Commit | Line | Data |
---|---|---|
ac27a0ec | 1 | /* |
617ba13b | 2 | * linux/fs/ext4/inode.c |
ac27a0ec DK |
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 | * | |
617ba13b | 22 | * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000 |
ac27a0ec DK |
23 | */ |
24 | ||
25 | #include <linux/module.h> | |
26 | #include <linux/fs.h> | |
27 | #include <linux/time.h> | |
dab291af | 28 | #include <linux/jbd2.h> |
ac27a0ec DK |
29 | #include <linux/highuid.h> |
30 | #include <linux/pagemap.h> | |
31 | #include <linux/quotaops.h> | |
32 | #include <linux/string.h> | |
33 | #include <linux/buffer_head.h> | |
34 | #include <linux/writeback.h> | |
35 | #include <linux/mpage.h> | |
36 | #include <linux/uio.h> | |
37 | #include <linux/bio.h> | |
3dcf5451 | 38 | #include "ext4_jbd2.h" |
ac27a0ec DK |
39 | #include "xattr.h" |
40 | #include "acl.h" | |
41 | ||
ac27a0ec DK |
42 | /* |
43 | * Test whether an inode is a fast symlink. | |
44 | */ | |
617ba13b | 45 | static int ext4_inode_is_fast_symlink(struct inode *inode) |
ac27a0ec | 46 | { |
617ba13b | 47 | int ea_blocks = EXT4_I(inode)->i_file_acl ? |
ac27a0ec DK |
48 | (inode->i_sb->s_blocksize >> 9) : 0; |
49 | ||
50 | return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0); | |
51 | } | |
52 | ||
53 | /* | |
617ba13b | 54 | * The ext4 forget function must perform a revoke if we are freeing data |
ac27a0ec DK |
55 | * which has been journaled. Metadata (eg. indirect blocks) must be |
56 | * revoked in all cases. | |
57 | * | |
58 | * "bh" may be NULL: a metadata block may have been freed from memory | |
59 | * but there may still be a record of it in the journal, and that record | |
60 | * still needs to be revoked. | |
61 | */ | |
617ba13b MC |
62 | int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode, |
63 | struct buffer_head *bh, ext4_fsblk_t blocknr) | |
ac27a0ec DK |
64 | { |
65 | int err; | |
66 | ||
67 | might_sleep(); | |
68 | ||
69 | BUFFER_TRACE(bh, "enter"); | |
70 | ||
71 | jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, " | |
72 | "data mode %lx\n", | |
73 | bh, is_metadata, inode->i_mode, | |
74 | test_opt(inode->i_sb, DATA_FLAGS)); | |
75 | ||
76 | /* Never use the revoke function if we are doing full data | |
77 | * journaling: there is no need to, and a V1 superblock won't | |
78 | * support it. Otherwise, only skip the revoke on un-journaled | |
79 | * data blocks. */ | |
80 | ||
617ba13b MC |
81 | if (test_opt(inode->i_sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA || |
82 | (!is_metadata && !ext4_should_journal_data(inode))) { | |
ac27a0ec | 83 | if (bh) { |
dab291af | 84 | BUFFER_TRACE(bh, "call jbd2_journal_forget"); |
617ba13b | 85 | return ext4_journal_forget(handle, bh); |
ac27a0ec DK |
86 | } |
87 | return 0; | |
88 | } | |
89 | ||
90 | /* | |
91 | * data!=journal && (is_metadata || should_journal_data(inode)) | |
92 | */ | |
617ba13b MC |
93 | BUFFER_TRACE(bh, "call ext4_journal_revoke"); |
94 | err = ext4_journal_revoke(handle, blocknr, bh); | |
ac27a0ec | 95 | if (err) |
46e665e9 | 96 | ext4_abort(inode->i_sb, __func__, |
ac27a0ec DK |
97 | "error %d when attempting revoke", err); |
98 | BUFFER_TRACE(bh, "exit"); | |
99 | return err; | |
100 | } | |
101 | ||
102 | /* | |
103 | * Work out how many blocks we need to proceed with the next chunk of a | |
104 | * truncate transaction. | |
105 | */ | |
106 | static unsigned long blocks_for_truncate(struct inode *inode) | |
107 | { | |
725d26d3 | 108 | ext4_lblk_t needed; |
ac27a0ec DK |
109 | |
110 | needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9); | |
111 | ||
112 | /* Give ourselves just enough room to cope with inodes in which | |
113 | * i_blocks is corrupt: we've seen disk corruptions in the past | |
114 | * which resulted in random data in an inode which looked enough | |
617ba13b | 115 | * like a regular file for ext4 to try to delete it. Things |
ac27a0ec DK |
116 | * will go a bit crazy if that happens, but at least we should |
117 | * try not to panic the whole kernel. */ | |
118 | if (needed < 2) | |
119 | needed = 2; | |
120 | ||
121 | /* But we need to bound the transaction so we don't overflow the | |
122 | * journal. */ | |
617ba13b MC |
123 | if (needed > EXT4_MAX_TRANS_DATA) |
124 | needed = EXT4_MAX_TRANS_DATA; | |
ac27a0ec | 125 | |
617ba13b | 126 | return EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + needed; |
ac27a0ec DK |
127 | } |
128 | ||
129 | /* | |
130 | * Truncate transactions can be complex and absolutely huge. So we need to | |
131 | * be able to restart the transaction at a conventient checkpoint to make | |
132 | * sure we don't overflow the journal. | |
133 | * | |
134 | * start_transaction gets us a new handle for a truncate transaction, | |
135 | * and extend_transaction tries to extend the existing one a bit. If | |
136 | * extend fails, we need to propagate the failure up and restart the | |
137 | * transaction in the top-level truncate loop. --sct | |
138 | */ | |
139 | static handle_t *start_transaction(struct inode *inode) | |
140 | { | |
141 | handle_t *result; | |
142 | ||
617ba13b | 143 | result = ext4_journal_start(inode, blocks_for_truncate(inode)); |
ac27a0ec DK |
144 | if (!IS_ERR(result)) |
145 | return result; | |
146 | ||
617ba13b | 147 | ext4_std_error(inode->i_sb, PTR_ERR(result)); |
ac27a0ec DK |
148 | return result; |
149 | } | |
150 | ||
151 | /* | |
152 | * Try to extend this transaction for the purposes of truncation. | |
153 | * | |
154 | * Returns 0 if we managed to create more room. If we can't create more | |
155 | * room, and the transaction must be restarted we return 1. | |
156 | */ | |
157 | static int try_to_extend_transaction(handle_t *handle, struct inode *inode) | |
158 | { | |
617ba13b | 159 | if (handle->h_buffer_credits > EXT4_RESERVE_TRANS_BLOCKS) |
ac27a0ec | 160 | return 0; |
617ba13b | 161 | if (!ext4_journal_extend(handle, blocks_for_truncate(inode))) |
ac27a0ec DK |
162 | return 0; |
163 | return 1; | |
164 | } | |
165 | ||
166 | /* | |
167 | * Restart the transaction associated with *handle. This does a commit, | |
168 | * so before we call here everything must be consistently dirtied against | |
169 | * this transaction. | |
170 | */ | |
617ba13b | 171 | static int ext4_journal_test_restart(handle_t *handle, struct inode *inode) |
ac27a0ec DK |
172 | { |
173 | jbd_debug(2, "restarting handle %p\n", handle); | |
617ba13b | 174 | return ext4_journal_restart(handle, blocks_for_truncate(inode)); |
ac27a0ec DK |
175 | } |
176 | ||
177 | /* | |
178 | * Called at the last iput() if i_nlink is zero. | |
179 | */ | |
617ba13b | 180 | void ext4_delete_inode (struct inode * inode) |
ac27a0ec DK |
181 | { |
182 | handle_t *handle; | |
183 | ||
184 | truncate_inode_pages(&inode->i_data, 0); | |
185 | ||
186 | if (is_bad_inode(inode)) | |
187 | goto no_delete; | |
188 | ||
189 | handle = start_transaction(inode); | |
190 | if (IS_ERR(handle)) { | |
191 | /* | |
192 | * If we're going to skip the normal cleanup, we still need to | |
193 | * make sure that the in-core orphan linked list is properly | |
194 | * cleaned up. | |
195 | */ | |
617ba13b | 196 | ext4_orphan_del(NULL, inode); |
ac27a0ec DK |
197 | goto no_delete; |
198 | } | |
199 | ||
200 | if (IS_SYNC(inode)) | |
201 | handle->h_sync = 1; | |
202 | inode->i_size = 0; | |
203 | if (inode->i_blocks) | |
617ba13b | 204 | ext4_truncate(inode); |
ac27a0ec | 205 | /* |
617ba13b | 206 | * Kill off the orphan record which ext4_truncate created. |
ac27a0ec | 207 | * AKPM: I think this can be inside the above `if'. |
617ba13b | 208 | * Note that ext4_orphan_del() has to be able to cope with the |
ac27a0ec | 209 | * deletion of a non-existent orphan - this is because we don't |
617ba13b | 210 | * know if ext4_truncate() actually created an orphan record. |
ac27a0ec DK |
211 | * (Well, we could do this if we need to, but heck - it works) |
212 | */ | |
617ba13b MC |
213 | ext4_orphan_del(handle, inode); |
214 | EXT4_I(inode)->i_dtime = get_seconds(); | |
ac27a0ec DK |
215 | |
216 | /* | |
217 | * One subtle ordering requirement: if anything has gone wrong | |
218 | * (transaction abort, IO errors, whatever), then we can still | |
219 | * do these next steps (the fs will already have been marked as | |
220 | * having errors), but we can't free the inode if the mark_dirty | |
221 | * fails. | |
222 | */ | |
617ba13b | 223 | if (ext4_mark_inode_dirty(handle, inode)) |
ac27a0ec DK |
224 | /* If that failed, just do the required in-core inode clear. */ |
225 | clear_inode(inode); | |
226 | else | |
617ba13b MC |
227 | ext4_free_inode(handle, inode); |
228 | ext4_journal_stop(handle); | |
ac27a0ec DK |
229 | return; |
230 | no_delete: | |
231 | clear_inode(inode); /* We must guarantee clearing of inode... */ | |
232 | } | |
233 | ||
234 | typedef struct { | |
235 | __le32 *p; | |
236 | __le32 key; | |
237 | struct buffer_head *bh; | |
238 | } Indirect; | |
239 | ||
240 | static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) | |
241 | { | |
242 | p->key = *(p->p = v); | |
243 | p->bh = bh; | |
244 | } | |
245 | ||
ac27a0ec | 246 | /** |
617ba13b | 247 | * ext4_block_to_path - parse the block number into array of offsets |
ac27a0ec DK |
248 | * @inode: inode in question (we are only interested in its superblock) |
249 | * @i_block: block number to be parsed | |
250 | * @offsets: array to store the offsets in | |
8c55e204 DK |
251 | * @boundary: set this non-zero if the referred-to block is likely to be |
252 | * followed (on disk) by an indirect block. | |
ac27a0ec | 253 | * |
617ba13b | 254 | * To store the locations of file's data ext4 uses a data structure common |
ac27a0ec DK |
255 | * for UNIX filesystems - tree of pointers anchored in the inode, with |
256 | * data blocks at leaves and indirect blocks in intermediate nodes. | |
257 | * This function translates the block number into path in that tree - | |
258 | * return value is the path length and @offsets[n] is the offset of | |
259 | * pointer to (n+1)th node in the nth one. If @block is out of range | |
260 | * (negative or too large) warning is printed and zero returned. | |
261 | * | |
262 | * Note: function doesn't find node addresses, so no IO is needed. All | |
263 | * we need to know is the capacity of indirect blocks (taken from the | |
264 | * inode->i_sb). | |
265 | */ | |
266 | ||
267 | /* | |
268 | * Portability note: the last comparison (check that we fit into triple | |
269 | * indirect block) is spelled differently, because otherwise on an | |
270 | * architecture with 32-bit longs and 8Kb pages we might get into trouble | |
271 | * if our filesystem had 8Kb blocks. We might use long long, but that would | |
272 | * kill us on x86. Oh, well, at least the sign propagation does not matter - | |
273 | * i_block would have to be negative in the very beginning, so we would not | |
274 | * get there at all. | |
275 | */ | |
276 | ||
617ba13b | 277 | static int ext4_block_to_path(struct inode *inode, |
725d26d3 AK |
278 | ext4_lblk_t i_block, |
279 | ext4_lblk_t offsets[4], int *boundary) | |
ac27a0ec | 280 | { |
617ba13b MC |
281 | int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb); |
282 | int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb); | |
283 | const long direct_blocks = EXT4_NDIR_BLOCKS, | |
ac27a0ec DK |
284 | indirect_blocks = ptrs, |
285 | double_blocks = (1 << (ptrs_bits * 2)); | |
286 | int n = 0; | |
287 | int final = 0; | |
288 | ||
289 | if (i_block < 0) { | |
617ba13b | 290 | ext4_warning (inode->i_sb, "ext4_block_to_path", "block < 0"); |
ac27a0ec DK |
291 | } else if (i_block < direct_blocks) { |
292 | offsets[n++] = i_block; | |
293 | final = direct_blocks; | |
294 | } else if ( (i_block -= direct_blocks) < indirect_blocks) { | |
617ba13b | 295 | offsets[n++] = EXT4_IND_BLOCK; |
ac27a0ec DK |
296 | offsets[n++] = i_block; |
297 | final = ptrs; | |
298 | } else if ((i_block -= indirect_blocks) < double_blocks) { | |
617ba13b | 299 | offsets[n++] = EXT4_DIND_BLOCK; |
ac27a0ec DK |
300 | offsets[n++] = i_block >> ptrs_bits; |
301 | offsets[n++] = i_block & (ptrs - 1); | |
302 | final = ptrs; | |
303 | } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { | |
617ba13b | 304 | offsets[n++] = EXT4_TIND_BLOCK; |
ac27a0ec DK |
305 | offsets[n++] = i_block >> (ptrs_bits * 2); |
306 | offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); | |
307 | offsets[n++] = i_block & (ptrs - 1); | |
308 | final = ptrs; | |
309 | } else { | |
e2b46574 | 310 | ext4_warning(inode->i_sb, "ext4_block_to_path", |
0e855ac8 | 311 | "block %lu > max", |
e2b46574 ES |
312 | i_block + direct_blocks + |
313 | indirect_blocks + double_blocks); | |
ac27a0ec DK |
314 | } |
315 | if (boundary) | |
316 | *boundary = final - 1 - (i_block & (ptrs - 1)); | |
317 | return n; | |
318 | } | |
319 | ||
320 | /** | |
617ba13b | 321 | * ext4_get_branch - read the chain of indirect blocks leading to data |
ac27a0ec DK |
322 | * @inode: inode in question |
323 | * @depth: depth of the chain (1 - direct pointer, etc.) | |
324 | * @offsets: offsets of pointers in inode/indirect blocks | |
325 | * @chain: place to store the result | |
326 | * @err: here we store the error value | |
327 | * | |
328 | * Function fills the array of triples <key, p, bh> and returns %NULL | |
329 | * if everything went OK or the pointer to the last filled triple | |
330 | * (incomplete one) otherwise. Upon the return chain[i].key contains | |
331 | * the number of (i+1)-th block in the chain (as it is stored in memory, | |
332 | * i.e. little-endian 32-bit), chain[i].p contains the address of that | |
333 | * number (it points into struct inode for i==0 and into the bh->b_data | |
334 | * for i>0) and chain[i].bh points to the buffer_head of i-th indirect | |
335 | * block for i>0 and NULL for i==0. In other words, it holds the block | |
336 | * numbers of the chain, addresses they were taken from (and where we can | |
337 | * verify that chain did not change) and buffer_heads hosting these | |
338 | * numbers. | |
339 | * | |
340 | * Function stops when it stumbles upon zero pointer (absent block) | |
341 | * (pointer to last triple returned, *@err == 0) | |
342 | * or when it gets an IO error reading an indirect block | |
343 | * (ditto, *@err == -EIO) | |
ac27a0ec DK |
344 | * or when it reads all @depth-1 indirect blocks successfully and finds |
345 | * the whole chain, all way to the data (returns %NULL, *err == 0). | |
c278bfec AK |
346 | * |
347 | * Need to be called with | |
0e855ac8 | 348 | * down_read(&EXT4_I(inode)->i_data_sem) |
ac27a0ec | 349 | */ |
725d26d3 AK |
350 | static Indirect *ext4_get_branch(struct inode *inode, int depth, |
351 | ext4_lblk_t *offsets, | |
ac27a0ec DK |
352 | Indirect chain[4], int *err) |
353 | { | |
354 | struct super_block *sb = inode->i_sb; | |
355 | Indirect *p = chain; | |
356 | struct buffer_head *bh; | |
357 | ||
358 | *err = 0; | |
359 | /* i_data is not going away, no lock needed */ | |
617ba13b | 360 | add_chain (chain, NULL, EXT4_I(inode)->i_data + *offsets); |
ac27a0ec DK |
361 | if (!p->key) |
362 | goto no_block; | |
363 | while (--depth) { | |
364 | bh = sb_bread(sb, le32_to_cpu(p->key)); | |
365 | if (!bh) | |
366 | goto failure; | |
ac27a0ec DK |
367 | add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); |
368 | /* Reader: end */ | |
369 | if (!p->key) | |
370 | goto no_block; | |
371 | } | |
372 | return NULL; | |
373 | ||
ac27a0ec DK |
374 | failure: |
375 | *err = -EIO; | |
376 | no_block: | |
377 | return p; | |
378 | } | |
379 | ||
380 | /** | |
617ba13b | 381 | * ext4_find_near - find a place for allocation with sufficient locality |
ac27a0ec DK |
382 | * @inode: owner |
383 | * @ind: descriptor of indirect block. | |
384 | * | |
1cc8dcf5 | 385 | * This function returns the preferred place for block allocation. |
ac27a0ec DK |
386 | * It is used when heuristic for sequential allocation fails. |
387 | * Rules are: | |
388 | * + if there is a block to the left of our position - allocate near it. | |
389 | * + if pointer will live in indirect block - allocate near that block. | |
390 | * + if pointer will live in inode - allocate in the same | |
391 | * cylinder group. | |
392 | * | |
393 | * In the latter case we colour the starting block by the callers PID to | |
394 | * prevent it from clashing with concurrent allocations for a different inode | |
395 | * in the same block group. The PID is used here so that functionally related | |
396 | * files will be close-by on-disk. | |
397 | * | |
398 | * Caller must make sure that @ind is valid and will stay that way. | |
399 | */ | |
617ba13b | 400 | static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind) |
ac27a0ec | 401 | { |
617ba13b | 402 | struct ext4_inode_info *ei = EXT4_I(inode); |
ac27a0ec DK |
403 | __le32 *start = ind->bh ? (__le32*) ind->bh->b_data : ei->i_data; |
404 | __le32 *p; | |
617ba13b | 405 | ext4_fsblk_t bg_start; |
74d3487f | 406 | ext4_fsblk_t last_block; |
617ba13b | 407 | ext4_grpblk_t colour; |
ac27a0ec DK |
408 | |
409 | /* Try to find previous block */ | |
410 | for (p = ind->p - 1; p >= start; p--) { | |
411 | if (*p) | |
412 | return le32_to_cpu(*p); | |
413 | } | |
414 | ||
415 | /* No such thing, so let's try location of indirect block */ | |
416 | if (ind->bh) | |
417 | return ind->bh->b_blocknr; | |
418 | ||
419 | /* | |
420 | * It is going to be referred to from the inode itself? OK, just put it | |
421 | * into the same cylinder group then. | |
422 | */ | |
617ba13b | 423 | bg_start = ext4_group_first_block_no(inode->i_sb, ei->i_block_group); |
74d3487f VC |
424 | last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1; |
425 | ||
426 | if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block) | |
427 | colour = (current->pid % 16) * | |
617ba13b | 428 | (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16); |
74d3487f VC |
429 | else |
430 | colour = (current->pid % 16) * ((last_block - bg_start) / 16); | |
ac27a0ec DK |
431 | return bg_start + colour; |
432 | } | |
433 | ||
434 | /** | |
1cc8dcf5 | 435 | * ext4_find_goal - find a preferred place for allocation. |
ac27a0ec DK |
436 | * @inode: owner |
437 | * @block: block we want | |
ac27a0ec | 438 | * @partial: pointer to the last triple within a chain |
ac27a0ec | 439 | * |
1cc8dcf5 | 440 | * Normally this function find the preferred place for block allocation, |
fb01bfda | 441 | * returns it. |
ac27a0ec | 442 | */ |
725d26d3 | 443 | static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block, |
fb01bfda | 444 | Indirect *partial) |
ac27a0ec | 445 | { |
617ba13b | 446 | struct ext4_block_alloc_info *block_i; |
ac27a0ec | 447 | |
617ba13b | 448 | block_i = EXT4_I(inode)->i_block_alloc_info; |
ac27a0ec DK |
449 | |
450 | /* | |
451 | * try the heuristic for sequential allocation, | |
452 | * failing that at least try to get decent locality. | |
