_block_to_path - parse the block number into array of offsets
331 * @inode: inode in question (we are only interested in its superblock)
332 * @i_block: block number to be parsed
333 * @offsets: array to store the offsets in
334 * @boundary: set this non-zero if the referred-to block is likely to be
335 * followed (on disk) by an indirect block.
337 * To store the locations of file's data ext3 uses a data structure common
338 * for UNIX filesystems - tree of pointers anchored in the inode, with
339 * data blocks at leaves and indirect blocks in intermediate nodes.
340 * This function translates the block number into path in that tree -
341 * return value is the path length and @offsets[n] is the offset of
342 * pointer to (n+1)th node in the nth one. If @block is out of range
343 * (negative or too large) warning is printed and zero returned.
345 * Note: function doesn't find node addresses, so no IO is needed. All
346 * we need to know is the capacity of indirect blocks (taken from the
351 * Portability note: the last comparison (check that we fit into triple
352 * indirect block) is spelled differently, because otherwise on an
353 * architecture with 32-bit longs and 8Kb pages we might get into trouble
354 * if our filesystem had 8Kb blocks. We might use long long, but that would
355 * kill us on x86. Oh, well, at least the sign propagation does not matter -
356 * i_block would have to be negative in the very beginning, so we would not
360 static int ext3_block_to_path(struct inode *inode,
361 long i_block, int offsets[4], int *boundary)
363 int ptrs = EXT3_ADDR_PER_BLOCK(inode->i_sb);
364 int ptrs_bits = EXT3_ADDR_PER_BLOCK_BITS(inode->i_sb);
365 const long direct_blocks = EXT3_NDIR_BLOCKS,
366 indirect_blocks = ptrs,
367 double_blocks = (1 << (ptrs_bits * 2));
372 ext3_warning (inode->i_sb, "ext3_block_to_path", "block < 0");
373 } else if (i_block < direct_blocks) {
374 offsets[n++] = i_block;
375 final = direct_blocks;
376 } else if ( (i_block -= direct_blocks) < indirect_blocks) {
377 offsets[n++] = EXT3_IND_BLOCK;
378 offsets[n++] = i_block;
380 } else if ((i_block -= indirect_blocks) < double_blocks) {
381 offsets[n++] = EXT3_DIND_BLOCK;
382 offsets[n++] = i_block >> ptrs_bits;
383 offsets[n++] = i_block & (ptrs - 1);
385 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
386 offsets[n++] = EXT3_TIND_BLOCK;
387 offsets[n++] = i_block >> (ptrs_bits * 2);
388 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
389 offsets[n++] = i_block & (ptrs - 1);
392 ext3_warning (inode->i_sb, "ext3_block_to_path", "block > big");
395 *boundary = (i_block & (ptrs - 1)) == (final - 1);
400 * ext3_get_branch - read the chain of indirect blocks leading to data
401 * @inode: inode in question
402 * @depth: depth of the chain (1 - direct pointer, etc.)
403 * @offsets: offsets of pointers in inode/indirect blocks
404 * @chain: place to store the result
405 * @err: here we store the error value
407 * Function fills the array of triples <key, p, bh> and returns %NULL
408 * if everything went OK or the pointer to the last filled triple
409 * (incomplete one) otherwise. Upon the return chain[i].key contains
410 * the number of (i+1)-th block in the chain (as it is stored in memory,
411 * i.e. little-endian 32-bit), chain[i].p contains the address of that
412 * number (it points into struct inode for i==0 and into the bh->b_data
413 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
414 * block for i>0 and NULL for i==0. In other words, it holds the block
415 * numbers of the chain, addresses they were taken from (and where we can
416 * verify that chain did not change) and buffer_heads hosting these
419 * Function stops when it stumbles upon zero pointer (absent block)
420 * (pointer to last triple returned, *@err == 0)
421 * or when it gets an IO error reading an indirect block
422 * (ditto, *@err == -EIO)
423 * or when it notices that chain had been changed while it was reading
424 * (ditto, *@err == -EAGAIN)
425 * or when it reads all @depth-1 indirect blocks successfully and finds
426 * the whole chain, all way to the data (returns %NULL, *err == 0).
428 static Indirect *ext3_get_branch(struct inode *inode, int depth, int *offsets,
429 Indirect chain[4], int *err)
431 struct super_block *sb = inode->i_sb;
433 struct buffer_head *bh;
436 /* i_data is not going away, no lock needed */
437 add_chain (chain, NULL, EXT3_I(inode)->i_data + *offsets);
441 bh = sb_bread(sb, le32_to_cpu(p->key));
444 /* Reader: pointers */
445 if (!verify_chain(chain, p))
447 add_chain(++p, bh, (u32*)bh->b_data + *++offsets);
465 * ext3_find_near - find a place for allocation with sufficient locality
467 * @ind: descriptor of indirect block.
469 * This function returns the prefered place for block allocation.
470 * It is used when heuristic for sequential allocation fails.
472 * + if there is a block to the left of our position - allocate near it.
473 * + if pointer will live in indirect block - allocate near that block.
474 * + if pointer will live in inode - allocate in the same
477 * In the latter case we colour the starting block by the callers PID to
478 * prevent it from clashing with concurrent allocations for a different inode
479 * in the same block group. The PID is used here so that functionally related
480 * files will be close-by on-disk.
482 * Caller must make sure that @ind is valid and will stay that way.
485 static unsigned long ext3_find_near(struct inode *inode, Indirect *ind)
487 struct ext3_inode_info *ei = EXT3_I(inode);
488 u32 *start = ind->bh ? (u32*) ind->bh->b_data : ei->i_data;
490 unsigned long bg_start;
491 unsigned long colour;
493 /* Try to find previous block */
494 for (p = ind->p - 1; p >= start; p--)
496 return le32_to_cpu(*p);
498 /* No such thing, so let's try location of indirect block */
500 return ind->bh->b_blocknr;
503 * It is going to be refered from inode itself? OK, just put it into
504 * the same cylinder group then.
506 bg_start = (ei->i_block_group * EXT3_BLOCKS_PER_GROUP(inode->i_sb)) +
507 le32_to_cpu(EXT3_SB(inode->i_sb)->s_es->s_first_data_block);
508 colour = (current->pid % 16) *
509 (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
510 return bg_start + colour;
514 * ext3_find_goal - find a prefered place for allocation.
516 * @block: block we want
517 * @chain: chain of indirect blocks
518 * @partial: pointer to the last triple within a chain
519 * @goal: place to store the result.
521 * Normally this function find the prefered place for block allocation,
522 * stores it in *@goal and returns zero. If the branch had been changed
523 * under us we return -EAGAIN.
526 static int ext3_find_goal(struct inode *inode, long block, Indirect chain[4],
527 Indirect *partial, unsigned long *goal)
529 struct ext3_inode_info *ei = EXT3_I(inode);
530 /* Writer: ->i_next_alloc* */
531 if (block == ei->i_next_alloc_block + 1) {
532 ei->i_next_alloc_block++;
533 ei->i_next_alloc_goal++;
536 /* Reader: pointers, ->i_next_alloc* */
537 if (verify_chain(chain, partial)) {
539 * try the heuristic for sequential allocation,
540 * failing that at least try to get decent locality.
542 if (block == ei->i_next_alloc_block)
543 *goal = ei->i_next_alloc_goal;
545 *goal = ext3_find_near(inode, partial);
553 * ext3_alloc_branch - allocate and set up a chain of blocks.
555 * @num: depth of the chain (number of blocks to allocate)
556 * @offsets: offsets (in the blocks) to store the pointers to next.
557 * @branch: place to store the chain in.
559 * This function allocates @num blocks, zeroes out all but the last one,
560 * links them into chain and (if we are synchronous) writes them to disk.
561 * In other words, it prepares a branch that can be spliced onto the
562 * inode. It stores the information about that chain in the branch[], in
563 * the same format as ext3_get_branch() would do. We are calling it after
564 * we had read the existing part of chain and partial points to the last
565 * triple of that (one with zero ->key). Upon the exit we have the same
566 * picture as after the successful ext3_get_block(), excpet that in one
567 * place chain is disconnected - *branch->p is still zero (we did not
568 * set the last link), but branch->key contains the number that should
569 * be placed into *branch->p to fill that gap.
571 * If allocation fails we free all blocks we've allocated (and forget
572 * their buffer_heads) and return the error value the from failed
573 * ext3_alloc_block() (normally -ENOSPC). Otherwise we set the chain
574 * as described above and return 0.
577 static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
583 int blocksize = inode->i_sb->s_blocksize;
587 int parent = ext3_alloc_block(handle, inode, goal, &err);
589 branch[0].key = cpu_to_le32(parent);
591 for (n = 1; n < num; n++) {
592 struct buffer_head *bh;
593 /* Allocate the next block */
594 int nr = ext3_alloc_block(handle, inode, parent, &err);
597 branch[n].key = cpu_to_le32(nr);
601 * Get buffer_head for parent block, zero it out
602 * and set the pointer to new one, then send
605 bh = sb_getblk(inode->i_sb, parent);
608 BUFFER_TRACE(bh, "call get_create_access");
609 err = ext3_journal_get_create_access(handle, bh);
616 memset(bh->b_data, 0, blocksize);
617 branch[n].p = (u32*) bh->b_data + offsets[n];
618 *branch[n].p = branch[n].key;
619 BUFFER_TRACE(bh, "marking uptodate");
620 set_buffer_uptodate(bh);
623 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
624 err = ext3_journal_dirty_metadata(handle, bh);
634 /* Allocation failed, free what we already allocated */
635 for (i = 1; i < keys; i++) {
636 BUFFER_TRACE(branch[i].bh, "call journal_forget");
637 ext3_journal_forget(handle, branch[i].bh);
639 for (i = 0; i < keys; i++)
640 ext3_free_blocks(handle, inode, le32_to_cpu(branch[i].key), 1);
645 * ext3_splice_branch - splice the allocated branch onto inode.
