blob: 354ed3b47b301dc34fb13c0ace2e5123311a9e89 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/ext3/inode.c
3 *
4 * Copyright (C) 1992, 1993, 1994, 1995
5 * Remy Card (card@masi.ibp.fr)
6 * Laboratoire MASI - Institut Blaise Pascal
7 * Universite Pierre et Marie Curie (Paris VI)
8 *
9 * from
10 *
11 * linux/fs/minix/inode.c
12 *
13 * Copyright (C) 1991, 1992 Linus Torvalds
14 *
15 * Goal-directed block allocation by Stephen Tweedie
Dave Kleikampe9ad5622006-09-27 01:49:35 -070016 * (sct@redhat.com), 1993, 1998
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 * Big-endian to little-endian byte-swapping/bitmaps by
18 * David S. Miller (davem@caip.rutgers.edu), 1995
19 * 64-bit file support on 64-bit platforms by Jakub Jelinek
Dave Kleikampe9ad5622006-09-27 01:49:35 -070020 * (jj@sunsite.ms.mff.cuni.cz)
Linus Torvalds1da177e2005-04-16 15:20:36 -070021 *
22 * Assorted race fixes, rewrite of ext3_get_block() by Al Viro, 2000
23 */
24
25#include <linux/module.h>
26#include <linux/fs.h>
27#include <linux/time.h>
28#include <linux/ext3_jbd.h>
29#include <linux/jbd.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <linux/highuid.h>
31#include <linux/pagemap.h>
32#include <linux/quotaops.h>
33#include <linux/string.h>
34#include <linux/buffer_head.h>
35#include <linux/writeback.h>
36#include <linux/mpage.h>
37#include <linux/uio.h>
Jens Axboecaa38fb2006-07-23 01:41:26 +020038#include <linux/bio.h>
Josef Bacik68c9d702008-10-03 17:32:43 -040039#include <linux/fiemap.h>
Duane Griffinb5ed3112008-12-19 20:47:14 +000040#include <linux/namei.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#include "xattr.h"
42#include "acl.h"
43
44static int ext3_writepage_trans_blocks(struct inode *inode);
45
46/*
47 * Test whether an inode is a fast symlink.
48 */
Andrew Mortond6859bf2006-03-26 01:38:03 -080049static int ext3_inode_is_fast_symlink(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -070050{
51 int ea_blocks = EXT3_I(inode)->i_file_acl ?
52 (inode->i_sb->s_blocksize >> 9) : 0;
53
Andrew Mortond6859bf2006-03-26 01:38:03 -080054 return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070055}
56
Andrew Mortond6859bf2006-03-26 01:38:03 -080057/*
58 * The ext3 forget function must perform a revoke if we are freeing data
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 * which has been journaled. Metadata (eg. indirect blocks) must be
Mingming Caoae6ddcc2006-09-27 01:49:27 -070060 * revoked in all cases.
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 *
62 * "bh" may be NULL: a metadata block may have been freed from memory
63 * but there may still be a record of it in the journal, and that record
64 * still needs to be revoked.
65 */
Andrew Mortond6859bf2006-03-26 01:38:03 -080066int ext3_forget(handle_t *handle, int is_metadata, struct inode *inode,
Mingming Cao1c2bf372006-06-25 05:48:06 -070067 struct buffer_head *bh, ext3_fsblk_t blocknr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070068{
69 int err;
70
71 might_sleep();
72
73 BUFFER_TRACE(bh, "enter");
74
75 jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
76 "data mode %lx\n",
77 bh, is_metadata, inode->i_mode,
78 test_opt(inode->i_sb, DATA_FLAGS));
79
80 /* Never use the revoke function if we are doing full data
81 * journaling: there is no need to, and a V1 superblock won't
82 * support it. Otherwise, only skip the revoke on un-journaled
83 * data blocks. */
84
85 if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ||
86 (!is_metadata && !ext3_should_journal_data(inode))) {
87 if (bh) {
88 BUFFER_TRACE(bh, "call journal_forget");
89 return ext3_journal_forget(handle, bh);
90 }
91 return 0;
92 }
93
94 /*
95 * data!=journal && (is_metadata || should_journal_data(inode))
96 */
97 BUFFER_TRACE(bh, "call ext3_journal_revoke");
98 err = ext3_journal_revoke(handle, blocknr, bh);
99 if (err)
Harvey Harrisone05b6b52008-04-28 02:16:15 -0700100 ext3_abort(inode->i_sb, __func__,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101 "error %d when attempting revoke", err);
102 BUFFER_TRACE(bh, "exit");
103 return err;
104}
105
106/*
Andrew Mortond6859bf2006-03-26 01:38:03 -0800107 * Work out how many blocks we need to proceed with the next chunk of a
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108 * truncate transaction.
109 */
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700110static unsigned long blocks_for_truncate(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111{
112 unsigned long needed;
113
114 needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
115
116 /* Give ourselves just enough room to cope with inodes in which
117 * i_blocks is corrupt: we've seen disk corruptions in the past
118 * which resulted in random data in an inode which looked enough
119 * like a regular file for ext3 to try to delete it. Things
120 * will go a bit crazy if that happens, but at least we should
121 * try not to panic the whole kernel. */
122 if (needed < 2)
123 needed = 2;
124
125 /* But we need to bound the transaction so we don't overflow the
126 * journal. */
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700127 if (needed > EXT3_MAX_TRANS_DATA)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 needed = EXT3_MAX_TRANS_DATA;
129
Jan Kara1f545872005-06-23 22:01:04 -0700130 return EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131}
132
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700133/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 * Truncate transactions can be complex and absolutely huge. So we need to
135 * be able to restart the transaction at a conventient checkpoint to make
136 * sure we don't overflow the journal.
137 *
138 * start_transaction gets us a new handle for a truncate transaction,
139 * and extend_transaction tries to extend the existing one a bit. If
140 * extend fails, we need to propagate the failure up and restart the
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700141 * transaction in the top-level truncate loop. --sct
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 */
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700143static handle_t *start_transaction(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144{
145 handle_t *result;
146
147 result = ext3_journal_start(inode, blocks_for_truncate(inode));
148 if (!IS_ERR(result))
149 return result;
150
151 ext3_std_error(inode->i_sb, PTR_ERR(result));
152 return result;
153}
154
155/*
156 * Try to extend this transaction for the purposes of truncation.
157 *
158 * Returns 0 if we managed to create more room. If we can't create more
159 * room, and the transaction must be restarted we return 1.
160 */
161static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
162{
163 if (handle->h_buffer_credits > EXT3_RESERVE_TRANS_BLOCKS)
164 return 0;
165 if (!ext3_journal_extend(handle, blocks_for_truncate(inode)))
166 return 0;
167 return 1;
168}
169
170/*
171 * Restart the transaction associated with *handle. This does a commit,
172 * so before we call here everything must be consistently dirtied against
173 * this transaction.
174 */
Jan Kara00171d32009-08-11 19:06:10 +0200175static int truncate_restart_transaction(handle_t *handle, struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176{
Jan Kara00171d32009-08-11 19:06:10 +0200177 int ret;
178
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 jbd_debug(2, "restarting handle %p\n", handle);
Jan Kara00171d32009-08-11 19:06:10 +0200180 /*
181 * Drop truncate_mutex to avoid deadlock with ext3_get_blocks_handle
182 * At this moment, get_block can be called only for blocks inside
183 * i_size since page cache has been already dropped and writes are
184 * blocked by i_mutex. So we can safely drop the truncate_mutex.
185 */
186 mutex_unlock(&EXT3_I(inode)->truncate_mutex);
187 ret = ext3_journal_restart(handle, blocks_for_truncate(inode));
188 mutex_lock(&EXT3_I(inode)->truncate_mutex);
189 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700190}
191
192/*
193 * Called at the last iput() if i_nlink is zero.
194 */
195void ext3_delete_inode (struct inode * inode)
196{
197 handle_t *handle;
198
Mark Fashehfef26652005-09-09 13:01:31 -0700199 truncate_inode_pages(&inode->i_data, 0);
200
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201 if (is_bad_inode(inode))
202 goto no_delete;
203
204 handle = start_transaction(inode);
205 if (IS_ERR(handle)) {
Andrew Mortond6859bf2006-03-26 01:38:03 -0800206 /*
207 * If we're going to skip the normal cleanup, we still need to
208 * make sure that the in-core orphan linked list is properly
209 * cleaned up.
210 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 ext3_orphan_del(NULL, inode);
212 goto no_delete;
213 }
214
215 if (IS_SYNC(inode))
216 handle->h_sync = 1;
217 inode->i_size = 0;
218 if (inode->i_blocks)
219 ext3_truncate(inode);
220 /*
221 * Kill off the orphan record which ext3_truncate created.
222 * AKPM: I think this can be inside the above `if'.
223 * Note that ext3_orphan_del() has to be able to cope with the
224 * deletion of a non-existent orphan - this is because we don't
225 * know if ext3_truncate() actually created an orphan record.
226 * (Well, we could do this if we need to, but heck - it works)
227 */
228 ext3_orphan_del(handle, inode);
229 EXT3_I(inode)->i_dtime = get_seconds();
230
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700231 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 * One subtle ordering requirement: if anything has gone wrong
233 * (transaction abort, IO errors, whatever), then we can still
234 * do these next steps (the fs will already have been marked as
235 * having errors), but we can't free the inode if the mark_dirty
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700236 * fails.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 */
238 if (ext3_mark_inode_dirty(handle, inode))
239 /* If that failed, just do the required in-core inode clear. */
240 clear_inode(inode);
241 else
242 ext3_free_inode(handle, inode);
243 ext3_journal_stop(handle);
244 return;
245no_delete:
246 clear_inode(inode); /* We must guarantee clearing of inode... */
247}
248
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249typedef struct {
250 __le32 *p;
251 __le32 key;
252 struct buffer_head *bh;
253} Indirect;
254
255static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
256{
257 p->key = *(p->p = v);
258 p->bh = bh;
259}
260
Andrew Mortond6859bf2006-03-26 01:38:03 -0800261static int verify_chain(Indirect *from, Indirect *to)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262{
263 while (from <= to && from->key == *from->p)
264 from++;
265 return (from > to);
266}
267
268/**
269 * ext3_block_to_path - parse the block number into array of offsets
270 * @inode: inode in question (we are only interested in its superblock)
271 * @i_block: block number to be parsed
272 * @offsets: array to store the offsets in
273 * @boundary: set this non-zero if the referred-to block is likely to be
274 * followed (on disk) by an indirect block.
275 *
276 * To store the locations of file's data ext3 uses a data structure common
277 * for UNIX filesystems - tree of pointers anchored in the inode, with
278 * data blocks at leaves and indirect blocks in intermediate nodes.
279 * This function translates the block number into path in that tree -
280 * return value is the path length and @offsets[n] is the offset of
281 * pointer to (n+1)th node in the nth one. If @block is out of range
282 * (negative or too large) warning is printed and zero returned.
283 *
284 * Note: function doesn't find node addresses, so no IO is needed. All
285 * we need to know is the capacity of indirect blocks (taken from the
286 * inode->i_sb).
287 */
288
289/*
290 * Portability note: the last comparison (check that we fit into triple
291 * indirect block) is spelled differently, because otherwise on an
292 * architecture with 32-bit longs and 8Kb pages we might get into trouble
293 * if our filesystem had 8Kb blocks. We might use long long, but that would
294 * kill us on x86. Oh, well, at least the sign propagation does not matter -
295 * i_block would have to be negative in the very beginning, so we would not
296 * get there at all.
297 */
298
299static int ext3_block_to_path(struct inode *inode,
300 long i_block, int offsets[4], int *boundary)
301{
302 int ptrs = EXT3_ADDR_PER_BLOCK(inode->i_sb);
303 int ptrs_bits = EXT3_ADDR_PER_BLOCK_BITS(inode->i_sb);
304 const long direct_blocks = EXT3_NDIR_BLOCKS,
305 indirect_blocks = ptrs,
306 double_blocks = (1 << (ptrs_bits * 2));
307 int n = 0;
308 int final = 0;
309
310 if (i_block < 0) {
311 ext3_warning (inode->i_sb, "ext3_block_to_path", "block < 0");
312 } else if (i_block < direct_blocks) {
313 offsets[n++] = i_block;
314 final = direct_blocks;
315 } else if ( (i_block -= direct_blocks) < indirect_blocks) {
316 offsets[n++] = EXT3_IND_BLOCK;
317 offsets[n++] = i_block;
318 final = ptrs;
319 } else if ((i_block -= indirect_blocks) < double_blocks) {
320 offsets[n++] = EXT3_DIND_BLOCK;
321 offsets[n++] = i_block >> ptrs_bits;
322 offsets[n++] = i_block & (ptrs - 1);
323 final = ptrs;
324 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
325 offsets[n++] = EXT3_TIND_BLOCK;
326 offsets[n++] = i_block >> (ptrs_bits * 2);
327 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
328 offsets[n++] = i_block & (ptrs - 1);
329 final = ptrs;
330 } else {
Andrew Mortond6859bf2006-03-26 01:38:03 -0800331 ext3_warning(inode->i_sb, "ext3_block_to_path", "block > big");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 }
333 if (boundary)
Mingming Cao89747d32006-03-26 01:37:55 -0800334 *boundary = final - 1 - (i_block & (ptrs - 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 return n;
336}
337
338/**
339 * ext3_get_branch - read the chain of indirect blocks leading to data
340 * @inode: inode in question
341 * @depth: depth of the chain (1 - direct pointer, etc.)
342 * @offsets: offsets of pointers in inode/indirect blocks
343 * @chain: place to store the result
344 * @err: here we store the error value
345 *
346 * Function fills the array of triples <key, p, bh> and returns %NULL
347 * if everything went OK or the pointer to the last filled triple
348 * (incomplete one) otherwise. Upon the return chain[i].key contains
349 * the number of (i+1)-th block in the chain (as it is stored in memory,
350 * i.e. little-endian 32-bit), chain[i].p contains the address of that
351 * number (it points into struct inode for i==0 and into the bh->b_data
352 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
353 * block for i>0 and NULL for i==0. In other words, it holds the block
354 * numbers of the chain, addresses they were taken from (and where we can
355 * verify that chain did not change) and buffer_heads hosting these
356 * numbers.
357 *
358 * Function stops when it stumbles upon zero pointer (absent block)
359 * (pointer to last triple returned, *@err == 0)
360 * or when it gets an IO error reading an indirect block
361 * (ditto, *@err == -EIO)
362 * or when it notices that chain had been changed while it was reading
363 * (ditto, *@err == -EAGAIN)
364 * or when it reads all @depth-1 indirect blocks successfully and finds
365 * the whole chain, all way to the data (returns %NULL, *err == 0).
366 */
367static Indirect *ext3_get_branch(struct inode *inode, int depth, int *offsets,
368 Indirect chain[4], int *err)
369{
370 struct super_block *sb = inode->i_sb;
371 Indirect *p = chain;
372 struct buffer_head *bh;
373
374 *err = 0;
375 /* i_data is not going away, no lock needed */
376 add_chain (chain, NULL, EXT3_I(inode)->i_data + *offsets);
377 if (!p->key)
378 goto no_block;
379 while (--depth) {
380 bh = sb_bread(sb, le32_to_cpu(p->key));
381 if (!bh)
382 goto failure;
383 /* Reader: pointers */
384 if (!verify_chain(chain, p))
385 goto changed;
386 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
387 /* Reader: end */
388 if (!p->key)
389 goto no_block;
390 }
391 return NULL;
392
393changed:
394 brelse(bh);
395 *err = -EAGAIN;
396 goto no_block;
397failure:
398 *err = -EIO;
399no_block:
400 return p;
401}
402
403/**
404 * ext3_find_near - find a place for allocation with sufficient locality
405 * @inode: owner
406 * @ind: descriptor of indirect block.
407 *
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000408 * This function returns the preferred place for block allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 * It is used when heuristic for sequential allocation fails.
410 * Rules are:
411 * + if there is a block to the left of our position - allocate near it.
412 * + if pointer will live in indirect block - allocate near that block.
413 * + if pointer will live in inode - allocate in the same
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700414 * cylinder group.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 *
416 * In the latter case we colour the starting block by the callers PID to
417 * prevent it from clashing with concurrent allocations for a different inode
418 * in the same block group. The PID is used here so that functionally related
419 * files will be close-by on-disk.
420 *
421 * Caller must make sure that @ind is valid and will stay that way.
422 */
Mingming Cao43d23f92006-06-25 05:48:07 -0700423static ext3_fsblk_t ext3_find_near(struct inode *inode, Indirect *ind)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424{
425 struct ext3_inode_info *ei = EXT3_I(inode);
426 __le32 *start = ind->bh ? (__le32*) ind->bh->b_data : ei->i_data;
427 __le32 *p;
Mingming Cao43d23f92006-06-25 05:48:07 -0700428 ext3_fsblk_t bg_start;
429 ext3_grpblk_t colour;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430
431 /* Try to find previous block */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800432 for (p = ind->p - 1; p >= start; p--) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 if (*p)
434 return le32_to_cpu(*p);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800435 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700436
437 /* No such thing, so let's try location of indirect block */
438 if (ind->bh)
439 return ind->bh->b_blocknr;
440
441 /*
Andrew Mortond6859bf2006-03-26 01:38:03 -0800442 * It is going to be referred to from the inode itself? OK, just put it
443 * into the same cylinder group then.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 */
Mingming Cao43d23f92006-06-25 05:48:07 -0700445 bg_start = ext3_group_first_block_no(inode->i_sb, ei->i_block_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446 colour = (current->pid % 16) *
447 (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
448 return bg_start + colour;
449}
450
451/**
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000452 * ext3_find_goal - find a preferred place for allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 * @inode: owner
454 * @block: block we want
Linus Torvalds1da177e2005-04-16 15:20:36 -0700455 * @partial: pointer to the last triple within a chain
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 *
Benoit Boissinot1cc8dcf2008-04-21 22:45:55 +0000457 * Normally this function find the preferred place for block allocation,
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800458 * returns it.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 */
460
Mingming Cao43d23f92006-06-25 05:48:07 -0700461static ext3_fsblk_t ext3_find_goal(struct inode *inode, long block,
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800462 Indirect *partial)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463{
Andrew Mortond6859bf2006-03-26 01:38:03 -0800464 struct ext3_block_alloc_info *block_i;
465
466 block_i = EXT3_I(inode)->i_block_alloc_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467
468 /*
469 * try the heuristic for sequential allocation,
470 * failing that at least try to get decent locality.
