Commit | Line | Data |
---|---|---|
a86c6181 AT |
1 | /* |
2 | * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com | |
3 | * Written by Alex Tomas <alex@clusterfs.com> | |
4 | * | |
5 | * Architecture independence: | |
6 | * Copyright (c) 2005, Bull S.A. | |
7 | * Written by Pierre Peiffer <pierre.peiffer@bull.net> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public Licens | |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- | |
21 | */ | |
22 | ||
23 | /* | |
24 | * Extents support for EXT4 | |
25 | * | |
26 | * TODO: | |
27 | * - ext4*_error() should be used in some situations | |
28 | * - analyze all BUG()/BUG_ON(), use -EIO where appropriate | |
29 | * - smart tree reduction | |
30 | */ | |
31 | ||
32 | #include <linux/module.h> | |
33 | #include <linux/fs.h> | |
34 | #include <linux/time.h> | |
35 | #include <linux/ext4_jbd2.h> | |
36 | #include <linux/jbd.h> | |
37 | #include <linux/smp_lock.h> | |
38 | #include <linux/highuid.h> | |
39 | #include <linux/pagemap.h> | |
40 | #include <linux/quotaops.h> | |
41 | #include <linux/string.h> | |
42 | #include <linux/slab.h> | |
43 | #include <linux/ext4_fs_extents.h> | |
44 | #include <asm/uaccess.h> | |
45 | ||
46 | ||
d0d856e8 RD |
47 | /* |
48 | * ext_pblock: | |
49 | * combine low and high parts of physical block number into ext4_fsblk_t | |
50 | */ | |
f65e6fba AT |
51 | static inline ext4_fsblk_t ext_pblock(struct ext4_extent *ex) |
52 | { | |
53 | ext4_fsblk_t block; | |
54 | ||
55 | block = le32_to_cpu(ex->ee_start); | |
9b8f1f01 | 56 | block |= ((ext4_fsblk_t) le16_to_cpu(ex->ee_start_hi) << 31) << 1; |
f65e6fba AT |
57 | return block; |
58 | } | |
59 | ||
d0d856e8 RD |
60 | /* |
61 | * idx_pblock: | |
62 | * combine low and high parts of a leaf physical block number into ext4_fsblk_t | |
63 | */ | |
f65e6fba AT |
64 | static inline ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix) |
65 | { | |
66 | ext4_fsblk_t block; | |
67 | ||
68 | block = le32_to_cpu(ix->ei_leaf); | |
9b8f1f01 | 69 | block |= ((ext4_fsblk_t) le16_to_cpu(ix->ei_leaf_hi) << 31) << 1; |
f65e6fba AT |
70 | return block; |
71 | } | |
72 | ||
d0d856e8 RD |
73 | /* |
74 | * ext4_ext_store_pblock: | |
75 | * stores a large physical block number into an extent struct, | |
76 | * breaking it into parts | |
77 | */ | |
f65e6fba AT |
78 | static inline void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb) |
79 | { | |
80 | ex->ee_start = cpu_to_le32((unsigned long) (pb & 0xffffffff)); | |
9b8f1f01 | 81 | ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff); |
f65e6fba AT |
82 | } |
83 | ||
d0d856e8 RD |
84 | /* |
85 | * ext4_idx_store_pblock: | |
86 | * stores a large physical block number into an index struct, | |
87 | * breaking it into parts | |
88 | */ | |
f65e6fba AT |
89 | static inline void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb) |
90 | { | |
91 | ix->ei_leaf = cpu_to_le32((unsigned long) (pb & 0xffffffff)); | |
9b8f1f01 | 92 | ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff); |
f65e6fba AT |
93 | } |
94 | ||
a86c6181 AT |
95 | static int ext4_ext_check_header(const char *function, struct inode *inode, |
96 | struct ext4_extent_header *eh) | |
97 | { | |
98 | const char *error_msg = NULL; | |
99 | ||
100 | if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { | |
101 | error_msg = "invalid magic"; | |
102 | goto corrupted; | |
103 | } | |
104 | if (unlikely(eh->eh_max == 0)) { | |
105 | error_msg = "invalid eh_max"; | |
106 | goto corrupted; | |
107 | } | |
108 | if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { | |
109 | error_msg = "invalid eh_entries"; | |
110 | goto corrupted; | |
111 | } | |
112 | return 0; | |
113 | ||
114 | corrupted: | |
115 | ext4_error(inode->i_sb, function, | |
116 | "bad header in inode #%lu: %s - magic %x, " | |
117 | "entries %u, max %u, depth %u", | |
118 | inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic), | |
119 | le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), | |
120 | le16_to_cpu(eh->eh_depth)); | |
121 | ||
122 | return -EIO; | |
123 | } | |
124 | ||
125 | static handle_t *ext4_ext_journal_restart(handle_t *handle, int needed) | |
126 | { | |
127 | int err; | |
128 | ||
129 | if (handle->h_buffer_credits > needed) | |
130 | return handle; | |
131 | if (!ext4_journal_extend(handle, needed)) | |
132 | return handle; | |
133 | err = ext4_journal_restart(handle, needed); | |
134 | ||
135 | return handle; | |
136 | } | |
137 | ||
138 | /* | |
139 | * could return: | |
140 | * - EROFS | |
141 | * - ENOMEM | |
142 | */ | |
143 | static int ext4_ext_get_access(handle_t *handle, struct inode *inode, | |
144 | struct ext4_ext_path *path) | |
145 | { | |
146 | if (path->p_bh) { | |
147 | /* path points to block */ | |
148 | return ext4_journal_get_write_access(handle, path->p_bh); | |
149 | } | |
150 | /* path points to leaf/index in inode body */ | |
151 | /* we use in-core data, no need to protect them */ | |
152 | return 0; | |
153 | } | |
154 | ||
155 | /* | |
156 | * could return: | |
157 | * - EROFS | |
158 | * - ENOMEM | |
159 | * - EIO | |
160 | */ | |
161 | static int ext4_ext_dirty(handle_t *handle, struct inode *inode, | |
162 | struct ext4_ext_path *path) | |
163 | { | |
164 | int err; | |
165 | if (path->p_bh) { | |
166 | /* path points to block */ | |
167 | err = ext4_journal_dirty_metadata(handle, path->p_bh); | |
168 | } else { | |
169 | /* path points to leaf/index in inode body */ | |
170 | err = ext4_mark_inode_dirty(handle, inode); | |
171 | } | |
172 | return err; | |
173 | } | |
174 | ||
f65e6fba | 175 | static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, |
a86c6181 | 176 | struct ext4_ext_path *path, |
f65e6fba | 177 | ext4_fsblk_t block) |
a86c6181 AT |
178 | { |
179 | struct ext4_inode_info *ei = EXT4_I(inode); | |
f65e6fba AT |
180 | ext4_fsblk_t bg_start; |
181 | ext4_grpblk_t colour; | |
a86c6181 AT |
182 | int depth; |
183 | ||
184 | if (path) { | |
185 | struct ext4_extent *ex; | |
186 | depth = path->p_depth; | |
187 | ||
188 | /* try to predict block placement */ | |
189 | if ((ex = path[depth].p_ext)) | |
f65e6fba | 190 | return ext_pblock(ex)+(block-le32_to_cpu(ex->ee_block)); |
a86c6181 | 191 | |
d0d856e8 RD |
192 | /* it looks like index is empty; |
193 | * try to find starting block from index itself */ | |
a86c6181 AT |
194 | if (path[depth].p_bh) |
195 | return path[depth].p_bh->b_blocknr; | |
196 | } | |
197 | ||
198 | /* OK. use inode's group */ | |
199 | bg_start = (ei->i_block_group * EXT4_BLOCKS_PER_GROUP(inode->i_sb)) + | |
200 | le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_first_data_block); | |
201 | colour = (current->pid % 16) * | |
202 | (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16); | |
203 | return bg_start + colour + block; | |
204 | } | |
205 | ||
f65e6fba | 206 | static ext4_fsblk_t |
a86c6181 AT |
207 | ext4_ext_new_block(handle_t *handle, struct inode *inode, |
208 | struct ext4_ext_path *path, | |
209 | struct ext4_extent *ex, int *err) | |
210 | { | |
f65e6fba | 211 | ext4_fsblk_t goal, newblock; |
a86c6181 AT |
212 | |
213 | goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block)); | |
214 | newblock = ext4_new_block(handle, inode, goal, err); | |
215 | return newblock; | |
216 | } | |
217 | ||
218 | static inline int ext4_ext_space_block(struct inode *inode) | |
219 | { | |
220 | int size; | |
221 | ||
222 | size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) | |
223 | / sizeof(struct ext4_extent); | |
224 | #ifdef AGRESSIVE_TEST | |
225 | if (size > 6) | |
226 | size = 6; | |
227 | #endif | |
228 | return size; | |
229 | } | |
230 | ||
231 | static inline int ext4_ext_space_block_idx(struct inode *inode) | |
232 | { | |
233 | int size; | |
234 | ||
235 | size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) | |
236 | / sizeof(struct ext4_extent_idx); | |
237 | #ifdef AGRESSIVE_TEST | |
238 | if (size > 5) | |
239 | size = 5; | |
240 | #endif | |
241 | return size; | |
242 | } | |
243 | ||
244 | static inline int ext4_ext_space_root(struct inode *inode) | |
245 | { | |
246 | int size; | |
247 | ||
248 | size = sizeof(EXT4_I(inode)->i_data); | |
249 | size -= sizeof(struct ext4_extent_header); | |
250 | size /= sizeof(struct ext4_extent); | |
251 | #ifdef AGRESSIVE_TEST | |
252 | if (size > 3) | |
253 | size = 3; | |
254 | #endif | |
255 | return size; | |
256 | } | |
257 | ||
258 | static inline int ext4_ext_space_root_idx(struct inode *inode) | |
259 | { | |
260 | int size; | |
261 | ||
262 | size = sizeof(EXT4_I(inode)->i_data); | |
263 | size -= sizeof(struct ext4_extent_header); | |
264 | size /= sizeof(struct ext4_extent_idx); | |
265 | #ifdef AGRESSIVE_TEST | |
266 | if (size > 4) | |
267 | size = 4; | |
268 | #endif | |
269 | return size; | |
270 | } | |
271 | ||
272 | #ifdef EXT_DEBUG | |
273 | static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) | |
274 | { | |
275 | int k, l = path->p_depth; | |
276 | ||
277 | ext_debug("path:"); | |
278 | for (k = 0; k <= l; k++, path++) { | |
279 | if (path->p_idx) { | |
2ae02107 | 280 | ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block), |
f65e6fba | 281 | idx_pblock(path->p_idx)); |
a86c6181 | 282 | } else if (path->p_ext) { |
2ae02107 | 283 | ext_debug(" %d:%d:%llu ", |
a86c6181 AT |
284 | le32_to_cpu(path->p_ext->ee_block), |
285 | le16_to_cpu(path->p_ext->ee_len), | |
f65e6fba | 286 | ext_pblock(path->p_ext)); |
a86c6181 AT |
287 | } else |
288 | ext_debug(" []"); | |
289 | } | |
290 | ext_debug("\n"); | |
291 | } | |
292 | ||
293 | static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) | |
294 | { | |
295 | int depth = ext_depth(inode); | |
296 | struct ext4_extent_header *eh; | |
