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1/*
2 * linux/fs/ext3/inode.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/inode.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * Goal-directed block allocation by Stephen Tweedie
16 * (sct@redhat.com), 1993, 1998
17 * Big-endian to little-endian byte-swapping/bitmaps by
18 * David S. Miller (davem@caip.rutgers.edu), 1995
19 * 64-bit file support on 64-bit platforms by Jakub Jelinek
20 * (jj@sunsite.ms.mff.cuni.cz)
21 *
22 * Assorted race fixes, rewrite of ext3_get_block() by Al Viro, 2000
23 */
24
25#include <linux/module.h>
26#include <linux/fs.h>
27#include <linux/time.h>
28#include <linux/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/bio.h>
40#include "xattr.h"
41#include "acl.h"
42
43static int ext3_writepage_trans_blocks(struct inode *inode);
44
45/*
46 * Test whether an inode is a fast symlink.
47 */
48static int ext3_inode_is_fast_symlink(struct inode *inode)
49{
50 int ea_blocks = EXT3_I(inode)->i_file_acl ?
51 (inode->i_sb->s_blocksize >> 9) : 0;
52
53 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
54}
55
56/*
57 * The ext3 forget function must perform a revoke if we are freeing data
58 * which has been journaled. Metadata (eg. indirect blocks) must be
59 * revoked in all cases.
60 *
61 * "bh" may be NULL: a metadata block may have been freed from memory
62 * but there may still be a record of it in the journal, and that record
63 * still needs to be revoked.
64 */
65int ext3_forget(handle_t *handle, int is_metadata, struct inode *inode,
66 struct buffer_head *bh, ext3_fsblk_t blocknr)
67{
68 int err;
69
70 might_sleep();
71
72 BUFFER_TRACE(bh, "enter");
73
74 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
75 "data mode %lx\n",
76 bh, is_metadata, inode->i_mode,
77 test_opt(inode->i_sb, DATA_FLAGS));
78
79 /* Never use the revoke function if we are doing full data
80 * journaling: there is no need to, and a V1 superblock won't
81 * support it. Otherwise, only skip the revoke on un-journaled
82 * data blocks. */
83
84 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ||
85 (!is_metadata && !ext3_should_journal_data(inode))) {
86 if (bh) {
87 BUFFER_TRACE(bh, "call journal_forget");
88 return ext3_journal_forget(handle, bh);
89 }
90 return 0;
91 }
92
93 /*
94 * data!=journal && (is_metadata || should_journal_data(inode))
95 */
96 BUFFER_TRACE(bh, "call ext3_journal_revoke");
97 err = ext3_journal_revoke(handle, blocknr, bh);
98 if (err)
99 ext3_abort(inode->i_sb, __FUNCTION__,
100 "error %d when attempting revoke", err);
101 BUFFER_TRACE(bh, "exit");
102 return err;
103}
104
105/*
106 * Work out how many blocks we need to proceed with the next chunk of a
107 * truncate transaction.
108 */
109static unsigned long blocks_for_truncate(struct inode *inode)
110{
111 unsigned long needed;
112
113 needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
114
115 /* Give ourselves just enough room to cope with inodes in which
116 * i_blocks is corrupt: we've seen disk corruptions in the past
117 * which resulted in random data in an inode which looked enough
118 * like a regular file for ext3 to try to delete it. Things
119 * will go a bit crazy if that happens, but at least we should
120 * try not to panic the whole kernel. */
121 if (needed < 2)
122 needed = 2;
123
124 /* But we need to bound the transaction so we don't overflow the
125 * journal. */
126 if (needed > EXT3_MAX_TRANS_DATA)
127 needed = EXT3_MAX_TRANS_DATA;
128
129 return EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
130}
131
132/*
133 * Truncate transactions can be complex and absolutely huge. So we need to
134 * be able to restart the transaction at a conventient checkpoint to make
135 * sure we don't overflow the journal.
136 *
137 * start_transaction gets us a new handle for a truncate transaction,
138 * and extend_transaction tries to extend the existing one a bit. If
139 * extend fails, we need to propagate the failure up and restart the
140 * transaction in the top-level truncate loop. --sct
141 */
142static handle_t *start_transaction(struct inode *inode)
143{
144 handle_t *result;
145
146 result = ext3_journal_start(inode, blocks_for_truncate(inode));
147 if (!IS_ERR(result))
148 return result;
149
150 ext3_std_error(inode->i_sb, PTR_ERR(result));
151 return result;
152}
153
154/*
155 * Try to extend this transaction for the purposes of truncation.
156 *
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.
159 */
160static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
161{
162 if (handle->h_buffer_credits > EXT3_RESERVE_TRANS_BLOCKS)
163 return 0;
164 if (!ext3_journal_extend(handle, blocks_for_truncate(inode)))
165 return 0;
166 return 1;
167}
168
169/*
170 * Restart the transaction associated with *handle. This does a commit,
171 * so before we call here everything must be consistently dirtied against
172 * this transaction.
173 */
174static int ext3_journal_test_restart(handle_t *handle, struct inode *inode)
175{
176 jbd_debug(2, "restarting handle %p\n", handle);
177 return ext3_journal_restart(handle, blocks_for_truncate(inode));
178}
179
180/*
181 * Called at the last iput() if i_nlink is zero.
182 */
183void ext3_delete_inode (struct inode * inode)
184{
185 handle_t *handle;
186
187 truncate_inode_pages(&inode->i_data, 0);
188
189 if (is_bad_inode(inode))
190 goto no_delete;
191
192 handle = start_transaction(inode);
193 if (IS_ERR(handle)) {
194 /*
195 * If we're going to skip the normal cleanup, we still need to
196 * make sure that the in-core orphan linked list is properly
197 * cleaned up.
198 */
199 ext3_orphan_del(NULL, inode);
200 goto no_delete;
201 }
202
203 if (IS_SYNC(inode))
204 handle->h_sync = 1;
205 inode->i_size = 0;
206 if (inode->i_blocks)
207 ext3_truncate(inode);
208 /*
209 * Kill off the orphan record which ext3_truncate created.
210 * AKPM: I think this can be inside the above `if'.
211 * Note that ext3_orphan_del() has to be able to cope with the
212 * deletion of a non-existent orphan - this is because we don't
213 * know if ext3_truncate() actually created an orphan record.
214 * (Well, we could do this if we need to, but heck - it works)
215 */
216 ext3_orphan_del(handle, inode);
217 EXT3_I(inode)->i_dtime = get_seconds();
218
219 /*
220 * One subtle ordering requirement: if anything has gone wrong
221 * (transaction abort, IO errors, whatever), then we can still
222 * do these next steps (the fs will already have been marked as
223 * having errors), but we can't free the inode if the mark_dirty
224 * fails.
225 */
226 if (ext3_mark_inode_dirty(handle, inode))
227 /* If that failed, just do the required in-core inode clear. */
228 clear_inode(inode);
229 else
230 ext3_free_inode(handle, inode);
231 ext3_journal_stop(handle);
232 return;
233no_delete:
234 clear_inode(inode); /* We must guarantee clearing of inode... */
235}
236
237typedef struct {
238 __le32 *p;
239 __le32 key;
240 struct buffer_head *bh;
241} Indirect;
242
243static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
244{
245 p->key = *(p->p = v);
246 p->bh = bh;
247}
248
249static int verify_chain(Indirect *from, Indirect *to)
250{
251 while (from <= to && from->key == *from->p)
252 from++;
253 return (from > to);
254}
255
256/**
257 * ext3_block_to_path - parse the block number into array of offsets
258 * @inode: inode in question (we are only interested in its superblock)
259 * @i_block: block number to be parsed
260 * @offsets: array to store the offsets in
261 * @boundary: set this non-zero if the referred-to block is likely to be
262 * followed (on disk) by an indirect block.
263 *
264 * To store the locations of file's data ext3 uses a data structure common
265 * for UNIX filesystems - tree of pointers anchored in the inode, with
266 * data blocks at leaves and indirect blocks in intermediate nodes.
267 * This function translates the block number into path in that tree -
268 * return value is the path length and @offsets[n] is the offset of
269 * pointer to (n+1)th node in the nth one. If @block is out of range
270 * (negative or too large) warning is printed and zero returned.
271 *
272 * Note: function doesn't find node addresses, so no IO is needed. All
273 * we need to know is the capacity of indirect blocks (taken from the
274 * inode->i_sb).
275 */
276
277/*
278 * Portability note: the last comparison (check that we fit into triple
279 * indirect block) is spelled differently, because otherwise on an
280 * architecture with 32-bit longs and 8Kb pages we might get into trouble
281 * if our filesystem had 8Kb blocks. We might use long long, but that would
282 * kill us on x86. Oh, well, at least the sign propagation does not matter -
283 * i_block would have to be negative in the very beginning, so we would not
284 * get there at all.
285 */
286
287static int ext3_block_to_path(struct inode *inode,
288 long i_block, int offsets[4], int *boundary)
289{
290 int ptrs = EXT3_ADDR_PER_BLOCK(inode->i_sb);
291 int ptrs_bits = EXT3_ADDR_PER_BLOCK_BITS(inode->i_sb);
292 const long direct_blocks = EXT3_NDIR_BLOCKS,
293 indirect_blocks = ptrs,
294 double_blocks = (1 << (ptrs_bits * 2));
295 int n = 0;
296 int final = 0;
297
298 if (i_block < 0) {
299 ext3_warning (inode->i_sb, "ext3_block_to_path", "block < 0");
300 } else if (i_block < direct_blocks) {
301 offsets[n++] = i_block;
302 final = direct_blocks;
303 } else if ( (i_block -= direct_blocks) < indirect_blocks) {
304 offsets[n++] = EXT3_IND_BLOCK;
305 offsets[n++] = i_block;
306 final = ptrs;
307 } else if ((i_block -= indirect_blocks) < double_blocks) {
308 offsets[n++] = EXT3_DIND_BLOCK;
309 offsets[n++] = i_block >> ptrs_bits;
310 offsets[n++] = i_block & (ptrs - 1);
311 final = ptrs;
312 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
313 offsets[n++] = EXT3_TIND_BLOCK;
314 offsets[n++] = i_block >> (ptrs_bits * 2);
315 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
316 offsets[n++] = i_block & (ptrs - 1);
317 final = ptrs;
318 } else {
319 ext3_warning(inode->i_sb, "ext3_block_to_path", "block > big");
320 }
321 if (boundary)
322 *boundary = final - 1 - (i_block & (ptrs - 1));
323 return n;
324}
325
326/**
327 * ext3_get_branch - read the chain of indirect blocks leading to data
328 * @inode: inode in question
329 * @depth: depth of the chain (1 - direct pointer, etc.)
330 * @offsets: offsets of pointers in inode/indirect blocks
331 * @chain: place to store the result
332 * @err: here we store the error value
333 *
334 * Function fills the array of triples <key, p, bh> and returns %NULL
335 * if everything went OK or the pointer to the last filled triple
336 * (incomplete one) otherwise. Upon the return chain[i].key contains
337 * the number of (i+1)-th block in the chain (as it is stored in memory,
338 * i.e. little-endian 32-bit), chain[i].p contains the address of that
339 * number (it points into struct inode for i==0 and into the bh->b_data
340 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
341 * block for i>0 and NULL for i==0. In other words, it holds the block
342 * numbers of the chain, addresses they were taken from (and where we can
343 * verify that chain did not change) and buffer_heads hosting these
344 * numbers.
345 *
346 * Function stops when it stumbles upon zero pointer (absent block)
347 * (pointer to last triple returned, *@err == 0)
348 * or when it gets an IO error reading an indirect block
349 * (ditto, *@err == -EIO)
350 * or when it notices that chain had been changed while it was reading
351 * (ditto, *@err == -EAGAIN)
352 * or when it reads all @depth-1 indirect blocks successfully and finds
353 * the whole chain, all way to the data (returns %NULL, *err == 0).
354 */
355static Indirect *ext3_get_branch(struct inode *inode, int depth, int *offsets,
356 Indirect chain[4], int *err)
357{
358 struct super_block *sb = inode->i_sb;
359 Indirect *p = chain;
360 struct buffer_head *bh;
361
362 *err = 0;
363 /* i_data is not going away, no lock needed */
364 add_chain (chain, NULL, EXT3_I(inode)->i_data + *offsets);
365 if (!p->key)
366 goto no_block;
367 while (--depth) {
368 bh = sb_bread(sb, le32_to_cpu(p->key));
369 if (!bh)
370 goto failure;
371 /* Reader: pointers */
372 if (!verify_chain(chain, p))
373 goto changed;
374 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
375 /* Reader: end */
376 if (!p->key)
377 goto no_block;
378 }
379 return NULL;
380
381changed:
382 brelse(bh);
383 *err = -EAGAIN;
384 goto no_block;
385failure:
386 *err = -EIO;
387no_block:
388 return p;
389}
390
391/**
392 * ext3_find_near - find a place for allocation with sufficient locality
393 * @inode: owner
394 * @ind: descriptor of indirect block.
395 *
396 * This function returns the prefered place for block allocation.
397 * It is used when heuristic for sequential allocation fails.
398 * Rules are:
399 * + if there is a block to the left of our position - allocate near it.
400 * + if pointer will live in indirect block - allocate near that block.
401 * + if pointer will live in inode - allocate in the same
402 * cylinder group.
403 *
404 * In the latter case we colour the starting block by the callers PID to
405 * prevent it from clashing with concurrent allocations for a different inode
406 * in the same block group. The PID is used here so that functionally related
407 * files will be close-by on-disk.
408 *
409 * Caller must make sure that @ind is valid and will stay that way.
410 */
411static ext3_fsblk_t ext3_find_near(struct inode *inode, Indirect *ind)
412{
413 struct ext3_inode_info *ei = EXT3_I(inode);
414 __le32 *start = ind->bh ? (__le32*) ind->bh->b_data : ei->i_data;
415 __le32 *p;
416 ext3_fsblk_t bg_start;
417 ext3_grpblk_t colour;
418
419 /* Try to find previous block */
420 for (p = ind->p - 1; p >= start; p--) {
421 if (*p)
422 return le32_to_cpu(*p);
423 }
424
425 /* No such thing, so let's try location of indirect block */
426 if (ind->bh)
427 return ind->bh->b_blocknr;
428
429 /*
430 * It is going to be referred to from the inode itself? OK, just put it
431 * into the same cylinder group then.
