blob: b49908a167ae09d366f76ddcef57432f338b5735 [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 */
175static int ext3_journal_test_restart(handle_t *handle, struct inode *inode)
176{
177 jbd_debug(2, "restarting handle %p\n", handle);
178 return ext3_journal_restart(handle, blocks_for_truncate(inode));
179}
180
181/*
182 * Called at the last iput() if i_nlink is zero.
183 */
184void ext3_delete_inode (struct inode * inode)
185{
186 handle_t *handle;
187
Mark Fashehfef26652005-09-09 13:01:31 -0700188 truncate_inode_pages(&inode->i_data, 0);
189
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190 if (is_bad_inode(inode))
191 goto no_delete;
192
193 handle = start_transaction(inode);
194 if (IS_ERR(handle)) {
Andrew Mortond6859bf2006-03-26 01:38:03 -0800195 /*
196 * If we're going to skip the normal cleanup, we still need to
197 * make sure that the in-core orphan linked list is properly
198 * cleaned up.
199 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 ext3_orphan_del(NULL, inode);
201 goto no_delete;
202 }
203
204 if (IS_SYNC(inode))
205 handle->h_sync = 1;
206 inode->i_size = 0;
207 if (inode->i_blocks)
208 ext3_truncate(inode);
209 /*
210 * Kill off the orphan record which ext3_truncate created.
211 * AKPM: I think this can be inside the above `if'.
212 * Note that ext3_orphan_del() has to be able to cope with the
213 * deletion of a non-existent orphan - this is because we don't
214 * know if ext3_truncate() actually created an orphan record.
215 * (Well, we could do this if we need to, but heck - it works)
216 */
217 ext3_orphan_del(handle, inode);
218 EXT3_I(inode)->i_dtime = get_seconds();
219
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700220 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 * One subtle ordering requirement: if anything has gone wrong
222 * (transaction abort, IO errors, whatever), then we can still
223 * do these next steps (the fs will already have been marked as
224 * having errors), but we can't free the inode if the mark_dirty
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700225 * fails.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 */
227 if (ext3_mark_inode_dirty(handle, inode))
228 /* If that failed, just do the required in-core inode clear. */
229 clear_inode(inode);
230 else
231 ext3_free_inode(handle, inode);
232 ext3_journal_stop(handle);
233 return;
234no_delete:
235 clear_inode(inode); /* We must guarantee clearing of inode... */
236}
237
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238typedef struct {
239 __le32 *p;
240 __le32 key;
241 struct buffer_head *bh;
242} Indirect;
243
244static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
245{
246 p->key = *(p->p = v);
247 p->bh = bh;
248}
249
Andrew Mortond6859bf2006-03-26 01:38:03 -0800250static int verify_chain(Indirect *from, Indirect *to)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251{
252 while (from <= to && from->key == *from->p)
253 from++;
254 return (from > to);
255}
256
257/**
258 * ext3_block_to_path - parse the block number into array of offsets
259 * @inode: inode in question (we are only interested in its superblock)
260 * @i_block: block number to be parsed
261 * @offsets: array to store the offsets in
262 * @boundary: set this non-zero if the referred-to block is likely to be
263 * followed (on disk) by an indirect block.
264 *
265 * To store the locations of file's data ext3 uses a data structure common
266 * for UNIX filesystems - tree of pointers anchored in the inode, with
267 * data blocks at leaves and indirect blocks in intermediate nodes.
268 * This function translates the block number into path in that tree -
269 * return value is the path length and @offsets[n] is the offset of
270 * pointer to (n+1)th node in the nth one. If @block is out of range
271 * (negative or too large) warning is printed and zero returned.
272 *
273 * Note: function doesn't find node addresses, so no IO is needed. All
274 * we need to know is the capacity of indirect blocks (taken from the
275 * inode->i_sb).
276 */
277
278/*
279 * Portability note: the last comparison (check that we fit into triple
280 * indirect block) is spelled differently, because otherwise on an
281 * architecture with 32-bit longs and 8Kb pages we might get into trouble
282 * if our filesystem had 8Kb blocks. We might use long long, but that would
283 * kill us on x86. Oh, well, at least the sign propagation does not matter -
284 * i_block would have to be negative in the very beginning, so we would not
285 * get there at all.
286 */
287
288static int ext3_block_to_path(struct inode *inode,
289 long i_block, int offsets[4], int *boundary)
290{
291 int ptrs = EXT3_ADDR_PER_BLOCK(inode->i_sb);
292 int ptrs_bits = EXT3_ADDR_PER_BLOCK_BITS(inode->i_sb);
293 const long direct_blocks = EXT3_NDIR_BLOCKS,
294 indirect_blocks = ptrs,
295 double_blocks = (1 << (ptrs_bits * 2));
296 int n = 0;
297 int final = 0;
298
299 if (i_block < 0) {
300 ext3_warning (inode->i_sb, "ext3_block_to_path", "block < 0");
301 } else if (i_block < direct_blocks) {
302 offsets[n++] = i_block;
303 final = direct_blocks;
304 } else if ( (i_block -= direct_blocks) < indirect_blocks) {
305 offsets[n++] = EXT3_IND_BLOCK;
306 offsets[n++] = i_block;
307 final = ptrs;
308 } else if ((i_block -= indirect_blocks) < double_blocks) {
309 offsets[n++] = EXT3_DIND_BLOCK;
310 offsets[n++] = i_block >> ptrs_bits;
311 offsets[n++] = i_block & (ptrs - 1);
312 final = ptrs;
313 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
314 offsets[n++] = EXT3_TIND_BLOCK;
315 offsets[n++] = i_block >> (ptrs_bits * 2);
316 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
317 offsets[n++] = i_block & (ptrs - 1);
318 final = ptrs;
319 } else {
Andrew Mortond6859bf2006-03-26 01:38:03 -0800320 ext3_warning(inode->i_sb, "ext3_block_to_path", "block > big");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 }
322 if (boundary)
Mingming Cao89747d32006-03-26 01:37:55 -0800323 *boundary = final - 1 - (i_block & (ptrs - 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 return n;
325}
326
327/**
328 * ext3_get_branch - read the chain of indirect blocks leading to data
329 * @inode: inode in question
330 * @depth: depth of the chain (1 - direct pointer, etc.)
331 * @offsets: offsets of pointers in inode/indirect blocks
332 * @chain: place to store the result
333 * @err: here we store the error value
334 *
335 * Function fills the array of triples <key, p, bh> and returns %NULL
336 * if everything went OK or the pointer to the last filled triple
337 * (incomplete one) otherwise. Upon the return chain[i].key contains
338 * the number of (i+1)-th block in the chain (as it is stored in memory,
339 * i.e. little-endian 32-bit), chain[i].p contains the address of that
340 * number (it points into struct inode for i==0 and into the bh->b_data
341 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
342 * block for i>0 and NULL for i==0. In other words, it holds the block
343 * numbers of the chain, addresses they were taken from (and where we can
344 * verify that chain did not change) and buffer_heads hosting these
345 * numbers.
346 *
347 * Function stops when it stumbles upon zero pointer (absent block)
348 * (pointer to last triple returned, *@err == 0)
349 * or when it gets an IO error reading an indirect block
350 * (ditto, *@err == -EIO)
351 * or when it notices that chain had been changed while it was reading
352 * (ditto, *@err == -EAGAIN)
353 * or when it reads all @depth-1 indirect blocks successfully and finds
354 * the whole chain, all way to the data (returns %NULL, *err == 0).
355 */
356static Indirect *ext3_get_branch(struct inode *inode, int depth, int *offsets,
357 Indirect chain[4], int *err)
358{
359 struct super_block *sb = inode->i_sb;
360 Indirect *p = chain;
361 struct buffer_head *bh;
362
363 *err = 0;
364 /* i_data is not going away, no lock needed */
365 add_chain (chain, NULL, EXT3_I(inode)->i_data + *offsets);
366 if (!p->key)
367 goto no_block;
368 while (--depth) {
369 bh = sb_bread(sb, le32_to_cpu(p->key));
370 if (!bh)
371 goto failure;
372 /* Reader: pointers */
373 if (!verify_chain(chain, p))
374 goto changed;
375 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
376 /* Reader: end */
377 if (!p->key)
378 goto no_block;
379 }
380 return NULL;
381
382changed:
383 brelse(bh);
384 *err = -EAGAIN;
385 goto no_block;
386failure:
387 *err = -EIO;
388no_block:
389 return p;
390}
391
392/**
393 * ext3_find_near - find a place for allocation with sufficient locality
394 * @inode: owner
395 * @ind: descriptor of indirect block.
396 *
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000397 * This function returns the preferred place for block allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 * It is used when heuristic for sequential allocation fails.
399 * Rules are:
400 * + if there is a block to the left of our position - allocate near it.
401 * + if pointer will live in indirect block - allocate near that block.
402 * + if pointer will live in inode - allocate in the same
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700403 * cylinder group.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 *
405 * In the latter case we colour the starting block by the callers PID to
406 * prevent it from clashing with concurrent allocations for a different inode
407 * in the same block group. The PID is used here so that functionally related
408 * files will be close-by on-disk.
409 *
410 * Caller must make sure that @ind is valid and will stay that way.
411 */
Mingming Cao43d23f92006-06-25 05:48:07 -0700412static ext3_fsblk_t ext3_find_near(struct inode *inode, Indirect *ind)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413{
414 struct ext3_inode_info *ei = EXT3_I(inode);
415 __le32 *start = ind->bh ? (__le32*) ind->bh->b_data : ei->i_data;
416 __le32 *p;
Mingming Cao43d23f92006-06-25 05:48:07 -0700417 ext3_fsblk_t bg_start;
418 ext3_grpblk_t colour;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419
420 /* Try to find previous block */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800421 for (p = ind->p - 1; p >= start; p--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 if (*p)
423 return le32_to_cpu(*p);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800424 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425
426 /* No such thing, so let's try location of indirect block */
427 if (ind->bh)
428 return ind->bh->b_blocknr;
429
430 /*
Andrew Mortond6859bf2006-03-26 01:38:03 -0800431 * It is going to be referred to from the inode itself? OK, just put it
432 * into the same cylinder group then.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 */
Mingming Cao43d23f92006-06-25 05:48:07 -0700434 bg_start = ext3_group_first_block_no(inode->i_sb, ei->i_block_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 colour = (current->pid % 16) *
436 (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
437 return bg_start + colour;
438}
439
440/**
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000441 * ext3_find_goal - find a preferred place for allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 * @inode: owner
443 * @block: block we want
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 * @partial: pointer to the last triple within a chain
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 *
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000446 * Normally this function find the preferred place for block allocation,
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800447 * returns it.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 */
449
Mingming Cao43d23f92006-06-25 05:48:07 -0700450static ext3_fsblk_t ext3_find_goal(struct inode *inode, long block,
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800451 Indirect *partial)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452{
Andrew Mortond6859bf2006-03-26 01:38:03 -0800453 struct ext3_block_alloc_info *block_i;
454
455 block_i = EXT3_I(inode)->i_block_alloc_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456
457 /*
458 * try the heuristic for sequential allocation,
459 * failing that at least try to get decent locality.
460 */
461 if (block_i && (block == block_i->last_alloc_logical_block + 1)
462 && (block_i->last_alloc_physical_block != 0)) {
Mingming Caofe55c452005-05-01 08:59:20 -0700463 return block_i->last_alloc_physical_block + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 }
465
Mingming Caofe55c452005-05-01 08:59:20 -0700466 return ext3_find_near(inode, partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467}
Andrew Mortond6859bf2006-03-26 01:38:03 -0800468
Mingming Caob47b2472006-03-26 01:37:56 -0800469/**
470 * ext3_blks_to_allocate: Look up the block map and count the number
471 * of direct blocks need to be allocated for the given branch.
472 *
Dave Kleikampe9ad5622006-09-27 01:49:35 -0700473 * @branch: chain of indirect blocks
Mingming Caob47b2472006-03-26 01:37:56 -0800474 * @k: number of blocks need for indirect blocks
475 * @blks: number of data blocks to be mapped.
476 * @blocks_to_boundary: the offset in the indirect block
477 *
478 * return the total number of blocks to be allocate, including the
479 * direct and indirect blocks.
480 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800481static int ext3_blks_to_allocate(Indirect *branch, int k, unsigned long blks,
Mingming Caob47b2472006-03-26 01:37:56 -0800482 int blocks_to_boundary)
483{
484 unsigned long count = 0;
485
486 /*
487 * Simple case, [t,d]Indirect block(s) has not allocated yet
488 * then it's clear blocks on that path have not allocated
489 */
490 if (k > 0) {
Andrew Mortond6859bf2006-03-26 01:38:03 -0800491 /* right now we don't handle cross boundary allocation */
Mingming Caob47b2472006-03-26 01:37:56 -0800492 if (blks < blocks_to_boundary + 1)
493 count += blks;
494 else
495 count += blocks_to_boundary + 1;
496 return count;
497 }
498
499 count++;
500 while (count < blks && count <= blocks_to_boundary &&
501 le32_to_cpu(*(branch[0].p + count)) == 0) {
502 count++;
503 }
504 return count;
505}
506
507/**
508 * ext3_alloc_blocks: multiple allocate blocks needed for a branch
509 * @indirect_blks: the number of blocks need to allocate for indirect
510 * blocks
511 *
512 * @new_blocks: on return it will store the new block numbers for
513 * the indirect blocks(if needed) and the first direct block,
514 * @blks: on return it will store the total number of allocated
515 * direct blocks
516 */
517static int ext3_alloc_blocks(handle_t *handle, struct inode *inode,
Mingming Cao43d23f92006-06-25 05:48:07 -0700518 ext3_fsblk_t goal, int indirect_blks, int blks,
519 ext3_fsblk_t new_blocks[4], int *err)
Mingming Caob47b2472006-03-26 01:37:56 -0800520{
521 int target, i;
522 unsigned long count = 0;
523 int index = 0;
Mingming Cao43d23f92006-06-25 05:48:07 -0700524 ext3_fsblk_t current_block = 0;
Mingming Caob47b2472006-03-26 01:37:56 -0800525 int ret = 0;
526
527 /*
528 * Here we try to allocate the requested multiple blocks at once,
529 * on a best-effort basis.
530 * To build a branch, we should allocate blocks for
531 * the indirect blocks(if not allocated yet), and at least
532 * the first direct block of this branch. That's the
533 * minimum number of blocks need to allocate(required)
534 */
535 target = blks + indirect_blks;
536
537 while (1) {
538 count = target;
539 /* allocating blocks for indirect blocks and direct blocks */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800540 current_block = ext3_new_blocks(handle,inode,goal,&count,err);
Mingming Caob47b2472006-03-26 01:37:56 -0800541 if (*err)
542 goto failed_out;
543
544 target -= count;
545 /* allocate blocks for indirect blocks */
546 while (index < indirect_blks && count) {
547 new_blocks[index++] = current_block++;
548 count--;
549 }
550
551 if (count > 0)
552 break;
553 }
554
555 /* save the new block number for the first direct block */
556 new_blocks[index] = current_block;
557
558 /* total number of blocks allocated for direct blocks */
559 ret = count;
560 *err = 0;
561 return ret;
562failed_out:
563 for (i = 0; i <index; i++)
564 ext3_free_blocks(handle, inode, new_blocks[i], 1);
565 return ret;
566}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700567
568/**
569 * ext3_alloc_branch - allocate and set up a chain of blocks.
570 * @inode: owner
Mingming Caob47b2472006-03-26 01:37:56 -0800571 * @indirect_blks: number of allocated indirect blocks
572 * @blks: number of allocated direct blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 * @offsets: offsets (in the blocks) to store the pointers to next.
574 * @branch: place to store the chain in.
575 *
Mingming Caob47b2472006-03-26 01:37:56 -0800576 * This function allocates blocks, zeroes out all but the last one,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 * links them into chain and (if we are synchronous) writes them to disk.
578 * In other words, it prepares a branch that can be spliced onto the
579 * inode. It stores the information about that chain in the branch[], in
580 * the same format as ext3_get_branch() would do. We are calling it after
581 * we had read the existing part of chain and partial points to the last
582 * triple of that (one with zero ->key). Upon the exit we have the same
Glauber de Oliveira Costa5b116872005-10-30 15:02:48 -0800583 * picture as after the successful ext3_get_block(), except that in one
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 * place chain is disconnected - *branch->p is still zero (we did not
585 * set the last link), but branch->key contains the number that should
586 * be placed into *branch->p to fill that gap.
