blob: 735f0190ec2abe8dd68320cf5dc0a188f67af9c9 [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>
Josef Bacik68c9d702008-10-03 17:32:43 -040039#include <linux/fiemap.h>
Duane Griffinb5ed3112008-12-19 20:47:14 +000040#include <linux/namei.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#include "xattr.h"
42#include "acl.h"
43
44static int ext3_writepage_trans_blocks(struct inode *inode);
45
46/*
47 * Test whether an inode is a fast symlink.
48 */
Andrew Mortond6859bf2006-03-26 01:38:03 -080049static int ext3_inode_is_fast_symlink(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -070050{
51 int ea_blocks = EXT3_I(inode)->i_file_acl ?
52 (inode->i_sb->s_blocksize >> 9) : 0;
53
Andrew Mortond6859bf2006-03-26 01:38:03 -080054 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070055}
56
Andrew Mortond6859bf2006-03-26 01:38:03 -080057/*
58 * The ext3 forget function must perform a revoke if we are freeing data
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 * which has been journaled. Metadata (eg. indirect blocks) must be
Mingming Caoae6ddcc2006-09-27 01:49:27 -070060 * revoked in all cases.
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 *
62 * "bh" may be NULL: a metadata block may have been freed from memory
63 * but there may still be a record of it in the journal, and that record
64 * still needs to be revoked.
65 */
Andrew Mortond6859bf2006-03-26 01:38:03 -080066int ext3_forget(handle_t *handle, int is_metadata, struct inode *inode,
Mingming Cao1c2bf372006-06-25 05:48:06 -070067 struct buffer_head *bh, ext3_fsblk_t blocknr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070068{
69 int err;
70
71 might_sleep();
72
73 BUFFER_TRACE(bh, "enter");
74
75 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
76 "data mode %lx\n",
77 bh, is_metadata, inode->i_mode,
78 test_opt(inode->i_sb, DATA_FLAGS));
79
80 /* Never use the revoke function if we are doing full data
81 * journaling: there is no need to, and a V1 superblock won't
82 * support it. Otherwise, only skip the revoke on un-journaled
83 * data blocks. */
84
85 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ||
86 (!is_metadata && !ext3_should_journal_data(inode))) {
87 if (bh) {
88 BUFFER_TRACE(bh, "call journal_forget");
89 return ext3_journal_forget(handle, bh);
90 }
91 return 0;
92 }
93
94 /*
95 * data!=journal && (is_metadata || should_journal_data(inode))
96 */
97 BUFFER_TRACE(bh, "call ext3_journal_revoke");
98 err = ext3_journal_revoke(handle, blocknr, bh);
99 if (err)
Harvey Harrisone05b6b52008-04-28 02:16:15 -0700100 ext3_abort(inode->i_sb, __func__,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 "error %d when attempting revoke", err);
102 BUFFER_TRACE(bh, "exit");
103 return err;
104}
105
106/*
Andrew Mortond6859bf2006-03-26 01:38:03 -0800107 * Work out how many blocks we need to proceed with the next chunk of a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 * truncate transaction.
109 */
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700110static unsigned long blocks_for_truncate(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111{
112 unsigned long needed;
113
114 needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
115
116 /* Give ourselves just enough room to cope with inodes in which
117 * i_blocks is corrupt: we've seen disk corruptions in the past
118 * which resulted in random data in an inode which looked enough
119 * like a regular file for ext3 to try to delete it. Things
120 * will go a bit crazy if that happens, but at least we should
121 * try not to panic the whole kernel. */
122 if (needed < 2)
123 needed = 2;
124
125 /* But we need to bound the transaction so we don't overflow the
126 * journal. */
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700127 if (needed > EXT3_MAX_TRANS_DATA)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 needed = EXT3_MAX_TRANS_DATA;
129
Jan Kara1f545872005-06-23 22:01:04 -0700130 return EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131}
132
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700133/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 * Truncate transactions can be complex and absolutely huge. So we need to
135 * be able to restart the transaction at a conventient checkpoint to make
136 * sure we don't overflow the journal.
137 *
138 * start_transaction gets us a new handle for a truncate transaction,
139 * and extend_transaction tries to extend the existing one a bit. If
140 * extend fails, we need to propagate the failure up and restart the
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700141 * transaction in the top-level truncate loop. --sct
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 */
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700143static handle_t *start_transaction(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144{
145 handle_t *result;
146
147 result = ext3_journal_start(inode, blocks_for_truncate(inode));
148 if (!IS_ERR(result))
149 return result;
150
151 ext3_std_error(inode->i_sb, PTR_ERR(result));
152 return result;
153}
154
155/*
156 * Try to extend this transaction for the purposes of truncation.
157 *
158 * Returns 0 if we managed to create more room. If we can't create more
159 * room, and the transaction must be restarted we return 1.
160 */
161static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
162{
163 if (handle->h_buffer_credits > EXT3_RESERVE_TRANS_BLOCKS)
164 return 0;
165 if (!ext3_journal_extend(handle, blocks_for_truncate(inode)))
166 return 0;
167 return 1;
168}
169
170/*
171 * Restart the transaction associated with *handle. This does a commit,
172 * so before we call here everything must be consistently dirtied against
173 * this transaction.
174 */
Jan Kara00171d32009-08-11 19:06:10 +0200175static int truncate_restart_transaction(handle_t *handle, struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176{
Jan Kara00171d32009-08-11 19:06:10 +0200177 int ret;
178
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 jbd_debug(2, "restarting handle %p\n", handle);
Jan Kara00171d32009-08-11 19:06:10 +0200180 /*
181 * Drop truncate_mutex to avoid deadlock with ext3_get_blocks_handle
182 * At this moment, get_block can be called only for blocks inside
183 * i_size since page cache has been already dropped and writes are
184 * blocked by i_mutex. So we can safely drop the truncate_mutex.
185 */
186 mutex_unlock(&EXT3_I(inode)->truncate_mutex);
187 ret = ext3_journal_restart(handle, blocks_for_truncate(inode));
188 mutex_lock(&EXT3_I(inode)->truncate_mutex);
189 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190}
191
192/*
193 * Called at the last iput() if i_nlink is zero.
194 */
195void ext3_delete_inode (struct inode * inode)
196{
197 handle_t *handle;
198
Christoph Hellwig907f4552010-03-03 09:05:06 -0500199 if (!is_bad_inode(inode))
Christoph Hellwig871a2932010-03-03 09:05:07 -0500200 dquot_initialize(inode);
Christoph Hellwig907f4552010-03-03 09:05:06 -0500201
Mark Fashehfef26652005-09-09 13:01:31 -0700202 truncate_inode_pages(&inode->i_data, 0);
203
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 if (is_bad_inode(inode))
205 goto no_delete;
206
207 handle = start_transaction(inode);
208 if (IS_ERR(handle)) {
Andrew Mortond6859bf2006-03-26 01:38:03 -0800209 /*
210 * If we're going to skip the normal cleanup, we still need to
211 * make sure that the in-core orphan linked list is properly
212 * cleaned up.
213 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 ext3_orphan_del(NULL, inode);
215 goto no_delete;
216 }
217
218 if (IS_SYNC(inode))
219 handle->h_sync = 1;
220 inode->i_size = 0;
221 if (inode->i_blocks)
222 ext3_truncate(inode);
223 /*
224 * Kill off the orphan record which ext3_truncate created.
225 * AKPM: I think this can be inside the above `if'.
226 * Note that ext3_orphan_del() has to be able to cope with the
227 * deletion of a non-existent orphan - this is because we don't
228 * know if ext3_truncate() actually created an orphan record.
229 * (Well, we could do this if we need to, but heck - it works)
230 */
231 ext3_orphan_del(handle, inode);
232 EXT3_I(inode)->i_dtime = get_seconds();
233
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700234 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 * One subtle ordering requirement: if anything has gone wrong
236 * (transaction abort, IO errors, whatever), then we can still
237 * do these next steps (the fs will already have been marked as
238 * having errors), but we can't free the inode if the mark_dirty
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700239 * fails.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 */
241 if (ext3_mark_inode_dirty(handle, inode))
242 /* If that failed, just do the required in-core inode clear. */
243 clear_inode(inode);
244 else
245 ext3_free_inode(handle, inode);
246 ext3_journal_stop(handle);
247 return;
248no_delete:
249 clear_inode(inode); /* We must guarantee clearing of inode... */
250}
251
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252typedef struct {
253 __le32 *p;
254 __le32 key;
255 struct buffer_head *bh;
256} Indirect;
257
258static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
259{
260 p->key = *(p->p = v);
261 p->bh = bh;
262}
263
Andrew Mortond6859bf2006-03-26 01:38:03 -0800264static int verify_chain(Indirect *from, Indirect *to)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265{
266 while (from <= to && from->key == *from->p)
267 from++;
268 return (from > to);
269}
270
271/**
272 * ext3_block_to_path - parse the block number into array of offsets
273 * @inode: inode in question (we are only interested in its superblock)
274 * @i_block: block number to be parsed
275 * @offsets: array to store the offsets in
276 * @boundary: set this non-zero if the referred-to block is likely to be
277 * followed (on disk) by an indirect block.
278 *
279 * To store the locations of file's data ext3 uses a data structure common
280 * for UNIX filesystems - tree of pointers anchored in the inode, with
281 * data blocks at leaves and indirect blocks in intermediate nodes.
282 * This function translates the block number into path in that tree -
283 * return value is the path length and @offsets[n] is the offset of
284 * pointer to (n+1)th node in the nth one. If @block is out of range
285 * (negative or too large) warning is printed and zero returned.
286 *
287 * Note: function doesn't find node addresses, so no IO is needed. All
288 * we need to know is the capacity of indirect blocks (taken from the
289 * inode->i_sb).
290 */
291
292/*
293 * Portability note: the last comparison (check that we fit into triple
294 * indirect block) is spelled differently, because otherwise on an
295 * architecture with 32-bit longs and 8Kb pages we might get into trouble
296 * if our filesystem had 8Kb blocks. We might use long long, but that would
297 * kill us on x86. Oh, well, at least the sign propagation does not matter -
298 * i_block would have to be negative in the very beginning, so we would not
299 * get there at all.
300 */
301
302static int ext3_block_to_path(struct inode *inode,
303 long i_block, int offsets[4], int *boundary)
304{
305 int ptrs = EXT3_ADDR_PER_BLOCK(inode->i_sb);
306 int ptrs_bits = EXT3_ADDR_PER_BLOCK_BITS(inode->i_sb);
307 const long direct_blocks = EXT3_NDIR_BLOCKS,
308 indirect_blocks = ptrs,
309 double_blocks = (1 << (ptrs_bits * 2));
310 int n = 0;
311 int final = 0;
312
313 if (i_block < 0) {
314 ext3_warning (inode->i_sb, "ext3_block_to_path", "block < 0");
315 } else if (i_block < direct_blocks) {
316 offsets[n++] = i_block;
317 final = direct_blocks;
318 } else if ( (i_block -= direct_blocks) < indirect_blocks) {
319 offsets[n++] = EXT3_IND_BLOCK;
320 offsets[n++] = i_block;
321 final = ptrs;
322 } else if ((i_block -= indirect_blocks) < double_blocks) {
323 offsets[n++] = EXT3_DIND_BLOCK;
324 offsets[n++] = i_block >> ptrs_bits;
325 offsets[n++] = i_block & (ptrs - 1);
326 final = ptrs;
327 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
328 offsets[n++] = EXT3_TIND_BLOCK;
329 offsets[n++] = i_block >> (ptrs_bits * 2);
330 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
331 offsets[n++] = i_block & (ptrs - 1);
332 final = ptrs;
333 } else {
Andrew Mortond6859bf2006-03-26 01:38:03 -0800334 ext3_warning(inode->i_sb, "ext3_block_to_path", "block > big");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 }
336 if (boundary)
Mingming Cao89747d32006-03-26 01:37:55 -0800337 *boundary = final - 1 - (i_block & (ptrs - 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 return n;
339}
340
341/**
342 * ext3_get_branch - read the chain of indirect blocks leading to data
343 * @inode: inode in question
344 * @depth: depth of the chain (1 - direct pointer, etc.)
345 * @offsets: offsets of pointers in inode/indirect blocks
346 * @chain: place to store the result
347 * @err: here we store the error value
348 *
349 * Function fills the array of triples <key, p, bh> and returns %NULL
350 * if everything went OK or the pointer to the last filled triple
351 * (incomplete one) otherwise. Upon the return chain[i].key contains
352 * the number of (i+1)-th block in the chain (as it is stored in memory,
353 * i.e. little-endian 32-bit), chain[i].p contains the address of that
354 * number (it points into struct inode for i==0 and into the bh->b_data
355 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
356 * block for i>0 and NULL for i==0. In other words, it holds the block
357 * numbers of the chain, addresses they were taken from (and where we can
358 * verify that chain did not change) and buffer_heads hosting these
359 * numbers.
360 *
361 * Function stops when it stumbles upon zero pointer (absent block)
362 * (pointer to last triple returned, *@err == 0)
363 * or when it gets an IO error reading an indirect block
364 * (ditto, *@err == -EIO)
365 * or when it notices that chain had been changed while it was reading
366 * (ditto, *@err == -EAGAIN)
367 * or when it reads all @depth-1 indirect blocks successfully and finds
368 * the whole chain, all way to the data (returns %NULL, *err == 0).
369 */
370static Indirect *ext3_get_branch(struct inode *inode, int depth, int *offsets,
371 Indirect chain[4], int *err)
372{
373 struct super_block *sb = inode->i_sb;
374 Indirect *p = chain;
375 struct buffer_head *bh;
376
377 *err = 0;
378 /* i_data is not going away, no lock needed */
379 add_chain (chain, NULL, EXT3_I(inode)->i_data + *offsets);
380 if (!p->key)
381 goto no_block;
382 while (--depth) {
383 bh = sb_bread(sb, le32_to_cpu(p->key));
384 if (!bh)
385 goto failure;
386 /* Reader: pointers */
387 if (!verify_chain(chain, p))
388 goto changed;
389 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
390 /* Reader: end */
391 if (!p->key)
392 goto no_block;
393 }
394 return NULL;
395
396changed:
397 brelse(bh);
398 *err = -EAGAIN;
399 goto no_block;
400failure:
401 *err = -EIO;
402no_block:
403 return p;
404}
405
406/**
407 * ext3_find_near - find a place for allocation with sufficient locality
408 * @inode: owner
409 * @ind: descriptor of indirect block.
410 *
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000411 * This function returns the preferred place for block allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 * It is used when heuristic for sequential allocation fails.
413 * Rules are:
414 * + if there is a block to the left of our position - allocate near it.
415 * + if pointer will live in indirect block - allocate near that block.
416 * + if pointer will live in inode - allocate in the same
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700417 * cylinder group.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 *
419 * In the latter case we colour the starting block by the callers PID to
420 * prevent it from clashing with concurrent allocations for a different inode
421 * in the same block group. The PID is used here so that functionally related
422 * files will be close-by on-disk.
423 *
424 * Caller must make sure that @ind is valid and will stay that way.
425 */
Mingming Cao43d23f92006-06-25 05:48:07 -0700426static ext3_fsblk_t ext3_find_near(struct inode *inode, Indirect *ind)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427{
428 struct ext3_inode_info *ei = EXT3_I(inode);
429 __le32 *start = ind->bh ? (__le32*) ind->bh->b_data : ei->i_data;
430 __le32 *p;
Mingming Cao43d23f92006-06-25 05:48:07 -0700431 ext3_fsblk_t bg_start;
432 ext3_grpblk_t colour;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433
434 /* Try to find previous block */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800435 for (p = ind->p - 1; p >= start; p--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436 if (*p)
437 return le32_to_cpu(*p);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800438 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439
440 /* No such thing, so let's try location of indirect block */
441 if (ind->bh)
442 return ind->bh->b_blocknr;
443
444 /*
Andrew Mortond6859bf2006-03-26 01:38:03 -0800445 * It is going to be referred to from the inode itself? OK, just put it
446 * into the same cylinder group then.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 */
Mingming Cao43d23f92006-06-25 05:48:07 -0700448 bg_start = ext3_group_first_block_no(inode->i_sb, ei->i_block_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 colour = (current->pid % 16) *
450 (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
451 return bg_start + colour;
452}
453
454/**
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000455 * ext3_find_goal - find a preferred place for allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 * @inode: owner
457 * @block: block we want
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 * @partial: pointer to the last triple within a chain
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 *
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000460 * Normally this function find the preferred place for block allocation,
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800461 * returns it.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 */
463
Mingming Cao43d23f92006-06-25 05:48:07 -0700464static ext3_fsblk_t ext3_find_goal(struct inode *inode, long block,
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800465 Indirect *partial)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466{
Andrew Mortond6859bf2006-03-26 01:38:03 -0800467 struct ext3_block_alloc_info *block_i;
468
469 block_i = EXT3_I(inode)->i_block_alloc_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470
471 /*
472 * try the heuristic for sequential allocation,
473 * failing that at least try to get decent locality.
474 */
475 if (block_i && (block == block_i->last_alloc_logical_block + 1)
476 && (block_i->last_alloc_physical_block != 0)) {
Mingming Caofe55c452005-05-01 08:59:20 -0700477 return block_i->last_alloc_physical_block + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 }
479
Mingming Caofe55c452005-05-01 08:59:20 -0700480 return ext3_find_near(inode, partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481}
Andrew Mortond6859bf2006-03-26 01:38:03 -0800482
Mingming Caob47b2472006-03-26 01:37:56 -0800483/**
484 * ext3_blks_to_allocate: Look up the block map and count the number
485 * of direct blocks need to be allocated for the given branch.