432 */
433 bg_start = ext3_group_first_block_no(inode->i_sb, ei->i_block_group);
434 colour = (current->pid % 16) *
435 (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
436 return bg_start + colour;
437}
438
439/**
440 * ext3_find_goal - find a prefered place for allocation.
441 * @inode: owner
442 * @block: block we want
443 * @chain: chain of indirect blocks
444 * @partial: pointer to the last triple within a chain
445 * @goal: place to store the result.
446 *
447 * Normally this function find the prefered place for block allocation,
448 * stores it in *@goal and returns zero.
449 */
450
451static ext3_fsblk_t ext3_find_goal(struct inode *inode, long block,
452 Indirect chain[4], Indirect *partial)
453{
454 struct ext3_block_alloc_info *block_i;
455
456 block_i = EXT3_I(inode)->i_block_alloc_info;
457
458 /*
459 * try the heuristic for sequential allocation,
460 * failing that at least try to get decent locality.
461 */
462 if (block_i && (block == block_i->last_alloc_logical_block + 1)
463 && (block_i->last_alloc_physical_block != 0)) {
464 return block_i->last_alloc_physical_block + 1;
465 }
466
467 return ext3_find_near(inode, partial);
468}
469
470/**
471 * ext3_blks_to_allocate: Look up the block map and count the number
472 * of direct blocks need to be allocated for the given branch.
473 *
474 * @branch: chain of indirect blocks
475 * @k: number of blocks need for indirect blocks
476 * @blks: number of data blocks to be mapped.
477 * @blocks_to_boundary: the offset in the indirect block
478 *
479 * return the total number of blocks to be allocate, including the
480 * direct and indirect blocks.
481 */
482static int ext3_blks_to_allocate(Indirect *branch, int k, unsigned long blks,
483 int blocks_to_boundary)
484{
485 unsigned long count = 0;
486
487 /*
488 * Simple case, [t,d]Indirect block(s) has not allocated yet
489 * then it's clear blocks on that path have not allocated
490 */
491 if (k > 0) {
492 /* right now we don't handle cross boundary allocation */
493 if (blks < blocks_to_boundary + 1)
494 count += blks;
495 else
496 count += blocks_to_boundary + 1;
497 return count;
498 }
499
500 count++;
501 while (count < blks && count <= blocks_to_boundary &&
502 le32_to_cpu(*(branch[0].p + count)) == 0) {
503 count++;
504 }
505 return count;
506}
507
508/**
509 * ext3_alloc_blocks: multiple allocate blocks needed for a branch
510 * @indirect_blks: the number of blocks need to allocate for indirect
511 * blocks
512 *
513 * @new_blocks: on return it will store the new block numbers for
514 * the indirect blocks(if needed) and the first direct block,
515 * @blks: on return it will store the total number of allocated
516 * direct blocks
517 */
518static int ext3_alloc_blocks(handle_t *handle, struct inode *inode,
519 ext3_fsblk_t goal, int indirect_blks, int blks,
520 ext3_fsblk_t new_blocks[4], int *err)
521{
522 int target, i;
523 unsigned long count = 0;
524 int index = 0;
525 ext3_fsblk_t current_block = 0;
526 int ret = 0;
527
528 /*
529 * Here we try to allocate the requested multiple blocks at once,
530 * on a best-effort basis.
531 * To build a branch, we should allocate blocks for
532 * the indirect blocks(if not allocated yet), and at least
533 * the first direct block of this branch. That's the
534 * minimum number of blocks need to allocate(required)
535 */
536 target = blks + indirect_blks;
537
538 while (1) {
539 count = target;
540 /* allocating blocks for indirect blocks and direct blocks */
541 current_block = ext3_new_blocks(handle,inode,goal,&count,err);
542 if (*err)
543 goto failed_out;
544
545 target -= count;
546 /* allocate blocks for indirect blocks */
547 while (index < indirect_blks && count) {
548 new_blocks[index++] = current_block++;
549 count--;
550 }
551
552 if (count > 0)
553 break;
554 }
555
556 /* save the new block number for the first direct block */
557 new_blocks[index] = current_block;
558
559 /* total number of blocks allocated for direct blocks */
560 ret = count;
561 *err = 0;
562 return ret;
563failed_out:
564 for (i = 0; i <index; i++)
565 ext3_free_blocks(handle, inode, new_blocks[i], 1);
566 return ret;
567}
568
569/**
570 * ext3_alloc_branch - allocate and set up a chain of blocks.
571 * @inode: owner
572 * @indirect_blks: number of allocated indirect blocks
573 * @blks: number of allocated direct blocks
574 * @offsets: offsets (in the blocks) to store the pointers to next.
575 * @branch: place to store the chain in.
576 *
577 * This function allocates blocks, zeroes out all but the last one,
578 * links them into chain and (if we are synchronous) writes them to disk.
579 * In other words, it prepares a branch that can be spliced onto the
580 * inode. It stores the information about that chain in the branch[], in
581 * the same format as ext3_get_branch() would do. We are calling it after
582 * we had read the existing part of chain and partial points to the last
583 * triple of that (one with zero ->key). Upon the exit we have the same
584 * picture as after the successful ext3_get_block(), except that in one
585 * place chain is disconnected - *branch->p is still zero (we did not
586 * set the last link), but branch->key contains the number that should
587 * be placed into *branch->p to fill that gap.
588 *
589 * If allocation fails we free all blocks we've allocated (and forget
590 * their buffer_heads) and return the error value the from failed
591 * ext3_alloc_block() (normally -ENOSPC). Otherwise we set the chain
592 * as described above and return 0.
593 */
594static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
595 int indirect_blks, int *blks, ext3_fsblk_t goal,
596 int *offsets, Indirect *branch)
597{
598 int blocksize = inode->i_sb->s_blocksize;
599 int i, n = 0;
600 int err = 0;
601 struct buffer_head *bh;
602 int num;
603 ext3_fsblk_t new_blocks[4];
604 ext3_fsblk_t current_block;
605
606 num = ext3_alloc_blocks(handle, inode, goal, indirect_blks,
607 *blks, new_blocks, &err);
608 if (err)
609 return err;
610
611 branch[0].key = cpu_to_le32(new_blocks[0]);
612 /*
613 * metadata blocks and data blocks are allocated.
614 */
615 for (n = 1; n <= indirect_blks; n++) {
616 /*
617 * Get buffer_head for parent block, zero it out
618 * and set the pointer to new one, then send
619 * parent to disk.
620 */
621 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
622 branch[n].bh = bh;
623 lock_buffer(bh);
624 BUFFER_TRACE(bh, "call get_create_access");
625 err = ext3_journal_get_create_access(handle, bh);
626 if (err) {
627 unlock_buffer(bh);
628 brelse(bh);
629 goto failed;
630 }
631
632 memset(bh->b_data, 0, blocksize);
633 branch[n].p = (__le32 *) bh->b_data + offsets[n];
634 branch[n].key = cpu_to_le32(new_blocks[n]);
635 *branch[n].p = branch[n].key;
636 if ( n == indirect_blks) {
637 current_block = new_blocks[n];
638 /*
639 * End of chain, update the last new metablock of
640 * the chain to point to the new allocated
641 * data blocks numbers
642 */
643 for (i=1; i < num; i++)
644 *(branch[n].p + i) = cpu_to_le32(++current_block);
645 }
646 BUFFER_TRACE(bh, "marking uptodate");
647 set_buffer_uptodate(bh);
648 unlock_buffer(bh);
649
650 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
651 err = ext3_journal_dirty_metadata(handle, bh);
652 if (err)
653 goto failed;
654 }
655 *blks = num;
656 return err;
657failed:
658 /* Allocation failed, free what we already allocated */
659 for (i = 1; i <= n ; i++) {
660 BUFFER_TRACE(branch[i].bh, "call journal_forget");
661 ext3_journal_forget(handle, branch[i].bh);
662 }
663 for (i = 0; i <indirect_blks; i++)
664 ext3_free_blocks(handle, inode, new_blocks[i], 1);
665
666 ext3_free_blocks(handle, inode, new_blocks[i], num);
667
668 return err;
669}
670
671/**
672 * ext3_splice_branch - splice the allocated branch onto inode.
673 * @inode: owner
674 * @block: (logical) number of block we are adding
675 * @chain: chain of indirect blocks (with a missing link - see
676 * ext3_alloc_branch)
677 * @where: location of missing link
678 * @num: number of indirect blocks we are adding
679 * @blks: number of direct blocks we are adding
680 *
681 * This function fills the missing link and does all housekeeping needed in
682 * inode (->i_blocks, etc.). In case of success we end up with the full
683 * chain to new block and return 0.
684 */
685static int ext3_splice_branch(handle_t *handle, struct inode *inode,
686 long block, Indirect *where, int num, int blks)
687{
688 int i;
689 int err = 0;
690 struct ext3_block_alloc_info *block_i;
691 ext3_fsblk_t current_block;
692
693 block_i = EXT3_I(inode)->i_block_alloc_info;
694 /*
695 * If we're splicing into a [td]indirect block (as opposed to the
696 * inode) then we need to get write access to the [td]indirect block
697 * before the splice.
698 */
699 if (where->bh) {
700 BUFFER_TRACE(where->bh, "get_write_access");
701 err = ext3_journal_get_write_access(handle, where->bh);
702 if (err)
703 goto err_out;
704 }
705 /* That's it */
706
707 *where->p = where->key;
708
709 /*
710 * Update the host buffer_head or inode to point to more just allocated
711 * direct blocks blocks
712 */
713 if (num == 0 && blks > 1) {
714 current_block = le32_to_cpu(where->key) + 1;
715 for (i = 1; i < blks; i++)
716 *(where->p + i ) = cpu_to_le32(current_block++);
717 }
718
719 /*
720 * update the most recently allocated logical & physical block
721 * in i_block_alloc_info, to assist find the proper goal block for next
722 * allocation
723 */
724 if (block_i) {
725 block_i->last_alloc_logical_block = block + blks - 1;
726 block_i->last_alloc_physical_block =
727 le32_to_cpu(where[num].key) + blks - 1;
728 }
729
730 /* We are done with atomic stuff, now do the rest of housekeeping */
731
732 inode->i_ctime = CURRENT_TIME_SEC;
733 ext3_mark_inode_dirty(handle, inode);
734
735 /* had we spliced it onto indirect block? */
736 if (where->bh) {
737 /*
738 * If we spliced it onto an indirect block, we haven't
739 * altered the inode. Note however that if it is being spliced
740 * onto an indirect block at the very end of the file (the
741 * file is growing) then we *will* alter the inode to reflect
742 * the new i_size. But that is not done here - it is done in
743 * generic_commit_write->__mark_inode_dirty->ext3_dirty_inode.
744 */
745 jbd_debug(5, "splicing indirect only\n");
746 BUFFER_TRACE(where->bh, "call ext3_journal_dirty_metadata");
747 err = ext3_journal_dirty_metadata(handle, where->bh);
748 if (err)
749 goto err_out;
750 } else {
751 /*
752 * OK, we spliced it into the inode itself on a direct block.
753 * Inode was dirtied above.
754 */
755 jbd_debug(5, "splicing direct\n");
756 }
757 return err;
758
759err_out:
760 for (i = 1; i <= num; i++) {
761 BUFFER_TRACE(where[i].bh, "call journal_forget");
762 ext3_journal_forget(handle, where[i].bh);
763 ext3_free_blocks(handle,inode,le32_to_cpu(where[i-1].key),1);
764 }
765 ext3_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks);
766
767 return err;
768}
769
770/*
771 * Allocation strategy is simple: if we have to allocate something, we will
772 * have to go the whole way to leaf. So let's do it before attaching anything
773 * to tree, set linkage between the newborn blocks, write them if sync is
774 * required, recheck the path, free and repeat if check fails, otherwise
775 * set the last missing link (that will protect us from any truncate-generated
776 * removals - all blocks on the path are immune now) and possibly force the
777 * write on the parent block.
778 * That has a nice additional property: no special recovery from the failed
779 * allocations is needed - we simply release blocks and do not touch anything
780 * reachable from inode.
781 *
782 * `handle' can be NULL if create == 0.
783 *
784 * The BKL may not be held on entry here. Be sure to take it early.
785 * return > 0, # of blocks mapped or allocated.
786 * return = 0, if plain lookup failed.
787 * return < 0, error case.
788 */
789int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
790 sector_t iblock, unsigned long maxblocks,
791 struct buffer_head *bh_result,
792 int create, int extend_disksize)
793{
794 int err = -EIO;
795 int offsets[4];
796 Indirect chain[4];
797 Indirect *partial;
798 ext3_fsblk_t goal;
799 int indirect_blks;
800 int blocks_to_boundary = 0;
801 int depth;
802 struct ext3_inode_info *ei = EXT3_I(inode);
803 int count = 0;
804 ext3_fsblk_t first_block = 0;
805
806
807 J_ASSERT(handle != NULL || create == 0);
808 depth = ext3_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
809
810 if (depth == 0)
811 goto out;
812
813 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
814
815 /* Simplest case - block found, no allocation needed */
816 if (!partial) {
817 first_block = le32_to_cpu(chain[depth - 1].key);
818 clear_buffer_new(bh_result);
819 count++;
820 /*map more blocks*/
821 while (count < maxblocks && count <= blocks_to_boundary) {
822 ext3_fsblk_t blk;
823
824 if (!verify_chain(chain, partial)) {
825 /*
826 * Indirect block might be removed by
827 * truncate while we were reading it.
828 * Handling of that case: forget what we've
829 * got now. Flag the err as EAGAIN, so it
830 * will reread.
