blob: 8b38f2232796fda9c0f25294654c49a8d25cde11 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 "xattr.h"
40#include "acl.h"
41
42static int ext3_writepage_trans_blocks(struct inode *inode);
43
44/*
45 * Test whether an inode is a fast symlink.
46 */
47static inline int ext3_inode_is_fast_symlink(struct inode *inode)
48{
49 int ea_blocks = EXT3_I(inode)->i_file_acl ?
50 (inode->i_sb->s_blocksize >> 9) : 0;
51
52 return (S_ISLNK(inode->i_mode) &&
53 inode->i_blocks - ea_blocks == 0);
54}
55
56/* The ext3 forget function must perform a revoke if we are freeing data
57 * which has been journaled. Metadata (eg. indirect blocks) must be
58 * revoked in all cases.
59 *
60 * "bh" may be NULL: a metadata block may have been freed from memory
61 * but there may still be a record of it in the journal, and that record
62 * still needs to be revoked.
63 */
64
65int ext3_forget(handle_t *handle, int is_metadata,
66 struct inode *inode, struct buffer_head *bh,
67 int blocknr)
68{
69 int err;
70
71 might_sleep();
72
73 BUFFER_TRACE(bh, "enter");
74
75 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
76 "data mode %lx\n",
77 bh, is_metadata, inode->i_mode,
78 test_opt(inode->i_sb, DATA_FLAGS));
79
80 /* Never use the revoke function if we are doing full data
81 * journaling: there is no need to, and a V1 superblock won't
82 * support it. Otherwise, only skip the revoke on un-journaled
83 * data blocks. */
84
85 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ||
86 (!is_metadata && !ext3_should_journal_data(inode))) {
87 if (bh) {
88 BUFFER_TRACE(bh, "call journal_forget");
89 return ext3_journal_forget(handle, bh);
90 }
91 return 0;
92 }
93
94 /*
95 * data!=journal && (is_metadata || should_journal_data(inode))
96 */
97 BUFFER_TRACE(bh, "call ext3_journal_revoke");
98 err = ext3_journal_revoke(handle, blocknr, bh);
99 if (err)
100 ext3_abort(inode->i_sb, __FUNCTION__,
101 "error %d when attempting revoke", err);
102 BUFFER_TRACE(bh, "exit");
103 return err;
104}
105
106/*
107 * Work out how many blocks we need to progress with the next chunk of a
108 * truncate transaction.
109 */
110
111static unsigned long blocks_for_truncate(struct inode *inode)
112{
113 unsigned long needed;
114
115 needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
116
117 /* Give ourselves just enough room to cope with inodes in which
118 * i_blocks is corrupt: we've seen disk corruptions in the past
119 * which resulted in random data in an inode which looked enough
120 * like a regular file for ext3 to try to delete it. Things
121 * will go a bit crazy if that happens, but at least we should
122 * try not to panic the whole kernel. */
123 if (needed < 2)
124 needed = 2;
125
126 /* But we need to bound the transaction so we don't overflow the
127 * journal. */
128 if (needed > EXT3_MAX_TRANS_DATA)
129 needed = EXT3_MAX_TRANS_DATA;
130
Jan Kara1f545872005-06-23 22:01:04 -0700131 return EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132}
133
134/*
135 * Truncate transactions can be complex and absolutely huge. So we need to
136 * be able to restart the transaction at a conventient checkpoint to make
137 * sure we don't overflow the journal.
138 *
139 * start_transaction gets us a new handle for a truncate transaction,
140 * and extend_transaction tries to extend the existing one a bit. If
141 * extend fails, we need to propagate the failure up and restart the
142 * transaction in the top-level truncate loop. --sct
143 */
144
145static handle_t *start_transaction(struct inode *inode)
146{
147 handle_t *result;
148
149 result = ext3_journal_start(inode, blocks_for_truncate(inode));
150 if (!IS_ERR(result))
151 return result;
152
153 ext3_std_error(inode->i_sb, PTR_ERR(result));
154 return result;
155}
156
157/*
158 * Try to extend this transaction for the purposes of truncation.
159 *
160 * Returns 0 if we managed to create more room. If we can't create more
161 * room, and the transaction must be restarted we return 1.
162 */
163static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
164{
165 if (handle->h_buffer_credits > EXT3_RESERVE_TRANS_BLOCKS)
166 return 0;
167 if (!ext3_journal_extend(handle, blocks_for_truncate(inode)))
168 return 0;
169 return 1;
170}
171
172/*
173 * Restart the transaction associated with *handle. This does a commit,
174 * so before we call here everything must be consistently dirtied against
175 * this transaction.
176 */
177static int ext3_journal_test_restart(handle_t *handle, struct inode *inode)
178{
179 jbd_debug(2, "restarting handle %p\n", handle);
180 return ext3_journal_restart(handle, blocks_for_truncate(inode));
181}
182
183/*
184 * Called at the last iput() if i_nlink is zero.
185 */
186void ext3_delete_inode (struct inode * inode)
187{
188 handle_t *handle;
189
Mark Fashehfef26652005-09-09 13:01:31 -0700190 truncate_inode_pages(&inode->i_data, 0);
191
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 if (is_bad_inode(inode))
193 goto no_delete;
194
195 handle = start_transaction(inode);
196 if (IS_ERR(handle)) {
197 /* If we're going to skip the normal cleanup, we still
198 * need to make sure that the in-core orphan linked list
199 * is properly cleaned up. */
200 ext3_orphan_del(NULL, inode);
201 goto no_delete;
202 }
203
204 if (IS_SYNC(inode))
205 handle->h_sync = 1;
206 inode->i_size = 0;
207 if (inode->i_blocks)
208 ext3_truncate(inode);
209 /*
210 * Kill off the orphan record which ext3_truncate created.
211 * AKPM: I think this can be inside the above `if'.
212 * Note that ext3_orphan_del() has to be able to cope with the
213 * deletion of a non-existent orphan - this is because we don't
214 * know if ext3_truncate() actually created an orphan record.
215 * (Well, we could do this if we need to, but heck - it works)
216 */
217 ext3_orphan_del(handle, inode);
218 EXT3_I(inode)->i_dtime = get_seconds();
219
220 /*
221 * One subtle ordering requirement: if anything has gone wrong
222 * (transaction abort, IO errors, whatever), then we can still
223 * do these next steps (the fs will already have been marked as
224 * having errors), but we can't free the inode if the mark_dirty
225 * fails.
226 */
227 if (ext3_mark_inode_dirty(handle, inode))
228 /* If that failed, just do the required in-core inode clear. */
229 clear_inode(inode);
230 else
231 ext3_free_inode(handle, inode);
232 ext3_journal_stop(handle);
233 return;
234no_delete:
235 clear_inode(inode); /* We must guarantee clearing of inode... */
236}
237
238static int ext3_alloc_block (handle_t *handle,
239 struct inode * inode, unsigned long goal, int *err)
240{
241 unsigned long result;
242
243 result = ext3_new_block(handle, inode, goal, err);
244 return result;
245}
246
247
248typedef struct {
249 __le32 *p;
250 __le32 key;
251 struct buffer_head *bh;
252} Indirect;
253
254static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
255{
256 p->key = *(p->p = v);
257 p->bh = bh;
258}
259
260static inline int verify_chain(Indirect *from, Indirect *to)
261{
262 while (from <= to && from->key == *from->p)
263 from++;
264 return (from > to);
265}
266
267/**
268 * ext3_block_to_path - parse the block number into array of offsets
269 * @inode: inode in question (we are only interested in its superblock)
270 * @i_block: block number to be parsed
271 * @offsets: array to store the offsets in
272 * @boundary: set this non-zero if the referred-to block is likely to be
273 * followed (on disk) by an indirect block.
274 *
275 * To store the locations of file's data ext3 uses a data structure common
276 * for UNIX filesystems - tree of pointers anchored in the inode, with
277 * data blocks at leaves and indirect blocks in intermediate nodes.
278 * This function translates the block number into path in that tree -
279 * return value is the path length and @offsets[n] is the offset of
280 * pointer to (n+1)th node in the nth one. If @block is out of range
281 * (negative or too large) warning is printed and zero returned.
282 *
283 * Note: function doesn't find node addresses, so no IO is needed. All
284 * we need to know is the capacity of indirect blocks (taken from the
285 * inode->i_sb).
286 */
287
288/*
289 * Portability note: the last comparison (check that we fit into triple
290 * indirect block) is spelled differently, because otherwise on an
291 * architecture with 32-bit longs and 8Kb pages we might get into trouble
292 * if our filesystem had 8Kb blocks. We might use long long, but that would
293 * kill us on x86. Oh, well, at least the sign propagation does not matter -
294 * i_block would have to be negative in the very beginning, so we would not
295 * get there at all.
296 */
297
298static int ext3_block_to_path(struct inode *inode,
299 long i_block, int offsets[4], int *boundary)
300{
301 int ptrs = EXT3_ADDR_PER_BLOCK(inode->i_sb);
302 int ptrs_bits = EXT3_ADDR_PER_BLOCK_BITS(inode->i_sb);
303 const long direct_blocks = EXT3_NDIR_BLOCKS,
304 indirect_blocks = ptrs,
305 double_blocks = (1 << (ptrs_bits * 2));
306 int n = 0;
307 int final = 0;
308
309 if (i_block < 0) {
310 ext3_warning (inode->i_sb, "ext3_block_to_path", "block < 0");
311 } else if (i_block < direct_blocks) {
312 offsets[n++] = i_block;
313 final = direct_blocks;
314 } else if ( (i_block -= direct_blocks) < indirect_blocks) {
315 offsets[n++] = EXT3_IND_BLOCK;
316 offsets[n++] = i_block;
317 final = ptrs;
318 } else if ((i_block -= indirect_blocks) < double_blocks) {
319 offsets[n++] = EXT3_DIND_BLOCK;
320 offsets[n++] = i_block >> ptrs_bits;
321 offsets[n++] = i_block & (ptrs - 1);
322 final = ptrs;
323 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
324 offsets[n++] = EXT3_TIND_BLOCK;
325 offsets[n++] = i_block >> (ptrs_bits * 2);
326 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
327 offsets[n++] = i_block & (ptrs - 1);
328 final = ptrs;
329 } else {
330 ext3_warning (inode->i_sb, "ext3_block_to_path", "block > big");
331 }
332 if (boundary)
333 *boundary = (i_block & (ptrs - 1)) == (final - 1);
334 return n;
335}
336
337/**
338 * ext3_get_branch - read the chain of indirect blocks leading to data
339 * @inode: inode in question
340 * @depth: depth of the chain (1 - direct pointer, etc.)
341 * @offsets: offsets of pointers in inode/indirect blocks
342 * @chain: place to store the result
343 * @err: here we store the error value
344 *
345 * Function fills the array of triples <key, p, bh> and returns %NULL
346 * if everything went OK or the pointer to the last filled triple
347 * (incomplete one) otherwise. Upon the return chain[i].key contains
348 * the number of (i+1)-th block in the chain (as it is stored in memory,
349 * i.e. little-endian 32-bit), chain[i].p contains the address of that
350 * number (it points into struct inode for i==0 and into the bh->b_data
351 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
352 * block for i>0 and NULL for i==0. In other words, it holds the block
353 * numbers of the chain, addresses they were taken from (and where we can
354 * verify that chain did not change) and buffer_heads hosting these
355 * numbers.
356 *
357 * Function stops when it stumbles upon zero pointer (absent block)
358 * (pointer to last triple returned, *@err == 0)
359 * or when it gets an IO error reading an indirect block
360 * (ditto, *@err == -EIO)
361 * or when it notices that chain had been changed while it was reading
362 * (ditto, *@err == -EAGAIN)
363 * or when it reads all @depth-1 indirect blocks successfully and finds
364 * the whole chain, all way to the data (returns %NULL, *err == 0).
365 */
366static Indirect *ext3_get_branch(struct inode *inode, int depth, int *offsets,
367 Indirect chain[4], int *err)
368{
369 struct super_block *sb = inode->i_sb;
370 Indirect *p = chain;
371 struct buffer_head *bh;
372
373 *err = 0;
374 /* i_data is not going away, no lock needed */
375 add_chain (chain, NULL, EXT3_I(inode)->i_data + *offsets);
376 if (!p->key)
377 goto no_block;
378 while (--depth) {
379 bh = sb_bread(sb, le32_to_cpu(p->key));
380 if (!bh)
381 goto failure;
382 /* Reader: pointers */
383 if (!verify_chain(chain, p))
384 goto changed;
385 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
386 /* Reader: end */
387 if (!p->key)
388 goto no_block;
389 }
390 return NULL;
391
392changed:
393 brelse(bh);
394 *err = -EAGAIN;
395 goto no_block;
396failure:
397 *err = -EIO;
398no_block:
399 return p;
400}
401
402/**
403 * ext3_find_near - find a place for allocation with sufficient locality
404 * @inode: owner
405 * @ind: descriptor of indirect block.
406 *
407 * This function returns the prefered place for block allocation.
408 * It is used when heuristic for sequential allocation fails.
409 * Rules are:
410 * + if there is a block to the left of our position - allocate near it.
411 * + if pointer will live in indirect block - allocate near that block.
412 * + if pointer will live in inode - allocate in the same
413 * cylinder group.
414 *
415 * In the latter case we colour the starting block by the callers PID to
416 * prevent it from clashing with concurrent allocations for a different inode
417 * in the same block group. The PID is used here so that functionally related
418 * files will be close-by on-disk.
419 *
420 * Caller must make sure that @ind is valid and will stay that way.
