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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
dae1e52c AG |
2 | /* |
3 | * linux/fs/ext4/indirect.c | |
4 | * | |
5 | * from | |
6 | * | |
7 | * linux/fs/ext4/inode.c | |
8 | * | |
9 | * Copyright (C) 1992, 1993, 1994, 1995 | |
10 | * Remy Card (card@masi.ibp.fr) | |
11 | * Laboratoire MASI - Institut Blaise Pascal | |
12 | * Universite Pierre et Marie Curie (Paris VI) | |
13 | * | |
14 | * from | |
15 | * | |
16 | * linux/fs/minix/inode.c | |
17 | * | |
18 | * Copyright (C) 1991, 1992 Linus Torvalds | |
19 | * | |
20 | * Goal-directed block allocation by Stephen Tweedie | |
21 | * (sct@redhat.com), 1993, 1998 | |
22 | */ | |
23 | ||
dae1e52c AG |
24 | #include "ext4_jbd2.h" |
25 | #include "truncate.h" | |
c94c2acf | 26 | #include <linux/dax.h> |
e2e40f2c | 27 | #include <linux/uio.h> |
dae1e52c AG |
28 | |
29 | #include <trace/events/ext4.h> | |
30 | ||
31 | typedef struct { | |
32 | __le32 *p; | |
33 | __le32 key; | |
34 | struct buffer_head *bh; | |
35 | } Indirect; | |
36 | ||
37 | static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) | |
38 | { | |
39 | p->key = *(p->p = v); | |
40 | p->bh = bh; | |
41 | } | |
42 | ||
43 | /** | |
44 | * ext4_block_to_path - parse the block number into array of offsets | |
45 | * @inode: inode in question (we are only interested in its superblock) | |
46 | * @i_block: block number to be parsed | |
47 | * @offsets: array to store the offsets in | |
48 | * @boundary: set this non-zero if the referred-to block is likely to be | |
49 | * followed (on disk) by an indirect block. | |
50 | * | |
51 | * To store the locations of file's data ext4 uses a data structure common | |
52 | * for UNIX filesystems - tree of pointers anchored in the inode, with | |
53 | * data blocks at leaves and indirect blocks in intermediate nodes. | |
54 | * This function translates the block number into path in that tree - | |
55 | * return value is the path length and @offsets[n] is the offset of | |
56 | * pointer to (n+1)th node in the nth one. If @block is out of range | |
57 | * (negative or too large) warning is printed and zero returned. | |
58 | * | |
59 | * Note: function doesn't find node addresses, so no IO is needed. All | |
60 | * we need to know is the capacity of indirect blocks (taken from the | |
61 | * inode->i_sb). | |
62 | */ | |
63 | ||
64 | /* | |
65 | * Portability note: the last comparison (check that we fit into triple | |
66 | * indirect block) is spelled differently, because otherwise on an | |
67 | * architecture with 32-bit longs and 8Kb pages we might get into trouble | |
68 | * if our filesystem had 8Kb blocks. We might use long long, but that would | |
69 | * kill us on x86. Oh, well, at least the sign propagation does not matter - | |
70 | * i_block would have to be negative in the very beginning, so we would not | |
71 | * get there at all. | |
72 | */ | |
73 | ||
74 | static int ext4_block_to_path(struct inode *inode, | |
75 | ext4_lblk_t i_block, | |
76 | ext4_lblk_t offsets[4], int *boundary) | |
77 | { | |
78 | int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb); | |
79 | int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb); | |
80 | const long direct_blocks = EXT4_NDIR_BLOCKS, | |
81 | indirect_blocks = ptrs, | |
82 | double_blocks = (1 << (ptrs_bits * 2)); | |
83 | int n = 0; | |
84 | int final = 0; | |
85 | ||
86 | if (i_block < direct_blocks) { | |
87 | offsets[n++] = i_block; | |
88 | final = direct_blocks; | |
89 | } else if ((i_block -= direct_blocks) < indirect_blocks) { | |
90 | offsets[n++] = EXT4_IND_BLOCK; | |
91 | offsets[n++] = i_block; | |
92 | final = ptrs; | |
93 | } else if ((i_block -= indirect_blocks) < double_blocks) { | |
94 | offsets[n++] = EXT4_DIND_BLOCK; | |
95 | offsets[n++] = i_block >> ptrs_bits; | |
96 | offsets[n++] = i_block & (ptrs - 1); | |
97 | final = ptrs; | |
98 | } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { | |
99 | offsets[n++] = EXT4_TIND_BLOCK; | |
100 | offsets[n++] = i_block >> (ptrs_bits * 2); | |
101 | offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); | |
102 | offsets[n++] = i_block & (ptrs - 1); | |
103 | final = ptrs; | |
104 | } else { | |
105 | ext4_warning(inode->i_sb, "block %lu > max in inode %lu", | |
106 | i_block + direct_blocks + | |
107 | indirect_blocks + double_blocks, inode->i_ino); | |
108 | } | |
109 | if (boundary) | |
110 | *boundary = final - 1 - (i_block & (ptrs - 1)); | |
111 | return n; | |
112 | } | |
113 | ||
114 | /** | |
115 | * ext4_get_branch - read the chain of indirect blocks leading to data | |
116 | * @inode: inode in question | |
117 | * @depth: depth of the chain (1 - direct pointer, etc.) | |
118 | * @offsets: offsets of pointers in inode/indirect blocks | |
119 | * @chain: place to store the result | |
120 | * @err: here we store the error value | |
121 | * | |
122 | * Function fills the array of triples <key, p, bh> and returns %NULL | |
123 | * if everything went OK or the pointer to the last filled triple | |
124 | * (incomplete one) otherwise. Upon the return chain[i].key contains | |
125 | * the number of (i+1)-th block in the chain (as it is stored in memory, | |
126 | * i.e. little-endian 32-bit), chain[i].p contains the address of that | |
127 | * number (it points into struct inode for i==0 and into the bh->b_data | |
128 | * for i>0) and chain[i].bh points to the buffer_head of i-th indirect | |
129 | * block for i>0 and NULL for i==0. In other words, it holds the block | |
130 | * numbers of the chain, addresses they were taken from (and where we can | |
131 | * verify that chain did not change) and buffer_heads hosting these | |
132 | * numbers. | |
133 | * | |
134 | * Function stops when it stumbles upon zero pointer (absent block) | |
135 | * (pointer to last triple returned, *@err == 0) | |
136 | * or when it gets an IO error reading an indirect block | |
137 | * (ditto, *@err == -EIO) | |
138 | * or when it reads all @depth-1 indirect blocks successfully and finds | |
139 | * the whole chain, all way to the data (returns %NULL, *err == 0). | |
140 | * | |
141 | * Need to be called with | |
142 | * down_read(&EXT4_I(inode)->i_data_sem) | |
143 | */ | |
144 | static Indirect *ext4_get_branch(struct inode *inode, int depth, | |
145 | ext4_lblk_t *offsets, | |
146 | Indirect chain[4], int *err) | |
147 | { | |
148 | struct super_block *sb = inode->i_sb; | |
149 | Indirect *p = chain; | |
150 | struct buffer_head *bh; | |
26d75a16 | 151 | unsigned int key; |
860d21e2 | 152 | int ret = -EIO; |
dae1e52c AG |
153 | |
154 | *err = 0; | |
155 | /* i_data is not going away, no lock needed */ | |
156 | add_chain(chain, NULL, EXT4_I(inode)->i_data + *offsets); | |
157 | if (!p->key) | |
158 | goto no_block; | |
159 | while (--depth) { | |
26d75a16 LH |
160 | key = le32_to_cpu(p->key); |
161 | if (key > ext4_blocks_count(EXT4_SB(sb)->s_es)) { | |
162 | /* the block was out of range */ | |
163 | ret = -EFSCORRUPTED; | |
164 | goto failure; | |
165 | } | |
166 | bh = sb_getblk(sb, key); | |
860d21e2 TT |
167 | if (unlikely(!bh)) { |
168 | ret = -ENOMEM; | |
dae1e52c | 169 | goto failure; |
860d21e2 | 170 | } |
dae1e52c AG |
171 | |
172 | if (!bh_uptodate_or_lock(bh)) { | |
2d069c08 | 173 | if (ext4_read_bh(bh, 0, NULL) < 0) { |
dae1e52c AG |
174 | put_bh(bh); |