831 */
832 err = -EAGAIN;
833 count = 0;
834 break;
835 }
836 blk = le32_to_cpu(*(chain[depth-1].p + count));
837
838 if (blk == first_block + count)
839 count++;
840 else
841 break;
842 }
843 if (err != -EAGAIN)
844 goto got_it;
845 }
846
847 /* Next simple case - plain lookup or failed read of indirect block */
848 if (!create || err == -EIO)
849 goto cleanup;
850
851 mutex_lock(&ei->truncate_mutex);
852
853 /*
854 * If the indirect block is missing while we are reading
855 * the chain(ext3_get_branch() returns -EAGAIN err), or
856 * if the chain has been changed after we grab the semaphore,
857 * (either because another process truncated this branch, or
858 * another get_block allocated this branch) re-grab the chain to see if
859 * the request block has been allocated or not.
860 *
861 * Since we already block the truncate/other get_block
862 * at this point, we will have the current copy of the chain when we
863 * splice the branch into the tree.
864 */
865 if (err == -EAGAIN || !verify_chain(chain, partial)) {
866 while (partial > chain) {
867 brelse(partial->bh);
868 partial--;
869 }
870 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
871 if (!partial) {
872 count++;
873 mutex_unlock(&ei->truncate_mutex);
874 if (err)
875 goto cleanup;
876 clear_buffer_new(bh_result);
877 goto got_it;
878 }
879 }
880
881 /*
882 * Okay, we need to do block allocation. Lazily initialize the block
883 * allocation info here if necessary
884 */
885 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
886 ext3_init_block_alloc_info(inode);
887
888 goal = ext3_find_goal(inode, iblock, chain, partial);
889
890 /* the number of blocks need to allocate for [d,t]indirect blocks */
891 indirect_blks = (chain + depth) - partial - 1;
892
893 /*
894 * Next look up the indirect map to count the totoal number of
895 * direct blocks to allocate for this branch.
896 */
897 count = ext3_blks_to_allocate(partial, indirect_blks,
898 maxblocks, blocks_to_boundary);
899 /*
900 * Block out ext3_truncate while we alter the tree
901 */
902 err = ext3_alloc_branch(handle, inode, indirect_blks, &count, goal,
903 offsets + (partial - chain), partial);
904
905 /*
906 * The ext3_splice_branch call will free and forget any buffers
907 * on the new chain if there is a failure, but that risks using
908 * up transaction credits, especially for bitmaps where the
909 * credits cannot be returned. Can we handle this somehow? We
910 * may need to return -EAGAIN upwards in the worst case. --sct
911 */
912 if (!err)
913 err = ext3_splice_branch(handle, inode, iblock,
914 partial, indirect_blks, count);
915 /*
916 * i_disksize growing is protected by truncate_mutex. Don't forget to
917 * protect it if you're about to implement concurrent
918 * ext3_get_block() -bzzz
919 */
920 if (!err && extend_disksize && inode->i_size > ei->i_disksize)
921 ei->i_disksize = inode->i_size;
922 mutex_unlock(&ei->truncate_mutex);
923 if (err)
924 goto cleanup;
925
926 set_buffer_new(bh_result);
927got_it:
928 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
929 if (count > blocks_to_boundary)
930 set_buffer_boundary(bh_result);
931 err = count;
932 /* Clean up and exit */
933 partial = chain + depth - 1; /* the whole chain */
934cleanup:
935 while (partial > chain) {
936 BUFFER_TRACE(partial->bh, "call brelse");
937 brelse(partial->bh);
938 partial--;
939 }
940 BUFFER_TRACE(bh_result, "returned");
941out:
942 return err;
943}
944
945#define DIO_CREDITS (EXT3_RESERVE_TRANS_BLOCKS + 32)
946
947static int ext3_get_block(struct inode *inode, sector_t iblock,
948 struct buffer_head *bh_result, int create)
949{
950 handle_t *handle = journal_current_handle();
951 int ret = 0;
952 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
953
954 if (!create)
955 goto get_block; /* A read */
956
957 if (max_blocks == 1)
958 goto get_block; /* A single block get */
959
960 if (handle->h_transaction->t_state == T_LOCKED) {
961 /*
962 * Huge direct-io writes can hold off commits for long
963 * periods of time. Let this commit run.
964 */
965 ext3_journal_stop(handle);
966 handle = ext3_journal_start(inode, DIO_CREDITS);
967 if (IS_ERR(handle))
968 ret = PTR_ERR(handle);
969 goto get_block;
970 }
971
972 if (handle->h_buffer_credits <= EXT3_RESERVE_TRANS_BLOCKS) {
973 /*
974 * Getting low on buffer credits...
975 */
976 ret = ext3_journal_extend(handle, DIO_CREDITS);
977 if (ret > 0) {
978 /*
979 * Couldn't extend the transaction. Start a new one.
980 */
981 ret = ext3_journal_restart(handle, DIO_CREDITS);
982 }
983 }
984
985get_block:
986 if (ret == 0) {
987 ret = ext3_get_blocks_handle(handle, inode, iblock,
988 max_blocks, bh_result, create, 0);
989 if (ret > 0) {
990 bh_result->b_size = (ret << inode->i_blkbits);
991 ret = 0;
992 }
993 }
994 return ret;
995}
996
997/*
998 * `handle' can be NULL if create is zero
999 */
1000struct buffer_head *ext3_getblk(handle_t *handle, struct inode *inode,
1001 long block, int create, int *errp)
1002{
1003 struct buffer_head dummy;
1004 int fatal = 0, err;
1005
1006 J_ASSERT(handle != NULL || create == 0);
1007
1008 dummy.b_state = 0;
1009 dummy.b_blocknr = -1000;
1010 buffer_trace_init(&dummy.b_history);
1011 err = ext3_get_blocks_handle(handle, inode, block, 1,
1012 &dummy, create, 1);
1013 /*
1014 * ext3_get_blocks_handle() returns number of blocks
1015 * mapped. 0 in case of a HOLE.
1016 */
1017 if (err > 0) {
1018 if (err > 1)
1019 WARN_ON(1);
1020 err = 0;
1021 }
1022 *errp = err;
1023 if (!err && buffer_mapped(&dummy)) {
1024 struct buffer_head *bh;
1025 bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
1026 if (!bh) {
1027 *errp = -EIO;
1028 goto err;
1029 }
1030 if (buffer_new(&dummy)) {
1031 J_ASSERT(create != 0);
1032 J_ASSERT(handle != 0);
1033
1034 /*
1035 * Now that we do not always journal data, we should
1036 * keep in mind whether this should always journal the
1037 * new buffer as metadata. For now, regular file
1038 * writes use ext3_get_block instead, so it's not a
1039 * problem.
1040 */
1041 lock_buffer(bh);
1042 BUFFER_TRACE(bh, "call get_create_access");
1043 fatal = ext3_journal_get_create_access(handle, bh);
1044 if (!fatal && !buffer_uptodate(bh)) {
1045 memset(bh->b_data,0,inode->i_sb->s_blocksize);
1046 set_buffer_uptodate(bh);
1047 }
1048 unlock_buffer(bh);
1049 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
1050 err = ext3_journal_dirty_metadata(handle, bh);
1051 if (!fatal)
1052 fatal = err;
1053 } else {
1054 BUFFER_TRACE(bh, "not a new buffer");
1055 }
1056 if (fatal) {
1057 *errp = fatal;
1058 brelse(bh);
1059 bh = NULL;
1060 }
1061 return bh;
1062 }
1063err:
1064 return NULL;
1065}
1066
1067struct buffer_head *ext3_bread(handle_t *handle, struct inode *inode,
1068 int block, int create, int *err)
1069{
1070 struct buffer_head * bh;
1071
1072 bh = ext3_getblk(handle, inode, block, create, err);
1073 if (!bh)
1074 return bh;
1075 if (buffer_uptodate(bh))
1076 return bh;
1077 ll_rw_block(READ_META, 1, &bh);
1078 wait_on_buffer(bh);
1079 if (buffer_uptodate(bh))
1080 return bh;
1081 put_bh(bh);
1082 *err = -EIO;
1083 return NULL;
1084}
1085
1086static int walk_page_buffers( handle_t *handle,
1087 struct buffer_head *head,
1088 unsigned from,
1089 unsigned to,
1090 int *partial,
1091 int (*fn)( handle_t *handle,
1092 struct buffer_head *bh))
1093{
1094 struct buffer_head *bh;
1095 unsigned block_start, block_end;
1096 unsigned blocksize = head->b_size;
1097 int err, ret = 0;
1098 struct buffer_head *next;
1099
1100 for ( bh = head, block_start = 0;
1101 ret == 0 && (bh != head || !block_start);
1102 block_start = block_end, bh = next)
1103 {
1104 next = bh->b_this_page;
1105 block_end = block_start + blocksize;
1106 if (block_end <= from || block_start >= to) {
1107 if (partial && !buffer_uptodate(bh))
1108 *partial = 1;
1109 continue;
1110 }
1111 err = (*fn)(handle, bh);
1112 if (!ret)
1113 ret = err;
1114 }
1115 return ret;
1116}
1117
1118/*
1119 * To preserve ordering, it is essential that the hole instantiation and
1120 * the data write be encapsulated in a single transaction. We cannot
1121 * close off a transaction and start a new one between the ext3_get_block()
1122 * and the commit_write(). So doing the journal_start at the start of
1123 * prepare_write() is the right place.
1124 *
1125 * Also, this function can nest inside ext3_writepage() ->
1126 * block_write_full_page(). In that case, we *know* that ext3_writepage()
1127 * has generated enough buffer credits to do the whole page. So we won't
1128 * block on the journal in that case, which is good, because the caller may
1129 * be PF_MEMALLOC.
1130 *
1131 * By accident, ext3 can be reentered when a transaction is open via
1132 * quota file writes. If we were to commit the transaction while thus
1133 * reentered, there can be a deadlock - we would be holding a quota
1134 * lock, and the commit would never complete if another thread had a
1135 * transaction open and was blocking on the quota lock - a ranking
1136 * violation.
1137 *
1138 * So what we do is to rely on the fact that journal_stop/journal_start
1139 * will _not_ run commit under these circumstances because handle->h_ref
1140 * is elevated. We'll still have enough credits for the tiny quotafile
1141 * write.
1142 */
1143static int do_journal_get_write_access(handle_t *handle,
1144 struct buffer_head *bh)
1145{
1146 if (!buffer_mapped(bh) || buffer_freed(bh))
1147 return 0;
1148 return ext3_journal_get_write_access(handle, bh);
1149}
1150
1151static int ext3_prepare_write(struct file *file, struct page *page,
1152 unsigned from, unsigned to)
1153{
1154 struct inode *inode = page->mapping->host;
1155 int ret, needed_blocks = ext3_writepage_trans_blocks(inode);
1156 handle_t *handle;
1157 int retries = 0;
1158
1159retry:
1160 handle = ext3_journal_start(inode, needed_blocks);
1161 if (IS_ERR(handle)) {
1162 ret = PTR_ERR(handle);
1163 goto out;
1164 }
1165 if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
1166 ret = nobh_prepare_write(page, from, to, ext3_get_block);
1167 else
1168 ret = block_prepare_write(page, from, to, ext3_get_block);
1169 if (ret)
1170 goto prepare_write_failed;
1171
1172 if (ext3_should_journal_data(inode)) {
1173 ret = walk_page_buffers(handle, page_buffers(page),
1174 from, to, NULL, do_journal_get_write_access);
1175 }
1176prepare_write_failed:
1177 if (ret)
1178 ext3_journal_stop(handle);
1179 if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
1180 goto retry;
1181out:
1182 return ret;
1183}
1184
1185int ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
1186{
1187 int err = journal_dirty_data(handle, bh);
1188 if (err)
1189 ext3_journal_abort_handle(__FUNCTION__, __FUNCTION__,
1190 bh, handle,err);
1191 return err;
1192}
1193
1194/* For commit_write() in data=journal mode */
1195static int commit_write_fn(handle_t *handle, struct buffer_head *bh)
1196{
1197 if (!buffer_mapped(bh) || buffer_freed(bh))
1198 return 0;
1199 set_buffer_uptodate(bh);
1200 return ext3_journal_dirty_metadata(handle, bh);
1201}
1202
1203/*
1204 * We need to pick up the new inode size which generic_commit_write gave us
1205 * `file' can be NULL - eg, when called from page_symlink().
1206 *
1207 * ext3 never places buffers on inode->i_mapping->private_list. metadata
1208 * buffers are managed internally.
1209 */
1210static int ext3_ordered_commit_write(struct file *file, struct page *page,
1211 unsigned from, unsigned to)
1212{
1213 handle_t *handle = ext3_journal_current_handle();
1214 struct inode *inode = page->mapping->host;
1215 int ret = 0, ret2;
1216
1217 ret = walk_page_buffers(handle, page_buffers(page),
1218 from, to, NULL, ext3_journal_dirty_data);
1219
1220 if (ret == 0) {
1221 /*
1222 * generic_commit_write() will run mark_inode_dirty() if i_size
1223 * changes. So let's piggyback the i_disksize mark_inode_dirty
1224 * into that.
1225 */
1226 loff_t new_i_size;
1227
1228 new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1229 if (new_i_size > EXT3_I(inode)->i_disksize)
1230 EXT3_I(inode)->i_disksize = new_i_size;
1231 ret = generic_commit_write(file, page, from, to);
1232 }
1233 ret2 = ext3_journal_stop(handle);
1234 if (!ret)
1235 ret = ret2;
1236 return ret;
1237}
1238
1239static int ext3_writeback_commit_write(struct file *file, struct page *page,
1240 unsigned from, unsigned to)
1241{
1242 handle_t *handle = ext3_journal_current_handle();
1243 struct inode *inode = page->mapping->host;
1244 int ret = 0, ret2;
1245 loff_t new_i_size;
1246
1247 new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1248 if (new_i_size > EXT3_I(inode)->i_disksize)
1249 EXT3_I(inode)->i_disksize = new_i_size;
1250
1251 if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
1252 ret = nobh_commit_write(file, page, from, to);
1253 else
1254 ret = generic_commit_write(file, page, from, to);
1255
1256 ret2 = ext3_journal_stop(handle);
1257 if (!ret)
1258 ret = ret2;
1259 return ret;
1260}
1261
1262static int ext3_journalled_commit_write(struct file *file,
1263 struct page *page, unsigned from, unsigned to)
1264{
1265 handle_t *handle = ext3_journal_current_handle();
1266 struct inode *inode = page->mapping->host;
1267 int ret = 0, ret2;
1268 int partial = 0;
1269 loff_t pos;
1270
1271 /*
1272 * Here we duplicate the generic_commit_write() functionality
1273 */
1274 pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1275
1276 ret = walk_page_buffers(handle, page_buffers(page), from,
1277 to, &partial, commit_write_fn);
1278 if (!partial)
1279 SetPageUptodate(page);
1280 if (pos > inode->i_size)
1281 i_size_write(inode, pos);
1282 EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1283 if (inode->i_size > EXT3_I(inode)->i_disksize) {
1284 EXT3_I(inode)->i_disksize = inode->i_size;
1285 ret2 = ext3_mark_inode_dirty(handle, inode);
1286 if (!ret)
1287 ret = ret2;
1288 }
1289 ret2 = ext3_journal_stop(handle);
1290 if (!ret)
1291 ret = ret2;
1292 return ret;
1293}
1294
1295/*
1296 * bmap() is special. It gets used by applications such as lilo and by
1297 * the swapper to find the on-disk block of a specific piece of data.