297 | struct ext4_extent *ex; | |
298 | int i; | |
299 | ||
300 | if (!path) | |
301 | return; | |
302 | ||
303 | eh = path[depth].p_hdr; | |
304 | ex = EXT_FIRST_EXTENT(eh); | |
305 | ||
306 | for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { | |
2ae02107 | 307 | ext_debug("%d:%d:%llu ", le32_to_cpu(ex->ee_block), |
f65e6fba | 308 | le16_to_cpu(ex->ee_len), ext_pblock(ex)); |
a86c6181 AT |
309 | } |
310 | ext_debug("\n"); | |
311 | } | |
312 | #else | |
313 | #define ext4_ext_show_path(inode,path) | |
314 | #define ext4_ext_show_leaf(inode,path) | |
315 | #endif | |
316 | ||
317 | static void ext4_ext_drop_refs(struct ext4_ext_path *path) | |
318 | { | |
319 | int depth = path->p_depth; | |
320 | int i; | |
321 | ||
322 | for (i = 0; i <= depth; i++, path++) | |
323 | if (path->p_bh) { | |
324 | brelse(path->p_bh); | |
325 | path->p_bh = NULL; | |
326 | } | |
327 | } | |
328 | ||
329 | /* | |
d0d856e8 RD |
330 | * ext4_ext_binsearch_idx: |
331 | * binary search for the closest index of the given block | |
a86c6181 AT |
332 | */ |
333 | static void | |
334 | ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int block) | |
335 | { | |
336 | struct ext4_extent_header *eh = path->p_hdr; | |
337 | struct ext4_extent_idx *r, *l, *m; | |
338 | ||
339 | BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC); | |
340 | BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max)); | |
341 | BUG_ON(le16_to_cpu(eh->eh_entries) <= 0); | |
342 | ||
343 | ext_debug("binsearch for %d(idx): ", block); | |
344 | ||
345 | l = EXT_FIRST_INDEX(eh) + 1; | |
346 | r = EXT_FIRST_INDEX(eh) + le16_to_cpu(eh->eh_entries) - 1; | |
347 | while (l <= r) { | |
348 | m = l + (r - l) / 2; | |
349 | if (block < le32_to_cpu(m->ei_block)) | |
350 | r = m - 1; | |
351 | else | |
352 | l = m + 1; | |
353 | ext_debug("%p(%u):%p(%u):%p(%u) ", l, l->ei_block, | |
354 | m, m->ei_block, r, r->ei_block); | |
355 | } | |
356 | ||
357 | path->p_idx = l - 1; | |
f65e6fba AT |
358 | ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block), |
359 | idx_block(path->p_idx)); | |
a86c6181 AT |
360 | |
361 | #ifdef CHECK_BINSEARCH | |
362 | { | |
363 | struct ext4_extent_idx *chix, *ix; | |
364 | int k; | |
365 | ||
366 | chix = ix = EXT_FIRST_INDEX(eh); | |
367 | for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) { | |
368 | if (k != 0 && | |
369 | le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) { | |
370 | printk("k=%d, ix=0x%p, first=0x%p\n", k, | |
371 | ix, EXT_FIRST_INDEX(eh)); | |
372 | printk("%u <= %u\n", | |
373 | le32_to_cpu(ix->ei_block), | |
374 | le32_to_cpu(ix[-1].ei_block)); | |
375 | } | |
376 | BUG_ON(k && le32_to_cpu(ix->ei_block) | |
377 | <= le32_to_cpu(ix[-1].ei_block)); | |
378 | if (block < le32_to_cpu(ix->ei_block)) | |
379 | break; | |
380 | chix = ix; | |
381 | } | |
382 | BUG_ON(chix != path->p_idx); | |
383 | } | |
384 | #endif | |
385 | ||
386 | } | |
387 | ||
388 | /* | |
d0d856e8 RD |
389 | * ext4_ext_binsearch: |
390 | * binary search for closest extent of the given block | |
a86c6181 AT |
391 | */ |
392 | static void | |
393 | ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block) | |
394 | { | |
395 | struct ext4_extent_header *eh = path->p_hdr; | |
396 | struct ext4_extent *r, *l, *m; | |
397 | ||
398 | BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC); | |
399 | BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max)); | |
400 | ||
401 | if (eh->eh_entries == 0) { | |
402 | /* | |
d0d856e8 RD |
403 | * this leaf is empty: |
404 | * we get such a leaf in split/add case | |
a86c6181 AT |
405 | */ |
406 | return; | |
407 | } | |
408 | ||
409 | ext_debug("binsearch for %d: ", block); | |
410 | ||
411 | l = EXT_FIRST_EXTENT(eh) + 1; | |
412 | r = EXT_FIRST_EXTENT(eh) + le16_to_cpu(eh->eh_entries) - 1; | |
413 | ||
414 | while (l <= r) { | |
415 | m = l + (r - l) / 2; | |
416 | if (block < le32_to_cpu(m->ee_block)) | |
417 | r = m - 1; | |
418 | else | |
419 | l = m + 1; | |
420 | ext_debug("%p(%u):%p(%u):%p(%u) ", l, l->ee_block, | |
421 | m, m->ee_block, r, r->ee_block); | |
422 | } | |
423 | ||
424 | path->p_ext = l - 1; | |
2ae02107 | 425 | ext_debug(" -> %d:%llu:%d ", |
a86c6181 | 426 | le32_to_cpu(path->p_ext->ee_block), |
f65e6fba AT |
427 | ext_pblock(path->p_ext), |
428 | le16_to_cpu(path->p_ext->ee_len)); | |
a86c6181 AT |
429 | |
430 | #ifdef CHECK_BINSEARCH | |
431 | { | |
432 | struct ext4_extent *chex, *ex; | |
433 | int k; | |
434 | ||
435 | chex = ex = EXT_FIRST_EXTENT(eh); | |
436 | for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) { | |
437 | BUG_ON(k && le32_to_cpu(ex->ee_block) | |
438 | <= le32_to_cpu(ex[-1].ee_block)); | |
439 | if (block < le32_to_cpu(ex->ee_block)) | |
440 | break; | |
441 | chex = ex; | |
442 | } | |
443 | BUG_ON(chex != path->p_ext); | |
444 | } | |
445 | #endif | |
446 | ||
447 | } | |
448 | ||
449 | int ext4_ext_tree_init(handle_t *handle, struct inode *inode) | |
450 | { | |
451 | struct ext4_extent_header *eh; | |
452 | ||
453 | eh = ext_inode_hdr(inode); | |
454 | eh->eh_depth = 0; | |
455 | eh->eh_entries = 0; | |
456 | eh->eh_magic = EXT4_EXT_MAGIC; | |
457 | eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode)); | |
458 | ext4_mark_inode_dirty(handle, inode); | |
459 | ext4_ext_invalidate_cache(inode); | |
460 | return 0; | |
461 | } | |
462 | ||
463 | struct ext4_ext_path * | |
464 | ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path) | |
465 | { | |
466 | struct ext4_extent_header *eh; | |
467 | struct buffer_head *bh; | |
468 | short int depth, i, ppos = 0, alloc = 0; | |
469 | ||
470 | eh = ext_inode_hdr(inode); | |
471 | BUG_ON(eh == NULL); | |
472 | if (ext4_ext_check_header(__FUNCTION__, inode, eh)) | |
473 | return ERR_PTR(-EIO); | |
474 | ||
475 | i = depth = ext_depth(inode); | |
476 | ||
477 | /* account possible depth increase */ | |
478 | if (!path) { | |
479 | path = kmalloc(sizeof(struct ext4_ext_path) * (depth + 2), | |
480 | GFP_NOFS); | |
481 | if (!path) | |
482 | return ERR_PTR(-ENOMEM); | |
483 | alloc = 1; | |
484 | } | |
485 | memset(path, 0, sizeof(struct ext4_ext_path) * (depth + 1)); | |
486 | path[0].p_hdr = eh; | |
487 | ||
488 | /* walk through the tree */ | |
489 | while (i) { | |
490 | ext_debug("depth %d: num %d, max %d\n", | |
491 | ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); | |
492 | ext4_ext_binsearch_idx(inode, path + ppos, block); | |
f65e6fba | 493 | path[ppos].p_block = idx_pblock(path[ppos].p_idx); |
a86c6181 AT |
494 | path[ppos].p_depth = i; |
495 | path[ppos].p_ext = NULL; | |
496 | ||
497 | bh = sb_bread(inode->i_sb, path[ppos].p_block); | |
498 | if (!bh) | |
499 | goto err; | |
500 | ||
501 | eh = ext_block_hdr(bh); | |
502 | ppos++; | |
503 | BUG_ON(ppos > depth); | |
504 | path[ppos].p_bh = bh; | |
505 | path[ppos].p_hdr = eh; | |
506 | i--; | |
507 | ||
508 | if (ext4_ext_check_header(__FUNCTION__, inode, eh)) | |
509 | goto err; | |
510 | } | |
511 | ||
512 | path[ppos].p_depth = i; | |
513 | path[ppos].p_hdr = eh; | |
514 | path[ppos].p_ext = NULL; | |
515 | path[ppos].p_idx = NULL; | |
516 | ||
517 | if (ext4_ext_check_header(__FUNCTION__, inode, eh)) | |
518 | goto err; | |
519 | ||
520 | /* find extent */ | |
521 | ext4_ext_binsearch(inode, path + ppos, block); | |
522 | ||
523 | ext4_ext_show_path(inode, path); | |
524 | ||
525 | return path; | |
526 | ||
527 | err: | |
528 | ext4_ext_drop_refs(path); | |
529 | if (alloc) | |
530 | kfree(path); | |
531 | return ERR_PTR(-EIO); | |
532 | } | |
533 | ||
534 | /* | |
d0d856e8 RD |
535 | * ext4_ext_insert_index: |
536 | * insert new index [@logical;@ptr] into the block at @curp; | |
537 | * check where to insert: before @curp or after @curp | |
a86c6181 AT |
538 | */ |
539 | static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, | |
540 | struct ext4_ext_path *curp, | |
f65e6fba | 541 | int logical, ext4_fsblk_t ptr) |
a86c6181 AT |
542 | { |
543 | struct ext4_extent_idx *ix; | |
544 | int len, err; | |
545 | ||
546 | if ((err = ext4_ext_get_access(handle, inode, curp))) | |
547 | return err; | |
548 | ||
549 | BUG_ON(logical == le32_to_cpu(curp->p_idx->ei_block)); | |
550 | len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx; | |
551 | if (logical > le32_to_cpu(curp->p_idx->ei_block)) { | |
552 | /* insert after */ | |
553 | if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) { | |
554 | len = (len - 1) * sizeof(struct ext4_extent_idx); | |
555 | len = len < 0 ? 0 : len; | |
556 | ext_debug("insert new index %d after: %d. " | |
557 | "move %d from 0x%p to 0x%p\n", | |
558 | logical, ptr, len, | |
559 | (curp->p_idx + 1), (curp->p_idx + 2)); | |
560 | memmove(curp->p_idx + 2, curp->p_idx + 1, len); | |
561 | } | |
562 | ix = curp->p_idx + 1; | |
563 | } else { | |
564 | /* insert before */ | |
565 | len = len * sizeof(struct ext4_extent_idx); | |
566 | len = len < 0 ? 0 : len; | |
567 | ext_debug("insert new index %d before: %d. " | |
568 | "move %d from 0x%p to 0x%p\n", | |
569 | logical, ptr, len, | |
570 | curp->p_idx, (curp->p_idx + 1)); | |
571 | memmove(curp->p_idx + 1, curp->p_idx, len); | |
572 | ix = curp->p_idx; | |
573 | } | |
574 | ||
575 | ix->ei_block = cpu_to_le32(logical); | |
f65e6fba | 576 | ext4_idx_store_pblock(ix, ptr); |
a86c6181 AT |
577 | curp->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(curp->p_hdr->eh_entries)+1); |
578 | ||
579 | BUG_ON(le16_to_cpu(curp->p_hdr->eh_entries) | |
580 | > le16_to_cpu(curp->p_hdr->eh_max)); | |
581 | BUG_ON(ix > EXT_LAST_INDEX(curp->p_hdr)); | |
582 | ||
583 | err = ext4_ext_dirty(handle, inode, curp); | |
584 | ext4_std_error(inode->i_sb, err); | |
585 | ||
586 | return err; | |
587 | } | |
588 | ||
589 | /* | |
d0d856e8 RD |
590 | * ext4_ext_split: |