587 *
588 * If allocation fails we free all blocks we've allocated (and forget
589 * their buffer_heads) and return the error value the from failed
590 * ext3_alloc_block() (normally -ENOSPC). Otherwise we set the chain
591 * as described above and return 0.
592 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
Mingming Cao43d23f92006-06-25 05:48:07 -0700594 int indirect_blks, int *blks, ext3_fsblk_t goal,
Mingming Caob47b2472006-03-26 01:37:56 -0800595 int *offsets, Indirect *branch)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596{
597 int blocksize = inode->i_sb->s_blocksize;
Mingming Caob47b2472006-03-26 01:37:56 -0800598 int i, n = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 int err = 0;
Mingming Caob47b2472006-03-26 01:37:56 -0800600 struct buffer_head *bh;
601 int num;
Mingming Cao43d23f92006-06-25 05:48:07 -0700602 ext3_fsblk_t new_blocks[4];
603 ext3_fsblk_t current_block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604
Mingming Caob47b2472006-03-26 01:37:56 -0800605 num = ext3_alloc_blocks(handle, inode, goal, indirect_blks,
606 *blks, new_blocks, &err);
607 if (err)
608 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609
Mingming Caob47b2472006-03-26 01:37:56 -0800610 branch[0].key = cpu_to_le32(new_blocks[0]);
611 /*
612 * metadata blocks and data blocks are allocated.
613 */
614 for (n = 1; n <= indirect_blks; n++) {
615 /*
616 * Get buffer_head for parent block, zero it out
617 * and set the pointer to new one, then send
618 * parent to disk.
619 */
620 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
621 branch[n].bh = bh;
622 lock_buffer(bh);
623 BUFFER_TRACE(bh, "call get_create_access");
624 err = ext3_journal_get_create_access(handle, bh);
625 if (err) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 unlock_buffer(bh);
Mingming Caob47b2472006-03-26 01:37:56 -0800627 brelse(bh);
628 goto failed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700629 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700630
Mingming Caob47b2472006-03-26 01:37:56 -0800631 memset(bh->b_data, 0, blocksize);
632 branch[n].p = (__le32 *) bh->b_data + offsets[n];
633 branch[n].key = cpu_to_le32(new_blocks[n]);
634 *branch[n].p = branch[n].key;
635 if ( n == indirect_blks) {
636 current_block = new_blocks[n];
637 /*
638 * End of chain, update the last new metablock of
639 * the chain to point to the new allocated
640 * data blocks numbers
641 */
642 for (i=1; i < num; i++)
643 *(branch[n].p + i) = cpu_to_le32(++current_block);
644 }
645 BUFFER_TRACE(bh, "marking uptodate");
646 set_buffer_uptodate(bh);
647 unlock_buffer(bh);
648
649 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
650 err = ext3_journal_dirty_metadata(handle, bh);
651 if (err)
652 goto failed;
653 }
654 *blks = num;
655 return err;
656failed:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657 /* Allocation failed, free what we already allocated */
Mingming Caob47b2472006-03-26 01:37:56 -0800658 for (i = 1; i <= n ; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700659 BUFFER_TRACE(branch[i].bh, "call journal_forget");
660 ext3_journal_forget(handle, branch[i].bh);
661 }
Mingming Caob47b2472006-03-26 01:37:56 -0800662 for (i = 0; i <indirect_blks; i++)
663 ext3_free_blocks(handle, inode, new_blocks[i], 1);
664
665 ext3_free_blocks(handle, inode, new_blocks[i], num);
666
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667 return err;
668}
669
670/**
Andrew Mortond6859bf2006-03-26 01:38:03 -0800671 * ext3_splice_branch - splice the allocated branch onto inode.
672 * @inode: owner
673 * @block: (logical) number of block we are adding
674 * @chain: chain of indirect blocks (with a missing link - see
675 * ext3_alloc_branch)
676 * @where: location of missing link
677 * @num: number of indirect blocks we are adding
678 * @blks: number of direct blocks we are adding
Linus Torvalds1da177e2005-04-16 15:20:36 -0700679 *
Andrew Mortond6859bf2006-03-26 01:38:03 -0800680 * This function fills the missing link and does all housekeeping needed in
681 * inode (->i_blocks, etc.). In case of success we end up with the full
682 * chain to new block and return 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700683 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800684static int ext3_splice_branch(handle_t *handle, struct inode *inode,
685 long block, Indirect *where, int num, int blks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686{
687 int i;
688 int err = 0;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800689 struct ext3_block_alloc_info *block_i;
Mingming Cao43d23f92006-06-25 05:48:07 -0700690 ext3_fsblk_t current_block;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800691
692 block_i = EXT3_I(inode)->i_block_alloc_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700693 /*
694 * If we're splicing into a [td]indirect block (as opposed to the
695 * inode) then we need to get write access to the [td]indirect block
696 * before the splice.
697 */
698 if (where->bh) {
699 BUFFER_TRACE(where->bh, "get_write_access");
700 err = ext3_journal_get_write_access(handle, where->bh);
701 if (err)
702 goto err_out;
703 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704 /* That's it */
705
706 *where->p = where->key;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800707
708 /*
709 * Update the host buffer_head or inode to point to more just allocated
710 * direct blocks blocks
711 */
Mingming Caob47b2472006-03-26 01:37:56 -0800712 if (num == 0 && blks > 1) {
Mingming Cao5dea5172006-05-03 19:55:12 -0700713 current_block = le32_to_cpu(where->key) + 1;
Mingming Caob47b2472006-03-26 01:37:56 -0800714 for (i = 1; i < blks; i++)
715 *(where->p + i ) = cpu_to_le32(current_block++);
716 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717
718 /*
719 * update the most recently allocated logical & physical block
720 * in i_block_alloc_info, to assist find the proper goal block for next
721 * allocation
722 */
723 if (block_i) {
Mingming Caob47b2472006-03-26 01:37:56 -0800724 block_i->last_alloc_logical_block = block + blks - 1;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800725 block_i->last_alloc_physical_block =
Mingming Cao5dea5172006-05-03 19:55:12 -0700726 le32_to_cpu(where[num].key) + blks - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700727 }
728
729 /* We are done with atomic stuff, now do the rest of housekeeping */
730
731 inode->i_ctime = CURRENT_TIME_SEC;
732 ext3_mark_inode_dirty(handle, inode);
733
734 /* had we spliced it onto indirect block? */
735 if (where->bh) {
736 /*
Andrew Mortond6859bf2006-03-26 01:38:03 -0800737 * If we spliced it onto an indirect block, we haven't
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 * altered the inode. Note however that if it is being spliced
739 * onto an indirect block at the very end of the file (the
740 * file is growing) then we *will* alter the inode to reflect
741 * the new i_size. But that is not done here - it is done in
742 * generic_commit_write->__mark_inode_dirty->ext3_dirty_inode.
743 */
744 jbd_debug(5, "splicing indirect only\n");
745 BUFFER_TRACE(where->bh, "call ext3_journal_dirty_metadata");
746 err = ext3_journal_dirty_metadata(handle, where->bh);
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700747 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700748 goto err_out;
749 } else {
750 /*
751 * OK, we spliced it into the inode itself on a direct block.
752 * Inode was dirtied above.
753 */
754 jbd_debug(5, "splicing direct\n");
755 }
756 return err;
757
Linus Torvalds1da177e2005-04-16 15:20:36 -0700758err_out:
Mingming Caob47b2472006-03-26 01:37:56 -0800759 for (i = 1; i <= num; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760 BUFFER_TRACE(where[i].bh, "call journal_forget");
761 ext3_journal_forget(handle, where[i].bh);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800762 ext3_free_blocks(handle,inode,le32_to_cpu(where[i-1].key),1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700763 }
Mingming Caob47b2472006-03-26 01:37:56 -0800764 ext3_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks);
765
Linus Torvalds1da177e2005-04-16 15:20:36 -0700766 return err;
767}
768
769/*
770 * Allocation strategy is simple: if we have to allocate something, we will
771 * have to go the whole way to leaf. So let's do it before attaching anything
772 * to tree, set linkage between the newborn blocks, write them if sync is
773 * required, recheck the path, free and repeat if check fails, otherwise
774 * set the last missing link (that will protect us from any truncate-generated
775 * removals - all blocks on the path are immune now) and possibly force the
776 * write on the parent block.
777 * That has a nice additional property: no special recovery from the failed
778 * allocations is needed - we simply release blocks and do not touch anything
779 * reachable from inode.
780 *
Andrew Mortond6859bf2006-03-26 01:38:03 -0800781 * `handle' can be NULL if create == 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782 *
783 * The BKL may not be held on entry here. Be sure to take it early.
Mingming Cao89747d32006-03-26 01:37:55 -0800784 * return > 0, # of blocks mapped or allocated.
785 * return = 0, if plain lookup failed.
786 * return < 0, error case.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700787 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800788int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
789 sector_t iblock, unsigned long maxblocks,
790 struct buffer_head *bh_result,
Jan Kara43237b52009-05-20 18:41:58 +0200791 int create)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700792{
793 int err = -EIO;
794 int offsets[4];
795 Indirect chain[4];
796 Indirect *partial;
Mingming Cao43d23f92006-06-25 05:48:07 -0700797 ext3_fsblk_t goal;
Mingming Caob47b2472006-03-26 01:37:56 -0800798 int indirect_blks;
Mingming Cao89747d32006-03-26 01:37:55 -0800799 int blocks_to_boundary = 0;
800 int depth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 struct ext3_inode_info *ei = EXT3_I(inode);
Mingming Cao89747d32006-03-26 01:37:55 -0800802 int count = 0;
Mingming Cao43d23f92006-06-25 05:48:07 -0700803 ext3_fsblk_t first_block = 0;
Mingming Cao89747d32006-03-26 01:37:55 -0800804
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805
806 J_ASSERT(handle != NULL || create == 0);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800807 depth = ext3_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808
809 if (depth == 0)
810 goto out;
811
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
813
814 /* Simplest case - block found, no allocation needed */
815 if (!partial) {
Mingming Cao5dea5172006-05-03 19:55:12 -0700816 first_block = le32_to_cpu(chain[depth - 1].key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700817 clear_buffer_new(bh_result);
Mingming Cao89747d32006-03-26 01:37:55 -0800818 count++;
819 /*map more blocks*/
820 while (count < maxblocks && count <= blocks_to_boundary) {
Mingming Cao43d23f92006-06-25 05:48:07 -0700821 ext3_fsblk_t blk;
Mingming Cao5dea5172006-05-03 19:55:12 -0700822
Jan Karae8ef7aa2009-06-17 16:26:23 -0700823 if (!verify_chain(chain, chain + depth - 1)) {
Mingming Cao89747d32006-03-26 01:37:55 -0800824 /*
825 * Indirect block might be removed by
826 * truncate while we were reading it.
827 * Handling of that case: forget what we've
828 * got now. Flag the err as EAGAIN, so it
829 * will reread.
830 */
831 err = -EAGAIN;
832 count = 0;
833 break;
834 }
Mingming Cao5dea5172006-05-03 19:55:12 -0700835 blk = le32_to_cpu(*(chain[depth-1].p + count));
836
837 if (blk == first_block + count)
Mingming Cao89747d32006-03-26 01:37:55 -0800838 count++;
839 else
840 break;
841 }
842 if (err != -EAGAIN)
843 goto got_it;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844 }
845
846 /* Next simple case - plain lookup or failed read of indirect block */
Mingming Caofe55c452005-05-01 08:59:20 -0700847 if (!create || err == -EIO)
848 goto cleanup;
849
Arjan van de Ven97461512006-03-23 03:00:42 -0800850 mutex_lock(&ei->truncate_mutex);
Mingming Caofe55c452005-05-01 08:59:20 -0700851
852 /*
853 * If the indirect block is missing while we are reading
854 * the chain(ext3_get_branch() returns -EAGAIN err), or
855 * if the chain has been changed after we grab the semaphore,
856 * (either because another process truncated this branch, or
857 * another get_block allocated this branch) re-grab the chain to see if
858 * the request block has been allocated or not.
859 *
860 * Since we already block the truncate/other get_block
861 * at this point, we will have the current copy of the chain when we
862 * splice the branch into the tree.
863 */
864 if (err == -EAGAIN || !verify_chain(chain, partial)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 while (partial > chain) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 brelse(partial->bh);
867 partial--;
868 }
Mingming Caofe55c452005-05-01 08:59:20 -0700869 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
870 if (!partial) {
Mingming Cao89747d32006-03-26 01:37:55 -0800871 count++;
Arjan van de Ven97461512006-03-23 03:00:42 -0800872 mutex_unlock(&ei->truncate_mutex);
Mingming Caofe55c452005-05-01 08:59:20 -0700873 if (err)
874 goto cleanup;
875 clear_buffer_new(bh_result);
876 goto got_it;
877 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700878 }
879
880 /*
Mingming Caofe55c452005-05-01 08:59:20 -0700881 * Okay, we need to do block allocation. Lazily initialize the block
882 * allocation info here if necessary
883 */
884 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700885 ext3_init_block_alloc_info(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800887 goal = ext3_find_goal(inode, iblock, partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700888
Mingming Caob47b2472006-03-26 01:37:56 -0800889 /* the number of blocks need to allocate for [d,t]indirect blocks */
890 indirect_blks = (chain + depth) - partial - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891
892 /*
Mingming Caob47b2472006-03-26 01:37:56 -0800893 * Next look up the indirect map to count the totoal number of
894 * direct blocks to allocate for this branch.
895 */
896 count = ext3_blks_to_allocate(partial, indirect_blks,
897 maxblocks, blocks_to_boundary);
898 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 * Block out ext3_truncate while we alter the tree
900 */
Mingming Caob47b2472006-03-26 01:37:56 -0800901 err = ext3_alloc_branch(handle, inode, indirect_blks, &count, goal,
Mingming Caofe55c452005-05-01 08:59:20 -0700902 offsets + (partial - chain), partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903
Mingming Caofe55c452005-05-01 08:59:20 -0700904 /*
905 * The ext3_splice_branch call will free and forget any buffers
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 * on the new chain if there is a failure, but that risks using
907 * up transaction credits, especially for bitmaps where the
908 * credits cannot be returned. Can we handle this somehow? We
Mingming Caofe55c452005-05-01 08:59:20 -0700909 * may need to return -EAGAIN upwards in the worst case. --sct
910 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700911 if (!err)
Mingming Caob47b2472006-03-26 01:37:56 -0800912 err = ext3_splice_branch(handle, inode, iblock,
913 partial, indirect_blks, count);
Arjan van de Ven97461512006-03-23 03:00:42 -0800914 mutex_unlock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 if (err)
916 goto cleanup;
917
918 set_buffer_new(bh_result);
Mingming Caofe55c452005-05-01 08:59:20 -0700919got_it:
920 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
Suparna Bhattacharya20acaa12006-09-16 12:15:58 -0700921 if (count > blocks_to_boundary)
Mingming Caofe55c452005-05-01 08:59:20 -0700922 set_buffer_boundary(bh_result);
Mingming Cao89747d32006-03-26 01:37:55 -0800923 err = count;
Mingming Caofe55c452005-05-01 08:59:20 -0700924 /* Clean up and exit */
925 partial = chain + depth - 1; /* the whole chain */
926cleanup:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927 while (partial > chain) {
Mingming Caofe55c452005-05-01 08:59:20 -0700928 BUFFER_TRACE(partial->bh, "call brelse");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929 brelse(partial->bh);
930 partial--;
931 }
Mingming Caofe55c452005-05-01 08:59:20 -0700932 BUFFER_TRACE(bh_result, "returned");
933out:
934 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935}
936
Jan Karabd1939d2008-02-06 01:40:21 -0800937/* Maximum number of blocks we map for direct IO at once. */
938#define DIO_MAX_BLOCKS 4096
939/*
940 * Number of credits we need for writing DIO_MAX_BLOCKS:
941 * We need sb + group descriptor + bitmap + inode -> 4
942 * For B blocks with A block pointers per block we need:
943 * 1 (triple ind.) + (B/A/A + 2) (doubly ind.) + (B/A + 2) (indirect).
