Branch data Line data Source code
1 : : /*
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
16 : : * (sct@redhat.com), 1993, 1998
17 : : * 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
20 : : * (jj@sunsite.ms.mff.cuni.cz)
21 : : *
22 : : * Assorted race fixes, rewrite of ext3_get_block() by Al Viro, 2000
23 : : */
24 : :
25 : : #include <linux/highuid.h>
26 : : #include <linux/quotaops.h>
27 : : #include <linux/writeback.h>
28 : : #include <linux/mpage.h>
29 : : #include <linux/namei.h>
30 : : #include <linux/aio.h>
31 : : #include "ext3.h"
32 : : #include "xattr.h"
33 : : #include "acl.h"
34 : :
35 : : static int ext3_writepage_trans_blocks(struct inode *inode);
36 : : static int ext3_block_truncate_page(struct inode *inode, loff_t from);
37 : :
38 : : /*
39 : : * Test whether an inode is a fast symlink.
40 : : */
41 : : static int ext3_inode_is_fast_symlink(struct inode *inode)
42 : : {
43 [ # # ][ # # ]: 0 : int ea_blocks = EXT3_I(inode)->i_file_acl ?
44 : 0 : (inode->i_sb->s_blocksize >> 9) : 0;
45 : :
46 [ # # ][ # # ]: 0 : return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
[ # # ][ # # ]
47 : : }
48 : :
49 : : /*
50 : : * The ext3 forget function must perform a revoke if we are freeing data
51 : : * which has been journaled. Metadata (eg. indirect blocks) must be
52 : : * revoked in all cases.
53 : : *
54 : : * "bh" may be NULL: a metadata block may have been freed from memory
55 : : * but there may still be a record of it in the journal, and that record
56 : : * still needs to be revoked.
57 : : */
58 : 0 : int ext3_forget(handle_t *handle, int is_metadata, struct inode *inode,
59 : : struct buffer_head *bh, ext3_fsblk_t blocknr)
60 : : {
61 : : int err;
62 : :
63 : : might_sleep();
64 : :
65 : : trace_ext3_forget(inode, is_metadata, blocknr);
66 : : BUFFER_TRACE(bh, "enter");
67 : :
68 : : jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
69 : : "data mode %lx\n",
70 : : bh, is_metadata, inode->i_mode,
71 : : test_opt(inode->i_sb, DATA_FLAGS));
72 : :
73 : : /* Never use the revoke function if we are doing full data
74 : : * journaling: there is no need to, and a V1 superblock won't
75 : : * support it. Otherwise, only skip the revoke on un-journaled
76 : : * data blocks. */
77 : :
78 [ # # ][ # # ]: 0 : if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ||
79 [ # # ]: 0 : (!is_metadata && !ext3_should_journal_data(inode))) {
80 [ # # ]: 0 : if (bh) {
81 : : BUFFER_TRACE(bh, "call journal_forget");
82 : 0 : return ext3_journal_forget(handle, bh);
83 : : }
84 : : return 0;
85 : : }
86 : :
87 : : /*
88 : : * data!=journal && (is_metadata || should_journal_data(inode))
89 : : */
90 : : BUFFER_TRACE(bh, "call ext3_journal_revoke");
91 : 0 : err = ext3_journal_revoke(handle, blocknr, bh);
92 [ # # ]: 0 : if (err)
93 : 0 : ext3_abort(inode->i_sb, __func__,
94 : : "error %d when attempting revoke", err);
95 : : BUFFER_TRACE(bh, "exit");
96 : 0 : return err;
97 : : }
98 : :
99 : : /*
100 : : * Work out how many blocks we need to proceed with the next chunk of a
101 : : * truncate transaction.
102 : : */
103 : 0 : static unsigned long blocks_for_truncate(struct inode *inode)
104 : : {
105 : : unsigned long needed;
106 : :
107 : 0 : needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
108 : :
109 : : /* Give ourselves just enough room to cope with inodes in which
110 : : * i_blocks is corrupt: we've seen disk corruptions in the past
111 : : * which resulted in random data in an inode which looked enough
112 : : * like a regular file for ext3 to try to delete it. Things
113 : : * will go a bit crazy if that happens, but at least we should
114 : : * try not to panic the whole kernel. */
115 [ # # ]: 0 : if (needed < 2)
116 : : needed = 2;
117 : :
118 : : /* But we need to bound the transaction so we don't overflow the
119 : : * journal. */
120 [ # # ]: 0 : if (needed > EXT3_MAX_TRANS_DATA)
121 : : needed = EXT3_MAX_TRANS_DATA;
122 : :
123 [ # # ]: 0 : return EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
124 : : }
125 : :
126 : : /*
127 : : * Truncate transactions can be complex and absolutely huge. So we need to
128 : : * be able to restart the transaction at a conventient checkpoint to make
129 : : * sure we don't overflow the journal.
130 : : *
131 : : * start_transaction gets us a new handle for a truncate transaction,
132 : : * and extend_transaction tries to extend the existing one a bit. If
133 : : * extend fails, we need to propagate the failure up and restart the
134 : : * transaction in the top-level truncate loop. --sct
135 : : */
136 : 0 : static handle_t *start_transaction(struct inode *inode)
137 : : {
138 : : handle_t *result;
139 : :
140 : 0 : result = ext3_journal_start(inode, blocks_for_truncate(inode));
141 [ # # ]: 0 : if (!IS_ERR(result))
142 : : return result;
143 : :
144 [ # # ]: 0 : ext3_std_error(inode->i_sb, PTR_ERR(result));
145 : : return result;
146 : : }
147 : :
148 : : /*
149 : : * Try to extend this transaction for the purposes of truncation.
150 : : *
151 : : * Returns 0 if we managed to create more room. If we can't create more
152 : : * room, and the transaction must be restarted we return 1.
153 : : */
154 : 0 : static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
155 : : {
156 [ # # ]: 0 : if (handle->h_buffer_credits > EXT3_RESERVE_TRANS_BLOCKS)
157 : : return 0;
158 [ # # ]: 0 : if (!ext3_journal_extend(handle, blocks_for_truncate(inode)))
159 : : return 0;
160 : 0 : return 1;
161 : : }
162 : :
163 : : /*
164 : : * Restart the transaction associated with *handle. This does a commit,
165 : : * so before we call here everything must be consistently dirtied against
166 : : * this transaction.
167 : : */
168 : 0 : static int truncate_restart_transaction(handle_t *handle, struct inode *inode)
169 : : {
170 : : int ret;
171 : :
172 : : jbd_debug(2, "restarting handle %p\n", handle);
173 : : /*
174 : : * Drop truncate_mutex to avoid deadlock with ext3_get_blocks_handle
175 : : * At this moment, get_block can be called only for blocks inside
176 : : * i_size since page cache has been already dropped and writes are
177 : : * blocked by i_mutex. So we can safely drop the truncate_mutex.
178 : : */
179 : 0 : mutex_unlock(&EXT3_I(inode)->truncate_mutex);
180 : 0 : ret = ext3_journal_restart(handle, blocks_for_truncate(inode));
181 : 0 : mutex_lock(&EXT3_I(inode)->truncate_mutex);
182 : 0 : return ret;
183 : : }
184 : :
185 : : /*
186 : : * Called at inode eviction from icache
187 : : */
188 : 0 : void ext3_evict_inode (struct inode *inode)
189 : : {
190 : : struct ext3_inode_info *ei = EXT3_I(inode);
191 : : struct ext3_block_alloc_info *rsv;
192 : : handle_t *handle;
193 : : int want_delete = 0;
194 : :
195 : : trace_ext3_evict_inode(inode);
196 [ # # ][ # # ]: 0 : if (!inode->i_nlink && !is_bad_inode(inode)) {
197 : 0 : dquot_initialize(inode);
198 : : want_delete = 1;
199 : : }
200 : :
201 : : /*
202 : : * When journalling data dirty buffers are tracked only in the journal.
203 : : * So although mm thinks everything is clean and ready for reaping the
204 : : * inode might still have some pages to write in the running
205 : : * transaction or waiting to be checkpointed. Thus calling
206 : : * journal_invalidatepage() (via truncate_inode_pages()) to discard
207 : : * these buffers can cause data loss. Also even if we did not discard
208 : : * these buffers, we would have no way to find them after the inode
209 : : * is reaped and thus user could see stale data if he tries to read
210 : : * them before the transaction is checkpointed. So be careful and
211 : : * force everything to disk here... We use ei->i_datasync_tid to
212 : : * store the newest transaction containing inode's data.
213 : : *
214 : : * Note that directories do not have this problem because they don't
215 : : * use page cache.
216 : : *
217 : : * The s_journal check handles the case when ext3_get_journal() fails
218 : : * and puts the journal inode.
219 : : */
220 [ # # ][ # # ]: 0 : if (inode->i_nlink && ext3_should_journal_data(inode) &&
[ # # ]
221 [ # # ]: 0 : EXT3_SB(inode->i_sb)->s_journal &&
222 [ # # ]: 0 : (S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode)) &&
223 : 0 : inode->i_ino != EXT3_JOURNAL_INO) {
224 : 0 : tid_t commit_tid = atomic_read(&ei->i_datasync_tid);
225 : : journal_t *journal = EXT3_SB(inode->i_sb)->s_journal;
226 : :
227 : 0 : log_start_commit(journal, commit_tid);
228 : 0 : log_wait_commit(journal, commit_tid);
229 : 0 : filemap_write_and_wait(&inode->i_data);
230 : : }
231 : 0 : truncate_inode_pages(&inode->i_data, 0);
232 : :
233 : 0 : ext3_discard_reservation(inode);
234 : 0 : rsv = ei->i_block_alloc_info;
235 : 0 : ei->i_block_alloc_info = NULL;
236 [ # # ]: 0 : if (unlikely(rsv))
237 : 0 : kfree(rsv);
238 : :
239 [ # # ]: 0 : if (!want_delete)
240 : : goto no_delete;
241 : :
242 : 0 : handle = start_transaction(inode);
243 [ # # ]: 0 : if (IS_ERR(handle)) {
244 : : /*
245 : : * If we're going to skip the normal cleanup, we still need to
246 : : * make sure that the in-core orphan linked list is properly
247 : : * cleaned up.
248 : : */
249 : 0 : ext3_orphan_del(NULL, inode);
250 : 0 : goto no_delete;
251 : : }
252 : :
253 [ # # ][ # # ]: 0 : if (IS_SYNC(inode))
254 : 0 : handle->h_sync = 1;
255 : 0 : inode->i_size = 0;
256 [ # # ]: 0 : if (inode->i_blocks)
257 : 0 : ext3_truncate(inode);
258 : : /*
259 : : * Kill off the orphan record created when the inode lost the last
260 : : * link. Note that ext3_orphan_del() has to be able to cope with the
261 : : * deletion of a non-existent orphan - ext3_truncate() could
262 : : * have removed the record.
263 : : */
264 : 0 : ext3_orphan_del(handle, inode);
265 : 0 : ei->i_dtime = get_seconds();
266 : :
267 : : /*
268 : : * One subtle ordering requirement: if anything has gone wrong
269 : : * (transaction abort, IO errors, whatever), then we can still
270 : : * do these next steps (the fs will already have been marked as
271 : : * having errors), but we can't free the inode if the mark_dirty
272 : : * fails.
273 : : */
274 [ # # ]: 0 : if (ext3_mark_inode_dirty(handle, inode)) {
275 : : /* If that failed, just dquot_drop() and be done with that */
276 : 0 : dquot_drop(inode);
277 : 0 : clear_inode(inode);
278 : : } else {
279 : 0 : ext3_xattr_delete_inode(handle, inode);
280 : 0 : dquot_free_inode(inode);
281 : 0 : dquot_drop(inode);
282 : 0 : clear_inode(inode);
283 : 0 : ext3_free_inode(handle, inode);
284 : : }
285 : 0 : ext3_journal_stop(handle);
286 : 0 : return;
287 : : no_delete:
288 : 0 : clear_inode(inode);
289 : 0 : dquot_drop(inode);
290 : : }
291 : :
292 : : typedef struct {
293 : : __le32 *p;
294 : : __le32 key;
295 : : struct buffer_head *bh;
296 : : } Indirect;
297 : :
298 : : static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
299 : : {
300 : 0 : p->key = *(p->p = v);
301 : 0 : p->bh = bh;
302 : : }
303 : :
304 : : static int verify_chain(Indirect *from, Indirect *to)
305 : : {
306 [ # # ][ # # ]: 0 : while (from <= to && from->key == *from->p)
[ # # ][ # # ]
[ # # ][ # # ]
307 : 0 : from++;
308 : : return (from > to);
309 : : }
310 : :
311 : : /**
312 : : * ext3_block_to_path - parse the block number into array of offsets
313 : : * @inode: inode in question (we are only interested in its superblock)
314 : : * @i_block: block number to be parsed
315 : : * @offsets: array to store the offsets in
316 : : * @boundary: set this non-zero if the referred-to block is likely to be
317 : : * followed (on disk) by an indirect block.
318 : : *
319 : : * To store the locations of file's data ext3 uses a data structure common
320 : : * for UNIX filesystems - tree of pointers anchored in the inode, with
321 : : * data blocks at leaves and indirect blocks in intermediate nodes.
322 : : * This function translates the block number into path in that tree -
323 : : * return value is the path length and @offsets[n] is the offset of
324 : : * pointer to (n+1)th node in the nth one. If @block is out of range
325 : : * (negative or too large) warning is printed and zero returned.
326 : : *
327 : : * Note: function doesn't find node addresses, so no IO is needed. All
328 : : * we need to know is the capacity of indirect blocks (taken from the
329 : : * inode->i_sb).
330 : : */
331 : :
332 : : /*
333 : : * Portability note: the last comparison (check that we fit into triple
334 : : * indirect block) is spelled differently, because otherwise on an
335 : : * architecture with 32-bit longs and 8Kb pages we might get into trouble
336 : : * if our filesystem had 8Kb blocks. We might use long long, but that would
337 : : * kill us on x86. Oh, well, at least the sign propagation does not matter -
338 : : * i_block would have to be negative in the very beginning, so we would not
339 : : * get there at all.
340 : : */
341 : :
342 : 0 : static int ext3_block_to_path(struct inode *inode,
343 : : long i_block, int offsets[4], int *boundary)
344 : : {
345 : 0 : int ptrs = EXT3_ADDR_PER_BLOCK(inode->i_sb);
346 : 0 : int ptrs_bits = EXT3_ADDR_PER_BLOCK_BITS(inode->i_sb);
347 : : const long direct_blocks = EXT3_NDIR_BLOCKS,
348 : : indirect_blocks = ptrs,
349 : 0 : double_blocks = (1 << (ptrs_bits * 2));
350 : : int n = 0;
351 : : int final = 0;
352 : :
353 [ # # ]: 0 : if (i_block < 0) {
354 : 0 : ext3_warning (inode->i_sb, "ext3_block_to_path", "block < 0");
355 [ # # ]: 0 : } else if (i_block < direct_blocks) {
356 : 0 : offsets[n++] = i_block;
357 : : final = direct_blocks;
358 [ # # ]: 0 : } else if ( (i_block -= direct_blocks) < indirect_blocks) {
359 : 0 : offsets[n++] = EXT3_IND_BLOCK;
360 : 0 : offsets[n++] = i_block;
361 : : final = ptrs;
362 [ # # ]: 0 : } else if ((i_block -= indirect_blocks) < double_blocks) {
363 : 0 : offsets[n++] = EXT3_DIND_BLOCK;
364 : 0 : offsets[n++] = i_block >> ptrs_bits;
365 : 0 : offsets[n++] = i_block & (ptrs - 1);
366 : : final = ptrs;
367 [ # # ]: 0 : } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
368 : 0 : offsets[n++] = EXT3_TIND_BLOCK;
369 : 0 : offsets[n++] = i_block >> (ptrs_bits * 2);
370 : 0 : offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
371 : 0 : offsets[n++] = i_block & (ptrs - 1);
372 : : final = ptrs;
373 : : } else {
374 : 0 : ext3_warning(inode->i_sb, "ext3_block_to_path", "block > big");
375 : : }
376 [ # # ]: 0 : if (boundary)
377 : 0 : *boundary = final - 1 - (i_block & (ptrs - 1));
378 : 0 : return n;
379 : : }
380 : :
381 : : /**
382 : : * ext3_get_branch - read the chain of indirect blocks leading to data
383 : : * @inode: inode in question
384 : : * @depth: depth of the chain (1 - direct pointer, etc.)
385 : : * @offsets: offsets of pointers in inode/indirect blocks
386 : : * @chain: place to store the result
387 : : * @err: here we store the error value
388 : : *
389 : : * Function fills the array of triples <key, p, bh> and returns %NULL
390 : : * if everything went OK or the pointer to the last filled triple
391 : : * (incomplete one) otherwise. Upon the return chain[i].key contains
392 : : * the number of (i+1)-th block in the chain (as it is stored in memory,
393 : : * i.e. little-endian 32-bit), chain[i].p contains the address of that
394 : : * number (it points into struct inode for i==0 and into the bh->b_data
395 : : * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
396 : : * block for i>0 and NULL for i==0. In other words, it holds the block
397 : : * numbers of the chain, addresses they were taken from (and where we can
398 : : * verify that chain did not change) and buffer_heads hosting these
399 : : * numbers.
400 : : *
401 : : * Function stops when it stumbles upon zero pointer (absent block)
402 : : * (pointer to last triple returned, *@err == 0)
403 : : * or when it gets an IO error reading an indirect block
404 : : * (ditto, *@err == -EIO)
405 : : * or when it notices that chain had been changed while it was reading
406 : : * (ditto, *@err == -EAGAIN)
407 : : * or when it reads all @depth-1 indirect blocks successfully and finds
408 : : * the whole chain, all way to the data (returns %NULL, *err == 0).
409 : : */
410 : 0 : static Indirect *ext3_get_branch(struct inode *inode, int depth, int *offsets,
411 : : Indirect chain[4], int *err)
412 : : {
413 : 0 : struct super_block *sb = inode->i_sb;
414 : : Indirect *p = chain;
415 : : struct buffer_head *bh;
416 : :
417 : 0 : *err = 0;
418 : : /* i_data is not going away, no lock needed */
419 : 0 : add_chain (chain, NULL, EXT3_I(inode)->i_data + *offsets);
420 [ # # ]: 0 : if (!p->key)
421 : : goto no_block;
422 [ # # ]: 0 : while (--depth) {
423 : 0 : bh = sb_bread(sb, le32_to_cpu(p->key));
424 [ # # ]: 0 : if (!bh)
425 : : goto failure;
426 : : /* Reader: pointers */
427 [ # # ]: 0 : if (!verify_chain(chain, p))
428 : : goto changed;
429 : 0 : add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
430 : : /* Reader: end */
431 [ # # ]: 0 : if (!p->key)
432 : : goto no_block;
433 : : }
434 : : return NULL;
435 : :
436 : : changed:
437 : : brelse(bh);
438 : 0 : *err = -EAGAIN;
439 : 0 : goto no_block;
440 : : failure:
441 : 0 : *err = -EIO;
442 : : no_block:
443 : 0 : return p;
444 : : }
445 : :
446 : : /**
447 : : * ext3_find_near - find a place for allocation with sufficient locality
448 : : * @inode: owner
449 : : * @ind: descriptor of indirect block.
450 : : *
451 : : * This function returns the preferred place for block allocation.
452 : : * It is used when heuristic for sequential allocation fails.
453 : : * Rules are:
454 : : * + if there is a block to the left of our position - allocate near it.
455 : : * + if pointer will live in indirect block - allocate near that block.
456 : : * + if pointer will live in inode - allocate in the same
457 : : * cylinder group.
458 : : *
459 : : * In the latter case we colour the starting block by the callers PID to
460 : : * prevent it from clashing with concurrent allocations for a different inode
461 : : * in the same block group. The PID is used here so that functionally related
462 : : * files will be close-by on-disk.
463 : : *
464 : : * Caller must make sure that @ind is valid and will stay that way.