486 *
Dave Kleikampe9ad5622006-09-27 01:49:35 -0700487 * @branch: chain of indirect blocks
Mingming Caob47b2472006-03-26 01:37:56 -0800488 * @k: number of blocks need for indirect blocks
489 * @blks: number of data blocks to be mapped.
490 * @blocks_to_boundary: the offset in the indirect block
491 *
492 * return the total number of blocks to be allocate, including the
493 * direct and indirect blocks.
494 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800495static int ext3_blks_to_allocate(Indirect *branch, int k, unsigned long blks,
Mingming Caob47b2472006-03-26 01:37:56 -0800496 int blocks_to_boundary)
497{
498 unsigned long count = 0;
499
500 /*
501 * Simple case, [t,d]Indirect block(s) has not allocated yet
502 * then it's clear blocks on that path have not allocated
503 */
504 if (k > 0) {
Andrew Mortond6859bf2006-03-26 01:38:03 -0800505 /* right now we don't handle cross boundary allocation */
Mingming Caob47b2472006-03-26 01:37:56 -0800506 if (blks < blocks_to_boundary + 1)
507 count += blks;
508 else
509 count += blocks_to_boundary + 1;
510 return count;
511 }
512
513 count++;
514 while (count < blks && count <= blocks_to_boundary &&
515 le32_to_cpu(*(branch[0].p + count)) == 0) {
516 count++;
517 }
518 return count;
519}
520
521/**
522 * ext3_alloc_blocks: multiple allocate blocks needed for a branch
523 * @indirect_blks: the number of blocks need to allocate for indirect
524 * blocks
525 *
526 * @new_blocks: on return it will store the new block numbers for
527 * the indirect blocks(if needed) and the first direct block,
528 * @blks: on return it will store the total number of allocated
529 * direct blocks
530 */
531static int ext3_alloc_blocks(handle_t *handle, struct inode *inode,
Mingming Cao43d23f92006-06-25 05:48:07 -0700532 ext3_fsblk_t goal, int indirect_blks, int blks,
533 ext3_fsblk_t new_blocks[4], int *err)
Mingming Caob47b2472006-03-26 01:37:56 -0800534{
535 int target, i;
536 unsigned long count = 0;
537 int index = 0;
Mingming Cao43d23f92006-06-25 05:48:07 -0700538 ext3_fsblk_t current_block = 0;
Mingming Caob47b2472006-03-26 01:37:56 -0800539 int ret = 0;
540
541 /*
542 * Here we try to allocate the requested multiple blocks at once,
543 * on a best-effort basis.
544 * To build a branch, we should allocate blocks for
545 * the indirect blocks(if not allocated yet), and at least
546 * the first direct block of this branch. That's the
547 * minimum number of blocks need to allocate(required)
548 */
549 target = blks + indirect_blks;
550
551 while (1) {
552 count = target;
553 /* allocating blocks for indirect blocks and direct blocks */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800554 current_block = ext3_new_blocks(handle,inode,goal,&count,err);
Mingming Caob47b2472006-03-26 01:37:56 -0800555 if (*err)
556 goto failed_out;
557
558 target -= count;
559 /* allocate blocks for indirect blocks */
560 while (index < indirect_blks && count) {
561 new_blocks[index++] = current_block++;
562 count--;
563 }
564
565 if (count > 0)
566 break;
567 }
568
569 /* save the new block number for the first direct block */
570 new_blocks[index] = current_block;
571
572 /* total number of blocks allocated for direct blocks */
573 ret = count;
574 *err = 0;
575 return ret;
576failed_out:
577 for (i = 0; i <index; i++)
578 ext3_free_blocks(handle, inode, new_blocks[i], 1);
579 return ret;
580}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581
582/**
583 * ext3_alloc_branch - allocate and set up a chain of blocks.
584 * @inode: owner
Mingming Caob47b2472006-03-26 01:37:56 -0800585 * @indirect_blks: number of allocated indirect blocks
586 * @blks: number of allocated direct blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -0700587 * @offsets: offsets (in the blocks) to store the pointers to next.
588 * @branch: place to store the chain in.
589 *
Mingming Caob47b2472006-03-26 01:37:56 -0800590 * This function allocates blocks, zeroes out all but the last one,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700591 * links them into chain and (if we are synchronous) writes them to disk.
592 * In other words, it prepares a branch that can be spliced onto the
593 * inode. It stores the information about that chain in the branch[], in
594 * the same format as ext3_get_branch() would do. We are calling it after
595 * we had read the existing part of chain and partial points to the last
596 * triple of that (one with zero ->key). Upon the exit we have the same
Glauber de Oliveira Costa5b116872005-10-30 15:02:48 -0800597 * picture as after the successful ext3_get_block(), except that in one
Linus Torvalds1da177e2005-04-16 15:20:36 -0700598 * place chain is disconnected - *branch->p is still zero (we did not
599 * set the last link), but branch->key contains the number that should
600 * be placed into *branch->p to fill that gap.
601 *
602 * If allocation fails we free all blocks we've allocated (and forget
603 * their buffer_heads) and return the error value the from failed
604 * ext3_alloc_block() (normally -ENOSPC). Otherwise we set the chain
605 * as described above and return 0.
606 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
Mingming Cao43d23f92006-06-25 05:48:07 -0700608 int indirect_blks, int *blks, ext3_fsblk_t goal,
Mingming Caob47b2472006-03-26 01:37:56 -0800609 int *offsets, Indirect *branch)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610{
611 int blocksize = inode->i_sb->s_blocksize;
Mingming Caob47b2472006-03-26 01:37:56 -0800612 int i, n = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613 int err = 0;
Mingming Caob47b2472006-03-26 01:37:56 -0800614 struct buffer_head *bh;
615 int num;
Mingming Cao43d23f92006-06-25 05:48:07 -0700616 ext3_fsblk_t new_blocks[4];
617 ext3_fsblk_t current_block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700618
Mingming Caob47b2472006-03-26 01:37:56 -0800619 num = ext3_alloc_blocks(handle, inode, goal, indirect_blks,
620 *blks, new_blocks, &err);
621 if (err)
622 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623
Mingming Caob47b2472006-03-26 01:37:56 -0800624 branch[0].key = cpu_to_le32(new_blocks[0]);
625 /*
626 * metadata blocks and data blocks are allocated.
627 */
628 for (n = 1; n <= indirect_blks; n++) {
629 /*
630 * Get buffer_head for parent block, zero it out
631 * and set the pointer to new one, then send
632 * parent to disk.
633 */
634 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
635 branch[n].bh = bh;
636 lock_buffer(bh);
637 BUFFER_TRACE(bh, "call get_create_access");
638 err = ext3_journal_get_create_access(handle, bh);
639 if (err) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 unlock_buffer(bh);
Mingming Caob47b2472006-03-26 01:37:56 -0800641 brelse(bh);
642 goto failed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644
Mingming Caob47b2472006-03-26 01:37:56 -0800645 memset(bh->b_data, 0, blocksize);
646 branch[n].p = (__le32 *) bh->b_data + offsets[n];
647 branch[n].key = cpu_to_le32(new_blocks[n]);
648 *branch[n].p = branch[n].key;
649 if ( n == indirect_blks) {
650 current_block = new_blocks[n];
651 /*
652 * End of chain, update the last new metablock of
653 * the chain to point to the new allocated
654 * data blocks numbers
655 */
656 for (i=1; i < num; i++)
657 *(branch[n].p + i) = cpu_to_le32(++current_block);
658 }
659 BUFFER_TRACE(bh, "marking uptodate");
660 set_buffer_uptodate(bh);
661 unlock_buffer(bh);
662
663 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
664 err = ext3_journal_dirty_metadata(handle, bh);
665 if (err)
666 goto failed;
667 }
668 *blks = num;
669 return err;
670failed:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700671 /* Allocation failed, free what we already allocated */
Mingming Caob47b2472006-03-26 01:37:56 -0800672 for (i = 1; i <= n ; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 BUFFER_TRACE(branch[i].bh, "call journal_forget");
674 ext3_journal_forget(handle, branch[i].bh);
675 }
Mingming Caob47b2472006-03-26 01:37:56 -0800676 for (i = 0; i <indirect_blks; i++)
677 ext3_free_blocks(handle, inode, new_blocks[i], 1);
678
679 ext3_free_blocks(handle, inode, new_blocks[i], num);
680
Linus Torvalds1da177e2005-04-16 15:20:36 -0700681 return err;
682}
683
684/**
Andrew Mortond6859bf2006-03-26 01:38:03 -0800685 * ext3_splice_branch - splice the allocated branch onto inode.
686 * @inode: owner
687 * @block: (logical) number of block we are adding
688 * @chain: chain of indirect blocks (with a missing link - see
689 * ext3_alloc_branch)
690 * @where: location of missing link
691 * @num: number of indirect blocks we are adding
692 * @blks: number of direct blocks we are adding
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 *
Andrew Mortond6859bf2006-03-26 01:38:03 -0800694 * This function fills the missing link and does all housekeeping needed in
695 * inode (->i_blocks, etc.). In case of success we end up with the full
696 * chain to new block and return 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800698static int ext3_splice_branch(handle_t *handle, struct inode *inode,
699 long block, Indirect *where, int num, int blks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700700{
701 int i;
702 int err = 0;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800703 struct ext3_block_alloc_info *block_i;
Mingming Cao43d23f92006-06-25 05:48:07 -0700704 ext3_fsblk_t current_block;
Jan Karafe8bc912009-10-16 19:26:15 +0200705 struct ext3_inode_info *ei = EXT3_I(inode);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800706
Jan Karafe8bc912009-10-16 19:26:15 +0200707 block_i = ei->i_block_alloc_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708 /*
709 * If we're splicing into a [td]indirect block (as opposed to the
710 * inode) then we need to get write access to the [td]indirect block
711 * before the splice.
712 */
713 if (where->bh) {
714 BUFFER_TRACE(where->bh, "get_write_access");
715 err = ext3_journal_get_write_access(handle, where->bh);
716 if (err)
717 goto err_out;
718 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 /* That's it */
720
721 *where->p = where->key;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800722
723 /*
724 * Update the host buffer_head or inode to point to more just allocated
725 * direct blocks blocks
726 */
Mingming Caob47b2472006-03-26 01:37:56 -0800727 if (num == 0 && blks > 1) {
Mingming Cao5dea5172006-05-03 19:55:12 -0700728 current_block = le32_to_cpu(where->key) + 1;
Mingming Caob47b2472006-03-26 01:37:56 -0800729 for (i = 1; i < blks; i++)
730 *(where->p + i ) = cpu_to_le32(current_block++);
731 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732
733 /*
734 * update the most recently allocated logical & physical block
735 * in i_block_alloc_info, to assist find the proper goal block for next
736 * allocation
737 */
738 if (block_i) {
Mingming Caob47b2472006-03-26 01:37:56 -0800739 block_i->last_alloc_logical_block = block + blks - 1;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800740 block_i->last_alloc_physical_block =
Mingming Cao5dea5172006-05-03 19:55:12 -0700741 le32_to_cpu(where[num].key) + blks - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 }
743
744 /* We are done with atomic stuff, now do the rest of housekeeping */
745
746 inode->i_ctime = CURRENT_TIME_SEC;
747 ext3_mark_inode_dirty(handle, inode);
Jan Karafe8bc912009-10-16 19:26:15 +0200748 /* ext3_mark_inode_dirty already updated i_sync_tid */
749 atomic_set(&ei->i_datasync_tid, handle->h_transaction->t_tid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700750
751 /* had we spliced it onto indirect block? */
752 if (where->bh) {
753 /*
Andrew Mortond6859bf2006-03-26 01:38:03 -0800754 * If we spliced it onto an indirect block, we haven't
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755 * altered the inode. Note however that if it is being spliced
756 * onto an indirect block at the very end of the file (the
757 * file is growing) then we *will* alter the inode to reflect
758 * the new i_size. But that is not done here - it is done in
759 * generic_commit_write->__mark_inode_dirty->ext3_dirty_inode.
760 */
761 jbd_debug(5, "splicing indirect only\n");
762 BUFFER_TRACE(where->bh, "call ext3_journal_dirty_metadata");
763 err = ext3_journal_dirty_metadata(handle, where->bh);
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700764 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765 goto err_out;
766 } else {
767 /*
768 * OK, we spliced it into the inode itself on a direct block.
769 * Inode was dirtied above.
770 */
771 jbd_debug(5, "splicing direct\n");
772 }
773 return err;
774
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775err_out:
Mingming Caob47b2472006-03-26 01:37:56 -0800776 for (i = 1; i <= num; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 BUFFER_TRACE(where[i].bh, "call journal_forget");
778 ext3_journal_forget(handle, where[i].bh);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800779 ext3_free_blocks(handle,inode,le32_to_cpu(where[i-1].key),1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 }
Mingming Caob47b2472006-03-26 01:37:56 -0800781 ext3_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks);
782
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 return err;
784}
785
786/*
787 * Allocation strategy is simple: if we have to allocate something, we will
788 * have to go the whole way to leaf. So let's do it before attaching anything
789 * to tree, set linkage between the newborn blocks, write them if sync is
790 * required, recheck the path, free and repeat if check fails, otherwise
791 * set the last missing link (that will protect us from any truncate-generated
792 * removals - all blocks on the path are immune now) and possibly force the
793 * write on the parent block.
794 * That has a nice additional property: no special recovery from the failed
795 * allocations is needed - we simply release blocks and do not touch anything
796 * reachable from inode.
797 *
Andrew Mortond6859bf2006-03-26 01:38:03 -0800798 * `handle' can be NULL if create == 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799 *
800 * The BKL may not be held on entry here. Be sure to take it early.
Mingming Cao89747d32006-03-26 01:37:55 -0800801 * return > 0, # of blocks mapped or allocated.
802 * return = 0, if plain lookup failed.
803 * return < 0, error case.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700804 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800805int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
806 sector_t iblock, unsigned long maxblocks,
807 struct buffer_head *bh_result,
Jan Kara43237b52009-05-20 18:41:58 +0200808 int create)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809{
810 int err = -EIO;
811 int offsets[4];
812 Indirect chain[4];
813 Indirect *partial;
Mingming Cao43d23f92006-06-25 05:48:07 -0700814 ext3_fsblk_t goal;
Mingming Caob47b2472006-03-26 01:37:56 -0800815 int indirect_blks;
Mingming Cao89747d32006-03-26 01:37:55 -0800816 int blocks_to_boundary = 0;
817 int depth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700818 struct ext3_inode_info *ei = EXT3_I(inode);
Mingming Cao89747d32006-03-26 01:37:55 -0800819 int count = 0;
Mingming Cao43d23f92006-06-25 05:48:07 -0700820 ext3_fsblk_t first_block = 0;
Mingming Cao89747d32006-03-26 01:37:55 -0800821
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822
823 J_ASSERT(handle != NULL || create == 0);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800824 depth = ext3_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700825
826 if (depth == 0)
827 goto out;
828
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
830
831 /* Simplest case - block found, no allocation needed */
832 if (!partial) {
Mingming Cao5dea5172006-05-03 19:55:12 -0700833 first_block = le32_to_cpu(chain[depth - 1].key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834 clear_buffer_new(bh_result);
Mingming Cao89747d32006-03-26 01:37:55 -0800835 count++;
836 /*map more blocks*/
837 while (count < maxblocks && count <= blocks_to_boundary) {
Mingming Cao43d23f92006-06-25 05:48:07 -0700838 ext3_fsblk_t blk;
Mingming Cao5dea5172006-05-03 19:55:12 -0700839
Jan Karae8ef7aa2009-06-17 16:26:23 -0700840 if (!verify_chain(chain, chain + depth - 1)) {
Mingming Cao89747d32006-03-26 01:37:55 -0800841 /*
842 * Indirect block might be removed by
843 * truncate while we were reading it.
844 * Handling of that case: forget what we've
845 * got now. Flag the err as EAGAIN, so it
846 * will reread.
847 */
848 err = -EAGAIN;
849 count = 0;
850 break;
851 }
Mingming Cao5dea5172006-05-03 19:55:12 -0700852 blk = le32_to_cpu(*(chain[depth-1].p + count));
853
854 if (blk == first_block + count)
Mingming Cao89747d32006-03-26 01:37:55 -0800855 count++;
856 else
857 break;
858 }
859 if (err != -EAGAIN)
860 goto got_it;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861 }
862
863 /* Next simple case - plain lookup or failed read of indirect block */
Mingming Caofe55c452005-05-01 08:59:20 -0700864 if (!create || err == -EIO)
865 goto cleanup;
866
Arjan van de Ven97461512006-03-23 03:00:42 -0800867 mutex_lock(&ei->truncate_mutex);
Mingming Caofe55c452005-05-01 08:59:20 -0700868
869 /*
870 * If the indirect block is missing while we are reading
871 * the chain(ext3_get_branch() returns -EAGAIN err), or
872 * if the chain has been changed after we grab the semaphore,
873 * (either because another process truncated this branch, or
874 * another get_block allocated this branch) re-grab the chain to see if
875 * the request block has been allocated or not.
876 *
877 * Since we already block the truncate/other get_block
878 * at this point, we will have the current copy of the chain when we
879 * splice the branch into the tree.