471 */
472 if (block_i && (block == block_i->last_alloc_logical_block + 1)
473 && (block_i->last_alloc_physical_block != 0)) {
Mingming Caofe55c452005-05-01 08:59:20 -0700474 return block_i->last_alloc_physical_block + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 }
476
Mingming Caofe55c452005-05-01 08:59:20 -0700477 return ext3_find_near(inode, partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478}
Andrew Mortond6859bf2006-03-26 01:38:03 -0800479
Mingming Caob47b2472006-03-26 01:37:56 -0800480/**
481 * ext3_blks_to_allocate: Look up the block map and count the number
482 * of direct blocks need to be allocated for the given branch.
483 *
Dave Kleikampe9ad5622006-09-27 01:49:35 -0700484 * @branch: chain of indirect blocks
Mingming Caob47b2472006-03-26 01:37:56 -0800485 * @k: number of blocks need for indirect blocks
486 * @blks: number of data blocks to be mapped.
487 * @blocks_to_boundary: the offset in the indirect block
488 *
489 * return the total number of blocks to be allocate, including the
490 * direct and indirect blocks.
491 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800492static int ext3_blks_to_allocate(Indirect *branch, int k, unsigned long blks,
Mingming Caob47b2472006-03-26 01:37:56 -0800493 int blocks_to_boundary)
494{
495 unsigned long count = 0;
496
497 /*
498 * Simple case, [t,d]Indirect block(s) has not allocated yet
499 * then it's clear blocks on that path have not allocated
500 */
501 if (k > 0) {
Andrew Mortond6859bf2006-03-26 01:38:03 -0800502 /* right now we don't handle cross boundary allocation */
Mingming Caob47b2472006-03-26 01:37:56 -0800503 if (blks < blocks_to_boundary + 1)
504 count += blks;
505 else
506 count += blocks_to_boundary + 1;
507 return count;
508 }
509
510 count++;
511 while (count < blks && count <= blocks_to_boundary &&
512 le32_to_cpu(*(branch[0].p + count)) == 0) {
513 count++;
514 }
515 return count;
516}
517
518/**
519 * ext3_alloc_blocks: multiple allocate blocks needed for a branch
520 * @indirect_blks: the number of blocks need to allocate for indirect
521 * blocks
522 *
523 * @new_blocks: on return it will store the new block numbers for
524 * the indirect blocks(if needed) and the first direct block,
525 * @blks: on return it will store the total number of allocated
526 * direct blocks
527 */
528static int ext3_alloc_blocks(handle_t *handle, struct inode *inode,
Mingming Cao43d23f92006-06-25 05:48:07 -0700529 ext3_fsblk_t goal, int indirect_blks, int blks,
530 ext3_fsblk_t new_blocks[4], int *err)
Mingming Caob47b2472006-03-26 01:37:56 -0800531{
532 int target, i;
533 unsigned long count = 0;
534 int index = 0;
Mingming Cao43d23f92006-06-25 05:48:07 -0700535 ext3_fsblk_t current_block = 0;
Mingming Caob47b2472006-03-26 01:37:56 -0800536 int ret = 0;
537
538 /*
539 * Here we try to allocate the requested multiple blocks at once,
540 * on a best-effort basis.
541 * To build a branch, we should allocate blocks for
542 * the indirect blocks(if not allocated yet), and at least
543 * the first direct block of this branch. That's the
544 * minimum number of blocks need to allocate(required)
545 */
546 target = blks + indirect_blks;
547
548 while (1) {
549 count = target;
550 /* allocating blocks for indirect blocks and direct blocks */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800551 current_block = ext3_new_blocks(handle,inode,goal,&count,err);
Mingming Caob47b2472006-03-26 01:37:56 -0800552 if (*err)
553 goto failed_out;
554
555 target -= count;
556 /* allocate blocks for indirect blocks */
557 while (index < indirect_blks && count) {
558 new_blocks[index++] = current_block++;
559 count--;
560 }
561
562 if (count > 0)
563 break;
564 }
565
566 /* save the new block number for the first direct block */
567 new_blocks[index] = current_block;
568
569 /* total number of blocks allocated for direct blocks */
570 ret = count;
571 *err = 0;
572 return ret;
573failed_out:
574 for (i = 0; i <index; i++)
575 ext3_free_blocks(handle, inode, new_blocks[i], 1);
576 return ret;
577}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700578
579/**
580 * ext3_alloc_branch - allocate and set up a chain of blocks.
581 * @inode: owner
Mingming Caob47b2472006-03-26 01:37:56 -0800582 * @indirect_blks: number of allocated indirect blocks
583 * @blks: number of allocated direct blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 * @offsets: offsets (in the blocks) to store the pointers to next.
585 * @branch: place to store the chain in.
586 *
Mingming Caob47b2472006-03-26 01:37:56 -0800587 * This function allocates blocks, zeroes out all but the last one,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588 * links them into chain and (if we are synchronous) writes them to disk.
589 * In other words, it prepares a branch that can be spliced onto the
590 * inode. It stores the information about that chain in the branch[], in
591 * the same format as ext3_get_branch() would do. We are calling it after
592 * we had read the existing part of chain and partial points to the last
593 * triple of that (one with zero ->key). Upon the exit we have the same
Glauber de Oliveira Costa5b116872005-10-30 15:02:48 -0800594 * picture as after the successful ext3_get_block(), except that in one
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 * place chain is disconnected - *branch->p is still zero (we did not
596 * set the last link), but branch->key contains the number that should
597 * be placed into *branch->p to fill that gap.
598 *
599 * If allocation fails we free all blocks we've allocated (and forget
600 * their buffer_heads) and return the error value the from failed
601 * ext3_alloc_block() (normally -ENOSPC). Otherwise we set the chain
602 * as described above and return 0.
603 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
Mingming Cao43d23f92006-06-25 05:48:07 -0700605 int indirect_blks, int *blks, ext3_fsblk_t goal,
Mingming Caob47b2472006-03-26 01:37:56 -0800606 int *offsets, Indirect *branch)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607{
608 int blocksize = inode->i_sb->s_blocksize;
Mingming Caob47b2472006-03-26 01:37:56 -0800609 int i, n = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 int err = 0;
Mingming Caob47b2472006-03-26 01:37:56 -0800611 struct buffer_head *bh;
612 int num;
Mingming Cao43d23f92006-06-25 05:48:07 -0700613 ext3_fsblk_t new_blocks[4];
614 ext3_fsblk_t current_block;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615
Mingming Caob47b2472006-03-26 01:37:56 -0800616 num = ext3_alloc_blocks(handle, inode, goal, indirect_blks,
617 *blks, new_blocks, &err);
618 if (err)
619 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620
Mingming Caob47b2472006-03-26 01:37:56 -0800621 branch[0].key = cpu_to_le32(new_blocks[0]);
622 /*
623 * metadata blocks and data blocks are allocated.
624 */
625 for (n = 1; n <= indirect_blks; n++) {
626 /*
627 * Get buffer_head for parent block, zero it out
628 * and set the pointer to new one, then send
629 * parent to disk.
630 */
631 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
632 branch[n].bh = bh;
633 lock_buffer(bh);
634 BUFFER_TRACE(bh, "call get_create_access");
635 err = ext3_journal_get_create_access(handle, bh);
636 if (err) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 unlock_buffer(bh);
Mingming Caob47b2472006-03-26 01:37:56 -0800638 brelse(bh);
639 goto failed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700641
Mingming Caob47b2472006-03-26 01:37:56 -0800642 memset(bh->b_data, 0, blocksize);
643 branch[n].p = (__le32 *) bh->b_data + offsets[n];
644 branch[n].key = cpu_to_le32(new_blocks[n]);
645 *branch[n].p = branch[n].key;
646 if ( n == indirect_blks) {
647 current_block = new_blocks[n];
648 /*
649 * End of chain, update the last new metablock of
650 * the chain to point to the new allocated
651 * data blocks numbers
652 */
653 for (i=1; i < num; i++)
654 *(branch[n].p + i) = cpu_to_le32(++current_block);
655 }
656 BUFFER_TRACE(bh, "marking uptodate");
657 set_buffer_uptodate(bh);
658 unlock_buffer(bh);
659
660 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
661 err = ext3_journal_dirty_metadata(handle, bh);
662 if (err)
663 goto failed;
664 }
665 *blks = num;
666 return err;
667failed:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 /* Allocation failed, free what we already allocated */
Mingming Caob47b2472006-03-26 01:37:56 -0800669 for (i = 1; i <= n ; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670 BUFFER_TRACE(branch[i].bh, "call journal_forget");
671 ext3_journal_forget(handle, branch[i].bh);
672 }
Mingming Caob47b2472006-03-26 01:37:56 -0800673 for (i = 0; i <indirect_blks; i++)
674 ext3_free_blocks(handle, inode, new_blocks[i], 1);
675
676 ext3_free_blocks(handle, inode, new_blocks[i], num);
677
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 return err;
679}
680
681/**
Andrew Mortond6859bf2006-03-26 01:38:03 -0800682 * ext3_splice_branch - splice the allocated branch onto inode.
683 * @inode: owner
684 * @block: (logical) number of block we are adding
685 * @chain: chain of indirect blocks (with a missing link - see
686 * ext3_alloc_branch)
687 * @where: location of missing link
688 * @num: number of indirect blocks we are adding
689 * @blks: number of direct blocks we are adding
Linus Torvalds1da177e2005-04-16 15:20:36 -0700690 *
Andrew Mortond6859bf2006-03-26 01:38:03 -0800691 * This function fills the missing link and does all housekeeping needed in
692 * inode (->i_blocks, etc.). In case of success we end up with the full
693 * chain to new block and return 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800695static int ext3_splice_branch(handle_t *handle, struct inode *inode,
696 long block, Indirect *where, int num, int blks)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700697{
698 int i;
699 int err = 0;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800700 struct ext3_block_alloc_info *block_i;
Mingming Cao43d23f92006-06-25 05:48:07 -0700701 ext3_fsblk_t current_block;
Jan Karafe8bc912009-10-16 19:26:15 +0200702 struct ext3_inode_info *ei = EXT3_I(inode);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800703
Jan Karafe8bc912009-10-16 19:26:15 +0200704 block_i = ei->i_block_alloc_info;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 /*
706 * If we're splicing into a [td]indirect block (as opposed to the
707 * inode) then we need to get write access to the [td]indirect block
708 * before the splice.
709 */
710 if (where->bh) {
711 BUFFER_TRACE(where->bh, "get_write_access");
712 err = ext3_journal_get_write_access(handle, where->bh);
713 if (err)
714 goto err_out;
715 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700716 /* That's it */
717
718 *where->p = where->key;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800719
720 /*
721 * Update the host buffer_head or inode to point to more just allocated
722 * direct blocks blocks
723 */
Mingming Caob47b2472006-03-26 01:37:56 -0800724 if (num == 0 && blks > 1) {
Mingming Cao5dea5172006-05-03 19:55:12 -0700725 current_block = le32_to_cpu(where->key) + 1;
Mingming Caob47b2472006-03-26 01:37:56 -0800726 for (i = 1; i < blks; i++)
727 *(where->p + i ) = cpu_to_le32(current_block++);
728 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729
730 /*
731 * update the most recently allocated logical & physical block
732 * in i_block_alloc_info, to assist find the proper goal block for next
733 * allocation
734 */
735 if (block_i) {
Mingming Caob47b2472006-03-26 01:37:56 -0800736 block_i->last_alloc_logical_block = block + blks - 1;
Andrew Mortond6859bf2006-03-26 01:38:03 -0800737 block_i->last_alloc_physical_block =
Mingming Cao5dea5172006-05-03 19:55:12 -0700738 le32_to_cpu(where[num].key) + blks - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739 }
740
741 /* We are done with atomic stuff, now do the rest of housekeeping */
742
743 inode->i_ctime = CURRENT_TIME_SEC;
744 ext3_mark_inode_dirty(handle, inode);
Jan Karafe8bc912009-10-16 19:26:15 +0200745 /* ext3_mark_inode_dirty already updated i_sync_tid */
746 atomic_set(&ei->i_datasync_tid, handle->h_transaction->t_tid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747
748 /* had we spliced it onto indirect block? */
749 if (where->bh) {
750 /*
Andrew Mortond6859bf2006-03-26 01:38:03 -0800751 * If we spliced it onto an indirect block, we haven't
Linus Torvalds1da177e2005-04-16 15:20:36 -0700752 * altered the inode. Note however that if it is being spliced
753 * onto an indirect block at the very end of the file (the
754 * file is growing) then we *will* alter the inode to reflect
755 * the new i_size. But that is not done here - it is done in
756 * generic_commit_write->__mark_inode_dirty->ext3_dirty_inode.
757 */
758 jbd_debug(5, "splicing indirect only\n");
759 BUFFER_TRACE(where->bh, "call ext3_journal_dirty_metadata");
760 err = ext3_journal_dirty_metadata(handle, where->bh);
Mingming Caoae6ddcc2006-09-27 01:49:27 -0700761 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762 goto err_out;
763 } else {
764 /*
765 * OK, we spliced it into the inode itself on a direct block.
766 * Inode was dirtied above.
767 */
768 jbd_debug(5, "splicing direct\n");
769 }
770 return err;
771
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772err_out:
Mingming Caob47b2472006-03-26 01:37:56 -0800773 for (i = 1; i <= num; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 BUFFER_TRACE(where[i].bh, "call journal_forget");
775 ext3_journal_forget(handle, where[i].bh);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800776 ext3_free_blocks(handle,inode,le32_to_cpu(where[i-1].key),1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 }
Mingming Caob47b2472006-03-26 01:37:56 -0800778 ext3_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks);
779
Linus Torvalds1da177e2005-04-16 15:20:36 -0700780 return err;
781}
782
783/*
784 * Allocation strategy is simple: if we have to allocate something, we will
785 * have to go the whole way to leaf. So let's do it before attaching anything
786 * to tree, set linkage between the newborn blocks, write them if sync is
787 * required, recheck the path, free and repeat if check fails, otherwise
788 * set the last missing link (that will protect us from any truncate-generated
789 * removals - all blocks on the path are immune now) and possibly force the
790 * write on the parent block.
791 * That has a nice additional property: no special recovery from the failed
792 * allocations is needed - we simply release blocks and do not touch anything
793 * reachable from inode.
794 *
Andrew Mortond6859bf2006-03-26 01:38:03 -0800795 * `handle' can be NULL if create == 0.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 *
797 * The BKL may not be held on entry here. Be sure to take it early.
Mingming Cao89747d32006-03-26 01:37:55 -0800798 * return > 0, # of blocks mapped or allocated.
799 * return = 0, if plain lookup failed.
800 * return < 0, error case.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700801 */
Andrew Mortond6859bf2006-03-26 01:38:03 -0800802int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
803 sector_t iblock, unsigned long maxblocks,
804 struct buffer_head *bh_result,
Jan Kara43237b52009-05-20 18:41:58 +0200805 int create)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806{
807 int err = -EIO;
808 int offsets[4];
809 Indirect chain[4];
810 Indirect *partial;
Mingming Cao43d23f92006-06-25 05:48:07 -0700811 ext3_fsblk_t goal;
Mingming Caob47b2472006-03-26 01:37:56 -0800812 int indirect_blks;
Mingming Cao89747d32006-03-26 01:37:55 -0800813 int blocks_to_boundary = 0;
814 int depth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815 struct ext3_inode_info *ei = EXT3_I(inode);
Mingming Cao89747d32006-03-26 01:37:55 -0800816 int count = 0;
Mingming Cao43d23f92006-06-25 05:48:07 -0700817 ext3_fsblk_t first_block = 0;
Mingming Cao89747d32006-03-26 01:37:55 -0800818
Linus Torvalds1da177e2005-04-16 15:20:36 -0700819
820 J_ASSERT(handle != NULL || create == 0);
Andrew Mortond6859bf2006-03-26 01:38:03 -0800821 depth = ext3_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822
823 if (depth == 0)
824 goto out;
825
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
827
828 /* Simplest case - block found, no allocation needed */
829 if (!partial) {
Mingming Cao5dea5172006-05-03 19:55:12 -0700830 first_block = le32_to_cpu(chain[depth - 1].key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700831 clear_buffer_new(bh_result);
Mingming Cao89747d32006-03-26 01:37:55 -0800832 count++;
833 /*map more blocks*/
834 while (count < maxblocks && count <= blocks_to_boundary) {
Mingming Cao43d23f92006-06-25 05:48:07 -0700835 ext3_fsblk_t blk;
Mingming Cao5dea5172006-05-03 19:55:12 -0700836
Jan Karae8ef7aa2009-06-17 16:26:23 -0700837 if (!verify_chain(chain, chain + depth - 1)) {
Mingming Cao89747d32006-03-26 01:37:55 -0800838 /*
839 * Indirect block might be removed by
840 * truncate while we were reading it.
841 * Handling of that case: forget what we've
842 * got now. Flag the err as EAGAIN, so it
843 * will reread.