453 | */ | |
454 | if (block_i && (block == block_i->last_alloc_logical_block + 1) | |
455 | && (block_i->last_alloc_physical_block != 0)) { | |
456 | return block_i->last_alloc_physical_block + 1; | |
457 | } | |
458 | ||
617ba13b | 459 | return ext4_find_near(inode, partial); |
ac27a0ec DK |
460 | } |
461 | ||
462 | /** | |
617ba13b | 463 | * ext4_blks_to_allocate: Look up the block map and count the number |
ac27a0ec DK |
464 | * of direct blocks need to be allocated for the given branch. |
465 | * | |
466 | * @branch: chain of indirect blocks | |
467 | * @k: number of blocks need for indirect blocks | |
468 | * @blks: number of data blocks to be mapped. | |
469 | * @blocks_to_boundary: the offset in the indirect block | |
470 | * | |
471 | * return the total number of blocks to be allocate, including the | |
472 | * direct and indirect blocks. | |
473 | */ | |
617ba13b | 474 | static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned long blks, |
ac27a0ec DK |
475 | int blocks_to_boundary) |
476 | { | |
477 | unsigned long count = 0; | |
478 | ||
479 | /* | |
480 | * Simple case, [t,d]Indirect block(s) has not allocated yet | |
481 | * then it's clear blocks on that path have not allocated | |
482 | */ | |
483 | if (k > 0) { | |
484 | /* right now we don't handle cross boundary allocation */ | |
485 | if (blks < blocks_to_boundary + 1) | |
486 | count += blks; | |
487 | else | |
488 | count += blocks_to_boundary + 1; | |
489 | return count; | |
490 | } | |
491 | ||
492 | count++; | |
493 | while (count < blks && count <= blocks_to_boundary && | |
494 | le32_to_cpu(*(branch[0].p + count)) == 0) { | |
495 | count++; | |
496 | } | |
497 | return count; | |
498 | } | |
499 | ||
500 | /** | |
617ba13b | 501 | * ext4_alloc_blocks: multiple allocate blocks needed for a branch |
ac27a0ec DK |
502 | * @indirect_blks: the number of blocks need to allocate for indirect |
503 | * blocks | |
504 | * | |
505 | * @new_blocks: on return it will store the new block numbers for | |
506 | * the indirect blocks(if needed) and the first direct block, | |
507 | * @blks: on return it will store the total number of allocated | |
508 | * direct blocks | |
509 | */ | |
617ba13b | 510 | static int ext4_alloc_blocks(handle_t *handle, struct inode *inode, |
7061eba7 AK |
511 | ext4_lblk_t iblock, ext4_fsblk_t goal, |
512 | int indirect_blks, int blks, | |
513 | ext4_fsblk_t new_blocks[4], int *err) | |
ac27a0ec DK |
514 | { |
515 | int target, i; | |
7061eba7 | 516 | unsigned long count = 0, blk_allocated = 0; |
ac27a0ec | 517 | int index = 0; |
617ba13b | 518 | ext4_fsblk_t current_block = 0; |
ac27a0ec DK |
519 | int ret = 0; |
520 | ||
521 | /* | |
522 | * Here we try to allocate the requested multiple blocks at once, | |
523 | * on a best-effort basis. | |
524 | * To build a branch, we should allocate blocks for | |
525 | * the indirect blocks(if not allocated yet), and at least | |
526 | * the first direct block of this branch. That's the | |
527 | * minimum number of blocks need to allocate(required) | |
528 | */ | |
7061eba7 AK |
529 | /* first we try to allocate the indirect blocks */ |
530 | target = indirect_blks; | |
531 | while (target > 0) { | |
ac27a0ec DK |
532 | count = target; |
533 | /* allocating blocks for indirect blocks and direct blocks */ | |
7061eba7 AK |
534 | current_block = ext4_new_meta_blocks(handle, inode, |
535 | goal, &count, err); | |
ac27a0ec DK |
536 | if (*err) |
537 | goto failed_out; | |
538 | ||
539 | target -= count; | |
540 | /* allocate blocks for indirect blocks */ | |
541 | while (index < indirect_blks && count) { | |
542 | new_blocks[index++] = current_block++; | |
543 | count--; | |
544 | } | |
7061eba7 AK |
545 | if (count > 0) { |
546 | /* | |
547 | * save the new block number | |
548 | * for the first direct block | |
549 | */ | |
550 | new_blocks[index] = current_block; | |
551 | printk(KERN_INFO "%s returned more blocks than " | |
552 | "requested\n", __func__); | |
553 | WARN_ON(1); | |
ac27a0ec | 554 | break; |
7061eba7 | 555 | } |
ac27a0ec DK |
556 | } |
557 | ||
7061eba7 AK |
558 | target = blks - count ; |
559 | blk_allocated = count; | |
560 | if (!target) | |
561 | goto allocated; | |
562 | /* Now allocate data blocks */ | |
563 | count = target; | |
654b4908 | 564 | /* allocating blocks for data blocks */ |
7061eba7 AK |
565 | current_block = ext4_new_blocks(handle, inode, iblock, |
566 | goal, &count, err); | |
567 | if (*err && (target == blks)) { | |
568 | /* | |
569 | * if the allocation failed and we didn't allocate | |
570 | * any blocks before | |
571 | */ | |
572 | goto failed_out; | |
573 | } | |
574 | if (!*err) { | |
575 | if (target == blks) { | |
576 | /* | |
577 | * save the new block number | |
578 | * for the first direct block | |
579 | */ | |
580 | new_blocks[index] = current_block; | |
581 | } | |
582 | blk_allocated += count; | |
583 | } | |
584 | allocated: | |
ac27a0ec | 585 | /* total number of blocks allocated for direct blocks */ |
7061eba7 | 586 | ret = blk_allocated; |
ac27a0ec DK |
587 | *err = 0; |
588 | return ret; | |
589 | failed_out: | |
590 | for (i = 0; i <index; i++) | |
c9de560d | 591 | ext4_free_blocks(handle, inode, new_blocks[i], 1, 0); |
ac27a0ec DK |
592 | return ret; |
593 | } | |
594 | ||
595 | /** | |
617ba13b | 596 | * ext4_alloc_branch - allocate and set up a chain of blocks. |
ac27a0ec DK |
597 | * @inode: owner |
598 | * @indirect_blks: number of allocated indirect blocks | |
599 | * @blks: number of allocated direct blocks | |
600 | * @offsets: offsets (in the blocks) to store the pointers to next. | |
601 | * @branch: place to store the chain in. | |
602 | * | |
603 | * This function allocates blocks, zeroes out all but the last one, | |
604 | * links them into chain and (if we are synchronous) writes them to disk. | |
605 | * In other words, it prepares a branch that can be spliced onto the | |
606 | * inode. It stores the information about that chain in the branch[], in | |
617ba13b | 607 | * the same format as ext4_get_branch() would do. We are calling it after |
ac27a0ec DK |
608 | * we had read the existing part of chain and partial points to the last |
609 | * triple of that (one with zero ->key). Upon the exit we have the same | |
617ba13b | 610 | * picture as after the successful ext4_get_block(), except that in one |
ac27a0ec DK |
611 | * place chain is disconnected - *branch->p is still zero (we did not |
612 | * set the last link), but branch->key contains the number that should | |
613 | * be placed into *branch->p to fill that gap. | |
614 | * | |
615 | * If allocation fails we free all blocks we've allocated (and forget | |
616 | * their buffer_heads) and return the error value the from failed | |
617ba13b | 617 | * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain |
ac27a0ec DK |
618 | * as described above and return 0. |
619 | */ | |
617ba13b | 620 | static int ext4_alloc_branch(handle_t *handle, struct inode *inode, |
7061eba7 AK |
621 | ext4_lblk_t iblock, int indirect_blks, |
622 | int *blks, ext4_fsblk_t goal, | |
623 | ext4_lblk_t *offsets, Indirect *branch) | |
ac27a0ec DK |
624 | { |
625 | int blocksize = inode->i_sb->s_blocksize; | |
626 | int i, n = 0; | |
627 | int err = 0; | |
628 | struct buffer_head *bh; | |
629 | int num; | |
617ba13b MC |
630 | ext4_fsblk_t new_blocks[4]; |
631 | ext4_fsblk_t current_block; | |
ac27a0ec | 632 | |
7061eba7 | 633 | num = ext4_alloc_blocks(handle, inode, iblock, goal, indirect_blks, |
ac27a0ec DK |
634 | *blks, new_blocks, &err); |
635 | if (err) | |
636 | return err; | |
637 | ||
638 | branch[0].key = cpu_to_le32(new_blocks[0]); | |
639 | /* | |
640 | * metadata blocks and data blocks are allocated. | |
641 | */ | |
642 | for (n = 1; n <= indirect_blks; n++) { | |
643 | /* | |
644 | * Get buffer_head for parent block, zero it out | |
645 | * and set the pointer to new one, then send | |
646 | * parent to disk. | |
647 | */ | |
648 | bh = sb_getblk(inode->i_sb, new_blocks[n-1]); | |
649 | branch[n].bh = bh; | |
650 | lock_buffer(bh); | |
651 | BUFFER_TRACE(bh, "call get_create_access"); | |
617ba13b | 652 | err = ext4_journal_get_create_access(handle, bh); |
ac27a0ec DK |
653 | if (err) { |
654 | unlock_buffer(bh); | |
655 | brelse(bh); | |
656 | goto failed; | |
657 | } | |
658 | ||
659 | memset(bh->b_data, 0, blocksize); | |
660 | branch[n].p = (__le32 *) bh->b_data + offsets[n]; | |
661 | branch[n].key = cpu_to_le32(new_blocks[n]); | |
662 | *branch[n].p = branch[n].key; | |
663 | if ( n == indirect_blks) { | |
664 | current_block = new_blocks[n]; | |
665 | /* | |
666 | * End of chain, update the last new metablock of | |
667 | * the chain to point to the new allocated | |
668 | * data blocks numbers | |
669 | */ | |
670 | for (i=1; i < num; i++) | |
671 | *(branch[n].p + i) = cpu_to_le32(++current_block); | |
672 | } | |
673 | BUFFER_TRACE(bh, "marking uptodate"); | |
674 | set_buffer_uptodate(bh); | |
675 | unlock_buffer(bh); | |
676 | ||
617ba13b MC |
677 | BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata"); |
678 | err = ext4_journal_dirty_metadata(handle, bh); | |
ac27a0ec DK |
679 | if (err) |
680 | goto failed; | |
681 | } | |
682 | *blks = num; | |
683 | return err; | |
684 | failed: | |
685 | /* Allocation failed, free what we already allocated */ | |
686 | for (i = 1; i <= n ; i++) { | |
dab291af | 687 | BUFFER_TRACE(branch[i].bh, "call jbd2_journal_forget"); |
617ba13b | 688 | ext4_journal_forget(handle, branch[i].bh); |
ac27a0ec DK |
689 | } |
690 | for (i = 0; i <indirect_blks; i++) | |
c9de560d | 691 | ext4_free_blocks(handle, inode, new_blocks[i], 1, 0); |
ac27a0ec | 692 | |
c9de560d | 693 | ext4_free_blocks(handle, inode, new_blocks[i], num, 0); |
ac27a0ec DK |
694 | |
695 | return err; | |
696 | } | |
697 | ||
698 | /** | |
617ba13b | 699 | * ext4_splice_branch - splice the allocated branch onto inode. |
ac27a0ec DK |
700 | * @inode: owner |
701 | * @block: (logical) number of block we are adding | |
702 | * @chain: chain of indirect blocks (with a missing link - see | |
617ba13b | 703 | * ext4_alloc_branch) |
ac27a0ec DK |
704 | * @where: location of missing link |
705 | * @num: number of indirect blocks we are adding | |
706 | * @blks: number of direct blocks we are adding | |
707 | * | |
708 | * This function fills the missing link and does all housekeeping needed in | |
709 | * inode (->i_blocks, etc.). In case of success we end up with the full | |
710 | * chain to new block and return 0. | |
711 | */ | |
617ba13b | 712 | static int ext4_splice_branch(handle_t *handle, struct inode *inode, |
725d26d3 | 713 | ext4_lblk_t block, Indirect *where, int num, int blks) |
ac27a0ec DK |
714 | { |
715 | int i; | |
716 | int err = 0; | |
617ba13b MC |
717 | struct ext4_block_alloc_info *block_i; |
718 | ext4_fsblk_t current_block; | |
ac27a0ec | 719 | |
617ba13b | 720 | block_i = EXT4_I(inode)->i_block_alloc_info; |
ac27a0ec DK |
721 | /* |
722 | * If we're splicing into a [td]indirect block (as opposed to the | |
723 | * inode) then we need to get write access to the [td]indirect block | |
724 | * before the splice. | |
725 | */ | |
726 | if (where->bh) { | |
727 | BUFFER_TRACE(where->bh, "get_write_access"); | |
617ba13b | 728 | err = ext4_journal_get_write_access(handle, where->bh); |
ac27a0ec DK |
729 | if (err) |
730 | goto err_out; | |
731 | } | |
732 | /* That's it */ | |
733 | ||
734 | *where->p = where->key; | |
735 | ||
736 | /* | |
737 | * Update the host buffer_head or inode to point to more just allocated | |
738 | * direct blocks blocks | |
739 | */ | |
740 | if (num == 0 && blks > 1) { | |
741 | current_block = le32_to_cpu(where->key) + 1; | |
742 | for (i = 1; i < blks; i++) | |
743 | *(where->p + i ) = cpu_to_le32(current_block++); | |
744 | } | |
745 | ||
746 | /* | |
747 | * update the most recently allocated logical & physical block | |
748 | * in i_block_alloc_info, to assist find the proper goal block for next | |
749 | * allocation | |
750 | */ | |
751 | if (block_i) { | |
752 | block_i->last_alloc_logical_block = block + blks - 1; | |
753 | block_i->last_alloc_physical_block = | |
754 | le32_to_cpu(where[num].key) + blks - 1; | |
755 | } | |
756 | ||
757 | /* We are done with atomic stuff, now do the rest of housekeeping */ | |
758 | ||
ef7f3835 | 759 | inode->i_ctime = ext4_current_time(inode); |
617ba13b | 760 | ext4_mark_inode_dirty(handle, inode); |
ac27a0ec DK |
761 | |
762 | /* had we spliced it onto indirect block? */ | |
763 | if (where->bh) { | |
764 | /* | |
765 | * If we spliced it onto an indirect block, we haven't | |
766 | * altered the inode. Note however that if it is being spliced | |
767 | * onto an indirect block at the very end of the file (the | |
768 | * file is growing) then we *will* alter the inode to reflect | |
769 | * the new i_size. But that is not done here - it is done in | |
617ba13b | 770 | * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode. |
ac27a0ec DK |
771 | */ |
772 | jbd_debug(5, "splicing indirect only\n"); | |
617ba13b MC |
773 | BUFFER_TRACE(where->bh, "call ext4_journal_dirty_metadata"); |
774 | err = ext4_journal_dirty_metadata(handle, where->bh); | |
ac27a0ec DK |
775 | if (err) |
776 | goto err_out; | |
777 | } else { | |
778 | /* | |
779 | * OK, we spliced it into the inode itself on a direct block. | |
780 | * Inode was dirtied above. | |
781 | */ | |
782 | jbd_debug(5, "splicing direct\n"); | |
783 | } | |
784 | return err; | |
785 | ||
786 | err_out: | |
787 | for (i = 1; i <= num; i++) { | |
dab291af | 788 | BUFFER_TRACE(where[i].bh, "call jbd2_journal_forget"); |
617ba13b | 789 | ext4_journal_forget(handle, where[i].bh); |
c9de560d AT |
790 | ext4_free_blocks(handle, inode, |
791 | le32_to_cpu(where[i-1].key), 1, 0); | |
ac27a0ec | 792 | } |
c9de560d | 793 | ext4_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks, 0); |
ac27a0ec DK |
794 | |
795 | return err; | |
796 | } | |
797 | ||
798 | /* | |
799 | * Allocation strategy is simple: if we have to allocate something, we will | |
800 | * have to go the whole way to leaf. So let's do it before attaching anything | |
801 | * to tree, set linkage between the newborn blocks, write them if sync is | |
802 | * required, recheck the path, free and repeat if check fails, otherwise | |
803 | * set the last missing link (that will protect us from any truncate-generated | |
804 | * removals - all blocks on the path are immune now) and possibly force the | |
805 | * write on the parent block. | |
806 | * That has a nice additional property: no special recovery from the failed | |
807 | * allocations is needed - we simply release blocks and do not touch anything | |
808 | * reachable from inode. | |
809 | * | |
810 | * `handle' can be NULL if create == 0. | |
811 | * | |
ac27a0ec DK |
812 | * return > 0, # of blocks mapped or allocated. |
813 | * return = 0, if plain lookup failed. | |
814 | * return < 0, error case. | |
c278bfec AK |
815 | * |
816 | * | |
817 | * Need to be called with | |
0e855ac8 AK |
818 | * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block |
819 | * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem) | |
ac27a0ec | 820 | */ |
617ba13b | 821 | int ext4_get_blocks_handle(handle_t *handle, struct inode *inode, |
725d26d3 | 822 | ext4_lblk_t iblock, unsigned long maxblocks, |
ac27a0ec DK |
823 | struct buffer_head *bh_result, |
824 | int create, int extend_disksize) | |
825 | { | |
826 | int err = -EIO; | |
725d26d3 | 827 | ext4_lblk_t offsets[4]; |
ac27a0ec DK |
828 | Indirect chain[4]; |
829 | Indirect *partial; | |
617ba13b | 830 | ext4_fsblk_t goal; |
ac27a0ec DK |
831 | int indirect_blks; |
832 | int blocks_to_boundary = 0; | |
833 | int depth; | |
617ba13b | 834 | struct ext4_inode_info *ei = EXT4_I(inode); |
ac27a0ec | 835 | int count = 0; |
617ba13b | 836 | ext4_fsblk_t first_block = 0; |
ac27a0ec DK |
837 | |
838 | ||
a86c6181 | 839 | J_ASSERT(!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)); |
ac27a0ec | 840 | J_ASSERT(handle != NULL || create == 0); |
725d26d3 AK |
841 | depth = ext4_block_to_path(inode, iblock, offsets, |
842 | &blocks_to_boundary); | |
ac27a0ec DK |
843 | |
844 | if (depth == 0) | |
845 | goto out; | |
846 | ||
617ba13b | 847 | partial = ext4_get_branch(inode, depth, offsets, chain, &err); |
ac27a0ec DK |
848 | |
849 | /* Simplest case - block found, no allocation needed */ | |
850 | if (!partial) { | |
851 | first_block = le32_to_cpu(chain[depth - 1].key); | |
852 | clear_buffer_new(bh_result); | |
853 | count++; | |
854 | /*map more blocks*/ | |
855 | while (count < maxblocks && count <= blocks_to_boundary) { | |
617ba13b | 856 | ext4_fsblk_t blk; |
ac27a0ec | 857 | |
ac27a0ec DK |
858 | blk = le32_to_cpu(*(chain[depth-1].p + count)); |
859 | ||
860 | if (blk == first_block + count) | |
861 | count++; | |
862 | else | |
863 | break; | |
864 | } | |
c278bfec | 865 | goto got_it; |
ac27a0ec DK |
866 | } |
867 | ||
868 | /* Next simple case - plain lookup or failed read of indirect block */ | |
869 | if (!create || err == -EIO) | |
870 | goto cleanup; | |
871 | ||
ac27a0ec DK |
872 | /* |
873 | * Okay, we need to do block allocation. Lazily initialize the block | |
874 | * allocation info here if necessary | |
875 | */ | |
876 | if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) | |
617ba13b | 877 | ext4_init_block_alloc_info(inode); |
ac27a0ec | 878 | |
fb01bfda | 879 | goal = ext4_find_goal(inode, iblock, partial); |
ac27a0ec DK |
880 | |
881 | /* the number of blocks need to allocate for [d,t]indirect blocks */ | |
882 | indirect_blks = (chain + depth) - partial - 1; | |
883 | ||
884 | /* | |
885 | * Next look up the indirect map to count the totoal number of | |
886 | * direct blocks to allocate for this branch. | |
887 | */ | |
617ba13b | 888 | count = ext4_blks_to_allocate(partial, indirect_blks, |
ac27a0ec DK |
889 | maxblocks, blocks_to_boundary); |
890 | /* | |
617ba13b | 891 | * Block out ext4_truncate while we alter the tree |
ac27a0ec | 892 | */ |
7061eba7 AK |
893 | err = ext4_alloc_branch(handle, inode, iblock, indirect_blks, |
894 | &count, goal, | |
895 | offsets + (partial - chain), partial); | |
ac27a0ec DK |
896 | |
897 | /* | |
617ba13b | 898 | * The ext4_splice_branch call will free and forget any buffers |
ac27a0ec DK |
899 | * on the new chain if there is a failure, but that risks using |
900 | * up transaction credits, especially for bitmaps where the | |
901 | * credits cannot be returned. Can we handle this somehow? We | |
902 | * may need to return -EAGAIN upwards in the worst case. --sct | |
903 | */ | |
904 | if (!err) | |
617ba13b | 905 | err = ext4_splice_branch(handle, inode, iblock, |
ac27a0ec DK |
906 | partial, indirect_blks, count); |
907 | /* | |
0e855ac8 | 908 | * i_disksize growing is protected by i_data_sem. Don't forget to |
ac27a0ec | 909 | * protect it if you're about to implement concurrent |