465 : : */
466 : 0 : static ext3_fsblk_t ext3_find_near(struct inode *inode, Indirect *ind)
467 : : {
468 : : struct ext3_inode_info *ei = EXT3_I(inode);
469 [ # # ]: 0 : __le32 *start = ind->bh ? (__le32*) ind->bh->b_data : ei->i_data;
470 : : __le32 *p;
471 : : ext3_fsblk_t bg_start;
472 : : ext3_grpblk_t colour;
473 : :
474 : : /* Try to find previous block */
475 [ # # ]: 0 : for (p = ind->p - 1; p >= start; p--) {
476 [ # # ]: 0 : if (*p)
477 : : return le32_to_cpu(*p);
478 : : }
479 : :
480 : : /* No such thing, so let's try location of indirect block */
481 [ # # ]: 0 : if (ind->bh)
482 : 0 : return ind->bh->b_blocknr;
483 : :
484 : : /*
485 : : * It is going to be referred to from the inode itself? OK, just put it
486 : : * into the same cylinder group then.
487 : : */
488 : 0 : bg_start = ext3_group_first_block_no(inode->i_sb, ei->i_block_group);
489 : 0 : colour = (current->pid % 16) *
490 : 0 : (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
491 : 0 : return bg_start + colour;
492 : : }
493 : :
494 : : /**
495 : : * ext3_find_goal - find a preferred place for allocation.
496 : : * @inode: owner
497 : : * @block: block we want
498 : : * @partial: pointer to the last triple within a chain
499 : : *
500 : : * Normally this function find the preferred place for block allocation,
501 : : * returns it.
502 : : */
503 : :
504 : 0 : static ext3_fsblk_t ext3_find_goal(struct inode *inode, long block,
505 : 0 : Indirect *partial)
506 : : {
507 : : struct ext3_block_alloc_info *block_i;
508 : :
509 : 0 : block_i = EXT3_I(inode)->i_block_alloc_info;
510 : :
511 : : /*
512 : : * try the heuristic for sequential allocation,
513 : : * failing that at least try to get decent locality.
514 : : */
515 [ # # ][ # # ]: 0 : if (block_i && (block == block_i->last_alloc_logical_block + 1)
516 [ # # ]: 0 : && (block_i->last_alloc_physical_block != 0)) {
517 : 0 : return block_i->last_alloc_physical_block + 1;
518 : : }
519 : :
520 : 0 : return ext3_find_near(inode, partial);
521 : : }
522 : :
523 : : /**
524 : : * ext3_blks_to_allocate - Look up the block map and count the number
525 : : * of direct blocks need to be allocated for the given branch.
526 : : *
527 : : * @branch: chain of indirect blocks
528 : : * @k: number of blocks need for indirect blocks
529 : : * @blks: number of data blocks to be mapped.
530 : : * @blocks_to_boundary: the offset in the indirect block
531 : : *
532 : : * return the total number of blocks to be allocate, including the
533 : : * direct and indirect blocks.
534 : : */
535 : 0 : static int ext3_blks_to_allocate(Indirect *branch, int k, unsigned long blks,
536 : : int blocks_to_boundary)
537 : : {
538 : : unsigned long count = 0;
539 : :
540 : : /*
541 : : * Simple case, [t,d]Indirect block(s) has not allocated yet
542 : : * then it's clear blocks on that path have not allocated
543 : : */
544 [ # # ]: 0 : if (k > 0) {
545 : : /* right now we don't handle cross boundary allocation */
546 [ # # ]: 0 : if (blks < blocks_to_boundary + 1)
547 : : count += blks;
548 : : else
549 : 0 : count += blocks_to_boundary + 1;
550 : 0 : return count;
551 : : }
552 : :
553 : : count++;
554 [ # # ][ # # ]: 0 : while (count < blks && count <= blocks_to_boundary &&
555 : 0 : le32_to_cpu(*(branch[0].p + count)) == 0) {
556 : 0 : count++;
557 : : }
558 : 0 : return count;
559 : : }
560 : :
561 : : /**
562 : : * ext3_alloc_blocks - multiple allocate blocks needed for a branch
563 : : * @handle: handle for this transaction
564 : : * @inode: owner
565 : : * @goal: preferred place for allocation
566 : : * @indirect_blks: the number of blocks need to allocate for indirect
567 : : * blocks
568 : : * @blks: number of blocks need to allocated for direct blocks
569 : : * @new_blocks: on return it will store the new block numbers for
570 : : * the indirect blocks(if needed) and the first direct block,
571 : : * @err: here we store the error value
572 : : *
573 : : * return the number of direct blocks allocated
574 : : */
575 : 0 : static int ext3_alloc_blocks(handle_t *handle, struct inode *inode,
576 : : ext3_fsblk_t goal, int indirect_blks, int blks,
577 : : ext3_fsblk_t new_blocks[4], int *err)
578 : : {
579 : : int target, i;
580 : 0 : unsigned long count = 0;
581 : : int index = 0;
582 : : ext3_fsblk_t current_block = 0;
583 : : int ret = 0;
584 : :
585 : : /*
586 : : * Here we try to allocate the requested multiple blocks at once,
587 : : * on a best-effort basis.
588 : : * To build a branch, we should allocate blocks for
589 : : * the indirect blocks(if not allocated yet), and at least
590 : : * the first direct block of this branch. That's the
591 : : * minimum number of blocks need to allocate(required)
592 : : */
593 : 0 : target = blks + indirect_blks;
594 : :
595 : : while (1) {
596 : 0 : count = target;
597 : : /* allocating blocks for indirect blocks and direct blocks */
598 : 0 : current_block = ext3_new_blocks(handle,inode,goal,&count,err);
599 [ # # ]: 0 : if (*err)
600 : : goto failed_out;
601 : :
602 : 0 : target -= count;
603 : : /* allocate blocks for indirect blocks */
604 [ # # ][ # # ]: 0 : while (index < indirect_blks && count) {
605 : 0 : new_blocks[index++] = current_block++;
606 : 0 : count--;
607 : : }
608 : :
609 [ # # ]: 0 : if (count > 0)
610 : : break;
611 : : }
612 : :
613 : : /* save the new block number for the first direct block */
614 : 0 : new_blocks[index] = current_block;
615 : :
616 : : /* total number of blocks allocated for direct blocks */
617 : 0 : ret = count;
618 : 0 : *err = 0;
619 : 0 : return ret;
620 : : failed_out:
621 [ # # ]: 0 : for (i = 0; i <index; i++)
622 : 0 : ext3_free_blocks(handle, inode, new_blocks[i], 1);
623 : : return ret;
624 : : }
625 : :
626 : : /**
627 : : * ext3_alloc_branch - allocate and set up a chain of blocks.
628 : : * @handle: handle for this transaction
629 : : * @inode: owner
630 : : * @indirect_blks: number of allocated indirect blocks
631 : : * @blks: number of allocated direct blocks
632 : : * @goal: preferred place for allocation
633 : : * @offsets: offsets (in the blocks) to store the pointers to next.
634 : : * @branch: place to store the chain in.
635 : : *
636 : : * This function allocates blocks, zeroes out all but the last one,
637 : : * links them into chain and (if we are synchronous) writes them to disk.
638 : : * In other words, it prepares a branch that can be spliced onto the
639 : : * inode. It stores the information about that chain in the branch[], in
640 : : * the same format as ext3_get_branch() would do. We are calling it after
641 : : * we had read the existing part of chain and partial points to the last
642 : : * triple of that (one with zero ->key). Upon the exit we have the same
643 : : * picture as after the successful ext3_get_block(), except that in one
644 : : * place chain is disconnected - *branch->p is still zero (we did not
645 : : * set the last link), but branch->key contains the number that should
646 : : * be placed into *branch->p to fill that gap.
647 : : *
648 : : * If allocation fails we free all blocks we've allocated (and forget
649 : : * their buffer_heads) and return the error value the from failed
650 : : * ext3_alloc_block() (normally -ENOSPC). Otherwise we set the chain
651 : : * as described above and return 0.
652 : : */
653 : 0 : static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
654 : : int indirect_blks, int *blks, ext3_fsblk_t goal,
655 : : int *offsets, Indirect *branch)
656 : : {
657 : 0 : int blocksize = inode->i_sb->s_blocksize;
658 : : int i, n = 0;
659 : 0 : int err = 0;
660 : : struct buffer_head *bh;
661 : : int num;
662 : : ext3_fsblk_t new_blocks[4];
663 : : ext3_fsblk_t current_block;
664 : :
665 : 0 : num = ext3_alloc_blocks(handle, inode, goal, indirect_blks,
666 : : *blks, new_blocks, &err);
667 [ # # ]: 0 : if (err)
668 : : return err;
669 : :
670 : 0 : branch[0].key = cpu_to_le32(new_blocks[0]);
671 : : /*
672 : : * metadata blocks and data blocks are allocated.
673 : : */
674 [ # # ]: 0 : for (n = 1; n <= indirect_blks; n++) {
675 : : /*
676 : : * Get buffer_head for parent block, zero it out
677 : : * and set the pointer to new one, then send
678 : : * parent to disk.
679 : : */
680 : 0 : bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
681 [ # # ]: 0 : if (unlikely(!bh)) {
682 : 0 : err = -ENOMEM;
683 : 0 : goto failed;
684 : : }
685 : 0 : branch[n].bh = bh;
686 : : lock_buffer(bh);
687 : : BUFFER_TRACE(bh, "call get_create_access");
688 : 0 : err = ext3_journal_get_create_access(handle, bh);
689 [ # # ]: 0 : if (err) {
690 : 0 : unlock_buffer(bh);
691 : : brelse(bh);
692 : : goto failed;
693 : : }
694 : :
695 [ # # ]: 0 : memset(bh->b_data, 0, blocksize);
696 : 0 : branch[n].p = (__le32 *) bh->b_data + offsets[n];
697 : 0 : branch[n].key = cpu_to_le32(new_blocks[n]);
698 : 0 : *branch[n].p = branch[n].key;
699 [ # # ]: 0 : if ( n == indirect_blks) {
700 : 0 : current_block = new_blocks[n];
701 : : /*
702 : : * End of chain, update the last new metablock of
703 : : * the chain to point to the new allocated
704 : : * data blocks numbers
705 : : */
706 [ # # ]: 0 : for (i=1; i < num; i++)
707 : 0 : *(branch[n].p + i) = cpu_to_le32(++current_block);
708 : : }
709 : : BUFFER_TRACE(bh, "marking uptodate");
710 : : set_buffer_uptodate(bh);
711 : 0 : unlock_buffer(bh);
712 : :
713 : : BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
714 : 0 : err = ext3_journal_dirty_metadata(handle, bh);
715 [ # # ]: 0 : if (err)
716 : : goto failed;
717 : : }
718 : 0 : *blks = num;
719 : 0 : return err;
720 : : failed:
721 : : /* Allocation failed, free what we already allocated */
722 [ # # ]: 0 : for (i = 1; i <= n ; i++) {
723 : : BUFFER_TRACE(branch[i].bh, "call journal_forget");
724 : 0 : ext3_journal_forget(handle, branch[i].bh);
725 : : }
726 [ # # ]: 0 : for (i = 0; i < indirect_blks; i++)
727 : 0 : ext3_free_blocks(handle, inode, new_blocks[i], 1);
728 : :
729 : 0 : ext3_free_blocks(handle, inode, new_blocks[i], num);
730 : :
731 : 0 : return err;
732 : : }
733 : :
734 : : /**
735 : : * ext3_splice_branch - splice the allocated branch onto inode.
736 : : * @handle: handle for this transaction
737 : : * @inode: owner
738 : : * @block: (logical) number of block we are adding
739 : : * @where: location of missing link
740 : : * @num: number of indirect blocks we are adding
741 : : * @blks: number of direct blocks we are adding
742 : : *
743 : : * This function fills the missing link and does all housekeeping needed in
744 : : * inode (->i_blocks, etc.). In case of success we end up with the full
745 : : * chain to new block and return 0.
746 : : */
747 : 0 : static int ext3_splice_branch(handle_t *handle, struct inode *inode,
748 : : long block, Indirect *where, int num, int blks)
749 : : {
750 : : int i;
751 : : int err = 0;
752 : : struct ext3_block_alloc_info *block_i;
753 : : ext3_fsblk_t current_block;
754 : : struct ext3_inode_info *ei = EXT3_I(inode);
755 : : struct timespec now;
756 : :
757 : 0 : block_i = ei->i_block_alloc_info;
758 : : /*
759 : : * If we're splicing into a [td]indirect block (as opposed to the
760 : : * inode) then we need to get write access to the [td]indirect block
761 : : * before the splice.
762 : : */
763 [ # # ]: 0 : if (where->bh) {
764 : : BUFFER_TRACE(where->bh, "get_write_access");
765 : 0 : err = ext3_journal_get_write_access(handle, where->bh);
766 [ # # ]: 0 : if (err)
767 : : goto err_out;
768 : : }
769 : : /* That's it */
770 : :
771 : 0 : *where->p = where->key;
772 : :
773 : : /*
774 : : * Update the host buffer_head or inode to point to more just allocated
775 : : * direct blocks blocks
776 : : */
777 [ # # ]: 0 : if (num == 0 && blks > 1) {
778 : 0 : current_block = le32_to_cpu(where->key) + 1;
779 [ # # ]: 0 : for (i = 1; i < blks; i++)
780 : 0 : *(where->p + i ) = cpu_to_le32(current_block++);
781 : : }
782 : :
783 : : /*
784 : : * update the most recently allocated logical & physical block
785 : : * in i_block_alloc_info, to assist find the proper goal block for next
786 : : * allocation
787 : : */
788 [ # # ]: 0 : if (block_i) {
789 : 0 : block_i->last_alloc_logical_block = block + blks - 1;
790 : 0 : block_i->last_alloc_physical_block =
791 : 0 : le32_to_cpu(where[num].key) + blks - 1;
792 : : }
793 : :
794 : : /* We are done with atomic stuff, now do the rest of housekeeping */
795 : 0 : now = CURRENT_TIME_SEC;
796 [ # # ][ # # ]: 0 : if (!timespec_equal(&inode->i_ctime, &now) || !where->bh) {
797 : 0 : inode->i_ctime = now;
798 : 0 : ext3_mark_inode_dirty(handle, inode);
799 : : }
800 : : /* ext3_mark_inode_dirty already updated i_sync_tid */
801 : 0 : atomic_set(&ei->i_datasync_tid, handle->h_transaction->t_tid);
802 : :
803 : : /* had we spliced it onto indirect block? */
804 [ # # ]: 0 : if (where->bh) {
805 : : /*
806 : : * If we spliced it onto an indirect block, we haven't
807 : : * altered the inode. Note however that if it is being spliced
808 : : * onto an indirect block at the very end of the file (the
809 : : * file is growing) then we *will* alter the inode to reflect
810 : : * the new i_size. But that is not done here - it is done in
811 : : * generic_commit_write->__mark_inode_dirty->ext3_dirty_inode.
812 : : */
813 : : jbd_debug(5, "splicing indirect only\n");
814 : : BUFFER_TRACE(where->bh, "call ext3_journal_dirty_metadata");
815 : 0 : err = ext3_journal_dirty_metadata(handle, where->bh);
816 [ # # ]: 0 : if (err)
817 : : goto err_out;
818 : : } else {
819 : : /*
820 : : * OK, we spliced it into the inode itself on a direct block.
821 : : * Inode was dirtied above.
822 : : */
823 : : jbd_debug(5, "splicing direct\n");
824 : : }
825 : 0 : return err;
826 : :
827 : : err_out:
828 [ # # ]: 0 : for (i = 1; i <= num; i++) {
829 : : BUFFER_TRACE(where[i].bh, "call journal_forget");
830 : 0 : ext3_journal_forget(handle, where[i].bh);
831 : 0 : ext3_free_blocks(handle,inode,le32_to_cpu(where[i-1].key),1);
832 : : }
833 : 0 : ext3_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks);
834 : :
835 : 0 : return err;
836 : : }
837 : :
838 : : /*
839 : : * Allocation strategy is simple: if we have to allocate something, we will
840 : : * have to go the whole way to leaf. So let's do it before attaching anything
841 : : * to tree, set linkage between the newborn blocks, write them if sync is
842 : : * required, recheck the path, free and repeat if check fails, otherwise
843 : : * set the last missing link (that will protect us from any truncate-generated
844 : : * removals - all blocks on the path are immune now) and possibly force the
845 : : * write on the parent block.
846 : : * That has a nice additional property: no special recovery from the failed
847 : : * allocations is needed - we simply release blocks and do not touch anything
848 : : * reachable from inode.
849 : : *
850 : : * `handle' can be NULL if create == 0.
851 : : *
852 : : * The BKL may not be held on entry here. Be sure to take it early.
853 : : * return > 0, # of blocks mapped or allocated.
854 : : * return = 0, if plain lookup failed.
855 : : * return < 0, error case.
856 : : */
857 : 0 : int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
858 : : sector_t iblock, unsigned long maxblocks,
859 : : struct buffer_head *bh_result,
860 : : int create)
861 : : {
862 : 0 : int err = -EIO;
863 : : int offsets[4];
864 : : Indirect chain[4];
865 : : Indirect *partial;
866 : : ext3_fsblk_t goal;
867 : : int indirect_blks;
868 : 0 : int blocks_to_boundary = 0;
869 : : int depth;
870 : : struct ext3_inode_info *ei = EXT3_I(inode);
871 : 0 : int count = 0;
872 : : ext3_fsblk_t first_block = 0;
873 : :
874 : :
875 : 0 : trace_ext3_get_blocks_enter(inode, iblock, maxblocks, create);
876 [ # # ]: 0 : J_ASSERT(handle != NULL || create == 0);
877 : 0 : depth = ext3_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
878 : :
879 [ # # ]: 0 : if (depth == 0)
880 : : goto out;
881 : :
882 : 0 : partial = ext3_get_branch(inode, depth, offsets, chain, &err);
883 : :
884 : : /* Simplest case - block found, no allocation needed */
885 [ # # ]: 0 : if (!partial) {
886 : 0 : first_block = le32_to_cpu(chain[depth - 1].key);
887 : : clear_buffer_new(bh_result);
888 : 0 : count++;
889 : : /*map more blocks*/
890 [ # # ][ # # ]: 0 : while (count < maxblocks && count <= blocks_to_boundary) {
891 : : ext3_fsblk_t blk;
892 : :
893 [ # # ]: 0 : if (!verify_chain(chain, chain + depth - 1)) {
894 : : /*
895 : : * Indirect block might be removed by
896 : : * truncate while we were reading it.
897 : : * Handling of that case: forget what we've
898 : : * got now. Flag the err as EAGAIN, so it
899 : : * will reread.
900 : : */
901 : 0 : err = -EAGAIN;
902 : 0 : count = 0;
903 : 0 : break;
904 : : }
905 : 0 : blk = le32_to_cpu(*(chain[depth-1].p + count));
906 : :
907 [ # # ]: 0 : if (blk == first_block + count)
908 : 0 : count++;
909 : : else
910 : : break;
911 : : }
912 [ # # ]: 0 : if (err != -EAGAIN)
913 : : goto got_it;
914 : : }
915 : :
916 : : /* Next simple case - plain lookup or failed read of indirect block */
917 [ # # ][ # # ]: 0 : if (!create || err == -EIO)
918 : : goto cleanup;
919 : :
920 : : /*
921 : : * Block out ext3_truncate while we alter the tree
922 : : */
923 : 0 : mutex_lock(&ei->truncate_mutex);
924 : :
925 : : /*
926 : : * If the indirect block is missing while we are reading
927 : : * the chain(ext3_get_branch() returns -EAGAIN err), or
928 : : * if the chain has been changed after we grab the semaphore,
929 : : * (either because another process truncated this branch, or
930 : : * another get_block allocated this branch) re-grab the chain to see if
931 : : * the request block has been allocated or not.
932 : : *
933 : : * Since we already block the truncate/other get_block
934 : : * at this point, we will have the current copy of the chain when we
935 : : * splice the branch into the tree.
936 : : */
937 [ # # ][ # # ]: 0 : if (err == -EAGAIN || !verify_chain(chain, partial)) {
938 [ # # ]: 0 : while (partial > chain) {
939 : 0 : brelse(partial->bh);
940 : 0 : partial--;
941 : : }
942 : 0 : partial = ext3_get_branch(inode, depth, offsets, chain, &err);
943 [ # # ]: 0 : if (!partial) {
944 : 0 : count++;
945 : 0 : mutex_unlock(&ei->truncate_mutex);
946 [ # # ]: 0 : if (err)
947 : : goto cleanup;
948 : : clear_buffer_new(bh_result);
949 : : goto got_it;
950 : : }
951 : : }
952 : :
953 : : /*
954 : : * Okay, we need to do block allocation. Lazily initialize the block
955 : : * allocation info here if necessary
956 : : */
957 [ # # ][ # # ]: 0 : if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
958 : 0 : ext3_init_block_alloc_info(inode);
959 : :
960 : 0 : goal = ext3_find_goal(inode, iblock, partial);
961 : :
962 : : /* the number of blocks need to allocate for [d,t]indirect blocks */
963 : 0 : indirect_blks = (chain + depth) - partial - 1;
964 : :
965 : : /*
966 : : * Next look up the indirect map to count the totoal number of
967 : : * direct blocks to allocate for this branch.
