blob: beaf25f5112fd9f427a393bac3b9f12b634e14de [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
Dave Kleikampe9ad5622006-09-27 01:49:35 -070016 * (sct@redhat.com), 1993, 1998
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 * 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
Dave Kleikampe9ad5622006-09-27 01:49:35 -070020 * (jj@sunsite.ms.mff.cuni.cz)
Linus Torvalds1da177e2005-04-16 15:20:36 -070021 *
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>
Jens Axboecaa38fb2006-07-23 01:41:26 +020039#include <linux/bio.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070040#include "xattr.h"
41#include "acl.h"
42
43static int ext3_writepage_trans_blocks(struct inode *inode);
44
45/*
46 * Test whether an inode is a fast symlink.
47 */
Andrew Mortond6859bf2006-03-26 01:38:03 -080048static int ext3_inode_is_fast_symlink(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -070049{
50 int ea_blocks = EXT3_I(inode)->i_file_acl ?
51 (inode->i_sb->s_blocksize >> 9) : 0;
52
Andrew Mortond6859bf2006-03-26 01:38:03 -080053 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070054}
55
Andrew Mortond6859bf2006-03-26 01:38:03 -080056/*
57 * The ext3 forget function must perform a revoke if we are freeing data
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 * which has been journaled. Metadata (eg. indirect blocks) must be
Mingming Caoae6ddcc2006-09-27 01:49:27 -070059 * revoked in all cases.
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 *
61 * "bh" may be NULL: a metadata block may have been freed from memory
62 * but there may still be a record of it in the journal, and that record
63 * still needs to be revoked.
64 */
Andrew Mortond6859bf2006-03-26 01:38:03 -080065int ext3_forget(handle_t *handle, int is_metadata, struct inode *inode,
Mingming Cao1c2bf372006-06-25 05:48:06 -070066 struct buffer_head *bh, ext3_fsblk_t blocknr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070067{
68 int err;
69
70 might_sleep();
71
72 BUFFER_TRACE(bh, "enter");
73
74 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
75 "data mode %lx\n",
76 bh, is_metadata, inode->i_mode,
77 test_opt(inode->i_sb, DATA_FLAGS));
78
79 /* Never use the revoke function if we are doing full data
80 * journaling: there is no need to, and a V1 superblock won't
81 * support it. Otherwise, only skip the revoke on un-journaled
82 * data blocks. */
83
84 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ||
85 (!is_metadata && !ext3_should_journal_data(inode))) {
86 if (bh) {
87 BUFFER_TRACE(bh, "call journal_forget");
88 return ext3_journal_forget(handle, bh);
89 }
90 return 0;
91 }
92
93 /*
94 * data!=journal && (is_metadata || should_journal_data(inode))
95 */
96 BUFFER_TRACE(bh, "call ext3_journal_revoke");
97 err = ext3_journal_revoke(handle, blocknr, bh);
98 if (err)
99 ext3_abort(inode->i_sb, __FUNCTION__,
100 "error %d when attempting revoke", err);
101 BUFFER_TRACE(bh, "exit");
102 return err;
103}
104
105/*
Andrew Mortond6859bf2006-03-26 01:38:03 -0800106 * Work out how many blocks we need to proceed with the next chunk of a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 * truncate transaction.
108 */
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700109static unsigned long blocks_for_truncate(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110{
111 unsigned long needed;
112
113 needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
114
115 /* Give ourselves just enough room to cope with inodes in which
116 * i_blocks is corrupt: we've seen disk corruptions in the past
117 * which resulted in random data in an inode which looked enough
118 * like a regular file for ext3 to try to delete it. Things
119 * will go a bit crazy if that happens, but at least we should
120 * try not to panic the whole kernel. */
121 if (needed < 2)
122 needed = 2;
123
124 /* But we need to bound the transaction so we don't overflow the
125 * journal. */
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700126 if (needed > EXT3_MAX_TRANS_DATA)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 needed = EXT3_MAX_TRANS_DATA;
128
Jan Kara1f545872005-06-23 22:01:04 -0700129 return EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130}
131
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700132/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 * Truncate transactions can be complex and absolutely huge. So we need to
134 * be able to restart the transaction at a conventient checkpoint to make
135 * sure we don't overflow the journal.
136 *
137 * start_transaction gets us a new handle for a truncate transaction,
138 * and extend_transaction tries to extend the existing one a bit. If
139 * extend fails, we need to propagate the failure up and restart the
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700140 * transaction in the top-level truncate loop. --sct
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141 */
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700142static handle_t *start_transaction(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143{
144 handle_t *result;
145
146 result = ext3_journal_start(inode, blocks_for_truncate(inode));
147 if (!IS_ERR(result))
148 return result;
149
150 ext3_std_error(inode->i_sb, PTR_ERR(result));
151 return result;
152}
153
154/*
155 * Try to extend this transaction for the purposes of truncation.
156 *
157 * Returns 0 if we managed to create more room. If we can't create more
158 * room, and the transaction must be restarted we return 1.
159 */
160static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
161{
162 if (handle->h_buffer_credits > EXT3_RESERVE_TRANS_BLOCKS)
163 return 0;
164 if (!ext3_journal_extend(handle, blocks_for_truncate(inode)))
165 return 0;
166 return 1;
167}
168
169/*
170 * Restart the transaction associated with *handle. This does a commit,
171 * so before we call here everything must be consistently dirtied against
172 * this transaction.
173 */
174static int ext3_journal_test_restart(handle_t *handle, struct inode *inode)
175{
176 jbd_debug(2, "restarting handle %p\n", handle);
177 return ext3_journal_restart(handle, blocks_for_truncate(inode));
178}
179
180/*
181 * Called at the last iput() if i_nlink is zero.
182 */
183void ext3_delete_inode (struct inode * inode)
184{
185 handle_t *handle;
186
Mark Fashehfef26652005-09-09 13:01:31 -0700187 truncate_inode_pages(&inode->i_data, 0);
188
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 if (is_bad_inode(inode))
190 goto no_delete;
191
192 handle = start_transaction(inode);
193 if (IS_ERR(handle)) {
Andrew Mortond6859bf2006-03-26 01:38:03 -0800194 /*
195 * If we're going to skip the normal cleanup, we still need to
196 * make sure that the in-core orphan linked list is properly
197 * cleaned up.
198 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 ext3_orphan_del(NULL, inode);
200 goto no_delete;
201 }
202
203 if (IS_SYNC(inode))
204 handle->h_sync = 1;
205 inode->i_size = 0;
206 if (inode->i_blocks)
207 ext3_truncate(inode);
208 /*
209 * Kill off the orphan record which ext3_truncate created.
210 * AKPM: I think this can be inside the above `if'.
211 * Note that ext3_orphan_del() has to be able to cope with the
212 * deletion of a non-existent orphan - this is because we don't
213 * know if ext3_truncate() actually created an orphan record.
214 * (Well, we could do this if we need to, but heck - it works)
215 */
216 ext3_orphan_del(handle, inode);
217 EXT3_I(inode)->i_dtime = get_seconds();
218
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700219 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 * One subtle ordering requirement: if anything has gone wrong
221 * (transaction abort, IO errors, whatever), then we can still
222 * do these next steps (the fs will already have been marked as
223 * having errors), but we can't free the inode if the mark_dirty
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700224 * fails.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 */
226 if (ext3_mark_inode_dirty(handle, inode))
227 /* If that failed, just do the required in-core inode clear. */
228 clear_inode(inode);
229 else
230 ext3_free_inode(handle, inode);
231 ext3_journal_stop(handle);
232 return;
233no_delete:
234 clear_inode(inode); /* We must guarantee clearing of inode... */
235}
236
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237typedef struct {
238 __le32 *p;
239 __le32 key;
240 struct buffer_head *bh;
241} Indirect;
242
243static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
244{
245 p->key = *(p->p = v);
246 p->bh = bh;
247}
248
Andrew Mortond6859bf2006-03-26 01:38:03 -0800249static int verify_chain(Indirect *from, Indirect *to)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250{
251 while (from <= to && from->key == *from->p)
252 from++;
253 return (from > to);
254}
255
256/**
257 * ext3_block_to_path - parse the block number into array of offsets
258 * @inode: inode in question (we are only interested in its superblock)
259 * @i_block: block number to be parsed
260 * @offsets: array to store the offsets in
261 * @boundary: set this non-zero if the referred-to block is likely to be
262 * followed (on disk) by an indirect block.
263 *
264 * To store the locations of file's data ext3 uses a data structure common
265 * for UNIX filesystems - tree of pointers anchored in the inode, with
266 * data blocks at leaves and indirect blocks in intermediate nodes.
267 * This function translates the block number into path in that tree -
268 * return value is the path length and @offsets[n] is the offset of
269 * pointer to (n+1)th node in the nth one. If @block is out of range
270 * (negative or too large) warning is printed and zero returned.
271 *
272 * Note: function doesn't find node addresses, so no IO is needed. All
273 * we need to know is the capacity of indirect blocks (taken from the
274 * inode->i_sb).
275 */
276
277/*
278 * Portability note: the last comparison (check that we fit into triple
279 * indirect block) is spelled differently, because otherwise on an
280 * architecture with 32-bit longs and 8Kb pages we might get into trouble
281 * if our filesystem had 8Kb blocks. We might use long long, but that would
282 * kill us on x86. Oh, well, at least the sign propagation does not matter -
283 * i_block would have to be negative in the very beginning, so we would not
284 * get there at all.
285 */
286
287static int ext3_block_to_path(struct inode *inode,
288 long i_block, int offsets[4], int *boundary)
289{
290 int ptrs = EXT3_ADDR_PER_BLOCK(inode->i_sb);
291 int ptrs_bits = EXT3_ADDR_PER_BLOCK_BITS(inode->i_sb);
292 const long direct_blocks = EXT3_NDIR_BLOCKS,
293 indirect_blocks = ptrs,
294 double_blocks = (1 << (ptrs_bits * 2));
295 int n = 0;
296 int final = 0;
297
298 if (i_block < 0) {
299 ext3_warning (inode->i_sb, "ext3_block_to_path", "block < 0");
300 } else if (i_block < direct_blocks) {
301 offsets[n++] = i_block;
302 final = direct_blocks;
303 } else if ( (i_block -= direct_blocks) < indirect_blocks) {
304 offsets[n++] = EXT3_IND_BLOCK;
305 offsets[n++] = i_block;
306 final = ptrs;
307 } else if ((i_block -= indirect_blocks) < double_blocks) {
308 offsets[n++] = EXT3_DIND_BLOCK;
309 offsets[n++] = i_block >> ptrs_bits;
310 offsets[n++] = i_block & (ptrs - 1);
311 final = ptrs;
312 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
313 offsets[n++] = EXT3_TIND_BLOCK;
314 offsets[n++] = i_block >> (ptrs_bits * 2);
315 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
316 offsets[n++] = i_block & (ptrs - 1);
317 final = ptrs;
318 } else {
Andrew Mortond6859bf2006-03-26 01:38:03 -0800319 ext3_warning(inode->i_sb, "ext3_block_to_path", "block > big");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 }
321 if (boundary)
Mingming Cao89747d32006-03-26 01:37:55 -0800322 *boundary = final - 1 - (i_block & (ptrs - 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 return n;
324}
325
326/**
327 * ext3_get_branch - read the chain of indirect blocks leading to data
328 * @inode: inode in question
329 * @depth: depth of the chain (1 - direct pointer, etc.)
330 * @offsets: offsets of pointers in inode/indirect blocks
331 * @chain: place to store the result
332 * @err: here we store the error value
333 *
334 * Function fills the array of triples <key, p, bh> and returns %NULL
335 * if everything went OK or the pointer to the last filled triple
336 * (incomplete one) otherwise. Upon the return chain[i].key contains
337 * the number of (i+1)-th block in the chain (as it is stored in memory,
338 * i.e. little-endian 32-bit), chain[i].p contains the address of that
339 * number (it points into struct inode for i==0 and into the bh->b_data
340 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
341 * block for i>0 and NULL for i==0. In other words, it holds the block
342 * numbers of the chain, addresses they were taken from (and where we can
343 * verify that chain did not change) and buffer_heads hosting these
344 * numbers.
345 *
346 * Function stops when it stumbles upon zero pointer (absent block)
347 * (pointer to last triple returned, *@err == 0)
348 * or when it gets an IO error reading an indirect block
349 * (ditto, *@err == -EIO)
350 * or when it notices that chain had been changed while it was reading
351 * (ditto, *@err == -EAGAIN)
352 * or when it reads all @depth-1 indirect blocks successfully and finds
353 * the whole chain, all way to the data (returns %NULL, *err == 0).
354 */
355static Indirect *ext3_get_branch(struct inode *inode, int depth, int *offsets,
356 Indirect chain[4], int *err)
357{
358 struct super_block *sb = inode->i_sb;
359 Indirect *p = chain;
360 struct buffer_head *bh;
361
362 *err = 0;
363 /* i_data is not going away, no lock needed */
364 add_chain (chain, NULL, EXT3_I(inode)->i_data + *offsets);
365 if (!p->key)
366 goto no_block;
367 while (--depth) {
368 bh = sb_bread(sb, le32_to_cpu(p->key));
369 if (!bh)
370 goto failure;
371 /* Reader: pointers */
372 if (!verify_chain(chain, p))
373 goto changed;
374 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
375 /* Reader: end */
376 if (!p->key)
377 goto no_block;
378 }
379 return NULL;
380
381changed:
382 brelse(bh);
383 *err = -EAGAIN;
384 goto no_block;
385failure:
386 *err = -EIO;
387no_block:
388 return p;
389}
390
391/**
392 * ext3_find_near - find a place for allocation with sufficient locality
393 * @inode: owner
394 * @ind: descriptor of indirect block.
395 *
396 * This function returns the prefered place for block allocation.
397 * It is used when heuristic for sequential allocation fails.
398 * Rules are:
399 * + if there is a block to the left of our position - allocate near it.
400 * + if pointer will live in indirect block - allocate near that block.
401 * + if pointer will live in inode - allocate in the same
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700402 * cylinder group.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 *
404 * In the latter case we colour the starting block by the callers PID to
405 * prevent it from clashing with concurrent allocations for a different inode
406 * in the same block group. The PID is used here so that functionally related
407 * files will be close-by on-disk.
408 *
409 * Caller must make sure that @ind is valid and will stay that way.
410 */
Mingming Cao43d23f92006-06-25 05:48:07 -0700411static ext3_fsblk_t ext3_find_near(struct inode *inode, Indirect *ind)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412{
413 struct ext3_inode_info *ei = EXT3_I(inode);
414 __le32 *start = ind->bh ? (__le32*) ind->bh->b_data : ei->i_data;
415 __le32 *p;
Mingming Cao43d23f92006-06-25 05:48:07 -0700416 ext3_fsblk_t bg_start;
417 ext3_grpblk_t colour;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418
419 /* Try to find previous block */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800420 for (p = ind->p - 1; p >= start; p--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 if (*p)
422 return le32_to_cpu(*p);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800423 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424
425 /* No such thing, so let's try location of indirect block */
426 if (ind->bh)
427 return ind->bh->b_blocknr;
428
429 /*
Andrew Mortond6859bf2006-03-26 01:38:03 -0800430 * It is going to be referred to from the inode itself? OK, just put it
431 * into the same cylinder group then.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432 */
Mingming Cao43d23f92006-06-25 05:48:07 -0700433 bg_start = ext3_group_first_block_no(inode->i_sb, ei->i_block_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434 colour = (current->pid % 16) *
435 (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
436 return bg_start + colour;
437}
438
439/**
440 * ext3_find_goal - find a prefered place for allocation.
441 * @inode: owner
442 * @block: block we want
443 * @chain: chain of indirect blocks
444 * @partial: pointer to the last triple within a chain
445 * @goal: place to store the result.