944 * If we plug in 4096 for B and 256 for A (for 1KB block size), we get 25.
945 */
946#define DIO_CREDITS 25
Linus Torvalds1da177e2005-04-16 15:20:36 -0700947
Badari Pulavartyf91a2ad2006-03-26 01:38:04 -0800948static int ext3_get_block(struct inode *inode, sector_t iblock,
949 struct buffer_head *bh_result, int create)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950{
Dmitriy Monakhov3e4fdaf2007-02-10 01:46:35 -0800951 handle_t *handle = ext3_journal_current_handle();
Jan Karabd1939d2008-02-06 01:40:21 -0800952 int ret = 0, started = 0;
Badari Pulavarty1d8fa7a2006-03-26 01:38:02 -0800953 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700954
Jan Karabd1939d2008-02-06 01:40:21 -0800955 if (create && !handle) { /* Direct IO write... */
956 if (max_blocks > DIO_MAX_BLOCKS)
957 max_blocks = DIO_MAX_BLOCKS;
958 handle = ext3_journal_start(inode, DIO_CREDITS +
959 2 * EXT3_QUOTA_TRANS_BLOCKS(inode->i_sb));
960 if (IS_ERR(handle)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 ret = PTR_ERR(handle);
Jan Karabd1939d2008-02-06 01:40:21 -0800962 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700963 }
Jan Karabd1939d2008-02-06 01:40:21 -0800964 started = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 }
966
Jan Karabd1939d2008-02-06 01:40:21 -0800967 ret = ext3_get_blocks_handle(handle, inode, iblock,
Jan Kara43237b52009-05-20 18:41:58 +0200968 max_blocks, bh_result, create);
Jan Karabd1939d2008-02-06 01:40:21 -0800969 if (ret > 0) {
970 bh_result->b_size = (ret << inode->i_blkbits);
971 ret = 0;
Mingming Cao89747d32006-03-26 01:37:55 -0800972 }
Jan Karabd1939d2008-02-06 01:40:21 -0800973 if (started)
974 ext3_journal_stop(handle);
975out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700976 return ret;
977}
978
Josef Bacik68c9d702008-10-03 17:32:43 -0400979int ext3_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
980 u64 start, u64 len)
981{
982 return generic_block_fiemap(inode, fieinfo, start, len,
983 ext3_get_block);
984}
985
Linus Torvalds1da177e2005-04-16 15:20:36 -0700986/*
987 * `handle' can be NULL if create is zero
988 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800989struct buffer_head *ext3_getblk(handle_t *handle, struct inode *inode,
990 long block, int create, int *errp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991{
992 struct buffer_head dummy;
993 int fatal = 0, err;
994
995 J_ASSERT(handle != NULL || create == 0);
996
997 dummy.b_state = 0;
998 dummy.b_blocknr = -1000;
999 buffer_trace_init(&dummy.b_history);
Mingming Cao89747d32006-03-26 01:37:55 -08001000 err = ext3_get_blocks_handle(handle, inode, block, 1,
Jan Kara43237b52009-05-20 18:41:58 +02001001 &dummy, create);
Badari Pulavarty3665d0e2006-09-08 09:48:21 -07001002 /*
1003 * ext3_get_blocks_handle() returns number of blocks
1004 * mapped. 0 in case of a HOLE.
1005 */
1006 if (err > 0) {
1007 if (err > 1)
1008 WARN_ON(1);
Mingming Cao89747d32006-03-26 01:37:55 -08001009 err = 0;
Mingming Cao89747d32006-03-26 01:37:55 -08001010 }
1011 *errp = err;
1012 if (!err && buffer_mapped(&dummy)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013 struct buffer_head *bh;
1014 bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
Glauber de Oliveira Costa2973dfd2005-10-30 15:03:05 -08001015 if (!bh) {
1016 *errp = -EIO;
1017 goto err;
1018 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019 if (buffer_new(&dummy)) {
1020 J_ASSERT(create != 0);
Stephen Hemmingerc80544d2007-10-18 03:07:05 -07001021 J_ASSERT(handle != NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022
Andrew Mortond6859bf2006-03-26 01:38:03 -08001023 /*
1024 * Now that we do not always journal data, we should
1025 * keep in mind whether this should always journal the
1026 * new buffer as metadata. For now, regular file
1027 * writes use ext3_get_block instead, so it's not a
1028 * problem.
1029 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001030 lock_buffer(bh);
1031 BUFFER_TRACE(bh, "call get_create_access");
1032 fatal = ext3_journal_get_create_access(handle, bh);
1033 if (!fatal && !buffer_uptodate(bh)) {
Andrew Mortond6859bf2006-03-26 01:38:03 -08001034 memset(bh->b_data,0,inode->i_sb->s_blocksize);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035 set_buffer_uptodate(bh);
1036 }
1037 unlock_buffer(bh);
1038 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
1039 err = ext3_journal_dirty_metadata(handle, bh);
1040 if (!fatal)
1041 fatal = err;
1042 } else {
1043 BUFFER_TRACE(bh, "not a new buffer");
1044 }
1045 if (fatal) {
1046 *errp = fatal;
1047 brelse(bh);
1048 bh = NULL;
1049 }
1050 return bh;
1051 }
Glauber de Oliveira Costa2973dfd2005-10-30 15:03:05 -08001052err:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053 return NULL;
1054}
1055
Andrew Mortond6859bf2006-03-26 01:38:03 -08001056struct buffer_head *ext3_bread(handle_t *handle, struct inode *inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001057 int block, int create, int *err)
1058{
1059 struct buffer_head * bh;
1060
1061 bh = ext3_getblk(handle, inode, block, create, err);
1062 if (!bh)
1063 return bh;
1064 if (buffer_uptodate(bh))
1065 return bh;
Jens Axboecaa38fb2006-07-23 01:41:26 +02001066 ll_rw_block(READ_META, 1, &bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067 wait_on_buffer(bh);
1068 if (buffer_uptodate(bh))
1069 return bh;
1070 put_bh(bh);
1071 *err = -EIO;
1072 return NULL;
1073}
1074
1075static int walk_page_buffers( handle_t *handle,
1076 struct buffer_head *head,
1077 unsigned from,
1078 unsigned to,
1079 int *partial,
1080 int (*fn)( handle_t *handle,
1081 struct buffer_head *bh))
1082{
1083 struct buffer_head *bh;
1084 unsigned block_start, block_end;
1085 unsigned blocksize = head->b_size;
1086 int err, ret = 0;
1087 struct buffer_head *next;
1088
1089 for ( bh = head, block_start = 0;
1090 ret == 0 && (bh != head || !block_start);
Dave Kleikampe9ad5622006-09-27 01:49:35 -07001091 block_start = block_end, bh = next)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001092 {
1093 next = bh->b_this_page;
1094 block_end = block_start + blocksize;
1095 if (block_end <= from || block_start >= to) {
1096 if (partial && !buffer_uptodate(bh))
1097 *partial = 1;
1098 continue;
1099 }
1100 err = (*fn)(handle, bh);
1101 if (!ret)
1102 ret = err;
1103 }
1104 return ret;
1105}
1106
1107/*
1108 * To preserve ordering, it is essential that the hole instantiation and
1109 * the data write be encapsulated in a single transaction. We cannot
1110 * close off a transaction and start a new one between the ext3_get_block()
1111 * and the commit_write(). So doing the journal_start at the start of
1112 * prepare_write() is the right place.
1113 *
1114 * Also, this function can nest inside ext3_writepage() ->
1115 * block_write_full_page(). In that case, we *know* that ext3_writepage()
1116 * has generated enough buffer credits to do the whole page. So we won't
1117 * block on the journal in that case, which is good, because the caller may
1118 * be PF_MEMALLOC.
1119 *
1120 * By accident, ext3 can be reentered when a transaction is open via
1121 * quota file writes. If we were to commit the transaction while thus
1122 * reentered, there can be a deadlock - we would be holding a quota
1123 * lock, and the commit would never complete if another thread had a
1124 * transaction open and was blocking on the quota lock - a ranking
1125 * violation.
1126 *
1127 * So what we do is to rely on the fact that journal_stop/journal_start
1128 * will _not_ run commit under these circumstances because handle->h_ref
1129 * is elevated. We'll still have enough credits for the tiny quotafile
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001130 * write.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001131 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08001132static int do_journal_get_write_access(handle_t *handle,
1133 struct buffer_head *bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134{
1135 if (!buffer_mapped(bh) || buffer_freed(bh))
1136 return 0;
1137 return ext3_journal_get_write_access(handle, bh);
1138}
1139
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001140static int ext3_write_begin(struct file *file, struct address_space *mapping,
1141 loff_t pos, unsigned len, unsigned flags,
1142 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001143{
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001144 struct inode *inode = mapping->host;
Jan Kara695f6ae2009-04-02 16:57:17 -07001145 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001146 handle_t *handle;
1147 int retries = 0;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001148 struct page *page;
1149 pgoff_t index;
1150 unsigned from, to;
Jan Kara695f6ae2009-04-02 16:57:17 -07001151 /* Reserve one block more for addition to orphan list in case
1152 * we allocate blocks but write fails for some reason */
1153 int needed_blocks = ext3_writepage_trans_blocks(inode) + 1;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001154
1155 index = pos >> PAGE_CACHE_SHIFT;
1156 from = pos & (PAGE_CACHE_SIZE - 1);
1157 to = from + len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158
1159retry:
Nick Piggin54566b22009-01-04 12:00:53 -08001160 page = grab_cache_page_write_begin(mapping, index, flags);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001161 if (!page)
1162 return -ENOMEM;
1163 *pagep = page;
1164
Linus Torvalds1da177e2005-04-16 15:20:36 -07001165 handle = ext3_journal_start(inode, needed_blocks);
Andrew Morton1aa9b4b2007-04-01 23:49:43 -07001166 if (IS_ERR(handle)) {
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001167 unlock_page(page);
1168 page_cache_release(page);
Andrew Morton1aa9b4b2007-04-01 23:49:43 -07001169 ret = PTR_ERR(handle);
1170 goto out;
1171 }
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001172 ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
1173 ext3_get_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001174 if (ret)
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001175 goto write_begin_failed;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001176
1177 if (ext3_should_journal_data(inode)) {
1178 ret = walk_page_buffers(handle, page_buffers(page),
1179 from, to, NULL, do_journal_get_write_access);
1180 }
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001181write_begin_failed:
1182 if (ret) {
Aneesh Kumar K.V5ec8b752008-10-18 20:28:00 -07001183 /*
1184 * block_write_begin may have instantiated a few blocks
1185 * outside i_size. Trim these off again. Don't need
1186 * i_size_read because we hold i_mutex.
Jan Kara695f6ae2009-04-02 16:57:17 -07001187 *
1188 * Add inode to orphan list in case we crash before truncate
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001189 * finishes. Do this only if ext3_can_truncate() agrees so
1190 * that orphan processing code is happy.
Aneesh Kumar K.V5ec8b752008-10-18 20:28:00 -07001191 */
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001192 if (pos + len > inode->i_size && ext3_can_truncate(inode))
Jan Kara695f6ae2009-04-02 16:57:17 -07001193 ext3_orphan_add(handle, inode);
1194 ext3_journal_stop(handle);
1195 unlock_page(page);
1196 page_cache_release(page);
1197 if (pos + len > inode->i_size)
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001198 ext3_truncate(inode);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001199 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001200 if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
1201 goto retry;
Andrew Morton1aa9b4b2007-04-01 23:49:43 -07001202out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203 return ret;
1204}
1205
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001206
Andrew Mortond6859bf2006-03-26 01:38:03 -08001207int ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208{
1209 int err = journal_dirty_data(handle, bh);
1210 if (err)
Harvey Harrisone05b6b52008-04-28 02:16:15 -07001211 ext3_journal_abort_handle(__func__, __func__,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001212 bh, handle, err);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213 return err;
1214}
1215
Jan Kara695f6ae2009-04-02 16:57:17 -07001216/* For ordered writepage and write_end functions */
1217static int journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
1218{
1219 /*
1220 * Write could have mapped the buffer but it didn't copy the data in
1221 * yet. So avoid filing such buffer into a transaction.
1222 */
1223 if (buffer_mapped(bh) && buffer_uptodate(bh))
1224 return ext3_journal_dirty_data(handle, bh);
1225 return 0;
1226}
1227
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001228/* For write_end() in data=journal mode */
1229static int write_end_fn(handle_t *handle, struct buffer_head *bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001230{
1231 if (!buffer_mapped(bh) || buffer_freed(bh))
1232 return 0;
1233 set_buffer_uptodate(bh);
1234 return ext3_journal_dirty_metadata(handle, bh);
1235}
1236
1237/*
Jan Kara695f6ae2009-04-02 16:57:17 -07001238 * This is nasty and subtle: ext3_write_begin() could have allocated blocks
1239 * for the whole page but later we failed to copy the data in. Update inode
1240 * size according to what we managed to copy. The rest is going to be
1241 * truncated in write_end function.
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001242 */
Jan Kara695f6ae2009-04-02 16:57:17 -07001243static void update_file_sizes(struct inode *inode, loff_t pos, unsigned copied)
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001244{
Jan Kara695f6ae2009-04-02 16:57:17 -07001245 /* What matters to us is i_disksize. We don't write i_size anywhere */
1246 if (pos + copied > inode->i_size)
1247 i_size_write(inode, pos + copied);
1248 if (pos + copied > EXT3_I(inode)->i_disksize) {
1249 EXT3_I(inode)->i_disksize = pos + copied;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001250 mark_inode_dirty(inode);
1251 }
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001252}
1253
1254/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001255 * We need to pick up the new inode size which generic_commit_write gave us
1256 * `file' can be NULL - eg, when called from page_symlink().
1257 *
1258 * ext3 never places buffers on inode->i_mapping->private_list. metadata
1259 * buffers are managed internally.
1260 */
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001261static int ext3_ordered_write_end(struct file *file,
1262 struct address_space *mapping,
1263 loff_t pos, unsigned len, unsigned copied,
1264 struct page *page, void *fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001265{
1266 handle_t *handle = ext3_journal_current_handle();
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001267 struct inode *inode = file->f_mapping->host;
1268 unsigned from, to;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269 int ret = 0, ret2;
1270
Jan Kara695f6ae2009-04-02 16:57:17 -07001271 copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
1272
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001273 from = pos & (PAGE_CACHE_SIZE - 1);
Jan Kara695f6ae2009-04-02 16:57:17 -07001274 to = from + copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001275 ret = walk_page_buffers(handle, page_buffers(page),
Jan Kara695f6ae2009-04-02 16:57:17 -07001276 from, to, NULL, journal_dirty_data_fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001277
Jan Kara695f6ae2009-04-02 16:57:17 -07001278 if (ret == 0)
1279 update_file_sizes(inode, pos, copied);
1280 /*
1281 * There may be allocated blocks outside of i_size because
1282 * we failed to copy some data. Prepare for truncate.
1283 */
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001284 if (pos + len > inode->i_size && ext3_can_truncate(inode))
Jan Kara695f6ae2009-04-02 16:57:17 -07001285 ext3_orphan_add(handle, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001286 ret2 = ext3_journal_stop(handle);
1287 if (!ret)
1288 ret = ret2;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001289 unlock_page(page);
1290 page_cache_release(page);
1291
Jan Kara695f6ae2009-04-02 16:57:17 -07001292 if (pos + len > inode->i_size)
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001293 ext3_truncate(inode);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001294 return ret ? ret : copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001295}
1296
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001297static int ext3_writeback_write_end(struct file *file,
1298 struct address_space *mapping,
1299 loff_t pos, unsigned len, unsigned copied,
1300 struct page *page, void *fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001301{
1302 handle_t *handle = ext3_journal_current_handle();
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001303 struct inode *inode = file->f_mapping->host;
Jan Kara695f6ae2009-04-02 16:57:17 -07001304 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001305
Jan Kara695f6ae2009-04-02 16:57:17 -07001306 copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
1307 update_file_sizes(inode, pos, copied);
1308 /*
1309 * There may be allocated blocks outside of i_size because
1310 * we failed to copy some data. Prepare for truncate.
