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2b27bdcc | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1e51764a AB |
2 | /* |
3 | * This file is part of UBIFS. | |
4 | * | |
5 | * Copyright (C) 2006-2008 Nokia Corporation. | |
6 | * | |
1e51764a AB |
7 | * Authors: Adrian Hunter |
8 | * Artem Bityutskiy (Битюцкий Артём) | |
9 | */ | |
10 | ||
11 | /* | |
12 | * This file implements TNC (Tree Node Cache) which caches indexing nodes of | |
13 | * the UBIFS B-tree. | |
14 | * | |
15 | * At the moment the locking rules of the TNC tree are quite simple and | |
16 | * straightforward. We just have a mutex and lock it when we traverse the | |
17 | * tree. If a znode is not in memory, we read it from flash while still having | |
18 | * the mutex locked. | |
19 | */ | |
20 | ||
21 | #include <linux/crc32.h> | |
5a0e3ad6 | 22 | #include <linux/slab.h> |
1e51764a AB |
23 | #include "ubifs.h" |
24 | ||
1cb51a15 | 25 | static int try_read_node(const struct ubifs_info *c, void *buf, int type, |
545bc8f6 | 26 | struct ubifs_zbranch *zbr); |
1cb51a15 RW |
27 | static int fallible_read_node(struct ubifs_info *c, const union ubifs_key *key, |
28 | struct ubifs_zbranch *zbr, void *node); | |
29 | ||
1e51764a AB |
30 | /* |
31 | * Returned codes of 'matches_name()' and 'fallible_matches_name()' functions. | |
32 | * @NAME_LESS: name corresponding to the first argument is less than second | |
33 | * @NAME_MATCHES: names match | |
34 | * @NAME_GREATER: name corresponding to the second argument is greater than | |
35 | * first | |
36 | * @NOT_ON_MEDIA: node referred by zbranch does not exist on the media | |
37 | * | |
38 | * These constants were introduce to improve readability. | |
39 | */ | |
40 | enum { | |
41 | NAME_LESS = 0, | |
42 | NAME_MATCHES = 1, | |
43 | NAME_GREATER = 2, | |
44 | NOT_ON_MEDIA = 3, | |
45 | }; | |
46 | ||
47 | /** | |
48 | * insert_old_idx - record an index node obsoleted since the last commit start. | |
49 | * @c: UBIFS file-system description object | |
50 | * @lnum: LEB number of obsoleted index node | |
51 | * @offs: offset of obsoleted index node | |
52 | * | |
53 | * Returns %0 on success, and a negative error code on failure. | |
54 | * | |
55 | * For recovery, there must always be a complete intact version of the index on | |
56 | * flash at all times. That is called the "old index". It is the index as at the | |
57 | * time of the last successful commit. Many of the index nodes in the old index | |
58 | * may be dirty, but they must not be erased until the next successful commit | |
59 | * (at which point that index becomes the old index). | |
60 | * | |
61 | * That means that the garbage collection and the in-the-gaps method of | |
62 | * committing must be able to determine if an index node is in the old index. | |
63 | * Most of the old index nodes can be found by looking up the TNC using the | |
64 | * 'lookup_znode()' function. However, some of the old index nodes may have | |
65 | * been deleted from the current index or may have been changed so much that | |
66 | * they cannot be easily found. In those cases, an entry is added to an RB-tree. | |
67 | * That is what this function does. The RB-tree is ordered by LEB number and | |
68 | * offset because they uniquely identify the old index node. | |
69 | */ | |
70 | static int insert_old_idx(struct ubifs_info *c, int lnum, int offs) | |
71 | { | |
72 | struct ubifs_old_idx *old_idx, *o; | |
73 | struct rb_node **p, *parent = NULL; | |
74 | ||
75 | old_idx = kmalloc(sizeof(struct ubifs_old_idx), GFP_NOFS); | |
76 | if (unlikely(!old_idx)) | |
77 | return -ENOMEM; | |
78 | old_idx->lnum = lnum; | |
79 | old_idx->offs = offs; | |
80 | ||
81 | p = &c->old_idx.rb_node; | |
82 | while (*p) { | |
83 | parent = *p; | |
84 | o = rb_entry(parent, struct ubifs_old_idx, rb); | |
85 | if (lnum < o->lnum) | |
86 | p = &(*p)->rb_left; | |
87 | else if (lnum > o->lnum) | |
88 | p = &(*p)->rb_right; | |
89 | else if (offs < o->offs) | |
90 | p = &(*p)->rb_left; | |
91 | else if (offs > o->offs) | |
92 | p = &(*p)->rb_right; | |
93 | else { | |
235c362b | 94 | ubifs_err(c, "old idx added twice!"); |
1e51764a AB |
95 | kfree(old_idx); |
96 | return 0; | |
97 | } | |
98 | } | |
99 | rb_link_node(&old_idx->rb, parent, p); | |
100 | rb_insert_color(&old_idx->rb, &c->old_idx); | |
101 | return 0; | |
102 | } | |
103 | ||
104 | /** | |
105 | * insert_old_idx_znode - record a znode obsoleted since last commit start. | |
106 | * @c: UBIFS file-system description object | |
107 | * @znode: znode of obsoleted index node | |
108 | * | |
109 | * Returns %0 on success, and a negative error code on failure. | |
110 | */ | |
111 | int insert_old_idx_znode(struct ubifs_info *c, struct ubifs_znode *znode) | |
112 | { | |
113 | if (znode->parent) { | |
114 | struct ubifs_zbranch *zbr; | |
115 | ||
116 | zbr = &znode->parent->zbranch[znode->iip]; | |
117 | if (zbr->len) | |
118 | return insert_old_idx(c, zbr->lnum, zbr->offs); | |
119 | } else | |
120 | if (c->zroot.len) | |
121 | return insert_old_idx(c, c->zroot.lnum, | |
122 | c->zroot.offs); | |
123 | return 0; | |
124 | } | |
125 | ||
126 | /** | |
127 | * ins_clr_old_idx_znode - record a znode obsoleted since last commit start. | |
128 | * @c: UBIFS file-system description object | |
129 | * @znode: znode of obsoleted index node | |
130 | * | |
131 | * Returns %0 on success, and a negative error code on failure. | |
132 | */ | |
133 | static int ins_clr_old_idx_znode(struct ubifs_info *c, | |
134 | struct ubifs_znode *znode) | |
135 | { | |
136 | int err; | |
137 | ||
138 | if (znode->parent) { | |
139 | struct ubifs_zbranch *zbr; | |
140 | ||
141 | zbr = &znode->parent->zbranch[znode->iip]; | |
142 | if (zbr->len) { | |
143 | err = insert_old_idx(c, zbr->lnum, zbr->offs); | |
144 | if (err) | |
145 | return err; | |
146 | zbr->lnum = 0; | |
147 | zbr->offs = 0; | |
148 | zbr->len = 0; | |
149 | } | |
150 | } else | |
151 | if (c->zroot.len) { | |
152 | err = insert_old_idx(c, c->zroot.lnum, c->zroot.offs); | |
153 | if (err) | |
154 | return err; | |
155 | c->zroot.lnum = 0; | |
156 | c->zroot.offs = 0; | |
157 | c->zroot.len = 0; | |
158 | } | |
159 | return 0; | |
160 | } | |
161 | ||
162 | /** | |
163 | * destroy_old_idx - destroy the old_idx RB-tree. | |
164 | * @c: UBIFS file-system description object | |
165 | * | |
166 | * During start commit, the old_idx RB-tree is used to avoid overwriting index | |
167 | * nodes that were in the index last commit but have since been deleted. This | |
168 | * is necessary for recovery i.e. the old index must be kept intact until the | |
169 | * new index is successfully written. The old-idx RB-tree is used for the | |
170 | * in-the-gaps method of writing index nodes and is destroyed every commit. | |
171 | */ | |
172 | void destroy_old_idx(struct ubifs_info *c) | |
173 | { | |
bb25e49f CS |
174 | struct ubifs_old_idx *old_idx, *n; |
175 | ||
176 | rbtree_postorder_for_each_entry_safe(old_idx, n, &c->old_idx, rb) | |
1e51764a | 177 | kfree(old_idx); |
bb25e49f | 178 | |
1e51764a AB |
179 | c->old_idx = RB_ROOT; |
180 | } | |
181 | ||
182 | /** | |
183 | * copy_znode - copy a dirty znode. | |
184 | * @c: UBIFS file-system description object | |
185 | * @znode: znode to copy | |
186 | * | |
187 | * A dirty znode being committed may not be changed, so it is copied. | |
188 | */ | |
189 | static struct ubifs_znode *copy_znode(struct ubifs_info *c, | |
190 | struct ubifs_znode *znode) | |
191 | { | |
192 | struct ubifs_znode *zn; | |
193 | ||
bbc8a004 | 194 | zn = kmemdup(znode, c->max_znode_sz, GFP_NOFS); |
1e51764a AB |
195 | if (unlikely(!zn)) |
196 | return ERR_PTR(-ENOMEM); | |
197 | ||
1e51764a AB |
198 | zn->cnext = NULL; |
199 | __set_bit(DIRTY_ZNODE, &zn->flags); | |
200 | __clear_bit(COW_ZNODE, &zn->flags); | |
201 | ||
6eb61d58 | 202 | ubifs_assert(c, !ubifs_zn_obsolete(znode)); |
1e51764a AB |