880 */
881 if (err == -EAGAIN || !verify_chain(chain, partial)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 while (partial > chain) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883 brelse(partial->bh);
884 partial--;
885 }
Mingming Caofe55c452005-05-01 08:59:20 -0700886 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
887 if (!partial) {
Mingming Cao89747d32006-03-26 01:37:55 -0800888 count++;
Arjan van de Ven97461512006-03-23 03:00:42 -0800889 mutex_unlock(&ei->truncate_mutex);
Mingming Caofe55c452005-05-01 08:59:20 -0700890 if (err)
891 goto cleanup;
892 clear_buffer_new(bh_result);
893 goto got_it;
894 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700895 }
896
897 /*
Mingming Caofe55c452005-05-01 08:59:20 -0700898 * Okay, we need to do block allocation. Lazily initialize the block
899 * allocation info here if necessary
900 */
901 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902 ext3_init_block_alloc_info(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800904 goal = ext3_find_goal(inode, iblock, partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905
Mingming Caob47b2472006-03-26 01:37:56 -0800906 /* the number of blocks need to allocate for [d,t]indirect blocks */
907 indirect_blks = (chain + depth) - partial - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908
909 /*
Mingming Caob47b2472006-03-26 01:37:56 -0800910 * Next look up the indirect map to count the totoal number of
911 * direct blocks to allocate for this branch.
912 */
913 count = ext3_blks_to_allocate(partial, indirect_blks,
914 maxblocks, blocks_to_boundary);
915 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700916 * Block out ext3_truncate while we alter the tree
917 */
Mingming Caob47b2472006-03-26 01:37:56 -0800918 err = ext3_alloc_branch(handle, inode, indirect_blks, &count, goal,
Mingming Caofe55c452005-05-01 08:59:20 -0700919 offsets + (partial - chain), partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920
Mingming Caofe55c452005-05-01 08:59:20 -0700921 /*
922 * The ext3_splice_branch call will free and forget any buffers
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923 * on the new chain if there is a failure, but that risks using
924 * up transaction credits, especially for bitmaps where the
925 * credits cannot be returned. Can we handle this somehow? We
Mingming Caofe55c452005-05-01 08:59:20 -0700926 * may need to return -EAGAIN upwards in the worst case. --sct
927 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928 if (!err)
Mingming Caob47b2472006-03-26 01:37:56 -0800929 err = ext3_splice_branch(handle, inode, iblock,
930 partial, indirect_blks, count);
Arjan van de Ven97461512006-03-23 03:00:42 -0800931 mutex_unlock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 if (err)
933 goto cleanup;
934
935 set_buffer_new(bh_result);
Mingming Caofe55c452005-05-01 08:59:20 -0700936got_it:
937 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
Suparna Bhattacharya20acaa12006-09-16 12:15:58 -0700938 if (count > blocks_to_boundary)
Mingming Caofe55c452005-05-01 08:59:20 -0700939 set_buffer_boundary(bh_result);
Mingming Cao89747d32006-03-26 01:37:55 -0800940 err = count;
Mingming Caofe55c452005-05-01 08:59:20 -0700941 /* Clean up and exit */
942 partial = chain + depth - 1; /* the whole chain */
943cleanup:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700944 while (partial > chain) {
Mingming Caofe55c452005-05-01 08:59:20 -0700945 BUFFER_TRACE(partial->bh, "call brelse");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946 brelse(partial->bh);
947 partial--;
948 }
Mingming Caofe55c452005-05-01 08:59:20 -0700949 BUFFER_TRACE(bh_result, "returned");
950out:
951 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700952}
953
Jan Karabd1939d2008-02-06 01:40:21 -0800954/* Maximum number of blocks we map for direct IO at once. */
955#define DIO_MAX_BLOCKS 4096
956/*
957 * Number of credits we need for writing DIO_MAX_BLOCKS:
958 * We need sb + group descriptor + bitmap + inode -> 4
959 * For B blocks with A block pointers per block we need:
960 * 1 (triple ind.) + (B/A/A + 2) (doubly ind.) + (B/A + 2) (indirect).
961 * If we plug in 4096 for B and 256 for A (for 1KB block size), we get 25.
962 */
963#define DIO_CREDITS 25
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964
Badari Pulavartyf91a2ad2006-03-26 01:38:04 -0800965static int ext3_get_block(struct inode *inode, sector_t iblock,
966 struct buffer_head *bh_result, int create)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967{
Dmitriy Monakhov3e4fdaf2007-02-10 01:46:35 -0800968 handle_t *handle = ext3_journal_current_handle();
Jan Karabd1939d2008-02-06 01:40:21 -0800969 int ret = 0, started = 0;
Badari Pulavarty1d8fa7a2006-03-26 01:38:02 -0800970 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971
Jan Karabd1939d2008-02-06 01:40:21 -0800972 if (create && !handle) { /* Direct IO write... */
973 if (max_blocks > DIO_MAX_BLOCKS)
974 max_blocks = DIO_MAX_BLOCKS;
975 handle = ext3_journal_start(inode, DIO_CREDITS +
Dmitry Monakhovc4590012009-12-09 03:05:30 +0300976 EXT3_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb));
Jan Karabd1939d2008-02-06 01:40:21 -0800977 if (IS_ERR(handle)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700978 ret = PTR_ERR(handle);
Jan Karabd1939d2008-02-06 01:40:21 -0800979 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 }
Jan Karabd1939d2008-02-06 01:40:21 -0800981 started = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700982 }
983
Jan Karabd1939d2008-02-06 01:40:21 -0800984 ret = ext3_get_blocks_handle(handle, inode, iblock,
Jan Kara43237b52009-05-20 18:41:58 +0200985 max_blocks, bh_result, create);
Jan Karabd1939d2008-02-06 01:40:21 -0800986 if (ret > 0) {
987 bh_result->b_size = (ret << inode->i_blkbits);
988 ret = 0;
Mingming Cao89747d32006-03-26 01:37:55 -0800989 }
Jan Karabd1939d2008-02-06 01:40:21 -0800990 if (started)
991 ext3_journal_stop(handle);
992out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 return ret;
994}
995
Josef Bacik68c9d702008-10-03 17:32:43 -0400996int ext3_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
997 u64 start, u64 len)
998{
999 return generic_block_fiemap(inode, fieinfo, start, len,
1000 ext3_get_block);
1001}
1002
Linus Torvalds1da177e2005-04-16 15:20:36 -07001003/*
1004 * `handle' can be NULL if create is zero
1005 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08001006struct buffer_head *ext3_getblk(handle_t *handle, struct inode *inode,
1007 long block, int create, int *errp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008{
1009 struct buffer_head dummy;
1010 int fatal = 0, err;
1011
1012 J_ASSERT(handle != NULL || create == 0);
1013
1014 dummy.b_state = 0;
1015 dummy.b_blocknr = -1000;
1016 buffer_trace_init(&dummy.b_history);
Mingming Cao89747d32006-03-26 01:37:55 -08001017 err = ext3_get_blocks_handle(handle, inode, block, 1,
Jan Kara43237b52009-05-20 18:41:58 +02001018 &dummy, create);
Badari Pulavarty3665d0e2006-09-08 09:48:21 -07001019 /*
1020 * ext3_get_blocks_handle() returns number of blocks
1021 * mapped. 0 in case of a HOLE.
1022 */
1023 if (err > 0) {
1024 if (err > 1)
1025 WARN_ON(1);
Mingming Cao89747d32006-03-26 01:37:55 -08001026 err = 0;
Mingming Cao89747d32006-03-26 01:37:55 -08001027 }
1028 *errp = err;
1029 if (!err && buffer_mapped(&dummy)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 struct buffer_head *bh;
1031 bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
Glauber de Oliveira Costa2973dfd2005-10-30 15:03:05 -08001032 if (!bh) {
1033 *errp = -EIO;
1034 goto err;
1035 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036 if (buffer_new(&dummy)) {
1037 J_ASSERT(create != 0);
Stephen Hemmingerc80544d2007-10-18 03:07:05 -07001038 J_ASSERT(handle != NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001039
Andrew Mortond6859bf2006-03-26 01:38:03 -08001040 /*
1041 * Now that we do not always journal data, we should
1042 * keep in mind whether this should always journal the
1043 * new buffer as metadata. For now, regular file
1044 * writes use ext3_get_block instead, so it's not a
1045 * problem.
1046 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047 lock_buffer(bh);
1048 BUFFER_TRACE(bh, "call get_create_access");
1049 fatal = ext3_journal_get_create_access(handle, bh);
1050 if (!fatal && !buffer_uptodate(bh)) {
Andrew Mortond6859bf2006-03-26 01:38:03 -08001051 memset(bh->b_data,0,inode->i_sb->s_blocksize);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001052 set_buffer_uptodate(bh);
1053 }
1054 unlock_buffer(bh);
1055 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
1056 err = ext3_journal_dirty_metadata(handle, bh);
1057 if (!fatal)
1058 fatal = err;
1059 } else {
1060 BUFFER_TRACE(bh, "not a new buffer");
1061 }
1062 if (fatal) {
1063 *errp = fatal;
1064 brelse(bh);
1065 bh = NULL;
1066 }
1067 return bh;
1068 }
Glauber de Oliveira Costa2973dfd2005-10-30 15:03:05 -08001069err:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001070 return NULL;
1071}
1072
Andrew Mortond6859bf2006-03-26 01:38:03 -08001073struct buffer_head *ext3_bread(handle_t *handle, struct inode *inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001074 int block, int create, int *err)
1075{
1076 struct buffer_head * bh;
1077
1078 bh = ext3_getblk(handle, inode, block, create, err);
1079 if (!bh)
1080 return bh;
1081 if (buffer_uptodate(bh))
1082 return bh;
Jens Axboecaa38fb2006-07-23 01:41:26 +02001083 ll_rw_block(READ_META, 1, &bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001084 wait_on_buffer(bh);
1085 if (buffer_uptodate(bh))
1086 return bh;
1087 put_bh(bh);
1088 *err = -EIO;
1089 return NULL;
1090}
1091
1092static int walk_page_buffers( handle_t *handle,
1093 struct buffer_head *head,
1094 unsigned from,
1095 unsigned to,
1096 int *partial,
1097 int (*fn)( handle_t *handle,
1098 struct buffer_head *bh))
1099{
1100 struct buffer_head *bh;
1101 unsigned block_start, block_end;
1102 unsigned blocksize = head->b_size;
1103 int err, ret = 0;
1104 struct buffer_head *next;
1105
1106 for ( bh = head, block_start = 0;
1107 ret == 0 && (bh != head || !block_start);
Dave Kleikampe9ad5622006-09-27 01:49:35 -07001108 block_start = block_end, bh = next)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001109 {
1110 next = bh->b_this_page;
1111 block_end = block_start + blocksize;
1112 if (block_end <= from || block_start >= to) {
1113 if (partial && !buffer_uptodate(bh))
1114 *partial = 1;
1115 continue;
1116 }
1117 err = (*fn)(handle, bh);
1118 if (!ret)
1119 ret = err;
1120 }
1121 return ret;
1122}
1123
1124/*
1125 * To preserve ordering, it is essential that the hole instantiation and
1126 * the data write be encapsulated in a single transaction. We cannot
1127 * close off a transaction and start a new one between the ext3_get_block()
1128 * and the commit_write(). So doing the journal_start at the start of
1129 * prepare_write() is the right place.
1130 *
1131 * Also, this function can nest inside ext3_writepage() ->
1132 * block_write_full_page(). In that case, we *know* that ext3_writepage()
1133 * has generated enough buffer credits to do the whole page. So we won't
1134 * block on the journal in that case, which is good, because the caller may
1135 * be PF_MEMALLOC.
1136 *
1137 * By accident, ext3 can be reentered when a transaction is open via
1138 * quota file writes. If we were to commit the transaction while thus
1139 * reentered, there can be a deadlock - we would be holding a quota
1140 * lock, and the commit would never complete if another thread had a
1141 * transaction open and was blocking on the quota lock - a ranking
1142 * violation.
1143 *
1144 * So what we do is to rely on the fact that journal_stop/journal_start
1145 * will _not_ run commit under these circumstances because handle->h_ref
1146 * is elevated. We'll still have enough credits for the tiny quotafile
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001147 * write.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08001149static int do_journal_get_write_access(handle_t *handle,
1150 struct buffer_head *bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001151{
1152 if (!buffer_mapped(bh) || buffer_freed(bh))
1153 return 0;
1154 return ext3_journal_get_write_access(handle, bh);
1155}
1156
Jan Kara68eb3db2009-12-01 16:53:06 +01001157/*
1158 * Truncate blocks that were not used by write. We have to truncate the
1159 * pagecache as well so that corresponding buffers get properly unmapped.
1160 */
1161static void ext3_truncate_failed_write(struct inode *inode)
1162{
1163 truncate_inode_pages(inode->i_mapping, inode->i_size);
1164 ext3_truncate(inode);
1165}
1166
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001167static int ext3_write_begin(struct file *file, struct address_space *mapping,
1168 loff_t pos, unsigned len, unsigned flags,
1169 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170{
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001171 struct inode *inode = mapping->host;
Jan Kara695f6ae2009-04-02 16:57:17 -07001172 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173 handle_t *handle;
1174 int retries = 0;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001175 struct page *page;
1176 pgoff_t index;
1177 unsigned from, to;
Jan Kara695f6ae2009-04-02 16:57:17 -07001178 /* Reserve one block more for addition to orphan list in case
1179 * we allocate blocks but write fails for some reason */
1180 int needed_blocks = ext3_writepage_trans_blocks(inode) + 1;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001181
1182 index = pos >> PAGE_CACHE_SHIFT;
1183 from = pos & (PAGE_CACHE_SIZE - 1);
1184 to = from + len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001185
1186retry:
Nick Piggin54566b22009-01-04 12:00:53 -08001187 page = grab_cache_page_write_begin(mapping, index, flags);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001188 if (!page)
1189 return -ENOMEM;
1190 *pagep = page;
1191
Linus Torvalds1da177e2005-04-16 15:20:36 -07001192 handle = ext3_journal_start(inode, needed_blocks);
Andrew Morton1aa9b4b2007-04-01 23:49:43 -07001193 if (IS_ERR(handle)) {
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001194 unlock_page(page);
1195 page_cache_release(page);
Andrew Morton1aa9b4b2007-04-01 23:49:43 -07001196 ret = PTR_ERR(handle);
1197 goto out;
1198 }
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001199 ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
1200 ext3_get_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001201 if (ret)
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001202 goto write_begin_failed;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203
1204 if (ext3_should_journal_data(inode)) {
1205 ret = walk_page_buffers(handle, page_buffers(page),
1206 from, to, NULL, do_journal_get_write_access);
1207 }
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001208write_begin_failed:
1209 if (ret) {
Aneesh Kumar K.V5ec8b752008-10-18 20:28:00 -07001210 /*
1211 * block_write_begin may have instantiated a few blocks
1212 * outside i_size. Trim these off again. Don't need
1213 * i_size_read because we hold i_mutex.
Jan Kara695f6ae2009-04-02 16:57:17 -07001214 *
1215 * Add inode to orphan list in case we crash before truncate
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001216 * finishes. Do this only if ext3_can_truncate() agrees so
1217 * that orphan processing code is happy.
Aneesh Kumar K.V5ec8b752008-10-18 20:28:00 -07001218 */
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001219 if (pos + len > inode->i_size && ext3_can_truncate(inode))
Jan Kara695f6ae2009-04-02 16:57:17 -07001220 ext3_orphan_add(handle, inode);
1221 ext3_journal_stop(handle);
1222 unlock_page(page);
1223 page_cache_release(page);
1224 if (pos + len > inode->i_size)
Jan Kara68eb3db2009-12-01 16:53:06 +01001225 ext3_truncate_failed_write(inode);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001226 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001227 if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
1228 goto retry;
Andrew Morton1aa9b4b2007-04-01 23:49:43 -07001229out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230 return ret;
1231}
1232
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001233
Andrew Mortond6859bf2006-03-26 01:38:03 -08001234int ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001235{
1236 int err = journal_dirty_data(handle, bh);
1237 if (err)
Harvey Harrisone05b6b52008-04-28 02:16:15 -07001238 ext3_journal_abort_handle(__func__, __func__,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001239 bh, handle, err);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001240 return err;
1241}
1242
Jan Kara695f6ae2009-04-02 16:57:17 -07001243/* For ordered writepage and write_end functions */
1244static int journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
1245{
1246 /*
1247 * Write could have mapped the buffer but it didn't copy the data in
1248 * yet. So avoid filing such buffer into a transaction.
1249 */
1250 if (buffer_mapped(bh) && buffer_uptodate(bh))
1251 return ext3_journal_dirty_data(handle, bh);
1252 return 0;
1253}
1254
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001255/* For write_end() in data=journal mode */
1256static int write_end_fn(handle_t *handle, struct buffer_head *bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001257{
1258 if (!buffer_mapped(bh) || buffer_freed(bh))
1259 return 0;
1260 set_buffer_uptodate(bh);
1261 return ext3_journal_dirty_metadata(handle, bh);
1262}
1263
1264/*
Jan Kara695f6ae2009-04-02 16:57:17 -07001265 * This is nasty and subtle: ext3_write_begin() could have allocated blocks
1266 * for the whole page but later we failed to copy the data in. Update inode
1267 * size according to what we managed to copy. The rest is going to be
1268 * truncated in write_end function.
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001269 */
Jan Kara695f6ae2009-04-02 16:57:17 -07001270static void update_file_sizes(struct inode *inode, loff_t pos, unsigned copied)
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001271{
Jan Kara695f6ae2009-04-02 16:57:17 -07001272 /* What matters to us is i_disksize. We don't write i_size anywhere */
1273 if (pos + copied > inode->i_size)
1274 i_size_write(inode, pos + copied);
1275 if (pos + copied > EXT3_I(inode)->i_disksize) {
1276 EXT3_I(inode)->i_disksize = pos + copied;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001277 mark_inode_dirty(inode);
1278 }
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001279}
1280
1281/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001282 * We need to pick up the new inode size which generic_commit_write gave us
1283 * `file' can be NULL - eg, when called from page_symlink().
1284 *
1285 * ext3 never places buffers on inode->i_mapping->private_list. metadata
1286 * buffers are managed internally.