844 */
845 err = -EAGAIN;
846 count = 0;
847 break;
848 }
Mingming Cao5dea5172006-05-03 19:55:12 -0700849 blk = le32_to_cpu(*(chain[depth-1].p + count));
850
851 if (blk == first_block + count)
Mingming Cao89747d32006-03-26 01:37:55 -0800852 count++;
853 else
854 break;
855 }
856 if (err != -EAGAIN)
857 goto got_it;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858 }
859
860 /* Next simple case - plain lookup or failed read of indirect block */
Mingming Caofe55c452005-05-01 08:59:20 -0700861 if (!create || err == -EIO)
862 goto cleanup;
863
Arjan van de Ven97461512006-03-23 03:00:42 -0800864 mutex_lock(&ei->truncate_mutex);
Mingming Caofe55c452005-05-01 08:59:20 -0700865
866 /*
867 * If the indirect block is missing while we are reading
868 * the chain(ext3_get_branch() returns -EAGAIN err), or
869 * if the chain has been changed after we grab the semaphore,
870 * (either because another process truncated this branch, or
871 * another get_block allocated this branch) re-grab the chain to see if
872 * the request block has been allocated or not.
873 *
874 * Since we already block the truncate/other get_block
875 * at this point, we will have the current copy of the chain when we
876 * splice the branch into the tree.
877 */
878 if (err == -EAGAIN || !verify_chain(chain, partial)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879 while (partial > chain) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 brelse(partial->bh);
881 partial--;
882 }
Mingming Caofe55c452005-05-01 08:59:20 -0700883 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
884 if (!partial) {
Mingming Cao89747d32006-03-26 01:37:55 -0800885 count++;
Arjan van de Ven97461512006-03-23 03:00:42 -0800886 mutex_unlock(&ei->truncate_mutex);
Mingming Caofe55c452005-05-01 08:59:20 -0700887 if (err)
888 goto cleanup;
889 clear_buffer_new(bh_result);
890 goto got_it;
891 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892 }
893
894 /*
Mingming Caofe55c452005-05-01 08:59:20 -0700895 * Okay, we need to do block allocation. Lazily initialize the block
896 * allocation info here if necessary
897 */
898 if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700899 ext3_init_block_alloc_info(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900
Akinobu Mitafb01bfd2008-02-06 01:40:16 -0800901 goal = ext3_find_goal(inode, iblock, partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700902
Mingming Caob47b2472006-03-26 01:37:56 -0800903 /* the number of blocks need to allocate for [d,t]indirect blocks */
904 indirect_blks = (chain + depth) - partial - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700905
906 /*
Mingming Caob47b2472006-03-26 01:37:56 -0800907 * Next look up the indirect map to count the totoal number of
908 * direct blocks to allocate for this branch.
909 */
910 count = ext3_blks_to_allocate(partial, indirect_blks,
911 maxblocks, blocks_to_boundary);
912 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913 * Block out ext3_truncate while we alter the tree
914 */
Mingming Caob47b2472006-03-26 01:37:56 -0800915 err = ext3_alloc_branch(handle, inode, indirect_blks, &count, goal,
Mingming Caofe55c452005-05-01 08:59:20 -0700916 offsets + (partial - chain), partial);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917
Mingming Caofe55c452005-05-01 08:59:20 -0700918 /*
919 * The ext3_splice_branch call will free and forget any buffers
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 * on the new chain if there is a failure, but that risks using
921 * up transaction credits, especially for bitmaps where the
922 * credits cannot be returned. Can we handle this somehow? We
Mingming Caofe55c452005-05-01 08:59:20 -0700923 * may need to return -EAGAIN upwards in the worst case. --sct
924 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700925 if (!err)
Mingming Caob47b2472006-03-26 01:37:56 -0800926 err = ext3_splice_branch(handle, inode, iblock,
927 partial, indirect_blks, count);
Arjan van de Ven97461512006-03-23 03:00:42 -0800928 mutex_unlock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929 if (err)
930 goto cleanup;
931
932 set_buffer_new(bh_result);
Mingming Caofe55c452005-05-01 08:59:20 -0700933got_it:
934 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
Suparna Bhattacharya20acaa12006-09-16 12:15:58 -0700935 if (count > blocks_to_boundary)
Mingming Caofe55c452005-05-01 08:59:20 -0700936 set_buffer_boundary(bh_result);
Mingming Cao89747d32006-03-26 01:37:55 -0800937 err = count;
Mingming Caofe55c452005-05-01 08:59:20 -0700938 /* Clean up and exit */
939 partial = chain + depth - 1; /* the whole chain */
940cleanup:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 while (partial > chain) {
Mingming Caofe55c452005-05-01 08:59:20 -0700942 BUFFER_TRACE(partial->bh, "call brelse");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943 brelse(partial->bh);
944 partial--;
945 }
Mingming Caofe55c452005-05-01 08:59:20 -0700946 BUFFER_TRACE(bh_result, "returned");
947out:
948 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700949}
950
Jan Karabd1939d2008-02-06 01:40:21 -0800951/* Maximum number of blocks we map for direct IO at once. */
952#define DIO_MAX_BLOCKS 4096
953/*
954 * Number of credits we need for writing DIO_MAX_BLOCKS:
955 * We need sb + group descriptor + bitmap + inode -> 4
956 * For B blocks with A block pointers per block we need:
957 * 1 (triple ind.) + (B/A/A + 2) (doubly ind.) + (B/A + 2) (indirect).
958 * If we plug in 4096 for B and 256 for A (for 1KB block size), we get 25.
959 */
960#define DIO_CREDITS 25
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961
Badari Pulavartyf91a2ad2006-03-26 01:38:04 -0800962static int ext3_get_block(struct inode *inode, sector_t iblock,
963 struct buffer_head *bh_result, int create)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964{
Dmitriy Monakhov3e4fdaf2007-02-10 01:46:35 -0800965 handle_t *handle = ext3_journal_current_handle();
Jan Karabd1939d2008-02-06 01:40:21 -0800966 int ret = 0, started = 0;
Badari Pulavarty1d8fa7a2006-03-26 01:38:02 -0800967 unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700968
Jan Karabd1939d2008-02-06 01:40:21 -0800969 if (create && !handle) { /* Direct IO write... */
970 if (max_blocks > DIO_MAX_BLOCKS)
971 max_blocks = DIO_MAX_BLOCKS;
972 handle = ext3_journal_start(inode, DIO_CREDITS +
973 2 * EXT3_QUOTA_TRANS_BLOCKS(inode->i_sb));
974 if (IS_ERR(handle)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700975 ret = PTR_ERR(handle);
Jan Karabd1939d2008-02-06 01:40:21 -0800976 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 }
Jan Karabd1939d2008-02-06 01:40:21 -0800978 started = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979 }
980
Jan Karabd1939d2008-02-06 01:40:21 -0800981 ret = ext3_get_blocks_handle(handle, inode, iblock,
Jan Kara43237b52009-05-20 18:41:58 +0200982 max_blocks, bh_result, create);
Jan Karabd1939d2008-02-06 01:40:21 -0800983 if (ret > 0) {
984 bh_result->b_size = (ret << inode->i_blkbits);
985 ret = 0;
Mingming Cao89747d32006-03-26 01:37:55 -0800986 }
Jan Karabd1939d2008-02-06 01:40:21 -0800987 if (started)
988 ext3_journal_stop(handle);
989out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700990 return ret;
991}
992
Josef Bacik68c9d702008-10-03 17:32:43 -0400993int ext3_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
994 u64 start, u64 len)
995{
996 return generic_block_fiemap(inode, fieinfo, start, len,
997 ext3_get_block);
998}
999
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000/*
1001 * `handle' can be NULL if create is zero
1002 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08001003struct buffer_head *ext3_getblk(handle_t *handle, struct inode *inode,
1004 long block, int create, int *errp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001005{
1006 struct buffer_head dummy;
1007 int fatal = 0, err;
1008
1009 J_ASSERT(handle != NULL || create == 0);
1010
1011 dummy.b_state = 0;
1012 dummy.b_blocknr = -1000;
1013 buffer_trace_init(&dummy.b_history);
Mingming Cao89747d32006-03-26 01:37:55 -08001014 err = ext3_get_blocks_handle(handle, inode, block, 1,
Jan Kara43237b52009-05-20 18:41:58 +02001015 &dummy, create);
Badari Pulavarty3665d0e2006-09-08 09:48:21 -07001016 /*
1017 * ext3_get_blocks_handle() returns number of blocks
1018 * mapped. 0 in case of a HOLE.
1019 */
1020 if (err > 0) {
1021 if (err > 1)
1022 WARN_ON(1);
Mingming Cao89747d32006-03-26 01:37:55 -08001023 err = 0;
Mingming Cao89747d32006-03-26 01:37:55 -08001024 }
1025 *errp = err;
1026 if (!err && buffer_mapped(&dummy)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001027 struct buffer_head *bh;
1028 bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
Glauber de Oliveira Costa2973dfd2005-10-30 15:03:05 -08001029 if (!bh) {
1030 *errp = -EIO;
1031 goto err;
1032 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001033 if (buffer_new(&dummy)) {
1034 J_ASSERT(create != 0);
Stephen Hemmingerc80544d2007-10-18 03:07:05 -07001035 J_ASSERT(handle != NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036
Andrew Mortond6859bf2006-03-26 01:38:03 -08001037 /*
1038 * Now that we do not always journal data, we should
1039 * keep in mind whether this should always journal the
1040 * new buffer as metadata. For now, regular file
1041 * writes use ext3_get_block instead, so it's not a
1042 * problem.
1043 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044 lock_buffer(bh);
1045 BUFFER_TRACE(bh, "call get_create_access");
1046 fatal = ext3_journal_get_create_access(handle, bh);
1047 if (!fatal && !buffer_uptodate(bh)) {
Andrew Mortond6859bf2006-03-26 01:38:03 -08001048 memset(bh->b_data,0,inode->i_sb->s_blocksize);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001049 set_buffer_uptodate(bh);
1050 }
1051 unlock_buffer(bh);
1052 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
1053 err = ext3_journal_dirty_metadata(handle, bh);
1054 if (!fatal)
1055 fatal = err;
1056 } else {
1057 BUFFER_TRACE(bh, "not a new buffer");
1058 }
1059 if (fatal) {
1060 *errp = fatal;
1061 brelse(bh);
1062 bh = NULL;
1063 }
1064 return bh;
1065 }
Glauber de Oliveira Costa2973dfd2005-10-30 15:03:05 -08001066err:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067 return NULL;
1068}
1069
Andrew Mortond6859bf2006-03-26 01:38:03 -08001070struct buffer_head *ext3_bread(handle_t *handle, struct inode *inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001071 int block, int create, int *err)
1072{
1073 struct buffer_head * bh;
1074
1075 bh = ext3_getblk(handle, inode, block, create, err);
1076 if (!bh)
1077 return bh;
1078 if (buffer_uptodate(bh))
1079 return bh;
Jens Axboecaa38fb2006-07-23 01:41:26 +02001080 ll_rw_block(READ_META, 1, &bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001081 wait_on_buffer(bh);
1082 if (buffer_uptodate(bh))
1083 return bh;
1084 put_bh(bh);
1085 *err = -EIO;
1086 return NULL;
1087}
1088
1089static int walk_page_buffers( handle_t *handle,
1090 struct buffer_head *head,
1091 unsigned from,
1092 unsigned to,
1093 int *partial,
1094 int (*fn)( handle_t *handle,
1095 struct buffer_head *bh))
1096{
1097 struct buffer_head *bh;
1098 unsigned block_start, block_end;
1099 unsigned blocksize = head->b_size;
1100 int err, ret = 0;
1101 struct buffer_head *next;
1102
1103 for ( bh = head, block_start = 0;
1104 ret == 0 && (bh != head || !block_start);
Dave Kleikampe9ad5622006-09-27 01:49:35 -07001105 block_start = block_end, bh = next)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001106 {
1107 next = bh->b_this_page;
1108 block_end = block_start + blocksize;
1109 if (block_end <= from || block_start >= to) {
1110 if (partial && !buffer_uptodate(bh))
1111 *partial = 1;
1112 continue;
1113 }
1114 err = (*fn)(handle, bh);
1115 if (!ret)
1116 ret = err;
1117 }
1118 return ret;
1119}
1120
1121/*
1122 * To preserve ordering, it is essential that the hole instantiation and
1123 * the data write be encapsulated in a single transaction. We cannot
1124 * close off a transaction and start a new one between the ext3_get_block()
1125 * and the commit_write(). So doing the journal_start at the start of
1126 * prepare_write() is the right place.
1127 *
1128 * Also, this function can nest inside ext3_writepage() ->
1129 * block_write_full_page(). In that case, we *know* that ext3_writepage()
1130 * has generated enough buffer credits to do the whole page. So we won't
1131 * block on the journal in that case, which is good, because the caller may
1132 * be PF_MEMALLOC.
1133 *
1134 * By accident, ext3 can be reentered when a transaction is open via
1135 * quota file writes. If we were to commit the transaction while thus
1136 * reentered, there can be a deadlock - we would be holding a quota
1137 * lock, and the commit would never complete if another thread had a
1138 * transaction open and was blocking on the quota lock - a ranking
1139 * violation.
1140 *
1141 * So what we do is to rely on the fact that journal_stop/journal_start
1142 * will _not_ run commit under these circumstances because handle->h_ref
1143 * is elevated. We'll still have enough credits for the tiny quotafile
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001144 * write.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001145 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08001146static int do_journal_get_write_access(handle_t *handle,
1147 struct buffer_head *bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001148{
1149 if (!buffer_mapped(bh) || buffer_freed(bh))
1150 return 0;
1151 return ext3_journal_get_write_access(handle, bh);
1152}
1153
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001154static int ext3_write_begin(struct file *file, struct address_space *mapping,
1155 loff_t pos, unsigned len, unsigned flags,
1156 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001157{
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001158 struct inode *inode = mapping->host;
Jan Kara695f6ae2009-04-02 16:57:17 -07001159 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001160 handle_t *handle;
1161 int retries = 0;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001162 struct page *page;
1163 pgoff_t index;
1164 unsigned from, to;
Jan Kara695f6ae2009-04-02 16:57:17 -07001165 /* Reserve one block more for addition to orphan list in case
1166 * we allocate blocks but write fails for some reason */
1167 int needed_blocks = ext3_writepage_trans_blocks(inode) + 1;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001168
1169 index = pos >> PAGE_CACHE_SHIFT;
1170 from = pos & (PAGE_CACHE_SIZE - 1);
1171 to = from + len;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172
1173retry:
Nick Piggin54566b22009-01-04 12:00:53 -08001174 page = grab_cache_page_write_begin(mapping, index, flags);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001175 if (!page)
1176 return -ENOMEM;
1177 *pagep = page;
1178
Linus Torvalds1da177e2005-04-16 15:20:36 -07001179 handle = ext3_journal_start(inode, needed_blocks);
Andrew Morton1aa9b4b2007-04-01 23:49:43 -07001180 if (IS_ERR(handle)) {
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001181 unlock_page(page);
1182 page_cache_release(page);
Andrew Morton1aa9b4b2007-04-01 23:49:43 -07001183 ret = PTR_ERR(handle);
1184 goto out;
1185 }
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001186 ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
1187 ext3_get_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001188 if (ret)
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001189 goto write_begin_failed;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190
1191 if (ext3_should_journal_data(inode)) {
1192 ret = walk_page_buffers(handle, page_buffers(page),
1193 from, to, NULL, do_journal_get_write_access);
1194 }
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001195write_begin_failed:
1196 if (ret) {
Aneesh Kumar K.V5ec8b752008-10-18 20:28:00 -07001197 /*
1198 * block_write_begin may have instantiated a few blocks
1199 * outside i_size. Trim these off again. Don't need
1200 * i_size_read because we hold i_mutex.
Jan Kara695f6ae2009-04-02 16:57:17 -07001201 *
1202 * Add inode to orphan list in case we crash before truncate
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001203 * finishes. Do this only if ext3_can_truncate() agrees so
1204 * that orphan processing code is happy.
Aneesh Kumar K.V5ec8b752008-10-18 20:28:00 -07001205 */
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001206 if (pos + len > inode->i_size && ext3_can_truncate(inode))
Jan Kara695f6ae2009-04-02 16:57:17 -07001207 ext3_orphan_add(handle, inode);
1208 ext3_journal_stop(handle);
1209 unlock_page(page);
1210 page_cache_release(page);
1211 if (pos + len > inode->i_size)
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001212 ext3_truncate(inode);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001213 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001214 if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
1215 goto retry;
Andrew Morton1aa9b4b2007-04-01 23:49:43 -07001216out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217 return ret;
1218}
1219
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001220
Andrew Mortond6859bf2006-03-26 01:38:03 -08001221int ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222{
1223 int err = journal_dirty_data(handle, bh);
1224 if (err)
Harvey Harrisone05b6b52008-04-28 02:16:15 -07001225 ext3_journal_abort_handle(__func__, __func__,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001226 bh, handle, err);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001227 return err;
1228}
1229
Jan Kara695f6ae2009-04-02 16:57:17 -07001230/* For ordered writepage and write_end functions */
1231static int journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
1232{
1233 /*
1234 * Write could have mapped the buffer but it didn't copy the data in
1235 * yet. So avoid filing such buffer into a transaction.
1236 */
1237 if (buffer_mapped(bh) && buffer_uptodate(bh))
1238 return ext3_journal_dirty_data(handle, bh);
1239 return 0;
1240}
1241
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001242/* For write_end() in data=journal mode */
1243static int write_end_fn(handle_t *handle, struct buffer_head *bh)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001244{
1245 if (!buffer_mapped(bh) || buffer_freed(bh))
1246 return 0;
1247 set_buffer_uptodate(bh);
1248 return ext3_journal_dirty_metadata(handle, bh);
1249}
1250
1251/*
Jan Kara695f6ae2009-04-02 16:57:17 -07001252 * This is nasty and subtle: ext3_write_begin() could have allocated blocks
1253 * for the whole page but later we failed to copy the data in. Update inode
1254 * size according to what we managed to copy. The rest is going to be
1255 * truncated in write_end function.