446 *
447 * Normally this function find the prefered place for block allocation,
Mingming Caofe55c452005-05-01 08:59:20 -0700448 * stores it in *@goal and returns zero.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 */
450
Mingming Cao43d23f92006-06-25 05:48:07 -0700451static ext3_fsblk_t ext3_find_goal(struct inode *inode, long block,
Mingming Caofe55c452005-05-01 08:59:20 -0700452 Indirect chain[4], Indirect *partial)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453{
Andrew Mortond6859bf2006-03-26 01:38:03 -0800454 struct ext3_block_alloc_info *block_i;
455
456 block_i = EXT3_I(inode)->i_block_alloc_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457
458 /*
459 * try the heuristic for sequential allocation,
460 * failing that at least try to get decent locality.
461 */
462 if (block_i && (block == block_i->last_alloc_logical_block + 1)
463 && (block_i->last_alloc_physical_block != 0)) {
Mingming Caofe55c452005-05-01 08:59:20 -0700464 return block_i->last_alloc_physical_block + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 }
466
Mingming Caofe55c452005-05-01 08:59:20 -0700467 return ext3_find_near(inode, partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468}
Andrew Mortond6859bf2006-03-26 01:38:03 -0800469
Mingming Caob47b2472006-03-26 01:37:56 -0800470/**
471 * ext3_blks_to_allocate: Look up the block map and count the number
472 * of direct blocks need to be allocated for the given branch.
473 *
Dave Kleikampe9ad5622006-09-27 01:49:35 -0700474 * @branch: chain of indirect blocks
Mingming Caob47b2472006-03-26 01:37:56 -0800475 * @k: number of blocks need for indirect blocks
476 * @blks: number of data blocks to be mapped.
477 * @blocks_to_boundary: the offset in the indirect block
478 *
479 * return the total number of blocks to be allocate, including the
480 * direct and indirect blocks.
481 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800482static int ext3_blks_to_allocate(Indirect *branch, int k, unsigned long blks,
Mingming Caob47b2472006-03-26 01:37:56 -0800483 int blocks_to_boundary)
484{
485 unsigned long count = 0;
486
487 /*
488 * Simple case, [t,d]Indirect block(s) has not allocated yet
489 * then it's clear blocks on that path have not allocated
490 */
491 if (k > 0) {
Andrew Mortond6859bf2006-03-26 01:38:03 -0800492 /* right now we don't handle cross boundary allocation */
Mingming Caob47b2472006-03-26 01:37:56 -0800493 if (blks < blocks_to_boundary + 1)
494 count += blks;
495 else
496 count += blocks_to_boundary + 1;
497 return count;
498 }
499
500 count++;
501 while (count < blks && count <= blocks_to_boundary &&
502 le32_to_cpu(*(branch[0].p + count)) == 0) {
503 count++;
504 }
505 return count;
506}
507
508/**
509 * ext3_alloc_blocks: multiple allocate blocks needed for a branch
510 * @indirect_blks: the number of blocks need to allocate for indirect
511 * blocks
512 *
513 * @new_blocks: on return it will store the new block numbers for
514 * the indirect blocks(if needed) and the first direct block,
515 * @blks: on return it will store the total number of allocated
516 * direct blocks
517 */
518static int ext3_alloc_blocks(handle_t *handle, struct inode *inode,
Mingming Cao43d23f92006-06-25 05:48:07 -0700519 ext3_fsblk_t goal, int indirect_blks, int blks,
520 ext3_fsblk_t new_blocks[4], int *err)
Mingming Caob47b2472006-03-26 01:37:56 -0800521{
522 int target, i;
523 unsigned long count = 0;
524 int index = 0;
Mingming Cao43d23f92006-06-25 05:48:07 -0700525 ext3_fsblk_t current_block = 0;
Mingming Caob47b2472006-03-26 01:37:56 -0800526 int ret = 0;
527
528 /*
529 * Here we try to allocate the requested multiple blocks at once,
530 * on a best-effort basis.
531 * To build a branch, we should allocate blocks for
532 * the indirect blocks(if not allocated yet), and at least
533 * the first direct block of this branch. That's the
534 * minimum number of blocks need to allocate(required)
535 */
536 target = blks + indirect_blks;
537
538 while (1) {
539 count = target;
540 /* allocating blocks for indirect blocks and direct blocks */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800541 current_block = ext3_new_blocks(handle,inode,goal,&count,err);
Mingming Caob47b2472006-03-26 01:37:56 -0800542 if (*err)
543 goto failed_out;
544
545 target -= count;
546 /* allocate blocks for indirect blocks */
547 while (index < indirect_blks && count) {
548 new_blocks[index++] = current_block++;
549 count--;
550 }
551
552 if (count > 0)
553 break;
554 }
555
556 /* save the new block number for the first direct block */
557 new_blocks[index] = current_block;
558
559 /* total number of blocks allocated for direct blocks */
560 ret = count;
561 *err = 0;
562 return ret;
563failed_out:
564 for (i = 0; i <index; i++)
565 ext3_free_blocks(handle, inode, new_blocks[i], 1);
566 return ret;
567}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568
569/**
570 * ext3_alloc_branch - allocate and set up a chain of blocks.
571 * @inode: owner
Mingming Caob47b2472006-03-26 01:37:56 -0800572 * @indirect_blks: number of allocated indirect blocks
573 * @blks: number of allocated direct blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 * @offsets: offsets (in the blocks) to store the pointers to next.
575 * @branch: place to store the chain in.
576 *
Mingming Caob47b2472006-03-26 01:37:56 -0800577 * This function allocates blocks, zeroes out all but the last one,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578 * links them into chain and (if we are synchronous) writes them to disk.
579 * In other words, it prepares a branch that can be spliced onto the
580 * inode. It stores the information about that chain in the branch[], in
581 * the same format as ext3_get_branch() would do. We are calling it after
582 * we had read the existing part of chain and partial points to the last
583 * triple of that (one with zero ->key). Upon the exit we have the same
Glauber de Oliveira Costa5b116872005-10-30 15:02:48 -0800584 * picture as after the successful ext3_get_block(), except that in one
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585 * place chain is disconnected - *branch->p is still zero (we did not
586 * set the last link), but branch->key contains the number that should
587 * be placed into *branch->p to fill that gap.
588 *
589 * If allocation fails we free all blocks we've allocated (and forget
590 * their buffer_heads) and return the error value the from failed
591 * ext3_alloc_block() (normally -ENOSPC). Otherwise we set the chain
592 * as described above and return 0.
593 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
Mingming Cao43d23f92006-06-25 05:48:07 -0700595 int indirect_blks, int *blks, ext3_fsblk_t goal,
Mingming Caob47b2472006-03-26 01:37:56 -0800596 int *offsets, Indirect *branch)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597{
598 int blocksize = inode->i_sb->s_blocksize;
Mingming Caob47b2472006-03-26 01:37:56 -0800599 int i, n = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 int err = 0;
Mingming Caob47b2472006-03-26 01:37:56 -0800601 struct buffer_head *bh;
602 int num;
Mingming Cao43d23f92006-06-25 05:48:07 -0700603 ext3_fsblk_t new_blocks[4];
604 ext3_fsblk_t current_block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700605
Mingming Caob47b2472006-03-26 01:37:56 -0800606 num = ext3_alloc_blocks(handle, inode, goal, indirect_blks,
607 *blks, new_blocks, &err);
608 if (err)
609 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610
Mingming Caob47b2472006-03-26 01:37:56 -0800611 branch[0].key = cpu_to_le32(new_blocks[0]);
612 /*
613 * metadata blocks and data blocks are allocated.
614 */
615 for (n = 1; n <= indirect_blks; n++) {
616 /*
617 * Get buffer_head for parent block, zero it out
618 * and set the pointer to new one, then send
619 * parent to disk.
620 */
621 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
622 branch[n].bh = bh;
623 lock_buffer(bh);
624 BUFFER_TRACE(bh, "call get_create_access");
625 err = ext3_journal_get_create_access(handle, bh);
626 if (err) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 unlock_buffer(bh);
Mingming Caob47b2472006-03-26 01:37:56 -0800628 brelse(bh);
629 goto failed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631
Mingming Caob47b2472006-03-26 01:37:56 -0800632 memset(bh->b_data, 0, blocksize);
633 branch[n].p = (__le32 *) bh->b_data + offsets[n];
634 branch[n].key = cpu_to_le32(new_blocks[n]);
635 *branch[n].p = branch[n].key;
636 if ( n == indirect_blks) {
637 current_block = new_blocks[n];
638 /*
639 * End of chain, update the last new metablock of
640 * the chain to point to the new allocated
641 * data blocks numbers
642 */
643 for (i=1; i < num; i++)
644 *(branch[n].p + i) = cpu_to_le32(++current_block);
645 }
646 BUFFER_TRACE(bh, "marking uptodate");
647 set_buffer_uptodate(bh);
648 unlock_buffer(bh);
649
650 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
651 err = ext3_journal_dirty_metadata(handle, bh);
652 if (err)
653 goto failed;
654 }
655 *blks = num;
656 return err;
657failed:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700658 /* Allocation failed, free what we already allocated */
Mingming Caob47b2472006-03-26 01:37:56 -0800659 for (i = 1; i <= n ; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 BUFFER_TRACE(branch[i].bh, "call journal_forget");
661 ext3_journal_forget(handle, branch[i].bh);
662 }
Mingming Caob47b2472006-03-26 01:37:56 -0800663 for (i = 0; i <indirect_blks; i++)
664 ext3_free_blocks(handle, inode, new_blocks[i], 1);
665
666 ext3_free_blocks(handle, inode, new_blocks[i], num);
667
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 return err;
669}
670
671/**
Andrew Mortond6859bf2006-03-26 01:38:03 -0800672 * ext3_splice_branch - splice the allocated branch onto inode.
673 * @inode: owner
674 * @block: (logical) number of block we are adding
675 * @chain: chain of indirect blocks (with a missing link - see
676 * ext3_alloc_branch)
677 * @where: location of missing link
678 * @num: number of indirect blocks we are adding
679 * @blks: number of direct blocks we are adding
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680 *
Andrew Mortond6859bf2006-03-26 01:38:03 -0800681 * This function fills the missing link and does all housekeeping needed in
682 * inode (->i_blocks, etc.). In case of success we end up with the full
683 * chain to new block and return 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800685static int ext3_splice_branch(handle_t *handle, struct inode *inode,
686 long block, Indirect *where, int num, int blks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687{
688 int i;
689 int err = 0;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800690 struct ext3_block_alloc_info *block_i;
Mingming Cao43d23f92006-06-25 05:48:07 -0700691 ext3_fsblk_t current_block;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800692
693 block_i = EXT3_I(inode)->i_block_alloc_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 /*
695 * If we're splicing into a [td]indirect block (as opposed to the
696 * inode) then we need to get write access to the [td]indirect block
697 * before the splice.
698 */
699 if (where->bh) {
700 BUFFER_TRACE(where->bh, "get_write_access");
701 err = ext3_journal_get_write_access(handle, where->bh);
702 if (err)
703 goto err_out;
704 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 /* That's it */
706
707 *where->p = where->key;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800708
709 /*
710 * Update the host buffer_head or inode to point to more just allocated
711 * direct blocks blocks
712 */
Mingming Caob47b2472006-03-26 01:37:56 -0800713 if (num == 0 && blks > 1) {
Mingming Cao5dea5172006-05-03 19:55:12 -0700714 current_block = le32_to_cpu(where->key) + 1;
Mingming Caob47b2472006-03-26 01:37:56 -0800715 for (i = 1; i < blks; i++)
716 *(where->p + i ) = cpu_to_le32(current_block++);
717 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718
719 /*
720 * update the most recently allocated logical & physical block
721 * in i_block_alloc_info, to assist find the proper goal block for next
722 * allocation
723 */
724 if (block_i) {
Mingming Caob47b2472006-03-26 01:37:56 -0800725 block_i->last_alloc_logical_block = block + blks - 1;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800726 block_i->last_alloc_physical_block =
Mingming Cao5dea5172006-05-03 19:55:12 -0700727 le32_to_cpu(where[num].key) + blks - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728 }
729
730 /* We are done with atomic stuff, now do the rest of housekeeping */
731
732 inode->i_ctime = CURRENT_TIME_SEC;
733 ext3_mark_inode_dirty(handle, inode);
734
735 /* had we spliced it onto indirect block? */
736 if (where->bh) {
737 /*
Andrew Mortond6859bf2006-03-26 01:38:03 -0800738 * If we spliced it onto an indirect block, we haven't
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 * altered the inode. Note however that if it is being spliced
740 * onto an indirect block at the very end of the file (the
741 * file is growing) then we *will* alter the inode to reflect
742 * the new i_size. But that is not done here - it is done in
743 * generic_commit_write->__mark_inode_dirty->ext3_dirty_inode.
744 */
745 jbd_debug(5, "splicing indirect only\n");
746 BUFFER_TRACE(where->bh, "call ext3_journal_dirty_metadata");
747 err = ext3_journal_dirty_metadata(handle, where->bh);
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700748 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 goto err_out;
750 } else {
751 /*
752 * OK, we spliced it into the inode itself on a direct block.
753 * Inode was dirtied above.
754 */
755 jbd_debug(5, "splicing direct\n");
756 }
757 return err;
758
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759err_out:
Mingming Caob47b2472006-03-26 01:37:56 -0800760 for (i = 1; i <= num; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 BUFFER_TRACE(where[i].bh, "call journal_forget");
762 ext3_journal_forget(handle, where[i].bh);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800763 ext3_free_blocks(handle,inode,le32_to_cpu(where[i-1].key),1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 }
Mingming Caob47b2472006-03-26 01:37:56 -0800765 ext3_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks);
766
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767 return err;
768}
769
770/*
771 * Allocation strategy is simple: if we have to allocate something, we will
772 * have to go the whole way to leaf. So let's do it before attaching anything
773 * to tree, set linkage between the newborn blocks, write them if sync is
774 * required, recheck the path, free and repeat if check fails, otherwise
775 * set the last missing link (that will protect us from any truncate-generated
776 * removals - all blocks on the path are immune now) and possibly force the
777 * write on the parent block.
778 * That has a nice additional property: no special recovery from the failed
779 * allocations is needed - we simply release blocks and do not touch anything
780 * reachable from inode.
781 *
Andrew Mortond6859bf2006-03-26 01:38:03 -0800782 * `handle' can be NULL if create == 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 *
784 * The BKL may not be held on entry here. Be sure to take it early.
Mingming Cao89747d32006-03-26 01:37:55 -0800785 * return > 0, # of blocks mapped or allocated.
786 * return = 0, if plain lookup failed.
787 * return < 0, error case.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800789int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
790 sector_t iblock, unsigned long maxblocks,
791 struct buffer_head *bh_result,
Mingming Cao89747d32006-03-26 01:37:55 -0800792 int create, int extend_disksize)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793{
794 int err = -EIO;
795 int offsets[4];
796 Indirect chain[4];
797 Indirect *partial;
Mingming Cao43d23f92006-06-25 05:48:07 -0700798 ext3_fsblk_t goal;
Mingming Caob47b2472006-03-26 01:37:56 -0800799 int indirect_blks;
Mingming Cao89747d32006-03-26 01:37:55 -0800800 int blocks_to_boundary = 0;
801 int depth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802 struct ext3_inode_info *ei = EXT3_I(inode);
Mingming Cao89747d32006-03-26 01:37:55 -0800803 int count = 0;
Mingming Cao43d23f92006-06-25 05:48:07 -0700804 ext3_fsblk_t first_block = 0;
Mingming Cao89747d32006-03-26 01:37:55 -0800805
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806
807 J_ASSERT(handle != NULL || create == 0);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800808 depth = ext3_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809
810 if (depth == 0)
811 goto out;
812
Linus Torvalds1da177e2005-04-16 15:20:36 -0700813 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
814
815 /* Simplest case - block found, no allocation needed */
816 if (!partial) {
Mingming Cao5dea5172006-05-03 19:55:12 -0700817 first_block = le32_to_cpu(chain[depth - 1].key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818 clear_buffer_new(bh_result);
Mingming Cao89747d32006-03-26 01:37:55 -0800819 count++;
820 /*map more blocks*/
821 while (count < maxblocks && count <= blocks_to_boundary) {
Mingming Cao43d23f92006-06-25 05:48:07 -0700822 ext3_fsblk_t blk;
Mingming Cao5dea5172006-05-03 19:55:12 -0700823
Mingming Cao89747d32006-03-26 01:37:55 -0800824 if (!verify_chain(chain, partial)) {
825 /*
826 * Indirect block might be removed by
827 * truncate while we were reading it.