968 : : */
969 : 0 : count = ext3_blks_to_allocate(partial, indirect_blks,
970 : : maxblocks, blocks_to_boundary);
971 : 0 : err = ext3_alloc_branch(handle, inode, indirect_blks, &count, goal,
972 : 0 : offsets + (partial - chain), partial);
973 : :
974 : : /*
975 : : * The ext3_splice_branch call will free and forget any buffers
976 : : * on the new chain if there is a failure, but that risks using
977 : : * up transaction credits, especially for bitmaps where the
978 : : * credits cannot be returned. Can we handle this somehow? We
979 : : * may need to return -EAGAIN upwards in the worst case. --sct
980 : : */
981 [ # # ]: 0 : if (!err)
982 : 0 : err = ext3_splice_branch(handle, inode, iblock,
983 : : partial, indirect_blks, count);
984 : 0 : mutex_unlock(&ei->truncate_mutex);
985 [ # # ]: 0 : if (err)
986 : : goto cleanup;
987 : :
988 : : set_buffer_new(bh_result);
989 : : got_it:
990 : 0 : map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
991 [ # # ]: 0 : if (count > blocks_to_boundary)
992 : : set_buffer_boundary(bh_result);
993 : 0 : err = count;
994 : : /* Clean up and exit */
995 : 0 : partial = chain + depth - 1; /* the whole chain */
996 : : cleanup:
997 [ # # ]: 0 : while (partial > chain) {
998 : : BUFFER_TRACE(partial->bh, "call brelse");
999 : 0 : brelse(partial->bh);
1000 : 0 : partial--;
1001 : : }
1002 : : BUFFER_TRACE(bh_result, "returned");
1003 : : out:
1004 [ # # ]: 0 : trace_ext3_get_blocks_exit(inode, iblock,
1005 : 0 : depth ? le32_to_cpu(chain[depth-1].key) : 0,
1006 : : count, err);
1007 : 0 : return err;
1008 : : }
1009 : :
1010 : : /* Maximum number of blocks we map for direct IO at once. */
1011 : : #define DIO_MAX_BLOCKS 4096
1012 : : /*
1013 : : * Number of credits we need for writing DIO_MAX_BLOCKS:
1014 : : * We need sb + group descriptor + bitmap + inode -> 4
1015 : : * For B blocks with A block pointers per block we need:
1016 : : * 1 (triple ind.) + (B/A/A + 2) (doubly ind.) + (B/A + 2) (indirect).
1017 : : * If we plug in 4096 for B and 256 for A (for 1KB block size), we get 25.
1018 : : */
1019 : : #define DIO_CREDITS 25
1020 : :
1021 : 0 : static int ext3_get_block(struct inode *inode, sector_t iblock,
1022 : : struct buffer_head *bh_result, int create)
1023 : : {
1024 : : handle_t *handle = ext3_journal_current_handle();
1025 : : int ret = 0, started = 0;
1026 : 0 : unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
1027 : :
1028 [ # # ]: 0 : if (create && !handle) { /* Direct IO write... */
1029 [ # # ]: 0 : if (max_blocks > DIO_MAX_BLOCKS)
1030 : : max_blocks = DIO_MAX_BLOCKS;
1031 [ # # ]: 0 : handle = ext3_journal_start(inode, DIO_CREDITS +
1032 : 0 : EXT3_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb));
1033 [ # # ]: 0 : if (IS_ERR(handle)) {
1034 : : ret = PTR_ERR(handle);
1035 : 0 : goto out;
1036 : : }
1037 : : started = 1;
1038 : : }
1039 : :
1040 : 0 : ret = ext3_get_blocks_handle(handle, inode, iblock,
1041 : : max_blocks, bh_result, create);
1042 [ # # ]: 0 : if (ret > 0) {
1043 : 0 : bh_result->b_size = (ret << inode->i_blkbits);
1044 : : ret = 0;
1045 : : }
1046 [ # # ]: 0 : if (started)
1047 : 0 : ext3_journal_stop(handle);
1048 : : out:
1049 : 0 : return ret;
1050 : : }
1051 : :
1052 : 0 : int ext3_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
1053 : : u64 start, u64 len)
1054 : : {
1055 : 0 : return generic_block_fiemap(inode, fieinfo, start, len,
1056 : : ext3_get_block);
1057 : : }
1058 : :
1059 : : /*
1060 : : * `handle' can be NULL if create is zero
1061 : : */
1062 : 0 : struct buffer_head *ext3_getblk(handle_t *handle, struct inode *inode,
1063 : : long block, int create, int *errp)
1064 : : {
1065 : : struct buffer_head dummy;
1066 : : int fatal = 0, err;
1067 : :
1068 [ # # ]: 0 : J_ASSERT(handle != NULL || create == 0);
1069 : :
1070 : 0 : dummy.b_state = 0;
1071 : 0 : dummy.b_blocknr = -1000;
1072 : : buffer_trace_init(&dummy.b_history);
1073 : 0 : err = ext3_get_blocks_handle(handle, inode, block, 1,
1074 : : &dummy, create);
1075 : : /*
1076 : : * ext3_get_blocks_handle() returns number of blocks
1077 : : * mapped. 0 in case of a HOLE.
1078 : : */
1079 [ # # ]: 0 : if (err > 0) {
1080 [ # # ]: 0 : WARN_ON(err > 1);
1081 : : err = 0;
1082 : : }
1083 : 0 : *errp = err;
1084 [ # # ][ # # ]: 0 : if (!err && buffer_mapped(&dummy)) {
1085 : : struct buffer_head *bh;
1086 : 0 : bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
1087 [ # # ]: 0 : if (unlikely(!bh)) {
1088 : 0 : *errp = -ENOMEM;
1089 : 0 : goto err;
1090 : : }
1091 [ # # ]: 0 : if (buffer_new(&dummy)) {
1092 [ # # ]: 0 : J_ASSERT(create != 0);
1093 [ # # ]: 0 : J_ASSERT(handle != NULL);
1094 : :
1095 : : /*
1096 : : * Now that we do not always journal data, we should
1097 : : * keep in mind whether this should always journal the
1098 : : * new buffer as metadata. For now, regular file
1099 : : * writes use ext3_get_block instead, so it's not a
1100 : : * problem.
1101 : : */
1102 : : lock_buffer(bh);
1103 : : BUFFER_TRACE(bh, "call get_create_access");
1104 : 0 : fatal = ext3_journal_get_create_access(handle, bh);
1105 [ # # ][ # # ]: 0 : if (!fatal && !buffer_uptodate(bh)) {
1106 [ # # ]: 0 : memset(bh->b_data,0,inode->i_sb->s_blocksize);
1107 : : set_buffer_uptodate(bh);
1108 : : }
1109 : 0 : unlock_buffer(bh);
1110 : : BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
1111 : 0 : err = ext3_journal_dirty_metadata(handle, bh);
1112 [ # # ]: 0 : if (!fatal)
1113 : : fatal = err;
1114 : : } else {
1115 : : BUFFER_TRACE(bh, "not a new buffer");
1116 : : }
1117 [ # # ]: 0 : if (fatal) {
1118 : 0 : *errp = fatal;
1119 : : brelse(bh);
1120 : : bh = NULL;
1121 : : }
1122 : 0 : return bh;
1123 : : }
1124 : : err:
1125 : : return NULL;
1126 : : }
1127 : :
1128 : 0 : struct buffer_head *ext3_bread(handle_t *handle, struct inode *inode,
1129 : : int block, int create, int *err)
1130 : : {
1131 : : struct buffer_head * bh;
1132 : :
1133 : 0 : bh = ext3_getblk(handle, inode, block, create, err);
1134 [ # # ]: 0 : if (!bh)
1135 : : return bh;
1136 [ # # ]: 0 : if (bh_uptodate_or_lock(bh))
1137 : : return bh;
1138 : : get_bh(bh);
1139 : 0 : bh->b_end_io = end_buffer_read_sync;
1140 : 0 : submit_bh(READ | REQ_META | REQ_PRIO, bh);
1141 : : wait_on_buffer(bh);
1142 [ # # ]: 0 : if (buffer_uptodate(bh))
1143 : : return bh;
1144 : : put_bh(bh);
1145 : 0 : *err = -EIO;
1146 : 0 : return NULL;
1147 : : }
1148 : :
1149 : 0 : static int walk_page_buffers( handle_t *handle,
1150 : : struct buffer_head *head,
1151 : : unsigned from,
1152 : : unsigned to,
1153 : : int *partial,
1154 : : int (*fn)( handle_t *handle,
1155 : : struct buffer_head *bh))
1156 : : {
1157 : : struct buffer_head *bh;
1158 : : unsigned block_start, block_end;
1159 : 0 : unsigned blocksize = head->b_size;
1160 : : int err, ret = 0;
1161 : : struct buffer_head *next;
1162 : :
1163 [ # # ]: 0 : for ( bh = head, block_start = 0;
1164 [ # # ]: 0 : ret == 0 && (bh != head || !block_start);
1165 : : block_start = block_end, bh = next)
1166 : : {
1167 : 0 : next = bh->b_this_page;
1168 : 0 : block_end = block_start + blocksize;
1169 [ # # ]: 0 : if (block_end <= from || block_start >= to) {
1170 [ # # ][ # # ]: 0 : if (partial && !buffer_uptodate(bh))
1171 : 0 : *partial = 1;
1172 : 0 : continue;
1173 : : }
1174 : 0 : err = (*fn)(handle, bh);
1175 [ # # ]: 0 : if (!ret)
1176 : : ret = err;
1177 : : }
1178 : 0 : return ret;
1179 : : }
1180 : :
1181 : : /*
1182 : : * To preserve ordering, it is essential that the hole instantiation and
1183 : : * the data write be encapsulated in a single transaction. We cannot
1184 : : * close off a transaction and start a new one between the ext3_get_block()
1185 : : * and the commit_write(). So doing the journal_start at the start of
1186 : : * prepare_write() is the right place.
1187 : : *
1188 : : * Also, this function can nest inside ext3_writepage() ->
1189 : : * block_write_full_page(). In that case, we *know* that ext3_writepage()
1190 : : * has generated enough buffer credits to do the whole page. So we won't
1191 : : * block on the journal in that case, which is good, because the caller may
1192 : : * be PF_MEMALLOC.
1193 : : *
1194 : : * By accident, ext3 can be reentered when a transaction is open via
1195 : : * quota file writes. If we were to commit the transaction while thus
1196 : : * reentered, there can be a deadlock - we would be holding a quota
1197 : : * lock, and the commit would never complete if another thread had a
1198 : : * transaction open and was blocking on the quota lock - a ranking
1199 : : * violation.
1200 : : *
1201 : : * So what we do is to rely on the fact that journal_stop/journal_start
1202 : : * will _not_ run commit under these circumstances because handle->h_ref
1203 : : * is elevated. We'll still have enough credits for the tiny quotafile
1204 : : * write.
1205 : : */
1206 : 0 : static int do_journal_get_write_access(handle_t *handle,
1207 : : struct buffer_head *bh)
1208 : : {
1209 : : int dirty = buffer_dirty(bh);
1210 : : int ret;
1211 : :
1212 [ # # ][ # # ]: 0 : if (!buffer_mapped(bh) || buffer_freed(bh))
1213 : : return 0;
1214 : : /*
1215 : : * __block_prepare_write() could have dirtied some buffers. Clean
1216 : : * the dirty bit as jbd2_journal_get_write_access() could complain
1217 : : * otherwise about fs integrity issues. Setting of the dirty bit
1218 : : * by __block_prepare_write() isn't a real problem here as we clear
1219 : : * the bit before releasing a page lock and thus writeback cannot
1220 : : * ever write the buffer.
1221 : : */
1222 [ # # ]: 0 : if (dirty)
1223 : : clear_buffer_dirty(bh);
1224 : 0 : ret = ext3_journal_get_write_access(handle, bh);
1225 [ # # ]: 0 : if (!ret && dirty)
1226 : 0 : ret = ext3_journal_dirty_metadata(handle, bh);
1227 : 0 : return ret;
1228 : : }
1229 : :
1230 : : /*
1231 : : * Truncate blocks that were not used by write. We have to truncate the
1232 : : * pagecache as well so that corresponding buffers get properly unmapped.
1233 : : */
1234 : 0 : static void ext3_truncate_failed_write(struct inode *inode)
1235 : : {
1236 : 0 : truncate_inode_pages(inode->i_mapping, inode->i_size);
1237 : 0 : ext3_truncate(inode);
1238 : 0 : }
1239 : :
1240 : : /*
1241 : : * Truncate blocks that were not used by direct IO write. We have to zero out
1242 : : * the last file block as well because direct IO might have written to it.
1243 : : */
1244 : 0 : static void ext3_truncate_failed_direct_write(struct inode *inode)
1245 : : {
1246 : 0 : ext3_block_truncate_page(inode, inode->i_size);
1247 : 0 : ext3_truncate(inode);
1248 : 0 : }
1249 : :
1250 : 0 : static int ext3_write_begin(struct file *file, struct address_space *mapping,
1251 : : loff_t pos, unsigned len, unsigned flags,
1252 : : struct page **pagep, void **fsdata)
1253 : : {
1254 : 0 : struct inode *inode = mapping->host;
1255 : : int ret;
1256 : : handle_t *handle;
1257 : 0 : int retries = 0;
1258 : : struct page *page;
1259 : : pgoff_t index;
1260 : : unsigned from, to;
1261 : : /* Reserve one block more for addition to orphan list in case
1262 : : * we allocate blocks but write fails for some reason */
1263 : 0 : int needed_blocks = ext3_writepage_trans_blocks(inode) + 1;
1264 : :
1265 : : trace_ext3_write_begin(inode, pos, len, flags);
1266 : :
1267 : 0 : index = pos >> PAGE_CACHE_SHIFT;
1268 : 0 : from = pos & (PAGE_CACHE_SIZE - 1);
1269 : 0 : to = from + len;
1270 : :
1271 : : retry:
1272 : 0 : page = grab_cache_page_write_begin(mapping, index, flags);
1273 [ # # ]: 0 : if (!page)
1274 : : return -ENOMEM;
1275 : 0 : *pagep = page;
1276 : :
1277 : : handle = ext3_journal_start(inode, needed_blocks);
1278 [ # # ]: 0 : if (IS_ERR(handle)) {
1279 : 0 : unlock_page(page);
1280 : 0 : page_cache_release(page);
1281 : : ret = PTR_ERR(handle);
1282 : 0 : goto out;
1283 : : }
1284 : 0 : ret = __block_write_begin(page, pos, len, ext3_get_block);
1285 [ # # ]: 0 : if (ret)
1286 : : goto write_begin_failed;
1287 : :
1288 [ # # ]: 0 : if (ext3_should_journal_data(inode)) {
1289 [ # # ]: 0 : ret = walk_page_buffers(handle, page_buffers(page),
1290 : : from, to, NULL, do_journal_get_write_access);
1291 : : }
1292 : : write_begin_failed:
1293 [ # # ]: 0 : if (ret) {
1294 : : /*
1295 : : * block_write_begin may have instantiated a few blocks
1296 : : * outside i_size. Trim these off again. Don't need
1297 : : * i_size_read because we hold i_mutex.
1298 : : *
1299 : : * Add inode to orphan list in case we crash before truncate
1300 : : * finishes. Do this only if ext3_can_truncate() agrees so
1301 : : * that orphan processing code is happy.
1302 : : */
1303 [ # # ][ # # ]: 0 : if (pos + len > inode->i_size && ext3_can_truncate(inode))
1304 : 0 : ext3_orphan_add(handle, inode);
1305 : 0 : ext3_journal_stop(handle);
1306 : 0 : unlock_page(page);
1307 : 0 : page_cache_release(page);
1308 [ # # ]: 0 : if (pos + len > inode->i_size)
1309 : 0 : ext3_truncate_failed_write(inode);
1310 : : }
1311 [ # # ][ # # ]: 0 : if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
1312 : : goto retry;
1313 : : out:
1314 : 0 : return ret;
1315 : : }
1316 : :
1317 : :
1318 : 0 : int ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
1319 : : {
1320 : 0 : int err = journal_dirty_data(handle, bh);
1321 [ # # ]: 0 : if (err)
1322 : 0 : ext3_journal_abort_handle(__func__, __func__,
1323 : : bh, handle, err);
1324 : 0 : return err;
1325 : : }
1326 : :
1327 : : /* For ordered writepage and write_end functions */
1328 : 0 : static int journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
1329 : : {
1330 : : /*
1331 : : * Write could have mapped the buffer but it didn't copy the data in
1332 : : * yet. So avoid filing such buffer into a transaction.
1333 : : */
1334 [ # # ][ # # ]: 0 : if (buffer_mapped(bh) && buffer_uptodate(bh))
1335 : 0 : return ext3_journal_dirty_data(handle, bh);
1336 : : return 0;
1337 : : }
1338 : :
1339 : : /* For write_end() in data=journal mode */
1340 : 0 : static int write_end_fn(handle_t *handle, struct buffer_head *bh)
1341 : : {
1342 [ # # ][ # # ]: 0 : if (!buffer_mapped(bh) || buffer_freed(bh))
1343 : : return 0;
1344 : : set_buffer_uptodate(bh);
1345 : 0 : return ext3_journal_dirty_metadata(handle, bh);
1346 : : }
1347 : :
1348 : : /*
1349 : : * This is nasty and subtle: ext3_write_begin() could have allocated blocks
1350 : : * for the whole page but later we failed to copy the data in. Update inode
1351 : : * size according to what we managed to copy. The rest is going to be
1352 : : * truncated in write_end function.
1353 : : */
1354 : 0 : static void update_file_sizes(struct inode *inode, loff_t pos, unsigned copied)
1355 : : {
1356 : : /* What matters to us is i_disksize. We don't write i_size anywhere */
1357 [ # # ]: 0 : if (pos + copied > inode->i_size)
1358 : : i_size_write(inode, pos + copied);
1359 [ # # ]: 0 : if (pos + copied > EXT3_I(inode)->i_disksize) {
1360 : 0 : EXT3_I(inode)->i_disksize = pos + copied;
1361 : : mark_inode_dirty(inode);
1362 : : }
1363 : 0 : }
1364 : :
1365 : : /*
1366 : : * We need to pick up the new inode size which generic_commit_write gave us
1367 : : * `file' can be NULL - eg, when called from page_symlink().
1368 : : *
1369 : : * ext3 never places buffers on inode->i_mapping->private_list. metadata
1370 : : * buffers are managed internally.
1371 : : */
1372 : 0 : static int ext3_ordered_write_end(struct file *file,
1373 : : struct address_space *mapping,
1374 : : loff_t pos, unsigned len, unsigned copied,
1375 : : struct page *page, void *fsdata)
1376 : : {
1377 : : handle_t *handle = ext3_journal_current_handle();
1378 : 0 : struct inode *inode = file->f_mapping->host;
1379 : : unsigned from, to;
1380 : : int ret = 0, ret2;
1381 : :
1382 : : trace_ext3_ordered_write_end(inode, pos, len, copied);
1383 : 0 : copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
1384 : :
1385 : 0 : from = pos & (PAGE_CACHE_SIZE - 1);
1386 : 0 : to = from + copied;
1387 [ # # ]: 0 : ret = walk_page_buffers(handle, page_buffers(page),
1388 : : from, to, NULL, journal_dirty_data_fn);
1389 : :
1390 [ # # ]: 0 : if (ret == 0)
1391 : 0 : update_file_sizes(inode, pos, copied);
1392 : : /*
1393 : : * There may be allocated blocks outside of i_size because
1394 : : * we failed to copy some data. Prepare for truncate.
