blob: 6ae4ecf3ce40b646da679ba6b2a1ecb6149e7e00 [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>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <linux/highuid.h>
31#include <linux/pagemap.h>
32#include <linux/quotaops.h>
33#include <linux/string.h>
34#include <linux/buffer_head.h>
35#include <linux/writeback.h>
36#include <linux/mpage.h>
37#include <linux/uio.h>
Jens Axboecaa38fb2006-07-23 01:41:26 +020038#include <linux/bio.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070039#include "xattr.h"
40#include "acl.h"
41
42static int ext3_writepage_trans_blocks(struct inode *inode);
43
44/*
45 * Test whether an inode is a fast symlink.
46 */
Andrew Mortond6859bf2006-03-26 01:38:03 -080047static int ext3_inode_is_fast_symlink(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -070048{
49 int ea_blocks = EXT3_I(inode)->i_file_acl ?
50 (inode->i_sb->s_blocksize >> 9) : 0;
51
Andrew Mortond6859bf2006-03-26 01:38:03 -080052 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070053}
54
Andrew Mortond6859bf2006-03-26 01:38:03 -080055/*
56 * The ext3 forget function must perform a revoke if we are freeing data
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 * which has been journaled. Metadata (eg. indirect blocks) must be
Mingming Caoae6ddcc2006-09-27 01:49:27 -070058 * revoked in all cases.
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 *
60 * "bh" may be NULL: a metadata block may have been freed from memory
61 * but there may still be a record of it in the journal, and that record
62 * still needs to be revoked.
63 */
Andrew Mortond6859bf2006-03-26 01:38:03 -080064int ext3_forget(handle_t *handle, int is_metadata, struct inode *inode,
Mingming Cao1c2bf372006-06-25 05:48:06 -070065 struct buffer_head *bh, ext3_fsblk_t blocknr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070066{
67 int err;
68
69 might_sleep();
70
71 BUFFER_TRACE(bh, "enter");
72
73 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
74 "data mode %lx\n",
75 bh, is_metadata, inode->i_mode,
76 test_opt(inode->i_sb, DATA_FLAGS));
77
78 /* Never use the revoke function if we are doing full data
79 * journaling: there is no need to, and a V1 superblock won't
80 * support it. Otherwise, only skip the revoke on un-journaled
81 * data blocks. */
82
83 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ||
84 (!is_metadata && !ext3_should_journal_data(inode))) {
85 if (bh) {
86 BUFFER_TRACE(bh, "call journal_forget");
87 return ext3_journal_forget(handle, bh);
88 }
89 return 0;
90 }
91
92 /*
93 * data!=journal && (is_metadata || should_journal_data(inode))
94 */
95 BUFFER_TRACE(bh, "call ext3_journal_revoke");
96 err = ext3_journal_revoke(handle, blocknr, bh);
97 if (err)
Harvey Harrisone05b6b52008-04-28 02:16:15 -070098 ext3_abort(inode->i_sb, __func__,
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 "error %d when attempting revoke", err);
100 BUFFER_TRACE(bh, "exit");
101 return err;
102}
103
104/*
Andrew Mortond6859bf2006-03-26 01:38:03 -0800105 * Work out how many blocks we need to proceed with the next chunk of a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 * truncate transaction.
107 */
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700108static unsigned long blocks_for_truncate(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109{
110 unsigned long needed;
111
112 needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
113
114 /* Give ourselves just enough room to cope with inodes in which
115 * i_blocks is corrupt: we've seen disk corruptions in the past
116 * which resulted in random data in an inode which looked enough
117 * like a regular file for ext3 to try to delete it. Things
118 * will go a bit crazy if that happens, but at least we should
119 * try not to panic the whole kernel. */
120 if (needed < 2)
121 needed = 2;
122
123 /* But we need to bound the transaction so we don't overflow the
124 * journal. */
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700125 if (needed > EXT3_MAX_TRANS_DATA)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 needed = EXT3_MAX_TRANS_DATA;
127
Jan Kara1f545872005-06-23 22:01:04 -0700128 return EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129}
130
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700131/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 * Truncate transactions can be complex and absolutely huge. So we need to
133 * be able to restart the transaction at a conventient checkpoint to make
134 * sure we don't overflow the journal.
135 *
136 * start_transaction gets us a new handle for a truncate transaction,
137 * and extend_transaction tries to extend the existing one a bit. If
138 * extend fails, we need to propagate the failure up and restart the
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700139 * transaction in the top-level truncate loop. --sct
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 */
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700141static handle_t *start_transaction(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142{
143 handle_t *result;
144
145 result = ext3_journal_start(inode, blocks_for_truncate(inode));
146 if (!IS_ERR(result))
147 return result;
148
149 ext3_std_error(inode->i_sb, PTR_ERR(result));
150 return result;
151}
152
153/*
154 * Try to extend this transaction for the purposes of truncation.
155 *
156 * Returns 0 if we managed to create more room. If we can't create more
157 * room, and the transaction must be restarted we return 1.
158 */
159static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
160{
161 if (handle->h_buffer_credits > EXT3_RESERVE_TRANS_BLOCKS)
162 return 0;
163 if (!ext3_journal_extend(handle, blocks_for_truncate(inode)))
164 return 0;
165 return 1;
166}
167
168/*
169 * Restart the transaction associated with *handle. This does a commit,
170 * so before we call here everything must be consistently dirtied against
171 * this transaction.
172 */
173static int ext3_journal_test_restart(handle_t *handle, struct inode *inode)
174{
175 jbd_debug(2, "restarting handle %p\n", handle);
176 return ext3_journal_restart(handle, blocks_for_truncate(inode));
177}
178
179/*
180 * Called at the last iput() if i_nlink is zero.
181 */
182void ext3_delete_inode (struct inode * inode)
183{
184 handle_t *handle;
185
Mark Fashehfef26652005-09-09 13:01:31 -0700186 truncate_inode_pages(&inode->i_data, 0);
187
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 if (is_bad_inode(inode))
189 goto no_delete;
190
191 handle = start_transaction(inode);
192 if (IS_ERR(handle)) {
Andrew Mortond6859bf2006-03-26 01:38:03 -0800193 /*
194 * If we're going to skip the normal cleanup, we still need to
195 * make sure that the in-core orphan linked list is properly
196 * cleaned up.
197 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198 ext3_orphan_del(NULL, inode);
199 goto no_delete;
200 }
201
202 if (IS_SYNC(inode))
203 handle->h_sync = 1;
204 inode->i_size = 0;
205 if (inode->i_blocks)
206 ext3_truncate(inode);
207 /*
208 * Kill off the orphan record which ext3_truncate created.
209 * AKPM: I think this can be inside the above `if'.
210 * Note that ext3_orphan_del() has to be able to cope with the
211 * deletion of a non-existent orphan - this is because we don't
212 * know if ext3_truncate() actually created an orphan record.
213 * (Well, we could do this if we need to, but heck - it works)
214 */
215 ext3_orphan_del(handle, inode);
216 EXT3_I(inode)->i_dtime = get_seconds();
217
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700218 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 * One subtle ordering requirement: if anything has gone wrong
220 * (transaction abort, IO errors, whatever), then we can still
221 * do these next steps (the fs will already have been marked as
222 * having errors), but we can't free the inode if the mark_dirty
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700223 * fails.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 */
225 if (ext3_mark_inode_dirty(handle, inode))
226 /* If that failed, just do the required in-core inode clear. */
227 clear_inode(inode);
228 else
229 ext3_free_inode(handle, inode);
230 ext3_journal_stop(handle);
231 return;
232no_delete:
233 clear_inode(inode); /* We must guarantee clearing of inode... */
234}
235
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236typedef struct {
237 __le32 *p;
238 __le32 key;
239 struct buffer_head *bh;
240} Indirect;
241
242static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
243{
244 p->key = *(p->p = v);
245 p->bh = bh;
246}
247
Andrew Mortond6859bf2006-03-26 01:38:03 -0800248static int verify_chain(Indirect *from, Indirect *to)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249{
250 while (from <= to && from->key == *from->p)
251 from++;
252 return (from > to);
253}
254
255/**
256 * ext3_block_to_path - parse the block number into array of offsets
257 * @inode: inode in question (we are only interested in its superblock)
258 * @i_block: block number to be parsed
259 * @offsets: array to store the offsets in
260 * @boundary: set this non-zero if the referred-to block is likely to be
261 * followed (on disk) by an indirect block.
262 *
263 * To store the locations of file's data ext3 uses a data structure common
264 * for UNIX filesystems - tree of pointers anchored in the inode, with
265 * data blocks at leaves and indirect blocks in intermediate nodes.
266 * This function translates the block number into path in that tree -
267 * return value is the path length and @offsets[n] is the offset of
268 * pointer to (n+1)th node in the nth one. If @block is out of range
269 * (negative or too large) warning is printed and zero returned.
270 *
271 * Note: function doesn't find node addresses, so no IO is needed. All
272 * we need to know is the capacity of indirect blocks (taken from the
273 * inode->i_sb).
274 */
275
276/*
277 * Portability note: the last comparison (check that we fit into triple
278 * indirect block) is spelled differently, because otherwise on an
279 * architecture with 32-bit longs and 8Kb pages we might get into trouble
280 * if our filesystem had 8Kb blocks. We might use long long, but that would
281 * kill us on x86. Oh, well, at least the sign propagation does not matter -
282 * i_block would have to be negative in the very beginning, so we would not
283 * get there at all.
284 */
285
286static int ext3_block_to_path(struct inode *inode,
287 long i_block, int offsets[4], int *boundary)
288{
289 int ptrs = EXT3_ADDR_PER_BLOCK(inode->i_sb);
290 int ptrs_bits = EXT3_ADDR_PER_BLOCK_BITS(inode->i_sb);
291 const long direct_blocks = EXT3_NDIR_BLOCKS,
292 indirect_blocks = ptrs,
293 double_blocks = (1 << (ptrs_bits * 2));
294 int n = 0;
295 int final = 0;
296
297 if (i_block < 0) {
298 ext3_warning (inode->i_sb, "ext3_block_to_path", "block < 0");
299 } else if (i_block < direct_blocks) {
300 offsets[n++] = i_block;
301 final = direct_blocks;
302 } else if ( (i_block -= direct_blocks) < indirect_blocks) {
303 offsets[n++] = EXT3_IND_BLOCK;
304 offsets[n++] = i_block;
305 final = ptrs;
306 } else if ((i_block -= indirect_blocks) < double_blocks) {
307 offsets[n++] = EXT3_DIND_BLOCK;
308 offsets[n++] = i_block >> ptrs_bits;
309 offsets[n++] = i_block & (ptrs - 1);
310 final = ptrs;
311 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
312 offsets[n++] = EXT3_TIND_BLOCK;
313 offsets[n++] = i_block >> (ptrs_bits * 2);
314 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
315 offsets[n++] = i_block & (ptrs - 1);
316 final = ptrs;
317 } else {
Andrew Mortond6859bf2006-03-26 01:38:03 -0800318 ext3_warning(inode->i_sb, "ext3_block_to_path", "block > big");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 }
320 if (boundary)
Mingming Cao89747d32006-03-26 01:37:55 -0800321 *boundary = final - 1 - (i_block & (ptrs - 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 return n;
323}
324
325/**
326 * ext3_get_branch - read the chain of indirect blocks leading to data
327 * @inode: inode in question
328 * @depth: depth of the chain (1 - direct pointer, etc.)
329 * @offsets: offsets of pointers in inode/indirect blocks
330 * @chain: place to store the result
331 * @err: here we store the error value
332 *
333 * Function fills the array of triples <key, p, bh> and returns %NULL
334 * if everything went OK or the pointer to the last filled triple
335 * (incomplete one) otherwise. Upon the return chain[i].key contains
336 * the number of (i+1)-th block in the chain (as it is stored in memory,
337 * i.e. little-endian 32-bit), chain[i].p contains the address of that
338 * number (it points into struct inode for i==0 and into the bh->b_data
339 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
340 * block for i>0 and NULL for i==0. In other words, it holds the block
341 * numbers of the chain, addresses they were taken from (and where we can
342 * verify that chain did not change) and buffer_heads hosting these
343 * numbers.
344 *
345 * Function stops when it stumbles upon zero pointer (absent block)
346 * (pointer to last triple returned, *@err == 0)
347 * or when it gets an IO error reading an indirect block
348 * (ditto, *@err == -EIO)
349 * or when it notices that chain had been changed while it was reading
350 * (ditto, *@err == -EAGAIN)
351 * or when it reads all @depth-1 indirect blocks successfully and finds
352 * the whole chain, all way to the data (returns %NULL, *err == 0).
353 */
354static Indirect *ext3_get_branch(struct inode *inode, int depth, int *offsets,
355 Indirect chain[4], int *err)
356{
357 struct super_block *sb = inode->i_sb;
358 Indirect *p = chain;
359 struct buffer_head *bh;
360
361 *err = 0;
362 /* i_data is not going away, no lock needed */
363 add_chain (chain, NULL, EXT3_I(inode)->i_data + *offsets);
364 if (!p->key)
365 goto no_block;
366 while (--depth) {
367 bh = sb_bread(sb, le32_to_cpu(p->key));
368 if (!bh)
369 goto failure;
370 /* Reader: pointers */
371 if (!verify_chain(chain, p))
372 goto changed;
373 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
374 /* Reader: end */
375 if (!p->key)
376 goto no_block;
377 }
378 return NULL;
379
380changed:
381 brelse(bh);
382 *err = -EAGAIN;
383 goto no_block;
384failure:
385 *err = -EIO;
386no_block:
387 return p;
388}
389
390/**
391 * ext3_find_near - find a place for allocation with sufficient locality
392 * @inode: owner
393 * @ind: descriptor of indirect block.
394 *
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000395 * This function returns the preferred place for block allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 * It is used when heuristic for sequential allocation fails.
397 * Rules are:
398 * + if there is a block to the left of our position - allocate near it.
399 * + if pointer will live in indirect block - allocate near that block.
400 * + if pointer will live in inode - allocate in the same
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700401 * cylinder group.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 *
403 * In the latter case we colour the starting block by the callers PID to
404 * prevent it from clashing with concurrent allocations for a different inode
405 * in the same block group. The PID is used here so that functionally related
406 * files will be close-by on-disk.
407 *
408 * Caller must make sure that @ind is valid and will stay that way.
409 */
Mingming Cao43d23f92006-06-25 05:48:07 -0700410static ext3_fsblk_t ext3_find_near(struct inode *inode, Indirect *ind)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700411{
412 struct ext3_inode_info *ei = EXT3_I(inode);
413 __le32 *start = ind->bh ? (__le32*) ind->bh->b_data : ei->i_data;
414 __le32 *p;
Mingming Cao43d23f92006-06-25 05:48:07 -0700415 ext3_fsblk_t bg_start;
416 ext3_grpblk_t colour;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417
418 /* Try to find previous block */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800419 for (p = ind->p - 1; p >= start; p--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 if (*p)
421 return le32_to_cpu(*p);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800422 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423
424 /* No such thing, so let's try location of indirect block */
425 if (ind->bh)
426 return ind->bh->b_blocknr;
427
428 /*
Andrew Mortond6859bf2006-03-26 01:38:03 -0800429 * It is going to be referred to from the inode itself? OK, just put it
430 * into the same cylinder group then.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 */
Mingming Cao43d23f92006-06-25 05:48:07 -0700432 bg_start = ext3_group_first_block_no(inode->i_sb, ei->i_block_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 colour = (current->pid % 16) *
434 (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
435 return bg_start + colour;
436}
437
438/**
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000439 * ext3_find_goal - find a preferred place for allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 * @inode: owner
441 * @block: block we want
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 * @partial: pointer to the last triple within a chain
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 *
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000444 * Normally this function find the preferred place for block allocation,
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800445 * returns it.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 */
447
Mingming Cao43d23f92006-06-25 05:48:07 -0700448static ext3_fsblk_t ext3_find_goal(struct inode *inode, long block,
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800449 Indirect *partial)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450{
Andrew Mortond6859bf2006-03-26 01:38:03 -0800451 struct ext3_block_alloc_info *block_i;
452
453 block_i = EXT3_I(inode)->i_block_alloc_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454
455 /*
456 * try the heuristic for sequential allocation,
457 * failing that at least try to get decent locality.