647 * @block: (logical) number of block we are adding
648 * @chain: chain of indirect blocks (with a missing link - see
650 * @where: location of missing link
651 * @num: number of blocks we are adding
653 * This function verifies that chain (up to the missing link) had not
654 * changed, fills the missing link and does all housekeeping needed in
655 * inode (->i_blocks, etc.). In case of success we end up with the full
656 * chain to new block and return 0. Otherwise (== chain had been changed)
657 * we free the new blocks (forgetting their buffer_heads, indeed) and
661 static int ext3_splice_branch(handle_t *handle, struct inode *inode, long block,
662 Indirect chain[4], Indirect *where, int num)
666 struct ext3_inode_info *ei = EXT3_I(inode);
669 * If we're splicing into a [td]indirect block (as opposed to the
670 * inode) then we need to get write access to the [td]indirect block
674 BUFFER_TRACE(where->bh, "get_write_access");
675 err = ext3_journal_get_write_access(handle, where->bh);
679 /* Verify that place we are splicing to is still there and vacant */
681 /* Writer: pointers, ->i_next_alloc* */
682 if (!verify_chain(chain, where-1) || *where->p)
688 *where->p = where->key;
689 ei->i_next_alloc_block = block;
690 ei->i_next_alloc_goal = le32_to_cpu(where[num-1].key);
693 /* We are done with atomic stuff, now do the rest of housekeeping */
695 inode->i_ctime = CURRENT_TIME;
696 ext3_mark_inode_dirty(handle, inode);
698 /* had we spliced it onto indirect block? */
701 * akpm: If we spliced it onto an indirect block, we haven't
702 * altered the inode. Note however that if it is being spliced
703 * onto an indirect block at the very end of the file (the
704 * file is growing) then we *will* alter the inode to reflect
705 * the new i_size. But that is not done here - it is done in
706 * generic_commit_write->__mark_inode_dirty->ext3_dirty_inode.
708 jbd_debug(5, "splicing indirect only\n");
709 BUFFER_TRACE(where->bh, "call ext3_journal_dirty_metadata");
710 err = ext3_journal_dirty_metadata(handle, where->bh);
715 * OK, we spliced it into the inode itself on a direct block.
716 * Inode was dirtied above.
718 jbd_debug(5, "splicing direct\n");
724 * AKPM: if where[i].bh isn't part of the current updating
725 * transaction then we explode nastily. Test this code path.
727 jbd_debug(1, "the chain changed: try again\n");
731 for (i = 1; i < num; i++) {
732 BUFFER_TRACE(where[i].bh, "call journal_forget");
733 ext3_journal_forget(handle, where[i].bh);
735 /* For the normal collision cleanup case, we free up the blocks.
736 * On genuine filesystem errors we don't even think about doing
739 for (i = 0; i < num; i++)
740 ext3_free_blocks(handle, inode,
741 le32_to_cpu(where[i].key), 1);
746 * Allocation strategy is simple: if we have to allocate something, we will
747 * have to go the whole way to leaf. So let's do it before attaching anything
748 * to tree, set linkage between the newborn blocks, write them if sync is
749 * required, recheck the path, free and repeat if check fails, otherwise
750 * set the last missing link (that will protect us from any truncate-generated
751 * removals - all blocks on the path are immune now) and possibly force the
752 * write on the parent block.
753 * That has a nice additional property: no special recovery from the failed
754 * allocations is needed - we simply release blocks and do not touch anything
755 * reachable from inode.
757 * akpm: `handle' can be NULL if create == 0.
759 * The BKL may not be held on entry here. Be sure to take it early.
763 ext3_get_block_handle(handle_t *handle, struct inode *inode, sector_t iblock,
764 struct buffer_head *bh_result, int create, int extend_disksize)
773 int depth = ext3_block_to_path(inode, iblock, offsets, &boundary);
774 struct ext3_inode_info *ei = EXT3_I(inode);
776 J_ASSERT(handle != NULL || create == 0);
782 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
784 /* Simplest case - block found, no allocation needed */
786 clear_buffer_new(bh_result);
788 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
790 set_buffer_boundary(bh_result);
791 /* Clean up and exit */
792 partial = chain+depth-1; /* the whole chain */
796 /* Next simple case - plain lookup or failed read of indirect block */
797 if (!create || err == -EIO) {
799 while (partial > chain) {
800 BUFFER_TRACE(partial->bh, "call brelse");
804 BUFFER_TRACE(bh_result, "returned");
810 * Indirect block might be removed by truncate while we were
811 * reading it. Handling of that case (forget what we've got and
812 * reread) is taken out of the main path.
817 down(&ei->truncate_sem);
818 if (ext3_find_goal(inode, iblock, chain, partial, &goal) < 0) {
819 up(&ei->truncate_sem);
823 left = (chain + depth) - partial;
826 * Block out ext3_truncate while we alter the tree
828 err = ext3_alloc_branch(handle, inode, left, goal,
829 offsets+(partial-chain), partial);
831 /* The ext3_splice_branch call will free and forget any buffers
832 * on the new chain if there is a failure, but that risks using
833 * up transaction credits, especially for bitmaps where the
834 * credits cannot be returned. Can we handle this somehow? We
835 * may need to return -EAGAIN upwards in the worst case. --sct */
837 err = ext3_splice_branch(handle, inode, iblock, chain,
839 /* i_disksize growing is protected by truncate_sem
840 * don't forget to protect it if you're about to implement
841 * concurrent ext3_get_block() -bzzz */
842 if (!err && extend_disksize && inode->i_size > ei->i_disksize)
843 ei->i_disksize = inode->i_size;
844 up(&ei->truncate_sem);
850 set_buffer_new(bh_result);
854 while (partial > chain) {
855 jbd_debug(1, "buffer chain changed, retrying\n");
856 BUFFER_TRACE(partial->bh, "brelsing");
863 static int ext3_get_block(struct inode *inode, sector_t iblock,
864 struct buffer_head *bh_result, int create)
866 handle_t *handle = 0;
870 handle = ext3_journal_current_handle();
871 J_ASSERT(handle != 0);
873 ret = ext3_get_block_handle(handle, inode, iblock,
874 bh_result, create, 1);
878 #define DIO_CREDITS (EXT3_RESERVE_TRANS_BLOCKS + 32)
881 ext3_direct_io_get_blocks(struct inode *inode, sector_t iblock,
882 unsigned long max_blocks, struct buffer_head *bh_result,
885 handle_t *handle = journal_current_handle();
888 if (handle && handle->h_buffer_credits <= EXT3_RESERVE_TRANS_BLOCKS) {
890 * Getting low on buffer credits...
892 if (!ext3_journal_extend(handle, DIO_CREDITS)) {
894 * Couldn't extend the transaction. Start a new one
896 ret = ext3_journal_restart(handle, DIO_CREDITS);
900 ret = ext3_get_block_handle(handle, inode, iblock,
901 bh_result, create, 0);
903 bh_result->b_size = (1 << inode->i_blkbits);
909 * `handle' can be NULL if create is zero
911 struct buffer_head *ext3_getblk(handle_t *handle, struct inode * inode,
912 long block, int create, int * errp)
914 struct buffer_head dummy;
917 J_ASSERT(handle != NULL || create == 0);
920 dummy.b_blocknr = -1000;
921 buffer_trace_init(&dummy.b_history);
922 *errp = ext3_get_block_handle(handle, inode, block, &dummy, create, 1);
923 if (!*errp && buffer_mapped(&dummy)) {
924 struct buffer_head *bh;
925 bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
926 if (buffer_new(&dummy)) {
927 J_ASSERT(create != 0);
928 J_ASSERT(handle != 0);
930 /* Now that we do not always journal data, we
931 should keep in mind whether this should
932 always journal the new buffer as metadata.
933 For now, regular file writes use
934 ext3_get_block instead, so it's not a
937 BUFFER_TRACE(bh, "call get_create_access");
938 fatal = ext3_journal_get_create_access(handle, bh);
939 if (!fatal && !buffer_uptodate(bh)) {
940 memset(bh->b_data, 0, inode->i_sb->s_blocksize);
941 set_buffer_uptodate(bh);
944 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
945 err = ext3_journal_dirty_metadata(handle, bh);
949 BUFFER_TRACE(bh, "not a new buffer");
961 struct buffer_head *ext3_bread(handle_t *handle, struct inode * inode,
962 int block, int create, int *err)
964 struct buffer_head * bh;
967 prev_blocks = inode->i_blocks;
969 bh = ext3_getblk (handle, inode, block, create, err);
972 #ifdef EXT3_PREALLOCATE
974 * If the inode has grown, and this is a directory, then use a few
975 * more of the preallocated blocks to keep directory fragmentation
976 * down. The preallocated blocks are guaranteed to be contiguous.
979 S_ISDIR(inode->i_mode) &&
980 inode->i_blocks > prev_blocks &&
981 EXT3_HAS_COMPAT_FEATURE(inode->i_sb,
982 EXT3_FEATURE_COMPAT_DIR_PREALLOC)) {
984 struct buffer_head *tmp_bh;
987 EXT3_I(inode)->i_prealloc_count &&
988 i < EXT3_SB(inode->i_sb)->s_es->s_prealloc_dir_blocks;
991 * ext3_getblk will zero out the contents of the
994 tmp_bh = ext3_getblk(handle, inode,
995 block+i, create, err);
1004 if (buffer_uptodate(bh))
1006 ll_rw_block (READ, 1, &bh);
1007 wait_on_buffer (bh);
1008 if (buffer_uptodate(bh))
1015 static int walk_page_buffers( handle_t *handle,
1016 struct buffer_head *head,
1020 int (*fn)( handle_t *handle,
1021 struct buffer_head *bh))
1023 struct buffer_head *bh;
1024 unsigned block_start, block_end;
1025 unsigned blocksize = head->b_size;
1027 struct buffer_head *next;
1029 for ( bh = head, block_start = 0;
1030 ret == 0 && (bh != head || !block_start);
1031 block_start = block_end, bh = next)
1033 next = bh->b_this_page;
1034 block_end = block_start + blocksize;
1035 if (block_end <= from || block_start >= to) {
1036 if (partial && !buffer_uptodate(bh))
1040 err = (*fn)(handle, bh);
1048 * To preserve ordering, it is essential that the hole instantiation and
1049 * the data write be encapsulated in a single transaction. We cannot
1050 * close off a transaction and start a new one between the ext3_get_block()
1051 * and the commit_write(). So doing the journal_start at the start of
1052 * prepare_write() is the right place.