1395 : : */
1396 [ # # ][ # # ]: 0 : if (pos + len > inode->i_size && ext3_can_truncate(inode))
1397 : 0 : ext3_orphan_add(handle, inode);
1398 : 0 : ret2 = ext3_journal_stop(handle);
1399 [ # # ]: 0 : if (!ret)
1400 : : ret = ret2;
1401 : 0 : unlock_page(page);
1402 : 0 : page_cache_release(page);
1403 : :
1404 [ # # ]: 0 : if (pos + len > inode->i_size)
1405 : 0 : ext3_truncate_failed_write(inode);
1406 [ # # ]: 0 : return ret ? ret : copied;
1407 : : }
1408 : :
1409 : 0 : static int ext3_writeback_write_end(struct file *file,
1410 : : struct address_space *mapping,
1411 : : loff_t pos, unsigned len, unsigned copied,
1412 : : struct page *page, void *fsdata)
1413 : : {
1414 : : handle_t *handle = ext3_journal_current_handle();
1415 : 0 : struct inode *inode = file->f_mapping->host;
1416 : : int ret;
1417 : :
1418 : : trace_ext3_writeback_write_end(inode, pos, len, copied);
1419 : 0 : copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
1420 : 0 : update_file_sizes(inode, pos, copied);
1421 : : /*
1422 : : * There may be allocated blocks outside of i_size because
1423 : : * we failed to copy some data. Prepare for truncate.
1424 : : */
1425 [ # # ][ # # ]: 0 : if (pos + len > inode->i_size && ext3_can_truncate(inode))
1426 : 0 : ext3_orphan_add(handle, inode);
1427 : 0 : ret = ext3_journal_stop(handle);
1428 : 0 : unlock_page(page);
1429 : 0 : page_cache_release(page);
1430 : :
1431 [ # # ]: 0 : if (pos + len > inode->i_size)
1432 : 0 : ext3_truncate_failed_write(inode);
1433 [ # # ]: 0 : return ret ? ret : copied;
1434 : : }
1435 : :
1436 : 0 : static int ext3_journalled_write_end(struct file *file,
1437 : : struct address_space *mapping,
1438 : : loff_t pos, unsigned len, unsigned copied,
1439 : : struct page *page, void *fsdata)
1440 : : {
1441 : : handle_t *handle = ext3_journal_current_handle();
1442 : 0 : struct inode *inode = mapping->host;
1443 : : struct ext3_inode_info *ei = EXT3_I(inode);
1444 : : int ret = 0, ret2;
1445 : 0 : int partial = 0;
1446 : : unsigned from, to;
1447 : :
1448 : : trace_ext3_journalled_write_end(inode, pos, len, copied);
1449 : 0 : from = pos & (PAGE_CACHE_SIZE - 1);
1450 : 0 : to = from + len;
1451 : :
1452 [ # # ]: 0 : if (copied < len) {
1453 [ # # ]: 0 : if (!PageUptodate(page))
1454 : : copied = 0;
1455 : 0 : page_zero_new_buffers(page, from + copied, to);
1456 : : to = from + copied;
1457 : : }
1458 : :
1459 [ # # ]: 0 : ret = walk_page_buffers(handle, page_buffers(page), from,
1460 : : to, &partial, write_end_fn);
1461 [ # # ]: 0 : if (!partial)
1462 : : SetPageUptodate(page);
1463 : :
1464 [ # # ]: 0 : if (pos + copied > inode->i_size)
1465 : : i_size_write(inode, pos + copied);
1466 : : /*
1467 : : * There may be allocated blocks outside of i_size because
1468 : : * we failed to copy some data. Prepare for truncate.
1469 : : */
1470 [ # # ][ # # ]: 0 : if (pos + len > inode->i_size && ext3_can_truncate(inode))
1471 : 0 : ext3_orphan_add(handle, inode);
1472 : : ext3_set_inode_state(inode, EXT3_STATE_JDATA);
1473 : 0 : atomic_set(&ei->i_datasync_tid, handle->h_transaction->t_tid);
1474 [ # # ]: 0 : if (inode->i_size > ei->i_disksize) {
1475 : 0 : ei->i_disksize = inode->i_size;
1476 : 0 : ret2 = ext3_mark_inode_dirty(handle, inode);
1477 [ # # ]: 0 : if (!ret)
1478 : : ret = ret2;
1479 : : }
1480 : :
1481 : 0 : ret2 = ext3_journal_stop(handle);
1482 [ # # ]: 0 : if (!ret)
1483 : : ret = ret2;
1484 : 0 : unlock_page(page);
1485 : 0 : page_cache_release(page);
1486 : :
1487 [ # # ]: 0 : if (pos + len > inode->i_size)
1488 : 0 : ext3_truncate_failed_write(inode);
1489 [ # # ]: 0 : return ret ? ret : copied;
1490 : : }
1491 : :
1492 : : /*
1493 : : * bmap() is special. It gets used by applications such as lilo and by
1494 : : * the swapper to find the on-disk block of a specific piece of data.
1495 : : *
1496 : : * Naturally, this is dangerous if the block concerned is still in the
1497 : : * journal. If somebody makes a swapfile on an ext3 data-journaling
1498 : : * filesystem and enables swap, then they may get a nasty shock when the
1499 : : * data getting swapped to that swapfile suddenly gets overwritten by
1500 : : * the original zero's written out previously to the journal and
1501 : : * awaiting writeback in the kernel's buffer cache.
1502 : : *
1503 : : * So, if we see any bmap calls here on a modified, data-journaled file,
1504 : : * take extra steps to flush any blocks which might be in the cache.
1505 : : */
1506 : 0 : static sector_t ext3_bmap(struct address_space *mapping, sector_t block)
1507 : : {
1508 : 0 : struct inode *inode = mapping->host;
1509 : : journal_t *journal;
1510 : : int err;
1511 : :
1512 [ # # ]: 0 : if (ext3_test_inode_state(inode, EXT3_STATE_JDATA)) {
1513 : : /*
1514 : : * This is a REALLY heavyweight approach, but the use of
1515 : : * bmap on dirty files is expected to be extremely rare:
1516 : : * only if we run lilo or swapon on a freshly made file
1517 : : * do we expect this to happen.
1518 : : *
1519 : : * (bmap requires CAP_SYS_RAWIO so this does not
1520 : : * represent an unprivileged user DOS attack --- we'd be
1521 : : * in trouble if mortal users could trigger this path at
1522 : : * will.)
1523 : : *
1524 : : * NB. EXT3_STATE_JDATA is not set on files other than
1525 : : * regular files. If somebody wants to bmap a directory
1526 : : * or symlink and gets confused because the buffer
1527 : : * hasn't yet been flushed to disk, they deserve
1528 : : * everything they get.
1529 : : */
1530 : :
1531 : : ext3_clear_inode_state(inode, EXT3_STATE_JDATA);
1532 : 0 : journal = EXT3_JOURNAL(inode);
1533 : 0 : journal_lock_updates(journal);
1534 : 0 : err = journal_flush(journal);
1535 : 0 : journal_unlock_updates(journal);
1536 : :
1537 [ # # ]: 0 : if (err)
1538 : : return 0;
1539 : : }
1540 : :
1541 : 0 : return generic_block_bmap(mapping,block,ext3_get_block);
1542 : : }
1543 : :
1544 : 0 : static int bget_one(handle_t *handle, struct buffer_head *bh)
1545 : : {
1546 : : get_bh(bh);
1547 : 0 : return 0;
1548 : : }
1549 : :
1550 : 0 : static int bput_one(handle_t *handle, struct buffer_head *bh)
1551 : : {
1552 : : put_bh(bh);
1553 : 0 : return 0;
1554 : : }
1555 : :
1556 : 0 : static int buffer_unmapped(handle_t *handle, struct buffer_head *bh)
1557 : : {
1558 : 0 : return !buffer_mapped(bh);
1559 : : }
1560 : :
1561 : : /*
1562 : : * Note that we always start a transaction even if we're not journalling
1563 : : * data. This is to preserve ordering: any hole instantiation within
1564 : : * __block_write_full_page -> ext3_get_block() should be journalled
1565 : : * along with the data so we don't crash and then get metadata which
1566 : : * refers to old data.
1567 : : *
1568 : : * In all journalling modes block_write_full_page() will start the I/O.
1569 : : *
1570 : : * Problem:
1571 : : *
1572 : : * ext3_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1573 : : * ext3_writepage()
1574 : : *
1575 : : * Similar for:
1576 : : *
1577 : : * ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ...
1578 : : *
1579 : : * Same applies to ext3_get_block(). We will deadlock on various things like
1580 : : * lock_journal and i_truncate_mutex.
1581 : : *
1582 : : * Setting PF_MEMALLOC here doesn't work - too many internal memory
1583 : : * allocations fail.
1584 : : *
1585 : : * 16May01: If we're reentered then journal_current_handle() will be
1586 : : * non-zero. We simply *return*.
1587 : : *
1588 : : * 1 July 2001: @@@ FIXME:
1589 : : * In journalled data mode, a data buffer may be metadata against the
1590 : : * current transaction. But the same file is part of a shared mapping
1591 : : * and someone does a writepage() on it.
1592 : : *
1593 : : * We will move the buffer onto the async_data list, but *after* it has
1594 : : * been dirtied. So there's a small window where we have dirty data on
1595 : : * BJ_Metadata.
1596 : : *
1597 : : * Note that this only applies to the last partial page in the file. The
1598 : : * bit which block_write_full_page() uses prepare/commit for. (That's
1599 : : * broken code anyway: it's wrong for msync()).
1600 : : *
1601 : : * It's a rare case: affects the final partial page, for journalled data
1602 : : * where the file is subject to bith write() and writepage() in the same
1603 : : * transction. To fix it we'll need a custom block_write_full_page().
1604 : : * We'll probably need that anyway for journalling writepage() output.
1605 : : *
1606 : : * We don't honour synchronous mounts for writepage(). That would be
1607 : : * disastrous. Any write() or metadata operation will sync the fs for
1608 : : * us.
1609 : : *
1610 : : * AKPM2: if all the page's buffers are mapped to disk and !data=journal,
1611 : : * we don't need to open a transaction here.
1612 : : */
1613 : 0 : static int ext3_ordered_writepage(struct page *page,
1614 : : struct writeback_control *wbc)
1615 : : {
1616 : 0 : struct inode *inode = page->mapping->host;
1617 : : struct buffer_head *page_bufs;
1618 : : handle_t *handle = NULL;
1619 : : int ret = 0;
1620 : : int err;
1621 : :
1622 [ # # ]: 0 : J_ASSERT(PageLocked(page));
1623 : : /*
1624 : : * We don't want to warn for emergency remount. The condition is
1625 : : * ordered to avoid dereferencing inode->i_sb in non-error case to
1626 : : * avoid slow-downs.
1627 : : */
1628 [ # # ][ # # ]: 0 : WARN_ON_ONCE(IS_RDONLY(inode) &&
[ # # ][ # # ]
[ # # ]
1629 : : !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS));
1630 : :
1631 : : /*
1632 : : * We give up here if we're reentered, because it might be for a
1633 : : * different filesystem.
1634 : : */
1635 [ # # ]: 0 : if (ext3_journal_current_handle())
1636 : : goto out_fail;
1637 : :
1638 : : trace_ext3_ordered_writepage(page);
1639 [ # # ]: 0 : if (!page_has_buffers(page)) {
1640 : 0 : create_empty_buffers(page, inode->i_sb->s_blocksize,
1641 : : (1 << BH_Dirty)|(1 << BH_Uptodate));
1642 [ # # ]: 0 : page_bufs = page_buffers(page);
1643 : : } else {
1644 [ # # ]: 0 : page_bufs = page_buffers(page);
1645 [ # # ]: 0 : if (!walk_page_buffers(NULL, page_bufs, 0, PAGE_CACHE_SIZE,
1646 : : NULL, buffer_unmapped)) {
1647 : : /* Provide NULL get_block() to catch bugs if buffers
1648 : : * weren't really mapped */
1649 : 0 : return block_write_full_page(page, NULL, wbc);
1650 : : }
1651 : : }
1652 : 0 : handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1653 : :
1654 [ # # ]: 0 : if (IS_ERR(handle)) {
1655 : : ret = PTR_ERR(handle);
1656 : 0 : goto out_fail;
1657 : : }
1658 : :
1659 : 0 : walk_page_buffers(handle, page_bufs, 0,
1660 : : PAGE_CACHE_SIZE, NULL, bget_one);
1661 : :
1662 : 0 : ret = block_write_full_page(page, ext3_get_block, wbc);
1663 : :
1664 : : /*
1665 : : * The page can become unlocked at any point now, and
1666 : : * truncate can then come in and change things. So we
1667 : : * can't touch *page from now on. But *page_bufs is
1668 : : * safe due to elevated refcount.
1669 : : */
1670 : :
1671 : : /*
1672 : : * And attach them to the current transaction. But only if
1673 : : * block_write_full_page() succeeded. Otherwise they are unmapped,
1674 : : * and generally junk.
1675 : : */
1676 [ # # ]: 0 : if (ret == 0) {
1677 : 0 : err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
1678 : : NULL, journal_dirty_data_fn);
1679 [ # # ]: 0 : if (!ret)
1680 : : ret = err;
1681 : : }
1682 : 0 : walk_page_buffers(handle, page_bufs, 0,
1683 : : PAGE_CACHE_SIZE, NULL, bput_one);
1684 : 0 : err = ext3_journal_stop(handle);
1685 [ # # ]: 0 : if (!ret)
1686 : : ret = err;
1687 : 0 : return ret;
1688 : :
1689 : : out_fail:
1690 : 0 : redirty_page_for_writepage(wbc, page);
1691 : 0 : unlock_page(page);
1692 : 0 : return ret;
1693 : : }
1694 : :
1695 : 0 : static int ext3_writeback_writepage(struct page *page,
1696 : : struct writeback_control *wbc)
1697 : : {
1698 : 0 : struct inode *inode = page->mapping->host;
1699 : : handle_t *handle = NULL;
1700 : : int ret = 0;
1701 : : int err;
1702 : :
1703 [ # # ]: 0 : J_ASSERT(PageLocked(page));
1704 : : /*
1705 : : * We don't want to warn for emergency remount. The condition is
1706 : : * ordered to avoid dereferencing inode->i_sb in non-error case to
1707 : : * avoid slow-downs.
1708 : : */
1709 [ # # ][ # # ]: 0 : WARN_ON_ONCE(IS_RDONLY(inode) &&
[ # # ][ # # ]
[ # # ]
1710 : : !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS));
1711 : :
1712 [ # # ]: 0 : if (ext3_journal_current_handle())
1713 : : goto out_fail;
1714 : :
1715 : : trace_ext3_writeback_writepage(page);
1716 [ # # ]: 0 : if (page_has_buffers(page)) {
1717 [ # # ][ # # ]: 0 : if (!walk_page_buffers(NULL, page_buffers(page), 0,
1718 : : PAGE_CACHE_SIZE, NULL, buffer_unmapped)) {
1719 : : /* Provide NULL get_block() to catch bugs if buffers
1720 : : * weren't really mapped */
1721 : 0 : return block_write_full_page(page, NULL, wbc);
1722 : : }
1723 : : }
1724 : :
1725 : 0 : handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1726 [ # # ]: 0 : if (IS_ERR(handle)) {
1727 : : ret = PTR_ERR(handle);
1728 : 0 : goto out_fail;
1729 : : }
1730 : :
1731 : 0 : ret = block_write_full_page(page, ext3_get_block, wbc);
1732 : :
1733 : 0 : err = ext3_journal_stop(handle);
1734 [ # # ]: 0 : if (!ret)
1735 : : ret = err;
1736 : 0 : return ret;
1737 : :
1738 : : out_fail:
1739 : 0 : redirty_page_for_writepage(wbc, page);
1740 : 0 : unlock_page(page);
1741 : 0 : return ret;
1742 : : }
1743 : :
1744 : 0 : static int ext3_journalled_writepage(struct page *page,
1745 : : struct writeback_control *wbc)
1746 : : {
1747 : 0 : struct inode *inode = page->mapping->host;
1748 : : handle_t *handle = NULL;
1749 : : int ret = 0;
1750 : : int err;
1751 : :
1752 [ # # ]: 0 : J_ASSERT(PageLocked(page));
1753 : : /*
1754 : : * We don't want to warn for emergency remount. The condition is
1755 : : * ordered to avoid dereferencing inode->i_sb in non-error case to
1756 : : * avoid slow-downs.
1757 : : */
1758 [ # # ][ # # ]: 0 : WARN_ON_ONCE(IS_RDONLY(inode) &&
[ # # ][ # # ]
[ # # ]
1759 : : !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS));
1760 : :
1761 [ # # ]: 0 : if (ext3_journal_current_handle())
1762 : : goto no_write;
1763 : :
1764 : : trace_ext3_journalled_writepage(page);
1765 : 0 : handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1766 [ # # ]: 0 : if (IS_ERR(handle)) {
1767 : : ret = PTR_ERR(handle);
1768 : 0 : goto no_write;
1769 : : }
1770 : :
1771 [ # # ][ # # ]: 0 : if (!page_has_buffers(page) || PageChecked(page)) {
1772 : : /*
1773 : : * It's mmapped pagecache. Add buffers and journal it. There
1774 : : * doesn't seem much point in redirtying the page here.
1775 : : */
1776 : : ClearPageChecked(page);
1777 : 0 : ret = __block_write_begin(page, 0, PAGE_CACHE_SIZE,
1778 : : ext3_get_block);
1779 [ # # ]: 0 : if (ret != 0) {
1780 : 0 : ext3_journal_stop(handle);
1781 : 0 : goto out_unlock;
1782 : : }
1783 [ # # ]: 0 : ret = walk_page_buffers(handle, page_buffers(page), 0,
1784 : : PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
1785 : :
1786 [ # # ]: 0 : err = walk_page_buffers(handle, page_buffers(page), 0,
1787 : : PAGE_CACHE_SIZE, NULL, write_end_fn);
1788 [ # # ]: 0 : if (ret == 0)
1789 : : ret = err;
1790 : : ext3_set_inode_state(inode, EXT3_STATE_JDATA);
1791 : 0 : atomic_set(&EXT3_I(inode)->i_datasync_tid,
1792 : : handle->h_transaction->t_tid);
1793 : 0 : unlock_page(page);
1794 : : } else {
1795 : : /*
1796 : : * It may be a page full of checkpoint-mode buffers. We don't
1797 : : * really know unless we go poke around in the buffer_heads.
1798 : : * But block_write_full_page will do the right thing.
1799 : : */
1800 : 0 : ret = block_write_full_page(page, ext3_get_block, wbc);
1801 : : }
1802 : 0 : err = ext3_journal_stop(handle);
1803 [ # # ]: 0 : if (!ret)
1804 : : ret = err;
1805 : : out:
1806 : 0 : return ret;
1807 : :
1808 : : no_write:
1809 : 0 : redirty_page_for_writepage(wbc, page);
1810 : : out_unlock:
1811 : 0 : unlock_page(page);
1812 : 0 : goto out;
1813 : : }
1814 : :
1815 : 0 : static int ext3_readpage(struct file *file, struct page *page)
1816 : : {
1817 : : trace_ext3_readpage(page);
1818 : 0 : return mpage_readpage(page, ext3_get_block);
1819 : : }
1820 : :
1821 : : static int
1822 : 0 : ext3_readpages(struct file *file, struct address_space *mapping,
1823 : : struct list_head *pages, unsigned nr_pages)
1824 : : {
1825 : 0 : return mpage_readpages(mapping, pages, nr_pages, ext3_get_block);
1826 : : }
1827 : :
1828 : 0 : static void ext3_invalidatepage(struct page *page, unsigned int offset,
1829 : : unsigned int length)
1830 : : {
1831 : 0 : journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1832 : :
1833 : : trace_ext3_invalidatepage(page, offset, length);
1834 : :
1835 : : /*
1836 : : * If it's a full truncate we just forget about the pending dirtying
1837 : : */
1838 [ # # ]: 0 : if (offset == 0 && length == PAGE_CACHE_SIZE)
1839 : : ClearPageChecked(page);
1840 : :
1841 : 0 : journal_invalidatepage(journal, page, offset, length);
1842 : 0 : }
1843 : :
1844 : 0 : static int ext3_releasepage(struct page *page, gfp_t wait)
1845 : : {
1846 : 0 : journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1847 : :
1848 : : trace_ext3_releasepage(page);
1849 [ # # ]: 0 : WARN_ON(PageChecked(page));
1850 [ # # ]: 0 : if (!page_has_buffers(page))
1851 : : return 0;
1852 : 0 : return journal_try_to_free_buffers(journal, page, wait);
1853 : : }
1854 : :
1855 : : /*
1856 : : * If the O_DIRECT write will extend the file then add this inode to the
1857 : : * orphan list. So recovery will truncate it back to the original size
1858 : : * if the machine crashes during the write.