203 | __set_bit(OBSOLETE_ZNODE, &znode->flags); |
204 | ||
205 | if (znode->level != 0) { | |
206 | int i; | |
207 | const int n = zn->child_cnt; | |
208 | ||
209 | /* The children now have new parent */ | |
210 | for (i = 0; i < n; i++) { | |
211 | struct ubifs_zbranch *zbr = &zn->zbranch[i]; | |
212 | ||
213 | if (zbr->znode) | |
214 | zbr->znode->parent = zn; | |
215 | } | |
216 | } | |
217 | ||
218 | atomic_long_inc(&c->dirty_zn_cnt); | |
219 | return zn; | |
220 | } | |
221 | ||
222 | /** | |
223 | * add_idx_dirt - add dirt due to a dirty znode. | |
224 | * @c: UBIFS file-system description object | |
225 | * @lnum: LEB number of index node | |
226 | * @dirt: size of index node | |
227 | * | |
228 | * This function updates lprops dirty space and the new size of the index. | |
229 | */ | |
230 | static int add_idx_dirt(struct ubifs_info *c, int lnum, int dirt) | |
231 | { | |
232 | c->calc_idx_sz -= ALIGN(dirt, 8); | |
233 | return ubifs_add_dirt(c, lnum, dirt); | |
234 | } | |
235 | ||
236 | /** | |
237 | * dirty_cow_znode - ensure a znode is not being committed. | |
238 | * @c: UBIFS file-system description object | |
239 | * @zbr: branch of znode to check | |
240 | * | |
241 | * Returns dirtied znode on success or negative error code on failure. | |
242 | */ | |
243 | static struct ubifs_znode *dirty_cow_znode(struct ubifs_info *c, | |
244 | struct ubifs_zbranch *zbr) | |
245 | { | |
246 | struct ubifs_znode *znode = zbr->znode; | |
247 | struct ubifs_znode *zn; | |
248 | int err; | |
249 | ||
f42eed7c | 250 | if (!ubifs_zn_cow(znode)) { |
1e51764a AB |
251 | /* znode is not being committed */ |
252 | if (!test_and_set_bit(DIRTY_ZNODE, &znode->flags)) { | |
253 | atomic_long_inc(&c->dirty_zn_cnt); | |
254 | atomic_long_dec(&c->clean_zn_cnt); | |
255 | atomic_long_dec(&ubifs_clean_zn_cnt); | |
256 | err = add_idx_dirt(c, zbr->lnum, zbr->len); | |
257 | if (unlikely(err)) | |
258 | return ERR_PTR(err); | |
259 | } | |
260 | return znode; | |
261 | } | |
262 | ||
263 | zn = copy_znode(c, znode); | |
8d47aef4 | 264 | if (IS_ERR(zn)) |
1e51764a AB |
265 | return zn; |
266 | ||
267 | if (zbr->len) { | |
268 | err = insert_old_idx(c, zbr->lnum, zbr->offs); | |
269 | if (unlikely(err)) | |
270 | return ERR_PTR(err); | |
271 | err = add_idx_dirt(c, zbr->lnum, zbr->len); | |
272 | } else | |
273 | err = 0; | |
274 | ||
275 | zbr->znode = zn; | |
276 | zbr->lnum = 0; | |
277 | zbr->offs = 0; | |
278 | zbr->len = 0; | |
279 | ||
280 | if (unlikely(err)) | |
281 | return ERR_PTR(err); | |
282 | return zn; | |
283 | } | |
284 | ||
285 | /** | |
286 | * lnc_add - add a leaf node to the leaf node cache. | |
287 | * @c: UBIFS file-system description object | |
288 | * @zbr: zbranch of leaf node | |
289 | * @node: leaf node | |
290 | * | |
291 | * Leaf nodes are non-index nodes directory entry nodes or data nodes. The | |
292 | * purpose of the leaf node cache is to save re-reading the same leaf node over | |
293 | * and over again. Most things are cached by VFS, however the file system must | |
294 | * cache directory entries for readdir and for resolving hash collisions. The | |
295 | * present implementation of the leaf node cache is extremely simple, and | |
296 | * allows for error returns that are not used but that may be needed if a more | |
297 | * complex implementation is created. | |
298 | * | |
299 | * Note, this function does not add the @node object to LNC directly, but | |
300 | * allocates a copy of the object and adds the copy to LNC. The reason for this | |
301 | * is that @node has been allocated outside of the TNC subsystem and will be | |
302 | * used with @c->tnc_mutex unlock upon return from the TNC subsystem. But LNC | |
303 | * may be changed at any time, e.g. freed by the shrinker. | |
304 | */ | |
305 | static int lnc_add(struct ubifs_info *c, struct ubifs_zbranch *zbr, | |
306 | const void *node) | |
307 | { | |
308 | int err; | |
309 | void *lnc_node; | |
310 | const struct ubifs_dent_node *dent = node; | |
311 | ||
6eb61d58 RW |
312 | ubifs_assert(c, !zbr->leaf); |
313 | ubifs_assert(c, zbr->len != 0); | |
314 | ubifs_assert(c, is_hash_key(c, &zbr->key)); | |
1e51764a AB |
315 | |
316 | err = ubifs_validate_entry(c, dent); | |
317 | if (err) { | |
7c46d0ae | 318 | dump_stack(); |
edf6be24 | 319 | ubifs_dump_node(c, dent); |
1e51764a AB |
320 | return err; |
321 | } | |
322 | ||
eaecf43a | 323 | lnc_node = kmemdup(node, zbr->len, GFP_NOFS); |
1e51764a AB |
324 | if (!lnc_node) |
325 | /* We don't have to have the cache, so no error */ | |
326 | return 0; | |
327 | ||
1e51764a AB |
328 | zbr->leaf = lnc_node; |
329 | return 0; | |
330 | } | |
331 | ||
332 | /** | |
333 | * lnc_add_directly - add a leaf node to the leaf-node-cache. | |
334 | * @c: UBIFS file-system description object | |
335 | * @zbr: zbranch of leaf node | |
336 | * @node: leaf node | |
337 | * | |
338 | * This function is similar to 'lnc_add()', but it does not create a copy of | |
339 | * @node but inserts @node to TNC directly. | |
340 | */ | |
341 | static int lnc_add_directly(struct ubifs_info *c, struct ubifs_zbranch *zbr, | |
342 | void *node) | |
343 | { | |
344 | int err; | |
345 | ||
6eb61d58 RW |
346 | ubifs_assert(c, !zbr->leaf); |
347 | ubifs_assert(c, zbr->len != 0); | |
1e51764a AB |
348 | |
349 | err = ubifs_validate_entry(c, node); | |
350 | if (err) { | |
7c46d0ae | 351 | dump_stack(); |
edf6be24 | 352 | ubifs_dump_node(c, node); |
1e51764a AB |
353 | return err; |
354 | } | |
355 | ||
356 | zbr->leaf = node; | |
357 | return 0; | |
358 | } | |
359 | ||
360 | /** | |
361 | * lnc_free - remove a leaf node from the leaf node cache. | |
362 | * @zbr: zbranch of leaf node | |
363 | * @node: leaf node | |
364 | */ | |
365 | static void lnc_free(struct ubifs_zbranch *zbr) | |
366 | { | |
367 | if (!zbr->leaf) | |
368 | return; | |
369 | kfree(zbr->leaf); | |
370 | zbr->leaf = NULL; | |
371 | } | |
372 | ||
373 | /** | |
b91dc981 | 374 | * tnc_read_hashed_node - read a "hashed" leaf node. |
1e51764a AB |
375 | * @c: UBIFS file-system description object |
376 | * @zbr: key and position of the node | |
377 | * @node: node is returned here | |
378 | * | |
379 | * This function reads a "hashed" node defined by @zbr from the leaf node cache | |
380 | * (in it is there) or from the hash media, in which case the node is also | |
381 | * added to LNC. Returns zero in case of success or a negative negative error | |
382 | * code in case of failure. | |
383 | */ | |
b91dc981 RW |
384 | static int tnc_read_hashed_node(struct ubifs_info *c, struct ubifs_zbranch *zbr, |
385 | void *node) | |
1e51764a AB |
386 | { |
387 | int err; | |
388 | ||
6eb61d58 | 389 | ubifs_assert(c, is_hash_key(c, &zbr->key)); |
1e51764a AB |
390 | |
391 | if (zbr->leaf) { | |
392 | /* Read from the leaf node cache */ | |
6eb61d58 | 393 | ubifs_assert(c, zbr->len != 0); |
1e51764a AB |
394 | memcpy(node, zbr->leaf, zbr->len); |
395 | return 0; | |
396 | } | |
397 | ||
1cb51a15 RW |
398 | if (c->replaying) { |
399 | err = fallible_read_node(c, &zbr->key, zbr, node); | |
400 | /* | |
401 | * When the node was not found, return -ENOENT, 0 otherwise. | |
402 | * Negative return codes stay as-is. | |
403 | */ | |
404 | if (err == 0) | |
405 | err = -ENOENT; | |
406 | else if (err == 1) | |
407 | err = 0; | |
408 | } else { | |
409 | err = ubifs_tnc_read_node(c, zbr, node); | |
410 | } | |
1e51764a AB |
411 | if (err) |
412 | return err; | |
413 | ||
414 | /* Add the node to the leaf node cache */ | |
415 | err = lnc_add(c, zbr, node); | |
416 | return err; | |
417 | } | |
418 | ||
419 | /** | |
420 | * try_read_node - read a node if it is a node. | |
421 | * @c: UBIFS file-system description object | |
422 | * @buf: buffer to read to | |
423 | * @type: node type | |
545bc8f6 | 424 | * @zbr: the zbranch describing the node to read |
1e51764a AB |
425 | * |
426 | * This function tries to read a node of known type and length, checks it and | |