828 * Handling of that case: forget what we've
829 * got now. Flag the err as EAGAIN, so it
830 * will reread.
831 */
832 err = -EAGAIN;
833 count = 0;
834 break;
835 }
Mingming Cao5dea5172006-05-03 19:55:12 -0700836 blk = le32_to_cpu(*(chain[depth-1].p + count));
837
838 if (blk == first_block + count)
Mingming Cao89747d32006-03-26 01:37:55 -0800839 count++;
840 else
841 break;
842 }
843 if (err != -EAGAIN)
844 goto got_it;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700845 }
846
847 /* Next simple case - plain lookup or failed read of indirect block */
Mingming Caofe55c452005-05-01 08:59:20 -0700848 if (!create || err == -EIO)
849 goto cleanup;
850
Arjan van de Ven97461512006-03-23 03:00:42 -0800851 mutex_lock(&ei->truncate_mutex);
Mingming Caofe55c452005-05-01 08:59:20 -0700852
853 /*
854 * If the indirect block is missing while we are reading
855 * the chain(ext3_get_branch() returns -EAGAIN err), or
856 * if the chain has been changed after we grab the semaphore,
857 * (either because another process truncated this branch, or
858 * another get_block allocated this branch) re-grab the chain to see if
859 * the request block has been allocated or not.
860 *
861 * Since we already block the truncate/other get_block
862 * at this point, we will have the current copy of the chain when we
863 * splice the branch into the tree.
864 */
865 if (err == -EAGAIN || !verify_chain(chain, partial)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 while (partial > chain) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867 brelse(partial->bh);
868 partial--;
869 }
Mingming Caofe55c452005-05-01 08:59:20 -0700870 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
871 if (!partial) {
Mingming Cao89747d32006-03-26 01:37:55 -0800872 count++;
Arjan van de Ven97461512006-03-23 03:00:42 -0800873 mutex_unlock(&ei->truncate_mutex);
Mingming Caofe55c452005-05-01 08:59:20 -0700874 if (err)
875 goto cleanup;
876 clear_buffer_new(bh_result);
877 goto got_it;
878 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879 }
880
881 /*
Mingming Caofe55c452005-05-01 08:59:20 -0700882 * Okay, we need to do block allocation. Lazily initialize the block
883 * allocation info here if necessary
884 */
885 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886 ext3_init_block_alloc_info(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700887
Mingming Caofe55c452005-05-01 08:59:20 -0700888 goal = ext3_find_goal(inode, iblock, chain, partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889
Mingming Caob47b2472006-03-26 01:37:56 -0800890 /* the number of blocks need to allocate for [d,t]indirect blocks */
891 indirect_blks = (chain + depth) - partial - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892
893 /*
Mingming Caob47b2472006-03-26 01:37:56 -0800894 * Next look up the indirect map to count the totoal number of
895 * direct blocks to allocate for this branch.
896 */
897 count = ext3_blks_to_allocate(partial, indirect_blks,
898 maxblocks, blocks_to_boundary);
899 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900 * Block out ext3_truncate while we alter the tree
901 */
Mingming Caob47b2472006-03-26 01:37:56 -0800902 err = ext3_alloc_branch(handle, inode, indirect_blks, &count, goal,
Mingming Caofe55c452005-05-01 08:59:20 -0700903 offsets + (partial - chain), partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904
Mingming Caofe55c452005-05-01 08:59:20 -0700905 /*
906 * The ext3_splice_branch call will free and forget any buffers
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907 * on the new chain if there is a failure, but that risks using
908 * up transaction credits, especially for bitmaps where the
909 * credits cannot be returned. Can we handle this somehow? We
Mingming Caofe55c452005-05-01 08:59:20 -0700910 * may need to return -EAGAIN upwards in the worst case. --sct
911 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912 if (!err)
Mingming Caob47b2472006-03-26 01:37:56 -0800913 err = ext3_splice_branch(handle, inode, iblock,
914 partial, indirect_blks, count);
Mingming Caofe55c452005-05-01 08:59:20 -0700915 /*
Arjan van de Ven97461512006-03-23 03:00:42 -0800916 * i_disksize growing is protected by truncate_mutex. Don't forget to
Mingming Caofe55c452005-05-01 08:59:20 -0700917 * protect it if you're about to implement concurrent
918 * ext3_get_block() -bzzz
919 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 if (!err && extend_disksize && inode->i_size > ei->i_disksize)
921 ei->i_disksize = inode->i_size;
Arjan van de Ven97461512006-03-23 03:00:42 -0800922 mutex_unlock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923 if (err)
924 goto cleanup;
925
926 set_buffer_new(bh_result);
Mingming Caofe55c452005-05-01 08:59:20 -0700927got_it:
928 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
Suparna Bhattacharya20acaa12006-09-16 12:15:58 -0700929 if (count > blocks_to_boundary)
Mingming Caofe55c452005-05-01 08:59:20 -0700930 set_buffer_boundary(bh_result);
Mingming Cao89747d32006-03-26 01:37:55 -0800931 err = count;
Mingming Caofe55c452005-05-01 08:59:20 -0700932 /* Clean up and exit */
933 partial = chain + depth - 1; /* the whole chain */
934cleanup:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935 while (partial > chain) {
Mingming Caofe55c452005-05-01 08:59:20 -0700936 BUFFER_TRACE(partial->bh, "call brelse");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 brelse(partial->bh);
938 partial--;
939 }
Mingming Caofe55c452005-05-01 08:59:20 -0700940 BUFFER_TRACE(bh_result, "returned");
941out:
942 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943}
944
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945#define DIO_CREDITS (EXT3_RESERVE_TRANS_BLOCKS + 32)
946
Badari Pulavartyf91a2ad2006-03-26 01:38:04 -0800947static int ext3_get_block(struct inode *inode, sector_t iblock,
948 struct buffer_head *bh_result, int create)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949{
950 handle_t *handle = journal_current_handle();
951 int ret = 0;
Badari Pulavarty1d8fa7a2006-03-26 01:38:02 -0800952 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953
Mingming Cao89747d32006-03-26 01:37:55 -0800954 if (!create)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955 goto get_block; /* A read */
956
Mingming Cao89747d32006-03-26 01:37:55 -0800957 if (max_blocks == 1)
958 goto get_block; /* A single block get */
959
Linus Torvalds1da177e2005-04-16 15:20:36 -0700960 if (handle->h_transaction->t_state == T_LOCKED) {
961 /*
962 * Huge direct-io writes can hold off commits for long
963 * periods of time. Let this commit run.
964 */
965 ext3_journal_stop(handle);
966 handle = ext3_journal_start(inode, DIO_CREDITS);
967 if (IS_ERR(handle))
968 ret = PTR_ERR(handle);
969 goto get_block;
970 }
971
972 if (handle->h_buffer_credits <= EXT3_RESERVE_TRANS_BLOCKS) {
973 /*
974 * Getting low on buffer credits...
975 */
976 ret = ext3_journal_extend(handle, DIO_CREDITS);
977 if (ret > 0) {
978 /*
979 * Couldn't extend the transaction. Start a new one.
980 */
981 ret = ext3_journal_restart(handle, DIO_CREDITS);
982 }
983 }
984
985get_block:
Mingming Cao89747d32006-03-26 01:37:55 -0800986 if (ret == 0) {
987 ret = ext3_get_blocks_handle(handle, inode, iblock,
988 max_blocks, bh_result, create, 0);
989 if (ret > 0) {
990 bh_result->b_size = (ret << inode->i_blkbits);
991 ret = 0;
992 }
993 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 return ret;
995}
996
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997/*
998 * `handle' can be NULL if create is zero
999 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08001000struct buffer_head *ext3_getblk(handle_t *handle, struct inode *inode,
1001 long block, int create, int *errp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002{
1003 struct buffer_head dummy;
1004 int fatal = 0, err;
1005
1006 J_ASSERT(handle != NULL || create == 0);
1007
1008 dummy.b_state = 0;
1009 dummy.b_blocknr = -1000;
1010 buffer_trace_init(&dummy.b_history);
Mingming Cao89747d32006-03-26 01:37:55 -08001011 err = ext3_get_blocks_handle(handle, inode, block, 1,
1012 &dummy, create, 1);
Badari Pulavarty3665d0e2006-09-08 09:48:21 -07001013 /*
1014 * ext3_get_blocks_handle() returns number of blocks
1015 * mapped. 0 in case of a HOLE.
1016 */
1017 if (err > 0) {
1018 if (err > 1)
1019 WARN_ON(1);
Mingming Cao89747d32006-03-26 01:37:55 -08001020 err = 0;
Mingming Cao89747d32006-03-26 01:37:55 -08001021 }
1022 *errp = err;
1023 if (!err && buffer_mapped(&dummy)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001024 struct buffer_head *bh;
1025 bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
Glauber de Oliveira Costa2973dfd2005-10-30 15:03:05 -08001026 if (!bh) {
1027 *errp = -EIO;
1028 goto err;
1029 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 if (buffer_new(&dummy)) {
1031 J_ASSERT(create != 0);
1032 J_ASSERT(handle != 0);
1033
Andrew Mortond6859bf2006-03-26 01:38:03 -08001034 /*
1035 * Now that we do not always journal data, we should
1036 * keep in mind whether this should always journal the
1037 * new buffer as metadata. For now, regular file
1038 * writes use ext3_get_block instead, so it's not a
1039 * problem.
1040 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041 lock_buffer(bh);
1042 BUFFER_TRACE(bh, "call get_create_access");
1043 fatal = ext3_journal_get_create_access(handle, bh);
1044 if (!fatal && !buffer_uptodate(bh)) {
Andrew Mortond6859bf2006-03-26 01:38:03 -08001045 memset(bh->b_data,0,inode->i_sb->s_blocksize);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001046 set_buffer_uptodate(bh);
1047 }
1048 unlock_buffer(bh);
1049 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
1050 err = ext3_journal_dirty_metadata(handle, bh);
1051 if (!fatal)
1052 fatal = err;
1053 } else {
1054 BUFFER_TRACE(bh, "not a new buffer");
1055 }
1056 if (fatal) {
1057 *errp = fatal;
1058 brelse(bh);
1059 bh = NULL;
1060 }
1061 return bh;
1062 }
Glauber de Oliveira Costa2973dfd2005-10-30 15:03:05 -08001063err:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001064 return NULL;
1065}
1066
Andrew Mortond6859bf2006-03-26 01:38:03 -08001067struct buffer_head *ext3_bread(handle_t *handle, struct inode *inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001068 int block, int create, int *err)
1069{
1070 struct buffer_head * bh;
1071
1072 bh = ext3_getblk(handle, inode, block, create, err);
1073 if (!bh)
1074 return bh;
1075 if (buffer_uptodate(bh))
1076 return bh;
Jens Axboecaa38fb2006-07-23 01:41:26 +02001077 ll_rw_block(READ_META, 1, &bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001078 wait_on_buffer(bh);
1079 if (buffer_uptodate(bh))
1080 return bh;
1081 put_bh(bh);
1082 *err = -EIO;
1083 return NULL;
1084}
1085
1086static int walk_page_buffers( handle_t *handle,
1087 struct buffer_head *head,
1088 unsigned from,
1089 unsigned to,
1090 int *partial,
1091 int (*fn)( handle_t *handle,
1092 struct buffer_head *bh))
1093{
1094 struct buffer_head *bh;
1095 unsigned block_start, block_end;
1096 unsigned blocksize = head->b_size;
1097 int err, ret = 0;
1098 struct buffer_head *next;
1099
1100 for ( bh = head, block_start = 0;
1101 ret == 0 && (bh != head || !block_start);
Dave Kleikampe9ad5622006-09-27 01:49:35 -07001102 block_start = block_end, bh = next)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103 {
1104 next = bh->b_this_page;
1105 block_end = block_start + blocksize;
1106 if (block_end <= from || block_start >= to) {
1107 if (partial && !buffer_uptodate(bh))
1108 *partial = 1;
1109 continue;
1110 }
1111 err = (*fn)(handle, bh);
1112 if (!ret)
1113 ret = err;
1114 }
1115 return ret;
1116}
1117
1118/*
1119 * To preserve ordering, it is essential that the hole instantiation and
1120 * the data write be encapsulated in a single transaction. We cannot
1121 * close off a transaction and start a new one between the ext3_get_block()
1122 * and the commit_write(). So doing the journal_start at the start of
1123 * prepare_write() is the right place.
1124 *
1125 * Also, this function can nest inside ext3_writepage() ->
1126 * block_write_full_page(). In that case, we *know* that ext3_writepage()
1127 * has generated enough buffer credits to do the whole page. So we won't
1128 * block on the journal in that case, which is good, because the caller may
1129 * be PF_MEMALLOC.
1130 *
1131 * By accident, ext3 can be reentered when a transaction is open via
1132 * quota file writes. If we were to commit the transaction while thus
1133 * reentered, there can be a deadlock - we would be holding a quota
1134 * lock, and the commit would never complete if another thread had a
1135 * transaction open and was blocking on the quota lock - a ranking
1136 * violation.
1137 *
1138 * So what we do is to rely on the fact that journal_stop/journal_start
1139 * will _not_ run commit under these circumstances because handle->h_ref
1140 * is elevated. We'll still have enough credits for the tiny quotafile
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001141 * write.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001142 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08001143static int do_journal_get_write_access(handle_t *handle,
1144 struct buffer_head *bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145{
1146 if (!buffer_mapped(bh) || buffer_freed(bh))
1147 return 0;
1148 return ext3_journal_get_write_access(handle, bh);
1149}
1150
Andrey Savochkine92a4d52006-12-06 20:37:34 -08001151/*
1152 * The idea of this helper function is following:
1153 * if prepare_write has allocated some blocks, but not all of them, the
1154 * transaction must include the content of the newly allocated blocks.
1155 * This content is expected to be set to zeroes by block_prepare_write().
1156 * 2006/10/14 SAW
1157 */
1158static int ext3_prepare_failure(struct file *file, struct page *page,
1159 unsigned from, unsigned to)
1160{
1161 struct address_space *mapping;
1162 struct buffer_head *bh, *head, *next;
1163 unsigned block_start, block_end;
1164 unsigned blocksize;
1165 int ret;
1166 handle_t *handle = ext3_journal_current_handle();
1167
1168 mapping = page->mapping;
1169 if (ext3_should_writeback_data(mapping->host)) {
1170 /* optimization: no constraints about data */
1171skip:
1172 return ext3_journal_stop(handle);
1173 }
1174
1175 head = page_buffers(page);
1176 blocksize = head->b_size;
1177 for ( bh = head, block_start = 0;
1178 bh != head || !block_start;
1179 block_start = block_end, bh = next)
1180 {
1181 next = bh->b_this_page;
1182 block_end = block_start + blocksize;
1183 if (block_end <= from)
1184 continue;
1185 if (block_start >= to) {
1186 block_start = to;
1187 break;
1188 }
1189 if (!buffer_mapped(bh))
1190 /* prepare_write failed on this bh */
1191 break;
1192 if (ext3_should_journal_data(mapping->host)) {
1193 ret = do_journal_get_write_access(handle, bh);
1194 if (ret) {
1195 ext3_journal_stop(handle);
1196 return ret;
1197 }
1198 }
1199 /*
1200 * block_start here becomes the first block where the current iteration
1201 * of prepare_write failed.