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001256 */
Jan Kara695f6ae2009-04-02 16:57:17 -07001257static void update_file_sizes(struct inode *inode, loff_t pos, unsigned copied)
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001258{
Jan Kara695f6ae2009-04-02 16:57:17 -07001259 /* What matters to us is i_disksize. We don't write i_size anywhere */
1260 if (pos + copied > inode->i_size)
1261 i_size_write(inode, pos + copied);
1262 if (pos + copied > EXT3_I(inode)->i_disksize) {
1263 EXT3_I(inode)->i_disksize = pos + copied;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001264 mark_inode_dirty(inode);
1265 }
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001266}
1267
1268/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269 * We need to pick up the new inode size which generic_commit_write gave us
1270 * `file' can be NULL - eg, when called from page_symlink().
1271 *
1272 * ext3 never places buffers on inode->i_mapping->private_list. metadata
1273 * buffers are managed internally.
1274 */
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001275static int ext3_ordered_write_end(struct file *file,
1276 struct address_space *mapping,
1277 loff_t pos, unsigned len, unsigned copied,
1278 struct page *page, void *fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001279{
1280 handle_t *handle = ext3_journal_current_handle();
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001281 struct inode *inode = file->f_mapping->host;
1282 unsigned from, to;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283 int ret = 0, ret2;
1284
Jan Kara695f6ae2009-04-02 16:57:17 -07001285 copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
1286
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001287 from = pos & (PAGE_CACHE_SIZE - 1);
Jan Kara695f6ae2009-04-02 16:57:17 -07001288 to = from + copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001289 ret = walk_page_buffers(handle, page_buffers(page),
Jan Kara695f6ae2009-04-02 16:57:17 -07001290 from, to, NULL, journal_dirty_data_fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001291
Jan Kara695f6ae2009-04-02 16:57:17 -07001292 if (ret == 0)
1293 update_file_sizes(inode, pos, copied);
1294 /*
1295 * There may be allocated blocks outside of i_size because
1296 * we failed to copy some data. Prepare for truncate.
1297 */
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001298 if (pos + len > inode->i_size && ext3_can_truncate(inode))
Jan Kara695f6ae2009-04-02 16:57:17 -07001299 ext3_orphan_add(handle, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001300 ret2 = ext3_journal_stop(handle);
1301 if (!ret)
1302 ret = ret2;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001303 unlock_page(page);
1304 page_cache_release(page);
1305
Jan Kara695f6ae2009-04-02 16:57:17 -07001306 if (pos + len > inode->i_size)
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001307 ext3_truncate(inode);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001308 return ret ? ret : copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001309}
1310
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001311static int ext3_writeback_write_end(struct file *file,
1312 struct address_space *mapping,
1313 loff_t pos, unsigned len, unsigned copied,
1314 struct page *page, void *fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001315{
1316 handle_t *handle = ext3_journal_current_handle();
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001317 struct inode *inode = file->f_mapping->host;
Jan Kara695f6ae2009-04-02 16:57:17 -07001318 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001319
Jan Kara695f6ae2009-04-02 16:57:17 -07001320 copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
1321 update_file_sizes(inode, pos, copied);
1322 /*
1323 * There may be allocated blocks outside of i_size because
1324 * we failed to copy some data. Prepare for truncate.
1325 */
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001326 if (pos + len > inode->i_size && ext3_can_truncate(inode))
Jan Kara695f6ae2009-04-02 16:57:17 -07001327 ext3_orphan_add(handle, inode);
1328 ret = ext3_journal_stop(handle);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001329 unlock_page(page);
1330 page_cache_release(page);
1331
Jan Kara695f6ae2009-04-02 16:57:17 -07001332 if (pos + len > inode->i_size)
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001333 ext3_truncate(inode);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001334 return ret ? ret : copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335}
1336
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001337static int ext3_journalled_write_end(struct file *file,
1338 struct address_space *mapping,
1339 loff_t pos, unsigned len, unsigned copied,
1340 struct page *page, void *fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001341{
1342 handle_t *handle = ext3_journal_current_handle();
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001343 struct inode *inode = mapping->host;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001344 int ret = 0, ret2;
1345 int partial = 0;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001346 unsigned from, to;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001347
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001348 from = pos & (PAGE_CACHE_SIZE - 1);
1349 to = from + len;
1350
1351 if (copied < len) {
1352 if (!PageUptodate(page))
1353 copied = 0;
Jan Kara695f6ae2009-04-02 16:57:17 -07001354 page_zero_new_buffers(page, from + copied, to);
1355 to = from + copied;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001356 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001357
1358 ret = walk_page_buffers(handle, page_buffers(page), from,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001359 to, &partial, write_end_fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001360 if (!partial)
1361 SetPageUptodate(page);
Jan Kara695f6ae2009-04-02 16:57:17 -07001362
1363 if (pos + copied > inode->i_size)
1364 i_size_write(inode, pos + copied);
1365 /*
1366 * There may be allocated blocks outside of i_size because
1367 * we failed to copy some data. Prepare for truncate.
1368 */
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001369 if (pos + len > inode->i_size && ext3_can_truncate(inode))
Jan Kara695f6ae2009-04-02 16:57:17 -07001370 ext3_orphan_add(handle, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001371 EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1372 if (inode->i_size > EXT3_I(inode)->i_disksize) {
1373 EXT3_I(inode)->i_disksize = inode->i_size;
1374 ret2 = ext3_mark_inode_dirty(handle, inode);
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001375 if (!ret)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001376 ret = ret2;
1377 }
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001378
Linus Torvalds1da177e2005-04-16 15:20:36 -07001379 ret2 = ext3_journal_stop(handle);
1380 if (!ret)
1381 ret = ret2;
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001382 unlock_page(page);
1383 page_cache_release(page);
1384
Jan Kara695f6ae2009-04-02 16:57:17 -07001385 if (pos + len > inode->i_size)
Jan Kara9eaaa2d2009-07-13 20:26:52 +02001386 ext3_truncate(inode);
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001387 return ret ? ret : copied;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001388}
1389
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001390/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001391 * bmap() is special. It gets used by applications such as lilo and by
1392 * the swapper to find the on-disk block of a specific piece of data.
1393 *
1394 * Naturally, this is dangerous if the block concerned is still in the
1395 * journal. If somebody makes a swapfile on an ext3 data-journaling
1396 * filesystem and enables swap, then they may get a nasty shock when the
1397 * data getting swapped to that swapfile suddenly gets overwritten by
1398 * the original zero's written out previously to the journal and
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001399 * awaiting writeback in the kernel's buffer cache.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001400 *
1401 * So, if we see any bmap calls here on a modified, data-journaled file,
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001402 * take extra steps to flush any blocks which might be in the cache.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001403 */
1404static sector_t ext3_bmap(struct address_space *mapping, sector_t block)
1405{
1406 struct inode *inode = mapping->host;
1407 journal_t *journal;
1408 int err;
1409
1410 if (EXT3_I(inode)->i_state & EXT3_STATE_JDATA) {
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001411 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -07001412 * This is a REALLY heavyweight approach, but the use of
1413 * bmap on dirty files is expected to be extremely rare:
1414 * only if we run lilo or swapon on a freshly made file
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001415 * do we expect this to happen.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001416 *
1417 * (bmap requires CAP_SYS_RAWIO so this does not
1418 * represent an unprivileged user DOS attack --- we'd be
1419 * in trouble if mortal users could trigger this path at
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001420 * will.)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001421 *
1422 * NB. EXT3_STATE_JDATA is not set on files other than
1423 * regular files. If somebody wants to bmap a directory
1424 * or symlink and gets confused because the buffer
1425 * hasn't yet been flushed to disk, they deserve
1426 * everything they get.
1427 */
1428
1429 EXT3_I(inode)->i_state &= ~EXT3_STATE_JDATA;
1430 journal = EXT3_JOURNAL(inode);
1431 journal_lock_updates(journal);
1432 err = journal_flush(journal);
1433 journal_unlock_updates(journal);
1434
1435 if (err)
1436 return 0;
1437 }
1438
1439 return generic_block_bmap(mapping,block,ext3_get_block);
1440}
1441
1442static int bget_one(handle_t *handle, struct buffer_head *bh)
1443{
1444 get_bh(bh);
1445 return 0;
1446}
1447
1448static int bput_one(handle_t *handle, struct buffer_head *bh)
1449{
1450 put_bh(bh);
1451 return 0;
1452}
1453
Jan Kara9e80d402009-03-26 13:08:04 +01001454static int buffer_unmapped(handle_t *handle, struct buffer_head *bh)
1455{
1456 return !buffer_mapped(bh);
1457}
Jan Kara695f6ae2009-04-02 16:57:17 -07001458
Linus Torvalds1da177e2005-04-16 15:20:36 -07001459/*
1460 * Note that we always start a transaction even if we're not journalling
1461 * data. This is to preserve ordering: any hole instantiation within
1462 * __block_write_full_page -> ext3_get_block() should be journalled
1463 * along with the data so we don't crash and then get metadata which
1464 * refers to old data.
1465 *
1466 * In all journalling modes block_write_full_page() will start the I/O.
1467 *
1468 * Problem:
1469 *
1470 * ext3_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1471 * ext3_writepage()
1472 *
1473 * Similar for:
1474 *
1475 * ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ...
1476 *
1477 * Same applies to ext3_get_block(). We will deadlock on various things like
Arjan van de Ven97461512006-03-23 03:00:42 -08001478 * lock_journal and i_truncate_mutex.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001479 *
1480 * Setting PF_MEMALLOC here doesn't work - too many internal memory
1481 * allocations fail.
1482 *
1483 * 16May01: If we're reentered then journal_current_handle() will be
1484 * non-zero. We simply *return*.
1485 *
1486 * 1 July 2001: @@@ FIXME:
1487 * In journalled data mode, a data buffer may be metadata against the
1488 * current transaction. But the same file is part of a shared mapping
1489 * and someone does a writepage() on it.
1490 *
1491 * We will move the buffer onto the async_data list, but *after* it has
1492 * been dirtied. So there's a small window where we have dirty data on
1493 * BJ_Metadata.
1494 *
1495 * Note that this only applies to the last partial page in the file. The
1496 * bit which block_write_full_page() uses prepare/commit for. (That's
1497 * broken code anyway: it's wrong for msync()).
1498 *
1499 * It's a rare case: affects the final partial page, for journalled data
1500 * where the file is subject to bith write() and writepage() in the same
1501 * transction. To fix it we'll need a custom block_write_full_page().
1502 * We'll probably need that anyway for journalling writepage() output.
1503 *
1504 * We don't honour synchronous mounts for writepage(). That would be
1505 * disastrous. Any write() or metadata operation will sync the fs for
1506 * us.
1507 *
1508 * AKPM2: if all the page's buffers are mapped to disk and !data=journal,
1509 * we don't need to open a transaction here.
1510 */
1511static int ext3_ordered_writepage(struct page *page,
Andrew Mortond6859bf2006-03-26 01:38:03 -08001512 struct writeback_control *wbc)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001513{
1514 struct inode *inode = page->mapping->host;
1515 struct buffer_head *page_bufs;
1516 handle_t *handle = NULL;
1517 int ret = 0;
1518 int err;
1519
1520 J_ASSERT(PageLocked(page));
1521
1522 /*
1523 * We give up here if we're reentered, because it might be for a
1524 * different filesystem.
1525 */
1526 if (ext3_journal_current_handle())
1527 goto out_fail;
1528
Jan Kara9e80d402009-03-26 13:08:04 +01001529 if (!page_has_buffers(page)) {
1530 create_empty_buffers(page, inode->i_sb->s_blocksize,
1531 (1 << BH_Dirty)|(1 << BH_Uptodate));
Jan Kara430db322009-04-07 18:25:01 -04001532 page_bufs = page_buffers(page);
1533 } else {
1534 page_bufs = page_buffers(page);
1535 if (!walk_page_buffers(NULL, page_bufs, 0, PAGE_CACHE_SIZE,
1536 NULL, buffer_unmapped)) {
1537 /* Provide NULL get_block() to catch bugs if buffers
1538 * weren't really mapped */
1539 return block_write_full_page(page, NULL, wbc);
1540 }
Jan Kara9e80d402009-03-26 13:08:04 +01001541 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001542 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1543
1544 if (IS_ERR(handle)) {
1545 ret = PTR_ERR(handle);
1546 goto out_fail;
1547 }
1548
Linus Torvalds1da177e2005-04-16 15:20:36 -07001549 walk_page_buffers(handle, page_bufs, 0,
1550 PAGE_CACHE_SIZE, NULL, bget_one);
1551
1552 ret = block_write_full_page(page, ext3_get_block, wbc);
1553
1554 /*
1555 * The page can become unlocked at any point now, and
1556 * truncate can then come in and change things. So we
1557 * can't touch *page from now on. But *page_bufs is
1558 * safe due to elevated refcount.
1559 */
1560
1561 /*
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001562 * And attach them to the current transaction. But only if
Linus Torvalds1da177e2005-04-16 15:20:36 -07001563 * block_write_full_page() succeeded. Otherwise they are unmapped,
1564 * and generally junk.
1565 */
1566 if (ret == 0) {
1567 err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
1568 NULL, journal_dirty_data_fn);
1569 if (!ret)
1570 ret = err;
1571 }
1572 walk_page_buffers(handle, page_bufs, 0,
1573 PAGE_CACHE_SIZE, NULL, bput_one);
1574 err = ext3_journal_stop(handle);
1575 if (!ret)
1576 ret = err;
1577 return ret;
1578
1579out_fail:
1580 redirty_page_for_writepage(wbc, page);
1581 unlock_page(page);
1582 return ret;
1583}
1584
Linus Torvalds1da177e2005-04-16 15:20:36 -07001585static int ext3_writeback_writepage(struct page *page,
1586 struct writeback_control *wbc)
1587{
1588 struct inode *inode = page->mapping->host;
1589 handle_t *handle = NULL;
1590 int ret = 0;
1591 int err;
1592
1593 if (ext3_journal_current_handle())
1594 goto out_fail;
1595
Jan Kara430db322009-04-07 18:25:01 -04001596 if (page_has_buffers(page)) {
1597 if (!walk_page_buffers(NULL, page_buffers(page), 0,
1598 PAGE_CACHE_SIZE, NULL, buffer_unmapped)) {
1599 /* Provide NULL get_block() to catch bugs if buffers
1600 * weren't really mapped */
1601 return block_write_full_page(page, NULL, wbc);
1602 }
1603 }
1604
Linus Torvalds1da177e2005-04-16 15:20:36 -07001605 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1606 if (IS_ERR(handle)) {
1607 ret = PTR_ERR(handle);
1608 goto out_fail;
1609 }
1610
Badari Pulavarty0e31f512006-07-30 03:04:14 -07001611 if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001612 ret = nobh_writepage(page, ext3_get_block, wbc);
1613 else
1614 ret = block_write_full_page(page, ext3_get_block, wbc);
1615
1616 err = ext3_journal_stop(handle);
1617 if (!ret)
1618 ret = err;
1619 return ret;
1620
1621out_fail:
1622 redirty_page_for_writepage(wbc, page);
1623 unlock_page(page);
1624 return ret;
1625}
1626
1627static int ext3_journalled_writepage(struct page *page,
1628 struct writeback_control *wbc)
1629{
1630 struct inode *inode = page->mapping->host;
1631 handle_t *handle = NULL;
1632 int ret = 0;
1633 int err;
1634
1635 if (ext3_journal_current_handle())
1636 goto no_write;
1637
1638 handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1639 if (IS_ERR(handle)) {
1640 ret = PTR_ERR(handle);
1641 goto no_write;
1642 }
1643
1644 if (!page_has_buffers(page) || PageChecked(page)) {
1645 /*
1646 * It's mmapped pagecache. Add buffers and journal it. There
1647 * doesn't seem much point in redirtying the page here.
1648 */
1649 ClearPageChecked(page);
1650 ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
1651 ext3_get_block);
Denis Lunevab4eb432005-11-13 16:07:17 -08001652 if (ret != 0) {
1653 ext3_journal_stop(handle);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001654 goto out_unlock;
Denis Lunevab4eb432005-11-13 16:07:17 -08001655 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001656 ret = walk_page_buffers(handle, page_buffers(page), 0,
1657 PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
1658
1659 err = walk_page_buffers(handle, page_buffers(page), 0,
Nick Pigginf4fc66a2007-10-16 01:25:05 -07001660 PAGE_CACHE_SIZE, NULL, write_end_fn);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001661 if (ret == 0)
1662 ret = err;
1663 EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1664 unlock_page(page);
1665 } else {
1666 /*
1667 * It may be a page full of checkpoint-mode buffers. We don't
1668 * really know unless we go poke around in the buffer_heads.
1669 * But block_write_full_page will do the right thing.