1311 */
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001312 if (pos + len > inode->i_size && ext3_can_truncate(inode))
Jan Kara695f6ae2009-04-02 16:57:17 -07001313 ext3_orphan_add(handle, inode);
1314 ret = ext3_journal_stop(handle);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001315 unlock_page(page);
1316 page_cache_release(page);
1317
Jan Kara695f6ae2009-04-02 16:57:17 -07001318 if (pos + len > inode->i_size)
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001319 ext3_truncate(inode);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001320 return ret ? ret : copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321}
1322
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001323static int ext3_journalled_write_end(struct file *file,
1324 struct address_space *mapping,
1325 loff_t pos, unsigned len, unsigned copied,
1326 struct page *page, void *fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001327{
1328 handle_t *handle = ext3_journal_current_handle();
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001329 struct inode *inode = mapping->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001330 int ret = 0, ret2;
1331 int partial = 0;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001332 unsigned from, to;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001333
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001334 from = pos & (PAGE_CACHE_SIZE - 1);
1335 to = from + len;
1336
1337 if (copied < len) {
1338 if (!PageUptodate(page))
1339 copied = 0;
Jan Kara695f6ae2009-04-02 16:57:17 -07001340 page_zero_new_buffers(page, from + copied, to);
1341 to = from + copied;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001342 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001343
1344 ret = walk_page_buffers(handle, page_buffers(page), from,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001345 to, &partial, write_end_fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001346 if (!partial)
1347 SetPageUptodate(page);
Jan Kara695f6ae2009-04-02 16:57:17 -07001348
1349 if (pos + copied > inode->i_size)
1350 i_size_write(inode, pos + copied);
1351 /*
1352 * There may be allocated blocks outside of i_size because
1353 * we failed to copy some data. Prepare for truncate.
1354 */
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001355 if (pos + len > inode->i_size && ext3_can_truncate(inode))
Jan Kara695f6ae2009-04-02 16:57:17 -07001356 ext3_orphan_add(handle, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001357 EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1358 if (inode->i_size > EXT3_I(inode)->i_disksize) {
1359 EXT3_I(inode)->i_disksize = inode->i_size;
1360 ret2 = ext3_mark_inode_dirty(handle, inode);
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001361 if (!ret)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001362 ret = ret2;
1363 }
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001364
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365 ret2 = ext3_journal_stop(handle);
1366 if (!ret)
1367 ret = ret2;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001368 unlock_page(page);
1369 page_cache_release(page);
1370
Jan Kara695f6ae2009-04-02 16:57:17 -07001371 if (pos + len > inode->i_size)
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001372 ext3_truncate(inode);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001373 return ret ? ret : copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001374}
1375
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001376/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001377 * bmap() is special. It gets used by applications such as lilo and by
1378 * the swapper to find the on-disk block of a specific piece of data.
1379 *
1380 * Naturally, this is dangerous if the block concerned is still in the
1381 * journal. If somebody makes a swapfile on an ext3 data-journaling
1382 * filesystem and enables swap, then they may get a nasty shock when the
1383 * data getting swapped to that swapfile suddenly gets overwritten by
1384 * the original zero's written out previously to the journal and
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001385 * awaiting writeback in the kernel's buffer cache.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001386 *
1387 * So, if we see any bmap calls here on a modified, data-journaled file,
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001388 * take extra steps to flush any blocks which might be in the cache.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001389 */
1390static sector_t ext3_bmap(struct address_space *mapping, sector_t block)
1391{
1392 struct inode *inode = mapping->host;
1393 journal_t *journal;
1394 int err;
1395
1396 if (EXT3_I(inode)->i_state & EXT3_STATE_JDATA) {
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001397 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001398 * This is a REALLY heavyweight approach, but the use of
1399 * bmap on dirty files is expected to be extremely rare:
1400 * only if we run lilo or swapon on a freshly made file
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001401 * do we expect this to happen.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001402 *
1403 * (bmap requires CAP_SYS_RAWIO so this does not
1404 * represent an unprivileged user DOS attack --- we'd be
1405 * in trouble if mortal users could trigger this path at
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001406 * will.)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407 *
1408 * NB. EXT3_STATE_JDATA is not set on files other than
1409 * regular files. If somebody wants to bmap a directory
1410 * or symlink and gets confused because the buffer
1411 * hasn't yet been flushed to disk, they deserve
1412 * everything they get.
1413 */
1414
1415 EXT3_I(inode)->i_state &= ~EXT3_STATE_JDATA;
1416 journal = EXT3_JOURNAL(inode);
1417 journal_lock_updates(journal);
1418 err = journal_flush(journal);
1419 journal_unlock_updates(journal);
1420
1421 if (err)
1422 return 0;
1423 }
1424
1425 return generic_block_bmap(mapping,block,ext3_get_block);
1426}
1427
1428static int bget_one(handle_t *handle, struct buffer_head *bh)
1429{
1430 get_bh(bh);
1431 return 0;
1432}
1433
1434static int bput_one(handle_t *handle, struct buffer_head *bh)
1435{
1436 put_bh(bh);
1437 return 0;
1438}
1439
Jan Kara9e80d402009-03-26 13:08:04 +01001440static int buffer_unmapped(handle_t *handle, struct buffer_head *bh)
1441{
1442 return !buffer_mapped(bh);
1443}
Jan Kara695f6ae2009-04-02 16:57:17 -07001444
Linus Torvalds1da177e2005-04-16 15:20:36 -07001445/*
1446 * Note that we always start a transaction even if we're not journalling
1447 * data. This is to preserve ordering: any hole instantiation within
1448 * __block_write_full_page -> ext3_get_block() should be journalled
1449 * along with the data so we don't crash and then get metadata which
1450 * refers to old data.
1451 *
1452 * In all journalling modes block_write_full_page() will start the I/O.
1453 *
1454 * Problem:
1455 *
1456 * ext3_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1457 * ext3_writepage()
1458 *
1459 * Similar for:
1460 *
1461 * ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ...
1462 *
1463 * Same applies to ext3_get_block(). We will deadlock on various things like
Arjan van de Ven97461512006-03-23 03:00:42 -08001464 * lock_journal and i_truncate_mutex.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001465 *
1466 * Setting PF_MEMALLOC here doesn't work - too many internal memory
1467 * allocations fail.
1468 *
1469 * 16May01: If we're reentered then journal_current_handle() will be
1470 * non-zero. We simply *return*.
1471 *
1472 * 1 July 2001: @@@ FIXME:
1473 * In journalled data mode, a data buffer may be metadata against the
1474 * current transaction. But the same file is part of a shared mapping
1475 * and someone does a writepage() on it.
1476 *
1477 * We will move the buffer onto the async_data list, but *after* it has
1478 * been dirtied. So there's a small window where we have dirty data on
1479 * BJ_Metadata.
1480 *
1481 * Note that this only applies to the last partial page in the file. The
1482 * bit which block_write_full_page() uses prepare/commit for. (That's
1483 * broken code anyway: it's wrong for msync()).
1484 *
1485 * It's a rare case: affects the final partial page, for journalled data
1486 * where the file is subject to bith write() and writepage() in the same
1487 * transction. To fix it we'll need a custom block_write_full_page().
1488 * We'll probably need that anyway for journalling writepage() output.
1489 *
1490 * We don't honour synchronous mounts for writepage(). That would be
1491 * disastrous. Any write() or metadata operation will sync the fs for
1492 * us.
1493 *
1494 * AKPM2: if all the page's buffers are mapped to disk and !data=journal,
1495 * we don't need to open a transaction here.
1496 */
1497static int ext3_ordered_writepage(struct page *page,
Andrew Mortond6859bf2006-03-26 01:38:03 -08001498 struct writeback_control *wbc)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001499{
1500 struct inode *inode = page->mapping->host;
1501 struct buffer_head *page_bufs;
1502 handle_t *handle = NULL;
1503 int ret = 0;
1504 int err;
1505
1506 J_ASSERT(PageLocked(page));
1507
1508 /*
1509 * We give up here if we're reentered, because it might be for a
1510 * different filesystem.
1511 */
1512 if (ext3_journal_current_handle())
1513 goto out_fail;
1514
Jan Kara9e80d402009-03-26 13:08:04 +01001515 if (!page_has_buffers(page)) {
1516 create_empty_buffers(page, inode->i_sb->s_blocksize,
1517 (1 << BH_Dirty)|(1 << BH_Uptodate));
Jan Kara430db322009-04-07 18:25:01 -04001518 page_bufs = page_buffers(page);
1519 } else {
1520 page_bufs = page_buffers(page);
1521 if (!walk_page_buffers(NULL, page_bufs, 0, PAGE_CACHE_SIZE,
1522 NULL, buffer_unmapped)) {
1523 /* Provide NULL get_block() to catch bugs if buffers
1524 * weren't really mapped */
1525 return block_write_full_page(page, NULL, wbc);
1526 }
Jan Kara9e80d402009-03-26 13:08:04 +01001527 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001528 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1529
1530 if (IS_ERR(handle)) {
1531 ret = PTR_ERR(handle);
1532 goto out_fail;
1533 }
1534
Linus Torvalds1da177e2005-04-16 15:20:36 -07001535 walk_page_buffers(handle, page_bufs, 0,
1536 PAGE_CACHE_SIZE, NULL, bget_one);
1537
1538 ret = block_write_full_page(page, ext3_get_block, wbc);
1539
1540 /*
1541 * The page can become unlocked at any point now, and
1542 * truncate can then come in and change things. So we
1543 * can't touch *page from now on. But *page_bufs is
1544 * safe due to elevated refcount.
1545 */
1546
1547 /*
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001548 * And attach them to the current transaction. But only if
Linus Torvalds1da177e2005-04-16 15:20:36 -07001549 * block_write_full_page() succeeded. Otherwise they are unmapped,
1550 * and generally junk.
1551 */
1552 if (ret == 0) {
1553 err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
1554 NULL, journal_dirty_data_fn);
1555 if (!ret)
1556 ret = err;
1557 }
1558 walk_page_buffers(handle, page_bufs, 0,
1559 PAGE_CACHE_SIZE, NULL, bput_one);
1560 err = ext3_journal_stop(handle);
1561 if (!ret)
1562 ret = err;
1563 return ret;
1564
1565out_fail:
1566 redirty_page_for_writepage(wbc, page);
1567 unlock_page(page);
1568 return ret;
1569}
1570
Linus Torvalds1da177e2005-04-16 15:20:36 -07001571static int ext3_writeback_writepage(struct page *page,
1572 struct writeback_control *wbc)
1573{
1574 struct inode *inode = page->mapping->host;
1575 handle_t *handle = NULL;
1576 int ret = 0;
1577 int err;
1578
1579 if (ext3_journal_current_handle())
1580 goto out_fail;
1581
Jan Kara430db322009-04-07 18:25:01 -04001582 if (page_has_buffers(page)) {
1583 if (!walk_page_buffers(NULL, page_buffers(page), 0,
1584 PAGE_CACHE_SIZE, NULL, buffer_unmapped)) {
1585 /* Provide NULL get_block() to catch bugs if buffers
1586 * weren't really mapped */
1587 return block_write_full_page(page, NULL, wbc);
1588 }
1589 }
1590
Linus Torvalds1da177e2005-04-16 15:20:36 -07001591 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1592 if (IS_ERR(handle)) {
1593 ret = PTR_ERR(handle);
1594 goto out_fail;
1595 }
1596
Badari Pulavarty0e31f512006-07-30 03:04:14 -07001597 if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001598 ret = nobh_writepage(page, ext3_get_block, wbc);
1599 else
1600 ret = block_write_full_page(page, ext3_get_block, wbc);
1601
1602 err = ext3_journal_stop(handle);
1603 if (!ret)
1604 ret = err;
1605 return ret;
1606
1607out_fail:
1608 redirty_page_for_writepage(wbc, page);
1609 unlock_page(page);
1610 return ret;
1611}
1612
1613static int ext3_journalled_writepage(struct page *page,
1614 struct writeback_control *wbc)
1615{
1616 struct inode *inode = page->mapping->host;
1617 handle_t *handle = NULL;
1618 int ret = 0;
1619 int err;
1620
1621 if (ext3_journal_current_handle())
1622 goto no_write;
1623
1624 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1625 if (IS_ERR(handle)) {
1626 ret = PTR_ERR(handle);
1627 goto no_write;
1628 }
1629
1630 if (!page_has_buffers(page) || PageChecked(page)) {
1631 /*
1632 * It's mmapped pagecache. Add buffers and journal it. There
1633 * doesn't seem much point in redirtying the page here.
1634 */
1635 ClearPageChecked(page);
1636 ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
1637 ext3_get_block);
Denis Lunevab4eb432005-11-13 16:07:17 -08001638 if (ret != 0) {
1639 ext3_journal_stop(handle);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001640 goto out_unlock;
Denis Lunevab4eb432005-11-13 16:07:17 -08001641 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001642 ret = walk_page_buffers(handle, page_buffers(page), 0,
1643 PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
1644
1645 err = walk_page_buffers(handle, page_buffers(page), 0,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001646 PAGE_CACHE_SIZE, NULL, write_end_fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001647 if (ret == 0)
1648 ret = err;
1649 EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1650 unlock_page(page);
1651 } else {
1652 /*
1653 * It may be a page full of checkpoint-mode buffers. We don't
1654 * really know unless we go poke around in the buffer_heads.
1655 * But block_write_full_page will do the right thing.
1656 */
1657 ret = block_write_full_page(page, ext3_get_block, wbc);
1658 }
1659 err = ext3_journal_stop(handle);
1660 if (!ret)
1661 ret = err;
1662out:
1663 return ret;
1664
1665no_write:
1666 redirty_page_for_writepage(wbc, page);
1667out_unlock:
1668 unlock_page(page);
1669 goto out;
1670}
1671
1672static int ext3_readpage(struct file *file, struct page *page)
1673{
1674 return mpage_readpage(page, ext3_get_block);
1675}
1676
1677static int
1678ext3_readpages(struct file *file, struct address_space *mapping,
1679 struct list_head *pages, unsigned nr_pages)
1680{
1681 return mpage_readpages(mapping, pages, nr_pages, ext3_get_block);
1682}
1683
NeilBrown2ff28e22006-03-26 01:37:18 -08001684static void ext3_invalidatepage(struct page *page, unsigned long offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001685{
1686 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1687
1688 /*
1689 * If it's a full truncate we just forget about the pending dirtying
1690 */
1691 if (offset == 0)
1692 ClearPageChecked(page);
1693
NeilBrown2ff28e22006-03-26 01:37:18 -08001694 journal_invalidatepage(journal, page, offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001695}
1696
Al Viro27496a82005-10-21 03:20:48 -04001697static int ext3_releasepage(struct page *page, gfp_t wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001698{
1699 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1700
1701 WARN_ON(PageChecked(page));
1702 if (!page_has_buffers(page))
1703 return 0;
1704 return journal_try_to_free_buffers(journal, page, wait);
1705}
1706
1707/*
1708 * If the O_DIRECT write will extend the file then add this inode to the
1709 * orphan list. So recovery will truncate it back to the original size
1710 * if the machine crashes during the write.