617ba13b | 910 | * ext4_get_block() -bzzz |
ac27a0ec DK |
911 | */ |
912 | if (!err && extend_disksize && inode->i_size > ei->i_disksize) | |
913 | ei->i_disksize = inode->i_size; | |
ac27a0ec DK |
914 | if (err) |
915 | goto cleanup; | |
916 | ||
917 | set_buffer_new(bh_result); | |
918 | got_it: | |
919 | map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); | |
920 | if (count > blocks_to_boundary) | |
921 | set_buffer_boundary(bh_result); | |
922 | err = count; | |
923 | /* Clean up and exit */ | |
924 | partial = chain + depth - 1; /* the whole chain */ | |
925 | cleanup: | |
926 | while (partial > chain) { | |
927 | BUFFER_TRACE(partial->bh, "call brelse"); | |
928 | brelse(partial->bh); | |
929 | partial--; | |
930 | } | |
931 | BUFFER_TRACE(bh_result, "returned"); | |
932 | out: | |
933 | return err; | |
934 | } | |
935 | ||
7fb5409d JK |
936 | /* Maximum number of blocks we map for direct IO at once. */ |
937 | #define DIO_MAX_BLOCKS 4096 | |
938 | /* | |
939 | * Number of credits we need for writing DIO_MAX_BLOCKS: | |
940 | * We need sb + group descriptor + bitmap + inode -> 4 | |
941 | * For B blocks with A block pointers per block we need: | |
942 | * 1 (triple ind.) + (B/A/A + 2) (doubly ind.) + (B/A + 2) (indirect). | |
943 | * If we plug in 4096 for B and 256 for A (for 1KB block size), we get 25. | |
944 | */ | |
945 | #define DIO_CREDITS 25 | |
ac27a0ec | 946 | |
f5ab0d1f MC |
947 | |
948 | /* | |
949 | * | |
950 | * | |
951 | * ext4_ext4 get_block() wrapper function | |
952 | * It will do a look up first, and returns if the blocks already mapped. | |
953 | * Otherwise it takes the write lock of the i_data_sem and allocate blocks | |
954 | * and store the allocated blocks in the result buffer head and mark it | |
955 | * mapped. | |
956 | * | |
957 | * If file type is extents based, it will call ext4_ext_get_blocks(), | |
958 | * Otherwise, call with ext4_get_blocks_handle() to handle indirect mapping | |
959 | * based files | |
960 | * | |
961 | * On success, it returns the number of blocks being mapped or allocate. | |
962 | * if create==0 and the blocks are pre-allocated and uninitialized block, | |
963 | * the result buffer head is unmapped. If the create ==1, it will make sure | |
964 | * the buffer head is mapped. | |
965 | * | |
966 | * It returns 0 if plain look up failed (blocks have not been allocated), in | |
967 | * that casem, buffer head is unmapped | |
968 | * | |
969 | * It returns the error in case of allocation failure. | |
970 | */ | |
0e855ac8 AK |
971 | int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block, |
972 | unsigned long max_blocks, struct buffer_head *bh, | |
973 | int create, int extend_disksize) | |
974 | { | |
975 | int retval; | |
f5ab0d1f MC |
976 | |
977 | clear_buffer_mapped(bh); | |
978 | ||
4df3d265 AK |
979 | /* |
980 | * Try to see if we can get the block without requesting | |
981 | * for new file system block. | |
982 | */ | |
983 | down_read((&EXT4_I(inode)->i_data_sem)); | |
984 | if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) { | |
985 | retval = ext4_ext_get_blocks(handle, inode, block, max_blocks, | |
986 | bh, 0, 0); | |
0e855ac8 | 987 | } else { |
4df3d265 AK |
988 | retval = ext4_get_blocks_handle(handle, |
989 | inode, block, max_blocks, bh, 0, 0); | |
0e855ac8 | 990 | } |
4df3d265 | 991 | up_read((&EXT4_I(inode)->i_data_sem)); |
f5ab0d1f MC |
992 | |
993 | /* If it is only a block(s) look up */ | |
994 | if (!create) | |
995 | return retval; | |
996 | ||
997 | /* | |
998 | * Returns if the blocks have already allocated | |
999 | * | |
1000 | * Note that if blocks have been preallocated | |
1001 | * ext4_ext_get_block() returns th create = 0 | |
1002 | * with buffer head unmapped. | |
1003 | */ | |
1004 | if (retval > 0 && buffer_mapped(bh)) | |
4df3d265 AK |
1005 | return retval; |
1006 | ||
1007 | /* | |
f5ab0d1f MC |
1008 | * New blocks allocate and/or writing to uninitialized extent |
1009 | * will possibly result in updating i_data, so we take | |
1010 | * the write lock of i_data_sem, and call get_blocks() | |
1011 | * with create == 1 flag. | |
4df3d265 AK |
1012 | */ |
1013 | down_write((&EXT4_I(inode)->i_data_sem)); | |
1014 | /* | |
1015 | * We need to check for EXT4 here because migrate | |
1016 | * could have changed the inode type in between | |
1017 | */ | |
0e855ac8 AK |
1018 | if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) { |
1019 | retval = ext4_ext_get_blocks(handle, inode, block, max_blocks, | |
1020 | bh, create, extend_disksize); | |
1021 | } else { | |
1022 | retval = ext4_get_blocks_handle(handle, inode, block, | |
1023 | max_blocks, bh, create, extend_disksize); | |
267e4db9 AK |
1024 | |
1025 | if (retval > 0 && buffer_new(bh)) { | |
1026 | /* | |
1027 | * We allocated new blocks which will result in | |
1028 | * i_data's format changing. Force the migrate | |
1029 | * to fail by clearing migrate flags | |
1030 | */ | |
1031 | EXT4_I(inode)->i_flags = EXT4_I(inode)->i_flags & | |
1032 | ~EXT4_EXT_MIGRATE; | |
1033 | } | |
0e855ac8 | 1034 | } |
4df3d265 | 1035 | up_write((&EXT4_I(inode)->i_data_sem)); |
0e855ac8 AK |
1036 | return retval; |
1037 | } | |
1038 | ||
617ba13b | 1039 | static int ext4_get_block(struct inode *inode, sector_t iblock, |
ac27a0ec DK |
1040 | struct buffer_head *bh_result, int create) |
1041 | { | |
3e4fdaf8 | 1042 | handle_t *handle = ext4_journal_current_handle(); |
7fb5409d | 1043 | int ret = 0, started = 0; |
ac27a0ec DK |
1044 | unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; |
1045 | ||
7fb5409d JK |
1046 | if (create && !handle) { |
1047 | /* Direct IO write... */ | |
1048 | if (max_blocks > DIO_MAX_BLOCKS) | |
1049 | max_blocks = DIO_MAX_BLOCKS; | |
1050 | handle = ext4_journal_start(inode, DIO_CREDITS + | |
1051 | 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb)); | |
1052 | if (IS_ERR(handle)) { | |
ac27a0ec | 1053 | ret = PTR_ERR(handle); |
7fb5409d | 1054 | goto out; |
ac27a0ec | 1055 | } |
7fb5409d | 1056 | started = 1; |
ac27a0ec DK |
1057 | } |
1058 | ||
7fb5409d | 1059 | ret = ext4_get_blocks_wrap(handle, inode, iblock, |
ac27a0ec | 1060 | max_blocks, bh_result, create, 0); |
7fb5409d JK |
1061 | if (ret > 0) { |
1062 | bh_result->b_size = (ret << inode->i_blkbits); | |
1063 | ret = 0; | |
ac27a0ec | 1064 | } |
7fb5409d JK |
1065 | if (started) |
1066 | ext4_journal_stop(handle); | |
1067 | out: | |
ac27a0ec DK |
1068 | return ret; |
1069 | } | |
1070 | ||
1071 | /* | |
1072 | * `handle' can be NULL if create is zero | |
1073 | */ | |
617ba13b | 1074 | struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode, |
725d26d3 | 1075 | ext4_lblk_t block, int create, int *errp) |
ac27a0ec DK |
1076 | { |
1077 | struct buffer_head dummy; | |
1078 | int fatal = 0, err; | |
1079 | ||
1080 | J_ASSERT(handle != NULL || create == 0); | |
1081 | ||
1082 | dummy.b_state = 0; | |
1083 | dummy.b_blocknr = -1000; | |
1084 | buffer_trace_init(&dummy.b_history); | |
a86c6181 | 1085 | err = ext4_get_blocks_wrap(handle, inode, block, 1, |
ac27a0ec DK |
1086 | &dummy, create, 1); |
1087 | /* | |
617ba13b | 1088 | * ext4_get_blocks_handle() returns number of blocks |
ac27a0ec DK |
1089 | * mapped. 0 in case of a HOLE. |
1090 | */ | |
1091 | if (err > 0) { | |
1092 | if (err > 1) | |
1093 | WARN_ON(1); | |
1094 | err = 0; | |
1095 | } | |
1096 | *errp = err; | |
1097 | if (!err && buffer_mapped(&dummy)) { | |
1098 | struct buffer_head *bh; | |
1099 | bh = sb_getblk(inode->i_sb, dummy.b_blocknr); | |
1100 | if (!bh) { | |
1101 | *errp = -EIO; | |
1102 | goto err; | |
1103 | } | |
1104 | if (buffer_new(&dummy)) { | |
1105 | J_ASSERT(create != 0); | |
ac39849d | 1106 | J_ASSERT(handle != NULL); |
ac27a0ec DK |
1107 | |
1108 | /* | |
1109 | * Now that we do not always journal data, we should | |
1110 | * keep in mind whether this should always journal the | |
1111 | * new buffer as metadata. For now, regular file | |
617ba13b | 1112 | * writes use ext4_get_block instead, so it's not a |
ac27a0ec DK |
1113 | * problem. |
1114 | */ | |
1115 | lock_buffer(bh); | |
1116 | BUFFER_TRACE(bh, "call get_create_access"); | |
617ba13b | 1117 | fatal = ext4_journal_get_create_access(handle, bh); |
ac27a0ec DK |
1118 | if (!fatal && !buffer_uptodate(bh)) { |
1119 | memset(bh->b_data,0,inode->i_sb->s_blocksize); | |
1120 | set_buffer_uptodate(bh); | |
1121 | } | |
1122 | unlock_buffer(bh); | |
617ba13b MC |
1123 | BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata"); |
1124 | err = ext4_journal_dirty_metadata(handle, bh); | |
ac27a0ec DK |
1125 | if (!fatal) |
1126 | fatal = err; | |
1127 | } else { | |
1128 | BUFFER_TRACE(bh, "not a new buffer"); | |
1129 | } | |
1130 | if (fatal) { | |
1131 | *errp = fatal; | |
1132 | brelse(bh); | |
1133 | bh = NULL; | |
1134 | } | |
1135 | return bh; | |
1136 | } | |
1137 | err: | |
1138 | return NULL; | |
1139 | } | |
1140 | ||
617ba13b | 1141 | struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode, |
725d26d3 | 1142 | ext4_lblk_t block, int create, int *err) |
ac27a0ec DK |
1143 | { |
1144 | struct buffer_head * bh; | |
1145 | ||
617ba13b | 1146 | bh = ext4_getblk(handle, inode, block, create, err); |
ac27a0ec DK |
1147 | if (!bh) |
1148 | return bh; | |
1149 | if (buffer_uptodate(bh)) | |
1150 | return bh; | |
1151 | ll_rw_block(READ_META, 1, &bh); | |
1152 | wait_on_buffer(bh); | |
1153 | if (buffer_uptodate(bh)) | |
1154 | return bh; | |
1155 | put_bh(bh); | |
1156 | *err = -EIO; | |
1157 | return NULL; | |
1158 | } | |
1159 | ||
1160 | static int walk_page_buffers( handle_t *handle, | |
1161 | struct buffer_head *head, | |
1162 | unsigned from, | |
1163 | unsigned to, | |
1164 | int *partial, | |
1165 | int (*fn)( handle_t *handle, | |
1166 | struct buffer_head *bh)) | |
1167 | { | |
1168 | struct buffer_head *bh; | |
1169 | unsigned block_start, block_end; | |
1170 | unsigned blocksize = head->b_size; | |
1171 | int err, ret = 0; | |
1172 | struct buffer_head *next; | |
1173 | ||
1174 | for ( bh = head, block_start = 0; | |
1175 | ret == 0 && (bh != head || !block_start); | |
1176 | block_start = block_end, bh = next) | |
1177 | { | |
1178 | next = bh->b_this_page; | |
1179 | block_end = block_start + blocksize; | |
1180 | if (block_end <= from || block_start >= to) { | |
1181 | if (partial && !buffer_uptodate(bh)) | |
1182 | *partial = 1; | |
1183 | continue; | |
1184 | } | |
1185 | err = (*fn)(handle, bh); | |
1186 | if (!ret) | |
1187 | ret = err; | |
1188 | } | |
1189 | return ret; | |
1190 | } | |
1191 | ||
1192 | /* | |
1193 | * To preserve ordering, it is essential that the hole instantiation and | |
1194 | * the data write be encapsulated in a single transaction. We cannot | |
617ba13b | 1195 | * close off a transaction and start a new one between the ext4_get_block() |
dab291af | 1196 | * and the commit_write(). So doing the jbd2_journal_start at the start of |
ac27a0ec DK |
1197 | * prepare_write() is the right place. |
1198 | * | |
617ba13b MC |
1199 | * Also, this function can nest inside ext4_writepage() -> |
1200 | * block_write_full_page(). In that case, we *know* that ext4_writepage() | |
ac27a0ec DK |
1201 | * has generated enough buffer credits to do the whole page. So we won't |
1202 | * block on the journal in that case, which is good, because the caller may | |
1203 | * be PF_MEMALLOC. | |
1204 | * | |
617ba13b | 1205 | * By accident, ext4 can be reentered when a transaction is open via |
ac27a0ec DK |
1206 | * quota file writes. If we were to commit the transaction while thus |
1207 | * reentered, there can be a deadlock - we would be holding a quota | |
1208 | * lock, and the commit would never complete if another thread had a | |
1209 | * transaction open and was blocking on the quota lock - a ranking | |
1210 | * violation. | |
1211 | * | |
dab291af | 1212 | * So what we do is to rely on the fact that jbd2_journal_stop/journal_start |
ac27a0ec DK |
1213 | * will _not_ run commit under these circumstances because handle->h_ref |
1214 | * is elevated. We'll still have enough credits for the tiny quotafile | |
1215 | * write. | |
1216 | */ | |
1217 | static int do_journal_get_write_access(handle_t *handle, | |
1218 | struct buffer_head *bh) | |
1219 | { | |
1220 | if (!buffer_mapped(bh) || buffer_freed(bh)) | |
1221 | return 0; | |
617ba13b | 1222 | return ext4_journal_get_write_access(handle, bh); |
ac27a0ec DK |
1223 | } |
1224 | ||
bfc1af65 NP |
1225 | static int ext4_write_begin(struct file *file, struct address_space *mapping, |
1226 | loff_t pos, unsigned len, unsigned flags, | |
1227 | struct page **pagep, void **fsdata) | |
ac27a0ec | 1228 | { |
bfc1af65 | 1229 | struct inode *inode = mapping->host; |
7479d2b9 | 1230 | int ret, needed_blocks = ext4_writepage_trans_blocks(inode); |
ac27a0ec DK |
1231 | handle_t *handle; |
1232 | int retries = 0; | |
bfc1af65 NP |
1233 | struct page *page; |
1234 | pgoff_t index; | |
1235 | unsigned from, to; | |
1236 | ||
1237 | index = pos >> PAGE_CACHE_SHIFT; | |
1238 | from = pos & (PAGE_CACHE_SIZE - 1); | |
1239 | to = from + len; | |
ac27a0ec DK |
1240 | |
1241 | retry: | |
bfc1af65 NP |
1242 | handle = ext4_journal_start(inode, needed_blocks); |
1243 | if (IS_ERR(handle)) { | |
bfc1af65 NP |
1244 | ret = PTR_ERR(handle); |
1245 | goto out; | |
7479d2b9 | 1246 | } |
ac27a0ec | 1247 | |
cf108bca JK |
1248 | page = __grab_cache_page(mapping, index); |
1249 | if (!page) { | |
1250 | ext4_journal_stop(handle); | |
1251 | ret = -ENOMEM; | |
1252 | goto out; | |
1253 | } | |
1254 | *pagep = page; | |
1255 | ||
bfc1af65 NP |
1256 | ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, |
1257 | ext4_get_block); | |
1258 | ||
1259 | if (!ret && ext4_should_journal_data(inode)) { | |
ac27a0ec DK |
1260 | ret = walk_page_buffers(handle, page_buffers(page), |
1261 | from, to, NULL, do_journal_get_write_access); | |
1262 | } | |
bfc1af65 NP |
1263 | |
1264 | if (ret) { | |
bfc1af65 | 1265 | unlock_page(page); |
cf108bca | 1266 | ext4_journal_stop(handle); |
bfc1af65 NP |
1267 | page_cache_release(page); |
1268 | } | |
1269 | ||
617ba13b | 1270 | if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) |
ac27a0ec | 1271 | goto retry; |
7479d2b9 | 1272 | out: |
ac27a0ec DK |
1273 | return ret; |
1274 | } | |
1275 | ||
617ba13b | 1276 | int ext4_journal_dirty_data(handle_t *handle, struct buffer_head *bh) |
ac27a0ec | 1277 | { |
dab291af | 1278 | int err = jbd2_journal_dirty_data(handle, bh); |
ac27a0ec | 1279 | if (err) |
46e665e9 | 1280 | ext4_journal_abort_handle(__func__, __func__, |
bfc1af65 | 1281 | bh, handle, err); |
ac27a0ec DK |
1282 | return err; |
1283 | } | |
1284 | ||
bfc1af65 NP |
1285 | /* For write_end() in data=journal mode */ |
1286 | static int write_end_fn(handle_t *handle, struct buffer_head *bh) | |
ac27a0ec DK |
1287 | { |
1288 | if (!buffer_mapped(bh) || buffer_freed(bh)) | |
1289 | return 0; | |
1290 | set_buffer_uptodate(bh); | |
617ba13b | 1291 | return ext4_journal_dirty_metadata(handle, bh); |
ac27a0ec DK |
1292 | } |
1293 | ||
1294 | /* | |
1295 | * We need to pick up the new inode size which generic_commit_write gave us | |
1296 | * `file' can be NULL - eg, when called from page_symlink(). | |
1297 | * | |
617ba13b | 1298 | * ext4 never places buffers on inode->i_mapping->private_list. metadata |
ac27a0ec DK |
1299 | * buffers are managed internally. |
1300 | */ | |
bfc1af65 NP |
1301 | static int ext4_ordered_write_end(struct file *file, |
1302 | struct address_space *mapping, | |
1303 | loff_t pos, unsigned len, unsigned copied, | |
1304 | struct page *page, void *fsdata) | |
ac27a0ec | 1305 | { |
617ba13b | 1306 | handle_t *handle = ext4_journal_current_handle(); |
cf108bca | 1307 | struct inode *inode = mapping->host; |
bfc1af65 | 1308 | unsigned from, to; |
ac27a0ec DK |
1309 | int ret = 0, ret2; |
1310 | ||
bfc1af65 NP |
1311 | from = pos & (PAGE_CACHE_SIZE - 1); |
1312 | to = from + len; | |
1313 | ||
ac27a0ec | 1314 | ret = walk_page_buffers(handle, page_buffers(page), |
617ba13b | 1315 | from, to, NULL, ext4_journal_dirty_data); |
ac27a0ec DK |
1316 | |
1317 | if (ret == 0) { | |
1318 | /* | |
bfc1af65 | 1319 | * generic_write_end() will run mark_inode_dirty() if i_size |
ac27a0ec DK |
1320 | * changes. So let's piggyback the i_disksize mark_inode_dirty |
1321 | * into that. | |
1322 | */ | |
1323 | loff_t new_i_size; | |
1324 | ||
bfc1af65 | 1325 | new_i_size = pos + copied; |
617ba13b MC |
1326 | if (new_i_size > EXT4_I(inode)->i_disksize) |
1327 | EXT4_I(inode)->i_disksize = new_i_size; | |
cf108bca | 1328 | ret2 = generic_write_end(file, mapping, pos, len, copied, |
bfc1af65 | 1329 | page, fsdata); |
f8a87d89 RK |
1330 | copied = ret2; |
1331 | if (ret2 < 0) | |
1332 | ret = ret2; | |
ac27a0ec | 1333 | } |
617ba13b | 1334 | ret2 = ext4_journal_stop(handle); |
ac27a0ec DK |
1335 | if (!ret) |
1336 | ret = ret2; | |
bfc1af65 NP |
1337 | |
1338 | return ret ? ret : copied; | |
ac27a0ec DK |
1339 | } |
1340 | ||
bfc1af65 NP |
1341 | static int ext4_writeback_write_end(struct file *file, |
1342 | struct address_space *mapping, | |
1343 | loff_t pos, unsigned len, unsigned copied, | |
1344 | struct page *page, void *fsdata) | |
ac27a0ec | 1345 | { |
617ba13b | 1346 | handle_t *handle = ext4_journal_current_handle(); |
cf108bca | 1347 | struct inode *inode = mapping->host; |
ac27a0ec DK |
1348 | int ret = 0, ret2; |
1349 | loff_t new_i_size; | |
1350 | ||
bfc1af65 | 1351 | new_i_size = pos + copied; |
617ba13b MC |
1352 | if (new_i_size > EXT4_I(inode)->i_disksize) |
1353 | EXT4_I(inode)->i_disksize = new_i_size; | |
ac27a0ec | 1354 | |
cf108bca | 1355 | ret2 = generic_write_end(file, mapping, pos, len, copied, |
bfc1af65 | 1356 | page, fsdata); |
f8a87d89 RK |
1357 | copied = ret2; |
1358 | if (ret2 < 0) | |
1359 | ret = ret2; | |
ac27a0ec | 1360 | |
617ba13b | 1361 | ret2 = ext4_journal_stop(handle); |
ac27a0ec DK |
1362 | if (!ret) |
1363 | ret = ret2; | |
bfc1af65 NP |
1364 | |
1365 | return ret ? ret : copied; | |
ac27a0ec DK |
1366 | } |
1367 | ||
bfc1af65 NP |
1368 | static int ext4_journalled_write_end(struct file *file, |
1369 | struct address_space *mapping, | |
1370 | loff_t pos, unsigned len, unsigned copied, | |
1371 | struct page *page, void *fsdata) | |
ac27a0ec | 1372 | { |
617ba13b | 1373 | handle_t *handle = ext4_journal_current_handle(); |
bfc1af65 | 1374 | struct inode *inode = mapping->host; |
ac27a0ec DK |
1375 | int ret = 0, ret2; |
1376 | int partial = 0; | |
bfc1af65 | 1377 | unsigned from, to; |
ac27a0ec | 1378 | |
bfc1af65 NP |
1379 | from = pos & (PAGE_CACHE_SIZE - 1); |
1380 | to = from + len; | |
1381 | ||
1382 | if (copied < len) { | |
1383 | if (!PageUptodate(page)) | |
1384 | copied = 0; | |
1385 | page_zero_new_buffers(page, from+copied, to); | |
1386 | } | |
ac27a0ec DK |
1387 | |
1388 | ret = walk_page_buffers(handle, page_buffers(page), from, | |