421 */
422
423static unsigned long ext3_find_near(struct inode *inode, Indirect *ind)
424{
425 struct ext3_inode_info *ei = EXT3_I(inode);
426 __le32 *start = ind->bh ? (__le32*) ind->bh->b_data : ei->i_data;
427 __le32 *p;
428 unsigned long bg_start;
429 unsigned long colour;
430
431 /* Try to find previous block */
432 for (p = ind->p - 1; p >= start; p--)
433 if (*p)
434 return le32_to_cpu(*p);
435
436 /* No such thing, so let's try location of indirect block */
437 if (ind->bh)
438 return ind->bh->b_blocknr;
439
440 /*
441 * It is going to be refered from inode itself? OK, just put it into
442 * the same cylinder group then.
443 */
444 bg_start = (ei->i_block_group * EXT3_BLOCKS_PER_GROUP(inode->i_sb)) +
445 le32_to_cpu(EXT3_SB(inode->i_sb)->s_es->s_first_data_block);
446 colour = (current->pid % 16) *
447 (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
448 return bg_start + colour;
449}
450
451/**
452 * ext3_find_goal - find a prefered place for allocation.
453 * @inode: owner
454 * @block: block we want
455 * @chain: chain of indirect blocks
456 * @partial: pointer to the last triple within a chain
457 * @goal: place to store the result.
458 *
459 * Normally this function find the prefered place for block allocation,
Mingming Caofe55c452005-05-01 08:59:20 -0700460 * stores it in *@goal and returns zero.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 */
462
Mingming Caofe55c452005-05-01 08:59:20 -0700463static unsigned long ext3_find_goal(struct inode *inode, long block,
464 Indirect chain[4], Indirect *partial)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465{
466 struct ext3_block_alloc_info *block_i = EXT3_I(inode)->i_block_alloc_info;
467
468 /*
469 * try the heuristic for sequential allocation,
470 * failing that at least try to get decent locality.
471 */
472 if (block_i && (block == block_i->last_alloc_logical_block + 1)
473 && (block_i->last_alloc_physical_block != 0)) {
Mingming Caofe55c452005-05-01 08:59:20 -0700474 return block_i->last_alloc_physical_block + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 }
476
Mingming Caofe55c452005-05-01 08:59:20 -0700477 return ext3_find_near(inode, partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478}
479
480/**
481 * ext3_alloc_branch - allocate and set up a chain of blocks.
482 * @inode: owner
483 * @num: depth of the chain (number of blocks to allocate)
484 * @offsets: offsets (in the blocks) to store the pointers to next.
485 * @branch: place to store the chain in.
486 *
487 * This function allocates @num blocks, zeroes out all but the last one,
488 * links them into chain and (if we are synchronous) writes them to disk.
489 * In other words, it prepares a branch that can be spliced onto the
490 * inode. It stores the information about that chain in the branch[], in
491 * the same format as ext3_get_branch() would do. We are calling it after
492 * we had read the existing part of chain and partial points to the last
493 * triple of that (one with zero ->key). Upon the exit we have the same
494 * picture as after the successful ext3_get_block(), excpet that in one
495 * place chain is disconnected - *branch->p is still zero (we did not
496 * set the last link), but branch->key contains the number that should
497 * be placed into *branch->p to fill that gap.
498 *
499 * If allocation fails we free all blocks we've allocated (and forget
500 * their buffer_heads) and return the error value the from failed
501 * ext3_alloc_block() (normally -ENOSPC). Otherwise we set the chain
502 * as described above and return 0.
503 */
504
505static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
506 int num,
507 unsigned long goal,
508 int *offsets,
509 Indirect *branch)
510{
511 int blocksize = inode->i_sb->s_blocksize;
512 int n = 0, keys = 0;
513 int err = 0;
514 int i;
515 int parent = ext3_alloc_block(handle, inode, goal, &err);
516
517 branch[0].key = cpu_to_le32(parent);
518 if (parent) {
519 for (n = 1; n < num; n++) {
520 struct buffer_head *bh;
521 /* Allocate the next block */
522 int nr = ext3_alloc_block(handle, inode, parent, &err);
523 if (!nr)
524 break;
525 branch[n].key = cpu_to_le32(nr);
526 keys = n+1;
527
528 /*
529 * Get buffer_head for parent block, zero it out
530 * and set the pointer to new one, then send
531 * parent to disk.
532 */
533 bh = sb_getblk(inode->i_sb, parent);
534 branch[n].bh = bh;
535 lock_buffer(bh);
536 BUFFER_TRACE(bh, "call get_create_access");
537 err = ext3_journal_get_create_access(handle, bh);
538 if (err) {
539 unlock_buffer(bh);
540 brelse(bh);
541 break;
542 }
543
544 memset(bh->b_data, 0, blocksize);
545 branch[n].p = (__le32*) bh->b_data + offsets[n];
546 *branch[n].p = branch[n].key;
547 BUFFER_TRACE(bh, "marking uptodate");
548 set_buffer_uptodate(bh);
549 unlock_buffer(bh);
550
551 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
552 err = ext3_journal_dirty_metadata(handle, bh);
553 if (err)
554 break;
555
556 parent = nr;
557 }
558 }
559 if (n == num)
560 return 0;
561
562 /* Allocation failed, free what we already allocated */
563 for (i = 1; i < keys; i++) {
564 BUFFER_TRACE(branch[i].bh, "call journal_forget");
565 ext3_journal_forget(handle, branch[i].bh);
566 }
567 for (i = 0; i < keys; i++)
568 ext3_free_blocks(handle, inode, le32_to_cpu(branch[i].key), 1);
569 return err;
570}
571
572/**
573 * ext3_splice_branch - splice the allocated branch onto inode.
574 * @inode: owner
575 * @block: (logical) number of block we are adding
576 * @chain: chain of indirect blocks (with a missing link - see
577 * ext3_alloc_branch)
578 * @where: location of missing link
579 * @num: number of blocks we are adding
580 *
Mingming Caofe55c452005-05-01 08:59:20 -0700581 * This function fills the missing link and does all housekeeping needed in
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 * inode (->i_blocks, etc.). In case of success we end up with the full
Mingming Caofe55c452005-05-01 08:59:20 -0700583 * chain to new block and return 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 */
585
586static int ext3_splice_branch(handle_t *handle, struct inode *inode, long block,
587 Indirect chain[4], Indirect *where, int num)
588{
589 int i;
590 int err = 0;
591 struct ext3_block_alloc_info *block_i = EXT3_I(inode)->i_block_alloc_info;
592
593 /*
594 * If we're splicing into a [td]indirect block (as opposed to the
595 * inode) then we need to get write access to the [td]indirect block
596 * before the splice.
597 */
598 if (where->bh) {
599 BUFFER_TRACE(where->bh, "get_write_access");
600 err = ext3_journal_get_write_access(handle, where->bh);
601 if (err)
602 goto err_out;
603 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 /* That's it */
605
606 *where->p = where->key;
607
608 /*
609 * update the most recently allocated logical & physical block
610 * in i_block_alloc_info, to assist find the proper goal block for next
611 * allocation
612 */
613 if (block_i) {
614 block_i->last_alloc_logical_block = block;
615 block_i->last_alloc_physical_block = le32_to_cpu(where[num-1].key);
616 }
617
618 /* We are done with atomic stuff, now do the rest of housekeeping */
619
620 inode->i_ctime = CURRENT_TIME_SEC;
621 ext3_mark_inode_dirty(handle, inode);
622
623 /* had we spliced it onto indirect block? */
624 if (where->bh) {
625 /*
626 * akpm: If we spliced it onto an indirect block, we haven't
627 * altered the inode. Note however that if it is being spliced
628 * onto an indirect block at the very end of the file (the
629 * file is growing) then we *will* alter the inode to reflect
630 * the new i_size. But that is not done here - it is done in
631 * generic_commit_write->__mark_inode_dirty->ext3_dirty_inode.
632 */
633 jbd_debug(5, "splicing indirect only\n");
634 BUFFER_TRACE(where->bh, "call ext3_journal_dirty_metadata");
635 err = ext3_journal_dirty_metadata(handle, where->bh);
636 if (err)
637 goto err_out;
638 } else {
639 /*
640 * OK, we spliced it into the inode itself on a direct block.
641 * Inode was dirtied above.
642 */
643 jbd_debug(5, "splicing direct\n");
644 }
645 return err;
646
Linus Torvalds1da177e2005-04-16 15:20:36 -0700647err_out:
648 for (i = 1; i < num; i++) {
649 BUFFER_TRACE(where[i].bh, "call journal_forget");
650 ext3_journal_forget(handle, where[i].bh);
651 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700652 return err;
653}
654
655/*
656 * Allocation strategy is simple: if we have to allocate something, we will
657 * have to go the whole way to leaf. So let's do it before attaching anything
658 * to tree, set linkage between the newborn blocks, write them if sync is
659 * required, recheck the path, free and repeat if check fails, otherwise
660 * set the last missing link (that will protect us from any truncate-generated
661 * removals - all blocks on the path are immune now) and possibly force the
662 * write on the parent block.
663 * That has a nice additional property: no special recovery from the failed
664 * allocations is needed - we simply release blocks and do not touch anything
665 * reachable from inode.
666 *
667 * akpm: `handle' can be NULL if create == 0.
668 *
669 * The BKL may not be held on entry here. Be sure to take it early.
670 */
671
672static int
673ext3_get_block_handle(handle_t *handle, struct inode *inode, sector_t iblock,
674 struct buffer_head *bh_result, int create, int extend_disksize)
675{
676 int err = -EIO;
677 int offsets[4];
678 Indirect chain[4];
679 Indirect *partial;
680 unsigned long goal;
681 int left;
682 int boundary = 0;
Mingming Caofe55c452005-05-01 08:59:20 -0700683 const int depth = ext3_block_to_path(inode, iblock, offsets, &boundary);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 struct ext3_inode_info *ei = EXT3_I(inode);
685
686 J_ASSERT(handle != NULL || create == 0);
687
688 if (depth == 0)
689 goto out;
690
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
692
693 /* Simplest case - block found, no allocation needed */
694 if (!partial) {
695 clear_buffer_new(bh_result);
Mingming Caofe55c452005-05-01 08:59:20 -0700696 goto got_it;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 }
698
699 /* Next simple case - plain lookup or failed read of indirect block */
Mingming Caofe55c452005-05-01 08:59:20 -0700700 if (!create || err == -EIO)
701 goto cleanup;
702
703 down(&ei->truncate_sem);
704
705 /*
706 * If the indirect block is missing while we are reading
707 * the chain(ext3_get_branch() returns -EAGAIN err), or
708 * if the chain has been changed after we grab the semaphore,
709 * (either because another process truncated this branch, or
710 * another get_block allocated this branch) re-grab the chain to see if
711 * the request block has been allocated or not.
712 *
713 * Since we already block the truncate/other get_block
714 * at this point, we will have the current copy of the chain when we
715 * splice the branch into the tree.
716 */
717 if (err == -EAGAIN || !verify_chain(chain, partial)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718 while (partial > chain) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 brelse(partial->bh);
720 partial--;
721 }
Mingming Caofe55c452005-05-01 08:59:20 -0700722 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
723 if (!partial) {
724 up(&ei->truncate_sem);
725 if (err)
726 goto cleanup;
727 clear_buffer_new(bh_result);
728 goto got_it;
729 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730 }
731
732 /*
Mingming Caofe55c452005-05-01 08:59:20 -0700733 * Okay, we need to do block allocation. Lazily initialize the block
734 * allocation info here if necessary
735 */
736 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 ext3_init_block_alloc_info(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738
Mingming Caofe55c452005-05-01 08:59:20 -0700739 goal = ext3_find_goal(inode, iblock, chain, partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740
741 left = (chain + depth) - partial;
742
743 /*
744 * Block out ext3_truncate while we alter the tree
745 */
746 err = ext3_alloc_branch(handle, inode, left, goal,
Mingming Caofe55c452005-05-01 08:59:20 -0700747 offsets + (partial - chain), partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748
Mingming Caofe55c452005-05-01 08:59:20 -0700749 /*
750 * The ext3_splice_branch call will free and forget any buffers
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751 * on the new chain if there is a failure, but that risks using
752 * up transaction credits, especially for bitmaps where the
753 * credits cannot be returned. Can we handle this somehow? We
Mingming Caofe55c452005-05-01 08:59:20 -0700754 * may need to return -EAGAIN upwards in the worst case. --sct
755 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756 if (!err)
757 err = ext3_splice_branch(handle, inode, iblock, chain,
758 partial, left);
Mingming Caofe55c452005-05-01 08:59:20 -0700759 /*
760 * i_disksize growing is protected by truncate_sem. Don't forget to
761 * protect it if you're about to implement concurrent
762 * ext3_get_block() -bzzz
763 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 if (!err && extend_disksize && inode->i_size > ei->i_disksize)
765 ei->i_disksize = inode->i_size;
766 up(&ei->truncate_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 if (err)
768 goto cleanup;
769
770 set_buffer_new(bh_result);
Mingming Caofe55c452005-05-01 08:59:20 -0700771got_it:
772 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
773 if (boundary)
774 set_buffer_boundary(bh_result);
775 /* Clean up and exit */
776 partial = chain + depth - 1; /* the whole chain */
777cleanup:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778 while (partial > chain) {
Mingming Caofe55c452005-05-01 08:59:20 -0700779 BUFFER_TRACE(partial->bh, "call brelse");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 brelse(partial->bh);
781 partial--;
782 }
Mingming Caofe55c452005-05-01 08:59:20 -0700783 BUFFER_TRACE(bh_result, "returned");
784out:
785 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786}
787
788static int ext3_get_block(struct inode *inode, sector_t iblock,
789 struct buffer_head *bh_result, int create)
790{
791 handle_t *handle = NULL;
792 int ret;
793
794 if (create) {
795 handle = ext3_journal_current_handle();
796 J_ASSERT(handle != 0);
797 }
798 ret = ext3_get_block_handle(handle, inode, iblock,
799 bh_result, create, 1);
800 return ret;
801}
802
803#define DIO_CREDITS (EXT3_RESERVE_TRANS_BLOCKS + 32)
804
805static int
806ext3_direct_io_get_blocks(struct inode *inode, sector_t iblock,
807 unsigned long max_blocks, struct buffer_head *bh_result,
808 int create)
809{
810 handle_t *handle = journal_current_handle();
811 int ret = 0;
812
813 if (!handle)
814 goto get_block; /* A read */
815
816 if (handle->h_transaction->t_state == T_LOCKED) {
817 /*
818 * Huge direct-io writes can hold off commits for long
819 * periods of time. Let this commit run.