1054 * Also, this function can nest inside ext3_writepage() ->
1055 * block_write_full_page(). In that case, we *know* that ext3_writepage()
1056 * has generated enough buffer credits to do the whole page. So we won't
1057 * block on the journal in that case, which is good, because the caller may
1060 * By accident, ext3 can be reentered when a transaction is open via
1061 * quota file writes. If we were to commit the transaction while thus
1062 * reentered, there can be a deadlock - we would be holding a quota
1063 * lock, and the commit would never complete if another thread had a
1064 * transaction open and was blocking on the quota lock - a ranking
1067 * So what we do is to rely on the fact that journal_stop/journal_start
1068 * will _not_ run commit under these circumstances because handle->h_ref
1069 * is elevated. We'll still have enough credits for the tiny quotafile
1073 static int do_journal_get_write_access(handle_t *handle,
1074 struct buffer_head *bh)
1076 if (!buffer_mapped(bh) || buffer_freed(bh))
1078 return ext3_journal_get_write_access(handle, bh);
1081 static int ext3_prepare_write(struct file *file, struct page *page,
1082 unsigned from, unsigned to)
1084 struct inode *inode = page->mapping->host;
1085 int ret, needed_blocks = ext3_writepage_trans_blocks(inode);
1088 handle = ext3_journal_start(inode, needed_blocks);
1089 if (IS_ERR(handle)) {
1090 ret = PTR_ERR(handle);
1093 ret = block_prepare_write(page, from, to, ext3_get_block);
1095 goto prepare_write_failed;
1097 if (ext3_should_journal_data(inode)) {
1098 ret = walk_page_buffers(handle, page_buffers(page),
1099 from, to, NULL, do_journal_get_write_access);
1101 prepare_write_failed:
1103 ext3_journal_stop(handle);
1109 ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
1111 int err = journal_dirty_data(handle, bh);
1113 ext3_journal_abort_handle(__FUNCTION__, __FUNCTION__,
1118 /* For commit_write() in data=journal mode */
1119 static int commit_write_fn(handle_t *handle, struct buffer_head *bh)
1121 if (!buffer_mapped(bh) || buffer_freed(bh))
1123 set_buffer_uptodate(bh);
1124 return ext3_journal_dirty_metadata(handle, bh);
1128 * We need to pick up the new inode size which generic_commit_write gave us
1129 * `file' can be NULL - eg, when called from page_symlink().
1131 * ext3 never places buffers on inode->i_mapping->private_list. metadata
1132 * buffers are managed internally.
1135 static int ext3_ordered_commit_write(struct file *file, struct page *page,
1136 unsigned from, unsigned to)
1138 handle_t *handle = ext3_journal_current_handle();
1139 struct inode *inode = page->mapping->host;
1142 ret = walk_page_buffers(handle, page_buffers(page),
1143 from, to, NULL, ext3_journal_dirty_data);
1147 * generic_commit_write() will run mark_inode_dirty() if i_size
1148 * changes. So let's piggyback the i_disksize mark_inode_dirty
1153 new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1154 if (new_i_size > EXT3_I(inode)->i_disksize)
1155 EXT3_I(inode)->i_disksize = new_i_size;
1156 ret = generic_commit_write(file, page, from, to);
1158 ret2 = ext3_journal_stop(handle);
1164 static int ext3_writeback_commit_write(struct file *file, struct page *page,
1165 unsigned from, unsigned to)
1167 handle_t *handle = ext3_journal_current_handle();
1168 struct inode *inode = page->mapping->host;
1172 new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1173 if (new_i_size > EXT3_I(inode)->i_disksize)
1174 EXT3_I(inode)->i_disksize = new_i_size;
1175 ret = generic_commit_write(file, page, from, to);
1176 ret2 = ext3_journal_stop(handle);
1182 static int ext3_journalled_commit_write(struct file *file,
1183 struct page *page, unsigned from, unsigned to)
1185 handle_t *handle = ext3_journal_current_handle();
1186 struct inode *inode = page->mapping->host;
1192 * Here we duplicate the generic_commit_write() functionality
1194 pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1196 ret = walk_page_buffers(handle, page_buffers(page), from,
1197 to, &partial, commit_write_fn);
1199 SetPageUptodate(page);
1200 if (pos > inode->i_size)
1201 i_size_write(inode, pos);
1202 EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1203 if (inode->i_size > EXT3_I(inode)->i_disksize) {
1204 EXT3_I(inode)->i_disksize = inode->i_size;
1205 ret2 = ext3_mark_inode_dirty(handle, inode);
1209 ret2 = ext3_journal_stop(handle);
1216 * bmap() is special. It gets used by applications such as lilo and by
1217 * the swapper to find the on-disk block of a specific piece of data.
1219 * Naturally, this is dangerous if the block concerned is still in the
1220 * journal. If somebody makes a swapfile on an ext3 data-journaling
1221 * filesystem and enables swap, then they may get a nasty shock when the
1222 * data getting swapped to that swapfile suddenly gets overwritten by
1223 * the original zero's written out previously to the journal and
1224 * awaiting writeback in the kernel's buffer cache.
1226 * So, if we see any bmap calls here on a modified, data-journaled file,
1227 * take extra steps to flush any blocks which might be in the cache.
1229 static sector_t ext3_bmap(struct address_space *mapping, sector_t block)
1231 struct inode *inode = mapping->host;
1235 if (EXT3_I(inode)->i_state & EXT3_STATE_JDATA) {
1237 * This is a REALLY heavyweight approach, but the use of
1238 * bmap on dirty files is expected to be extremely rare:
1239 * only if we run lilo or swapon on a freshly made file
1240 * do we expect this to happen.
1242 * (bmap requires CAP_SYS_RAWIO so this does not
1243 * represent an unprivileged user DOS attack --- we'd be
1244 * in trouble if mortal users could trigger this path at
1247 * NB. EXT3_STATE_JDATA is not set on files other than
1248 * regular files. If somebody wants to bmap a directory
1249 * or symlink and gets confused because the buffer
1250 * hasn't yet been flushed to disk, they deserve
1251 * everything they get.
1254 EXT3_I(inode)->i_state &= ~EXT3_STATE_JDATA;
1255 journal = EXT3_JOURNAL(inode);
1256 journal_lock_updates(journal);
1257 err = journal_flush(journal);
1258 journal_unlock_updates(journal);
1264 return generic_block_bmap(mapping,block,ext3_get_block);
1267 static int bget_one(handle_t *handle, struct buffer_head *bh)
1273 static int bput_one(handle_t *handle, struct buffer_head *bh)
1279 static int journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
1281 if (buffer_mapped(bh))
1282 return ext3_journal_dirty_data(handle, bh);
1287 * Note that we always start a transaction even if we're not journalling
1288 * data. This is to preserve ordering: any hole instantiation within
1289 * __block_write_full_page -> ext3_get_block() should be journalled
1290 * along with the data so we don't crash and then get metadata which
1291 * refers to old data.
1293 * In all journalling modes block_write_full_page() will start the I/O.
1297 * ext3_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1302 * ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ...
1304 * Same applies to ext3_get_block(). We will deadlock on various things like
1305 * lock_journal and i_truncate_sem.
1307 * Setting PF_MEMALLOC here doesn't work - too many internal memory
1310 * 16May01: If we're reentered then journal_current_handle() will be
1311 * non-zero. We simply *return*.
1313 * 1 July 2001: @@@ FIXME:
1314 * In journalled data mode, a data buffer may be metadata against the
1315 * current transaction. But the same file is part of a shared mapping
1316 * and someone does a writepage() on it.
1318 * We will move the buffer onto the async_data list, but *after* it has
1319 * been dirtied. So there's a small window where we have dirty data on
1322 * Note that this only applies to the last partial page in the file. The
1323 * bit which block_write_full_page() uses prepare/commit for. (That's
1324 * broken code anyway: it's wrong for msync()).
1326 * It's a rare case: affects the final partial page, for journalled data
1327 * where the file is subject to bith write() and writepage() in the same
1328 * transction. To fix it we'll need a custom block_write_full_page().
1329 * We'll probably need that anyway for journalling writepage() output.
1331 * We don't honour synchronous mounts for writepage(). That would be
1332 * disastrous. Any write() or metadata operation will sync the fs for
1335 * AKPM2: if all the page's buffers are mapped to disk and !data=journal,
1336 * we don't need to open a transaction here.
1338 static int ext3_ordered_writepage(struct page *page,
1339 struct writeback_control *wbc)
1341 struct inode *inode = page->mapping->host;
1342 struct buffer_head *page_bufs;
1343 handle_t *handle = NULL;
1347 J_ASSERT(PageLocked(page));
1350 * We give up here if we're reentered, because it might be for a
1351 * different filesystem.
1353 if (ext3_journal_current_handle())
1356 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1358 if (IS_ERR(handle)) {
1359 ret = PTR_ERR(handle);
1363 if (!page_has_buffers(page)) {
1364 create_empty_buffers(page, inode->i_sb->s_blocksize,
1365 (1 << BH_Dirty)|(1 << BH_Uptodate));
1367 page_bufs = page_buffers(page);
1368 walk_page_buffers(handle, page_bufs, 0,
1369 PAGE_CACHE_SIZE, NULL, bget_one);
1371 ret = block_write_full_page(page, ext3_get_block, wbc);
1374 * The page can become unlocked at any point now, and
1375 * truncate can then come in and change things. So we
1376 * can't touch *page from now on. But *page_bufs is
1377 * safe due to elevated refcount.
1381 * And attach them to the current transaction. But only if
1382 * block_write_full_page() succeeded. Otherwise they are unmapped,
1383 * and generally junk.