458 */
459 if (block_i && (block == block_i->last_alloc_logical_block + 1)
460 && (block_i->last_alloc_physical_block != 0)) {
Mingming Caofe55c452005-05-01 08:59:20 -0700461 return block_i->last_alloc_physical_block + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 }
463
Mingming Caofe55c452005-05-01 08:59:20 -0700464 return ext3_find_near(inode, partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465}
Andrew Mortond6859bf2006-03-26 01:38:03 -0800466
Mingming Caob47b2472006-03-26 01:37:56 -0800467/**
468 * ext3_blks_to_allocate: Look up the block map and count the number
469 * of direct blocks need to be allocated for the given branch.
470 *
Dave Kleikampe9ad5622006-09-27 01:49:35 -0700471 * @branch: chain of indirect blocks
Mingming Caob47b2472006-03-26 01:37:56 -0800472 * @k: number of blocks need for indirect blocks
473 * @blks: number of data blocks to be mapped.
474 * @blocks_to_boundary: the offset in the indirect block
475 *
476 * return the total number of blocks to be allocate, including the
477 * direct and indirect blocks.
478 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800479static int ext3_blks_to_allocate(Indirect *branch, int k, unsigned long blks,
Mingming Caob47b2472006-03-26 01:37:56 -0800480 int blocks_to_boundary)
481{
482 unsigned long count = 0;
483
484 /*
485 * Simple case, [t,d]Indirect block(s) has not allocated yet
486 * then it's clear blocks on that path have not allocated
487 */
488 if (k > 0) {
Andrew Mortond6859bf2006-03-26 01:38:03 -0800489 /* right now we don't handle cross boundary allocation */
Mingming Caob47b2472006-03-26 01:37:56 -0800490 if (blks < blocks_to_boundary + 1)
491 count += blks;
492 else
493 count += blocks_to_boundary + 1;
494 return count;
495 }
496
497 count++;
498 while (count < blks && count <= blocks_to_boundary &&
499 le32_to_cpu(*(branch[0].p + count)) == 0) {
500 count++;
501 }
502 return count;
503}
504
505/**
506 * ext3_alloc_blocks: multiple allocate blocks needed for a branch
507 * @indirect_blks: the number of blocks need to allocate for indirect
508 * blocks
509 *
510 * @new_blocks: on return it will store the new block numbers for
511 * the indirect blocks(if needed) and the first direct block,
512 * @blks: on return it will store the total number of allocated
513 * direct blocks
514 */
515static int ext3_alloc_blocks(handle_t *handle, struct inode *inode,
Mingming Cao43d23f92006-06-25 05:48:07 -0700516 ext3_fsblk_t goal, int indirect_blks, int blks,
517 ext3_fsblk_t new_blocks[4], int *err)
Mingming Caob47b2472006-03-26 01:37:56 -0800518{
519 int target, i;
520 unsigned long count = 0;
521 int index = 0;
Mingming Cao43d23f92006-06-25 05:48:07 -0700522 ext3_fsblk_t current_block = 0;
Mingming Caob47b2472006-03-26 01:37:56 -0800523 int ret = 0;
524
525 /*
526 * Here we try to allocate the requested multiple blocks at once,
527 * on a best-effort basis.
528 * To build a branch, we should allocate blocks for
529 * the indirect blocks(if not allocated yet), and at least
530 * the first direct block of this branch. That's the
531 * minimum number of blocks need to allocate(required)
532 */
533 target = blks + indirect_blks;
534
535 while (1) {
536 count = target;
537 /* allocating blocks for indirect blocks and direct blocks */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800538 current_block = ext3_new_blocks(handle,inode,goal,&count,err);
Mingming Caob47b2472006-03-26 01:37:56 -0800539 if (*err)
540 goto failed_out;
541
542 target -= count;
543 /* allocate blocks for indirect blocks */
544 while (index < indirect_blks && count) {
545 new_blocks[index++] = current_block++;
546 count--;
547 }
548
549 if (count > 0)
550 break;
551 }
552
553 /* save the new block number for the first direct block */
554 new_blocks[index] = current_block;
555
556 /* total number of blocks allocated for direct blocks */
557 ret = count;
558 *err = 0;
559 return ret;
560failed_out:
561 for (i = 0; i <index; i++)
562 ext3_free_blocks(handle, inode, new_blocks[i], 1);
563 return ret;
564}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565
566/**
567 * ext3_alloc_branch - allocate and set up a chain of blocks.
568 * @inode: owner
Mingming Caob47b2472006-03-26 01:37:56 -0800569 * @indirect_blks: number of allocated indirect blocks
570 * @blks: number of allocated direct blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -0700571 * @offsets: offsets (in the blocks) to store the pointers to next.
572 * @branch: place to store the chain in.
573 *
Mingming Caob47b2472006-03-26 01:37:56 -0800574 * This function allocates blocks, zeroes out all but the last one,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700575 * links them into chain and (if we are synchronous) writes them to disk.
576 * In other words, it prepares a branch that can be spliced onto the
577 * inode. It stores the information about that chain in the branch[], in
578 * the same format as ext3_get_branch() would do. We are calling it after
579 * we had read the existing part of chain and partial points to the last
580 * triple of that (one with zero ->key). Upon the exit we have the same
Glauber de Oliveira Costa5b116872005-10-30 15:02:48 -0800581 * picture as after the successful ext3_get_block(), except that in one
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 * place chain is disconnected - *branch->p is still zero (we did not
583 * set the last link), but branch->key contains the number that should
584 * be placed into *branch->p to fill that gap.
585 *
586 * If allocation fails we free all blocks we've allocated (and forget
587 * their buffer_heads) and return the error value the from failed
588 * ext3_alloc_block() (normally -ENOSPC). Otherwise we set the chain
589 * as described above and return 0.
590 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
Mingming Cao43d23f92006-06-25 05:48:07 -0700592 int indirect_blks, int *blks, ext3_fsblk_t goal,
Mingming Caob47b2472006-03-26 01:37:56 -0800593 int *offsets, Indirect *branch)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594{
595 int blocksize = inode->i_sb->s_blocksize;
Mingming Caob47b2472006-03-26 01:37:56 -0800596 int i, n = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700597 int err = 0;
Mingming Caob47b2472006-03-26 01:37:56 -0800598 struct buffer_head *bh;
599 int num;
Mingming Cao43d23f92006-06-25 05:48:07 -0700600 ext3_fsblk_t new_blocks[4];
601 ext3_fsblk_t current_block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700602
Mingming Caob47b2472006-03-26 01:37:56 -0800603 num = ext3_alloc_blocks(handle, inode, goal, indirect_blks,
604 *blks, new_blocks, &err);
605 if (err)
606 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607
Mingming Caob47b2472006-03-26 01:37:56 -0800608 branch[0].key = cpu_to_le32(new_blocks[0]);
609 /*
610 * metadata blocks and data blocks are allocated.
611 */
612 for (n = 1; n <= indirect_blks; n++) {
613 /*
614 * Get buffer_head for parent block, zero it out
615 * and set the pointer to new one, then send
616 * parent to disk.
617 */
618 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
619 branch[n].bh = bh;
620 lock_buffer(bh);
621 BUFFER_TRACE(bh, "call get_create_access");
622 err = ext3_journal_get_create_access(handle, bh);
623 if (err) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 unlock_buffer(bh);
Mingming Caob47b2472006-03-26 01:37:56 -0800625 brelse(bh);
626 goto failed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700627 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700628
Mingming Caob47b2472006-03-26 01:37:56 -0800629 memset(bh->b_data, 0, blocksize);
630 branch[n].p = (__le32 *) bh->b_data + offsets[n];
631 branch[n].key = cpu_to_le32(new_blocks[n]);
632 *branch[n].p = branch[n].key;
633 if ( n == indirect_blks) {
634 current_block = new_blocks[n];
635 /*
636 * End of chain, update the last new metablock of
637 * the chain to point to the new allocated
638 * data blocks numbers
639 */
640 for (i=1; i < num; i++)
641 *(branch[n].p + i) = cpu_to_le32(++current_block);
642 }
643 BUFFER_TRACE(bh, "marking uptodate");
644 set_buffer_uptodate(bh);
645 unlock_buffer(bh);
646
647 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
648 err = ext3_journal_dirty_metadata(handle, bh);
649 if (err)
650 goto failed;
651 }
652 *blks = num;
653 return err;
654failed:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 /* Allocation failed, free what we already allocated */
Mingming Caob47b2472006-03-26 01:37:56 -0800656 for (i = 1; i <= n ; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 BUFFER_TRACE(branch[i].bh, "call journal_forget");
658 ext3_journal_forget(handle, branch[i].bh);
659 }
Mingming Caob47b2472006-03-26 01:37:56 -0800660 for (i = 0; i <indirect_blks; i++)
661 ext3_free_blocks(handle, inode, new_blocks[i], 1);
662
663 ext3_free_blocks(handle, inode, new_blocks[i], num);
664
Linus Torvalds1da177e2005-04-16 15:20:36 -0700665 return err;
666}
667
668/**
Andrew Mortond6859bf2006-03-26 01:38:03 -0800669 * ext3_splice_branch - splice the allocated branch onto inode.
670 * @inode: owner
671 * @block: (logical) number of block we are adding
672 * @chain: chain of indirect blocks (with a missing link - see
673 * ext3_alloc_branch)
674 * @where: location of missing link
675 * @num: number of indirect blocks we are adding
676 * @blks: number of direct blocks we are adding
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677 *
Andrew Mortond6859bf2006-03-26 01:38:03 -0800678 * This function fills the missing link and does all housekeeping needed in
679 * inode (->i_blocks, etc.). In case of success we end up with the full
680 * chain to new block and return 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800682static int ext3_splice_branch(handle_t *handle, struct inode *inode,
683 long block, Indirect *where, int num, int blks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700684{
685 int i;
686 int err = 0;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800687 struct ext3_block_alloc_info *block_i;
Mingming Cao43d23f92006-06-25 05:48:07 -0700688 ext3_fsblk_t current_block;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800689
690 block_i = EXT3_I(inode)->i_block_alloc_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 /*
692 * If we're splicing into a [td]indirect block (as opposed to the
693 * inode) then we need to get write access to the [td]indirect block
694 * before the splice.
695 */
696 if (where->bh) {
697 BUFFER_TRACE(where->bh, "get_write_access");
698 err = ext3_journal_get_write_access(handle, where->bh);
699 if (err)
700 goto err_out;
701 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700702 /* That's it */
703
704 *where->p = where->key;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800705
706 /*
707 * Update the host buffer_head or inode to point to more just allocated
708 * direct blocks blocks
709 */
Mingming Caob47b2472006-03-26 01:37:56 -0800710 if (num == 0 && blks > 1) {
Mingming Cao5dea5172006-05-03 19:55:12 -0700711 current_block = le32_to_cpu(where->key) + 1;
Mingming Caob47b2472006-03-26 01:37:56 -0800712 for (i = 1; i < blks; i++)
713 *(where->p + i ) = cpu_to_le32(current_block++);
714 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715
716 /*
717 * update the most recently allocated logical & physical block
718 * in i_block_alloc_info, to assist find the proper goal block for next
719 * allocation
720 */
721 if (block_i) {
Mingming Caob47b2472006-03-26 01:37:56 -0800722 block_i->last_alloc_logical_block = block + blks - 1;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800723 block_i->last_alloc_physical_block =
Mingming Cao5dea5172006-05-03 19:55:12 -0700724 le32_to_cpu(where[num].key) + blks - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 }
726
727 /* We are done with atomic stuff, now do the rest of housekeeping */
728
729 inode->i_ctime = CURRENT_TIME_SEC;
730 ext3_mark_inode_dirty(handle, inode);
731
732 /* had we spliced it onto indirect block? */
733 if (where->bh) {
734 /*
Andrew Mortond6859bf2006-03-26 01:38:03 -0800735 * If we spliced it onto an indirect block, we haven't
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 * altered the inode. Note however that if it is being spliced
737 * onto an indirect block at the very end of the file (the
738 * file is growing) then we *will* alter the inode to reflect
739 * the new i_size. But that is not done here - it is done in
740 * generic_commit_write->__mark_inode_dirty->ext3_dirty_inode.
741 */
742 jbd_debug(5, "splicing indirect only\n");
743 BUFFER_TRACE(where->bh, "call ext3_journal_dirty_metadata");
744 err = ext3_journal_dirty_metadata(handle, where->bh);
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700745 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746 goto err_out;
747 } else {
748 /*
749 * OK, we spliced it into the inode itself on a direct block.
750 * Inode was dirtied above.
751 */
752 jbd_debug(5, "splicing direct\n");
753 }
754 return err;
755
Linus Torvalds1da177e2005-04-16 15:20:36 -0700756err_out:
Mingming Caob47b2472006-03-26 01:37:56 -0800757 for (i = 1; i <= num; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758 BUFFER_TRACE(where[i].bh, "call journal_forget");
759 ext3_journal_forget(handle, where[i].bh);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800760 ext3_free_blocks(handle,inode,le32_to_cpu(where[i-1].key),1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 }
Mingming Caob47b2472006-03-26 01:37:56 -0800762 ext3_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks);
763
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 return err;
765}
766
767/*
768 * Allocation strategy is simple: if we have to allocate something, we will
769 * have to go the whole way to leaf. So let's do it before attaching anything
770 * to tree, set linkage between the newborn blocks, write them if sync is
771 * required, recheck the path, free and repeat if check fails, otherwise
772 * set the last missing link (that will protect us from any truncate-generated
773 * removals - all blocks on the path are immune now) and possibly force the
774 * write on the parent block.
775 * That has a nice additional property: no special recovery from the failed
776 * allocations is needed - we simply release blocks and do not touch anything
777 * reachable from inode.
778 *
Andrew Mortond6859bf2006-03-26 01:38:03 -0800779 * `handle' can be NULL if create == 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 *
781 * The BKL may not be held on entry here. Be sure to take it early.
Mingming Cao89747d32006-03-26 01:37:55 -0800782 * return > 0, # of blocks mapped or allocated.
783 * return = 0, if plain lookup failed.
784 * return < 0, error case.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700785 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800786int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
787 sector_t iblock, unsigned long maxblocks,
788 struct buffer_head *bh_result,
Mingming Cao89747d32006-03-26 01:37:55 -0800789 int create, int extend_disksize)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790{
791 int err = -EIO;
792 int offsets[4];
793 Indirect chain[4];
794 Indirect *partial;
Mingming Cao43d23f92006-06-25 05:48:07 -0700795 ext3_fsblk_t goal;
Mingming Caob47b2472006-03-26 01:37:56 -0800796 int indirect_blks;
Mingming Cao89747d32006-03-26 01:37:55 -0800797 int blocks_to_boundary = 0;
798 int depth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 struct ext3_inode_info *ei = EXT3_I(inode);
Mingming Cao89747d32006-03-26 01:37:55 -0800800 int count = 0;
Mingming Cao43d23f92006-06-25 05:48:07 -0700801 ext3_fsblk_t first_block = 0;
Mingming Cao89747d32006-03-26 01:37:55 -0800802
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803
804 J_ASSERT(handle != NULL || create == 0);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800805 depth = ext3_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806
807 if (depth == 0)
808 goto out;
809
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
811
812 /* Simplest case - block found, no allocation needed */
813 if (!partial) {
Mingming Cao5dea5172006-05-03 19:55:12 -0700814 first_block = le32_to_cpu(chain[depth - 1].key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815 clear_buffer_new(bh_result);
Mingming Cao89747d32006-03-26 01:37:55 -0800816 count++;
817 /*map more blocks*/
818 while (count < maxblocks && count <= blocks_to_boundary) {
Mingming Cao43d23f92006-06-25 05:48:07 -0700819 ext3_fsblk_t blk;
Mingming Cao5dea5172006-05-03 19:55:12 -0700820
Mingming Cao89747d32006-03-26 01:37:55 -0800821 if (!verify_chain(chain, partial)) {
822 /*
823 * Indirect block might be removed by
824 * truncate while we were reading it.