1859 : : *
1860 : : * If the O_DIRECT write is intantiating holes inside i_size and the machine
1861 : : * crashes then stale disk data _may_ be exposed inside the file. But current
1862 : : * VFS code falls back into buffered path in that case so we are safe.
1863 : : */
1864 : 0 : static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
1865 : : const struct iovec *iov, loff_t offset,
1866 : : unsigned long nr_segs)
1867 : : {
1868 : 0 : struct file *file = iocb->ki_filp;
1869 : 0 : struct inode *inode = file->f_mapping->host;
1870 : : struct ext3_inode_info *ei = EXT3_I(inode);
1871 : : handle_t *handle;
1872 : : ssize_t ret;
1873 : : int orphan = 0;
1874 : : size_t count = iov_length(iov, nr_segs);
1875 : 0 : int retries = 0;
1876 : :
1877 : : trace_ext3_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw);
1878 : :
1879 [ # # ]: 0 : if (rw == WRITE) {
1880 : 0 : loff_t final_size = offset + count;
1881 : :
1882 [ # # ]: 0 : if (final_size > inode->i_size) {
1883 : : /* Credits for sb + inode write */
1884 : : handle = ext3_journal_start(inode, 2);
1885 [ # # ]: 0 : if (IS_ERR(handle)) {
1886 : : ret = PTR_ERR(handle);
1887 : 0 : goto out;
1888 : : }
1889 : 0 : ret = ext3_orphan_add(handle, inode);
1890 [ # # ]: 0 : if (ret) {
1891 : 0 : ext3_journal_stop(handle);
1892 : 0 : goto out;
1893 : : }
1894 : : orphan = 1;
1895 : 0 : ei->i_disksize = inode->i_size;
1896 : 0 : ext3_journal_stop(handle);
1897 : : }
1898 : : }
1899 : :
1900 : : retry:
1901 : : ret = blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs,
1902 : : ext3_get_block);
1903 : : /*
1904 : : * In case of error extending write may have instantiated a few
1905 : : * blocks outside i_size. Trim these off again.
1906 : : */
1907 [ # # ][ # # ]: 0 : if (unlikely((rw & WRITE) && ret < 0)) {
1908 : : loff_t isize = i_size_read(inode);
1909 : 0 : loff_t end = offset + iov_length(iov, nr_segs);
1910 : :
1911 [ # # ]: 0 : if (end > isize)
1912 : 0 : ext3_truncate_failed_direct_write(inode);
1913 : : }
1914 [ # # ][ # # ]: 0 : if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
1915 : : goto retry;
1916 : :
1917 [ # # ]: 0 : if (orphan) {
1918 : : int err;
1919 : :
1920 : : /* Credits for sb + inode write */
1921 : : handle = ext3_journal_start(inode, 2);
1922 [ # # ]: 0 : if (IS_ERR(handle)) {
1923 : : /* This is really bad luck. We've written the data
1924 : : * but cannot extend i_size. Truncate allocated blocks
1925 : : * and pretend the write failed... */
1926 : 0 : ext3_truncate_failed_direct_write(inode);
1927 : : ret = PTR_ERR(handle);
1928 : 0 : goto out;
1929 : : }
1930 [ # # ]: 0 : if (inode->i_nlink)
1931 : 0 : ext3_orphan_del(handle, inode);
1932 [ # # ]: 0 : if (ret > 0) {
1933 : 0 : loff_t end = offset + ret;
1934 [ # # ]: 0 : if (end > inode->i_size) {
1935 : 0 : ei->i_disksize = end;
1936 : : i_size_write(inode, end);
1937 : : /*
1938 : : * We're going to return a positive `ret'
1939 : : * here due to non-zero-length I/O, so there's
1940 : : * no way of reporting error returns from
1941 : : * ext3_mark_inode_dirty() to userspace. So
1942 : : * ignore it.
1943 : : */
1944 : 0 : ext3_mark_inode_dirty(handle, inode);
1945 : : }
1946 : : }
1947 : 0 : err = ext3_journal_stop(handle);
1948 [ # # ]: 0 : if (ret == 0)
1949 : : ret = err;
1950 : : }
1951 : : out:
1952 : : trace_ext3_direct_IO_exit(inode, offset,
1953 : : iov_length(iov, nr_segs), rw, ret);
1954 : 0 : return ret;
1955 : : }
1956 : :
1957 : : /*
1958 : : * Pages can be marked dirty completely asynchronously from ext3's journalling
1959 : : * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
1960 : : * much here because ->set_page_dirty is called under VFS locks. The page is
1961 : : * not necessarily locked.
1962 : : *
1963 : : * We cannot just dirty the page and leave attached buffers clean, because the
1964 : : * buffers' dirty state is "definitive". We cannot just set the buffers dirty
1965 : : * or jbddirty because all the journalling code will explode.
1966 : : *
1967 : : * So what we do is to mark the page "pending dirty" and next time writepage
1968 : : * is called, propagate that into the buffers appropriately.
1969 : : */
1970 : 0 : static int ext3_journalled_set_page_dirty(struct page *page)
1971 : : {
1972 : : SetPageChecked(page);
1973 : 0 : return __set_page_dirty_nobuffers(page);
1974 : : }
1975 : :
1976 : : static const struct address_space_operations ext3_ordered_aops = {
1977 : : .readpage = ext3_readpage,
1978 : : .readpages = ext3_readpages,
1979 : : .writepage = ext3_ordered_writepage,
1980 : : .write_begin = ext3_write_begin,
1981 : : .write_end = ext3_ordered_write_end,
1982 : : .bmap = ext3_bmap,
1983 : : .invalidatepage = ext3_invalidatepage,
1984 : : .releasepage = ext3_releasepage,
1985 : : .direct_IO = ext3_direct_IO,
1986 : : .migratepage = buffer_migrate_page,
1987 : : .is_partially_uptodate = block_is_partially_uptodate,
1988 : : .is_dirty_writeback = buffer_check_dirty_writeback,
1989 : : .error_remove_page = generic_error_remove_page,
1990 : : };
1991 : :
1992 : : static const struct address_space_operations ext3_writeback_aops = {
1993 : : .readpage = ext3_readpage,
1994 : : .readpages = ext3_readpages,
1995 : : .writepage = ext3_writeback_writepage,
1996 : : .write_begin = ext3_write_begin,
1997 : : .write_end = ext3_writeback_write_end,
1998 : : .bmap = ext3_bmap,
1999 : : .invalidatepage = ext3_invalidatepage,
2000 : : .releasepage = ext3_releasepage,
2001 : : .direct_IO = ext3_direct_IO,
2002 : : .migratepage = buffer_migrate_page,
2003 : : .is_partially_uptodate = block_is_partially_uptodate,
2004 : : .error_remove_page = generic_error_remove_page,
2005 : : };
2006 : :
2007 : : static const struct address_space_operations ext3_journalled_aops = {
2008 : : .readpage = ext3_readpage,
2009 : : .readpages = ext3_readpages,
2010 : : .writepage = ext3_journalled_writepage,
2011 : : .write_begin = ext3_write_begin,
2012 : : .write_end = ext3_journalled_write_end,
2013 : : .set_page_dirty = ext3_journalled_set_page_dirty,
2014 : : .bmap = ext3_bmap,
2015 : : .invalidatepage = ext3_invalidatepage,
2016 : : .releasepage = ext3_releasepage,
2017 : : .is_partially_uptodate = block_is_partially_uptodate,
2018 : : .error_remove_page = generic_error_remove_page,
2019 : : };
2020 : :
2021 : 0 : void ext3_set_aops(struct inode *inode)
2022 : : {
2023 [ # # ]: 0 : if (ext3_should_order_data(inode))
2024 : 0 : inode->i_mapping->a_ops = &ext3_ordered_aops;
2025 [ # # ]: 0 : else if (ext3_should_writeback_data(inode))
2026 : 0 : inode->i_mapping->a_ops = &ext3_writeback_aops;
2027 : : else
2028 : 0 : inode->i_mapping->a_ops = &ext3_journalled_aops;
2029 : 0 : }
2030 : :
2031 : : /*
2032 : : * ext3_block_truncate_page() zeroes out a mapping from file offset `from'
2033 : : * up to the end of the block which corresponds to `from'.
2034 : : * This required during truncate. We need to physically zero the tail end
2035 : : * of that block so it doesn't yield old data if the file is later grown.
2036 : : */
2037 : 0 : static int ext3_block_truncate_page(struct inode *inode, loff_t from)
2038 : : {
2039 : 0 : ext3_fsblk_t index = from >> PAGE_CACHE_SHIFT;
2040 : 0 : unsigned offset = from & (PAGE_CACHE_SIZE - 1);
2041 : : unsigned blocksize, iblock, length, pos;
2042 : : struct page *page;
2043 : : handle_t *handle = NULL;
2044 : : struct buffer_head *bh;
2045 : : int err = 0;
2046 : :
2047 : : /* Truncated on block boundary - nothing to do */
2048 : 0 : blocksize = inode->i_sb->s_blocksize;
2049 [ # # ]: 0 : if ((from & (blocksize - 1)) == 0)
2050 : : return 0;
2051 : :
2052 : 0 : page = grab_cache_page(inode->i_mapping, index);
2053 [ # # ]: 0 : if (!page)
2054 : : return -ENOMEM;
2055 : 0 : length = blocksize - (offset & (blocksize - 1));
2056 : 0 : iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
2057 : :
2058 [ # # ]: 0 : if (!page_has_buffers(page))
2059 : 0 : create_empty_buffers(page, blocksize, 0);
2060 : :
2061 : : /* Find the buffer that contains "offset" */
2062 [ # # ]: 0 : bh = page_buffers(page);
2063 : : pos = blocksize;
2064 [ # # ]: 0 : while (offset >= pos) {
2065 : 0 : bh = bh->b_this_page;
2066 : 0 : iblock++;
2067 : 0 : pos += blocksize;
2068 : : }
2069 : :
2070 : : err = 0;
2071 [ # # ]: 0 : if (buffer_freed(bh)) {
2072 : : BUFFER_TRACE(bh, "freed: skip");
2073 : : goto unlock;
2074 : : }
2075 : :
2076 [ # # ]: 0 : if (!buffer_mapped(bh)) {
2077 : : BUFFER_TRACE(bh, "unmapped");
2078 : 0 : ext3_get_block(inode, iblock, bh, 0);
2079 : : /* unmapped? It's a hole - nothing to do */
2080 [ # # ]: 0 : if (!buffer_mapped(bh)) {
2081 : : BUFFER_TRACE(bh, "still unmapped");
2082 : : goto unlock;
2083 : : }
2084 : : }
2085 : :
2086 : : /* Ok, it's mapped. Make sure it's up-to-date */
2087 [ # # ]: 0 : if (PageUptodate(page))
2088 : : set_buffer_uptodate(bh);
2089 : :
2090 [ # # ]: 0 : if (!bh_uptodate_or_lock(bh)) {
2091 : 0 : err = bh_submit_read(bh);
2092 : : /* Uhhuh. Read error. Complain and punt. */
2093 [ # # ]: 0 : if (err)
2094 : : goto unlock;
2095 : : }
2096 : :
2097 : : /* data=writeback mode doesn't need transaction to zero-out data */
2098 [ # # ]: 0 : if (!ext3_should_writeback_data(inode)) {
2099 : : /* We journal at most one block */
2100 : : handle = ext3_journal_start(inode, 1);
2101 [ # # ]: 0 : if (IS_ERR(handle)) {
2102 : : clear_highpage(page);
2103 : 0 : flush_dcache_page(page);
2104 : : err = PTR_ERR(handle);
2105 : 0 : goto unlock;
2106 : : }
2107 : : }
2108 : :
2109 [ # # ]: 0 : if (ext3_should_journal_data(inode)) {
2110 : : BUFFER_TRACE(bh, "get write access");
2111 : 0 : err = ext3_journal_get_write_access(handle, bh);
2112 [ # # ]: 0 : if (err)
2113 : : goto stop;
2114 : : }
2115 : :
2116 : : zero_user(page, offset, length);
2117 : : BUFFER_TRACE(bh, "zeroed end of block");
2118 : :
2119 : : err = 0;
2120 [ # # ]: 0 : if (ext3_should_journal_data(inode)) {
2121 : 0 : err = ext3_journal_dirty_metadata(handle, bh);
2122 : : } else {
2123 [ # # ]: 0 : if (ext3_should_order_data(inode))
2124 : 0 : err = ext3_journal_dirty_data(handle, bh);
2125 : 0 : mark_buffer_dirty(bh);
2126 : : }
2127 : : stop:
2128 [ # # ]: 0 : if (handle)
2129 : 0 : ext3_journal_stop(handle);
2130 : :
2131 : : unlock:
2132 : 0 : unlock_page(page);
2133 : 0 : page_cache_release(page);
2134 : 0 : return err;
2135 : : }
2136 : :
2137 : : /*
2138 : : * Probably it should be a library function... search for first non-zero word
2139 : : * or memcmp with zero_page, whatever is better for particular architecture.
2140 : : * Linus?
2141 : : */
2142 : : static inline int all_zeroes(__le32 *p, __le32 *q)
2143 : : {
2144 [ # # ]: 0 : while (p < q)
2145 [ # # ]: 0 : if (*p++)
2146 : : return 0;
2147 : : return 1;
2148 : : }
2149 : :
2150 : : /**
2151 : : * ext3_find_shared - find the indirect blocks for partial truncation.
2152 : : * @inode: inode in question
2153 : : * @depth: depth of the affected branch
2154 : : * @offsets: offsets of pointers in that branch (see ext3_block_to_path)
2155 : : * @chain: place to store the pointers to partial indirect blocks
2156 : : * @top: place to the (detached) top of branch
2157 : : *
2158 : : * This is a helper function used by ext3_truncate().
2159 : : *
2160 : : * When we do truncate() we may have to clean the ends of several
2161 : : * indirect blocks but leave the blocks themselves alive. Block is
2162 : : * partially truncated if some data below the new i_size is referred
2163 : : * from it (and it is on the path to the first completely truncated
2164 : : * data block, indeed). We have to free the top of that path along
2165 : : * with everything to the right of the path. Since no allocation
2166 : : * past the truncation point is possible until ext3_truncate()
2167 : : * finishes, we may safely do the latter, but top of branch may
2168 : : * require special attention - pageout below the truncation point
2169 : : * might try to populate it.
2170 : : *
2171 : : * We atomically detach the top of branch from the tree, store the
2172 : : * block number of its root in *@top, pointers to buffer_heads of
2173 : : * partially truncated blocks - in @chain[].bh and pointers to
2174 : : * their last elements that should not be removed - in
2175 : : * @chain[].p. Return value is the pointer to last filled element
2176 : : * of @chain.
2177 : : *
2178 : : * The work left to caller to do the actual freeing of subtrees:
2179 : : * a) free the subtree starting from *@top
2180 : : * b) free the subtrees whose roots are stored in
2181 : : * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
2182 : : * c) free the subtrees growing from the inode past the @chain[0].
2183 : : * (no partially truncated stuff there). */
2184 : :
2185 : 0 : static Indirect *ext3_find_shared(struct inode *inode, int depth,
2186 : : int offsets[4], Indirect chain[4], __le32 *top)
2187 : : {
2188 : : Indirect *partial, *p;
2189 : : int k, err;
2190 : :
2191 : 0 : *top = 0;
2192 : : /* Make k index the deepest non-null offset + 1 */
2193 [ # # ][ # # ]: 0 : for (k = depth; k > 1 && !offsets[k-1]; k--)
2194 : : ;
2195 : 0 : partial = ext3_get_branch(inode, k, offsets, chain, &err);
2196 : : /* Writer: pointers */
2197 [ # # ]: 0 : if (!partial)
2198 : 0 : partial = chain + k-1;
2199 : : /*
2200 : : * If the branch acquired continuation since we've looked at it -
2201 : : * fine, it should all survive and (new) top doesn't belong to us.
2202 : : */
2203 [ # # ][ # # ]: 0 : if (!partial->key && *partial->p)
2204 : : /* Writer: end */
2205 : : goto no_top;
2206 [ # # ][ # # ]: 0 : for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
2207 : : ;
2208 : : /*
2209 : : * OK, we've found the last block that must survive. The rest of our
2210 : : * branch should be detached before unlocking. However, if that rest
2211 : : * of branch is all ours and does not grow immediately from the inode
2212 : : * it's easier to cheat and just decrement partial->p.
2213 : : */
2214 [ # # ][ # # ]: 0 : if (p == chain + k - 1 && p > chain) {
2215 : 0 : p->p--;
2216 : : } else {
2217 : 0 : *top = *p->p;
2218 : : /* Nope, don't do this in ext3. Must leave the tree intact */
2219 : : #if 0
2220 : : *p->p = 0;
2221 : : #endif
2222 : : }
2223 : : /* Writer: end */
2224 : :
2225 [ # # ]: 0 : while(partial > p) {
2226 : 0 : brelse(partial->bh);
2227 : 0 : partial--;
2228 : : }
2229 : : no_top:
2230 : 0 : return partial;
2231 : : }
2232 : :
2233 : : /*
2234 : : * Zero a number of block pointers in either an inode or an indirect block.
2235 : : * If we restart the transaction we must again get write access to the
2236 : : * indirect block for further modification.
2237 : : *
2238 : : * We release `count' blocks on disk, but (last - first) may be greater
2239 : : * than `count' because there can be holes in there.
2240 : : */
2241 : 0 : static void ext3_clear_blocks(handle_t *handle, struct inode *inode,
2242 : : struct buffer_head *bh, ext3_fsblk_t block_to_free,
2243 : : unsigned long count, __le32 *first, __le32 *last)
2244 : : {
2245 : : __le32 *p;
2246 [ # # ]: 0 : if (try_to_extend_transaction(handle, inode)) {
2247 [ # # ]: 0 : if (bh) {
2248 : : BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
2249 [ # # ]: 0 : if (ext3_journal_dirty_metadata(handle, bh))
2250 : : return;
2251 : : }
2252 : 0 : ext3_mark_inode_dirty(handle, inode);
2253 : 0 : truncate_restart_transaction(handle, inode);
2254 [ # # ]: 0 : if (bh) {
2255 : : BUFFER_TRACE(bh, "retaking write access");
2256 [ # # ]: 0 : if (ext3_journal_get_write_access(handle, bh))
2257 : : return;
2258 : : }
2259 : : }
2260 : :
2261 : : /*
2262 : : * Any buffers which are on the journal will be in memory. We find
2263 : : * them on the hash table so journal_revoke() will run journal_forget()
2264 : : * on them. We've already detached each block from the file, so
2265 : : * bforget() in journal_forget() should be safe.
2266 : : *
2267 : : * AKPM: turn on bforget in journal_forget()!!!
2268 : : */
2269 [ # # ]: 0 : for (p = first; p < last; p++) {
2270 : 0 : u32 nr = le32_to_cpu(*p);
2271 [ # # ]: 0 : if (nr) {
2272 : : struct buffer_head *bh;
2273 : :
2274 : 0 : *p = 0;
2275 : 0 : bh = sb_find_get_block(inode->i_sb, nr);
2276 : 0 : ext3_forget(handle, 0, inode, bh, nr);
2277 : : }
2278 : : }
2279 : :
2280 : 0 : ext3_free_blocks(handle, inode, block_to_free, count);
2281 : : }
2282 : :
2283 : : /**
2284 : : * ext3_free_data - free a list of data blocks
2285 : : * @handle: handle for this transaction
2286 : : * @inode: inode we are dealing with
2287 : : * @this_bh: indirect buffer_head which contains *@first and *@last
2288 : : * @first: array of block numbers
2289 : : * @last: points immediately past the end of array
2290 : : *
2291 : : * We are freeing all blocks referred from that array (numbers are stored as
2292 : : * little-endian 32-bit) and updating @inode->i_blocks appropriately.
2293 : : *
2294 : : * We accumulate contiguous runs of blocks to free. Conveniently, if these
2295 : : * blocks are contiguous then releasing them at one time will only affect one
2296 : : * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
2297 : : * actually use a lot of journal space.
2298 : : *
2299 : : * @this_bh will be %NULL if @first and @last point into the inode's direct
2300 : : * block pointers.