1386 err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
1387 NULL, journal_dirty_data_fn);
1391 walk_page_buffers(handle, page_bufs, 0,
1392 PAGE_CACHE_SIZE, NULL, bput_one);
1393 err = ext3_journal_stop(handle);
1399 redirty_page_for_writepage(wbc, page);
1404 static int ext3_writeback_writepage(struct page *page,
1405 struct writeback_control *wbc)
1407 struct inode *inode = page->mapping->host;
1408 handle_t *handle = NULL;
1412 if (ext3_journal_current_handle())
1415 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1416 if (IS_ERR(handle)) {
1417 ret = PTR_ERR(handle);
1421 ret = block_write_full_page(page, ext3_get_block, wbc);
1422 err = ext3_journal_stop(handle);
1428 redirty_page_for_writepage(wbc, page);
1433 static int ext3_journalled_writepage(struct page *page,
1434 struct writeback_control *wbc)
1436 struct inode *inode = page->mapping->host;
1437 handle_t *handle = NULL;
1441 if (ext3_journal_current_handle())
1444 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1445 if (IS_ERR(handle)) {
1446 ret = PTR_ERR(handle);
1450 if (!page_has_buffers(page) || PageChecked(page)) {
1452 * It's mmapped pagecache. Add buffers and journal it. There
1453 * doesn't seem much point in redirtying the page here.
1455 ClearPageChecked(page);
1456 ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
1460 ret = walk_page_buffers(handle, page_buffers(page), 0,
1461 PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
1463 err = walk_page_buffers(handle, page_buffers(page), 0,
1464 PAGE_CACHE_SIZE, NULL, commit_write_fn);
1467 EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1471 * It may be a page full of checkpoint-mode buffers. We don't
1472 * really know unless we go poke around in the buffer_heads.
1473 * But block_write_full_page will do the right thing.
1475 ret = block_write_full_page(page, ext3_get_block, wbc);
1477 err = ext3_journal_stop(handle);
1484 redirty_page_for_writepage(wbc, page);
1490 static int ext3_readpage(struct file *file, struct page *page)
1492 return mpage_readpage(page, ext3_get_block);
1496 ext3_readpages(struct file *file, struct address_space *mapping,
1497 struct list_head *pages, unsigned nr_pages)
1499 return mpage_readpages(mapping, pages, nr_pages, ext3_get_block);
1502 static int ext3_invalidatepage(struct page *page, unsigned long offset)
1504 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1507 * If it's a full truncate we just forget about the pending dirtying
1510 ClearPageChecked(page);
1512 return journal_invalidatepage(journal, page, offset);
1515 static int ext3_releasepage(struct page *page, int wait)
1517 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1519 WARN_ON(PageChecked(page));
1520 return journal_try_to_free_buffers(journal, page, wait);
1524 * If the O_DIRECT write will extend the file then add this inode to the
1525 * orphan list. So recovery will truncate it back to the original size
1526 * if the machine crashes during the write.
1528 * If the O_DIRECT write is intantiating holes inside i_size and the machine
1529 * crashes then stale disk data _may_ be exposed inside the file.
1531 static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
1532 const struct iovec *iov, loff_t offset,
1533 unsigned long nr_segs)
1535 struct file *file = iocb->ki_filp;
1536 struct inode *inode = file->f_mapping->host;
1537 struct ext3_inode_info *ei = EXT3_I(inode);
1538 handle_t *handle = NULL;
1541 size_t count = iov_length(iov, nr_segs);
1544 loff_t final_size = offset + count;
1546 handle = ext3_journal_start(inode, DIO_CREDITS);
1547 if (IS_ERR(handle)) {
1548 ret = PTR_ERR(handle);
1551 if (final_size > inode->i_size) {
1552 ret = ext3_orphan_add(handle, inode);
1556 ei->i_disksize = inode->i_size;
1560 ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
1562 ext3_direct_io_get_blocks, NULL);
1569 ext3_orphan_del(handle, inode);
1570 if (orphan && ret > 0) {
1571 loff_t end = offset + ret;
1572 if (end > inode->i_size) {
1573 ei->i_disksize = end;
1574 i_size_write(inode, end);
1575 err = ext3_mark_inode_dirty(handle, inode);
1580 err = ext3_journal_stop(handle);
1589 * Pages can be marked dirty completely asynchronously from ext3's journalling
1590 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
1591 * much here because ->set_page_dirty is called under VFS locks. The page is
1592 * not necessarily locked.
1594 * We cannot just dirty the page and leave attached buffers clean, because the
1595 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
1596 * or jbddirty because all the journalling code will explode.
1598 * So what we do is to mark the page "pending dirty" and next time writepage
1599 * is called, propagate that into the buffers appropriately.
1601 static int ext3_journalled_set_page_dirty(struct page *page)
1603 SetPageChecked(page);
1604 return __set_page_dirty_nobuffers(page);
1607 static struct address_space_operations ext3_ordered_aops = {
1608 .readpage = ext3_readpage,
1609 .readpages = ext3_readpages,
1610 .writepage = ext3_ordered_writepage,
1611 .sync_page = block_sync_page,
1612 .prepare_write = ext3_prepare_write,
1613 .commit_write = ext3_ordered_commit_write,
1615 .invalidatepage = ext3_invalidatepage,
1616 .releasepage = ext3_releasepage,
1617 .direct_IO = ext3_direct_IO,
1620 static struct address_space_operations ext3_writeback_aops = {
1621 .readpage = ext3_readpage,
1622 .readpages = ext3_readpages,
1623 .writepage = ext3_writeback_writepage,
1624 .sync_page = block_sync_page,
1625 .prepare_write = ext3_prepare_write,
1626 .commit_write = ext3_writeback_commit_write,
1628 .invalidatepage = ext3_invalidatepage,
1629 .releasepage = ext3_releasepage,
1630 .direct_IO = ext3_direct_IO,
1633 static struct address_space_operations ext3_journalled_aops = {
1634 .readpage = ext3_readpage,
1635 .readpages = ext3_readpages,
1636 .writepage = ext3_journalled_writepage,
1637 .sync_page = block_sync_page,
1638 .prepare_write = ext3_prepare_write,
1639 .commit_write = ext3_journalled_commit_write,
1640 .set_page_dirty = ext3_journalled_set_page_dirty,
1642 .invalidatepage = ext3_invalidatepage,
1643 .releasepage = ext3_releasepage,
1646 void ext3_set_aops(struct inode *inode)
1648 if (ext3_should_order_data(inode))
1649 inode->i_mapping->a_ops = &ext3_ordered_aops;
1650 else if (ext3_should_writeback_data(inode))
1651 inode->i_mapping->a_ops = &ext3_writeback_aops;
1653 inode->i_mapping->a_ops = &ext3_journalled_aops;
1657 * ext3_block_truncate_page() zeroes out a mapping from file offset `from'
1658 * up to the end of the block which corresponds to `from'.
1659 * This required during truncate. We need to physically zero the tail end
1660 * of that block so it doesn't yield old data if the file is later grown.
1662 static int ext3_block_truncate_page(handle_t *handle, struct page *page,
1663 struct address_space *mapping, loff_t from)
1665 unsigned long index = from >> PAGE_CACHE_SHIFT;
1666 unsigned offset = from & (PAGE_CACHE_SIZE-1);
1667 unsigned blocksize, iblock, length, pos;
1668 struct inode *inode = mapping->host;
1669 struct buffer_head *bh;
1673 blocksize = inode->i_sb->s_blocksize;
1674 length = blocksize - (offset & (blocksize - 1));
1675 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1677 if (!page_has_buffers(page))
1678 create_empty_buffers(page, blocksize, 0);
1680 /* Find the buffer that contains "offset" */
1681 bh = page_buffers(page);
1683 while (offset >= pos) {
1684 bh = bh->b_this_page;
1690 if (buffer_freed(bh)) {
1691 BUFFER_TRACE(bh, "freed: skip");
1695 if (!buffer_mapped(bh)) {
1696 BUFFER_TRACE(bh, "unmapped");
1697 ext3_get_block(inode, iblock, bh, 0);
1698 /* unmapped? It's a hole - nothing to do */
1699 if (!buffer_mapped(bh)) {
1700 BUFFER_TRACE(bh, "still unmapped");
1705 /* Ok, it's mapped. Make sure it's up-to-date */
1706 if (PageUptodate(page))
1707 set_buffer_uptodate(bh);
1709 if (!buffer_uptodate(bh)) {
1711 ll_rw_block(READ, 1, &bh);
1713 /* Uhhuh. Read error. Complain and punt. */
1714 if (!buffer_uptodate(bh))
1718 if (ext3_should_journal_data(inode)) {
1719 BUFFER_TRACE(bh, "get write access");
1720 err = ext3_journal_get_write_access(handle, bh);
1725 kaddr = kmap_atomic(page, KM_USER0);
1726 memset(kaddr + offset, 0, length);
1727 flush_dcache_page(page);
1728 kunmap_atomic(kaddr, KM_USER0);
1730 BUFFER_TRACE(bh, "zeroed end of block");
1733 if (ext3_should_journal_data(inode)) {
1734 err = ext3_journal_dirty_metadata(handle, bh);
1736 if (ext3_should_order_data(inode))
1737 err = ext3_journal_dirty_data(handle, bh);
1738 mark_buffer_dirty(bh);
1743 page_cache_release(page);
1748 * Probably it should be a library function... search for first non-zero word
1749 * or memcmp with zero_page, whatever is better for particular architecture.
1752 static inline int all_zeroes(u32 *p, u32 *q)
1761 * ext3_find_shared - find the indirect blocks for partial truncation.
1762 * @inode: inode in question
1763 * @depth: depth of the affected branch
1764 * @offsets: offsets of pointers in that branch (see ext3_block_to_path)
1765 * @chain: place to store the pointers to partial indirect blocks
1766 * @top: place to the (detached) top of branch
1768 * This is a helper function used by ext3_truncate().
1770 * When we do truncate() we may have to clean the ends of several
1771 * indirect blocks but leave the blocks themselves alive. Block is
1772 * partially truncated if some data below the new i_size is refered
1773 * from it (and it is on the path to the first completely truncated
1774 * data block, indeed). We have to free the top of that path along
1775 * with everything to the right of the path. Since no allocation
1776 * past the truncation point is possible until ext3_truncate()
1777 * finishes, we may safely do the latter, but top of branch may
1778 * require special attention - pageout below the truncation point
1779 * might try to populate it.