820 */
821 ext3_journal_stop(handle);
822 handle = ext3_journal_start(inode, DIO_CREDITS);
823 if (IS_ERR(handle))
824 ret = PTR_ERR(handle);
825 goto get_block;
826 }
827
828 if (handle->h_buffer_credits <= EXT3_RESERVE_TRANS_BLOCKS) {
829 /*
830 * Getting low on buffer credits...
831 */
832 ret = ext3_journal_extend(handle, DIO_CREDITS);
833 if (ret > 0) {
834 /*
835 * Couldn't extend the transaction. Start a new one.
836 */
837 ret = ext3_journal_restart(handle, DIO_CREDITS);
838 }
839 }
840
841get_block:
842 if (ret == 0)
843 ret = ext3_get_block_handle(handle, inode, iblock,
844 bh_result, create, 0);
845 bh_result->b_size = (1 << inode->i_blkbits);
846 return ret;
847}
848
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849/*
850 * `handle' can be NULL if create is zero
851 */
852struct buffer_head *ext3_getblk(handle_t *handle, struct inode * inode,
853 long block, int create, int * errp)
854{
855 struct buffer_head dummy;
856 int fatal = 0, err;
857
858 J_ASSERT(handle != NULL || create == 0);
859
860 dummy.b_state = 0;
861 dummy.b_blocknr = -1000;
862 buffer_trace_init(&dummy.b_history);
863 *errp = ext3_get_block_handle(handle, inode, block, &dummy, create, 1);
864 if (!*errp && buffer_mapped(&dummy)) {
865 struct buffer_head *bh;
866 bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
867 if (buffer_new(&dummy)) {
868 J_ASSERT(create != 0);
869 J_ASSERT(handle != 0);
870
871 /* Now that we do not always journal data, we
872 should keep in mind whether this should
873 always journal the new buffer as metadata.
874 For now, regular file writes use
875 ext3_get_block instead, so it's not a
876 problem. */
877 lock_buffer(bh);
878 BUFFER_TRACE(bh, "call get_create_access");
879 fatal = ext3_journal_get_create_access(handle, bh);
880 if (!fatal && !buffer_uptodate(bh)) {
881 memset(bh->b_data, 0, inode->i_sb->s_blocksize);
882 set_buffer_uptodate(bh);
883 }
884 unlock_buffer(bh);
885 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
886 err = ext3_journal_dirty_metadata(handle, bh);
887 if (!fatal)
888 fatal = err;
889 } else {
890 BUFFER_TRACE(bh, "not a new buffer");
891 }
892 if (fatal) {
893 *errp = fatal;
894 brelse(bh);
895 bh = NULL;
896 }
897 return bh;
898 }
899 return NULL;
900}
901
902struct buffer_head *ext3_bread(handle_t *handle, struct inode * inode,
903 int block, int create, int *err)
904{
905 struct buffer_head * bh;
906
907 bh = ext3_getblk(handle, inode, block, create, err);
908 if (!bh)
909 return bh;
910 if (buffer_uptodate(bh))
911 return bh;
912 ll_rw_block(READ, 1, &bh);
913 wait_on_buffer(bh);
914 if (buffer_uptodate(bh))
915 return bh;
916 put_bh(bh);
917 *err = -EIO;
918 return NULL;
919}
920
921static int walk_page_buffers( handle_t *handle,
922 struct buffer_head *head,
923 unsigned from,
924 unsigned to,
925 int *partial,
926 int (*fn)( handle_t *handle,
927 struct buffer_head *bh))
928{
929 struct buffer_head *bh;
930 unsigned block_start, block_end;
931 unsigned blocksize = head->b_size;
932 int err, ret = 0;
933 struct buffer_head *next;
934
935 for ( bh = head, block_start = 0;
936 ret == 0 && (bh != head || !block_start);
937 block_start = block_end, bh = next)
938 {
939 next = bh->b_this_page;
940 block_end = block_start + blocksize;
941 if (block_end <= from || block_start >= to) {
942 if (partial && !buffer_uptodate(bh))
943 *partial = 1;
944 continue;
945 }
946 err = (*fn)(handle, bh);
947 if (!ret)
948 ret = err;
949 }
950 return ret;
951}
952
953/*
954 * To preserve ordering, it is essential that the hole instantiation and
955 * the data write be encapsulated in a single transaction. We cannot
956 * close off a transaction and start a new one between the ext3_get_block()
957 * and the commit_write(). So doing the journal_start at the start of
958 * prepare_write() is the right place.
959 *
960 * Also, this function can nest inside ext3_writepage() ->
961 * block_write_full_page(). In that case, we *know* that ext3_writepage()
962 * has generated enough buffer credits to do the whole page. So we won't
963 * block on the journal in that case, which is good, because the caller may
964 * be PF_MEMALLOC.
965 *
966 * By accident, ext3 can be reentered when a transaction is open via
967 * quota file writes. If we were to commit the transaction while thus
968 * reentered, there can be a deadlock - we would be holding a quota
969 * lock, and the commit would never complete if another thread had a
970 * transaction open and was blocking on the quota lock - a ranking
971 * violation.
972 *
973 * So what we do is to rely on the fact that journal_stop/journal_start
974 * will _not_ run commit under these circumstances because handle->h_ref
975 * is elevated. We'll still have enough credits for the tiny quotafile
976 * write.
977 */
978
979static int do_journal_get_write_access(handle_t *handle,
980 struct buffer_head *bh)
981{
982 if (!buffer_mapped(bh) || buffer_freed(bh))
983 return 0;
984 return ext3_journal_get_write_access(handle, bh);
985}
986
987static int ext3_prepare_write(struct file *file, struct page *page,
988 unsigned from, unsigned to)
989{
990 struct inode *inode = page->mapping->host;
991 int ret, needed_blocks = ext3_writepage_trans_blocks(inode);
992 handle_t *handle;
993 int retries = 0;
994
995retry:
996 handle = ext3_journal_start(inode, needed_blocks);
997 if (IS_ERR(handle)) {
998 ret = PTR_ERR(handle);
999 goto out;
1000 }
1001 if (test_opt(inode->i_sb, NOBH))
1002 ret = nobh_prepare_write(page, from, to, ext3_get_block);
1003 else
1004 ret = block_prepare_write(page, from, to, ext3_get_block);
1005 if (ret)
1006 goto prepare_write_failed;
1007
1008 if (ext3_should_journal_data(inode)) {
1009 ret = walk_page_buffers(handle, page_buffers(page),
1010 from, to, NULL, do_journal_get_write_access);
1011 }
1012prepare_write_failed:
1013 if (ret)
1014 ext3_journal_stop(handle);
1015 if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
1016 goto retry;
1017out:
1018 return ret;
1019}
1020
1021int
1022ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
1023{
1024 int err = journal_dirty_data(handle, bh);
1025 if (err)
1026 ext3_journal_abort_handle(__FUNCTION__, __FUNCTION__,
1027 bh, handle,err);
1028 return err;
1029}
1030
1031/* For commit_write() in data=journal mode */
1032static int commit_write_fn(handle_t *handle, struct buffer_head *bh)
1033{
1034 if (!buffer_mapped(bh) || buffer_freed(bh))
1035 return 0;
1036 set_buffer_uptodate(bh);
1037 return ext3_journal_dirty_metadata(handle, bh);
1038}
1039
1040/*
1041 * We need to pick up the new inode size which generic_commit_write gave us
1042 * `file' can be NULL - eg, when called from page_symlink().
1043 *
1044 * ext3 never places buffers on inode->i_mapping->private_list. metadata
1045 * buffers are managed internally.
1046 */
1047
1048static int ext3_ordered_commit_write(struct file *file, struct page *page,
1049 unsigned from, unsigned to)
1050{
1051 handle_t *handle = ext3_journal_current_handle();
1052 struct inode *inode = page->mapping->host;
1053 int ret = 0, ret2;
1054
1055 ret = walk_page_buffers(handle, page_buffers(page),
1056 from, to, NULL, ext3_journal_dirty_data);
1057
1058 if (ret == 0) {
1059 /*
1060 * generic_commit_write() will run mark_inode_dirty() if i_size
1061 * changes. So let's piggyback the i_disksize mark_inode_dirty
1062 * into that.
1063 */
1064 loff_t new_i_size;
1065
1066 new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1067 if (new_i_size > EXT3_I(inode)->i_disksize)
1068 EXT3_I(inode)->i_disksize = new_i_size;
1069 ret = generic_commit_write(file, page, from, to);
1070 }
1071 ret2 = ext3_journal_stop(handle);
1072 if (!ret)
1073 ret = ret2;
1074 return ret;
1075}
1076
1077static int ext3_writeback_commit_write(struct file *file, struct page *page,
1078 unsigned from, unsigned to)
1079{
1080 handle_t *handle = ext3_journal_current_handle();
1081 struct inode *inode = page->mapping->host;
1082 int ret = 0, ret2;
1083 loff_t new_i_size;
1084
1085 new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1086 if (new_i_size > EXT3_I(inode)->i_disksize)
1087 EXT3_I(inode)->i_disksize = new_i_size;
1088
1089 if (test_opt(inode->i_sb, NOBH))
1090 ret = nobh_commit_write(file, page, from, to);
1091 else
1092 ret = generic_commit_write(file, page, from, to);
1093
1094 ret2 = ext3_journal_stop(handle);
1095 if (!ret)
1096 ret = ret2;
1097 return ret;
1098}
1099
1100static int ext3_journalled_commit_write(struct file *file,
1101 struct page *page, unsigned from, unsigned to)
1102{
1103 handle_t *handle = ext3_journal_current_handle();
1104 struct inode *inode = page->mapping->host;
1105 int ret = 0, ret2;
1106 int partial = 0;
1107 loff_t pos;
1108
1109 /*
1110 * Here we duplicate the generic_commit_write() functionality
1111 */
1112 pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1113
1114 ret = walk_page_buffers(handle, page_buffers(page), from,
1115 to, &partial, commit_write_fn);
1116 if (!partial)
1117 SetPageUptodate(page);
1118 if (pos > inode->i_size)
1119 i_size_write(inode, pos);
1120 EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1121 if (inode->i_size > EXT3_I(inode)->i_disksize) {
1122 EXT3_I(inode)->i_disksize = inode->i_size;
1123 ret2 = ext3_mark_inode_dirty(handle, inode);
1124 if (!ret)
1125 ret = ret2;
1126 }
1127 ret2 = ext3_journal_stop(handle);
1128 if (!ret)
1129 ret = ret2;
1130 return ret;
1131}
1132
1133/*
1134 * bmap() is special. It gets used by applications such as lilo and by
1135 * the swapper to find the on-disk block of a specific piece of data.
1136 *
1137 * Naturally, this is dangerous if the block concerned is still in the
1138 * journal. If somebody makes a swapfile on an ext3 data-journaling
1139 * filesystem and enables swap, then they may get a nasty shock when the
1140 * data getting swapped to that swapfile suddenly gets overwritten by
1141 * the original zero's written out previously to the journal and
1142 * awaiting writeback in the kernel's buffer cache.
1143 *
1144 * So, if we see any bmap calls here on a modified, data-journaled file,
1145 * take extra steps to flush any blocks which might be in the cache.
1146 */
1147static sector_t ext3_bmap(struct address_space *mapping, sector_t block)
1148{
1149 struct inode *inode = mapping->host;
1150 journal_t *journal;
1151 int err;
1152
1153 if (EXT3_I(inode)->i_state & EXT3_STATE_JDATA) {
1154 /*
1155 * This is a REALLY heavyweight approach, but the use of
1156 * bmap on dirty files is expected to be extremely rare:
1157 * only if we run lilo or swapon on a freshly made file
1158 * do we expect this to happen.
1159 *
1160 * (bmap requires CAP_SYS_RAWIO so this does not
1161 * represent an unprivileged user DOS attack --- we'd be
1162 * in trouble if mortal users could trigger this path at
1163 * will.)
1164 *
1165 * NB. EXT3_STATE_JDATA is not set on files other than
1166 * regular files. If somebody wants to bmap a directory
1167 * or symlink and gets confused because the buffer
1168 * hasn't yet been flushed to disk, they deserve
1169 * everything they get.