1298 *
1299 * Naturally, this is dangerous if the block concerned is still in the
1300 * journal. If somebody makes a swapfile on an ext3 data-journaling
1301 * filesystem and enables swap, then they may get a nasty shock when the
1302 * data getting swapped to that swapfile suddenly gets overwritten by
1303 * the original zero's written out previously to the journal and
1304 * awaiting writeback in the kernel's buffer cache.
1305 *
1306 * So, if we see any bmap calls here on a modified, data-journaled file,
1307 * take extra steps to flush any blocks which might be in the cache.
1308 */
1309static sector_t ext3_bmap(struct address_space *mapping, sector_t block)
1310{
1311 struct inode *inode = mapping->host;
1312 journal_t *journal;
1313 int err;
1314
1315 if (EXT3_I(inode)->i_state & EXT3_STATE_JDATA) {
1316 /*
1317 * This is a REALLY heavyweight approach, but the use of
1318 * bmap on dirty files is expected to be extremely rare:
1319 * only if we run lilo or swapon on a freshly made file
1320 * do we expect this to happen.
1321 *
1322 * (bmap requires CAP_SYS_RAWIO so this does not
1323 * represent an unprivileged user DOS attack --- we'd be
1324 * in trouble if mortal users could trigger this path at
1325 * will.)
1326 *
1327 * NB. EXT3_STATE_JDATA is not set on files other than
1328 * regular files. If somebody wants to bmap a directory
1329 * or symlink and gets confused because the buffer
1330 * hasn't yet been flushed to disk, they deserve
1331 * everything they get.
1332 */
1333
1334 EXT3_I(inode)->i_state &= ~EXT3_STATE_JDATA;
1335 journal = EXT3_JOURNAL(inode);
1336 journal_lock_updates(journal);
1337 err = journal_flush(journal);
1338 journal_unlock_updates(journal);
1339
1340 if (err)
1341 return 0;
1342 }
1343
1344 return generic_block_bmap(mapping,block,ext3_get_block);
1345}
1346
1347static int bget_one(handle_t *handle, struct buffer_head *bh)
1348{
1349 get_bh(bh);
1350 return 0;
1351}
1352
1353static int bput_one(handle_t *handle, struct buffer_head *bh)
1354{
1355 put_bh(bh);
1356 return 0;
1357}
1358
1359static int journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
1360{
1361 if (buffer_mapped(bh))
1362 return ext3_journal_dirty_data(handle, bh);
1363 return 0;
1364}
1365
1366/*
1367 * Note that we always start a transaction even if we're not journalling
1368 * data. This is to preserve ordering: any hole instantiation within
1369 * __block_write_full_page -> ext3_get_block() should be journalled
1370 * along with the data so we don't crash and then get metadata which
1371 * refers to old data.
1372 *
1373 * In all journalling modes block_write_full_page() will start the I/O.
1374 *
1375 * Problem:
1376 *
1377 * ext3_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1378 * ext3_writepage()
1379 *
1380 * Similar for:
1381 *
1382 * ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ...
1383 *
1384 * Same applies to ext3_get_block(). We will deadlock on various things like
1385 * lock_journal and i_truncate_mutex.
1386 *
1387 * Setting PF_MEMALLOC here doesn't work - too many internal memory
1388 * allocations fail.
1389 *
1390 * 16May01: If we're reentered then journal_current_handle() will be
1391 * non-zero. We simply *return*.
1392 *
1393 * 1 July 2001: @@@ FIXME:
1394 * In journalled data mode, a data buffer may be metadata against the
1395 * current transaction. But the same file is part of a shared mapping
1396 * and someone does a writepage() on it.
1397 *
1398 * We will move the buffer onto the async_data list, but *after* it has
1399 * been dirtied. So there's a small window where we have dirty data on
1400 * BJ_Metadata.
1401 *
1402 * Note that this only applies to the last partial page in the file. The
1403 * bit which block_write_full_page() uses prepare/commit for. (That's
1404 * broken code anyway: it's wrong for msync()).
1405 *
1406 * It's a rare case: affects the final partial page, for journalled data
1407 * where the file is subject to bith write() and writepage() in the same
1408 * transction. To fix it we'll need a custom block_write_full_page().
1409 * We'll probably need that anyway for journalling writepage() output.
1410 *
1411 * We don't honour synchronous mounts for writepage(). That would be
1412 * disastrous. Any write() or metadata operation will sync the fs for
1413 * us.
1414 *
1415 * AKPM2: if all the page's buffers are mapped to disk and !data=journal,
1416 * we don't need to open a transaction here.
1417 */
1418static int ext3_ordered_writepage(struct page *page,
1419 struct writeback_control *wbc)
1420{
1421 struct inode *inode = page->mapping->host;
1422 struct buffer_head *page_bufs;
1423 handle_t *handle = NULL;
1424 int ret = 0;
1425 int err;
1426
1427 J_ASSERT(PageLocked(page));
1428
1429 /*
1430 * We give up here if we're reentered, because it might be for a
1431 * different filesystem.
1432 */
1433 if (ext3_journal_current_handle())
1434 goto out_fail;
1435
1436 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1437
1438 if (IS_ERR(handle)) {
1439 ret = PTR_ERR(handle);
1440 goto out_fail;
1441 }
1442
1443 if (!page_has_buffers(page)) {
1444 create_empty_buffers(page, inode->i_sb->s_blocksize,
1445 (1 << BH_Dirty)|(1 << BH_Uptodate));
1446 }
1447 page_bufs = page_buffers(page);
1448 walk_page_buffers(handle, page_bufs, 0,
1449 PAGE_CACHE_SIZE, NULL, bget_one);
1450
1451 ret = block_write_full_page(page, ext3_get_block, wbc);
1452
1453 /*
1454 * The page can become unlocked at any point now, and
1455 * truncate can then come in and change things. So we
1456 * can't touch *page from now on. But *page_bufs is
1457 * safe due to elevated refcount.
1458 */
1459
1460 /*
1461 * And attach them to the current transaction. But only if
1462 * block_write_full_page() succeeded. Otherwise they are unmapped,
1463 * and generally junk.
1464 */
1465 if (ret == 0) {
1466 err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
1467 NULL, journal_dirty_data_fn);
1468 if (!ret)
1469 ret = err;
1470 }
1471 walk_page_buffers(handle, page_bufs, 0,
1472 PAGE_CACHE_SIZE, NULL, bput_one);
1473 err = ext3_journal_stop(handle);
1474 if (!ret)
1475 ret = err;
1476 return ret;
1477
1478out_fail:
1479 redirty_page_for_writepage(wbc, page);
1480 unlock_page(page);
1481 return ret;
1482}
1483
1484static int ext3_writeback_writepage(struct page *page,
1485 struct writeback_control *wbc)
1486{
1487 struct inode *inode = page->mapping->host;
1488 handle_t *handle = NULL;
1489 int ret = 0;
1490 int err;
1491
1492 if (ext3_journal_current_handle())
1493 goto out_fail;
1494
1495 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1496 if (IS_ERR(handle)) {
1497 ret = PTR_ERR(handle);
1498 goto out_fail;
1499 }
1500
1501 if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
1502 ret = nobh_writepage(page, ext3_get_block, wbc);
1503 else
1504 ret = block_write_full_page(page, ext3_get_block, wbc);
1505
1506 err = ext3_journal_stop(handle);
1507 if (!ret)
1508 ret = err;
1509 return ret;
1510
1511out_fail:
1512 redirty_page_for_writepage(wbc, page);
1513 unlock_page(page);
1514 return ret;
1515}
1516
1517static int ext3_journalled_writepage(struct page *page,
1518 struct writeback_control *wbc)
1519{
1520 struct inode *inode = page->mapping->host;
1521 handle_t *handle = NULL;
1522 int ret = 0;
1523 int err;
1524
1525 if (ext3_journal_current_handle())
1526 goto no_write;
1527
1528 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1529 if (IS_ERR(handle)) {
1530 ret = PTR_ERR(handle);
1531 goto no_write;
1532 }
1533
1534 if (!page_has_buffers(page) || PageChecked(page)) {
1535 /*
1536 * It's mmapped pagecache. Add buffers and journal it. There
1537 * doesn't seem much point in redirtying the page here.
1538 */
1539 ClearPageChecked(page);
1540 ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
1541 ext3_get_block);
1542 if (ret != 0) {
1543 ext3_journal_stop(handle);
1544 goto out_unlock;
1545 }
1546 ret = walk_page_buffers(handle, page_buffers(page), 0,
1547 PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
1548
1549 err = walk_page_buffers(handle, page_buffers(page), 0,
1550 PAGE_CACHE_SIZE, NULL, commit_write_fn);
1551 if (ret == 0)
1552 ret = err;
1553 EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1554 unlock_page(page);
1555 } else {
1556 /*
1557 * It may be a page full of checkpoint-mode buffers. We don't
1558 * really know unless we go poke around in the buffer_heads.
1559 * But block_write_full_page will do the right thing.
1560 */
1561 ret = block_write_full_page(page, ext3_get_block, wbc);
1562 }
1563 err = ext3_journal_stop(handle);
1564 if (!ret)
1565 ret = err;
1566out:
1567 return ret;
1568
1569no_write:
1570 redirty_page_for_writepage(wbc, page);
1571out_unlock:
1572 unlock_page(page);
1573 goto out;
1574}
1575
1576static int ext3_readpage(struct file *file, struct page *page)
1577{
1578 return mpage_readpage(page, ext3_get_block);
1579}
1580
1581static int
1582ext3_readpages(struct file *file, struct address_space *mapping,
1583 struct list_head *pages, unsigned nr_pages)
1584{
1585 return mpage_readpages(mapping, pages, nr_pages, ext3_get_block);
1586}
1587
1588static void ext3_invalidatepage(struct page *page, unsigned long offset)
1589{
1590 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1591
1592 /*
1593 * If it's a full truncate we just forget about the pending dirtying
1594 */
1595 if (offset == 0)
1596 ClearPageChecked(page);
1597
1598 journal_invalidatepage(journal, page, offset);
1599}
1600
1601static int ext3_releasepage(struct page *page, gfp_t wait)
1602{
1603 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1604
1605 WARN_ON(PageChecked(page));
1606 if (!page_has_buffers(page))
1607 return 0;
1608 return journal_try_to_free_buffers(journal, page, wait);
1609}
1610
1611/*
1612 * If the O_DIRECT write will extend the file then add this inode to the
1613 * orphan list. So recovery will truncate it back to the original size
1614 * if the machine crashes during the write.
1615 *
1616 * If the O_DIRECT write is intantiating holes inside i_size and the machine
1617 * crashes then stale disk data _may_ be exposed inside the file.
1618 */
1619static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
1620 const struct iovec *iov, loff_t offset,
1621 unsigned long nr_segs)
1622{
1623 struct file *file = iocb->ki_filp;
1624 struct inode *inode = file->f_mapping->host;
1625 struct ext3_inode_info *ei = EXT3_I(inode);
1626 handle_t *handle = NULL;
1627 ssize_t ret;
1628 int orphan = 0;
1629 size_t count = iov_length(iov, nr_segs);
1630
1631 if (rw == WRITE) {
1632 loff_t final_size = offset + count;
1633
1634 handle = ext3_journal_start(inode, DIO_CREDITS);
1635 if (IS_ERR(handle)) {
1636 ret = PTR_ERR(handle);
1637 goto out;
1638 }
1639 if (final_size > inode->i_size) {
1640 ret = ext3_orphan_add(handle, inode);
1641 if (ret)
1642 goto out_stop;
1643 orphan = 1;
1644 ei->i_disksize = inode->i_size;
1645 }
1646 }
1647
1648 ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
1649 offset, nr_segs,
1650 ext3_get_block, NULL);
1651
1652 /*
1653 * Reacquire the handle: ext3_get_block() can restart the transaction
1654 */
1655 handle = journal_current_handle();
1656
1657out_stop:
1658 if (handle) {
1659 int err;
1660
1661 if (orphan && inode->i_nlink)
1662 ext3_orphan_del(handle, inode);
1663 if (orphan && ret > 0) {
1664 loff_t end = offset + ret;
1665 if (end > inode->i_size) {
1666 ei->i_disksize = end;
1667 i_size_write(inode, end);
1668 /*
1669 * We're going to return a positive `ret'
1670 * here due to non-zero-length I/O, so there's
1671 * no way of reporting error returns from
1672 * ext3_mark_inode_dirty() to userspace. So
1673 * ignore it.
1674 */
1675 ext3_mark_inode_dirty(handle, inode);
1676 }
1677 }
1678 err = ext3_journal_stop(handle);
1679 if (ret == 0)
1680 ret = err;
1681 }
1682out:
1683 return ret;
1684}
1685
1686/*
1687 * Pages can be marked dirty completely asynchronously from ext3's journalling
1688 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
1689 * much here because ->set_page_dirty is called under VFS locks. The page is
1690 * not necessarily locked.
1691 *
1692 * We cannot just dirty the page and leave attached buffers clean, because the
1693 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
1694 * or jbddirty because all the journalling code will explode.