1781 * We atomically detach the top of branch from the tree, store the
1782 * block number of its root in *@top, pointers to buffer_heads of
1783 * partially truncated blocks - in @chain[].bh and pointers to
1784 * their last elements that should not be removed - in
1785 * @chain[].p. Return value is the pointer to last filled element
1788 * The work left to caller to do the actual freeing of subtrees:
1789 * a) free the subtree starting from *@top
1790 * b) free the subtrees whose roots are stored in
1791 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
1792 * c) free the subtrees growing from the inode past the @chain[0].
1793 * (no partially truncated stuff there). */
1795 static Indirect *ext3_find_shared(struct inode *inode,
1801 Indirect *partial, *p;
1805 /* Make k index the deepest non-null offest + 1 */
1806 for (k = depth; k > 1 && !offsets[k-1]; k--)
1808 partial = ext3_get_branch(inode, k, offsets, chain, &err);
1809 /* Writer: pointers */
1811 partial = chain + k-1;
1813 * If the branch acquired continuation since we've looked at it -
1814 * fine, it should all survive and (new) top doesn't belong to us.
1816 if (!partial->key && *partial->p)
1819 for (p=partial; p>chain && all_zeroes((u32*)p->bh->b_data,p->p); p--)
1822 * OK, we've found the last block that must survive. The rest of our
1823 * branch should be detached before unlocking. However, if that rest
1824 * of branch is all ours and does not grow immediately from the inode
1825 * it's easier to cheat and just decrement partial->p.
1827 if (p == chain + k - 1 && p > chain) {
1831 /* Nope, don't do this in ext3. Must leave the tree intact */
1840 brelse(partial->bh);
1848 * Zero a number of block pointers in either an inode or an indirect block.
1849 * If we restart the transaction we must again get write access to the
1850 * indirect block for further modification.
1852 * We release `count' blocks on disk, but (last - first) may be greater
1853 * than `count' because there can be holes in there.
1856 ext3_clear_blocks(handle_t *handle, struct inode *inode, struct buffer_head *bh,
1857 unsigned long block_to_free, unsigned long count,
1858 u32 *first, u32 *last)
1861 if (try_to_extend_transaction(handle, inode)) {
1863 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
1864 ext3_journal_dirty_metadata(handle, bh);
1866 ext3_mark_inode_dirty(handle, inode);
1867 ext3_journal_test_restart(handle, inode);
1869 BUFFER_TRACE(bh, "retaking write access");
1870 ext3_journal_get_write_access(handle, bh);
1875 * Any buffers which are on the journal will be in memory. We find
1876 * them on the hash table so journal_revoke() will run journal_forget()
1877 * on them. We've already detached each block from the file, so
1878 * bforget() in journal_forget() should be safe.
1880 * AKPM: turn on bforget in journal_forget()!!!
1882 for (p = first; p < last; p++) {
1883 u32 nr = le32_to_cpu(*p);
1885 struct buffer_head *bh;
1888 bh = sb_find_get_block(inode->i_sb, nr);
1889 ext3_forget(handle, 0, inode, bh, nr);
1893 ext3_free_blocks(handle, inode, block_to_free, count);
1897 * ext3_free_data - free a list of data blocks
1898 * @handle: handle for this transaction
1899 * @inode: inode we are dealing with
1900 * @this_bh: indirect buffer_head which contains *@first and *@last
1901 * @first: array of block numbers
1902 * @last: points immediately past the end of array
1904 * We are freeing all blocks refered from that array (numbers are stored as
1905 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
1907 * We accumulate contiguous runs of blocks to free. Conveniently, if these
1908 * blocks are contiguous then releasing them at one time will only affect one
1909 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
1910 * actually use a lot of journal space.
1912 * @this_bh will be %NULL if @first and @last point into the inode's direct
1915 static void ext3_free_data(handle_t *handle, struct inode *inode,
1916 struct buffer_head *this_bh, u32 *first, u32 *last)
1918 unsigned long block_to_free = 0; /* Starting block # of a run */
1919 unsigned long count = 0; /* Number of blocks in the run */
1920 u32 *block_to_free_p = NULL; /* Pointer into inode/ind
1923 unsigned long nr; /* Current block # */
1924 u32 *p; /* Pointer into inode/ind
1925 for current block */
1928 if (this_bh) { /* For indirect block */
1929 BUFFER_TRACE(this_bh, "get_write_access");
1930 err = ext3_journal_get_write_access(handle, this_bh);
1931 /* Important: if we can't update the indirect pointers
1932 * to the blocks, we can't free them. */
1937 for (p = first; p < last; p++) {
1938 nr = le32_to_cpu(*p);
1940 /* accumulate blocks to free if they're contiguous */
1943 block_to_free_p = p;
1945 } else if (nr == block_to_free + count) {
1948 ext3_clear_blocks(handle, inode, this_bh,
1950 count, block_to_free_p, p);
1952 block_to_free_p = p;
1959 ext3_clear_blocks(handle, inode, this_bh, block_to_free,
1960 count, block_to_free_p, p);
1963 BUFFER_TRACE(this_bh, "call ext3_journal_dirty_metadata");
1964 ext3_journal_dirty_metadata(handle, this_bh);
1969 * ext3_free_branches - free an array of branches
1970 * @handle: JBD handle for this transaction
1971 * @inode: inode we are dealing with
1972 * @parent_bh: the buffer_head which contains *@first and *@last
1973 * @first: array of block numbers
1974 * @last: pointer immediately past the end of array
1975 * @depth: depth of the branches to free
1977 * We are freeing all blocks refered from these branches (numbers are
1978 * stored as little-endian 32-bit) and updating @inode->i_blocks
1981 static void ext3_free_branches(handle_t *handle, struct inode *inode,
1982 struct buffer_head *parent_bh,
1983 u32 *first, u32 *last, int depth)
1988 if (is_handle_aborted(handle))
1992 struct buffer_head *bh;
1993 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
1995 while (--p >= first) {
1996 nr = le32_to_cpu(*p);
1998 continue; /* A hole */
2000 /* Go read the buffer for the next level down */
2001 bh = sb_bread(inode->i_sb, nr);
2004 * A read failure? Report error and clear slot
2008 ext3_error(inode->i_sb, "ext3_free_branches",
2009 "Read failure, inode=%ld, block=%ld",
2014 /* This zaps the entire block. Bottom up. */
2015 BUFFER_TRACE(bh, "free child branches");
2016 ext3_free_branches(handle, inode, bh, (u32*)bh->b_data,
2017 (u32*)bh->b_data + addr_per_block,
2021 * We've probably journalled the indirect block several
2022 * times during the truncate. But it's no longer
2023 * needed and we now drop it from the transaction via
2026 * That's easy if it's exclusively part of this
2027 * transaction. But if it's part of the committing
2028 * transaction then journal_forget() will simply
2029 * brelse() it. That means that if the underlying
2030 * block is reallocated in ext3_get_block(),
2031 * unmap_underlying_metadata() will find this block
2032 * and will try to get rid of it. damn, damn.
2034 * If this block has already been committed to the
2035 * journal, a revoke record will be written. And
2036 * revoke records must be emitted *before* clearing
2037 * this block's bit in the bitmaps.
2039 ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
2042 * Everything below this this pointer has been
2043 * released. Now let this top-of-subtree go.
2045 * We want the freeing of this indirect block to be
2046 * atomic in the journal with the updating of the
2047 * bitmap block which owns it. So make some room in
2050 * We zero the parent pointer *after* freeing its
2051 * pointee in the bitmaps, so if extend_transaction()
2052 * for some reason fails to put the bitmap changes and
2053 * the release into the same transaction, recovery
2054 * will merely complain about releasing a free block,
2055 * rather than leaking blocks.
2057 if (is_handle_aborted(handle))
2059 if (try_to_extend_transaction(handle, inode)) {
2060 ext3_mark_inode_dirty(handle, inode);
2061 ext3_journal_test_restart(handle, inode);
2064 ext3_free_blocks(handle, inode, nr, 1);
2068 * The block which we have just freed is
2069 * pointed to by an indirect block: journal it
2071 BUFFER_TRACE(parent_bh, "get_write_access");
2072 if (!ext3_journal_get_write_access(handle,
2075 BUFFER_TRACE(parent_bh,
2076 "call ext3_journal_dirty_metadata");
2077 ext3_journal_dirty_metadata(handle,
2083 /* We have reached the bottom of the tree. */
2084 BUFFER_TRACE(parent_bh, "free data blocks");
2085 ext3_free_data(handle, inode, parent_bh, first, last);
2092 * We block out ext3_get_block() block instantiations across the entire
2093 * transaction, and VFS/VM ensures that ext3_truncate() cannot run
2094 * simultaneously on behalf of the same inode.
2096 * As we work through the truncate and commmit bits of it to the journal there
2097 * is one core, guiding principle: the file's tree must always be consistent on
2098 * disk. We must be able to restart the truncate after a crash.
2100 * The file's tree may be transiently inconsistent in memory (although it
2101 * probably isn't), but whenever we close off and commit a journal transaction,
2102 * the contents of (the filesystem + the journal) must be consistent and
2103 * restartable. It's pretty simple, really: bottom up, right to left (although
2104 * left-to-right works OK too).
2106 * Note that at recovery time, journal replay occurs *before* the restart of
2107 * truncate against the orphan inode list.
2109 * The committed inode has the new, desired i_size (which is the same as
2110 * i_disksize in this case). After a crash, ext3_orphan_cleanup() will see
2111 * that this inode's truncate did not complete and it will again call
2112 * ext3_truncate() to have another go. So there will be instantiated blocks
2113 * to the right of the truncation point in a crashed ext3 filesystem. But
2114 * that's fine - as long as they are linked from the inode, the post-crash
2115 * ext3_truncate() run will find them and release them.
2118 void ext3_truncate_nocheck(struct inode * inode)
2121 struct ext3_inode_info *ei = EXT3_I(inode);
2122 u32 *i_data = ei->i_data;
2123 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2124 struct address_space *mapping = inode->i_mapping;
2131 unsigned blocksize = inode->i_sb->s_blocksize;
2134 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2135 S_ISLNK(inode->i_mode)))
2137 if (ext3_inode_is_fast_symlink(inode))
2140 ext3_discard_prealloc(inode);
2143 * We have to lock the EOF page here, because lock_page() nests
2144 * outside journal_start().