1670 */
1671 ret = block_write_full_page(page, ext3_get_block, wbc);
1672 }
1673 err = ext3_journal_stop(handle);
1674 if (!ret)
1675 ret = err;
1676out:
1677 return ret;
1678
1679no_write:
1680 redirty_page_for_writepage(wbc, page);
1681out_unlock:
1682 unlock_page(page);
1683 goto out;
1684}
1685
1686static int ext3_readpage(struct file *file, struct page *page)
1687{
1688 return mpage_readpage(page, ext3_get_block);
1689}
1690
1691static int
1692ext3_readpages(struct file *file, struct address_space *mapping,
1693 struct list_head *pages, unsigned nr_pages)
1694{
1695 return mpage_readpages(mapping, pages, nr_pages, ext3_get_block);
1696}
1697
NeilBrown2ff28e22006-03-26 01:37:18 -08001698static void ext3_invalidatepage(struct page *page, unsigned long offset)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001699{
1700 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1701
1702 /*
1703 * If it's a full truncate we just forget about the pending dirtying
1704 */
1705 if (offset == 0)
1706 ClearPageChecked(page);
1707
NeilBrown2ff28e22006-03-26 01:37:18 -08001708 journal_invalidatepage(journal, page, offset);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001709}
1710
Al Viro27496a82005-10-21 03:20:48 -04001711static int ext3_releasepage(struct page *page, gfp_t wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001712{
1713 journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1714
1715 WARN_ON(PageChecked(page));
1716 if (!page_has_buffers(page))
1717 return 0;
1718 return journal_try_to_free_buffers(journal, page, wait);
1719}
1720
1721/*
1722 * If the O_DIRECT write will extend the file then add this inode to the
1723 * orphan list. So recovery will truncate it back to the original size
1724 * if the machine crashes during the write.
1725 *
1726 * If the O_DIRECT write is intantiating holes inside i_size and the machine
Jan Karabd1939d2008-02-06 01:40:21 -08001727 * crashes then stale disk data _may_ be exposed inside the file. But current
1728 * VFS code falls back into buffered path in that case so we are safe.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001729 */
1730static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
1731 const struct iovec *iov, loff_t offset,
1732 unsigned long nr_segs)
1733{
1734 struct file *file = iocb->ki_filp;
1735 struct inode *inode = file->f_mapping->host;
1736 struct ext3_inode_info *ei = EXT3_I(inode);
Jan Karabd1939d2008-02-06 01:40:21 -08001737 handle_t *handle;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001738 ssize_t ret;
1739 int orphan = 0;
1740 size_t count = iov_length(iov, nr_segs);
Eric Sandeenea0174a2009-10-12 21:34:27 -05001741 int retries = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001742
1743 if (rw == WRITE) {
1744 loff_t final_size = offset + count;
1745
Linus Torvalds1da177e2005-04-16 15:20:36 -07001746 if (final_size > inode->i_size) {
Jan Karabd1939d2008-02-06 01:40:21 -08001747 /* Credits for sb + inode write */
1748 handle = ext3_journal_start(inode, 2);
1749 if (IS_ERR(handle)) {
1750 ret = PTR_ERR(handle);
1751 goto out;
1752 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001753 ret = ext3_orphan_add(handle, inode);
Jan Karabd1939d2008-02-06 01:40:21 -08001754 if (ret) {
1755 ext3_journal_stop(handle);
1756 goto out;
1757 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001758 orphan = 1;
1759 ei->i_disksize = inode->i_size;
Jan Karabd1939d2008-02-06 01:40:21 -08001760 ext3_journal_stop(handle);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001761 }
1762 }
1763
Eric Sandeenea0174a2009-10-12 21:34:27 -05001764retry:
Mingming Caoae6ddcc2006-09-27 01:49:27 -07001765 ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001766 offset, nr_segs,
Badari Pulavartyf91a2ad2006-03-26 01:38:04 -08001767 ext3_get_block, NULL);
Eric Sandeenea0174a2009-10-12 21:34:27 -05001768 if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
1769 goto retry;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001770
Jan Karabd1939d2008-02-06 01:40:21 -08001771 if (orphan) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001772 int err;
1773
Jan Karabd1939d2008-02-06 01:40:21 -08001774 /* Credits for sb + inode write */
1775 handle = ext3_journal_start(inode, 2);
1776 if (IS_ERR(handle)) {
1777 /* This is really bad luck. We've written the data
1778 * but cannot extend i_size. Bail out and pretend
1779 * the write failed... */
1780 ret = PTR_ERR(handle);
1781 goto out;
1782 }
1783 if (inode->i_nlink)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001784 ext3_orphan_del(handle, inode);
Jan Karabd1939d2008-02-06 01:40:21 -08001785 if (ret > 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001786 loff_t end = offset + ret;
1787 if (end > inode->i_size) {
1788 ei->i_disksize = end;
1789 i_size_write(inode, end);
1790 /*
1791 * We're going to return a positive `ret'
1792 * here due to non-zero-length I/O, so there's
1793 * no way of reporting error returns from
1794 * ext3_mark_inode_dirty() to userspace. So
1795 * ignore it.
1796 */
1797 ext3_mark_inode_dirty(handle, inode);
1798 }
1799 }
1800 err = ext3_journal_stop(handle);
1801 if (ret == 0)
1802 ret = err;
1803 }
1804out:
1805 return ret;
1806}
1807
1808/*
1809 * Pages can be marked dirty completely asynchronously from ext3's journalling
1810 * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
1811 * much here because ->set_page_dirty is called under VFS locks. The page is
1812 * not necessarily locked.
1813 *
1814 * We cannot just dirty the page and leave attached buffers clean, because the
1815 * buffers' dirty state is "definitive". We cannot just set the buffers dirty
1816 * or jbddirty because all the journalling code will explode.
1817 *
1818 * So what we do is to mark the page "pending dirty" and next time writepage
1819 * is called, propagate that into the buffers appropriately.
1820 */
1821static int ext3_journalled_set_page_dirty(struct page *page)
1822{
1823 SetPageChecked(page);
1824 return __set_page_dirty_nobuffers(page);
1825}
1826
Christoph Hellwigf5e54d62006-06-28 04:26:44 -07001827static const struct address_space_operations ext3_ordered_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07001828 .readpage = ext3_readpage,
1829 .readpages = ext3_readpages,
1830 .writepage = ext3_ordered_writepage,
1831 .sync_page = block_sync_page,
1832 .write_begin = ext3_write_begin,
1833 .write_end = ext3_ordered_write_end,
1834 .bmap = ext3_bmap,
1835 .invalidatepage = ext3_invalidatepage,
1836 .releasepage = ext3_releasepage,
1837 .direct_IO = ext3_direct_IO,
1838 .migratepage = buffer_migrate_page,
1839 .is_partially_uptodate = block_is_partially_uptodate,
Andi Kleenaa261f52009-09-16 11:50:16 +02001840 .error_remove_page = generic_error_remove_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001841};
1842
Christoph Hellwigf5e54d62006-06-28 04:26:44 -07001843static const struct address_space_operations ext3_writeback_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07001844 .readpage = ext3_readpage,
1845 .readpages = ext3_readpages,
1846 .writepage = ext3_writeback_writepage,
1847 .sync_page = block_sync_page,
1848 .write_begin = ext3_write_begin,
1849 .write_end = ext3_writeback_write_end,
1850 .bmap = ext3_bmap,
1851 .invalidatepage = ext3_invalidatepage,
1852 .releasepage = ext3_releasepage,
1853 .direct_IO = ext3_direct_IO,
1854 .migratepage = buffer_migrate_page,
1855 .is_partially_uptodate = block_is_partially_uptodate,
Andi Kleenaa261f52009-09-16 11:50:16 +02001856 .error_remove_page = generic_error_remove_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001857};
1858
Christoph Hellwigf5e54d62006-06-28 04:26:44 -07001859static const struct address_space_operations ext3_journalled_aops = {
Hisashi Hifumi8ab22b92008-07-28 15:46:36 -07001860 .readpage = ext3_readpage,
1861 .readpages = ext3_readpages,
1862 .writepage = ext3_journalled_writepage,
1863 .sync_page = block_sync_page,
1864 .write_begin = ext3_write_begin,
1865 .write_end = ext3_journalled_write_end,
1866 .set_page_dirty = ext3_journalled_set_page_dirty,
1867 .bmap = ext3_bmap,
1868 .invalidatepage = ext3_invalidatepage,
1869 .releasepage = ext3_releasepage,
1870 .is_partially_uptodate = block_is_partially_uptodate,
Andi Kleenaa261f52009-09-16 11:50:16 +02001871 .error_remove_page = generic_error_remove_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001872};
1873
1874void ext3_set_aops(struct inode *inode)
1875{
1876 if (ext3_should_order_data(inode))
1877 inode->i_mapping->a_ops = &ext3_ordered_aops;
1878 else if (ext3_should_writeback_data(inode))
1879 inode->i_mapping->a_ops = &ext3_writeback_aops;
1880 else
1881 inode->i_mapping->a_ops = &ext3_journalled_aops;
1882}
1883
1884/*
1885 * ext3_block_truncate_page() zeroes out a mapping from file offset `from'
1886 * up to the end of the block which corresponds to `from'.
1887 * This required during truncate. We need to physically zero the tail end
1888 * of that block so it doesn't yield old data if the file is later grown.
1889 */
1890static int ext3_block_truncate_page(handle_t *handle, struct page *page,
1891 struct address_space *mapping, loff_t from)
1892{
Mingming Cao43d23f92006-06-25 05:48:07 -07001893 ext3_fsblk_t index = from >> PAGE_CACHE_SHIFT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001894 unsigned offset = from & (PAGE_CACHE_SIZE-1);
1895 unsigned blocksize, iblock, length, pos;
1896 struct inode *inode = mapping->host;
1897 struct buffer_head *bh;
1898 int err = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001899
1900 blocksize = inode->i_sb->s_blocksize;
1901 length = blocksize - (offset & (blocksize - 1));
1902 iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1903
1904 /*
1905 * For "nobh" option, we can only work if we don't need to
1906 * read-in the page - otherwise we create buffers to do the IO.
1907 */
Badari Pulavartycd6ef842006-03-11 03:27:14 -08001908 if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
1909 ext3_should_writeback_data(inode) && PageUptodate(page)) {
Christoph Lametereebd2aa2008-02-04 22:28:29 -08001910 zero_user(page, offset, length);
Badari Pulavartycd6ef842006-03-11 03:27:14 -08001911 set_page_dirty(page);
1912 goto unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001913 }
1914
1915 if (!page_has_buffers(page))
1916 create_empty_buffers(page, blocksize, 0);
1917
1918 /* Find the buffer that contains "offset" */
1919 bh = page_buffers(page);
1920 pos = blocksize;
1921 while (offset >= pos) {
1922 bh = bh->b_this_page;
1923 iblock++;
1924 pos += blocksize;
1925 }
1926
1927 err = 0;
1928 if (buffer_freed(bh)) {
1929 BUFFER_TRACE(bh, "freed: skip");
1930 goto unlock;
1931 }
1932
1933 if (!buffer_mapped(bh)) {
1934 BUFFER_TRACE(bh, "unmapped");
1935 ext3_get_block(inode, iblock, bh, 0);
1936 /* unmapped? It's a hole - nothing to do */
1937 if (!buffer_mapped(bh)) {
1938 BUFFER_TRACE(bh, "still unmapped");
1939 goto unlock;
1940 }
1941 }
1942
1943 /* Ok, it's mapped. Make sure it's up-to-date */
1944 if (PageUptodate(page))
1945 set_buffer_uptodate(bh);
1946
1947 if (!buffer_uptodate(bh)) {
1948 err = -EIO;
1949 ll_rw_block(READ, 1, &bh);
1950 wait_on_buffer(bh);
1951 /* Uhhuh. Read error. Complain and punt. */
1952 if (!buffer_uptodate(bh))
1953 goto unlock;
1954 }
1955
1956 if (ext3_should_journal_data(inode)) {
1957 BUFFER_TRACE(bh, "get write access");
1958 err = ext3_journal_get_write_access(handle, bh);
1959 if (err)
1960 goto unlock;
1961 }
1962
Christoph Lametereebd2aa2008-02-04 22:28:29 -08001963 zero_user(page, offset, length);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001964 BUFFER_TRACE(bh, "zeroed end of block");
1965
1966 err = 0;
1967 if (ext3_should_journal_data(inode)) {
1968 err = ext3_journal_dirty_metadata(handle, bh);
1969 } else {
1970 if (ext3_should_order_data(inode))
1971 err = ext3_journal_dirty_data(handle, bh);
1972 mark_buffer_dirty(bh);
1973 }
1974
1975unlock:
1976 unlock_page(page);
1977 page_cache_release(page);
1978 return err;
1979}
1980
1981/*
1982 * Probably it should be a library function... search for first non-zero word
1983 * or memcmp with zero_page, whatever is better for particular architecture.
1984 * Linus?
1985 */
1986static inline int all_zeroes(__le32 *p, __le32 *q)
1987{
1988 while (p < q)
1989 if (*p++)
1990 return 0;
1991 return 1;
1992}
1993
1994/**
1995 * ext3_find_shared - find the indirect blocks for partial truncation.
1996 * @inode: inode in question
1997 * @depth: depth of the affected branch
1998 * @offsets: offsets of pointers in that branch (see ext3_block_to_path)
1999 * @chain: place to store the pointers to partial indirect blocks
2000 * @top: place to the (detached) top of branch
2001 *
2002 * This is a helper function used by ext3_truncate().
2003 *
2004 * When we do truncate() we may have to clean the ends of several
2005 * indirect blocks but leave the blocks themselves alive. Block is
2006 * partially truncated if some data below the new i_size is refered
2007 * from it (and it is on the path to the first completely truncated
2008 * data block, indeed). We have to free the top of that path along
2009 * with everything to the right of the path. Since no allocation
2010 * past the truncation point is possible until ext3_truncate()
2011 * finishes, we may safely do the latter, but top of branch may
2012 * require special attention - pageout below the truncation point
2013 * might try to populate it.
2014 *
2015 * We atomically detach the top of branch from the tree, store the
2016 * block number of its root in *@top, pointers to buffer_heads of
2017 * partially truncated blocks - in @chain[].bh and pointers to
2018 * their last elements that should not be removed - in
2019 * @chain[].p. Return value is the pointer to last filled element
2020 * of @chain.
2021 *
2022 * The work left to caller to do the actual freeing of subtrees:
2023 * a) free the subtree starting from *@top
2024 * b) free the subtrees whose roots are stored in
2025 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
2026 * c) free the subtrees growing from the inode past the @chain[0].
2027 * (no partially truncated stuff there). */
2028
Andrew Mortond6859bf2006-03-26 01:38:03 -08002029static Indirect *ext3_find_shared(struct inode *inode, int depth,
2030 int offsets[4], Indirect chain[4], __le32 *top)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002031{
2032 Indirect *partial, *p;
2033 int k, err;
2034
2035 *top = 0;
2036 /* Make k index the deepest non-null offest + 1 */
2037 for (k = depth; k > 1 && !offsets[k-1]; k--)
2038 ;
2039 partial = ext3_get_branch(inode, k, offsets, chain, &err);
2040 /* Writer: pointers */
2041 if (!partial)
2042 partial = chain + k-1;
2043 /*
2044 * If the branch acquired continuation since we've looked at it -
2045 * fine, it should all survive and (new) top doesn't belong to us.
2046 */
2047 if (!partial->key && *partial->p)
2048 /* Writer: end */
2049 goto no_top;
2050 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
2051 ;
2052 /*
2053 * OK, we've found the last block that must survive. The rest of our
2054 * branch should be detached before unlocking. However, if that rest
2055 * of branch is all ours and does not grow immediately from the inode
2056 * it's easier to cheat and just decrement partial->p.
2057 */
2058 if (p == chain + k - 1 && p > chain) {
2059 p->p--;
2060 } else {
2061 *top = *p->p;
2062 /* Nope, don't do this in ext3. Must leave the tree intact */
2063#if 0
2064 *p->p = 0;
2065#endif
2066 }
2067 /* Writer: end */
2068
Andrew Mortond6859bf2006-03-26 01:38:03 -08002069 while(partial > p) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002070 brelse(partial->bh);
2071 partial--;
2072 }
2073no_top:
2074 return partial;
2075}
2076
2077/*
2078 * Zero a number of block pointers in either an inode or an indirect block.
2079 * If we restart the transaction we must again get write access to the
2080 * indirect block for further modification.
2081 *
2082 * We release `count' blocks on disk, but (last - first) may be greater
2083 * than `count' because there can be holes in there.
2084 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08002085static void ext3_clear_blocks(handle_t *handle, struct inode *inode,
Mingming Cao43d23f92006-06-25 05:48:07 -07002086 struct buffer_head *bh, ext3_fsblk_t block_to_free,
Andrew Mortond6859bf2006-03-26 01:38:03 -08002087 unsigned long count, __le32 *first, __le32 *last)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002088{
2089 __le32 *p;
2090 if (try_to_extend_transaction(handle, inode)) {
2091 if (bh) {
2092 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
2093 ext3_journal_dirty_metadata(handle, bh);
2094 }
2095 ext3_mark_inode_dirty(handle, inode);
Jan Kara00171d32009-08-11 19:06:10 +02002096 truncate_restart_transaction(handle, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002097 if (bh) {
2098 BUFFER_TRACE(bh, "retaking write access");
2099 ext3_journal_get_write_access(handle, bh);
2100 }
2101 }
2102
2103 /*
2104 * Any buffers which are on the journal will be in memory. We find
2105 * them on the hash table so journal_revoke() will run journal_forget()
2106 * on them. We've already detached each block from the file, so
2107 * bforget() in journal_forget() should be safe.
2108 *
2109 * AKPM: turn on bforget in journal_forget()!!!
2110 */
2111 for (p = first; p < last; p++) {
2112 u32 nr = le32_to_cpu(*p);
2113 if (nr) {
2114 struct buffer_head *bh;
2115
2116 *p = 0;
2117 bh = sb_find_get_block(inode->i_sb, nr);
2118 ext3_forget(handle, 0, inode, bh, nr);
2119 }
2120 }
2121
2122 ext3_free_blocks(handle, inode, block_to_free, count);
2123}
2124
2125/**
2126 * ext3_free_data - free a list of data blocks
2127 * @handle: handle for this transaction
2128 * @inode: inode we are dealing with
2129 * @this_bh: indirect buffer_head which contains *@first and *@last
2130 * @first: array of block numbers
2131 * @last: points immediately past the end of array
2132 *
2133 * We are freeing all blocks refered from that array (numbers are stored as
2134 * little-endian 32-bit) and updating @inode->i_blocks appropriately.