1711 *
1712 * If the O_DIRECT write is intantiating holes inside i_size and the machine
Jan Karabd1939d2008-02-06 01:40:21 -08001713 * crashes then stale disk data _may_ be exposed inside the file. But current
1714 * VFS code falls back into buffered path in that case so we are safe.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001715 */
1716static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
1717 const struct iovec *iov, loff_t offset,
1718 unsigned long nr_segs)
1719{
1720 struct file *file = iocb->ki_filp;
1721 struct inode *inode = file->f_mapping->host;
1722 struct ext3_inode_info *ei = EXT3_I(inode);
Jan Karabd1939d2008-02-06 01:40:21 -08001723 handle_t *handle;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001724 ssize_t ret;
1725 int orphan = 0;
1726 size_t count = iov_length(iov, nr_segs);
1727
1728 if (rw == WRITE) {
1729 loff_t final_size = offset + count;
1730
Linus Torvalds1da177e2005-04-16 15:20:36 -07001731 if (final_size > inode->i_size) {
Jan Karabd1939d2008-02-06 01:40:21 -08001732 /* Credits for sb + inode write */
1733 handle = ext3_journal_start(inode, 2);
1734 if (IS_ERR(handle)) {
1735 ret = PTR_ERR(handle);
1736 goto out;
1737 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001738 ret = ext3_orphan_add(handle, inode);
Jan Karabd1939d2008-02-06 01:40:21 -08001739 if (ret) {
1740 ext3_journal_stop(handle);
1741 goto out;
1742 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001743 orphan = 1;
1744 ei->i_disksize = inode->i_size;
Jan Karabd1939d2008-02-06 01:40:21 -08001745 ext3_journal_stop(handle);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001746 }
1747 }
1748
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001749 ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001750 offset, nr_segs,
Badari Pulavartyf91a2ad2006-03-26 01:38:04 -08001751 ext3_get_block, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001752
Jan Karabd1939d2008-02-06 01:40:21 -08001753 if (orphan) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001754 int err;
1755
Jan Karabd1939d2008-02-06 01:40:21 -08001756 /* Credits for sb + inode write */
1757 handle = ext3_journal_start(inode, 2);
1758 if (IS_ERR(handle)) {
1759 /* This is really bad luck. We've written the data
1760 * but cannot extend i_size. Bail out and pretend
1761 * the write failed... */
1762 ret = PTR_ERR(handle);
1763 goto out;
1764 }
1765 if (inode->i_nlink)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001766 ext3_orphan_del(handle, inode);
Jan Karabd1939d2008-02-06 01:40:21 -08001767 if (ret > 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001768 loff_t end = offset + ret;
1769 if (end > inode->i_size) {
1770 ei->i_disksize = end;
1771 i_size_write(inode, end);
1772 /*
1773 * We're going to return a positive `ret'
1774 * here due to non-zero-length I/O, so there's
1775 * no way of reporting error returns from
1776 * ext3_mark_inode_dirty() to userspace. So
1777 * ignore it.
1778 */
1779 ext3_mark_inode_dirty(handle, inode);
1780 }
1781 }
1782 err = ext3_journal_stop(handle);
1783 if (ret == 0)
1784 ret = err;
1785 }
1786out:
1787 return ret;
1788}
1789
1790/*
1791 * Pages can be marked dirty completely asynchronously from ext3's journalling
1792 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
1793 * much here because ->set_page_dirty is called under VFS locks. The page is
1794 * not necessarily locked.
1795 *
1796 * We cannot just dirty the page and leave attached buffers clean, because the
1797 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
1798 * or jbddirty because all the journalling code will explode.
1799 *
1800 * So what we do is to mark the page "pending dirty" and next time writepage
1801 * is called, propagate that into the buffers appropriately.
1802 */
1803static int ext3_journalled_set_page_dirty(struct page *page)
1804{
1805 SetPageChecked(page);
1806 return __set_page_dirty_nobuffers(page);
1807}
1808
Christoph Hellwigf5e54d62006-06-28 04:26:44 -07001809static const struct address_space_operations ext3_ordered_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07001810 .readpage = ext3_readpage,
1811 .readpages = ext3_readpages,
1812 .writepage = ext3_ordered_writepage,
1813 .sync_page = block_sync_page,
1814 .write_begin = ext3_write_begin,
1815 .write_end = ext3_ordered_write_end,
1816 .bmap = ext3_bmap,
1817 .invalidatepage = ext3_invalidatepage,
1818 .releasepage = ext3_releasepage,
1819 .direct_IO = ext3_direct_IO,
1820 .migratepage = buffer_migrate_page,
1821 .is_partially_uptodate = block_is_partially_uptodate,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001822};
1823
Christoph Hellwigf5e54d62006-06-28 04:26:44 -07001824static const struct address_space_operations ext3_writeback_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07001825 .readpage = ext3_readpage,
1826 .readpages = ext3_readpages,
1827 .writepage = ext3_writeback_writepage,
1828 .sync_page = block_sync_page,
1829 .write_begin = ext3_write_begin,
1830 .write_end = ext3_writeback_write_end,
1831 .bmap = ext3_bmap,
1832 .invalidatepage = ext3_invalidatepage,
1833 .releasepage = ext3_releasepage,
1834 .direct_IO = ext3_direct_IO,
1835 .migratepage = buffer_migrate_page,
1836 .is_partially_uptodate = block_is_partially_uptodate,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001837};
1838
Christoph Hellwigf5e54d62006-06-28 04:26:44 -07001839static const struct address_space_operations ext3_journalled_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07001840 .readpage = ext3_readpage,
1841 .readpages = ext3_readpages,
1842 .writepage = ext3_journalled_writepage,
1843 .sync_page = block_sync_page,
1844 .write_begin = ext3_write_begin,
1845 .write_end = ext3_journalled_write_end,
1846 .set_page_dirty = ext3_journalled_set_page_dirty,
1847 .bmap = ext3_bmap,
1848 .invalidatepage = ext3_invalidatepage,
1849 .releasepage = ext3_releasepage,
1850 .is_partially_uptodate = block_is_partially_uptodate,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001851};
1852
1853void ext3_set_aops(struct inode *inode)
1854{
1855 if (ext3_should_order_data(inode))
1856 inode->i_mapping->a_ops = &ext3_ordered_aops;
1857 else if (ext3_should_writeback_data(inode))
1858 inode->i_mapping->a_ops = &ext3_writeback_aops;
1859 else
1860 inode->i_mapping->a_ops = &ext3_journalled_aops;
1861}
1862
1863/*
1864 * ext3_block_truncate_page() zeroes out a mapping from file offset `from'
1865 * up to the end of the block which corresponds to `from'.
1866 * This required during truncate. We need to physically zero the tail end
1867 * of that block so it doesn't yield old data if the file is later grown.
1868 */
1869static int ext3_block_truncate_page(handle_t *handle, struct page *page,
1870 struct address_space *mapping, loff_t from)
1871{
Mingming Cao43d23f92006-06-25 05:48:07 -07001872 ext3_fsblk_t index = from >> PAGE_CACHE_SHIFT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001873 unsigned offset = from & (PAGE_CACHE_SIZE-1);
1874 unsigned blocksize, iblock, length, pos;
1875 struct inode *inode = mapping->host;
1876 struct buffer_head *bh;
1877 int err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001878
1879 blocksize = inode->i_sb->s_blocksize;
1880 length = blocksize - (offset & (blocksize - 1));
1881 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1882
1883 /*
1884 * For "nobh" option, we can only work if we don't need to
1885 * read-in the page - otherwise we create buffers to do the IO.
1886 */
Badari Pulavartycd6ef842006-03-11 03:27:14 -08001887 if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
1888 ext3_should_writeback_data(inode) && PageUptodate(page)) {
Christoph Lametereebd2aa2008-02-04 22:28:29 -08001889 zero_user(page, offset, length);
Badari Pulavartycd6ef842006-03-11 03:27:14 -08001890 set_page_dirty(page);
1891 goto unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001892 }
1893
1894 if (!page_has_buffers(page))
1895 create_empty_buffers(page, blocksize, 0);
1896
1897 /* Find the buffer that contains "offset" */
1898 bh = page_buffers(page);
1899 pos = blocksize;
1900 while (offset >= pos) {
1901 bh = bh->b_this_page;
1902 iblock++;
1903 pos += blocksize;
1904 }
1905
1906 err = 0;
1907 if (buffer_freed(bh)) {
1908 BUFFER_TRACE(bh, "freed: skip");
1909 goto unlock;
1910 }
1911
1912 if (!buffer_mapped(bh)) {
1913 BUFFER_TRACE(bh, "unmapped");
1914 ext3_get_block(inode, iblock, bh, 0);
1915 /* unmapped? It's a hole - nothing to do */
1916 if (!buffer_mapped(bh)) {
1917 BUFFER_TRACE(bh, "still unmapped");
1918 goto unlock;
1919 }
1920 }
1921
1922 /* Ok, it's mapped. Make sure it's up-to-date */
1923 if (PageUptodate(page))
1924 set_buffer_uptodate(bh);
1925
1926 if (!buffer_uptodate(bh)) {
1927 err = -EIO;
1928 ll_rw_block(READ, 1, &bh);
1929 wait_on_buffer(bh);
1930 /* Uhhuh. Read error. Complain and punt. */
1931 if (!buffer_uptodate(bh))
1932 goto unlock;
1933 }
1934
1935 if (ext3_should_journal_data(inode)) {
1936 BUFFER_TRACE(bh, "get write access");
1937 err = ext3_journal_get_write_access(handle, bh);
1938 if (err)
1939 goto unlock;
1940 }
1941
Christoph Lametereebd2aa2008-02-04 22:28:29 -08001942 zero_user(page, offset, length);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001943 BUFFER_TRACE(bh, "zeroed end of block");
1944
1945 err = 0;
1946 if (ext3_should_journal_data(inode)) {
1947 err = ext3_journal_dirty_metadata(handle, bh);
1948 } else {
1949 if (ext3_should_order_data(inode))
1950 err = ext3_journal_dirty_data(handle, bh);
1951 mark_buffer_dirty(bh);
1952 }
1953
1954unlock:
1955 unlock_page(page);
1956 page_cache_release(page);
1957 return err;
1958}
1959
1960/*
1961 * Probably it should be a library function... search for first non-zero word
1962 * or memcmp with zero_page, whatever is better for particular architecture.
1963 * Linus?
1964 */
1965static inline int all_zeroes(__le32 *p, __le32 *q)
1966{
1967 while (p < q)
1968 if (*p++)
1969 return 0;
1970 return 1;
1971}
1972
1973/**
1974 * ext3_find_shared - find the indirect blocks for partial truncation.
1975 * @inode: inode in question
1976 * @depth: depth of the affected branch
1977 * @offsets: offsets of pointers in that branch (see ext3_block_to_path)
1978 * @chain: place to store the pointers to partial indirect blocks
1979 * @top: place to the (detached) top of branch
1980 *
1981 * This is a helper function used by ext3_truncate().
1982 *
1983 * When we do truncate() we may have to clean the ends of several
1984 * indirect blocks but leave the blocks themselves alive. Block is
1985 * partially truncated if some data below the new i_size is refered
1986 * from it (and it is on the path to the first completely truncated
1987 * data block, indeed). We have to free the top of that path along
1988 * with everything to the right of the path. Since no allocation
1989 * past the truncation point is possible until ext3_truncate()
1990 * finishes, we may safely do the latter, but top of branch may
1991 * require special attention - pageout below the truncation point
1992 * might try to populate it.
1993 *
1994 * We atomically detach the top of branch from the tree, store the
1995 * block number of its root in *@top, pointers to buffer_heads of
1996 * partially truncated blocks - in @chain[].bh and pointers to
1997 * their last elements that should not be removed - in
1998 * @chain[].p. Return value is the pointer to last filled element
1999 * of @chain.
2000 *
2001 * The work left to caller to do the actual freeing of subtrees:
2002 * a) free the subtree starting from *@top
2003 * b) free the subtrees whose roots are stored in
2004 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
2005 * c) free the subtrees growing from the inode past the @chain[0].
2006 * (no partially truncated stuff there). */
2007
Andrew Mortond6859bf2006-03-26 01:38:03 -08002008static Indirect *ext3_find_shared(struct inode *inode, int depth,
2009 int offsets[4], Indirect chain[4], __le32 *top)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002010{
2011 Indirect *partial, *p;
2012 int k, err;
2013
2014 *top = 0;
2015 /* Make k index the deepest non-null offest + 1 */
2016 for (k = depth; k > 1 && !offsets[k-1]; k--)
2017 ;
2018 partial = ext3_get_branch(inode, k, offsets, chain, &err);
2019 /* Writer: pointers */
2020 if (!partial)
2021 partial = chain + k-1;
2022 /*
2023 * If the branch acquired continuation since we've looked at it -
2024 * fine, it should all survive and (new) top doesn't belong to us.
2025 */
2026 if (!partial->key && *partial->p)
2027 /* Writer: end */
2028 goto no_top;
2029 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
2030 ;
2031 /*
2032 * OK, we've found the last block that must survive. The rest of our
2033 * branch should be detached before unlocking. However, if that rest
2034 * of branch is all ours and does not grow immediately from the inode
2035 * it's easier to cheat and just decrement partial->p.
2036 */
2037 if (p == chain + k - 1 && p > chain) {
2038 p->p--;
2039 } else {
2040 *top = *p->p;
2041 /* Nope, don't do this in ext3. Must leave the tree intact */
2042#if 0
2043 *p->p = 0;
2044#endif
2045 }
2046 /* Writer: end */
2047
Andrew Mortond6859bf2006-03-26 01:38:03 -08002048 while(partial > p) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002049 brelse(partial->bh);
2050 partial--;
2051 }
2052no_top:
2053 return partial;
2054}
2055
2056/*
2057 * Zero a number of block pointers in either an inode or an indirect block.
2058 * If we restart the transaction we must again get write access to the
2059 * indirect block for further modification.
2060 *
2061 * We release `count' blocks on disk, but (last - first) may be greater
2062 * than `count' because there can be holes in there.
2063 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08002064static void ext3_clear_blocks(handle_t *handle, struct inode *inode,
Mingming Cao43d23f92006-06-25 05:48:07 -07002065 struct buffer_head *bh, ext3_fsblk_t block_to_free,
Andrew Mortond6859bf2006-03-26 01:38:03 -08002066 unsigned long count, __le32 *first, __le32 *last)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002067{
2068 __le32 *p;
2069 if (try_to_extend_transaction(handle, inode)) {
2070 if (bh) {
2071 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
2072 ext3_journal_dirty_metadata(handle, bh);
2073 }
2074 ext3_mark_inode_dirty(handle, inode);
2075 ext3_journal_test_restart(handle, inode);
2076 if (bh) {
2077 BUFFER_TRACE(bh, "retaking write access");
2078 ext3_journal_get_write_access(handle, bh);
2079 }
2080 }
2081
2082 /*
2083 * Any buffers which are on the journal will be in memory. We find
2084 * them on the hash table so journal_revoke() will run journal_forget()
2085 * on them. We've already detached each block from the file, so
2086 * bforget() in journal_forget() should be safe.
2087 *
2088 * AKPM: turn on bforget in journal_forget()!!!
2089 */
2090 for (p = first; p < last; p++) {
2091 u32 nr = le32_to_cpu(*p);
2092 if (nr) {
2093 struct buffer_head *bh;
2094
2095 *p = 0;
2096 bh = sb_find_get_block(inode->i_sb, nr);
2097 ext3_forget(handle, 0, inode, bh, nr);
2098 }
2099 }
2100
2101 ext3_free_blocks(handle, inode, block_to_free, count);
2102}
2103
2104/**
2105 * ext3_free_data - free a list of data blocks
2106 * @handle: handle for this transaction
2107 * @inode: inode we are dealing with
2108 * @this_bh: indirect buffer_head which contains *@first and *@last
2109 * @first: array of block numbers
2110 * @last: points immediately past the end of array
2111 *
2112 * We are freeing all blocks refered from that array (numbers are stored as
2113 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
2114 *
2115 * We accumulate contiguous runs of blocks to free. Conveniently, if these
2116 * blocks are contiguous then releasing them at one time will only affect one
2117 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
2118 * actually use a lot of journal space.
2119 *
2120 * @this_bh will be %NULL if @first and @last point into the inode's direct
2121 * block pointers.