591 | * inserts new subtree into the path, using free index entry | |
592 | * at depth @at: | |
593 | * - allocates all needed blocks (new leaf and all intermediate index blocks) | |
594 | * - makes decision where to split | |
595 | * - moves remaining extents and index entries (right to the split point) | |
596 | * into the newly allocated blocks | |
597 | * - initializes subtree | |
a86c6181 AT |
598 | */ |
599 | static int ext4_ext_split(handle_t *handle, struct inode *inode, | |
600 | struct ext4_ext_path *path, | |
601 | struct ext4_extent *newext, int at) | |
602 | { | |
603 | struct buffer_head *bh = NULL; | |
604 | int depth = ext_depth(inode); | |
605 | struct ext4_extent_header *neh; | |
606 | struct ext4_extent_idx *fidx; | |
607 | struct ext4_extent *ex; | |
608 | int i = at, k, m, a; | |
f65e6fba | 609 | ext4_fsblk_t newblock, oldblock; |
a86c6181 | 610 | __le32 border; |
f65e6fba | 611 | ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */ |
a86c6181 AT |
612 | int err = 0; |
613 | ||
614 | /* make decision: where to split? */ | |
d0d856e8 | 615 | /* FIXME: now decision is simplest: at current extent */ |
a86c6181 | 616 | |
d0d856e8 | 617 | /* if current leaf will be split, then we should use |
a86c6181 AT |
618 | * border from split point */ |
619 | BUG_ON(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr)); | |
620 | if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { | |
621 | border = path[depth].p_ext[1].ee_block; | |
d0d856e8 | 622 | ext_debug("leaf will be split." |
a86c6181 AT |
623 | " next leaf starts at %d\n", |
624 | le32_to_cpu(border)); | |
625 | } else { | |
626 | border = newext->ee_block; | |
627 | ext_debug("leaf will be added." | |
628 | " next leaf starts at %d\n", | |
629 | le32_to_cpu(border)); | |
630 | } | |
631 | ||
632 | /* | |
d0d856e8 RD |
633 | * If error occurs, then we break processing |
634 | * and mark filesystem read-only. index won't | |
a86c6181 | 635 | * be inserted and tree will be in consistent |
d0d856e8 | 636 | * state. Next mount will repair buffers too. |
a86c6181 AT |
637 | */ |
638 | ||
639 | /* | |
d0d856e8 RD |
640 | * Get array to track all allocated blocks. |
641 | * We need this to handle errors and free blocks | |
642 | * upon them. | |
a86c6181 | 643 | */ |
f65e6fba | 644 | ablocks = kmalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS); |
a86c6181 AT |
645 | if (!ablocks) |
646 | return -ENOMEM; | |
f65e6fba | 647 | memset(ablocks, 0, sizeof(ext4_fsblk_t) * depth); |
a86c6181 AT |
648 | |
649 | /* allocate all needed blocks */ | |
650 | ext_debug("allocate %d blocks for indexes/leaf\n", depth - at); | |
651 | for (a = 0; a < depth - at; a++) { | |
652 | newblock = ext4_ext_new_block(handle, inode, path, newext, &err); | |
653 | if (newblock == 0) | |
654 | goto cleanup; | |
655 | ablocks[a] = newblock; | |
656 | } | |
657 | ||
658 | /* initialize new leaf */ | |
659 | newblock = ablocks[--a]; | |
660 | BUG_ON(newblock == 0); | |
661 | bh = sb_getblk(inode->i_sb, newblock); | |
662 | if (!bh) { | |
663 | err = -EIO; | |
664 | goto cleanup; | |
665 | } | |
666 | lock_buffer(bh); | |
667 | ||
668 | if ((err = ext4_journal_get_create_access(handle, bh))) | |
669 | goto cleanup; | |
670 | ||
671 | neh = ext_block_hdr(bh); | |
672 | neh->eh_entries = 0; | |
673 | neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode)); | |
674 | neh->eh_magic = EXT4_EXT_MAGIC; | |
675 | neh->eh_depth = 0; | |
676 | ex = EXT_FIRST_EXTENT(neh); | |
677 | ||
d0d856e8 | 678 | /* move remainder of path[depth] to the new leaf */ |
a86c6181 AT |
679 | BUG_ON(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max); |
680 | /* start copy from next extent */ | |
681 | /* TODO: we could do it by single memmove */ | |
682 | m = 0; | |
683 | path[depth].p_ext++; | |
684 | while (path[depth].p_ext <= | |
685 | EXT_MAX_EXTENT(path[depth].p_hdr)) { | |
2ae02107 | 686 | ext_debug("move %d:%llu:%d in new leaf %llu\n", |
a86c6181 | 687 | le32_to_cpu(path[depth].p_ext->ee_block), |
f65e6fba | 688 | ext_pblock(path[depth].p_ext), |
a86c6181 AT |
689 | le16_to_cpu(path[depth].p_ext->ee_len), |
690 | newblock); | |
691 | /*memmove(ex++, path[depth].p_ext++, | |
692 | sizeof(struct ext4_extent)); | |
693 | neh->eh_entries++;*/ | |
694 | path[depth].p_ext++; | |
695 | m++; | |
696 | } | |
697 | if (m) { | |
698 | memmove(ex, path[depth].p_ext-m, sizeof(struct ext4_extent)*m); | |
699 | neh->eh_entries = cpu_to_le16(le16_to_cpu(neh->eh_entries)+m); | |
700 | } | |
701 | ||
702 | set_buffer_uptodate(bh); | |
703 | unlock_buffer(bh); | |
704 | ||
705 | if ((err = ext4_journal_dirty_metadata(handle, bh))) | |
706 | goto cleanup; | |
707 | brelse(bh); | |
708 | bh = NULL; | |
709 | ||
710 | /* correct old leaf */ | |
711 | if (m) { | |
712 | if ((err = ext4_ext_get_access(handle, inode, path + depth))) | |
713 | goto cleanup; | |
714 | path[depth].p_hdr->eh_entries = | |
715 | cpu_to_le16(le16_to_cpu(path[depth].p_hdr->eh_entries)-m); | |
716 | if ((err = ext4_ext_dirty(handle, inode, path + depth))) | |
717 | goto cleanup; | |
718 | ||
719 | } | |
720 | ||
721 | /* create intermediate indexes */ | |
722 | k = depth - at - 1; | |
723 | BUG_ON(k < 0); | |
724 | if (k) | |
725 | ext_debug("create %d intermediate indices\n", k); | |
726 | /* insert new index into current index block */ | |
727 | /* current depth stored in i var */ | |
728 | i = depth - 1; | |
729 | while (k--) { | |
730 | oldblock = newblock; | |
731 | newblock = ablocks[--a]; | |
f65e6fba | 732 | bh = sb_getblk(inode->i_sb, (ext4_fsblk_t)newblock); |
a86c6181 AT |
733 | if (!bh) { |
734 | err = -EIO; | |
735 | goto cleanup; | |
736 | } | |
737 | lock_buffer(bh); | |
738 | ||
739 | if ((err = ext4_journal_get_create_access(handle, bh))) | |
740 | goto cleanup; | |
741 | ||
742 | neh = ext_block_hdr(bh); | |
743 | neh->eh_entries = cpu_to_le16(1); | |
744 | neh->eh_magic = EXT4_EXT_MAGIC; | |
745 | neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode)); | |
746 | neh->eh_depth = cpu_to_le16(depth - i); | |
747 | fidx = EXT_FIRST_INDEX(neh); | |
748 | fidx->ei_block = border; | |
f65e6fba | 749 | ext4_idx_store_pblock(fidx, oldblock); |
a86c6181 | 750 | |
2ae02107 | 751 | ext_debug("int.index at %d (block %llu): %lu -> %llu\n", i, |
a86c6181 AT |
752 | newblock, (unsigned long) le32_to_cpu(border), |
753 | oldblock); | |
754 | /* copy indexes */ | |
755 | m = 0; | |
756 | path[i].p_idx++; | |
757 | ||
758 | ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx, | |
759 | EXT_MAX_INDEX(path[i].p_hdr)); | |
760 | BUG_ON(EXT_MAX_INDEX(path[i].p_hdr) != | |
761 | EXT_LAST_INDEX(path[i].p_hdr)); | |
762 | while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) { | |
2ae02107 | 763 | ext_debug("%d: move %d:%d in new index %llu\n", i, |
a86c6181 | 764 | le32_to_cpu(path[i].p_idx->ei_block), |
f65e6fba | 765 | idx_pblock(path[i].p_idx), |
a86c6181 AT |
766 | newblock); |
767 | /*memmove(++fidx, path[i].p_idx++, | |
768 | sizeof(struct ext4_extent_idx)); | |
769 | neh->eh_entries++; | |
770 | BUG_ON(neh->eh_entries > neh->eh_max);*/ | |
771 | path[i].p_idx++; | |
772 | m++; | |
773 | } | |
774 | if (m) { | |
775 | memmove(++fidx, path[i].p_idx - m, | |
776 | sizeof(struct ext4_extent_idx) * m); | |
777 | neh->eh_entries = | |
778 | cpu_to_le16(le16_to_cpu(neh->eh_entries) + m); | |
779 | } | |
780 | set_buffer_uptodate(bh); | |
781 | unlock_buffer(bh); | |
782 | ||
783 | if ((err = ext4_journal_dirty_metadata(handle, bh))) | |
784 | goto cleanup; | |
785 | brelse(bh); | |
786 | bh = NULL; | |
787 | ||
788 | /* correct old index */ | |
789 | if (m) { | |
790 | err = ext4_ext_get_access(handle, inode, path + i); | |
791 | if (err) | |
792 | goto cleanup; | |
793 | path[i].p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path[i].p_hdr->eh_entries)-m); | |
794 | err = ext4_ext_dirty(handle, inode, path + i); | |
795 | if (err) | |
796 | goto cleanup; | |
797 | } | |
798 | ||
799 | i--; | |
800 | } | |
801 | ||
802 | /* insert new index */ | |
803 | if (err) | |
804 | goto cleanup; | |
805 | ||
806 | err = ext4_ext_insert_index(handle, inode, path + at, | |
807 | le32_to_cpu(border), newblock); | |
808 | ||
809 | cleanup: | |
810 | if (bh) { | |
811 | if (buffer_locked(bh)) | |
812 | unlock_buffer(bh); | |
813 | brelse(bh); | |
814 | } | |
815 | ||
816 | if (err) { | |
817 | /* free all allocated blocks in error case */ | |
818 | for (i = 0; i < depth; i++) { | |
819 | if (!ablocks[i]) | |
820 | continue; | |
821 | ext4_free_blocks(handle, inode, ablocks[i], 1); | |
822 | } | |
823 | } | |
824 | kfree(ablocks); | |
825 | ||
826 | return err; | |
827 | } | |
828 | ||
829 | /* | |
d0d856e8 RD |
830 | * ext4_ext_grow_indepth: |
831 | * implements tree growing procedure: | |
832 | * - allocates new block | |
833 | * - moves top-level data (index block or leaf) into the new block | |
834 | * - initializes new top-level, creating index that points to the | |
835 | * just created block | |
a86c6181 AT |
836 | */ |
837 | static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, | |
838 | struct ext4_ext_path *path, | |
839 | struct ext4_extent *newext) | |
840 | { | |
841 | struct ext4_ext_path *curp = path; | |
842 | struct ext4_extent_header *neh; | |
843 | struct ext4_extent_idx *fidx; | |
844 | struct buffer_head *bh; | |
f65e6fba | 845 | ext4_fsblk_t newblock; |
a86c6181 AT |
846 | int err = 0; |
847 | ||
848 | newblock = ext4_ext_new_block(handle, inode, path, newext, &err); | |
849 | if (newblock == 0) | |
850 | return err; | |
851 | ||
852 | bh = sb_getblk(inode->i_sb, newblock); | |
853 | if (!bh) { | |
854 | err = -EIO; | |
855 | ext4_std_error(inode->i_sb, err); | |
856 | return err; | |
857 | } | |