1170 */
1171
1172 EXT3_I(inode)->i_state &= ~EXT3_STATE_JDATA;
1173 journal = EXT3_JOURNAL(inode);
1174 journal_lock_updates(journal);
1175 err = journal_flush(journal);
1176 journal_unlock_updates(journal);
1177
1178 if (err)
1179 return 0;
1180 }
1181
1182 return generic_block_bmap(mapping,block,ext3_get_block);
1183}
1184
1185static int bget_one(handle_t *handle, struct buffer_head *bh)
1186{
1187 get_bh(bh);
1188 return 0;
1189}
1190
1191static int bput_one(handle_t *handle, struct buffer_head *bh)
1192{
1193 put_bh(bh);
1194 return 0;
1195}
1196
1197static int journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
1198{
1199 if (buffer_mapped(bh))
1200 return ext3_journal_dirty_data(handle, bh);
1201 return 0;
1202}
1203
1204/*
1205 * Note that we always start a transaction even if we're not journalling
1206 * data. This is to preserve ordering: any hole instantiation within
1207 * __block_write_full_page -> ext3_get_block() should be journalled
1208 * along with the data so we don't crash and then get metadata which
1209 * refers to old data.
1210 *
1211 * In all journalling modes block_write_full_page() will start the I/O.
1212 *
1213 * Problem:
1214 *
1215 * ext3_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1216 * ext3_writepage()
1217 *
1218 * Similar for:
1219 *
1220 * ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ...
1221 *
1222 * Same applies to ext3_get_block(). We will deadlock on various things like
1223 * lock_journal and i_truncate_sem.
1224 *
1225 * Setting PF_MEMALLOC here doesn't work - too many internal memory
1226 * allocations fail.
1227 *
1228 * 16May01: If we're reentered then journal_current_handle() will be
1229 * non-zero. We simply *return*.
1230 *
1231 * 1 July 2001: @@@ FIXME:
1232 * In journalled data mode, a data buffer may be metadata against the
1233 * current transaction. But the same file is part of a shared mapping
1234 * and someone does a writepage() on it.
1235 *
1236 * We will move the buffer onto the async_data list, but *after* it has
1237 * been dirtied. So there's a small window where we have dirty data on
1238 * BJ_Metadata.
1239 *
1240 * Note that this only applies to the last partial page in the file. The
1241 * bit which block_write_full_page() uses prepare/commit for. (That's
1242 * broken code anyway: it's wrong for msync()).
1243 *
1244 * It's a rare case: affects the final partial page, for journalled data
1245 * where the file is subject to bith write() and writepage() in the same
1246 * transction. To fix it we'll need a custom block_write_full_page().
1247 * We'll probably need that anyway for journalling writepage() output.
1248 *
1249 * We don't honour synchronous mounts for writepage(). That would be
1250 * disastrous. Any write() or metadata operation will sync the fs for
1251 * us.
1252 *
1253 * AKPM2: if all the page's buffers are mapped to disk and !data=journal,
1254 * we don't need to open a transaction here.
1255 */
1256static int ext3_ordered_writepage(struct page *page,
1257 struct writeback_control *wbc)
1258{
1259 struct inode *inode = page->mapping->host;
1260 struct buffer_head *page_bufs;
1261 handle_t *handle = NULL;
1262 int ret = 0;
1263 int err;
1264
1265 J_ASSERT(PageLocked(page));
1266
1267 /*
1268 * We give up here if we're reentered, because it might be for a
1269 * different filesystem.
1270 */
1271 if (ext3_journal_current_handle())
1272 goto out_fail;
1273
1274 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1275
1276 if (IS_ERR(handle)) {
1277 ret = PTR_ERR(handle);
1278 goto out_fail;
1279 }
1280
1281 if (!page_has_buffers(page)) {
1282 create_empty_buffers(page, inode->i_sb->s_blocksize,
1283 (1 << BH_Dirty)|(1 << BH_Uptodate));
1284 }
1285 page_bufs = page_buffers(page);
1286 walk_page_buffers(handle, page_bufs, 0,
1287 PAGE_CACHE_SIZE, NULL, bget_one);
1288
1289 ret = block_write_full_page(page, ext3_get_block, wbc);
1290
1291 /*
1292 * The page can become unlocked at any point now, and
1293 * truncate can then come in and change things. So we
1294 * can't touch *page from now on. But *page_bufs is
1295 * safe due to elevated refcount.
1296 */
1297
1298 /*
1299 * And attach them to the current transaction. But only if
1300 * block_write_full_page() succeeded. Otherwise they are unmapped,
1301 * and generally junk.
1302 */
1303 if (ret == 0) {
1304 err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
1305 NULL, journal_dirty_data_fn);
1306 if (!ret)
1307 ret = err;
1308 }
1309 walk_page_buffers(handle, page_bufs, 0,
1310 PAGE_CACHE_SIZE, NULL, bput_one);
1311 err = ext3_journal_stop(handle);
1312 if (!ret)
1313 ret = err;
1314 return ret;
1315
1316out_fail:
1317 redirty_page_for_writepage(wbc, page);
1318 unlock_page(page);
1319 return ret;
1320}
1321
Linus Torvalds1da177e2005-04-16 15:20:36 -07001322static int ext3_writeback_writepage(struct page *page,
1323 struct writeback_control *wbc)
1324{
1325 struct inode *inode = page->mapping->host;
1326 handle_t *handle = NULL;
1327 int ret = 0;
1328 int err;
1329
1330 if (ext3_journal_current_handle())
1331 goto out_fail;
1332
1333 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1334 if (IS_ERR(handle)) {
1335 ret = PTR_ERR(handle);
1336 goto out_fail;
1337 }
1338
1339 if (test_opt(inode->i_sb, NOBH))
1340 ret = nobh_writepage(page, ext3_get_block, wbc);
1341 else
1342 ret = block_write_full_page(page, ext3_get_block, wbc);
1343
1344 err = ext3_journal_stop(handle);
1345 if (!ret)
1346 ret = err;
1347 return ret;
1348
1349out_fail:
1350 redirty_page_for_writepage(wbc, page);
1351 unlock_page(page);
1352 return ret;
1353}
1354
1355static int ext3_journalled_writepage(struct page *page,
1356 struct writeback_control *wbc)
1357{
1358 struct inode *inode = page->mapping->host;
1359 handle_t *handle = NULL;
1360 int ret = 0;
1361 int err;
1362
1363 if (ext3_journal_current_handle())
1364 goto no_write;
1365
1366 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1367 if (IS_ERR(handle)) {
1368 ret = PTR_ERR(handle);
1369 goto no_write;
1370 }
1371
1372 if (!page_has_buffers(page) || PageChecked(page)) {
1373 /*
1374 * It's mmapped pagecache. Add buffers and journal it. There
1375 * doesn't seem much point in redirtying the page here.
1376 */
1377 ClearPageChecked(page);
1378 ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
1379 ext3_get_block);
1380 if (ret != 0)
1381 goto out_unlock;
1382 ret = walk_page_buffers(handle, page_buffers(page), 0,
1383 PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
1384
1385 err = walk_page_buffers(handle, page_buffers(page), 0,
1386 PAGE_CACHE_SIZE, NULL, commit_write_fn);
1387 if (ret == 0)
1388 ret = err;
1389 EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1390 unlock_page(page);
1391 } else {
1392 /*
1393 * It may be a page full of checkpoint-mode buffers. We don't
1394 * really know unless we go poke around in the buffer_heads.
1395 * But block_write_full_page will do the right thing.
1396 */
1397 ret = block_write_full_page(page, ext3_get_block, wbc);
1398 }
1399 err = ext3_journal_stop(handle);
1400 if (!ret)
1401 ret = err;
1402out:
1403 return ret;
1404
1405no_write:
1406 redirty_page_for_writepage(wbc, page);
1407out_unlock:
1408 unlock_page(page);
1409 goto out;
1410}
1411
1412static int ext3_readpage(struct file *file, struct page *page)
1413{
1414 return mpage_readpage(page, ext3_get_block);
1415}
1416
1417static int
1418ext3_readpages(struct file *file, struct address_space *mapping,
1419 struct list_head *pages, unsigned nr_pages)
1420{
1421 return mpage_readpages(mapping, pages, nr_pages, ext3_get_block);
1422}
1423
1424static int ext3_invalidatepage(struct page *page, unsigned long offset)
1425{
1426 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1427
1428 /*
1429 * If it's a full truncate we just forget about the pending dirtying
1430 */
1431 if (offset == 0)
1432 ClearPageChecked(page);
1433
1434 return journal_invalidatepage(journal, page, offset);
1435}
1436
Al Viro27496a82005-10-21 03:20:48 -04001437static int ext3_releasepage(struct page *page, gfp_t wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001438{
1439 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1440
1441 WARN_ON(PageChecked(page));
1442 if (!page_has_buffers(page))
1443 return 0;
1444 return journal_try_to_free_buffers(journal, page, wait);
1445}
1446
1447/*
1448 * If the O_DIRECT write will extend the file then add this inode to the
1449 * orphan list. So recovery will truncate it back to the original size
1450 * if the machine crashes during the write.
1451 *
1452 * If the O_DIRECT write is intantiating holes inside i_size and the machine
1453 * crashes then stale disk data _may_ be exposed inside the file.
1454 */
1455static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
1456 const struct iovec *iov, loff_t offset,
1457 unsigned long nr_segs)
1458{
1459 struct file *file = iocb->ki_filp;
1460 struct inode *inode = file->f_mapping->host;
1461 struct ext3_inode_info *ei = EXT3_I(inode);
1462 handle_t *handle = NULL;
1463 ssize_t ret;
1464 int orphan = 0;
1465 size_t count = iov_length(iov, nr_segs);
1466
1467 if (rw == WRITE) {
1468 loff_t final_size = offset + count;
1469
1470 handle = ext3_journal_start(inode, DIO_CREDITS);
1471 if (IS_ERR(handle)) {
1472 ret = PTR_ERR(handle);
1473 goto out;
1474 }
1475 if (final_size > inode->i_size) {
1476 ret = ext3_orphan_add(handle, inode);
1477 if (ret)
1478 goto out_stop;
1479 orphan = 1;
1480 ei->i_disksize = inode->i_size;
1481 }
1482 }
1483
1484 ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
1485 offset, nr_segs,
1486 ext3_direct_io_get_blocks, NULL);
1487
1488 /*
1489 * Reacquire the handle: ext3_direct_io_get_block() can restart the
1490 * transaction
1491 */
1492 handle = journal_current_handle();
1493
1494out_stop:
1495 if (handle) {
1496 int err;
1497
1498 if (orphan && inode->i_nlink)
1499 ext3_orphan_del(handle, inode);
1500 if (orphan && ret > 0) {
1501 loff_t end = offset + ret;
1502 if (end > inode->i_size) {
1503 ei->i_disksize = end;
1504 i_size_write(inode, end);
1505 /*
1506 * We're going to return a positive `ret'
1507 * here due to non-zero-length I/O, so there's
1508 * no way of reporting error returns from
1509 * ext3_mark_inode_dirty() to userspace. So
1510 * ignore it.
1511 */
1512 ext3_mark_inode_dirty(handle, inode);
1513 }
1514 }
1515 err = ext3_journal_stop(handle);
1516 if (ret == 0)
1517 ret = err;
1518 }
1519out:
1520 return ret;
1521}
1522
1523/*
1524 * Pages can be marked dirty completely asynchronously from ext3's journalling
1525 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
1526 * much here because ->set_page_dirty is called under VFS locks. The page is
1527 * not necessarily locked.
1528 *
1529 * We cannot just dirty the page and leave attached buffers clean, because the
1530 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
1531 * or jbddirty because all the journalling code will explode.
1532 *
1533 * So what we do is to mark the page "pending dirty" and next time writepage
1534 * is called, propagate that into the buffers appropriately.
1535 */
1536static int ext3_journalled_set_page_dirty(struct page *page)
1537{
1538 SetPageChecked(page);
1539 return __set_page_dirty_nobuffers(page);
1540}
1541
1542static struct address_space_operations ext3_ordered_aops = {
1543 .readpage = ext3_readpage,
1544 .readpages = ext3_readpages,
1545 .writepage = ext3_ordered_writepage,
1546 .sync_page = block_sync_page,
1547 .prepare_write = ext3_prepare_write,
1548 .commit_write = ext3_ordered_commit_write,
1549 .bmap = ext3_bmap,
1550 .invalidatepage = ext3_invalidatepage,
1551 .releasepage = ext3_releasepage,
1552 .direct_IO = ext3_direct_IO,
1553};
1554
1555static struct address_space_operations ext3_writeback_aops = {
1556 .readpage = ext3_readpage,
1557 .readpages = ext3_readpages,
1558 .writepage = ext3_writeback_writepage,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001559 .sync_page = block_sync_page,
1560 .prepare_write = ext3_prepare_write,
1561 .commit_write = ext3_writeback_commit_write,
1562 .bmap = ext3_bmap,
1563 .invalidatepage = ext3_invalidatepage,
1564 .releasepage = ext3_releasepage,
1565 .direct_IO = ext3_direct_IO,
1566};
1567
1568static struct address_space_operations ext3_journalled_aops = {
1569 .readpage = ext3_readpage,
1570 .readpages = ext3_readpages,
1571 .writepage = ext3_journalled_writepage,
1572 .sync_page = block_sync_page,
1573 .prepare_write = ext3_prepare_write,
1574 .commit_write = ext3_journalled_commit_write,
1575 .set_page_dirty = ext3_journalled_set_page_dirty,
1576 .bmap = ext3_bmap,
1577 .invalidatepage = ext3_invalidatepage,
1578 .releasepage = ext3_releasepage,
1579};
1580
1581void ext3_set_aops(struct inode *inode)
1582{
1583 if (ext3_should_order_data(inode))
1584 inode->i_mapping->a_ops = &ext3_ordered_aops;
1585 else if (ext3_should_writeback_data(inode))
1586 inode->i_mapping->a_ops = &ext3_writeback_aops;
1587 else
1588 inode->i_mapping->a_ops = &ext3_journalled_aops;
1589}
1590
1591/*
1592 * ext3_block_truncate_page() zeroes out a mapping from file offset `from'
1593 * up to the end of the block which corresponds to `from'.