2146 if ((inode->i_size & (blocksize - 1)) == 0) {
2147 /* Block boundary? Nothing to do */
2150 page = grab_cache_page(mapping,
2151 inode->i_size >> PAGE_CACHE_SHIFT);
2156 handle = start_transaction(inode);
2157 if (IS_ERR(handle)) {
2159 clear_highpage(page);
2160 flush_dcache_page(page);
2162 page_cache_release(page);
2164 return; /* AKPM: return what? */
2167 last_block = (inode->i_size + blocksize-1)
2168 >> EXT3_BLOCK_SIZE_BITS(inode->i_sb);
2171 ext3_block_truncate_page(handle, page, mapping, inode->i_size);
2173 n = ext3_block_to_path(inode, last_block, offsets, NULL);
2175 goto out_stop; /* error */
2178 * OK. This truncate is going to happen. We add the inode to the
2179 * orphan list, so that if this truncate spans multiple transactions,
2180 * and we crash, we will resume the truncate when the filesystem
2181 * recovers. It also marks the inode dirty, to catch the new size.
2183 * Implication: the file must always be in a sane, consistent
2184 * truncatable state while each transaction commits.
2186 if (ext3_orphan_add(handle, inode))
2190 * The orphan list entry will now protect us from any crash which
2191 * occurs before the truncate completes, so it is now safe to propagate
2192 * the new, shorter inode size (held for now in i_size) into the
2193 * on-disk inode. We do this via i_disksize, which is the value which
2194 * ext3 *really* writes onto the disk inode.
2196 ei->i_disksize = inode->i_size;
2199 * From here we block out all ext3_get_block() callers who want to
2200 * modify the block allocation tree.
2202 down(&ei->truncate_sem);
2204 if (n == 1) { /* direct blocks */
2205 ext3_free_data(handle, inode, NULL, i_data+offsets[0],
2206 i_data + EXT3_NDIR_BLOCKS);
2210 partial = ext3_find_shared(inode, n, offsets, chain, &nr);
2211 /* Kill the top of shared branch (not detached) */
2213 if (partial == chain) {
2214 /* Shared branch grows from the inode */
2215 ext3_free_branches(handle, inode, NULL,
2216 &nr, &nr+1, (chain+n-1) - partial);
2219 * We mark the inode dirty prior to restart,
2220 * and prior to stop. No need for it here.
2223 /* Shared branch grows from an indirect block */
2224 BUFFER_TRACE(partial->bh, "get_write_access");
2225 ext3_free_branches(handle, inode, partial->bh,
2227 partial->p+1, (chain+n-1) - partial);
2230 /* Clear the ends of indirect blocks on the shared branch */
2231 while (partial > chain) {
2232 ext3_free_branches(handle, inode, partial->bh, partial->p + 1,
2233 (u32*)partial->bh->b_data + addr_per_block,
2234 (chain+n-1) - partial);
2235 BUFFER_TRACE(partial->bh, "call brelse");
2236 brelse (partial->bh);
2240 /* Kill the remaining (whole) subtrees */
2241 switch (offsets[0]) {
2243 nr = i_data[EXT3_IND_BLOCK];
2245 ext3_free_branches(handle, inode, NULL,
2247 i_data[EXT3_IND_BLOCK] = 0;
2249 case EXT3_IND_BLOCK:
2250 nr = i_data[EXT3_DIND_BLOCK];
2252 ext3_free_branches(handle, inode, NULL,
2254 i_data[EXT3_DIND_BLOCK] = 0;
2256 case EXT3_DIND_BLOCK:
2257 nr = i_data[EXT3_TIND_BLOCK];
2259 ext3_free_branches(handle, inode, NULL,
2261 i_data[EXT3_TIND_BLOCK] = 0;
2263 case EXT3_TIND_BLOCK:
2266 up(&ei->truncate_sem);
2267 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2268 ext3_mark_inode_dirty(handle, inode);
2270 /* In a multi-transaction truncate, we only make the final
2271 * transaction synchronous */
2276 * If this was a simple ftruncate(), and the file will remain alive
2277 * then we need to clear up the orphan record which we created above.
2278 * However, if this was a real unlink then we were called by
2279 * ext3_delete_inode(), and we allow that function to clean up the
2280 * orphan info for us.
2283 ext3_orphan_del(handle, inode);
2285 ext3_journal_stop(handle);
2288 static unsigned long ext3_get_inode_block(struct super_block *sb,
2289 unsigned long ino, struct ext3_iloc *iloc)
2291 unsigned long desc, group_desc, block_group;
2292 unsigned long offset, block;
2293 struct buffer_head *bh;
2294 struct ext3_group_desc * gdp;
2296 if ((ino != EXT3_ROOT_INO &&
2297 ino != EXT3_JOURNAL_INO &&
2298 ino < EXT3_FIRST_INO(sb)) ||
2300 EXT3_SB(sb)->s_es->s_inodes_count)) {
2301 ext3_error (sb, "ext3_get_inode_block",
2302 "bad inode number: %lu", ino);
2305 block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
2306 if (block_group >= EXT3_SB(sb)->s_groups_count) {
2307 ext3_error (sb, "ext3_get_inode_block",
2308 "group >= groups count");
2311 group_desc = block_group >> EXT3_DESC_PER_BLOCK_BITS(sb);
2312 desc = block_group & (EXT3_DESC_PER_BLOCK(sb) - 1);
2313 bh = EXT3_SB(sb)->s_group_desc[group_desc];
2315 ext3_error (sb, "ext3_get_inode_block",
2316 "Descriptor not loaded");
2320 gdp = (struct ext3_group_desc *) bh->b_data;
2322 * Figure out the offset within the block group inode table
2324 offset = ((ino - 1) % EXT3_INODES_PER_GROUP(sb)) *
2325 EXT3_INODE_SIZE(sb);
2326 block = le32_to_cpu(gdp[desc].bg_inode_table) +
2327 (offset >> EXT3_BLOCK_SIZE_BITS(sb));
2329 iloc->block_group = block_group;
2330 iloc->offset = offset & (EXT3_BLOCK_SIZE(sb) - 1);
2335 * ext3_get_inode_loc returns with an extra refcount against the inode's
2336 * underlying buffer_head on success. If `in_mem' is false then we're purely
2337 * trying to determine the inode's location on-disk and no read need be
2340 static int ext3_get_inode_loc(struct inode *inode,
2341 struct ext3_iloc *iloc, int in_mem)
2343 unsigned long block;
2344 struct buffer_head *bh;
2346 block = ext3_get_inode_block(inode->i_sb, inode->i_ino, iloc);
2350 bh = sb_getblk(inode->i_sb, block);
2352 ext3_error (inode->i_sb, "ext3_get_inode_loc",
2353 "unable to read inode block - "
2354 "inode=%lu, block=%lu", inode->i_ino, block);
2357 if (!buffer_uptodate(bh)) {
2359 if (buffer_uptodate(bh)) {
2360 /* someone brought it uptodate while we waited */
2365 /* we can't skip I/O if inode is on a disk only */
2367 struct buffer_head *bitmap_bh;
2368 struct ext3_group_desc *desc;
2369 int inodes_per_buffer;
2370 int inode_offset, i;
2375 * If this is the only valid inode in the block we
2376 * need not read the block.
2378 block_group = (inode->i_ino - 1) /
2379 EXT3_INODES_PER_GROUP(inode->i_sb);
2380 inodes_per_buffer = bh->b_size /
2381 EXT3_INODE_SIZE(inode->i_sb);
2382 inode_offset = ((inode->i_ino - 1) %
2383 EXT3_INODES_PER_GROUP(inode->i_sb));
2384 start = inode_offset & ~(inodes_per_buffer - 1);
2386 /* Is the inode bitmap in cache? */
2387 desc = ext3_get_group_desc(inode->i_sb,
2392 bitmap_bh = sb_getblk(inode->i_sb,
2393 le32_to_cpu(desc->bg_inode_bitmap));
2398 * If the inode bitmap isn't in cache then the
2399 * optimisation may end up performing two reads instead
2400 * of one, so skip it.
2402 if (!buffer_uptodate(bitmap_bh)) {
2406 for (i = start; i < start + inodes_per_buffer; i++) {
2407 if (i == inode_offset)
2409 if (ext3_test_bit(i, bitmap_bh->b_data))
2413 if (i == start + inodes_per_buffer) {
2414 /* all other inodes are free, so skip I/O */
2415 memset(bh->b_data, 0, bh->b_size);
2416 set_buffer_uptodate(bh);
2424 * There are another valid inodes in the buffer so we must
2425 * read the block from disk
2428 bh->b_end_io = end_buffer_read_sync;
2429 submit_bh(READ, bh);
2431 if (!buffer_uptodate(bh)) {
2432 ext3_error(inode->i_sb, "ext3_get_inode_loc",
2433 "unable to read inode block - "
2434 "inode=%lu, block=%lu",
2435 inode->i_ino, block);
2445 void ext3_truncate(struct inode * inode)
2447 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2449 ext3_truncate_nocheck(inode);
2452 void ext3_set_inode_flags(struct inode *inode)
2454 unsigned int flags = EXT3_I(inode)->i_flags;
2456 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
2457 if (flags & EXT3_SYNC_FL)
2458 inode->i_flags |= S_SYNC;
2459 if (flags & EXT3_APPEND_FL)
2460 inode->i_flags |= S_APPEND;
2461 if (flags & EXT3_IMMUTABLE_FL)
2462 inode->i_flags |= S_IMMUTABLE;
2463 if (flags & EXT3_IUNLINK_FL)
2464 inode->i_flags |= S_IUNLINK;
2465 if (flags & EXT3_BARRIER_FL)
2466 inode->i_flags |= S_BARRIER;
2467 if (flags & EXT3_NOATIME_FL)
2468 inode->i_flags |= S_NOATIME;
2469 if (flags & EXT3_DIRSYNC_FL)
2470 inode->i_flags |= S_DIRSYNC;
2473 void ext3_read_inode(struct inode * inode)
2475 struct ext3_iloc iloc;
2476 struct ext3_inode *raw_inode;
2477 struct ext3_inode_info *ei = EXT3_I(inode);
2478 struct buffer_head *bh;
2483 #ifdef CONFIG_EXT3_FS_POSIX_ACL
2484 ei->i_acl = EXT3_ACL_NOT_CACHED;
2485 ei->i_default_acl = EXT3_ACL_NOT_CACHED;
2487 if (ext3_get_inode_loc(inode, &iloc, 0))
2490 raw_inode = ext3_raw_inode(&iloc);
2491 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
2492 uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
2493 gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
2494 if(!(test_opt (inode->i_sb, NO_UID32))) {
2495 uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
2496 gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
2498 inode->i_uid = INOXID_UID(uid, gid);
2499 inode->i_gid = INOXID_GID(uid, gid);
2500 if (inode->i_sb->s_flags & MS_TAGXID)
2501 inode->i_xid = INOXID_XID(uid, gid, le16_to_cpu(raw_inode->i_raw_xid));
2503 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
2504 inode->i_size = le32_to_cpu(raw_inode->i_size);
2505 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->i_atime);
2506 inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->i_ctime);
2507 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->i_mtime);
2508 inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
2511 ei->i_next_alloc_block = 0;
2512 ei->i_next_alloc_goal = 0;
2513 ei->i_dir_start_lookup = 0;
2514 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
2515 /* We now have enough fields to check if the inode was active or not.