427 | * stores it in @buf. This function returns %1 if a node is present and %0 if | |
428 | * a node is not present. A negative error code is returned for I/O errors. | |
429 | * This function performs that same function as ubifs_read_node except that | |
430 | * it does not require that there is actually a node present and instead | |
431 | * the return code indicates if a node was read. | |
6f7ab6d4 AB |
432 | * |
433 | * Note, this function does not check CRC of data nodes if @c->no_chk_data_crc | |
434 | * is true (it is controlled by corresponding mount option). However, if | |
18d1d7fb AB |
435 | * @c->mounting or @c->remounting_rw is true (we are mounting or re-mounting to |
436 | * R/W mode), @c->no_chk_data_crc is ignored and CRC is checked. This is | |
437 | * because during mounting or re-mounting from R/O mode to R/W mode we may read | |
438 | * journal nodes (when replying the journal or doing the recovery) and the | |
439 | * journal nodes may potentially be corrupted, so checking is required. | |
1e51764a AB |
440 | */ |
441 | static int try_read_node(const struct ubifs_info *c, void *buf, int type, | |
545bc8f6 | 442 | struct ubifs_zbranch *zbr) |
1e51764a | 443 | { |
545bc8f6 SH |
444 | int len = zbr->len; |
445 | int lnum = zbr->lnum; | |
446 | int offs = zbr->offs; | |
1e51764a AB |
447 | int err, node_len; |
448 | struct ubifs_ch *ch = buf; | |
449 | uint32_t crc, node_crc; | |
450 | ||
451 | dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len); | |
452 | ||
d304820a | 453 | err = ubifs_leb_read(c, lnum, buf, offs, len, 1); |
1e51764a | 454 | if (err) { |
235c362b | 455 | ubifs_err(c, "cannot read node type %d from LEB %d:%d, error %d", |
1e51764a AB |
456 | type, lnum, offs, err); |
457 | return err; | |
458 | } | |
459 | ||
460 | if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC) | |
461 | return 0; | |
462 | ||
463 | if (ch->node_type != type) | |
464 | return 0; | |
465 | ||
466 | node_len = le32_to_cpu(ch->len); | |
467 | if (node_len != len) | |
468 | return 0; | |
469 | ||
e9cd7dfd SH |
470 | if (type != UBIFS_DATA_NODE || !c->no_chk_data_crc || c->mounting || |
471 | c->remounting_rw) { | |
472 | crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8); | |
473 | node_crc = le32_to_cpu(ch->crc); | |
474 | if (crc != node_crc) | |
475 | return 0; | |
476 | } | |
1e51764a | 477 | |
16a26b20 SH |
478 | err = ubifs_node_check_hash(c, buf, zbr->hash); |
479 | if (err) { | |
480 | ubifs_bad_hash(c, buf, zbr->hash, lnum, offs); | |
481 | return 0; | |
482 | } | |
483 | ||
1e51764a AB |
484 | return 1; |
485 | } | |
486 | ||
487 | /** | |
488 | * fallible_read_node - try to read a leaf node. | |
489 | * @c: UBIFS file-system description object | |
490 | * @key: key of node to read | |
491 | * @zbr: position of node | |
492 | * @node: node returned | |
493 | * | |
494 | * This function tries to read a node and returns %1 if the node is read, %0 | |
495 | * if the node is not present, and a negative error code in the case of error. | |
496 | */ | |
497 | static int fallible_read_node(struct ubifs_info *c, const union ubifs_key *key, | |
498 | struct ubifs_zbranch *zbr, void *node) | |
499 | { | |
500 | int ret; | |
501 | ||
515315a1 | 502 | dbg_tnck(key, "LEB %d:%d, key ", zbr->lnum, zbr->offs); |
1e51764a | 503 | |
545bc8f6 | 504 | ret = try_read_node(c, node, key_type(c, key), zbr); |
1e51764a AB |
505 | if (ret == 1) { |
506 | union ubifs_key node_key; | |
507 | struct ubifs_dent_node *dent = node; | |
508 | ||
509 | /* All nodes have key in the same place */ | |
510 | key_read(c, &dent->key, &node_key); | |
511 | if (keys_cmp(c, key, &node_key) != 0) | |
512 | ret = 0; | |
513 | } | |
601c0bc4 | 514 | if (ret == 0 && c->replaying) |
515315a1 AB |
515 | dbg_mntk(key, "dangling branch LEB %d:%d len %d, key ", |
516 | zbr->lnum, zbr->offs, zbr->len); | |
1e51764a AB |
517 | return ret; |
518 | } | |
519 | ||
520 | /** | |
521 | * matches_name - determine if a direntry or xattr entry matches a given name. | |
522 | * @c: UBIFS file-system description object | |
523 | * @zbr: zbranch of dent | |
524 | * @nm: name to match | |
525 | * | |
526 | * This function checks if xentry/direntry referred by zbranch @zbr matches name | |
527 | * @nm. Returns %NAME_MATCHES if it does, %NAME_LESS if the name referred by | |
528 | * @zbr is less than @nm, and %NAME_GREATER if it is greater than @nm. In case | |
529 | * of failure, a negative error code is returned. | |
530 | */ | |
531 | static int matches_name(struct ubifs_info *c, struct ubifs_zbranch *zbr, | |
f4f61d2c | 532 | const struct fscrypt_name *nm) |
1e51764a AB |
533 | { |
534 | struct ubifs_dent_node *dent; | |
535 | int nlen, err; | |
536 | ||
537 | /* If possible, match against the dent in the leaf node cache */ | |
538 | if (!zbr->leaf) { | |
539 | dent = kmalloc(zbr->len, GFP_NOFS); | |
540 | if (!dent) | |
541 | return -ENOMEM; | |
542 | ||
543 | err = ubifs_tnc_read_node(c, zbr, dent); | |
544 | if (err) | |
545 | goto out_free; | |
546 | ||
547 | /* Add the node to the leaf node cache */ | |
548 | err = lnc_add_directly(c, zbr, dent); | |
549 | if (err) | |
550 | goto out_free; | |
551 | } else | |
552 | dent = zbr->leaf; | |
553 | ||
554 | nlen = le16_to_cpu(dent->nlen); | |
f4f61d2c | 555 | err = memcmp(dent->name, fname_name(nm), min_t(int, nlen, fname_len(nm))); |
1e51764a | 556 | if (err == 0) { |
f4f61d2c | 557 | if (nlen == fname_len(nm)) |
1e51764a | 558 | return NAME_MATCHES; |
f4f61d2c | 559 | else if (nlen < fname_len(nm)) |
1e51764a AB |
560 | return NAME_LESS; |
561 | else | |
562 | return NAME_GREATER; | |
563 | } else if (err < 0) | |
564 | return NAME_LESS; | |
565 | else | |
566 | return NAME_GREATER; | |
567 | ||
568 | out_free: | |
569 | kfree(dent); | |
570 | return err; | |
571 | } | |
572 | ||
573 | /** | |
574 | * get_znode - get a TNC znode that may not be loaded yet. | |
575 | * @c: UBIFS file-system description object | |
576 | * @znode: parent znode | |
577 | * @n: znode branch slot number | |
578 | * | |
579 | * This function returns the znode or a negative error code. | |
580 | */ | |
581 | static struct ubifs_znode *get_znode(struct ubifs_info *c, | |
582 | struct ubifs_znode *znode, int n) | |
583 | { | |
584 | struct ubifs_zbranch *zbr; | |
585 | ||
586 | zbr = &znode->zbranch[n]; | |
587 | if (zbr->znode) | |
588 | znode = zbr->znode; | |
589 | else | |
590 | znode = ubifs_load_znode(c, zbr, znode, n); | |
591 | return znode; | |
592 | } | |
593 | ||
594 | /** | |
595 | * tnc_next - find next TNC entry. | |
596 | * @c: UBIFS file-system description object | |
597 | * @zn: znode is passed and returned here | |
598 | * @n: znode branch slot number is passed and returned here | |
599 | * | |
600 | * This function returns %0 if the next TNC entry is found, %-ENOENT if there is | |
601 | * no next entry, or a negative error code otherwise. | |
602 | */ | |
603 | static int tnc_next(struct ubifs_info *c, struct ubifs_znode **zn, int *n) | |
604 | { | |
605 | struct ubifs_znode *znode = *zn; | |
606 | int nn = *n; | |
607 | ||
608 | nn += 1; | |
609 | if (nn < znode->child_cnt) { | |
610 | *n = nn; | |
611 | return 0; | |
612 | } | |
613 | while (1) { | |
614 | struct ubifs_znode *zp; | |
615 | ||
616 | zp = znode->parent; | |
617 | if (!zp) | |
618 | return -ENOENT; | |
619 | nn = znode->iip + 1; | |
620 | znode = zp; | |
621 | if (nn < znode->child_cnt) { | |
622 | znode = get_znode(c, znode, nn); | |
623 | if (IS_ERR(znode)) | |
624 | return PTR_ERR(znode); | |
625 | while (znode->level != 0) { | |
626 | znode = get_znode(c, znode, 0); | |
627 | if (IS_ERR(znode)) | |
628 | return PTR_ERR(znode); | |
629 | } | |
630 | nn = 0; | |
631 | break; | |
632 | } | |
633 | } | |
634 | *zn = znode; | |
635 | *n = nn; | |
636 | return 0; | |
637 | } | |
638 | ||
639 | /** | |
640 | * tnc_prev - find previous TNC entry. | |