1695 *
1696 * So what we do is to mark the page "pending dirty" and next time writepage
1697 * is called, propagate that into the buffers appropriately.
1698 */
1699static int ext3_journalled_set_page_dirty(struct page *page)
1700{
1701 SetPageChecked(page);
1702 return __set_page_dirty_nobuffers(page);
1703}
1704
1705static const struct address_space_operations ext3_ordered_aops = {
1706 .readpage = ext3_readpage,
1707 .readpages = ext3_readpages,
1708 .writepage = ext3_ordered_writepage,
1709 .sync_page = block_sync_page,
1710 .prepare_write = ext3_prepare_write,
1711 .commit_write = ext3_ordered_commit_write,
1712 .bmap = ext3_bmap,
1713 .invalidatepage = ext3_invalidatepage,
1714 .releasepage = ext3_releasepage,
1715 .direct_IO = ext3_direct_IO,
1716 .migratepage = buffer_migrate_page,
1717};
1718
1719static const struct address_space_operations ext3_writeback_aops = {
1720 .readpage = ext3_readpage,
1721 .readpages = ext3_readpages,
1722 .writepage = ext3_writeback_writepage,
1723 .sync_page = block_sync_page,
1724 .prepare_write = ext3_prepare_write,
1725 .commit_write = ext3_writeback_commit_write,
1726 .bmap = ext3_bmap,
1727 .invalidatepage = ext3_invalidatepage,
1728 .releasepage = ext3_releasepage,
1729 .direct_IO = ext3_direct_IO,
1730 .migratepage = buffer_migrate_page,
1731};
1732
1733static const struct address_space_operations ext3_journalled_aops = {
1734 .readpage = ext3_readpage,
1735 .readpages = ext3_readpages,
1736 .writepage = ext3_journalled_writepage,
1737 .sync_page = block_sync_page,
1738 .prepare_write = ext3_prepare_write,
1739 .commit_write = ext3_journalled_commit_write,
1740 .set_page_dirty = ext3_journalled_set_page_dirty,
1741 .bmap = ext3_bmap,
1742 .invalidatepage = ext3_invalidatepage,
1743 .releasepage = ext3_releasepage,
1744};
1745
1746void ext3_set_aops(struct inode *inode)
1747{
1748 if (ext3_should_order_data(inode))
1749 inode->i_mapping->a_ops = &ext3_ordered_aops;
1750 else if (ext3_should_writeback_data(inode))
1751 inode->i_mapping->a_ops = &ext3_writeback_aops;
1752 else
1753 inode->i_mapping->a_ops = &ext3_journalled_aops;
1754}
1755
1756/*
1757 * ext3_block_truncate_page() zeroes out a mapping from file offset `from'
1758 * up to the end of the block which corresponds to `from'.
1759 * This required during truncate. We need to physically zero the tail end
1760 * of that block so it doesn't yield old data if the file is later grown.
1761 */
1762static int ext3_block_truncate_page(handle_t *handle, struct page *page,
1763 struct address_space *mapping, loff_t from)
1764{
1765 ext3_fsblk_t index = from >> PAGE_CACHE_SHIFT;
1766 unsigned offset = from & (PAGE_CACHE_SIZE-1);
1767 unsigned blocksize, iblock, length, pos;
1768 struct inode *inode = mapping->host;
1769 struct buffer_head *bh;
1770 int err = 0;
1771 void *kaddr;
1772
1773 blocksize = inode->i_sb->s_blocksize;
1774 length = blocksize - (offset & (blocksize - 1));
1775 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1776
1777 /*
1778 * For "nobh" option, we can only work if we don't need to
1779 * read-in the page - otherwise we create buffers to do the IO.
1780 */
1781 if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
1782 ext3_should_writeback_data(inode) && PageUptodate(page)) {
1783 kaddr = kmap_atomic(page, KM_USER0);
1784 memset(kaddr + offset, 0, length);
1785 flush_dcache_page(page);
1786 kunmap_atomic(kaddr, KM_USER0);
1787 set_page_dirty(page);
1788 goto unlock;
1789 }
1790
1791 if (!page_has_buffers(page))
1792 create_empty_buffers(page, blocksize, 0);
1793
1794 /* Find the buffer that contains "offset" */
1795 bh = page_buffers(page);
1796 pos = blocksize;
1797 while (offset >= pos) {
1798 bh = bh->b_this_page;
1799 iblock++;
1800 pos += blocksize;
1801 }
1802
1803 err = 0;
1804 if (buffer_freed(bh)) {
1805 BUFFER_TRACE(bh, "freed: skip");
1806 goto unlock;
1807 }
1808
1809 if (!buffer_mapped(bh)) {
1810 BUFFER_TRACE(bh, "unmapped");
1811 ext3_get_block(inode, iblock, bh, 0);
1812 /* unmapped? It's a hole - nothing to do */
1813 if (!buffer_mapped(bh)) {
1814 BUFFER_TRACE(bh, "still unmapped");
1815 goto unlock;
1816 }
1817 }
1818
1819 /* Ok, it's mapped. Make sure it's up-to-date */
1820 if (PageUptodate(page))
1821 set_buffer_uptodate(bh);
1822
1823 if (!buffer_uptodate(bh)) {
1824 err = -EIO;
1825 ll_rw_block(READ, 1, &bh);
1826 wait_on_buffer(bh);
1827 /* Uhhuh. Read error. Complain and punt. */
1828 if (!buffer_uptodate(bh))
1829 goto unlock;
1830 }
1831
1832 if (ext3_should_journal_data(inode)) {
1833 BUFFER_TRACE(bh, "get write access");
1834 err = ext3_journal_get_write_access(handle, bh);
1835 if (err)
1836 goto unlock;
1837 }
1838
1839 kaddr = kmap_atomic(page, KM_USER0);
1840 memset(kaddr + offset, 0, length);
1841 flush_dcache_page(page);
1842 kunmap_atomic(kaddr, KM_USER0);
1843
1844 BUFFER_TRACE(bh, "zeroed end of block");
1845
1846 err = 0;
1847 if (ext3_should_journal_data(inode)) {
1848 err = ext3_journal_dirty_metadata(handle, bh);
1849 } else {
1850 if (ext3_should_order_data(inode))
1851 err = ext3_journal_dirty_data(handle, bh);
1852 mark_buffer_dirty(bh);
1853 }
1854
1855unlock:
1856 unlock_page(page);
1857 page_cache_release(page);
1858 return err;
1859}
1860
1861/*
1862 * Probably it should be a library function... search for first non-zero word
1863 * or memcmp with zero_page, whatever is better for particular architecture.
1864 * Linus?
1865 */
1866static inline int all_zeroes(__le32 *p, __le32 *q)
1867{
1868 while (p < q)
1869 if (*p++)
1870 return 0;
1871 return 1;
1872}
1873
1874/**
1875 * ext3_find_shared - find the indirect blocks for partial truncation.
1876 * @inode: inode in question
1877 * @depth: depth of the affected branch
1878 * @offsets: offsets of pointers in that branch (see ext3_block_to_path)
1879 * @chain: place to store the pointers to partial indirect blocks
1880 * @top: place to the (detached) top of branch
1881 *
1882 * This is a helper function used by ext3_truncate().
1883 *
1884 * When we do truncate() we may have to clean the ends of several
1885 * indirect blocks but leave the blocks themselves alive. Block is
1886 * partially truncated if some data below the new i_size is refered
1887 * from it (and it is on the path to the first completely truncated
1888 * data block, indeed). We have to free the top of that path along
1889 * with everything to the right of the path. Since no allocation
1890 * past the truncation point is possible until ext3_truncate()
1891 * finishes, we may safely do the latter, but top of branch may
1892 * require special attention - pageout below the truncation point
1893 * might try to populate it.
1894 *
1895 * We atomically detach the top of branch from the tree, store the
1896 * block number of its root in *@top, pointers to buffer_heads of
1897 * partially truncated blocks - in @chain[].bh and pointers to
1898 * their last elements that should not be removed - in
1899 * @chain[].p. Return value is the pointer to last filled element
1900 * of @chain.
1901 *
1902 * The work left to caller to do the actual freeing of subtrees:
1903 * a) free the subtree starting from *@top
1904 * b) free the subtrees whose roots are stored in
1905 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
1906 * c) free the subtrees growing from the inode past the @chain[0].
1907 * (no partially truncated stuff there). */
1908
1909static Indirect *ext3_find_shared(struct inode *inode, int depth,
1910 int offsets[4], Indirect chain[4], __le32 *top)
1911{
1912 Indirect *partial, *p;
1913 int k, err;
1914
1915 *top = 0;
1916 /* Make k index the deepest non-null offest + 1 */
1917 for (k = depth; k > 1 && !offsets[k-1]; k--)
1918 ;
1919 partial = ext3_get_branch(inode, k, offsets, chain, &err);
1920 /* Writer: pointers */
1921 if (!partial)
1922 partial = chain + k-1;
1923 /*
1924 * If the branch acquired continuation since we've looked at it -
1925 * fine, it should all survive and (new) top doesn't belong to us.
1926 */
1927 if (!partial->key && *partial->p)
1928 /* Writer: end */
1929 goto no_top;
1930 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
1931 ;
1932 /*
1933 * OK, we've found the last block that must survive. The rest of our
1934 * branch should be detached before unlocking. However, if that rest
1935 * of branch is all ours and does not grow immediately from the inode
1936 * it's easier to cheat and just decrement partial->p.
1937 */
1938 if (p == chain + k - 1 && p > chain) {
1939 p->p--;
1940 } else {
1941 *top = *p->p;
1942 /* Nope, don't do this in ext3. Must leave the tree intact */
1943#if 0
1944 *p->p = 0;
1945#endif
1946 }
1947 /* Writer: end */
1948
1949 while(partial > p) {
1950 brelse(partial->bh);
1951 partial--;
1952 }
1953no_top:
1954 return partial;
1955}
1956
1957/*
1958 * Zero a number of block pointers in either an inode or an indirect block.
1959 * If we restart the transaction we must again get write access to the
1960 * indirect block for further modification.
1961 *
1962 * We release `count' blocks on disk, but (last - first) may be greater
1963 * than `count' because there can be holes in there.
1964 */
1965static void ext3_clear_blocks(handle_t *handle, struct inode *inode,
1966 struct buffer_head *bh, ext3_fsblk_t block_to_free,
1967 unsigned long count, __le32 *first, __le32 *last)
1968{
1969 __le32 *p;
1970 if (try_to_extend_transaction(handle, inode)) {
1971 if (bh) {
1972 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
1973 ext3_journal_dirty_metadata(handle, bh);
1974 }
1975 ext3_mark_inode_dirty(handle, inode);
1976 ext3_journal_test_restart(handle, inode);
1977 if (bh) {
1978 BUFFER_TRACE(bh, "retaking write access");
1979 ext3_journal_get_write_access(handle, bh);
1980 }
1981 }
1982
1983 /*
1984 * Any buffers which are on the journal will be in memory. We find
1985 * them on the hash table so journal_revoke() will run journal_forget()
1986 * on them. We've already detached each block from the file, so
1987 * bforget() in journal_forget() should be safe.
1988 *
1989 * AKPM: turn on bforget in journal_forget()!!!
1990 */
1991 for (p = first; p < last; p++) {
1992 u32 nr = le32_to_cpu(*p);
1993 if (nr) {
1994 struct buffer_head *bh;
1995
1996 *p = 0;
1997 bh = sb_find_get_block(inode->i_sb, nr);
1998 ext3_forget(handle, 0, inode, bh, nr);
1999 }
2000 }
2001
2002 ext3_free_blocks(handle, inode, block_to_free, count);
2003}
2004
2005/**
2006 * ext3_free_data - free a list of data blocks
2007 * @handle: handle for this transaction
2008 * @inode: inode we are dealing with
2009 * @this_bh: indirect buffer_head which contains *@first and *@last
2010 * @first: array of block numbers
2011 * @last: points immediately past the end of array
2012 *
2013 * We are freeing all blocks refered from that array (numbers are stored as
2014 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
2015 *
2016 * We accumulate contiguous runs of blocks to free. Conveniently, if these
2017 * blocks are contiguous then releasing them at one time will only affect one
2018 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
2019 * actually use a lot of journal space.
2020 *
2021 * @this_bh will be %NULL if @first and @last point into the inode's direct
2022 * block pointers.
2023 */
2024static void ext3_free_data(handle_t *handle, struct inode *inode,
2025 struct buffer_head *this_bh,
2026 __le32 *first, __le32 *last)
2027{
2028 ext3_fsblk_t block_to_free = 0; /* Starting block # of a run */
2029 unsigned long count = 0; /* Number of blocks in the run */
2030 __le32 *block_to_free_p = NULL; /* Pointer into inode/ind
2031 corresponding to
2032 block_to_free */
2033 ext3_fsblk_t nr; /* Current block # */
2034 __le32 *p; /* Pointer into inode/ind
2035 for current block */
2036 int err;
2037
2038 if (this_bh) { /* For indirect block */
2039 BUFFER_TRACE(this_bh, "get_write_access");
2040 err = ext3_journal_get_write_access(handle, this_bh);
2041 /* Important: if we can't update the indirect pointers
2042 * to the blocks, we can't free them. */
2043 if (err)
2044 return;
2045 }
2046
2047 for (p = first; p < last; p++) {
2048 nr = le32_to_cpu(*p);
2049 if (nr) {
2050 /* accumulate blocks to free if they're contiguous */
2051 if (count == 0) {
2052 block_to_free = nr;
2053 block_to_free_p = p;
2054 count = 1;
2055 } else if (nr == block_to_free + count) {
2056 count++;
2057 } else {
2058 ext3_clear_blocks(handle, inode, this_bh,
2059 block_to_free,
2060 count, block_to_free_p, p);
2061 block_to_free = nr;
2062 block_to_free_p = p;
2063 count = 1;
2064 }
2065 }
2066 }
2067
2068 if (count > 0)
2069 ext3_clear_blocks(handle, inode, this_bh, block_to_free,
2070 count, block_to_free_p, p);
2071
2072 if (this_bh) {
2073 BUFFER_TRACE(this_bh, "call ext3_journal_dirty_metadata");
2074 ext3_journal_dirty_metadata(handle, this_bh);
2075 }
2076}
2077
2078/**
2079 * ext3_free_branches - free an array of branches
2080 * @handle: JBD handle for this transaction
2081 * @inode: inode we are dealing with
2082 * @parent_bh: the buffer_head which contains *@first and *@last
2083 * @first: array of block numbers
2084 * @last: pointer immediately past the end of array
2085 * @depth: depth of the branches to free
2086 *
2087 * We are freeing all blocks refered from these branches (numbers are
2088 * stored as little-endian 32-bit) and updating @inode->i_blocks
2089 * appropriately.