1202 */
1203 }
1204 if (block_start <= from)
1205 goto skip;
1206
1207 /* commit allocated and zeroed buffers */
1208 return mapping->a_ops->commit_write(file, page, from, block_start);
1209}
1210
Linus Torvalds1da177e2005-04-16 15:20:36 -07001211static int ext3_prepare_write(struct file *file, struct page *page,
1212 unsigned from, unsigned to)
1213{
1214 struct inode *inode = page->mapping->host;
Andrey Savochkine92a4d52006-12-06 20:37:34 -08001215 int ret, ret2;
1216 int needed_blocks = ext3_writepage_trans_blocks(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217 handle_t *handle;
1218 int retries = 0;
1219
1220retry:
1221 handle = ext3_journal_start(inode, needed_blocks);
Andrey Savochkine92a4d52006-12-06 20:37:34 -08001222 if (IS_ERR(handle))
1223 return PTR_ERR(handle);
Badari Pulavarty0e31f512006-07-30 03:04:14 -07001224 if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001225 ret = nobh_prepare_write(page, from, to, ext3_get_block);
1226 else
1227 ret = block_prepare_write(page, from, to, ext3_get_block);
1228 if (ret)
Andrey Savochkine92a4d52006-12-06 20:37:34 -08001229 goto failure;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230
1231 if (ext3_should_journal_data(inode)) {
1232 ret = walk_page_buffers(handle, page_buffers(page),
1233 from, to, NULL, do_journal_get_write_access);
Andrey Savochkine92a4d52006-12-06 20:37:34 -08001234 if (ret)
1235 /* fatal error, just put the handle and return */
1236 journal_stop(handle);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001237 }
Andrey Savochkine92a4d52006-12-06 20:37:34 -08001238 return ret;
1239
1240failure:
1241 ret2 = ext3_prepare_failure(file, page, from, to);
1242 if (ret2 < 0)
1243 return ret2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244 if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
1245 goto retry;
Andrey Savochkine92a4d52006-12-06 20:37:34 -08001246 /* retry number exceeded, or other error like -EDQUOT */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247 return ret;
1248}
1249
Andrew Mortond6859bf2006-03-26 01:38:03 -08001250int ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001251{
1252 int err = journal_dirty_data(handle, bh);
1253 if (err)
1254 ext3_journal_abort_handle(__FUNCTION__, __FUNCTION__,
1255 bh, handle,err);
1256 return err;
1257}
1258
1259/* For commit_write() in data=journal mode */
1260static int commit_write_fn(handle_t *handle, struct buffer_head *bh)
1261{
1262 if (!buffer_mapped(bh) || buffer_freed(bh))
1263 return 0;
1264 set_buffer_uptodate(bh);
1265 return ext3_journal_dirty_metadata(handle, bh);
1266}
1267
1268/*
1269 * We need to pick up the new inode size which generic_commit_write gave us
1270 * `file' can be NULL - eg, when called from page_symlink().
1271 *
1272 * ext3 never places buffers on inode->i_mapping->private_list. metadata
1273 * buffers are managed internally.
1274 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001275static int ext3_ordered_commit_write(struct file *file, struct page *page,
1276 unsigned from, unsigned to)
1277{
1278 handle_t *handle = ext3_journal_current_handle();
1279 struct inode *inode = page->mapping->host;
1280 int ret = 0, ret2;
1281
1282 ret = walk_page_buffers(handle, page_buffers(page),
1283 from, to, NULL, ext3_journal_dirty_data);
1284
1285 if (ret == 0) {
1286 /*
1287 * generic_commit_write() will run mark_inode_dirty() if i_size
1288 * changes. So let's piggyback the i_disksize mark_inode_dirty
1289 * into that.
1290 */
1291 loff_t new_i_size;
1292
1293 new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1294 if (new_i_size > EXT3_I(inode)->i_disksize)
1295 EXT3_I(inode)->i_disksize = new_i_size;
1296 ret = generic_commit_write(file, page, from, to);
1297 }
1298 ret2 = ext3_journal_stop(handle);
1299 if (!ret)
1300 ret = ret2;
1301 return ret;
1302}
1303
1304static int ext3_writeback_commit_write(struct file *file, struct page *page,
1305 unsigned from, unsigned to)
1306{
1307 handle_t *handle = ext3_journal_current_handle();
1308 struct inode *inode = page->mapping->host;
1309 int ret = 0, ret2;
1310 loff_t new_i_size;
1311
1312 new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1313 if (new_i_size > EXT3_I(inode)->i_disksize)
1314 EXT3_I(inode)->i_disksize = new_i_size;
1315
Badari Pulavarty0e31f512006-07-30 03:04:14 -07001316 if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001317 ret = nobh_commit_write(file, page, from, to);
1318 else
1319 ret = generic_commit_write(file, page, from, to);
1320
1321 ret2 = ext3_journal_stop(handle);
1322 if (!ret)
1323 ret = ret2;
1324 return ret;
1325}
1326
1327static int ext3_journalled_commit_write(struct file *file,
1328 struct page *page, unsigned from, unsigned to)
1329{
1330 handle_t *handle = ext3_journal_current_handle();
1331 struct inode *inode = page->mapping->host;
1332 int ret = 0, ret2;
1333 int partial = 0;
1334 loff_t pos;
1335
1336 /*
1337 * Here we duplicate the generic_commit_write() functionality
1338 */
1339 pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1340
1341 ret = walk_page_buffers(handle, page_buffers(page), from,
1342 to, &partial, commit_write_fn);
1343 if (!partial)
1344 SetPageUptodate(page);
1345 if (pos > inode->i_size)
1346 i_size_write(inode, pos);
1347 EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1348 if (inode->i_size > EXT3_I(inode)->i_disksize) {
1349 EXT3_I(inode)->i_disksize = inode->i_size;
1350 ret2 = ext3_mark_inode_dirty(handle, inode);
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001351 if (!ret)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352 ret = ret2;
1353 }
1354 ret2 = ext3_journal_stop(handle);
1355 if (!ret)
1356 ret = ret2;
1357 return ret;
1358}
1359
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001360/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001361 * bmap() is special. It gets used by applications such as lilo and by
1362 * the swapper to find the on-disk block of a specific piece of data.
1363 *
1364 * Naturally, this is dangerous if the block concerned is still in the
1365 * journal. If somebody makes a swapfile on an ext3 data-journaling
1366 * filesystem and enables swap, then they may get a nasty shock when the
1367 * data getting swapped to that swapfile suddenly gets overwritten by
1368 * the original zero's written out previously to the journal and
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001369 * awaiting writeback in the kernel's buffer cache.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001370 *
1371 * So, if we see any bmap calls here on a modified, data-journaled file,
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001372 * take extra steps to flush any blocks which might be in the cache.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001373 */
1374static sector_t ext3_bmap(struct address_space *mapping, sector_t block)
1375{
1376 struct inode *inode = mapping->host;
1377 journal_t *journal;
1378 int err;
1379
1380 if (EXT3_I(inode)->i_state & EXT3_STATE_JDATA) {
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001381 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001382 * This is a REALLY heavyweight approach, but the use of
1383 * bmap on dirty files is expected to be extremely rare:
1384 * only if we run lilo or swapon on a freshly made file
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001385 * do we expect this to happen.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001386 *
1387 * (bmap requires CAP_SYS_RAWIO so this does not
1388 * represent an unprivileged user DOS attack --- we'd be
1389 * in trouble if mortal users could trigger this path at
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001390 * will.)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001391 *
1392 * NB. EXT3_STATE_JDATA is not set on files other than
1393 * regular files. If somebody wants to bmap a directory
1394 * or symlink and gets confused because the buffer
1395 * hasn't yet been flushed to disk, they deserve
1396 * everything they get.
1397 */
1398
1399 EXT3_I(inode)->i_state &= ~EXT3_STATE_JDATA;
1400 journal = EXT3_JOURNAL(inode);
1401 journal_lock_updates(journal);
1402 err = journal_flush(journal);
1403 journal_unlock_updates(journal);
1404
1405 if (err)
1406 return 0;
1407 }
1408
1409 return generic_block_bmap(mapping,block,ext3_get_block);
1410}
1411
1412static int bget_one(handle_t *handle, struct buffer_head *bh)
1413{
1414 get_bh(bh);
1415 return 0;
1416}
1417
1418static int bput_one(handle_t *handle, struct buffer_head *bh)
1419{
1420 put_bh(bh);
1421 return 0;
1422}
1423
1424static int journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
1425{
1426 if (buffer_mapped(bh))
1427 return ext3_journal_dirty_data(handle, bh);
1428 return 0;
1429}
1430
1431/*
1432 * Note that we always start a transaction even if we're not journalling
1433 * data. This is to preserve ordering: any hole instantiation within
1434 * __block_write_full_page -> ext3_get_block() should be journalled
1435 * along with the data so we don't crash and then get metadata which
1436 * refers to old data.
1437 *
1438 * In all journalling modes block_write_full_page() will start the I/O.
1439 *
1440 * Problem:
1441 *
1442 * ext3_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1443 * ext3_writepage()
1444 *
1445 * Similar for:
1446 *
1447 * ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ...
1448 *
1449 * Same applies to ext3_get_block(). We will deadlock on various things like
Arjan van de Ven97461512006-03-23 03:00:42 -08001450 * lock_journal and i_truncate_mutex.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001451 *
1452 * Setting PF_MEMALLOC here doesn't work - too many internal memory
1453 * allocations fail.
1454 *
1455 * 16May01: If we're reentered then journal_current_handle() will be
1456 * non-zero. We simply *return*.
1457 *
1458 * 1 July 2001: @@@ FIXME:
1459 * In journalled data mode, a data buffer may be metadata against the
1460 * current transaction. But the same file is part of a shared mapping
1461 * and someone does a writepage() on it.
1462 *
1463 * We will move the buffer onto the async_data list, but *after* it has
1464 * been dirtied. So there's a small window where we have dirty data on
1465 * BJ_Metadata.
1466 *
1467 * Note that this only applies to the last partial page in the file. The
1468 * bit which block_write_full_page() uses prepare/commit for. (That's
1469 * broken code anyway: it's wrong for msync()).
1470 *
1471 * It's a rare case: affects the final partial page, for journalled data
1472 * where the file is subject to bith write() and writepage() in the same
1473 * transction. To fix it we'll need a custom block_write_full_page().
1474 * We'll probably need that anyway for journalling writepage() output.
1475 *
1476 * We don't honour synchronous mounts for writepage(). That would be
1477 * disastrous. Any write() or metadata operation will sync the fs for
1478 * us.
1479 *
1480 * AKPM2: if all the page's buffers are mapped to disk and !data=journal,
1481 * we don't need to open a transaction here.
1482 */
1483static int ext3_ordered_writepage(struct page *page,
Andrew Mortond6859bf2006-03-26 01:38:03 -08001484 struct writeback_control *wbc)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001485{
1486 struct inode *inode = page->mapping->host;
1487 struct buffer_head *page_bufs;
1488 handle_t *handle = NULL;
1489 int ret = 0;
1490 int err;
1491
1492 J_ASSERT(PageLocked(page));
1493
1494 /*
1495 * We give up here if we're reentered, because it might be for a
1496 * different filesystem.
1497 */
1498 if (ext3_journal_current_handle())
1499 goto out_fail;
1500
1501 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1502
1503 if (IS_ERR(handle)) {
1504 ret = PTR_ERR(handle);
1505 goto out_fail;
1506 }
1507
1508 if (!page_has_buffers(page)) {
1509 create_empty_buffers(page, inode->i_sb->s_blocksize,
1510 (1 << BH_Dirty)|(1 << BH_Uptodate));
1511 }
1512 page_bufs = page_buffers(page);
1513 walk_page_buffers(handle, page_bufs, 0,
1514 PAGE_CACHE_SIZE, NULL, bget_one);
1515
1516 ret = block_write_full_page(page, ext3_get_block, wbc);
1517
1518 /*
1519 * The page can become unlocked at any point now, and
1520 * truncate can then come in and change things. So we
1521 * can't touch *page from now on. But *page_bufs is
1522 * safe due to elevated refcount.
1523 */
1524
1525 /*
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001526 * And attach them to the current transaction. But only if
Linus Torvalds1da177e2005-04-16 15:20:36 -07001527 * block_write_full_page() succeeded. Otherwise they are unmapped,
1528 * and generally junk.
1529 */
1530 if (ret == 0) {
1531 err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
1532 NULL, journal_dirty_data_fn);
1533 if (!ret)
1534 ret = err;
1535 }
1536 walk_page_buffers(handle, page_bufs, 0,
1537 PAGE_CACHE_SIZE, NULL, bput_one);
1538 err = ext3_journal_stop(handle);
1539 if (!ret)
1540 ret = err;
1541 return ret;
1542
1543out_fail:
1544 redirty_page_for_writepage(wbc, page);
1545 unlock_page(page);
1546 return ret;
1547}
1548
Linus Torvalds1da177e2005-04-16 15:20:36 -07001549static int ext3_writeback_writepage(struct page *page,
1550 struct writeback_control *wbc)
1551{
1552 struct inode *inode = page->mapping->host;
1553 handle_t *handle = NULL;
1554 int ret = 0;
1555 int err;
1556
1557 if (ext3_journal_current_handle())
1558 goto out_fail;
1559
1560 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1561 if (IS_ERR(handle)) {
1562 ret = PTR_ERR(handle);
1563 goto out_fail;
1564 }
1565
Badari Pulavarty0e31f512006-07-30 03:04:14 -07001566 if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001567 ret = nobh_writepage(page, ext3_get_block, wbc);
1568 else
1569 ret = block_write_full_page(page, ext3_get_block, wbc);
1570
1571 err = ext3_journal_stop(handle);
1572 if (!ret)
1573 ret = err;
1574 return ret;
1575
1576out_fail:
1577 redirty_page_for_writepage(wbc, page);
1578 unlock_page(page);
1579 return ret;
1580}
1581
1582static int ext3_journalled_writepage(struct page *page,
1583 struct writeback_control *wbc)
1584{
1585 struct inode *inode = page->mapping->host;
1586 handle_t *handle = NULL;
1587 int ret = 0;
1588 int err;
1589
1590 if (ext3_journal_current_handle())
1591 goto no_write;
1592
1593 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1594 if (IS_ERR(handle)) {
1595 ret = PTR_ERR(handle);
1596 goto no_write;
1597 }
1598
1599 if (!page_has_buffers(page) || PageChecked(page)) {
1600 /*
1601 * It's mmapped pagecache. Add buffers and journal it. There
1602 * doesn't seem much point in redirtying the page here.
1603 */
1604 ClearPageChecked(page);
1605 ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
1606 ext3_get_block);
Denis Lunevab4eb432005-11-13 16:07:17 -08001607 if (ret != 0) {
1608 ext3_journal_stop(handle);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001609 goto out_unlock;
Denis Lunevab4eb432005-11-13 16:07:17 -08001610 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001611 ret = walk_page_buffers(handle, page_buffers(page), 0,
1612 PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
1613
1614 err = walk_page_buffers(handle, page_buffers(page), 0,
1615 PAGE_CACHE_SIZE, NULL, commit_write_fn);
1616 if (ret == 0)
1617 ret = err;
1618 EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1619 unlock_page(page);
1620 } else {
1621 /*
1622 * It may be a page full of checkpoint-mode buffers. We don't
1623 * really know unless we go poke around in the buffer_heads.
1624 * But block_write_full_page will do the right thing.