641 | * @c: UBIFS file-system description object | |
642 | * @zn: znode is returned here | |
643 | * @n: znode branch slot number is passed and returned here | |
644 | * | |
645 | * This function returns %0 if the previous TNC entry is found, %-ENOENT if | |
646 | * there is no next entry, or a negative error code otherwise. | |
647 | */ | |
648 | static int tnc_prev(struct ubifs_info *c, struct ubifs_znode **zn, int *n) | |
649 | { | |
650 | struct ubifs_znode *znode = *zn; | |
651 | int nn = *n; | |
652 | ||
653 | if (nn > 0) { | |
654 | *n = nn - 1; | |
655 | return 0; | |
656 | } | |
657 | while (1) { | |
658 | struct ubifs_znode *zp; | |
659 | ||
660 | zp = znode->parent; | |
661 | if (!zp) | |
662 | return -ENOENT; | |
663 | nn = znode->iip - 1; | |
664 | znode = zp; | |
665 | if (nn >= 0) { | |
666 | znode = get_znode(c, znode, nn); | |
667 | if (IS_ERR(znode)) | |
668 | return PTR_ERR(znode); | |
669 | while (znode->level != 0) { | |
670 | nn = znode->child_cnt - 1; | |
671 | znode = get_znode(c, znode, nn); | |
672 | if (IS_ERR(znode)) | |
673 | return PTR_ERR(znode); | |
674 | } | |
675 | nn = znode->child_cnt - 1; | |
676 | break; | |
677 | } | |
678 | } | |
679 | *zn = znode; | |
680 | *n = nn; | |
681 | return 0; | |
682 | } | |
683 | ||
684 | /** | |
685 | * resolve_collision - resolve a collision. | |
686 | * @c: UBIFS file-system description object | |
687 | * @key: key of a directory or extended attribute entry | |
688 | * @zn: znode is returned here | |
689 | * @n: zbranch number is passed and returned here | |
690 | * @nm: name of the entry | |
691 | * | |
692 | * This function is called for "hashed" keys to make sure that the found key | |
693 | * really corresponds to the looked up node (directory or extended attribute | |
694 | * entry). It returns %1 and sets @zn and @n if the collision is resolved. | |
695 | * %0 is returned if @nm is not found and @zn and @n are set to the previous | |
696 | * entry, i.e. to the entry after which @nm could follow if it were in TNC. | |
697 | * This means that @n may be set to %-1 if the leftmost key in @zn is the | |
698 | * previous one. A negative error code is returned on failures. | |
699 | */ | |
700 | static int resolve_collision(struct ubifs_info *c, const union ubifs_key *key, | |
701 | struct ubifs_znode **zn, int *n, | |
f4f61d2c | 702 | const struct fscrypt_name *nm) |
1e51764a AB |
703 | { |
704 | int err; | |
705 | ||
706 | err = matches_name(c, &(*zn)->zbranch[*n], nm); | |
707 | if (unlikely(err < 0)) | |
708 | return err; | |
709 | if (err == NAME_MATCHES) | |
710 | return 1; | |
711 | ||
712 | if (err == NAME_GREATER) { | |
713 | /* Look left */ | |
714 | while (1) { | |
715 | err = tnc_prev(c, zn, n); | |
716 | if (err == -ENOENT) { | |
6eb61d58 | 717 | ubifs_assert(c, *n == 0); |
1e51764a AB |
718 | *n = -1; |
719 | return 0; | |
720 | } | |
721 | if (err < 0) | |
722 | return err; | |
723 | if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) { | |
724 | /* | |
725 | * We have found the branch after which we would | |
726 | * like to insert, but inserting in this znode | |
727 | * may still be wrong. Consider the following 3 | |
728 | * znodes, in the case where we are resolving a | |
729 | * collision with Key2. | |
730 | * | |
731 | * znode zp | |
732 | * ---------------------- | |
733 | * level 1 | Key0 | Key1 | | |
734 | * ----------------------- | |
735 | * | | | |
736 | * znode za | | znode zb | |
737 | * ------------ ------------ | |
738 | * level 0 | Key0 | | Key2 | | |
739 | * ------------ ------------ | |
740 | * | |
741 | * The lookup finds Key2 in znode zb. Lets say | |
742 | * there is no match and the name is greater so | |
743 | * we look left. When we find Key0, we end up | |
744 | * here. If we return now, we will insert into | |
745 | * znode za at slot n = 1. But that is invalid | |
746 | * according to the parent's keys. Key2 must | |
747 | * be inserted into znode zb. | |
748 | * | |
749 | * Note, this problem is not relevant for the | |
750 | * case when we go right, because | |
751 | * 'tnc_insert()' would correct the parent key. | |
752 | */ | |
753 | if (*n == (*zn)->child_cnt - 1) { | |
754 | err = tnc_next(c, zn, n); | |
755 | if (err) { | |
756 | /* Should be impossible */ | |
6eb61d58 | 757 | ubifs_assert(c, 0); |
1e51764a AB |
758 | if (err == -ENOENT) |
759 | err = -EINVAL; | |
760 | return err; | |
761 | } | |
6eb61d58 | 762 | ubifs_assert(c, *n == 0); |
1e51764a AB |
763 | *n = -1; |
764 | } | |
765 | return 0; | |
766 | } | |
767 | err = matches_name(c, &(*zn)->zbranch[*n], nm); | |
768 | if (err < 0) | |
769 | return err; | |
770 | if (err == NAME_LESS) | |
771 | return 0; | |
772 | if (err == NAME_MATCHES) | |
773 | return 1; | |
6eb61d58 | 774 | ubifs_assert(c, err == NAME_GREATER); |
1e51764a AB |
775 | } |
776 | } else { | |
777 | int nn = *n; | |
778 | struct ubifs_znode *znode = *zn; | |
779 | ||
780 | /* Look right */ | |
781 | while (1) { | |
782 | err = tnc_next(c, &znode, &nn); | |
783 | if (err == -ENOENT) | |
784 | return 0; | |
785 | if (err < 0) | |
786 | return err; | |
787 | if (keys_cmp(c, &znode->zbranch[nn].key, key)) | |
788 | return 0; | |
789 | err = matches_name(c, &znode->zbranch[nn], nm); | |
790 | if (err < 0) | |
791 | return err; | |
792 | if (err == NAME_GREATER) | |
793 | return 0; | |
794 | *zn = znode; | |
795 | *n = nn; | |
796 | if (err == NAME_MATCHES) | |
797 | return 1; | |
6eb61d58 | 798 | ubifs_assert(c, err == NAME_LESS); |
1e51764a AB |
799 | } |
800 | } | |
801 | } | |
802 | ||
803 | /** | |
804 | * fallible_matches_name - determine if a dent matches a given name. | |
805 | * @c: UBIFS file-system description object | |
806 | * @zbr: zbranch of dent | |
807 | * @nm: name to match | |
808 | * | |
809 | * This is a "fallible" version of 'matches_name()' function which does not | |
810 | * panic if the direntry/xentry referred by @zbr does not exist on the media. | |
811 | * | |
812 | * This function checks if xentry/direntry referred by zbranch @zbr matches name | |
813 | * @nm. Returns %NAME_MATCHES it does, %NAME_LESS if the name referred by @zbr | |
814 | * is less than @nm, %NAME_GREATER if it is greater than @nm, and @NOT_ON_MEDIA | |
815 | * if xentry/direntry referred by @zbr does not exist on the media. A negative | |
816 | * error code is returned in case of failure. | |
817 | */ | |
818 | static int fallible_matches_name(struct ubifs_info *c, | |
819 | struct ubifs_zbranch *zbr, | |
f4f61d2c | 820 | const struct fscrypt_name *nm) |
1e51764a AB |
821 | { |
822 | struct ubifs_dent_node *dent; | |
823 | int nlen, err; | |
824 | ||
825 | /* If possible, match against the dent in the leaf node cache */ | |
826 | if (!zbr->leaf) { | |
827 | dent = kmalloc(zbr->len, GFP_NOFS); | |
828 | if (!dent) | |
829 | return -ENOMEM; | |
830 | ||
831 | err = fallible_read_node(c, &zbr->key, zbr, dent); | |
832 | if (err < 0) | |
833 | goto out_free; | |
834 | if (err == 0) { | |
835 | /* The node was not present */ | |
836 | err = NOT_ON_MEDIA; | |
837 | goto out_free; | |
838 | } | |
6eb61d58 | 839 | ubifs_assert(c, err == 1); |
1e51764a AB |
840 | |
841 | err = lnc_add_directly(c, zbr, dent); | |
842 | if (err) | |
843 | goto out_free; | |
844 | } else | |
845 | dent = zbr->leaf; | |
846 | ||
847 | nlen = le16_to_cpu(dent->nlen); | |
f4f61d2c | 848 | err = memcmp(dent->name, fname_name(nm), min_t(int, nlen, fname_len(nm))); |
1e51764a | 849 | if (err == 0) { |
f4f61d2c | 850 | if (nlen == fname_len(nm)) |
1e51764a | 851 | return NAME_MATCHES; |
f4f61d2c | 852 | else if (nlen < fname_len(nm)) |
1e51764a AB |
853 | return NAME_LESS; |
854 | else | |
855 | return NAME_GREATER; | |
856 | } else if (err < 0) | |
857 | return NAME_LESS; | |
858 | else | |
859 | return NAME_GREATER; | |
860 | ||
861 | out_free: | |
862 | kfree(dent); | |
863 | return err; | |
864 | } | |
865 | ||
866 | /** | |