858 | lock_buffer(bh); | |
859 | ||
860 | if ((err = ext4_journal_get_create_access(handle, bh))) { | |
861 | unlock_buffer(bh); | |
862 | goto out; | |
863 | } | |
864 | ||
865 | /* move top-level index/leaf into new block */ | |
866 | memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data)); | |
867 | ||
868 | /* set size of new block */ | |
869 | neh = ext_block_hdr(bh); | |
870 | /* old root could have indexes or leaves | |
871 | * so calculate e_max right way */ | |
872 | if (ext_depth(inode)) | |
873 | neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode)); | |
874 | else | |
875 | neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode)); | |
876 | neh->eh_magic = EXT4_EXT_MAGIC; | |
877 | set_buffer_uptodate(bh); | |
878 | unlock_buffer(bh); | |
879 | ||
880 | if ((err = ext4_journal_dirty_metadata(handle, bh))) | |
881 | goto out; | |
882 | ||
883 | /* create index in new top-level index: num,max,pointer */ | |
884 | if ((err = ext4_ext_get_access(handle, inode, curp))) | |
885 | goto out; | |
886 | ||
887 | curp->p_hdr->eh_magic = EXT4_EXT_MAGIC; | |
888 | curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode)); | |
889 | curp->p_hdr->eh_entries = cpu_to_le16(1); | |
890 | curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr); | |
891 | /* FIXME: it works, but actually path[0] can be index */ | |
892 | curp->p_idx->ei_block = EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block; | |
f65e6fba | 893 | ext4_idx_store_pblock(curp->p_idx, newblock); |
a86c6181 AT |
894 | |
895 | neh = ext_inode_hdr(inode); | |
896 | fidx = EXT_FIRST_INDEX(neh); | |
2ae02107 | 897 | ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n", |
a86c6181 | 898 | le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), |
f65e6fba | 899 | le32_to_cpu(fidx->ei_block), idx_pblock(fidx)); |
a86c6181 AT |
900 | |
901 | neh->eh_depth = cpu_to_le16(path->p_depth + 1); | |
902 | err = ext4_ext_dirty(handle, inode, curp); | |
903 | out: | |
904 | brelse(bh); | |
905 | ||
906 | return err; | |
907 | } | |
908 | ||
909 | /* | |
d0d856e8 RD |
910 | * ext4_ext_create_new_leaf: |
911 | * finds empty index and adds new leaf. | |
912 | * if no free index is found, then it requests in-depth growing. | |
a86c6181 AT |
913 | */ |
914 | static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, | |
915 | struct ext4_ext_path *path, | |
916 | struct ext4_extent *newext) | |
917 | { | |
918 | struct ext4_ext_path *curp; | |
919 | int depth, i, err = 0; | |
920 | ||
921 | repeat: | |
922 | i = depth = ext_depth(inode); | |
923 | ||
924 | /* walk up to the tree and look for free index entry */ | |
925 | curp = path + depth; | |
926 | while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) { | |
927 | i--; | |
928 | curp--; | |
929 | } | |
930 | ||
d0d856e8 RD |
931 | /* we use already allocated block for index block, |
932 | * so subsequent data blocks should be contiguous */ | |
a86c6181 AT |
933 | if (EXT_HAS_FREE_INDEX(curp)) { |
934 | /* if we found index with free entry, then use that | |
935 | * entry: create all needed subtree and add new leaf */ | |
936 | err = ext4_ext_split(handle, inode, path, newext, i); | |
937 | ||
938 | /* refill path */ | |
939 | ext4_ext_drop_refs(path); | |
940 | path = ext4_ext_find_extent(inode, | |
941 | le32_to_cpu(newext->ee_block), | |
942 | path); | |
943 | if (IS_ERR(path)) | |
944 | err = PTR_ERR(path); | |
945 | } else { | |
946 | /* tree is full, time to grow in depth */ | |
947 | err = ext4_ext_grow_indepth(handle, inode, path, newext); | |
948 | if (err) | |
949 | goto out; | |
950 | ||
951 | /* refill path */ | |
952 | ext4_ext_drop_refs(path); | |
953 | path = ext4_ext_find_extent(inode, | |
954 | le32_to_cpu(newext->ee_block), | |
955 | path); | |
956 | if (IS_ERR(path)) { | |
957 | err = PTR_ERR(path); | |
958 | goto out; | |
959 | } | |
960 | ||
961 | /* | |
d0d856e8 RD |
962 | * only first (depth 0 -> 1) produces free space; |
963 | * in all other cases we have to split the grown tree | |
a86c6181 AT |
964 | */ |
965 | depth = ext_depth(inode); | |
966 | if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { | |
d0d856e8 | 967 | /* now we need to split */ |
a86c6181 AT |
968 | goto repeat; |
969 | } | |
970 | } | |
971 | ||
972 | out: | |
973 | return err; | |
974 | } | |
975 | ||
976 | /* | |
d0d856e8 RD |
977 | * ext4_ext_next_allocated_block: |
978 | * returns allocated block in subsequent extent or EXT_MAX_BLOCK. | |
979 | * NOTE: it considers block number from index entry as | |
980 | * allocated block. Thus, index entries have to be consistent | |
981 | * with leaves. | |
a86c6181 AT |
982 | */ |
983 | static unsigned long | |
984 | ext4_ext_next_allocated_block(struct ext4_ext_path *path) | |
985 | { | |
986 | int depth; | |
987 | ||
988 | BUG_ON(path == NULL); | |
989 | depth = path->p_depth; | |
990 | ||
991 | if (depth == 0 && path->p_ext == NULL) | |
992 | return EXT_MAX_BLOCK; | |
993 | ||
994 | while (depth >= 0) { | |
995 | if (depth == path->p_depth) { | |
996 | /* leaf */ | |
997 | if (path[depth].p_ext != | |
998 | EXT_LAST_EXTENT(path[depth].p_hdr)) | |
999 | return le32_to_cpu(path[depth].p_ext[1].ee_block); | |
1000 | } else { | |
1001 | /* index */ | |
1002 | if (path[depth].p_idx != | |
1003 | EXT_LAST_INDEX(path[depth].p_hdr)) | |
1004 | return le32_to_cpu(path[depth].p_idx[1].ei_block); | |
1005 | } | |
1006 | depth--; | |
1007 | } | |
1008 | ||
1009 | return EXT_MAX_BLOCK; | |
1010 | } | |
1011 | ||
1012 | /* | |
d0d856e8 | 1013 | * ext4_ext_next_leaf_block: |
a86c6181 AT |
1014 | * returns first allocated block from next leaf or EXT_MAX_BLOCK |
1015 | */ | |
1016 | static unsigned ext4_ext_next_leaf_block(struct inode *inode, | |
63f57933 | 1017 | struct ext4_ext_path *path) |
a86c6181 AT |
1018 | { |
1019 | int depth; | |
1020 | ||
1021 | BUG_ON(path == NULL); | |
1022 | depth = path->p_depth; | |
1023 | ||
1024 | /* zero-tree has no leaf blocks at all */ | |
1025 | if (depth == 0) | |
1026 | return EXT_MAX_BLOCK; | |
1027 | ||
1028 | /* go to index block */ | |
1029 | depth--; | |
1030 | ||
1031 | while (depth >= 0) { | |
1032 | if (path[depth].p_idx != | |
1033 | EXT_LAST_INDEX(path[depth].p_hdr)) | |
1034 | return le32_to_cpu(path[depth].p_idx[1].ei_block); | |
1035 | depth--; | |
1036 | } | |
1037 | ||
1038 | return EXT_MAX_BLOCK; | |
1039 | } | |
1040 | ||
1041 | /* | |
d0d856e8 RD |
1042 | * ext4_ext_correct_indexes: |
1043 | * if leaf gets modified and modified extent is first in the leaf, | |
1044 | * then we have to correct all indexes above. | |
a86c6181 AT |
1045 | * TODO: do we need to correct tree in all cases? |
1046 | */ | |
1047 | int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, | |
1048 | struct ext4_ext_path *path) | |
1049 | { | |
1050 | struct ext4_extent_header *eh; | |
1051 | int depth = ext_depth(inode); | |
1052 | struct ext4_extent *ex; | |
1053 | __le32 border; | |
1054 | int k, err = 0; | |
1055 | ||
1056 | eh = path[depth].p_hdr; | |
1057 | ex = path[depth].p_ext; | |
1058 | BUG_ON(ex == NULL); | |
1059 | BUG_ON(eh == NULL); | |
1060 | ||
1061 | if (depth == 0) { | |
1062 | /* there is no tree at all */ | |
1063 | return 0; | |
1064 | } | |
1065 | ||
1066 | if (ex != EXT_FIRST_EXTENT(eh)) { | |
1067 | /* we correct tree if first leaf got modified only */ | |
1068 | return 0; | |
1069 | } | |
1070 | ||
1071 | /* | |
d0d856e8 | 1072 | * TODO: we need correction if border is smaller than current one |
a86c6181 AT |
1073 | */ |
1074 | k = depth - 1; | |
1075 | border = path[depth].p_ext->ee_block; | |
1076 | if ((err = ext4_ext_get_access(handle, inode, path + k))) | |
1077 | return err; | |
1078 | path[k].p_idx->ei_block = border; | |
1079 | if ((err = ext4_ext_dirty(handle, inode, path + k))) | |
1080 | return err; | |
1081 | ||
1082 | while (k--) { | |
1083 | /* change all left-side indexes */ | |
1084 | if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr)) | |
1085 | break; | |
1086 | if ((err = ext4_ext_get_access(handle, inode, path + k))) | |
1087 | break; | |
1088 | path[k].p_idx->ei_block = border; | |
1089 | if ((err = ext4_ext_dirty(handle, inode, path + k))) | |
1090 | break; | |
1091 | } | |
1092 | ||
1093 | return err; | |
1094 | } | |
1095 | ||
1096 | static int inline | |
1097 | ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, | |
1098 | struct ext4_extent *ex2) | |
1099 | { | |
63f57933 AM |
1100 | if (le32_to_cpu(ex1->ee_block) + le16_to_cpu(ex1->ee_len) != |
1101 | le32_to_cpu(ex2->ee_block)) | |
a86c6181 AT |
1102 | return 0; |
1103 | ||
471d4011 SB |
1104 | /* |
1105 | * To allow future support for preallocated extents to be added | |
1106 | * as an RO_COMPAT feature, refuse to merge to extents if | |
d0d856e8 | 1107 | * this can result in the top bit of ee_len being set. |
471d4011 SB |
1108 | */ |
1109 | if (le16_to_cpu(ex1->ee_len) + le16_to_cpu(ex2->ee_len) > EXT_MAX_LEN) | |
1110 | return 0; | |
a86c6181 AT |
1111 | #ifdef AGRESSIVE_TEST |
1112 | if (le16_to_cpu(ex1->ee_len) >= 4) | |
1113 | return 0; | |
1114 | #endif | |
1115 | ||
63f57933 | 1116 | if (ext_pblock(ex1) + le16_to_cpu(ex1->ee_len) == ext_pblock(ex2)) |
a86c6181 AT |
1117 | return 1; |
1118 | return 0; | |
1119 | } | |
1120 | ||
1121 | /* | |
d0d856e8 RD |
1122 | * ext4_ext_insert_extent: |
1123 | * tries to merge requsted extent into the existing extent or | |
1124 | * inserts requested extent as new one into the tree, | |
1125 | * creating new leaf in the no-space case. | |
a86c6181 AT |
1126 | */ |
1127 | int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, | |
1128 | struct ext4_ext_path *path, | |
1129 | struct ext4_extent *newext) | |
1130 | { | |
1131 | struct ext4_extent_header * eh; | |