1594 * This required during truncate. We need to physically zero the tail end
1595 * of that block so it doesn't yield old data if the file is later grown.
1596 */
1597static int ext3_block_truncate_page(handle_t *handle, struct page *page,
1598 struct address_space *mapping, loff_t from)
1599{
1600 unsigned long index = from >> PAGE_CACHE_SHIFT;
1601 unsigned offset = from & (PAGE_CACHE_SIZE-1);
1602 unsigned blocksize, iblock, length, pos;
1603 struct inode *inode = mapping->host;
1604 struct buffer_head *bh;
1605 int err = 0;
1606 void *kaddr;
1607
1608 blocksize = inode->i_sb->s_blocksize;
1609 length = blocksize - (offset & (blocksize - 1));
1610 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1611
1612 /*
1613 * For "nobh" option, we can only work if we don't need to
1614 * read-in the page - otherwise we create buffers to do the IO.
1615 */
1616 if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH)) {
1617 if (PageUptodate(page)) {
1618 kaddr = kmap_atomic(page, KM_USER0);
1619 memset(kaddr + offset, 0, length);
1620 flush_dcache_page(page);
1621 kunmap_atomic(kaddr, KM_USER0);
1622 set_page_dirty(page);
1623 goto unlock;
1624 }
1625 }
1626
1627 if (!page_has_buffers(page))
1628 create_empty_buffers(page, blocksize, 0);
1629
1630 /* Find the buffer that contains "offset" */
1631 bh = page_buffers(page);
1632 pos = blocksize;
1633 while (offset >= pos) {
1634 bh = bh->b_this_page;
1635 iblock++;
1636 pos += blocksize;
1637 }
1638
1639 err = 0;
1640 if (buffer_freed(bh)) {
1641 BUFFER_TRACE(bh, "freed: skip");
1642 goto unlock;
1643 }
1644
1645 if (!buffer_mapped(bh)) {
1646 BUFFER_TRACE(bh, "unmapped");
1647 ext3_get_block(inode, iblock, bh, 0);
1648 /* unmapped? It's a hole - nothing to do */
1649 if (!buffer_mapped(bh)) {
1650 BUFFER_TRACE(bh, "still unmapped");
1651 goto unlock;
1652 }
1653 }
1654
1655 /* Ok, it's mapped. Make sure it's up-to-date */
1656 if (PageUptodate(page))
1657 set_buffer_uptodate(bh);
1658
1659 if (!buffer_uptodate(bh)) {
1660 err = -EIO;
1661 ll_rw_block(READ, 1, &bh);
1662 wait_on_buffer(bh);
1663 /* Uhhuh. Read error. Complain and punt. */
1664 if (!buffer_uptodate(bh))
1665 goto unlock;
1666 }
1667
1668 if (ext3_should_journal_data(inode)) {
1669 BUFFER_TRACE(bh, "get write access");
1670 err = ext3_journal_get_write_access(handle, bh);
1671 if (err)
1672 goto unlock;
1673 }
1674
1675 kaddr = kmap_atomic(page, KM_USER0);
1676 memset(kaddr + offset, 0, length);
1677 flush_dcache_page(page);
1678 kunmap_atomic(kaddr, KM_USER0);
1679
1680 BUFFER_TRACE(bh, "zeroed end of block");
1681
1682 err = 0;
1683 if (ext3_should_journal_data(inode)) {
1684 err = ext3_journal_dirty_metadata(handle, bh);
1685 } else {
1686 if (ext3_should_order_data(inode))
1687 err = ext3_journal_dirty_data(handle, bh);
1688 mark_buffer_dirty(bh);
1689 }
1690
1691unlock:
1692 unlock_page(page);
1693 page_cache_release(page);
1694 return err;
1695}
1696
1697/*
1698 * Probably it should be a library function... search for first non-zero word
1699 * or memcmp with zero_page, whatever is better for particular architecture.
1700 * Linus?
1701 */
1702static inline int all_zeroes(__le32 *p, __le32 *q)
1703{
1704 while (p < q)
1705 if (*p++)
1706 return 0;
1707 return 1;
1708}
1709
1710/**
1711 * ext3_find_shared - find the indirect blocks for partial truncation.
1712 * @inode: inode in question
1713 * @depth: depth of the affected branch
1714 * @offsets: offsets of pointers in that branch (see ext3_block_to_path)
1715 * @chain: place to store the pointers to partial indirect blocks
1716 * @top: place to the (detached) top of branch
1717 *
1718 * This is a helper function used by ext3_truncate().
1719 *
1720 * When we do truncate() we may have to clean the ends of several
1721 * indirect blocks but leave the blocks themselves alive. Block is
1722 * partially truncated if some data below the new i_size is refered
1723 * from it (and it is on the path to the first completely truncated
1724 * data block, indeed). We have to free the top of that path along
1725 * with everything to the right of the path. Since no allocation
1726 * past the truncation point is possible until ext3_truncate()
1727 * finishes, we may safely do the latter, but top of branch may
1728 * require special attention - pageout below the truncation point
1729 * might try to populate it.
1730 *
1731 * We atomically detach the top of branch from the tree, store the
1732 * block number of its root in *@top, pointers to buffer_heads of
1733 * partially truncated blocks - in @chain[].bh and pointers to
1734 * their last elements that should not be removed - in
1735 * @chain[].p. Return value is the pointer to last filled element
1736 * of @chain.
1737 *
1738 * The work left to caller to do the actual freeing of subtrees:
1739 * a) free the subtree starting from *@top
1740 * b) free the subtrees whose roots are stored in
1741 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
1742 * c) free the subtrees growing from the inode past the @chain[0].
1743 * (no partially truncated stuff there). */
1744
1745static Indirect *ext3_find_shared(struct inode *inode,
1746 int depth,
1747 int offsets[4],
1748 Indirect chain[4],
1749 __le32 *top)
1750{
1751 Indirect *partial, *p;
1752 int k, err;
1753
1754 *top = 0;
1755 /* Make k index the deepest non-null offest + 1 */
1756 for (k = depth; k > 1 && !offsets[k-1]; k--)
1757 ;
1758 partial = ext3_get_branch(inode, k, offsets, chain, &err);
1759 /* Writer: pointers */
1760 if (!partial)
1761 partial = chain + k-1;
1762 /*
1763 * If the branch acquired continuation since we've looked at it -
1764 * fine, it should all survive and (new) top doesn't belong to us.
1765 */
1766 if (!partial->key && *partial->p)
1767 /* Writer: end */
1768 goto no_top;
1769 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
1770 ;
1771 /*
1772 * OK, we've found the last block that must survive. The rest of our
1773 * branch should be detached before unlocking. However, if that rest
1774 * of branch is all ours and does not grow immediately from the inode
1775 * it's easier to cheat and just decrement partial->p.
1776 */
1777 if (p == chain + k - 1 && p > chain) {
1778 p->p--;
1779 } else {
1780 *top = *p->p;
1781 /* Nope, don't do this in ext3. Must leave the tree intact */
1782#if 0
1783 *p->p = 0;
1784#endif
1785 }
1786 /* Writer: end */
1787
1788 while(partial > p)
1789 {
1790 brelse(partial->bh);
1791 partial--;
1792 }
1793no_top:
1794 return partial;
1795}
1796
1797/*
1798 * Zero a number of block pointers in either an inode or an indirect block.
1799 * If we restart the transaction we must again get write access to the
1800 * indirect block for further modification.
1801 *
1802 * We release `count' blocks on disk, but (last - first) may be greater
1803 * than `count' because there can be holes in there.
1804 */
1805static void
1806ext3_clear_blocks(handle_t *handle, struct inode *inode, struct buffer_head *bh,
1807 unsigned long block_to_free, unsigned long count,
1808 __le32 *first, __le32 *last)
1809{
1810 __le32 *p;
1811 if (try_to_extend_transaction(handle, inode)) {
1812 if (bh) {
1813 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
1814 ext3_journal_dirty_metadata(handle, bh);
1815 }
1816 ext3_mark_inode_dirty(handle, inode);
1817 ext3_journal_test_restart(handle, inode);
1818 if (bh) {
1819 BUFFER_TRACE(bh, "retaking write access");
1820 ext3_journal_get_write_access(handle, bh);
1821 }
1822 }
1823
1824 /*
1825 * Any buffers which are on the journal will be in memory. We find
1826 * them on the hash table so journal_revoke() will run journal_forget()
1827 * on them. We've already detached each block from the file, so
1828 * bforget() in journal_forget() should be safe.
1829 *
1830 * AKPM: turn on bforget in journal_forget()!!!
1831 */
1832 for (p = first; p < last; p++) {
1833 u32 nr = le32_to_cpu(*p);
1834 if (nr) {
1835 struct buffer_head *bh;
1836
1837 *p = 0;
1838 bh = sb_find_get_block(inode->i_sb, nr);
1839 ext3_forget(handle, 0, inode, bh, nr);
1840 }
1841 }
1842
1843 ext3_free_blocks(handle, inode, block_to_free, count);
1844}
1845
1846/**
1847 * ext3_free_data - free a list of data blocks
1848 * @handle: handle for this transaction
1849 * @inode: inode we are dealing with
1850 * @this_bh: indirect buffer_head which contains *@first and *@last
1851 * @first: array of block numbers
1852 * @last: points immediately past the end of array
1853 *
1854 * We are freeing all blocks refered from that array (numbers are stored as
1855 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
1856 *
1857 * We accumulate contiguous runs of blocks to free. Conveniently, if these
1858 * blocks are contiguous then releasing them at one time will only affect one
1859 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
1860 * actually use a lot of journal space.
1861 *
1862 * @this_bh will be %NULL if @first and @last point into the inode's direct
1863 * block pointers.
1864 */
1865static void ext3_free_data(handle_t *handle, struct inode *inode,
1866 struct buffer_head *this_bh,
1867 __le32 *first, __le32 *last)
1868{
1869 unsigned long block_to_free = 0; /* Starting block # of a run */
1870 unsigned long count = 0; /* Number of blocks in the run */
1871 __le32 *block_to_free_p = NULL; /* Pointer into inode/ind
1872 corresponding to
1873 block_to_free */
1874 unsigned long nr; /* Current block # */
1875 __le32 *p; /* Pointer into inode/ind
1876 for current block */
1877 int err;
1878
1879 if (this_bh) { /* For indirect block */
1880 BUFFER_TRACE(this_bh, "get_write_access");
1881 err = ext3_journal_get_write_access(handle, this_bh);
1882 /* Important: if we can't update the indirect pointers
1883 * to the blocks, we can't free them. */
1884 if (err)
1885 return;
1886 }
1887
1888 for (p = first; p < last; p++) {
1889 nr = le32_to_cpu(*p);
1890 if (nr) {
1891 /* accumulate blocks to free if they're contiguous */
1892 if (count == 0) {
1893 block_to_free = nr;
1894 block_to_free_p = p;
1895 count = 1;
1896 } else if (nr == block_to_free + count) {
1897 count++;
1898 } else {
1899 ext3_clear_blocks(handle, inode, this_bh,
1900 block_to_free,
1901 count, block_to_free_p, p);
1902 block_to_free = nr;
1903 block_to_free_p = p;
1904 count = 1;
1905 }
1906 }
1907 }
1908
1909 if (count > 0)
1910 ext3_clear_blocks(handle, inode, this_bh, block_to_free,
1911 count, block_to_free_p, p);
1912
1913 if (this_bh) {
1914 BUFFER_TRACE(this_bh, "call ext3_journal_dirty_metadata");
1915 ext3_journal_dirty_metadata(handle, this_bh);
1916 }
1917}
1918
1919/**
1920 * ext3_free_branches - free an array of branches
1921 * @handle: JBD handle for this transaction
1922 * @inode: inode we are dealing with
1923 * @parent_bh: the buffer_head which contains *@first and *@last
1924 * @first: array of block numbers
1925 * @last: pointer immediately past the end of array
1926 * @depth: depth of the branches to free
1927 *
1928 * We are freeing all blocks refered from these branches (numbers are
1929 * stored as little-endian 32-bit) and updating @inode->i_blocks
1930 * appropriately.
1931 */
1932static void ext3_free_branches(handle_t *handle, struct inode *inode,
1933 struct buffer_head *parent_bh,
1934 __le32 *first, __le32 *last, int depth)
1935{
1936 unsigned long nr;
1937 __le32 *p;
1938
1939 if (is_handle_aborted(handle))
1940 return;
1941
1942 if (depth--) {
1943 struct buffer_head *bh;
1944 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
1945 p = last;
1946 while (--p >= first) {
1947 nr = le32_to_cpu(*p);
1948 if (!nr)
1949 continue; /* A hole */
1950
1951 /* Go read the buffer for the next level down */
1952 bh = sb_bread(inode->i_sb, nr);
1953
1954 /*
1955 * A read failure? Report error and clear slot
1956 * (should be rare).
1957 */
1958 if (!bh) {
1959 ext3_error(inode->i_sb, "ext3_free_branches",
1960 "Read failure, inode=%ld, block=%ld",
1961 inode->i_ino, nr);
1962 continue;
1963 }
1964
1965 /* This zaps the entire block. Bottom up. */
1966 BUFFER_TRACE(bh, "free child branches");
1967 ext3_free_branches(handle, inode, bh,
1968 (__le32*)bh->b_data,
1969 (__le32*)bh->b_data + addr_per_block,
1970 depth);
1971
1972 /*
1973 * We've probably journalled the indirect block several
1974 * times during the truncate. But it's no longer
1975 * needed and we now drop it from the transaction via
1976 * journal_revoke().