867 | * fallible_resolve_collision - resolve a collision even if nodes are missing. | |
868 | * @c: UBIFS file-system description object | |
869 | * @key: key | |
870 | * @zn: znode is returned here | |
871 | * @n: branch number is passed and returned here | |
872 | * @nm: name of directory entry | |
873 | * @adding: indicates caller is adding a key to the TNC | |
874 | * | |
875 | * This is a "fallible" version of the 'resolve_collision()' function which | |
876 | * does not panic if one of the nodes referred to by TNC does not exist on the | |
877 | * media. This may happen when replaying the journal if a deleted node was | |
878 | * Garbage-collected and the commit was not done. A branch that refers to a node | |
879 | * that is not present is called a dangling branch. The following are the return | |
880 | * codes for this function: | |
881 | * o if @nm was found, %1 is returned and @zn and @n are set to the found | |
882 | * branch; | |
883 | * o if we are @adding and @nm was not found, %0 is returned; | |
884 | * o if we are not @adding and @nm was not found, but a dangling branch was | |
885 | * found, then %1 is returned and @zn and @n are set to the dangling branch; | |
886 | * o a negative error code is returned in case of failure. | |
887 | */ | |
888 | static int fallible_resolve_collision(struct ubifs_info *c, | |
889 | const union ubifs_key *key, | |
890 | struct ubifs_znode **zn, int *n, | |
f4f61d2c RW |
891 | const struct fscrypt_name *nm, |
892 | int adding) | |
1e51764a AB |
893 | { |
894 | struct ubifs_znode *o_znode = NULL, *znode = *zn; | |
895 | int uninitialized_var(o_n), err, cmp, unsure = 0, nn = *n; | |
896 | ||
897 | cmp = fallible_matches_name(c, &znode->zbranch[nn], nm); | |
898 | if (unlikely(cmp < 0)) | |
899 | return cmp; | |
900 | if (cmp == NAME_MATCHES) | |
901 | return 1; | |
902 | if (cmp == NOT_ON_MEDIA) { | |
903 | o_znode = znode; | |
904 | o_n = nn; | |
905 | /* | |
906 | * We are unlucky and hit a dangling branch straight away. | |
907 | * Now we do not really know where to go to find the needed | |
908 | * branch - to the left or to the right. Well, let's try left. | |
909 | */ | |
910 | unsure = 1; | |
911 | } else if (!adding) | |
912 | unsure = 1; /* Remove a dangling branch wherever it is */ | |
913 | ||
914 | if (cmp == NAME_GREATER || unsure) { | |
915 | /* Look left */ | |
916 | while (1) { | |
917 | err = tnc_prev(c, zn, n); | |
918 | if (err == -ENOENT) { | |
6eb61d58 | 919 | ubifs_assert(c, *n == 0); |
1e51764a AB |
920 | *n = -1; |
921 | break; | |
922 | } | |
923 | if (err < 0) | |
924 | return err; | |
925 | if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) { | |
926 | /* See comments in 'resolve_collision()' */ | |
927 | if (*n == (*zn)->child_cnt - 1) { | |
928 | err = tnc_next(c, zn, n); | |
929 | if (err) { | |
930 | /* Should be impossible */ | |
6eb61d58 | 931 | ubifs_assert(c, 0); |
1e51764a AB |
932 | if (err == -ENOENT) |
933 | err = -EINVAL; | |
934 | return err; | |
935 | } | |
6eb61d58 | 936 | ubifs_assert(c, *n == 0); |
1e51764a AB |
937 | *n = -1; |
938 | } | |
939 | break; | |
940 | } | |
941 | err = fallible_matches_name(c, &(*zn)->zbranch[*n], nm); | |
942 | if (err < 0) | |
943 | return err; | |
944 | if (err == NAME_MATCHES) | |
945 | return 1; | |
946 | if (err == NOT_ON_MEDIA) { | |
947 | o_znode = *zn; | |
948 | o_n = *n; | |
949 | continue; | |
950 | } | |
951 | if (!adding) | |
952 | continue; | |
953 | if (err == NAME_LESS) | |
954 | break; | |
955 | else | |
956 | unsure = 0; | |
957 | } | |
958 | } | |
959 | ||
960 | if (cmp == NAME_LESS || unsure) { | |
961 | /* Look right */ | |
962 | *zn = znode; | |
963 | *n = nn; | |
964 | while (1) { | |
965 | err = tnc_next(c, &znode, &nn); | |
966 | if (err == -ENOENT) | |
967 | break; | |
968 | if (err < 0) | |
969 | return err; | |
970 | if (keys_cmp(c, &znode->zbranch[nn].key, key)) | |
971 | break; | |
972 | err = fallible_matches_name(c, &znode->zbranch[nn], nm); | |
973 | if (err < 0) | |
974 | return err; | |
975 | if (err == NAME_GREATER) | |
976 | break; | |
977 | *zn = znode; | |
978 | *n = nn; | |
979 | if (err == NAME_MATCHES) | |
980 | return 1; | |
981 | if (err == NOT_ON_MEDIA) { | |
982 | o_znode = znode; | |
983 | o_n = nn; | |
984 | } | |
985 | } | |
986 | } | |
987 | ||
988 | /* Never match a dangling branch when adding */ | |
989 | if (adding || !o_znode) | |
990 | return 0; | |
991 | ||
515315a1 | 992 | dbg_mntk(key, "dangling match LEB %d:%d len %d key ", |
1e51764a | 993 | o_znode->zbranch[o_n].lnum, o_znode->zbranch[o_n].offs, |
515315a1 | 994 | o_znode->zbranch[o_n].len); |
1e51764a AB |
995 | *zn = o_znode; |
996 | *n = o_n; | |
997 | return 1; | |
998 | } | |
999 | ||
1000 | /** | |
1001 | * matches_position - determine if a zbranch matches a given position. | |
1002 | * @zbr: zbranch of dent | |
1003 | * @lnum: LEB number of dent to match | |
1004 | * @offs: offset of dent to match | |
1005 | * | |
1006 | * This function returns %1 if @lnum:@offs matches, and %0 otherwise. | |
1007 | */ | |
1008 | static int matches_position(struct ubifs_zbranch *zbr, int lnum, int offs) | |
1009 | { | |
1010 | if (zbr->lnum == lnum && zbr->offs == offs) | |
1011 | return 1; | |
1012 | else | |
1013 | return 0; | |
1014 | } | |
1015 | ||
1016 | /** | |
1017 | * resolve_collision_directly - resolve a collision directly. | |
1018 | * @c: UBIFS file-system description object | |
1019 | * @key: key of directory entry | |
1020 | * @zn: znode is passed and returned here | |
1021 | * @n: zbranch number is passed and returned here | |
1022 | * @lnum: LEB number of dent node to match | |
1023 | * @offs: offset of dent node to match | |
1024 | * | |
1025 | * This function is used for "hashed" keys to make sure the found directory or | |
1026 | * extended attribute entry node is what was looked for. It is used when the | |
1027 | * flash address of the right node is known (@lnum:@offs) which makes it much | |
1028 | * easier to resolve collisions (no need to read entries and match full | |
1029 | * names). This function returns %1 and sets @zn and @n if the collision is | |
1030 | * resolved, %0 if @lnum:@offs is not found and @zn and @n are set to the | |
1031 | * previous directory entry. Otherwise a negative error code is returned. | |
1032 | */ | |
1033 | static int resolve_collision_directly(struct ubifs_info *c, | |
1034 | const union ubifs_key *key, | |
1035 | struct ubifs_znode **zn, int *n, | |
1036 | int lnum, int offs) | |
1037 | { | |
1038 | struct ubifs_znode *znode; | |
1039 | int nn, err; | |
1040 | ||
1041 | znode = *zn; | |
1042 | nn = *n; | |
1043 | if (matches_position(&znode->zbranch[nn], lnum, offs)) | |
1044 | return 1; | |
1045 | ||
1046 | /* Look left */ | |
1047 | while (1) { | |
1048 | err = tnc_prev(c, &znode, &nn); | |
1049 | if (err == -ENOENT) | |
1050 | break; | |
1051 | if (err < 0) | |
1052 | return err; | |
1053 | if (keys_cmp(c, &znode->zbranch[nn].key, key)) | |
1054 | break; | |
1055 | if (matches_position(&znode->zbranch[nn], lnum, offs)) { | |
1056 | *zn = znode; | |
1057 | *n = nn; | |
1058 | return 1; | |
1059 | } | |
1060 | } | |
1061 | ||
1062 | /* Look right */ | |
1063 | znode = *zn; | |
1064 | nn = *n; | |
1065 | while (1) { | |
1066 | err = tnc_next(c, &znode, &nn); | |
1067 | if (err == -ENOENT) | |
1068 | return 0; | |
1069 | if (err < 0) | |
1070 | return err; | |
1071 | if (keys_cmp(c, &znode->zbranch[nn].key, key)) | |
1072 | return 0; | |
1073 | *zn = znode; | |
1074 | *n = nn; | |
1075 | if (matches_position(&znode->zbranch[nn], lnum, offs)) | |
1076 | return 1; | |
1077 | } | |
1078 | } | |
1079 | ||
1080 | /** | |
1081 | * dirty_cow_bottom_up - dirty a znode and its ancestors. | |
1082 | * @c: UBIFS file-system description object | |
1083 | * @znode: znode to dirty | |
1084 | * | |
1085 | * If we do not have a unique key that resides in a znode, then we cannot | |