2122 */
2123static void ext3_free_data(handle_t *handle, struct inode *inode,
2124 struct buffer_head *this_bh,
2125 __le32 *first, __le32 *last)
2126{
Mingming Cao43d23f92006-06-25 05:48:07 -07002127 ext3_fsblk_t block_to_free = 0; /* Starting block # of a run */
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002128 unsigned long count = 0; /* Number of blocks in the run */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002129 __le32 *block_to_free_p = NULL; /* Pointer into inode/ind
2130 corresponding to
2131 block_to_free */
Mingming Cao43d23f92006-06-25 05:48:07 -07002132 ext3_fsblk_t nr; /* Current block # */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002133 __le32 *p; /* Pointer into inode/ind
2134 for current block */
2135 int err;
2136
2137 if (this_bh) { /* For indirect block */
2138 BUFFER_TRACE(this_bh, "get_write_access");
2139 err = ext3_journal_get_write_access(handle, this_bh);
2140 /* Important: if we can't update the indirect pointers
2141 * to the blocks, we can't free them. */
2142 if (err)
2143 return;
2144 }
2145
2146 for (p = first; p < last; p++) {
2147 nr = le32_to_cpu(*p);
2148 if (nr) {
2149 /* accumulate blocks to free if they're contiguous */
2150 if (count == 0) {
2151 block_to_free = nr;
2152 block_to_free_p = p;
2153 count = 1;
2154 } else if (nr == block_to_free + count) {
2155 count++;
2156 } else {
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002157 ext3_clear_blocks(handle, inode, this_bh,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002158 block_to_free,
2159 count, block_to_free_p, p);
2160 block_to_free = nr;
2161 block_to_free_p = p;
2162 count = 1;
2163 }
2164 }
2165 }
2166
2167 if (count > 0)
2168 ext3_clear_blocks(handle, inode, this_bh, block_to_free,
2169 count, block_to_free_p, p);
2170
2171 if (this_bh) {
2172 BUFFER_TRACE(this_bh, "call ext3_journal_dirty_metadata");
Duane Griffin3ccc3162008-07-25 01:46:26 -07002173
2174 /*
2175 * The buffer head should have an attached journal head at this
2176 * point. However, if the data is corrupted and an indirect
2177 * block pointed to itself, it would have been detached when
2178 * the block was cleared. Check for this instead of OOPSing.
2179 */
2180 if (bh2jh(this_bh))
2181 ext3_journal_dirty_metadata(handle, this_bh);
2182 else
2183 ext3_error(inode->i_sb, "ext3_free_data",
2184 "circular indirect block detected, "
2185 "inode=%lu, block=%llu",
2186 inode->i_ino,
2187 (unsigned long long)this_bh->b_blocknr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002188 }
2189}
2190
2191/**
2192 * ext3_free_branches - free an array of branches
2193 * @handle: JBD handle for this transaction
2194 * @inode: inode we are dealing with
2195 * @parent_bh: the buffer_head which contains *@first and *@last
2196 * @first: array of block numbers
2197 * @last: pointer immediately past the end of array
2198 * @depth: depth of the branches to free
2199 *
2200 * We are freeing all blocks refered from these branches (numbers are
2201 * stored as little-endian 32-bit) and updating @inode->i_blocks
2202 * appropriately.
2203 */
2204static void ext3_free_branches(handle_t *handle, struct inode *inode,
2205 struct buffer_head *parent_bh,
2206 __le32 *first, __le32 *last, int depth)
2207{
Mingming Cao43d23f92006-06-25 05:48:07 -07002208 ext3_fsblk_t nr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002209 __le32 *p;
2210
2211 if (is_handle_aborted(handle))
2212 return;
2213
2214 if (depth--) {
2215 struct buffer_head *bh;
2216 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2217 p = last;
2218 while (--p >= first) {
2219 nr = le32_to_cpu(*p);
2220 if (!nr)
2221 continue; /* A hole */
2222
2223 /* Go read the buffer for the next level down */
2224 bh = sb_bread(inode->i_sb, nr);
2225
2226 /*
2227 * A read failure? Report error and clear slot
2228 * (should be rare).
2229 */
2230 if (!bh) {
2231 ext3_error(inode->i_sb, "ext3_free_branches",
Eric Sandeeneee194e2006-09-27 01:49:30 -07002232 "Read failure, inode=%lu, block="E3FSBLK,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002233 inode->i_ino, nr);
2234 continue;
2235 }
2236
2237 /* This zaps the entire block. Bottom up. */
2238 BUFFER_TRACE(bh, "free child branches");
2239 ext3_free_branches(handle, inode, bh,
2240 (__le32*)bh->b_data,
2241 (__le32*)bh->b_data + addr_per_block,
2242 depth);
2243
2244 /*
2245 * We've probably journalled the indirect block several
2246 * times during the truncate. But it's no longer
2247 * needed and we now drop it from the transaction via
2248 * journal_revoke().
2249 *
2250 * That's easy if it's exclusively part of this
2251 * transaction. But if it's part of the committing
2252 * transaction then journal_forget() will simply
2253 * brelse() it. That means that if the underlying
2254 * block is reallocated in ext3_get_block(),
2255 * unmap_underlying_metadata() will find this block
2256 * and will try to get rid of it. damn, damn.
2257 *
2258 * If this block has already been committed to the
2259 * journal, a revoke record will be written. And
2260 * revoke records must be emitted *before* clearing
2261 * this block's bit in the bitmaps.
2262 */
2263 ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
2264
2265 /*
2266 * Everything below this this pointer has been
2267 * released. Now let this top-of-subtree go.
2268 *
2269 * We want the freeing of this indirect block to be
2270 * atomic in the journal with the updating of the
2271 * bitmap block which owns it. So make some room in
2272 * the journal.
2273 *
2274 * We zero the parent pointer *after* freeing its
2275 * pointee in the bitmaps, so if extend_transaction()
2276 * for some reason fails to put the bitmap changes and
2277 * the release into the same transaction, recovery
2278 * will merely complain about releasing a free block,
2279 * rather than leaking blocks.
2280 */
2281 if (is_handle_aborted(handle))
2282 return;
2283 if (try_to_extend_transaction(handle, inode)) {
2284 ext3_mark_inode_dirty(handle, inode);
2285 ext3_journal_test_restart(handle, inode);
2286 }
2287
2288 ext3_free_blocks(handle, inode, nr, 1);
2289
2290 if (parent_bh) {
2291 /*
2292 * The block which we have just freed is
2293 * pointed to by an indirect block: journal it
2294 */
2295 BUFFER_TRACE(parent_bh, "get_write_access");
2296 if (!ext3_journal_get_write_access(handle,
2297 parent_bh)){
2298 *p = 0;
2299 BUFFER_TRACE(parent_bh,
2300 "call ext3_journal_dirty_metadata");
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002301 ext3_journal_dirty_metadata(handle,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002302 parent_bh);
2303 }
2304 }
2305 }
2306 } else {
2307 /* We have reached the bottom of the tree. */
2308 BUFFER_TRACE(parent_bh, "free data blocks");
2309 ext3_free_data(handle, inode, parent_bh, first, last);
2310 }
2311}
2312
Duane Griffinae76dd92008-07-25 01:46:23 -07002313int ext3_can_truncate(struct inode *inode)
2314{
2315 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2316 return 0;
2317 if (S_ISREG(inode->i_mode))
2318 return 1;
2319 if (S_ISDIR(inode->i_mode))
2320 return 1;
2321 if (S_ISLNK(inode->i_mode))
2322 return !ext3_inode_is_fast_symlink(inode);
2323 return 0;
2324}
2325
Linus Torvalds1da177e2005-04-16 15:20:36 -07002326/*
2327 * ext3_truncate()
2328 *
2329 * We block out ext3_get_block() block instantiations across the entire
2330 * transaction, and VFS/VM ensures that ext3_truncate() cannot run
2331 * simultaneously on behalf of the same inode.
2332 *
2333 * As we work through the truncate and commmit bits of it to the journal there
2334 * is one core, guiding principle: the file's tree must always be consistent on
2335 * disk. We must be able to restart the truncate after a crash.
2336 *
2337 * The file's tree may be transiently inconsistent in memory (although it
2338 * probably isn't), but whenever we close off and commit a journal transaction,
2339 * the contents of (the filesystem + the journal) must be consistent and
2340 * restartable. It's pretty simple, really: bottom up, right to left (although
2341 * left-to-right works OK too).
2342 *
2343 * Note that at recovery time, journal replay occurs *before* the restart of
2344 * truncate against the orphan inode list.
2345 *
2346 * The committed inode has the new, desired i_size (which is the same as
2347 * i_disksize in this case). After a crash, ext3_orphan_cleanup() will see
2348 * that this inode's truncate did not complete and it will again call
2349 * ext3_truncate() to have another go. So there will be instantiated blocks
2350 * to the right of the truncation point in a crashed ext3 filesystem. But
2351 * that's fine - as long as they are linked from the inode, the post-crash
2352 * ext3_truncate() run will find them and release them.
2353 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08002354void ext3_truncate(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002355{
2356 handle_t *handle;
2357 struct ext3_inode_info *ei = EXT3_I(inode);
2358 __le32 *i_data = ei->i_data;
2359 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2360 struct address_space *mapping = inode->i_mapping;
2361 int offsets[4];
2362 Indirect chain[4];
2363 Indirect *partial;
2364 __le32 nr = 0;
2365 int n;
2366 long last_block;
2367 unsigned blocksize = inode->i_sb->s_blocksize;
2368 struct page *page;
2369
Duane Griffinae76dd92008-07-25 01:46:23 -07002370 if (!ext3_can_truncate(inode))
Jan Karaef436182009-06-17 16:26:24 -07002371 goto out_notrans;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002372
Theodore Ts'of7ab34e2009-04-03 01:34:35 -04002373 if (inode->i_size == 0 && ext3_should_writeback_data(inode))
2374 ei->i_state |= EXT3_STATE_FLUSH_ON_CLOSE;
2375
Linus Torvalds1da177e2005-04-16 15:20:36 -07002376 /*
2377 * We have to lock the EOF page here, because lock_page() nests
2378 * outside journal_start().
2379 */
2380 if ((inode->i_size & (blocksize - 1)) == 0) {
2381 /* Block boundary? Nothing to do */
2382 page = NULL;
2383 } else {
2384 page = grab_cache_page(mapping,
2385 inode->i_size >> PAGE_CACHE_SHIFT);
2386 if (!page)
Jan Karaef436182009-06-17 16:26:24 -07002387 goto out_notrans;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002388 }
2389
2390 handle = start_transaction(inode);
2391 if (IS_ERR(handle)) {
2392 if (page) {
2393 clear_highpage(page);
2394 flush_dcache_page(page);
2395 unlock_page(page);
2396 page_cache_release(page);
2397 }
Jan Karaef436182009-06-17 16:26:24 -07002398 goto out_notrans;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002399 }
2400
2401 last_block = (inode->i_size + blocksize-1)
2402 >> EXT3_BLOCK_SIZE_BITS(inode->i_sb);
2403
2404 if (page)
2405 ext3_block_truncate_page(handle, page, mapping, inode->i_size);
2406
2407 n = ext3_block_to_path(inode, last_block, offsets, NULL);
2408 if (n == 0)
2409 goto out_stop; /* error */
2410
2411 /*
2412 * OK. This truncate is going to happen. We add the inode to the
2413 * orphan list, so that if this truncate spans multiple transactions,
2414 * and we crash, we will resume the truncate when the filesystem
2415 * recovers. It also marks the inode dirty, to catch the new size.
2416 *
2417 * Implication: the file must always be in a sane, consistent
2418 * truncatable state while each transaction commits.
2419 */
2420 if (ext3_orphan_add(handle, inode))
2421 goto out_stop;
2422
2423 /*
2424 * The orphan list entry will now protect us from any crash which
2425 * occurs before the truncate completes, so it is now safe to propagate
2426 * the new, shorter inode size (held for now in i_size) into the
2427 * on-disk inode. We do this via i_disksize, which is the value which
2428 * ext3 *really* writes onto the disk inode.
2429 */
2430 ei->i_disksize = inode->i_size;
2431
2432 /*
2433 * From here we block out all ext3_get_block() callers who want to
2434 * modify the block allocation tree.
2435 */
Arjan van de Ven97461512006-03-23 03:00:42 -08002436 mutex_lock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002437
2438 if (n == 1) { /* direct blocks */
2439 ext3_free_data(handle, inode, NULL, i_data+offsets[0],
2440 i_data + EXT3_NDIR_BLOCKS);
2441 goto do_indirects;
2442 }
2443
2444 partial = ext3_find_shared(inode, n, offsets, chain, &nr);
2445 /* Kill the top of shared branch (not detached) */
2446 if (nr) {
2447 if (partial == chain) {
2448 /* Shared branch grows from the inode */
2449 ext3_free_branches(handle, inode, NULL,
2450 &nr, &nr+1, (chain+n-1) - partial);
2451 *partial->p = 0;
2452 /*
2453 * We mark the inode dirty prior to restart,
2454 * and prior to stop. No need for it here.
2455 */
2456 } else {
2457 /* Shared branch grows from an indirect block */
2458 BUFFER_TRACE(partial->bh, "get_write_access");
2459 ext3_free_branches(handle, inode, partial->bh,
2460 partial->p,
2461 partial->p+1, (chain+n-1) - partial);
2462 }
2463 }
2464 /* Clear the ends of indirect blocks on the shared branch */
2465 while (partial > chain) {
2466 ext3_free_branches(handle, inode, partial->bh, partial->p + 1,
2467 (__le32*)partial->bh->b_data+addr_per_block,
2468 (chain+n-1) - partial);
2469 BUFFER_TRACE(partial->bh, "call brelse");
2470 brelse (partial->bh);
2471 partial--;
2472 }
2473do_indirects:
2474 /* Kill the remaining (whole) subtrees */
2475 switch (offsets[0]) {
Andrew Mortond6859bf2006-03-26 01:38:03 -08002476 default:
2477 nr = i_data[EXT3_IND_BLOCK];
2478 if (nr) {
2479 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
2480 i_data[EXT3_IND_BLOCK] = 0;
2481 }
2482 case EXT3_IND_BLOCK:
2483 nr = i_data[EXT3_DIND_BLOCK];
2484 if (nr) {
2485 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
2486 i_data[EXT3_DIND_BLOCK] = 0;
2487 }
2488 case EXT3_DIND_BLOCK:
2489 nr = i_data[EXT3_TIND_BLOCK];
2490 if (nr) {
2491 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
2492 i_data[EXT3_TIND_BLOCK] = 0;
2493 }
2494 case EXT3_TIND_BLOCK:
2495 ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002496 }
2497
2498 ext3_discard_reservation(inode);
2499
Arjan van de Ven97461512006-03-23 03:00:42 -08002500 mutex_unlock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002501 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
2502 ext3_mark_inode_dirty(handle, inode);
2503
Andrew Mortond6859bf2006-03-26 01:38:03 -08002504 /*
2505 * In a multi-transaction truncate, we only make the final transaction
2506 * synchronous
2507 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002508 if (IS_SYNC(inode))
2509 handle->h_sync = 1;
2510out_stop:
2511 /*
2512 * If this was a simple ftruncate(), and the file will remain alive
2513 * then we need to clear up the orphan record which we created above.
2514 * However, if this was a real unlink then we were called by
2515 * ext3_delete_inode(), and we allow that function to clean up the
2516 * orphan info for us.
2517 */
2518 if (inode->i_nlink)
2519 ext3_orphan_del(handle, inode);
2520
2521 ext3_journal_stop(handle);
Jan Karaef436182009-06-17 16:26:24 -07002522 return;
2523out_notrans:
2524 /*
2525 * Delete the inode from orphan list so that it doesn't stay there
2526 * forever and trigger assertion on umount.
2527 */
2528 if (inode->i_nlink)
2529 ext3_orphan_del(NULL, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002530}
2531
Mingming Cao43d23f92006-06-25 05:48:07 -07002532static ext3_fsblk_t ext3_get_inode_block(struct super_block *sb,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002533 unsigned long ino, struct ext3_iloc *iloc)
2534{
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002535 unsigned long block_group;
Mingming Cao43d23f92006-06-25 05:48:07 -07002536 unsigned long offset;
2537 ext3_fsblk_t block;
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002538 struct ext3_group_desc *gdp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002539
Neil Brown2ccb48e2006-07-30 03:03:01 -07002540 if (!ext3_valid_inum(sb, ino)) {
2541 /*
2542 * This error is already checked for in namei.c unless we are
2543 * looking at an NFS filehandle, in which case no error
2544 * report is needed
2545 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002546 return 0;
2547 }
Neil Brown2ccb48e2006-07-30 03:03:01 -07002548
Linus Torvalds1da177e2005-04-16 15:20:36 -07002549 block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002550 gdp = ext3_get_group_desc(sb, block_group, NULL);
2551 if (!gdp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002552 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002553 /*
2554 * Figure out the offset within the block group inode table
2555 */
2556 offset = ((ino - 1) % EXT3_INODES_PER_GROUP(sb)) *
2557 EXT3_INODE_SIZE(sb);
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002558 block = le32_to_cpu(gdp->bg_inode_table) +
Linus Torvalds1da177e2005-04-16 15:20:36 -07002559 (offset >> EXT3_BLOCK_SIZE_BITS(sb));
2560
2561 iloc->block_group = block_group;
2562 iloc->offset = offset & (EXT3_BLOCK_SIZE(sb) - 1);
2563 return block;
2564}
2565
2566/*
2567 * ext3_get_inode_loc returns with an extra refcount against the inode's
2568 * underlying buffer_head on success. If 'in_mem' is true, we have all
2569 * data in memory that is needed to recreate the on-disk version of this
2570 * inode.