1625 */
1626 ret = block_write_full_page(page, ext3_get_block, wbc);
1627 }
1628 err = ext3_journal_stop(handle);
1629 if (!ret)
1630 ret = err;
1631out:
1632 return ret;
1633
1634no_write:
1635 redirty_page_for_writepage(wbc, page);
1636out_unlock:
1637 unlock_page(page);
1638 goto out;
1639}
1640
1641static int ext3_readpage(struct file *file, struct page *page)
1642{
1643 return mpage_readpage(page, ext3_get_block);
1644}
1645
1646static int
1647ext3_readpages(struct file *file, struct address_space *mapping,
1648 struct list_head *pages, unsigned nr_pages)
1649{
1650 return mpage_readpages(mapping, pages, nr_pages, ext3_get_block);
1651}
1652
NeilBrown2ff28e22006-03-26 01:37:18 -08001653static void ext3_invalidatepage(struct page *page, unsigned long offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001654{
1655 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1656
1657 /*
1658 * If it's a full truncate we just forget about the pending dirtying
1659 */
1660 if (offset == 0)
1661 ClearPageChecked(page);
1662
NeilBrown2ff28e22006-03-26 01:37:18 -08001663 journal_invalidatepage(journal, page, offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001664}
1665
Al Viro27496a82005-10-21 03:20:48 -04001666static int ext3_releasepage(struct page *page, gfp_t wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001667{
1668 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1669
1670 WARN_ON(PageChecked(page));
1671 if (!page_has_buffers(page))
1672 return 0;
1673 return journal_try_to_free_buffers(journal, page, wait);
1674}
1675
1676/*
1677 * If the O_DIRECT write will extend the file then add this inode to the
1678 * orphan list. So recovery will truncate it back to the original size
1679 * if the machine crashes during the write.
1680 *
1681 * If the O_DIRECT write is intantiating holes inside i_size and the machine
1682 * crashes then stale disk data _may_ be exposed inside the file.
1683 */
1684static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
1685 const struct iovec *iov, loff_t offset,
1686 unsigned long nr_segs)
1687{
1688 struct file *file = iocb->ki_filp;
1689 struct inode *inode = file->f_mapping->host;
1690 struct ext3_inode_info *ei = EXT3_I(inode);
1691 handle_t *handle = NULL;
1692 ssize_t ret;
1693 int orphan = 0;
1694 size_t count = iov_length(iov, nr_segs);
1695
1696 if (rw == WRITE) {
1697 loff_t final_size = offset + count;
1698
1699 handle = ext3_journal_start(inode, DIO_CREDITS);
1700 if (IS_ERR(handle)) {
1701 ret = PTR_ERR(handle);
1702 goto out;
1703 }
1704 if (final_size > inode->i_size) {
1705 ret = ext3_orphan_add(handle, inode);
1706 if (ret)
1707 goto out_stop;
1708 orphan = 1;
1709 ei->i_disksize = inode->i_size;
1710 }
1711 }
1712
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001713 ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001714 offset, nr_segs,
Badari Pulavartyf91a2ad2006-03-26 01:38:04 -08001715 ext3_get_block, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001716
1717 /*
Badari Pulavartyf91a2ad2006-03-26 01:38:04 -08001718 * Reacquire the handle: ext3_get_block() can restart the transaction
Linus Torvalds1da177e2005-04-16 15:20:36 -07001719 */
1720 handle = journal_current_handle();
1721
1722out_stop:
1723 if (handle) {
1724 int err;
1725
1726 if (orphan && inode->i_nlink)
1727 ext3_orphan_del(handle, inode);
1728 if (orphan && ret > 0) {
1729 loff_t end = offset + ret;
1730 if (end > inode->i_size) {
1731 ei->i_disksize = end;
1732 i_size_write(inode, end);
1733 /*
1734 * We're going to return a positive `ret'
1735 * here due to non-zero-length I/O, so there's
1736 * no way of reporting error returns from
1737 * ext3_mark_inode_dirty() to userspace. So
1738 * ignore it.
1739 */
1740 ext3_mark_inode_dirty(handle, inode);
1741 }
1742 }
1743 err = ext3_journal_stop(handle);
1744 if (ret == 0)
1745 ret = err;
1746 }
1747out:
1748 return ret;
1749}
1750
1751/*
1752 * Pages can be marked dirty completely asynchronously from ext3's journalling
1753 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
1754 * much here because ->set_page_dirty is called under VFS locks. The page is
1755 * not necessarily locked.
1756 *
1757 * We cannot just dirty the page and leave attached buffers clean, because the
1758 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
1759 * or jbddirty because all the journalling code will explode.
1760 *
1761 * So what we do is to mark the page "pending dirty" and next time writepage
1762 * is called, propagate that into the buffers appropriately.
1763 */
1764static int ext3_journalled_set_page_dirty(struct page *page)
1765{
1766 SetPageChecked(page);
1767 return __set_page_dirty_nobuffers(page);
1768}
1769
Christoph Hellwigf5e54d62006-06-28 04:26:44 -07001770static const struct address_space_operations ext3_ordered_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001771 .readpage = ext3_readpage,
1772 .readpages = ext3_readpages,
1773 .writepage = ext3_ordered_writepage,
1774 .sync_page = block_sync_page,
1775 .prepare_write = ext3_prepare_write,
1776 .commit_write = ext3_ordered_commit_write,
1777 .bmap = ext3_bmap,
1778 .invalidatepage = ext3_invalidatepage,
1779 .releasepage = ext3_releasepage,
1780 .direct_IO = ext3_direct_IO,
Christoph Lametere965f962006-02-01 03:05:41 -08001781 .migratepage = buffer_migrate_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001782};
1783
Christoph Hellwigf5e54d62006-06-28 04:26:44 -07001784static const struct address_space_operations ext3_writeback_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001785 .readpage = ext3_readpage,
1786 .readpages = ext3_readpages,
1787 .writepage = ext3_writeback_writepage,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001788 .sync_page = block_sync_page,
1789 .prepare_write = ext3_prepare_write,
1790 .commit_write = ext3_writeback_commit_write,
1791 .bmap = ext3_bmap,
1792 .invalidatepage = ext3_invalidatepage,
1793 .releasepage = ext3_releasepage,
1794 .direct_IO = ext3_direct_IO,
Christoph Lametere965f962006-02-01 03:05:41 -08001795 .migratepage = buffer_migrate_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001796};
1797
Christoph Hellwigf5e54d62006-06-28 04:26:44 -07001798static const struct address_space_operations ext3_journalled_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001799 .readpage = ext3_readpage,
1800 .readpages = ext3_readpages,
1801 .writepage = ext3_journalled_writepage,
1802 .sync_page = block_sync_page,
1803 .prepare_write = ext3_prepare_write,
1804 .commit_write = ext3_journalled_commit_write,
1805 .set_page_dirty = ext3_journalled_set_page_dirty,
1806 .bmap = ext3_bmap,
1807 .invalidatepage = ext3_invalidatepage,
1808 .releasepage = ext3_releasepage,
1809};
1810
1811void ext3_set_aops(struct inode *inode)
1812{
1813 if (ext3_should_order_data(inode))
1814 inode->i_mapping->a_ops = &ext3_ordered_aops;
1815 else if (ext3_should_writeback_data(inode))
1816 inode->i_mapping->a_ops = &ext3_writeback_aops;
1817 else
1818 inode->i_mapping->a_ops = &ext3_journalled_aops;
1819}
1820
1821/*
1822 * ext3_block_truncate_page() zeroes out a mapping from file offset `from'
1823 * up to the end of the block which corresponds to `from'.
1824 * This required during truncate. We need to physically zero the tail end
1825 * of that block so it doesn't yield old data if the file is later grown.
1826 */
1827static int ext3_block_truncate_page(handle_t *handle, struct page *page,
1828 struct address_space *mapping, loff_t from)
1829{
Mingming Cao43d23f92006-06-25 05:48:07 -07001830 ext3_fsblk_t index = from >> PAGE_CACHE_SHIFT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001831 unsigned offset = from & (PAGE_CACHE_SIZE-1);
1832 unsigned blocksize, iblock, length, pos;
1833 struct inode *inode = mapping->host;
1834 struct buffer_head *bh;
1835 int err = 0;
1836 void *kaddr;
1837
1838 blocksize = inode->i_sb->s_blocksize;
1839 length = blocksize - (offset & (blocksize - 1));
1840 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1841
1842 /*
1843 * For "nobh" option, we can only work if we don't need to
1844 * read-in the page - otherwise we create buffers to do the IO.
1845 */
Badari Pulavartycd6ef842006-03-11 03:27:14 -08001846 if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
1847 ext3_should_writeback_data(inode) && PageUptodate(page)) {
1848 kaddr = kmap_atomic(page, KM_USER0);
1849 memset(kaddr + offset, 0, length);
1850 flush_dcache_page(page);
1851 kunmap_atomic(kaddr, KM_USER0);
1852 set_page_dirty(page);
1853 goto unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001854 }
1855
1856 if (!page_has_buffers(page))
1857 create_empty_buffers(page, blocksize, 0);
1858
1859 /* Find the buffer that contains "offset" */
1860 bh = page_buffers(page);
1861 pos = blocksize;
1862 while (offset >= pos) {
1863 bh = bh->b_this_page;
1864 iblock++;
1865 pos += blocksize;
1866 }
1867
1868 err = 0;
1869 if (buffer_freed(bh)) {
1870 BUFFER_TRACE(bh, "freed: skip");
1871 goto unlock;
1872 }
1873
1874 if (!buffer_mapped(bh)) {
1875 BUFFER_TRACE(bh, "unmapped");
1876 ext3_get_block(inode, iblock, bh, 0);
1877 /* unmapped? It's a hole - nothing to do */
1878 if (!buffer_mapped(bh)) {
1879 BUFFER_TRACE(bh, "still unmapped");
1880 goto unlock;
1881 }
1882 }
1883
1884 /* Ok, it's mapped. Make sure it's up-to-date */
1885 if (PageUptodate(page))
1886 set_buffer_uptodate(bh);
1887
1888 if (!buffer_uptodate(bh)) {
1889 err = -EIO;
1890 ll_rw_block(READ, 1, &bh);
1891 wait_on_buffer(bh);
1892 /* Uhhuh. Read error. Complain and punt. */
1893 if (!buffer_uptodate(bh))
1894 goto unlock;
1895 }
1896
1897 if (ext3_should_journal_data(inode)) {
1898 BUFFER_TRACE(bh, "get write access");
1899 err = ext3_journal_get_write_access(handle, bh);
1900 if (err)
1901 goto unlock;
1902 }
1903
1904 kaddr = kmap_atomic(page, KM_USER0);
1905 memset(kaddr + offset, 0, length);
1906 flush_dcache_page(page);
1907 kunmap_atomic(kaddr, KM_USER0);
1908
1909 BUFFER_TRACE(bh, "zeroed end of block");
1910
1911 err = 0;
1912 if (ext3_should_journal_data(inode)) {
1913 err = ext3_journal_dirty_metadata(handle, bh);
1914 } else {
1915 if (ext3_should_order_data(inode))
1916 err = ext3_journal_dirty_data(handle, bh);
1917 mark_buffer_dirty(bh);
1918 }
1919
1920unlock:
1921 unlock_page(page);
1922 page_cache_release(page);
1923 return err;
1924}
1925
1926/*
1927 * Probably it should be a library function... search for first non-zero word
1928 * or memcmp with zero_page, whatever is better for particular architecture.
1929 * Linus?
1930 */
1931static inline int all_zeroes(__le32 *p, __le32 *q)
1932{
1933 while (p < q)
1934 if (*p++)
1935 return 0;
1936 return 1;
1937}
1938
1939/**
1940 * ext3_find_shared - find the indirect blocks for partial truncation.
1941 * @inode: inode in question
1942 * @depth: depth of the affected branch
1943 * @offsets: offsets of pointers in that branch (see ext3_block_to_path)
1944 * @chain: place to store the pointers to partial indirect blocks
1945 * @top: place to the (detached) top of branch
1946 *
1947 * This is a helper function used by ext3_truncate().
1948 *
1949 * When we do truncate() we may have to clean the ends of several
1950 * indirect blocks but leave the blocks themselves alive. Block is
1951 * partially truncated if some data below the new i_size is refered
1952 * from it (and it is on the path to the first completely truncated
1953 * data block, indeed). We have to free the top of that path along
1954 * with everything to the right of the path. Since no allocation
1955 * past the truncation point is possible until ext3_truncate()
1956 * finishes, we may safely do the latter, but top of branch may
1957 * require special attention - pageout below the truncation point
1958 * might try to populate it.
1959 *
1960 * We atomically detach the top of branch from the tree, store the
1961 * block number of its root in *@top, pointers to buffer_heads of
1962 * partially truncated blocks - in @chain[].bh and pointers to
1963 * their last elements that should not be removed - in
1964 * @chain[].p. Return value is the pointer to last filled element
1965 * of @chain.
1966 *
1967 * The work left to caller to do the actual freeing of subtrees:
1968 * a) free the subtree starting from *@top
1969 * b) free the subtrees whose roots are stored in
1970 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
1971 * c) free the subtrees growing from the inode past the @chain[0].
1972 * (no partially truncated stuff there). */
1973
Andrew Mortond6859bf2006-03-26 01:38:03 -08001974static Indirect *ext3_find_shared(struct inode *inode, int depth,
1975 int offsets[4], Indirect chain[4], __le32 *top)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001976{
1977 Indirect *partial, *p;
1978 int k, err;
1979
1980 *top = 0;
1981 /* Make k index the deepest non-null offest + 1 */
1982 for (k = depth; k > 1 && !offsets[k-1]; k--)
1983 ;
1984 partial = ext3_get_branch(inode, k, offsets, chain, &err);
1985 /* Writer: pointers */
1986 if (!partial)
1987 partial = chain + k-1;
1988 /*
1989 * If the branch acquired continuation since we've looked at it -
1990 * fine, it should all survive and (new) top doesn't belong to us.
1991 */
1992 if (!partial->key && *partial->p)
1993 /* Writer: end */
1994 goto no_top;
1995 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
1996 ;
1997 /*
1998 * OK, we've found the last block that must survive. The rest of our
1999 * branch should be detached before unlocking. However, if that rest
2000 * of branch is all ours and does not grow immediately from the inode
2001 * it's easier to cheat and just decrement partial->p.
2002 */
2003 if (p == chain + k - 1 && p > chain) {
2004 p->p--;
2005 } else {
2006 *top = *p->p;
2007 /* Nope, don't do this in ext3. Must leave the tree intact */
2008#if 0
2009 *p->p = 0;
2010#endif
2011 }
2012 /* Writer: end */
2013
Andrew Mortond6859bf2006-03-26 01:38:03 -08002014 while(partial > p) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002015 brelse(partial->bh);
2016 partial--;
2017 }
2018no_top:
2019 return partial;
2020}
2021
2022/*
2023 * Zero a number of block pointers in either an inode or an indirect block.
2024 * If we restart the transaction we must again get write access to the
2025 * indirect block for further modification.
2026 *
2027 * We release `count' blocks on disk, but (last - first) may be greater
2028 * than `count' because there can be holes in there.
2029 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08002030static void ext3_clear_blocks(handle_t *handle, struct inode *inode,
Mingming Cao43d23f92006-06-25 05:48:07 -07002031 struct buffer_head *bh, ext3_fsblk_t block_to_free,
Andrew Mortond6859bf2006-03-26 01:38:03 -08002032 unsigned long count, __le32 *first, __le32 *last)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002033{
2034 __le32 *p;
2035 if (try_to_extend_transaction(handle, inode)) {
2036 if (bh) {
2037 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
2038 ext3_journal_dirty_metadata(handle, bh);
2039 }
2040 ext3_mark_inode_dirty(handle, inode);
2041 ext3_journal_test_restart(handle, inode);
2042 if (bh) {
2043 BUFFER_TRACE(bh, "retaking write access");
2044 ext3_journal_get_write_access(handle, bh);
2045 }
2046 }
2047
2048 /*
2049 * Any buffers which are on the journal will be in memory. We find
2050 * them on the hash table so journal_revoke() will run journal_forget()
2051 * on them. We've already detached each block from the file, so
2052 * bforget() in journal_forget() should be safe.