1977 *
1978 * That's easy if it's exclusively part of this
1979 * transaction. But if it's part of the committing
1980 * transaction then journal_forget() will simply
1981 * brelse() it. That means that if the underlying
1982 * block is reallocated in ext3_get_block(),
1983 * unmap_underlying_metadata() will find this block
1984 * and will try to get rid of it. damn, damn.
1985 *
1986 * If this block has already been committed to the
1987 * journal, a revoke record will be written. And
1988 * revoke records must be emitted *before* clearing
1989 * this block's bit in the bitmaps.
1990 */
1991 ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
1992
1993 /*
1994 * Everything below this this pointer has been
1995 * released. Now let this top-of-subtree go.
1996 *
1997 * We want the freeing of this indirect block to be
1998 * atomic in the journal with the updating of the
1999 * bitmap block which owns it. So make some room in
2000 * the journal.
2001 *
2002 * We zero the parent pointer *after* freeing its
2003 * pointee in the bitmaps, so if extend_transaction()
2004 * for some reason fails to put the bitmap changes and
2005 * the release into the same transaction, recovery
2006 * will merely complain about releasing a free block,
2007 * rather than leaking blocks.
2008 */
2009 if (is_handle_aborted(handle))
2010 return;
2011 if (try_to_extend_transaction(handle, inode)) {
2012 ext3_mark_inode_dirty(handle, inode);
2013 ext3_journal_test_restart(handle, inode);
2014 }
2015
2016 ext3_free_blocks(handle, inode, nr, 1);
2017
2018 if (parent_bh) {
2019 /*
2020 * The block which we have just freed is
2021 * pointed to by an indirect block: journal it
2022 */
2023 BUFFER_TRACE(parent_bh, "get_write_access");
2024 if (!ext3_journal_get_write_access(handle,
2025 parent_bh)){
2026 *p = 0;
2027 BUFFER_TRACE(parent_bh,
2028 "call ext3_journal_dirty_metadata");
2029 ext3_journal_dirty_metadata(handle,
2030 parent_bh);
2031 }
2032 }
2033 }
2034 } else {
2035 /* We have reached the bottom of the tree. */
2036 BUFFER_TRACE(parent_bh, "free data blocks");
2037 ext3_free_data(handle, inode, parent_bh, first, last);
2038 }
2039}
2040
2041/*
2042 * ext3_truncate()
2043 *
2044 * We block out ext3_get_block() block instantiations across the entire
2045 * transaction, and VFS/VM ensures that ext3_truncate() cannot run
2046 * simultaneously on behalf of the same inode.
2047 *
2048 * As we work through the truncate and commmit bits of it to the journal there
2049 * is one core, guiding principle: the file's tree must always be consistent on
2050 * disk. We must be able to restart the truncate after a crash.
2051 *
2052 * The file's tree may be transiently inconsistent in memory (although it
2053 * probably isn't), but whenever we close off and commit a journal transaction,
2054 * the contents of (the filesystem + the journal) must be consistent and
2055 * restartable. It's pretty simple, really: bottom up, right to left (although
2056 * left-to-right works OK too).
2057 *
2058 * Note that at recovery time, journal replay occurs *before* the restart of
2059 * truncate against the orphan inode list.
2060 *
2061 * The committed inode has the new, desired i_size (which is the same as
2062 * i_disksize in this case). After a crash, ext3_orphan_cleanup() will see
2063 * that this inode's truncate did not complete and it will again call
2064 * ext3_truncate() to have another go. So there will be instantiated blocks
2065 * to the right of the truncation point in a crashed ext3 filesystem. But
2066 * that's fine - as long as they are linked from the inode, the post-crash
2067 * ext3_truncate() run will find them and release them.
2068 */
2069
2070void ext3_truncate(struct inode * inode)
2071{
2072 handle_t *handle;
2073 struct ext3_inode_info *ei = EXT3_I(inode);
2074 __le32 *i_data = ei->i_data;
2075 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2076 struct address_space *mapping = inode->i_mapping;
2077 int offsets[4];
2078 Indirect chain[4];
2079 Indirect *partial;
2080 __le32 nr = 0;
2081 int n;
2082 long last_block;
2083 unsigned blocksize = inode->i_sb->s_blocksize;
2084 struct page *page;
2085
2086 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2087 S_ISLNK(inode->i_mode)))
2088 return;
2089 if (ext3_inode_is_fast_symlink(inode))
2090 return;
2091 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2092 return;
2093
2094 /*
2095 * We have to lock the EOF page here, because lock_page() nests
2096 * outside journal_start().
2097 */
2098 if ((inode->i_size & (blocksize - 1)) == 0) {
2099 /* Block boundary? Nothing to do */
2100 page = NULL;
2101 } else {
2102 page = grab_cache_page(mapping,
2103 inode->i_size >> PAGE_CACHE_SHIFT);
2104 if (!page)
2105 return;
2106 }
2107
2108 handle = start_transaction(inode);
2109 if (IS_ERR(handle)) {
2110 if (page) {
2111 clear_highpage(page);
2112 flush_dcache_page(page);
2113 unlock_page(page);
2114 page_cache_release(page);
2115 }
2116 return; /* AKPM: return what? */
2117 }
2118
2119 last_block = (inode->i_size + blocksize-1)
2120 >> EXT3_BLOCK_SIZE_BITS(inode->i_sb);
2121
2122 if (page)
2123 ext3_block_truncate_page(handle, page, mapping, inode->i_size);
2124
2125 n = ext3_block_to_path(inode, last_block, offsets, NULL);
2126 if (n == 0)
2127 goto out_stop; /* error */
2128
2129 /*
2130 * OK. This truncate is going to happen. We add the inode to the
2131 * orphan list, so that if this truncate spans multiple transactions,
2132 * and we crash, we will resume the truncate when the filesystem
2133 * recovers. It also marks the inode dirty, to catch the new size.
2134 *
2135 * Implication: the file must always be in a sane, consistent
2136 * truncatable state while each transaction commits.
2137 */
2138 if (ext3_orphan_add(handle, inode))
2139 goto out_stop;
2140
2141 /*
2142 * The orphan list entry will now protect us from any crash which
2143 * occurs before the truncate completes, so it is now safe to propagate
2144 * the new, shorter inode size (held for now in i_size) into the
2145 * on-disk inode. We do this via i_disksize, which is the value which
2146 * ext3 *really* writes onto the disk inode.
2147 */
2148 ei->i_disksize = inode->i_size;
2149
2150 /*
2151 * From here we block out all ext3_get_block() callers who want to
2152 * modify the block allocation tree.
2153 */
2154 down(&ei->truncate_sem);
2155
2156 if (n == 1) { /* direct blocks */
2157 ext3_free_data(handle, inode, NULL, i_data+offsets[0],
2158 i_data + EXT3_NDIR_BLOCKS);
2159 goto do_indirects;
2160 }
2161
2162 partial = ext3_find_shared(inode, n, offsets, chain, &nr);
2163 /* Kill the top of shared branch (not detached) */
2164 if (nr) {
2165 if (partial == chain) {
2166 /* Shared branch grows from the inode */
2167 ext3_free_branches(handle, inode, NULL,
2168 &nr, &nr+1, (chain+n-1) - partial);
2169 *partial->p = 0;
2170 /*
2171 * We mark the inode dirty prior to restart,
2172 * and prior to stop. No need for it here.
2173 */
2174 } else {
2175 /* Shared branch grows from an indirect block */
2176 BUFFER_TRACE(partial->bh, "get_write_access");
2177 ext3_free_branches(handle, inode, partial->bh,
2178 partial->p,
2179 partial->p+1, (chain+n-1) - partial);
2180 }
2181 }
2182 /* Clear the ends of indirect blocks on the shared branch */
2183 while (partial > chain) {
2184 ext3_free_branches(handle, inode, partial->bh, partial->p + 1,
2185 (__le32*)partial->bh->b_data+addr_per_block,
2186 (chain+n-1) - partial);
2187 BUFFER_TRACE(partial->bh, "call brelse");
2188 brelse (partial->bh);
2189 partial--;
2190 }
2191do_indirects:
2192 /* Kill the remaining (whole) subtrees */
2193 switch (offsets[0]) {
2194 default:
2195 nr = i_data[EXT3_IND_BLOCK];
2196 if (nr) {
2197 ext3_free_branches(handle, inode, NULL,
2198 &nr, &nr+1, 1);
2199 i_data[EXT3_IND_BLOCK] = 0;
2200 }
2201 case EXT3_IND_BLOCK:
2202 nr = i_data[EXT3_DIND_BLOCK];
2203 if (nr) {
2204 ext3_free_branches(handle, inode, NULL,
2205 &nr, &nr+1, 2);
2206 i_data[EXT3_DIND_BLOCK] = 0;
2207 }
2208 case EXT3_DIND_BLOCK:
2209 nr = i_data[EXT3_TIND_BLOCK];
2210 if (nr) {
2211 ext3_free_branches(handle, inode, NULL,
2212 &nr, &nr+1, 3);
2213 i_data[EXT3_TIND_BLOCK] = 0;
2214 }
2215 case EXT3_TIND_BLOCK:
2216 ;
2217 }
2218
2219 ext3_discard_reservation(inode);
2220
2221 up(&ei->truncate_sem);
2222 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
2223 ext3_mark_inode_dirty(handle, inode);
2224
2225 /* In a multi-transaction truncate, we only make the final
2226 * transaction synchronous */
2227 if (IS_SYNC(inode))
2228 handle->h_sync = 1;
2229out_stop:
2230 /*
2231 * If this was a simple ftruncate(), and the file will remain alive
2232 * then we need to clear up the orphan record which we created above.
2233 * However, if this was a real unlink then we were called by
2234 * ext3_delete_inode(), and we allow that function to clean up the
2235 * orphan info for us.
2236 */
2237 if (inode->i_nlink)
2238 ext3_orphan_del(handle, inode);
2239
2240 ext3_journal_stop(handle);
2241}
2242
2243static unsigned long ext3_get_inode_block(struct super_block *sb,
2244 unsigned long ino, struct ext3_iloc *iloc)
2245{
2246 unsigned long desc, group_desc, block_group;
2247 unsigned long offset, block;
2248 struct buffer_head *bh;
2249 struct ext3_group_desc * gdp;
2250
2251
2252 if ((ino != EXT3_ROOT_INO &&
2253 ino != EXT3_JOURNAL_INO &&
2254 ino != EXT3_RESIZE_INO &&
2255 ino < EXT3_FIRST_INO(sb)) ||
2256 ino > le32_to_cpu(
2257 EXT3_SB(sb)->s_es->s_inodes_count)) {
2258 ext3_error (sb, "ext3_get_inode_block",
2259 "bad inode number: %lu", ino);
2260 return 0;
2261 }
2262 block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
2263 if (block_group >= EXT3_SB(sb)->s_groups_count) {
2264 ext3_error (sb, "ext3_get_inode_block",
2265 "group >= groups count");
2266 return 0;
2267 }
2268 smp_rmb();
2269 group_desc = block_group >> EXT3_DESC_PER_BLOCK_BITS(sb);
2270 desc = block_group & (EXT3_DESC_PER_BLOCK(sb) - 1);
2271 bh = EXT3_SB(sb)->s_group_desc[group_desc];
2272 if (!bh) {
2273 ext3_error (sb, "ext3_get_inode_block",
2274 "Descriptor not loaded");
2275 return 0;
2276 }
2277
2278 gdp = (struct ext3_group_desc *) bh->b_data;
2279 /*
2280 * Figure out the offset within the block group inode table
2281 */
2282 offset = ((ino - 1) % EXT3_INODES_PER_GROUP(sb)) *
2283 EXT3_INODE_SIZE(sb);
2284 block = le32_to_cpu(gdp[desc].bg_inode_table) +
2285 (offset >> EXT3_BLOCK_SIZE_BITS(sb));
2286
2287 iloc->block_group = block_group;
2288 iloc->offset = offset & (EXT3_BLOCK_SIZE(sb) - 1);
2289 return block;
2290}
2291
2292/*
2293 * ext3_get_inode_loc returns with an extra refcount against the inode's
2294 * underlying buffer_head on success. If 'in_mem' is true, we have all
2295 * data in memory that is needed to recreate the on-disk version of this
2296 * inode.
2297 */
2298static int __ext3_get_inode_loc(struct inode *inode,
2299 struct ext3_iloc *iloc, int in_mem)
2300{
2301 unsigned long block;
2302 struct buffer_head *bh;
2303
2304 block = ext3_get_inode_block(inode->i_sb, inode->i_ino, iloc);
2305 if (!block)
2306 return -EIO;
2307
2308 bh = sb_getblk(inode->i_sb, block);
2309 if (!bh) {
2310 ext3_error (inode->i_sb, "ext3_get_inode_loc",
2311 "unable to read inode block - "
2312 "inode=%lu, block=%lu", inode->i_ino, block);
2313 return -EIO;
2314 }
2315 if (!buffer_uptodate(bh)) {
2316 lock_buffer(bh);
2317 if (buffer_uptodate(bh)) {
2318 /* someone brought it uptodate while we waited */
2319 unlock_buffer(bh);
2320 goto has_buffer;
2321 }
2322
2323 /*
2324 * If we have all information of the inode in memory and this
2325 * is the only valid inode in the block, we need not read the
2326 * block.