825 * Handling of that case: forget what we've
826 * got now. Flag the err as EAGAIN, so it
827 * will reread.
828 */
829 err = -EAGAIN;
830 count = 0;
831 break;
832 }
Mingming Cao5dea5172006-05-03 19:55:12 -0700833 blk = le32_to_cpu(*(chain[depth-1].p + count));
834
835 if (blk == first_block + count)
Mingming Cao89747d32006-03-26 01:37:55 -0800836 count++;
837 else
838 break;
839 }
840 if (err != -EAGAIN)
841 goto got_it;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700842 }
843
844 /* Next simple case - plain lookup or failed read of indirect block */
Mingming Caofe55c452005-05-01 08:59:20 -0700845 if (!create || err == -EIO)
846 goto cleanup;
847
Arjan van de Ven97461512006-03-23 03:00:42 -0800848 mutex_lock(&ei->truncate_mutex);
Mingming Caofe55c452005-05-01 08:59:20 -0700849
850 /*
851 * If the indirect block is missing while we are reading
852 * the chain(ext3_get_branch() returns -EAGAIN err), or
853 * if the chain has been changed after we grab the semaphore,
854 * (either because another process truncated this branch, or
855 * another get_block allocated this branch) re-grab the chain to see if
856 * the request block has been allocated or not.
857 *
858 * Since we already block the truncate/other get_block
859 * at this point, we will have the current copy of the chain when we
860 * splice the branch into the tree.
861 */
862 if (err == -EAGAIN || !verify_chain(chain, partial)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700863 while (partial > chain) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864 brelse(partial->bh);
865 partial--;
866 }
Mingming Caofe55c452005-05-01 08:59:20 -0700867 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
868 if (!partial) {
Mingming Cao89747d32006-03-26 01:37:55 -0800869 count++;
Arjan van de Ven97461512006-03-23 03:00:42 -0800870 mutex_unlock(&ei->truncate_mutex);
Mingming Caofe55c452005-05-01 08:59:20 -0700871 if (err)
872 goto cleanup;
873 clear_buffer_new(bh_result);
874 goto got_it;
875 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 }
877
878 /*
Mingming Caofe55c452005-05-01 08:59:20 -0700879 * Okay, we need to do block allocation. Lazily initialize the block
880 * allocation info here if necessary
881 */
882 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883 ext3_init_block_alloc_info(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800885 goal = ext3_find_goal(inode, iblock, partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886
Mingming Caob47b2472006-03-26 01:37:56 -0800887 /* the number of blocks need to allocate for [d,t]indirect blocks */
888 indirect_blks = (chain + depth) - partial - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700889
890 /*
Mingming Caob47b2472006-03-26 01:37:56 -0800891 * Next look up the indirect map to count the totoal number of
892 * direct blocks to allocate for this branch.
893 */
894 count = ext3_blks_to_allocate(partial, indirect_blks,
895 maxblocks, blocks_to_boundary);
896 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 * Block out ext3_truncate while we alter the tree
898 */
Mingming Caob47b2472006-03-26 01:37:56 -0800899 err = ext3_alloc_branch(handle, inode, indirect_blks, &count, goal,
Mingming Caofe55c452005-05-01 08:59:20 -0700900 offsets + (partial - chain), partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700901
Mingming Caofe55c452005-05-01 08:59:20 -0700902 /*
903 * The ext3_splice_branch call will free and forget any buffers
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 * on the new chain if there is a failure, but that risks using
905 * up transaction credits, especially for bitmaps where the
906 * credits cannot be returned. Can we handle this somehow? We
Mingming Caofe55c452005-05-01 08:59:20 -0700907 * may need to return -EAGAIN upwards in the worst case. --sct
908 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909 if (!err)
Mingming Caob47b2472006-03-26 01:37:56 -0800910 err = ext3_splice_branch(handle, inode, iblock,
911 partial, indirect_blks, count);
Mingming Caofe55c452005-05-01 08:59:20 -0700912 /*
Arjan van de Ven97461512006-03-23 03:00:42 -0800913 * i_disksize growing is protected by truncate_mutex. Don't forget to
Mingming Caofe55c452005-05-01 08:59:20 -0700914 * protect it if you're about to implement concurrent
915 * ext3_get_block() -bzzz
916 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917 if (!err && extend_disksize && inode->i_size > ei->i_disksize)
918 ei->i_disksize = inode->i_size;
Arjan van de Ven97461512006-03-23 03:00:42 -0800919 mutex_unlock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 if (err)
921 goto cleanup;
922
923 set_buffer_new(bh_result);
Mingming Caofe55c452005-05-01 08:59:20 -0700924got_it:
925 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
Suparna Bhattacharya20acaa12006-09-16 12:15:58 -0700926 if (count > blocks_to_boundary)
Mingming Caofe55c452005-05-01 08:59:20 -0700927 set_buffer_boundary(bh_result);
Mingming Cao89747d32006-03-26 01:37:55 -0800928 err = count;
Mingming Caofe55c452005-05-01 08:59:20 -0700929 /* Clean up and exit */
930 partial = chain + depth - 1; /* the whole chain */
931cleanup:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 while (partial > chain) {
Mingming Caofe55c452005-05-01 08:59:20 -0700933 BUFFER_TRACE(partial->bh, "call brelse");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700934 brelse(partial->bh);
935 partial--;
936 }
Mingming Caofe55c452005-05-01 08:59:20 -0700937 BUFFER_TRACE(bh_result, "returned");
938out:
939 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700940}
941
Jan Karabd1939d2008-02-06 01:40:21 -0800942/* Maximum number of blocks we map for direct IO at once. */
943#define DIO_MAX_BLOCKS 4096
944/*
945 * Number of credits we need for writing DIO_MAX_BLOCKS:
946 * We need sb + group descriptor + bitmap + inode -> 4
947 * For B blocks with A block pointers per block we need:
948 * 1 (triple ind.) + (B/A/A + 2) (doubly ind.) + (B/A + 2) (indirect).
949 * If we plug in 4096 for B and 256 for A (for 1KB block size), we get 25.
950 */
951#define DIO_CREDITS 25
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952
Badari Pulavartyf91a2ad2006-03-26 01:38:04 -0800953static int ext3_get_block(struct inode *inode, sector_t iblock,
954 struct buffer_head *bh_result, int create)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955{
Dmitriy Monakhov3e4fdaf2007-02-10 01:46:35 -0800956 handle_t *handle = ext3_journal_current_handle();
Jan Karabd1939d2008-02-06 01:40:21 -0800957 int ret = 0, started = 0;
Badari Pulavarty1d8fa7a2006-03-26 01:38:02 -0800958 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700959
Jan Karabd1939d2008-02-06 01:40:21 -0800960 if (create && !handle) { /* Direct IO write... */
961 if (max_blocks > DIO_MAX_BLOCKS)
962 max_blocks = DIO_MAX_BLOCKS;
963 handle = ext3_journal_start(inode, DIO_CREDITS +
964 2 * EXT3_QUOTA_TRANS_BLOCKS(inode->i_sb));
965 if (IS_ERR(handle)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966 ret = PTR_ERR(handle);
Jan Karabd1939d2008-02-06 01:40:21 -0800967 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968 }
Jan Karabd1939d2008-02-06 01:40:21 -0800969 started = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970 }
971
Jan Karabd1939d2008-02-06 01:40:21 -0800972 ret = ext3_get_blocks_handle(handle, inode, iblock,
Mingming Cao89747d32006-03-26 01:37:55 -0800973 max_blocks, bh_result, create, 0);
Jan Karabd1939d2008-02-06 01:40:21 -0800974 if (ret > 0) {
975 bh_result->b_size = (ret << inode->i_blkbits);
976 ret = 0;
Mingming Cao89747d32006-03-26 01:37:55 -0800977 }
Jan Karabd1939d2008-02-06 01:40:21 -0800978 if (started)
979 ext3_journal_stop(handle);
980out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981 return ret;
982}
983
Linus Torvalds1da177e2005-04-16 15:20:36 -0700984/*
985 * `handle' can be NULL if create is zero
986 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800987struct buffer_head *ext3_getblk(handle_t *handle, struct inode *inode,
988 long block, int create, int *errp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989{
990 struct buffer_head dummy;
991 int fatal = 0, err;
992
993 J_ASSERT(handle != NULL || create == 0);
994
995 dummy.b_state = 0;
996 dummy.b_blocknr = -1000;
997 buffer_trace_init(&dummy.b_history);
Mingming Cao89747d32006-03-26 01:37:55 -0800998 err = ext3_get_blocks_handle(handle, inode, block, 1,
999 &dummy, create, 1);
Badari Pulavarty3665d0e2006-09-08 09:48:21 -07001000 /*
1001 * ext3_get_blocks_handle() returns number of blocks
1002 * mapped. 0 in case of a HOLE.
1003 */
1004 if (err > 0) {
1005 if (err > 1)
1006 WARN_ON(1);
Mingming Cao89747d32006-03-26 01:37:55 -08001007 err = 0;
Mingming Cao89747d32006-03-26 01:37:55 -08001008 }
1009 *errp = err;
1010 if (!err && buffer_mapped(&dummy)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001011 struct buffer_head *bh;
1012 bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
Glauber de Oliveira Costa2973dfd2005-10-30 15:03:05 -08001013 if (!bh) {
1014 *errp = -EIO;
1015 goto err;
1016 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017 if (buffer_new(&dummy)) {
1018 J_ASSERT(create != 0);
Stephen Hemmingerc80544d2007-10-18 03:07:05 -07001019 J_ASSERT(handle != NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001020
Andrew Mortond6859bf2006-03-26 01:38:03 -08001021 /*
1022 * Now that we do not always journal data, we should
1023 * keep in mind whether this should always journal the
1024 * new buffer as metadata. For now, regular file
1025 * writes use ext3_get_block instead, so it's not a
1026 * problem.
1027 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028 lock_buffer(bh);
1029 BUFFER_TRACE(bh, "call get_create_access");
1030 fatal = ext3_journal_get_create_access(handle, bh);
1031 if (!fatal && !buffer_uptodate(bh)) {
Andrew Mortond6859bf2006-03-26 01:38:03 -08001032 memset(bh->b_data,0,inode->i_sb->s_blocksize);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001033 set_buffer_uptodate(bh);
1034 }
1035 unlock_buffer(bh);
1036 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
1037 err = ext3_journal_dirty_metadata(handle, bh);
1038 if (!fatal)
1039 fatal = err;
1040 } else {
1041 BUFFER_TRACE(bh, "not a new buffer");
1042 }
1043 if (fatal) {
1044 *errp = fatal;
1045 brelse(bh);
1046 bh = NULL;
1047 }
1048 return bh;
1049 }
Glauber de Oliveira Costa2973dfd2005-10-30 15:03:05 -08001050err:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001051 return NULL;
1052}
1053
Andrew Mortond6859bf2006-03-26 01:38:03 -08001054struct buffer_head *ext3_bread(handle_t *handle, struct inode *inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001055 int block, int create, int *err)
1056{
1057 struct buffer_head * bh;
1058
1059 bh = ext3_getblk(handle, inode, block, create, err);
1060 if (!bh)
1061 return bh;
1062 if (buffer_uptodate(bh))
1063 return bh;
Jens Axboecaa38fb2006-07-23 01:41:26 +02001064 ll_rw_block(READ_META, 1, &bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001065 wait_on_buffer(bh);
1066 if (buffer_uptodate(bh))
1067 return bh;
1068 put_bh(bh);
1069 *err = -EIO;
1070 return NULL;
1071}
1072
1073static int walk_page_buffers( handle_t *handle,
1074 struct buffer_head *head,
1075 unsigned from,
1076 unsigned to,
1077 int *partial,
1078 int (*fn)( handle_t *handle,
1079 struct buffer_head *bh))
1080{
1081 struct buffer_head *bh;
1082 unsigned block_start, block_end;
1083 unsigned blocksize = head->b_size;
1084 int err, ret = 0;
1085 struct buffer_head *next;
1086
1087 for ( bh = head, block_start = 0;
1088 ret == 0 && (bh != head || !block_start);
Dave Kleikampe9ad5622006-09-27 01:49:35 -07001089 block_start = block_end, bh = next)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001090 {
1091 next = bh->b_this_page;
1092 block_end = block_start + blocksize;
1093 if (block_end <= from || block_start >= to) {
1094 if (partial && !buffer_uptodate(bh))
1095 *partial = 1;
1096 continue;
1097 }
1098 err = (*fn)(handle, bh);
1099 if (!ret)
1100 ret = err;
1101 }
1102 return ret;
1103}
1104
1105/*
1106 * To preserve ordering, it is essential that the hole instantiation and
1107 * the data write be encapsulated in a single transaction. We cannot
1108 * close off a transaction and start a new one between the ext3_get_block()
1109 * and the commit_write(). So doing the journal_start at the start of
1110 * prepare_write() is the right place.
1111 *
1112 * Also, this function can nest inside ext3_writepage() ->
1113 * block_write_full_page(). In that case, we *know* that ext3_writepage()
1114 * has generated enough buffer credits to do the whole page. So we won't
1115 * block on the journal in that case, which is good, because the caller may
1116 * be PF_MEMALLOC.
1117 *
1118 * By accident, ext3 can be reentered when a transaction is open via
1119 * quota file writes. If we were to commit the transaction while thus
1120 * reentered, there can be a deadlock - we would be holding a quota
1121 * lock, and the commit would never complete if another thread had a
1122 * transaction open and was blocking on the quota lock - a ranking
1123 * violation.
1124 *
1125 * So what we do is to rely on the fact that journal_stop/journal_start
1126 * will _not_ run commit under these circumstances because handle->h_ref
1127 * is elevated. We'll still have enough credits for the tiny quotafile
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001128 * write.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001129 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08001130static int do_journal_get_write_access(handle_t *handle,
1131 struct buffer_head *bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001132{
1133 if (!buffer_mapped(bh) || buffer_freed(bh))
1134 return 0;
1135 return ext3_journal_get_write_access(handle, bh);
1136}
1137
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001138static int ext3_write_begin(struct file *file, struct address_space *mapping,
1139 loff_t pos, unsigned len, unsigned flags,
1140 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141{
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001142 struct inode *inode = mapping->host;
Andrew Morton1aa9b4b2007-04-01 23:49:43 -07001143 int ret, needed_blocks = ext3_writepage_trans_blocks(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144 handle_t *handle;
1145 int retries = 0;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001146 struct page *page;
1147 pgoff_t index;
1148 unsigned from, to;
1149
1150 index = pos >> PAGE_CACHE_SHIFT;
1151 from = pos & (PAGE_CACHE_SIZE - 1);
1152 to = from + len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153
1154retry:
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001155 page = __grab_cache_page(mapping, index);
1156 if (!page)
1157 return -ENOMEM;
1158 *pagep = page;
1159
Linus Torvalds1da177e2005-04-16 15:20:36 -07001160 handle = ext3_journal_start(inode, needed_blocks);
Andrew Morton1aa9b4b2007-04-01 23:49:43 -07001161 if (IS_ERR(handle)) {
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001162 unlock_page(page);
1163 page_cache_release(page);
Andrew Morton1aa9b4b2007-04-01 23:49:43 -07001164 ret = PTR_ERR(handle);
1165 goto out;
1166 }
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001167 ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
1168 ext3_get_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001169 if (ret)
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001170 goto write_begin_failed;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001171
1172 if (ext3_should_journal_data(inode)) {
1173 ret = walk_page_buffers(handle, page_buffers(page),
1174 from, to, NULL, do_journal_get_write_access);
1175 }
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001176write_begin_failed:
1177 if (ret) {
Andrew Morton1aa9b4b2007-04-01 23:49:43 -07001178 ext3_journal_stop(handle);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001179 unlock_page(page);
1180 page_cache_release(page);
1181 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182 if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
1183 goto retry;
Andrew Morton1aa9b4b2007-04-01 23:49:43 -07001184out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185 return ret;
1186}
1187
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001188
Andrew Mortond6859bf2006-03-26 01:38:03 -08001189int ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190{
1191 int err = journal_dirty_data(handle, bh);
1192 if (err)
Harvey Harrisone05b6b52008-04-28 02:16:15 -07001193 ext3_journal_abort_handle(__func__, __func__,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001194 bh, handle, err);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001195 return err;
1196}
1197
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001198/* For write_end() in data=journal mode */
1199static int write_end_fn(handle_t *handle, struct buffer_head *bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001200{
1201 if (!buffer_mapped(bh) || buffer_freed(bh))
1202 return 0;
1203 set_buffer_uptodate(bh);
1204 return ext3_journal_dirty_metadata(handle, bh);
1205}
1206
1207/*
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001208 * Generic write_end handler for ordered and writeback ext3 journal modes.