bfc1af65 | 1389 | to, &partial, write_end_fn); |
ac27a0ec DK |
1390 | if (!partial) |
1391 | SetPageUptodate(page); | |
bfc1af65 NP |
1392 | if (pos+copied > inode->i_size) |
1393 | i_size_write(inode, pos+copied); | |
617ba13b MC |
1394 | EXT4_I(inode)->i_state |= EXT4_STATE_JDATA; |
1395 | if (inode->i_size > EXT4_I(inode)->i_disksize) { | |
1396 | EXT4_I(inode)->i_disksize = inode->i_size; | |
1397 | ret2 = ext4_mark_inode_dirty(handle, inode); | |
ac27a0ec DK |
1398 | if (!ret) |
1399 | ret = ret2; | |
1400 | } | |
bfc1af65 | 1401 | |
cf108bca | 1402 | unlock_page(page); |
617ba13b | 1403 | ret2 = ext4_journal_stop(handle); |
ac27a0ec DK |
1404 | if (!ret) |
1405 | ret = ret2; | |
bfc1af65 NP |
1406 | page_cache_release(page); |
1407 | ||
1408 | return ret ? ret : copied; | |
ac27a0ec DK |
1409 | } |
1410 | ||
1411 | /* | |
1412 | * bmap() is special. It gets used by applications such as lilo and by | |
1413 | * the swapper to find the on-disk block of a specific piece of data. | |
1414 | * | |
1415 | * Naturally, this is dangerous if the block concerned is still in the | |
617ba13b | 1416 | * journal. If somebody makes a swapfile on an ext4 data-journaling |
ac27a0ec DK |
1417 | * filesystem and enables swap, then they may get a nasty shock when the |
1418 | * data getting swapped to that swapfile suddenly gets overwritten by | |
1419 | * the original zero's written out previously to the journal and | |
1420 | * awaiting writeback in the kernel's buffer cache. | |
1421 | * | |
1422 | * So, if we see any bmap calls here on a modified, data-journaled file, | |
1423 | * take extra steps to flush any blocks which might be in the cache. | |
1424 | */ | |
617ba13b | 1425 | static sector_t ext4_bmap(struct address_space *mapping, sector_t block) |
ac27a0ec DK |
1426 | { |
1427 | struct inode *inode = mapping->host; | |
1428 | journal_t *journal; | |
1429 | int err; | |
1430 | ||
617ba13b | 1431 | if (EXT4_I(inode)->i_state & EXT4_STATE_JDATA) { |
ac27a0ec DK |
1432 | /* |
1433 | * This is a REALLY heavyweight approach, but the use of | |
1434 | * bmap on dirty files is expected to be extremely rare: | |
1435 | * only if we run lilo or swapon on a freshly made file | |
1436 | * do we expect this to happen. | |
1437 | * | |
1438 | * (bmap requires CAP_SYS_RAWIO so this does not | |
1439 | * represent an unprivileged user DOS attack --- we'd be | |
1440 | * in trouble if mortal users could trigger this path at | |
1441 | * will.) | |
1442 | * | |
617ba13b | 1443 | * NB. EXT4_STATE_JDATA is not set on files other than |
ac27a0ec DK |
1444 | * regular files. If somebody wants to bmap a directory |
1445 | * or symlink and gets confused because the buffer | |
1446 | * hasn't yet been flushed to disk, they deserve | |
1447 | * everything they get. | |
1448 | */ | |
1449 | ||
617ba13b MC |
1450 | EXT4_I(inode)->i_state &= ~EXT4_STATE_JDATA; |
1451 | journal = EXT4_JOURNAL(inode); | |
dab291af MC |
1452 | jbd2_journal_lock_updates(journal); |
1453 | err = jbd2_journal_flush(journal); | |
1454 | jbd2_journal_unlock_updates(journal); | |
ac27a0ec DK |
1455 | |
1456 | if (err) | |
1457 | return 0; | |
1458 | } | |
1459 | ||
617ba13b | 1460 | return generic_block_bmap(mapping,block,ext4_get_block); |
ac27a0ec DK |
1461 | } |
1462 | ||
1463 | static int bget_one(handle_t *handle, struct buffer_head *bh) | |
1464 | { | |
1465 | get_bh(bh); | |
1466 | return 0; | |
1467 | } | |
1468 | ||
1469 | static int bput_one(handle_t *handle, struct buffer_head *bh) | |
1470 | { | |
1471 | put_bh(bh); | |
1472 | return 0; | |
1473 | } | |
1474 | ||
dab291af | 1475 | static int jbd2_journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh) |
ac27a0ec DK |
1476 | { |
1477 | if (buffer_mapped(bh)) | |
617ba13b | 1478 | return ext4_journal_dirty_data(handle, bh); |
ac27a0ec DK |
1479 | return 0; |
1480 | } | |
1481 | ||
cf108bca JK |
1482 | static int ext4_bh_unmapped_or_delay(handle_t *handle, struct buffer_head *bh) |
1483 | { | |
1484 | return !buffer_mapped(bh) || buffer_delay(bh); | |
1485 | } | |
1486 | ||
ac27a0ec | 1487 | /* |
cf108bca JK |
1488 | * Note that we don't need to start a transaction unless we're journaling |
1489 | * data because we should have holes filled from ext4_page_mkwrite(). If | |
1490 | * we are journaling data, we cannot start transaction directly because | |
1491 | * transaction start ranks above page lock so we have to do some magic... | |
ac27a0ec DK |
1492 | * |
1493 | * In all journalling modes block_write_full_page() will start the I/O. | |
1494 | * | |
1495 | * Problem: | |
1496 | * | |
617ba13b MC |
1497 | * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() -> |
1498 | * ext4_writepage() | |
ac27a0ec DK |
1499 | * |
1500 | * Similar for: | |
1501 | * | |
617ba13b | 1502 | * ext4_file_write() -> generic_file_write() -> __alloc_pages() -> ... |
ac27a0ec | 1503 | * |
617ba13b | 1504 | * Same applies to ext4_get_block(). We will deadlock on various things like |
0e855ac8 | 1505 | * lock_journal and i_data_sem |
ac27a0ec DK |
1506 | * |
1507 | * Setting PF_MEMALLOC here doesn't work - too many internal memory | |
1508 | * allocations fail. | |
1509 | * | |
1510 | * 16May01: If we're reentered then journal_current_handle() will be | |
1511 | * non-zero. We simply *return*. | |
1512 | * | |
1513 | * 1 July 2001: @@@ FIXME: | |
1514 | * In journalled data mode, a data buffer may be metadata against the | |
1515 | * current transaction. But the same file is part of a shared mapping | |
1516 | * and someone does a writepage() on it. | |
1517 | * | |
1518 | * We will move the buffer onto the async_data list, but *after* it has | |
1519 | * been dirtied. So there's a small window where we have dirty data on | |
1520 | * BJ_Metadata. | |
1521 | * | |
1522 | * Note that this only applies to the last partial page in the file. The | |
1523 | * bit which block_write_full_page() uses prepare/commit for. (That's | |
1524 | * broken code anyway: it's wrong for msync()). | |
1525 | * | |
1526 | * It's a rare case: affects the final partial page, for journalled data | |
1527 | * where the file is subject to bith write() and writepage() in the same | |
1528 | * transction. To fix it we'll need a custom block_write_full_page(). | |
1529 | * We'll probably need that anyway for journalling writepage() output. | |
1530 | * | |
1531 | * We don't honour synchronous mounts for writepage(). That would be | |
1532 | * disastrous. Any write() or metadata operation will sync the fs for | |
1533 | * us. | |
1534 | * | |
ac27a0ec | 1535 | */ |
cf108bca | 1536 | static int __ext4_ordered_writepage(struct page *page, |
ac27a0ec DK |
1537 | struct writeback_control *wbc) |
1538 | { | |
1539 | struct inode *inode = page->mapping->host; | |
1540 | struct buffer_head *page_bufs; | |
1541 | handle_t *handle = NULL; | |
1542 | int ret = 0; | |
1543 | int err; | |
1544 | ||
ac27a0ec DK |
1545 | if (!page_has_buffers(page)) { |
1546 | create_empty_buffers(page, inode->i_sb->s_blocksize, | |
1547 | (1 << BH_Dirty)|(1 << BH_Uptodate)); | |
1548 | } | |
1549 | page_bufs = page_buffers(page); | |
1550 | walk_page_buffers(handle, page_bufs, 0, | |
1551 | PAGE_CACHE_SIZE, NULL, bget_one); | |
1552 | ||
617ba13b | 1553 | ret = block_write_full_page(page, ext4_get_block, wbc); |
ac27a0ec DK |
1554 | |
1555 | /* | |
1556 | * The page can become unlocked at any point now, and | |
1557 | * truncate can then come in and change things. So we | |
1558 | * can't touch *page from now on. But *page_bufs is | |
1559 | * safe due to elevated refcount. | |
1560 | */ | |
1561 | ||
1562 | /* | |
1563 | * And attach them to the current transaction. But only if | |
1564 | * block_write_full_page() succeeded. Otherwise they are unmapped, | |
1565 | * and generally junk. | |
1566 | */ | |
1567 | if (ret == 0) { | |
cf108bca JK |
1568 | handle = ext4_journal_start(inode, |
1569 | ext4_writepage_trans_blocks(inode)); | |
1570 | if (IS_ERR(handle)) { | |
1571 | ret = PTR_ERR(handle); | |
1572 | goto out_put; | |
1573 | } | |
1574 | ||
1575 | ret = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE, | |
dab291af | 1576 | NULL, jbd2_journal_dirty_data_fn); |
cf108bca | 1577 | err = ext4_journal_stop(handle); |
ac27a0ec DK |
1578 | if (!ret) |
1579 | ret = err; | |
1580 | } | |
cf108bca JK |
1581 | out_put: |
1582 | walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE, NULL, | |
1583 | bput_one); | |
ac27a0ec | 1584 | return ret; |
cf108bca JK |
1585 | } |
1586 | ||
1587 | static int ext4_ordered_writepage(struct page *page, | |
1588 | struct writeback_control *wbc) | |
1589 | { | |
1590 | struct inode *inode = page->mapping->host; | |
1591 | loff_t size = i_size_read(inode); | |
1592 | loff_t len; | |
1593 | ||
1594 | J_ASSERT(PageLocked(page)); | |
1595 | J_ASSERT(page_has_buffers(page)); | |
1596 | if (page->index == size >> PAGE_CACHE_SHIFT) | |
1597 | len = size & ~PAGE_CACHE_MASK; | |
1598 | else | |
1599 | len = PAGE_CACHE_SIZE; | |
1600 | BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL, | |
1601 | ext4_bh_unmapped_or_delay)); | |
1602 | ||
1603 | /* | |
1604 | * We give up here if we're reentered, because it might be for a | |
1605 | * different filesystem. | |
1606 | */ | |
1607 | if (!ext4_journal_current_handle()) | |
1608 | return __ext4_ordered_writepage(page, wbc); | |
ac27a0ec | 1609 | |
ac27a0ec DK |
1610 | redirty_page_for_writepage(wbc, page); |
1611 | unlock_page(page); | |
cf108bca | 1612 | return 0; |
ac27a0ec DK |
1613 | } |
1614 | ||
cf108bca JK |
1615 | static int __ext4_writeback_writepage(struct page *page, |
1616 | struct writeback_control *wbc) | |
1617 | { | |
1618 | struct inode *inode = page->mapping->host; | |
1619 | ||
1620 | if (test_opt(inode->i_sb, NOBH)) | |
1621 | return nobh_writepage(page, ext4_get_block, wbc); | |
1622 | else | |
1623 | return block_write_full_page(page, ext4_get_block, wbc); | |
1624 | } | |
1625 | ||
1626 | ||
617ba13b | 1627 | static int ext4_writeback_writepage(struct page *page, |
ac27a0ec DK |
1628 | struct writeback_control *wbc) |
1629 | { | |
1630 | struct inode *inode = page->mapping->host; | |
cf108bca JK |
1631 | loff_t size = i_size_read(inode); |
1632 | loff_t len; | |
1633 | ||
1634 | J_ASSERT(PageLocked(page)); | |
1635 | J_ASSERT(page_has_buffers(page)); | |
1636 | if (page->index == size >> PAGE_CACHE_SHIFT) | |
1637 | len = size & ~PAGE_CACHE_MASK; | |
1638 | else | |
1639 | len = PAGE_CACHE_SIZE; | |
1640 | BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL, | |
1641 | ext4_bh_unmapped_or_delay)); | |
1642 | ||
1643 | if (!ext4_journal_current_handle()) | |
1644 | return __ext4_writeback_writepage(page, wbc); | |
1645 | ||
1646 | redirty_page_for_writepage(wbc, page); | |
1647 | unlock_page(page); | |
1648 | return 0; | |
1649 | } | |
1650 | ||
1651 | static int __ext4_journalled_writepage(struct page *page, | |
1652 | struct writeback_control *wbc) | |
1653 | { | |
1654 | struct address_space *mapping = page->mapping; | |
1655 | struct inode *inode = mapping->host; | |
1656 | struct buffer_head *page_bufs; | |
ac27a0ec DK |
1657 | handle_t *handle = NULL; |
1658 | int ret = 0; | |
1659 | int err; | |
1660 | ||
cf108bca JK |
1661 | ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE, ext4_get_block); |
1662 | if (ret != 0) | |
1663 | goto out_unlock; | |
1664 | ||
1665 | page_bufs = page_buffers(page); | |
1666 | walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE, NULL, | |
1667 | bget_one); | |
1668 | /* As soon as we unlock the page, it can go away, but we have | |
1669 | * references to buffers so we are safe */ | |
1670 | unlock_page(page); | |
ac27a0ec | 1671 | |
617ba13b | 1672 | handle = ext4_journal_start(inode, ext4_writepage_trans_blocks(inode)); |
ac27a0ec DK |
1673 | if (IS_ERR(handle)) { |
1674 | ret = PTR_ERR(handle); | |
cf108bca | 1675 | goto out; |
ac27a0ec DK |
1676 | } |
1677 | ||
cf108bca JK |
1678 | ret = walk_page_buffers(handle, page_bufs, 0, |
1679 | PAGE_CACHE_SIZE, NULL, do_journal_get_write_access); | |
ac27a0ec | 1680 | |
cf108bca JK |
1681 | err = walk_page_buffers(handle, page_bufs, 0, |
1682 | PAGE_CACHE_SIZE, NULL, write_end_fn); | |
1683 | if (ret == 0) | |
1684 | ret = err; | |
617ba13b | 1685 | err = ext4_journal_stop(handle); |
ac27a0ec DK |
1686 | if (!ret) |
1687 | ret = err; | |
ac27a0ec | 1688 | |
cf108bca JK |
1689 | walk_page_buffers(handle, page_bufs, 0, |
1690 | PAGE_CACHE_SIZE, NULL, bput_one); | |
1691 | EXT4_I(inode)->i_state |= EXT4_STATE_JDATA; | |
1692 | goto out; | |
1693 | ||
1694 | out_unlock: | |
ac27a0ec | 1695 | unlock_page(page); |
cf108bca | 1696 | out: |
ac27a0ec DK |
1697 | return ret; |
1698 | } | |
1699 | ||
617ba13b | 1700 | static int ext4_journalled_writepage(struct page *page, |
ac27a0ec DK |
1701 | struct writeback_control *wbc) |
1702 | { | |
1703 | struct inode *inode = page->mapping->host; | |
cf108bca JK |
1704 | loff_t size = i_size_read(inode); |
1705 | loff_t len; | |
ac27a0ec | 1706 | |
cf108bca JK |
1707 | J_ASSERT(PageLocked(page)); |
1708 | J_ASSERT(page_has_buffers(page)); | |
1709 | if (page->index == size >> PAGE_CACHE_SHIFT) | |
1710 | len = size & ~PAGE_CACHE_MASK; | |
1711 | else | |
1712 | len = PAGE_CACHE_SIZE; | |
1713 | BUG_ON(walk_page_buffers(NULL, page_buffers(page), 0, len, NULL, | |
1714 | ext4_bh_unmapped_or_delay)); | |
ac27a0ec | 1715 | |
cf108bca | 1716 | if (ext4_journal_current_handle()) |
ac27a0ec | 1717 | goto no_write; |
ac27a0ec | 1718 | |
cf108bca | 1719 | if (PageChecked(page)) { |
ac27a0ec DK |
1720 | /* |
1721 | * It's mmapped pagecache. Add buffers and journal it. There | |
1722 | * doesn't seem much point in redirtying the page here. | |
1723 | */ | |
1724 | ClearPageChecked(page); | |
cf108bca | 1725 | return __ext4_journalled_writepage(page, wbc); |
ac27a0ec DK |
1726 | } else { |
1727 | /* | |
1728 | * It may be a page full of checkpoint-mode buffers. We don't | |
1729 | * really know unless we go poke around in the buffer_heads. | |
1730 | * But block_write_full_page will do the right thing. | |
1731 | */ | |
cf108bca | 1732 | return block_write_full_page(page, ext4_get_block, wbc); |
ac27a0ec | 1733 | } |
ac27a0ec DK |
1734 | no_write: |
1735 | redirty_page_for_writepage(wbc, page); | |
ac27a0ec | 1736 | unlock_page(page); |
cf108bca | 1737 | return 0; |
ac27a0ec DK |
1738 | } |
1739 | ||
617ba13b | 1740 | static int ext4_readpage(struct file *file, struct page *page) |
ac27a0ec | 1741 | { |
617ba13b | 1742 | return mpage_readpage(page, ext4_get_block); |
ac27a0ec DK |
1743 | } |
1744 | ||
1745 | static int | |
617ba13b | 1746 | ext4_readpages(struct file *file, struct address_space *mapping, |
ac27a0ec DK |
1747 | struct list_head *pages, unsigned nr_pages) |
1748 | { | |
617ba13b | 1749 | return mpage_readpages(mapping, pages, nr_pages, ext4_get_block); |
ac27a0ec DK |
1750 | } |
1751 | ||
617ba13b | 1752 | static void ext4_invalidatepage(struct page *page, unsigned long offset) |
ac27a0ec | 1753 | { |
617ba13b | 1754 | journal_t *journal = EXT4_JOURNAL(page->mapping->host); |
ac27a0ec DK |
1755 | |
1756 | /* | |
1757 | * If it's a full truncate we just forget about the pending dirtying | |
1758 | */ | |
1759 | if (offset == 0) | |
1760 | ClearPageChecked(page); | |
1761 | ||
dab291af | 1762 | jbd2_journal_invalidatepage(journal, page, offset); |
ac27a0ec DK |
1763 | } |
1764 | ||
617ba13b | 1765 | static int ext4_releasepage(struct page *page, gfp_t wait) |
ac27a0ec | 1766 | { |
617ba13b | 1767 | journal_t *journal = EXT4_JOURNAL(page->mapping->host); |
ac27a0ec DK |
1768 | |
1769 | WARN_ON(PageChecked(page)); | |
1770 | if (!page_has_buffers(page)) | |
1771 | return 0; | |
dab291af | 1772 | return jbd2_journal_try_to_free_buffers(journal, page, wait); |
ac27a0ec DK |
1773 | } |
1774 | ||
1775 | /* | |
1776 | * If the O_DIRECT write will extend the file then add this inode to the | |
1777 | * orphan list. So recovery will truncate it back to the original size | |
1778 | * if the machine crashes during the write. | |
1779 | * | |
1780 | * If the O_DIRECT write is intantiating holes inside i_size and the machine | |
7fb5409d JK |
1781 | * crashes then stale disk data _may_ be exposed inside the file. But current |
1782 | * VFS code falls back into buffered path in that case so we are safe. | |
ac27a0ec | 1783 | */ |
617ba13b | 1784 | static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb, |
ac27a0ec DK |
1785 | const struct iovec *iov, loff_t offset, |
1786 | unsigned long nr_segs) | |
1787 | { | |
1788 | struct file *file = iocb->ki_filp; | |
1789 | struct inode *inode = file->f_mapping->host; | |
617ba13b | 1790 | struct ext4_inode_info *ei = EXT4_I(inode); |
7fb5409d | 1791 | handle_t *handle; |
ac27a0ec DK |
1792 | ssize_t ret; |
1793 | int orphan = 0; | |
1794 | size_t count = iov_length(iov, nr_segs); | |
1795 | ||
1796 | if (rw == WRITE) { | |
1797 | loff_t final_size = offset + count; | |
1798 | ||
ac27a0ec | 1799 | if (final_size > inode->i_size) { |
7fb5409d JK |
1800 | /* Credits for sb + inode write */ |
1801 | handle = ext4_journal_start(inode, 2); | |
1802 | if (IS_ERR(handle)) { | |
1803 | ret = PTR_ERR(handle); | |
1804 | goto out; | |
1805 | } | |
617ba13b | 1806 | ret = ext4_orphan_add(handle, inode); |
7fb5409d JK |
1807 | if (ret) { |
1808 | ext4_journal_stop(handle); | |
1809 | goto out; | |
1810 | } | |
ac27a0ec DK |
1811 | orphan = 1; |
1812 | ei->i_disksize = inode->i_size; | |
7fb5409d | 1813 | ext4_journal_stop(handle); |
ac27a0ec DK |
1814 | } |
1815 | } | |
1816 | ||
1817 | ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, | |
1818 | offset, nr_segs, | |
617ba13b | 1819 | ext4_get_block, NULL); |
ac27a0ec | 1820 | |
7fb5409d | 1821 | if (orphan) { |
ac27a0ec DK |
1822 | int err; |
1823 | ||
7fb5409d JK |
1824 | /* Credits for sb + inode write */ |
1825 | handle = ext4_journal_start(inode, 2); | |
1826 | if (IS_ERR(handle)) { | |
1827 | /* This is really bad luck. We've written the data | |
1828 | * but cannot extend i_size. Bail out and pretend | |
1829 | * the write failed... */ | |
1830 | ret = PTR_ERR(handle); | |
1831 | goto out; | |
1832 | } | |
1833 | if (inode->i_nlink) | |
617ba13b | 1834 | ext4_orphan_del(handle, inode); |
7fb5409d | 1835 | if (ret > 0) { |
ac27a0ec DK |
1836 | loff_t end = offset + ret; |
1837 | if (end > inode->i_size) { | |
1838 | ei->i_disksize = end; | |
1839 | i_size_write(inode, end); | |
1840 | /* | |
1841 | * We're going to return a positive `ret' | |
1842 | * here due to non-zero-length I/O, so there's | |
1843 | * no way of reporting error returns from | |
617ba13b | 1844 | * ext4_mark_inode_dirty() to userspace. So |
ac27a0ec DK |
1845 | * ignore it. |
1846 | */ | |
617ba13b | 1847 | ext4_mark_inode_dirty(handle, inode); |
ac27a0ec DK |
1848 | } |
1849 | } | |
617ba13b | 1850 | err = ext4_journal_stop(handle); |
ac27a0ec DK |