1132 | struct ext4_extent *ex, *fex; | |
1133 | struct ext4_extent *nearex; /* nearest extent */ | |
1134 | struct ext4_ext_path *npath = NULL; | |
1135 | int depth, len, err, next; | |
1136 | ||
1137 | BUG_ON(newext->ee_len == 0); | |
1138 | depth = ext_depth(inode); | |
1139 | ex = path[depth].p_ext; | |
1140 | BUG_ON(path[depth].p_hdr == NULL); | |
1141 | ||
1142 | /* try to insert block into found extent and return */ | |
1143 | if (ex && ext4_can_extents_be_merged(inode, ex, newext)) { | |
2ae02107 | 1144 | ext_debug("append %d block to %d:%d (from %llu)\n", |
a86c6181 AT |
1145 | le16_to_cpu(newext->ee_len), |
1146 | le32_to_cpu(ex->ee_block), | |
f65e6fba | 1147 | le16_to_cpu(ex->ee_len), ext_pblock(ex)); |
a86c6181 AT |
1148 | if ((err = ext4_ext_get_access(handle, inode, path + depth))) |
1149 | return err; | |
1150 | ex->ee_len = cpu_to_le16(le16_to_cpu(ex->ee_len) | |
1151 | + le16_to_cpu(newext->ee_len)); | |
1152 | eh = path[depth].p_hdr; | |
1153 | nearex = ex; | |
1154 | goto merge; | |
1155 | } | |
1156 | ||
1157 | repeat: | |
1158 | depth = ext_depth(inode); | |
1159 | eh = path[depth].p_hdr; | |
1160 | if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) | |
1161 | goto has_space; | |
1162 | ||
1163 | /* probably next leaf has space for us? */ | |
1164 | fex = EXT_LAST_EXTENT(eh); | |
1165 | next = ext4_ext_next_leaf_block(inode, path); | |
1166 | if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block) | |
1167 | && next != EXT_MAX_BLOCK) { | |
1168 | ext_debug("next leaf block - %d\n", next); | |
1169 | BUG_ON(npath != NULL); | |
1170 | npath = ext4_ext_find_extent(inode, next, NULL); | |
1171 | if (IS_ERR(npath)) | |
1172 | return PTR_ERR(npath); | |
1173 | BUG_ON(npath->p_depth != path->p_depth); | |
1174 | eh = npath[depth].p_hdr; | |
1175 | if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) { | |
1176 | ext_debug("next leaf isnt full(%d)\n", | |
1177 | le16_to_cpu(eh->eh_entries)); | |
1178 | path = npath; | |
1179 | goto repeat; | |
1180 | } | |
1181 | ext_debug("next leaf has no free space(%d,%d)\n", | |
1182 | le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); | |
1183 | } | |
1184 | ||
1185 | /* | |
d0d856e8 RD |
1186 | * There is no free space in the found leaf. |
1187 | * We're gonna add a new leaf in the tree. | |
a86c6181 AT |
1188 | */ |
1189 | err = ext4_ext_create_new_leaf(handle, inode, path, newext); | |
1190 | if (err) | |
1191 | goto cleanup; | |
1192 | depth = ext_depth(inode); | |
1193 | eh = path[depth].p_hdr; | |
1194 | ||
1195 | has_space: | |
1196 | nearex = path[depth].p_ext; | |
1197 | ||
1198 | if ((err = ext4_ext_get_access(handle, inode, path + depth))) | |
1199 | goto cleanup; | |
1200 | ||
1201 | if (!nearex) { | |
1202 | /* there is no extent in this leaf, create first one */ | |
2ae02107 | 1203 | ext_debug("first extent in the leaf: %d:%llu:%d\n", |
a86c6181 | 1204 | le32_to_cpu(newext->ee_block), |
f65e6fba | 1205 | ext_pblock(newext), |
a86c6181 AT |
1206 | le16_to_cpu(newext->ee_len)); |
1207 | path[depth].p_ext = EXT_FIRST_EXTENT(eh); | |
1208 | } else if (le32_to_cpu(newext->ee_block) | |
1209 | > le32_to_cpu(nearex->ee_block)) { | |
1210 | /* BUG_ON(newext->ee_block == nearex->ee_block); */ | |
1211 | if (nearex != EXT_LAST_EXTENT(eh)) { | |
1212 | len = EXT_MAX_EXTENT(eh) - nearex; | |
1213 | len = (len - 1) * sizeof(struct ext4_extent); | |
1214 | len = len < 0 ? 0 : len; | |
2ae02107 | 1215 | ext_debug("insert %d:%llu:%d after: nearest 0x%p, " |
a86c6181 AT |
1216 | "move %d from 0x%p to 0x%p\n", |
1217 | le32_to_cpu(newext->ee_block), | |
f65e6fba | 1218 | ext_pblock(newext), |
a86c6181 AT |
1219 | le16_to_cpu(newext->ee_len), |
1220 | nearex, len, nearex + 1, nearex + 2); | |
1221 | memmove(nearex + 2, nearex + 1, len); | |
1222 | } | |
1223 | path[depth].p_ext = nearex + 1; | |
1224 | } else { | |
1225 | BUG_ON(newext->ee_block == nearex->ee_block); | |
1226 | len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent); | |
1227 | len = len < 0 ? 0 : len; | |
2ae02107 | 1228 | ext_debug("insert %d:%llu:%d before: nearest 0x%p, " |
a86c6181 AT |
1229 | "move %d from 0x%p to 0x%p\n", |
1230 | le32_to_cpu(newext->ee_block), | |
f65e6fba | 1231 | ext_pblock(newext), |
a86c6181 AT |
1232 | le16_to_cpu(newext->ee_len), |
1233 | nearex, len, nearex + 1, nearex + 2); | |
1234 | memmove(nearex + 1, nearex, len); | |
1235 | path[depth].p_ext = nearex; | |
1236 | } | |
1237 | ||
1238 | eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)+1); | |
1239 | nearex = path[depth].p_ext; | |
1240 | nearex->ee_block = newext->ee_block; | |
1241 | nearex->ee_start = newext->ee_start; | |
f65e6fba | 1242 | nearex->ee_start_hi = newext->ee_start_hi; |
a86c6181 | 1243 | nearex->ee_len = newext->ee_len; |
a86c6181 AT |
1244 | |
1245 | merge: | |
1246 | /* try to merge extents to the right */ | |
1247 | while (nearex < EXT_LAST_EXTENT(eh)) { | |
1248 | if (!ext4_can_extents_be_merged(inode, nearex, nearex + 1)) | |
1249 | break; | |
1250 | /* merge with next extent! */ | |
1251 | nearex->ee_len = cpu_to_le16(le16_to_cpu(nearex->ee_len) | |
1252 | + le16_to_cpu(nearex[1].ee_len)); | |
1253 | if (nearex + 1 < EXT_LAST_EXTENT(eh)) { | |
1254 | len = (EXT_LAST_EXTENT(eh) - nearex - 1) | |
1255 | * sizeof(struct ext4_extent); | |
1256 | memmove(nearex + 1, nearex + 2, len); | |
1257 | } | |
1258 | eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1); | |
1259 | BUG_ON(eh->eh_entries == 0); | |
1260 | } | |
1261 | ||
1262 | /* try to merge extents to the left */ | |
1263 | ||
1264 | /* time to correct all indexes above */ | |
1265 | err = ext4_ext_correct_indexes(handle, inode, path); | |
1266 | if (err) | |
1267 | goto cleanup; | |
1268 | ||
1269 | err = ext4_ext_dirty(handle, inode, path + depth); | |
1270 | ||
1271 | cleanup: | |
1272 | if (npath) { | |
1273 | ext4_ext_drop_refs(npath); | |
1274 | kfree(npath); | |
1275 | } | |
1276 | ext4_ext_tree_changed(inode); | |
1277 | ext4_ext_invalidate_cache(inode); | |
1278 | return err; | |
1279 | } | |
1280 | ||
1281 | int ext4_ext_walk_space(struct inode *inode, unsigned long block, | |
1282 | unsigned long num, ext_prepare_callback func, | |
1283 | void *cbdata) | |
1284 | { | |
1285 | struct ext4_ext_path *path = NULL; | |
1286 | struct ext4_ext_cache cbex; | |
1287 | struct ext4_extent *ex; | |
1288 | unsigned long next, start = 0, end = 0; | |
1289 | unsigned long last = block + num; | |
1290 | int depth, exists, err = 0; | |
1291 | ||
1292 | BUG_ON(func == NULL); | |
1293 | BUG_ON(inode == NULL); | |
1294 | ||
1295 | while (block < last && block != EXT_MAX_BLOCK) { | |
1296 | num = last - block; | |
1297 | /* find extent for this block */ | |
1298 | path = ext4_ext_find_extent(inode, block, path); | |
1299 | if (IS_ERR(path)) { | |
1300 | err = PTR_ERR(path); | |
1301 | path = NULL; | |
1302 | break; | |
1303 | } | |
1304 | ||
1305 | depth = ext_depth(inode); | |
1306 | BUG_ON(path[depth].p_hdr == NULL); | |
1307 | ex = path[depth].p_ext; | |
1308 | next = ext4_ext_next_allocated_block(path); | |
1309 | ||
1310 | exists = 0; | |
1311 | if (!ex) { | |
1312 | /* there is no extent yet, so try to allocate | |
1313 | * all requested space */ | |
1314 | start = block; | |
1315 | end = block + num; | |
1316 | } else if (le32_to_cpu(ex->ee_block) > block) { | |
1317 | /* need to allocate space before found extent */ | |
1318 | start = block; | |
1319 | end = le32_to_cpu(ex->ee_block); | |
1320 | if (block + num < end) | |
1321 | end = block + num; | |
1322 | } else if (block >= | |
1323 | le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len)) { | |
1324 | /* need to allocate space after found extent */ | |
1325 | start = block; | |
1326 | end = block + num; | |
1327 | if (end >= next) | |
1328 | end = next; | |
1329 | } else if (block >= le32_to_cpu(ex->ee_block)) { | |
1330 | /* | |
1331 | * some part of requested space is covered | |
1332 | * by found extent | |
1333 | */ | |
1334 | start = block; | |
1335 | end = le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len); | |
1336 | if (block + num < end) | |
1337 | end = block + num; | |
1338 | exists = 1; | |
1339 | } else { | |
1340 | BUG(); | |
1341 | } | |
1342 | BUG_ON(end <= start); | |
1343 | ||
1344 | if (!exists) { | |
1345 | cbex.ec_block = start; | |
1346 | cbex.ec_len = end - start; | |
1347 | cbex.ec_start = 0; | |
1348 | cbex.ec_type = EXT4_EXT_CACHE_GAP; | |
1349 | } else { | |
1350 | cbex.ec_block = le32_to_cpu(ex->ee_block); | |
1351 | cbex.ec_len = le16_to_cpu(ex->ee_len); | |
f65e6fba | 1352 | cbex.ec_start = ext_pblock(ex); |
a86c6181 AT |
1353 | cbex.ec_type = EXT4_EXT_CACHE_EXTENT; |
1354 | } | |
1355 | ||
1356 | BUG_ON(cbex.ec_len == 0); | |
1357 | err = func(inode, path, &cbex, cbdata); | |
1358 | ext4_ext_drop_refs(path); | |
1359 | ||
1360 | if (err < 0) | |
1361 | break; | |
1362 | if (err == EXT_REPEAT) | |
1363 | continue; | |
1364 | else if (err == EXT_BREAK) { | |
1365 | err = 0; | |
1366 | break; | |
1367 | } | |
1368 | ||
1369 | if (ext_depth(inode) != depth) { | |
1370 | /* depth was changed. we have to realloc path */ | |
1371 | kfree(path); | |
1372 | path = NULL; | |
1373 | } | |
1374 | ||
1375 | block = cbex.ec_block + cbex.ec_len; | |
1376 | } | |
1377 | ||
1378 | if (path) { | |
1379 | ext4_ext_drop_refs(path); | |
1380 | kfree(path); | |
1381 | } | |
1382 | ||
1383 | return err; | |
1384 | } | |
1385 | ||
1386 | static inline void | |
1387 | ext4_ext_put_in_cache(struct inode *inode, __u32 block, | |
1388 | __u32 len, __u32 start, int type) | |
1389 | { | |
1390 | struct ext4_ext_cache *cex; | |
1391 | BUG_ON(len == 0); | |
1392 | cex = &EXT4_I(inode)->i_cached_extent; | |
1393 | cex->ec_type = type; | |