2571 */
2572static int __ext3_get_inode_loc(struct inode *inode,
2573 struct ext3_iloc *iloc, int in_mem)
2574{
Mingming Cao43d23f92006-06-25 05:48:07 -07002575 ext3_fsblk_t block;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002576 struct buffer_head *bh;
2577
2578 block = ext3_get_inode_block(inode->i_sb, inode->i_ino, iloc);
2579 if (!block)
2580 return -EIO;
2581
2582 bh = sb_getblk(inode->i_sb, block);
2583 if (!bh) {
2584 ext3_error (inode->i_sb, "ext3_get_inode_loc",
2585 "unable to read inode block - "
Mingming Cao43d23f92006-06-25 05:48:07 -07002586 "inode=%lu, block="E3FSBLK,
2587 inode->i_ino, block);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002588 return -EIO;
2589 }
2590 if (!buffer_uptodate(bh)) {
2591 lock_buffer(bh);
Hidehiro Kawai95450f52008-07-25 01:46:24 -07002592
2593 /*
2594 * If the buffer has the write error flag, we have failed
2595 * to write out another inode in the same block. In this
2596 * case, we don't have to read the block because we may
2597 * read the old inode data successfully.
2598 */
2599 if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
2600 set_buffer_uptodate(bh);
2601
Linus Torvalds1da177e2005-04-16 15:20:36 -07002602 if (buffer_uptodate(bh)) {
2603 /* someone brought it uptodate while we waited */
2604 unlock_buffer(bh);
2605 goto has_buffer;
2606 }
2607
2608 /*
2609 * If we have all information of the inode in memory and this
2610 * is the only valid inode in the block, we need not read the
2611 * block.
2612 */
2613 if (in_mem) {
2614 struct buffer_head *bitmap_bh;
2615 struct ext3_group_desc *desc;
2616 int inodes_per_buffer;
2617 int inode_offset, i;
2618 int block_group;
2619 int start;
2620
2621 block_group = (inode->i_ino - 1) /
2622 EXT3_INODES_PER_GROUP(inode->i_sb);
2623 inodes_per_buffer = bh->b_size /
2624 EXT3_INODE_SIZE(inode->i_sb);
2625 inode_offset = ((inode->i_ino - 1) %
2626 EXT3_INODES_PER_GROUP(inode->i_sb));
2627 start = inode_offset & ~(inodes_per_buffer - 1);
2628
2629 /* Is the inode bitmap in cache? */
2630 desc = ext3_get_group_desc(inode->i_sb,
2631 block_group, NULL);
2632 if (!desc)
2633 goto make_io;
2634
2635 bitmap_bh = sb_getblk(inode->i_sb,
2636 le32_to_cpu(desc->bg_inode_bitmap));
2637 if (!bitmap_bh)
2638 goto make_io;
2639
2640 /*
2641 * If the inode bitmap isn't in cache then the
2642 * optimisation may end up performing two reads instead
2643 * of one, so skip it.
2644 */
2645 if (!buffer_uptodate(bitmap_bh)) {
2646 brelse(bitmap_bh);
2647 goto make_io;
2648 }
2649 for (i = start; i < start + inodes_per_buffer; i++) {
2650 if (i == inode_offset)
2651 continue;
2652 if (ext3_test_bit(i, bitmap_bh->b_data))
2653 break;
2654 }
2655 brelse(bitmap_bh);
2656 if (i == start + inodes_per_buffer) {
2657 /* all other inodes are free, so skip I/O */
2658 memset(bh->b_data, 0, bh->b_size);
2659 set_buffer_uptodate(bh);
2660 unlock_buffer(bh);
2661 goto has_buffer;
2662 }
2663 }
2664
2665make_io:
2666 /*
2667 * There are other valid inodes in the buffer, this inode
2668 * has in-inode xattrs, or we don't have this inode in memory.
2669 * Read the block from disk.
2670 */
2671 get_bh(bh);
2672 bh->b_end_io = end_buffer_read_sync;
Jens Axboecaa38fb2006-07-23 01:41:26 +02002673 submit_bh(READ_META, bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002674 wait_on_buffer(bh);
2675 if (!buffer_uptodate(bh)) {
2676 ext3_error(inode->i_sb, "ext3_get_inode_loc",
2677 "unable to read inode block - "
Mingming Cao43d23f92006-06-25 05:48:07 -07002678 "inode=%lu, block="E3FSBLK,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002679 inode->i_ino, block);
2680 brelse(bh);
2681 return -EIO;
2682 }
2683 }
2684has_buffer:
2685 iloc->bh = bh;
2686 return 0;
2687}
2688
2689int ext3_get_inode_loc(struct inode *inode, struct ext3_iloc *iloc)
2690{
2691 /* We have all inode data except xattrs in memory here. */
2692 return __ext3_get_inode_loc(inode, iloc,
2693 !(EXT3_I(inode)->i_state & EXT3_STATE_XATTR));
2694}
2695
2696void ext3_set_inode_flags(struct inode *inode)
2697{
2698 unsigned int flags = EXT3_I(inode)->i_flags;
2699
2700 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
2701 if (flags & EXT3_SYNC_FL)
2702 inode->i_flags |= S_SYNC;
2703 if (flags & EXT3_APPEND_FL)
2704 inode->i_flags |= S_APPEND;
2705 if (flags & EXT3_IMMUTABLE_FL)
2706 inode->i_flags |= S_IMMUTABLE;
2707 if (flags & EXT3_NOATIME_FL)
2708 inode->i_flags |= S_NOATIME;
2709 if (flags & EXT3_DIRSYNC_FL)
2710 inode->i_flags |= S_DIRSYNC;
2711}
2712
Jan Kara28be5ab2007-05-08 00:30:33 -07002713/* Propagate flags from i_flags to EXT3_I(inode)->i_flags */
2714void ext3_get_inode_flags(struct ext3_inode_info *ei)
2715{
2716 unsigned int flags = ei->vfs_inode.i_flags;
2717
2718 ei->i_flags &= ~(EXT3_SYNC_FL|EXT3_APPEND_FL|
2719 EXT3_IMMUTABLE_FL|EXT3_NOATIME_FL|EXT3_DIRSYNC_FL);
2720 if (flags & S_SYNC)
2721 ei->i_flags |= EXT3_SYNC_FL;
2722 if (flags & S_APPEND)
2723 ei->i_flags |= EXT3_APPEND_FL;
2724 if (flags & S_IMMUTABLE)
2725 ei->i_flags |= EXT3_IMMUTABLE_FL;
2726 if (flags & S_NOATIME)
2727 ei->i_flags |= EXT3_NOATIME_FL;
2728 if (flags & S_DIRSYNC)
2729 ei->i_flags |= EXT3_DIRSYNC_FL;
2730}
2731
David Howells473043d2008-02-07 00:15:36 -08002732struct inode *ext3_iget(struct super_block *sb, unsigned long ino)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002733{
2734 struct ext3_iloc iloc;
2735 struct ext3_inode *raw_inode;
David Howells473043d2008-02-07 00:15:36 -08002736 struct ext3_inode_info *ei;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002737 struct buffer_head *bh;
David Howells473043d2008-02-07 00:15:36 -08002738 struct inode *inode;
2739 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002740 int block;
2741
David Howells473043d2008-02-07 00:15:36 -08002742 inode = iget_locked(sb, ino);
2743 if (!inode)
2744 return ERR_PTR(-ENOMEM);
2745 if (!(inode->i_state & I_NEW))
2746 return inode;
2747
2748 ei = EXT3_I(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002749 ei->i_block_alloc_info = NULL;
2750
David Howells473043d2008-02-07 00:15:36 -08002751 ret = __ext3_get_inode_loc(inode, &iloc, 0);
2752 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002753 goto bad_inode;
2754 bh = iloc.bh;
2755 raw_inode = ext3_raw_inode(&iloc);
2756 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
2757 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
2758 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
2759 if(!(test_opt (inode->i_sb, NO_UID32))) {
2760 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
2761 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
2762 }
2763 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
2764 inode->i_size = le32_to_cpu(raw_inode->i_size);
Markus Rechberger4d7bf112007-05-08 00:23:39 -07002765 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
2766 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
2767 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002768 inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
2769
2770 ei->i_state = 0;
2771 ei->i_dir_start_lookup = 0;
2772 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
2773 /* We now have enough fields to check if the inode was active or not.
2774 * This is needed because nfsd might try to access dead inodes
2775 * the test is that same one that e2fsck uses
2776 * NeilBrown 1999oct15
2777 */
2778 if (inode->i_nlink == 0) {
2779 if (inode->i_mode == 0 ||
2780 !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) {
2781 /* this inode is deleted */
2782 brelse (bh);
David Howells473043d2008-02-07 00:15:36 -08002783 ret = -ESTALE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002784 goto bad_inode;
2785 }
2786 /* The only unlinked inodes we let through here have
2787 * valid i_mode and are being read by the orphan
2788 * recovery code: that's fine, we're about to complete
2789 * the process of deleting those. */
2790 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002791 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
2792 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
2793#ifdef EXT3_FRAGMENTS
2794 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
2795 ei->i_frag_no = raw_inode->i_frag;
2796 ei->i_frag_size = raw_inode->i_fsize;
2797#endif
2798 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
2799 if (!S_ISREG(inode->i_mode)) {
2800 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
2801 } else {
2802 inode->i_size |=
2803 ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
2804 }
2805 ei->i_disksize = inode->i_size;
2806 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
2807 ei->i_block_group = iloc.block_group;
2808 /*
2809 * NOTE! The in-memory inode i_data array is in little-endian order
2810 * even on big-endian machines: we do NOT byteswap the block numbers!
2811 */
2812 for (block = 0; block < EXT3_N_BLOCKS; block++)
2813 ei->i_data[block] = raw_inode->i_block[block];
2814 INIT_LIST_HEAD(&ei->i_orphan);
2815
2816 if (inode->i_ino >= EXT3_FIRST_INO(inode->i_sb) + 1 &&
2817 EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) {
2818 /*
2819 * When mke2fs creates big inodes it does not zero out
2820 * the unused bytes above EXT3_GOOD_OLD_INODE_SIZE,
2821 * so ignore those first few inodes.
2822 */
2823 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
2824 if (EXT3_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
Kirill Korotaeve4a10a32007-06-23 17:16:48 -07002825 EXT3_INODE_SIZE(inode->i_sb)) {
2826 brelse (bh);
David Howells473043d2008-02-07 00:15:36 -08002827 ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002828 goto bad_inode;
Kirill Korotaeve4a10a32007-06-23 17:16:48 -07002829 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002830 if (ei->i_extra_isize == 0) {
2831 /* The extra space is currently unused. Use it. */
2832 ei->i_extra_isize = sizeof(struct ext3_inode) -
2833 EXT3_GOOD_OLD_INODE_SIZE;
2834 } else {
2835 __le32 *magic = (void *)raw_inode +
2836 EXT3_GOOD_OLD_INODE_SIZE +
2837 ei->i_extra_isize;
2838 if (*magic == cpu_to_le32(EXT3_XATTR_MAGIC))
2839 ei->i_state |= EXT3_STATE_XATTR;
2840 }
2841 } else
2842 ei->i_extra_isize = 0;
2843
2844 if (S_ISREG(inode->i_mode)) {
2845 inode->i_op = &ext3_file_inode_operations;
2846 inode->i_fop = &ext3_file_operations;
2847 ext3_set_aops(inode);
2848 } else if (S_ISDIR(inode->i_mode)) {
2849 inode->i_op = &ext3_dir_inode_operations;
2850 inode->i_fop = &ext3_dir_operations;
2851 } else if (S_ISLNK(inode->i_mode)) {
Duane Griffinb5ed3112008-12-19 20:47:14 +00002852 if (ext3_inode_is_fast_symlink(inode)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002853 inode->i_op = &ext3_fast_symlink_inode_operations;
Duane Griffinb5ed3112008-12-19 20:47:14 +00002854 nd_terminate_link(ei->i_data, inode->i_size,
2855 sizeof(ei->i_data) - 1);
2856 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002857 inode->i_op = &ext3_symlink_inode_operations;
2858 ext3_set_aops(inode);
2859 }
2860 } else {
2861 inode->i_op = &ext3_special_inode_operations;
2862 if (raw_inode->i_block[0])
2863 init_special_inode(inode, inode->i_mode,
2864 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002865 else
Linus Torvalds1da177e2005-04-16 15:20:36 -07002866 init_special_inode(inode, inode->i_mode,
2867 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
2868 }
2869 brelse (iloc.bh);
2870 ext3_set_inode_flags(inode);
David Howells473043d2008-02-07 00:15:36 -08002871 unlock_new_inode(inode);
2872 return inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002873
2874bad_inode:
David Howells473043d2008-02-07 00:15:36 -08002875 iget_failed(inode);
2876 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002877}
2878
2879/*
2880 * Post the struct inode info into an on-disk inode location in the
2881 * buffer-cache. This gobbles the caller's reference to the
2882 * buffer_head in the inode location struct.
2883 *
2884 * The caller must have write access to iloc->bh.
2885 */
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002886static int ext3_do_update_inode(handle_t *handle,
2887 struct inode *inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002888 struct ext3_iloc *iloc)
2889{
2890 struct ext3_inode *raw_inode = ext3_raw_inode(iloc);
2891 struct ext3_inode_info *ei = EXT3_I(inode);
2892 struct buffer_head *bh = iloc->bh;
2893 int err = 0, rc, block;
2894
2895 /* For fields not not tracking in the in-memory inode,
2896 * initialise them to zero for new inodes. */
2897 if (ei->i_state & EXT3_STATE_NEW)
2898 memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
2899
Jan Kara28be5ab2007-05-08 00:30:33 -07002900 ext3_get_inode_flags(ei);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002901 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
2902 if(!(test_opt(inode->i_sb, NO_UID32))) {
2903 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
2904 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
2905/*
2906 * Fix up interoperability with old kernels. Otherwise, old inodes get
2907 * re-used with the upper 16 bits of the uid/gid intact
2908 */
2909 if(!ei->i_dtime) {
2910 raw_inode->i_uid_high =
2911 cpu_to_le16(high_16_bits(inode->i_uid));
2912 raw_inode->i_gid_high =
2913 cpu_to_le16(high_16_bits(inode->i_gid));
2914 } else {
2915 raw_inode->i_uid_high = 0;
2916 raw_inode->i_gid_high = 0;
2917 }
2918 } else {
2919 raw_inode->i_uid_low =
2920 cpu_to_le16(fs_high2lowuid(inode->i_uid));
2921 raw_inode->i_gid_low =
2922 cpu_to_le16(fs_high2lowgid(inode->i_gid));
2923 raw_inode->i_uid_high = 0;
2924 raw_inode->i_gid_high = 0;
2925 }
2926 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
2927 raw_inode->i_size = cpu_to_le32(ei->i_disksize);
2928 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
2929 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
2930 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
2931 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
2932 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
2933 raw_inode->i_flags = cpu_to_le32(ei->i_flags);
2934#ifdef EXT3_FRAGMENTS
2935 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
2936 raw_inode->i_frag = ei->i_frag_no;
2937 raw_inode->i_fsize = ei->i_frag_size;
2938#endif
2939 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
2940 if (!S_ISREG(inode->i_mode)) {
2941 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
2942 } else {
2943 raw_inode->i_size_high =
2944 cpu_to_le32(ei->i_disksize >> 32);
2945 if (ei->i_disksize > 0x7fffffffULL) {
2946 struct super_block *sb = inode->i_sb;
2947 if (!EXT3_HAS_RO_COMPAT_FEATURE(sb,
2948 EXT3_FEATURE_RO_COMPAT_LARGE_FILE) ||
2949 EXT3_SB(sb)->s_es->s_rev_level ==
2950 cpu_to_le32(EXT3_GOOD_OLD_REV)) {
2951 /* If this is the first large file
2952 * created, add a flag to the superblock.