2053 *
2054 * AKPM: turn on bforget in journal_forget()!!!
2055 */
2056 for (p = first; p < last; p++) {
2057 u32 nr = le32_to_cpu(*p);
2058 if (nr) {
2059 struct buffer_head *bh;
2060
2061 *p = 0;
2062 bh = sb_find_get_block(inode->i_sb, nr);
2063 ext3_forget(handle, 0, inode, bh, nr);
2064 }
2065 }
2066
2067 ext3_free_blocks(handle, inode, block_to_free, count);
2068}
2069
2070/**
2071 * ext3_free_data - free a list of data blocks
2072 * @handle: handle for this transaction
2073 * @inode: inode we are dealing with
2074 * @this_bh: indirect buffer_head which contains *@first and *@last
2075 * @first: array of block numbers
2076 * @last: points immediately past the end of array
2077 *
2078 * We are freeing all blocks refered from that array (numbers are stored as
2079 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
2080 *
2081 * We accumulate contiguous runs of blocks to free. Conveniently, if these
2082 * blocks are contiguous then releasing them at one time will only affect one
2083 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
2084 * actually use a lot of journal space.
2085 *
2086 * @this_bh will be %NULL if @first and @last point into the inode's direct
2087 * block pointers.
2088 */
2089static void ext3_free_data(handle_t *handle, struct inode *inode,
2090 struct buffer_head *this_bh,
2091 __le32 *first, __le32 *last)
2092{
Mingming Cao43d23f92006-06-25 05:48:07 -07002093 ext3_fsblk_t block_to_free = 0; /* Starting block # of a run */
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002094 unsigned long count = 0; /* Number of blocks in the run */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002095 __le32 *block_to_free_p = NULL; /* Pointer into inode/ind
2096 corresponding to
2097 block_to_free */
Mingming Cao43d23f92006-06-25 05:48:07 -07002098 ext3_fsblk_t nr; /* Current block # */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002099 __le32 *p; /* Pointer into inode/ind
2100 for current block */
2101 int err;
2102
2103 if (this_bh) { /* For indirect block */
2104 BUFFER_TRACE(this_bh, "get_write_access");
2105 err = ext3_journal_get_write_access(handle, this_bh);
2106 /* Important: if we can't update the indirect pointers
2107 * to the blocks, we can't free them. */
2108 if (err)
2109 return;
2110 }
2111
2112 for (p = first; p < last; p++) {
2113 nr = le32_to_cpu(*p);
2114 if (nr) {
2115 /* accumulate blocks to free if they're contiguous */
2116 if (count == 0) {
2117 block_to_free = nr;
2118 block_to_free_p = p;
2119 count = 1;
2120 } else if (nr == block_to_free + count) {
2121 count++;
2122 } else {
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002123 ext3_clear_blocks(handle, inode, this_bh,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002124 block_to_free,
2125 count, block_to_free_p, p);
2126 block_to_free = nr;
2127 block_to_free_p = p;
2128 count = 1;
2129 }
2130 }
2131 }
2132
2133 if (count > 0)
2134 ext3_clear_blocks(handle, inode, this_bh, block_to_free,
2135 count, block_to_free_p, p);
2136
2137 if (this_bh) {
2138 BUFFER_TRACE(this_bh, "call ext3_journal_dirty_metadata");
2139 ext3_journal_dirty_metadata(handle, this_bh);
2140 }
2141}
2142
2143/**
2144 * ext3_free_branches - free an array of branches
2145 * @handle: JBD handle for this transaction
2146 * @inode: inode we are dealing with
2147 * @parent_bh: the buffer_head which contains *@first and *@last
2148 * @first: array of block numbers
2149 * @last: pointer immediately past the end of array
2150 * @depth: depth of the branches to free
2151 *
2152 * We are freeing all blocks refered from these branches (numbers are
2153 * stored as little-endian 32-bit) and updating @inode->i_blocks
2154 * appropriately.
2155 */
2156static void ext3_free_branches(handle_t *handle, struct inode *inode,
2157 struct buffer_head *parent_bh,
2158 __le32 *first, __le32 *last, int depth)
2159{
Mingming Cao43d23f92006-06-25 05:48:07 -07002160 ext3_fsblk_t nr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002161 __le32 *p;
2162
2163 if (is_handle_aborted(handle))
2164 return;
2165
2166 if (depth--) {
2167 struct buffer_head *bh;
2168 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2169 p = last;
2170 while (--p >= first) {
2171 nr = le32_to_cpu(*p);
2172 if (!nr)
2173 continue; /* A hole */
2174
2175 /* Go read the buffer for the next level down */
2176 bh = sb_bread(inode->i_sb, nr);
2177
2178 /*
2179 * A read failure? Report error and clear slot
2180 * (should be rare).
2181 */
2182 if (!bh) {
2183 ext3_error(inode->i_sb, "ext3_free_branches",
Eric Sandeeneee194e2006-09-27 01:49:30 -07002184 "Read failure, inode=%lu, block="E3FSBLK,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002185 inode->i_ino, nr);
2186 continue;
2187 }
2188
2189 /* This zaps the entire block. Bottom up. */
2190 BUFFER_TRACE(bh, "free child branches");
2191 ext3_free_branches(handle, inode, bh,
2192 (__le32*)bh->b_data,
2193 (__le32*)bh->b_data + addr_per_block,
2194 depth);
2195
2196 /*
2197 * We've probably journalled the indirect block several
2198 * times during the truncate. But it's no longer
2199 * needed and we now drop it from the transaction via
2200 * journal_revoke().
2201 *
2202 * That's easy if it's exclusively part of this
2203 * transaction. But if it's part of the committing
2204 * transaction then journal_forget() will simply
2205 * brelse() it. That means that if the underlying
2206 * block is reallocated in ext3_get_block(),
2207 * unmap_underlying_metadata() will find this block
2208 * and will try to get rid of it. damn, damn.
2209 *
2210 * If this block has already been committed to the
2211 * journal, a revoke record will be written. And
2212 * revoke records must be emitted *before* clearing
2213 * this block's bit in the bitmaps.
2214 */
2215 ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
2216
2217 /*
2218 * Everything below this this pointer has been
2219 * released. Now let this top-of-subtree go.
2220 *
2221 * We want the freeing of this indirect block to be
2222 * atomic in the journal with the updating of the
2223 * bitmap block which owns it. So make some room in
2224 * the journal.
2225 *
2226 * We zero the parent pointer *after* freeing its
2227 * pointee in the bitmaps, so if extend_transaction()
2228 * for some reason fails to put the bitmap changes and
2229 * the release into the same transaction, recovery
2230 * will merely complain about releasing a free block,
2231 * rather than leaking blocks.
2232 */
2233 if (is_handle_aborted(handle))
2234 return;
2235 if (try_to_extend_transaction(handle, inode)) {
2236 ext3_mark_inode_dirty(handle, inode);
2237 ext3_journal_test_restart(handle, inode);
2238 }
2239
2240 ext3_free_blocks(handle, inode, nr, 1);
2241
2242 if (parent_bh) {
2243 /*
2244 * The block which we have just freed is
2245 * pointed to by an indirect block: journal it
2246 */
2247 BUFFER_TRACE(parent_bh, "get_write_access");
2248 if (!ext3_journal_get_write_access(handle,
2249 parent_bh)){
2250 *p = 0;
2251 BUFFER_TRACE(parent_bh,
2252 "call ext3_journal_dirty_metadata");
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002253 ext3_journal_dirty_metadata(handle,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002254 parent_bh);
2255 }
2256 }
2257 }
2258 } else {
2259 /* We have reached the bottom of the tree. */
2260 BUFFER_TRACE(parent_bh, "free data blocks");
2261 ext3_free_data(handle, inode, parent_bh, first, last);
2262 }
2263}
2264
2265/*
2266 * ext3_truncate()
2267 *
2268 * We block out ext3_get_block() block instantiations across the entire
2269 * transaction, and VFS/VM ensures that ext3_truncate() cannot run
2270 * simultaneously on behalf of the same inode.
2271 *
2272 * As we work through the truncate and commmit bits of it to the journal there
2273 * is one core, guiding principle: the file's tree must always be consistent on
2274 * disk. We must be able to restart the truncate after a crash.
2275 *
2276 * The file's tree may be transiently inconsistent in memory (although it
2277 * probably isn't), but whenever we close off and commit a journal transaction,
2278 * the contents of (the filesystem + the journal) must be consistent and
2279 * restartable. It's pretty simple, really: bottom up, right to left (although
2280 * left-to-right works OK too).
2281 *
2282 * Note that at recovery time, journal replay occurs *before* the restart of
2283 * truncate against the orphan inode list.
2284 *
2285 * The committed inode has the new, desired i_size (which is the same as
2286 * i_disksize in this case). After a crash, ext3_orphan_cleanup() will see
2287 * that this inode's truncate did not complete and it will again call
2288 * ext3_truncate() to have another go. So there will be instantiated blocks
2289 * to the right of the truncation point in a crashed ext3 filesystem. But
2290 * that's fine - as long as they are linked from the inode, the post-crash
2291 * ext3_truncate() run will find them and release them.
2292 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08002293void ext3_truncate(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002294{
2295 handle_t *handle;
2296 struct ext3_inode_info *ei = EXT3_I(inode);
2297 __le32 *i_data = ei->i_data;
2298 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2299 struct address_space *mapping = inode->i_mapping;
2300 int offsets[4];
2301 Indirect chain[4];
2302 Indirect *partial;
2303 __le32 nr = 0;
2304 int n;
2305 long last_block;
2306 unsigned blocksize = inode->i_sb->s_blocksize;
2307 struct page *page;
2308
2309 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2310 S_ISLNK(inode->i_mode)))
2311 return;
2312 if (ext3_inode_is_fast_symlink(inode))
2313 return;
2314 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2315 return;
2316
2317 /*
2318 * We have to lock the EOF page here, because lock_page() nests
2319 * outside journal_start().
2320 */
2321 if ((inode->i_size & (blocksize - 1)) == 0) {
2322 /* Block boundary? Nothing to do */
2323 page = NULL;
2324 } else {
2325 page = grab_cache_page(mapping,
2326 inode->i_size >> PAGE_CACHE_SHIFT);
2327 if (!page)
2328 return;
2329 }
2330
2331 handle = start_transaction(inode);
2332 if (IS_ERR(handle)) {
2333 if (page) {
2334 clear_highpage(page);
2335 flush_dcache_page(page);
2336 unlock_page(page);
2337 page_cache_release(page);
2338 }
2339 return; /* AKPM: return what? */
2340 }
2341
2342 last_block = (inode->i_size + blocksize-1)
2343 >> EXT3_BLOCK_SIZE_BITS(inode->i_sb);
2344
2345 if (page)
2346 ext3_block_truncate_page(handle, page, mapping, inode->i_size);
2347
2348 n = ext3_block_to_path(inode, last_block, offsets, NULL);
2349 if (n == 0)
2350 goto out_stop; /* error */
2351
2352 /*
2353 * OK. This truncate is going to happen. We add the inode to the
2354 * orphan list, so that if this truncate spans multiple transactions,
2355 * and we crash, we will resume the truncate when the filesystem
2356 * recovers. It also marks the inode dirty, to catch the new size.
2357 *
2358 * Implication: the file must always be in a sane, consistent
2359 * truncatable state while each transaction commits.
2360 */
2361 if (ext3_orphan_add(handle, inode))
2362 goto out_stop;
2363
2364 /*
2365 * The orphan list entry will now protect us from any crash which
2366 * occurs before the truncate completes, so it is now safe to propagate
2367 * the new, shorter inode size (held for now in i_size) into the
2368 * on-disk inode. We do this via i_disksize, which is the value which
2369 * ext3 *really* writes onto the disk inode.
2370 */
2371 ei->i_disksize = inode->i_size;
2372
2373 /*
2374 * From here we block out all ext3_get_block() callers who want to
2375 * modify the block allocation tree.
2376 */
Arjan van de Ven97461512006-03-23 03:00:42 -08002377 mutex_lock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002378
2379 if (n == 1) { /* direct blocks */
2380 ext3_free_data(handle, inode, NULL, i_data+offsets[0],
2381 i_data + EXT3_NDIR_BLOCKS);
2382 goto do_indirects;
2383 }
2384
2385 partial = ext3_find_shared(inode, n, offsets, chain, &nr);
2386 /* Kill the top of shared branch (not detached) */
2387 if (nr) {
2388 if (partial == chain) {
2389 /* Shared branch grows from the inode */
2390 ext3_free_branches(handle, inode, NULL,
2391 &nr, &nr+1, (chain+n-1) - partial);
2392 *partial->p = 0;
2393 /*
2394 * We mark the inode dirty prior to restart,
2395 * and prior to stop. No need for it here.
2396 */
2397 } else {
2398 /* Shared branch grows from an indirect block */
2399 BUFFER_TRACE(partial->bh, "get_write_access");
2400 ext3_free_branches(handle, inode, partial->bh,
2401 partial->p,
2402 partial->p+1, (chain+n-1) - partial);
2403 }
2404 }
2405 /* Clear the ends of indirect blocks on the shared branch */
2406 while (partial > chain) {
2407 ext3_free_branches(handle, inode, partial->bh, partial->p + 1,
2408 (__le32*)partial->bh->b_data+addr_per_block,
2409 (chain+n-1) - partial);
2410 BUFFER_TRACE(partial->bh, "call brelse");
2411 brelse (partial->bh);
2412 partial--;
2413 }
2414do_indirects:
2415 /* Kill the remaining (whole) subtrees */
2416 switch (offsets[0]) {
Andrew Mortond6859bf2006-03-26 01:38:03 -08002417 default:
2418 nr = i_data[EXT3_IND_BLOCK];
2419 if (nr) {
2420 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
2421 i_data[EXT3_IND_BLOCK] = 0;
2422 }
2423 case EXT3_IND_BLOCK:
2424 nr = i_data[EXT3_DIND_BLOCK];
2425 if (nr) {
2426 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
2427 i_data[EXT3_DIND_BLOCK] = 0;
2428 }
2429 case EXT3_DIND_BLOCK:
2430 nr = i_data[EXT3_TIND_BLOCK];
2431 if (nr) {
2432 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
2433 i_data[EXT3_TIND_BLOCK] = 0;
2434 }
2435 case EXT3_TIND_BLOCK:
2436 ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002437 }
2438
2439 ext3_discard_reservation(inode);
2440
Arjan van de Ven97461512006-03-23 03:00:42 -08002441 mutex_unlock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002442 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
2443 ext3_mark_inode_dirty(handle, inode);
2444
Andrew Mortond6859bf2006-03-26 01:38:03 -08002445 /*
2446 * In a multi-transaction truncate, we only make the final transaction
2447 * synchronous
2448 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002449 if (IS_SYNC(inode))
2450 handle->h_sync = 1;
2451out_stop:
2452 /*
2453 * If this was a simple ftruncate(), and the file will remain alive
2454 * then we need to clear up the orphan record which we created above.
2455 * However, if this was a real unlink then we were called by
2456 * ext3_delete_inode(), and we allow that function to clean up the
2457 * orphan info for us.