2301 : : */
2302 : 0 : static void ext3_free_data(handle_t *handle, struct inode *inode,
2303 : 0 : struct buffer_head *this_bh,
2304 : : __le32 *first, __le32 *last)
2305 : : {
2306 : : ext3_fsblk_t block_to_free = 0; /* Starting block # of a run */
2307 : : unsigned long count = 0; /* Number of blocks in the run */
2308 : : __le32 *block_to_free_p = NULL; /* Pointer into inode/ind
2309 : : corresponding to
2310 : : block_to_free */
2311 : : ext3_fsblk_t nr; /* Current block # */
2312 : : __le32 *p; /* Pointer into inode/ind
2313 : : for current block */
2314 : : int err;
2315 : :
2316 [ # # ]: 0 : if (this_bh) { /* For indirect block */
2317 : : BUFFER_TRACE(this_bh, "get_write_access");
2318 : 0 : err = ext3_journal_get_write_access(handle, this_bh);
2319 : : /* Important: if we can't update the indirect pointers
2320 : : * to the blocks, we can't free them. */
2321 [ # # ]: 0 : if (err)
2322 : 0 : return;
2323 : : }
2324 : :
2325 [ # # ]: 0 : for (p = first; p < last; p++) {
2326 : 0 : nr = le32_to_cpu(*p);
2327 [ # # ]: 0 : if (nr) {
2328 : : /* accumulate blocks to free if they're contiguous */
2329 [ # # ]: 0 : if (count == 0) {
2330 : : block_to_free = nr;
2331 : : block_to_free_p = p;
2332 : : count = 1;
2333 [ # # ]: 0 : } else if (nr == block_to_free + count) {
2334 : 0 : count++;
2335 : : } else {
2336 : 0 : ext3_clear_blocks(handle, inode, this_bh,
2337 : : block_to_free,
2338 : : count, block_to_free_p, p);
2339 : : block_to_free = nr;
2340 : : block_to_free_p = p;
2341 : : count = 1;
2342 : : }
2343 : : }
2344 : : }
2345 : :
2346 [ # # ]: 0 : if (count > 0)
2347 : 0 : ext3_clear_blocks(handle, inode, this_bh, block_to_free,
2348 : : count, block_to_free_p, p);
2349 : :
2350 [ # # ]: 0 : if (this_bh) {
2351 : : BUFFER_TRACE(this_bh, "call ext3_journal_dirty_metadata");
2352 : :
2353 : : /*
2354 : : * The buffer head should have an attached journal head at this
2355 : : * point. However, if the data is corrupted and an indirect
2356 : : * block pointed to itself, it would have been detached when
2357 : : * the block was cleared. Check for this instead of OOPSing.
2358 : : */
2359 [ # # ]: 0 : if (bh2jh(this_bh))
2360 : 0 : ext3_journal_dirty_metadata(handle, this_bh);
2361 : : else
2362 : 0 : ext3_error(inode->i_sb, "ext3_free_data",
2363 : : "circular indirect block detected, "
2364 : : "inode=%lu, block=%llu",
2365 : : inode->i_ino,
2366 : : (unsigned long long)this_bh->b_blocknr);
2367 : : }
2368 : : }
2369 : :
2370 : : /**
2371 : : * ext3_free_branches - free an array of branches
2372 : : * @handle: JBD handle for this transaction
2373 : : * @inode: inode we are dealing with
2374 : : * @parent_bh: the buffer_head which contains *@first and *@last
2375 : : * @first: array of block numbers
2376 : : * @last: pointer immediately past the end of array
2377 : : * @depth: depth of the branches to free
2378 : : *
2379 : : * We are freeing all blocks referred from these branches (numbers are
2380 : : * stored as little-endian 32-bit) and updating @inode->i_blocks
2381 : : * appropriately.
2382 : : */
2383 : 0 : static void ext3_free_branches(handle_t *handle, struct inode *inode,
2384 : : struct buffer_head *parent_bh,
2385 : : __le32 *first, __le32 *last, int depth)
2386 : : {
2387 : : ext3_fsblk_t nr;
2388 : : __le32 *p;
2389 : :
2390 [ # # ]: 0 : if (is_handle_aborted(handle))
2391 : : return;
2392 : :
2393 [ # # ]: 0 : if (depth--) {
2394 : : struct buffer_head *bh;
2395 : 0 : int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2396 : : p = last;
2397 [ # # ]: 0 : while (--p >= first) {
2398 : 0 : nr = le32_to_cpu(*p);
2399 [ # # ]: 0 : if (!nr)
2400 : 0 : continue; /* A hole */
2401 : :
2402 : : /* Go read the buffer for the next level down */
2403 : 0 : bh = sb_bread(inode->i_sb, nr);
2404 : :
2405 : : /*
2406 : : * A read failure? Report error and clear slot
2407 : : * (should be rare).
2408 : : */
2409 [ # # ]: 0 : if (!bh) {
2410 : 0 : ext3_error(inode->i_sb, "ext3_free_branches",
2411 : : "Read failure, inode=%lu, block="E3FSBLK,
2412 : : inode->i_ino, nr);
2413 : 0 : continue;
2414 : : }
2415 : :
2416 : : /* This zaps the entire block. Bottom up. */
2417 : : BUFFER_TRACE(bh, "free child branches");
2418 : 0 : ext3_free_branches(handle, inode, bh,
2419 : : (__le32*)bh->b_data,
2420 : 0 : (__le32*)bh->b_data + addr_per_block,
2421 : : depth);
2422 : :
2423 : : /*
2424 : : * Everything below this this pointer has been
2425 : : * released. Now let this top-of-subtree go.
2426 : : *
2427 : : * We want the freeing of this indirect block to be
2428 : : * atomic in the journal with the updating of the
2429 : : * bitmap block which owns it. So make some room in
2430 : : * the journal.
2431 : : *
2432 : : * We zero the parent pointer *after* freeing its
2433 : : * pointee in the bitmaps, so if extend_transaction()
2434 : : * for some reason fails to put the bitmap changes and
2435 : : * the release into the same transaction, recovery
2436 : : * will merely complain about releasing a free block,
2437 : : * rather than leaking blocks.
2438 : : */
2439 [ # # ]: 0 : if (is_handle_aborted(handle))
2440 : : return;
2441 [ # # ]: 0 : if (try_to_extend_transaction(handle, inode)) {
2442 : 0 : ext3_mark_inode_dirty(handle, inode);
2443 : 0 : truncate_restart_transaction(handle, inode);
2444 : : }
2445 : :
2446 : : /*
2447 : : * We've probably journalled the indirect block several
2448 : : * times during the truncate. But it's no longer
2449 : : * needed and we now drop it from the transaction via
2450 : : * journal_revoke().
2451 : : *
2452 : : * That's easy if it's exclusively part of this
2453 : : * transaction. But if it's part of the committing
2454 : : * transaction then journal_forget() will simply
2455 : : * brelse() it. That means that if the underlying
2456 : : * block is reallocated in ext3_get_block(),
2457 : : * unmap_underlying_metadata() will find this block
2458 : : * and will try to get rid of it. damn, damn. Thus
2459 : : * we don't allow a block to be reallocated until
2460 : : * a transaction freeing it has fully committed.
2461 : : *
2462 : : * We also have to make sure journal replay after a
2463 : : * crash does not overwrite non-journaled data blocks
2464 : : * with old metadata when the block got reallocated for
2465 : : * data. Thus we have to store a revoke record for a
2466 : : * block in the same transaction in which we free the
2467 : : * block.
2468 : : */
2469 : 0 : ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
2470 : :
2471 : 0 : ext3_free_blocks(handle, inode, nr, 1);
2472 : :
2473 [ # # ]: 0 : if (parent_bh) {
2474 : : /*
2475 : : * The block which we have just freed is
2476 : : * pointed to by an indirect block: journal it
2477 : : */
2478 : : BUFFER_TRACE(parent_bh, "get_write_access");
2479 [ # # ]: 0 : if (!ext3_journal_get_write_access(handle,
2480 : : parent_bh)){
2481 : 0 : *p = 0;
2482 : : BUFFER_TRACE(parent_bh,
2483 : : "call ext3_journal_dirty_metadata");
2484 : 0 : ext3_journal_dirty_metadata(handle,
2485 : : parent_bh);
2486 : : }
2487 : : }
2488 : : }
2489 : : } else {
2490 : : /* We have reached the bottom of the tree. */
2491 : : BUFFER_TRACE(parent_bh, "free data blocks");
2492 : 0 : ext3_free_data(handle, inode, parent_bh, first, last);
2493 : : }
2494 : : }
2495 : :
2496 : 0 : int ext3_can_truncate(struct inode *inode)
2497 : : {
2498 [ # # ]: 0 : if (S_ISREG(inode->i_mode))
2499 : : return 1;
2500 [ # # ]: 0 : if (S_ISDIR(inode->i_mode))
2501 : : return 1;
2502 [ # # ]: 0 : if (S_ISLNK(inode->i_mode))
2503 : 0 : return !ext3_inode_is_fast_symlink(inode);
2504 : : return 0;
2505 : : }
2506 : :
2507 : : /*
2508 : : * ext3_truncate()
2509 : : *
2510 : : * We block out ext3_get_block() block instantiations across the entire
2511 : : * transaction, and VFS/VM ensures that ext3_truncate() cannot run
2512 : : * simultaneously on behalf of the same inode.
2513 : : *
2514 : : * As we work through the truncate and commit bits of it to the journal there
2515 : : * is one core, guiding principle: the file's tree must always be consistent on
2516 : : * disk. We must be able to restart the truncate after a crash.
2517 : : *
2518 : : * The file's tree may be transiently inconsistent in memory (although it
2519 : : * probably isn't), but whenever we close off and commit a journal transaction,
2520 : : * the contents of (the filesystem + the journal) must be consistent and
2521 : : * restartable. It's pretty simple, really: bottom up, right to left (although
2522 : : * left-to-right works OK too).
2523 : : *
2524 : : * Note that at recovery time, journal replay occurs *before* the restart of
2525 : : * truncate against the orphan inode list.
2526 : : *
2527 : : * The committed inode has the new, desired i_size (which is the same as
2528 : : * i_disksize in this case). After a crash, ext3_orphan_cleanup() will see
2529 : : * that this inode's truncate did not complete and it will again call
2530 : : * ext3_truncate() to have another go. So there will be instantiated blocks
2531 : : * to the right of the truncation point in a crashed ext3 filesystem. But
2532 : : * that's fine - as long as they are linked from the inode, the post-crash
2533 : : * ext3_truncate() run will find them and release them.
2534 : : */
2535 : 0 : void ext3_truncate(struct inode *inode)
2536 : : {
2537 : : handle_t *handle;
2538 : : struct ext3_inode_info *ei = EXT3_I(inode);
2539 : 0 : __le32 *i_data = ei->i_data;
2540 : 0 : int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2541 : : int offsets[4];
2542 : : Indirect chain[4];
2543 : : Indirect *partial;
2544 : 0 : __le32 nr = 0;
2545 : : int n;
2546 : : long last_block;
2547 : : unsigned blocksize = inode->i_sb->s_blocksize;
2548 : :
2549 : : trace_ext3_truncate_enter(inode);
2550 : :
2551 [ # # ]: 0 : if (!ext3_can_truncate(inode))
2552 : : goto out_notrans;
2553 : :
2554 [ # # ][ # # ]: 0 : if (inode->i_size == 0 && ext3_should_writeback_data(inode))
2555 : : ext3_set_inode_state(inode, EXT3_STATE_FLUSH_ON_CLOSE);
2556 : :
2557 : 0 : handle = start_transaction(inode);
2558 [ # # ]: 0 : if (IS_ERR(handle))
2559 : : goto out_notrans;
2560 : :
2561 : 0 : last_block = (inode->i_size + blocksize-1)
2562 : 0 : >> EXT3_BLOCK_SIZE_BITS(inode->i_sb);
2563 : 0 : n = ext3_block_to_path(inode, last_block, offsets, NULL);
2564 [ # # ]: 0 : if (n == 0)
2565 : : goto out_stop; /* error */
2566 : :
2567 : : /*
2568 : : * OK. This truncate is going to happen. We add the inode to the
2569 : : * orphan list, so that if this truncate spans multiple transactions,
2570 : : * and we crash, we will resume the truncate when the filesystem
2571 : : * recovers. It also marks the inode dirty, to catch the new size.
2572 : : *
2573 : : * Implication: the file must always be in a sane, consistent
2574 : : * truncatable state while each transaction commits.
2575 : : */
2576 [ # # ]: 0 : if (ext3_orphan_add(handle, inode))
2577 : : goto out_stop;
2578 : :
2579 : : /*
2580 : : * The orphan list entry will now protect us from any crash which
2581 : : * occurs before the truncate completes, so it is now safe to propagate
2582 : : * the new, shorter inode size (held for now in i_size) into the
2583 : : * on-disk inode. We do this via i_disksize, which is the value which
2584 : : * ext3 *really* writes onto the disk inode.
2585 : : */
2586 : 0 : ei->i_disksize = inode->i_size;
2587 : :
2588 : : /*
2589 : : * From here we block out all ext3_get_block() callers who want to
2590 : : * modify the block allocation tree.
2591 : : */
2592 : 0 : mutex_lock(&ei->truncate_mutex);
2593 : :
2594 [ # # ]: 0 : if (n == 1) { /* direct blocks */
2595 : 0 : ext3_free_data(handle, inode, NULL, i_data+offsets[0],
2596 : : i_data + EXT3_NDIR_BLOCKS);
2597 : 0 : goto do_indirects;
2598 : : }
2599 : :
2600 : 0 : partial = ext3_find_shared(inode, n, offsets, chain, &nr);
2601 : : /* Kill the top of shared branch (not detached) */
2602 [ # # ]: 0 : if (nr) {
2603 [ # # ]: 0 : if (partial == chain) {
2604 : : /* Shared branch grows from the inode */
2605 : 0 : ext3_free_branches(handle, inode, NULL,
2606 : 0 : &nr, &nr+1, (chain+n-1) - partial);
2607 : 0 : *partial->p = 0;
2608 : : /*
2609 : : * We mark the inode dirty prior to restart,
2610 : : * and prior to stop. No need for it here.
2611 : : */
2612 : : } else {
2613 : : /* Shared branch grows from an indirect block */
2614 : 0 : ext3_free_branches(handle, inode, partial->bh,
2615 : : partial->p,
2616 : 0 : partial->p+1, (chain+n-1) - partial);
2617 : : }
2618 : : }
2619 : : /* Clear the ends of indirect blocks on the shared branch */
2620 [ # # ]: 0 : while (partial > chain) {
2621 : 0 : ext3_free_branches(handle, inode, partial->bh, partial->p + 1,
2622 : 0 : (__le32*)partial->bh->b_data+addr_per_block,
2623 : 0 : (chain+n-1) - partial);
2624 : : BUFFER_TRACE(partial->bh, "call brelse");
2625 : 0 : brelse (partial->bh);
2626 : 0 : partial--;
2627 : : }
2628 : : do_indirects:
2629 : : /* Kill the remaining (whole) subtrees */
2630 [ # # # # ]: 0 : switch (offsets[0]) {
2631 : : default:
2632 : 0 : nr = i_data[EXT3_IND_BLOCK];
2633 [ # # ]: 0 : if (nr) {
2634 : 0 : ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
2635 : 0 : i_data[EXT3_IND_BLOCK] = 0;
2636 : : }
2637 : : case EXT3_IND_BLOCK:
2638 : 0 : nr = i_data[EXT3_DIND_BLOCK];
2639 [ # # ]: 0 : if (nr) {
2640 : 0 : ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
2641 : 0 : i_data[EXT3_DIND_BLOCK] = 0;
2642 : : }
2643 : : case EXT3_DIND_BLOCK:
2644 : 0 : nr = i_data[EXT3_TIND_BLOCK];
2645 [ # # ]: 0 : if (nr) {
2646 : 0 : ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
2647 : 0 : i_data[EXT3_TIND_BLOCK] = 0;
2648 : : }
2649 : : case EXT3_TIND_BLOCK:
2650 : : ;
2651 : : }
2652 : :
2653 : 0 : ext3_discard_reservation(inode);
2654 : :
2655 : 0 : mutex_unlock(&ei->truncate_mutex);
2656 : 0 : inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
2657 : 0 : ext3_mark_inode_dirty(handle, inode);
2658 : :
2659 : : /*
2660 : : * In a multi-transaction truncate, we only make the final transaction
2661 : : * synchronous
2662 : : */
2663 [ # # ][ # # ]: 0 : if (IS_SYNC(inode))
2664 : 0 : handle->h_sync = 1;
2665 : : out_stop:
2666 : : /*
2667 : : * If this was a simple ftruncate(), and the file will remain alive
2668 : : * then we need to clear up the orphan record which we created above.
2669 : : * However, if this was a real unlink then we were called by
2670 : : * ext3_evict_inode(), and we allow that function to clean up the
2671 : : * orphan info for us.
2672 : : */
2673 [ # # ]: 0 : if (inode->i_nlink)
2674 : 0 : ext3_orphan_del(handle, inode);
2675 : :
2676 : 0 : ext3_journal_stop(handle);
2677 : : trace_ext3_truncate_exit(inode);
2678 : 0 : return;
2679 : : out_notrans:
2680 : : /*
2681 : : * Delete the inode from orphan list so that it doesn't stay there
2682 : : * forever and trigger assertion on umount.
2683 : : */
2684 [ # # ]: 0 : if (inode->i_nlink)
2685 : 0 : ext3_orphan_del(NULL, inode);
2686 : : trace_ext3_truncate_exit(inode);
2687 : : }
2688 : :
2689 : 0 : static ext3_fsblk_t ext3_get_inode_block(struct super_block *sb,
2690 : : unsigned long ino, struct ext3_iloc *iloc)
2691 : : {
2692 : : unsigned long block_group;
2693 : : unsigned long offset;
2694 : : ext3_fsblk_t block;
2695 : : struct ext3_group_desc *gdp;
2696 : :
2697 [ # # ]: 0 : if (!ext3_valid_inum(sb, ino)) {
2698 : : /*
2699 : : * This error is already checked for in namei.c unless we are
2700 : : * looking at an NFS filehandle, in which case no error
2701 : : * report is needed
2702 : : */
2703 : : return 0;
2704 : : }
2705 : :
2706 : 0 : block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
2707 : 0 : gdp = ext3_get_group_desc(sb, block_group, NULL);
2708 [ # # ]: 0 : if (!gdp)
2709 : : return 0;
2710 : : /*
2711 : : * Figure out the offset within the block group inode table
2712 : : */
2713 : 0 : offset = ((ino - 1) % EXT3_INODES_PER_GROUP(sb)) *
2714 : 0 : EXT3_INODE_SIZE(sb);
2715 : 0 : block = le32_to_cpu(gdp->bg_inode_table) +
2716 : 0 : (offset >> EXT3_BLOCK_SIZE_BITS(sb));
2717 : :
2718 : 0 : iloc->block_group = block_group;
2719 : 0 : iloc->offset = offset & (EXT3_BLOCK_SIZE(sb) - 1);
2720 : : return block;
2721 : : }
2722 : :
2723 : : /*
2724 : : * ext3_get_inode_loc returns with an extra refcount against the inode's
2725 : : * underlying buffer_head on success. If 'in_mem' is true, we have all
2726 : : * data in memory that is needed to recreate the on-disk version of this
2727 : : * inode.
2728 : : */
2729 : 0 : static int __ext3_get_inode_loc(struct inode *inode,
2730 : : struct ext3_iloc *iloc, int in_mem)
2731 : : {
2732 : : ext3_fsblk_t block;
2733 : : struct buffer_head *bh;
2734 : :
2735 : 0 : block = ext3_get_inode_block(inode->i_sb, inode->i_ino, iloc);
2736 [ # # ]: 0 : if (!block)
2737 : : return -EIO;
2738 : :
2739 : 0 : bh = sb_getblk(inode->i_sb, block);
2740 [ # # ]: 0 : if (unlikely(!bh)) {
2741 : 0 : ext3_error (inode->i_sb, "ext3_get_inode_loc",
2742 : : "unable to read inode block - "
2743 : : "inode=%lu, block="E3FSBLK,
2744 : : inode->i_ino, block);
2745 : 0 : return -ENOMEM;
2746 : : }
2747 [ # # ]: 0 : if (!buffer_uptodate(bh)) {
2748 : : lock_buffer(bh);
2749 : :
2750 : : /*
2751 : : * If the buffer has the write error flag, we have failed
2752 : : * to write out another inode in the same block. In this
2753 : : * case, we don't have to read the block because we may
2754 : : * read the old inode data successfully.