1209 * We can't use generic_write_end, because that unlocks the page and we need to
1210 * unlock the page after ext3_journal_stop, but ext3_journal_stop must run
1211 * after block_write_end.
1212 */
1213static int ext3_generic_write_end(struct file *file,
1214 struct address_space *mapping,
1215 loff_t pos, unsigned len, unsigned copied,
1216 struct page *page, void *fsdata)
1217{
1218 struct inode *inode = file->f_mapping->host;
1219
1220 copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
1221
1222 if (pos+copied > inode->i_size) {
1223 i_size_write(inode, pos+copied);
1224 mark_inode_dirty(inode);
1225 }
1226
1227 return copied;
1228}
1229
1230/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231 * We need to pick up the new inode size which generic_commit_write gave us
1232 * `file' can be NULL - eg, when called from page_symlink().
1233 *
1234 * ext3 never places buffers on inode->i_mapping->private_list. metadata
1235 * buffers are managed internally.
1236 */
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001237static int ext3_ordered_write_end(struct file *file,
1238 struct address_space *mapping,
1239 loff_t pos, unsigned len, unsigned copied,
1240 struct page *page, void *fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241{
1242 handle_t *handle = ext3_journal_current_handle();
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001243 struct inode *inode = file->f_mapping->host;
1244 unsigned from, to;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001245 int ret = 0, ret2;
1246
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001247 from = pos & (PAGE_CACHE_SIZE - 1);
1248 to = from + len;
1249
Linus Torvalds1da177e2005-04-16 15:20:36 -07001250 ret = walk_page_buffers(handle, page_buffers(page),
1251 from, to, NULL, ext3_journal_dirty_data);
1252
1253 if (ret == 0) {
1254 /*
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001255 * generic_write_end() will run mark_inode_dirty() if i_size
Linus Torvalds1da177e2005-04-16 15:20:36 -07001256 * changes. So let's piggyback the i_disksize mark_inode_dirty
1257 * into that.
1258 */
1259 loff_t new_i_size;
1260
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001261 new_i_size = pos + copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001262 if (new_i_size > EXT3_I(inode)->i_disksize)
1263 EXT3_I(inode)->i_disksize = new_i_size;
Roel Kluin7c2f3d62008-04-29 22:01:27 -04001264 ret2 = ext3_generic_write_end(file, mapping, pos, len, copied,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001265 page, fsdata);
Roel Kluin7c2f3d62008-04-29 22:01:27 -04001266 copied = ret2;
1267 if (ret2 < 0)
1268 ret = ret2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269 }
1270 ret2 = ext3_journal_stop(handle);
1271 if (!ret)
1272 ret = ret2;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001273 unlock_page(page);
1274 page_cache_release(page);
1275
1276 return ret ? ret : copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277}
1278
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001279static int ext3_writeback_write_end(struct file *file,
1280 struct address_space *mapping,
1281 loff_t pos, unsigned len, unsigned copied,
1282 struct page *page, void *fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283{
1284 handle_t *handle = ext3_journal_current_handle();
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001285 struct inode *inode = file->f_mapping->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 int ret = 0, ret2;
1287 loff_t new_i_size;
1288
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001289 new_i_size = pos + copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001290 if (new_i_size > EXT3_I(inode)->i_disksize)
1291 EXT3_I(inode)->i_disksize = new_i_size;
1292
Roel Kluin7c2f3d62008-04-29 22:01:27 -04001293 ret2 = ext3_generic_write_end(file, mapping, pos, len, copied,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001294 page, fsdata);
Roel Kluin7c2f3d62008-04-29 22:01:27 -04001295 copied = ret2;
1296 if (ret2 < 0)
1297 ret = ret2;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001298
1299 ret2 = ext3_journal_stop(handle);
1300 if (!ret)
1301 ret = ret2;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001302 unlock_page(page);
1303 page_cache_release(page);
1304
1305 return ret ? ret : copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001306}
1307
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001308static int ext3_journalled_write_end(struct file *file,
1309 struct address_space *mapping,
1310 loff_t pos, unsigned len, unsigned copied,
1311 struct page *page, void *fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001312{
1313 handle_t *handle = ext3_journal_current_handle();
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001314 struct inode *inode = mapping->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315 int ret = 0, ret2;
1316 int partial = 0;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001317 unsigned from, to;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001318
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001319 from = pos & (PAGE_CACHE_SIZE - 1);
1320 to = from + len;
1321
1322 if (copied < len) {
1323 if (!PageUptodate(page))
1324 copied = 0;
1325 page_zero_new_buffers(page, from+copied, to);
1326 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327
1328 ret = walk_page_buffers(handle, page_buffers(page), from,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001329 to, &partial, write_end_fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330 if (!partial)
1331 SetPageUptodate(page);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001332 if (pos+copied > inode->i_size)
1333 i_size_write(inode, pos+copied);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001334 EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1335 if (inode->i_size > EXT3_I(inode)->i_disksize) {
1336 EXT3_I(inode)->i_disksize = inode->i_size;
1337 ret2 = ext3_mark_inode_dirty(handle, inode);
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001338 if (!ret)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001339 ret = ret2;
1340 }
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001341
Linus Torvalds1da177e2005-04-16 15:20:36 -07001342 ret2 = ext3_journal_stop(handle);
1343 if (!ret)
1344 ret = ret2;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001345 unlock_page(page);
1346 page_cache_release(page);
1347
1348 return ret ? ret : copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001349}
1350
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001351/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001352 * bmap() is special. It gets used by applications such as lilo and by
1353 * the swapper to find the on-disk block of a specific piece of data.
1354 *
1355 * Naturally, this is dangerous if the block concerned is still in the
1356 * journal. If somebody makes a swapfile on an ext3 data-journaling
1357 * filesystem and enables swap, then they may get a nasty shock when the
1358 * data getting swapped to that swapfile suddenly gets overwritten by
1359 * the original zero's written out previously to the journal and
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001360 * awaiting writeback in the kernel's buffer cache.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001361 *
1362 * So, if we see any bmap calls here on a modified, data-journaled file,
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001363 * take extra steps to flush any blocks which might be in the cache.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001364 */
1365static sector_t ext3_bmap(struct address_space *mapping, sector_t block)
1366{
1367 struct inode *inode = mapping->host;
1368 journal_t *journal;
1369 int err;
1370
1371 if (EXT3_I(inode)->i_state & EXT3_STATE_JDATA) {
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001372 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001373 * This is a REALLY heavyweight approach, but the use of
1374 * bmap on dirty files is expected to be extremely rare:
1375 * only if we run lilo or swapon on a freshly made file
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001376 * do we expect this to happen.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001377 *
1378 * (bmap requires CAP_SYS_RAWIO so this does not
1379 * represent an unprivileged user DOS attack --- we'd be
1380 * in trouble if mortal users could trigger this path at
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001381 * will.)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001382 *
1383 * NB. EXT3_STATE_JDATA is not set on files other than
1384 * regular files. If somebody wants to bmap a directory
1385 * or symlink and gets confused because the buffer
1386 * hasn't yet been flushed to disk, they deserve
1387 * everything they get.
1388 */
1389
1390 EXT3_I(inode)->i_state &= ~EXT3_STATE_JDATA;
1391 journal = EXT3_JOURNAL(inode);
1392 journal_lock_updates(journal);
1393 err = journal_flush(journal);
1394 journal_unlock_updates(journal);
1395
1396 if (err)
1397 return 0;
1398 }
1399
1400 return generic_block_bmap(mapping,block,ext3_get_block);
1401}
1402
1403static int bget_one(handle_t *handle, struct buffer_head *bh)
1404{
1405 get_bh(bh);
1406 return 0;
1407}
1408
1409static int bput_one(handle_t *handle, struct buffer_head *bh)
1410{
1411 put_bh(bh);
1412 return 0;
1413}
1414
1415static int journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
1416{
1417 if (buffer_mapped(bh))
1418 return ext3_journal_dirty_data(handle, bh);
1419 return 0;
1420}
1421
1422/*
1423 * Note that we always start a transaction even if we're not journalling
1424 * data. This is to preserve ordering: any hole instantiation within
1425 * __block_write_full_page -> ext3_get_block() should be journalled
1426 * along with the data so we don't crash and then get metadata which
1427 * refers to old data.
1428 *
1429 * In all journalling modes block_write_full_page() will start the I/O.
1430 *
1431 * Problem:
1432 *
1433 * ext3_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1434 * ext3_writepage()
1435 *
1436 * Similar for:
1437 *
1438 * ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ...
1439 *
1440 * Same applies to ext3_get_block(). We will deadlock on various things like
Arjan van de Ven97461512006-03-23 03:00:42 -08001441 * lock_journal and i_truncate_mutex.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001442 *
1443 * Setting PF_MEMALLOC here doesn't work - too many internal memory
1444 * allocations fail.
1445 *
1446 * 16May01: If we're reentered then journal_current_handle() will be
1447 * non-zero. We simply *return*.
1448 *
1449 * 1 July 2001: @@@ FIXME:
1450 * In journalled data mode, a data buffer may be metadata against the
1451 * current transaction. But the same file is part of a shared mapping
1452 * and someone does a writepage() on it.
1453 *
1454 * We will move the buffer onto the async_data list, but *after* it has
1455 * been dirtied. So there's a small window where we have dirty data on
1456 * BJ_Metadata.
1457 *
1458 * Note that this only applies to the last partial page in the file. The
1459 * bit which block_write_full_page() uses prepare/commit for. (That's
1460 * broken code anyway: it's wrong for msync()).
1461 *
1462 * It's a rare case: affects the final partial page, for journalled data
1463 * where the file is subject to bith write() and writepage() in the same
1464 * transction. To fix it we'll need a custom block_write_full_page().
1465 * We'll probably need that anyway for journalling writepage() output.
1466 *
1467 * We don't honour synchronous mounts for writepage(). That would be
1468 * disastrous. Any write() or metadata operation will sync the fs for
1469 * us.
1470 *
1471 * AKPM2: if all the page's buffers are mapped to disk and !data=journal,
1472 * we don't need to open a transaction here.
1473 */
1474static int ext3_ordered_writepage(struct page *page,
Andrew Mortond6859bf2006-03-26 01:38:03 -08001475 struct writeback_control *wbc)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001476{
1477 struct inode *inode = page->mapping->host;
1478 struct buffer_head *page_bufs;
1479 handle_t *handle = NULL;
1480 int ret = 0;
1481 int err;
1482
1483 J_ASSERT(PageLocked(page));
1484
1485 /*
1486 * We give up here if we're reentered, because it might be for a
1487 * different filesystem.
1488 */
1489 if (ext3_journal_current_handle())
1490 goto out_fail;
1491
1492 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1493
1494 if (IS_ERR(handle)) {
1495 ret = PTR_ERR(handle);
1496 goto out_fail;
1497 }
1498
1499 if (!page_has_buffers(page)) {
1500 create_empty_buffers(page, inode->i_sb->s_blocksize,
1501 (1 << BH_Dirty)|(1 << BH_Uptodate));
1502 }
1503 page_bufs = page_buffers(page);
1504 walk_page_buffers(handle, page_bufs, 0,
1505 PAGE_CACHE_SIZE, NULL, bget_one);
1506
1507 ret = block_write_full_page(page, ext3_get_block, wbc);
1508
1509 /*
1510 * The page can become unlocked at any point now, and
1511 * truncate can then come in and change things. So we
1512 * can't touch *page from now on. But *page_bufs is
1513 * safe due to elevated refcount.
1514 */
1515
1516 /*
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001517 * And attach them to the current transaction. But only if
Linus Torvalds1da177e2005-04-16 15:20:36 -07001518 * block_write_full_page() succeeded. Otherwise they are unmapped,
1519 * and generally junk.
1520 */
1521 if (ret == 0) {
1522 err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
1523 NULL, journal_dirty_data_fn);
1524 if (!ret)
1525 ret = err;
1526 }
1527 walk_page_buffers(handle, page_bufs, 0,
1528 PAGE_CACHE_SIZE, NULL, bput_one);
1529 err = ext3_journal_stop(handle);
1530 if (!ret)
1531 ret = err;
1532 return ret;
1533
1534out_fail:
1535 redirty_page_for_writepage(wbc, page);
1536 unlock_page(page);
1537 return ret;
1538}
1539
Linus Torvalds1da177e2005-04-16 15:20:36 -07001540static int ext3_writeback_writepage(struct page *page,
1541 struct writeback_control *wbc)
1542{
1543 struct inode *inode = page->mapping->host;
1544 handle_t *handle = NULL;
1545 int ret = 0;
1546 int err;
1547
1548 if (ext3_journal_current_handle())
1549 goto out_fail;
1550
1551 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1552 if (IS_ERR(handle)) {
1553 ret = PTR_ERR(handle);
1554 goto out_fail;
1555 }
1556
Badari Pulavarty0e31f512006-07-30 03:04:14 -07001557 if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001558 ret = nobh_writepage(page, ext3_get_block, wbc);
1559 else
1560 ret = block_write_full_page(page, ext3_get_block, wbc);
1561
1562 err = ext3_journal_stop(handle);
1563 if (!ret)
1564 ret = err;
1565 return ret;
1566
1567out_fail:
1568 redirty_page_for_writepage(wbc, page);
1569 unlock_page(page);
1570 return ret;
1571}
1572
1573static int ext3_journalled_writepage(struct page *page,
1574 struct writeback_control *wbc)
1575{
1576 struct inode *inode = page->mapping->host;
1577 handle_t *handle = NULL;
1578 int ret = 0;
1579 int err;
1580
1581 if (ext3_journal_current_handle())
1582 goto no_write;
1583
1584 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1585 if (IS_ERR(handle)) {
1586 ret = PTR_ERR(handle);
1587 goto no_write;
1588 }
1589
1590 if (!page_has_buffers(page) || PageChecked(page)) {
1591 /*
1592 * It's mmapped pagecache. Add buffers and journal it. There
1593 * doesn't seem much point in redirtying the page here.
1594 */
1595 ClearPageChecked(page);
1596 ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
1597 ext3_get_block);
Denis Lunevab4eb432005-11-13 16:07:17 -08001598 if (ret != 0) {
1599 ext3_journal_stop(handle);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001600 goto out_unlock;
Denis Lunevab4eb432005-11-13 16:07:17 -08001601 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001602 ret = walk_page_buffers(handle, page_buffers(page), 0,
1603 PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
1604
1605 err = walk_page_buffers(handle, page_buffers(page), 0,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001606 PAGE_CACHE_SIZE, NULL, write_end_fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001607 if (ret == 0)
1608 ret = err;
1609 EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1610 unlock_page(page);
1611 } else {
1612 /*
1613 * It may be a page full of checkpoint-mode buffers. We don't
1614 * really know unless we go poke around in the buffer_heads.
1615 * But block_write_full_page will do the right thing.