2135 *
2136 * We accumulate contiguous runs of blocks to free. Conveniently, if these
2137 * blocks are contiguous then releasing them at one time will only affect one
2138 * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
2139 * actually use a lot of journal space.
2140 *
2141 * @this_bh will be %NULL if @first and @last point into the inode's direct
2142 * block pointers.
2143 */
2144static void ext3_free_data(handle_t *handle, struct inode *inode,
2145 struct buffer_head *this_bh,
2146 __le32 *first, __le32 *last)
2147{
Mingming Cao43d23f92006-06-25 05:48:07 -07002148 ext3_fsblk_t block_to_free = 0; /* Starting block # of a run */
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002149 unsigned long count = 0; /* Number of blocks in the run */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002150 __le32 *block_to_free_p = NULL; /* Pointer into inode/ind
2151 corresponding to
2152 block_to_free */
Mingming Cao43d23f92006-06-25 05:48:07 -07002153 ext3_fsblk_t nr; /* Current block # */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002154 __le32 *p; /* Pointer into inode/ind
2155 for current block */
2156 int err;
2157
2158 if (this_bh) { /* For indirect block */
2159 BUFFER_TRACE(this_bh, "get_write_access");
2160 err = ext3_journal_get_write_access(handle, this_bh);
2161 /* Important: if we can't update the indirect pointers
2162 * to the blocks, we can't free them. */
2163 if (err)
2164 return;
2165 }
2166
2167 for (p = first; p < last; p++) {
2168 nr = le32_to_cpu(*p);
2169 if (nr) {
2170 /* accumulate blocks to free if they're contiguous */
2171 if (count == 0) {
2172 block_to_free = nr;
2173 block_to_free_p = p;
2174 count = 1;
2175 } else if (nr == block_to_free + count) {
2176 count++;
2177 } else {
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002178 ext3_clear_blocks(handle, inode, this_bh,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002179 block_to_free,
2180 count, block_to_free_p, p);
2181 block_to_free = nr;
2182 block_to_free_p = p;
2183 count = 1;
2184 }
2185 }
2186 }
2187
2188 if (count > 0)
2189 ext3_clear_blocks(handle, inode, this_bh, block_to_free,
2190 count, block_to_free_p, p);
2191
2192 if (this_bh) {
2193 BUFFER_TRACE(this_bh, "call ext3_journal_dirty_metadata");
Duane Griffin3ccc3162008-07-25 01:46:26 -07002194
2195 /*
2196 * The buffer head should have an attached journal head at this
2197 * point. However, if the data is corrupted and an indirect
2198 * block pointed to itself, it would have been detached when
2199 * the block was cleared. Check for this instead of OOPSing.
2200 */
2201 if (bh2jh(this_bh))
2202 ext3_journal_dirty_metadata(handle, this_bh);
2203 else
2204 ext3_error(inode->i_sb, "ext3_free_data",
2205 "circular indirect block detected, "
2206 "inode=%lu, block=%llu",
2207 inode->i_ino,
2208 (unsigned long long)this_bh->b_blocknr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002209 }
2210}
2211
2212/**
2213 * ext3_free_branches - free an array of branches
2214 * @handle: JBD handle for this transaction
2215 * @inode: inode we are dealing with
2216 * @parent_bh: the buffer_head which contains *@first and *@last
2217 * @first: array of block numbers
2218 * @last: pointer immediately past the end of array
2219 * @depth: depth of the branches to free
2220 *
2221 * We are freeing all blocks refered from these branches (numbers are
2222 * stored as little-endian 32-bit) and updating @inode->i_blocks
2223 * appropriately.
2224 */
2225static void ext3_free_branches(handle_t *handle, struct inode *inode,
2226 struct buffer_head *parent_bh,
2227 __le32 *first, __le32 *last, int depth)
2228{
Mingming Cao43d23f92006-06-25 05:48:07 -07002229 ext3_fsblk_t nr;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002230 __le32 *p;
2231
2232 if (is_handle_aborted(handle))
2233 return;
2234
2235 if (depth--) {
2236 struct buffer_head *bh;
2237 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2238 p = last;
2239 while (--p >= first) {
2240 nr = le32_to_cpu(*p);
2241 if (!nr)
2242 continue; /* A hole */
2243
2244 /* Go read the buffer for the next level down */
2245 bh = sb_bread(inode->i_sb, nr);
2246
2247 /*
2248 * A read failure? Report error and clear slot
2249 * (should be rare).
2250 */
2251 if (!bh) {
2252 ext3_error(inode->i_sb, "ext3_free_branches",
Eric Sandeeneee194e2006-09-27 01:49:30 -07002253 "Read failure, inode=%lu, block="E3FSBLK,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002254 inode->i_ino, nr);
2255 continue;
2256 }
2257
2258 /* This zaps the entire block. Bottom up. */
2259 BUFFER_TRACE(bh, "free child branches");
2260 ext3_free_branches(handle, inode, bh,
2261 (__le32*)bh->b_data,
2262 (__le32*)bh->b_data + addr_per_block,
2263 depth);
2264
2265 /*
2266 * We've probably journalled the indirect block several
2267 * times during the truncate. But it's no longer
2268 * needed and we now drop it from the transaction via
2269 * journal_revoke().
2270 *
2271 * That's easy if it's exclusively part of this
2272 * transaction. But if it's part of the committing
2273 * transaction then journal_forget() will simply
2274 * brelse() it. That means that if the underlying
2275 * block is reallocated in ext3_get_block(),
2276 * unmap_underlying_metadata() will find this block
2277 * and will try to get rid of it. damn, damn.
2278 *
2279 * If this block has already been committed to the
2280 * journal, a revoke record will be written. And
2281 * revoke records must be emitted *before* clearing
2282 * this block's bit in the bitmaps.
2283 */
2284 ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
2285
2286 /*
2287 * Everything below this this pointer has been
2288 * released. Now let this top-of-subtree go.
2289 *
2290 * We want the freeing of this indirect block to be
2291 * atomic in the journal with the updating of the
2292 * bitmap block which owns it. So make some room in
2293 * the journal.
2294 *
2295 * We zero the parent pointer *after* freeing its
2296 * pointee in the bitmaps, so if extend_transaction()
2297 * for some reason fails to put the bitmap changes and
2298 * the release into the same transaction, recovery
2299 * will merely complain about releasing a free block,
2300 * rather than leaking blocks.
2301 */
2302 if (is_handle_aborted(handle))
2303 return;
2304 if (try_to_extend_transaction(handle, inode)) {
2305 ext3_mark_inode_dirty(handle, inode);
Jan Kara00171d32009-08-11 19:06:10 +02002306 truncate_restart_transaction(handle, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002307 }
2308
2309 ext3_free_blocks(handle, inode, nr, 1);
2310
2311 if (parent_bh) {
2312 /*
2313 * The block which we have just freed is
2314 * pointed to by an indirect block: journal it
2315 */
2316 BUFFER_TRACE(parent_bh, "get_write_access");
2317 if (!ext3_journal_get_write_access(handle,
2318 parent_bh)){
2319 *p = 0;
2320 BUFFER_TRACE(parent_bh,
2321 "call ext3_journal_dirty_metadata");
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002322 ext3_journal_dirty_metadata(handle,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002323 parent_bh);
2324 }
2325 }
2326 }
2327 } else {
2328 /* We have reached the bottom of the tree. */
2329 BUFFER_TRACE(parent_bh, "free data blocks");
2330 ext3_free_data(handle, inode, parent_bh, first, last);
2331 }
2332}
2333
Duane Griffinae76dd92008-07-25 01:46:23 -07002334int ext3_can_truncate(struct inode *inode)
2335{
2336 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2337 return 0;
2338 if (S_ISREG(inode->i_mode))
2339 return 1;
2340 if (S_ISDIR(inode->i_mode))
2341 return 1;
2342 if (S_ISLNK(inode->i_mode))
2343 return !ext3_inode_is_fast_symlink(inode);
2344 return 0;
2345}
2346
Linus Torvalds1da177e2005-04-16 15:20:36 -07002347/*
2348 * ext3_truncate()
2349 *
2350 * We block out ext3_get_block() block instantiations across the entire
2351 * transaction, and VFS/VM ensures that ext3_truncate() cannot run
2352 * simultaneously on behalf of the same inode.
2353 *
2354 * As we work through the truncate and commmit bits of it to the journal there
2355 * is one core, guiding principle: the file's tree must always be consistent on
2356 * disk. We must be able to restart the truncate after a crash.
2357 *
2358 * The file's tree may be transiently inconsistent in memory (although it
2359 * probably isn't), but whenever we close off and commit a journal transaction,
2360 * the contents of (the filesystem + the journal) must be consistent and
2361 * restartable. It's pretty simple, really: bottom up, right to left (although
2362 * left-to-right works OK too).
2363 *
2364 * Note that at recovery time, journal replay occurs *before* the restart of
2365 * truncate against the orphan inode list.
2366 *
2367 * The committed inode has the new, desired i_size (which is the same as
2368 * i_disksize in this case). After a crash, ext3_orphan_cleanup() will see
2369 * that this inode's truncate did not complete and it will again call
2370 * ext3_truncate() to have another go. So there will be instantiated blocks
2371 * to the right of the truncation point in a crashed ext3 filesystem. But
2372 * that's fine - as long as they are linked from the inode, the post-crash
2373 * ext3_truncate() run will find them and release them.
2374 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08002375void ext3_truncate(struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002376{
2377 handle_t *handle;
2378 struct ext3_inode_info *ei = EXT3_I(inode);
2379 __le32 *i_data = ei->i_data;
2380 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2381 struct address_space *mapping = inode->i_mapping;
2382 int offsets[4];
2383 Indirect chain[4];
2384 Indirect *partial;
2385 __le32 nr = 0;
2386 int n;
2387 long last_block;
2388 unsigned blocksize = inode->i_sb->s_blocksize;
2389 struct page *page;
2390
Duane Griffinae76dd92008-07-25 01:46:23 -07002391 if (!ext3_can_truncate(inode))
Jan Karaef436182009-06-17 16:26:24 -07002392 goto out_notrans;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002393
Theodore Ts'of7ab34e2009-04-03 01:34:35 -04002394 if (inode->i_size == 0 && ext3_should_writeback_data(inode))
2395 ei->i_state |= EXT3_STATE_FLUSH_ON_CLOSE;
2396
Linus Torvalds1da177e2005-04-16 15:20:36 -07002397 /*
2398 * We have to lock the EOF page here, because lock_page() nests
2399 * outside journal_start().
2400 */
2401 if ((inode->i_size & (blocksize - 1)) == 0) {
2402 /* Block boundary? Nothing to do */
2403 page = NULL;
2404 } else {
2405 page = grab_cache_page(mapping,
2406 inode->i_size >> PAGE_CACHE_SHIFT);
2407 if (!page)
Jan Karaef436182009-06-17 16:26:24 -07002408 goto out_notrans;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002409 }
2410
2411 handle = start_transaction(inode);
2412 if (IS_ERR(handle)) {
2413 if (page) {
2414 clear_highpage(page);
2415 flush_dcache_page(page);
2416 unlock_page(page);
2417 page_cache_release(page);
2418 }
Jan Karaef436182009-06-17 16:26:24 -07002419 goto out_notrans;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002420 }
2421
2422 last_block = (inode->i_size + blocksize-1)
2423 >> EXT3_BLOCK_SIZE_BITS(inode->i_sb);
2424
2425 if (page)
2426 ext3_block_truncate_page(handle, page, mapping, inode->i_size);
2427
2428 n = ext3_block_to_path(inode, last_block, offsets, NULL);
2429 if (n == 0)
2430 goto out_stop; /* error */
2431
2432 /*
2433 * OK. This truncate is going to happen. We add the inode to the
2434 * orphan list, so that if this truncate spans multiple transactions,
2435 * and we crash, we will resume the truncate when the filesystem
2436 * recovers. It also marks the inode dirty, to catch the new size.
2437 *
2438 * Implication: the file must always be in a sane, consistent
2439 * truncatable state while each transaction commits.
2440 */
2441 if (ext3_orphan_add(handle, inode))
2442 goto out_stop;
2443
2444 /*
2445 * The orphan list entry will now protect us from any crash which
2446 * occurs before the truncate completes, so it is now safe to propagate
2447 * the new, shorter inode size (held for now in i_size) into the
2448 * on-disk inode. We do this via i_disksize, which is the value which
2449 * ext3 *really* writes onto the disk inode.
2450 */
2451 ei->i_disksize = inode->i_size;
2452
2453 /*
2454 * From here we block out all ext3_get_block() callers who want to
2455 * modify the block allocation tree.
2456 */
Arjan van de Ven97461512006-03-23 03:00:42 -08002457 mutex_lock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002458
2459 if (n == 1) { /* direct blocks */
2460 ext3_free_data(handle, inode, NULL, i_data+offsets[0],
2461 i_data + EXT3_NDIR_BLOCKS);
2462 goto do_indirects;
2463 }
2464
2465 partial = ext3_find_shared(inode, n, offsets, chain, &nr);
2466 /* Kill the top of shared branch (not detached) */
2467 if (nr) {
2468 if (partial == chain) {
2469 /* Shared branch grows from the inode */
2470 ext3_free_branches(handle, inode, NULL,
2471 &nr, &nr+1, (chain+n-1) - partial);
2472 *partial->p = 0;
2473 /*
2474 * We mark the inode dirty prior to restart,
2475 * and prior to stop. No need for it here.
2476 */
2477 } else {
2478 /* Shared branch grows from an indirect block */
2479 BUFFER_TRACE(partial->bh, "get_write_access");
2480 ext3_free_branches(handle, inode, partial->bh,
2481 partial->p,
2482 partial->p+1, (chain+n-1) - partial);
2483 }
2484 }
2485 /* Clear the ends of indirect blocks on the shared branch */
2486 while (partial > chain) {
2487 ext3_free_branches(handle, inode, partial->bh, partial->p + 1,
2488 (__le32*)partial->bh->b_data+addr_per_block,
2489 (chain+n-1) - partial);
2490 BUFFER_TRACE(partial->bh, "call brelse");
2491 brelse (partial->bh);
2492 partial--;
2493 }
2494do_indirects:
2495 /* Kill the remaining (whole) subtrees */
2496 switch (offsets[0]) {
Andrew Mortond6859bf2006-03-26 01:38:03 -08002497 default:
2498 nr = i_data[EXT3_IND_BLOCK];
2499 if (nr) {
2500 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
2501 i_data[EXT3_IND_BLOCK] = 0;
2502 }
2503 case EXT3_IND_BLOCK:
2504 nr = i_data[EXT3_DIND_BLOCK];
2505 if (nr) {
2506 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
2507 i_data[EXT3_DIND_BLOCK] = 0;
2508 }
2509 case EXT3_DIND_BLOCK:
2510 nr = i_data[EXT3_TIND_BLOCK];
2511 if (nr) {
2512 ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
2513 i_data[EXT3_TIND_BLOCK] = 0;
2514 }
2515 case EXT3_TIND_BLOCK:
2516 ;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002517 }
2518
2519 ext3_discard_reservation(inode);
2520
Arjan van de Ven97461512006-03-23 03:00:42 -08002521 mutex_unlock(&ei->truncate_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002522 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
2523 ext3_mark_inode_dirty(handle, inode);
2524
Andrew Mortond6859bf2006-03-26 01:38:03 -08002525 /*
2526 * In a multi-transaction truncate, we only make the final transaction
2527 * synchronous
2528 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002529 if (IS_SYNC(inode))
2530 handle->h_sync = 1;
2531out_stop:
2532 /*
2533 * If this was a simple ftruncate(), and the file will remain alive
2534 * then we need to clear up the orphan record which we created above.
2535 * However, if this was a real unlink then we were called by
2536 * ext3_delete_inode(), and we allow that function to clean up the
2537 * orphan info for us.
2538 */
2539 if (inode->i_nlink)
2540 ext3_orphan_del(handle, inode);
2541
2542 ext3_journal_stop(handle);
Jan Karaef436182009-06-17 16:26:24 -07002543 return;
2544out_notrans:
2545 /*
2546 * Delete the inode from orphan list so that it doesn't stay there
2547 * forever and trigger assertion on umount.
2548 */
2549 if (inode->i_nlink)
2550 ext3_orphan_del(NULL, inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002551}
2552
Mingming Cao43d23f92006-06-25 05:48:07 -07002553static ext3_fsblk_t ext3_get_inode_block(struct super_block *sb,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002554 unsigned long ino, struct ext3_iloc *iloc)
2555{
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002556 unsigned long block_group;
Mingming Cao43d23f92006-06-25 05:48:07 -07002557 unsigned long offset;
2558 ext3_fsblk_t block;
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002559 struct ext3_group_desc *gdp;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002560
Neil Brown2ccb48e2006-07-30 03:03:01 -07002561 if (!ext3_valid_inum(sb, ino)) {
2562 /*
2563 * This error is already checked for in namei.c unless we are
2564 * looking at an NFS filehandle, in which case no error
2565 * report is needed
2566 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07002567 return 0;
2568 }
Neil Brown2ccb48e2006-07-30 03:03:01 -07002569
Linus Torvalds1da177e2005-04-16 15:20:36 -07002570 block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002571 gdp = ext3_get_group_desc(sb, block_group, NULL);
2572 if (!gdp)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002573 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002574 /*
2575 * Figure out the offset within the block group inode table
2576 */
2577 offset = ((ino - 1) % EXT3_INODES_PER_GROUP(sb)) *
2578 EXT3_INODE_SIZE(sb);
Akinobu Mitae0e369a2008-04-28 02:16:08 -07002579 block = le32_to_cpu(gdp->bg_inode_table) +
Linus Torvalds1da177e2005-04-16 15:20:36 -07002580 (offset >> EXT3_BLOCK_SIZE_BITS(sb));
2581
2582 iloc->block_group = block_group;
2583 iloc->offset = offset & (EXT3_BLOCK_SIZE(sb) - 1);
2584 return block;
2585}
2586
2587/*
2588 * ext3_get_inode_loc returns with an extra refcount against the inode's
2589 * underlying buffer_head on success. If 'in_mem' is true, we have all
2590 * data in memory that is needed to recreate the on-disk version of this
2591 * inode.