1851 | if (ret == 0) |
1852 | ret = err; | |
1853 | } | |
1854 | out: | |
1855 | return ret; | |
1856 | } | |
1857 | ||
1858 | /* | |
617ba13b | 1859 | * Pages can be marked dirty completely asynchronously from ext4's journalling |
ac27a0ec DK |
1860 | * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do |
1861 | * much here because ->set_page_dirty is called under VFS locks. The page is | |
1862 | * not necessarily locked. | |
1863 | * | |
1864 | * We cannot just dirty the page and leave attached buffers clean, because the | |
1865 | * buffers' dirty state is "definitive". We cannot just set the buffers dirty | |
1866 | * or jbddirty because all the journalling code will explode. | |
1867 | * | |
1868 | * So what we do is to mark the page "pending dirty" and next time writepage | |
1869 | * is called, propagate that into the buffers appropriately. | |
1870 | */ | |
617ba13b | 1871 | static int ext4_journalled_set_page_dirty(struct page *page) |
ac27a0ec DK |
1872 | { |
1873 | SetPageChecked(page); | |
1874 | return __set_page_dirty_nobuffers(page); | |
1875 | } | |
1876 | ||
617ba13b MC |
1877 | static const struct address_space_operations ext4_ordered_aops = { |
1878 | .readpage = ext4_readpage, | |
1879 | .readpages = ext4_readpages, | |
1880 | .writepage = ext4_ordered_writepage, | |
ac27a0ec | 1881 | .sync_page = block_sync_page, |
bfc1af65 NP |
1882 | .write_begin = ext4_write_begin, |
1883 | .write_end = ext4_ordered_write_end, | |
617ba13b MC |
1884 | .bmap = ext4_bmap, |
1885 | .invalidatepage = ext4_invalidatepage, | |
1886 | .releasepage = ext4_releasepage, | |
1887 | .direct_IO = ext4_direct_IO, | |
ac27a0ec DK |
1888 | .migratepage = buffer_migrate_page, |
1889 | }; | |
1890 | ||
617ba13b MC |
1891 | static const struct address_space_operations ext4_writeback_aops = { |
1892 | .readpage = ext4_readpage, | |
1893 | .readpages = ext4_readpages, | |
1894 | .writepage = ext4_writeback_writepage, | |
ac27a0ec | 1895 | .sync_page = block_sync_page, |
bfc1af65 NP |
1896 | .write_begin = ext4_write_begin, |
1897 | .write_end = ext4_writeback_write_end, | |
617ba13b MC |
1898 | .bmap = ext4_bmap, |
1899 | .invalidatepage = ext4_invalidatepage, | |
1900 | .releasepage = ext4_releasepage, | |
1901 | .direct_IO = ext4_direct_IO, | |
ac27a0ec DK |
1902 | .migratepage = buffer_migrate_page, |
1903 | }; | |
1904 | ||
617ba13b MC |
1905 | static const struct address_space_operations ext4_journalled_aops = { |
1906 | .readpage = ext4_readpage, | |
1907 | .readpages = ext4_readpages, | |
1908 | .writepage = ext4_journalled_writepage, | |
ac27a0ec | 1909 | .sync_page = block_sync_page, |
bfc1af65 NP |
1910 | .write_begin = ext4_write_begin, |
1911 | .write_end = ext4_journalled_write_end, | |
617ba13b MC |
1912 | .set_page_dirty = ext4_journalled_set_page_dirty, |
1913 | .bmap = ext4_bmap, | |
1914 | .invalidatepage = ext4_invalidatepage, | |
1915 | .releasepage = ext4_releasepage, | |
ac27a0ec DK |
1916 | }; |
1917 | ||
617ba13b | 1918 | void ext4_set_aops(struct inode *inode) |
ac27a0ec | 1919 | { |
617ba13b MC |
1920 | if (ext4_should_order_data(inode)) |
1921 | inode->i_mapping->a_ops = &ext4_ordered_aops; | |
1922 | else if (ext4_should_writeback_data(inode)) | |
1923 | inode->i_mapping->a_ops = &ext4_writeback_aops; | |
ac27a0ec | 1924 | else |
617ba13b | 1925 | inode->i_mapping->a_ops = &ext4_journalled_aops; |
ac27a0ec DK |
1926 | } |
1927 | ||
1928 | /* | |
617ba13b | 1929 | * ext4_block_truncate_page() zeroes out a mapping from file offset `from' |
ac27a0ec DK |
1930 | * up to the end of the block which corresponds to `from'. |
1931 | * This required during truncate. We need to physically zero the tail end | |
1932 | * of that block so it doesn't yield old data if the file is later grown. | |
1933 | */ | |
cf108bca | 1934 | int ext4_block_truncate_page(handle_t *handle, |
ac27a0ec DK |
1935 | struct address_space *mapping, loff_t from) |
1936 | { | |
617ba13b | 1937 | ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT; |
ac27a0ec | 1938 | unsigned offset = from & (PAGE_CACHE_SIZE-1); |
725d26d3 AK |
1939 | unsigned blocksize, length, pos; |
1940 | ext4_lblk_t iblock; | |
ac27a0ec DK |
1941 | struct inode *inode = mapping->host; |
1942 | struct buffer_head *bh; | |
cf108bca | 1943 | struct page *page; |
ac27a0ec | 1944 | int err = 0; |
ac27a0ec | 1945 | |
cf108bca JK |
1946 | page = grab_cache_page(mapping, from >> PAGE_CACHE_SHIFT); |
1947 | if (!page) | |
1948 | return -EINVAL; | |
1949 | ||
ac27a0ec DK |
1950 | blocksize = inode->i_sb->s_blocksize; |
1951 | length = blocksize - (offset & (blocksize - 1)); | |
1952 | iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); | |
1953 | ||
1954 | /* | |
1955 | * For "nobh" option, we can only work if we don't need to | |
1956 | * read-in the page - otherwise we create buffers to do the IO. | |
1957 | */ | |
1958 | if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) && | |
617ba13b | 1959 | ext4_should_writeback_data(inode) && PageUptodate(page)) { |
eebd2aa3 | 1960 | zero_user(page, offset, length); |
ac27a0ec DK |
1961 | set_page_dirty(page); |
1962 | goto unlock; | |
1963 | } | |
1964 | ||
1965 | if (!page_has_buffers(page)) | |
1966 | create_empty_buffers(page, blocksize, 0); | |
1967 | ||
1968 | /* Find the buffer that contains "offset" */ | |
1969 | bh = page_buffers(page); | |
1970 | pos = blocksize; | |
1971 | while (offset >= pos) { | |
1972 | bh = bh->b_this_page; | |
1973 | iblock++; | |
1974 | pos += blocksize; | |
1975 | } | |
1976 | ||
1977 | err = 0; | |
1978 | if (buffer_freed(bh)) { | |
1979 | BUFFER_TRACE(bh, "freed: skip"); | |
1980 | goto unlock; | |
1981 | } | |
1982 | ||
1983 | if (!buffer_mapped(bh)) { | |
1984 | BUFFER_TRACE(bh, "unmapped"); | |
617ba13b | 1985 | ext4_get_block(inode, iblock, bh, 0); |
ac27a0ec DK |
1986 | /* unmapped? It's a hole - nothing to do */ |
1987 | if (!buffer_mapped(bh)) { | |
1988 | BUFFER_TRACE(bh, "still unmapped"); | |
1989 | goto unlock; | |
1990 | } | |
1991 | } | |
1992 | ||
1993 | /* Ok, it's mapped. Make sure it's up-to-date */ | |
1994 | if (PageUptodate(page)) | |
1995 | set_buffer_uptodate(bh); | |
1996 | ||
1997 | if (!buffer_uptodate(bh)) { | |
1998 | err = -EIO; | |
1999 | ll_rw_block(READ, 1, &bh); | |
2000 | wait_on_buffer(bh); | |
2001 | /* Uhhuh. Read error. Complain and punt. */ | |
2002 | if (!buffer_uptodate(bh)) | |
2003 | goto unlock; | |
2004 | } | |
2005 | ||
617ba13b | 2006 | if (ext4_should_journal_data(inode)) { |
ac27a0ec | 2007 | BUFFER_TRACE(bh, "get write access"); |
617ba13b | 2008 | err = ext4_journal_get_write_access(handle, bh); |
ac27a0ec DK |
2009 | if (err) |
2010 | goto unlock; | |
2011 | } | |
2012 | ||
eebd2aa3 | 2013 | zero_user(page, offset, length); |
ac27a0ec DK |
2014 | |
2015 | BUFFER_TRACE(bh, "zeroed end of block"); | |
2016 | ||
2017 | err = 0; | |
617ba13b MC |
2018 | if (ext4_should_journal_data(inode)) { |
2019 | err = ext4_journal_dirty_metadata(handle, bh); | |
ac27a0ec | 2020 | } else { |
617ba13b MC |
2021 | if (ext4_should_order_data(inode)) |
2022 | err = ext4_journal_dirty_data(handle, bh); | |
ac27a0ec DK |
2023 | mark_buffer_dirty(bh); |
2024 | } | |
2025 | ||
2026 | unlock: | |
2027 | unlock_page(page); | |
2028 | page_cache_release(page); | |
2029 | return err; | |
2030 | } | |
2031 | ||
2032 | /* | |
2033 | * Probably it should be a library function... search for first non-zero word | |
2034 | * or memcmp with zero_page, whatever is better for particular architecture. | |
2035 | * Linus? | |
2036 | */ | |
2037 | static inline int all_zeroes(__le32 *p, __le32 *q) | |
2038 | { | |
2039 | while (p < q) | |
2040 | if (*p++) | |
2041 | return 0; | |
2042 | return 1; | |
2043 | } | |
2044 | ||
2045 | /** | |
617ba13b | 2046 | * ext4_find_shared - find the indirect blocks for partial truncation. |
ac27a0ec DK |
2047 | * @inode: inode in question |
2048 | * @depth: depth of the affected branch | |
617ba13b | 2049 | * @offsets: offsets of pointers in that branch (see ext4_block_to_path) |
ac27a0ec DK |
2050 | * @chain: place to store the pointers to partial indirect blocks |
2051 | * @top: place to the (detached) top of branch | |
2052 | * | |
617ba13b | 2053 | * This is a helper function used by ext4_truncate(). |
ac27a0ec DK |
2054 | * |
2055 | * When we do truncate() we may have to clean the ends of several | |
2056 | * indirect blocks but leave the blocks themselves alive. Block is | |
2057 | * partially truncated if some data below the new i_size is refered | |
2058 | * from it (and it is on the path to the first completely truncated | |
2059 | * data block, indeed). We have to free the top of that path along | |
2060 | * with everything to the right of the path. Since no allocation | |
617ba13b | 2061 | * past the truncation point is possible until ext4_truncate() |
ac27a0ec DK |
2062 | * finishes, we may safely do the latter, but top of branch may |
2063 | * require special attention - pageout below the truncation point | |
2064 | * might try to populate it. | |
2065 | * | |
2066 | * We atomically detach the top of branch from the tree, store the | |
2067 | * block number of its root in *@top, pointers to buffer_heads of | |
2068 | * partially truncated blocks - in @chain[].bh and pointers to | |
2069 | * their last elements that should not be removed - in | |
2070 | * @chain[].p. Return value is the pointer to last filled element | |
2071 | * of @chain. | |
2072 | * | |
2073 | * The work left to caller to do the actual freeing of subtrees: | |
2074 | * a) free the subtree starting from *@top | |
2075 | * b) free the subtrees whose roots are stored in | |
2076 | * (@chain[i].p+1 .. end of @chain[i].bh->b_data) | |
2077 | * c) free the subtrees growing from the inode past the @chain[0]. | |
2078 | * (no partially truncated stuff there). */ | |
2079 | ||
617ba13b | 2080 | static Indirect *ext4_find_shared(struct inode *inode, int depth, |
725d26d3 | 2081 | ext4_lblk_t offsets[4], Indirect chain[4], __le32 *top) |
ac27a0ec DK |
2082 | { |
2083 | Indirect *partial, *p; | |
2084 | int k, err; | |
2085 | ||
2086 | *top = 0; | |
2087 | /* Make k index the deepest non-null offest + 1 */ | |
2088 | for (k = depth; k > 1 && !offsets[k-1]; k--) | |
2089 | ; | |
617ba13b | 2090 | partial = ext4_get_branch(inode, k, offsets, chain, &err); |
ac27a0ec DK |
2091 | /* Writer: pointers */ |
2092 | if (!partial) | |
2093 | partial = chain + k-1; | |
2094 | /* | |
2095 | * If the branch acquired continuation since we've looked at it - | |
2096 | * fine, it should all survive and (new) top doesn't belong to us. | |
2097 | */ | |
2098 | if (!partial->key && *partial->p) | |
2099 | /* Writer: end */ | |
2100 | goto no_top; | |
2101 | for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) | |
2102 | ; | |
2103 | /* | |
2104 | * OK, we've found the last block that must survive. The rest of our | |
2105 | * branch should be detached before unlocking. However, if that rest | |
2106 | * of branch is all ours and does not grow immediately from the inode | |
2107 | * it's easier to cheat and just decrement partial->p. | |
2108 | */ | |
2109 | if (p == chain + k - 1 && p > chain) { | |
2110 | p->p--; | |
2111 | } else { | |
2112 | *top = *p->p; | |
617ba13b | 2113 | /* Nope, don't do this in ext4. Must leave the tree intact */ |
ac27a0ec DK |
2114 | #if 0 |
2115 | *p->p = 0; | |
2116 | #endif | |
2117 | } | |
2118 | /* Writer: end */ | |
2119 | ||
2120 | while(partial > p) { | |
2121 | brelse(partial->bh); | |
2122 | partial--; | |
2123 | } | |
2124 | no_top: | |
2125 | return partial; | |
2126 | } | |
2127 | ||
2128 | /* | |
2129 | * Zero a number of block pointers in either an inode or an indirect block. | |
2130 | * If we restart the transaction we must again get write access to the | |
2131 | * indirect block for further modification. | |
2132 | * | |
2133 | * We release `count' blocks on disk, but (last - first) may be greater | |
2134 | * than `count' because there can be holes in there. | |
2135 | */ | |
617ba13b MC |
2136 | static void ext4_clear_blocks(handle_t *handle, struct inode *inode, |
2137 | struct buffer_head *bh, ext4_fsblk_t block_to_free, | |
ac27a0ec DK |
2138 | unsigned long count, __le32 *first, __le32 *last) |
2139 | { | |
2140 | __le32 *p; | |
2141 | if (try_to_extend_transaction(handle, inode)) { | |
2142 | if (bh) { | |
617ba13b MC |
2143 | BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata"); |
2144 | ext4_journal_dirty_metadata(handle, bh); | |
ac27a0ec | 2145 | } |
617ba13b MC |
2146 | ext4_mark_inode_dirty(handle, inode); |
2147 | ext4_journal_test_restart(handle, inode); | |
ac27a0ec DK |
2148 | if (bh) { |
2149 | BUFFER_TRACE(bh, "retaking write access"); | |
617ba13b | 2150 | ext4_journal_get_write_access(handle, bh); |
ac27a0ec DK |
2151 | } |
2152 | } | |
2153 | ||
2154 | /* | |
2155 | * Any buffers which are on the journal will be in memory. We find | |
dab291af | 2156 | * them on the hash table so jbd2_journal_revoke() will run jbd2_journal_forget() |
ac27a0ec | 2157 | * on them. We've already detached each block from the file, so |
dab291af | 2158 | * bforget() in jbd2_journal_forget() should be safe. |
ac27a0ec | 2159 | * |
dab291af | 2160 | * AKPM: turn on bforget in jbd2_journal_forget()!!! |
ac27a0ec DK |
2161 | */ |
2162 | for (p = first; p < last; p++) { | |
2163 | u32 nr = le32_to_cpu(*p); | |
2164 | if (nr) { | |
1d03ec98 | 2165 | struct buffer_head *tbh; |
ac27a0ec DK |
2166 | |
2167 | *p = 0; | |
1d03ec98 AK |
2168 | tbh = sb_find_get_block(inode->i_sb, nr); |
2169 | ext4_forget(handle, 0, inode, tbh, nr); | |
ac27a0ec DK |
2170 | } |
2171 | } | |
2172 | ||
c9de560d | 2173 | ext4_free_blocks(handle, inode, block_to_free, count, 0); |
ac27a0ec DK |
2174 | } |
2175 | ||
2176 | /** | |
617ba13b | 2177 | * ext4_free_data - free a list of data blocks |
ac27a0ec DK |
2178 | * @handle: handle for this transaction |
2179 | * @inode: inode we are dealing with | |
2180 | * @this_bh: indirect buffer_head which contains *@first and *@last | |
2181 | * @first: array of block numbers | |
2182 | * @last: points immediately past the end of array | |
2183 | * | |
2184 | * We are freeing all blocks refered from that array (numbers are stored as | |
2185 | * little-endian 32-bit) and updating @inode->i_blocks appropriately. | |
2186 | * | |
2187 | * We accumulate contiguous runs of blocks to free. Conveniently, if these | |
2188 | * blocks are contiguous then releasing them at one time will only affect one | |
2189 | * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't | |
2190 | * actually use a lot of journal space. | |
2191 | * | |
2192 | * @this_bh will be %NULL if @first and @last point into the inode's direct | |
2193 | * block pointers. | |
2194 | */ | |
617ba13b | 2195 | static void ext4_free_data(handle_t *handle, struct inode *inode, |
ac27a0ec DK |
2196 | struct buffer_head *this_bh, |
2197 | __le32 *first, __le32 *last) | |
2198 | { | |
617ba13b | 2199 | ext4_fsblk_t block_to_free = 0; /* Starting block # of a run */ |
ac27a0ec DK |
2200 | unsigned long count = 0; /* Number of blocks in the run */ |
2201 | __le32 *block_to_free_p = NULL; /* Pointer into inode/ind | |
2202 | corresponding to | |
2203 | block_to_free */ | |
617ba13b | 2204 | ext4_fsblk_t nr; /* Current block # */ |
ac27a0ec DK |
2205 | __le32 *p; /* Pointer into inode/ind |
2206 | for current block */ | |
2207 | int err; | |
2208 | ||
2209 | if (this_bh) { /* For indirect block */ | |
2210 | BUFFER_TRACE(this_bh, "get_write_access"); | |
617ba13b | 2211 | err = ext4_journal_get_write_access(handle, this_bh); |
ac27a0ec DK |
2212 | /* Important: if we can't update the indirect pointers |
2213 | * to the blocks, we can't free them. */ | |
2214 | if (err) | |
2215 | return; | |
2216 | } | |
2217 | ||
2218 | for (p = first; p < last; p++) { | |
2219 | nr = le32_to_cpu(*p); | |
2220 | if (nr) { | |
2221 | /* accumulate blocks to free if they're contiguous */ | |
2222 | if (count == 0) { | |
2223 | block_to_free = nr; | |
2224 | block_to_free_p = p; | |
2225 | count = 1; | |
2226 | } else if (nr == block_to_free + count) { | |
2227 | count++; | |
2228 | } else { | |
617ba13b | 2229 | ext4_clear_blocks(handle, inode, this_bh, |
ac27a0ec DK |
2230 | block_to_free, |
2231 | count, block_to_free_p, p); | |
2232 | block_to_free = nr; | |
2233 | block_to_free_p = p; | |
2234 | count = 1; | |
2235 | } | |
2236 | } | |
2237 | } | |
2238 | ||
2239 | if (count > 0) | |
617ba13b | 2240 | ext4_clear_blocks(handle, inode, this_bh, block_to_free, |
ac27a0ec DK |
2241 | count, block_to_free_p, p); |
2242 | ||
2243 | if (this_bh) { | |
617ba13b | 2244 | BUFFER_TRACE(this_bh, "call ext4_journal_dirty_metadata"); |
71dc8fbc DG |
2245 | |
2246 | /* | |
2247 | * The buffer head should have an attached journal head at this | |
2248 | * point. However, if the data is corrupted and an indirect | |
2249 | * block pointed to itself, it would have been detached when | |
2250 | * the block was cleared. Check for this instead of OOPSing. | |
2251 | */ | |
2252 | if (bh2jh(this_bh)) | |
2253 | ext4_journal_dirty_metadata(handle, this_bh); | |
2254 | else | |
2255 | ext4_error(inode->i_sb, __func__, | |
2256 | "circular indirect block detected, " | |
2257 | "inode=%lu, block=%llu", | |
2258 | inode->i_ino, | |
2259 | (unsigned long long) this_bh->b_blocknr); | |
ac27a0ec DK |
2260 | } |
2261 | } | |
2262 | ||
2263 | /** | |
617ba13b | 2264 | * ext4_free_branches - free an array of branches |
ac27a0ec DK |
2265 | * @handle: JBD handle for this transaction |
2266 | * @inode: inode we are dealing with | |
2267 | * @parent_bh: the buffer_head which contains *@first and *@last | |
2268 | * @first: array of block numbers | |
2269 | * @last: pointer immediately past the end of array | |
2270 | * @depth: depth of the branches to free | |
2271 | * | |
2272 | * We are freeing all blocks refered from these branches (numbers are | |
2273 | * stored as little-endian 32-bit) and updating @inode->i_blocks | |
2274 | * appropriately. | |
2275 | */ | |
617ba13b | 2276 | static void ext4_free_branches(handle_t *handle, struct inode *inode, |
ac27a0ec DK |
2277 | struct buffer_head *parent_bh, |
2278 | __le32 *first, __le32 *last, int depth) | |
2279 | { | |
617ba13b | 2280 | ext4_fsblk_t nr; |
ac27a0ec DK |
2281 | __le32 *p; |
2282 | ||
2283 | if (is_handle_aborted(handle)) | |
2284 | return; | |
2285 | ||
2286 | if (depth--) { | |
2287 | struct buffer_head *bh; | |
617ba13b | 2288 | int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb); |
ac27a0ec DK |
2289 | p = last; |
2290 | while (--p >= first) { | |
2291 | nr = le32_to_cpu(*p); | |
2292 | if (!nr) | |
2293 | continue; /* A hole */ | |
2294 | ||
2295 | /* Go read the buffer for the next level down */ | |
2296 | bh = sb_bread(inode->i_sb, nr); | |
2297 | ||
2298 | /* | |
2299 | * A read failure? Report error and clear slot | |