1394 | cex->ec_block = block; | |
1395 | cex->ec_len = len; | |
1396 | cex->ec_start = start; | |
1397 | } | |
1398 | ||
1399 | /* | |
d0d856e8 RD |
1400 | * ext4_ext_put_gap_in_cache: |
1401 | * calculate boundaries of the gap that the requested block fits into | |
a86c6181 AT |
1402 | * and cache this gap |
1403 | */ | |
1404 | static inline void | |
1405 | ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path, | |
1406 | unsigned long block) | |
1407 | { | |
1408 | int depth = ext_depth(inode); | |
1409 | unsigned long lblock, len; | |
1410 | struct ext4_extent *ex; | |
1411 | ||
1412 | ex = path[depth].p_ext; | |
1413 | if (ex == NULL) { | |
1414 | /* there is no extent yet, so gap is [0;-] */ | |
1415 | lblock = 0; | |
1416 | len = EXT_MAX_BLOCK; | |
1417 | ext_debug("cache gap(whole file):"); | |
1418 | } else if (block < le32_to_cpu(ex->ee_block)) { | |
1419 | lblock = block; | |
1420 | len = le32_to_cpu(ex->ee_block) - block; | |
1421 | ext_debug("cache gap(before): %lu [%lu:%lu]", | |
1422 | (unsigned long) block, | |
1423 | (unsigned long) le32_to_cpu(ex->ee_block), | |
1424 | (unsigned long) le16_to_cpu(ex->ee_len)); | |
1425 | } else if (block >= le32_to_cpu(ex->ee_block) | |
1426 | + le16_to_cpu(ex->ee_len)) { | |
1427 | lblock = le32_to_cpu(ex->ee_block) | |
1428 | + le16_to_cpu(ex->ee_len); | |
1429 | len = ext4_ext_next_allocated_block(path); | |
1430 | ext_debug("cache gap(after): [%lu:%lu] %lu", | |
1431 | (unsigned long) le32_to_cpu(ex->ee_block), | |
1432 | (unsigned long) le16_to_cpu(ex->ee_len), | |
1433 | (unsigned long) block); | |
1434 | BUG_ON(len == lblock); | |
1435 | len = len - lblock; | |
1436 | } else { | |
1437 | lblock = len = 0; | |
1438 | BUG(); | |
1439 | } | |
1440 | ||
1441 | ext_debug(" -> %lu:%lu\n", (unsigned long) lblock, len); | |
1442 | ext4_ext_put_in_cache(inode, lblock, len, 0, EXT4_EXT_CACHE_GAP); | |
1443 | } | |
1444 | ||
1445 | static inline int | |
1446 | ext4_ext_in_cache(struct inode *inode, unsigned long block, | |
1447 | struct ext4_extent *ex) | |
1448 | { | |
1449 | struct ext4_ext_cache *cex; | |
1450 | ||
1451 | cex = &EXT4_I(inode)->i_cached_extent; | |
1452 | ||
1453 | /* has cache valid data? */ | |
1454 | if (cex->ec_type == EXT4_EXT_CACHE_NO) | |
1455 | return EXT4_EXT_CACHE_NO; | |
1456 | ||
1457 | BUG_ON(cex->ec_type != EXT4_EXT_CACHE_GAP && | |
1458 | cex->ec_type != EXT4_EXT_CACHE_EXTENT); | |
1459 | if (block >= cex->ec_block && block < cex->ec_block + cex->ec_len) { | |
1460 | ex->ee_block = cpu_to_le32(cex->ec_block); | |
f65e6fba | 1461 | ext4_ext_store_pblock(ex, cex->ec_start); |
a86c6181 | 1462 | ex->ee_len = cpu_to_le16(cex->ec_len); |
2ae02107 | 1463 | ext_debug("%lu cached by %lu:%lu:%llu\n", |
a86c6181 AT |
1464 | (unsigned long) block, |
1465 | (unsigned long) cex->ec_block, | |
1466 | (unsigned long) cex->ec_len, | |
f65e6fba | 1467 | cex->ec_start); |
a86c6181 AT |
1468 | return cex->ec_type; |
1469 | } | |
1470 | ||
1471 | /* not in cache */ | |
1472 | return EXT4_EXT_CACHE_NO; | |
1473 | } | |
1474 | ||
1475 | /* | |
d0d856e8 RD |
1476 | * ext4_ext_rm_idx: |
1477 | * removes index from the index block. | |
1478 | * It's used in truncate case only, thus all requests are for | |
1479 | * last index in the block only. | |
a86c6181 AT |
1480 | */ |
1481 | int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, | |
1482 | struct ext4_ext_path *path) | |
1483 | { | |
1484 | struct buffer_head *bh; | |
1485 | int err; | |
f65e6fba | 1486 | ext4_fsblk_t leaf; |
a86c6181 AT |
1487 | |
1488 | /* free index block */ | |
1489 | path--; | |
f65e6fba | 1490 | leaf = idx_pblock(path->p_idx); |
a86c6181 AT |
1491 | BUG_ON(path->p_hdr->eh_entries == 0); |
1492 | if ((err = ext4_ext_get_access(handle, inode, path))) | |
1493 | return err; | |
1494 | path->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path->p_hdr->eh_entries)-1); | |
1495 | if ((err = ext4_ext_dirty(handle, inode, path))) | |
1496 | return err; | |
2ae02107 | 1497 | ext_debug("index is empty, remove it, free block %llu\n", leaf); |
a86c6181 AT |
1498 | bh = sb_find_get_block(inode->i_sb, leaf); |
1499 | ext4_forget(handle, 1, inode, bh, leaf); | |
1500 | ext4_free_blocks(handle, inode, leaf, 1); | |
1501 | return err; | |
1502 | } | |
1503 | ||
1504 | /* | |
d0d856e8 RD |
1505 | * ext4_ext_calc_credits_for_insert: |
1506 | * This routine returns max. credits that the extent tree can consume. | |
a86c6181 | 1507 | * It should be OK for low-performance paths like ->writepage() |
d0d856e8 RD |
1508 | * To allow many writing processes to fit into a single transaction, |
1509 | * the caller should calculate credits under truncate_mutex and | |
1510 | * pass the actual path. | |
a86c6181 AT |
1511 | */ |
1512 | int inline ext4_ext_calc_credits_for_insert(struct inode *inode, | |
1513 | struct ext4_ext_path *path) | |
1514 | { | |
1515 | int depth, needed; | |
1516 | ||
1517 | if (path) { | |
1518 | /* probably there is space in leaf? */ | |
1519 | depth = ext_depth(inode); | |
1520 | if (le16_to_cpu(path[depth].p_hdr->eh_entries) | |
1521 | < le16_to_cpu(path[depth].p_hdr->eh_max)) | |
1522 | return 1; | |
1523 | } | |
1524 | ||
1525 | /* | |
d0d856e8 | 1526 | * given 32-bit logical block (4294967296 blocks), max. tree |
a86c6181 | 1527 | * can be 4 levels in depth -- 4 * 340^4 == 53453440000. |
d0d856e8 | 1528 | * Let's also add one more level for imbalance. |
a86c6181 AT |
1529 | */ |
1530 | depth = 5; | |
1531 | ||
1532 | /* allocation of new data block(s) */ | |
1533 | needed = 2; | |
1534 | ||
1535 | /* | |
d0d856e8 | 1536 | * tree can be full, so it would need to grow in depth: |
a86c6181 AT |
1537 | * allocation + old root + new root |
1538 | */ | |
1539 | needed += 2 + 1 + 1; | |
1540 | ||
1541 | /* | |
d0d856e8 | 1542 | * Index split can happen, we would need: |
a86c6181 AT |
1543 | * allocate intermediate indexes (bitmap + group) |
1544 | * + change two blocks at each level, but root (already included) | |
1545 | */ | |
1546 | needed = (depth * 2) + (depth * 2); | |
1547 | ||
1548 | /* any allocation modifies superblock */ | |
1549 | needed += 1; | |
1550 | ||
1551 | return needed; | |
1552 | } | |
1553 | ||
1554 | static int ext4_remove_blocks(handle_t *handle, struct inode *inode, | |
1555 | struct ext4_extent *ex, | |
1556 | unsigned long from, unsigned long to) | |
1557 | { | |
1558 | struct buffer_head *bh; | |
1559 | int i; | |
1560 | ||
1561 | #ifdef EXTENTS_STATS | |
1562 | { | |
1563 | struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); | |
1564 | unsigned short ee_len = le16_to_cpu(ex->ee_len); | |
1565 | spin_lock(&sbi->s_ext_stats_lock); | |
1566 | sbi->s_ext_blocks += ee_len; | |
1567 | sbi->s_ext_extents++; | |
1568 | if (ee_len < sbi->s_ext_min) | |
1569 | sbi->s_ext_min = ee_len; | |
1570 | if (ee_len > sbi->s_ext_max) | |
1571 | sbi->s_ext_max = ee_len; | |
1572 | if (ext_depth(inode) > sbi->s_depth_max) | |
1573 | sbi->s_depth_max = ext_depth(inode); | |
1574 | spin_unlock(&sbi->s_ext_stats_lock); | |
1575 | } | |
1576 | #endif | |
1577 | if (from >= le32_to_cpu(ex->ee_block) | |
1578 | && to == le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - 1) { | |
1579 | /* tail removal */ | |
f65e6fba AT |
1580 | unsigned long num; |
1581 | ext4_fsblk_t start; | |
a86c6181 | 1582 | num = le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - from; |
f65e6fba | 1583 | start = ext_pblock(ex) + le16_to_cpu(ex->ee_len) - num; |
2ae02107 | 1584 | ext_debug("free last %lu blocks starting %llu\n", num, start); |
a86c6181 AT |
1585 | for (i = 0; i < num; i++) { |
1586 | bh = sb_find_get_block(inode->i_sb, start + i); | |
1587 | ext4_forget(handle, 0, inode, bh, start + i); | |
1588 | } | |
1589 | ext4_free_blocks(handle, inode, start, num); | |
1590 | } else if (from == le32_to_cpu(ex->ee_block) | |
1591 | && to <= le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - 1) { | |
1592 | printk("strange request: removal %lu-%lu from %u:%u\n", | |
1593 | from, to, le32_to_cpu(ex->ee_block), le16_to_cpu(ex->ee_len)); | |
1594 | } else { | |
1595 | printk("strange request: removal(2) %lu-%lu from %u:%u\n", | |
1596 | from, to, le32_to_cpu(ex->ee_block), le16_to_cpu(ex->ee_len)); | |
1597 | } | |
1598 | return 0; | |
1599 | } | |
1600 | ||
1601 | static int | |
1602 | ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, | |
1603 | struct ext4_ext_path *path, unsigned long start) | |
1604 | { | |
1605 | int err = 0, correct_index = 0; | |
1606 | int depth = ext_depth(inode), credits; | |
1607 | struct ext4_extent_header *eh; | |
1608 | unsigned a, b, block, num; | |
1609 | unsigned long ex_ee_block; | |
1610 | unsigned short ex_ee_len; | |
1611 | struct ext4_extent *ex; | |
1612 | ||
1613 | ext_debug("truncate since %lu in leaf\n", start); | |
1614 | if (!path[depth].p_hdr) | |
1615 | path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); | |
1616 | eh = path[depth].p_hdr; | |
1617 | BUG_ON(eh == NULL); | |
1618 | BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max)); | |
1619 | BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC); | |
1620 | ||
1621 | /* find where to start removing */ | |
1622 | ex = EXT_LAST_EXTENT(eh); | |
1623 | ||
1624 | ex_ee_block = le32_to_cpu(ex->ee_block); | |
1625 | ex_ee_len = le16_to_cpu(ex->ee_len); | |
1626 | ||
1627 | while (ex >= EXT_FIRST_EXTENT(eh) && | |
1628 | ex_ee_block + ex_ee_len > start) { | |
1629 | ext_debug("remove ext %lu:%u\n", ex_ee_block, ex_ee_len); | |
1630 | path[depth].p_ext = ex; | |
1631 | ||
1632 | a = ex_ee_block > start ? ex_ee_block : start; | |
1633 | b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ? | |
1634 | ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK; | |