2327 */
2328 if (in_mem) {
2329 struct buffer_head *bitmap_bh;
2330 struct ext3_group_desc *desc;
2331 int inodes_per_buffer;
2332 int inode_offset, i;
2333 int block_group;
2334 int start;
2335
2336 block_group = (inode->i_ino - 1) /
2337 EXT3_INODES_PER_GROUP(inode->i_sb);
2338 inodes_per_buffer = bh->b_size /
2339 EXT3_INODE_SIZE(inode->i_sb);
2340 inode_offset = ((inode->i_ino - 1) %
2341 EXT3_INODES_PER_GROUP(inode->i_sb));
2342 start = inode_offset & ~(inodes_per_buffer - 1);
2343
2344 /* Is the inode bitmap in cache? */
2345 desc = ext3_get_group_desc(inode->i_sb,
2346 block_group, NULL);
2347 if (!desc)
2348 goto make_io;
2349
2350 bitmap_bh = sb_getblk(inode->i_sb,
2351 le32_to_cpu(desc->bg_inode_bitmap));
2352 if (!bitmap_bh)
2353 goto make_io;
2354
2355 /*
2356 * If the inode bitmap isn't in cache then the
2357 * optimisation may end up performing two reads instead
2358 * of one, so skip it.
2359 */
2360 if (!buffer_uptodate(bitmap_bh)) {
2361 brelse(bitmap_bh);
2362 goto make_io;
2363 }
2364 for (i = start; i < start + inodes_per_buffer; i++) {
2365 if (i == inode_offset)
2366 continue;
2367 if (ext3_test_bit(i, bitmap_bh->b_data))
2368 break;
2369 }
2370 brelse(bitmap_bh);
2371 if (i == start + inodes_per_buffer) {
2372 /* all other inodes are free, so skip I/O */
2373 memset(bh->b_data, 0, bh->b_size);
2374 set_buffer_uptodate(bh);
2375 unlock_buffer(bh);
2376 goto has_buffer;
2377 }
2378 }
2379
2380make_io:
2381 /*
2382 * There are other valid inodes in the buffer, this inode
2383 * has in-inode xattrs, or we don't have this inode in memory.
2384 * Read the block from disk.
2385 */
2386 get_bh(bh);
2387 bh->b_end_io = end_buffer_read_sync;
2388 submit_bh(READ, bh);
2389 wait_on_buffer(bh);
2390 if (!buffer_uptodate(bh)) {
2391 ext3_error(inode->i_sb, "ext3_get_inode_loc",
2392 "unable to read inode block - "
2393 "inode=%lu, block=%lu",
2394 inode->i_ino, block);
2395 brelse(bh);
2396 return -EIO;
2397 }
2398 }
2399has_buffer:
2400 iloc->bh = bh;
2401 return 0;
2402}
2403
2404int ext3_get_inode_loc(struct inode *inode, struct ext3_iloc *iloc)
2405{
2406 /* We have all inode data except xattrs in memory here. */
2407 return __ext3_get_inode_loc(inode, iloc,
2408 !(EXT3_I(inode)->i_state & EXT3_STATE_XATTR));
2409}
2410
2411void ext3_set_inode_flags(struct inode *inode)
2412{
2413 unsigned int flags = EXT3_I(inode)->i_flags;
2414
2415 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
2416 if (flags & EXT3_SYNC_FL)
2417 inode->i_flags |= S_SYNC;
2418 if (flags & EXT3_APPEND_FL)
2419 inode->i_flags |= S_APPEND;
2420 if (flags & EXT3_IMMUTABLE_FL)
2421 inode->i_flags |= S_IMMUTABLE;
2422 if (flags & EXT3_NOATIME_FL)
2423 inode->i_flags |= S_NOATIME;
2424 if (flags & EXT3_DIRSYNC_FL)
2425 inode->i_flags |= S_DIRSYNC;
2426}
2427
2428void ext3_read_inode(struct inode * inode)
2429{
2430 struct ext3_iloc iloc;
2431 struct ext3_inode *raw_inode;
2432 struct ext3_inode_info *ei = EXT3_I(inode);
2433 struct buffer_head *bh;
2434 int block;
2435
2436#ifdef CONFIG_EXT3_FS_POSIX_ACL
2437 ei->i_acl = EXT3_ACL_NOT_CACHED;
2438 ei->i_default_acl = EXT3_ACL_NOT_CACHED;
2439#endif
2440 ei->i_block_alloc_info = NULL;
2441
2442 if (__ext3_get_inode_loc(inode, &iloc, 0))
2443 goto bad_inode;
2444 bh = iloc.bh;
2445 raw_inode = ext3_raw_inode(&iloc);
2446 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
2447 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
2448 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
2449 if(!(test_opt (inode->i_sb, NO_UID32))) {
2450 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
2451 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
2452 }
2453 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
2454 inode->i_size = le32_to_cpu(raw_inode->i_size);
2455 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->i_atime);
2456 inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->i_ctime);
2457 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->i_mtime);
2458 inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
2459
2460 ei->i_state = 0;
2461 ei->i_dir_start_lookup = 0;
2462 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
2463 /* We now have enough fields to check if the inode was active or not.
2464 * This is needed because nfsd might try to access dead inodes
2465 * the test is that same one that e2fsck uses
2466 * NeilBrown 1999oct15
2467 */
2468 if (inode->i_nlink == 0) {
2469 if (inode->i_mode == 0 ||
2470 !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) {
2471 /* this inode is deleted */
2472 brelse (bh);
2473 goto bad_inode;
2474 }
2475 /* The only unlinked inodes we let through here have
2476 * valid i_mode and are being read by the orphan
2477 * recovery code: that's fine, we're about to complete
2478 * the process of deleting those. */
2479 }
2480 inode->i_blksize = PAGE_SIZE; /* This is the optimal IO size
2481 * (for stat), not the fs block
2482 * size */
2483 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
2484 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
2485#ifdef EXT3_FRAGMENTS
2486 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
2487 ei->i_frag_no = raw_inode->i_frag;
2488 ei->i_frag_size = raw_inode->i_fsize;
2489#endif
2490 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
2491 if (!S_ISREG(inode->i_mode)) {
2492 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
2493 } else {
2494 inode->i_size |=
2495 ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
2496 }
2497 ei->i_disksize = inode->i_size;
2498 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
2499 ei->i_block_group = iloc.block_group;
2500 /*
2501 * NOTE! The in-memory inode i_data array is in little-endian order
2502 * even on big-endian machines: we do NOT byteswap the block numbers!
2503 */
2504 for (block = 0; block < EXT3_N_BLOCKS; block++)
2505 ei->i_data[block] = raw_inode->i_block[block];
2506 INIT_LIST_HEAD(&ei->i_orphan);
2507
2508 if (inode->i_ino >= EXT3_FIRST_INO(inode->i_sb) + 1 &&
2509 EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) {
2510 /*
2511 * When mke2fs creates big inodes it does not zero out
2512 * the unused bytes above EXT3_GOOD_OLD_INODE_SIZE,
2513 * so ignore those first few inodes.
2514 */
2515 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
2516 if (EXT3_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
2517 EXT3_INODE_SIZE(inode->i_sb))
2518 goto bad_inode;
2519 if (ei->i_extra_isize == 0) {
2520 /* The extra space is currently unused. Use it. */
2521 ei->i_extra_isize = sizeof(struct ext3_inode) -
2522 EXT3_GOOD_OLD_INODE_SIZE;
2523 } else {
2524 __le32 *magic = (void *)raw_inode +
2525 EXT3_GOOD_OLD_INODE_SIZE +
2526 ei->i_extra_isize;
2527 if (*magic == cpu_to_le32(EXT3_XATTR_MAGIC))
2528 ei->i_state |= EXT3_STATE_XATTR;
2529 }
2530 } else
2531 ei->i_extra_isize = 0;
2532
2533 if (S_ISREG(inode->i_mode)) {
2534 inode->i_op = &ext3_file_inode_operations;
2535 inode->i_fop = &ext3_file_operations;
2536 ext3_set_aops(inode);
2537 } else if (S_ISDIR(inode->i_mode)) {
2538 inode->i_op = &ext3_dir_inode_operations;
2539 inode->i_fop = &ext3_dir_operations;
2540 } else if (S_ISLNK(inode->i_mode)) {
2541 if (ext3_inode_is_fast_symlink(inode))
2542 inode->i_op = &ext3_fast_symlink_inode_operations;
2543 else {
2544 inode->i_op = &ext3_symlink_inode_operations;
2545 ext3_set_aops(inode);
2546 }
2547 } else {
2548 inode->i_op = &ext3_special_inode_operations;
2549 if (raw_inode->i_block[0])
2550 init_special_inode(inode, inode->i_mode,
2551 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
2552 else
2553 init_special_inode(inode, inode->i_mode,
2554 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
2555 }
2556 brelse (iloc.bh);
2557 ext3_set_inode_flags(inode);
2558 return;
2559
2560bad_inode:
2561 make_bad_inode(inode);
2562 return;
2563}
2564
2565/*
2566 * Post the struct inode info into an on-disk inode location in the
2567 * buffer-cache. This gobbles the caller's reference to the
2568 * buffer_head in the inode location struct.
2569 *
2570 * The caller must have write access to iloc->bh.
2571 */
2572static int ext3_do_update_inode(handle_t *handle,
2573 struct inode *inode,
2574 struct ext3_iloc *iloc)
2575{
2576 struct ext3_inode *raw_inode = ext3_raw_inode(iloc);
2577 struct ext3_inode_info *ei = EXT3_I(inode);
2578 struct buffer_head *bh = iloc->bh;
2579 int err = 0, rc, block;
2580
2581 /* For fields not not tracking in the in-memory inode,
2582 * initialise them to zero for new inodes. */
2583 if (ei->i_state & EXT3_STATE_NEW)
2584 memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
2585
2586 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
2587 if(!(test_opt(inode->i_sb, NO_UID32))) {
2588 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
2589 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
2590/*
2591 * Fix up interoperability with old kernels. Otherwise, old inodes get
2592 * re-used with the upper 16 bits of the uid/gid intact
2593 */
2594 if(!ei->i_dtime) {
2595 raw_inode->i_uid_high =
2596 cpu_to_le16(high_16_bits(inode->i_uid));
2597 raw_inode->i_gid_high =
2598 cpu_to_le16(high_16_bits(inode->i_gid));
2599 } else {
2600 raw_inode->i_uid_high = 0;
2601 raw_inode->i_gid_high = 0;
2602 }
2603 } else {
2604 raw_inode->i_uid_low =
2605 cpu_to_le16(fs_high2lowuid(inode->i_uid));
2606 raw_inode->i_gid_low =
2607 cpu_to_le16(fs_high2lowgid(inode->i_gid));
2608 raw_inode->i_uid_high = 0;
2609 raw_inode->i_gid_high = 0;
2610 }
2611 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
2612 raw_inode->i_size = cpu_to_le32(ei->i_disksize);
2613 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
2614 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
2615 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
2616 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
2617 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
2618 raw_inode->i_flags = cpu_to_le32(ei->i_flags);
2619#ifdef EXT3_FRAGMENTS
2620 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
2621 raw_inode->i_frag = ei->i_frag_no;
2622 raw_inode->i_fsize = ei->i_frag_size;
2623#endif
2624 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
2625 if (!S_ISREG(inode->i_mode)) {
2626 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
2627 } else {
2628 raw_inode->i_size_high =
2629 cpu_to_le32(ei->i_disksize >> 32);
2630 if (ei->i_disksize > 0x7fffffffULL) {
2631 struct super_block *sb = inode->i_sb;
2632 if (!EXT3_HAS_RO_COMPAT_FEATURE(sb,
2633 EXT3_FEATURE_RO_COMPAT_LARGE_FILE) ||
2634 EXT3_SB(sb)->s_es->s_rev_level ==
2635 cpu_to_le32(EXT3_GOOD_OLD_REV)) {
2636 /* If this is the first large file
2637 * created, add a flag to the superblock.
2638 */
2639 err = ext3_journal_get_write_access(handle,
2640 EXT3_SB(sb)->s_sbh);
2641 if (err)
2642 goto out_brelse;
2643 ext3_update_dynamic_rev(sb);
2644 EXT3_SET_RO_COMPAT_FEATURE(sb,
2645 EXT3_FEATURE_RO_COMPAT_LARGE_FILE);
2646 sb->s_dirt = 1;
2647 handle->h_sync = 1;
2648 err = ext3_journal_dirty_metadata(handle,
2649 EXT3_SB(sb)->s_sbh);
2650 }
2651 }
2652 }
2653 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
2654 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
2655 if (old_valid_dev(inode->i_rdev)) {
2656 raw_inode->i_block[0] =
2657 cpu_to_le32(old_encode_dev(inode->i_rdev));
2658 raw_inode->i_block[1] = 0;
2659 } else {
2660 raw_inode->i_block[0] = 0;
2661 raw_inode->i_block[1] =
2662 cpu_to_le32(new_encode_dev(inode->i_rdev));
2663 raw_inode->i_block[2] = 0;
2664 }
2665 } else for (block = 0; block < EXT3_N_BLOCKS; block++)
2666 raw_inode->i_block[block] = ei->i_data[block];
2667
Andreas Gruenbacherff87b372005-07-07 17:57:00 -07002668 if (ei->i_extra_isize)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002669 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
2670
2671 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
2672 rc = ext3_journal_dirty_metadata(handle, bh);
2673 if (!err)
2674 err = rc;
2675 ei->i_state &= ~EXT3_STATE_NEW;
2676
2677out_brelse:
2678 brelse (bh);
2679 ext3_std_error(inode->i_sb, err);
2680 return err;
2681}
2682
2683/*
2684 * ext3_write_inode()
2685 *
2686 * We are called from a few places:
2687 *
2688 * - Within generic_file_write() for O_SYNC files.
2689 * Here, there will be no transaction running. We wait for any running
2690 * trasnaction to commit.
2691 *
2692 * - Within sys_sync(), kupdate and such.
2693 * We wait on commit, if tol to.