2300 | * (should be rare). | |
2301 | */ | |
2302 | if (!bh) { | |
617ba13b | 2303 | ext4_error(inode->i_sb, "ext4_free_branches", |
2ae02107 | 2304 | "Read failure, inode=%lu, block=%llu", |
ac27a0ec DK |
2305 | inode->i_ino, nr); |
2306 | continue; | |
2307 | } | |
2308 | ||
2309 | /* This zaps the entire block. Bottom up. */ | |
2310 | BUFFER_TRACE(bh, "free child branches"); | |
617ba13b | 2311 | ext4_free_branches(handle, inode, bh, |
ac27a0ec DK |
2312 | (__le32*)bh->b_data, |
2313 | (__le32*)bh->b_data + addr_per_block, | |
2314 | depth); | |
2315 | ||
2316 | /* | |
2317 | * We've probably journalled the indirect block several | |
2318 | * times during the truncate. But it's no longer | |
2319 | * needed and we now drop it from the transaction via | |
dab291af | 2320 | * jbd2_journal_revoke(). |
ac27a0ec DK |
2321 | * |
2322 | * That's easy if it's exclusively part of this | |
2323 | * transaction. But if it's part of the committing | |
dab291af | 2324 | * transaction then jbd2_journal_forget() will simply |
ac27a0ec | 2325 | * brelse() it. That means that if the underlying |
617ba13b | 2326 | * block is reallocated in ext4_get_block(), |
ac27a0ec DK |
2327 | * unmap_underlying_metadata() will find this block |
2328 | * and will try to get rid of it. damn, damn. | |
2329 | * | |
2330 | * If this block has already been committed to the | |
2331 | * journal, a revoke record will be written. And | |
2332 | * revoke records must be emitted *before* clearing | |
2333 | * this block's bit in the bitmaps. | |
2334 | */ | |
617ba13b | 2335 | ext4_forget(handle, 1, inode, bh, bh->b_blocknr); |
ac27a0ec DK |
2336 | |
2337 | /* | |
2338 | * Everything below this this pointer has been | |
2339 | * released. Now let this top-of-subtree go. | |
2340 | * | |
2341 | * We want the freeing of this indirect block to be | |
2342 | * atomic in the journal with the updating of the | |
2343 | * bitmap block which owns it. So make some room in | |
2344 | * the journal. | |
2345 | * | |
2346 | * We zero the parent pointer *after* freeing its | |
2347 | * pointee in the bitmaps, so if extend_transaction() | |
2348 | * for some reason fails to put the bitmap changes and | |
2349 | * the release into the same transaction, recovery | |
2350 | * will merely complain about releasing a free block, | |
2351 | * rather than leaking blocks. | |
2352 | */ | |
2353 | if (is_handle_aborted(handle)) | |
2354 | return; | |
2355 | if (try_to_extend_transaction(handle, inode)) { | |
617ba13b MC |
2356 | ext4_mark_inode_dirty(handle, inode); |
2357 | ext4_journal_test_restart(handle, inode); | |
ac27a0ec DK |
2358 | } |
2359 | ||
c9de560d | 2360 | ext4_free_blocks(handle, inode, nr, 1, 1); |
ac27a0ec DK |
2361 | |
2362 | if (parent_bh) { | |
2363 | /* | |
2364 | * The block which we have just freed is | |
2365 | * pointed to by an indirect block: journal it | |
2366 | */ | |
2367 | BUFFER_TRACE(parent_bh, "get_write_access"); | |
617ba13b | 2368 | if (!ext4_journal_get_write_access(handle, |
ac27a0ec DK |
2369 | parent_bh)){ |
2370 | *p = 0; | |
2371 | BUFFER_TRACE(parent_bh, | |
617ba13b MC |
2372 | "call ext4_journal_dirty_metadata"); |
2373 | ext4_journal_dirty_metadata(handle, | |
ac27a0ec DK |
2374 | parent_bh); |
2375 | } | |
2376 | } | |
2377 | } | |
2378 | } else { | |
2379 | /* We have reached the bottom of the tree. */ | |
2380 | BUFFER_TRACE(parent_bh, "free data blocks"); | |
617ba13b | 2381 | ext4_free_data(handle, inode, parent_bh, first, last); |
ac27a0ec DK |
2382 | } |
2383 | } | |
2384 | ||
91ef4caf DG |
2385 | int ext4_can_truncate(struct inode *inode) |
2386 | { | |
2387 | if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) | |
2388 | return 0; | |
2389 | if (S_ISREG(inode->i_mode)) | |
2390 | return 1; | |
2391 | if (S_ISDIR(inode->i_mode)) | |
2392 | return 1; | |
2393 | if (S_ISLNK(inode->i_mode)) | |
2394 | return !ext4_inode_is_fast_symlink(inode); | |
2395 | return 0; | |
2396 | } | |
2397 | ||
ac27a0ec | 2398 | /* |
617ba13b | 2399 | * ext4_truncate() |
ac27a0ec | 2400 | * |
617ba13b MC |
2401 | * We block out ext4_get_block() block instantiations across the entire |
2402 | * transaction, and VFS/VM ensures that ext4_truncate() cannot run | |
ac27a0ec DK |
2403 | * simultaneously on behalf of the same inode. |
2404 | * | |
2405 | * As we work through the truncate and commmit bits of it to the journal there | |
2406 | * is one core, guiding principle: the file's tree must always be consistent on | |
2407 | * disk. We must be able to restart the truncate after a crash. | |
2408 | * | |
2409 | * The file's tree may be transiently inconsistent in memory (although it | |
2410 | * probably isn't), but whenever we close off and commit a journal transaction, | |
2411 | * the contents of (the filesystem + the journal) must be consistent and | |
2412 | * restartable. It's pretty simple, really: bottom up, right to left (although | |
2413 | * left-to-right works OK too). | |
2414 | * | |
2415 | * Note that at recovery time, journal replay occurs *before* the restart of | |
2416 | * truncate against the orphan inode list. | |
2417 | * | |
2418 | * The committed inode has the new, desired i_size (which is the same as | |
617ba13b | 2419 | * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see |
ac27a0ec | 2420 | * that this inode's truncate did not complete and it will again call |
617ba13b MC |
2421 | * ext4_truncate() to have another go. So there will be instantiated blocks |
2422 | * to the right of the truncation point in a crashed ext4 filesystem. But | |
ac27a0ec | 2423 | * that's fine - as long as they are linked from the inode, the post-crash |
617ba13b | 2424 | * ext4_truncate() run will find them and release them. |
ac27a0ec | 2425 | */ |
617ba13b | 2426 | void ext4_truncate(struct inode *inode) |
ac27a0ec DK |
2427 | { |
2428 | handle_t *handle; | |
617ba13b | 2429 | struct ext4_inode_info *ei = EXT4_I(inode); |
ac27a0ec | 2430 | __le32 *i_data = ei->i_data; |
617ba13b | 2431 | int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb); |
ac27a0ec | 2432 | struct address_space *mapping = inode->i_mapping; |
725d26d3 | 2433 | ext4_lblk_t offsets[4]; |
ac27a0ec DK |
2434 | Indirect chain[4]; |
2435 | Indirect *partial; | |
2436 | __le32 nr = 0; | |
2437 | int n; | |
725d26d3 | 2438 | ext4_lblk_t last_block; |
ac27a0ec | 2439 | unsigned blocksize = inode->i_sb->s_blocksize; |
ac27a0ec | 2440 | |
91ef4caf | 2441 | if (!ext4_can_truncate(inode)) |
ac27a0ec DK |
2442 | return; |
2443 | ||
1d03ec98 | 2444 | if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) { |
cf108bca | 2445 | ext4_ext_truncate(inode); |
1d03ec98 AK |
2446 | return; |
2447 | } | |
a86c6181 | 2448 | |
ac27a0ec | 2449 | handle = start_transaction(inode); |
cf108bca | 2450 | if (IS_ERR(handle)) |
ac27a0ec | 2451 | return; /* AKPM: return what? */ |
ac27a0ec DK |
2452 | |
2453 | last_block = (inode->i_size + blocksize-1) | |
617ba13b | 2454 | >> EXT4_BLOCK_SIZE_BITS(inode->i_sb); |
ac27a0ec | 2455 | |
cf108bca JK |
2456 | if (inode->i_size & (blocksize - 1)) |
2457 | if (ext4_block_truncate_page(handle, mapping, inode->i_size)) | |
2458 | goto out_stop; | |
ac27a0ec | 2459 | |
617ba13b | 2460 | n = ext4_block_to_path(inode, last_block, offsets, NULL); |
ac27a0ec DK |
2461 | if (n == 0) |
2462 | goto out_stop; /* error */ | |
2463 | ||
2464 | /* | |
2465 | * OK. This truncate is going to happen. We add the inode to the | |
2466 | * orphan list, so that if this truncate spans multiple transactions, | |
2467 | * and we crash, we will resume the truncate when the filesystem | |
2468 | * recovers. It also marks the inode dirty, to catch the new size. | |
2469 | * | |
2470 | * Implication: the file must always be in a sane, consistent | |
2471 | * truncatable state while each transaction commits. | |
2472 | */ | |
617ba13b | 2473 | if (ext4_orphan_add(handle, inode)) |
ac27a0ec DK |
2474 | goto out_stop; |
2475 | ||
2476 | /* | |
2477 | * The orphan list entry will now protect us from any crash which | |
2478 | * occurs before the truncate completes, so it is now safe to propagate | |
2479 | * the new, shorter inode size (held for now in i_size) into the | |
2480 | * on-disk inode. We do this via i_disksize, which is the value which | |
617ba13b | 2481 | * ext4 *really* writes onto the disk inode. |
ac27a0ec DK |
2482 | */ |
2483 | ei->i_disksize = inode->i_size; | |
2484 | ||
2485 | /* | |
617ba13b | 2486 | * From here we block out all ext4_get_block() callers who want to |
ac27a0ec DK |
2487 | * modify the block allocation tree. |
2488 | */ | |
0e855ac8 | 2489 | down_write(&ei->i_data_sem); |
ac27a0ec DK |
2490 | |
2491 | if (n == 1) { /* direct blocks */ | |
617ba13b MC |
2492 | ext4_free_data(handle, inode, NULL, i_data+offsets[0], |
2493 | i_data + EXT4_NDIR_BLOCKS); | |
ac27a0ec DK |
2494 | goto do_indirects; |
2495 | } | |
2496 | ||
617ba13b | 2497 | partial = ext4_find_shared(inode, n, offsets, chain, &nr); |
ac27a0ec DK |
2498 | /* Kill the top of shared branch (not detached) */ |
2499 | if (nr) { | |
2500 | if (partial == chain) { | |
2501 | /* Shared branch grows from the inode */ | |
617ba13b | 2502 | ext4_free_branches(handle, inode, NULL, |
ac27a0ec DK |
2503 | &nr, &nr+1, (chain+n-1) - partial); |
2504 | *partial->p = 0; | |
2505 | /* | |
2506 | * We mark the inode dirty prior to restart, | |
2507 | * and prior to stop. No need for it here. | |
2508 | */ | |
2509 | } else { | |
2510 | /* Shared branch grows from an indirect block */ | |
2511 | BUFFER_TRACE(partial->bh, "get_write_access"); | |
617ba13b | 2512 | ext4_free_branches(handle, inode, partial->bh, |
ac27a0ec DK |
2513 | partial->p, |
2514 | partial->p+1, (chain+n-1) - partial); | |
2515 | } | |
2516 | } | |
2517 | /* Clear the ends of indirect blocks on the shared branch */ | |
2518 | while (partial > chain) { | |
617ba13b | 2519 | ext4_free_branches(handle, inode, partial->bh, partial->p + 1, |
ac27a0ec DK |
2520 | (__le32*)partial->bh->b_data+addr_per_block, |
2521 | (chain+n-1) - partial); | |
2522 | BUFFER_TRACE(partial->bh, "call brelse"); | |
2523 | brelse (partial->bh); | |
2524 | partial--; | |
2525 | } | |
2526 | do_indirects: | |
2527 | /* Kill the remaining (whole) subtrees */ | |
2528 | switch (offsets[0]) { | |
2529 | default: | |
617ba13b | 2530 | nr = i_data[EXT4_IND_BLOCK]; |
ac27a0ec | 2531 | if (nr) { |
617ba13b MC |
2532 | ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1); |
2533 | i_data[EXT4_IND_BLOCK] = 0; | |
ac27a0ec | 2534 | } |
617ba13b MC |
2535 | case EXT4_IND_BLOCK: |
2536 | nr = i_data[EXT4_DIND_BLOCK]; | |
ac27a0ec | 2537 | if (nr) { |
617ba13b MC |
2538 | ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2); |
2539 | i_data[EXT4_DIND_BLOCK] = 0; | |
ac27a0ec | 2540 | } |
617ba13b MC |
2541 | case EXT4_DIND_BLOCK: |
2542 | nr = i_data[EXT4_TIND_BLOCK]; | |
ac27a0ec | 2543 | if (nr) { |
617ba13b MC |
2544 | ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3); |
2545 | i_data[EXT4_TIND_BLOCK] = 0; | |
ac27a0ec | 2546 | } |
617ba13b | 2547 | case EXT4_TIND_BLOCK: |
ac27a0ec DK |
2548 | ; |
2549 | } | |
2550 | ||
617ba13b | 2551 | ext4_discard_reservation(inode); |
ac27a0ec | 2552 | |
0e855ac8 | 2553 | up_write(&ei->i_data_sem); |
ef7f3835 | 2554 | inode->i_mtime = inode->i_ctime = ext4_current_time(inode); |
617ba13b | 2555 | ext4_mark_inode_dirty(handle, inode); |
ac27a0ec DK |
2556 | |
2557 | /* | |
2558 | * In a multi-transaction truncate, we only make the final transaction | |
2559 | * synchronous | |
2560 | */ | |
2561 | if (IS_SYNC(inode)) | |
2562 | handle->h_sync = 1; | |
2563 | out_stop: | |
2564 | /* | |
2565 | * If this was a simple ftruncate(), and the file will remain alive | |
2566 | * then we need to clear up the orphan record which we created above. | |
2567 | * However, if this was a real unlink then we were called by | |
617ba13b | 2568 | * ext4_delete_inode(), and we allow that function to clean up the |
ac27a0ec DK |
2569 | * orphan info for us. |
2570 | */ | |
2571 | if (inode->i_nlink) | |
617ba13b | 2572 | ext4_orphan_del(handle, inode); |
ac27a0ec | 2573 | |
617ba13b | 2574 | ext4_journal_stop(handle); |
ac27a0ec DK |
2575 | } |
2576 | ||
617ba13b MC |
2577 | static ext4_fsblk_t ext4_get_inode_block(struct super_block *sb, |
2578 | unsigned long ino, struct ext4_iloc *iloc) | |
ac27a0ec | 2579 | { |
fd2d4291 | 2580 | ext4_group_t block_group; |
ac27a0ec | 2581 | unsigned long offset; |
617ba13b | 2582 | ext4_fsblk_t block; |
c0a4ef38 | 2583 | struct ext4_group_desc *gdp; |
ac27a0ec | 2584 | |
617ba13b | 2585 | if (!ext4_valid_inum(sb, ino)) { |
ac27a0ec DK |
2586 | /* |
2587 | * This error is already checked for in namei.c unless we are | |
2588 | * looking at an NFS filehandle, in which case no error | |
2589 | * report is needed | |
2590 | */ | |
2591 | return 0; | |
2592 | } | |
2593 | ||
617ba13b | 2594 | block_group = (ino - 1) / EXT4_INODES_PER_GROUP(sb); |
c0a4ef38 AM |
2595 | gdp = ext4_get_group_desc(sb, block_group, NULL); |
2596 | if (!gdp) | |
ac27a0ec | 2597 | return 0; |
ac27a0ec | 2598 | |
ac27a0ec DK |
2599 | /* |
2600 | * Figure out the offset within the block group inode table | |
2601 | */ | |
617ba13b MC |
2602 | offset = ((ino - 1) % EXT4_INODES_PER_GROUP(sb)) * |
2603 | EXT4_INODE_SIZE(sb); | |
8fadc143 AR |
2604 | block = ext4_inode_table(sb, gdp) + |
2605 | (offset >> EXT4_BLOCK_SIZE_BITS(sb)); | |
ac27a0ec DK |
2606 | |
2607 | iloc->block_group = block_group; | |
617ba13b | 2608 | iloc->offset = offset & (EXT4_BLOCK_SIZE(sb) - 1); |
ac27a0ec DK |
2609 | return block; |
2610 | } | |
2611 | ||
2612 | /* | |
617ba13b | 2613 | * ext4_get_inode_loc returns with an extra refcount against the inode's |
ac27a0ec DK |
2614 | * underlying buffer_head on success. If 'in_mem' is true, we have all |
2615 | * data in memory that is needed to recreate the on-disk version of this | |
2616 | * inode. | |
2617 | */ | |
617ba13b MC |
2618 | static int __ext4_get_inode_loc(struct inode *inode, |
2619 | struct ext4_iloc *iloc, int in_mem) | |
ac27a0ec | 2620 | { |
617ba13b | 2621 | ext4_fsblk_t block; |
ac27a0ec DK |
2622 | struct buffer_head *bh; |
2623 | ||
617ba13b | 2624 | block = ext4_get_inode_block(inode->i_sb, inode->i_ino, iloc); |
ac27a0ec DK |
2625 | if (!block) |
2626 | return -EIO; | |
2627 | ||
2628 | bh = sb_getblk(inode->i_sb, block); | |
2629 | if (!bh) { | |
617ba13b | 2630 | ext4_error (inode->i_sb, "ext4_get_inode_loc", |
ac27a0ec | 2631 | "unable to read inode block - " |
2ae02107 | 2632 | "inode=%lu, block=%llu", |
ac27a0ec DK |
2633 | inode->i_ino, block); |
2634 | return -EIO; | |
2635 | } | |
2636 | if (!buffer_uptodate(bh)) { | |
2637 | lock_buffer(bh); | |
2638 | if (buffer_uptodate(bh)) { | |
2639 | /* someone brought it uptodate while we waited */ | |
2640 | unlock_buffer(bh); | |
2641 | goto has_buffer; | |
2642 | } | |
2643 | ||
2644 | /* | |
2645 | * If we have all information of the inode in memory and this | |
2646 | * is the only valid inode in the block, we need not read the | |
2647 | * block. | |
2648 | */ | |
2649 | if (in_mem) { | |
2650 | struct buffer_head *bitmap_bh; | |
617ba13b | 2651 | struct ext4_group_desc *desc; |
ac27a0ec DK |
2652 | int inodes_per_buffer; |
2653 | int inode_offset, i; | |
fd2d4291 | 2654 | ext4_group_t block_group; |
ac27a0ec DK |
2655 | int start; |
2656 | ||
2657 | block_group = (inode->i_ino - 1) / | |
617ba13b | 2658 | EXT4_INODES_PER_GROUP(inode->i_sb); |
ac27a0ec | 2659 | inodes_per_buffer = bh->b_size / |
617ba13b | 2660 | EXT4_INODE_SIZE(inode->i_sb); |
ac27a0ec | 2661 | inode_offset = ((inode->i_ino - 1) % |
617ba13b | 2662 | EXT4_INODES_PER_GROUP(inode->i_sb)); |
ac27a0ec DK |
2663 | start = inode_offset & ~(inodes_per_buffer - 1); |
2664 | ||
2665 | /* Is the inode bitmap in cache? */ | |
617ba13b | 2666 | desc = ext4_get_group_desc(inode->i_sb, |
ac27a0ec DK |
2667 | block_group, NULL); |
2668 | if (!desc) | |
2669 | goto make_io; | |
2670 | ||
2671 | bitmap_bh = sb_getblk(inode->i_sb, | |
8fadc143 | 2672 | ext4_inode_bitmap(inode->i_sb, desc)); |
ac27a0ec DK |
2673 | if (!bitmap_bh) |
2674 | goto make_io; | |
2675 | ||
2676 | /* | |
2677 | * If the inode bitmap isn't in cache then the | |
2678 | * optimisation may end up performing two reads instead | |
2679 | * of one, so skip it. | |
2680 | */ | |
2681 | if (!buffer_uptodate(bitmap_bh)) { | |
2682 | brelse(bitmap_bh); | |
2683 | goto make_io; | |
2684 | } | |
2685 | for (i = start; i < start + inodes_per_buffer; i++) { | |
2686 | if (i == inode_offset) | |
2687 | continue; | |
617ba13b | 2688 | if (ext4_test_bit(i, bitmap_bh->b_data)) |
ac27a0ec DK |
2689 | break; |
2690 | } | |
2691 | brelse(bitmap_bh); | |
2692 | if (i == start + inodes_per_buffer) { | |
2693 | /* all other inodes are free, so skip I/O */ | |
2694 | memset(bh->b_data, 0, bh->b_size); | |
2695 | set_buffer_uptodate(bh); | |
2696 | unlock_buffer(bh); | |
2697 | goto has_buffer; | |
2698 | } | |
2699 | } | |
2700 | ||
2701 | make_io: | |
2702 | /* | |
2703 | * There are other valid inodes in the buffer, this inode | |
2704 | * has in-inode xattrs, or we don't have this inode in memory. | |
2705 | * Read the block from disk. | |
2706 | */ | |
2707 | get_bh(bh); | |
2708 | bh->b_end_io = end_buffer_read_sync; | |
2709 | submit_bh(READ_META, bh); | |
2710 | wait_on_buffer(bh); | |
2711 | if (!buffer_uptodate(bh)) { | |
617ba13b | 2712 | ext4_error(inode->i_sb, "ext4_get_inode_loc", |
ac27a0ec | 2713 | "unable to read inode block - " |
2ae02107 | 2714 | "inode=%lu, block=%llu", |
ac27a0ec DK |
2715 | inode->i_ino, block); |
2716 | brelse(bh); | |
2717 | return -EIO; | |
2718 | } | |
2719 | } | |
2720 | has_buffer: | |
2721 | iloc->bh = bh; | |
2722 | return 0; | |
2723 | } | |
2724 | ||
617ba13b | 2725 | int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc) |
ac27a0ec DK |
2726 | { |
2727 | /* We have all inode data except xattrs in memory here. */ | |
617ba13b MC |
2728 | return __ext4_get_inode_loc(inode, iloc, |
2729 | !(EXT4_I(inode)->i_state & EXT4_STATE_XATTR)); | |
ac27a0ec DK |
2730 | } |
2731 | ||
617ba13b | 2732 | void ext4_set_inode_flags(struct inode *inode) |
ac27a0ec | 2733 | { |
617ba13b | 2734 | unsigned int flags = EXT4_I(inode)->i_flags; |
ac27a0ec DK |
2735 | |
2736 | inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); | |
617ba13b | 2737 | if (flags & EXT4_SYNC_FL) |
ac27a0ec | 2738 | inode->i_flags |= S_SYNC; |
617ba13b | 2739 | if (flags & EXT4_APPEND_FL) |
ac27a0ec | 2740 | inode->i_flags |= S_APPEND; |
617ba13b | 2741 | if (flags & EXT4_IMMUTABLE_FL) |
ac27a0ec | 2742 | inode->i_flags |= S_IMMUTABLE; |
617ba13b | 2743 | if (flags & EXT4_NOATIME_FL) |
ac27a0ec | 2744 | inode->i_flags |= S_NOATIME; |
617ba13b | 2745 | if (flags & EXT4_DIRSYNC_FL) |
ac27a0ec DK |
2746 | inode->i_flags |= S_DIRSYNC; |
2747 | } | |
2748 | ||
ff9ddf7e JK |