2090 */
2091static void ext3_free_branches(handle_t *handle, struct inode *inode,
2092 struct buffer_head *parent_bh,
2093 __le32 *first, __le32 *last, int depth)
2094{
2095 ext3_fsblk_t nr;
2096 __le32 *p;
2097
2098 if (is_handle_aborted(handle))
2099 return;
2100
2101 if (depth--) {
2102 struct buffer_head *bh;
2103 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2104 p = last;
2105 while (--p >= first) {
2106 nr = le32_to_cpu(*p);
2107 if (!nr)
2108 continue; /* A hole */
2109
2110 /* Go read the buffer for the next level down */
2111 bh = sb_bread(inode->i_sb, nr);
2112
2113 /*
2114 * A read failure? Report error and clear slot
2115 * (should be rare).
2116 */
2117 if (!bh) {
2118 ext3_error(inode->i_sb, "ext3_free_branches",
2119 "Read failure, inode=%lu, block="E3FSBLK,
2120 inode->i_ino, nr);
2121 continue;
2122 }
2123
2124 /* This zaps the entire block. Bottom up. */
2125 BUFFER_TRACE(bh, "free child branches");
2126 ext3_free_branches(handle, inode, bh,
2127 (__le32*)bh->b_data,
2128 (__le32*)bh->b_data + addr_per_block,
2129 depth);
2130
2131 /*
2132 * We've probably journalled the indirect block several
2133 * times during the truncate. But it's no longer
2134 * needed and we now drop it from the transaction via
2135 * journal_revoke().
2136 *
2137 * That's easy if it's exclusively part of this
2138 * transaction. But if it's part of the committing
2139 * transaction then journal_forget() will simply
2140 * brelse() it. That means that if the underlying
2141 * block is reallocated in ext3_get_block(),
2142 * unmap_underlying_metadata() will find this block
2143 * and will try to get rid of it. damn, damn.
2144 *
2145 * If this block has already been committed to the
2146 * journal, a revoke record will be written. And
2147 * revoke records must be emitted *before* clearing
2148 * this block's bit in the bitmaps.
2149 */
2150 ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
2151
2152 /*
2153 * Everything below this this pointer has been
2154 * released. Now let this top-of-subtree go.
2155 *
2156 * We want the freeing of this indirect block to be
2157 * atomic in the journal with the updating of the
2158 * bitmap block which owns it. So make some room in
2159 * the journal.
2160 *
2161 * We zero the parent pointer *after* freeing its
2162 * pointee in the bitmaps, so if extend_transaction()
2163 * for some reason fails to put the bitmap changes and
2164 * the release into the same transaction, recovery
2165 * will merely complain about releasing a free block,
2166 * rather than leaking blocks.
2167 */
2168 if (is_handle_aborted(handle))
2169 return;
2170 if (try_to_extend_transaction(handle, inode)) {
2171 ext3_mark_inode_dirty(handle, inode);
2172 ext3_journal_test_restart(handle, inode);
2173 }
2174
2175 ext3_free_blocks(handle, inode, nr, 1);
2176
2177 if (parent_bh) {
2178 /*
2179 * The block which we have just freed is
2180 * pointed to by an indirect block: journal it
2181 */
2182 BUFFER_TRACE(parent_bh, "get_write_access");
2183 if (!ext3_journal_get_write_access(handle,
2184 parent_bh)){
2185 *p = 0;
2186 BUFFER_TRACE(parent_bh,
2187 "call ext3_journal_dirty_metadata");
2188 ext3_journal_dirty_metadata(handle,
2189 parent_bh);
2190 }
2191 }
2192 }
2193 } else {
2194 /* We have reached the bottom of the tree. */
2195 BUFFER_TRACE(parent_bh, "free data blocks");
2196 ext3_free_data(handle, inode, parent_bh, first, last);
2197 }
2198}
2199
2200/*
2201 * ext3_truncate()
2202 *
2203 * We block out ext3_get_block() block instantiations across the entire
2204 * transaction, and VFS/VM ensures that ext3_truncate() cannot run
2205 * simultaneously on behalf of the same inode.
2206 *
2207 * As we work through the truncate and commmit bits of it to the journal there
2208 * is one core, guiding principle: the file's tree must always be consistent on
2209 * disk. We must be able to restart the truncate after a crash.
2210 *
2211 * The file's tree may be transiently inconsistent in memory (although it
2212 * probably isn't), but whenever we close off and commit a journal transaction,
2213 * the contents of (the filesystem + the journal) must be consistent and
2214 * restartable. It's pretty simple, really: bottom up, right to left (although
2215 * left-to-right works OK too).
2216 *
2217 * Note that at recovery time, journal replay occurs *before* the restart of
2218 * truncate against the orphan inode list.
2219 *
2220 * The committed inode has the new, desired i_size (which is the same as
2221 * i_disksize in this case). After a crash, ext3_orphan_cleanup() will see
2222 * that this inode's truncate did not complete and it will again call
2223 * ext3_truncate() to have another go. So there will be instantiated blocks
2224 * to the right of the truncation point in a crashed ext3 filesystem. But
2225 * that's fine - as long as they are linked from the inode, the post-crash
2226 * ext3_truncate() run will find them and release them.
2227 */
2228void ext3_truncate(struct inode *inode)
2229{
2230 handle_t *handle;
2231 struct ext3_inode_info *ei = EXT3_I(inode);
2232 __le32 *i_data = ei->i_data;
2233 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2234 struct address_space *mapping = inode->i_mapping;
2235 int offsets[4];
2236 Indirect chain[4];
2237 Indirect *partial;
2238 __le32 nr = 0;
2239 int n;
2240 long last_block;
2241 unsigned blocksize = inode->i_sb->s_blocksize;
2242 struct page *page;
2243
2244 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2245 S_ISLNK(inode->i_mode)))
2246 return;
2247 if (ext3_inode_is_fast_symlink(inode))
2248 return;
2249 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2250 return;
2251
2252 /*
2253 * We have to lock the EOF page here, because lock_page() nests
2254 * outside journal_start().
2255 */
2256 if ((inode->i_size & (blocksize - 1)) == 0) {
2257 /* Block boundary? Nothing to do */
2258 page = NULL;
2259 } else {
2260 page = grab_cache_page(mapping,
2261 inode->i_size >> PAGE_CACHE_SHIFT);
2262 if (!page)
2263 return;
2264 }
2265
2266 handle = start_transaction(inode);
2267 if (IS_ERR(handle)) {
2268 if (page) {
2269 clear_highpage(page);
2270 flush_dcache_page(page);
2271 unlock_page(page);
2272 page_cache_release(page);
2273 }
2274 return; /* AKPM: return what? */
2275 }
2276
2277 last_block = (inode->i_size + blocksize-1)
2278 >> EXT3_BLOCK_SIZE_BITS(inode->i_sb);
2279
2280 if (page)
2281 ext3_block_truncate_page(handle, page, mapping, inode->i_size);
2282
2283 n = ext3_block_to_path(inode, last_block, offsets, NULL);
2284 if (n == 0)
2285 goto out_stop; /* error */
2286
2287 /*
2288 * OK. This truncate is going to happen. We add the inode to the
2289 * orphan list, so that if this truncate spans multiple transactions,
2290 * and we crash, we will resume the truncate when the filesystem
2291 * recovers. It also marks the inode dirty, to catch the new size.
2292 *
2293 * Implication: the file must always be in a sane, consistent
2294 * truncatable state while each transaction commits.
2295 */
2296 if (ext3_orphan_add(handle, inode))
2297 goto out_stop;
2298
2299 /*
2300 * The orphan list entry will now protect us from any crash which
2301 * occurs before the truncate completes, so it is now safe to propagate
2302 * the new, shorter inode size (held for now in i_size) into the
2303 * on-disk inode. We do this via i_disksize, which is the value which
2304 * ext3 *really* writes onto the disk inode.
2305 */
2306 ei->i_disksize = inode->i_size;
2307
2308 /*
2309 * From here we block out all ext3_get_block() callers who want to
2310 * modify the block allocation tree.
2311 */
2312 mutex_lock(&ei->truncate_mutex);
2313
2314 if (n == 1) { /* direct blocks */
2315 ext3_free_data(handle, inode, NULL, i_data+offsets[0],
2316 i_data + EXT3_NDIR_BLOCKS);
2317 goto do_indirects;
2318 }
2319
2320 partial = ext3_find_shared(inode, n, offsets, chain, &nr);
2321 /* Kill the top of shared branch (not detached) */
2322 if (nr) {
2323 if (partial == chain) {
2324 /* Shared branch grows from the inode */
2325 ext3_free_branches(handle, inode, NULL,
2326 &nr, &nr+1, (chain+n-1) - partial);
2327 *partial->p = 0;
2328 /*
2329 * We mark the inode dirty prior to restart,
2330 * and prior to stop. No need for it here.
2331 */
2332 } else {
2333 /* Shared branch grows from an indirect block */
2334 BUFFER_TRACE(partial->bh, "get_write_access");
2335 ext3_free_branches(handle, inode, partial->bh,
2336 partial->p,
2337 partial->p+1, (chain+n-1) - partial);
2338 }
2339 }
2340 /* Clear the ends of indirect blocks on the shared branch */
2341 while (partial > chain) {
2342 ext3_free_branches(handle, inode, partial->bh, partial->p + 1,
2343 (__le32*)partial->bh->b_data+addr_per_block,
2344 (chain+n-1) - partial);
2345 BUFFER_TRACE(partial->bh, "call brelse");
2346 brelse (partial->bh);
2347 partial--;
2348 }
2349do_indirects:
2350 /* Kill the remaining (whole) subtrees */
2351 switch (offsets[0]) {
2352 default:
2353 nr = i_data[EXT3_IND_BLOCK];
2354 if (nr) {
2355 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
2356 i_data[EXT3_IND_BLOCK] = 0;
2357 }
2358 case EXT3_IND_BLOCK:
2359 nr = i_data[EXT3_DIND_BLOCK];
2360 if (nr) {
2361 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
2362 i_data[EXT3_DIND_BLOCK] = 0;
2363 }
2364 case EXT3_DIND_BLOCK:
2365 nr = i_data[EXT3_TIND_BLOCK];
2366 if (nr) {
2367 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
2368 i_data[EXT3_TIND_BLOCK] = 0;
2369 }
2370 case EXT3_TIND_BLOCK:
2371 ;
2372 }
2373
2374 ext3_discard_reservation(inode);
2375
2376 mutex_unlock(&ei->truncate_mutex);
2377 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
2378 ext3_mark_inode_dirty(handle, inode);
2379
2380 /*
2381 * In a multi-transaction truncate, we only make the final transaction
2382 * synchronous
2383 */
2384 if (IS_SYNC(inode))
2385 handle->h_sync = 1;
2386out_stop:
2387 /*
2388 * If this was a simple ftruncate(), and the file will remain alive
2389 * then we need to clear up the orphan record which we created above.
2390 * However, if this was a real unlink then we were called by
2391 * ext3_delete_inode(), and we allow that function to clean up the
2392 * orphan info for us.
2393 */
2394 if (inode->i_nlink)
2395 ext3_orphan_del(handle, inode);
2396
2397 ext3_journal_stop(handle);
2398}
2399
2400static ext3_fsblk_t ext3_get_inode_block(struct super_block *sb,
2401 unsigned long ino, struct ext3_iloc *iloc)
2402{
2403 unsigned long desc, group_desc, block_group;
2404 unsigned long offset;
2405 ext3_fsblk_t block;
2406 struct buffer_head *bh;
2407 struct ext3_group_desc * gdp;
2408
2409 if (!ext3_valid_inum(sb, ino)) {
2410 /*
2411 * This error is already checked for in namei.c unless we are
2412 * looking at an NFS filehandle, in which case no error
2413 * report is needed
2414 */
2415 return 0;
2416 }
2417
2418 block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
2419 if (block_group >= EXT3_SB(sb)->s_groups_count) {
2420 ext3_error(sb,"ext3_get_inode_block","group >= groups count");
2421 return 0;
2422 }
2423 smp_rmb();
2424 group_desc = block_group >> EXT3_DESC_PER_BLOCK_BITS(sb);
2425 desc = block_group & (EXT3_DESC_PER_BLOCK(sb) - 1);
2426 bh = EXT3_SB(sb)->s_group_desc[group_desc];
2427 if (!bh) {
2428 ext3_error (sb, "ext3_get_inode_block",
2429 "Descriptor not loaded");
2430 return 0;
2431 }
2432
2433 gdp = (struct ext3_group_desc *)bh->b_data;
2434 /*
2435 * Figure out the offset within the block group inode table
2436 */
2437 offset = ((ino - 1) % EXT3_INODES_PER_GROUP(sb)) *
2438 EXT3_INODE_SIZE(sb);
2439 block = le32_to_cpu(gdp[desc].bg_inode_table) +
2440 (offset >> EXT3_BLOCK_SIZE_BITS(sb));
2441
2442 iloc->block_group = block_group;
2443 iloc->offset = offset & (EXT3_BLOCK_SIZE(sb) - 1);
2444 return block;
2445}
2446
2447/*
2448 * ext3_get_inode_loc returns with an extra refcount against the inode's
2449 * underlying buffer_head on success. If 'in_mem' is true, we have all
2450 * data in memory that is needed to recreate the on-disk version of this
2451 * inode.