2592 */
2593static int __ext3_get_inode_loc(struct inode *inode,
2594 struct ext3_iloc *iloc, int in_mem)
2595{
Mingming Cao43d23f92006-06-25 05:48:07 -07002596 ext3_fsblk_t block;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002597 struct buffer_head *bh;
2598
2599 block = ext3_get_inode_block(inode->i_sb, inode->i_ino, iloc);
2600 if (!block)
2601 return -EIO;
2602
2603 bh = sb_getblk(inode->i_sb, block);
2604 if (!bh) {
2605 ext3_error (inode->i_sb, "ext3_get_inode_loc",
2606 "unable to read inode block - "
Mingming Cao43d23f92006-06-25 05:48:07 -07002607 "inode=%lu, block="E3FSBLK,
2608 inode->i_ino, block);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002609 return -EIO;
2610 }
2611 if (!buffer_uptodate(bh)) {
2612 lock_buffer(bh);
Hidehiro Kawai95450f52008-07-25 01:46:24 -07002613
2614 /*
2615 * If the buffer has the write error flag, we have failed
2616 * to write out another inode in the same block. In this
2617 * case, we don't have to read the block because we may
2618 * read the old inode data successfully.
2619 */
2620 if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
2621 set_buffer_uptodate(bh);
2622
Linus Torvalds1da177e2005-04-16 15:20:36 -07002623 if (buffer_uptodate(bh)) {
2624 /* someone brought it uptodate while we waited */
2625 unlock_buffer(bh);
2626 goto has_buffer;
2627 }
2628
2629 /*
2630 * If we have all information of the inode in memory and this
2631 * is the only valid inode in the block, we need not read the
2632 * block.
2633 */
2634 if (in_mem) {
2635 struct buffer_head *bitmap_bh;
2636 struct ext3_group_desc *desc;
2637 int inodes_per_buffer;
2638 int inode_offset, i;
2639 int block_group;
2640 int start;
2641
2642 block_group = (inode->i_ino - 1) /
2643 EXT3_INODES_PER_GROUP(inode->i_sb);
2644 inodes_per_buffer = bh->b_size /
2645 EXT3_INODE_SIZE(inode->i_sb);
2646 inode_offset = ((inode->i_ino - 1) %
2647 EXT3_INODES_PER_GROUP(inode->i_sb));
2648 start = inode_offset & ~(inodes_per_buffer - 1);
2649
2650 /* Is the inode bitmap in cache? */
2651 desc = ext3_get_group_desc(inode->i_sb,
2652 block_group, NULL);
2653 if (!desc)
2654 goto make_io;
2655
2656 bitmap_bh = sb_getblk(inode->i_sb,
2657 le32_to_cpu(desc->bg_inode_bitmap));
2658 if (!bitmap_bh)
2659 goto make_io;
2660
2661 /*
2662 * If the inode bitmap isn't in cache then the
2663 * optimisation may end up performing two reads instead
2664 * of one, so skip it.
2665 */
2666 if (!buffer_uptodate(bitmap_bh)) {
2667 brelse(bitmap_bh);
2668 goto make_io;
2669 }
2670 for (i = start; i < start + inodes_per_buffer; i++) {
2671 if (i == inode_offset)
2672 continue;
2673 if (ext3_test_bit(i, bitmap_bh->b_data))
2674 break;
2675 }
2676 brelse(bitmap_bh);
2677 if (i == start + inodes_per_buffer) {
2678 /* all other inodes are free, so skip I/O */
2679 memset(bh->b_data, 0, bh->b_size);
2680 set_buffer_uptodate(bh);
2681 unlock_buffer(bh);
2682 goto has_buffer;
2683 }
2684 }
2685
2686make_io:
2687 /*
2688 * There are other valid inodes in the buffer, this inode
2689 * has in-inode xattrs, or we don't have this inode in memory.
2690 * Read the block from disk.
2691 */
2692 get_bh(bh);
2693 bh->b_end_io = end_buffer_read_sync;
Jens Axboecaa38fb2006-07-23 01:41:26 +02002694 submit_bh(READ_META, bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002695 wait_on_buffer(bh);
2696 if (!buffer_uptodate(bh)) {
2697 ext3_error(inode->i_sb, "ext3_get_inode_loc",
2698 "unable to read inode block - "
Mingming Cao43d23f92006-06-25 05:48:07 -07002699 "inode=%lu, block="E3FSBLK,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002700 inode->i_ino, block);
2701 brelse(bh);
2702 return -EIO;
2703 }
2704 }
2705has_buffer:
2706 iloc->bh = bh;
2707 return 0;
2708}
2709
2710int ext3_get_inode_loc(struct inode *inode, struct ext3_iloc *iloc)
2711{
2712 /* We have all inode data except xattrs in memory here. */
2713 return __ext3_get_inode_loc(inode, iloc,
2714 !(EXT3_I(inode)->i_state & EXT3_STATE_XATTR));
2715}
2716
2717void ext3_set_inode_flags(struct inode *inode)
2718{
2719 unsigned int flags = EXT3_I(inode)->i_flags;
2720
2721 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
2722 if (flags & EXT3_SYNC_FL)
2723 inode->i_flags |= S_SYNC;
2724 if (flags & EXT3_APPEND_FL)
2725 inode->i_flags |= S_APPEND;
2726 if (flags & EXT3_IMMUTABLE_FL)
2727 inode->i_flags |= S_IMMUTABLE;
2728 if (flags & EXT3_NOATIME_FL)
2729 inode->i_flags |= S_NOATIME;
2730 if (flags & EXT3_DIRSYNC_FL)
2731 inode->i_flags |= S_DIRSYNC;
2732}
2733
Jan Kara28be5ab2007-05-08 00:30:33 -07002734/* Propagate flags from i_flags to EXT3_I(inode)->i_flags */
2735void ext3_get_inode_flags(struct ext3_inode_info *ei)
2736{
2737 unsigned int flags = ei->vfs_inode.i_flags;
2738
2739 ei->i_flags &= ~(EXT3_SYNC_FL|EXT3_APPEND_FL|
2740 EXT3_IMMUTABLE_FL|EXT3_NOATIME_FL|EXT3_DIRSYNC_FL);
2741 if (flags & S_SYNC)
2742 ei->i_flags |= EXT3_SYNC_FL;
2743 if (flags & S_APPEND)
2744 ei->i_flags |= EXT3_APPEND_FL;
2745 if (flags & S_IMMUTABLE)
2746 ei->i_flags |= EXT3_IMMUTABLE_FL;
2747 if (flags & S_NOATIME)
2748 ei->i_flags |= EXT3_NOATIME_FL;
2749 if (flags & S_DIRSYNC)
2750 ei->i_flags |= EXT3_DIRSYNC_FL;
2751}
2752
David Howells473043d2008-02-07 00:15:36 -08002753struct inode *ext3_iget(struct super_block *sb, unsigned long ino)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002754{
2755 struct ext3_iloc iloc;
2756 struct ext3_inode *raw_inode;
David Howells473043d2008-02-07 00:15:36 -08002757 struct ext3_inode_info *ei;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002758 struct buffer_head *bh;
David Howells473043d2008-02-07 00:15:36 -08002759 struct inode *inode;
Jan Karafe8bc912009-10-16 19:26:15 +02002760 journal_t *journal = EXT3_SB(sb)->s_journal;
2761 transaction_t *transaction;
David Howells473043d2008-02-07 00:15:36 -08002762 long ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002763 int block;
2764
David Howells473043d2008-02-07 00:15:36 -08002765 inode = iget_locked(sb, ino);
2766 if (!inode)
2767 return ERR_PTR(-ENOMEM);
2768 if (!(inode->i_state & I_NEW))
2769 return inode;
2770
2771 ei = EXT3_I(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002772 ei->i_block_alloc_info = NULL;
2773
David Howells473043d2008-02-07 00:15:36 -08002774 ret = __ext3_get_inode_loc(inode, &iloc, 0);
2775 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002776 goto bad_inode;
2777 bh = iloc.bh;
2778 raw_inode = ext3_raw_inode(&iloc);
2779 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
2780 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
2781 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
2782 if(!(test_opt (inode->i_sb, NO_UID32))) {
2783 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
2784 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
2785 }
2786 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
2787 inode->i_size = le32_to_cpu(raw_inode->i_size);
Markus Rechberger4d7bf112007-05-08 00:23:39 -07002788 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
2789 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
2790 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002791 inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
2792
2793 ei->i_state = 0;
2794 ei->i_dir_start_lookup = 0;
2795 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
2796 /* We now have enough fields to check if the inode was active or not.
2797 * This is needed because nfsd might try to access dead inodes
2798 * the test is that same one that e2fsck uses
2799 * NeilBrown 1999oct15
2800 */
2801 if (inode->i_nlink == 0) {
2802 if (inode->i_mode == 0 ||
2803 !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) {
2804 /* this inode is deleted */
2805 brelse (bh);
David Howells473043d2008-02-07 00:15:36 -08002806 ret = -ESTALE;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002807 goto bad_inode;
2808 }
2809 /* The only unlinked inodes we let through here have
2810 * valid i_mode and are being read by the orphan
2811 * recovery code: that's fine, we're about to complete
2812 * the process of deleting those. */
2813 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002814 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
2815 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
2816#ifdef EXT3_FRAGMENTS
2817 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
2818 ei->i_frag_no = raw_inode->i_frag;
2819 ei->i_frag_size = raw_inode->i_fsize;
2820#endif
2821 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
2822 if (!S_ISREG(inode->i_mode)) {
2823 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
2824 } else {
2825 inode->i_size |=
2826 ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
2827 }
2828 ei->i_disksize = inode->i_size;
2829 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
2830 ei->i_block_group = iloc.block_group;
2831 /*
2832 * NOTE! The in-memory inode i_data array is in little-endian order
2833 * even on big-endian machines: we do NOT byteswap the block numbers!
2834 */
2835 for (block = 0; block < EXT3_N_BLOCKS; block++)
2836 ei->i_data[block] = raw_inode->i_block[block];
2837 INIT_LIST_HEAD(&ei->i_orphan);
2838
Jan Karafe8bc912009-10-16 19:26:15 +02002839 /*
2840 * Set transaction id's of transactions that have to be committed
2841 * to finish f[data]sync. We set them to currently running transaction
2842 * as we cannot be sure that the inode or some of its metadata isn't
2843 * part of the transaction - the inode could have been reclaimed and
2844 * now it is reread from disk.
2845 */
2846 if (journal) {
2847 tid_t tid;
2848
2849 spin_lock(&journal->j_state_lock);
2850 if (journal->j_running_transaction)
2851 transaction = journal->j_running_transaction;
2852 else
2853 transaction = journal->j_committing_transaction;
2854 if (transaction)
2855 tid = transaction->t_tid;
2856 else
2857 tid = journal->j_commit_sequence;
2858 spin_unlock(&journal->j_state_lock);
2859 atomic_set(&ei->i_sync_tid, tid);
2860 atomic_set(&ei->i_datasync_tid, tid);
2861 }
2862
Linus Torvalds1da177e2005-04-16 15:20:36 -07002863 if (inode->i_ino >= EXT3_FIRST_INO(inode->i_sb) + 1 &&
2864 EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) {
2865 /*
2866 * When mke2fs creates big inodes it does not zero out
2867 * the unused bytes above EXT3_GOOD_OLD_INODE_SIZE,
2868 * so ignore those first few inodes.
2869 */
2870 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
2871 if (EXT3_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
Kirill Korotaeve4a10a32007-06-23 17:16:48 -07002872 EXT3_INODE_SIZE(inode->i_sb)) {
2873 brelse (bh);
David Howells473043d2008-02-07 00:15:36 -08002874 ret = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002875 goto bad_inode;
Kirill Korotaeve4a10a32007-06-23 17:16:48 -07002876 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07002877 if (ei->i_extra_isize == 0) {
2878 /* The extra space is currently unused. Use it. */
2879 ei->i_extra_isize = sizeof(struct ext3_inode) -
2880 EXT3_GOOD_OLD_INODE_SIZE;
2881 } else {
2882 __le32 *magic = (void *)raw_inode +
2883 EXT3_GOOD_OLD_INODE_SIZE +
2884 ei->i_extra_isize;
2885 if (*magic == cpu_to_le32(EXT3_XATTR_MAGIC))
2886 ei->i_state |= EXT3_STATE_XATTR;
2887 }
2888 } else
2889 ei->i_extra_isize = 0;
2890
2891 if (S_ISREG(inode->i_mode)) {
2892 inode->i_op = &ext3_file_inode_operations;
2893 inode->i_fop = &ext3_file_operations;
2894 ext3_set_aops(inode);
2895 } else if (S_ISDIR(inode->i_mode)) {
2896 inode->i_op = &ext3_dir_inode_operations;
2897 inode->i_fop = &ext3_dir_operations;
2898 } else if (S_ISLNK(inode->i_mode)) {
Duane Griffinb5ed3112008-12-19 20:47:14 +00002899 if (ext3_inode_is_fast_symlink(inode)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002900 inode->i_op = &ext3_fast_symlink_inode_operations;
Duane Griffinb5ed3112008-12-19 20:47:14 +00002901 nd_terminate_link(ei->i_data, inode->i_size,
2902 sizeof(ei->i_data) - 1);
2903 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07002904 inode->i_op = &ext3_symlink_inode_operations;
2905 ext3_set_aops(inode);
2906 }
2907 } else {
2908 inode->i_op = &ext3_special_inode_operations;
2909 if (raw_inode->i_block[0])
2910 init_special_inode(inode, inode->i_mode,
2911 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002912 else
Linus Torvalds1da177e2005-04-16 15:20:36 -07002913 init_special_inode(inode, inode->i_mode,
2914 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
2915 }
2916 brelse (iloc.bh);
2917 ext3_set_inode_flags(inode);
David Howells473043d2008-02-07 00:15:36 -08002918 unlock_new_inode(inode);
2919 return inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07002920
2921bad_inode:
David Howells473043d2008-02-07 00:15:36 -08002922 iget_failed(inode);
2923 return ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002924}
2925
2926/*
2927 * Post the struct inode info into an on-disk inode location in the
2928 * buffer-cache. This gobbles the caller's reference to the
2929 * buffer_head in the inode location struct.
2930 *
2931 * The caller must have write access to iloc->bh.
2932 */
Mingming Caoae6ddcc2006-09-27 01:49:27 -07002933static int ext3_do_update_inode(handle_t *handle,
2934 struct inode *inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07002935 struct ext3_iloc *iloc)
2936{
2937 struct ext3_inode *raw_inode = ext3_raw_inode(iloc);
2938 struct ext3_inode_info *ei = EXT3_I(inode);
2939 struct buffer_head *bh = iloc->bh;
2940 int err = 0, rc, block;
2941
Chris Mason4f003fd2009-09-08 00:22:14 +02002942again:
2943 /* we can't allow multiple procs in here at once, its a bit racey */
2944 lock_buffer(bh);
2945
Linus Torvalds1da177e2005-04-16 15:20:36 -07002946 /* For fields not not tracking in the in-memory inode,
2947 * initialise them to zero for new inodes. */
2948 if (ei->i_state & EXT3_STATE_NEW)
2949 memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
2950
Jan Kara28be5ab2007-05-08 00:30:33 -07002951 ext3_get_inode_flags(ei);
Linus Torvalds1da177e2005-04-16 15:20:36 -07002952 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
2953 if(!(test_opt(inode->i_sb, NO_UID32))) {
2954 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
2955 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
2956/*
2957 * Fix up interoperability with old kernels. Otherwise, old inodes get
2958 * re-used with the upper 16 bits of the uid/gid intact
2959 */
2960 if(!ei->i_dtime) {
2961 raw_inode->i_uid_high =
2962 cpu_to_le16(high_16_bits(inode->i_uid));
2963 raw_inode->i_gid_high =
2964 cpu_to_le16(high_16_bits(inode->i_gid));
2965 } else {
2966 raw_inode->i_uid_high = 0;
2967 raw_inode->i_gid_high = 0;
2968 }
2969 } else {
2970 raw_inode->i_uid_low =
2971 cpu_to_le16(fs_high2lowuid(inode->i_uid));
2972 raw_inode->i_gid_low =
2973 cpu_to_le16(fs_high2lowgid(inode->i_gid));
2974 raw_inode->i_uid_high = 0;
2975 raw_inode->i_gid_high = 0;
2976 }
2977 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
2978 raw_inode->i_size = cpu_to_le32(ei->i_disksize);
2979 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
2980 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
2981 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
2982 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
2983 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
2984 raw_inode->i_flags = cpu_to_le32(ei->i_flags);
2985#ifdef EXT3_FRAGMENTS
2986 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
2987 raw_inode->i_frag = ei->i_frag_no;
2988 raw_inode->i_fsize = ei->i_frag_size;
2989#endif
2990 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
2991 if (!S_ISREG(inode->i_mode)) {
2992 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
2993 } else {
2994 raw_inode->i_size_high =
2995 cpu_to_le32(ei->i_disksize >> 32);
2996 if (ei->i_disksize > 0x7fffffffULL) {
2997 struct super_block *sb = inode->i_sb;
2998 if (!EXT3_HAS_RO_COMPAT_FEATURE(sb,
2999 EXT3_FEATURE_RO_COMPAT_LARGE_FILE) ||
3000 EXT3_SB(sb)->s_es->s_rev_level ==
3001 cpu_to_le32(EXT3_GOOD_OLD_REV)) {
3002 /* If this is the first large file
3003 * created, add a flag to the superblock.