1616 */
1617 ret = block_write_full_page(page, ext3_get_block, wbc);
1618 }
1619 err = ext3_journal_stop(handle);
1620 if (!ret)
1621 ret = err;
1622out:
1623 return ret;
1624
1625no_write:
1626 redirty_page_for_writepage(wbc, page);
1627out_unlock:
1628 unlock_page(page);
1629 goto out;
1630}
1631
1632static int ext3_readpage(struct file *file, struct page *page)
1633{
1634 return mpage_readpage(page, ext3_get_block);
1635}
1636
1637static int
1638ext3_readpages(struct file *file, struct address_space *mapping,
1639 struct list_head *pages, unsigned nr_pages)
1640{
1641 return mpage_readpages(mapping, pages, nr_pages, ext3_get_block);
1642}
1643
NeilBrown2ff28e22006-03-26 01:37:18 -08001644static void ext3_invalidatepage(struct page *page, unsigned long offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001645{
1646 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1647
1648 /*
1649 * If it's a full truncate we just forget about the pending dirtying
1650 */
1651 if (offset == 0)
1652 ClearPageChecked(page);
1653
NeilBrown2ff28e22006-03-26 01:37:18 -08001654 journal_invalidatepage(journal, page, offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001655}
1656
Al Viro27496a82005-10-21 03:20:48 -04001657static int ext3_releasepage(struct page *page, gfp_t wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001658{
1659 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1660
1661 WARN_ON(PageChecked(page));
1662 if (!page_has_buffers(page))
1663 return 0;
1664 return journal_try_to_free_buffers(journal, page, wait);
1665}
1666
1667/*
1668 * If the O_DIRECT write will extend the file then add this inode to the
1669 * orphan list. So recovery will truncate it back to the original size
1670 * if the machine crashes during the write.
1671 *
1672 * If the O_DIRECT write is intantiating holes inside i_size and the machine
Jan Karabd1939d2008-02-06 01:40:21 -08001673 * crashes then stale disk data _may_ be exposed inside the file. But current
1674 * VFS code falls back into buffered path in that case so we are safe.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001675 */
1676static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
1677 const struct iovec *iov, loff_t offset,
1678 unsigned long nr_segs)
1679{
1680 struct file *file = iocb->ki_filp;
1681 struct inode *inode = file->f_mapping->host;
1682 struct ext3_inode_info *ei = EXT3_I(inode);
Jan Karabd1939d2008-02-06 01:40:21 -08001683 handle_t *handle;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001684 ssize_t ret;
1685 int orphan = 0;
1686 size_t count = iov_length(iov, nr_segs);
1687
1688 if (rw == WRITE) {
1689 loff_t final_size = offset + count;
1690
Linus Torvalds1da177e2005-04-16 15:20:36 -07001691 if (final_size > inode->i_size) {
Jan Karabd1939d2008-02-06 01:40:21 -08001692 /* Credits for sb + inode write */
1693 handle = ext3_journal_start(inode, 2);
1694 if (IS_ERR(handle)) {
1695 ret = PTR_ERR(handle);
1696 goto out;
1697 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001698 ret = ext3_orphan_add(handle, inode);
Jan Karabd1939d2008-02-06 01:40:21 -08001699 if (ret) {
1700 ext3_journal_stop(handle);
1701 goto out;
1702 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001703 orphan = 1;
1704 ei->i_disksize = inode->i_size;
Jan Karabd1939d2008-02-06 01:40:21 -08001705 ext3_journal_stop(handle);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001706 }
1707 }
1708
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001709 ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001710 offset, nr_segs,
Badari Pulavartyf91a2ad2006-03-26 01:38:04 -08001711 ext3_get_block, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001712
Jan Karabd1939d2008-02-06 01:40:21 -08001713 if (orphan) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001714 int err;
1715
Jan Karabd1939d2008-02-06 01:40:21 -08001716 /* Credits for sb + inode write */
1717 handle = ext3_journal_start(inode, 2);
1718 if (IS_ERR(handle)) {
1719 /* This is really bad luck. We've written the data
1720 * but cannot extend i_size. Bail out and pretend
1721 * the write failed... */
1722 ret = PTR_ERR(handle);
1723 goto out;
1724 }
1725 if (inode->i_nlink)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001726 ext3_orphan_del(handle, inode);
Jan Karabd1939d2008-02-06 01:40:21 -08001727 if (ret > 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001728 loff_t end = offset + ret;
1729 if (end > inode->i_size) {
1730 ei->i_disksize = end;
1731 i_size_write(inode, end);
1732 /*
1733 * We're going to return a positive `ret'
1734 * here due to non-zero-length I/O, so there's
1735 * no way of reporting error returns from
1736 * ext3_mark_inode_dirty() to userspace. So
1737 * ignore it.
1738 */
1739 ext3_mark_inode_dirty(handle, inode);
1740 }
1741 }
1742 err = ext3_journal_stop(handle);
1743 if (ret == 0)
1744 ret = err;
1745 }
1746out:
1747 return ret;
1748}
1749
1750/*
1751 * Pages can be marked dirty completely asynchronously from ext3's journalling
1752 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
1753 * much here because ->set_page_dirty is called under VFS locks. The page is
1754 * not necessarily locked.
1755 *
1756 * We cannot just dirty the page and leave attached buffers clean, because the
1757 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
1758 * or jbddirty because all the journalling code will explode.
1759 *
1760 * So what we do is to mark the page "pending dirty" and next time writepage
1761 * is called, propagate that into the buffers appropriately.
1762 */
1763static int ext3_journalled_set_page_dirty(struct page *page)
1764{
1765 SetPageChecked(page);
1766 return __set_page_dirty_nobuffers(page);
1767}
1768
Christoph Hellwigf5e54d62006-06-28 04:26:44 -07001769static const struct address_space_operations ext3_ordered_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001770 .readpage = ext3_readpage,
1771 .readpages = ext3_readpages,
1772 .writepage = ext3_ordered_writepage,
1773 .sync_page = block_sync_page,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001774 .write_begin = ext3_write_begin,
1775 .write_end = ext3_ordered_write_end,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001776 .bmap = ext3_bmap,
1777 .invalidatepage = ext3_invalidatepage,
1778 .releasepage = ext3_releasepage,
1779 .direct_IO = ext3_direct_IO,
Christoph Lametere965f962006-02-01 03:05:41 -08001780 .migratepage = buffer_migrate_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001781};
1782
Christoph Hellwigf5e54d62006-06-28 04:26:44 -07001783static const struct address_space_operations ext3_writeback_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001784 .readpage = ext3_readpage,
1785 .readpages = ext3_readpages,
1786 .writepage = ext3_writeback_writepage,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001787 .sync_page = block_sync_page,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001788 .write_begin = ext3_write_begin,
1789 .write_end = ext3_writeback_write_end,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001790 .bmap = ext3_bmap,
1791 .invalidatepage = ext3_invalidatepage,
1792 .releasepage = ext3_releasepage,
1793 .direct_IO = ext3_direct_IO,
Christoph Lametere965f962006-02-01 03:05:41 -08001794 .migratepage = buffer_migrate_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001795};
1796
Christoph Hellwigf5e54d62006-06-28 04:26:44 -07001797static const struct address_space_operations ext3_journalled_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001798 .readpage = ext3_readpage,
1799 .readpages = ext3_readpages,
1800 .writepage = ext3_journalled_writepage,
1801 .sync_page = block_sync_page,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001802 .write_begin = ext3_write_begin,
1803 .write_end = ext3_journalled_write_end,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001804 .set_page_dirty = ext3_journalled_set_page_dirty,
1805 .bmap = ext3_bmap,
1806 .invalidatepage = ext3_invalidatepage,
1807 .releasepage = ext3_releasepage,
1808};
1809
1810void ext3_set_aops(struct inode *inode)
1811{
1812 if (ext3_should_order_data(inode))
1813 inode->i_mapping->a_ops = &ext3_ordered_aops;
1814 else if (ext3_should_writeback_data(inode))
1815 inode->i_mapping->a_ops = &ext3_writeback_aops;
1816 else
1817 inode->i_mapping->a_ops = &ext3_journalled_aops;
1818}
1819
1820/*
1821 * ext3_block_truncate_page() zeroes out a mapping from file offset `from'
1822 * up to the end of the block which corresponds to `from'.
1823 * This required during truncate. We need to physically zero the tail end
1824 * of that block so it doesn't yield old data if the file is later grown.
1825 */
1826static int ext3_block_truncate_page(handle_t *handle, struct page *page,
1827 struct address_space *mapping, loff_t from)
1828{
Mingming Cao43d23f92006-06-25 05:48:07 -07001829 ext3_fsblk_t index = from >> PAGE_CACHE_SHIFT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001830 unsigned offset = from & (PAGE_CACHE_SIZE-1);
1831 unsigned blocksize, iblock, length, pos;
1832 struct inode *inode = mapping->host;
1833 struct buffer_head *bh;
1834 int err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001835
1836 blocksize = inode->i_sb->s_blocksize;
1837 length = blocksize - (offset & (blocksize - 1));
1838 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1839
1840 /*
1841 * For "nobh" option, we can only work if we don't need to
1842 * read-in the page - otherwise we create buffers to do the IO.
1843 */
Badari Pulavartycd6ef842006-03-11 03:27:14 -08001844 if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
1845 ext3_should_writeback_data(inode) && PageUptodate(page)) {
Christoph Lametereebd2aa2008-02-04 22:28:29 -08001846 zero_user(page, offset, length);
Badari Pulavartycd6ef842006-03-11 03:27:14 -08001847 set_page_dirty(page);
1848 goto unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001849 }
1850
1851 if (!page_has_buffers(page))
1852 create_empty_buffers(page, blocksize, 0);
1853
1854 /* Find the buffer that contains "offset" */
1855 bh = page_buffers(page);
1856 pos = blocksize;
1857 while (offset >= pos) {
1858 bh = bh->b_this_page;
1859 iblock++;
1860 pos += blocksize;
1861 }
1862
1863 err = 0;
1864 if (buffer_freed(bh)) {
1865 BUFFER_TRACE(bh, "freed: skip");
1866 goto unlock;
1867 }
1868
1869 if (!buffer_mapped(bh)) {
1870 BUFFER_TRACE(bh, "unmapped");
1871 ext3_get_block(inode, iblock, bh, 0);
1872 /* unmapped? It's a hole - nothing to do */
1873 if (!buffer_mapped(bh)) {
1874 BUFFER_TRACE(bh, "still unmapped");
1875 goto unlock;
1876 }
1877 }
1878
1879 /* Ok, it's mapped. Make sure it's up-to-date */
1880 if (PageUptodate(page))
1881 set_buffer_uptodate(bh);
1882
1883 if (!buffer_uptodate(bh)) {
1884 err = -EIO;
1885 ll_rw_block(READ, 1, &bh);
1886 wait_on_buffer(bh);
1887 /* Uhhuh. Read error. Complain and punt. */
1888 if (!buffer_uptodate(bh))
1889 goto unlock;
1890 }
1891
1892 if (ext3_should_journal_data(inode)) {
1893 BUFFER_TRACE(bh, "get write access");
1894 err = ext3_journal_get_write_access(handle, bh);
1895 if (err)
1896 goto unlock;
1897 }
1898
Christoph Lametereebd2aa2008-02-04 22:28:29 -08001899 zero_user(page, offset, length);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001900 BUFFER_TRACE(bh, "zeroed end of block");
1901
1902 err = 0;
1903 if (ext3_should_journal_data(inode)) {
1904 err = ext3_journal_dirty_metadata(handle, bh);
1905 } else {
1906 if (ext3_should_order_data(inode))
1907 err = ext3_journal_dirty_data(handle, bh);
1908 mark_buffer_dirty(bh);
1909 }
1910
1911unlock:
1912 unlock_page(page);
1913 page_cache_release(page);
1914 return err;
1915}
1916
1917/*
1918 * Probably it should be a library function... search for first non-zero word
1919 * or memcmp with zero_page, whatever is better for particular architecture.
1920 * Linus?
1921 */
1922static inline int all_zeroes(__le32 *p, __le32 *q)
1923{
1924 while (p < q)
1925 if (*p++)
1926 return 0;
1927 return 1;
1928}
1929
1930/**
1931 * ext3_find_shared - find the indirect blocks for partial truncation.
1932 * @inode: inode in question
1933 * @depth: depth of the affected branch
1934 * @offsets: offsets of pointers in that branch (see ext3_block_to_path)
1935 * @chain: place to store the pointers to partial indirect blocks
1936 * @top: place to the (detached) top of branch
1937 *
1938 * This is a helper function used by ext3_truncate().
1939 *
1940 * When we do truncate() we may have to clean the ends of several
1941 * indirect blocks but leave the blocks themselves alive. Block is
1942 * partially truncated if some data below the new i_size is refered
1943 * from it (and it is on the path to the first completely truncated
1944 * data block, indeed). We have to free the top of that path along
1945 * with everything to the right of the path. Since no allocation
1946 * past the truncation point is possible until ext3_truncate()
1947 * finishes, we may safely do the latter, but top of branch may
1948 * require special attention - pageout below the truncation point
1949 * might try to populate it.
1950 *
1951 * We atomically detach the top of branch from the tree, store the
1952 * block number of its root in *@top, pointers to buffer_heads of
1953 * partially truncated blocks - in @chain[].bh and pointers to
1954 * their last elements that should not be removed - in
1955 * @chain[].p. Return value is the pointer to last filled element
1956 * of @chain.
1957 *
1958 * The work left to caller to do the actual freeing of subtrees:
1959 * a) free the subtree starting from *@top
1960 * b) free the subtrees whose roots are stored in
1961 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
1962 * c) free the subtrees growing from the inode past the @chain[0].
1963 * (no partially truncated stuff there). */
1964
Andrew Mortond6859bf2006-03-26 01:38:03 -08001965static Indirect *ext3_find_shared(struct inode *inode, int depth,
1966 int offsets[4], Indirect chain[4], __le32 *top)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001967{
1968 Indirect *partial, *p;
1969 int k, err;
1970
1971 *top = 0;
1972 /* Make k index the deepest non-null offest + 1 */
1973 for (k = depth; k > 1 && !offsets[k-1]; k--)
1974 ;
1975 partial = ext3_get_branch(inode, k, offsets, chain, &err);
1976 /* Writer: pointers */
1977 if (!partial)
1978 partial = chain + k-1;
1979 /*
1980 * If the branch acquired continuation since we've looked at it -
1981 * fine, it should all survive and (new) top doesn't belong to us.
1982 */
1983 if (!partial->key && *partial->p)
1984 /* Writer: end */
1985 goto no_top;
1986 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
1987 ;
1988 /*
1989 * OK, we've found the last block that must survive. The rest of our
1990 * branch should be detached before unlocking. However, if that rest
1991 * of branch is all ours and does not grow immediately from the inode
1992 * it's easier to cheat and just decrement partial->p.
1993 */
1994 if (p == chain + k - 1 && p > chain) {
1995 p->p--;
1996 } else {
1997 *top = *p->p;
1998 /* Nope, don't do this in ext3. Must leave the tree intact */
1999#if 0
2000 *p->p = 0;
2001#endif
2002 }
2003 /* Writer: end */
2004
Andrew Mortond6859bf2006-03-26 01:38:03 -08002005 while(partial > p) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002006 brelse(partial->bh);
2007 partial--;
2008 }
2009no_top:
2010 return partial;
2011}
2012
2013/*
2014 * Zero a number of block pointers in either an inode or an indirect block.
2015 * If we restart the transaction we must again get write access to the
2016 * indirect block for further modification.
2017 *
2018 * We release `count' blocks on disk, but (last - first) may be greater
2019 * than `count' because there can be holes in there.
2020 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08002021static void ext3_clear_blocks(handle_t *handle, struct inode *inode,
Mingming Cao43d23f92006-06-25 05:48:07 -07002022 struct buffer_head *bh, ext3_fsblk_t block_to_free,
Andrew Mortond6859bf2006-03-26 01:38:03 -08002023 unsigned long count, __le32 *first, __le32 *last)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002024{
2025 __le32 *p;
2026 if (try_to_extend_transaction(handle, inode)) {
2027 if (bh) {
2028 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
2029 ext3_journal_dirty_metadata(handle, bh);
2030 }
2031 ext3_mark_inode_dirty(handle, inode);
2032 ext3_journal_test_restart(handle, inode);
2033 if (bh) {
2034 BUFFER_TRACE(bh, "retaking write access");
2035 ext3_journal_get_write_access(handle, bh);
2036 }
2037 }
2038
2039 /*
2040 * Any buffers which are on the journal will be in memory. We find
2041 * them on the hash table so journal_revoke() will run journal_forget()
2042 * on them. We've already detached each block from the file, so
2043 * bforget() in journal_forget() should be safe.
2044 *
2045 * AKPM: turn on bforget in journal_forget()!!!