175 | goto failure; | |
176 | } | |
177 | /* validate block references */ | |
178 | if (ext4_check_indirect_blockref(inode, bh)) { | |
179 | put_bh(bh); | |
180 | goto failure; | |
181 | } | |
182 | } | |
183 | ||
184 | add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets); | |
185 | /* Reader: end */ | |
186 | if (!p->key) | |
187 | goto no_block; | |
188 | } | |
189 | return NULL; | |
190 | ||
191 | failure: | |
860d21e2 | 192 | *err = ret; |
dae1e52c AG |
193 | no_block: |
194 | return p; | |
195 | } | |
196 | ||
197 | /** | |
198 | * ext4_find_near - find a place for allocation with sufficient locality | |
199 | * @inode: owner | |
200 | * @ind: descriptor of indirect block. | |
201 | * | |
202 | * This function returns the preferred place for block allocation. | |
203 | * It is used when heuristic for sequential allocation fails. | |
204 | * Rules are: | |
205 | * + if there is a block to the left of our position - allocate near it. | |
206 | * + if pointer will live in indirect block - allocate near that block. | |
207 | * + if pointer will live in inode - allocate in the same | |
208 | * cylinder group. | |
209 | * | |
210 | * In the latter case we colour the starting block by the callers PID to | |
211 | * prevent it from clashing with concurrent allocations for a different inode | |
212 | * in the same block group. The PID is used here so that functionally related | |
213 | * files will be close-by on-disk. | |
214 | * | |
215 | * Caller must make sure that @ind is valid and will stay that way. | |
216 | */ | |
217 | static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind) | |
218 | { | |
219 | struct ext4_inode_info *ei = EXT4_I(inode); | |
220 | __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; | |
221 | __le32 *p; | |
dae1e52c AG |
222 | |
223 | /* Try to find previous block */ | |
224 | for (p = ind->p - 1; p >= start; p--) { | |
225 | if (*p) | |
226 | return le32_to_cpu(*p); | |
227 | } | |
228 | ||
229 | /* No such thing, so let's try location of indirect block */ | |
230 | if (ind->bh) | |
231 | return ind->bh->b_blocknr; | |
232 | ||
233 | /* | |
234 | * It is going to be referred to from the inode itself? OK, just put it | |
235 | * into the same cylinder group then. | |
236 | */ | |
f86186b4 | 237 | return ext4_inode_to_goal_block(inode); |
dae1e52c AG |
238 | } |
239 | ||
240 | /** | |
241 | * ext4_find_goal - find a preferred place for allocation. | |
242 | * @inode: owner | |
243 | * @block: block we want | |
244 | * @partial: pointer to the last triple within a chain | |
245 | * | |
246 | * Normally this function find the preferred place for block allocation, | |
247 | * returns it. | |
248 | * Because this is only used for non-extent files, we limit the block nr | |
249 | * to 32 bits. | |
250 | */ | |
251 | static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block, | |
252 | Indirect *partial) | |
253 | { | |
254 | ext4_fsblk_t goal; | |
255 | ||
256 | /* | |
257 | * XXX need to get goal block from mballoc's data structures | |
258 | */ | |
259 | ||
260 | goal = ext4_find_near(inode, partial); | |
261 | goal = goal & EXT4_MAX_BLOCK_FILE_PHYS; | |
262 | return goal; | |
263 | } | |
264 | ||
265 | /** | |
266 | * ext4_blks_to_allocate - Look up the block map and count the number | |
267 | * of direct blocks need to be allocated for the given branch. | |
268 | * | |
269 | * @branch: chain of indirect blocks | |
270 | * @k: number of blocks need for indirect blocks | |
271 | * @blks: number of data blocks to be mapped. | |
272 | * @blocks_to_boundary: the offset in the indirect block | |
273 | * | |
274 | * return the total number of blocks to be allocate, including the | |
275 | * direct and indirect blocks. | |
276 | */ | |
277 | static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned int blks, | |
278 | int blocks_to_boundary) | |
279 | { | |
280 | unsigned int count = 0; | |
281 | ||
282 | /* | |
283 | * Simple case, [t,d]Indirect block(s) has not allocated yet | |
284 | * then it's clear blocks on that path have not allocated | |
285 | */ | |
286 | if (k > 0) { | |
287 | /* right now we don't handle cross boundary allocation */ | |
288 | if (blks < blocks_to_boundary + 1) | |
289 | count += blks; | |
290 | else | |
291 | count += blocks_to_boundary + 1; | |
292 | return count; | |
293 | } | |
294 | ||
295 | count++; | |
296 | while (count < blks && count <= blocks_to_boundary && | |
297 | le32_to_cpu(*(branch[0].p + count)) == 0) { | |
298 | count++; | |
299 | } | |
300 | return count; | |
301 | } | |
302 | ||
dae1e52c | 303 | /** |
c60990b3 TT |
304 | * ext4_alloc_branch() - allocate and set up a chain of blocks |
305 | * @handle: handle for this transaction | |
306 | * @ar: structure describing the allocation request | |
307 | * @indirect_blks: number of allocated indirect blocks | |
308 | * @offsets: offsets (in the blocks) to store the pointers to next. | |
309 | * @branch: place to store the chain in. | |
dae1e52c AG |
310 | * |
311 | * This function allocates blocks, zeroes out all but the last one, | |
312 | * links them into chain and (if we are synchronous) writes them to disk. | |
313 | * In other words, it prepares a branch that can be spliced onto the | |
314 | * inode. It stores the information about that chain in the branch[], in | |
315 | * the same format as ext4_get_branch() would do. We are calling it after | |
316 | * we had read the existing part of chain and partial points to the last | |
317 | * triple of that (one with zero ->key). Upon the exit we have the same | |
318 | * picture as after the successful ext4_get_block(), except that in one | |
319 | * place chain is disconnected - *branch->p is still zero (we did not | |
320 | * set the last link), but branch->key contains the number that should | |
321 | * be placed into *branch->p to fill that gap. | |
322 | * | |
323 | * If allocation fails we free all blocks we've allocated (and forget | |
324 | * their buffer_heads) and return the error value the from failed | |
325 | * ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain | |
326 | * as described above and return 0. | |
327 | */ | |
a5211002 TT |
328 | static int ext4_alloc_branch(handle_t *handle, |
329 | struct ext4_allocation_request *ar, | |
330 | int indirect_blks, ext4_lblk_t *offsets, | |
331 | Indirect *branch) | |
dae1e52c | 332 | { |
781f143e TT |
333 | struct buffer_head * bh; |
334 | ext4_fsblk_t b, new_blocks[4]; | |
335 | __le32 *p; | |
336 | int i, j, err, len = 1; | |
dae1e52c | 337 | |
781f143e TT |
338 | for (i = 0; i <= indirect_blks; i++) { |
339 | if (i == indirect_blks) { | |
a5211002 | 340 | new_blocks[i] = ext4_mb_new_blocks(handle, ar, &err); |
f2890730 | 341 | } else { |
a5211002 | 342 | ar->goal = new_blocks[i] = ext4_new_meta_blocks(handle, |
e3cf5d5d TT |
343 | ar->inode, ar->goal, |
344 | ar->flags & EXT4_MB_DELALLOC_RESERVED, | |
345 | NULL, &err); | |
f2890730 JK |
346 | /* Simplify error cleanup... */ |
347 | branch[i+1].bh = NULL; | |
348 | } | |
781f143e TT |
349 | if (err) { |
350 | i--; | |
351 | goto failed; | |
352 | } | |
353 | branch[i].key = cpu_to_le32(new_blocks[i]); | |
354 | if (i == 0) | |
355 | continue; | |
356 | ||
a5211002 | 357 | bh = branch[i].bh = sb_getblk(ar->inode->i_sb, new_blocks[i-1]); |
dae1e52c | 358 | if (unlikely(!bh)) { |