1287 */
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001288static int ext3_ordered_write_end(struct file *file,
1289 struct address_space *mapping,
1290 loff_t pos, unsigned len, unsigned copied,
1291 struct page *page, void *fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001292{
1293 handle_t *handle = ext3_journal_current_handle();
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001294 struct inode *inode = file->f_mapping->host;
1295 unsigned from, to;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001296 int ret = 0, ret2;
1297
Jan Kara695f6ae2009-04-02 16:57:17 -07001298 copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
1299
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001300 from = pos & (PAGE_CACHE_SIZE - 1);
Jan Kara695f6ae2009-04-02 16:57:17 -07001301 to = from + copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001302 ret = walk_page_buffers(handle, page_buffers(page),
Jan Kara695f6ae2009-04-02 16:57:17 -07001303 from, to, NULL, journal_dirty_data_fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304
Jan Kara695f6ae2009-04-02 16:57:17 -07001305 if (ret == 0)
1306 update_file_sizes(inode, pos, copied);
1307 /*
1308 * There may be allocated blocks outside of i_size because
1309 * we failed to copy some data. Prepare for truncate.
1310 */
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001311 if (pos + len > inode->i_size && ext3_can_truncate(inode))
Jan Kara695f6ae2009-04-02 16:57:17 -07001312 ext3_orphan_add(handle, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001313 ret2 = ext3_journal_stop(handle);
1314 if (!ret)
1315 ret = ret2;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001316 unlock_page(page);
1317 page_cache_release(page);
1318
Jan Kara695f6ae2009-04-02 16:57:17 -07001319 if (pos + len > inode->i_size)
Jan Kara68eb3db2009-12-01 16:53:06 +01001320 ext3_truncate_failed_write(inode);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001321 return ret ? ret : copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001322}
1323
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001324static int ext3_writeback_write_end(struct file *file,
1325 struct address_space *mapping,
1326 loff_t pos, unsigned len, unsigned copied,
1327 struct page *page, void *fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001328{
1329 handle_t *handle = ext3_journal_current_handle();
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001330 struct inode *inode = file->f_mapping->host;
Jan Kara695f6ae2009-04-02 16:57:17 -07001331 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001332
Jan Kara695f6ae2009-04-02 16:57:17 -07001333 copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
1334 update_file_sizes(inode, pos, copied);
1335 /*
1336 * There may be allocated blocks outside of i_size because
1337 * we failed to copy some data. Prepare for truncate.
1338 */
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001339 if (pos + len > inode->i_size && ext3_can_truncate(inode))
Jan Kara695f6ae2009-04-02 16:57:17 -07001340 ext3_orphan_add(handle, inode);
1341 ret = ext3_journal_stop(handle);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001342 unlock_page(page);
1343 page_cache_release(page);
1344
Jan Kara695f6ae2009-04-02 16:57:17 -07001345 if (pos + len > inode->i_size)
Jan Kara68eb3db2009-12-01 16:53:06 +01001346 ext3_truncate_failed_write(inode);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001347 return ret ? ret : copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001348}
1349
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001350static int ext3_journalled_write_end(struct file *file,
1351 struct address_space *mapping,
1352 loff_t pos, unsigned len, unsigned copied,
1353 struct page *page, void *fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001354{
1355 handle_t *handle = ext3_journal_current_handle();
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001356 struct inode *inode = mapping->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001357 int ret = 0, ret2;
1358 int partial = 0;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001359 unsigned from, to;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001360
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001361 from = pos & (PAGE_CACHE_SIZE - 1);
1362 to = from + len;
1363
1364 if (copied < len) {
1365 if (!PageUptodate(page))
1366 copied = 0;
Jan Kara695f6ae2009-04-02 16:57:17 -07001367 page_zero_new_buffers(page, from + copied, to);
1368 to = from + copied;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001369 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001370
1371 ret = walk_page_buffers(handle, page_buffers(page), from,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001372 to, &partial, write_end_fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001373 if (!partial)
1374 SetPageUptodate(page);
Jan Kara695f6ae2009-04-02 16:57:17 -07001375
1376 if (pos + copied > inode->i_size)
1377 i_size_write(inode, pos + copied);
1378 /*
1379 * There may be allocated blocks outside of i_size because
1380 * we failed to copy some data. Prepare for truncate.
1381 */
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001382 if (pos + len > inode->i_size && ext3_can_truncate(inode))
Jan Kara695f6ae2009-04-02 16:57:17 -07001383 ext3_orphan_add(handle, inode);
Jan Kara9df93932010-01-06 21:58:48 +01001384 ext3_set_inode_state(inode, EXT3_STATE_JDATA);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001385 if (inode->i_size > EXT3_I(inode)->i_disksize) {
1386 EXT3_I(inode)->i_disksize = inode->i_size;
1387 ret2 = ext3_mark_inode_dirty(handle, inode);
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001388 if (!ret)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389 ret = ret2;
1390 }
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001391
Linus Torvalds1da177e2005-04-16 15:20:36 -07001392 ret2 = ext3_journal_stop(handle);
1393 if (!ret)
1394 ret = ret2;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001395 unlock_page(page);
1396 page_cache_release(page);
1397
Jan Kara695f6ae2009-04-02 16:57:17 -07001398 if (pos + len > inode->i_size)
Jan Kara68eb3db2009-12-01 16:53:06 +01001399 ext3_truncate_failed_write(inode);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001400 return ret ? ret : copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001401}
1402
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001403/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001404 * bmap() is special. It gets used by applications such as lilo and by
1405 * the swapper to find the on-disk block of a specific piece of data.
1406 *
1407 * Naturally, this is dangerous if the block concerned is still in the
1408 * journal. If somebody makes a swapfile on an ext3 data-journaling
1409 * filesystem and enables swap, then they may get a nasty shock when the
1410 * data getting swapped to that swapfile suddenly gets overwritten by
1411 * the original zero's written out previously to the journal and
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001412 * awaiting writeback in the kernel's buffer cache.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001413 *
1414 * So, if we see any bmap calls here on a modified, data-journaled file,
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001415 * take extra steps to flush any blocks which might be in the cache.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001416 */
1417static sector_t ext3_bmap(struct address_space *mapping, sector_t block)
1418{
1419 struct inode *inode = mapping->host;
1420 journal_t *journal;
1421 int err;
1422
Jan Kara9df93932010-01-06 21:58:48 +01001423 if (ext3_test_inode_state(inode, EXT3_STATE_JDATA)) {
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001424 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001425 * This is a REALLY heavyweight approach, but the use of
1426 * bmap on dirty files is expected to be extremely rare:
1427 * only if we run lilo or swapon on a freshly made file
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001428 * do we expect this to happen.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001429 *
1430 * (bmap requires CAP_SYS_RAWIO so this does not
1431 * represent an unprivileged user DOS attack --- we'd be
1432 * in trouble if mortal users could trigger this path at
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001433 * will.)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001434 *
1435 * NB. EXT3_STATE_JDATA is not set on files other than
1436 * regular files. If somebody wants to bmap a directory
1437 * or symlink and gets confused because the buffer
1438 * hasn't yet been flushed to disk, they deserve
1439 * everything they get.
1440 */
1441
Jan Kara9df93932010-01-06 21:58:48 +01001442 ext3_clear_inode_state(inode, EXT3_STATE_JDATA);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001443 journal = EXT3_JOURNAL(inode);
1444 journal_lock_updates(journal);
1445 err = journal_flush(journal);
1446 journal_unlock_updates(journal);
1447
1448 if (err)
1449 return 0;
1450 }
1451
1452 return generic_block_bmap(mapping,block,ext3_get_block);
1453}
1454
1455static int bget_one(handle_t *handle, struct buffer_head *bh)
1456{
1457 get_bh(bh);
1458 return 0;
1459}
1460
1461static int bput_one(handle_t *handle, struct buffer_head *bh)
1462{
1463 put_bh(bh);
1464 return 0;
1465}
1466
Jan Kara9e80d402009-03-26 13:08:04 +01001467static int buffer_unmapped(handle_t *handle, struct buffer_head *bh)
1468{
1469 return !buffer_mapped(bh);
1470}
Jan Kara695f6ae2009-04-02 16:57:17 -07001471
Linus Torvalds1da177e2005-04-16 15:20:36 -07001472/*
1473 * Note that we always start a transaction even if we're not journalling
1474 * data. This is to preserve ordering: any hole instantiation within
1475 * __block_write_full_page -> ext3_get_block() should be journalled
1476 * along with the data so we don't crash and then get metadata which
1477 * refers to old data.
1478 *
1479 * In all journalling modes block_write_full_page() will start the I/O.
1480 *
1481 * Problem:
1482 *
1483 * ext3_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1484 * ext3_writepage()
1485 *
1486 * Similar for:
1487 *
1488 * ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ...
1489 *
1490 * Same applies to ext3_get_block(). We will deadlock on various things like
Arjan van de Ven97461512006-03-23 03:00:42 -08001491 * lock_journal and i_truncate_mutex.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001492 *
1493 * Setting PF_MEMALLOC here doesn't work - too many internal memory
1494 * allocations fail.
1495 *
1496 * 16May01: If we're reentered then journal_current_handle() will be
1497 * non-zero. We simply *return*.
1498 *
1499 * 1 July 2001: @@@ FIXME:
1500 * In journalled data mode, a data buffer may be metadata against the
1501 * current transaction. But the same file is part of a shared mapping
1502 * and someone does a writepage() on it.
1503 *
1504 * We will move the buffer onto the async_data list, but *after* it has
1505 * been dirtied. So there's a small window where we have dirty data on
1506 * BJ_Metadata.
1507 *
1508 * Note that this only applies to the last partial page in the file. The
1509 * bit which block_write_full_page() uses prepare/commit for. (That's
1510 * broken code anyway: it's wrong for msync()).
1511 *
1512 * It's a rare case: affects the final partial page, for journalled data
1513 * where the file is subject to bith write() and writepage() in the same
1514 * transction. To fix it we'll need a custom block_write_full_page().
1515 * We'll probably need that anyway for journalling writepage() output.
1516 *
1517 * We don't honour synchronous mounts for writepage(). That would be
1518 * disastrous. Any write() or metadata operation will sync the fs for
1519 * us.
1520 *
1521 * AKPM2: if all the page's buffers are mapped to disk and !data=journal,
1522 * we don't need to open a transaction here.
1523 */
1524static int ext3_ordered_writepage(struct page *page,
Andrew Mortond6859bf2006-03-26 01:38:03 -08001525 struct writeback_control *wbc)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001526{
1527 struct inode *inode = page->mapping->host;
1528 struct buffer_head *page_bufs;
1529 handle_t *handle = NULL;
1530 int ret = 0;
1531 int err;
1532
1533 J_ASSERT(PageLocked(page));
Dmitry Monakhov49792c82010-03-02 15:51:02 +03001534 WARN_ON_ONCE(IS_RDONLY(inode));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001535
1536 /*
1537 * We give up here if we're reentered, because it might be for a
1538 * different filesystem.
1539 */
1540 if (ext3_journal_current_handle())
1541 goto out_fail;
1542
Jan Kara9e80d402009-03-26 13:08:04 +01001543 if (!page_has_buffers(page)) {
1544 create_empty_buffers(page, inode->i_sb->s_blocksize,
1545 (1 << BH_Dirty)|(1 << BH_Uptodate));
Jan Kara430db322009-04-07 18:25:01 -04001546 page_bufs = page_buffers(page);
1547 } else {
1548 page_bufs = page_buffers(page);
1549 if (!walk_page_buffers(NULL, page_bufs, 0, PAGE_CACHE_SIZE,
1550 NULL, buffer_unmapped)) {
1551 /* Provide NULL get_block() to catch bugs if buffers
1552 * weren't really mapped */
1553 return block_write_full_page(page, NULL, wbc);
1554 }
Jan Kara9e80d402009-03-26 13:08:04 +01001555 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001556 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1557
1558 if (IS_ERR(handle)) {
1559 ret = PTR_ERR(handle);
1560 goto out_fail;
1561 }
1562
Linus Torvalds1da177e2005-04-16 15:20:36 -07001563 walk_page_buffers(handle, page_bufs, 0,
1564 PAGE_CACHE_SIZE, NULL, bget_one);
1565
1566 ret = block_write_full_page(page, ext3_get_block, wbc);
1567
1568 /*
1569 * The page can become unlocked at any point now, and
1570 * truncate can then come in and change things. So we
1571 * can't touch *page from now on. But *page_bufs is
1572 * safe due to elevated refcount.
1573 */
1574
1575 /*
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001576 * And attach them to the current transaction. But only if
Linus Torvalds1da177e2005-04-16 15:20:36 -07001577 * block_write_full_page() succeeded. Otherwise they are unmapped,
1578 * and generally junk.
1579 */
1580 if (ret == 0) {
1581 err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
1582 NULL, journal_dirty_data_fn);
1583 if (!ret)
1584 ret = err;
1585 }
1586 walk_page_buffers(handle, page_bufs, 0,
1587 PAGE_CACHE_SIZE, NULL, bput_one);
1588 err = ext3_journal_stop(handle);
1589 if (!ret)
1590 ret = err;
1591 return ret;
1592
1593out_fail:
1594 redirty_page_for_writepage(wbc, page);
1595 unlock_page(page);
1596 return ret;
1597}
1598
Linus Torvalds1da177e2005-04-16 15:20:36 -07001599static int ext3_writeback_writepage(struct page *page,
1600 struct writeback_control *wbc)
1601{
1602 struct inode *inode = page->mapping->host;
1603 handle_t *handle = NULL;
1604 int ret = 0;
1605 int err;
1606
Dmitry Monakhov49792c82010-03-02 15:51:02 +03001607 J_ASSERT(PageLocked(page));
1608 WARN_ON_ONCE(IS_RDONLY(inode));
1609
Linus Torvalds1da177e2005-04-16 15:20:36 -07001610 if (ext3_journal_current_handle())
1611 goto out_fail;
1612
Jan Kara430db322009-04-07 18:25:01 -04001613 if (page_has_buffers(page)) {
1614 if (!walk_page_buffers(NULL, page_buffers(page), 0,
1615 PAGE_CACHE_SIZE, NULL, buffer_unmapped)) {
1616 /* Provide NULL get_block() to catch bugs if buffers
1617 * weren't really mapped */
1618 return block_write_full_page(page, NULL, wbc);
1619 }
1620 }
1621
Linus Torvalds1da177e2005-04-16 15:20:36 -07001622 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1623 if (IS_ERR(handle)) {
1624 ret = PTR_ERR(handle);
1625 goto out_fail;
1626 }
1627
Badari Pulavarty0e31f512006-07-30 03:04:14 -07001628 if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001629 ret = nobh_writepage(page, ext3_get_block, wbc);
1630 else
1631 ret = block_write_full_page(page, ext3_get_block, wbc);
1632
1633 err = ext3_journal_stop(handle);
1634 if (!ret)
1635 ret = err;
1636 return ret;
1637
1638out_fail:
1639 redirty_page_for_writepage(wbc, page);
1640 unlock_page(page);
1641 return ret;
1642}
1643
1644static int ext3_journalled_writepage(struct page *page,
1645 struct writeback_control *wbc)
1646{
1647 struct inode *inode = page->mapping->host;
1648 handle_t *handle = NULL;
1649 int ret = 0;
1650 int err;
1651
Dmitry Monakhov49792c82010-03-02 15:51:02 +03001652 J_ASSERT(PageLocked(page));
1653 WARN_ON_ONCE(IS_RDONLY(inode));
1654
Linus Torvalds1da177e2005-04-16 15:20:36 -07001655 if (ext3_journal_current_handle())
1656 goto no_write;
1657
1658 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1659 if (IS_ERR(handle)) {
1660 ret = PTR_ERR(handle);
1661 goto no_write;
1662 }
1663
1664 if (!page_has_buffers(page) || PageChecked(page)) {
1665 /*
1666 * It's mmapped pagecache. Add buffers and journal it. There
1667 * doesn't seem much point in redirtying the page here.
1668 */
1669 ClearPageChecked(page);
1670 ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
1671 ext3_get_block);
Denis Lunevab4eb432005-11-13 16:07:17 -08001672 if (ret != 0) {
1673 ext3_journal_stop(handle);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001674 goto out_unlock;
Denis Lunevab4eb432005-11-13 16:07:17 -08001675 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001676 ret = walk_page_buffers(handle, page_buffers(page), 0,
1677 PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
1678
1679 err = walk_page_buffers(handle, page_buffers(page), 0,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001680 PAGE_CACHE_SIZE, NULL, write_end_fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001681 if (ret == 0)
1682 ret = err;
Jan Kara9df93932010-01-06 21:58:48 +01001683 ext3_set_inode_state(inode, EXT3_STATE_JDATA);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001684 unlock_page(page);
1685 } else {
1686 /*
1687 * It may be a page full of checkpoint-mode buffers. We don't
1688 * really know unless we go poke around in the buffer_heads.
1689 * But block_write_full_page will do the right thing.
1690 */
1691 ret = block_write_full_page(page, ext3_get_block, wbc);
1692 }
1693 err = ext3_journal_stop(handle);
1694 if (!ret)
1695 ret = err;
1696out:
1697 return ret;
1698
1699no_write:
1700 redirty_page_for_writepage(wbc, page);
1701out_unlock:
1702 unlock_page(page);
1703 goto out;
1704}
1705
1706static int ext3_readpage(struct file *file, struct page *page)
1707{
1708 return mpage_readpage(page, ext3_get_block);
1709}
1710
1711static int
1712ext3_readpages(struct file *file, struct address_space *mapping,
1713 struct list_head *pages, unsigned nr_pages)
1714{
1715 return mpage_readpages(mapping, pages, nr_pages, ext3_get_block);
1716}
1717
NeilBrown2ff28e22006-03-26 01:37:18 -08001718static void ext3_invalidatepage(struct page *page, unsigned long offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001719{
1720 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1721
1722 /*
1723 * If it's a full truncate we just forget about the pending dirtying
1724 */
1725 if (offset == 0)
1726 ClearPageChecked(page);
1727
NeilBrown2ff28e22006-03-26 01:37:18 -08001728 journal_invalidatepage(journal, page, offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001729}
1730
Al Viro27496a82005-10-21 03:20:48 -04001731static int ext3_releasepage(struct page *page, gfp_t wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001732{
1733 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1734
1735 WARN_ON(PageChecked(page));
1736 if (!page_has_buffers(page))
1737 return 0;
1738 return journal_try_to_free_buffers(journal, page, wait);
1739}
1740
1741/*
1742 * If the O_DIRECT write will extend the file then add this inode to the
1743 * orphan list. So recovery will truncate it back to the original size
1744 * if the machine crashes during the write.