2046 */
2047 for (p = first; p < last; p++) {
2048 u32 nr = le32_to_cpu(*p);
2049 if (nr) {
2050 struct buffer_head *bh;
2051
2052 *p = 0;
2053 bh = sb_find_get_block(inode->i_sb, nr);
2054 ext3_forget(handle, 0, inode, bh, nr);
2055 }
2056 }
2057
2058 ext3_free_blocks(handle, inode, block_to_free, count);
2059}
2060
2061/**
2062 * ext3_free_data - free a list of data blocks
2063 * @handle: handle for this transaction
2064 * @inode: inode we are dealing with
2065 * @this_bh: indirect buffer_head which contains *@first and *@last
2066 * @first: array of block numbers
2067 * @last: points immediately past the end of array
2068 *
2069 * We are freeing all blocks refered from that array (numbers are stored as
2070 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
2071 *
2072 * We accumulate contiguous runs of blocks to free. Conveniently, if these
2073 * blocks are contiguous then releasing them at one time will only affect one
2074 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
2075 * actually use a lot of journal space.
2076 *
2077 * @this_bh will be %NULL if @first and @last point into the inode's direct
2078 * block pointers.
2079 */
2080static void ext3_free_data(handle_t *handle, struct inode *inode,
2081 struct buffer_head *this_bh,
2082 __le32 *first, __le32 *last)
2083{
Mingming Cao43d23f92006-06-25 05:48:07 -07002084 ext3_fsblk_t block_to_free = 0; /* Starting block # of a run */
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002085 unsigned long count = 0; /* Number of blocks in the run */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002086 __le32 *block_to_free_p = NULL; /* Pointer into inode/ind
2087 corresponding to
2088 block_to_free */
Mingming Cao43d23f92006-06-25 05:48:07 -07002089 ext3_fsblk_t nr; /* Current block # */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002090 __le32 *p; /* Pointer into inode/ind
2091 for current block */
2092 int err;
2093
2094 if (this_bh) { /* For indirect block */
2095 BUFFER_TRACE(this_bh, "get_write_access");
2096 err = ext3_journal_get_write_access(handle, this_bh);
2097 /* Important: if we can't update the indirect pointers
2098 * to the blocks, we can't free them. */
2099 if (err)
2100 return;
2101 }
2102
2103 for (p = first; p < last; p++) {
2104 nr = le32_to_cpu(*p);
2105 if (nr) {
2106 /* accumulate blocks to free if they're contiguous */
2107 if (count == 0) {
2108 block_to_free = nr;
2109 block_to_free_p = p;
2110 count = 1;
2111 } else if (nr == block_to_free + count) {
2112 count++;
2113 } else {
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002114 ext3_clear_blocks(handle, inode, this_bh,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002115 block_to_free,
2116 count, block_to_free_p, p);
2117 block_to_free = nr;
2118 block_to_free_p = p;
2119 count = 1;
2120 }
2121 }
2122 }
2123
2124 if (count > 0)
2125 ext3_clear_blocks(handle, inode, this_bh, block_to_free,
2126 count, block_to_free_p, p);
2127
2128 if (this_bh) {
2129 BUFFER_TRACE(this_bh, "call ext3_journal_dirty_metadata");
2130 ext3_journal_dirty_metadata(handle, this_bh);
2131 }
2132}
2133
2134/**
2135 * ext3_free_branches - free an array of branches
2136 * @handle: JBD handle for this transaction
2137 * @inode: inode we are dealing with
2138 * @parent_bh: the buffer_head which contains *@first and *@last
2139 * @first: array of block numbers
2140 * @last: pointer immediately past the end of array
2141 * @depth: depth of the branches to free
2142 *
2143 * We are freeing all blocks refered from these branches (numbers are
2144 * stored as little-endian 32-bit) and updating @inode->i_blocks
2145 * appropriately.
2146 */
2147static void ext3_free_branches(handle_t *handle, struct inode *inode,
2148 struct buffer_head *parent_bh,
2149 __le32 *first, __le32 *last, int depth)
2150{
Mingming Cao43d23f92006-06-25 05:48:07 -07002151 ext3_fsblk_t nr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002152 __le32 *p;
2153
2154 if (is_handle_aborted(handle))
2155 return;
2156
2157 if (depth--) {
2158 struct buffer_head *bh;
2159 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2160 p = last;
2161 while (--p >= first) {
2162 nr = le32_to_cpu(*p);
2163 if (!nr)
2164 continue; /* A hole */
2165
2166 /* Go read the buffer for the next level down */
2167 bh = sb_bread(inode->i_sb, nr);
2168
2169 /*
2170 * A read failure? Report error and clear slot
2171 * (should be rare).
2172 */
2173 if (!bh) {
2174 ext3_error(inode->i_sb, "ext3_free_branches",
Eric Sandeeneee194e2006-09-27 01:49:30 -07002175 "Read failure, inode=%lu, block="E3FSBLK,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002176 inode->i_ino, nr);
2177 continue;
2178 }
2179
2180 /* This zaps the entire block. Bottom up. */
2181 BUFFER_TRACE(bh, "free child branches");
2182 ext3_free_branches(handle, inode, bh,
2183 (__le32*)bh->b_data,
2184 (__le32*)bh->b_data + addr_per_block,
2185 depth);
2186
2187 /*
2188 * We've probably journalled the indirect block several
2189 * times during the truncate. But it's no longer
2190 * needed and we now drop it from the transaction via
2191 * journal_revoke().
2192 *
2193 * That's easy if it's exclusively part of this
2194 * transaction. But if it's part of the committing
2195 * transaction then journal_forget() will simply
2196 * brelse() it. That means that if the underlying
2197 * block is reallocated in ext3_get_block(),
2198 * unmap_underlying_metadata() will find this block
2199 * and will try to get rid of it. damn, damn.
2200 *
2201 * If this block has already been committed to the
2202 * journal, a revoke record will be written. And
2203 * revoke records must be emitted *before* clearing
2204 * this block's bit in the bitmaps.
2205 */
2206 ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
2207
2208 /*
2209 * Everything below this this pointer has been
2210 * released. Now let this top-of-subtree go.
2211 *
2212 * We want the freeing of this indirect block to be
2213 * atomic in the journal with the updating of the
2214 * bitmap block which owns it. So make some room in
2215 * the journal.
2216 *
2217 * We zero the parent pointer *after* freeing its
2218 * pointee in the bitmaps, so if extend_transaction()
2219 * for some reason fails to put the bitmap changes and
2220 * the release into the same transaction, recovery
2221 * will merely complain about releasing a free block,
2222 * rather than leaking blocks.
2223 */
2224 if (is_handle_aborted(handle))
2225 return;
2226 if (try_to_extend_transaction(handle, inode)) {
2227 ext3_mark_inode_dirty(handle, inode);
2228 ext3_journal_test_restart(handle, inode);
2229 }
2230
2231 ext3_free_blocks(handle, inode, nr, 1);
2232
2233 if (parent_bh) {
2234 /*
2235 * The block which we have just freed is
2236 * pointed to by an indirect block: journal it
2237 */
2238 BUFFER_TRACE(parent_bh, "get_write_access");
2239 if (!ext3_journal_get_write_access(handle,
2240 parent_bh)){
2241 *p = 0;
2242 BUFFER_TRACE(parent_bh,
2243 "call ext3_journal_dirty_metadata");
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002244 ext3_journal_dirty_metadata(handle,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002245 parent_bh);
2246 }
2247 }
2248 }
2249 } else {
2250 /* We have reached the bottom of the tree. */
2251 BUFFER_TRACE(parent_bh, "free data blocks");
2252 ext3_free_data(handle, inode, parent_bh, first, last);
2253 }
2254}
2255
2256/*
2257 * ext3_truncate()
2258 *
2259 * We block out ext3_get_block() block instantiations across the entire
2260 * transaction, and VFS/VM ensures that ext3_truncate() cannot run
2261 * simultaneously on behalf of the same inode.
2262 *
2263 * As we work through the truncate and commmit bits of it to the journal there
2264 * is one core, guiding principle: the file's tree must always be consistent on
2265 * disk. We must be able to restart the truncate after a crash.
2266 *
2267 * The file's tree may be transiently inconsistent in memory (although it
2268 * probably isn't), but whenever we close off and commit a journal transaction,
2269 * the contents of (the filesystem + the journal) must be consistent and
2270 * restartable. It's pretty simple, really: bottom up, right to left (although
2271 * left-to-right works OK too).
2272 *
2273 * Note that at recovery time, journal replay occurs *before* the restart of
2274 * truncate against the orphan inode list.
2275 *
2276 * The committed inode has the new, desired i_size (which is the same as
2277 * i_disksize in this case). After a crash, ext3_orphan_cleanup() will see
2278 * that this inode's truncate did not complete and it will again call
2279 * ext3_truncate() to have another go. So there will be instantiated blocks
2280 * to the right of the truncation point in a crashed ext3 filesystem. But
2281 * that's fine - as long as they are linked from the inode, the post-crash
2282 * ext3_truncate() run will find them and release them.
2283 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08002284void ext3_truncate(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002285{
2286 handle_t *handle;
2287 struct ext3_inode_info *ei = EXT3_I(inode);
2288 __le32 *i_data = ei->i_data;
2289 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2290 struct address_space *mapping = inode->i_mapping;
2291 int offsets[4];
2292 Indirect chain[4];
2293 Indirect *partial;
2294 __le32 nr = 0;
2295 int n;
2296 long last_block;
2297 unsigned blocksize = inode->i_sb->s_blocksize;
2298 struct page *page;
2299
2300 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2301 S_ISLNK(inode->i_mode)))
2302 return;
2303 if (ext3_inode_is_fast_symlink(inode))
2304 return;
2305 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2306 return;
2307
2308 /*
2309 * We have to lock the EOF page here, because lock_page() nests
2310 * outside journal_start().
2311 */
2312 if ((inode->i_size & (blocksize - 1)) == 0) {
2313 /* Block boundary? Nothing to do */
2314 page = NULL;
2315 } else {
2316 page = grab_cache_page(mapping,
2317 inode->i_size >> PAGE_CACHE_SHIFT);
2318 if (!page)
2319 return;
2320 }
2321
2322 handle = start_transaction(inode);
2323 if (IS_ERR(handle)) {
2324 if (page) {
2325 clear_highpage(page);
2326 flush_dcache_page(page);
2327 unlock_page(page);
2328 page_cache_release(page);
2329 }
2330 return; /* AKPM: return what? */
2331 }
2332
2333 last_block = (inode->i_size + blocksize-1)
2334 >> EXT3_BLOCK_SIZE_BITS(inode->i_sb);
2335
2336 if (page)
2337 ext3_block_truncate_page(handle, page, mapping, inode->i_size);
2338
2339 n = ext3_block_to_path(inode, last_block, offsets, NULL);
2340 if (n == 0)
2341 goto out_stop; /* error */
2342
2343 /*
2344 * OK. This truncate is going to happen. We add the inode to the
2345 * orphan list, so that if this truncate spans multiple transactions,
2346 * and we crash, we will resume the truncate when the filesystem
2347 * recovers. It also marks the inode dirty, to catch the new size.
2348 *
2349 * Implication: the file must always be in a sane, consistent
2350 * truncatable state while each transaction commits.
2351 */
2352 if (ext3_orphan_add(handle, inode))
2353 goto out_stop;
2354
2355 /*
2356 * The orphan list entry will now protect us from any crash which
2357 * occurs before the truncate completes, so it is now safe to propagate
2358 * the new, shorter inode size (held for now in i_size) into the
2359 * on-disk inode. We do this via i_disksize, which is the value which
2360 * ext3 *really* writes onto the disk inode.
2361 */
2362 ei->i_disksize = inode->i_size;
2363
2364 /*
2365 * From here we block out all ext3_get_block() callers who want to
2366 * modify the block allocation tree.
2367 */
Arjan van de Ven97461512006-03-23 03:00:42 -08002368 mutex_lock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002369
2370 if (n == 1) { /* direct blocks */
2371 ext3_free_data(handle, inode, NULL, i_data+offsets[0],
2372 i_data + EXT3_NDIR_BLOCKS);
2373 goto do_indirects;
2374 }
2375
2376 partial = ext3_find_shared(inode, n, offsets, chain, &nr);
2377 /* Kill the top of shared branch (not detached) */
2378 if (nr) {
2379 if (partial == chain) {
2380 /* Shared branch grows from the inode */
2381 ext3_free_branches(handle, inode, NULL,
2382 &nr, &nr+1, (chain+n-1) - partial);
2383 *partial->p = 0;
2384 /*
2385 * We mark the inode dirty prior to restart,
2386 * and prior to stop. No need for it here.
2387 */
2388 } else {
2389 /* Shared branch grows from an indirect block */
2390 BUFFER_TRACE(partial->bh, "get_write_access");
2391 ext3_free_branches(handle, inode, partial->bh,
2392 partial->p,
2393 partial->p+1, (chain+n-1) - partial);
2394 }
2395 }
2396 /* Clear the ends of indirect blocks on the shared branch */
2397 while (partial > chain) {
2398 ext3_free_branches(handle, inode, partial->bh, partial->p + 1,
2399 (__le32*)partial->bh->b_data+addr_per_block,
2400 (chain+n-1) - partial);
2401 BUFFER_TRACE(partial->bh, "call brelse");
2402 brelse (partial->bh);
2403 partial--;
2404 }
2405do_indirects:
2406 /* Kill the remaining (whole) subtrees */
2407 switch (offsets[0]) {
Andrew Mortond6859bf2006-03-26 01:38:03 -08002408 default:
2409 nr = i_data[EXT3_IND_BLOCK];
2410 if (nr) {
2411 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
2412 i_data[EXT3_IND_BLOCK] = 0;
2413 }
2414 case EXT3_IND_BLOCK:
2415 nr = i_data[EXT3_DIND_BLOCK];
2416 if (nr) {
2417 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
2418 i_data[EXT3_DIND_BLOCK] = 0;
2419 }
2420 case EXT3_DIND_BLOCK:
2421 nr = i_data[EXT3_TIND_BLOCK];
2422 if (nr) {
2423 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
2424 i_data[EXT3_TIND_BLOCK] = 0;
2425 }
2426 case EXT3_TIND_BLOCK:
2427 ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002428 }
2429
2430 ext3_discard_reservation(inode);
2431
Arjan van de Ven97461512006-03-23 03:00:42 -08002432 mutex_unlock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002433 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
2434 ext3_mark_inode_dirty(handle, inode);
2435
Andrew Mortond6859bf2006-03-26 01:38:03 -08002436 /*
2437 * In a multi-transaction truncate, we only make the final transaction
2438 * synchronous
2439 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002440 if (IS_SYNC(inode))
2441 handle->h_sync = 1;
2442out_stop:
2443 /*
2444 * If this was a simple ftruncate(), and the file will remain alive
2445 * then we need to clear up the orphan record which we created above.
2446 * However, if this was a real unlink then we were called by
2447 * ext3_delete_inode(), and we allow that function to clean up the
2448 * orphan info for us.
2449 */
2450 if (inode->i_nlink)
2451 ext3_orphan_del(handle, inode);
2452
2453 ext3_journal_stop(handle);
2454}
2455
Mingming Cao43d23f92006-06-25 05:48:07 -07002456static ext3_fsblk_t ext3_get_inode_block(struct super_block *sb,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002457 unsigned long ino, struct ext3_iloc *iloc)
2458{
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002459 unsigned long block_group;
Mingming Cao43d23f92006-06-25 05:48:07 -07002460 unsigned long offset;
2461 ext3_fsblk_t block;
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002462 struct ext3_group_desc *gdp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002463
Neil Brown2ccb48e2006-07-30 03:03:01 -07002464 if (!ext3_valid_inum(sb, ino)) {
2465 /*
2466 * This error is already checked for in namei.c unless we are
2467 * looking at an NFS filehandle, in which case no error
2468 * report is needed
2469 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002470 return 0;
2471 }
Neil Brown2ccb48e2006-07-30 03:03:01 -07002472
Linus Torvalds1da177e2005-04-16 15:20:36 -07002473 block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002474 gdp = ext3_get_group_desc(sb, block_group, NULL);
2475 if (!gdp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002476 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002477 /*
2478 * Figure out the offset within the block group inode table
2479 */
2480 offset = ((ino - 1) % EXT3_INODES_PER_GROUP(sb)) *
2481 EXT3_INODE_SIZE(sb);
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002482 block = le32_to_cpu(gdp->bg_inode_table) +
Linus Torvalds1da177e2005-04-16 15:20:36 -07002483 (offset >> EXT3_BLOCK_SIZE_BITS(sb));
2484
2485 iloc->block_group = block_group;
2486 iloc->offset = offset & (EXT3_BLOCK_SIZE(sb) - 1);
2487 return block;
2488}
2489
2490/*
2491 * ext3_get_inode_loc returns with an extra refcount against the inode's
2492 * underlying buffer_head on success. If 'in_mem' is true, we have all
2493 * data in memory that is needed to recreate the on-disk version of this
2494 * inode.