860d21e2 | 359 | err = -ENOMEM; |
dae1e52c AG |
360 | goto failed; |
361 | } | |
dae1e52c AG |
362 | lock_buffer(bh); |
363 | BUFFER_TRACE(bh, "call get_create_access"); | |
188c299e JK |
364 | err = ext4_journal_get_create_access(handle, ar->inode->i_sb, |
365 | bh, EXT4_JTR_NONE); | |
dae1e52c | 366 | if (err) { |
dae1e52c AG |
367 | unlock_buffer(bh); |
368 | goto failed; | |
369 | } | |
370 | ||
781f143e TT |
371 | memset(bh->b_data, 0, bh->b_size); |
372 | p = branch[i].p = (__le32 *) bh->b_data + offsets[i]; | |
373 | b = new_blocks[i]; | |
374 | ||
375 | if (i == indirect_blks) | |
a5211002 | 376 | len = ar->len; |
781f143e TT |
377 | for (j = 0; j < len; j++) |
378 | *p++ = cpu_to_le32(b++); | |
379 | ||
dae1e52c AG |
380 | BUFFER_TRACE(bh, "marking uptodate"); |
381 | set_buffer_uptodate(bh); | |
382 | unlock_buffer(bh); | |
383 | ||
384 | BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); | |
a5211002 | 385 | err = ext4_handle_dirty_metadata(handle, ar->inode, bh); |
dae1e52c AG |
386 | if (err) |
387 | goto failed; | |
388 | } | |
781f143e | 389 | return 0; |
dae1e52c | 390 | failed: |
f2890730 JK |
391 | if (i == indirect_blks) { |
392 | /* Free data blocks */ | |
393 | ext4_free_blocks(handle, ar->inode, NULL, new_blocks[i], | |
394 | ar->len, 0); | |
395 | i--; | |
396 | } | |
781f143e | 397 | for (; i >= 0; i--) { |
c5c7b8dd JK |
398 | /* |
399 | * We want to ext4_forget() only freshly allocated indirect | |
f2890730 JK |
400 | * blocks. Buffer for new_blocks[i] is at branch[i+1].bh |
401 | * (buffer at branch[0].bh is indirect block / inode already | |
402 | * existing before ext4_alloc_branch() was called). Also | |
403 | * because blocks are freshly allocated, we don't need to | |
404 | * revoke them which is why we don't set | |
405 | * EXT4_FREE_BLOCKS_METADATA. | |
c5c7b8dd | 406 | */ |
f2890730 JK |
407 | ext4_free_blocks(handle, ar->inode, branch[i+1].bh, |
408 | new_blocks[i], 1, | |
409 | branch[i+1].bh ? EXT4_FREE_BLOCKS_FORGET : 0); | |
dae1e52c | 410 | } |
dae1e52c AG |
411 | return err; |
412 | } | |
413 | ||
414 | /** | |
c60990b3 | 415 | * ext4_splice_branch() - splice the allocated branch onto inode. |
dae1e52c | 416 | * @handle: handle for this transaction |
c60990b3 | 417 | * @ar: structure describing the allocation request |
dae1e52c AG |
418 | * @where: location of missing link |
419 | * @num: number of indirect blocks we are adding | |
dae1e52c AG |
420 | * |
421 | * This function fills the missing link and does all housekeeping needed in | |
422 | * inode (->i_blocks, etc.). In case of success we end up with the full | |
423 | * chain to new block and return 0. | |
424 | */ | |
a5211002 TT |
425 | static int ext4_splice_branch(handle_t *handle, |
426 | struct ext4_allocation_request *ar, | |
427 | Indirect *where, int num) | |
dae1e52c AG |
428 | { |
429 | int i; | |
430 | int err = 0; | |
431 | ext4_fsblk_t current_block; | |
432 | ||
433 | /* | |
434 | * If we're splicing into a [td]indirect block (as opposed to the | |
435 | * inode) then we need to get write access to the [td]indirect block | |
436 | * before the splice. | |
437 | */ | |
438 | if (where->bh) { | |
439 | BUFFER_TRACE(where->bh, "get_write_access"); | |
188c299e JK |
440 | err = ext4_journal_get_write_access(handle, ar->inode->i_sb, |
441 | where->bh, EXT4_JTR_NONE); | |
dae1e52c AG |
442 | if (err) |
443 | goto err_out; | |
444 | } | |
445 | /* That's it */ | |
446 | ||
447 | *where->p = where->key; | |
448 | ||
449 | /* | |
450 | * Update the host buffer_head or inode to point to more just allocated | |
451 | * direct blocks blocks | |
452 | */ | |
a5211002 | 453 | if (num == 0 && ar->len > 1) { |
dae1e52c | 454 | current_block = le32_to_cpu(where->key) + 1; |
a5211002 | 455 | for (i = 1; i < ar->len; i++) |
dae1e52c AG |
456 | *(where->p + i) = cpu_to_le32(current_block++); |
457 | } | |
458 | ||
459 | /* We are done with atomic stuff, now do the rest of housekeeping */ | |
460 | /* had we spliced it onto indirect block? */ | |
461 | if (where->bh) { | |
462 | /* | |
463 | * If we spliced it onto an indirect block, we haven't | |
464 | * altered the inode. Note however that if it is being spliced | |
465 | * onto an indirect block at the very end of the file (the | |
466 | * file is growing) then we *will* alter the inode to reflect | |
467 | * the new i_size. But that is not done here - it is done in | |
468 | * generic_commit_write->__mark_inode_dirty->ext4_dirty_inode. | |
469 | */ | |
4978c659 | 470 | ext4_debug("splicing indirect only\n"); |
dae1e52c | 471 | BUFFER_TRACE(where->bh, "call ext4_handle_dirty_metadata"); |
a5211002 | 472 | err = ext4_handle_dirty_metadata(handle, ar->inode, where->bh); |
dae1e52c AG |
473 | if (err) |
474 | goto err_out; | |
475 | } else { | |
476 | /* | |
477 | * OK, we spliced it into the inode itself on a direct block. | |
478 | */ | |
4209ae12 HS |
479 | err = ext4_mark_inode_dirty(handle, ar->inode); |
480 | if (unlikely(err)) | |
481 | goto err_out; | |
4978c659 | 482 | ext4_debug("splicing direct\n"); |
dae1e52c AG |
483 | } |
484 | return err; | |
485 | ||
486 | err_out: | |
487 | for (i = 1; i <= num; i++) { | |
488 | /* | |
489 | * branch[i].bh is newly allocated, so there is no | |
490 | * need to revoke the block, which is why we don't | |
491 | * need to set EXT4_FREE_BLOCKS_METADATA. | |
492 | */ | |
a5211002 | 493 | ext4_free_blocks(handle, ar->inode, where[i].bh, 0, 1, |
dae1e52c AG |
494 | EXT4_FREE_BLOCKS_FORGET); |
495 | } | |
a5211002 TT |
496 | ext4_free_blocks(handle, ar->inode, NULL, le32_to_cpu(where[num].key), |
497 | ar->len, 0); | |
dae1e52c AG |
498 | |
499 | return err; | |
500 | } | |
501 | ||
502 | /* | |
503 | * The ext4_ind_map_blocks() function handles non-extents inodes | |
504 | * (i.e., using the traditional indirect/double-indirect i_blocks | |
505 | * scheme) for ext4_map_blocks(). | |
506 | * | |
507 | * Allocation strategy is simple: if we have to allocate something, we will | |
508 | * have to go the whole way to leaf. So let's do it before attaching anything | |
509 | * to tree, set linkage between the newborn blocks, write them if sync is | |
510 | * required, recheck the path, free and repeat if check fails, otherwise | |
511 | * set the last missing link (that will protect us from any truncate-generated | |
512 | * removals - all blocks on the path are immune now) and possibly force the | |
513 | * write on the parent block. | |
514 | * That has a nice additional property: no special recovery from the failed | |
515 | * allocations is needed - we simply release blocks and do not touch anything | |
516 | * reachable from inode. | |
517 | * | |
518 | * `handle' can be NULL if create == 0. | |
519 | * | |
520 | * return > 0, # of blocks mapped or allocated. | |
521 | * return = 0, if plain lookup failed. | |
522 | * return < 0, error case. | |
523 | * | |
524 | * The ext4_ind_get_blocks() function should be called with | |
525 | * down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem | |
526 | * blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or | |
527 | * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system | |
528 | * blocks. | |
529 | */ | |
530 | int ext4_ind_map_blocks(handle_t *handle, struct inode *inode, | |
531 | struct ext4_map_blocks *map, | |
532 | int flags) | |
533 | { | |