1086 | * dirty that znode from the top down (i.e. by using lookup_level0_dirty) | |
1087 | * This function records the path back to the last dirty ancestor, and then | |
1088 | * dirties the znodes on that path. | |
1089 | */ | |
1090 | static struct ubifs_znode *dirty_cow_bottom_up(struct ubifs_info *c, | |
1091 | struct ubifs_znode *znode) | |
1092 | { | |
1093 | struct ubifs_znode *zp; | |
1094 | int *path = c->bottom_up_buf, p = 0; | |
1095 | ||
6eb61d58 RW |
1096 | ubifs_assert(c, c->zroot.znode); |
1097 | ubifs_assert(c, znode); | |
1e51764a AB |
1098 | if (c->zroot.znode->level > BOTTOM_UP_HEIGHT) { |
1099 | kfree(c->bottom_up_buf); | |
6da2ec56 KC |
1100 | c->bottom_up_buf = kmalloc_array(c->zroot.znode->level, |
1101 | sizeof(int), | |
1102 | GFP_NOFS); | |
1e51764a AB |
1103 | if (!c->bottom_up_buf) |
1104 | return ERR_PTR(-ENOMEM); | |
1105 | path = c->bottom_up_buf; | |
1106 | } | |
1107 | if (c->zroot.znode->level) { | |
1108 | /* Go up until parent is dirty */ | |
1109 | while (1) { | |
1110 | int n; | |
1111 | ||
1112 | zp = znode->parent; | |
1113 | if (!zp) | |
1114 | break; | |
1115 | n = znode->iip; | |
6eb61d58 | 1116 | ubifs_assert(c, p < c->zroot.znode->level); |
1e51764a AB |
1117 | path[p++] = n; |
1118 | if (!zp->cnext && ubifs_zn_dirty(znode)) | |
1119 | break; | |
1120 | znode = zp; | |
1121 | } | |
1122 | } | |
1123 | ||
1124 | /* Come back down, dirtying as we go */ | |
1125 | while (1) { | |
1126 | struct ubifs_zbranch *zbr; | |
1127 | ||
1128 | zp = znode->parent; | |
1129 | if (zp) { | |
6eb61d58 RW |
1130 | ubifs_assert(c, path[p - 1] >= 0); |
1131 | ubifs_assert(c, path[p - 1] < zp->child_cnt); | |
1e51764a AB |
1132 | zbr = &zp->zbranch[path[--p]]; |
1133 | znode = dirty_cow_znode(c, zbr); | |
1134 | } else { | |
6eb61d58 | 1135 | ubifs_assert(c, znode == c->zroot.znode); |
1e51764a AB |
1136 | znode = dirty_cow_znode(c, &c->zroot); |
1137 | } | |
8d47aef4 | 1138 | if (IS_ERR(znode) || !p) |
1e51764a | 1139 | break; |
6eb61d58 RW |
1140 | ubifs_assert(c, path[p - 1] >= 0); |
1141 | ubifs_assert(c, path[p - 1] < znode->child_cnt); | |
1e51764a AB |
1142 | znode = znode->zbranch[path[p - 1]].znode; |
1143 | } | |
1144 | ||
1145 | return znode; | |
1146 | } | |
1147 | ||
1148 | /** | |
1149 | * ubifs_lookup_level0 - search for zero-level znode. | |
1150 | * @c: UBIFS file-system description object | |
1151 | * @key: key to lookup | |
1152 | * @zn: znode is returned here | |
1153 | * @n: znode branch slot number is returned here | |
1154 | * | |
1155 | * This function looks up the TNC tree and search for zero-level znode which | |
1156 | * refers key @key. The found zero-level znode is returned in @zn. There are 3 | |
1157 | * cases: | |
1158 | * o exact match, i.e. the found zero-level znode contains key @key, then %1 | |
1159 | * is returned and slot number of the matched branch is stored in @n; | |
1160 | * o not exact match, which means that zero-level znode does not contain | |
bacfa94b RW |
1161 | * @key, then %0 is returned and slot number of the closest branch or %-1 |
1162 | * is stored in @n; In this case calling tnc_next() is mandatory. | |
1e51764a AB |
1163 | * o @key is so small that it is even less than the lowest key of the |
1164 | * leftmost zero-level node, then %0 is returned and %0 is stored in @n. | |
1165 | * | |
1166 | * Note, when the TNC tree is traversed, some znodes may be absent, then this | |
1167 | * function reads corresponding indexing nodes and inserts them to TNC. In | |
1168 | * case of failure, a negative error code is returned. | |
1169 | */ | |
1170 | int ubifs_lookup_level0(struct ubifs_info *c, const union ubifs_key *key, | |
1171 | struct ubifs_znode **zn, int *n) | |
1172 | { | |
1173 | int err, exact; | |
1174 | struct ubifs_znode *znode; | |
6cff5732 | 1175 | time64_t time = ktime_get_seconds(); |
1e51764a | 1176 | |
515315a1 | 1177 | dbg_tnck(key, "search key "); |
6eb61d58 | 1178 | ubifs_assert(c, key_type(c, key) < UBIFS_INVALID_KEY); |
1e51764a AB |
1179 | |
1180 | znode = c->zroot.znode; | |
1181 | if (unlikely(!znode)) { | |
1182 | znode = ubifs_load_znode(c, &c->zroot, NULL, 0); | |
1183 | if (IS_ERR(znode)) | |
1184 | return PTR_ERR(znode); | |
1185 | } | |
1186 | ||
1187 | znode->time = time; | |
1188 | ||
1189 | while (1) { | |
1190 | struct ubifs_zbranch *zbr; | |
1191 | ||
1192 | exact = ubifs_search_zbranch(c, znode, key, n); | |
1193 | ||
1194 | if (znode->level == 0) | |
1195 | break; | |
1196 | ||
1197 | if (*n < 0) | |
1198 | *n = 0; | |
1199 | zbr = &znode->zbranch[*n]; | |
1200 | ||
1201 | if (zbr->znode) { | |
1202 | znode->time = time; | |
1203 | znode = zbr->znode; | |
1204 | continue; | |
1205 | } | |
1206 | ||
1207 | /* znode is not in TNC cache, load it from the media */ | |
1208 | znode = ubifs_load_znode(c, zbr, znode, *n); | |
1209 | if (IS_ERR(znode)) | |
1210 | return PTR_ERR(znode); | |
1211 | } | |
1212 | ||
1213 | *zn = znode; | |
1214 | if (exact || !is_hash_key(c, key) || *n != -1) { | |
1215 | dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n); | |
1216 | return exact; | |
1217 | } | |
1218 | ||
1219 | /* | |
1220 | * Here is a tricky place. We have not found the key and this is a | |
1221 | * "hashed" key, which may collide. The rest of the code deals with | |
1222 | * situations like this: | |
1223 | * | |
1224 | * | 3 | 5 | | |
1225 | * / \ | |
1226 | * | 3 | 5 | | 6 | 7 | (x) | |
1227 | * | |
1228 | * Or more a complex example: | |
1229 | * | |
1230 | * | 1 | 5 | | |
1231 | * / \ | |
1232 | * | 1 | 3 | | 5 | 8 | | |
1233 | * \ / | |
1234 | * | 5 | 5 | | 6 | 7 | (x) | |
1235 | * | |
1236 | * In the examples, if we are looking for key "5", we may reach nodes | |
1237 | * marked with "(x)". In this case what we have do is to look at the | |
1238 | * left and see if there is "5" key there. If there is, we have to | |
1239 | * return it. | |
1240 | * | |
1241 | * Note, this whole situation is possible because we allow to have | |
1242 | * elements which are equivalent to the next key in the parent in the | |
1243 | * children of current znode. For example, this happens if we split a | |
1244 | * znode like this: | 3 | 5 | 5 | 6 | 7 |, which results in something | |
1245 | * like this: | |
1246 | * | 3 | 5 | | |
1247 | * / \ | |
1248 | * | 3 | 5 | | 5 | 6 | 7 | | |
1249 | * ^ | |
1250 | * And this becomes what is at the first "picture" after key "5" marked | |
1251 | * with "^" is removed. What could be done is we could prohibit | |
1252 | * splitting in the middle of the colliding sequence. Also, when | |
1253 | * removing the leftmost key, we would have to correct the key of the | |
1254 | * parent node, which would introduce additional complications. Namely, | |
7d4e9ccb | 1255 | * if we changed the leftmost key of the parent znode, the garbage |
1e51764a AB |
1256 | * collector would be unable to find it (GC is doing this when GC'ing |
1257 | * indexing LEBs). Although we already have an additional RB-tree where | |
1258 | * we save such changed znodes (see 'ins_clr_old_idx_znode()') until | |
1259 | * after the commit. But anyway, this does not look easy to implement | |
1260 | * so we did not try this. | |
1261 | */ | |
1262 | err = tnc_prev(c, &znode, n); | |
1263 | if (err == -ENOENT) { | |
1264 | dbg_tnc("found 0, lvl %d, n -1", znode->level); | |
1265 | *n = -1; | |
1266 | return 0; | |
1267 | } | |
1268 | if (unlikely(err < 0)) | |
1269 | return err; | |
1270 | if (keys_cmp(c, key, &znode->zbranch[*n].key)) { | |
1271 | dbg_tnc("found 0, lvl %d, n -1", znode->level); | |
1272 | *n = -1; | |
1273 | return 0; | |
1274 | } | |
1275 | ||
1276 | dbg_tnc("found 1, lvl %d, n %d", znode->level, *n); | |
1277 | *zn = znode; | |
1278 | return 1; | |
1279 | } | |
1280 | ||
1281 | /** | |
1282 | * lookup_level0_dirty - search for zero-level znode dirtying. | |
1283 | * @c: UBIFS file-system description object | |
1284 | * @key: key to lookup | |
1285 | * @zn: znode is returned here | |