2749 | /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */ |
2750 | void ext4_get_inode_flags(struct ext4_inode_info *ei) | |
2751 | { | |
2752 | unsigned int flags = ei->vfs_inode.i_flags; | |
2753 | ||
2754 | ei->i_flags &= ~(EXT4_SYNC_FL|EXT4_APPEND_FL| | |
2755 | EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL|EXT4_DIRSYNC_FL); | |
2756 | if (flags & S_SYNC) | |
2757 | ei->i_flags |= EXT4_SYNC_FL; | |
2758 | if (flags & S_APPEND) | |
2759 | ei->i_flags |= EXT4_APPEND_FL; | |
2760 | if (flags & S_IMMUTABLE) | |
2761 | ei->i_flags |= EXT4_IMMUTABLE_FL; | |
2762 | if (flags & S_NOATIME) | |
2763 | ei->i_flags |= EXT4_NOATIME_FL; | |
2764 | if (flags & S_DIRSYNC) | |
2765 | ei->i_flags |= EXT4_DIRSYNC_FL; | |
2766 | } | |
0fc1b451 AK |
2767 | static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode, |
2768 | struct ext4_inode_info *ei) | |
2769 | { | |
2770 | blkcnt_t i_blocks ; | |
8180a562 AK |
2771 | struct inode *inode = &(ei->vfs_inode); |
2772 | struct super_block *sb = inode->i_sb; | |
0fc1b451 AK |
2773 | |
2774 | if (EXT4_HAS_RO_COMPAT_FEATURE(sb, | |
2775 | EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) { | |
2776 | /* we are using combined 48 bit field */ | |
2777 | i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 | | |
2778 | le32_to_cpu(raw_inode->i_blocks_lo); | |
8180a562 AK |
2779 | if (ei->i_flags & EXT4_HUGE_FILE_FL) { |
2780 | /* i_blocks represent file system block size */ | |
2781 | return i_blocks << (inode->i_blkbits - 9); | |
2782 | } else { | |
2783 | return i_blocks; | |
2784 | } | |
0fc1b451 AK |
2785 | } else { |
2786 | return le32_to_cpu(raw_inode->i_blocks_lo); | |
2787 | } | |
2788 | } | |
ff9ddf7e | 2789 | |
1d1fe1ee | 2790 | struct inode *ext4_iget(struct super_block *sb, unsigned long ino) |
ac27a0ec | 2791 | { |
617ba13b MC |
2792 | struct ext4_iloc iloc; |
2793 | struct ext4_inode *raw_inode; | |
1d1fe1ee | 2794 | struct ext4_inode_info *ei; |
ac27a0ec | 2795 | struct buffer_head *bh; |
1d1fe1ee DH |
2796 | struct inode *inode; |
2797 | long ret; | |
ac27a0ec DK |
2798 | int block; |
2799 | ||
1d1fe1ee DH |
2800 | inode = iget_locked(sb, ino); |
2801 | if (!inode) | |
2802 | return ERR_PTR(-ENOMEM); | |
2803 | if (!(inode->i_state & I_NEW)) | |
2804 | return inode; | |
2805 | ||
2806 | ei = EXT4_I(inode); | |
617ba13b MC |
2807 | #ifdef CONFIG_EXT4DEV_FS_POSIX_ACL |
2808 | ei->i_acl = EXT4_ACL_NOT_CACHED; | |
2809 | ei->i_default_acl = EXT4_ACL_NOT_CACHED; | |
ac27a0ec DK |
2810 | #endif |
2811 | ei->i_block_alloc_info = NULL; | |
2812 | ||
1d1fe1ee DH |
2813 | ret = __ext4_get_inode_loc(inode, &iloc, 0); |
2814 | if (ret < 0) | |
ac27a0ec DK |
2815 | goto bad_inode; |
2816 | bh = iloc.bh; | |
617ba13b | 2817 | raw_inode = ext4_raw_inode(&iloc); |
ac27a0ec DK |
2818 | inode->i_mode = le16_to_cpu(raw_inode->i_mode); |
2819 | inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); | |
2820 | inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); | |
2821 | if(!(test_opt (inode->i_sb, NO_UID32))) { | |
2822 | inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; | |
2823 | inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; | |
2824 | } | |
2825 | inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); | |
ac27a0ec DK |
2826 | |
2827 | ei->i_state = 0; | |
2828 | ei->i_dir_start_lookup = 0; | |
2829 | ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); | |
2830 | /* We now have enough fields to check if the inode was active or not. | |
2831 | * This is needed because nfsd might try to access dead inodes | |
2832 | * the test is that same one that e2fsck uses | |
2833 | * NeilBrown 1999oct15 | |
2834 | */ | |
2835 | if (inode->i_nlink == 0) { | |
2836 | if (inode->i_mode == 0 || | |
617ba13b | 2837 | !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) { |
ac27a0ec DK |
2838 | /* this inode is deleted */ |
2839 | brelse (bh); | |
1d1fe1ee | 2840 | ret = -ESTALE; |
ac27a0ec DK |
2841 | goto bad_inode; |
2842 | } | |
2843 | /* The only unlinked inodes we let through here have | |
2844 | * valid i_mode and are being read by the orphan | |
2845 | * recovery code: that's fine, we're about to complete | |
2846 | * the process of deleting those. */ | |
2847 | } | |
ac27a0ec | 2848 | ei->i_flags = le32_to_cpu(raw_inode->i_flags); |
0fc1b451 | 2849 | inode->i_blocks = ext4_inode_blocks(raw_inode, ei); |
7973c0c1 | 2850 | ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo); |
9b8f1f01 | 2851 | if (EXT4_SB(inode->i_sb)->s_es->s_creator_os != |
a48380f7 | 2852 | cpu_to_le32(EXT4_OS_HURD)) { |
a1ddeb7e BP |
2853 | ei->i_file_acl |= |
2854 | ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32; | |
ac27a0ec | 2855 | } |
a48380f7 | 2856 | inode->i_size = ext4_isize(raw_inode); |
ac27a0ec DK |
2857 | ei->i_disksize = inode->i_size; |
2858 | inode->i_generation = le32_to_cpu(raw_inode->i_generation); | |
2859 | ei->i_block_group = iloc.block_group; | |
2860 | /* | |
2861 | * NOTE! The in-memory inode i_data array is in little-endian order | |
2862 | * even on big-endian machines: we do NOT byteswap the block numbers! | |
2863 | */ | |
617ba13b | 2864 | for (block = 0; block < EXT4_N_BLOCKS; block++) |
ac27a0ec DK |
2865 | ei->i_data[block] = raw_inode->i_block[block]; |
2866 | INIT_LIST_HEAD(&ei->i_orphan); | |
2867 | ||
0040d987 | 2868 | if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { |
ac27a0ec | 2869 | ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize); |
617ba13b | 2870 | if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > |
e5d2861f KK |
2871 | EXT4_INODE_SIZE(inode->i_sb)) { |
2872 | brelse (bh); | |
1d1fe1ee | 2873 | ret = -EIO; |
ac27a0ec | 2874 | goto bad_inode; |
e5d2861f | 2875 | } |
ac27a0ec DK |
2876 | if (ei->i_extra_isize == 0) { |
2877 | /* The extra space is currently unused. Use it. */ | |
617ba13b MC |
2878 | ei->i_extra_isize = sizeof(struct ext4_inode) - |
2879 | EXT4_GOOD_OLD_INODE_SIZE; | |
ac27a0ec DK |
2880 | } else { |
2881 | __le32 *magic = (void *)raw_inode + | |
617ba13b | 2882 | EXT4_GOOD_OLD_INODE_SIZE + |
ac27a0ec | 2883 | ei->i_extra_isize; |
617ba13b MC |
2884 | if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC)) |
2885 | ei->i_state |= EXT4_STATE_XATTR; | |
ac27a0ec DK |
2886 | } |
2887 | } else | |
2888 | ei->i_extra_isize = 0; | |
2889 | ||
ef7f3835 KS |
2890 | EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode); |
2891 | EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode); | |
2892 | EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode); | |
2893 | EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode); | |
2894 | ||
25ec56b5 JNC |
2895 | inode->i_version = le32_to_cpu(raw_inode->i_disk_version); |
2896 | if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { | |
2897 | if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi)) | |
2898 | inode->i_version |= | |
2899 | (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32; | |
2900 | } | |
2901 | ||
ac27a0ec | 2902 | if (S_ISREG(inode->i_mode)) { |
617ba13b MC |
2903 | inode->i_op = &ext4_file_inode_operations; |
2904 | inode->i_fop = &ext4_file_operations; | |
2905 | ext4_set_aops(inode); | |
ac27a0ec | 2906 | } else if (S_ISDIR(inode->i_mode)) { |
617ba13b MC |
2907 | inode->i_op = &ext4_dir_inode_operations; |
2908 | inode->i_fop = &ext4_dir_operations; | |
ac27a0ec | 2909 | } else if (S_ISLNK(inode->i_mode)) { |
617ba13b MC |
2910 | if (ext4_inode_is_fast_symlink(inode)) |
2911 | inode->i_op = &ext4_fast_symlink_inode_operations; | |
ac27a0ec | 2912 | else { |
617ba13b MC |
2913 | inode->i_op = &ext4_symlink_inode_operations; |
2914 | ext4_set_aops(inode); | |
ac27a0ec DK |
2915 | } |
2916 | } else { | |
617ba13b | 2917 | inode->i_op = &ext4_special_inode_operations; |
ac27a0ec DK |
2918 | if (raw_inode->i_block[0]) |
2919 | init_special_inode(inode, inode->i_mode, | |
2920 | old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); | |
2921 | else | |
2922 | init_special_inode(inode, inode->i_mode, | |
2923 | new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); | |
2924 | } | |
2925 | brelse (iloc.bh); | |
617ba13b | 2926 | ext4_set_inode_flags(inode); |
1d1fe1ee DH |
2927 | unlock_new_inode(inode); |
2928 | return inode; | |
ac27a0ec DK |
2929 | |
2930 | bad_inode: | |
1d1fe1ee DH |
2931 | iget_failed(inode); |
2932 | return ERR_PTR(ret); | |
ac27a0ec DK |
2933 | } |
2934 | ||
0fc1b451 AK |
2935 | static int ext4_inode_blocks_set(handle_t *handle, |
2936 | struct ext4_inode *raw_inode, | |
2937 | struct ext4_inode_info *ei) | |
2938 | { | |
2939 | struct inode *inode = &(ei->vfs_inode); | |
2940 | u64 i_blocks = inode->i_blocks; | |
2941 | struct super_block *sb = inode->i_sb; | |
2942 | int err = 0; | |
2943 | ||
2944 | if (i_blocks <= ~0U) { | |
2945 | /* | |
2946 | * i_blocks can be represnted in a 32 bit variable | |
2947 | * as multiple of 512 bytes | |
2948 | */ | |
8180a562 | 2949 | raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); |
0fc1b451 | 2950 | raw_inode->i_blocks_high = 0; |
8180a562 | 2951 | ei->i_flags &= ~EXT4_HUGE_FILE_FL; |
0fc1b451 AK |
2952 | } else if (i_blocks <= 0xffffffffffffULL) { |
2953 | /* | |
2954 | * i_blocks can be represented in a 48 bit variable | |
2955 | * as multiple of 512 bytes | |
2956 | */ | |
2957 | err = ext4_update_rocompat_feature(handle, sb, | |
2958 | EXT4_FEATURE_RO_COMPAT_HUGE_FILE); | |
2959 | if (err) | |
2960 | goto err_out; | |
2961 | /* i_block is stored in the split 48 bit fields */ | |
8180a562 | 2962 | raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); |
0fc1b451 | 2963 | raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32); |
8180a562 | 2964 | ei->i_flags &= ~EXT4_HUGE_FILE_FL; |
0fc1b451 | 2965 | } else { |
8180a562 AK |
2966 | /* |
2967 | * i_blocks should be represented in a 48 bit variable | |
2968 | * as multiple of file system block size | |
2969 | */ | |
2970 | err = ext4_update_rocompat_feature(handle, sb, | |
2971 | EXT4_FEATURE_RO_COMPAT_HUGE_FILE); | |
2972 | if (err) | |
2973 | goto err_out; | |
2974 | ei->i_flags |= EXT4_HUGE_FILE_FL; | |
2975 | /* i_block is stored in file system block size */ | |
2976 | i_blocks = i_blocks >> (inode->i_blkbits - 9); | |
2977 | raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); | |
2978 | raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32); | |
0fc1b451 AK |
2979 | } |
2980 | err_out: | |
2981 | return err; | |
2982 | } | |
2983 | ||
ac27a0ec DK |
2984 | /* |
2985 | * Post the struct inode info into an on-disk inode location in the | |
2986 | * buffer-cache. This gobbles the caller's reference to the | |
2987 | * buffer_head in the inode location struct. | |
2988 | * | |
2989 | * The caller must have write access to iloc->bh. | |
2990 | */ | |
617ba13b | 2991 | static int ext4_do_update_inode(handle_t *handle, |
ac27a0ec | 2992 | struct inode *inode, |
617ba13b | 2993 | struct ext4_iloc *iloc) |
ac27a0ec | 2994 | { |
617ba13b MC |
2995 | struct ext4_inode *raw_inode = ext4_raw_inode(iloc); |
2996 | struct ext4_inode_info *ei = EXT4_I(inode); | |
ac27a0ec DK |
2997 | struct buffer_head *bh = iloc->bh; |
2998 | int err = 0, rc, block; | |
2999 | ||
3000 | /* For fields not not tracking in the in-memory inode, | |
3001 | * initialise them to zero for new inodes. */ | |
617ba13b MC |
3002 | if (ei->i_state & EXT4_STATE_NEW) |
3003 | memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); | |
ac27a0ec | 3004 | |
ff9ddf7e | 3005 | ext4_get_inode_flags(ei); |
ac27a0ec DK |
3006 | raw_inode->i_mode = cpu_to_le16(inode->i_mode); |
3007 | if(!(test_opt(inode->i_sb, NO_UID32))) { | |
3008 | raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid)); | |
3009 | raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid)); | |
3010 | /* | |
3011 | * Fix up interoperability with old kernels. Otherwise, old inodes get | |
3012 | * re-used with the upper 16 bits of the uid/gid intact | |
3013 | */ | |
3014 | if(!ei->i_dtime) { | |
3015 | raw_inode->i_uid_high = | |
3016 | cpu_to_le16(high_16_bits(inode->i_uid)); | |
3017 | raw_inode->i_gid_high = | |
3018 | cpu_to_le16(high_16_bits(inode->i_gid)); | |
3019 | } else { | |
3020 | raw_inode->i_uid_high = 0; | |
3021 | raw_inode->i_gid_high = 0; | |
3022 | } | |
3023 | } else { | |
3024 | raw_inode->i_uid_low = | |
3025 | cpu_to_le16(fs_high2lowuid(inode->i_uid)); | |
3026 | raw_inode->i_gid_low = | |
3027 | cpu_to_le16(fs_high2lowgid(inode->i_gid)); | |
3028 | raw_inode->i_uid_high = 0; | |
3029 | raw_inode->i_gid_high = 0; | |
3030 | } | |
3031 | raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); | |
ef7f3835 KS |
3032 | |
3033 | EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode); | |
3034 | EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode); | |
3035 | EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode); | |
3036 | EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode); | |
3037 | ||
0fc1b451 AK |
3038 | if (ext4_inode_blocks_set(handle, raw_inode, ei)) |
3039 | goto out_brelse; | |
ac27a0ec | 3040 | raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); |
267e4db9 AK |
3041 | /* clear the migrate flag in the raw_inode */ |
3042 | raw_inode->i_flags = cpu_to_le32(ei->i_flags & ~EXT4_EXT_MIGRATE); | |
9b8f1f01 MC |
3043 | if (EXT4_SB(inode->i_sb)->s_es->s_creator_os != |
3044 | cpu_to_le32(EXT4_OS_HURD)) | |
a1ddeb7e BP |
3045 | raw_inode->i_file_acl_high = |
3046 | cpu_to_le16(ei->i_file_acl >> 32); | |
7973c0c1 | 3047 | raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl); |
a48380f7 AK |
3048 | ext4_isize_set(raw_inode, ei->i_disksize); |
3049 | if (ei->i_disksize > 0x7fffffffULL) { | |
3050 | struct super_block *sb = inode->i_sb; | |
3051 | if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, | |
3052 | EXT4_FEATURE_RO_COMPAT_LARGE_FILE) || | |
3053 | EXT4_SB(sb)->s_es->s_rev_level == | |
3054 | cpu_to_le32(EXT4_GOOD_OLD_REV)) { | |
3055 | /* If this is the first large file | |
3056 | * created, add a flag to the superblock. | |
3057 | */ | |
3058 | err = ext4_journal_get_write_access(handle, | |
3059 | EXT4_SB(sb)->s_sbh); | |
3060 | if (err) | |
3061 | goto out_brelse; | |
3062 | ext4_update_dynamic_rev(sb); | |
3063 | EXT4_SET_RO_COMPAT_FEATURE(sb, | |
617ba13b | 3064 | EXT4_FEATURE_RO_COMPAT_LARGE_FILE); |
a48380f7 AK |
3065 | sb->s_dirt = 1; |
3066 | handle->h_sync = 1; | |
3067 | err = ext4_journal_dirty_metadata(handle, | |
3068 | EXT4_SB(sb)->s_sbh); | |
ac27a0ec DK |
3069 | } |
3070 | } | |
3071 | raw_inode->i_generation = cpu_to_le32(inode->i_generation); | |
3072 | if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { | |
3073 | if (old_valid_dev(inode->i_rdev)) { | |
3074 | raw_inode->i_block[0] = | |
3075 | cpu_to_le32(old_encode_dev(inode->i_rdev)); | |
3076 | raw_inode->i_block[1] = 0; | |
3077 | } else { | |
3078 | raw_inode->i_block[0] = 0; | |
3079 | raw_inode->i_block[1] = | |
3080 | cpu_to_le32(new_encode_dev(inode->i_rdev)); | |
3081 | raw_inode->i_block[2] = 0; | |
3082 | } | |
617ba13b | 3083 | } else for (block = 0; block < EXT4_N_BLOCKS; block++) |
ac27a0ec DK |
3084 | raw_inode->i_block[block] = ei->i_data[block]; |
3085 | ||
25ec56b5 JNC |
3086 | raw_inode->i_disk_version = cpu_to_le32(inode->i_version); |
3087 | if (ei->i_extra_isize) { | |
3088 | if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi)) | |
3089 | raw_inode->i_version_hi = | |
3090 | cpu_to_le32(inode->i_version >> 32); | |
ac27a0ec | 3091 | raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize); |
25ec56b5 JNC |
3092 | } |
3093 | ||
ac27a0ec | 3094 | |
617ba13b MC |
3095 | BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata"); |
3096 | rc = ext4_journal_dirty_metadata(handle, bh); | |
ac27a0ec DK |
3097 | if (!err) |
3098 | err = rc; | |
617ba13b | 3099 | ei->i_state &= ~EXT4_STATE_NEW; |
ac27a0ec DK |
3100 | |
3101 | out_brelse: | |
3102 | brelse (bh); | |
617ba13b | 3103 | ext4_std_error(inode->i_sb, err); |
ac27a0ec DK |
3104 | return err; |
3105 | } | |
3106 | ||
3107 | /* | |
617ba13b | 3108 | * ext4_write_inode() |
ac27a0ec DK |
3109 | * |
3110 | * We are called from a few places: | |
3111 | * | |
3112 | * - Within generic_file_write() for O_SYNC files. | |
3113 | * Here, there will be no transaction running. We wait for any running | |
3114 | * trasnaction to commit. | |
3115 | * | |
3116 | * - Within sys_sync(), kupdate and such. | |
3117 | * We wait on commit, if tol to. | |
3118 | * | |
3119 | * - Within prune_icache() (PF_MEMALLOC == true) | |
3120 | * Here we simply return. We can't afford to block kswapd on the | |
3121 | * journal commit. | |
3122 | * | |
3123 | * In all cases it is actually safe for us to return without doing anything, | |
3124 | * because the inode has been copied into a raw inode buffer in | |
617ba13b | 3125 | * ext4_mark_inode_dirty(). This is a correctness thing for O_SYNC and for |
ac27a0ec DK |
3126 | * knfsd. |
3127 | * | |
3128 | * Note that we are absolutely dependent upon all inode dirtiers doing the | |
3129 | * right thing: they *must* call mark_inode_dirty() after dirtying info in | |
3130 | * which we are interested. | |
3131 | * | |
3132 | * It would be a bug for them to not do this. The code: | |
3133 | * | |
3134 | * mark_inode_dirty(inode) | |
3135 | * stuff(); | |
3136 | * inode->i_size = expr; | |
3137 | * | |
3138 | * is in error because a kswapd-driven write_inode() could occur while | |
3139 | * `stuff()' is running, and the new i_size will be lost. Plus the inode | |
3140 | * will no longer be on the superblock's dirty inode list. | |
3141 | */ | |
617ba13b | 3142 | int ext4_write_inode(struct inode *inode, int wait) |
ac27a0ec DK |
3143 | { |
3144 | if (current->flags & PF_MEMALLOC) | |
3145 | return 0; | |
3146 | ||
617ba13b | 3147 | if (ext4_journal_current_handle()) { |
b38bd33a | 3148 | jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n"); |
ac27a0ec DK |
3149 | dump_stack(); |
3150 | return -EIO; | |
3151 | } | |
3152 | ||
3153 | if (!wait) | |
3154 | return 0; | |
3155 | ||
617ba13b | 3156 | return ext4_force_commit(inode->i_sb); |
ac27a0ec DK |
3157 | } |
3158 | ||
3159 | /* | |
617ba13b | 3160 | * ext4_setattr() |
ac27a0ec DK |
3161 | * |
3162 | * Called from notify_change. | |
3163 | * | |
3164 | * We want to trap VFS attempts to truncate the file as soon as | |
3165 | * possible. In particular, we want to make sure that when the VFS | |
3166 | * shrinks i_size, we put the inode on the orphan list and modify | |
3167 | * i_disksize immediately, so that during the subsequent flushing of | |
3168 | * dirty pages and freeing of disk blocks, we can guarantee that any | |
3169 | * commit will leave the blocks being flushed in an unused state on | |
3170 | * disk. (On recovery, the inode will get truncated and the blocks will | |
3171 | * be freed, so we have a strong guarantee that no future commit will | |
3172 | * leave these blocks visible to the user.) | |