2495 */
2496static int __ext3_get_inode_loc(struct inode *inode,
2497 struct ext3_iloc *iloc, int in_mem)
2498{
Mingming Cao43d23f92006-06-25 05:48:07 -07002499 ext3_fsblk_t block;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002500 struct buffer_head *bh;
2501
2502 block = ext3_get_inode_block(inode->i_sb, inode->i_ino, iloc);
2503 if (!block)
2504 return -EIO;
2505
2506 bh = sb_getblk(inode->i_sb, block);
2507 if (!bh) {
2508 ext3_error (inode->i_sb, "ext3_get_inode_loc",
2509 "unable to read inode block - "
Mingming Cao43d23f92006-06-25 05:48:07 -07002510 "inode=%lu, block="E3FSBLK,
2511 inode->i_ino, block);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002512 return -EIO;
2513 }
2514 if (!buffer_uptodate(bh)) {
2515 lock_buffer(bh);
2516 if (buffer_uptodate(bh)) {
2517 /* someone brought it uptodate while we waited */
2518 unlock_buffer(bh);
2519 goto has_buffer;
2520 }
2521
2522 /*
2523 * If we have all information of the inode in memory and this
2524 * is the only valid inode in the block, we need not read the
2525 * block.
2526 */
2527 if (in_mem) {
2528 struct buffer_head *bitmap_bh;
2529 struct ext3_group_desc *desc;
2530 int inodes_per_buffer;
2531 int inode_offset, i;
2532 int block_group;
2533 int start;
2534
2535 block_group = (inode->i_ino - 1) /
2536 EXT3_INODES_PER_GROUP(inode->i_sb);
2537 inodes_per_buffer = bh->b_size /
2538 EXT3_INODE_SIZE(inode->i_sb);
2539 inode_offset = ((inode->i_ino - 1) %
2540 EXT3_INODES_PER_GROUP(inode->i_sb));
2541 start = inode_offset & ~(inodes_per_buffer - 1);
2542
2543 /* Is the inode bitmap in cache? */
2544 desc = ext3_get_group_desc(inode->i_sb,
2545 block_group, NULL);
2546 if (!desc)
2547 goto make_io;
2548
2549 bitmap_bh = sb_getblk(inode->i_sb,
2550 le32_to_cpu(desc->bg_inode_bitmap));
2551 if (!bitmap_bh)
2552 goto make_io;
2553
2554 /*
2555 * If the inode bitmap isn't in cache then the
2556 * optimisation may end up performing two reads instead
2557 * of one, so skip it.
2558 */
2559 if (!buffer_uptodate(bitmap_bh)) {
2560 brelse(bitmap_bh);
2561 goto make_io;
2562 }
2563 for (i = start; i < start + inodes_per_buffer; i++) {
2564 if (i == inode_offset)
2565 continue;
2566 if (ext3_test_bit(i, bitmap_bh->b_data))
2567 break;
2568 }
2569 brelse(bitmap_bh);
2570 if (i == start + inodes_per_buffer) {
2571 /* all other inodes are free, so skip I/O */
2572 memset(bh->b_data, 0, bh->b_size);
2573 set_buffer_uptodate(bh);
2574 unlock_buffer(bh);
2575 goto has_buffer;
2576 }
2577 }
2578
2579make_io:
2580 /*
2581 * There are other valid inodes in the buffer, this inode
2582 * has in-inode xattrs, or we don't have this inode in memory.
2583 * Read the block from disk.
2584 */
2585 get_bh(bh);
2586 bh->b_end_io = end_buffer_read_sync;
Jens Axboecaa38fb2006-07-23 01:41:26 +02002587 submit_bh(READ_META, bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002588 wait_on_buffer(bh);
2589 if (!buffer_uptodate(bh)) {
2590 ext3_error(inode->i_sb, "ext3_get_inode_loc",
2591 "unable to read inode block - "
Mingming Cao43d23f92006-06-25 05:48:07 -07002592 "inode=%lu, block="E3FSBLK,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002593 inode->i_ino, block);
2594 brelse(bh);
2595 return -EIO;
2596 }
2597 }
2598has_buffer:
2599 iloc->bh = bh;
2600 return 0;
2601}
2602
2603int ext3_get_inode_loc(struct inode *inode, struct ext3_iloc *iloc)
2604{
2605 /* We have all inode data except xattrs in memory here. */
2606 return __ext3_get_inode_loc(inode, iloc,
2607 !(EXT3_I(inode)->i_state & EXT3_STATE_XATTR));
2608}
2609
2610void ext3_set_inode_flags(struct inode *inode)
2611{
2612 unsigned int flags = EXT3_I(inode)->i_flags;
2613
2614 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
2615 if (flags & EXT3_SYNC_FL)
2616 inode->i_flags |= S_SYNC;
2617 if (flags & EXT3_APPEND_FL)
2618 inode->i_flags |= S_APPEND;
2619 if (flags & EXT3_IMMUTABLE_FL)
2620 inode->i_flags |= S_IMMUTABLE;
2621 if (flags & EXT3_NOATIME_FL)
2622 inode->i_flags |= S_NOATIME;
2623 if (flags & EXT3_DIRSYNC_FL)
2624 inode->i_flags |= S_DIRSYNC;
2625}
2626
Jan Kara28be5ab2007-05-08 00:30:33 -07002627/* Propagate flags from i_flags to EXT3_I(inode)->i_flags */
2628void ext3_get_inode_flags(struct ext3_inode_info *ei)
2629{
2630 unsigned int flags = ei->vfs_inode.i_flags;
2631
2632 ei->i_flags &= ~(EXT3_SYNC_FL|EXT3_APPEND_FL|
2633 EXT3_IMMUTABLE_FL|EXT3_NOATIME_FL|EXT3_DIRSYNC_FL);
2634 if (flags & S_SYNC)
2635 ei->i_flags |= EXT3_SYNC_FL;
2636 if (flags & S_APPEND)
2637 ei->i_flags |= EXT3_APPEND_FL;
2638 if (flags & S_IMMUTABLE)
2639 ei->i_flags |= EXT3_IMMUTABLE_FL;
2640 if (flags & S_NOATIME)
2641 ei->i_flags |= EXT3_NOATIME_FL;
2642 if (flags & S_DIRSYNC)
2643 ei->i_flags |= EXT3_DIRSYNC_FL;
2644}
2645
David Howells473043d2008-02-07 00:15:36 -08002646struct inode *ext3_iget(struct super_block *sb, unsigned long ino)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002647{
2648 struct ext3_iloc iloc;
2649 struct ext3_inode *raw_inode;
David Howells473043d2008-02-07 00:15:36 -08002650 struct ext3_inode_info *ei;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002651 struct buffer_head *bh;
David Howells473043d2008-02-07 00:15:36 -08002652 struct inode *inode;
2653 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002654 int block;
2655
David Howells473043d2008-02-07 00:15:36 -08002656 inode = iget_locked(sb, ino);
2657 if (!inode)
2658 return ERR_PTR(-ENOMEM);
2659 if (!(inode->i_state & I_NEW))
2660 return inode;
2661
2662 ei = EXT3_I(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002663#ifdef CONFIG_EXT3_FS_POSIX_ACL
2664 ei->i_acl = EXT3_ACL_NOT_CACHED;
2665 ei->i_default_acl = EXT3_ACL_NOT_CACHED;
2666#endif
2667 ei->i_block_alloc_info = NULL;
2668
David Howells473043d2008-02-07 00:15:36 -08002669 ret = __ext3_get_inode_loc(inode, &iloc, 0);
2670 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002671 goto bad_inode;
2672 bh = iloc.bh;
2673 raw_inode = ext3_raw_inode(&iloc);
2674 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
2675 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
2676 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
2677 if(!(test_opt (inode->i_sb, NO_UID32))) {
2678 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
2679 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
2680 }
2681 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
2682 inode->i_size = le32_to_cpu(raw_inode->i_size);
Markus Rechberger4d7bf112007-05-08 00:23:39 -07002683 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
2684 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
2685 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002686 inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
2687
2688 ei->i_state = 0;
2689 ei->i_dir_start_lookup = 0;
2690 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
2691 /* We now have enough fields to check if the inode was active or not.
2692 * This is needed because nfsd might try to access dead inodes
2693 * the test is that same one that e2fsck uses
2694 * NeilBrown 1999oct15
2695 */
2696 if (inode->i_nlink == 0) {
2697 if (inode->i_mode == 0 ||
2698 !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) {
2699 /* this inode is deleted */
2700 brelse (bh);
David Howells473043d2008-02-07 00:15:36 -08002701 ret = -ESTALE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002702 goto bad_inode;
2703 }
2704 /* The only unlinked inodes we let through here have
2705 * valid i_mode and are being read by the orphan
2706 * recovery code: that's fine, we're about to complete
2707 * the process of deleting those. */
2708 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002709 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
2710 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
2711#ifdef EXT3_FRAGMENTS
2712 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
2713 ei->i_frag_no = raw_inode->i_frag;
2714 ei->i_frag_size = raw_inode->i_fsize;
2715#endif
2716 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
2717 if (!S_ISREG(inode->i_mode)) {
2718 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
2719 } else {
2720 inode->i_size |=
2721 ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
2722 }
2723 ei->i_disksize = inode->i_size;
2724 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
2725 ei->i_block_group = iloc.block_group;
2726 /*
2727 * NOTE! The in-memory inode i_data array is in little-endian order
2728 * even on big-endian machines: we do NOT byteswap the block numbers!
2729 */
2730 for (block = 0; block < EXT3_N_BLOCKS; block++)
2731 ei->i_data[block] = raw_inode->i_block[block];
2732 INIT_LIST_HEAD(&ei->i_orphan);
2733
2734 if (inode->i_ino >= EXT3_FIRST_INO(inode->i_sb) + 1 &&
2735 EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) {
2736 /*
2737 * When mke2fs creates big inodes it does not zero out
2738 * the unused bytes above EXT3_GOOD_OLD_INODE_SIZE,
2739 * so ignore those first few inodes.
2740 */
2741 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
2742 if (EXT3_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
Kirill Korotaeve4a10a32007-06-23 17:16:48 -07002743 EXT3_INODE_SIZE(inode->i_sb)) {
2744 brelse (bh);
David Howells473043d2008-02-07 00:15:36 -08002745 ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002746 goto bad_inode;
Kirill Korotaeve4a10a32007-06-23 17:16:48 -07002747 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002748 if (ei->i_extra_isize == 0) {
2749 /* The extra space is currently unused. Use it. */
2750 ei->i_extra_isize = sizeof(struct ext3_inode) -
2751 EXT3_GOOD_OLD_INODE_SIZE;
2752 } else {
2753 __le32 *magic = (void *)raw_inode +
2754 EXT3_GOOD_OLD_INODE_SIZE +
2755 ei->i_extra_isize;
2756 if (*magic == cpu_to_le32(EXT3_XATTR_MAGIC))
2757 ei->i_state |= EXT3_STATE_XATTR;
2758 }
2759 } else
2760 ei->i_extra_isize = 0;
2761
2762 if (S_ISREG(inode->i_mode)) {
2763 inode->i_op = &ext3_file_inode_operations;
2764 inode->i_fop = &ext3_file_operations;
2765 ext3_set_aops(inode);
2766 } else if (S_ISDIR(inode->i_mode)) {
2767 inode->i_op = &ext3_dir_inode_operations;
2768 inode->i_fop = &ext3_dir_operations;
2769 } else if (S_ISLNK(inode->i_mode)) {
2770 if (ext3_inode_is_fast_symlink(inode))
2771 inode->i_op = &ext3_fast_symlink_inode_operations;
2772 else {
2773 inode->i_op = &ext3_symlink_inode_operations;
2774 ext3_set_aops(inode);
2775 }
2776 } else {
2777 inode->i_op = &ext3_special_inode_operations;
2778 if (raw_inode->i_block[0])
2779 init_special_inode(inode, inode->i_mode,
2780 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002781 else
Linus Torvalds1da177e2005-04-16 15:20:36 -07002782 init_special_inode(inode, inode->i_mode,
2783 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
2784 }
2785 brelse (iloc.bh);
2786 ext3_set_inode_flags(inode);
David Howells473043d2008-02-07 00:15:36 -08002787 unlock_new_inode(inode);
2788 return inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002789
2790bad_inode:
David Howells473043d2008-02-07 00:15:36 -08002791 iget_failed(inode);
2792 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002793}
2794
2795/*
2796 * Post the struct inode info into an on-disk inode location in the
2797 * buffer-cache. This gobbles the caller's reference to the
2798 * buffer_head in the inode location struct.
2799 *
2800 * The caller must have write access to iloc->bh.
2801 */
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002802static int ext3_do_update_inode(handle_t *handle,
2803 struct inode *inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002804 struct ext3_iloc *iloc)
2805{
2806 struct ext3_inode *raw_inode = ext3_raw_inode(iloc);
2807 struct ext3_inode_info *ei = EXT3_I(inode);
2808 struct buffer_head *bh = iloc->bh;
2809 int err = 0, rc, block;
2810
2811 /* For fields not not tracking in the in-memory inode,
2812 * initialise them to zero for new inodes. */
2813 if (ei->i_state & EXT3_STATE_NEW)
2814 memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
2815
Jan Kara28be5ab2007-05-08 00:30:33 -07002816 ext3_get_inode_flags(ei);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002817 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
2818 if(!(test_opt(inode->i_sb, NO_UID32))) {
2819 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
2820 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
2821/*
2822 * Fix up interoperability with old kernels. Otherwise, old inodes get
2823 * re-used with the upper 16 bits of the uid/gid intact
2824 */
2825 if(!ei->i_dtime) {
2826 raw_inode->i_uid_high =
2827 cpu_to_le16(high_16_bits(inode->i_uid));
2828 raw_inode->i_gid_high =
2829 cpu_to_le16(high_16_bits(inode->i_gid));
2830 } else {
2831 raw_inode->i_uid_high = 0;
2832 raw_inode->i_gid_high = 0;
2833 }
2834 } else {
2835 raw_inode->i_uid_low =
2836 cpu_to_le16(fs_high2lowuid(inode->i_uid));
2837 raw_inode->i_gid_low =
2838 cpu_to_le16(fs_high2lowgid(inode->i_gid));
2839 raw_inode->i_uid_high = 0;
2840 raw_inode->i_gid_high = 0;
2841 }
2842 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
2843 raw_inode->i_size = cpu_to_le32(ei->i_disksize);
2844 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
2845 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
2846 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
2847 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
2848 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
2849 raw_inode->i_flags = cpu_to_le32(ei->i_flags);
2850#ifdef EXT3_FRAGMENTS
2851 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
2852 raw_inode->i_frag = ei->i_frag_no;
2853 raw_inode->i_fsize = ei->i_frag_size;
2854#endif
2855 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
2856 if (!S_ISREG(inode->i_mode)) {
2857 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
2858 } else {
2859 raw_inode->i_size_high =
2860 cpu_to_le32(ei->i_disksize >> 32);
2861 if (ei->i_disksize > 0x7fffffffULL) {
2862 struct super_block *sb = inode->i_sb;
2863 if (!EXT3_HAS_RO_COMPAT_FEATURE(sb,
2864 EXT3_FEATURE_RO_COMPAT_LARGE_FILE) ||
2865 EXT3_SB(sb)->s_es->s_rev_level ==
2866 cpu_to_le32(EXT3_GOOD_OLD_REV)) {
2867 /* If this is the first large file
2868 * created, add a flag to the superblock.