1286 | * @n: znode branch slot number is returned here | |
1287 | * | |
1288 | * This function looks up the TNC tree and search for zero-level znode which | |
1289 | * refers key @key. The found zero-level znode is returned in @zn. There are 3 | |
1290 | * cases: | |
1291 | * o exact match, i.e. the found zero-level znode contains key @key, then %1 | |
1292 | * is returned and slot number of the matched branch is stored in @n; | |
1293 | * o not exact match, which means that zero-level znode does not contain @key | |
1294 | * then %0 is returned and slot number of the closed branch is stored in | |
1295 | * @n; | |
1296 | * o @key is so small that it is even less than the lowest key of the | |
1297 | * leftmost zero-level node, then %0 is returned and %-1 is stored in @n. | |
1298 | * | |
1299 | * Additionally all znodes in the path from the root to the located zero-level | |
1300 | * znode are marked as dirty. | |
1301 | * | |
1302 | * Note, when the TNC tree is traversed, some znodes may be absent, then this | |
1303 | * function reads corresponding indexing nodes and inserts them to TNC. In | |
1304 | * case of failure, a negative error code is returned. | |
1305 | */ | |
1306 | static int lookup_level0_dirty(struct ubifs_info *c, const union ubifs_key *key, | |
1307 | struct ubifs_znode **zn, int *n) | |
1308 | { | |
1309 | int err, exact; | |
1310 | struct ubifs_znode *znode; | |
6cff5732 | 1311 | time64_t time = ktime_get_seconds(); |
1e51764a | 1312 | |
515315a1 | 1313 | dbg_tnck(key, "search and dirty key "); |
1e51764a AB |
1314 | |
1315 | znode = c->zroot.znode; | |
1316 | if (unlikely(!znode)) { | |
1317 | znode = ubifs_load_znode(c, &c->zroot, NULL, 0); | |
1318 | if (IS_ERR(znode)) | |
1319 | return PTR_ERR(znode); | |
1320 | } | |
1321 | ||
1322 | znode = dirty_cow_znode(c, &c->zroot); | |
1323 | if (IS_ERR(znode)) | |
1324 | return PTR_ERR(znode); | |
1325 | ||
1326 | znode->time = time; | |
1327 | ||
1328 | while (1) { | |
1329 | struct ubifs_zbranch *zbr; | |
1330 | ||
1331 | exact = ubifs_search_zbranch(c, znode, key, n); | |
1332 | ||
1333 | if (znode->level == 0) | |
1334 | break; | |
1335 | ||
1336 | if (*n < 0) | |
1337 | *n = 0; | |
1338 | zbr = &znode->zbranch[*n]; | |
1339 | ||
1340 | if (zbr->znode) { | |
1341 | znode->time = time; | |
1342 | znode = dirty_cow_znode(c, zbr); | |
1343 | if (IS_ERR(znode)) | |
1344 | return PTR_ERR(znode); | |
1345 | continue; | |
1346 | } | |
1347 | ||
1348 | /* znode is not in TNC cache, load it from the media */ | |
1349 | znode = ubifs_load_znode(c, zbr, znode, *n); | |
1350 | if (IS_ERR(znode)) | |
1351 | return PTR_ERR(znode); | |
1352 | znode = dirty_cow_znode(c, zbr); | |
1353 | if (IS_ERR(znode)) | |
1354 | return PTR_ERR(znode); | |
1355 | } | |
1356 | ||
1357 | *zn = znode; | |
1358 | if (exact || !is_hash_key(c, key) || *n != -1) { | |
1359 | dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n); | |
1360 | return exact; | |
1361 | } | |
1362 | ||
1363 | /* | |
1364 | * See huge comment at 'lookup_level0_dirty()' what is the rest of the | |
1365 | * code. | |
1366 | */ | |
1367 | err = tnc_prev(c, &znode, n); | |
1368 | if (err == -ENOENT) { | |
1369 | *n = -1; | |
1370 | dbg_tnc("found 0, lvl %d, n -1", znode->level); | |
1371 | return 0; | |
1372 | } | |
1373 | if (unlikely(err < 0)) | |
1374 | return err; | |
1375 | if (keys_cmp(c, key, &znode->zbranch[*n].key)) { | |
1376 | *n = -1; | |
1377 | dbg_tnc("found 0, lvl %d, n -1", znode->level); | |
1378 | return 0; | |
1379 | } | |
1380 | ||
1381 | if (znode->cnext || !ubifs_zn_dirty(znode)) { | |
1382 | znode = dirty_cow_bottom_up(c, znode); | |
1383 | if (IS_ERR(znode)) | |
1384 | return PTR_ERR(znode); | |
1385 | } | |
1386 | ||
1387 | dbg_tnc("found 1, lvl %d, n %d", znode->level, *n); | |
1388 | *zn = znode; | |
1389 | return 1; | |
1390 | } | |
1391 | ||
1392 | /** | |
601c0bc4 | 1393 | * maybe_leb_gced - determine if a LEB may have been garbage collected. |
1e51764a | 1394 | * @c: UBIFS file-system description object |
601c0bc4 AH |
1395 | * @lnum: LEB number |
1396 | * @gc_seq1: garbage collection sequence number | |
1e51764a | 1397 | * |
601c0bc4 AH |
1398 | * This function determines if @lnum may have been garbage collected since |
1399 | * sequence number @gc_seq1. If it may have been then %1 is returned, otherwise | |
1400 | * %0 is returned. | |
1e51764a | 1401 | */ |
601c0bc4 | 1402 | static int maybe_leb_gced(struct ubifs_info *c, int lnum, int gc_seq1) |
1e51764a | 1403 | { |
601c0bc4 | 1404 | int gc_seq2, gced_lnum; |
1e51764a | 1405 | |
601c0bc4 AH |
1406 | gced_lnum = c->gced_lnum; |
1407 | smp_rmb(); | |
1408 | gc_seq2 = c->gc_seq; | |
1409 | /* Same seq means no GC */ | |
1410 | if (gc_seq1 == gc_seq2) | |
1411 | return 0; | |
1412 | /* Different by more than 1 means we don't know */ | |
1413 | if (gc_seq1 + 1 != gc_seq2) | |
1414 | return 1; | |
1415 | /* | |
1416 | * We have seen the sequence number has increased by 1. Now we need to | |
1417 | * be sure we read the right LEB number, so read it again. | |
1418 | */ | |
1419 | smp_rmb(); | |
1420 | if (gced_lnum != c->gced_lnum) | |
1421 | return 1; | |
1422 | /* Finally we can check lnum */ | |
1423 | if (gced_lnum == lnum) | |
1424 | return 1; | |
1425 | return 0; | |
1e51764a AB |
1426 | } |
1427 | ||
1428 | /** | |
1429 | * ubifs_tnc_locate - look up a file-system node and return it and its location. | |
1430 | * @c: UBIFS file-system description object | |
1431 | * @key: node key to lookup | |
1432 | * @node: the node is returned here | |
1433 | * @lnum: LEB number is returned here | |
1434 | * @offs: offset is returned here | |
1435 | * | |
e3c3efc2 | 1436 | * This function looks up and reads node with key @key. The caller has to make |
601c0bc4 AH |
1437 | * sure the @node buffer is large enough to fit the node. Returns zero in case |
1438 | * of success, %-ENOENT if the node was not found, and a negative error code in | |
1439 | * case of failure. The node location can be returned in @lnum and @offs. | |
1e51764a AB |
1440 | */ |
1441 | int ubifs_tnc_locate(struct ubifs_info *c, const union ubifs_key *key, | |
1442 | void *node, int *lnum, int *offs) | |
1443 | { | |
601c0bc4 | 1444 | int found, n, err, safely = 0, gc_seq1; |
1e51764a AB |
1445 | struct ubifs_znode *znode; |
1446 | struct ubifs_zbranch zbr, *zt; | |
1447 | ||
601c0bc4 | 1448 | again: |
1e51764a AB |
1449 | mutex_lock(&c->tnc_mutex); |
1450 | found = ubifs_lookup_level0(c, key, &znode, &n); | |
1451 | if (!found) { | |
1452 | err = -ENOENT; | |
1453 | goto out; | |
1454 | } else if (found < 0) { | |
1455 | err = found; | |
1456 | goto out; | |
1457 | } | |
1458 | zt = &znode->zbranch[n]; | |
601c0bc4 AH |
1459 | if (lnum) { |
1460 | *lnum = zt->lnum; | |
1461 | *offs = zt->offs; | |
1462 | } | |
1e51764a AB |
1463 | if (is_hash_key(c, key)) { |
1464 | /* | |
1465 | * In this case the leaf node cache gets used, so we pass the | |
1466 | * address of the zbranch and keep the mutex locked | |
1467 | */ | |
b91dc981 | 1468 | err = tnc_read_hashed_node(c, zt, node); |
1e51764a AB |
1469 | goto out; |
1470 | } | |
601c0bc4 AH |
1471 | if (safely) { |
1472 | err = ubifs_tnc_read_node(c, zt, node); | |
1473 | goto out; | |
1474 | } | |
1475 | /* Drop the TNC mutex prematurely and race with garbage collection */ | |
1e51764a | 1476 | zbr = znode->zbranch[n]; |
601c0bc4 | 1477 | gc_seq1 = c->gc_seq; |
1e51764a AB |
1478 | mutex_unlock(&c->tnc_mutex); |
1479 | ||
601c0bc4 AH |
1480 | if (ubifs_get_wbuf(c, zbr.lnum)) { |
1481 | /* We do not GC journal heads */ | |
1482 | err = ubifs_tnc_read_node(c, &zbr, node); | |
1483 | return err; | |
1484 | } | |
1e51764a | 1485 | |
601c0bc4 | 1486 | err = fallible_read_node(c, key, &zbr, node); |
6dcfac4f | 1487 | if (err <= 0 || maybe_leb_gced(c, zbr.lnum, gc_seq1)) { |
601c0bc4 AH |
1488 | /* |
1489 | * The node may have been GC'ed out from under us so try again | |