1745 *
1746 * If the O_DIRECT write is intantiating holes inside i_size and the machine
Jan Karabd1939d2008-02-06 01:40:21 -08001747 * crashes then stale disk data _may_ be exposed inside the file. But current
1748 * VFS code falls back into buffered path in that case so we are safe.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001749 */
1750static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
1751 const struct iovec *iov, loff_t offset,
1752 unsigned long nr_segs)
1753{
1754 struct file *file = iocb->ki_filp;
1755 struct inode *inode = file->f_mapping->host;
1756 struct ext3_inode_info *ei = EXT3_I(inode);
Jan Karabd1939d2008-02-06 01:40:21 -08001757 handle_t *handle;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001758 ssize_t ret;
1759 int orphan = 0;
1760 size_t count = iov_length(iov, nr_segs);
Eric Sandeenea0174a2009-10-12 21:34:27 -05001761 int retries = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001762
1763 if (rw == WRITE) {
1764 loff_t final_size = offset + count;
1765
Linus Torvalds1da177e2005-04-16 15:20:36 -07001766 if (final_size > inode->i_size) {
Jan Karabd1939d2008-02-06 01:40:21 -08001767 /* Credits for sb + inode write */
1768 handle = ext3_journal_start(inode, 2);
1769 if (IS_ERR(handle)) {
1770 ret = PTR_ERR(handle);
1771 goto out;
1772 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001773 ret = ext3_orphan_add(handle, inode);
Jan Karabd1939d2008-02-06 01:40:21 -08001774 if (ret) {
1775 ext3_journal_stop(handle);
1776 goto out;
1777 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001778 orphan = 1;
1779 ei->i_disksize = inode->i_size;
Jan Karabd1939d2008-02-06 01:40:21 -08001780 ext3_journal_stop(handle);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001781 }
1782 }
1783
Eric Sandeenea0174a2009-10-12 21:34:27 -05001784retry:
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001785 ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001786 offset, nr_segs,
Badari Pulavartyf91a2ad2006-03-26 01:38:04 -08001787 ext3_get_block, NULL);
Eric Sandeenea0174a2009-10-12 21:34:27 -05001788 if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
1789 goto retry;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001790
Jan Karabd1939d2008-02-06 01:40:21 -08001791 if (orphan) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001792 int err;
1793
Jan Karabd1939d2008-02-06 01:40:21 -08001794 /* Credits for sb + inode write */
1795 handle = ext3_journal_start(inode, 2);
1796 if (IS_ERR(handle)) {
1797 /* This is really bad luck. We've written the data
Jan Kara7eb49692010-03-01 14:02:37 +01001798 * but cannot extend i_size. Truncate allocated blocks
1799 * and pretend the write failed... */
1800 ext3_truncate(inode);
Jan Karabd1939d2008-02-06 01:40:21 -08001801 ret = PTR_ERR(handle);
1802 goto out;
1803 }
1804 if (inode->i_nlink)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001805 ext3_orphan_del(handle, inode);
Jan Karabd1939d2008-02-06 01:40:21 -08001806 if (ret > 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001807 loff_t end = offset + ret;
1808 if (end > inode->i_size) {
1809 ei->i_disksize = end;
1810 i_size_write(inode, end);
1811 /*
1812 * We're going to return a positive `ret'
1813 * here due to non-zero-length I/O, so there's
1814 * no way of reporting error returns from
1815 * ext3_mark_inode_dirty() to userspace. So
1816 * ignore it.
1817 */
1818 ext3_mark_inode_dirty(handle, inode);
1819 }
1820 }
1821 err = ext3_journal_stop(handle);
1822 if (ret == 0)
1823 ret = err;
1824 }
1825out:
1826 return ret;
1827}
1828
1829/*
1830 * Pages can be marked dirty completely asynchronously from ext3's journalling
1831 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
1832 * much here because ->set_page_dirty is called under VFS locks. The page is
1833 * not necessarily locked.
1834 *
1835 * We cannot just dirty the page and leave attached buffers clean, because the
1836 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
1837 * or jbddirty because all the journalling code will explode.
1838 *
1839 * So what we do is to mark the page "pending dirty" and next time writepage
1840 * is called, propagate that into the buffers appropriately.
1841 */
1842static int ext3_journalled_set_page_dirty(struct page *page)
1843{
1844 SetPageChecked(page);
1845 return __set_page_dirty_nobuffers(page);
1846}
1847
Christoph Hellwigf5e54d62006-06-28 04:26:44 -07001848static const struct address_space_operations ext3_ordered_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07001849 .readpage = ext3_readpage,
1850 .readpages = ext3_readpages,
1851 .writepage = ext3_ordered_writepage,
1852 .sync_page = block_sync_page,
1853 .write_begin = ext3_write_begin,
1854 .write_end = ext3_ordered_write_end,
1855 .bmap = ext3_bmap,
1856 .invalidatepage = ext3_invalidatepage,
1857 .releasepage = ext3_releasepage,
1858 .direct_IO = ext3_direct_IO,
1859 .migratepage = buffer_migrate_page,
1860 .is_partially_uptodate = block_is_partially_uptodate,
Andi Kleenaa261f52009-09-16 11:50:16 +02001861 .error_remove_page = generic_error_remove_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001862};
1863
Christoph Hellwigf5e54d62006-06-28 04:26:44 -07001864static const struct address_space_operations ext3_writeback_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07001865 .readpage = ext3_readpage,
1866 .readpages = ext3_readpages,
1867 .writepage = ext3_writeback_writepage,
1868 .sync_page = block_sync_page,
1869 .write_begin = ext3_write_begin,
1870 .write_end = ext3_writeback_write_end,
1871 .bmap = ext3_bmap,
1872 .invalidatepage = ext3_invalidatepage,
1873 .releasepage = ext3_releasepage,
1874 .direct_IO = ext3_direct_IO,
1875 .migratepage = buffer_migrate_page,
1876 .is_partially_uptodate = block_is_partially_uptodate,
Andi Kleenaa261f52009-09-16 11:50:16 +02001877 .error_remove_page = generic_error_remove_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001878};
1879
Christoph Hellwigf5e54d62006-06-28 04:26:44 -07001880static const struct address_space_operations ext3_journalled_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07001881 .readpage = ext3_readpage,
1882 .readpages = ext3_readpages,
1883 .writepage = ext3_journalled_writepage,
1884 .sync_page = block_sync_page,
1885 .write_begin = ext3_write_begin,
1886 .write_end = ext3_journalled_write_end,
1887 .set_page_dirty = ext3_journalled_set_page_dirty,
1888 .bmap = ext3_bmap,
1889 .invalidatepage = ext3_invalidatepage,
1890 .releasepage = ext3_releasepage,
1891 .is_partially_uptodate = block_is_partially_uptodate,
Andi Kleenaa261f52009-09-16 11:50:16 +02001892 .error_remove_page = generic_error_remove_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001893};
1894
1895void ext3_set_aops(struct inode *inode)
1896{
1897 if (ext3_should_order_data(inode))
1898 inode->i_mapping->a_ops = &ext3_ordered_aops;
1899 else if (ext3_should_writeback_data(inode))
1900 inode->i_mapping->a_ops = &ext3_writeback_aops;
1901 else
1902 inode->i_mapping->a_ops = &ext3_journalled_aops;
1903}
1904
1905/*
1906 * ext3_block_truncate_page() zeroes out a mapping from file offset `from'
1907 * up to the end of the block which corresponds to `from'.
1908 * This required during truncate. We need to physically zero the tail end
1909 * of that block so it doesn't yield old data if the file is later grown.
1910 */
1911static int ext3_block_truncate_page(handle_t *handle, struct page *page,
1912 struct address_space *mapping, loff_t from)
1913{
Mingming Cao43d23f92006-06-25 05:48:07 -07001914 ext3_fsblk_t index = from >> PAGE_CACHE_SHIFT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001915 unsigned offset = from & (PAGE_CACHE_SIZE-1);
1916 unsigned blocksize, iblock, length, pos;
1917 struct inode *inode = mapping->host;
1918 struct buffer_head *bh;
1919 int err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001920
1921 blocksize = inode->i_sb->s_blocksize;
1922 length = blocksize - (offset & (blocksize - 1));
1923 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1924
1925 /*
1926 * For "nobh" option, we can only work if we don't need to
1927 * read-in the page - otherwise we create buffers to do the IO.
1928 */
Badari Pulavartycd6ef842006-03-11 03:27:14 -08001929 if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
1930 ext3_should_writeback_data(inode) && PageUptodate(page)) {
Christoph Lametereebd2aa2008-02-04 22:28:29 -08001931 zero_user(page, offset, length);
Badari Pulavartycd6ef842006-03-11 03:27:14 -08001932 set_page_dirty(page);
1933 goto unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001934 }
1935
1936 if (!page_has_buffers(page))
1937 create_empty_buffers(page, blocksize, 0);
1938
1939 /* Find the buffer that contains "offset" */
1940 bh = page_buffers(page);
1941 pos = blocksize;
1942 while (offset >= pos) {
1943 bh = bh->b_this_page;
1944 iblock++;
1945 pos += blocksize;
1946 }
1947
1948 err = 0;
1949 if (buffer_freed(bh)) {
1950 BUFFER_TRACE(bh, "freed: skip");
1951 goto unlock;
1952 }
1953
1954 if (!buffer_mapped(bh)) {
1955 BUFFER_TRACE(bh, "unmapped");
1956 ext3_get_block(inode, iblock, bh, 0);
1957 /* unmapped? It's a hole - nothing to do */
1958 if (!buffer_mapped(bh)) {
1959 BUFFER_TRACE(bh, "still unmapped");
1960 goto unlock;
1961 }
1962 }
1963
1964 /* Ok, it's mapped. Make sure it's up-to-date */
1965 if (PageUptodate(page))
1966 set_buffer_uptodate(bh);
1967
1968 if (!buffer_uptodate(bh)) {
1969 err = -EIO;
1970 ll_rw_block(READ, 1, &bh);
1971 wait_on_buffer(bh);
1972 /* Uhhuh. Read error. Complain and punt. */
1973 if (!buffer_uptodate(bh))
1974 goto unlock;
1975 }
1976
1977 if (ext3_should_journal_data(inode)) {
1978 BUFFER_TRACE(bh, "get write access");
1979 err = ext3_journal_get_write_access(handle, bh);
1980 if (err)
1981 goto unlock;
1982 }
1983
Christoph Lametereebd2aa2008-02-04 22:28:29 -08001984 zero_user(page, offset, length);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001985 BUFFER_TRACE(bh, "zeroed end of block");
1986
1987 err = 0;
1988 if (ext3_should_journal_data(inode)) {
1989 err = ext3_journal_dirty_metadata(handle, bh);
1990 } else {
1991 if (ext3_should_order_data(inode))
1992 err = ext3_journal_dirty_data(handle, bh);
1993 mark_buffer_dirty(bh);
1994 }
1995
1996unlock:
1997 unlock_page(page);
1998 page_cache_release(page);
1999 return err;
2000}
2001
2002/*
2003 * Probably it should be a library function... search for first non-zero word
2004 * or memcmp with zero_page, whatever is better for particular architecture.
2005 * Linus?
2006 */
2007static inline int all_zeroes(__le32 *p, __le32 *q)
2008{
2009 while (p < q)
2010 if (*p++)
2011 return 0;
2012 return 1;
2013}
2014
2015/**
2016 * ext3_find_shared - find the indirect blocks for partial truncation.
2017 * @inode: inode in question
2018 * @depth: depth of the affected branch
2019 * @offsets: offsets of pointers in that branch (see ext3_block_to_path)
2020 * @chain: place to store the pointers to partial indirect blocks
2021 * @top: place to the (detached) top of branch
2022 *
2023 * This is a helper function used by ext3_truncate().
2024 *
2025 * When we do truncate() we may have to clean the ends of several
2026 * indirect blocks but leave the blocks themselves alive. Block is
2027 * partially truncated if some data below the new i_size is refered
2028 * from it (and it is on the path to the first completely truncated
2029 * data block, indeed). We have to free the top of that path along
2030 * with everything to the right of the path. Since no allocation
2031 * past the truncation point is possible until ext3_truncate()
2032 * finishes, we may safely do the latter, but top of branch may
2033 * require special attention - pageout below the truncation point
2034 * might try to populate it.
2035 *
2036 * We atomically detach the top of branch from the tree, store the
2037 * block number of its root in *@top, pointers to buffer_heads of
2038 * partially truncated blocks - in @chain[].bh and pointers to
2039 * their last elements that should not be removed - in
2040 * @chain[].p. Return value is the pointer to last filled element
2041 * of @chain.
2042 *
2043 * The work left to caller to do the actual freeing of subtrees:
2044 * a) free the subtree starting from *@top
2045 * b) free the subtrees whose roots are stored in
2046 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
2047 * c) free the subtrees growing from the inode past the @chain[0].
2048 * (no partially truncated stuff there). */
2049
Andrew Mortond6859bf2006-03-26 01:38:03 -08002050static Indirect *ext3_find_shared(struct inode *inode, int depth,
2051 int offsets[4], Indirect chain[4], __le32 *top)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002052{
2053 Indirect *partial, *p;
2054 int k, err;
2055
2056 *top = 0;
Uwe Kleine-Königbf48aab2009-10-28 20:11:03 +01002057 /* Make k index the deepest non-null offset + 1 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002058 for (k = depth; k > 1 && !offsets[k-1]; k--)
2059 ;
2060 partial = ext3_get_branch(inode, k, offsets, chain, &err);
2061 /* Writer: pointers */
2062 if (!partial)
2063 partial = chain + k-1;
2064 /*
2065 * If the branch acquired continuation since we've looked at it -
2066 * fine, it should all survive and (new) top doesn't belong to us.
2067 */
2068 if (!partial->key && *partial->p)
2069 /* Writer: end */
2070 goto no_top;
2071 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
2072 ;
2073 /*
2074 * OK, we've found the last block that must survive. The rest of our
2075 * branch should be detached before unlocking. However, if that rest
2076 * of branch is all ours and does not grow immediately from the inode
2077 * it's easier to cheat and just decrement partial->p.
2078 */
2079 if (p == chain + k - 1 && p > chain) {
2080 p->p--;
2081 } else {
2082 *top = *p->p;
2083 /* Nope, don't do this in ext3. Must leave the tree intact */
2084#if 0
2085 *p->p = 0;
2086#endif
2087 }
2088 /* Writer: end */
2089
Andrew Mortond6859bf2006-03-26 01:38:03 -08002090 while(partial > p) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002091 brelse(partial->bh);
2092 partial--;
2093 }
2094no_top:
2095 return partial;
2096}
2097
2098/*
2099 * Zero a number of block pointers in either an inode or an indirect block.
2100 * If we restart the transaction we must again get write access to the
2101 * indirect block for further modification.
2102 *
2103 * We release `count' blocks on disk, but (last - first) may be greater
2104 * than `count' because there can be holes in there.
2105 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08002106static void ext3_clear_blocks(handle_t *handle, struct inode *inode,
Mingming Cao43d23f92006-06-25 05:48:07 -07002107 struct buffer_head *bh, ext3_fsblk_t block_to_free,
Andrew Mortond6859bf2006-03-26 01:38:03 -08002108 unsigned long count, __le32 *first, __le32 *last)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002109{
2110 __le32 *p;
2111 if (try_to_extend_transaction(handle, inode)) {
2112 if (bh) {
2113 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
2114 ext3_journal_dirty_metadata(handle, bh);
2115 }
2116 ext3_mark_inode_dirty(handle, inode);
Jan Kara00171d32009-08-11 19:06:10 +02002117 truncate_restart_transaction(handle, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002118 if (bh) {
2119 BUFFER_TRACE(bh, "retaking write access");
2120 ext3_journal_get_write_access(handle, bh);
2121 }
2122 }
2123
2124 /*
2125 * Any buffers which are on the journal will be in memory. We find
2126 * them on the hash table so journal_revoke() will run journal_forget()
2127 * on them. We've already detached each block from the file, so
2128 * bforget() in journal_forget() should be safe.
2129 *
2130 * AKPM: turn on bforget in journal_forget()!!!
2131 */
2132 for (p = first; p < last; p++) {
2133 u32 nr = le32_to_cpu(*p);
2134 if (nr) {
2135 struct buffer_head *bh;
2136
2137 *p = 0;
2138 bh = sb_find_get_block(inode->i_sb, nr);
2139 ext3_forget(handle, 0, inode, bh, nr);
2140 }
2141 }
2142
2143 ext3_free_blocks(handle, inode, block_to_free, count);
2144}
2145
2146/**
2147 * ext3_free_data - free a list of data blocks
2148 * @handle: handle for this transaction
2149 * @inode: inode we are dealing with
2150 * @this_bh: indirect buffer_head which contains *@first and *@last
2151 * @first: array of block numbers
2152 * @last: points immediately past the end of array
2153 *
2154 * We are freeing all blocks refered from that array (numbers are stored as
2155 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
2156 *
2157 * We accumulate contiguous runs of blocks to free. Conveniently, if these
2158 * blocks are contiguous then releasing them at one time will only affect one
2159 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
2160 * actually use a lot of journal space.