3173 | * | |
3174 | * Called with inode->sem down. | |
3175 | */ | |
617ba13b | 3176 | int ext4_setattr(struct dentry *dentry, struct iattr *attr) |
ac27a0ec DK |
3177 | { |
3178 | struct inode *inode = dentry->d_inode; | |
3179 | int error, rc = 0; | |
3180 | const unsigned int ia_valid = attr->ia_valid; | |
3181 | ||
3182 | error = inode_change_ok(inode, attr); | |
3183 | if (error) | |
3184 | return error; | |
3185 | ||
3186 | if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) || | |
3187 | (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) { | |
3188 | handle_t *handle; | |
3189 | ||
3190 | /* (user+group)*(old+new) structure, inode write (sb, | |
3191 | * inode block, ? - but truncate inode update has it) */ | |
617ba13b MC |
3192 | handle = ext4_journal_start(inode, 2*(EXT4_QUOTA_INIT_BLOCKS(inode->i_sb)+ |
3193 | EXT4_QUOTA_DEL_BLOCKS(inode->i_sb))+3); | |
ac27a0ec DK |
3194 | if (IS_ERR(handle)) { |
3195 | error = PTR_ERR(handle); | |
3196 | goto err_out; | |
3197 | } | |
3198 | error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0; | |
3199 | if (error) { | |
617ba13b | 3200 | ext4_journal_stop(handle); |
ac27a0ec DK |
3201 | return error; |
3202 | } | |
3203 | /* Update corresponding info in inode so that everything is in | |
3204 | * one transaction */ | |
3205 | if (attr->ia_valid & ATTR_UID) | |
3206 | inode->i_uid = attr->ia_uid; | |
3207 | if (attr->ia_valid & ATTR_GID) | |
3208 | inode->i_gid = attr->ia_gid; | |
617ba13b MC |
3209 | error = ext4_mark_inode_dirty(handle, inode); |
3210 | ext4_journal_stop(handle); | |
ac27a0ec DK |
3211 | } |
3212 | ||
e2b46574 ES |
3213 | if (attr->ia_valid & ATTR_SIZE) { |
3214 | if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) { | |
3215 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); | |
3216 | ||
3217 | if (attr->ia_size > sbi->s_bitmap_maxbytes) { | |
3218 | error = -EFBIG; | |
3219 | goto err_out; | |
3220 | } | |
3221 | } | |
3222 | } | |
3223 | ||
ac27a0ec DK |
3224 | if (S_ISREG(inode->i_mode) && |
3225 | attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) { | |
3226 | handle_t *handle; | |
3227 | ||
617ba13b | 3228 | handle = ext4_journal_start(inode, 3); |
ac27a0ec DK |
3229 | if (IS_ERR(handle)) { |
3230 | error = PTR_ERR(handle); | |
3231 | goto err_out; | |
3232 | } | |
3233 | ||
617ba13b MC |
3234 | error = ext4_orphan_add(handle, inode); |
3235 | EXT4_I(inode)->i_disksize = attr->ia_size; | |
3236 | rc = ext4_mark_inode_dirty(handle, inode); | |
ac27a0ec DK |
3237 | if (!error) |
3238 | error = rc; | |
617ba13b | 3239 | ext4_journal_stop(handle); |
ac27a0ec DK |
3240 | } |
3241 | ||
3242 | rc = inode_setattr(inode, attr); | |
3243 | ||
617ba13b | 3244 | /* If inode_setattr's call to ext4_truncate failed to get a |
ac27a0ec DK |
3245 | * transaction handle at all, we need to clean up the in-core |
3246 | * orphan list manually. */ | |
3247 | if (inode->i_nlink) | |
617ba13b | 3248 | ext4_orphan_del(NULL, inode); |
ac27a0ec DK |
3249 | |
3250 | if (!rc && (ia_valid & ATTR_MODE)) | |
617ba13b | 3251 | rc = ext4_acl_chmod(inode); |
ac27a0ec DK |
3252 | |
3253 | err_out: | |
617ba13b | 3254 | ext4_std_error(inode->i_sb, error); |
ac27a0ec DK |
3255 | if (!error) |
3256 | error = rc; | |
3257 | return error; | |
3258 | } | |
3259 | ||
3260 | ||
3261 | /* | |
3262 | * How many blocks doth make a writepage()? | |
3263 | * | |
3264 | * With N blocks per page, it may be: | |
3265 | * N data blocks | |
3266 | * 2 indirect block | |
3267 | * 2 dindirect | |
3268 | * 1 tindirect | |
3269 | * N+5 bitmap blocks (from the above) | |
3270 | * N+5 group descriptor summary blocks | |
3271 | * 1 inode block | |
3272 | * 1 superblock. | |
617ba13b | 3273 | * 2 * EXT4_SINGLEDATA_TRANS_BLOCKS for the quote files |
ac27a0ec | 3274 | * |
617ba13b | 3275 | * 3 * (N + 5) + 2 + 2 * EXT4_SINGLEDATA_TRANS_BLOCKS |
ac27a0ec DK |
3276 | * |
3277 | * With ordered or writeback data it's the same, less the N data blocks. | |
3278 | * | |
3279 | * If the inode's direct blocks can hold an integral number of pages then a | |
3280 | * page cannot straddle two indirect blocks, and we can only touch one indirect | |
3281 | * and dindirect block, and the "5" above becomes "3". | |
3282 | * | |
3283 | * This still overestimates under most circumstances. If we were to pass the | |
3284 | * start and end offsets in here as well we could do block_to_path() on each | |
3285 | * block and work out the exact number of indirects which are touched. Pah. | |
3286 | */ | |
3287 | ||
a86c6181 | 3288 | int ext4_writepage_trans_blocks(struct inode *inode) |
ac27a0ec | 3289 | { |
617ba13b MC |
3290 | int bpp = ext4_journal_blocks_per_page(inode); |
3291 | int indirects = (EXT4_NDIR_BLOCKS % bpp) ? 5 : 3; | |
ac27a0ec DK |
3292 | int ret; |
3293 | ||
a86c6181 AT |
3294 | if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) |
3295 | return ext4_ext_writepage_trans_blocks(inode, bpp); | |
3296 | ||
617ba13b | 3297 | if (ext4_should_journal_data(inode)) |
ac27a0ec DK |
3298 | ret = 3 * (bpp + indirects) + 2; |
3299 | else | |
3300 | ret = 2 * (bpp + indirects) + 2; | |
3301 | ||
3302 | #ifdef CONFIG_QUOTA | |
3303 | /* We know that structure was already allocated during DQUOT_INIT so | |
3304 | * we will be updating only the data blocks + inodes */ | |
617ba13b | 3305 | ret += 2*EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb); |
ac27a0ec DK |
3306 | #endif |
3307 | ||
3308 | return ret; | |
3309 | } | |
3310 | ||
3311 | /* | |
617ba13b | 3312 | * The caller must have previously called ext4_reserve_inode_write(). |
ac27a0ec DK |
3313 | * Give this, we know that the caller already has write access to iloc->bh. |
3314 | */ | |
617ba13b MC |
3315 | int ext4_mark_iloc_dirty(handle_t *handle, |
3316 | struct inode *inode, struct ext4_iloc *iloc) | |
ac27a0ec DK |
3317 | { |
3318 | int err = 0; | |
3319 | ||
25ec56b5 JNC |
3320 | if (test_opt(inode->i_sb, I_VERSION)) |
3321 | inode_inc_iversion(inode); | |
3322 | ||
ac27a0ec DK |
3323 | /* the do_update_inode consumes one bh->b_count */ |
3324 | get_bh(iloc->bh); | |
3325 | ||
dab291af | 3326 | /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */ |
617ba13b | 3327 | err = ext4_do_update_inode(handle, inode, iloc); |
ac27a0ec DK |
3328 | put_bh(iloc->bh); |
3329 | return err; | |
3330 | } | |
3331 | ||
3332 | /* | |
3333 | * On success, We end up with an outstanding reference count against | |
3334 | * iloc->bh. This _must_ be cleaned up later. | |
3335 | */ | |
3336 | ||
3337 | int | |
617ba13b MC |
3338 | ext4_reserve_inode_write(handle_t *handle, struct inode *inode, |
3339 | struct ext4_iloc *iloc) | |
ac27a0ec DK |
3340 | { |
3341 | int err = 0; | |
3342 | if (handle) { | |
617ba13b | 3343 | err = ext4_get_inode_loc(inode, iloc); |
ac27a0ec DK |
3344 | if (!err) { |
3345 | BUFFER_TRACE(iloc->bh, "get_write_access"); | |
617ba13b | 3346 | err = ext4_journal_get_write_access(handle, iloc->bh); |
ac27a0ec DK |
3347 | if (err) { |
3348 | brelse(iloc->bh); | |
3349 | iloc->bh = NULL; | |
3350 | } | |
3351 | } | |
3352 | } | |
617ba13b | 3353 | ext4_std_error(inode->i_sb, err); |
ac27a0ec DK |
3354 | return err; |
3355 | } | |
3356 | ||
6dd4ee7c KS |
3357 | /* |
3358 | * Expand an inode by new_extra_isize bytes. | |
3359 | * Returns 0 on success or negative error number on failure. | |
3360 | */ | |
1d03ec98 AK |
3361 | static int ext4_expand_extra_isize(struct inode *inode, |
3362 | unsigned int new_extra_isize, | |
3363 | struct ext4_iloc iloc, | |
3364 | handle_t *handle) | |
6dd4ee7c KS |
3365 | { |
3366 | struct ext4_inode *raw_inode; | |
3367 | struct ext4_xattr_ibody_header *header; | |
3368 | struct ext4_xattr_entry *entry; | |
3369 | ||
3370 | if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) | |
3371 | return 0; | |
3372 | ||
3373 | raw_inode = ext4_raw_inode(&iloc); | |
3374 | ||
3375 | header = IHDR(inode, raw_inode); | |
3376 | entry = IFIRST(header); | |
3377 | ||
3378 | /* No extended attributes present */ | |
3379 | if (!(EXT4_I(inode)->i_state & EXT4_STATE_XATTR) || | |
3380 | header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) { | |
3381 | memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0, | |
3382 | new_extra_isize); | |
3383 | EXT4_I(inode)->i_extra_isize = new_extra_isize; | |
3384 | return 0; | |
3385 | } | |
3386 | ||
3387 | /* try to expand with EAs present */ | |
3388 | return ext4_expand_extra_isize_ea(inode, new_extra_isize, | |
3389 | raw_inode, handle); | |
3390 | } | |
3391 | ||
ac27a0ec DK |
3392 | /* |
3393 | * What we do here is to mark the in-core inode as clean with respect to inode | |
3394 | * dirtiness (it may still be data-dirty). | |
3395 | * This means that the in-core inode may be reaped by prune_icache | |
3396 | * without having to perform any I/O. This is a very good thing, | |
3397 | * because *any* task may call prune_icache - even ones which | |
3398 | * have a transaction open against a different journal. | |
3399 | * | |
3400 | * Is this cheating? Not really. Sure, we haven't written the | |
3401 | * inode out, but prune_icache isn't a user-visible syncing function. | |
3402 | * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync) | |
3403 | * we start and wait on commits. | |
3404 | * | |
3405 | * Is this efficient/effective? Well, we're being nice to the system | |
3406 | * by cleaning up our inodes proactively so they can be reaped | |
3407 | * without I/O. But we are potentially leaving up to five seconds' | |
3408 | * worth of inodes floating about which prune_icache wants us to | |
3409 | * write out. One way to fix that would be to get prune_icache() | |
3410 | * to do a write_super() to free up some memory. It has the desired | |
3411 | * effect. | |
3412 | */ | |
617ba13b | 3413 | int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode) |
ac27a0ec | 3414 | { |
617ba13b | 3415 | struct ext4_iloc iloc; |
6dd4ee7c KS |
3416 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
3417 | static unsigned int mnt_count; | |
3418 | int err, ret; | |
ac27a0ec DK |
3419 | |
3420 | might_sleep(); | |
617ba13b | 3421 | err = ext4_reserve_inode_write(handle, inode, &iloc); |
6dd4ee7c KS |
3422 | if (EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize && |
3423 | !(EXT4_I(inode)->i_state & EXT4_STATE_NO_EXPAND)) { | |
3424 | /* | |
3425 | * We need extra buffer credits since we may write into EA block | |
3426 | * with this same handle. If journal_extend fails, then it will | |
3427 | * only result in a minor loss of functionality for that inode. | |
3428 | * If this is felt to be critical, then e2fsck should be run to | |
3429 | * force a large enough s_min_extra_isize. | |
3430 | */ | |
3431 | if ((jbd2_journal_extend(handle, | |
3432 | EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) { | |
3433 | ret = ext4_expand_extra_isize(inode, | |
3434 | sbi->s_want_extra_isize, | |
3435 | iloc, handle); | |
3436 | if (ret) { | |
3437 | EXT4_I(inode)->i_state |= EXT4_STATE_NO_EXPAND; | |
c1bddad9 AK |
3438 | if (mnt_count != |
3439 | le16_to_cpu(sbi->s_es->s_mnt_count)) { | |
46e665e9 | 3440 | ext4_warning(inode->i_sb, __func__, |
6dd4ee7c KS |
3441 | "Unable to expand inode %lu. Delete" |
3442 | " some EAs or run e2fsck.", | |
3443 | inode->i_ino); | |
c1bddad9 AK |
3444 | mnt_count = |
3445 | le16_to_cpu(sbi->s_es->s_mnt_count); | |
6dd4ee7c KS |
3446 | } |
3447 | } | |
3448 | } | |
3449 | } | |
ac27a0ec | 3450 | if (!err) |
617ba13b | 3451 | err = ext4_mark_iloc_dirty(handle, inode, &iloc); |
ac27a0ec DK |
3452 | return err; |
3453 | } | |
3454 | ||
3455 | /* | |
617ba13b | 3456 | * ext4_dirty_inode() is called from __mark_inode_dirty() |
ac27a0ec DK |
3457 | * |
3458 | * We're really interested in the case where a file is being extended. | |
3459 | * i_size has been changed by generic_commit_write() and we thus need | |
3460 | * to include the updated inode in the current transaction. | |
3461 | * | |
3462 | * Also, DQUOT_ALLOC_SPACE() will always dirty the inode when blocks | |
3463 | * are allocated to the file. | |
3464 | * | |
3465 | * If the inode is marked synchronous, we don't honour that here - doing | |
3466 | * so would cause a commit on atime updates, which we don't bother doing. | |
3467 | * We handle synchronous inodes at the highest possible level. | |
3468 | */ | |
617ba13b | 3469 | void ext4_dirty_inode(struct inode *inode) |
ac27a0ec | 3470 | { |
617ba13b | 3471 | handle_t *current_handle = ext4_journal_current_handle(); |
ac27a0ec DK |
3472 | handle_t *handle; |
3473 | ||
617ba13b | 3474 | handle = ext4_journal_start(inode, 2); |
ac27a0ec DK |
3475 | if (IS_ERR(handle)) |
3476 | goto out; | |
3477 | if (current_handle && | |
3478 | current_handle->h_transaction != handle->h_transaction) { | |
3479 | /* This task has a transaction open against a different fs */ | |
3480 | printk(KERN_EMERG "%s: transactions do not match!\n", | |
46e665e9 | 3481 | __func__); |
ac27a0ec DK |
3482 | } else { |
3483 | jbd_debug(5, "marking dirty. outer handle=%p\n", | |
3484 | current_handle); | |
617ba13b | 3485 | ext4_mark_inode_dirty(handle, inode); |
ac27a0ec | 3486 | } |
617ba13b | 3487 | ext4_journal_stop(handle); |
ac27a0ec DK |
3488 | out: |
3489 | return; | |
3490 | } | |
3491 | ||
3492 | #if 0 | |
3493 | /* | |
3494 | * Bind an inode's backing buffer_head into this transaction, to prevent | |
3495 | * it from being flushed to disk early. Unlike | |
617ba13b | 3496 | * ext4_reserve_inode_write, this leaves behind no bh reference and |
ac27a0ec DK |
3497 | * returns no iloc structure, so the caller needs to repeat the iloc |
3498 | * lookup to mark the inode dirty later. | |
3499 | */ | |
617ba13b | 3500 | static int ext4_pin_inode(handle_t *handle, struct inode *inode) |
ac27a0ec | 3501 | { |
617ba13b | 3502 | struct ext4_iloc iloc; |
ac27a0ec DK |
3503 | |
3504 | int err = 0; | |
3505 | if (handle) { | |
617ba13b | 3506 | err = ext4_get_inode_loc(inode, &iloc); |
ac27a0ec DK |
3507 | if (!err) { |
3508 | BUFFER_TRACE(iloc.bh, "get_write_access"); | |
dab291af | 3509 | err = jbd2_journal_get_write_access(handle, iloc.bh); |
ac27a0ec | 3510 | if (!err) |
617ba13b | 3511 | err = ext4_journal_dirty_metadata(handle, |
ac27a0ec DK |
3512 | iloc.bh); |
3513 | brelse(iloc.bh); | |
3514 | } | |
3515 | } | |
617ba13b | 3516 | ext4_std_error(inode->i_sb, err); |
ac27a0ec DK |
3517 | return err; |
3518 | } | |
3519 | #endif | |
3520 | ||
617ba13b | 3521 | int ext4_change_inode_journal_flag(struct inode *inode, int val) |
ac27a0ec DK |
3522 | { |
3523 | journal_t *journal; | |
3524 | handle_t *handle; | |
3525 | int err; | |
3526 | ||
3527 | /* | |
3528 | * We have to be very careful here: changing a data block's | |
3529 | * journaling status dynamically is dangerous. If we write a | |
3530 | * data block to the journal, change the status and then delete | |
3531 | * that block, we risk forgetting to revoke the old log record | |
3532 | * from the journal and so a subsequent replay can corrupt data. | |
3533 | * So, first we make sure that the journal is empty and that | |
3534 | * nobody is changing anything. | |
3535 | */ | |
3536 | ||
617ba13b | 3537 | journal = EXT4_JOURNAL(inode); |
d699594d | 3538 | if (is_journal_aborted(journal)) |
ac27a0ec DK |
3539 | return -EROFS; |
3540 | ||
dab291af MC |
3541 | jbd2_journal_lock_updates(journal); |
3542 | jbd2_journal_flush(journal); | |
ac27a0ec DK |
3543 | |
3544 | /* | |
3545 | * OK, there are no updates running now, and all cached data is | |
3546 | * synced to disk. We are now in a completely consistent state | |
3547 | * which doesn't have anything in the journal, and we know that | |
3548 | * no filesystem updates are running, so it is safe to modify | |
3549 | * the inode's in-core data-journaling state flag now. | |
3550 | */ | |
3551 | ||
3552 | if (val) | |
617ba13b | 3553 | EXT4_I(inode)->i_flags |= EXT4_JOURNAL_DATA_FL; |
ac27a0ec | 3554 | else |
617ba13b MC |
3555 | EXT4_I(inode)->i_flags &= ~EXT4_JOURNAL_DATA_FL; |
3556 | ext4_set_aops(inode); | |
ac27a0ec | 3557 | |
dab291af | 3558 | jbd2_journal_unlock_updates(journal); |
ac27a0ec DK |
3559 | |
3560 | /* Finally we can mark the inode as dirty. */ | |
3561 | ||
617ba13b | 3562 | handle = ext4_journal_start(inode, 1); |
ac27a0ec DK |
3563 | if (IS_ERR(handle)) |
3564 | return PTR_ERR(handle); | |
3565 | ||
617ba13b | 3566 | err = ext4_mark_inode_dirty(handle, inode); |
ac27a0ec | 3567 | handle->h_sync = 1; |
617ba13b MC |
3568 | ext4_journal_stop(handle); |
3569 | ext4_std_error(inode->i_sb, err); | |
ac27a0ec DK |
3570 | |
3571 | return err; | |
3572 | } | |
2e9ee850 AK |
3573 | |
3574 | static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh) | |
3575 | { | |
3576 | return !buffer_mapped(bh); | |
3577 | } | |
3578 | ||
3579 | int ext4_page_mkwrite(struct vm_area_struct *vma, struct page *page) | |
3580 | { | |
3581 | loff_t size; | |
3582 | unsigned long len; | |
3583 | int ret = -EINVAL; | |
3584 | struct file *file = vma->vm_file; | |
3585 | struct inode *inode = file->f_path.dentry->d_inode; | |
3586 | struct address_space *mapping = inode->i_mapping; | |
3587 | ||
3588 | /* | |
3589 | * Get i_alloc_sem to stop truncates messing with the inode. We cannot | |
3590 | * get i_mutex because we are already holding mmap_sem. | |
3591 | */ | |
3592 | down_read(&inode->i_alloc_sem); | |
3593 | size = i_size_read(inode); | |
3594 | if (page->mapping != mapping || size <= page_offset(page) | |
3595 | || !PageUptodate(page)) { | |
3596 | /* page got truncated from under us? */ | |
3597 | goto out_unlock; | |
3598 | } | |
3599 | ret = 0; | |
3600 | if (PageMappedToDisk(page)) | |
3601 | goto out_unlock; | |
3602 | ||
3603 | if (page->index == size >> PAGE_CACHE_SHIFT) | |
3604 | len = size & ~PAGE_CACHE_MASK; | |
3605 | else | |
3606 | len = PAGE_CACHE_SIZE; | |
3607 | ||
3608 | if (page_has_buffers(page)) { | |
3609 | /* return if we have all the buffers mapped */ | |
3610 | if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL, | |
3611 | ext4_bh_unmapped)) | |
3612 | goto out_unlock; | |
3613 | } | |
3614 | /* | |
3615 | * OK, we need to fill the hole... Do write_begin write_end | |
3616 | * to do block allocation/reservation.We are not holding | |
3617 | * inode.i__mutex here. That allow * parallel write_begin, | |
3618 | * write_end call. lock_page prevent this from happening | |
3619 | * on the same page though | |
3620 | */ | |
3621 | ret = mapping->a_ops->write_begin(file, mapping, page_offset(page), | |
3622 | len, AOP_FLAG_UNINTERRUPTIBLE, &page, NULL); | |
3623 | if (ret < 0) | |
3624 | goto out_unlock; | |
3625 | ret = mapping->a_ops->write_end(file, mapping, page_offset(page), | |
3626 | len, len, page, NULL); | |
3627 | if (ret < 0) | |
3628 | goto out_unlock; | |
3629 | ret = 0; | |
3630 | out_unlock: | |
3631 | up_read(&inode->i_alloc_sem); | |
3632 | return ret; | |
3633 | } |