2694 *
2695 * - Within prune_icache() (PF_MEMALLOC == true)
2696 * Here we simply return. We can't afford to block kswapd on the
2697 * journal commit.
2698 *
2699 * In all cases it is actually safe for us to return without doing anything,
2700 * because the inode has been copied into a raw inode buffer in
2701 * ext3_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
2702 * knfsd.
2703 *
2704 * Note that we are absolutely dependent upon all inode dirtiers doing the
2705 * right thing: they *must* call mark_inode_dirty() after dirtying info in
2706 * which we are interested.
2707 *
2708 * It would be a bug for them to not do this. The code:
2709 *
2710 * mark_inode_dirty(inode)
2711 * stuff();
2712 * inode->i_size = expr;
2713 *
2714 * is in error because a kswapd-driven write_inode() could occur while
2715 * `stuff()' is running, and the new i_size will be lost. Plus the inode
2716 * will no longer be on the superblock's dirty inode list.
2717 */
2718int ext3_write_inode(struct inode *inode, int wait)
2719{
2720 if (current->flags & PF_MEMALLOC)
2721 return 0;
2722
2723 if (ext3_journal_current_handle()) {
2724 jbd_debug(0, "called recursively, non-PF_MEMALLOC!\n");
2725 dump_stack();
2726 return -EIO;
2727 }
2728
2729 if (!wait)
2730 return 0;
2731
2732 return ext3_force_commit(inode->i_sb);
2733}
2734
2735/*
2736 * ext3_setattr()
2737 *
2738 * Called from notify_change.
2739 *
2740 * We want to trap VFS attempts to truncate the file as soon as
2741 * possible. In particular, we want to make sure that when the VFS
2742 * shrinks i_size, we put the inode on the orphan list and modify
2743 * i_disksize immediately, so that during the subsequent flushing of
2744 * dirty pages and freeing of disk blocks, we can guarantee that any
2745 * commit will leave the blocks being flushed in an unused state on
2746 * disk. (On recovery, the inode will get truncated and the blocks will
2747 * be freed, so we have a strong guarantee that no future commit will
2748 * leave these blocks visible to the user.)
2749 *
2750 * Called with inode->sem down.
2751 */
2752int ext3_setattr(struct dentry *dentry, struct iattr *attr)
2753{
2754 struct inode *inode = dentry->d_inode;
2755 int error, rc = 0;
2756 const unsigned int ia_valid = attr->ia_valid;
2757
2758 error = inode_change_ok(inode, attr);
2759 if (error)
2760 return error;
2761
2762 if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
2763 (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
2764 handle_t *handle;
2765
2766 /* (user+group)*(old+new) structure, inode write (sb,
2767 * inode block, ? - but truncate inode update has it) */
Jan Kara1f545872005-06-23 22:01:04 -07002768 handle = ext3_journal_start(inode, 2*(EXT3_QUOTA_INIT_BLOCKS(inode->i_sb)+
2769 EXT3_QUOTA_DEL_BLOCKS(inode->i_sb))+3);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002770 if (IS_ERR(handle)) {
2771 error = PTR_ERR(handle);
2772 goto err_out;
2773 }
2774 error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0;
2775 if (error) {
2776 ext3_journal_stop(handle);
2777 return error;
2778 }
2779 /* Update corresponding info in inode so that everything is in
2780 * one transaction */
2781 if (attr->ia_valid & ATTR_UID)
2782 inode->i_uid = attr->ia_uid;
2783 if (attr->ia_valid & ATTR_GID)
2784 inode->i_gid = attr->ia_gid;
2785 error = ext3_mark_inode_dirty(handle, inode);
2786 ext3_journal_stop(handle);
2787 }
2788
2789 if (S_ISREG(inode->i_mode) &&
2790 attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
2791 handle_t *handle;
2792
2793 handle = ext3_journal_start(inode, 3);
2794 if (IS_ERR(handle)) {
2795 error = PTR_ERR(handle);
2796 goto err_out;
2797 }
2798
2799 error = ext3_orphan_add(handle, inode);
2800 EXT3_I(inode)->i_disksize = attr->ia_size;
2801 rc = ext3_mark_inode_dirty(handle, inode);
2802 if (!error)
2803 error = rc;
2804 ext3_journal_stop(handle);
2805 }
2806
2807 rc = inode_setattr(inode, attr);
2808
2809 /* If inode_setattr's call to ext3_truncate failed to get a
2810 * transaction handle at all, we need to clean up the in-core
2811 * orphan list manually. */
2812 if (inode->i_nlink)
2813 ext3_orphan_del(NULL, inode);
2814
2815 if (!rc && (ia_valid & ATTR_MODE))
2816 rc = ext3_acl_chmod(inode);
2817
2818err_out:
2819 ext3_std_error(inode->i_sb, error);
2820 if (!error)
2821 error = rc;
2822 return error;
2823}
2824
2825
2826/*
2827 * akpm: how many blocks doth make a writepage()?
2828 *
2829 * With N blocks per page, it may be:
2830 * N data blocks
2831 * 2 indirect block
2832 * 2 dindirect
2833 * 1 tindirect
2834 * N+5 bitmap blocks (from the above)
2835 * N+5 group descriptor summary blocks
2836 * 1 inode block
2837 * 1 superblock.
2838 * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quote files
2839 *
2840 * 3 * (N + 5) + 2 + 2 * EXT3_SINGLEDATA_TRANS_BLOCKS
2841 *
2842 * With ordered or writeback data it's the same, less the N data blocks.
2843 *
2844 * If the inode's direct blocks can hold an integral number of pages then a
2845 * page cannot straddle two indirect blocks, and we can only touch one indirect
2846 * and dindirect block, and the "5" above becomes "3".
2847 *
2848 * This still overestimates under most circumstances. If we were to pass the
2849 * start and end offsets in here as well we could do block_to_path() on each
2850 * block and work out the exact number of indirects which are touched. Pah.
2851 */
2852
2853static int ext3_writepage_trans_blocks(struct inode *inode)
2854{
2855 int bpp = ext3_journal_blocks_per_page(inode);
2856 int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3;
2857 int ret;
2858
2859 if (ext3_should_journal_data(inode))
2860 ret = 3 * (bpp + indirects) + 2;
2861 else
2862 ret = 2 * (bpp + indirects) + 2;
2863
2864#ifdef CONFIG_QUOTA
2865 /* We know that structure was already allocated during DQUOT_INIT so
2866 * we will be updating only the data blocks + inodes */
Jan Kara1f545872005-06-23 22:01:04 -07002867 ret += 2*EXT3_QUOTA_TRANS_BLOCKS(inode->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002868#endif
2869
2870 return ret;
2871}
2872
2873/*
2874 * The caller must have previously called ext3_reserve_inode_write().
2875 * Give this, we know that the caller already has write access to iloc->bh.
2876 */
2877int ext3_mark_iloc_dirty(handle_t *handle,
2878 struct inode *inode, struct ext3_iloc *iloc)
2879{
2880 int err = 0;
2881
2882 /* the do_update_inode consumes one bh->b_count */
2883 get_bh(iloc->bh);
2884
2885 /* ext3_do_update_inode() does journal_dirty_metadata */
2886 err = ext3_do_update_inode(handle, inode, iloc);
2887 put_bh(iloc->bh);
2888 return err;
2889}
2890
2891/*
2892 * On success, We end up with an outstanding reference count against
2893 * iloc->bh. This _must_ be cleaned up later.
2894 */
2895
2896int
2897ext3_reserve_inode_write(handle_t *handle, struct inode *inode,
2898 struct ext3_iloc *iloc)
2899{
2900 int err = 0;
2901 if (handle) {
2902 err = ext3_get_inode_loc(inode, iloc);
2903 if (!err) {
2904 BUFFER_TRACE(iloc->bh, "get_write_access");
2905 err = ext3_journal_get_write_access(handle, iloc->bh);
2906 if (err) {
2907 brelse(iloc->bh);
2908 iloc->bh = NULL;
2909 }
2910 }
2911 }
2912 ext3_std_error(inode->i_sb, err);
2913 return err;
2914}
2915
2916/*
2917 * akpm: What we do here is to mark the in-core inode as clean
2918 * with respect to inode dirtiness (it may still be data-dirty).
2919 * This means that the in-core inode may be reaped by prune_icache
2920 * without having to perform any I/O. This is a very good thing,
2921 * because *any* task may call prune_icache - even ones which
2922 * have a transaction open against a different journal.
2923 *
2924 * Is this cheating? Not really. Sure, we haven't written the
2925 * inode out, but prune_icache isn't a user-visible syncing function.
2926 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
2927 * we start and wait on commits.
2928 *
2929 * Is this efficient/effective? Well, we're being nice to the system
2930 * by cleaning up our inodes proactively so they can be reaped
2931 * without I/O. But we are potentially leaving up to five seconds'
2932 * worth of inodes floating about which prune_icache wants us to
2933 * write out. One way to fix that would be to get prune_icache()
2934 * to do a write_super() to free up some memory. It has the desired
2935 * effect.
2936 */
2937int ext3_mark_inode_dirty(handle_t *handle, struct inode *inode)
2938{
2939 struct ext3_iloc iloc;
2940 int err;
2941
2942 might_sleep();
2943 err = ext3_reserve_inode_write(handle, inode, &iloc);
2944 if (!err)
2945 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
2946 return err;
2947}
2948
2949/*
2950 * akpm: ext3_dirty_inode() is called from __mark_inode_dirty()
2951 *
2952 * We're really interested in the case where a file is being extended.
2953 * i_size has been changed by generic_commit_write() and we thus need
2954 * to include the updated inode in the current transaction.
2955 *
2956 * Also, DQUOT_ALLOC_SPACE() will always dirty the inode when blocks
2957 * are allocated to the file.
2958 *
2959 * If the inode is marked synchronous, we don't honour that here - doing
2960 * so would cause a commit on atime updates, which we don't bother doing.
2961 * We handle synchronous inodes at the highest possible level.
2962 */
2963void ext3_dirty_inode(struct inode *inode)
2964{
2965 handle_t *current_handle = ext3_journal_current_handle();
2966 handle_t *handle;
2967
2968 handle = ext3_journal_start(inode, 2);
2969 if (IS_ERR(handle))
2970 goto out;
2971 if (current_handle &&
2972 current_handle->h_transaction != handle->h_transaction) {
2973 /* This task has a transaction open against a different fs */
2974 printk(KERN_EMERG "%s: transactions do not match!\n",
2975 __FUNCTION__);
2976 } else {
2977 jbd_debug(5, "marking dirty. outer handle=%p\n",
2978 current_handle);
2979 ext3_mark_inode_dirty(handle, inode);
2980 }
2981 ext3_journal_stop(handle);
2982out:
2983 return;
2984}
2985
2986#ifdef AKPM
2987/*
2988 * Bind an inode's backing buffer_head into this transaction, to prevent
2989 * it from being flushed to disk early. Unlike
2990 * ext3_reserve_inode_write, this leaves behind no bh reference and
2991 * returns no iloc structure, so the caller needs to repeat the iloc
2992 * lookup to mark the inode dirty later.
2993 */
2994static inline int
2995ext3_pin_inode(handle_t *handle, struct inode *inode)
2996{
2997 struct ext3_iloc iloc;
2998
2999 int err = 0;
3000 if (handle) {
3001 err = ext3_get_inode_loc(inode, &iloc);
3002 if (!err) {
3003 BUFFER_TRACE(iloc.bh, "get_write_access");
3004 err = journal_get_write_access(handle, iloc.bh);
3005 if (!err)
3006 err = ext3_journal_dirty_metadata(handle,
3007 iloc.bh);
3008 brelse(iloc.bh);
3009 }
3010 }
3011 ext3_std_error(inode->i_sb, err);
3012 return err;
3013}
3014#endif
3015
3016int ext3_change_inode_journal_flag(struct inode *inode, int val)
3017{
3018 journal_t *journal;
3019 handle_t *handle;
3020 int err;
3021
3022 /*
3023 * We have to be very careful here: changing a data block's
3024 * journaling status dynamically is dangerous. If we write a
3025 * data block to the journal, change the status and then delete
3026 * that block, we risk forgetting to revoke the old log record
3027 * from the journal and so a subsequent replay can corrupt data.
3028 * So, first we make sure that the journal is empty and that
3029 * nobody is changing anything.
3030 */
3031
3032 journal = EXT3_JOURNAL(inode);
3033 if (is_journal_aborted(journal) || IS_RDONLY(inode))
3034 return -EROFS;
3035
3036 journal_lock_updates(journal);
3037 journal_flush(journal);
3038
3039 /*
3040 * OK, there are no updates running now, and all cached data is
3041 * synced to disk. We are now in a completely consistent state
3042 * which doesn't have anything in the journal, and we know that
3043 * no filesystem updates are running, so it is safe to modify
3044 * the inode's in-core data-journaling state flag now.
3045 */
3046
3047 if (val)
3048 EXT3_I(inode)->i_flags |= EXT3_JOURNAL_DATA_FL;
3049 else
3050 EXT3_I(inode)->i_flags &= ~EXT3_JOURNAL_DATA_FL;
3051 ext3_set_aops(inode);
3052
3053 journal_unlock_updates(journal);
3054
3055 /* Finally we can mark the inode as dirty. */
3056
3057 handle = ext3_journal_start(inode, 1);
3058 if (IS_ERR(handle))
3059 return PTR_ERR(handle);
3060
3061 err = ext3_mark_inode_dirty(handle, inode);
3062 handle->h_sync = 1;
3063 ext3_journal_stop(handle);
3064 ext3_std_error(inode->i_sb, err);
3065
3066 return err;
3067}