2755 : : */
2756 [ # # ][ # # ]: 0 : if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
2757 : : set_buffer_uptodate(bh);
2758 : :
2759 [ # # ]: 0 : if (buffer_uptodate(bh)) {
2760 : : /* someone brought it uptodate while we waited */
2761 : 0 : unlock_buffer(bh);
2762 : 0 : goto has_buffer;
2763 : : }
2764 : :
2765 : : /*
2766 : : * If we have all information of the inode in memory and this
2767 : : * is the only valid inode in the block, we need not read the
2768 : : * block.
2769 : : */
2770 [ # # ]: 0 : if (in_mem) {
2771 : : struct buffer_head *bitmap_bh;
2772 : : struct ext3_group_desc *desc;
2773 : : int inodes_per_buffer;
2774 : : int inode_offset, i;
2775 : : int block_group;
2776 : : int start;
2777 : :
2778 : 0 : block_group = (inode->i_ino - 1) /
2779 : 0 : EXT3_INODES_PER_GROUP(inode->i_sb);
2780 : 0 : inodes_per_buffer = bh->b_size /
2781 : 0 : EXT3_INODE_SIZE(inode->i_sb);
2782 : 0 : inode_offset = ((inode->i_ino - 1) %
2783 : : EXT3_INODES_PER_GROUP(inode->i_sb));
2784 : 0 : start = inode_offset & ~(inodes_per_buffer - 1);
2785 : :
2786 : : /* Is the inode bitmap in cache? */
2787 : 0 : desc = ext3_get_group_desc(inode->i_sb,
2788 : : block_group, NULL);
2789 [ # # ]: 0 : if (!desc)
2790 : : goto make_io;
2791 : :
2792 : 0 : bitmap_bh = sb_getblk(inode->i_sb,
2793 : 0 : le32_to_cpu(desc->bg_inode_bitmap));
2794 [ # # ]: 0 : if (unlikely(!bitmap_bh))
2795 : : goto make_io;
2796 : :
2797 : : /*
2798 : : * If the inode bitmap isn't in cache then the
2799 : : * optimisation may end up performing two reads instead
2800 : : * of one, so skip it.
2801 : : */
2802 [ # # ]: 0 : if (!buffer_uptodate(bitmap_bh)) {
2803 : : brelse(bitmap_bh);
2804 : : goto make_io;
2805 : : }
2806 [ # # ]: 0 : for (i = start; i < start + inodes_per_buffer; i++) {
2807 [ # # ]: 0 : if (i == inode_offset)
2808 : 0 : continue;
2809 [ # # ]: 0 : if (ext3_test_bit(i, bitmap_bh->b_data))
2810 : : break;
2811 : : }
2812 : : brelse(bitmap_bh);
2813 [ # # ]: 0 : if (i == start + inodes_per_buffer) {
2814 : : /* all other inodes are free, so skip I/O */
2815 [ # # ]: 0 : memset(bh->b_data, 0, bh->b_size);
2816 : : set_buffer_uptodate(bh);
2817 : 0 : unlock_buffer(bh);
2818 : 0 : goto has_buffer;
2819 : : }
2820 : : }
2821 : :
2822 : : make_io:
2823 : : /*
2824 : : * There are other valid inodes in the buffer, this inode
2825 : : * has in-inode xattrs, or we don't have this inode in memory.
2826 : : * Read the block from disk.
2827 : : */
2828 : : trace_ext3_load_inode(inode);
2829 : : get_bh(bh);
2830 : 0 : bh->b_end_io = end_buffer_read_sync;
2831 : 0 : submit_bh(READ | REQ_META | REQ_PRIO, bh);
2832 : : wait_on_buffer(bh);
2833 [ # # ]: 0 : if (!buffer_uptodate(bh)) {
2834 : 0 : ext3_error(inode->i_sb, "ext3_get_inode_loc",
2835 : : "unable to read inode block - "
2836 : : "inode=%lu, block="E3FSBLK,
2837 : : inode->i_ino, block);
2838 : : brelse(bh);
2839 : : return -EIO;
2840 : : }
2841 : : }
2842 : : has_buffer:
2843 : 0 : iloc->bh = bh;
2844 : 0 : return 0;
2845 : : }
2846 : :
2847 : 0 : int ext3_get_inode_loc(struct inode *inode, struct ext3_iloc *iloc)
2848 : : {
2849 : : /* We have all inode data except xattrs in memory here. */
2850 : 0 : return __ext3_get_inode_loc(inode, iloc,
2851 : : !ext3_test_inode_state(inode, EXT3_STATE_XATTR));
2852 : : }
2853 : :
2854 : 0 : void ext3_set_inode_flags(struct inode *inode)
2855 : : {
2856 : 0 : unsigned int flags = EXT3_I(inode)->i_flags;
2857 : :
2858 : 0 : inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
2859 [ # # ]: 0 : if (flags & EXT3_SYNC_FL)
2860 : 0 : inode->i_flags |= S_SYNC;
2861 [ # # ]: 0 : if (flags & EXT3_APPEND_FL)
2862 : 0 : inode->i_flags |= S_APPEND;
2863 [ # # ]: 0 : if (flags & EXT3_IMMUTABLE_FL)
2864 : 0 : inode->i_flags |= S_IMMUTABLE;
2865 [ # # ]: 0 : if (flags & EXT3_NOATIME_FL)
2866 : 0 : inode->i_flags |= S_NOATIME;
2867 [ # # ]: 0 : if (flags & EXT3_DIRSYNC_FL)
2868 : 0 : inode->i_flags |= S_DIRSYNC;
2869 : 0 : }
2870 : :
2871 : : /* Propagate flags from i_flags to EXT3_I(inode)->i_flags */
2872 : 0 : void ext3_get_inode_flags(struct ext3_inode_info *ei)
2873 : : {
2874 : 0 : unsigned int flags = ei->vfs_inode.i_flags;
2875 : :
2876 : 0 : ei->i_flags &= ~(EXT3_SYNC_FL|EXT3_APPEND_FL|
2877 : : EXT3_IMMUTABLE_FL|EXT3_NOATIME_FL|EXT3_DIRSYNC_FL);
2878 [ # # ]: 0 : if (flags & S_SYNC)
2879 : 0 : ei->i_flags |= EXT3_SYNC_FL;
2880 [ # # ]: 0 : if (flags & S_APPEND)
2881 : 0 : ei->i_flags |= EXT3_APPEND_FL;
2882 [ # # ]: 0 : if (flags & S_IMMUTABLE)
2883 : 0 : ei->i_flags |= EXT3_IMMUTABLE_FL;
2884 [ # # ]: 0 : if (flags & S_NOATIME)
2885 : 0 : ei->i_flags |= EXT3_NOATIME_FL;
2886 [ # # ]: 0 : if (flags & S_DIRSYNC)
2887 : 0 : ei->i_flags |= EXT3_DIRSYNC_FL;
2888 : 0 : }
2889 : :
2890 : 0 : struct inode *ext3_iget(struct super_block *sb, unsigned long ino)
2891 : : {
2892 : : struct ext3_iloc iloc;
2893 : : struct ext3_inode *raw_inode;
2894 : : struct ext3_inode_info *ei;
2895 : : struct buffer_head *bh;
2896 : : struct inode *inode;
2897 : 0 : journal_t *journal = EXT3_SB(sb)->s_journal;
2898 : : transaction_t *transaction;
2899 : : long ret;
2900 : : int block;
2901 : : uid_t i_uid;
2902 : : gid_t i_gid;
2903 : :
2904 : 0 : inode = iget_locked(sb, ino);
2905 [ # # ]: 0 : if (!inode)
2906 : : return ERR_PTR(-ENOMEM);
2907 [ # # ]: 0 : if (!(inode->i_state & I_NEW))
2908 : : return inode;
2909 : :
2910 : : ei = EXT3_I(inode);
2911 : 0 : ei->i_block_alloc_info = NULL;
2912 : :
2913 : 0 : ret = __ext3_get_inode_loc(inode, &iloc, 0);
2914 [ # # ]: 0 : if (ret < 0)
2915 : : goto bad_inode;
2916 : 0 : bh = iloc.bh;
2917 : 0 : raw_inode = ext3_raw_inode(&iloc);
2918 : 0 : inode->i_mode = le16_to_cpu(raw_inode->i_mode);
2919 : 0 : i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
2920 : 0 : i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
2921 [ # # ]: 0 : if(!(test_opt (inode->i_sb, NO_UID32))) {
2922 : 0 : i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
2923 : 0 : i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
2924 : : }
2925 : : i_uid_write(inode, i_uid);
2926 : : i_gid_write(inode, i_gid);
2927 : 0 : set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
2928 : 0 : inode->i_size = le32_to_cpu(raw_inode->i_size);
2929 : 0 : inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
2930 : 0 : inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
2931 : 0 : inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
2932 : 0 : inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
2933 : :
2934 : 0 : ei->i_state_flags = 0;
2935 : 0 : ei->i_dir_start_lookup = 0;
2936 : 0 : ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
2937 : : /* We now have enough fields to check if the inode was active or not.
2938 : : * This is needed because nfsd might try to access dead inodes
2939 : : * the test is that same one that e2fsck uses
2940 : : * NeilBrown 1999oct15
2941 : : */
2942 [ # # ]: 0 : if (inode->i_nlink == 0) {
2943 [ # # ][ # # ]: 0 : if (inode->i_mode == 0 ||
2944 : 0 : !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) {
2945 : : /* this inode is deleted */
2946 : : brelse (bh);
2947 : : ret = -ESTALE;
2948 : : goto bad_inode;
2949 : : }
2950 : : /* The only unlinked inodes we let through here have
2951 : : * valid i_mode and are being read by the orphan
2952 : : * recovery code: that's fine, we're about to complete
2953 : : * the process of deleting those. */
2954 : : }
2955 : 0 : inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
2956 : 0 : ei->i_flags = le32_to_cpu(raw_inode->i_flags);
2957 : : #ifdef EXT3_FRAGMENTS
2958 : : ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
2959 : : ei->i_frag_no = raw_inode->i_frag;
2960 : : ei->i_frag_size = raw_inode->i_fsize;
2961 : : #endif
2962 : 0 : ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
2963 [ # # ]: 0 : if (!S_ISREG(inode->i_mode)) {
2964 : 0 : ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
2965 : : } else {
2966 : 0 : inode->i_size |=
2967 : 0 : ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
2968 : : }
2969 : 0 : ei->i_disksize = inode->i_size;
2970 : 0 : inode->i_generation = le32_to_cpu(raw_inode->i_generation);
2971 : 0 : ei->i_block_group = iloc.block_group;
2972 : : /*
2973 : : * NOTE! The in-memory inode i_data array is in little-endian order
2974 : : * even on big-endian machines: we do NOT byteswap the block numbers!
2975 : : */
2976 [ # # ]: 0 : for (block = 0; block < EXT3_N_BLOCKS; block++)
2977 : 0 : ei->i_data[block] = raw_inode->i_block[block];
2978 : 0 : INIT_LIST_HEAD(&ei->i_orphan);
2979 : :
2980 : : /*
2981 : : * Set transaction id's of transactions that have to be committed
2982 : : * to finish f[data]sync. We set them to currently running transaction
2983 : : * as we cannot be sure that the inode or some of its metadata isn't
2984 : : * part of the transaction - the inode could have been reclaimed and
2985 : : * now it is reread from disk.
2986 : : */
2987 [ # # ]: 0 : if (journal) {
2988 : : tid_t tid;
2989 : :
2990 : : spin_lock(&journal->j_state_lock);
2991 [ # # ]: 0 : if (journal->j_running_transaction)
2992 : : transaction = journal->j_running_transaction;
2993 : : else
2994 : 0 : transaction = journal->j_committing_transaction;
2995 [ # # ]: 0 : if (transaction)
2996 : 0 : tid = transaction->t_tid;
2997 : : else
2998 : 0 : tid = journal->j_commit_sequence;
2999 : : spin_unlock(&journal->j_state_lock);
3000 : 0 : atomic_set(&ei->i_sync_tid, tid);
3001 : 0 : atomic_set(&ei->i_datasync_tid, tid);
3002 : : }
3003 : :
3004 [ # # ][ # # ]: 0 : if (inode->i_ino >= EXT3_FIRST_INO(inode->i_sb) + 1 &&
3005 : 0 : EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) {
3006 : : /*
3007 : : * When mke2fs creates big inodes it does not zero out
3008 : : * the unused bytes above EXT3_GOOD_OLD_INODE_SIZE,
3009 : : * so ignore those first few inodes.
3010 : : */
3011 : 0 : ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
3012 [ # # ]: 0 : if (EXT3_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
3013 : 0 : EXT3_INODE_SIZE(inode->i_sb)) {
3014 : : brelse (bh);
3015 : : ret = -EIO;
3016 : : goto bad_inode;
3017 : : }
3018 [ # # ]: 0 : if (ei->i_extra_isize == 0) {
3019 : : /* The extra space is currently unused. Use it. */
3020 : 0 : ei->i_extra_isize = sizeof(struct ext3_inode) -
3021 : : EXT3_GOOD_OLD_INODE_SIZE;
3022 : : } else {
3023 : 0 : __le32 *magic = (void *)raw_inode +
3024 : 0 : EXT3_GOOD_OLD_INODE_SIZE +
3025 : : ei->i_extra_isize;
3026 [ # # ]: 0 : if (*magic == cpu_to_le32(EXT3_XATTR_MAGIC))
3027 : : ext3_set_inode_state(inode, EXT3_STATE_XATTR);
3028 : : }
3029 : : } else
3030 : 0 : ei->i_extra_isize = 0;
3031 : :
3032 [ # # ]: 0 : if (S_ISREG(inode->i_mode)) {
3033 : 0 : inode->i_op = &ext3_file_inode_operations;
3034 : 0 : inode->i_fop = &ext3_file_operations;
3035 : 0 : ext3_set_aops(inode);
3036 [ # # ]: 0 : } else if (S_ISDIR(inode->i_mode)) {
3037 : 0 : inode->i_op = &ext3_dir_inode_operations;
3038 : 0 : inode->i_fop = &ext3_dir_operations;
3039 [ # # ]: 0 : } else if (S_ISLNK(inode->i_mode)) {
3040 [ # # ]: 0 : if (ext3_inode_is_fast_symlink(inode)) {
3041 : 0 : inode->i_op = &ext3_fast_symlink_inode_operations;
3042 : 0 : nd_terminate_link(ei->i_data, inode->i_size,
3043 : : sizeof(ei->i_data) - 1);
3044 : : } else {
3045 : 0 : inode->i_op = &ext3_symlink_inode_operations;
3046 : 0 : ext3_set_aops(inode);
3047 : : }
3048 : : } else {
3049 : 0 : inode->i_op = &ext3_special_inode_operations;
3050 [ # # ]: 0 : if (raw_inode->i_block[0])
3051 : 0 : init_special_inode(inode, inode->i_mode,
3052 : : old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
3053 : : else
3054 : 0 : init_special_inode(inode, inode->i_mode,
3055 : : new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
3056 : : }
3057 : 0 : brelse (iloc.bh);
3058 : 0 : ext3_set_inode_flags(inode);
3059 : 0 : unlock_new_inode(inode);
3060 : 0 : return inode;
3061 : :
3062 : : bad_inode:
3063 : 0 : iget_failed(inode);
3064 : 0 : return ERR_PTR(ret);
3065 : : }
3066 : :
3067 : : /*
3068 : : * Post the struct inode info into an on-disk inode location in the
3069 : : * buffer-cache. This gobbles the caller's reference to the
3070 : : * buffer_head in the inode location struct.
3071 : : *
3072 : : * The caller must have write access to iloc->bh.
3073 : : */
3074 : 0 : static int ext3_do_update_inode(handle_t *handle,
3075 : 0 : struct inode *inode,
3076 : 0 : struct ext3_iloc *iloc)
3077 : : {
3078 : : struct ext3_inode *raw_inode = ext3_raw_inode(iloc);
3079 : 0 : struct ext3_inode_info *ei = EXT3_I(inode);
3080 : : struct buffer_head *bh = iloc->bh;
3081 : : int err = 0, rc, block;
3082 : : int need_datasync = 0;
3083 : : __le32 disksize;
3084 : : uid_t i_uid;
3085 : : gid_t i_gid;
3086 : :
3087 : : again:
3088 : : /* we can't allow multiple procs in here at once, its a bit racey */
3089 : : lock_buffer(bh);
3090 : :
3091 : : /* For fields not not tracking in the in-memory inode,
3092 : : * initialise them to zero for new inodes. */
3093 [ # # ]: 0 : if (ext3_test_inode_state(inode, EXT3_STATE_NEW))
3094 [ # # ]: 0 : memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
3095 : :
3096 : 0 : ext3_get_inode_flags(ei);
3097 : 0 : raw_inode->i_mode = cpu_to_le16(inode->i_mode);
3098 : : i_uid = i_uid_read(inode);
3099 : : i_gid = i_gid_read(inode);
3100 [ # # ]: 0 : if(!(test_opt(inode->i_sb, NO_UID32))) {
3101 : 0 : raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid));
3102 : 0 : raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid));
3103 : : /*
3104 : : * Fix up interoperability with old kernels. Otherwise, old inodes get
3105 : : * re-used with the upper 16 bits of the uid/gid intact
3106 : : */
3107 [ # # ]: 0 : if(!ei->i_dtime) {
3108 : 0 : raw_inode->i_uid_high =
3109 : 0 : cpu_to_le16(high_16_bits(i_uid));
3110 : 0 : raw_inode->i_gid_high =
3111 : 0 : cpu_to_le16(high_16_bits(i_gid));
3112 : : } else {
3113 : 0 : raw_inode->i_uid_high = 0;
3114 : 0 : raw_inode->i_gid_high = 0;
3115 : : }
3116 : : } else {
3117 : 0 : raw_inode->i_uid_low =
3118 [ # # ]: 0 : cpu_to_le16(fs_high2lowuid(i_uid));
3119 : 0 : raw_inode->i_gid_low =
3120 [ # # ]: 0 : cpu_to_le16(fs_high2lowgid(i_gid));
3121 : 0 : raw_inode->i_uid_high = 0;
3122 : 0 : raw_inode->i_gid_high = 0;
3123 : : }
3124 : 0 : raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
3125 : 0 : disksize = cpu_to_le32(ei->i_disksize);
3126 [ # # ]: 0 : if (disksize != raw_inode->i_size) {
3127 : : need_datasync = 1;
3128 : 0 : raw_inode->i_size = disksize;
3129 : : }
3130 : 0 : raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
3131 : 0 : raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
3132 : 0 : raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
3133 : 0 : raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
3134 : 0 : raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
3135 : 0 : raw_inode->i_flags = cpu_to_le32(ei->i_flags);
3136 : : #ifdef EXT3_FRAGMENTS
3137 : : raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
3138 : : raw_inode->i_frag = ei->i_frag_no;
3139 : : raw_inode->i_fsize = ei->i_frag_size;
3140 : : #endif
3141 : 0 : raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
3142 [ # # ]: 0 : if (!S_ISREG(inode->i_mode)) {
3143 : 0 : raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
3144 : : } else {
3145 : 0 : disksize = cpu_to_le32(ei->i_disksize >> 32);
3146 [ # # ]: 0 : if (disksize != raw_inode->i_size_high) {
3147 : 0 : raw_inode->i_size_high = disksize;
3148 : : need_datasync = 1;
3149 : : }
3150 [ # # ]: 0 : if (ei->i_disksize > 0x7fffffffULL) {
3151 : 0 : struct super_block *sb = inode->i_sb;
3152 [ # # ]: 0 : if (!EXT3_HAS_RO_COMPAT_FEATURE(sb,
3153 [ # # ]: 0 : EXT3_FEATURE_RO_COMPAT_LARGE_FILE) ||
3154 : 0 : EXT3_SB(sb)->s_es->s_rev_level ==
3155 : : cpu_to_le32(EXT3_GOOD_OLD_REV)) {
3156 : : /* If this is the first large file
3157 : : * created, add a flag to the superblock.