a5211002 | 534 | struct ext4_allocation_request ar; |
dae1e52c AG |
535 | int err = -EIO; |
536 | ext4_lblk_t offsets[4]; | |
537 | Indirect chain[4]; | |
538 | Indirect *partial; | |
dae1e52c AG |
539 | int indirect_blks; |
540 | int blocks_to_boundary = 0; | |
541 | int depth; | |
542 | int count = 0; | |
543 | ext4_fsblk_t first_block = 0; | |
544 | ||
545 | trace_ext4_ind_map_blocks_enter(inode, map->m_lblk, map->m_len, flags); | |
837c23fb CX |
546 | ASSERT(!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))); |
547 | ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0); | |
dae1e52c AG |
548 | depth = ext4_block_to_path(inode, map->m_lblk, offsets, |
549 | &blocks_to_boundary); | |
550 | ||
551 | if (depth == 0) | |
552 | goto out; | |
553 | ||
554 | partial = ext4_get_branch(inode, depth, offsets, chain, &err); | |
555 | ||
556 | /* Simplest case - block found, no allocation needed */ | |
557 | if (!partial) { | |
558 | first_block = le32_to_cpu(chain[depth - 1].key); | |
559 | count++; | |
560 | /*map more blocks*/ | |
561 | while (count < map->m_len && count <= blocks_to_boundary) { | |
562 | ext4_fsblk_t blk; | |
563 | ||
564 | blk = le32_to_cpu(*(chain[depth-1].p + count)); | |
565 | ||
566 | if (blk == first_block + count) | |
567 | count++; | |
568 | else | |
569 | break; | |
570 | } | |
571 | goto got_it; | |
572 | } | |
573 | ||
facab4d9 JK |
574 | /* Next simple case - plain lookup failed */ |
575 | if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { | |
576 | unsigned epb = inode->i_sb->s_blocksize / sizeof(u32); | |
577 | int i; | |
578 | ||
2ee3ee06 JK |
579 | /* |
580 | * Count number blocks in a subtree under 'partial'. At each | |
581 | * level we count number of complete empty subtrees beyond | |
582 | * current offset and then descend into the subtree only | |
583 | * partially beyond current offset. | |
584 | */ | |
585 | count = 0; | |
586 | for (i = partial - chain + 1; i < depth; i++) | |
587 | count = count * epb + (epb - offsets[i] - 1); | |
588 | count++; | |
facab4d9 JK |
589 | /* Fill in size of a hole we found */ |
590 | map->m_pblk = 0; | |
591 | map->m_len = min_t(unsigned int, map->m_len, count); | |
592 | goto cleanup; | |
593 | } | |
594 | ||
595 | /* Failed read of indirect block */ | |
596 | if (err == -EIO) | |
dae1e52c AG |
597 | goto cleanup; |
598 | ||
599 | /* | |
600 | * Okay, we need to do block allocation. | |
601 | */ | |
e2b911c5 | 602 | if (ext4_has_feature_bigalloc(inode->i_sb)) { |
bab08ab9 TT |
603 | EXT4_ERROR_INODE(inode, "Can't allocate blocks for " |
604 | "non-extent mapped inodes with bigalloc"); | |
2be7d717 ZQ |
605 | err = -EFSCORRUPTED; |
606 | goto out; | |
bab08ab9 TT |
607 | } |
608 | ||
a5211002 TT |
609 | /* Set up for the direct block allocation */ |
610 | memset(&ar, 0, sizeof(ar)); | |
611 | ar.inode = inode; | |
612 | ar.logical = map->m_lblk; | |
613 | if (S_ISREG(inode->i_mode)) | |
614 | ar.flags = EXT4_MB_HINT_DATA; | |
e3cf5d5d TT |
615 | if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) |
616 | ar.flags |= EXT4_MB_DELALLOC_RESERVED; | |
c5e298ae TT |
617 | if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL) |
618 | ar.flags |= EXT4_MB_USE_RESERVED; | |
a5211002 TT |
619 | |
620 | ar.goal = ext4_find_goal(inode, map->m_lblk, partial); | |
dae1e52c AG |
621 | |
622 | /* the number of blocks need to allocate for [d,t]indirect blocks */ | |
623 | indirect_blks = (chain + depth) - partial - 1; | |
624 | ||
625 | /* | |
626 | * Next look up the indirect map to count the totoal number of | |
627 | * direct blocks to allocate for this branch. | |
628 | */ | |
a5211002 TT |
629 | ar.len = ext4_blks_to_allocate(partial, indirect_blks, |
630 | map->m_len, blocks_to_boundary); | |
631 | ||
dae1e52c AG |
632 | /* |
633 | * Block out ext4_truncate while we alter the tree | |
634 | */ | |
a5211002 | 635 | err = ext4_alloc_branch(handle, &ar, indirect_blks, |
dae1e52c AG |
636 | offsets + (partial - chain), partial); |
637 | ||
638 | /* | |
639 | * The ext4_splice_branch call will free and forget any buffers | |
640 | * on the new chain if there is a failure, but that risks using | |
641 | * up transaction credits, especially for bitmaps where the | |
642 | * credits cannot be returned. Can we handle this somehow? We | |
643 | * may need to return -EAGAIN upwards in the worst case. --sct | |
644 | */ | |
645 | if (!err) | |
a5211002 | 646 | err = ext4_splice_branch(handle, &ar, partial, indirect_blks); |
dae1e52c AG |
647 | if (err) |
648 | goto cleanup; | |
649 | ||
650 | map->m_flags |= EXT4_MAP_NEW; | |
651 | ||
652 | ext4_update_inode_fsync_trans(handle, inode, 1); | |
a5211002 | 653 | count = ar.len; |
dae1e52c AG |
654 | got_it: |
655 | map->m_flags |= EXT4_MAP_MAPPED; | |
656 | map->m_pblk = le32_to_cpu(chain[depth-1].key); | |
657 | map->m_len = count; | |
658 | if (count > blocks_to_boundary) | |
659 | map->m_flags |= EXT4_MAP_BOUNDARY; | |
660 | err = count; | |
661 | /* Clean up and exit */ | |
662 | partial = chain + depth - 1; /* the whole chain */ | |
663 | cleanup: | |
664 | while (partial > chain) { | |
665 | BUFFER_TRACE(partial->bh, "call brelse"); | |
666 | brelse(partial->bh); | |
667 | partial--; | |
668 | } | |
669 | out: | |
21ddd568 | 670 | trace_ext4_ind_map_blocks_exit(inode, flags, map, err); |
dae1e52c AG |
671 | return err; |
672 | } | |
673 | ||
fa55a0ed JK |
674 | /* |
675 | * Calculate number of indirect blocks touched by mapping @nrblocks logically | |
676 | * contiguous blocks | |
677 | */ | |
678 | int ext4_ind_trans_blocks(struct inode *inode, int nrblocks) | |
dae1e52c | 679 | { |
dae1e52c | 680 | /* |
fa55a0ed JK |
681 | * With N contiguous data blocks, we need at most |
682 | * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks, | |
683 | * 2 dindirect blocks, and 1 tindirect block | |
dae1e52c | 684 | */ |
fa55a0ed | 685 | return DIV_ROUND_UP(nrblocks, EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4; |
dae1e52c AG |
686 | } |
687 | ||
a4130367 JK |
688 | static int ext4_ind_trunc_restart_fn(handle_t *handle, struct inode *inode, |
689 | struct buffer_head *bh, int *dropped) | |
690 | { | |
691 | int err; | |
692 | ||
693 | if (bh) { | |
694 | BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); | |
695 | err = ext4_handle_dirty_metadata(handle, inode, bh); | |
696 | if (unlikely(err)) | |
697 | return err; | |
698 | } | |
699 | err = ext4_mark_inode_dirty(handle, inode); | |
700 | if (unlikely(err)) | |
701 | return err; | |
702 | /* | |
703 | * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this | |
704 | * moment, get_block can be called only for blocks inside i_size since | |
705 | * page cache has been already dropped and writes are blocked by | |
f340b3d9 | 706 | * i_rwsem. So we can safely drop the i_data_sem here. |
a4130367 JK |
707 | */ |
708 | BUG_ON(EXT4_JOURNAL(inode) == NULL); | |
27bc446e | 709 | ext4_discard_preallocations(inode, 0); |
a4130367 JK |
710 | up_write(&EXT4_I(inode)->i_data_sem); |
711 | *dropped = 1; | |
712 | return 0; | |
713 | } | |
714 | ||
dae1e52c AG |
715 | /* |
716 | * Truncate transactions can be complex and absolutely huge. So we need to | |
3088e5a5 | 717 | * be able to restart the transaction at a convenient checkpoint to make |
dae1e52c AG |
718 | * sure we don't overflow the journal. |
719 | * | |