1635 | ||
1636 | ext_debug(" border %u:%u\n", a, b); | |
1637 | ||
1638 | if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) { | |
1639 | block = 0; | |
1640 | num = 0; | |
1641 | BUG(); | |
1642 | } else if (a != ex_ee_block) { | |
1643 | /* remove tail of the extent */ | |
1644 | block = ex_ee_block; | |
1645 | num = a - block; | |
1646 | } else if (b != ex_ee_block + ex_ee_len - 1) { | |
1647 | /* remove head of the extent */ | |
1648 | block = a; | |
1649 | num = b - a; | |
1650 | /* there is no "make a hole" API yet */ | |
1651 | BUG(); | |
1652 | } else { | |
1653 | /* remove whole extent: excellent! */ | |
1654 | block = ex_ee_block; | |
1655 | num = 0; | |
1656 | BUG_ON(a != ex_ee_block); | |
1657 | BUG_ON(b != ex_ee_block + ex_ee_len - 1); | |
1658 | } | |
1659 | ||
d0d856e8 | 1660 | /* at present, extent can't cross block group: */ |
a86c6181 AT |
1661 | /* leaf + bitmap + group desc + sb + inode */ |
1662 | credits = 5; | |
1663 | if (ex == EXT_FIRST_EXTENT(eh)) { | |
1664 | correct_index = 1; | |
1665 | credits += (ext_depth(inode)) + 1; | |
1666 | } | |
1667 | #ifdef CONFIG_QUOTA | |
1668 | credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb); | |
1669 | #endif | |
1670 | ||
1671 | handle = ext4_ext_journal_restart(handle, credits); | |
1672 | if (IS_ERR(handle)) { | |
1673 | err = PTR_ERR(handle); | |
1674 | goto out; | |
1675 | } | |
1676 | ||
1677 | err = ext4_ext_get_access(handle, inode, path + depth); | |
1678 | if (err) | |
1679 | goto out; | |
1680 | ||
1681 | err = ext4_remove_blocks(handle, inode, ex, a, b); | |
1682 | if (err) | |
1683 | goto out; | |
1684 | ||
1685 | if (num == 0) { | |
d0d856e8 | 1686 | /* this extent is removed; mark slot entirely unused */ |
f65e6fba | 1687 | ext4_ext_store_pblock(ex, 0); |
a86c6181 AT |
1688 | eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1); |
1689 | } | |
1690 | ||
1691 | ex->ee_block = cpu_to_le32(block); | |
1692 | ex->ee_len = cpu_to_le16(num); | |
1693 | ||
1694 | err = ext4_ext_dirty(handle, inode, path + depth); | |
1695 | if (err) | |
1696 | goto out; | |
1697 | ||
2ae02107 | 1698 | ext_debug("new extent: %u:%u:%llu\n", block, num, |
f65e6fba | 1699 | ext_pblock(ex)); |
a86c6181 AT |
1700 | ex--; |
1701 | ex_ee_block = le32_to_cpu(ex->ee_block); | |
1702 | ex_ee_len = le16_to_cpu(ex->ee_len); | |
1703 | } | |
1704 | ||
1705 | if (correct_index && eh->eh_entries) | |
1706 | err = ext4_ext_correct_indexes(handle, inode, path); | |
1707 | ||
1708 | /* if this leaf is free, then we should | |
1709 | * remove it from index block above */ | |
1710 | if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL) | |
1711 | err = ext4_ext_rm_idx(handle, inode, path + depth); | |
1712 | ||
1713 | out: | |
1714 | return err; | |
1715 | } | |
1716 | ||
1717 | /* | |
d0d856e8 RD |
1718 | * ext4_ext_more_to_rm: |
1719 | * returns 1 if current index has to be freed (even partial) | |
a86c6181 AT |
1720 | */ |
1721 | static int inline | |
1722 | ext4_ext_more_to_rm(struct ext4_ext_path *path) | |
1723 | { | |
1724 | BUG_ON(path->p_idx == NULL); | |
1725 | ||
1726 | if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr)) | |
1727 | return 0; | |
1728 | ||
1729 | /* | |
d0d856e8 | 1730 | * if truncate on deeper level happened, it wasn't partial, |
a86c6181 AT |
1731 | * so we have to consider current index for truncation |
1732 | */ | |
1733 | if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) | |
1734 | return 0; | |
1735 | return 1; | |
1736 | } | |
1737 | ||
1738 | int ext4_ext_remove_space(struct inode *inode, unsigned long start) | |
1739 | { | |
1740 | struct super_block *sb = inode->i_sb; | |
1741 | int depth = ext_depth(inode); | |
1742 | struct ext4_ext_path *path; | |
1743 | handle_t *handle; | |
1744 | int i = 0, err = 0; | |
1745 | ||
1746 | ext_debug("truncate since %lu\n", start); | |
1747 | ||
1748 | /* probably first extent we're gonna free will be last in block */ | |
1749 | handle = ext4_journal_start(inode, depth + 1); | |
1750 | if (IS_ERR(handle)) | |
1751 | return PTR_ERR(handle); | |
1752 | ||
1753 | ext4_ext_invalidate_cache(inode); | |
1754 | ||
1755 | /* | |
d0d856e8 RD |
1756 | * We start scanning from right side, freeing all the blocks |
1757 | * after i_size and walking into the tree depth-wise. | |
a86c6181 AT |
1758 | */ |
1759 | path = kmalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_KERNEL); | |
1760 | if (path == NULL) { | |
1761 | ext4_journal_stop(handle); | |
1762 | return -ENOMEM; | |
1763 | } | |
1764 | memset(path, 0, sizeof(struct ext4_ext_path) * (depth + 1)); | |
1765 | path[0].p_hdr = ext_inode_hdr(inode); | |
1766 | if (ext4_ext_check_header(__FUNCTION__, inode, path[0].p_hdr)) { | |
1767 | err = -EIO; | |
1768 | goto out; | |
1769 | } | |
1770 | path[0].p_depth = depth; | |
1771 | ||
1772 | while (i >= 0 && err == 0) { | |
1773 | if (i == depth) { | |
1774 | /* this is leaf block */ | |
1775 | err = ext4_ext_rm_leaf(handle, inode, path, start); | |
d0d856e8 | 1776 | /* root level has p_bh == NULL, brelse() eats this */ |
a86c6181 AT |
1777 | brelse(path[i].p_bh); |
1778 | path[i].p_bh = NULL; | |
1779 | i--; | |
1780 | continue; | |
1781 | } | |
1782 | ||
1783 | /* this is index block */ | |
1784 | if (!path[i].p_hdr) { | |
1785 | ext_debug("initialize header\n"); | |
1786 | path[i].p_hdr = ext_block_hdr(path[i].p_bh); | |
1787 | if (ext4_ext_check_header(__FUNCTION__, inode, | |
1788 | path[i].p_hdr)) { | |
1789 | err = -EIO; | |
1790 | goto out; | |
1791 | } | |
1792 | } | |
1793 | ||
1794 | BUG_ON(le16_to_cpu(path[i].p_hdr->eh_entries) | |
1795 | > le16_to_cpu(path[i].p_hdr->eh_max)); | |
1796 | BUG_ON(path[i].p_hdr->eh_magic != EXT4_EXT_MAGIC); | |
1797 | ||
1798 | if (!path[i].p_idx) { | |
d0d856e8 | 1799 | /* this level hasn't been touched yet */ |
a86c6181 AT |
1800 | path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); |
1801 | path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1; | |
1802 | ext_debug("init index ptr: hdr 0x%p, num %d\n", | |
1803 | path[i].p_hdr, | |
1804 | le16_to_cpu(path[i].p_hdr->eh_entries)); | |
1805 | } else { | |
d0d856e8 | 1806 | /* we were already here, see at next index */ |
a86c6181 AT |
1807 | path[i].p_idx--; |
1808 | } | |
1809 | ||
1810 | ext_debug("level %d - index, first 0x%p, cur 0x%p\n", | |
1811 | i, EXT_FIRST_INDEX(path[i].p_hdr), | |
1812 | path[i].p_idx); | |
1813 | if (ext4_ext_more_to_rm(path + i)) { | |
1814 | /* go to the next level */ | |
2ae02107 | 1815 | ext_debug("move to level %d (block %llu)\n", |
f65e6fba | 1816 | i + 1, idx_pblock(path[i].p_idx)); |
a86c6181 AT |
1817 | memset(path + i + 1, 0, sizeof(*path)); |
1818 | path[i+1].p_bh = | |
f65e6fba | 1819 | sb_bread(sb, idx_pblock(path[i].p_idx)); |
a86c6181 AT |
1820 | if (!path[i+1].p_bh) { |
1821 | /* should we reset i_size? */ | |
1822 | err = -EIO; | |
1823 | break; | |
1824 | } | |
1825 | ||
d0d856e8 RD |
1826 | /* save actual number of indexes since this |
1827 | * number is changed at the next iteration */ | |
a86c6181 AT |
1828 | path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries); |
1829 | i++; | |
1830 | } else { | |
d0d856e8 | 1831 | /* we finished processing this index, go up */ |
a86c6181 | 1832 | if (path[i].p_hdr->eh_entries == 0 && i > 0) { |
d0d856e8 | 1833 | /* index is empty, remove it; |
a86c6181 AT |
1834 | * handle must be already prepared by the |
1835 | * truncatei_leaf() */ | |
1836 | err = ext4_ext_rm_idx(handle, inode, path + i); | |
1837 | } | |
d0d856e8 | 1838 | /* root level has p_bh == NULL, brelse() eats this */ |
a86c6181 AT |
1839 | brelse(path[i].p_bh); |
1840 | path[i].p_bh = NULL; | |
1841 | i--; | |
1842 | ext_debug("return to level %d\n", i); | |
1843 | } | |
1844 | } | |
1845 | ||
1846 | /* TODO: flexible tree reduction should be here */ | |
1847 | if (path->p_hdr->eh_entries == 0) { | |
1848 | /* | |
d0d856e8 RD |
1849 | * truncate to zero freed all the tree, |
1850 | * so we need to correct eh_depth | |
a86c6181 AT |
1851 | */ |
1852 | err = ext4_ext_get_access(handle, inode, path); | |
1853 | if (err == 0) { | |
1854 | ext_inode_hdr(inode)->eh_depth = 0; | |
1855 | ext_inode_hdr(inode)->eh_max = | |
1856 | cpu_to_le16(ext4_ext_space_root(inode)); | |
1857 | err = ext4_ext_dirty(handle, inode, path); | |
1858 | } | |
1859 | } | |
1860 | out: | |
1861 | ext4_ext_tree_changed(inode); | |
1862 | ext4_ext_drop_refs(path); | |
1863 | kfree(path); | |
1864 | ext4_journal_stop(handle); | |
1865 | ||
1866 | return err; | |
1867 | } | |
1868 | ||
1869 | /* | |
1870 | * called at mount time | |
1871 | */ | |
1872 | void ext4_ext_init(struct super_block *sb) | |
1873 | { | |
1874 | /* | |
1875 | * possible initialization would be here | |
1876 | */ | |
1877 | ||
1878 | if (test_opt(sb, EXTENTS)) { | |
1879 | printk("EXT4-fs: file extents enabled"); | |
1880 | #ifdef AGRESSIVE_TEST | |
1881 | printk(", agressive tests"); | |
1882 | #endif | |
1883 | #ifdef CHECK_BINSEARCH | |
1884 | printk(", check binsearch"); | |
1885 | #endif | |
1886 | #ifdef EXTENTS_STATS | |
1887 | printk(", stats"); | |
1888 | #endif | |
1889 | printk("\n"); | |
1890 | #ifdef EXTENTS_STATS | |
1891 | spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock); | |
1892 | EXT4_SB(sb)->s_ext_min = 1 << 30; | |
1893 | EXT4_SB(sb)->s_ext_max = 0; | |
1894 | #endif | |
1895 | } | |
1896 | } | |
1897 | ||
1898 | /* | |
1899 | * called at umount time | |
1900 | */ | |
1901 | void ext4_ext_release(struct super_block *sb) | |
1902 | { | |
1903 | if (!test_opt(sb, EXTENTS)) | |
1904 | return; | |
1905 | ||
1906 | #ifdef EXTENTS_STATS | |
1907 | if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) { | |
1908 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