2458 */
2459 if (inode->i_nlink)
2460 ext3_orphan_del(handle, inode);
2461
2462 ext3_journal_stop(handle);
2463}
2464
Mingming Cao43d23f92006-06-25 05:48:07 -07002465static ext3_fsblk_t ext3_get_inode_block(struct super_block *sb,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002466 unsigned long ino, struct ext3_iloc *iloc)
2467{
2468 unsigned long desc, group_desc, block_group;
Mingming Cao43d23f92006-06-25 05:48:07 -07002469 unsigned long offset;
2470 ext3_fsblk_t block;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002471 struct buffer_head *bh;
2472 struct ext3_group_desc * gdp;
2473
Neil Brown2ccb48e2006-07-30 03:03:01 -07002474 if (!ext3_valid_inum(sb, ino)) {
2475 /*
2476 * This error is already checked for in namei.c unless we are
2477 * looking at an NFS filehandle, in which case no error
2478 * report is needed
2479 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002480 return 0;
2481 }
Neil Brown2ccb48e2006-07-30 03:03:01 -07002482
Linus Torvalds1da177e2005-04-16 15:20:36 -07002483 block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
2484 if (block_group >= EXT3_SB(sb)->s_groups_count) {
Andrew Mortond6859bf2006-03-26 01:38:03 -08002485 ext3_error(sb,"ext3_get_inode_block","group >= groups count");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002486 return 0;
2487 }
2488 smp_rmb();
2489 group_desc = block_group >> EXT3_DESC_PER_BLOCK_BITS(sb);
2490 desc = block_group & (EXT3_DESC_PER_BLOCK(sb) - 1);
2491 bh = EXT3_SB(sb)->s_group_desc[group_desc];
2492 if (!bh) {
2493 ext3_error (sb, "ext3_get_inode_block",
2494 "Descriptor not loaded");
2495 return 0;
2496 }
2497
Andrew Mortond6859bf2006-03-26 01:38:03 -08002498 gdp = (struct ext3_group_desc *)bh->b_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002499 /*
2500 * Figure out the offset within the block group inode table
2501 */
2502 offset = ((ino - 1) % EXT3_INODES_PER_GROUP(sb)) *
2503 EXT3_INODE_SIZE(sb);
2504 block = le32_to_cpu(gdp[desc].bg_inode_table) +
2505 (offset >> EXT3_BLOCK_SIZE_BITS(sb));
2506
2507 iloc->block_group = block_group;
2508 iloc->offset = offset & (EXT3_BLOCK_SIZE(sb) - 1);
2509 return block;
2510}
2511
2512/*
2513 * ext3_get_inode_loc returns with an extra refcount against the inode's
2514 * underlying buffer_head on success. If 'in_mem' is true, we have all
2515 * data in memory that is needed to recreate the on-disk version of this
2516 * inode.
2517 */
2518static int __ext3_get_inode_loc(struct inode *inode,
2519 struct ext3_iloc *iloc, int in_mem)
2520{
Mingming Cao43d23f92006-06-25 05:48:07 -07002521 ext3_fsblk_t block;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002522 struct buffer_head *bh;
2523
2524 block = ext3_get_inode_block(inode->i_sb, inode->i_ino, iloc);
2525 if (!block)
2526 return -EIO;
2527
2528 bh = sb_getblk(inode->i_sb, block);
2529 if (!bh) {
2530 ext3_error (inode->i_sb, "ext3_get_inode_loc",
2531 "unable to read inode block - "
Mingming Cao43d23f92006-06-25 05:48:07 -07002532 "inode=%lu, block="E3FSBLK,
2533 inode->i_ino, block);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002534 return -EIO;
2535 }
2536 if (!buffer_uptodate(bh)) {
2537 lock_buffer(bh);
2538 if (buffer_uptodate(bh)) {
2539 /* someone brought it uptodate while we waited */
2540 unlock_buffer(bh);
2541 goto has_buffer;
2542 }
2543
2544 /*
2545 * If we have all information of the inode in memory and this
2546 * is the only valid inode in the block, we need not read the
2547 * block.
2548 */
2549 if (in_mem) {
2550 struct buffer_head *bitmap_bh;
2551 struct ext3_group_desc *desc;
2552 int inodes_per_buffer;
2553 int inode_offset, i;
2554 int block_group;
2555 int start;
2556
2557 block_group = (inode->i_ino - 1) /
2558 EXT3_INODES_PER_GROUP(inode->i_sb);
2559 inodes_per_buffer = bh->b_size /
2560 EXT3_INODE_SIZE(inode->i_sb);
2561 inode_offset = ((inode->i_ino - 1) %
2562 EXT3_INODES_PER_GROUP(inode->i_sb));
2563 start = inode_offset & ~(inodes_per_buffer - 1);
2564
2565 /* Is the inode bitmap in cache? */
2566 desc = ext3_get_group_desc(inode->i_sb,
2567 block_group, NULL);
2568 if (!desc)
2569 goto make_io;
2570
2571 bitmap_bh = sb_getblk(inode->i_sb,
2572 le32_to_cpu(desc->bg_inode_bitmap));
2573 if (!bitmap_bh)
2574 goto make_io;
2575
2576 /*
2577 * If the inode bitmap isn't in cache then the
2578 * optimisation may end up performing two reads instead
2579 * of one, so skip it.
2580 */
2581 if (!buffer_uptodate(bitmap_bh)) {
2582 brelse(bitmap_bh);
2583 goto make_io;
2584 }
2585 for (i = start; i < start + inodes_per_buffer; i++) {
2586 if (i == inode_offset)
2587 continue;
2588 if (ext3_test_bit(i, bitmap_bh->b_data))
2589 break;
2590 }
2591 brelse(bitmap_bh);
2592 if (i == start + inodes_per_buffer) {
2593 /* all other inodes are free, so skip I/O */
2594 memset(bh->b_data, 0, bh->b_size);
2595 set_buffer_uptodate(bh);
2596 unlock_buffer(bh);
2597 goto has_buffer;
2598 }
2599 }
2600
2601make_io:
2602 /*
2603 * There are other valid inodes in the buffer, this inode
2604 * has in-inode xattrs, or we don't have this inode in memory.
2605 * Read the block from disk.
2606 */
2607 get_bh(bh);
2608 bh->b_end_io = end_buffer_read_sync;
Jens Axboecaa38fb2006-07-23 01:41:26 +02002609 submit_bh(READ_META, bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002610 wait_on_buffer(bh);
2611 if (!buffer_uptodate(bh)) {
2612 ext3_error(inode->i_sb, "ext3_get_inode_loc",
2613 "unable to read inode block - "
Mingming Cao43d23f92006-06-25 05:48:07 -07002614 "inode=%lu, block="E3FSBLK,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002615 inode->i_ino, block);
2616 brelse(bh);
2617 return -EIO;
2618 }
2619 }
2620has_buffer:
2621 iloc->bh = bh;
2622 return 0;
2623}
2624
2625int ext3_get_inode_loc(struct inode *inode, struct ext3_iloc *iloc)
2626{
2627 /* We have all inode data except xattrs in memory here. */
2628 return __ext3_get_inode_loc(inode, iloc,
2629 !(EXT3_I(inode)->i_state & EXT3_STATE_XATTR));
2630}
2631
2632void ext3_set_inode_flags(struct inode *inode)
2633{
2634 unsigned int flags = EXT3_I(inode)->i_flags;
2635
2636 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
2637 if (flags & EXT3_SYNC_FL)
2638 inode->i_flags |= S_SYNC;
2639 if (flags & EXT3_APPEND_FL)
2640 inode->i_flags |= S_APPEND;
2641 if (flags & EXT3_IMMUTABLE_FL)
2642 inode->i_flags |= S_IMMUTABLE;
2643 if (flags & EXT3_NOATIME_FL)
2644 inode->i_flags |= S_NOATIME;
2645 if (flags & EXT3_DIRSYNC_FL)
2646 inode->i_flags |= S_DIRSYNC;
2647}
2648
2649void ext3_read_inode(struct inode * inode)
2650{
2651 struct ext3_iloc iloc;
2652 struct ext3_inode *raw_inode;
2653 struct ext3_inode_info *ei = EXT3_I(inode);
2654 struct buffer_head *bh;
2655 int block;
2656
2657#ifdef CONFIG_EXT3_FS_POSIX_ACL
2658 ei->i_acl = EXT3_ACL_NOT_CACHED;
2659 ei->i_default_acl = EXT3_ACL_NOT_CACHED;
2660#endif
2661 ei->i_block_alloc_info = NULL;
2662
2663 if (__ext3_get_inode_loc(inode, &iloc, 0))
2664 goto bad_inode;
2665 bh = iloc.bh;
2666 raw_inode = ext3_raw_inode(&iloc);
2667 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
2668 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
2669 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
2670 if(!(test_opt (inode->i_sb, NO_UID32))) {
2671 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
2672 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
2673 }
2674 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
2675 inode->i_size = le32_to_cpu(raw_inode->i_size);
2676 inode->i_atime.tv_sec = le32_to_cpu(raw_inode->i_atime);
2677 inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->i_ctime);
2678 inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->i_mtime);
2679 inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
2680
2681 ei->i_state = 0;
2682 ei->i_dir_start_lookup = 0;
2683 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
2684 /* We now have enough fields to check if the inode was active or not.
2685 * This is needed because nfsd might try to access dead inodes
2686 * the test is that same one that e2fsck uses
2687 * NeilBrown 1999oct15
2688 */
2689 if (inode->i_nlink == 0) {
2690 if (inode->i_mode == 0 ||
2691 !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) {
2692 /* this inode is deleted */
2693 brelse (bh);
2694 goto bad_inode;
2695 }
2696 /* The only unlinked inodes we let through here have
2697 * valid i_mode and are being read by the orphan
2698 * recovery code: that's fine, we're about to complete
2699 * the process of deleting those. */
2700 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002701 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
2702 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
2703#ifdef EXT3_FRAGMENTS
2704 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
2705 ei->i_frag_no = raw_inode->i_frag;
2706 ei->i_frag_size = raw_inode->i_fsize;
2707#endif
2708 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
2709 if (!S_ISREG(inode->i_mode)) {
2710 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
2711 } else {
2712 inode->i_size |=
2713 ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
2714 }
2715 ei->i_disksize = inode->i_size;
2716 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
2717 ei->i_block_group = iloc.block_group;
2718 /*
2719 * NOTE! The in-memory inode i_data array is in little-endian order
2720 * even on big-endian machines: we do NOT byteswap the block numbers!
2721 */
2722 for (block = 0; block < EXT3_N_BLOCKS; block++)
2723 ei->i_data[block] = raw_inode->i_block[block];
2724 INIT_LIST_HEAD(&ei->i_orphan);
2725
2726 if (inode->i_ino >= EXT3_FIRST_INO(inode->i_sb) + 1 &&
2727 EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) {
2728 /*
2729 * When mke2fs creates big inodes it does not zero out
2730 * the unused bytes above EXT3_GOOD_OLD_INODE_SIZE,
2731 * so ignore those first few inodes.
2732 */
2733 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
2734 if (EXT3_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
2735 EXT3_INODE_SIZE(inode->i_sb))
2736 goto bad_inode;
2737 if (ei->i_extra_isize == 0) {
2738 /* The extra space is currently unused. Use it. */
2739 ei->i_extra_isize = sizeof(struct ext3_inode) -
2740 EXT3_GOOD_OLD_INODE_SIZE;
2741 } else {
2742 __le32 *magic = (void *)raw_inode +
2743 EXT3_GOOD_OLD_INODE_SIZE +
2744 ei->i_extra_isize;
2745 if (*magic == cpu_to_le32(EXT3_XATTR_MAGIC))
2746 ei->i_state |= EXT3_STATE_XATTR;
2747 }
2748 } else
2749 ei->i_extra_isize = 0;
2750
2751 if (S_ISREG(inode->i_mode)) {
2752 inode->i_op = &ext3_file_inode_operations;
2753 inode->i_fop = &ext3_file_operations;
2754 ext3_set_aops(inode);
2755 } else if (S_ISDIR(inode->i_mode)) {
2756 inode->i_op = &ext3_dir_inode_operations;
2757 inode->i_fop = &ext3_dir_operations;
2758 } else if (S_ISLNK(inode->i_mode)) {
2759 if (ext3_inode_is_fast_symlink(inode))
2760 inode->i_op = &ext3_fast_symlink_inode_operations;
2761 else {
2762 inode->i_op = &ext3_symlink_inode_operations;
2763 ext3_set_aops(inode);
2764 }
2765 } else {
2766 inode->i_op = &ext3_special_inode_operations;
2767 if (raw_inode->i_block[0])
2768 init_special_inode(inode, inode->i_mode,
2769 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002770 else
Linus Torvalds1da177e2005-04-16 15:20:36 -07002771 init_special_inode(inode, inode->i_mode,
2772 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
2773 }
2774 brelse (iloc.bh);
2775 ext3_set_inode_flags(inode);
2776 return;
2777
2778bad_inode:
2779 make_bad_inode(inode);
2780 return;
2781}
2782
2783/*
2784 * Post the struct inode info into an on-disk inode location in the
2785 * buffer-cache. This gobbles the caller's reference to the
2786 * buffer_head in the inode location struct.
2787 *
2788 * The caller must have write access to iloc->bh.
2789 */
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002790static int ext3_do_update_inode(handle_t *handle,
2791 struct inode *inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002792 struct ext3_iloc *iloc)
2793{
2794 struct ext3_inode *raw_inode = ext3_raw_inode(iloc);
2795 struct ext3_inode_info *ei = EXT3_I(inode);
2796 struct buffer_head *bh = iloc->bh;
2797 int err = 0, rc, block;
2798
2799 /* For fields not not tracking in the in-memory inode,
2800 * initialise them to zero for new inodes. */
2801 if (ei->i_state & EXT3_STATE_NEW)
2802 memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
2803
2804 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
2805 if(!(test_opt(inode->i_sb, NO_UID32))) {
2806 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
2807 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
2808/*
2809 * Fix up interoperability with old kernels. Otherwise, old inodes get
2810 * re-used with the upper 16 bits of the uid/gid intact
2811 */
2812 if(!ei->i_dtime) {
2813 raw_inode->i_uid_high =
2814 cpu_to_le16(high_16_bits(inode->i_uid));
2815 raw_inode->i_gid_high =
2816 cpu_to_le16(high_16_bits(inode->i_gid));
2817 } else {
2818 raw_inode->i_uid_high = 0;
2819 raw_inode->i_gid_high = 0;
2820 }
2821 } else {
2822 raw_inode->i_uid_low =
2823 cpu_to_le16(fs_high2lowuid(inode->i_uid));
2824 raw_inode->i_gid_low =
2825 cpu_to_le16(fs_high2lowgid(inode->i_gid));
2826 raw_inode->i_uid_high = 0;
2827 raw_inode->i_gid_high = 0;
2828 }
2829 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
2830 raw_inode->i_size = cpu_to_le32(ei->i_disksize);
2831 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
2832 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
2833 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
2834 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
2835 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
2836 raw_inode->i_flags = cpu_to_le32(ei->i_flags);
2837#ifdef EXT3_FRAGMENTS
2838 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
2839 raw_inode->i_frag = ei->i_frag_no;
2840 raw_inode->i_fsize = ei->i_frag_size;
2841#endif
2842 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
2843 if (!S_ISREG(inode->i_mode)) {
2844 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
2845 } else {
2846 raw_inode->i_size_high =
2847 cpu_to_le32(ei->i_disksize >> 32);
2848 if (ei->i_disksize > 0x7fffffffULL) {
2849 struct super_block *sb = inode->i_sb;
2850 if (!EXT3_HAS_RO_COMPAT_FEATURE(sb,
2851 EXT3_FEATURE_RO_COMPAT_LARGE_FILE) ||
2852 EXT3_SB(sb)->s_es->s_rev_level ==
2853 cpu_to_le32(EXT3_GOOD_OLD_REV)) {
2854 /* If this is the first large file
2855 * created, add a flag to the superblock.