2161 *
2162 * @this_bh will be %NULL if @first and @last point into the inode's direct
2163 * block pointers.
2164 */
2165static void ext3_free_data(handle_t *handle, struct inode *inode,
2166 struct buffer_head *this_bh,
2167 __le32 *first, __le32 *last)
2168{
Mingming Cao43d23f92006-06-25 05:48:07 -07002169 ext3_fsblk_t block_to_free = 0; /* Starting block # of a run */
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002170 unsigned long count = 0; /* Number of blocks in the run */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002171 __le32 *block_to_free_p = NULL; /* Pointer into inode/ind
2172 corresponding to
2173 block_to_free */
Mingming Cao43d23f92006-06-25 05:48:07 -07002174 ext3_fsblk_t nr; /* Current block # */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002175 __le32 *p; /* Pointer into inode/ind
2176 for current block */
2177 int err;
2178
2179 if (this_bh) { /* For indirect block */
2180 BUFFER_TRACE(this_bh, "get_write_access");
2181 err = ext3_journal_get_write_access(handle, this_bh);
2182 /* Important: if we can't update the indirect pointers
2183 * to the blocks, we can't free them. */
2184 if (err)
2185 return;
2186 }
2187
2188 for (p = first; p < last; p++) {
2189 nr = le32_to_cpu(*p);
2190 if (nr) {
2191 /* accumulate blocks to free if they're contiguous */
2192 if (count == 0) {
2193 block_to_free = nr;
2194 block_to_free_p = p;
2195 count = 1;
2196 } else if (nr == block_to_free + count) {
2197 count++;
2198 } else {
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002199 ext3_clear_blocks(handle, inode, this_bh,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002200 block_to_free,
2201 count, block_to_free_p, p);
2202 block_to_free = nr;
2203 block_to_free_p = p;
2204 count = 1;
2205 }
2206 }
2207 }
2208
2209 if (count > 0)
2210 ext3_clear_blocks(handle, inode, this_bh, block_to_free,
2211 count, block_to_free_p, p);
2212
2213 if (this_bh) {
2214 BUFFER_TRACE(this_bh, "call ext3_journal_dirty_metadata");
Duane Griffin3ccc3162008-07-25 01:46:26 -07002215
2216 /*
2217 * The buffer head should have an attached journal head at this
2218 * point. However, if the data is corrupted and an indirect
2219 * block pointed to itself, it would have been detached when
2220 * the block was cleared. Check for this instead of OOPSing.
2221 */
2222 if (bh2jh(this_bh))
2223 ext3_journal_dirty_metadata(handle, this_bh);
2224 else
2225 ext3_error(inode->i_sb, "ext3_free_data",
2226 "circular indirect block detected, "
2227 "inode=%lu, block=%llu",
2228 inode->i_ino,
2229 (unsigned long long)this_bh->b_blocknr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002230 }
2231}
2232
2233/**
2234 * ext3_free_branches - free an array of branches
2235 * @handle: JBD handle for this transaction
2236 * @inode: inode we are dealing with
2237 * @parent_bh: the buffer_head which contains *@first and *@last
2238 * @first: array of block numbers
2239 * @last: pointer immediately past the end of array
2240 * @depth: depth of the branches to free
2241 *
2242 * We are freeing all blocks refered from these branches (numbers are
2243 * stored as little-endian 32-bit) and updating @inode->i_blocks
2244 * appropriately.
2245 */
2246static void ext3_free_branches(handle_t *handle, struct inode *inode,
2247 struct buffer_head *parent_bh,
2248 __le32 *first, __le32 *last, int depth)
2249{
Mingming Cao43d23f92006-06-25 05:48:07 -07002250 ext3_fsblk_t nr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002251 __le32 *p;
2252
2253 if (is_handle_aborted(handle))
2254 return;
2255
2256 if (depth--) {
2257 struct buffer_head *bh;
2258 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2259 p = last;
2260 while (--p >= first) {
2261 nr = le32_to_cpu(*p);
2262 if (!nr)
2263 continue; /* A hole */
2264
2265 /* Go read the buffer for the next level down */
2266 bh = sb_bread(inode->i_sb, nr);
2267
2268 /*
2269 * A read failure? Report error and clear slot
2270 * (should be rare).
2271 */
2272 if (!bh) {
2273 ext3_error(inode->i_sb, "ext3_free_branches",
Eric Sandeeneee194e2006-09-27 01:49:30 -07002274 "Read failure, inode=%lu, block="E3FSBLK,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002275 inode->i_ino, nr);
2276 continue;
2277 }
2278
2279 /* This zaps the entire block. Bottom up. */
2280 BUFFER_TRACE(bh, "free child branches");
2281 ext3_free_branches(handle, inode, bh,
2282 (__le32*)bh->b_data,
2283 (__le32*)bh->b_data + addr_per_block,
2284 depth);
2285
2286 /*
2287 * We've probably journalled the indirect block several
2288 * times during the truncate. But it's no longer
2289 * needed and we now drop it from the transaction via
2290 * journal_revoke().
2291 *
2292 * That's easy if it's exclusively part of this
2293 * transaction. But if it's part of the committing
2294 * transaction then journal_forget() will simply
2295 * brelse() it. That means that if the underlying
2296 * block is reallocated in ext3_get_block(),
2297 * unmap_underlying_metadata() will find this block
2298 * and will try to get rid of it. damn, damn.
2299 *
2300 * If this block has already been committed to the
2301 * journal, a revoke record will be written. And
2302 * revoke records must be emitted *before* clearing
2303 * this block's bit in the bitmaps.
2304 */
2305 ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
2306
2307 /*
2308 * Everything below this this pointer has been
2309 * released. Now let this top-of-subtree go.
2310 *
2311 * We want the freeing of this indirect block to be
2312 * atomic in the journal with the updating of the
2313 * bitmap block which owns it. So make some room in
2314 * the journal.
2315 *
2316 * We zero the parent pointer *after* freeing its
2317 * pointee in the bitmaps, so if extend_transaction()
2318 * for some reason fails to put the bitmap changes and
2319 * the release into the same transaction, recovery
2320 * will merely complain about releasing a free block,
2321 * rather than leaking blocks.
2322 */
2323 if (is_handle_aborted(handle))
2324 return;
2325 if (try_to_extend_transaction(handle, inode)) {
2326 ext3_mark_inode_dirty(handle, inode);
Jan Kara00171d32009-08-11 19:06:10 +02002327 truncate_restart_transaction(handle, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002328 }
2329
2330 ext3_free_blocks(handle, inode, nr, 1);
2331
2332 if (parent_bh) {
2333 /*
2334 * The block which we have just freed is
2335 * pointed to by an indirect block: journal it
2336 */
2337 BUFFER_TRACE(parent_bh, "get_write_access");
2338 if (!ext3_journal_get_write_access(handle,
2339 parent_bh)){
2340 *p = 0;
2341 BUFFER_TRACE(parent_bh,
2342 "call ext3_journal_dirty_metadata");
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002343 ext3_journal_dirty_metadata(handle,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002344 parent_bh);
2345 }
2346 }
2347 }
2348 } else {
2349 /* We have reached the bottom of the tree. */
2350 BUFFER_TRACE(parent_bh, "free data blocks");
2351 ext3_free_data(handle, inode, parent_bh, first, last);
2352 }
2353}
2354
Duane Griffinae76dd92008-07-25 01:46:23 -07002355int ext3_can_truncate(struct inode *inode)
2356{
2357 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2358 return 0;
2359 if (S_ISREG(inode->i_mode))
2360 return 1;
2361 if (S_ISDIR(inode->i_mode))
2362 return 1;
2363 if (S_ISLNK(inode->i_mode))
2364 return !ext3_inode_is_fast_symlink(inode);
2365 return 0;
2366}
2367
Linus Torvalds1da177e2005-04-16 15:20:36 -07002368/*
2369 * ext3_truncate()
2370 *
2371 * We block out ext3_get_block() block instantiations across the entire
2372 * transaction, and VFS/VM ensures that ext3_truncate() cannot run
2373 * simultaneously on behalf of the same inode.
2374 *
2375 * As we work through the truncate and commmit bits of it to the journal there
2376 * is one core, guiding principle: the file's tree must always be consistent on
2377 * disk. We must be able to restart the truncate after a crash.
2378 *
2379 * The file's tree may be transiently inconsistent in memory (although it
2380 * probably isn't), but whenever we close off and commit a journal transaction,
2381 * the contents of (the filesystem + the journal) must be consistent and
2382 * restartable. It's pretty simple, really: bottom up, right to left (although
2383 * left-to-right works OK too).
2384 *
2385 * Note that at recovery time, journal replay occurs *before* the restart of
2386 * truncate against the orphan inode list.
2387 *
2388 * The committed inode has the new, desired i_size (which is the same as
2389 * i_disksize in this case). After a crash, ext3_orphan_cleanup() will see
2390 * that this inode's truncate did not complete and it will again call
2391 * ext3_truncate() to have another go. So there will be instantiated blocks
2392 * to the right of the truncation point in a crashed ext3 filesystem. But
2393 * that's fine - as long as they are linked from the inode, the post-crash
2394 * ext3_truncate() run will find them and release them.
2395 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08002396void ext3_truncate(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002397{
2398 handle_t *handle;
2399 struct ext3_inode_info *ei = EXT3_I(inode);
2400 __le32 *i_data = ei->i_data;
2401 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2402 struct address_space *mapping = inode->i_mapping;
2403 int offsets[4];
2404 Indirect chain[4];
2405 Indirect *partial;
2406 __le32 nr = 0;
2407 int n;
2408 long last_block;
2409 unsigned blocksize = inode->i_sb->s_blocksize;
2410 struct page *page;
2411
Duane Griffinae76dd92008-07-25 01:46:23 -07002412 if (!ext3_can_truncate(inode))
Jan Karaef436182009-06-17 16:26:24 -07002413 goto out_notrans;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002414
Theodore Ts'of7ab34e2009-04-03 01:34:35 -04002415 if (inode->i_size == 0 && ext3_should_writeback_data(inode))
Jan Kara9df93932010-01-06 21:58:48 +01002416 ext3_set_inode_state(inode, EXT3_STATE_FLUSH_ON_CLOSE);
Theodore Ts'of7ab34e2009-04-03 01:34:35 -04002417
Linus Torvalds1da177e2005-04-16 15:20:36 -07002418 /*
2419 * We have to lock the EOF page here, because lock_page() nests
2420 * outside journal_start().
2421 */
2422 if ((inode->i_size & (blocksize - 1)) == 0) {
2423 /* Block boundary? Nothing to do */
2424 page = NULL;
2425 } else {
2426 page = grab_cache_page(mapping,
2427 inode->i_size >> PAGE_CACHE_SHIFT);
2428 if (!page)
Jan Karaef436182009-06-17 16:26:24 -07002429 goto out_notrans;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002430 }
2431
2432 handle = start_transaction(inode);
2433 if (IS_ERR(handle)) {
2434 if (page) {
2435 clear_highpage(page);
2436 flush_dcache_page(page);
2437 unlock_page(page);
2438 page_cache_release(page);
2439 }
Jan Karaef436182009-06-17 16:26:24 -07002440 goto out_notrans;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002441 }
2442
2443 last_block = (inode->i_size + blocksize-1)
2444 >> EXT3_BLOCK_SIZE_BITS(inode->i_sb);
2445
2446 if (page)
2447 ext3_block_truncate_page(handle, page, mapping, inode->i_size);
2448
2449 n = ext3_block_to_path(inode, last_block, offsets, NULL);
2450 if (n == 0)
2451 goto out_stop; /* error */
2452
2453 /*
2454 * OK. This truncate is going to happen. We add the inode to the
2455 * orphan list, so that if this truncate spans multiple transactions,
2456 * and we crash, we will resume the truncate when the filesystem
2457 * recovers. It also marks the inode dirty, to catch the new size.
2458 *
2459 * Implication: the file must always be in a sane, consistent
2460 * truncatable state while each transaction commits.
2461 */
2462 if (ext3_orphan_add(handle, inode))
2463 goto out_stop;
2464
2465 /*
2466 * The orphan list entry will now protect us from any crash which
2467 * occurs before the truncate completes, so it is now safe to propagate
2468 * the new, shorter inode size (held for now in i_size) into the
2469 * on-disk inode. We do this via i_disksize, which is the value which
2470 * ext3 *really* writes onto the disk inode.
2471 */
2472 ei->i_disksize = inode->i_size;
2473
2474 /*
2475 * From here we block out all ext3_get_block() callers who want to
2476 * modify the block allocation tree.
2477 */
Arjan van de Ven97461512006-03-23 03:00:42 -08002478 mutex_lock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002479
2480 if (n == 1) { /* direct blocks */
2481 ext3_free_data(handle, inode, NULL, i_data+offsets[0],
2482 i_data + EXT3_NDIR_BLOCKS);
2483 goto do_indirects;
2484 }
2485
2486 partial = ext3_find_shared(inode, n, offsets, chain, &nr);
2487 /* Kill the top of shared branch (not detached) */
2488 if (nr) {
2489 if (partial == chain) {
2490 /* Shared branch grows from the inode */
2491 ext3_free_branches(handle, inode, NULL,
2492 &nr, &nr+1, (chain+n-1) - partial);
2493 *partial->p = 0;
2494 /*
2495 * We mark the inode dirty prior to restart,
2496 * and prior to stop. No need for it here.
2497 */
2498 } else {
2499 /* Shared branch grows from an indirect block */
2500 BUFFER_TRACE(partial->bh, "get_write_access");
2501 ext3_free_branches(handle, inode, partial->bh,
2502 partial->p,
2503 partial->p+1, (chain+n-1) - partial);
2504 }
2505 }
2506 /* Clear the ends of indirect blocks on the shared branch */
2507 while (partial > chain) {
2508 ext3_free_branches(handle, inode, partial->bh, partial->p + 1,
2509 (__le32*)partial->bh->b_data+addr_per_block,
2510 (chain+n-1) - partial);
2511 BUFFER_TRACE(partial->bh, "call brelse");
2512 brelse (partial->bh);
2513 partial--;
2514 }
2515do_indirects:
2516 /* Kill the remaining (whole) subtrees */
2517 switch (offsets[0]) {
Andrew Mortond6859bf2006-03-26 01:38:03 -08002518 default:
2519 nr = i_data[EXT3_IND_BLOCK];
2520 if (nr) {
2521 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
2522 i_data[EXT3_IND_BLOCK] = 0;
2523 }
2524 case EXT3_IND_BLOCK:
2525 nr = i_data[EXT3_DIND_BLOCK];
2526 if (nr) {
2527 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
2528 i_data[EXT3_DIND_BLOCK] = 0;
2529 }
2530 case EXT3_DIND_BLOCK:
2531 nr = i_data[EXT3_TIND_BLOCK];
2532 if (nr) {
2533 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
2534 i_data[EXT3_TIND_BLOCK] = 0;
2535 }
2536 case EXT3_TIND_BLOCK:
2537 ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002538 }
2539
2540 ext3_discard_reservation(inode);
2541
Arjan van de Ven97461512006-03-23 03:00:42 -08002542 mutex_unlock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002543 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
2544 ext3_mark_inode_dirty(handle, inode);
2545
Andrew Mortond6859bf2006-03-26 01:38:03 -08002546 /*
2547 * In a multi-transaction truncate, we only make the final transaction
2548 * synchronous
2549 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002550 if (IS_SYNC(inode))
2551 handle->h_sync = 1;
2552out_stop:
2553 /*
2554 * If this was a simple ftruncate(), and the file will remain alive
2555 * then we need to clear up the orphan record which we created above.
2556 * However, if this was a real unlink then we were called by
2557 * ext3_delete_inode(), and we allow that function to clean up the
2558 * orphan info for us.
2559 */
2560 if (inode->i_nlink)
2561 ext3_orphan_del(handle, inode);
2562
2563 ext3_journal_stop(handle);
Jan Karaef436182009-06-17 16:26:24 -07002564 return;
2565out_notrans:
2566 /*
2567 * Delete the inode from orphan list so that it doesn't stay there
2568 * forever and trigger assertion on umount.
2569 */
2570 if (inode->i_nlink)
2571 ext3_orphan_del(NULL, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002572}
2573
Mingming Cao43d23f92006-06-25 05:48:07 -07002574static ext3_fsblk_t ext3_get_inode_block(struct super_block *sb,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002575 unsigned long ino, struct ext3_iloc *iloc)
2576{
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002577 unsigned long block_group;
Mingming Cao43d23f92006-06-25 05:48:07 -07002578 unsigned long offset;
2579 ext3_fsblk_t block;
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002580 struct ext3_group_desc *gdp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002581
Neil Brown2ccb48e2006-07-30 03:03:01 -07002582 if (!ext3_valid_inum(sb, ino)) {
2583 /*
2584 * This error is already checked for in namei.c unless we are
2585 * looking at an NFS filehandle, in which case no error
2586 * report is needed
2587 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002588 return 0;
2589 }
Neil Brown2ccb48e2006-07-30 03:03:01 -07002590
Linus Torvalds1da177e2005-04-16 15:20:36 -07002591 block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002592 gdp = ext3_get_group_desc(sb, block_group, NULL);
2593 if (!gdp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002594 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002595 /*
2596 * Figure out the offset within the block group inode table
2597 */
2598 offset = ((ino - 1) % EXT3_INODES_PER_GROUP(sb)) *
2599 EXT3_INODE_SIZE(sb);
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002600 block = le32_to_cpu(gdp->bg_inode_table) +
Linus Torvalds1da177e2005-04-16 15:20:36 -07002601 (offset >> EXT3_BLOCK_SIZE_BITS(sb));
2602
2603 iloc->block_group = block_group;
2604 iloc->offset = offset & (EXT3_BLOCK_SIZE(sb) - 1);
2605 return block;
2606}
2607
2608/*
2609 * ext3_get_inode_loc returns with an extra refcount against the inode's
2610 * underlying buffer_head on success. If 'in_mem' is true, we have all
2611 * data in memory that is needed to recreate the on-disk version of this
2612 * inode.