819c4920 | 720 | * Try to extend this transaction for the purposes of truncation. If |
a4130367 | 721 | * extend fails, we restart transaction. |
dae1e52c | 722 | */ |
a4130367 JK |
723 | static int ext4_ind_truncate_ensure_credits(handle_t *handle, |
724 | struct inode *inode, | |
83448bdf JK |
725 | struct buffer_head *bh, |
726 | int revoke_creds) | |
dae1e52c | 727 | { |
a4130367 JK |
728 | int ret; |
729 | int dropped = 0; | |
730 | ||
731 | ret = ext4_journal_ensure_credits_fn(handle, EXT4_RESERVE_TRANS_BLOCKS, | |
83448bdf | 732 | ext4_blocks_for_truncate(inode), revoke_creds, |
a4130367 JK |
733 | ext4_ind_trunc_restart_fn(handle, inode, bh, &dropped)); |
734 | if (dropped) | |
735 | down_write(&EXT4_I(inode)->i_data_sem); | |
736 | if (ret <= 0) | |
737 | return ret; | |
738 | if (bh) { | |
739 | BUFFER_TRACE(bh, "retaking write access"); | |
188c299e JK |
740 | ret = ext4_journal_get_write_access(handle, inode->i_sb, bh, |
741 | EXT4_JTR_NONE); | |
a4130367 JK |
742 | if (unlikely(ret)) |
743 | return ret; | |
744 | } | |
745 | return 0; | |
dae1e52c AG |
746 | } |
747 | ||
748 | /* | |
749 | * Probably it should be a library function... search for first non-zero word | |
750 | * or memcmp with zero_page, whatever is better for particular architecture. | |
751 | * Linus? | |
752 | */ | |
753 | static inline int all_zeroes(__le32 *p, __le32 *q) | |
754 | { | |
755 | while (p < q) | |
756 | if (*p++) | |
757 | return 0; | |
758 | return 1; | |
759 | } | |
760 | ||
761 | /** | |
762 | * ext4_find_shared - find the indirect blocks for partial truncation. | |
763 | * @inode: inode in question | |
764 | * @depth: depth of the affected branch | |
765 | * @offsets: offsets of pointers in that branch (see ext4_block_to_path) | |
766 | * @chain: place to store the pointers to partial indirect blocks | |
767 | * @top: place to the (detached) top of branch | |
768 | * | |
769 | * This is a helper function used by ext4_truncate(). | |
770 | * | |
771 | * When we do truncate() we may have to clean the ends of several | |
772 | * indirect blocks but leave the blocks themselves alive. Block is | |
773 | * partially truncated if some data below the new i_size is referred | |
774 | * from it (and it is on the path to the first completely truncated | |
775 | * data block, indeed). We have to free the top of that path along | |
776 | * with everything to the right of the path. Since no allocation | |
777 | * past the truncation point is possible until ext4_truncate() | |
778 | * finishes, we may safely do the latter, but top of branch may | |
779 | * require special attention - pageout below the truncation point | |
780 | * might try to populate it. | |
781 | * | |
782 | * We atomically detach the top of branch from the tree, store the | |
783 | * block number of its root in *@top, pointers to buffer_heads of | |
784 | * partially truncated blocks - in @chain[].bh and pointers to | |
785 | * their last elements that should not be removed - in | |
786 | * @chain[].p. Return value is the pointer to last filled element | |
787 | * of @chain. | |
788 | * | |
789 | * The work left to caller to do the actual freeing of subtrees: | |
790 | * a) free the subtree starting from *@top | |
791 | * b) free the subtrees whose roots are stored in | |
792 | * (@chain[i].p+1 .. end of @chain[i].bh->b_data) | |
793 | * c) free the subtrees growing from the inode past the @chain[0]. | |
794 | * (no partially truncated stuff there). */ | |
795 | ||
796 | static Indirect *ext4_find_shared(struct inode *inode, int depth, | |
797 | ext4_lblk_t offsets[4], Indirect chain[4], | |
798 | __le32 *top) | |
799 | { | |
800 | Indirect *partial, *p; | |
801 | int k, err; | |
802 | ||
803 | *top = 0; | |
804 | /* Make k index the deepest non-null offset + 1 */ | |
805 | for (k = depth; k > 1 && !offsets[k-1]; k--) | |
806 | ; | |
807 | partial = ext4_get_branch(inode, k, offsets, chain, &err); | |
808 | /* Writer: pointers */ | |
809 | if (!partial) | |
810 | partial = chain + k-1; | |
811 | /* | |
812 | * If the branch acquired continuation since we've looked at it - | |
813 | * fine, it should all survive and (new) top doesn't belong to us. | |
814 | */ | |
815 | if (!partial->key && *partial->p) | |
816 | /* Writer: end */ | |
817 | goto no_top; | |
818 | for (p = partial; (p > chain) && all_zeroes((__le32 *) p->bh->b_data, p->p); p--) | |
819 | ; | |
820 | /* | |
821 | * OK, we've found the last block that must survive. The rest of our | |
822 | * branch should be detached before unlocking. However, if that rest | |
823 | * of branch is all ours and does not grow immediately from the inode | |
824 | * it's easier to cheat and just decrement partial->p. | |
825 | */ | |
826 | if (p == chain + k - 1 && p > chain) { | |
827 | p->p--; | |
828 | } else { | |
829 | *top = *p->p; | |
830 | /* Nope, don't do this in ext4. Must leave the tree intact */ | |
831 | #if 0 | |
832 | *p->p = 0; | |
833 | #endif | |
834 | } | |
835 | /* Writer: end */ | |
836 | ||
837 | while (partial > p) { | |
838 | brelse(partial->bh); | |
839 | partial--; | |
840 | } | |
841 | no_top: | |
842 | return partial; | |
843 | } | |
844 | ||
845 | /* | |
846 | * Zero a number of block pointers in either an inode or an indirect block. | |
847 | * If we restart the transaction we must again get write access to the | |
848 | * indirect block for further modification. | |
849 | * | |
850 | * We release `count' blocks on disk, but (last - first) may be greater | |
851 | * than `count' because there can be holes in there. | |
852 | * | |
853 | * Return 0 on success, 1 on invalid block range | |
854 | * and < 0 on fatal error. | |
855 | */ | |
856 | static int ext4_clear_blocks(handle_t *handle, struct inode *inode, | |
857 | struct buffer_head *bh, | |
858 | ext4_fsblk_t block_to_free, | |
859 | unsigned long count, __le32 *first, | |
860 | __le32 *last) | |
861 | { | |
862 | __le32 *p; | |
981250ca | 863 | int flags = EXT4_FREE_BLOCKS_VALIDATED; |
dae1e52c AG |
864 | int err; |
865 | ||
ddfa17e4 TE |
866 | if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) || |
867 | ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE)) | |
981250ca TT |
868 | flags |= EXT4_FREE_BLOCKS_FORGET | EXT4_FREE_BLOCKS_METADATA; |
869 | else if (ext4_should_journal_data(inode)) | |
870 | flags |= EXT4_FREE_BLOCKS_FORGET; | |
dae1e52c | 871 | |
ce9f24cc | 872 | if (!ext4_inode_block_valid(inode, block_to_free, count)) { |
dae1e52c AG |
873 | EXT4_ERROR_INODE(inode, "attempt to clear invalid " |
874 | "blocks %llu len %lu", | |
875 | (unsigned long long) block_to_free, count); | |
876 | return 1; | |
877 | } | |
878 | ||
83448bdf JK |
879 | err = ext4_ind_truncate_ensure_credits(handle, inode, bh, |
880 | ext4_free_data_revoke_credits(inode, count)); | |
a4130367 JK |
881 | if (err < 0) |
882 | goto out_err; | |
dae1e52c AG |
883 | |
884 | for (p = first; p < last; p++) | |
885 | *p = 0; | |
886 | ||
887 | ext4_free_blocks(handle, inode, NULL, block_to_free, count, flags); | |
888 | return 0; | |
889 | out_err: | |
890 | ext4_std_error(inode->i_sb, err); | |
891 | return err; | |
892 | } | |
893 | ||
894 | /** | |
895 | * ext4_free_data - free a list of data blocks | |
896 | * @handle: handle for this transaction | |
897 | * @inode: inode we are dealing with | |
898 | * @this_bh: indirect buffer_head which contains *@first and *@last | |