2856 */
2857 err = ext3_journal_get_write_access(handle,
2858 EXT3_SB(sb)->s_sbh);
2859 if (err)
2860 goto out_brelse;
2861 ext3_update_dynamic_rev(sb);
2862 EXT3_SET_RO_COMPAT_FEATURE(sb,
2863 EXT3_FEATURE_RO_COMPAT_LARGE_FILE);
2864 sb->s_dirt = 1;
2865 handle->h_sync = 1;
2866 err = ext3_journal_dirty_metadata(handle,
2867 EXT3_SB(sb)->s_sbh);
2868 }
2869 }
2870 }
2871 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
2872 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
2873 if (old_valid_dev(inode->i_rdev)) {
2874 raw_inode->i_block[0] =
2875 cpu_to_le32(old_encode_dev(inode->i_rdev));
2876 raw_inode->i_block[1] = 0;
2877 } else {
2878 raw_inode->i_block[0] = 0;
2879 raw_inode->i_block[1] =
2880 cpu_to_le32(new_encode_dev(inode->i_rdev));
2881 raw_inode->i_block[2] = 0;
2882 }
2883 } else for (block = 0; block < EXT3_N_BLOCKS; block++)
2884 raw_inode->i_block[block] = ei->i_data[block];
2885
Andreas Gruenbacherff87b372005-07-07 17:57:00 -07002886 if (ei->i_extra_isize)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002887 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
2888
2889 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
2890 rc = ext3_journal_dirty_metadata(handle, bh);
2891 if (!err)
2892 err = rc;
2893 ei->i_state &= ~EXT3_STATE_NEW;
2894
2895out_brelse:
2896 brelse (bh);
2897 ext3_std_error(inode->i_sb, err);
2898 return err;
2899}
2900
2901/*
2902 * ext3_write_inode()
2903 *
2904 * We are called from a few places:
2905 *
2906 * - Within generic_file_write() for O_SYNC files.
2907 * Here, there will be no transaction running. We wait for any running
2908 * trasnaction to commit.
2909 *
2910 * - Within sys_sync(), kupdate and such.
2911 * We wait on commit, if tol to.
2912 *
2913 * - Within prune_icache() (PF_MEMALLOC == true)
2914 * Here we simply return. We can't afford to block kswapd on the
2915 * journal commit.
2916 *
2917 * In all cases it is actually safe for us to return without doing anything,
2918 * because the inode has been copied into a raw inode buffer in
2919 * ext3_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
2920 * knfsd.
2921 *
2922 * Note that we are absolutely dependent upon all inode dirtiers doing the
2923 * right thing: they *must* call mark_inode_dirty() after dirtying info in
2924 * which we are interested.
2925 *
2926 * It would be a bug for them to not do this. The code:
2927 *
2928 * mark_inode_dirty(inode)
2929 * stuff();
2930 * inode->i_size = expr;
2931 *
2932 * is in error because a kswapd-driven write_inode() could occur while
2933 * `stuff()' is running, and the new i_size will be lost. Plus the inode
2934 * will no longer be on the superblock's dirty inode list.
2935 */
2936int ext3_write_inode(struct inode *inode, int wait)
2937{
2938 if (current->flags & PF_MEMALLOC)
2939 return 0;
2940
2941 if (ext3_journal_current_handle()) {
2942 jbd_debug(0, "called recursively, non-PF_MEMALLOC!\n");
2943 dump_stack();
2944 return -EIO;
2945 }
2946
2947 if (!wait)
2948 return 0;
2949
2950 return ext3_force_commit(inode->i_sb);
2951}
2952
2953/*
2954 * ext3_setattr()
2955 *
2956 * Called from notify_change.
2957 *
2958 * We want to trap VFS attempts to truncate the file as soon as
2959 * possible. In particular, we want to make sure that when the VFS
2960 * shrinks i_size, we put the inode on the orphan list and modify
2961 * i_disksize immediately, so that during the subsequent flushing of
2962 * dirty pages and freeing of disk blocks, we can guarantee that any
2963 * commit will leave the blocks being flushed in an unused state on
2964 * disk. (On recovery, the inode will get truncated and the blocks will
2965 * be freed, so we have a strong guarantee that no future commit will
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002966 * leave these blocks visible to the user.)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002967 *
2968 * Called with inode->sem down.
2969 */
2970int ext3_setattr(struct dentry *dentry, struct iattr *attr)
2971{
2972 struct inode *inode = dentry->d_inode;
2973 int error, rc = 0;
2974 const unsigned int ia_valid = attr->ia_valid;
2975
2976 error = inode_change_ok(inode, attr);
2977 if (error)
2978 return error;
2979
2980 if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
2981 (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
2982 handle_t *handle;
2983
2984 /* (user+group)*(old+new) structure, inode write (sb,
2985 * inode block, ? - but truncate inode update has it) */
Jan Kara1f545872005-06-23 22:01:04 -07002986 handle = ext3_journal_start(inode, 2*(EXT3_QUOTA_INIT_BLOCKS(inode->i_sb)+
2987 EXT3_QUOTA_DEL_BLOCKS(inode->i_sb))+3);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002988 if (IS_ERR(handle)) {
2989 error = PTR_ERR(handle);
2990 goto err_out;
2991 }
2992 error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0;
2993 if (error) {
2994 ext3_journal_stop(handle);
2995 return error;
2996 }
2997 /* Update corresponding info in inode so that everything is in
2998 * one transaction */
2999 if (attr->ia_valid & ATTR_UID)
3000 inode->i_uid = attr->ia_uid;
3001 if (attr->ia_valid & ATTR_GID)
3002 inode->i_gid = attr->ia_gid;
3003 error = ext3_mark_inode_dirty(handle, inode);
3004 ext3_journal_stop(handle);
3005 }
3006
3007 if (S_ISREG(inode->i_mode) &&
3008 attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
3009 handle_t *handle;
3010
3011 handle = ext3_journal_start(inode, 3);
3012 if (IS_ERR(handle)) {
3013 error = PTR_ERR(handle);
3014 goto err_out;
3015 }
3016
3017 error = ext3_orphan_add(handle, inode);
3018 EXT3_I(inode)->i_disksize = attr->ia_size;
3019 rc = ext3_mark_inode_dirty(handle, inode);
3020 if (!error)
3021 error = rc;
3022 ext3_journal_stop(handle);
3023 }
3024
3025 rc = inode_setattr(inode, attr);
3026
3027 /* If inode_setattr's call to ext3_truncate failed to get a
3028 * transaction handle at all, we need to clean up the in-core
3029 * orphan list manually. */
3030 if (inode->i_nlink)
3031 ext3_orphan_del(NULL, inode);
3032
3033 if (!rc && (ia_valid & ATTR_MODE))
3034 rc = ext3_acl_chmod(inode);
3035
3036err_out:
3037 ext3_std_error(inode->i_sb, error);
3038 if (!error)
3039 error = rc;
3040 return error;
3041}
3042
3043
3044/*
Andrew Mortond6859bf2006-03-26 01:38:03 -08003045 * How many blocks doth make a writepage()?
Linus Torvalds1da177e2005-04-16 15:20:36 -07003046 *
3047 * With N blocks per page, it may be:
3048 * N data blocks
3049 * 2 indirect block
3050 * 2 dindirect
3051 * 1 tindirect
3052 * N+5 bitmap blocks (from the above)
3053 * N+5 group descriptor summary blocks
3054 * 1 inode block
3055 * 1 superblock.
3056 * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quote files
3057 *
3058 * 3 * (N + 5) + 2 + 2 * EXT3_SINGLEDATA_TRANS_BLOCKS
3059 *
3060 * With ordered or writeback data it's the same, less the N data blocks.
3061 *
3062 * If the inode's direct blocks can hold an integral number of pages then a
3063 * page cannot straddle two indirect blocks, and we can only touch one indirect
3064 * and dindirect block, and the "5" above becomes "3".
3065 *
3066 * This still overestimates under most circumstances. If we were to pass the
3067 * start and end offsets in here as well we could do block_to_path() on each
3068 * block and work out the exact number of indirects which are touched. Pah.
3069 */
3070
3071static int ext3_writepage_trans_blocks(struct inode *inode)
3072{
3073 int bpp = ext3_journal_blocks_per_page(inode);
3074 int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3;
3075 int ret;
3076
3077 if (ext3_should_journal_data(inode))
3078 ret = 3 * (bpp + indirects) + 2;
3079 else
3080 ret = 2 * (bpp + indirects) + 2;
3081
3082#ifdef CONFIG_QUOTA
3083 /* We know that structure was already allocated during DQUOT_INIT so
3084 * we will be updating only the data blocks + inodes */
Jan Kara1f545872005-06-23 22:01:04 -07003085 ret += 2*EXT3_QUOTA_TRANS_BLOCKS(inode->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003086#endif
3087
3088 return ret;
3089}
3090
3091/*
3092 * The caller must have previously called ext3_reserve_inode_write().
3093 * Give this, we know that the caller already has write access to iloc->bh.
3094 */
3095int ext3_mark_iloc_dirty(handle_t *handle,
3096 struct inode *inode, struct ext3_iloc *iloc)
3097{
3098 int err = 0;
3099
3100 /* the do_update_inode consumes one bh->b_count */
3101 get_bh(iloc->bh);
3102
3103 /* ext3_do_update_inode() does journal_dirty_metadata */
3104 err = ext3_do_update_inode(handle, inode, iloc);
3105 put_bh(iloc->bh);
3106 return err;
3107}
3108
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003109/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003110 * On success, We end up with an outstanding reference count against
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003111 * iloc->bh. This _must_ be cleaned up later.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003112 */
3113
3114int
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003115ext3_reserve_inode_write(handle_t *handle, struct inode *inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003116 struct ext3_iloc *iloc)
3117{
3118 int err = 0;
3119 if (handle) {
3120 err = ext3_get_inode_loc(inode, iloc);
3121 if (!err) {
3122 BUFFER_TRACE(iloc->bh, "get_write_access");
3123 err = ext3_journal_get_write_access(handle, iloc->bh);
3124 if (err) {
3125 brelse(iloc->bh);
3126 iloc->bh = NULL;
3127 }
3128 }
3129 }
3130 ext3_std_error(inode->i_sb, err);
3131 return err;
3132}
3133
3134/*
Andrew Mortond6859bf2006-03-26 01:38:03 -08003135 * What we do here is to mark the in-core inode as clean with respect to inode
3136 * dirtiness (it may still be data-dirty).
Linus Torvalds1da177e2005-04-16 15:20:36 -07003137 * This means that the in-core inode may be reaped by prune_icache
3138 * without having to perform any I/O. This is a very good thing,
3139 * because *any* task may call prune_icache - even ones which
3140 * have a transaction open against a different journal.
3141 *
3142 * Is this cheating? Not really. Sure, we haven't written the
3143 * inode out, but prune_icache isn't a user-visible syncing function.
3144 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
3145 * we start and wait on commits.
3146 *
3147 * Is this efficient/effective? Well, we're being nice to the system
3148 * by cleaning up our inodes proactively so they can be reaped
3149 * without I/O. But we are potentially leaving up to five seconds'
3150 * worth of inodes floating about which prune_icache wants us to
3151 * write out. One way to fix that would be to get prune_icache()
3152 * to do a write_super() to free up some memory. It has the desired
3153 * effect.
3154 */
3155int ext3_mark_inode_dirty(handle_t *handle, struct inode *inode)
3156{
3157 struct ext3_iloc iloc;
3158 int err;
3159
3160 might_sleep();
3161 err = ext3_reserve_inode_write(handle, inode, &iloc);
3162 if (!err)
3163 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
3164 return err;
3165}
3166
3167/*
Andrew Mortond6859bf2006-03-26 01:38:03 -08003168 * ext3_dirty_inode() is called from __mark_inode_dirty()
Linus Torvalds1da177e2005-04-16 15:20:36 -07003169 *
3170 * We're really interested in the case where a file is being extended.
3171 * i_size has been changed by generic_commit_write() and we thus need
3172 * to include the updated inode in the current transaction.
3173 *
3174 * Also, DQUOT_ALLOC_SPACE() will always dirty the inode when blocks
3175 * are allocated to the file.
3176 *
3177 * If the inode is marked synchronous, we don't honour that here - doing
3178 * so would cause a commit on atime updates, which we don't bother doing.
3179 * We handle synchronous inodes at the highest possible level.
3180 */
3181void ext3_dirty_inode(struct inode *inode)
3182{
3183 handle_t *current_handle = ext3_journal_current_handle();
3184 handle_t *handle;
3185
3186 handle = ext3_journal_start(inode, 2);
3187 if (IS_ERR(handle))
3188 goto out;
3189 if (current_handle &&
3190 current_handle->h_transaction != handle->h_transaction) {
3191 /* This task has a transaction open against a different fs */
3192 printk(KERN_EMERG "%s: transactions do not match!\n",
3193 __FUNCTION__);
3194 } else {
3195 jbd_debug(5, "marking dirty. outer handle=%p\n",
3196 current_handle);
3197 ext3_mark_inode_dirty(handle, inode);
3198 }
3199 ext3_journal_stop(handle);
3200out:
3201 return;
3202}
3203
Andrew Mortond6859bf2006-03-26 01:38:03 -08003204#if 0
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003205/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003206 * Bind an inode's backing buffer_head into this transaction, to prevent
3207 * it from being flushed to disk early. Unlike
3208 * ext3_reserve_inode_write, this leaves behind no bh reference and
3209 * returns no iloc structure, so the caller needs to repeat the iloc
3210 * lookup to mark the inode dirty later.
3211 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08003212static int ext3_pin_inode(handle_t *handle, struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003213{
3214 struct ext3_iloc iloc;
3215
3216 int err = 0;
3217 if (handle) {
3218 err = ext3_get_inode_loc(inode, &iloc);
3219 if (!err) {
3220 BUFFER_TRACE(iloc.bh, "get_write_access");
3221 err = journal_get_write_access(handle, iloc.bh);
3222 if (!err)
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003223 err = ext3_journal_dirty_metadata(handle,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003224 iloc.bh);
3225 brelse(iloc.bh);
3226 }
3227 }
3228 ext3_std_error(inode->i_sb, err);
3229 return err;
3230}
3231#endif
3232
3233int ext3_change_inode_journal_flag(struct inode *inode, int val)
3234{
3235 journal_t *journal;
3236 handle_t *handle;
3237 int err;
3238
3239 /*
3240 * We have to be very careful here: changing a data block's
3241 * journaling status dynamically is dangerous. If we write a
3242 * data block to the journal, change the status and then delete
3243 * that block, we risk forgetting to revoke the old log record
3244 * from the journal and so a subsequent replay can corrupt data.
3245 * So, first we make sure that the journal is empty and that
3246 * nobody is changing anything.
3247 */
3248
3249 journal = EXT3_JOURNAL(inode);
3250 if (is_journal_aborted(journal) || IS_RDONLY(inode))
3251 return -EROFS;
3252
3253 journal_lock_updates(journal);
3254 journal_flush(journal);
3255
3256 /*
3257 * OK, there are no updates running now, and all cached data is
3258 * synced to disk. We are now in a completely consistent state
3259 * which doesn't have anything in the journal, and we know that
3260 * no filesystem updates are running, so it is safe to modify
3261 * the inode's in-core data-journaling state flag now.
3262 */
3263
3264 if (val)
3265 EXT3_I(inode)->i_flags |= EXT3_JOURNAL_DATA_FL;
3266 else
3267 EXT3_I(inode)->i_flags &= ~EXT3_JOURNAL_DATA_FL;
3268 ext3_set_aops(inode);
3269
3270 journal_unlock_updates(journal);
3271
3272 /* Finally we can mark the inode as dirty. */
3273
3274 handle = ext3_journal_start(inode, 1);
3275 if (IS_ERR(handle))
3276 return PTR_ERR(handle);
3277
3278 err = ext3_mark_inode_dirty(handle, inode);
3279 handle->h_sync = 1;
3280 ext3_journal_stop(handle);
3281 ext3_std_error(inode->i_sb, err);
3282
3283 return err;
3284}