2613 */
2614static int __ext3_get_inode_loc(struct inode *inode,
2615 struct ext3_iloc *iloc, int in_mem)
2616{
Mingming Cao43d23f92006-06-25 05:48:07 -07002617 ext3_fsblk_t block;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002618 struct buffer_head *bh;
2619
2620 block = ext3_get_inode_block(inode->i_sb, inode->i_ino, iloc);
2621 if (!block)
2622 return -EIO;
2623
2624 bh = sb_getblk(inode->i_sb, block);
2625 if (!bh) {
2626 ext3_error (inode->i_sb, "ext3_get_inode_loc",
2627 "unable to read inode block - "
Mingming Cao43d23f92006-06-25 05:48:07 -07002628 "inode=%lu, block="E3FSBLK,
2629 inode->i_ino, block);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002630 return -EIO;
2631 }
2632 if (!buffer_uptodate(bh)) {
2633 lock_buffer(bh);
Hidehiro Kawai95450f52008-07-25 01:46:24 -07002634
2635 /*
2636 * If the buffer has the write error flag, we have failed
2637 * to write out another inode in the same block. In this
2638 * case, we don't have to read the block because we may
2639 * read the old inode data successfully.
2640 */
2641 if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
2642 set_buffer_uptodate(bh);
2643
Linus Torvalds1da177e2005-04-16 15:20:36 -07002644 if (buffer_uptodate(bh)) {
2645 /* someone brought it uptodate while we waited */
2646 unlock_buffer(bh);
2647 goto has_buffer;
2648 }
2649
2650 /*
2651 * If we have all information of the inode in memory and this
2652 * is the only valid inode in the block, we need not read the
2653 * block.
2654 */
2655 if (in_mem) {
2656 struct buffer_head *bitmap_bh;
2657 struct ext3_group_desc *desc;
2658 int inodes_per_buffer;
2659 int inode_offset, i;
2660 int block_group;
2661 int start;
2662
2663 block_group = (inode->i_ino - 1) /
2664 EXT3_INODES_PER_GROUP(inode->i_sb);
2665 inodes_per_buffer = bh->b_size /
2666 EXT3_INODE_SIZE(inode->i_sb);
2667 inode_offset = ((inode->i_ino - 1) %
2668 EXT3_INODES_PER_GROUP(inode->i_sb));
2669 start = inode_offset & ~(inodes_per_buffer - 1);
2670
2671 /* Is the inode bitmap in cache? */
2672 desc = ext3_get_group_desc(inode->i_sb,
2673 block_group, NULL);
2674 if (!desc)
2675 goto make_io;
2676
2677 bitmap_bh = sb_getblk(inode->i_sb,
2678 le32_to_cpu(desc->bg_inode_bitmap));
2679 if (!bitmap_bh)
2680 goto make_io;
2681
2682 /*
2683 * If the inode bitmap isn't in cache then the
2684 * optimisation may end up performing two reads instead
2685 * of one, so skip it.
2686 */
2687 if (!buffer_uptodate(bitmap_bh)) {
2688 brelse(bitmap_bh);
2689 goto make_io;
2690 }
2691 for (i = start; i < start + inodes_per_buffer; i++) {
2692 if (i == inode_offset)
2693 continue;
2694 if (ext3_test_bit(i, bitmap_bh->b_data))
2695 break;
2696 }
2697 brelse(bitmap_bh);
2698 if (i == start + inodes_per_buffer) {
2699 /* all other inodes are free, so skip I/O */
2700 memset(bh->b_data, 0, bh->b_size);
2701 set_buffer_uptodate(bh);
2702 unlock_buffer(bh);
2703 goto has_buffer;
2704 }
2705 }
2706
2707make_io:
2708 /*
2709 * There are other valid inodes in the buffer, this inode
2710 * has in-inode xattrs, or we don't have this inode in memory.
2711 * Read the block from disk.
2712 */
2713 get_bh(bh);
2714 bh->b_end_io = end_buffer_read_sync;
Jens Axboecaa38fb2006-07-23 01:41:26 +02002715 submit_bh(READ_META, bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002716 wait_on_buffer(bh);
2717 if (!buffer_uptodate(bh)) {
2718 ext3_error(inode->i_sb, "ext3_get_inode_loc",
2719 "unable to read inode block - "
Mingming Cao43d23f92006-06-25 05:48:07 -07002720 "inode=%lu, block="E3FSBLK,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002721 inode->i_ino, block);
2722 brelse(bh);
2723 return -EIO;
2724 }
2725 }
2726has_buffer:
2727 iloc->bh = bh;
2728 return 0;
2729}
2730
2731int ext3_get_inode_loc(struct inode *inode, struct ext3_iloc *iloc)
2732{
2733 /* We have all inode data except xattrs in memory here. */
2734 return __ext3_get_inode_loc(inode, iloc,
Jan Kara9df93932010-01-06 21:58:48 +01002735 !ext3_test_inode_state(inode, EXT3_STATE_XATTR));
Linus Torvalds1da177e2005-04-16 15:20:36 -07002736}
2737
2738void ext3_set_inode_flags(struct inode *inode)
2739{
2740 unsigned int flags = EXT3_I(inode)->i_flags;
2741
2742 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
2743 if (flags & EXT3_SYNC_FL)
2744 inode->i_flags |= S_SYNC;
2745 if (flags & EXT3_APPEND_FL)
2746 inode->i_flags |= S_APPEND;
2747 if (flags & EXT3_IMMUTABLE_FL)
2748 inode->i_flags |= S_IMMUTABLE;
2749 if (flags & EXT3_NOATIME_FL)
2750 inode->i_flags |= S_NOATIME;
2751 if (flags & EXT3_DIRSYNC_FL)
2752 inode->i_flags |= S_DIRSYNC;
2753}
2754
Jan Kara28be5ab2007-05-08 00:30:33 -07002755/* Propagate flags from i_flags to EXT3_I(inode)->i_flags */
2756void ext3_get_inode_flags(struct ext3_inode_info *ei)
2757{
2758 unsigned int flags = ei->vfs_inode.i_flags;
2759
2760 ei->i_flags &= ~(EXT3_SYNC_FL|EXT3_APPEND_FL|
2761 EXT3_IMMUTABLE_FL|EXT3_NOATIME_FL|EXT3_DIRSYNC_FL);
2762 if (flags & S_SYNC)
2763 ei->i_flags |= EXT3_SYNC_FL;
2764 if (flags & S_APPEND)
2765 ei->i_flags |= EXT3_APPEND_FL;
2766 if (flags & S_IMMUTABLE)
2767 ei->i_flags |= EXT3_IMMUTABLE_FL;
2768 if (flags & S_NOATIME)
2769 ei->i_flags |= EXT3_NOATIME_FL;
2770 if (flags & S_DIRSYNC)
2771 ei->i_flags |= EXT3_DIRSYNC_FL;
2772}
2773
David Howells473043d2008-02-07 00:15:36 -08002774struct inode *ext3_iget(struct super_block *sb, unsigned long ino)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002775{
2776 struct ext3_iloc iloc;
2777 struct ext3_inode *raw_inode;
David Howells473043d2008-02-07 00:15:36 -08002778 struct ext3_inode_info *ei;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002779 struct buffer_head *bh;
David Howells473043d2008-02-07 00:15:36 -08002780 struct inode *inode;
Jan Karafe8bc912009-10-16 19:26:15 +02002781 journal_t *journal = EXT3_SB(sb)->s_journal;
2782 transaction_t *transaction;
David Howells473043d2008-02-07 00:15:36 -08002783 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002784 int block;
2785
David Howells473043d2008-02-07 00:15:36 -08002786 inode = iget_locked(sb, ino);
2787 if (!inode)
2788 return ERR_PTR(-ENOMEM);
2789 if (!(inode->i_state & I_NEW))
2790 return inode;
2791
2792 ei = EXT3_I(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002793 ei->i_block_alloc_info = NULL;
2794
David Howells473043d2008-02-07 00:15:36 -08002795 ret = __ext3_get_inode_loc(inode, &iloc, 0);
2796 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002797 goto bad_inode;
2798 bh = iloc.bh;
2799 raw_inode = ext3_raw_inode(&iloc);
2800 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
2801 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
2802 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
2803 if(!(test_opt (inode->i_sb, NO_UID32))) {
2804 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
2805 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
2806 }
2807 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
2808 inode->i_size = le32_to_cpu(raw_inode->i_size);
Markus Rechberger4d7bf112007-05-08 00:23:39 -07002809 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
2810 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
2811 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002812 inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
2813
Linus Torvaldsde329822010-03-29 14:30:19 -07002814 ei->i_state_flags = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002815 ei->i_dir_start_lookup = 0;
2816 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
2817 /* We now have enough fields to check if the inode was active or not.
2818 * This is needed because nfsd might try to access dead inodes
2819 * the test is that same one that e2fsck uses
2820 * NeilBrown 1999oct15
2821 */
2822 if (inode->i_nlink == 0) {
2823 if (inode->i_mode == 0 ||
2824 !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) {
2825 /* this inode is deleted */
2826 brelse (bh);
David Howells473043d2008-02-07 00:15:36 -08002827 ret = -ESTALE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002828 goto bad_inode;
2829 }
2830 /* The only unlinked inodes we let through here have
2831 * valid i_mode and are being read by the orphan
2832 * recovery code: that's fine, we're about to complete
2833 * the process of deleting those. */
2834 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002835 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
2836 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
2837#ifdef EXT3_FRAGMENTS
2838 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
2839 ei->i_frag_no = raw_inode->i_frag;
2840 ei->i_frag_size = raw_inode->i_fsize;
2841#endif
2842 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
2843 if (!S_ISREG(inode->i_mode)) {
2844 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
2845 } else {
2846 inode->i_size |=
2847 ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
2848 }
2849 ei->i_disksize = inode->i_size;
2850 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
2851 ei->i_block_group = iloc.block_group;
2852 /*
2853 * NOTE! The in-memory inode i_data array is in little-endian order
2854 * even on big-endian machines: we do NOT byteswap the block numbers!
2855 */
2856 for (block = 0; block < EXT3_N_BLOCKS; block++)
2857 ei->i_data[block] = raw_inode->i_block[block];
2858 INIT_LIST_HEAD(&ei->i_orphan);
2859
Jan Karafe8bc912009-10-16 19:26:15 +02002860 /*
2861 * Set transaction id's of transactions that have to be committed
2862 * to finish f[data]sync. We set them to currently running transaction
2863 * as we cannot be sure that the inode or some of its metadata isn't
2864 * part of the transaction - the inode could have been reclaimed and
2865 * now it is reread from disk.
2866 */
2867 if (journal) {
2868 tid_t tid;
2869
2870 spin_lock(&journal->j_state_lock);
2871 if (journal->j_running_transaction)
2872 transaction = journal->j_running_transaction;
2873 else
2874 transaction = journal->j_committing_transaction;
2875 if (transaction)
2876 tid = transaction->t_tid;
2877 else
2878 tid = journal->j_commit_sequence;
2879 spin_unlock(&journal->j_state_lock);
2880 atomic_set(&ei->i_sync_tid, tid);
2881 atomic_set(&ei->i_datasync_tid, tid);
2882 }
2883
Linus Torvalds1da177e2005-04-16 15:20:36 -07002884 if (inode->i_ino >= EXT3_FIRST_INO(inode->i_sb) + 1 &&
2885 EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) {
2886 /*
2887 * When mke2fs creates big inodes it does not zero out
2888 * the unused bytes above EXT3_GOOD_OLD_INODE_SIZE,
2889 * so ignore those first few inodes.
2890 */
2891 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
2892 if (EXT3_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
Kirill Korotaeve4a10a32007-06-23 17:16:48 -07002893 EXT3_INODE_SIZE(inode->i_sb)) {
2894 brelse (bh);
David Howells473043d2008-02-07 00:15:36 -08002895 ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002896 goto bad_inode;
Kirill Korotaeve4a10a32007-06-23 17:16:48 -07002897 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002898 if (ei->i_extra_isize == 0) {
2899 /* The extra space is currently unused. Use it. */
2900 ei->i_extra_isize = sizeof(struct ext3_inode) -
2901 EXT3_GOOD_OLD_INODE_SIZE;
2902 } else {
2903 __le32 *magic = (void *)raw_inode +
2904 EXT3_GOOD_OLD_INODE_SIZE +
2905 ei->i_extra_isize;
2906 if (*magic == cpu_to_le32(EXT3_XATTR_MAGIC))
Jan Kara9df93932010-01-06 21:58:48 +01002907 ext3_set_inode_state(inode, EXT3_STATE_XATTR);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002908 }
2909 } else
2910 ei->i_extra_isize = 0;
2911
2912 if (S_ISREG(inode->i_mode)) {
2913 inode->i_op = &ext3_file_inode_operations;
2914 inode->i_fop = &ext3_file_operations;
2915 ext3_set_aops(inode);
2916 } else if (S_ISDIR(inode->i_mode)) {
2917 inode->i_op = &ext3_dir_inode_operations;
2918 inode->i_fop = &ext3_dir_operations;
2919 } else if (S_ISLNK(inode->i_mode)) {
Duane Griffinb5ed3112008-12-19 20:47:14 +00002920 if (ext3_inode_is_fast_symlink(inode)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002921 inode->i_op = &ext3_fast_symlink_inode_operations;
Duane Griffinb5ed3112008-12-19 20:47:14 +00002922 nd_terminate_link(ei->i_data, inode->i_size,
2923 sizeof(ei->i_data) - 1);
2924 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002925 inode->i_op = &ext3_symlink_inode_operations;
2926 ext3_set_aops(inode);
2927 }
2928 } else {
2929 inode->i_op = &ext3_special_inode_operations;
2930 if (raw_inode->i_block[0])
2931 init_special_inode(inode, inode->i_mode,
2932 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002933 else
Linus Torvalds1da177e2005-04-16 15:20:36 -07002934 init_special_inode(inode, inode->i_mode,
2935 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
2936 }
2937 brelse (iloc.bh);
2938 ext3_set_inode_flags(inode);
David Howells473043d2008-02-07 00:15:36 -08002939 unlock_new_inode(inode);
2940 return inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002941
2942bad_inode:
David Howells473043d2008-02-07 00:15:36 -08002943 iget_failed(inode);
2944 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002945}
2946
2947/*
2948 * Post the struct inode info into an on-disk inode location in the
2949 * buffer-cache. This gobbles the caller's reference to the
2950 * buffer_head in the inode location struct.
2951 *
2952 * The caller must have write access to iloc->bh.
2953 */
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002954static int ext3_do_update_inode(handle_t *handle,
2955 struct inode *inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002956 struct ext3_iloc *iloc)
2957{
2958 struct ext3_inode *raw_inode = ext3_raw_inode(iloc);
2959 struct ext3_inode_info *ei = EXT3_I(inode);
2960 struct buffer_head *bh = iloc->bh;
2961 int err = 0, rc, block;
2962
Chris Mason4f003fd2009-09-08 00:22:14 +02002963again:
2964 /* we can't allow multiple procs in here at once, its a bit racey */
2965 lock_buffer(bh);
2966
Linus Torvalds1da177e2005-04-16 15:20:36 -07002967 /* For fields not not tracking in the in-memory inode,
2968 * initialise them to zero for new inodes. */
Jan Kara9df93932010-01-06 21:58:48 +01002969 if (ext3_test_inode_state(inode, EXT3_STATE_NEW))
Linus Torvalds1da177e2005-04-16 15:20:36 -07002970 memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
2971
Jan Kara28be5ab2007-05-08 00:30:33 -07002972 ext3_get_inode_flags(ei);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002973 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
2974 if(!(test_opt(inode->i_sb, NO_UID32))) {
2975 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
2976 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
2977/*
2978 * Fix up interoperability with old kernels. Otherwise, old inodes get
2979 * re-used with the upper 16 bits of the uid/gid intact
2980 */
2981 if(!ei->i_dtime) {
2982 raw_inode->i_uid_high =
2983 cpu_to_le16(high_16_bits(inode->i_uid));
2984 raw_inode->i_gid_high =
2985 cpu_to_le16(high_16_bits(inode->i_gid));
2986 } else {
2987 raw_inode->i_uid_high = 0;
2988 raw_inode->i_gid_high = 0;
2989 }
2990 } else {
2991 raw_inode->i_uid_low =
2992 cpu_to_le16(fs_high2lowuid(inode->i_uid));
2993 raw_inode->i_gid_low =
2994 cpu_to_le16(fs_high2lowgid(inode->i_gid));
2995 raw_inode->i_uid_high = 0;
2996 raw_inode->i_gid_high = 0;
2997 }
2998 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
2999 raw_inode->i_size = cpu_to_le32(ei->i_disksize);
3000 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
3001 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
3002 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
3003 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
3004 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
3005 raw_inode->i_flags = cpu_to_le32(ei->i_flags);
3006#ifdef EXT3_FRAGMENTS
3007 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
3008 raw_inode->i_frag = ei->i_frag_no;
3009 raw_inode->i_fsize = ei->i_frag_size;
3010#endif
3011 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
3012 if (!S_ISREG(inode->i_mode)) {
3013 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
3014 } else {
3015 raw_inode->i_size_high =
3016 cpu_to_le32(ei->i_disksize >> 32);
3017 if (ei->i_disksize > 0x7fffffffULL) {
3018 struct super_block *sb = inode->i_sb;
3019 if (!EXT3_HAS_RO_COMPAT_FEATURE(sb,
3020 EXT3_FEATURE_RO_COMPAT_LARGE_FILE) ||
3021 EXT3_SB(sb)->s_es->s_rev_level ==
3022 cpu_to_le32(EXT3_GOOD_OLD_REV)) {
3023 /* If this is the first large file
3024 * created, add a flag to the superblock.