1909 | printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n", | |
1910 | sbi->s_ext_blocks, sbi->s_ext_extents, | |
1911 | sbi->s_ext_blocks / sbi->s_ext_extents); | |
1912 | printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n", | |
1913 | sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max); | |
1914 | } | |
1915 | #endif | |
1916 | } | |
1917 | ||
f65e6fba AT |
1918 | int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, |
1919 | ext4_fsblk_t iblock, | |
a86c6181 AT |
1920 | unsigned long max_blocks, struct buffer_head *bh_result, |
1921 | int create, int extend_disksize) | |
1922 | { | |
1923 | struct ext4_ext_path *path = NULL; | |
1924 | struct ext4_extent newex, *ex; | |
f65e6fba AT |
1925 | ext4_fsblk_t goal, newblock; |
1926 | int err = 0, depth; | |
a86c6181 AT |
1927 | unsigned long allocated = 0; |
1928 | ||
1929 | __clear_bit(BH_New, &bh_result->b_state); | |
1930 | ext_debug("blocks %d/%lu requested for inode %u\n", (int) iblock, | |
1931 | max_blocks, (unsigned) inode->i_ino); | |
1932 | mutex_lock(&EXT4_I(inode)->truncate_mutex); | |
1933 | ||
1934 | /* check in cache */ | |
1935 | if ((goal = ext4_ext_in_cache(inode, iblock, &newex))) { | |
1936 | if (goal == EXT4_EXT_CACHE_GAP) { | |
1937 | if (!create) { | |
1938 | /* block isn't allocated yet and | |
d0d856e8 | 1939 | * user doesn't want to allocate it */ |
a86c6181 AT |
1940 | goto out2; |
1941 | } | |
1942 | /* we should allocate requested block */ | |
1943 | } else if (goal == EXT4_EXT_CACHE_EXTENT) { | |
1944 | /* block is already allocated */ | |
1945 | newblock = iblock | |
1946 | - le32_to_cpu(newex.ee_block) | |
f65e6fba | 1947 | + ext_pblock(&newex); |
d0d856e8 | 1948 | /* number of remaining blocks in the extent */ |
a86c6181 AT |
1949 | allocated = le16_to_cpu(newex.ee_len) - |
1950 | (iblock - le32_to_cpu(newex.ee_block)); | |
1951 | goto out; | |
1952 | } else { | |
1953 | BUG(); | |
1954 | } | |
1955 | } | |
1956 | ||
1957 | /* find extent for this block */ | |
1958 | path = ext4_ext_find_extent(inode, iblock, NULL); | |
1959 | if (IS_ERR(path)) { | |
1960 | err = PTR_ERR(path); | |
1961 | path = NULL; | |
1962 | goto out2; | |
1963 | } | |
1964 | ||
1965 | depth = ext_depth(inode); | |
1966 | ||
1967 | /* | |
d0d856e8 RD |
1968 | * consistent leaf must not be empty; |
1969 | * this situation is possible, though, _during_ tree modification; | |
a86c6181 AT |
1970 | * this is why assert can't be put in ext4_ext_find_extent() |
1971 | */ | |
1972 | BUG_ON(path[depth].p_ext == NULL && depth != 0); | |
1973 | ||
1974 | if ((ex = path[depth].p_ext)) { | |
1975 | unsigned long ee_block = le32_to_cpu(ex->ee_block); | |
f65e6fba | 1976 | ext4_fsblk_t ee_start = ext_pblock(ex); |
a86c6181 | 1977 | unsigned short ee_len = le16_to_cpu(ex->ee_len); |
471d4011 SB |
1978 | |
1979 | /* | |
1980 | * Allow future support for preallocated extents to be added | |
1981 | * as an RO_COMPAT feature: | |
1982 | * Uninitialized extents are treated as holes, except that | |
1983 | * we avoid (fail) allocating new blocks during a write. | |
1984 | */ | |
1985 | if (ee_len > EXT_MAX_LEN) | |
1986 | goto out2; | |
d0d856e8 | 1987 | /* if found extent covers block, simply return it */ |
a86c6181 AT |
1988 | if (iblock >= ee_block && iblock < ee_block + ee_len) { |
1989 | newblock = iblock - ee_block + ee_start; | |
d0d856e8 | 1990 | /* number of remaining blocks in the extent */ |
a86c6181 | 1991 | allocated = ee_len - (iblock - ee_block); |
2ae02107 | 1992 | ext_debug("%d fit into %lu:%d -> %llu\n", (int) iblock, |
a86c6181 AT |
1993 | ee_block, ee_len, newblock); |
1994 | ext4_ext_put_in_cache(inode, ee_block, ee_len, | |
1995 | ee_start, EXT4_EXT_CACHE_EXTENT); | |
1996 | goto out; | |
1997 | } | |
1998 | } | |
1999 | ||
2000 | /* | |
d0d856e8 | 2001 | * requested block isn't allocated yet; |
a86c6181 AT |
2002 | * we couldn't try to create block if create flag is zero |
2003 | */ | |
2004 | if (!create) { | |
d0d856e8 RD |
2005 | /* put just found gap into cache to speed up |
2006 | * subsequent requests */ | |
a86c6181 AT |
2007 | ext4_ext_put_gap_in_cache(inode, path, iblock); |
2008 | goto out2; | |
2009 | } | |
2010 | /* | |
63f57933 AM |
2011 | * Okay, we need to do block allocation. Lazily initialize the block |
2012 | * allocation info here if necessary. | |
2013 | */ | |
a86c6181 AT |
2014 | if (S_ISREG(inode->i_mode) && (!EXT4_I(inode)->i_block_alloc_info)) |
2015 | ext4_init_block_alloc_info(inode); | |
2016 | ||
2017 | /* allocate new block */ | |
2018 | goal = ext4_ext_find_goal(inode, path, iblock); | |
2019 | allocated = max_blocks; | |
2020 | newblock = ext4_new_blocks(handle, inode, goal, &allocated, &err); | |
2021 | if (!newblock) | |
2022 | goto out2; | |
2ae02107 | 2023 | ext_debug("allocate new block: goal %llu, found %llu/%lu\n", |
a86c6181 AT |
2024 | goal, newblock, allocated); |
2025 | ||
2026 | /* try to insert new extent into found leaf and return */ | |
2027 | newex.ee_block = cpu_to_le32(iblock); | |
f65e6fba | 2028 | ext4_ext_store_pblock(&newex, newblock); |
a86c6181 AT |
2029 | newex.ee_len = cpu_to_le16(allocated); |
2030 | err = ext4_ext_insert_extent(handle, inode, path, &newex); | |
2031 | if (err) | |
2032 | goto out2; | |
2033 | ||
2034 | if (extend_disksize && inode->i_size > EXT4_I(inode)->i_disksize) | |
2035 | EXT4_I(inode)->i_disksize = inode->i_size; | |
2036 | ||
2037 | /* previous routine could use block we allocated */ | |
f65e6fba | 2038 | newblock = ext_pblock(&newex); |
a86c6181 AT |
2039 | __set_bit(BH_New, &bh_result->b_state); |
2040 | ||
2041 | ext4_ext_put_in_cache(inode, iblock, allocated, newblock, | |
2042 | EXT4_EXT_CACHE_EXTENT); | |
2043 | out: | |
2044 | if (allocated > max_blocks) | |
2045 | allocated = max_blocks; | |
2046 | ext4_ext_show_leaf(inode, path); | |
2047 | __set_bit(BH_Mapped, &bh_result->b_state); | |
2048 | bh_result->b_bdev = inode->i_sb->s_bdev; | |
2049 | bh_result->b_blocknr = newblock; | |
2050 | out2: | |
2051 | if (path) { | |
2052 | ext4_ext_drop_refs(path); | |
2053 | kfree(path); | |
2054 | } | |
2055 | mutex_unlock(&EXT4_I(inode)->truncate_mutex); | |
2056 | ||
2057 | return err ? err : allocated; | |
2058 | } | |
2059 | ||
2060 | void ext4_ext_truncate(struct inode * inode, struct page *page) | |
2061 | { | |
2062 | struct address_space *mapping = inode->i_mapping; | |
2063 | struct super_block *sb = inode->i_sb; | |
2064 | unsigned long last_block; | |
2065 | handle_t *handle; | |
2066 | int err = 0; | |
2067 | ||
2068 | /* | |
2069 | * probably first extent we're gonna free will be last in block | |
2070 | */ | |
2071 | err = ext4_writepage_trans_blocks(inode) + 3; | |
2072 | handle = ext4_journal_start(inode, err); | |
2073 | if (IS_ERR(handle)) { | |
2074 | if (page) { | |
2075 | clear_highpage(page); | |
2076 | flush_dcache_page(page); | |
2077 | unlock_page(page); | |
2078 | page_cache_release(page); | |
2079 | } | |
2080 | return; | |
2081 | } | |
2082 | ||
2083 | if (page) | |
2084 | ext4_block_truncate_page(handle, page, mapping, inode->i_size); | |
2085 | ||
2086 | mutex_lock(&EXT4_I(inode)->truncate_mutex); | |
2087 | ext4_ext_invalidate_cache(inode); | |
2088 | ||
2089 | /* | |
d0d856e8 RD |
2090 | * TODO: optimization is possible here. |
2091 | * Probably we need not scan at all, | |
2092 | * because page truncation is enough. | |
a86c6181 AT |
2093 | */ |
2094 | if (ext4_orphan_add(handle, inode)) | |
2095 | goto out_stop; | |
2096 | ||
2097 | /* we have to know where to truncate from in crash case */ | |
2098 | EXT4_I(inode)->i_disksize = inode->i_size; | |
2099 | ext4_mark_inode_dirty(handle, inode); | |
2100 | ||
2101 | last_block = (inode->i_size + sb->s_blocksize - 1) | |
2102 | >> EXT4_BLOCK_SIZE_BITS(sb); | |
2103 | err = ext4_ext_remove_space(inode, last_block); | |
2104 | ||
2105 | /* In a multi-transaction truncate, we only make the final | |
d0d856e8 | 2106 | * transaction synchronous. */ |
a86c6181 AT |
2107 | if (IS_SYNC(inode)) |
2108 | handle->h_sync = 1; | |
2109 | ||
2110 | out_stop: | |
2111 | /* | |
d0d856e8 | 2112 | * If this was a simple ftruncate() and the file will remain alive, |
a86c6181 AT |
2113 | * then we need to clear up the orphan record which we created above. |
2114 | * However, if this was a real unlink then we were called by | |
2115 | * ext4_delete_inode(), and we allow that function to clean up the | |
2116 | * orphan info for us. | |
2117 | */ | |
2118 | if (inode->i_nlink) | |
2119 | ext4_orphan_del(handle, inode); | |
2120 | ||
2121 | mutex_unlock(&EXT4_I(inode)->truncate_mutex); | |
2122 | ext4_journal_stop(handle); | |
2123 | } | |
2124 | ||
2125 | /* | |
d0d856e8 RD |
2126 | * ext4_ext_writepage_trans_blocks: |
2127 | * calculate max number of blocks we could modify | |
a86c6181 AT |
2128 | * in order to allocate new block for an inode |
2129 | */ | |
2130 | int ext4_ext_writepage_trans_blocks(struct inode *inode, int num) | |
2131 | { | |
2132 | int needed; | |
2133 | ||
2134 | needed = ext4_ext_calc_credits_for_insert(inode, NULL); | |
2135 | ||
d0d856e8 | 2136 | /* caller wants to allocate num blocks, but note it includes sb */ |
a86c6181 AT |
2137 | needed = needed * num - (num - 1); |
2138 | ||
2139 | #ifdef CONFIG_QUOTA | |
2140 | needed += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb); | |
2141 | #endif | |
2142 | ||
2143 | return needed; | |
2144 | } | |
2145 | ||
2146 | EXPORT_SYMBOL(ext4_mark_inode_dirty); | |
2147 | EXPORT_SYMBOL(ext4_ext_invalidate_cache); | |
2148 | EXPORT_SYMBOL(ext4_ext_insert_extent); | |
2149 | EXPORT_SYMBOL(ext4_ext_walk_space); | |
2150 | EXPORT_SYMBOL(ext4_ext_find_goal); | |
2151 | EXPORT_SYMBOL(ext4_ext_calc_credits_for_insert); | |
2152 |