899 | * @first: array of block numbers | |
900 | * @last: points immediately past the end of array | |
901 | * | |
902 | * We are freeing all blocks referred from that array (numbers are stored as | |
903 | * little-endian 32-bit) and updating @inode->i_blocks appropriately. | |
904 | * | |
905 | * We accumulate contiguous runs of blocks to free. Conveniently, if these | |
906 | * blocks are contiguous then releasing them at one time will only affect one | |
907 | * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't | |
908 | * actually use a lot of journal space. | |
909 | * | |
910 | * @this_bh will be %NULL if @first and @last point into the inode's direct | |
911 | * block pointers. | |
912 | */ | |
913 | static void ext4_free_data(handle_t *handle, struct inode *inode, | |
914 | struct buffer_head *this_bh, | |
915 | __le32 *first, __le32 *last) | |
916 | { | |
917 | ext4_fsblk_t block_to_free = 0; /* Starting block # of a run */ | |
918 | unsigned long count = 0; /* Number of blocks in the run */ | |
919 | __le32 *block_to_free_p = NULL; /* Pointer into inode/ind | |
920 | corresponding to | |
921 | block_to_free */ | |
922 | ext4_fsblk_t nr; /* Current block # */ | |
923 | __le32 *p; /* Pointer into inode/ind | |
924 | for current block */ | |
925 | int err = 0; | |
926 | ||
927 | if (this_bh) { /* For indirect block */ | |
928 | BUFFER_TRACE(this_bh, "get_write_access"); | |
188c299e JK |
929 | err = ext4_journal_get_write_access(handle, inode->i_sb, |
930 | this_bh, EXT4_JTR_NONE); | |
dae1e52c AG |
931 | /* Important: if we can't update the indirect pointers |
932 | * to the blocks, we can't free them. */ | |
933 | if (err) | |
934 | return; | |
935 | } | |
936 | ||
937 | for (p = first; p < last; p++) { | |
938 | nr = le32_to_cpu(*p); | |
939 | if (nr) { | |
940 | /* accumulate blocks to free if they're contiguous */ | |
941 | if (count == 0) { | |
942 | block_to_free = nr; | |
943 | block_to_free_p = p; | |
944 | count = 1; | |
945 | } else if (nr == block_to_free + count) { | |
946 | count++; | |
947 | } else { | |
948 | err = ext4_clear_blocks(handle, inode, this_bh, | |
949 | block_to_free, count, | |
950 | block_to_free_p, p); | |
951 | if (err) | |
952 | break; | |
953 | block_to_free = nr; | |
954 | block_to_free_p = p; | |
955 | count = 1; | |
956 | } | |
957 | } | |
958 | } | |
959 | ||
960 | if (!err && count > 0) | |
961 | err = ext4_clear_blocks(handle, inode, this_bh, block_to_free, | |
962 | count, block_to_free_p, p); | |
963 | if (err < 0) | |
964 | /* fatal error */ | |
965 | return; | |
966 | ||
967 | if (this_bh) { | |
968 | BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata"); | |
969 | ||
970 | /* | |
971 | * The buffer head should have an attached journal head at this | |
972 | * point. However, if the data is corrupted and an indirect | |
973 | * block pointed to itself, it would have been detached when | |
974 | * the block was cleared. Check for this instead of OOPSing. | |
975 | */ | |
976 | if ((EXT4_JOURNAL(inode) == NULL) || bh2jh(this_bh)) | |
977 | ext4_handle_dirty_metadata(handle, inode, this_bh); | |
978 | else | |
979 | EXT4_ERROR_INODE(inode, | |
980 | "circular indirect block detected at " | |
981 | "block %llu", | |
982 | (unsigned long long) this_bh->b_blocknr); | |
983 | } | |
984 | } | |
985 | ||
986 | /** | |
987 | * ext4_free_branches - free an array of branches | |
988 | * @handle: JBD handle for this transaction | |
989 | * @inode: inode we are dealing with | |
990 | * @parent_bh: the buffer_head which contains *@first and *@last | |
991 | * @first: array of block numbers | |
992 | * @last: pointer immediately past the end of array | |
993 | * @depth: depth of the branches to free | |
994 | * | |
995 | * We are freeing all blocks referred from these branches (numbers are | |
996 | * stored as little-endian 32-bit) and updating @inode->i_blocks | |
997 | * appropriately. | |
998 | */ | |
999 | static void ext4_free_branches(handle_t *handle, struct inode *inode, | |
1000 | struct buffer_head *parent_bh, | |
1001 | __le32 *first, __le32 *last, int depth) | |
1002 | { | |
1003 | ext4_fsblk_t nr; | |
1004 | __le32 *p; | |
1005 | ||
1006 | if (ext4_handle_is_aborted(handle)) | |
1007 | return; | |
1008 | ||
1009 | if (depth--) { | |
1010 | struct buffer_head *bh; | |
1011 | int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb); | |
1012 | p = last; | |
1013 | while (--p >= first) { | |
1014 | nr = le32_to_cpu(*p); | |
1015 | if (!nr) | |
1016 | continue; /* A hole */ | |
1017 | ||
ce9f24cc | 1018 | if (!ext4_inode_block_valid(inode, nr, 1)) { |
dae1e52c AG |
1019 | EXT4_ERROR_INODE(inode, |
1020 | "invalid indirect mapped " | |
1021 | "block %lu (level %d)", | |
1022 | (unsigned long) nr, depth); | |
1023 | break; | |
1024 | } | |
1025 | ||
1026 | /* Go read the buffer for the next level down */ | |
0a846f49 | 1027 | bh = ext4_sb_bread(inode->i_sb, nr, 0); |
dae1e52c AG |
1028 | |
1029 | /* | |
1030 | * A read failure? Report error and clear slot | |
1031 | * (should be rare). | |
1032 | */ | |
0a846f49 | 1033 | if (IS_ERR(bh)) { |
1034 | ext4_error_inode_block(inode, nr, -PTR_ERR(bh), | |
dae1e52c AG |
1035 | "Read failure"); |
1036 | continue; | |
1037 | } | |
1038 | ||
1039 | /* This zaps the entire block. Bottom up. */ | |
1040 | BUFFER_TRACE(bh, "free child branches"); | |
1041 | ext4_free_branches(handle, inode, bh, | |
1042 | (__le32 *) bh->b_data, | |
1043 | (__le32 *) bh->b_data + addr_per_block, | |
1044 | depth); | |
1045 | brelse(bh); | |
1046 | ||
1047 | /* | |
b483bb77 | 1048 | * Everything below this pointer has been |
dae1e52c AG |
1049 | * released. Now let this top-of-subtree go. |
1050 | * | |
1051 | * We want the freeing of this indirect block to be | |
1052 | * atomic in the journal with the updating of the | |
1053 | * bitmap block which owns it. So make some room in | |
1054 | * the journal. | |
1055 | * | |
1056 | * We zero the parent pointer *after* freeing its | |
1057 | * pointee in the bitmaps, so if extend_transaction() | |
1058 | * for some reason fails to put the bitmap changes and | |
1059 | * the release into the same transaction, recovery | |
1060 | * will merely complain about releasing a free block, | |
1061 | * rather than leaking blocks. | |
1062 | */ | |
1063 | if (ext4_handle_is_aborted(handle)) | |
1064 | return; | |
a4130367 | 1065 | if (ext4_ind_truncate_ensure_credits(handle, inode, |
83448bdf JK |
1066 | NULL, |
1067 | ext4_free_metadata_revoke_credits( | |
1068 | inode->i_sb, 1)) < 0) | |
a4130367 | 1069 | return; |
dae1e52c AG |
1070 | |
1071 | /* | |
1072 | * The forget flag here is critical because if | |
1073 | * we are journaling (and not doing data | |
1074 | * journaling), we have to make sure a revoke | |
1075 | * record is written to prevent the journal | |
1076 | * replay from overwriting the (former) | |
1077 | * indirect block if it gets reallocated as a | |
1078 | * data block. This must happen in the same | |
1079 | * transaction where the data blocks are | |
1080 | * actually freed. | |
1081 | */ | |
1082 | ext4_free_blocks(handle, inode, NULL, nr, 1, | |
1083 | EXT4_FREE_BLOCKS_METADATA| | |
1084 | EXT4_FREE_BLOCKS_FORGET); | |
1085 | ||
1086 | if (parent_bh) { | |
1087 | /* | |
1088 | * The block which we have just freed is | |