2953 */
2954 err = ext3_journal_get_write_access(handle,
2955 EXT3_SB(sb)->s_sbh);
2956 if (err)
2957 goto out_brelse;
2958 ext3_update_dynamic_rev(sb);
2959 EXT3_SET_RO_COMPAT_FEATURE(sb,
2960 EXT3_FEATURE_RO_COMPAT_LARGE_FILE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002961 handle->h_sync = 1;
2962 err = ext3_journal_dirty_metadata(handle,
2963 EXT3_SB(sb)->s_sbh);
2964 }
2965 }
2966 }
2967 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
2968 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
2969 if (old_valid_dev(inode->i_rdev)) {
2970 raw_inode->i_block[0] =
2971 cpu_to_le32(old_encode_dev(inode->i_rdev));
2972 raw_inode->i_block[1] = 0;
2973 } else {
2974 raw_inode->i_block[0] = 0;
2975 raw_inode->i_block[1] =
2976 cpu_to_le32(new_encode_dev(inode->i_rdev));
2977 raw_inode->i_block[2] = 0;
2978 }
2979 } else for (block = 0; block < EXT3_N_BLOCKS; block++)
2980 raw_inode->i_block[block] = ei->i_data[block];
2981
Andreas Gruenbacherff87b372005-07-07 17:57:00 -07002982 if (ei->i_extra_isize)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002983 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
2984
2985 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
2986 rc = ext3_journal_dirty_metadata(handle, bh);
2987 if (!err)
2988 err = rc;
2989 ei->i_state &= ~EXT3_STATE_NEW;
2990
2991out_brelse:
2992 brelse (bh);
2993 ext3_std_error(inode->i_sb, err);
2994 return err;
2995}
2996
2997/*
2998 * ext3_write_inode()
2999 *
3000 * We are called from a few places:
3001 *
3002 * - Within generic_file_write() for O_SYNC files.
3003 * Here, there will be no transaction running. We wait for any running
3004 * trasnaction to commit.
3005 *
3006 * - Within sys_sync(), kupdate and such.
3007 * We wait on commit, if tol to.
3008 *
3009 * - Within prune_icache() (PF_MEMALLOC == true)
3010 * Here we simply return. We can't afford to block kswapd on the
3011 * journal commit.
3012 *
3013 * In all cases it is actually safe for us to return without doing anything,
3014 * because the inode has been copied into a raw inode buffer in
3015 * ext3_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
3016 * knfsd.
3017 *
3018 * Note that we are absolutely dependent upon all inode dirtiers doing the
3019 * right thing: they *must* call mark_inode_dirty() after dirtying info in
3020 * which we are interested.
3021 *
3022 * It would be a bug for them to not do this. The code:
3023 *
3024 * mark_inode_dirty(inode)
3025 * stuff();
3026 * inode->i_size = expr;
3027 *
3028 * is in error because a kswapd-driven write_inode() could occur while
3029 * `stuff()' is running, and the new i_size will be lost. Plus the inode
3030 * will no longer be on the superblock's dirty inode list.
3031 */
3032int ext3_write_inode(struct inode *inode, int wait)
3033{
3034 if (current->flags & PF_MEMALLOC)
3035 return 0;
3036
3037 if (ext3_journal_current_handle()) {
Jose R. Santos9ad163a2007-10-18 23:39:23 -07003038 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07003039 dump_stack();
3040 return -EIO;
3041 }
3042
3043 if (!wait)
3044 return 0;
3045
3046 return ext3_force_commit(inode->i_sb);
3047}
3048
3049/*
3050 * ext3_setattr()
3051 *
3052 * Called from notify_change.
3053 *
3054 * We want to trap VFS attempts to truncate the file as soon as
3055 * possible. In particular, we want to make sure that when the VFS
3056 * shrinks i_size, we put the inode on the orphan list and modify
3057 * i_disksize immediately, so that during the subsequent flushing of
3058 * dirty pages and freeing of disk blocks, we can guarantee that any
3059 * commit will leave the blocks being flushed in an unused state on
3060 * disk. (On recovery, the inode will get truncated and the blocks will
3061 * be freed, so we have a strong guarantee that no future commit will
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003062 * leave these blocks visible to the user.)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003063 *
3064 * Called with inode->sem down.
3065 */
3066int ext3_setattr(struct dentry *dentry, struct iattr *attr)
3067{
3068 struct inode *inode = dentry->d_inode;
3069 int error, rc = 0;
3070 const unsigned int ia_valid = attr->ia_valid;
3071
3072 error = inode_change_ok(inode, attr);
3073 if (error)
3074 return error;
3075
3076 if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
3077 (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
3078 handle_t *handle;
3079
3080 /* (user+group)*(old+new) structure, inode write (sb,
3081 * inode block, ? - but truncate inode update has it) */
Jan Kara1f545872005-06-23 22:01:04 -07003082 handle = ext3_journal_start(inode, 2*(EXT3_QUOTA_INIT_BLOCKS(inode->i_sb)+
3083 EXT3_QUOTA_DEL_BLOCKS(inode->i_sb))+3);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003084 if (IS_ERR(handle)) {
3085 error = PTR_ERR(handle);
3086 goto err_out;
3087 }
Jan Kara81a05222009-01-26 16:58:01 +01003088 error = vfs_dq_transfer(inode, attr) ? -EDQUOT : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003089 if (error) {
3090 ext3_journal_stop(handle);
3091 return error;
3092 }
3093 /* Update corresponding info in inode so that everything is in
3094 * one transaction */
3095 if (attr->ia_valid & ATTR_UID)
3096 inode->i_uid = attr->ia_uid;
3097 if (attr->ia_valid & ATTR_GID)
3098 inode->i_gid = attr->ia_gid;
3099 error = ext3_mark_inode_dirty(handle, inode);
3100 ext3_journal_stop(handle);
3101 }
3102
3103 if (S_ISREG(inode->i_mode) &&
3104 attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
3105 handle_t *handle;
3106
3107 handle = ext3_journal_start(inode, 3);
3108 if (IS_ERR(handle)) {
3109 error = PTR_ERR(handle);
3110 goto err_out;
3111 }
3112
3113 error = ext3_orphan_add(handle, inode);
3114 EXT3_I(inode)->i_disksize = attr->ia_size;
3115 rc = ext3_mark_inode_dirty(handle, inode);
3116 if (!error)
3117 error = rc;
3118 ext3_journal_stop(handle);
3119 }
3120
3121 rc = inode_setattr(inode, attr);
3122
Linus Torvalds1da177e2005-04-16 15:20:36 -07003123 if (!rc && (ia_valid & ATTR_MODE))
3124 rc = ext3_acl_chmod(inode);
3125
3126err_out:
3127 ext3_std_error(inode->i_sb, error);
3128 if (!error)
3129 error = rc;
3130 return error;
3131}
3132
3133
3134/*
Andrew Mortond6859bf2006-03-26 01:38:03 -08003135 * How many blocks doth make a writepage()?
Linus Torvalds1da177e2005-04-16 15:20:36 -07003136 *
3137 * With N blocks per page, it may be:
3138 * N data blocks
3139 * 2 indirect block
3140 * 2 dindirect
3141 * 1 tindirect
3142 * N+5 bitmap blocks (from the above)
3143 * N+5 group descriptor summary blocks
3144 * 1 inode block
3145 * 1 superblock.
3146 * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quote files
3147 *
3148 * 3 * (N + 5) + 2 + 2 * EXT3_SINGLEDATA_TRANS_BLOCKS
3149 *
3150 * With ordered or writeback data it's the same, less the N data blocks.
3151 *
3152 * If the inode's direct blocks can hold an integral number of pages then a
3153 * page cannot straddle two indirect blocks, and we can only touch one indirect
3154 * and dindirect block, and the "5" above becomes "3".
3155 *
3156 * This still overestimates under most circumstances. If we were to pass the
3157 * start and end offsets in here as well we could do block_to_path() on each
3158 * block and work out the exact number of indirects which are touched. Pah.
3159 */
3160
3161static int ext3_writepage_trans_blocks(struct inode *inode)
3162{
3163 int bpp = ext3_journal_blocks_per_page(inode);
3164 int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3;
3165 int ret;
3166
3167 if (ext3_should_journal_data(inode))
3168 ret = 3 * (bpp + indirects) + 2;
3169 else
3170 ret = 2 * (bpp + indirects) + 2;
3171
3172#ifdef CONFIG_QUOTA
Jan Kara81a05222009-01-26 16:58:01 +01003173 /* We know that structure was already allocated during vfs_dq_init so
Linus Torvalds1da177e2005-04-16 15:20:36 -07003174 * we will be updating only the data blocks + inodes */
Jan Kara1f545872005-06-23 22:01:04 -07003175 ret += 2*EXT3_QUOTA_TRANS_BLOCKS(inode->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003176#endif
3177
3178 return ret;
3179}
3180
3181/*
3182 * The caller must have previously called ext3_reserve_inode_write().
3183 * Give this, we know that the caller already has write access to iloc->bh.
3184 */
3185int ext3_mark_iloc_dirty(handle_t *handle,
3186 struct inode *inode, struct ext3_iloc *iloc)
3187{
3188 int err = 0;
3189
3190 /* the do_update_inode consumes one bh->b_count */
3191 get_bh(iloc->bh);
3192
3193 /* ext3_do_update_inode() does journal_dirty_metadata */
3194 err = ext3_do_update_inode(handle, inode, iloc);
3195 put_bh(iloc->bh);
3196 return err;
3197}
3198
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003199/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003200 * On success, We end up with an outstanding reference count against
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003201 * iloc->bh. This _must_ be cleaned up later.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003202 */
3203
3204int
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003205ext3_reserve_inode_write(handle_t *handle, struct inode *inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003206 struct ext3_iloc *iloc)
3207{
3208 int err = 0;
3209 if (handle) {
3210 err = ext3_get_inode_loc(inode, iloc);
3211 if (!err) {
3212 BUFFER_TRACE(iloc->bh, "get_write_access");
3213 err = ext3_journal_get_write_access(handle, iloc->bh);
3214 if (err) {
3215 brelse(iloc->bh);
3216 iloc->bh = NULL;
3217 }
3218 }
3219 }
3220 ext3_std_error(inode->i_sb, err);
3221 return err;
3222}
3223
3224/*
Andrew Mortond6859bf2006-03-26 01:38:03 -08003225 * What we do here is to mark the in-core inode as clean with respect to inode
3226 * dirtiness (it may still be data-dirty).
Linus Torvalds1da177e2005-04-16 15:20:36 -07003227 * This means that the in-core inode may be reaped by prune_icache
3228 * without having to perform any I/O. This is a very good thing,
3229 * because *any* task may call prune_icache - even ones which
3230 * have a transaction open against a different journal.
3231 *
3232 * Is this cheating? Not really. Sure, we haven't written the
3233 * inode out, but prune_icache isn't a user-visible syncing function.
3234 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
3235 * we start and wait on commits.
3236 *
3237 * Is this efficient/effective? Well, we're being nice to the system
3238 * by cleaning up our inodes proactively so they can be reaped
3239 * without I/O. But we are potentially leaving up to five seconds'
3240 * worth of inodes floating about which prune_icache wants us to
3241 * write out. One way to fix that would be to get prune_icache()
3242 * to do a write_super() to free up some memory. It has the desired
3243 * effect.
3244 */
3245int ext3_mark_inode_dirty(handle_t *handle, struct inode *inode)
3246{
3247 struct ext3_iloc iloc;
3248 int err;
3249
3250 might_sleep();
3251 err = ext3_reserve_inode_write(handle, inode, &iloc);
3252 if (!err)
3253 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
3254 return err;
3255}
3256
3257/*
Andrew Mortond6859bf2006-03-26 01:38:03 -08003258 * ext3_dirty_inode() is called from __mark_inode_dirty()
Linus Torvalds1da177e2005-04-16 15:20:36 -07003259 *
3260 * We're really interested in the case where a file is being extended.
3261 * i_size has been changed by generic_commit_write() and we thus need
3262 * to include the updated inode in the current transaction.
3263 *
Jan Kara81a05222009-01-26 16:58:01 +01003264 * Also, vfs_dq_alloc_space() will always dirty the inode when blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -07003265 * are allocated to the file.
3266 *
3267 * If the inode is marked synchronous, we don't honour that here - doing
3268 * so would cause a commit on atime updates, which we don't bother doing.
3269 * We handle synchronous inodes at the highest possible level.
3270 */
3271void ext3_dirty_inode(struct inode *inode)
3272{
3273 handle_t *current_handle = ext3_journal_current_handle();
3274 handle_t *handle;
3275
3276 handle = ext3_journal_start(inode, 2);
3277 if (IS_ERR(handle))
3278 goto out;
3279 if (current_handle &&
3280 current_handle->h_transaction != handle->h_transaction) {
3281 /* This task has a transaction open against a different fs */
3282 printk(KERN_EMERG "%s: transactions do not match!\n",
Harvey Harrisone05b6b52008-04-28 02:16:15 -07003283 __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003284 } else {
3285 jbd_debug(5, "marking dirty. outer handle=%p\n",
3286 current_handle);
3287 ext3_mark_inode_dirty(handle, inode);
3288 }
3289 ext3_journal_stop(handle);
3290out:
3291 return;
3292}
3293
Andrew Mortond6859bf2006-03-26 01:38:03 -08003294#if 0
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003295/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003296 * Bind an inode's backing buffer_head into this transaction, to prevent
3297 * it from being flushed to disk early. Unlike
3298 * ext3_reserve_inode_write, this leaves behind no bh reference and
3299 * returns no iloc structure, so the caller needs to repeat the iloc
3300 * lookup to mark the inode dirty later.
3301 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08003302static int ext3_pin_inode(handle_t *handle, struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003303{
3304 struct ext3_iloc iloc;
3305
3306 int err = 0;
3307 if (handle) {
3308 err = ext3_get_inode_loc(inode, &iloc);
3309 if (!err) {
3310 BUFFER_TRACE(iloc.bh, "get_write_access");
3311 err = journal_get_write_access(handle, iloc.bh);
3312 if (!err)
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003313 err = ext3_journal_dirty_metadata(handle,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003314 iloc.bh);
3315 brelse(iloc.bh);
3316 }
3317 }
3318 ext3_std_error(inode->i_sb, err);
3319 return err;
3320}
3321#endif
3322
3323int ext3_change_inode_journal_flag(struct inode *inode, int val)
3324{
3325 journal_t *journal;
3326 handle_t *handle;
3327 int err;
3328
3329 /*
3330 * We have to be very careful here: changing a data block's
3331 * journaling status dynamically is dangerous. If we write a
3332 * data block to the journal, change the status and then delete
3333 * that block, we risk forgetting to revoke the old log record
3334 * from the journal and so a subsequent replay can corrupt data.
3335 * So, first we make sure that the journal is empty and that
3336 * nobody is changing anything.
3337 */
3338
3339 journal = EXT3_JOURNAL(inode);
Dave Hansene3a68e32007-07-15 23:41:14 -07003340 if (is_journal_aborted(journal))
Linus Torvalds1da177e2005-04-16 15:20:36 -07003341 return -EROFS;
3342
3343 journal_lock_updates(journal);
3344 journal_flush(journal);
3345
3346 /*
3347 * OK, there are no updates running now, and all cached data is
3348 * synced to disk. We are now in a completely consistent state
3349 * which doesn't have anything in the journal, and we know that
3350 * no filesystem updates are running, so it is safe to modify
3351 * the inode's in-core data-journaling state flag now.
3352 */
3353
3354 if (val)
3355 EXT3_I(inode)->i_flags |= EXT3_JOURNAL_DATA_FL;
3356 else
3357 EXT3_I(inode)->i_flags &= ~EXT3_JOURNAL_DATA_FL;
3358 ext3_set_aops(inode);
3359
3360 journal_unlock_updates(journal);
3361
3362 /* Finally we can mark the inode as dirty. */
3363
3364 handle = ext3_journal_start(inode, 1);
3365 if (IS_ERR(handle))
3366 return PTR_ERR(handle);
3367
3368 err = ext3_mark_inode_dirty(handle, inode);
3369 handle->h_sync = 1;
3370 ext3_journal_stop(handle);
3371 ext3_std_error(inode->i_sb, err);
3372
3373 return err;
3374}