3025 */
Chris Mason4f003fd2009-09-08 00:22:14 +02003026 unlock_buffer(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003027 err = ext3_journal_get_write_access(handle,
3028 EXT3_SB(sb)->s_sbh);
3029 if (err)
3030 goto out_brelse;
Chris Mason4f003fd2009-09-08 00:22:14 +02003031
Linus Torvalds1da177e2005-04-16 15:20:36 -07003032 ext3_update_dynamic_rev(sb);
3033 EXT3_SET_RO_COMPAT_FEATURE(sb,
3034 EXT3_FEATURE_RO_COMPAT_LARGE_FILE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003035 handle->h_sync = 1;
3036 err = ext3_journal_dirty_metadata(handle,
3037 EXT3_SB(sb)->s_sbh);
Chris Mason4f003fd2009-09-08 00:22:14 +02003038 /* get our lock and start over */
3039 goto again;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003040 }
3041 }
3042 }
3043 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
3044 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
3045 if (old_valid_dev(inode->i_rdev)) {
3046 raw_inode->i_block[0] =
3047 cpu_to_le32(old_encode_dev(inode->i_rdev));
3048 raw_inode->i_block[1] = 0;
3049 } else {
3050 raw_inode->i_block[0] = 0;
3051 raw_inode->i_block[1] =
3052 cpu_to_le32(new_encode_dev(inode->i_rdev));
3053 raw_inode->i_block[2] = 0;
3054 }
3055 } else for (block = 0; block < EXT3_N_BLOCKS; block++)
3056 raw_inode->i_block[block] = ei->i_data[block];
3057
Andreas Gruenbacherff87b372005-07-07 17:57:00 -07003058 if (ei->i_extra_isize)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003059 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
3060
3061 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
Chris Mason4f003fd2009-09-08 00:22:14 +02003062 unlock_buffer(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003063 rc = ext3_journal_dirty_metadata(handle, bh);
3064 if (!err)
3065 err = rc;
Jan Kara9df93932010-01-06 21:58:48 +01003066 ext3_clear_inode_state(inode, EXT3_STATE_NEW);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003067
Jan Karafe8bc912009-10-16 19:26:15 +02003068 atomic_set(&ei->i_sync_tid, handle->h_transaction->t_tid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003069out_brelse:
3070 brelse (bh);
3071 ext3_std_error(inode->i_sb, err);
3072 return err;
3073}
3074
3075/*
3076 * ext3_write_inode()
3077 *
3078 * We are called from a few places:
3079 *
3080 * - Within generic_file_write() for O_SYNC files.
3081 * Here, there will be no transaction running. We wait for any running
3082 * trasnaction to commit.
3083 *
3084 * - Within sys_sync(), kupdate and such.
3085 * We wait on commit, if tol to.
3086 *
3087 * - Within prune_icache() (PF_MEMALLOC == true)
3088 * Here we simply return. We can't afford to block kswapd on the
3089 * journal commit.
3090 *
3091 * In all cases it is actually safe for us to return without doing anything,
3092 * because the inode has been copied into a raw inode buffer in
3093 * ext3_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
3094 * knfsd.
3095 *
3096 * Note that we are absolutely dependent upon all inode dirtiers doing the
3097 * right thing: they *must* call mark_inode_dirty() after dirtying info in
3098 * which we are interested.
3099 *
3100 * It would be a bug for them to not do this. The code:
3101 *
3102 * mark_inode_dirty(inode)
3103 * stuff();
3104 * inode->i_size = expr;
3105 *
3106 * is in error because a kswapd-driven write_inode() could occur while
3107 * `stuff()' is running, and the new i_size will be lost. Plus the inode
3108 * will no longer be on the superblock's dirty inode list.
3109 */
Christoph Hellwiga9185b42010-03-05 09:21:37 +01003110int ext3_write_inode(struct inode *inode, struct writeback_control *wbc)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003111{
3112 if (current->flags & PF_MEMALLOC)
3113 return 0;
3114
3115 if (ext3_journal_current_handle()) {
Jose R. Santos9ad163a2007-10-18 23:39:23 -07003116 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07003117 dump_stack();
3118 return -EIO;
3119 }
3120
Christoph Hellwiga9185b42010-03-05 09:21:37 +01003121 if (wbc->sync_mode != WB_SYNC_ALL)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003122 return 0;
3123
3124 return ext3_force_commit(inode->i_sb);
3125}
3126
3127/*
3128 * ext3_setattr()
3129 *
3130 * Called from notify_change.
3131 *
3132 * We want to trap VFS attempts to truncate the file as soon as
3133 * possible. In particular, we want to make sure that when the VFS
3134 * shrinks i_size, we put the inode on the orphan list and modify
3135 * i_disksize immediately, so that during the subsequent flushing of
3136 * dirty pages and freeing of disk blocks, we can guarantee that any
3137 * commit will leave the blocks being flushed in an unused state on
3138 * disk. (On recovery, the inode will get truncated and the blocks will
3139 * be freed, so we have a strong guarantee that no future commit will
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003140 * leave these blocks visible to the user.)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003141 *
3142 * Called with inode->sem down.
3143 */
3144int ext3_setattr(struct dentry *dentry, struct iattr *attr)
3145{
3146 struct inode *inode = dentry->d_inode;
3147 int error, rc = 0;
3148 const unsigned int ia_valid = attr->ia_valid;
3149
3150 error = inode_change_ok(inode, attr);
3151 if (error)
3152 return error;
3153
Dmitry Monakhov12755622010-04-08 22:04:20 +04003154 if (is_quota_modification(inode, attr))
Christoph Hellwig871a2932010-03-03 09:05:07 -05003155 dquot_initialize(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003156 if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
3157 (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
3158 handle_t *handle;
3159
3160 /* (user+group)*(old+new) structure, inode write (sb,
3161 * inode block, ? - but truncate inode update has it) */
Dmitry Monakhovc4590012009-12-09 03:05:30 +03003162 handle = ext3_journal_start(inode, EXT3_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)+
3163 EXT3_MAXQUOTAS_DEL_BLOCKS(inode->i_sb)+3);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003164 if (IS_ERR(handle)) {
3165 error = PTR_ERR(handle);
3166 goto err_out;
3167 }
Christoph Hellwigb43fa822010-03-03 09:05:03 -05003168 error = dquot_transfer(inode, attr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003169 if (error) {
3170 ext3_journal_stop(handle);
3171 return error;
3172 }
3173 /* Update corresponding info in inode so that everything is in
3174 * one transaction */
3175 if (attr->ia_valid & ATTR_UID)
3176 inode->i_uid = attr->ia_uid;
3177 if (attr->ia_valid & ATTR_GID)
3178 inode->i_gid = attr->ia_gid;
3179 error = ext3_mark_inode_dirty(handle, inode);
3180 ext3_journal_stop(handle);
3181 }
3182
3183 if (S_ISREG(inode->i_mode) &&
3184 attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
3185 handle_t *handle;
3186
3187 handle = ext3_journal_start(inode, 3);
3188 if (IS_ERR(handle)) {
3189 error = PTR_ERR(handle);
3190 goto err_out;
3191 }
3192
3193 error = ext3_orphan_add(handle, inode);
3194 EXT3_I(inode)->i_disksize = attr->ia_size;
3195 rc = ext3_mark_inode_dirty(handle, inode);
3196 if (!error)
3197 error = rc;
3198 ext3_journal_stop(handle);
3199 }
3200
3201 rc = inode_setattr(inode, attr);
3202
Linus Torvalds1da177e2005-04-16 15:20:36 -07003203 if (!rc && (ia_valid & ATTR_MODE))
3204 rc = ext3_acl_chmod(inode);
3205
3206err_out:
3207 ext3_std_error(inode->i_sb, error);
3208 if (!error)
3209 error = rc;
3210 return error;
3211}
3212
3213
3214/*
Andrew Mortond6859bf2006-03-26 01:38:03 -08003215 * How many blocks doth make a writepage()?
Linus Torvalds1da177e2005-04-16 15:20:36 -07003216 *
3217 * With N blocks per page, it may be:
3218 * N data blocks
3219 * 2 indirect block
3220 * 2 dindirect
3221 * 1 tindirect
3222 * N+5 bitmap blocks (from the above)
3223 * N+5 group descriptor summary blocks
3224 * 1 inode block
3225 * 1 superblock.
3226 * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quote files
3227 *
3228 * 3 * (N + 5) + 2 + 2 * EXT3_SINGLEDATA_TRANS_BLOCKS
3229 *
3230 * With ordered or writeback data it's the same, less the N data blocks.
3231 *
3232 * If the inode's direct blocks can hold an integral number of pages then a
3233 * page cannot straddle two indirect blocks, and we can only touch one indirect
3234 * and dindirect block, and the "5" above becomes "3".
3235 *
3236 * This still overestimates under most circumstances. If we were to pass the
3237 * start and end offsets in here as well we could do block_to_path() on each
3238 * block and work out the exact number of indirects which are touched. Pah.
3239 */
3240
3241static int ext3_writepage_trans_blocks(struct inode *inode)
3242{
3243 int bpp = ext3_journal_blocks_per_page(inode);
3244 int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3;
3245 int ret;
3246
3247 if (ext3_should_journal_data(inode))
3248 ret = 3 * (bpp + indirects) + 2;
3249 else
3250 ret = 2 * (bpp + indirects) + 2;
3251
3252#ifdef CONFIG_QUOTA
Christoph Hellwig871a2932010-03-03 09:05:07 -05003253 /* We know that structure was already allocated during dquot_initialize so
Linus Torvalds1da177e2005-04-16 15:20:36 -07003254 * we will be updating only the data blocks + inodes */
Dmitry Monakhovc4590012009-12-09 03:05:30 +03003255 ret += EXT3_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003256#endif
3257
3258 return ret;
3259}
3260
3261/*
3262 * The caller must have previously called ext3_reserve_inode_write().
3263 * Give this, we know that the caller already has write access to iloc->bh.
3264 */
3265int ext3_mark_iloc_dirty(handle_t *handle,
3266 struct inode *inode, struct ext3_iloc *iloc)
3267{
3268 int err = 0;
3269
3270 /* the do_update_inode consumes one bh->b_count */
3271 get_bh(iloc->bh);
3272
3273 /* ext3_do_update_inode() does journal_dirty_metadata */
3274 err = ext3_do_update_inode(handle, inode, iloc);
3275 put_bh(iloc->bh);
3276 return err;
3277}
3278
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003279/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003280 * On success, We end up with an outstanding reference count against
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003281 * iloc->bh. This _must_ be cleaned up later.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003282 */
3283
3284int
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003285ext3_reserve_inode_write(handle_t *handle, struct inode *inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003286 struct ext3_iloc *iloc)
3287{
3288 int err = 0;
3289 if (handle) {
3290 err = ext3_get_inode_loc(inode, iloc);
3291 if (!err) {
3292 BUFFER_TRACE(iloc->bh, "get_write_access");
3293 err = ext3_journal_get_write_access(handle, iloc->bh);
3294 if (err) {
3295 brelse(iloc->bh);
3296 iloc->bh = NULL;
3297 }
3298 }
3299 }
3300 ext3_std_error(inode->i_sb, err);
3301 return err;
3302}
3303
3304/*
Andrew Mortond6859bf2006-03-26 01:38:03 -08003305 * What we do here is to mark the in-core inode as clean with respect to inode
3306 * dirtiness (it may still be data-dirty).
Linus Torvalds1da177e2005-04-16 15:20:36 -07003307 * This means that the in-core inode may be reaped by prune_icache
3308 * without having to perform any I/O. This is a very good thing,
3309 * because *any* task may call prune_icache - even ones which
3310 * have a transaction open against a different journal.
3311 *
3312 * Is this cheating? Not really. Sure, we haven't written the
3313 * inode out, but prune_icache isn't a user-visible syncing function.
3314 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
3315 * we start and wait on commits.
3316 *
3317 * Is this efficient/effective? Well, we're being nice to the system
3318 * by cleaning up our inodes proactively so they can be reaped
3319 * without I/O. But we are potentially leaving up to five seconds'
3320 * worth of inodes floating about which prune_icache wants us to
3321 * write out. One way to fix that would be to get prune_icache()
3322 * to do a write_super() to free up some memory. It has the desired
3323 * effect.
3324 */
3325int ext3_mark_inode_dirty(handle_t *handle, struct inode *inode)
3326{
3327 struct ext3_iloc iloc;
3328 int err;
3329
3330 might_sleep();
3331 err = ext3_reserve_inode_write(handle, inode, &iloc);
3332 if (!err)
3333 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
3334 return err;
3335}
3336
3337/*
Andrew Mortond6859bf2006-03-26 01:38:03 -08003338 * ext3_dirty_inode() is called from __mark_inode_dirty()
Linus Torvalds1da177e2005-04-16 15:20:36 -07003339 *
3340 * We're really interested in the case where a file is being extended.
3341 * i_size has been changed by generic_commit_write() and we thus need
3342 * to include the updated inode in the current transaction.
3343 *
Christoph Hellwig5dd40562010-03-03 09:05:00 -05003344 * Also, dquot_alloc_space() will always dirty the inode when blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -07003345 * are allocated to the file.
3346 *
3347 * If the inode is marked synchronous, we don't honour that here - doing
3348 * so would cause a commit on atime updates, which we don't bother doing.
3349 * We handle synchronous inodes at the highest possible level.
3350 */
3351void ext3_dirty_inode(struct inode *inode)
3352{
3353 handle_t *current_handle = ext3_journal_current_handle();
3354 handle_t *handle;
3355
3356 handle = ext3_journal_start(inode, 2);
3357 if (IS_ERR(handle))
3358 goto out;
3359 if (current_handle &&
3360 current_handle->h_transaction != handle->h_transaction) {
3361 /* This task has a transaction open against a different fs */
3362 printk(KERN_EMERG "%s: transactions do not match!\n",
Harvey Harrisone05b6b52008-04-28 02:16:15 -07003363 __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003364 } else {
3365 jbd_debug(5, "marking dirty. outer handle=%p\n",
3366 current_handle);
3367 ext3_mark_inode_dirty(handle, inode);
3368 }
3369 ext3_journal_stop(handle);
3370out:
3371 return;
3372}
3373
Andrew Mortond6859bf2006-03-26 01:38:03 -08003374#if 0
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003375/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003376 * Bind an inode's backing buffer_head into this transaction, to prevent
3377 * it from being flushed to disk early. Unlike
3378 * ext3_reserve_inode_write, this leaves behind no bh reference and
3379 * returns no iloc structure, so the caller needs to repeat the iloc
3380 * lookup to mark the inode dirty later.
3381 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08003382static int ext3_pin_inode(handle_t *handle, struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003383{
3384 struct ext3_iloc iloc;
3385
3386 int err = 0;
3387 if (handle) {
3388 err = ext3_get_inode_loc(inode, &iloc);
3389 if (!err) {
3390 BUFFER_TRACE(iloc.bh, "get_write_access");
3391 err = journal_get_write_access(handle, iloc.bh);
3392 if (!err)
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003393 err = ext3_journal_dirty_metadata(handle,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003394 iloc.bh);
3395 brelse(iloc.bh);
3396 }
3397 }
3398 ext3_std_error(inode->i_sb, err);
3399 return err;
3400}
3401#endif
3402
3403int ext3_change_inode_journal_flag(struct inode *inode, int val)
3404{
3405 journal_t *journal;
3406 handle_t *handle;
3407 int err;
3408
3409 /*
3410 * We have to be very careful here: changing a data block's
3411 * journaling status dynamically is dangerous. If we write a
3412 * data block to the journal, change the status and then delete
3413 * that block, we risk forgetting to revoke the old log record
3414 * from the journal and so a subsequent replay can corrupt data.
3415 * So, first we make sure that the journal is empty and that
3416 * nobody is changing anything.
3417 */
3418
3419 journal = EXT3_JOURNAL(inode);
Dave Hansene3a68e32007-07-15 23:41:14 -07003420 if (is_journal_aborted(journal))
Linus Torvalds1da177e2005-04-16 15:20:36 -07003421 return -EROFS;
3422
3423 journal_lock_updates(journal);
3424 journal_flush(journal);
3425
3426 /*
3427 * OK, there are no updates running now, and all cached data is
3428 * synced to disk. We are now in a completely consistent state
3429 * which doesn't have anything in the journal, and we know that
3430 * no filesystem updates are running, so it is safe to modify
3431 * the inode's in-core data-journaling state flag now.
3432 */
3433
3434 if (val)
3435 EXT3_I(inode)->i_flags |= EXT3_JOURNAL_DATA_FL;
3436 else
3437 EXT3_I(inode)->i_flags &= ~EXT3_JOURNAL_DATA_FL;
3438 ext3_set_aops(inode);
3439
3440 journal_unlock_updates(journal);
3441
3442 /* Finally we can mark the inode as dirty. */
3443
3444 handle = ext3_journal_start(inode, 1);
3445 if (IS_ERR(handle))
3446 return PTR_ERR(handle);
3447
3448 err = ext3_mark_inode_dirty(handle, inode);
3449 handle->h_sync = 1;
3450 ext3_journal_stop(handle);
3451 ext3_std_error(inode->i_sb, err);
3452
3453 return err;
3454}