2452 */
2453static int __ext3_get_inode_loc(struct inode *inode,
2454 struct ext3_iloc *iloc, int in_mem)
2455{
2456 ext3_fsblk_t block;
2457 struct buffer_head *bh;
2458
2459 block = ext3_get_inode_block(inode->i_sb, inode->i_ino, iloc);
2460 if (!block)
2461 return -EIO;
2462
2463 bh = sb_getblk(inode->i_sb, block);
2464 if (!bh) {
2465 ext3_error (inode->i_sb, "ext3_get_inode_loc",
2466 "unable to read inode block - "
2467 "inode=%lu, block="E3FSBLK,
2468 inode->i_ino, block);
2469 return -EIO;
2470 }
2471 if (!buffer_uptodate(bh)) {
2472 lock_buffer(bh);
2473 if (buffer_uptodate(bh)) {
2474 /* someone brought it uptodate while we waited */
2475 unlock_buffer(bh);
2476 goto has_buffer;
2477 }
2478
2479 /*
2480 * If we have all information of the inode in memory and this
2481 * is the only valid inode in the block, we need not read the
2482 * block.
2483 */
2484 if (in_mem) {
2485 struct buffer_head *bitmap_bh;
2486 struct ext3_group_desc *desc;
2487 int inodes_per_buffer;
2488 int inode_offset, i;
2489 int block_group;
2490 int start;
2491
2492 block_group = (inode->i_ino - 1) /
2493 EXT3_INODES_PER_GROUP(inode->i_sb);
2494 inodes_per_buffer = bh->b_size /
2495 EXT3_INODE_SIZE(inode->i_sb);
2496 inode_offset = ((inode->i_ino - 1) %
2497 EXT3_INODES_PER_GROUP(inode->i_sb));
2498 start = inode_offset & ~(inodes_per_buffer - 1);
2499
2500 /* Is the inode bitmap in cache? */
2501 desc = ext3_get_group_desc(inode->i_sb,
2502 block_group, NULL);
2503 if (!desc)
2504 goto make_io;
2505
2506 bitmap_bh = sb_getblk(inode->i_sb,
2507 le32_to_cpu(desc->bg_inode_bitmap));
2508 if (!bitmap_bh)
2509 goto make_io;
2510
2511 /*
2512 * If the inode bitmap isn't in cache then the
2513 * optimisation may end up performing two reads instead
2514 * of one, so skip it.
2515 */
2516 if (!buffer_uptodate(bitmap_bh)) {
2517 brelse(bitmap_bh);
2518 goto make_io;
2519 }
2520 for (i = start; i < start + inodes_per_buffer; i++) {
2521 if (i == inode_offset)
2522 continue;
2523 if (ext3_test_bit(i, bitmap_bh->b_data))
2524 break;
2525 }
2526 brelse(bitmap_bh);
2527 if (i == start + inodes_per_buffer) {
2528 /* all other inodes are free, so skip I/O */
2529 memset(bh->b_data, 0, bh->b_size);
2530 set_buffer_uptodate(bh);
2531 unlock_buffer(bh);
2532 goto has_buffer;
2533 }
2534 }
2535
2536make_io:
2537 /*
2538 * There are other valid inodes in the buffer, this inode
2539 * has in-inode xattrs, or we don't have this inode in memory.
2540 * Read the block from disk.
2541 */
2542 get_bh(bh);
2543 bh->b_end_io = end_buffer_read_sync;
2544 submit_bh(READ_META, bh);
2545 wait_on_buffer(bh);
2546 if (!buffer_uptodate(bh)) {
2547 ext3_error(inode->i_sb, "ext3_get_inode_loc",
2548 "unable to read inode block - "
2549 "inode=%lu, block="E3FSBLK,
2550 inode->i_ino, block);
2551 brelse(bh);
2552 return -EIO;
2553 }
2554 }
2555has_buffer:
2556 iloc->bh = bh;
2557 return 0;
2558}
2559
2560int ext3_get_inode_loc(struct inode *inode, struct ext3_iloc *iloc)
2561{
2562 /* We have all inode data except xattrs in memory here. */
2563 return __ext3_get_inode_loc(inode, iloc,
2564 !(EXT3_I(inode)->i_state & EXT3_STATE_XATTR));
2565}
2566
2567void ext3_set_inode_flags(struct inode *inode)
2568{
2569 unsigned int flags = EXT3_I(inode)->i_flags;
2570
2571 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
2572 if (flags & EXT3_SYNC_FL)
2573 inode->i_flags |= S_SYNC;
2574 if (flags & EXT3_APPEND_FL)
2575 inode->i_flags |= S_APPEND;
2576 if (flags & EXT3_IMMUTABLE_FL)
2577 inode->i_flags |= S_IMMUTABLE;
2578 if (flags & EXT3_NOATIME_FL)
2579 inode->i_flags |= S_NOATIME;
2580 if (flags & EXT3_DIRSYNC_FL)
2581 inode->i_flags |= S_DIRSYNC;
2582}
2583
2584void ext3_read_inode(struct inode * inode)
2585{
2586 struct ext3_iloc iloc;
2587 struct ext3_inode *raw_inode;
2588 struct ext3_inode_info *ei = EXT3_I(inode);
2589 struct buffer_head *bh;
2590 int block;
2591
2592#ifdef CONFIG_EXT3_FS_POSIX_ACL
2593 ei->i_acl = EXT3_ACL_NOT_CACHED;
2594 ei->i_default_acl = EXT3_ACL_NOT_CACHED;
2595#endif
2596 ei->i_block_alloc_info = NULL;
2597
2598 if (__ext3_get_inode_loc(inode, &iloc, 0))
2599 goto bad_inode;
2600 bh = iloc.bh;
2601 raw_inode = ext3_raw_inode(&iloc);
2602 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
2603 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
2604 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
2605 if(!(test_opt (inode->i_sb, NO_UID32))) {
2606 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
2607 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
2608 }
2609 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
2610 inode->i_size = le32_to_cpu(raw_inode->i_size);
2611 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->i_atime);
2612 inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->i_ctime);
2613 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->i_mtime);
2614 inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
2615
2616 ei->i_state = 0;
2617 ei->i_dir_start_lookup = 0;
2618 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
2619 /* We now have enough fields to check if the inode was active or not.
2620 * This is needed because nfsd might try to access dead inodes
2621 * the test is that same one that e2fsck uses
2622 * NeilBrown 1999oct15
2623 */
2624 if (inode->i_nlink == 0) {
2625 if (inode->i_mode == 0 ||
2626 !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) {
2627 /* this inode is deleted */
2628 brelse (bh);
2629 goto bad_inode;
2630 }
2631 /* The only unlinked inodes we let through here have
2632 * valid i_mode and are being read by the orphan
2633 * recovery code: that's fine, we're about to complete
2634 * the process of deleting those. */
2635 }
2636 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
2637 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
2638#ifdef EXT3_FRAGMENTS
2639 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
2640 ei->i_frag_no = raw_inode->i_frag;
2641 ei->i_frag_size = raw_inode->i_fsize;
2642#endif
2643 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
2644 if (!S_ISREG(inode->i_mode)) {
2645 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
2646 } else {
2647 inode->i_size |=
2648 ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
2649 }
2650 ei->i_disksize = inode->i_size;
2651 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
2652 ei->i_block_group = iloc.block_group;
2653 /*
2654 * NOTE! The in-memory inode i_data array is in little-endian order
2655 * even on big-endian machines: we do NOT byteswap the block numbers!
2656 */
2657 for (block = 0; block < EXT3_N_BLOCKS; block++)
2658 ei->i_data[block] = raw_inode->i_block[block];
2659 INIT_LIST_HEAD(&ei->i_orphan);
2660
2661 if (inode->i_ino >= EXT3_FIRST_INO(inode->i_sb) + 1 &&
2662 EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) {
2663 /*
2664 * When mke2fs creates big inodes it does not zero out
2665 * the unused bytes above EXT3_GOOD_OLD_INODE_SIZE,
2666 * so ignore those first few inodes.
2667 */
2668 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
2669 if (EXT3_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
2670 EXT3_INODE_SIZE(inode->i_sb))
2671 goto bad_inode;
2672 if (ei->i_extra_isize == 0) {
2673 /* The extra space is currently unused. Use it. */
2674 ei->i_extra_isize = sizeof(struct ext3_inode) -
2675 EXT3_GOOD_OLD_INODE_SIZE;
2676 } else {
2677 __le32 *magic = (void *)raw_inode +
2678 EXT3_GOOD_OLD_INODE_SIZE +
2679 ei->i_extra_isize;
2680 if (*magic == cpu_to_le32(EXT3_XATTR_MAGIC))
2681 ei->i_state |= EXT3_STATE_XATTR;
2682 }
2683 } else
2684 ei->i_extra_isize = 0;
2685
2686 if (S_ISREG(inode->i_mode)) {
2687 inode->i_op = &ext3_file_inode_operations;
2688 inode->i_fop = &ext3_file_operations;
2689 ext3_set_aops(inode);
2690 } else if (S_ISDIR(inode->i_mode)) {
2691 inode->i_op = &ext3_dir_inode_operations;
2692 inode->i_fop = &ext3_dir_operations;
2693 } else if (S_ISLNK(inode->i_mode)) {
2694 if (ext3_inode_is_fast_symlink(inode))
2695 inode->i_op = &ext3_fast_symlink_inode_operations;
2696 else {
2697 inode->i_op = &ext3_symlink_inode_operations;
2698 ext3_set_aops(inode);
2699 }
2700 } else {
2701 inode->i_op = &ext3_special_inode_operations;
2702 if (raw_inode->i_block[0])
2703 init_special_inode(inode, inode->i_mode,
2704 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
2705 else
2706 init_special_inode(inode, inode->i_mode,
2707 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
2708 }
2709 brelse (iloc.bh);
2710 ext3_set_inode_flags(inode);
2711 return;
2712
2713bad_inode:
2714 make_bad_inode(inode);
2715 return;
2716}
2717
2718/*
2719 * Post the struct inode info into an on-disk inode location in the
2720 * buffer-cache. This gobbles the caller's reference to the
2721 * buffer_head in the inode location struct.
2722 *
2723 * The caller must have write access to iloc->bh.
2724 */
2725static int ext3_do_update_inode(handle_t *handle,
2726 struct inode *inode,
2727 struct ext3_iloc *iloc)
2728{
2729 struct ext3_inode *raw_inode = ext3_raw_inode(iloc);
2730 struct ext3_inode_info *ei = EXT3_I(inode);
2731 struct buffer_head *bh = iloc->bh;
2732 int err = 0, rc, block;
2733
2734 /* For fields not not tracking in the in-memory inode,
2735 * initialise them to zero for new inodes. */
2736 if (ei->i_state & EXT3_STATE_NEW)
2737 memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
2738
2739 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
2740 if(!(test_opt(inode->i_sb, NO_UID32))) {
2741 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
2742 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
2743/*
2744 * Fix up interoperability with old kernels. Otherwise, old inodes get
2745 * re-used with the upper 16 bits of the uid/gid intact
2746 */
2747 if(!ei->i_dtime) {
2748 raw_inode->i_uid_high =
2749 cpu_to_le16(high_16_bits(inode->i_uid));
2750 raw_inode->i_gid_high =
2751 cpu_to_le16(high_16_bits(inode->i_gid));
2752 } else {
2753 raw_inode->i_uid_high = 0;
2754 raw_inode->i_gid_high = 0;
2755 }
2756 } else {
2757 raw_inode->i_uid_low =
2758 cpu_to_le16(fs_high2lowuid(inode->i_uid));
2759 raw_inode->i_gid_low =
2760 cpu_to_le16(fs_high2lowgid(inode->i_gid));
2761 raw_inode->i_uid_high = 0;
2762 raw_inode->i_gid_high = 0;
2763 }
2764 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
2765 raw_inode->i_size = cpu_to_le32(ei->i_disksize);
2766 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
2767 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
2768 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
2769 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
2770 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
2771 raw_inode->i_flags = cpu_to_le32(ei->i_flags);
2772#ifdef EXT3_FRAGMENTS
2773 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
2774 raw_inode->i_frag = ei->i_frag_no;
2775 raw_inode->i_fsize = ei->i_frag_size;
2776#endif
2777 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
2778 if (!S_ISREG(inode->i_mode)) {
2779 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
2780 } else {
2781 raw_inode->i_size_high =
2782 cpu_to_le32(ei->i_disksize >> 32);
2783 if (ei->i_disksize > 0x7fffffffULL) {
2784 struct super_block *sb = inode->i_sb;
2785 if (!EXT3_HAS_RO_COMPAT_FEATURE(sb,
2786 EXT3_FEATURE_RO_COMPAT_LARGE_FILE) ||
2787 EXT3_SB(sb)->s_es->s_rev_level ==
2788 cpu_to_le32(EXT3_GOOD_OLD_REV)) {
2789 /* If this is the first large file
2790 * created, add a flag to the superblock.
2791 */
2792 err = ext3_journal_get_write_access(handle,
2793 EXT3_SB(sb)->s_sbh);
2794 if (err)
2795 goto out_brelse;
2796 ext3_update_dynamic_rev(sb);
2797 EXT3_SET_RO_COMPAT_FEATURE(sb,
2798 EXT3_FEATURE_RO_COMPAT_LARGE_FILE);
2799 sb->s_dirt = 1;
2800 handle->h_sync = 1;
2801 err = ext3_journal_dirty_metadata(handle,
2802 EXT3_SB(sb)->s_sbh);
2803 }
2804 }
2805 }
2806 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
2807 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
2808 if (old_valid_dev(inode->i_rdev)) {
2809 raw_inode->i_block[0] =
2810 cpu_to_le32(old_encode_dev(inode->i_rdev));
2811 raw_inode->i_block[1] = 0;
2812 } else {
2813 raw_inode->i_block[0] = 0;
2814 raw_inode->i_block[1] =
2815 cpu_to_le32(new_encode_dev(inode->i_rdev));
2816 raw_inode->i_block[2] = 0;
2817 }
2818 } else for (block = 0; block < EXT3_N_BLOCKS; block++)
2819 raw_inode->i_block[block] = ei->i_data[block];
2820
2821 if (ei->i_extra_isize)
2822 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
2823
2824 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
2825 rc = ext3_journal_dirty_metadata(handle, bh);
2826 if (!err)
2827 err = rc;
2828 ei->i_state &= ~EXT3_STATE_NEW;
2829
2830out_brelse:
2831 brelse (bh);
2832 ext3_std_error(inode->i_sb, err);
2833 return err;
2834}
2835
2836/*
2837 * ext3_write_inode()
2838 *
2839 * We are called from a few places:
2840 *
2841 * - Within generic_file_write() for O_SYNC files.