3004 */
Chris Mason4f003fd2009-09-08 00:22:14 +02003005 unlock_buffer(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003006 err = ext3_journal_get_write_access(handle,
3007 EXT3_SB(sb)->s_sbh);
3008 if (err)
3009 goto out_brelse;
Chris Mason4f003fd2009-09-08 00:22:14 +02003010
Linus Torvalds1da177e2005-04-16 15:20:36 -07003011 ext3_update_dynamic_rev(sb);
3012 EXT3_SET_RO_COMPAT_FEATURE(sb,
3013 EXT3_FEATURE_RO_COMPAT_LARGE_FILE);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003014 handle->h_sync = 1;
3015 err = ext3_journal_dirty_metadata(handle,
3016 EXT3_SB(sb)->s_sbh);
Chris Mason4f003fd2009-09-08 00:22:14 +02003017 /* get our lock and start over */
3018 goto again;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003019 }
3020 }
3021 }
3022 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
3023 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
3024 if (old_valid_dev(inode->i_rdev)) {
3025 raw_inode->i_block[0] =
3026 cpu_to_le32(old_encode_dev(inode->i_rdev));
3027 raw_inode->i_block[1] = 0;
3028 } else {
3029 raw_inode->i_block[0] = 0;
3030 raw_inode->i_block[1] =
3031 cpu_to_le32(new_encode_dev(inode->i_rdev));
3032 raw_inode->i_block[2] = 0;
3033 }
3034 } else for (block = 0; block < EXT3_N_BLOCKS; block++)
3035 raw_inode->i_block[block] = ei->i_data[block];
3036
Andreas Gruenbacherff87b372005-07-07 17:57:00 -07003037 if (ei->i_extra_isize)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003038 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
3039
3040 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
Chris Mason4f003fd2009-09-08 00:22:14 +02003041 unlock_buffer(bh);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003042 rc = ext3_journal_dirty_metadata(handle, bh);
3043 if (!err)
3044 err = rc;
3045 ei->i_state &= ~EXT3_STATE_NEW;
3046
Jan Karafe8bc912009-10-16 19:26:15 +02003047 atomic_set(&ei->i_sync_tid, handle->h_transaction->t_tid);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003048out_brelse:
3049 brelse (bh);
3050 ext3_std_error(inode->i_sb, err);
3051 return err;
3052}
3053
3054/*
3055 * ext3_write_inode()
3056 *
3057 * We are called from a few places:
3058 *
3059 * - Within generic_file_write() for O_SYNC files.
3060 * Here, there will be no transaction running. We wait for any running
3061 * trasnaction to commit.
3062 *
3063 * - Within sys_sync(), kupdate and such.
3064 * We wait on commit, if tol to.
3065 *
3066 * - Within prune_icache() (PF_MEMALLOC == true)
3067 * Here we simply return. We can't afford to block kswapd on the
3068 * journal commit.
3069 *
3070 * In all cases it is actually safe for us to return without doing anything,
3071 * because the inode has been copied into a raw inode buffer in
3072 * ext3_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
3073 * knfsd.
3074 *
3075 * Note that we are absolutely dependent upon all inode dirtiers doing the
3076 * right thing: they *must* call mark_inode_dirty() after dirtying info in
3077 * which we are interested.
3078 *
3079 * It would be a bug for them to not do this. The code:
3080 *
3081 * mark_inode_dirty(inode)
3082 * stuff();
3083 * inode->i_size = expr;
3084 *
3085 * is in error because a kswapd-driven write_inode() could occur while
3086 * `stuff()' is running, and the new i_size will be lost. Plus the inode
3087 * will no longer be on the superblock's dirty inode list.
3088 */
3089int ext3_write_inode(struct inode *inode, int wait)
3090{
3091 if (current->flags & PF_MEMALLOC)
3092 return 0;
3093
3094 if (ext3_journal_current_handle()) {
Jose R. Santos9ad163a2007-10-18 23:39:23 -07003095 jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -07003096 dump_stack();
3097 return -EIO;
3098 }
3099
3100 if (!wait)
3101 return 0;
3102
3103 return ext3_force_commit(inode->i_sb);
3104}
3105
3106/*
3107 * ext3_setattr()
3108 *
3109 * Called from notify_change.
3110 *
3111 * We want to trap VFS attempts to truncate the file as soon as
3112 * possible. In particular, we want to make sure that when the VFS
3113 * shrinks i_size, we put the inode on the orphan list and modify
3114 * i_disksize immediately, so that during the subsequent flushing of
3115 * dirty pages and freeing of disk blocks, we can guarantee that any
3116 * commit will leave the blocks being flushed in an unused state on
3117 * disk. (On recovery, the inode will get truncated and the blocks will
3118 * be freed, so we have a strong guarantee that no future commit will
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003119 * leave these blocks visible to the user.)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003120 *
3121 * Called with inode->sem down.
3122 */
3123int ext3_setattr(struct dentry *dentry, struct iattr *attr)
3124{
3125 struct inode *inode = dentry->d_inode;
3126 int error, rc = 0;
3127 const unsigned int ia_valid = attr->ia_valid;
3128
3129 error = inode_change_ok(inode, attr);
3130 if (error)
3131 return error;
3132
3133 if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
3134 (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
3135 handle_t *handle;
3136
3137 /* (user+group)*(old+new) structure, inode write (sb,
3138 * inode block, ? - but truncate inode update has it) */
Jan Kara1f545872005-06-23 22:01:04 -07003139 handle = ext3_journal_start(inode, 2*(EXT3_QUOTA_INIT_BLOCKS(inode->i_sb)+
3140 EXT3_QUOTA_DEL_BLOCKS(inode->i_sb))+3);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003141 if (IS_ERR(handle)) {
3142 error = PTR_ERR(handle);
3143 goto err_out;
3144 }
Jan Kara81a05222009-01-26 16:58:01 +01003145 error = vfs_dq_transfer(inode, attr) ? -EDQUOT : 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07003146 if (error) {
3147 ext3_journal_stop(handle);
3148 return error;
3149 }
3150 /* Update corresponding info in inode so that everything is in
3151 * one transaction */
3152 if (attr->ia_valid & ATTR_UID)
3153 inode->i_uid = attr->ia_uid;
3154 if (attr->ia_valid & ATTR_GID)
3155 inode->i_gid = attr->ia_gid;
3156 error = ext3_mark_inode_dirty(handle, inode);
3157 ext3_journal_stop(handle);
3158 }
3159
3160 if (S_ISREG(inode->i_mode) &&
3161 attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
3162 handle_t *handle;
3163
3164 handle = ext3_journal_start(inode, 3);
3165 if (IS_ERR(handle)) {
3166 error = PTR_ERR(handle);
3167 goto err_out;
3168 }
3169
3170 error = ext3_orphan_add(handle, inode);
3171 EXT3_I(inode)->i_disksize = attr->ia_size;
3172 rc = ext3_mark_inode_dirty(handle, inode);
3173 if (!error)
3174 error = rc;
3175 ext3_journal_stop(handle);
3176 }
3177
3178 rc = inode_setattr(inode, attr);
3179
Linus Torvalds1da177e2005-04-16 15:20:36 -07003180 if (!rc && (ia_valid & ATTR_MODE))
3181 rc = ext3_acl_chmod(inode);
3182
3183err_out:
3184 ext3_std_error(inode->i_sb, error);
3185 if (!error)
3186 error = rc;
3187 return error;
3188}
3189
3190
3191/*
Andrew Mortond6859bf2006-03-26 01:38:03 -08003192 * How many blocks doth make a writepage()?
Linus Torvalds1da177e2005-04-16 15:20:36 -07003193 *
3194 * With N blocks per page, it may be:
3195 * N data blocks
3196 * 2 indirect block
3197 * 2 dindirect
3198 * 1 tindirect
3199 * N+5 bitmap blocks (from the above)
3200 * N+5 group descriptor summary blocks
3201 * 1 inode block
3202 * 1 superblock.
3203 * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quote files
3204 *
3205 * 3 * (N + 5) + 2 + 2 * EXT3_SINGLEDATA_TRANS_BLOCKS
3206 *
3207 * With ordered or writeback data it's the same, less the N data blocks.
3208 *
3209 * If the inode's direct blocks can hold an integral number of pages then a
3210 * page cannot straddle two indirect blocks, and we can only touch one indirect
3211 * and dindirect block, and the "5" above becomes "3".
3212 *
3213 * This still overestimates under most circumstances. If we were to pass the
3214 * start and end offsets in here as well we could do block_to_path() on each
3215 * block and work out the exact number of indirects which are touched. Pah.
3216 */
3217
3218static int ext3_writepage_trans_blocks(struct inode *inode)
3219{
3220 int bpp = ext3_journal_blocks_per_page(inode);
3221 int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3;
3222 int ret;
3223
3224 if (ext3_should_journal_data(inode))
3225 ret = 3 * (bpp + indirects) + 2;
3226 else
3227 ret = 2 * (bpp + indirects) + 2;
3228
3229#ifdef CONFIG_QUOTA
Jan Kara81a05222009-01-26 16:58:01 +01003230 /* We know that structure was already allocated during vfs_dq_init so
Linus Torvalds1da177e2005-04-16 15:20:36 -07003231 * we will be updating only the data blocks + inodes */
Jan Kara1f545872005-06-23 22:01:04 -07003232 ret += 2*EXT3_QUOTA_TRANS_BLOCKS(inode->i_sb);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003233#endif
3234
3235 return ret;
3236}
3237
3238/*
3239 * The caller must have previously called ext3_reserve_inode_write().
3240 * Give this, we know that the caller already has write access to iloc->bh.
3241 */
3242int ext3_mark_iloc_dirty(handle_t *handle,
3243 struct inode *inode, struct ext3_iloc *iloc)
3244{
3245 int err = 0;
3246
3247 /* the do_update_inode consumes one bh->b_count */
3248 get_bh(iloc->bh);
3249
3250 /* ext3_do_update_inode() does journal_dirty_metadata */
3251 err = ext3_do_update_inode(handle, inode, iloc);
3252 put_bh(iloc->bh);
3253 return err;
3254}
3255
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003256/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003257 * On success, We end up with an outstanding reference count against
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003258 * iloc->bh. This _must_ be cleaned up later.
Linus Torvalds1da177e2005-04-16 15:20:36 -07003259 */
3260
3261int
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003262ext3_reserve_inode_write(handle_t *handle, struct inode *inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003263 struct ext3_iloc *iloc)
3264{
3265 int err = 0;
3266 if (handle) {
3267 err = ext3_get_inode_loc(inode, iloc);
3268 if (!err) {
3269 BUFFER_TRACE(iloc->bh, "get_write_access");
3270 err = ext3_journal_get_write_access(handle, iloc->bh);
3271 if (err) {
3272 brelse(iloc->bh);
3273 iloc->bh = NULL;
3274 }
3275 }
3276 }
3277 ext3_std_error(inode->i_sb, err);
3278 return err;
3279}
3280
3281/*
Andrew Mortond6859bf2006-03-26 01:38:03 -08003282 * What we do here is to mark the in-core inode as clean with respect to inode
3283 * dirtiness (it may still be data-dirty).
Linus Torvalds1da177e2005-04-16 15:20:36 -07003284 * This means that the in-core inode may be reaped by prune_icache
3285 * without having to perform any I/O. This is a very good thing,
3286 * because *any* task may call prune_icache - even ones which
3287 * have a transaction open against a different journal.
3288 *
3289 * Is this cheating? Not really. Sure, we haven't written the
3290 * inode out, but prune_icache isn't a user-visible syncing function.
3291 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
3292 * we start and wait on commits.
3293 *
3294 * Is this efficient/effective? Well, we're being nice to the system
3295 * by cleaning up our inodes proactively so they can be reaped
3296 * without I/O. But we are potentially leaving up to five seconds'
3297 * worth of inodes floating about which prune_icache wants us to
3298 * write out. One way to fix that would be to get prune_icache()
3299 * to do a write_super() to free up some memory. It has the desired
3300 * effect.
3301 */
3302int ext3_mark_inode_dirty(handle_t *handle, struct inode *inode)
3303{
3304 struct ext3_iloc iloc;
3305 int err;
3306
3307 might_sleep();
3308 err = ext3_reserve_inode_write(handle, inode, &iloc);
3309 if (!err)
3310 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
3311 return err;
3312}
3313
3314/*
Andrew Mortond6859bf2006-03-26 01:38:03 -08003315 * ext3_dirty_inode() is called from __mark_inode_dirty()
Linus Torvalds1da177e2005-04-16 15:20:36 -07003316 *
3317 * We're really interested in the case where a file is being extended.
3318 * i_size has been changed by generic_commit_write() and we thus need
3319 * to include the updated inode in the current transaction.
3320 *
Jan Kara81a05222009-01-26 16:58:01 +01003321 * Also, vfs_dq_alloc_space() will always dirty the inode when blocks
Linus Torvalds1da177e2005-04-16 15:20:36 -07003322 * are allocated to the file.
3323 *
3324 * If the inode is marked synchronous, we don't honour that here - doing
3325 * so would cause a commit on atime updates, which we don't bother doing.
3326 * We handle synchronous inodes at the highest possible level.
3327 */
3328void ext3_dirty_inode(struct inode *inode)
3329{
3330 handle_t *current_handle = ext3_journal_current_handle();
3331 handle_t *handle;
3332
3333 handle = ext3_journal_start(inode, 2);
3334 if (IS_ERR(handle))
3335 goto out;
3336 if (current_handle &&
3337 current_handle->h_transaction != handle->h_transaction) {
3338 /* This task has a transaction open against a different fs */
3339 printk(KERN_EMERG "%s: transactions do not match!\n",
Harvey Harrisone05b6b52008-04-28 02:16:15 -07003340 __func__);
Linus Torvalds1da177e2005-04-16 15:20:36 -07003341 } else {
3342 jbd_debug(5, "marking dirty. outer handle=%p\n",
3343 current_handle);
3344 ext3_mark_inode_dirty(handle, inode);
3345 }
3346 ext3_journal_stop(handle);
3347out:
3348 return;
3349}
3350
Andrew Mortond6859bf2006-03-26 01:38:03 -08003351#if 0
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003352/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07003353 * Bind an inode's backing buffer_head into this transaction, to prevent
3354 * it from being flushed to disk early. Unlike
3355 * ext3_reserve_inode_write, this leaves behind no bh reference and
3356 * returns no iloc structure, so the caller needs to repeat the iloc
3357 * lookup to mark the inode dirty later.
3358 */
Andrew Mortond6859bf2006-03-26 01:38:03 -08003359static int ext3_pin_inode(handle_t *handle, struct inode *inode)
Linus Torvalds1da177e2005-04-16 15:20:36 -07003360{
3361 struct ext3_iloc iloc;
3362
3363 int err = 0;
3364 if (handle) {
3365 err = ext3_get_inode_loc(inode, &iloc);
3366 if (!err) {
3367 BUFFER_TRACE(iloc.bh, "get_write_access");
3368 err = journal_get_write_access(handle, iloc.bh);
3369 if (!err)
Mingming Caoae6ddcc2006-09-27 01:49:27 -07003370 err = ext3_journal_dirty_metadata(handle,
Linus Torvalds1da177e2005-04-16 15:20:36 -07003371 iloc.bh);
3372 brelse(iloc.bh);
3373 }
3374 }
3375 ext3_std_error(inode->i_sb, err);
3376 return err;
3377}
3378#endif
3379
3380int ext3_change_inode_journal_flag(struct inode *inode, int val)
3381{
3382 journal_t *journal;
3383 handle_t *handle;
3384 int err;
3385
3386 /*
3387 * We have to be very careful here: changing a data block's
3388 * journaling status dynamically is dangerous. If we write a
3389 * data block to the journal, change the status and then delete
3390 * that block, we risk forgetting to revoke the old log record
3391 * from the journal and so a subsequent replay can corrupt data.
3392 * So, first we make sure that the journal is empty and that
3393 * nobody is changing anything.
3394 */
3395
3396 journal = EXT3_JOURNAL(inode);
Dave Hansene3a68e32007-07-15 23:41:14 -07003397 if (is_journal_aborted(journal))
Linus Torvalds1da177e2005-04-16 15:20:36 -07003398 return -EROFS;
3399
3400 journal_lock_updates(journal);
3401 journal_flush(journal);
3402
3403 /*
3404 * OK, there are no updates running now, and all cached data is
3405 * synced to disk. We are now in a completely consistent state
3406 * which doesn't have anything in the journal, and we know that
3407 * no filesystem updates are running, so it is safe to modify
3408 * the inode's in-core data-journaling state flag now.
3409 */
3410
3411 if (val)
3412 EXT3_I(inode)->i_flags |= EXT3_JOURNAL_DATA_FL;
3413 else
3414 EXT3_I(inode)->i_flags &= ~EXT3_JOURNAL_DATA_FL;
3415 ext3_set_aops(inode);
3416
3417 journal_unlock_updates(journal);
3418
3419 /* Finally we can mark the inode as dirty. */
3420
3421 handle = ext3_journal_start(inode, 1);
3422 if (IS_ERR(handle))
3423 return PTR_ERR(handle);
3424
3425 err = ext3_mark_inode_dirty(handle, inode);
3426 handle->h_sync = 1;
3427 ext3_journal_stop(handle);
3428 ext3_std_error(inode->i_sb, err);
3429
3430 return err;
3431}