2516 * This is needed because nfsd might try to access dead inodes
2517 * the test is that same one that e2fsck uses
2518 * NeilBrown 1999oct15
2520 if (inode->i_nlink == 0) {
2521 if (inode->i_mode == 0 ||
2522 !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) {
2523 /* this inode is deleted */
2527 /* The only unlinked inodes we let through here have
2528 * valid i_mode and are being read by the orphan
2529 * recovery code: that's fine, we're about to complete
2530 * the process of deleting those. */
2532 inode->i_blksize = PAGE_SIZE; /* This is the optimal IO size
2533 * (for stat), not the fs block
2535 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
2536 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
2537 #ifdef EXT3_FRAGMENTS
2538 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
2539 ei->i_frag_no = raw_inode->i_frag;
2540 ei->i_frag_size = raw_inode->i_fsize;
2542 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
2543 if (!S_ISREG(inode->i_mode)) {
2544 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
2547 ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
2549 ei->i_disksize = inode->i_size;
2550 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
2551 #ifdef EXT3_PREALLOCATE
2552 ei->i_prealloc_count = 0;
2554 ei->i_block_group = iloc.block_group;
2557 * NOTE! The in-memory inode i_data array is in little-endian order
2558 * even on big-endian machines: we do NOT byteswap the block numbers!
2560 for (block = 0; block < EXT3_N_BLOCKS; block++)
2561 ei->i_data[block] = raw_inode->i_block[block];
2562 INIT_LIST_HEAD(&ei->i_orphan);
2564 if (S_ISREG(inode->i_mode)) {
2565 inode->i_op = &ext3_file_inode_operations;
2566 inode->i_fop = &ext3_file_operations;
2567 ext3_set_aops(inode);
2568 } else if (S_ISDIR(inode->i_mode)) {
2569 inode->i_op = &ext3_dir_inode_operations;
2570 inode->i_fop = &ext3_dir_operations;
2571 } else if (S_ISLNK(inode->i_mode)) {
2572 if (ext3_inode_is_fast_symlink(inode))
2573 inode->i_op = &ext3_fast_symlink_inode_operations;
2575 inode->i_op = &ext3_symlink_inode_operations;
2576 ext3_set_aops(inode);
2579 inode->i_op = &ext3_special_inode_operations;
2580 if (raw_inode->i_block[0])
2581 init_special_inode(inode, inode->i_mode,
2582 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
2584 init_special_inode(inode, inode->i_mode,
2585 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
2588 ext3_set_inode_flags(inode);
2592 make_bad_inode(inode);
2597 * Post the struct inode info into an on-disk inode location in the
2598 * buffer-cache. This gobbles the caller's reference to the
2599 * buffer_head in the inode location struct.
2601 * The caller must have write access to iloc->bh.
2603 static int ext3_do_update_inode(handle_t *handle,
2604 struct inode *inode,
2605 struct ext3_iloc *iloc)
2607 struct ext3_inode *raw_inode = ext3_raw_inode(iloc);
2608 struct ext3_inode_info *ei = EXT3_I(inode);
2609 struct buffer_head *bh = iloc->bh;
2610 uid_t uid = XIDINO_UID(inode->i_uid, inode->i_xid);
2611 gid_t gid = XIDINO_GID(inode->i_gid, inode->i_xid);
2612 int err = 0, rc, block;
2614 /* For fields not not tracking in the in-memory inode,
2615 * initialise them to zero for new inodes. */
2616 if (ei->i_state & EXT3_STATE_NEW)
2617 memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
2619 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
2620 if(!(test_opt(inode->i_sb, NO_UID32))) {
2621 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid));
2622 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid));
2624 * Fix up interoperability with old kernels. Otherwise, old inodes get
2625 * re-used with the upper 16 bits of the uid/gid intact
2628 raw_inode->i_uid_high =
2629 cpu_to_le16(high_16_bits(uid));
2630 raw_inode->i_gid_high =
2631 cpu_to_le16(high_16_bits(gid));
2633 raw_inode->i_uid_high = 0;
2634 raw_inode->i_gid_high = 0;
2637 raw_inode->i_uid_low =
2638 cpu_to_le16(fs_high2lowuid(uid));
2639 raw_inode->i_gid_low =
2640 cpu_to_le16(fs_high2lowgid(gid));
2641 raw_inode->i_uid_high = 0;
2642 raw_inode->i_gid_high = 0;
2644 #ifdef CONFIG_INOXID_GID32
2645 raw_inode->i_raw_xid = cpu_to_le16(inode->i_xid);
2647 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
2648 raw_inode->i_size = cpu_to_le32(ei->i_disksize);
2649 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
2650 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
2651 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
2652 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
2653 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
2654 raw_inode->i_flags = cpu_to_le32(ei->i_flags);
2655 #ifdef EXT3_FRAGMENTS
2656 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
2657 raw_inode->i_frag = ei->i_frag_no;
2658 raw_inode->i_fsize = ei->i_frag_size;
2660 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
2661 if (!S_ISREG(inode->i_mode)) {
2662 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
2664 raw_inode->i_size_high =
2665 cpu_to_le32(ei->i_disksize >> 32);
2666 if (ei->i_disksize > 0x7fffffffULL) {
2667 struct super_block *sb = inode->i_sb;
2668 if (!EXT3_HAS_RO_COMPAT_FEATURE(sb,
2669 EXT3_FEATURE_RO_COMPAT_LARGE_FILE) ||
2670 EXT3_SB(sb)->s_es->s_rev_level ==
2671 cpu_to_le32(EXT3_GOOD_OLD_REV)) {
2672 /* If this is the first large file
2673 * created, add a flag to the superblock.
2675 err = ext3_journal_get_write_access(handle,
2676 EXT3_SB(sb)->s_sbh);
2679 ext3_update_dynamic_rev(sb);
2680 EXT3_SET_RO_COMPAT_FEATURE(sb,
2681 EXT3_FEATURE_RO_COMPAT_LARGE_FILE);
2684 err = ext3_journal_dirty_metadata(handle,
2685 EXT3_SB(sb)->s_sbh);
2689 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
2690 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
2691 if (old_valid_dev(inode->i_rdev)) {
2692 raw_inode->i_block[0] =
2693 cpu_to_le32(old_encode_dev(inode->i_rdev));
2694 raw_inode->i_block[1] = 0;
2696 raw_inode->i_block[0] = 0;
2697 raw_inode->i_block[1] =
2698 cpu_to_le32(new_encode_dev(inode->i_rdev));
2699 raw_inode->i_block[2] = 0;
2701 } else for (block = 0; block < EXT3_N_BLOCKS; block++)
2702 raw_inode->i_block[block] = ei->i_data[block];
2704 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
2705 rc = ext3_journal_dirty_metadata(handle, bh);
2708 ei->i_state &= ~EXT3_STATE_NEW;
2712 ext3_std_error(inode->i_sb, err);
2717 * ext3_write_inode()
2719 * We are called from a few places:
2721 * - Within generic_file_write() for O_SYNC files.
2722 * Here, there will be no transaction running. We wait for any running
2723 * trasnaction to commit.
2725 * - Within sys_sync(), kupdate and such.
2726 * We wait on commit, if tol to.
2728 * - Within prune_icache() (PF_MEMALLOC == true)
2729 * Here we simply return. We can't afford to block kswapd on the
2732 * In all cases it is actually safe for us to return without doing anything,
2733 * because the inode has been copied into a raw inode buffer in
2734 * ext3_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
2737 * Note that we are absolutely dependent upon all inode dirtiers doing the
2738 * right thing: they *must* call mark_inode_dirty() after dirtying info in
2739 * which we are interested.
2741 * It would be a bug for them to not do this. The code:
2743 * mark_inode_dirty(inode)
2745 * inode->i_size = expr;
2747 * is in error because a kswapd-driven write_inode() could occur while
2748 * `stuff()' is running, and the new i_size will be lost. Plus the inode
2749 * will no longer be on the superblock's dirty inode list.
2751 void ext3_write_inode(struct inode *inode, int wait)
2753 if (current->flags & PF_MEMALLOC)
2756 if (ext3_journal_current_handle()) {
2757 jbd_debug(0, "called recursively, non-PF_MEMALLOC!\n");
2765 ext3_force_commit(inode->i_sb);
2768 int ext3_setattr_flags(struct inode *inode, unsigned int flags)
2770 unsigned int oldflags, newflags;
2773 oldflags = EXT3_I(inode)->i_flags;
2774 newflags = oldflags &
2775 ~(EXT3_IMMUTABLE_FL | EXT3_IUNLINK_FL | EXT3_BARRIER_FL);
2776 if (flags & ATTR_FLAG_IMMUTABLE)
2777 newflags |= EXT3_IMMUTABLE_FL;
2778 if (flags & ATTR_FLAG_IUNLINK)
2779 newflags |= EXT3_IUNLINK_FL;
2780 if (flags & ATTR_FLAG_BARRIER)
2781 newflags |= EXT3_BARRIER_FL;
2783 if (oldflags ^ newflags) {
2785 struct ext3_iloc iloc;
2787 handle = ext3_journal_start(inode, 1);
2789 return PTR_ERR(handle);
2792 err = ext3_reserve_inode_write(handle, inode, &iloc);
2796 EXT3_I(inode)->i_flags = newflags;
2797 inode->i_ctime = CURRENT_TIME;
2799 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
2801 ext3_journal_stop(handle);
2809 * Called from notify_change.