3158 : : */
3159 : 0 : unlock_buffer(bh);
3160 : 0 : err = ext3_journal_get_write_access(handle,
3161 : : EXT3_SB(sb)->s_sbh);
3162 [ # # ]: 0 : if (err)
3163 : : goto out_brelse;
3164 : :
3165 : 0 : ext3_update_dynamic_rev(sb);
3166 : 0 : EXT3_SET_RO_COMPAT_FEATURE(sb,
3167 : : EXT3_FEATURE_RO_COMPAT_LARGE_FILE);
3168 : 0 : handle->h_sync = 1;
3169 : 0 : err = ext3_journal_dirty_metadata(handle,
3170 : : EXT3_SB(sb)->s_sbh);
3171 : : /* get our lock and start over */
3172 : 0 : goto again;
3173 : : }
3174 : : }
3175 : : }
3176 : 0 : raw_inode->i_generation = cpu_to_le32(inode->i_generation);
3177 [ # # ]: 0 : if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
3178 [ # # ]: 0 : if (old_valid_dev(inode->i_rdev)) {
3179 : 0 : raw_inode->i_block[0] =
3180 : 0 : cpu_to_le32(old_encode_dev(inode->i_rdev));
3181 : 0 : raw_inode->i_block[1] = 0;
3182 : : } else {
3183 : 0 : raw_inode->i_block[0] = 0;
3184 : 0 : raw_inode->i_block[1] =
3185 : 0 : cpu_to_le32(new_encode_dev(inode->i_rdev));
3186 : 0 : raw_inode->i_block[2] = 0;
3187 : : }
3188 [ # # ]: 0 : } else for (block = 0; block < EXT3_N_BLOCKS; block++)
3189 : 0 : raw_inode->i_block[block] = ei->i_data[block];
3190 : :
3191 [ # # ]: 0 : if (ei->i_extra_isize)
3192 : 0 : raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
3193 : :
3194 : : BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
3195 : 0 : unlock_buffer(bh);
3196 : 0 : rc = ext3_journal_dirty_metadata(handle, bh);
3197 [ # # ]: 0 : if (!err)
3198 : : err = rc;
3199 : : ext3_clear_inode_state(inode, EXT3_STATE_NEW);
3200 : :
3201 : 0 : atomic_set(&ei->i_sync_tid, handle->h_transaction->t_tid);
3202 [ # # ]: 0 : if (need_datasync)
3203 : 0 : atomic_set(&ei->i_datasync_tid, handle->h_transaction->t_tid);
3204 : : out_brelse:
3205 : : brelse (bh);
3206 [ # # ]: 0 : ext3_std_error(inode->i_sb, err);
3207 : 0 : return err;
3208 : : }
3209 : :
3210 : : /*
3211 : : * ext3_write_inode()
3212 : : *
3213 : : * We are called from a few places:
3214 : : *
3215 : : * - Within generic_file_write() for O_SYNC files.
3216 : : * Here, there will be no transaction running. We wait for any running
3217 : : * transaction to commit.
3218 : : *
3219 : : * - Within sys_sync(), kupdate and such.
3220 : : * We wait on commit, if tol to.
3221 : : *
3222 : : * - Within prune_icache() (PF_MEMALLOC == true)
3223 : : * Here we simply return. We can't afford to block kswapd on the
3224 : : * journal commit.
3225 : : *
3226 : : * In all cases it is actually safe for us to return without doing anything,
3227 : : * because the inode has been copied into a raw inode buffer in
3228 : : * ext3_mark_inode_dirty(). This is a correctness thing for O_SYNC and for
3229 : : * knfsd.
3230 : : *
3231 : : * Note that we are absolutely dependent upon all inode dirtiers doing the
3232 : : * right thing: they *must* call mark_inode_dirty() after dirtying info in
3233 : : * which we are interested.
3234 : : *
3235 : : * It would be a bug for them to not do this. The code:
3236 : : *
3237 : : * mark_inode_dirty(inode)
3238 : : * stuff();
3239 : : * inode->i_size = expr;
3240 : : *
3241 : : * is in error because a kswapd-driven write_inode() could occur while
3242 : : * `stuff()' is running, and the new i_size will be lost. Plus the inode
3243 : : * will no longer be on the superblock's dirty inode list.
3244 : : */
3245 : 0 : int ext3_write_inode(struct inode *inode, struct writeback_control *wbc)
3246 : : {
3247 [ # # ]: 0 : if (current->flags & PF_MEMALLOC)
3248 : : return 0;
3249 : :
3250 [ # # ]: 0 : if (ext3_journal_current_handle()) {
3251 : : jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
3252 : 0 : dump_stack();
3253 : 0 : return -EIO;
3254 : : }
3255 : :
3256 [ # # ]: 0 : if (wbc->sync_mode != WB_SYNC_ALL)
3257 : : return 0;
3258 : :
3259 : 0 : return ext3_force_commit(inode->i_sb);
3260 : : }
3261 : :
3262 : : /*
3263 : : * ext3_setattr()
3264 : : *
3265 : : * Called from notify_change.
3266 : : *
3267 : : * We want to trap VFS attempts to truncate the file as soon as
3268 : : * possible. In particular, we want to make sure that when the VFS
3269 : : * shrinks i_size, we put the inode on the orphan list and modify
3270 : : * i_disksize immediately, so that during the subsequent flushing of
3271 : : * dirty pages and freeing of disk blocks, we can guarantee that any
3272 : : * commit will leave the blocks being flushed in an unused state on
3273 : : * disk. (On recovery, the inode will get truncated and the blocks will
3274 : : * be freed, so we have a strong guarantee that no future commit will
3275 : : * leave these blocks visible to the user.)
3276 : : *
3277 : : * Called with inode->sem down.
3278 : : */
3279 : 0 : int ext3_setattr(struct dentry *dentry, struct iattr *attr)
3280 : : {
3281 : 0 : struct inode *inode = dentry->d_inode;
3282 : : int error, rc = 0;
3283 : 0 : const unsigned int ia_valid = attr->ia_valid;
3284 : :
3285 : 0 : error = inode_change_ok(inode, attr);
3286 [ # # ]: 0 : if (error)
3287 : : return error;
3288 : :
3289 [ # # ]: 0 : if (is_quota_modification(inode, attr))
3290 : 0 : dquot_initialize(inode);
3291 [ # # ][ # # ]: 0 : if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, inode->i_uid)) ||
[ # # ]
3292 [ # # ]: 0 : (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, inode->i_gid))) {
3293 : : handle_t *handle;
3294 : :
3295 : : /* (user+group)*(old+new) structure, inode write (sb,
3296 : : * inode block, ? - but truncate inode update has it) */
3297 [ # # ]: 0 : handle = ext3_journal_start(inode, EXT3_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)+
3298 [ # # ]: 0 : EXT3_MAXQUOTAS_DEL_BLOCKS(inode->i_sb)+3);
3299 [ # # ]: 0 : if (IS_ERR(handle)) {
3300 : : error = PTR_ERR(handle);
3301 : 0 : goto err_out;
3302 : : }
3303 : 0 : error = dquot_transfer(inode, attr);
3304 [ # # ]: 0 : if (error) {
3305 : 0 : ext3_journal_stop(handle);
3306 : 0 : return error;
3307 : : }
3308 : : /* Update corresponding info in inode so that everything is in
3309 : : * one transaction */
3310 [ # # ]: 0 : if (attr->ia_valid & ATTR_UID)
3311 : 0 : inode->i_uid = attr->ia_uid;
3312 [ # # ]: 0 : if (attr->ia_valid & ATTR_GID)
3313 : 0 : inode->i_gid = attr->ia_gid;
3314 : 0 : error = ext3_mark_inode_dirty(handle, inode);
3315 : 0 : ext3_journal_stop(handle);
3316 : : }
3317 : :
3318 [ # # ]: 0 : if (attr->ia_valid & ATTR_SIZE)
3319 : 0 : inode_dio_wait(inode);
3320 : :
3321 [ # # ][ # # ]: 0 : if (S_ISREG(inode->i_mode) &&
3322 [ # # ]: 0 : attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
3323 : : handle_t *handle;
3324 : :
3325 : : handle = ext3_journal_start(inode, 3);
3326 [ # # ]: 0 : if (IS_ERR(handle)) {
3327 : : error = PTR_ERR(handle);
3328 : 0 : goto err_out;
3329 : : }
3330 : :
3331 : 0 : error = ext3_orphan_add(handle, inode);
3332 [ # # ]: 0 : if (error) {
3333 : 0 : ext3_journal_stop(handle);
3334 : 0 : goto err_out;
3335 : : }
3336 : 0 : EXT3_I(inode)->i_disksize = attr->ia_size;
3337 : 0 : error = ext3_mark_inode_dirty(handle, inode);
3338 : 0 : ext3_journal_stop(handle);
3339 [ # # ]: 0 : if (error) {
3340 : : /* Some hard fs error must have happened. Bail out. */
3341 : 0 : ext3_orphan_del(NULL, inode);
3342 : 0 : goto err_out;
3343 : : }
3344 : 0 : rc = ext3_block_truncate_page(inode, attr->ia_size);
3345 [ # # ]: 0 : if (rc) {
3346 : : /* Cleanup orphan list and exit */
3347 : : handle = ext3_journal_start(inode, 3);
3348 [ # # ]: 0 : if (IS_ERR(handle)) {
3349 : 0 : ext3_orphan_del(NULL, inode);
3350 : 0 : goto err_out;
3351 : : }
3352 : 0 : ext3_orphan_del(handle, inode);
3353 : 0 : ext3_journal_stop(handle);
3354 : 0 : goto err_out;
3355 : : }
3356 : : }
3357 : :
3358 [ # # ][ # # ]: 0 : if ((attr->ia_valid & ATTR_SIZE) &&
3359 : 0 : attr->ia_size != i_size_read(inode)) {
3360 : 0 : truncate_setsize(inode, attr->ia_size);
3361 : 0 : ext3_truncate(inode);
3362 : : }
3363 : :
3364 : 0 : setattr_copy(inode, attr);
3365 : : mark_inode_dirty(inode);
3366 : :
3367 [ # # ]: 0 : if (ia_valid & ATTR_MODE)
3368 : : rc = ext3_acl_chmod(inode);
3369 : :
3370 : : err_out:
3371 [ # # ]: 0 : ext3_std_error(inode->i_sb, error);
3372 [ # # ]: 0 : if (!error)
3373 : : error = rc;
3374 : 0 : return error;
3375 : : }
3376 : :
3377 : :
3378 : : /*
3379 : : * How many blocks doth make a writepage()?
3380 : : *
3381 : : * With N blocks per page, it may be:
3382 : : * N data blocks
3383 : : * 2 indirect block
3384 : : * 2 dindirect
3385 : : * 1 tindirect
3386 : : * N+5 bitmap blocks (from the above)
3387 : : * N+5 group descriptor summary blocks
3388 : : * 1 inode block
3389 : : * 1 superblock.
3390 : : * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quote files
3391 : : *
3392 : : * 3 * (N + 5) + 2 + 2 * EXT3_SINGLEDATA_TRANS_BLOCKS
3393 : : *
3394 : : * With ordered or writeback data it's the same, less the N data blocks.
3395 : : *
3396 : : * If the inode's direct blocks can hold an integral number of pages then a
3397 : : * page cannot straddle two indirect blocks, and we can only touch one indirect
3398 : : * and dindirect block, and the "5" above becomes "3".
3399 : : *
3400 : : * This still overestimates under most circumstances. If we were to pass the
3401 : : * start and end offsets in here as well we could do block_to_path() on each
3402 : : * block and work out the exact number of indirects which are touched. Pah.
3403 : : */
3404 : :
3405 : 0 : static int ext3_writepage_trans_blocks(struct inode *inode)
3406 : : {
3407 : : int bpp = ext3_journal_blocks_per_page(inode);
3408 [ # # ]: 0 : int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3;
3409 : : int ret;
3410 : :
3411 [ # # ]: 0 : if (ext3_should_journal_data(inode))
3412 : 0 : ret = 3 * (bpp + indirects) + 2;
3413 : : else
3414 : 0 : ret = 2 * (bpp + indirects) + indirects + 2;
3415 : :
3416 : : #ifdef CONFIG_QUOTA
3417 : : /* We know that structure was already allocated during dquot_initialize so
3418 : : * we will be updating only the data blocks + inodes */
3419 [ # # ]: 0 : ret += EXT3_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
3420 : : #endif
3421 : :
3422 : 0 : return ret;
3423 : : }
3424 : :
3425 : : /*
3426 : : * The caller must have previously called ext3_reserve_inode_write().
3427 : : * Give this, we know that the caller already has write access to iloc->bh.
3428 : : */
3429 : 0 : int ext3_mark_iloc_dirty(handle_t *handle,
3430 : : struct inode *inode, struct ext3_iloc *iloc)
3431 : : {
3432 : : int err = 0;
3433 : :
3434 : : /* the do_update_inode consumes one bh->b_count */
3435 : 0 : get_bh(iloc->bh);
3436 : :
3437 : : /* ext3_do_update_inode() does journal_dirty_metadata */
3438 : 0 : err = ext3_do_update_inode(handle, inode, iloc);
3439 : 0 : put_bh(iloc->bh);
3440 : 0 : return err;
3441 : : }
3442 : :
3443 : : /*
3444 : : * On success, We end up with an outstanding reference count against
3445 : : * iloc->bh. This _must_ be cleaned up later.
3446 : : */
3447 : :
3448 : : int
3449 : 0 : ext3_reserve_inode_write(handle_t *handle, struct inode *inode,
3450 : : struct ext3_iloc *iloc)
3451 : : {
3452 : : int err = 0;
3453 [ # # ]: 0 : if (handle) {
3454 : : err = ext3_get_inode_loc(inode, iloc);
3455 [ # # ]: 0 : if (!err) {
3456 : : BUFFER_TRACE(iloc->bh, "get_write_access");
3457 : 0 : err = ext3_journal_get_write_access(handle, iloc->bh);
3458 [ # # ]: 0 : if (err) {
3459 : 0 : brelse(iloc->bh);
3460 : 0 : iloc->bh = NULL;
3461 : : }
3462 : : }
3463 : : }
3464 [ # # ]: 0 : ext3_std_error(inode->i_sb, err);
3465 : 0 : return err;
3466 : : }
3467 : :
3468 : : /*
3469 : : * What we do here is to mark the in-core inode as clean with respect to inode
3470 : : * dirtiness (it may still be data-dirty).
3471 : : * This means that the in-core inode may be reaped by prune_icache
3472 : : * without having to perform any I/O. This is a very good thing,
3473 : : * because *any* task may call prune_icache - even ones which
3474 : : * have a transaction open against a different journal.
3475 : : *
3476 : : * Is this cheating? Not really. Sure, we haven't written the
3477 : : * inode out, but prune_icache isn't a user-visible syncing function.
3478 : : * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
3479 : : * we start and wait on commits.
3480 : : */
3481 : 0 : int ext3_mark_inode_dirty(handle_t *handle, struct inode *inode)
3482 : : {
3483 : : struct ext3_iloc iloc;
3484 : : int err;
3485 : :
3486 : : might_sleep();
3487 : 0 : trace_ext3_mark_inode_dirty(inode, _RET_IP_);
3488 : 0 : err = ext3_reserve_inode_write(handle, inode, &iloc);
3489 [ # # ]: 0 : if (!err)
3490 : 0 : err = ext3_mark_iloc_dirty(handle, inode, &iloc);
3491 : 0 : return err;
3492 : : }
3493 : :
3494 : : /*
3495 : : * ext3_dirty_inode() is called from __mark_inode_dirty()
3496 : : *
3497 : : * We're really interested in the case where a file is being extended.
3498 : : * i_size has been changed by generic_commit_write() and we thus need
3499 : : * to include the updated inode in the current transaction.
3500 : : *
3501 : : * Also, dquot_alloc_space() will always dirty the inode when blocks
3502 : : * are allocated to the file.
3503 : : *
3504 : : * If the inode is marked synchronous, we don't honour that here - doing
3505 : : * so would cause a commit on atime updates, which we don't bother doing.
3506 : : * We handle synchronous inodes at the highest possible level.
3507 : : */
3508 : 0 : void ext3_dirty_inode(struct inode *inode, int flags)
3509 : : {
3510 : : handle_t *current_handle = ext3_journal_current_handle();
3511 : : handle_t *handle;
3512 : :
3513 : : handle = ext3_journal_start(inode, 2);
3514 [ # # ]: 0 : if (IS_ERR(handle))
3515 : : goto out;
3516 [ # # ][ # # ]: 0 : if (current_handle &&
3517 : 0 : current_handle->h_transaction != handle->h_transaction) {
3518 : : /* This task has a transaction open against a different fs */
3519 : 0 : printk(KERN_EMERG "%s: transactions do not match!\n",
3520 : : __func__);
3521 : : } else {
3522 : : jbd_debug(5, "marking dirty. outer handle=%p\n",
3523 : : current_handle);
3524 : 0 : ext3_mark_inode_dirty(handle, inode);
3525 : : }
3526 : 0 : ext3_journal_stop(handle);
3527 : : out:
3528 : 0 : return;
3529 : : }
3530 : :
3531 : : #if 0
3532 : : /*
3533 : : * Bind an inode's backing buffer_head into this transaction, to prevent
3534 : : * it from being flushed to disk early. Unlike
3535 : : * ext3_reserve_inode_write, this leaves behind no bh reference and
3536 : : * returns no iloc structure, so the caller needs to repeat the iloc
3537 : : * lookup to mark the inode dirty later.
3538 : : */
3539 : : static int ext3_pin_inode(handle_t *handle, struct inode *inode)
3540 : : {
3541 : : struct ext3_iloc iloc;
3542 : :
3543 : : int err = 0;
3544 : : if (handle) {
3545 : : err = ext3_get_inode_loc(inode, &iloc);
3546 : : if (!err) {
3547 : : BUFFER_TRACE(iloc.bh, "get_write_access");
3548 : : err = journal_get_write_access(handle, iloc.bh);
3549 : : if (!err)
3550 : : err = ext3_journal_dirty_metadata(handle,
3551 : : iloc.bh);
3552 : : brelse(iloc.bh);
3553 : : }
3554 : : }
3555 : : ext3_std_error(inode->i_sb, err);
3556 : : return err;
3557 : : }
3558 : : #endif
3559 : :
3560 : 0 : int ext3_change_inode_journal_flag(struct inode *inode, int val)
3561 : : {
3562 : 0 : journal_t *journal;
3563 : : handle_t *handle;
3564 : : int err;
3565 : :
3566 : : /*
3567 : : * We have to be very careful here: changing a data block's
3568 : : * journaling status dynamically is dangerous. If we write a
3569 : : * data block to the journal, change the status and then delete
3570 : : * that block, we risk forgetting to revoke the old log record
3571 : : * from the journal and so a subsequent replay can corrupt data.
3572 : : * So, first we make sure that the journal is empty and that
3573 : : * nobody is changing anything.
3574 : : */
3575 : :
3576 : 0 : journal = EXT3_JOURNAL(inode);
3577 [ # # ]: 0 : if (is_journal_aborted(journal))
3578 : : return -EROFS;
3579 : :
3580 : 0 : journal_lock_updates(journal);
3581 : 0 : journal_flush(journal);
3582 : :
3583 : : /*
3584 : : * OK, there are no updates running now, and all cached data is
3585 : : * synced to disk. We are now in a completely consistent state
3586 : : * which doesn't have anything in the journal, and we know that
3587 : : * no filesystem updates are running, so it is safe to modify
3588 : : * the inode's in-core data-journaling state flag now.
3589 : : */
3590 : :
3591 [ # # ]: 0 : if (val)
3592 : 0 : EXT3_I(inode)->i_flags |= EXT3_JOURNAL_DATA_FL;
3593 : : else
3594 : 0 : EXT3_I(inode)->i_flags &= ~EXT3_JOURNAL_DATA_FL;
3595 : 0 : ext3_set_aops(inode);
3596 : :
3597 : 0 : journal_unlock_updates(journal);
3598 : :
3599 : : /* Finally we can mark the inode as dirty. */
3600 : :
3601 : : handle = ext3_journal_start(inode, 1);
3602 [ # # ]: 0 : if (IS_ERR(handle))
3603 : 0 : return PTR_ERR(handle);
3604 : :
3605 : 0 : err = ext3_mark_inode_dirty(handle, inode);
3606 : 0 : handle->h_sync = 1;
3607 : 0 : ext3_journal_stop(handle);
3608 [ # # ]: 0 : ext3_std_error(inode->i_sb, err);
3609 : :
3610 : 0 : return err;
3611 : : }
|