1089 | * pointed to by an indirect block: journal it | |
1090 | */ | |
1091 | BUFFER_TRACE(parent_bh, "get_write_access"); | |
1092 | if (!ext4_journal_get_write_access(handle, | |
188c299e JK |
1093 | inode->i_sb, parent_bh, |
1094 | EXT4_JTR_NONE)) { | |
dae1e52c AG |
1095 | *p = 0; |
1096 | BUFFER_TRACE(parent_bh, | |
1097 | "call ext4_handle_dirty_metadata"); | |
1098 | ext4_handle_dirty_metadata(handle, | |
1099 | inode, | |
1100 | parent_bh); | |
1101 | } | |
1102 | } | |
1103 | } | |
1104 | } else { | |
1105 | /* We have reached the bottom of the tree. */ | |
1106 | BUFFER_TRACE(parent_bh, "free data blocks"); | |
1107 | ext4_free_data(handle, inode, parent_bh, first, last); | |
1108 | } | |
1109 | } | |
1110 | ||
819c4920 | 1111 | void ext4_ind_truncate(handle_t *handle, struct inode *inode) |
dae1e52c | 1112 | { |
dae1e52c AG |
1113 | struct ext4_inode_info *ei = EXT4_I(inode); |
1114 | __le32 *i_data = ei->i_data; | |
1115 | int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb); | |
dae1e52c AG |
1116 | ext4_lblk_t offsets[4]; |
1117 | Indirect chain[4]; | |
1118 | Indirect *partial; | |
1119 | __le32 nr = 0; | |
1120 | int n = 0; | |
1121 | ext4_lblk_t last_block, max_block; | |
1122 | unsigned blocksize = inode->i_sb->s_blocksize; | |
dae1e52c AG |
1123 | |
1124 | last_block = (inode->i_size + blocksize-1) | |
1125 | >> EXT4_BLOCK_SIZE_BITS(inode->i_sb); | |
1126 | max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1) | |
1127 | >> EXT4_BLOCK_SIZE_BITS(inode->i_sb); | |
1128 | ||
dae1e52c AG |
1129 | if (last_block != max_block) { |
1130 | n = ext4_block_to_path(inode, last_block, offsets, NULL); | |
1131 | if (n == 0) | |
819c4920 | 1132 | return; |
dae1e52c AG |
1133 | } |
1134 | ||
51865fda | 1135 | ext4_es_remove_extent(inode, last_block, EXT_MAX_BLOCKS - last_block); |
dae1e52c AG |
1136 | |
1137 | /* | |
1138 | * The orphan list entry will now protect us from any crash which | |
1139 | * occurs before the truncate completes, so it is now safe to propagate | |
1140 | * the new, shorter inode size (held for now in i_size) into the | |
1141 | * on-disk inode. We do this via i_disksize, which is the value which | |
1142 | * ext4 *really* writes onto the disk inode. | |
1143 | */ | |
1144 | ei->i_disksize = inode->i_size; | |
1145 | ||
1146 | if (last_block == max_block) { | |
1147 | /* | |
1148 | * It is unnecessary to free any data blocks if last_block is | |
1149 | * equal to the indirect block limit. | |
1150 | */ | |
819c4920 | 1151 | return; |
dae1e52c AG |
1152 | } else if (n == 1) { /* direct blocks */ |
1153 | ext4_free_data(handle, inode, NULL, i_data+offsets[0], | |
1154 | i_data + EXT4_NDIR_BLOCKS); | |
1155 | goto do_indirects; | |
1156 | } | |
1157 | ||
1158 | partial = ext4_find_shared(inode, n, offsets, chain, &nr); | |
1159 | /* Kill the top of shared branch (not detached) */ | |
1160 | if (nr) { | |
1161 | if (partial == chain) { | |
1162 | /* Shared branch grows from the inode */ | |
1163 | ext4_free_branches(handle, inode, NULL, | |
1164 | &nr, &nr+1, (chain+n-1) - partial); | |
1165 | *partial->p = 0; | |
1166 | /* | |
1167 | * We mark the inode dirty prior to restart, | |
1168 | * and prior to stop. No need for it here. | |
1169 | */ | |
1170 | } else { | |
1171 | /* Shared branch grows from an indirect block */ | |
1172 | BUFFER_TRACE(partial->bh, "get_write_access"); | |
1173 | ext4_free_branches(handle, inode, partial->bh, | |
1174 | partial->p, | |
1175 | partial->p+1, (chain+n-1) - partial); | |
1176 | } | |
1177 | } | |
1178 | /* Clear the ends of indirect blocks on the shared branch */ | |
1179 | while (partial > chain) { | |
1180 | ext4_free_branches(handle, inode, partial->bh, partial->p + 1, | |
1181 | (__le32*)partial->bh->b_data+addr_per_block, | |
1182 | (chain+n-1) - partial); | |
1183 | BUFFER_TRACE(partial->bh, "call brelse"); | |
1184 | brelse(partial->bh); | |
1185 | partial--; | |
1186 | } | |
1187 | do_indirects: | |
1188 | /* Kill the remaining (whole) subtrees */ | |
1189 | switch (offsets[0]) { | |
1190 | default: | |
1191 | nr = i_data[EXT4_IND_BLOCK]; | |
1192 | if (nr) { | |
1193 | ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1); | |
1194 | i_data[EXT4_IND_BLOCK] = 0; | |
1195 | } | |
70d7ced2 | 1196 | fallthrough; |
dae1e52c AG |
1197 | case EXT4_IND_BLOCK: |
1198 | nr = i_data[EXT4_DIND_BLOCK]; | |
1199 | if (nr) { | |
1200 | ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2); | |
1201 | i_data[EXT4_DIND_BLOCK] = 0; | |
1202 | } | |
70d7ced2 | 1203 | fallthrough; |
dae1e52c AG |
1204 | case EXT4_DIND_BLOCK: |
1205 | nr = i_data[EXT4_TIND_BLOCK]; | |
1206 | if (nr) { | |
1207 | ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3); | |
1208 | i_data[EXT4_TIND_BLOCK] = 0; | |
1209 | } | |
70d7ced2 | 1210 | fallthrough; |
dae1e52c AG |
1211 | case EXT4_TIND_BLOCK: |
1212 | ; | |
1213 | } | |
dae1e52c AG |
1214 | } |
1215 | ||
4f579ae7 LC |
1216 | /** |
1217 | * ext4_ind_remove_space - remove space from the range | |
1218 | * @handle: JBD handle for this transaction | |
1219 | * @inode: inode we are dealing with | |
1220 | * @start: First block to remove | |
1221 | * @end: One block after the last block to remove (exclusive) | |
1222 | * | |
1223 | * Free the blocks in the defined range (end is exclusive endpoint of | |
1224 | * range). This is used by ext4_punch_hole(). | |
1225 | */ | |
1226 | int ext4_ind_remove_space(handle_t *handle, struct inode *inode, | |
1227 | ext4_lblk_t start, ext4_lblk_t end) | |
8bad6fc8 | 1228 | { |
4f579ae7 LC |
1229 | struct ext4_inode_info *ei = EXT4_I(inode); |
1230 | __le32 *i_data = ei->i_data; | |
8bad6fc8 | 1231 | int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb); |
4f579ae7 LC |
1232 | ext4_lblk_t offsets[4], offsets2[4]; |
1233 | Indirect chain[4], chain2[4]; | |
1234 | Indirect *partial, *partial2; | |
5e86bdda | 1235 | Indirect *p = NULL, *p2 = NULL; |
4f579ae7 LC |
1236 | ext4_lblk_t max_block; |
1237 | __le32 nr = 0, nr2 = 0; | |
1238 | int n = 0, n2 = 0; | |
1239 | unsigned blocksize = inode->i_sb->s_blocksize; | |
a93cd4cf | 1240 | |
4f579ae7 LC |
1241 | max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1) |
1242 | >> EXT4_BLOCK_SIZE_BITS(inode->i_sb); | |
1243 | if (end >= max_block) | |
1244 | end = max_block; | |
1245 | if ((start >= end) || (start > max_block)) | |
1246 | return 0; | |
1247 | ||
1248 | n = ext4_block_to_path(inode, start, offsets, NULL); | |
1249 | n2 = ext4_block_to_path(inode, end, offsets2, NULL); | |
1250 | ||
1251 | BUG_ON(n > n2); | |
1252 | ||
1253 | if ((n == 1) && (n == n2)) { | |
1254 | /* We're punching only within direct block range */ | |
1255 | ext4_free_data(handle, inode, NULL, i_data + offsets[0], | |
1256 | i_data + offsets2[0]); | |
1257 | return 0; | |
1258 | } else if (n2 > n) { | |
1259 | /* | |
1260 | * Start and end are on a different levels so we're going to | |
1261 | * free partial block at start, and partial block at end of | |
1262 | * the range. If there are some levels in between then | |
1263 | * do_indirects label will take care of that. | |
1264 | */ | |
1265 | ||
1266 | if (n == 1) { | |
1267 | /* | |
1268 | * Start is at the direct block level, free | |
1269 | * everything to the end of the level. | |
1270 | */ | |
1271 | ext4_free_data(handle, inode, NULL, i_data + offsets[0], | |