2869 */
2870 err = ext3_journal_get_write_access(handle,
2871 EXT3_SB(sb)->s_sbh);
2872 if (err)
2873 goto out_brelse;
2874 ext3_update_dynamic_rev(sb);
2875 EXT3_SET_RO_COMPAT_FEATURE(sb,
2876 EXT3_FEATURE_RO_COMPAT_LARGE_FILE);
2877 sb->s_dirt = 1;
2878 handle->h_sync = 1;
2879 err = ext3_journal_dirty_metadata(handle,
2880 EXT3_SB(sb)->s_sbh);
2881 }
2882 }
2883 }
2884 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
2885 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
2886 if (old_valid_dev(inode->i_rdev)) {
2887 raw_inode->i_block[0] =
2888 cpu_to_le32(old_encode_dev(inode->i_rdev));
2889 raw_inode->i_block[1] = 0;
2890 } else {
2891 raw_inode->i_block[0] = 0;
2892 raw_inode->i_block[1] =
2893 cpu_to_le32(new_encode_dev(inode->i_rdev));
2894 raw_inode->i_block[2] = 0;
2895 }
2896 } else for (block = 0; block < EXT3_N_BLOCKS; block++)
2897 raw_inode->i_block[block] = ei->i_data[block];
2898
Andreas Gruenbacherff87b372005-07-07 17:57:00 -07002899 if (ei->i_extra_isize)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002900 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
2901
2902 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
2903 rc = ext3_journal_dirty_metadata(handle, bh);
2904 if (!err)
2905 err = rc;
2906 ei->i_state &= ~EXT3_STATE_NEW;
2907
2908out_brelse:
2909 brelse (bh);
2910 ext3_std_error(inode->i_sb, err);
2911 return err;
2912}
2913
2914/*
2915 * ext3_write_inode()
2916 *
2917 * We are called from a few places:
2918 *
2919 * - Within generic_file_write() for O_SYNC files.
2920 * Here, there will be no transaction running. We wait for any running
2921 * trasnaction to commit.
2922 *
2923 * - Within sys_sync(), kupdate and such.
2924 * We wait on commit, if tol to.
2925 *
2926 * - Within prune_icache() (PF_MEMALLOC == true)
2927 * Here we simply return. We can't afford to block kswapd on the
2928 * journal commit.
2929 *
2930 * In all cases it is actually safe for us to return without doing anything,
2931 * because the inode has been copied into a raw inode buffer in
2932 * ext3_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
2933 * knfsd.
2934 *
2935 * Note that we are absolutely dependent upon all inode dirtiers doing the
2936 * right thing: they *must* call mark_inode_dirty() after dirtying info in
2937 * which we are interested.
2938 *
2939 * It would be a bug for them to not do this. The code:
2940 *
2941 * mark_inode_dirty(inode)
2942 * stuff();
2943 * inode->i_size = expr;
2944 *
2945 * is in error because a kswapd-driven write_inode() could occur while
2946 * `stuff()' is running, and the new i_size will be lost. Plus the inode
2947 * will no longer be on the superblock's dirty inode list.
2948 */
2949int ext3_write_inode(struct inode *inode, int wait)
2950{
2951 if (current->flags & PF_MEMALLOC)
2952 return 0;
2953
2954 if (ext3_journal_current_handle()) {
Jose R. Santos9ad163a2007-10-18 23:39:23 -07002955 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07002956 dump_stack();
2957 return -EIO;
2958 }
2959
2960 if (!wait)
2961 return 0;
2962
2963 return ext3_force_commit(inode->i_sb);
2964}
2965
2966/*
2967 * ext3_setattr()
2968 *
2969 * Called from notify_change.
2970 *
2971 * We want to trap VFS attempts to truncate the file as soon as
2972 * possible. In particular, we want to make sure that when the VFS
2973 * shrinks i_size, we put the inode on the orphan list and modify
2974 * i_disksize immediately, so that during the subsequent flushing of
2975 * dirty pages and freeing of disk blocks, we can guarantee that any
2976 * commit will leave the blocks being flushed in an unused state on
2977 * disk. (On recovery, the inode will get truncated and the blocks will
2978 * be freed, so we have a strong guarantee that no future commit will
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002979 * leave these blocks visible to the user.)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002980 *
2981 * Called with inode->sem down.
2982 */
2983int ext3_setattr(struct dentry *dentry, struct iattr *attr)
2984{
2985 struct inode *inode = dentry->d_inode;
2986 int error, rc = 0;
2987 const unsigned int ia_valid = attr->ia_valid;
2988
2989 error = inode_change_ok(inode, attr);
2990 if (error)
2991 return error;
2992
2993 if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
2994 (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
2995 handle_t *handle;
2996
2997 /* (user+group)*(old+new) structure, inode write (sb,
2998 * inode block, ? - but truncate inode update has it) */
Jan Kara1f545872005-06-23 22:01:04 -07002999 handle = ext3_journal_start(inode, 2*(EXT3_QUOTA_INIT_BLOCKS(inode->i_sb)+
3000 EXT3_QUOTA_DEL_BLOCKS(inode->i_sb))+3);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003001 if (IS_ERR(handle)) {
3002 error = PTR_ERR(handle);
3003 goto err_out;
3004 }
3005 error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0;
3006 if (error) {
3007 ext3_journal_stop(handle);
3008 return error;
3009 }
3010 /* Update corresponding info in inode so that everything is in
3011 * one transaction */
3012 if (attr->ia_valid & ATTR_UID)
3013 inode->i_uid = attr->ia_uid;
3014 if (attr->ia_valid & ATTR_GID)
3015 inode->i_gid = attr->ia_gid;
3016 error = ext3_mark_inode_dirty(handle, inode);
3017 ext3_journal_stop(handle);
3018 }
3019
3020 if (S_ISREG(inode->i_mode) &&
3021 attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
3022 handle_t *handle;
3023
3024 handle = ext3_journal_start(inode, 3);
3025 if (IS_ERR(handle)) {
3026 error = PTR_ERR(handle);
3027 goto err_out;
3028 }
3029
3030 error = ext3_orphan_add(handle, inode);
3031 EXT3_I(inode)->i_disksize = attr->ia_size;
3032 rc = ext3_mark_inode_dirty(handle, inode);
3033 if (!error)
3034 error = rc;
3035 ext3_journal_stop(handle);
3036 }
3037
3038 rc = inode_setattr(inode, attr);
3039
3040 /* If inode_setattr's call to ext3_truncate failed to get a
3041 * transaction handle at all, we need to clean up the in-core
3042 * orphan list manually. */
3043 if (inode->i_nlink)
3044 ext3_orphan_del(NULL, inode);
3045
3046 if (!rc && (ia_valid & ATTR_MODE))
3047 rc = ext3_acl_chmod(inode);
3048
3049err_out:
3050 ext3_std_error(inode->i_sb, error);
3051 if (!error)
3052 error = rc;
3053 return error;
3054}
3055
3056
3057/*
Andrew Mortond6859bf2006-03-26 01:38:03 -08003058 * How many blocks doth make a writepage()?
Linus Torvalds1da177e2005-04-16 15:20:36 -07003059 *
3060 * With N blocks per page, it may be:
3061 * N data blocks
3062 * 2 indirect block
3063 * 2 dindirect
3064 * 1 tindirect
3065 * N+5 bitmap blocks (from the above)
3066 * N+5 group descriptor summary blocks
3067 * 1 inode block
3068 * 1 superblock.
3069 * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quote files
3070 *
3071 * 3 * (N + 5) + 2 + 2 * EXT3_SINGLEDATA_TRANS_BLOCKS
3072 *
3073 * With ordered or writeback data it's the same, less the N data blocks.
3074 *
3075 * If the inode's direct blocks can hold an integral number of pages then a
3076 * page cannot straddle two indirect blocks, and we can only touch one indirect
3077 * and dindirect block, and the "5" above becomes "3".
3078 *
3079 * This still overestimates under most circumstances. If we were to pass the
3080 * start and end offsets in here as well we could do block_to_path() on each
3081 * block and work out the exact number of indirects which are touched. Pah.
3082 */
3083
3084static int ext3_writepage_trans_blocks(struct inode *inode)
3085{
3086 int bpp = ext3_journal_blocks_per_page(inode);
3087 int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3;
3088 int ret;
3089
3090 if (ext3_should_journal_data(inode))
3091 ret = 3 * (bpp + indirects) + 2;
3092 else
3093 ret = 2 * (bpp + indirects) + 2;
3094
3095#ifdef CONFIG_QUOTA
3096 /* We know that structure was already allocated during DQUOT_INIT so
3097 * we will be updating only the data blocks + inodes */
Jan Kara1f545872005-06-23 22:01:04 -07003098 ret += 2*EXT3_QUOTA_TRANS_BLOCKS(inode->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003099#endif
3100
3101 return ret;
3102}
3103
3104/*
3105 * The caller must have previously called ext3_reserve_inode_write().
3106 * Give this, we know that the caller already has write access to iloc->bh.
3107 */
3108int ext3_mark_iloc_dirty(handle_t *handle,
3109 struct inode *inode, struct ext3_iloc *iloc)
3110{
3111 int err = 0;
3112
3113 /* the do_update_inode consumes one bh->b_count */
3114 get_bh(iloc->bh);
3115
3116 /* ext3_do_update_inode() does journal_dirty_metadata */
3117 err = ext3_do_update_inode(handle, inode, iloc);
3118 put_bh(iloc->bh);
3119 return err;
3120}
3121
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003122/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003123 * On success, We end up with an outstanding reference count against
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003124 * iloc->bh. This _must_ be cleaned up later.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003125 */
3126
3127int
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003128ext3_reserve_inode_write(handle_t *handle, struct inode *inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003129 struct ext3_iloc *iloc)
3130{
3131 int err = 0;
3132 if (handle) {
3133 err = ext3_get_inode_loc(inode, iloc);
3134 if (!err) {
3135 BUFFER_TRACE(iloc->bh, "get_write_access");
3136 err = ext3_journal_get_write_access(handle, iloc->bh);
3137 if (err) {
3138 brelse(iloc->bh);
3139 iloc->bh = NULL;
3140 }
3141 }
3142 }
3143 ext3_std_error(inode->i_sb, err);
3144 return err;
3145}
3146
3147/*
Andrew Mortond6859bf2006-03-26 01:38:03 -08003148 * What we do here is to mark the in-core inode as clean with respect to inode
3149 * dirtiness (it may still be data-dirty).
Linus Torvalds1da177e2005-04-16 15:20:36 -07003150 * This means that the in-core inode may be reaped by prune_icache
3151 * without having to perform any I/O. This is a very good thing,
3152 * because *any* task may call prune_icache - even ones which
3153 * have a transaction open against a different journal.
3154 *
3155 * Is this cheating? Not really. Sure, we haven't written the
3156 * inode out, but prune_icache isn't a user-visible syncing function.
3157 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
3158 * we start and wait on commits.
3159 *
3160 * Is this efficient/effective? Well, we're being nice to the system
3161 * by cleaning up our inodes proactively so they can be reaped
3162 * without I/O. But we are potentially leaving up to five seconds'
3163 * worth of inodes floating about which prune_icache wants us to
3164 * write out. One way to fix that would be to get prune_icache()
3165 * to do a write_super() to free up some memory. It has the desired
3166 * effect.
3167 */
3168int ext3_mark_inode_dirty(handle_t *handle, struct inode *inode)
3169{
3170 struct ext3_iloc iloc;
3171 int err;
3172
3173 might_sleep();
3174 err = ext3_reserve_inode_write(handle, inode, &iloc);
3175 if (!err)
3176 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
3177 return err;
3178}
3179
3180/*
Andrew Mortond6859bf2006-03-26 01:38:03 -08003181 * ext3_dirty_inode() is called from __mark_inode_dirty()
Linus Torvalds1da177e2005-04-16 15:20:36 -07003182 *
3183 * We're really interested in the case where a file is being extended.
3184 * i_size has been changed by generic_commit_write() and we thus need
3185 * to include the updated inode in the current transaction.
3186 *
3187 * Also, DQUOT_ALLOC_SPACE() will always dirty the inode when blocks
3188 * are allocated to the file.
3189 *
3190 * If the inode is marked synchronous, we don't honour that here - doing
3191 * so would cause a commit on atime updates, which we don't bother doing.
3192 * We handle synchronous inodes at the highest possible level.
3193 */
3194void ext3_dirty_inode(struct inode *inode)
3195{
3196 handle_t *current_handle = ext3_journal_current_handle();
3197 handle_t *handle;
3198
3199 handle = ext3_journal_start(inode, 2);
3200 if (IS_ERR(handle))
3201 goto out;
3202 if (current_handle &&
3203 current_handle->h_transaction != handle->h_transaction) {
3204 /* This task has a transaction open against a different fs */
3205 printk(KERN_EMERG "%s: transactions do not match!\n",
Harvey Harrisone05b6b52008-04-28 02:16:15 -07003206 __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003207 } else {
3208 jbd_debug(5, "marking dirty. outer handle=%p\n",
3209 current_handle);
3210 ext3_mark_inode_dirty(handle, inode);
3211 }
3212 ext3_journal_stop(handle);
3213out:
3214 return;
3215}
3216
Andrew Mortond6859bf2006-03-26 01:38:03 -08003217#if 0
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003218/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003219 * Bind an inode's backing buffer_head into this transaction, to prevent
3220 * it from being flushed to disk early. Unlike
3221 * ext3_reserve_inode_write, this leaves behind no bh reference and
3222 * returns no iloc structure, so the caller needs to repeat the iloc
3223 * lookup to mark the inode dirty later.
3224 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08003225static int ext3_pin_inode(handle_t *handle, struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003226{
3227 struct ext3_iloc iloc;
3228
3229 int err = 0;
3230 if (handle) {
3231 err = ext3_get_inode_loc(inode, &iloc);
3232 if (!err) {
3233 BUFFER_TRACE(iloc.bh, "get_write_access");
3234 err = journal_get_write_access(handle, iloc.bh);
3235 if (!err)
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003236 err = ext3_journal_dirty_metadata(handle,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003237 iloc.bh);
3238 brelse(iloc.bh);
3239 }
3240 }
3241 ext3_std_error(inode->i_sb, err);
3242 return err;
3243}
3244#endif
3245
3246int ext3_change_inode_journal_flag(struct inode *inode, int val)
3247{
3248 journal_t *journal;
3249 handle_t *handle;
3250 int err;
3251
3252 /*
3253 * We have to be very careful here: changing a data block's
3254 * journaling status dynamically is dangerous. If we write a
3255 * data block to the journal, change the status and then delete
3256 * that block, we risk forgetting to revoke the old log record
3257 * from the journal and so a subsequent replay can corrupt data.
3258 * So, first we make sure that the journal is empty and that
3259 * nobody is changing anything.
3260 */
3261
3262 journal = EXT3_JOURNAL(inode);
Dave Hansene3a68e32007-07-15 23:41:14 -07003263 if (is_journal_aborted(journal))
Linus Torvalds1da177e2005-04-16 15:20:36 -07003264 return -EROFS;
3265
3266 journal_lock_updates(journal);
3267 journal_flush(journal);
3268
3269 /*
3270 * OK, there are no updates running now, and all cached data is
3271 * synced to disk. We are now in a completely consistent state
3272 * which doesn't have anything in the journal, and we know that
3273 * no filesystem updates are running, so it is safe to modify
3274 * the inode's in-core data-journaling state flag now.
3275 */
3276
3277 if (val)
3278 EXT3_I(inode)->i_flags |= EXT3_JOURNAL_DATA_FL;
3279 else
3280 EXT3_I(inode)->i_flags &= ~EXT3_JOURNAL_DATA_FL;
3281 ext3_set_aops(inode);
3282
3283 journal_unlock_updates(journal);
3284
3285 /* Finally we can mark the inode as dirty. */
3286
3287 handle = ext3_journal_start(inode, 1);
3288 if (IS_ERR(handle))
3289 return PTR_ERR(handle);
3290
3291 err = ext3_mark_inode_dirty(handle, inode);
3292 handle->h_sync = 1;
3293 ext3_journal_stop(handle);
3294 ext3_std_error(inode->i_sb, err);
3295
3296 return err;
3297}