2811 * We want to trap VFS attempts to truncate the file as soon as
2812 * possible. In particular, we want to make sure that when the VFS
2813 * shrinks i_size, we put the inode on the orphan list and modify
2814 * i_disksize immediately, so that during the subsequent flushing of
2815 * dirty pages and freeing of disk blocks, we can guarantee that any
2816 * commit will leave the blocks being flushed in an unused state on
2817 * disk. (On recovery, the inode will get truncated and the blocks will
2818 * be freed, so we have a strong guarantee that no future commit will
2819 * leave these blocks visible to the user.)
2821 * Called with inode->sem down.
2823 int ext3_setattr(struct dentry *dentry, struct iattr *attr)
2825 struct inode *inode = dentry->d_inode;
2827 const unsigned int ia_valid = attr->ia_valid;
2829 error = inode_change_ok(inode, attr);
2833 if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
2834 (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
2837 /* (user+group)*(old+new) structure, inode write (sb,
2838 * inode block, ? - but truncate inode update has it) */
2839 handle = ext3_journal_start(inode, 4*EXT3_QUOTA_INIT_BLOCKS+3);
2840 if (IS_ERR(handle)) {
2841 error = PTR_ERR(handle);
2844 error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0;
2846 ext3_journal_stop(handle);
2849 /* Update corresponding info in inode so that everything is in
2850 * one transaction */
2851 if (attr->ia_valid & ATTR_UID)
2852 inode->i_uid = attr->ia_uid;
2853 if (attr->ia_valid & ATTR_GID)
2854 inode->i_gid = attr->ia_gid;
2855 error = ext3_mark_inode_dirty(handle, inode);
2856 ext3_journal_stop(handle);
2859 if (S_ISREG(inode->i_mode) &&
2860 attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
2863 handle = ext3_journal_start(inode, 3);
2864 if (IS_ERR(handle)) {
2865 error = PTR_ERR(handle);
2869 error = ext3_orphan_add(handle, inode);
2870 EXT3_I(inode)->i_disksize = attr->ia_size;
2871 rc = ext3_mark_inode_dirty(handle, inode);
2874 ext3_journal_stop(handle);
2877 if (ia_valid & ATTR_ATTR_FLAG) {
2878 rc = ext3_setattr_flags(inode, attr->ia_attr_flags);
2883 rc = inode_setattr(inode, attr);
2885 /* If inode_setattr's call to ext3_truncate failed to get a
2886 * transaction handle at all, we need to clean up the in-core
2887 * orphan list manually. */
2889 ext3_orphan_del(NULL, inode);
2891 if (!rc && (ia_valid & ATTR_MODE))
2892 rc = ext3_acl_chmod(inode);
2895 ext3_std_error(inode->i_sb, error);
2903 * akpm: how many blocks doth make a writepage()?
2905 * With N blocks per page, it may be:
2910 * N+5 bitmap blocks (from the above)
2911 * N+5 group descriptor summary blocks
2914 * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quote files
2916 * 3 * (N + 5) + 2 + 2 * EXT3_SINGLEDATA_TRANS_BLOCKS
2918 * With ordered or writeback data it's the same, less the N data blocks.
2920 * If the inode's direct blocks can hold an integral number of pages then a
2921 * page cannot straddle two indirect blocks, and we can only touch one indirect
2922 * and dindirect block, and the "5" above becomes "3".
2924 * This still overestimates under most circumstances. If we were to pass the
2925 * start and end offsets in here as well we could do block_to_path() on each
2926 * block and work out the exact number of indirects which are touched. Pah.
2929 int ext3_writepage_trans_blocks(struct inode *inode)
2931 int bpp = ext3_journal_blocks_per_page(inode);
2932 int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3;
2935 if (ext3_should_journal_data(inode))
2936 ret = 3 * (bpp + indirects) + 2;
2938 ret = 2 * (bpp + indirects) + 2;
2941 /* We know that structure was already allocated during DQUOT_INIT so
2942 * we will be updating only the data blocks + inodes */
2943 ret += 2*EXT3_QUOTA_TRANS_BLOCKS;
2950 * The caller must have previously called ext3_reserve_inode_write().
2951 * Give this, we know that the caller already has write access to iloc->bh.
2953 int ext3_mark_iloc_dirty(handle_t *handle,
2954 struct inode *inode, struct ext3_iloc *iloc)
2958 /* the do_update_inode consumes one bh->b_count */
2961 /* ext3_do_update_inode() does journal_dirty_metadata */
2962 err = ext3_do_update_inode(handle, inode, iloc);
2968 * On success, We end up with an outstanding reference count against
2969 * iloc->bh. This _must_ be cleaned up later.
2973 ext3_reserve_inode_write(handle_t *handle, struct inode *inode,
2974 struct ext3_iloc *iloc)
2978 err = ext3_get_inode_loc(inode, iloc, 1);
2980 BUFFER_TRACE(iloc->bh, "get_write_access");
2981 err = ext3_journal_get_write_access(handle, iloc->bh);
2988 ext3_std_error(inode->i_sb, err);
2993 * akpm: What we do here is to mark the in-core inode as clean
2994 * with respect to inode dirtiness (it may still be data-dirty).
2995 * This means that the in-core inode may be reaped by prune_icache
2996 * without having to perform any I/O. This is a very good thing,
2997 * because *any* task may call prune_icache - even ones which
2998 * have a transaction open against a different journal.
3000 * Is this cheating? Not really. Sure, we haven't written the
3001 * inode out, but prune_icache isn't a user-visible syncing function.
3002 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
3003 * we start and wait on commits.
3005 * Is this efficient/effective? Well, we're being nice to the system
3006 * by cleaning up our inodes proactively so they can be reaped
3007 * without I/O. But we are potentially leaving up to five seconds'
3008 * worth of inodes floating about which prune_icache wants us to
3009 * write out. One way to fix that would be to get prune_icache()
3010 * to do a write_super() to free up some memory. It has the desired
3013 int ext3_mark_inode_dirty(handle_t *handle, struct inode *inode)
3015 struct ext3_iloc iloc;
3018 err = ext3_reserve_inode_write(handle, inode, &iloc);
3020 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
3025 * akpm: ext3_dirty_inode() is called from __mark_inode_dirty()
3027 * We're really interested in the case where a file is being extended.
3028 * i_size has been changed by generic_commit_write() and we thus need
3029 * to include the updated inode in the current transaction.
3031 * Also, DQUOT_ALLOC_SPACE() will always dirty the inode when blocks
3032 * are allocated to the file.
3034 * If the inode is marked synchronous, we don't honour that here - doing
3035 * so would cause a commit on atime updates, which we don't bother doing.
3036 * We handle synchronous inodes at the highest possible level.
3038 void ext3_dirty_inode(struct inode *inode)
3040 handle_t *current_handle = ext3_journal_current_handle();
3043 handle = ext3_journal_start(inode, 2);
3046 if (current_handle &&
3047 current_handle->h_transaction != handle->h_transaction) {
3048 /* This task has a transaction open against a different fs */
3049 printk(KERN_EMERG "%s: transactions do not match!\n",
3052 jbd_debug(5, "marking dirty. outer handle=%p\n",
3054 ext3_mark_inode_dirty(handle, inode);
3056 ext3_journal_stop(handle);
3063 * Bind an inode's backing buffer_head into this transaction, to prevent
3064 * it from being flushed to disk early. Unlike
3065 * ext3_reserve_inode_write, this leaves behind no bh reference and
3066 * returns no iloc structure, so the caller needs to repeat the iloc
3067 * lookup to mark the inode dirty later.
3070 ext3_pin_inode(handle_t *handle, struct inode *inode)
3072 struct ext3_iloc iloc;
3076 err = ext3_get_inode_loc(inode, &iloc, 1);
3078 BUFFER_TRACE(iloc.bh, "get_write_access");
3079 err = journal_get_write_access(handle, iloc.bh);
3081 err = ext3_journal_dirty_metadata(handle,
3086 ext3_std_error(inode->i_sb, err);
3091 int ext3_change_inode_journal_flag(struct inode *inode, int val)
3098 * We have to be very careful here: changing a data block's
3099 * journaling status dynamically is dangerous. If we write a
3100 * data block to the journal, change the status and then delete
3101 * that block, we risk forgetting to revoke the old log record
3102 * from the journal and so a subsequent replay can corrupt data.
3103 * So, first we make sure that the journal is empty and that
3104 * nobody is changing anything.
3107 journal = EXT3_JOURNAL(inode);
3108 if (is_journal_aborted(journal) || IS_RDONLY(inode))
3111 journal_lock_updates(journal);
3112 journal_flush(journal);
3115 * OK, there are no updates running now, and all cached data is
3116 * synced to disk. We are now in a completely consistent state
3117 * which doesn't have anything in the journal, and we know that
3118 * no filesystem updates are running, so it is safe to modify
3119 * the inode's in-core data-journaling state flag now.
3123 EXT3_I(inode)->i_flags |= EXT3_JOURNAL_DATA_FL;
3125 EXT3_I(inode)->i_flags &= ~EXT3_JOURNAL_DATA_FL;
3126 ext3_set_aops(inode);
3128 journal_unlock_updates(journal);
3130 /* Finally we can mark the inode as dirty. */
3132 handle = ext3_journal_start(inode, 1);
3134 return PTR_ERR(handle);
3136 err = ext3_mark_inode_dirty(handle, inode);
3138 ext3_journal_stop(handle);
3139 ext3_std_error(inode->i_sb, err);