1272 | i_data + EXT4_NDIR_BLOCKS); | |
1273 | goto end_range; | |
1274 | } | |
1275 | ||
1276 | ||
5e86bdda | 1277 | partial = p = ext4_find_shared(inode, n, offsets, chain, &nr); |
4f579ae7 LC |
1278 | if (nr) { |
1279 | if (partial == chain) { | |
1280 | /* Shared branch grows from the inode */ | |
1281 | ext4_free_branches(handle, inode, NULL, | |
1282 | &nr, &nr+1, (chain+n-1) - partial); | |
1283 | *partial->p = 0; | |
a93cd4cf | 1284 | } else { |
4f579ae7 LC |
1285 | /* Shared branch grows from an indirect block */ |
1286 | BUFFER_TRACE(partial->bh, "get_write_access"); | |
1287 | ext4_free_branches(handle, inode, partial->bh, | |
1288 | partial->p, | |
1289 | partial->p+1, (chain+n-1) - partial); | |
a93cd4cf | 1290 | } |
4f579ae7 LC |
1291 | } |
1292 | ||
1293 | /* | |
1294 | * Clear the ends of indirect blocks on the shared branch | |
1295 | * at the start of the range | |
1296 | */ | |
1297 | while (partial > chain) { | |
1298 | ext4_free_branches(handle, inode, partial->bh, | |
1299 | partial->p + 1, | |
1300 | (__le32 *)partial->bh->b_data+addr_per_block, | |
1301 | (chain+n-1) - partial); | |
4f579ae7 LC |
1302 | partial--; |
1303 | } | |
1304 | ||
1305 | end_range: | |
5e86bdda | 1306 | partial2 = p2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2); |
4f579ae7 LC |
1307 | if (nr2) { |
1308 | if (partial2 == chain2) { | |
1309 | /* | |
1310 | * Remember, end is exclusive so here we're at | |
1311 | * the start of the next level we're not going | |
1312 | * to free. Everything was covered by the start | |
1313 | * of the range. | |
1314 | */ | |
6f30b7e3 | 1315 | goto do_indirects; |
8bad6fc8 | 1316 | } |
4f579ae7 LC |
1317 | } else { |
1318 | /* | |
1319 | * ext4_find_shared returns Indirect structure which | |
1320 | * points to the last element which should not be | |
1321 | * removed by truncate. But this is end of the range | |
1322 | * in punch_hole so we need to point to the next element | |
1323 | */ | |
1324 | partial2->p++; | |
8bad6fc8 | 1325 | } |
4f579ae7 LC |
1326 | |
1327 | /* | |
1328 | * Clear the ends of indirect blocks on the shared branch | |
1329 | * at the end of the range | |
1330 | */ | |
1331 | while (partial2 > chain2) { | |
1332 | ext4_free_branches(handle, inode, partial2->bh, | |
1333 | (__le32 *)partial2->bh->b_data, | |
1334 | partial2->p, | |
1335 | (chain2+n2-1) - partial2); | |
4f579ae7 | 1336 | partial2--; |
8bad6fc8 | 1337 | } |
4f579ae7 | 1338 | goto do_indirects; |
8bad6fc8 ZL |
1339 | } |
1340 | ||
4f579ae7 | 1341 | /* Punch happened within the same level (n == n2) */ |
5e86bdda | 1342 | partial = p = ext4_find_shared(inode, n, offsets, chain, &nr); |
1343 | partial2 = p2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2); | |
6f30b7e3 OS |
1344 | |
1345 | /* Free top, but only if partial2 isn't its subtree. */ | |
1346 | if (nr) { | |
1347 | int level = min(partial - chain, partial2 - chain2); | |
1348 | int i; | |
1349 | int subtree = 1; | |
1350 | ||
1351 | for (i = 0; i <= level; i++) { | |
1352 | if (offsets[i] != offsets2[i]) { | |
1353 | subtree = 0; | |
1354 | break; | |
1355 | } | |
1356 | } | |
1357 | ||
1358 | if (!subtree) { | |
1359 | if (partial == chain) { | |
1360 | /* Shared branch grows from the inode */ | |
1361 | ext4_free_branches(handle, inode, NULL, | |
1362 | &nr, &nr+1, | |
1363 | (chain+n-1) - partial); | |
1364 | *partial->p = 0; | |
1365 | } else { | |
1366 | /* Shared branch grows from an indirect block */ | |
1367 | BUFFER_TRACE(partial->bh, "get_write_access"); | |
4f579ae7 | 1368 | ext4_free_branches(handle, inode, partial->bh, |
6f30b7e3 OS |
1369 | partial->p, |
1370 | partial->p+1, | |
4f579ae7 | 1371 | (chain+n-1) - partial); |
4f579ae7 | 1372 | } |
8bad6fc8 | 1373 | } |
6f30b7e3 OS |
1374 | } |
1375 | ||
1376 | if (!nr2) { | |
4f579ae7 | 1377 | /* |
6f30b7e3 OS |
1378 | * ext4_find_shared returns Indirect structure which |
1379 | * points to the last element which should not be | |
1380 | * removed by truncate. But this is end of the range | |
1381 | * in punch_hole so we need to point to the next element | |
4f579ae7 | 1382 | */ |
6f30b7e3 OS |
1383 | partial2->p++; |
1384 | } | |
1385 | ||
1386 | while (partial > chain || partial2 > chain2) { | |
1387 | int depth = (chain+n-1) - partial; | |
1388 | int depth2 = (chain2+n2-1) - partial2; | |
1389 | ||
1390 | if (partial > chain && partial2 > chain2 && | |
1391 | partial->bh->b_blocknr == partial2->bh->b_blocknr) { | |
1392 | /* | |
1393 | * We've converged on the same block. Clear the range, | |
1394 | * then we're done. | |
1395 | */ | |
4f579ae7 | 1396 | ext4_free_branches(handle, inode, partial->bh, |
6f30b7e3 OS |
1397 | partial->p + 1, |
1398 | partial2->p, | |
1399 | (chain+n-1) - partial); | |
5e86bdda | 1400 | goto cleanup; |
4f579ae7 | 1401 | } |
6f30b7e3 | 1402 | |
4f579ae7 | 1403 | /* |
6f30b7e3 OS |
1404 | * The start and end partial branches may not be at the same |
1405 | * level even though the punch happened within one level. So, we | |
1406 | * give them a chance to arrive at the same level, then walk | |
1407 | * them in step with each other until we converge on the same | |
1408 | * block. | |
4f579ae7 | 1409 | */ |
6f30b7e3 OS |
1410 | if (partial > chain && depth <= depth2) { |
1411 | ext4_free_branches(handle, inode, partial->bh, | |
1412 | partial->p + 1, | |
1413 | (__le32 *)partial->bh->b_data+addr_per_block, | |
1414 | (chain+n-1) - partial); | |
6f30b7e3 OS |
1415 | partial--; |
1416 | } | |
1417 | if (partial2 > chain2 && depth2 <= depth) { | |
4f579ae7 LC |
1418 | ext4_free_branches(handle, inode, partial2->bh, |
1419 | (__le32 *)partial2->bh->b_data, | |
1420 | partial2->p, | |
6f30b7e3 | 1421 | (chain2+n2-1) - partial2); |
4f579ae7 | 1422 | partial2--; |
8bad6fc8 ZL |
1423 | } |
1424 | } | |
5e86bdda | 1425 | |
1426 | cleanup: | |
1427 | while (p && p > chain) { | |
1428 | BUFFER_TRACE(p->bh, "call brelse"); | |
1429 | brelse(p->bh); | |
1430 | p--; | |
1431 | } | |
1432 | while (p2 && p2 > chain2) { | |
1433 | BUFFER_TRACE(p2->bh, "call brelse"); | |
1434 | brelse(p2->bh); | |
1435 | p2--; | |
1436 | } | |
6f30b7e3 | 1437 | return 0; |
8bad6fc8 | 1438 | |
4f579ae7 LC |
1439 | do_indirects: |
1440 | /* Kill the remaining (whole) subtrees */ | |
1441 | switch (offsets[0]) { | |
1442 | default: | |
1443 | if (++n >= n2) | |
5e86bdda | 1444 | break; |
4f579ae7 LC |
1445 | nr = i_data[EXT4_IND_BLOCK]; |
1446 | if (nr) { | |
1447 | ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1); | |
1448 | i_data[EXT4_IND_BLOCK] = 0; | |
1449 | } | |
70d7ced2 | 1450 | fallthrough; |
4f579ae7 LC |
1451 | case EXT4_IND_BLOCK: |
1452 | if (++n >= n2) | |
5e86bdda | 1453 | break; |
4f579ae7 LC |
1454 | nr = i_data[EXT4_DIND_BLOCK]; |
1455 | if (nr) { | |
1456 | ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2); | |
1457 | i_data[EXT4_DIND_BLOCK] = 0; | |
1458 | } | |
70d7ced2 | 1459 | fallthrough; |
4f579ae7 LC |
1460 | case EXT4_DIND_BLOCK: |
1461 | if (++n >= n2) | |
5e86bdda | 1462 | break; |
4f579ae7 LC |
1463 | nr = i_data[EXT4_TIND_BLOCK]; |
1464 | if (nr) { | |
1465 | ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3); | |
1466 | i_data[EXT4_TIND_BLOCK] = 0; | |
1467 | } | |
70d7ced2 | 1468 | fallthrough; |
4f579ae7 LC |
1469 | case EXT4_TIND_BLOCK: |
1470 | ; | |
1471 | } | |
5e86bdda | 1472 | goto cleanup; |
8bad6fc8 | 1473 | } |