2842 * Here, there will be no transaction running. We wait for any running
2843 * trasnaction to commit.
2844 *
2845 * - Within sys_sync(), kupdate and such.
2846 * We wait on commit, if tol to.
2847 *
2848 * - Within prune_icache() (PF_MEMALLOC == true)
2849 * Here we simply return. We can't afford to block kswapd on the
2850 * journal commit.
2851 *
2852 * In all cases it is actually safe for us to return without doing anything,
2853 * because the inode has been copied into a raw inode buffer in
2854 * ext3_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
2855 * knfsd.
2856 *
2857 * Note that we are absolutely dependent upon all inode dirtiers doing the
2858 * right thing: they *must* call mark_inode_dirty() after dirtying info in
2859 * which we are interested.
2860 *
2861 * It would be a bug for them to not do this. The code:
2862 *
2863 * mark_inode_dirty(inode)
2864 * stuff();
2865 * inode->i_size = expr;
2866 *
2867 * is in error because a kswapd-driven write_inode() could occur while
2868 * `stuff()' is running, and the new i_size will be lost. Plus the inode
2869 * will no longer be on the superblock's dirty inode list.
2870 */
2871int ext3_write_inode(struct inode *inode, int wait)
2872{
2873 if (current->flags & PF_MEMALLOC)
2874 return 0;
2875
2876 if (ext3_journal_current_handle()) {
2877 jbd_debug(0, "called recursively, non-PF_MEMALLOC!\n");
2878 dump_stack();
2879 return -EIO;
2880 }
2881
2882 if (!wait)
2883 return 0;
2884
2885 return ext3_force_commit(inode->i_sb);
2886}
2887
2888/*
2889 * ext3_setattr()
2890 *
2891 * Called from notify_change.
2892 *
2893 * We want to trap VFS attempts to truncate the file as soon as
2894 * possible. In particular, we want to make sure that when the VFS
2895 * shrinks i_size, we put the inode on the orphan list and modify
2896 * i_disksize immediately, so that during the subsequent flushing of
2897 * dirty pages and freeing of disk blocks, we can guarantee that any
2898 * commit will leave the blocks being flushed in an unused state on
2899 * disk. (On recovery, the inode will get truncated and the blocks will
2900 * be freed, so we have a strong guarantee that no future commit will
2901 * leave these blocks visible to the user.)
2902 *
2903 * Called with inode->sem down.
2904 */
2905int ext3_setattr(struct dentry *dentry, struct iattr *attr)
2906{
2907 struct inode *inode = dentry->d_inode;
2908 int error, rc = 0;
2909 const unsigned int ia_valid = attr->ia_valid;
2910
2911 error = inode_change_ok(inode, attr);
2912 if (error)
2913 return error;
2914
2915 if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
2916 (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
2917 handle_t *handle;
2918
2919 /* (user+group)*(old+new) structure, inode write (sb,
2920 * inode block, ? - but truncate inode update has it) */
2921 handle = ext3_journal_start(inode, 2*(EXT3_QUOTA_INIT_BLOCKS(inode->i_sb)+
2922 EXT3_QUOTA_DEL_BLOCKS(inode->i_sb))+3);
2923 if (IS_ERR(handle)) {
2924 error = PTR_ERR(handle);
2925 goto err_out;
2926 }
2927 error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0;
2928 if (error) {
2929 ext3_journal_stop(handle);
2930 return error;
2931 }
2932 /* Update corresponding info in inode so that everything is in
2933 * one transaction */
2934 if (attr->ia_valid & ATTR_UID)
2935 inode->i_uid = attr->ia_uid;
2936 if (attr->ia_valid & ATTR_GID)
2937 inode->i_gid = attr->ia_gid;
2938 error = ext3_mark_inode_dirty(handle, inode);
2939 ext3_journal_stop(handle);
2940 }
2941
2942 if (S_ISREG(inode->i_mode) &&
2943 attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
2944 handle_t *handle;
2945
2946 handle = ext3_journal_start(inode, 3);
2947 if (IS_ERR(handle)) {
2948 error = PTR_ERR(handle);
2949 goto err_out;
2950 }
2951
2952 error = ext3_orphan_add(handle, inode);
2953 EXT3_I(inode)->i_disksize = attr->ia_size;
2954 rc = ext3_mark_inode_dirty(handle, inode);
2955 if (!error)
2956 error = rc;
2957 ext3_journal_stop(handle);
2958 }
2959
2960 rc = inode_setattr(inode, attr);
2961
2962 /* If inode_setattr's call to ext3_truncate failed to get a
2963 * transaction handle at all, we need to clean up the in-core
2964 * orphan list manually. */
2965 if (inode->i_nlink)
2966 ext3_orphan_del(NULL, inode);
2967
2968 if (!rc && (ia_valid & ATTR_MODE))
2969 rc = ext3_acl_chmod(inode);
2970
2971err_out:
2972 ext3_std_error(inode->i_sb, error);
2973 if (!error)
2974 error = rc;
2975 return error;
2976}
2977
2978
2979/*
2980 * How many blocks doth make a writepage()?
2981 *
2982 * With N blocks per page, it may be:
2983 * N data blocks
2984 * 2 indirect block
2985 * 2 dindirect
2986 * 1 tindirect
2987 * N+5 bitmap blocks (from the above)
2988 * N+5 group descriptor summary blocks
2989 * 1 inode block
2990 * 1 superblock.
2991 * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quote files
2992 *
2993 * 3 * (N + 5) + 2 + 2 * EXT3_SINGLEDATA_TRANS_BLOCKS
2994 *
2995 * With ordered or writeback data it's the same, less the N data blocks.
2996 *
2997 * If the inode's direct blocks can hold an integral number of pages then a
2998 * page cannot straddle two indirect blocks, and we can only touch one indirect
2999 * and dindirect block, and the "5" above becomes "3".
3000 *
3001 * This still overestimates under most circumstances. If we were to pass the
3002 * start and end offsets in here as well we could do block_to_path() on each
3003 * block and work out the exact number of indirects which are touched. Pah.
3004 */
3005
3006static int ext3_writepage_trans_blocks(struct inode *inode)
3007{
3008 int bpp = ext3_journal_blocks_per_page(inode);
3009 int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3;
3010 int ret;
3011
3012 if (ext3_should_journal_data(inode))
3013 ret = 3 * (bpp + indirects) + 2;
3014 else
3015 ret = 2 * (bpp + indirects) + 2;
3016
3017#ifdef CONFIG_QUOTA
3018 /* We know that structure was already allocated during DQUOT_INIT so
3019 * we will be updating only the data blocks + inodes */
3020 ret += 2*EXT3_QUOTA_TRANS_BLOCKS(inode->i_sb);
3021#endif
3022
3023 return ret;
3024}
3025
3026/*
3027 * The caller must have previously called ext3_reserve_inode_write().
3028 * Give this, we know that the caller already has write access to iloc->bh.
3029 */
3030int ext3_mark_iloc_dirty(handle_t *handle,
3031 struct inode *inode, struct ext3_iloc *iloc)
3032{
3033 int err = 0;
3034
3035 /* the do_update_inode consumes one bh->b_count */
3036 get_bh(iloc->bh);
3037
3038 /* ext3_do_update_inode() does journal_dirty_metadata */
3039 err = ext3_do_update_inode(handle, inode, iloc);
3040 put_bh(iloc->bh);
3041 return err;
3042}
3043
3044/*
3045 * On success, We end up with an outstanding reference count against
3046 * iloc->bh. This _must_ be cleaned up later.
3047 */
3048
3049int
3050ext3_reserve_inode_write(handle_t *handle, struct inode *inode,
3051 struct ext3_iloc *iloc)
3052{
3053 int err = 0;
3054 if (handle) {
3055 err = ext3_get_inode_loc(inode, iloc);
3056 if (!err) {
3057 BUFFER_TRACE(iloc->bh, "get_write_access");
3058 err = ext3_journal_get_write_access(handle, iloc->bh);
3059 if (err) {
3060 brelse(iloc->bh);
3061 iloc->bh = NULL;
3062 }
3063 }
3064 }
3065 ext3_std_error(inode->i_sb, err);
3066 return err;
3067}
3068
3069/*
3070 * What we do here is to mark the in-core inode as clean with respect to inode
3071 * dirtiness (it may still be data-dirty).
3072 * This means that the in-core inode may be reaped by prune_icache
3073 * without having to perform any I/O. This is a very good thing,
3074 * because *any* task may call prune_icache - even ones which
3075 * have a transaction open against a different journal.
3076 *
3077 * Is this cheating? Not really. Sure, we haven't written the
3078 * inode out, but prune_icache isn't a user-visible syncing function.
3079 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
3080 * we start and wait on commits.
3081 *
3082 * Is this efficient/effective? Well, we're being nice to the system
3083 * by cleaning up our inodes proactively so they can be reaped
3084 * without I/O. But we are potentially leaving up to five seconds'
3085 * worth of inodes floating about which prune_icache wants us to
3086 * write out. One way to fix that would be to get prune_icache()
3087 * to do a write_super() to free up some memory. It has the desired
3088 * effect.
3089 */
3090int ext3_mark_inode_dirty(handle_t *handle, struct inode *inode)
3091{
3092 struct ext3_iloc iloc;
3093 int err;
3094
3095 might_sleep();
3096 err = ext3_reserve_inode_write(handle, inode, &iloc);
3097 if (!err)
3098 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
3099 return err;
3100}
3101
3102/*
3103 * ext3_dirty_inode() is called from __mark_inode_dirty()
3104 *
3105 * We're really interested in the case where a file is being extended.
3106 * i_size has been changed by generic_commit_write() and we thus need
3107 * to include the updated inode in the current transaction.
3108 *
3109 * Also, DQUOT_ALLOC_SPACE() will always dirty the inode when blocks
3110 * are allocated to the file.
3111 *
3112 * If the inode is marked synchronous, we don't honour that here - doing
3113 * so would cause a commit on atime updates, which we don't bother doing.
3114 * We handle synchronous inodes at the highest possible level.
3115 */
3116void ext3_dirty_inode(struct inode *inode)
3117{
3118 handle_t *current_handle = ext3_journal_current_handle();
3119 handle_t *handle;
3120
3121 handle = ext3_journal_start(inode, 2);
3122 if (IS_ERR(handle))
3123 goto out;
3124 if (current_handle &&
3125 current_handle->h_transaction != handle->h_transaction) {
3126 /* This task has a transaction open against a different fs */
3127 printk(KERN_EMERG "%s: transactions do not match!\n",
3128 __FUNCTION__);
3129 } else {
3130 jbd_debug(5, "marking dirty. outer handle=%p\n",
3131 current_handle);
3132 ext3_mark_inode_dirty(handle, inode);
3133 }
3134 ext3_journal_stop(handle);
3135out:
3136 return;
3137}
3138
3139#if 0
3140/*
3141 * Bind an inode's backing buffer_head into this transaction, to prevent
3142 * it from being flushed to disk early. Unlike
3143 * ext3_reserve_inode_write, this leaves behind no bh reference and
3144 * returns no iloc structure, so the caller needs to repeat the iloc
3145 * lookup to mark the inode dirty later.
3146 */
3147static int ext3_pin_inode(handle_t *handle, struct inode *inode)
3148{
3149 struct ext3_iloc iloc;
3150
3151 int err = 0;
3152 if (handle) {
3153 err = ext3_get_inode_loc(inode, &iloc);
3154 if (!err) {
3155 BUFFER_TRACE(iloc.bh, "get_write_access");
3156 err = journal_get_write_access(handle, iloc.bh);
3157 if (!err)
3158 err = ext3_journal_dirty_metadata(handle,
3159 iloc.bh);
3160 brelse(iloc.bh);
3161 }
3162 }
3163 ext3_std_error(inode->i_sb, err);
3164 return err;
3165}
3166#endif
3167
3168int ext3_change_inode_journal_flag(struct inode *inode, int val)
3169{
3170 journal_t *journal;
3171 handle_t *handle;
3172 int err;
3173
3174 /*
3175 * We have to be very careful here: changing a data block's
3176 * journaling status dynamically is dangerous. If we write a
3177 * data block to the journal, change the status and then delete
3178 * that block, we risk forgetting to revoke the old log record
3179 * from the journal and so a subsequent replay can corrupt data.
3180 * So, first we make sure that the journal is empty and that
3181 * nobody is changing anything.
3182 */
3183
3184 journal = EXT3_JOURNAL(inode);
3185 if (is_journal_aborted(journal) || IS_RDONLY(inode))
3186 return -EROFS;
3187
3188 journal_lock_updates(journal);
3189 journal_flush(journal);
3190
3191 /*
3192 * OK, there are no updates running now, and all cached data is
3193 * synced to disk. We are now in a completely consistent state
3194 * which doesn't have anything in the journal, and we know that
3195 * no filesystem updates are running, so it is safe to modify
3196 * the inode's in-core data-journaling state flag now.
3197 */
3198
3199 if (val)
3200 EXT3_I(inode)->i_flags |= EXT3_JOURNAL_DATA_FL;
3201 else
3202 EXT3_I(inode)->i_flags &= ~EXT3_JOURNAL_DATA_FL;
3203 ext3_set_aops(inode);
3204
3205 journal_unlock_updates(journal);
3206
3207 /* Finally we can mark the inode as dirty. */
3208
3209 handle = ext3_journal_start(inode, 1);
3210 if (IS_ERR(handle))
3211 return PTR_ERR(handle);
3212
3213 err = ext3_mark_inode_dirty(handle, inode);
3214 handle->h_sync = 1;
3215 ext3_journal_stop(handle);
3216 ext3_std_error(inode->i_sb, err);
3217
3218 return err;
3219}
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-07 17:14:42 -0500