1490 | * while keeping the TNC mutex locked. | |
1491 | */ | |
1492 | safely = 1; | |
1493 | goto again; | |
1494 | } | |
1495 | return 0; | |
1e51764a AB |
1496 | |
1497 | out: | |
1498 | mutex_unlock(&c->tnc_mutex); | |
1499 | return err; | |
1500 | } | |
1501 | ||
4793e7c5 AH |
1502 | /** |
1503 | * ubifs_tnc_get_bu_keys - lookup keys for bulk-read. | |
1504 | * @c: UBIFS file-system description object | |
1505 | * @bu: bulk-read parameters and results | |
1506 | * | |
1507 | * Lookup consecutive data node keys for the same inode that reside | |
6c0c42cd AB |
1508 | * consecutively in the same LEB. This function returns zero in case of success |
1509 | * and a negative error code in case of failure. | |
1510 | * | |
1511 | * Note, if the bulk-read buffer length (@bu->buf_len) is known, this function | |
1512 | * makes sure bulk-read nodes fit the buffer. Otherwise, this function prepares | |
6f7ab6d4 | 1513 | * maximum possible amount of nodes for bulk-read. |
4793e7c5 AH |
1514 | */ |
1515 | int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu) | |
1516 | { | |
1517 | int n, err = 0, lnum = -1, uninitialized_var(offs); | |
1518 | int uninitialized_var(len); | |
1519 | unsigned int block = key_block(c, &bu->key); | |
1520 | struct ubifs_znode *znode; | |
1521 | ||
1522 | bu->cnt = 0; | |
1523 | bu->blk_cnt = 0; | |
1524 | bu->eof = 0; | |
1525 | ||
1526 | mutex_lock(&c->tnc_mutex); | |
1527 | /* Find first key */ | |
1528 | err = ubifs_lookup_level0(c, &bu->key, &znode, &n); | |
1529 | if (err < 0) | |
1530 | goto out; | |
1531 | if (err) { | |
1532 | /* Key found */ | |
1533 | len = znode->zbranch[n].len; | |
1534 | /* The buffer must be big enough for at least 1 node */ | |
1535 | if (len > bu->buf_len) { | |
1536 | err = -EINVAL; | |
1537 | goto out; | |
1538 | } | |
1539 | /* Add this key */ | |
1540 | bu->zbranch[bu->cnt++] = znode->zbranch[n]; | |
1541 | bu->blk_cnt += 1; | |
1542 | lnum = znode->zbranch[n].lnum; | |
1543 | offs = ALIGN(znode->zbranch[n].offs + len, 8); | |
1544 | } | |
1545 | while (1) { | |
1546 | struct ubifs_zbranch *zbr; | |
1547 | union ubifs_key *key; | |
1548 | unsigned int next_block; | |
1549 | ||
1550 | /* Find next key */ | |
1551 | err = tnc_next(c, &znode, &n); | |
1552 | if (err) | |
1553 | goto out; | |
1554 | zbr = &znode->zbranch[n]; | |
1555 | key = &zbr->key; | |
1556 | /* See if there is another data key for this file */ | |
1557 | if (key_inum(c, key) != key_inum(c, &bu->key) || | |
1558 | key_type(c, key) != UBIFS_DATA_KEY) { | |
1559 | err = -ENOENT; | |
1560 | goto out; | |
1561 | } | |
1562 | if (lnum < 0) { | |
1563 | /* First key found */ | |
1564 | lnum = zbr->lnum; | |
1565 | offs = ALIGN(zbr->offs + zbr->len, 8); | |
1566 | len = zbr->len; | |
1567 | if (len > bu->buf_len) { | |
1568 | err = -EINVAL; | |
1569 | goto out; | |
1570 | } | |
1571 | } else { | |
1572 | /* | |
1573 | * The data nodes must be in consecutive positions in | |
1574 | * the same LEB. | |
1575 | */ | |
1576 | if (zbr->lnum != lnum || zbr->offs != offs) | |
1577 | goto out; | |
1578 | offs += ALIGN(zbr->len, 8); | |
1579 | len = ALIGN(len, 8) + zbr->len; | |
1580 | /* Must not exceed buffer length */ | |
1581 | if (len > bu->buf_len) | |
1582 | goto out; | |
1583 | } | |
1584 | /* Allow for holes */ | |
1585 | next_block = key_block(c, key); | |
1586 | bu->blk_cnt += (next_block - block - 1); | |
1587 | if (bu->blk_cnt >= UBIFS_MAX_BULK_READ) | |
1588 | goto out; | |
1589 | block = next_block; | |
1590 | /* Add this key */ | |
1591 | bu->zbranch[bu->cnt++] = *zbr; | |
1592 | bu->blk_cnt += 1; | |
1593 | /* See if we have room for more */ | |
1594 | if (bu->cnt >= UBIFS_MAX_BULK_READ) | |
1595 | goto out; | |
1596 | if (bu->blk_cnt >= UBIFS_MAX_BULK_READ) | |
1597 | goto out; | |
1598 | } | |
1599 | out: | |
1600 | if (err == -ENOENT) { | |
1601 | bu->eof = 1; | |
1602 | err = 0; | |
1603 | } | |
1604 | bu->gc_seq = c->gc_seq; | |
1605 | mutex_unlock(&c->tnc_mutex); | |
1606 | if (err) | |
1607 | return err; | |
1608 | /* | |
1609 | * An enormous hole could cause bulk-read to encompass too many | |
1610 | * page cache pages, so limit the number here. | |
1611 | */ | |
63c300b6 | 1612 | if (bu->blk_cnt > UBIFS_MAX_BULK_READ) |
4793e7c5 AH |
1613 | bu->blk_cnt = UBIFS_MAX_BULK_READ; |
1614 | /* | |
1615 | * Ensure that bulk-read covers a whole number of page cache | |
1616 | * pages. | |
1617 | */ | |
1618 | if (UBIFS_BLOCKS_PER_PAGE == 1 || | |
1619 | !(bu->blk_cnt & (UBIFS_BLOCKS_PER_PAGE - 1))) | |
1620 | return 0; | |
1621 | if (bu->eof) { | |
1622 | /* At the end of file we can round up */ | |
1623 | bu->blk_cnt += UBIFS_BLOCKS_PER_PAGE - 1; | |
1624 | return 0; | |
1625 | } | |
1626 | /* Exclude data nodes that do not make up a whole page cache page */ | |
1627 | block = key_block(c, &bu->key) + bu->blk_cnt; | |
1628 | block &= ~(UBIFS_BLOCKS_PER_PAGE - 1); | |
1629 | while (bu->cnt) { | |
1630 | if (key_block(c, &bu->zbranch[bu->cnt - 1].key) < block) | |
1631 | break; | |
1632 | bu->cnt -= 1; | |
1633 | } | |
1634 | return 0; | |
1635 | } | |
1636 | ||
1637 | /** | |
1638 | * read_wbuf - bulk-read from a LEB with a wbuf. | |
1639 | * @wbuf: wbuf that may overlap the read | |
1640 | * @buf: buffer into which to read | |
1641 | * @len: read length | |
1642 | * @lnum: LEB number from which to read | |
1643 | * @offs: offset from which to read | |
1644 | * | |
1645 | * This functions returns %0 on success or a negative error code on failure. | |
1646 | */ | |
1647 | static int read_wbuf(struct ubifs_wbuf *wbuf, void *buf, int len, int lnum, | |
1648 | int offs) | |
1649 | { | |
1650 | const struct ubifs_info *c = wbuf->c; | |
1651 | int rlen, overlap; | |
1652 | ||
1653 | dbg_io("LEB %d:%d, length %d", lnum, offs, len); | |
6eb61d58 RW |
1654 | ubifs_assert(c, wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0); |
1655 | ubifs_assert(c, !(offs & 7) && offs < c->leb_size); | |
1656 | ubifs_assert(c, offs + len <= c->leb_size); | |
4793e7c5 AH |
1657 | |
1658 | spin_lock(&wbuf->lock); | |
1659 | overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs); | |
1660 | if (!overlap) { | |
1661 | /* We may safely unlock the write-buffer and read the data */ | |
1662 | spin_unlock(&wbuf->lock); | |
d304820a | 1663 | return ubifs_leb_read(c, lnum, buf, offs, len, 0); |
4793e7c5 AH |
1664 | } |
1665 | ||
1666 | /* Don't read under wbuf */ | |
1667 | rlen = wbuf->offs - offs; | |
1668 | if (rlen < 0) | |
1669 | rlen = 0; | |
1670 | ||
1671 | /* Copy the rest from the write-buffer */ | |
1672 | memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen); | |
1673 | spin_unlock(&wbuf->lock); | |
1674 | ||
1675 | if (rlen > 0) | |
1676 | /* Read everything that goes before write-buffer */ | |
d304820a | 1677 | return ubifs_leb_read(c, lnum, buf, offs, rlen, 0); |
4793e7c5 AH |
1678 | |
1679 | return 0; | |
1680 | } | |
1681 | ||
1682 | /** | |
1683 | * validate_data_node - validate data nodes for bulk-read. | |
1684 | * @c: UBIFS file-system description object | |
1685 | * @buf: buffer containing data node to validate | |
1686 | * @zbr: zbranch of data node to validate | |
1687 | * | |
1688 | * This functions returns %0 on success or a negative error code on failure. | |
1689 | */ | |
1690 | static int validate_data_node(struct ubifs_info *c, void *buf, | |
1691 | struct ubifs_zbranch *zbr) | |
1692 | { | |
1693 | union ubifs_key key1; | |
1694 | struct ubifs_ch *ch = buf; | |
1695 | int err, len; | |
1696 | ||
1697 | if (ch->node_type != UBIFS_DATA_NODE) { | |
235c362b | 1698 | ubifs_err(c, "bad node type (%d but expected %d)", |
4793e7c5 AH |
1699 | ch->node_type, UBIFS_DATA_NODE); |
1700 | goto out_err; | |
1701 | } | |
1702 | ||
2953e73f | 1703 | err = ubifs_check_node(c, buf, zbr->lnum, zbr->offs, 0, 0); |
4793e7c5 | 1704 | if (err) { |
235c362b | 1705 | ubifs_err(c, "expected node type %d", UBIFS_DATA_NODE); |
4793e7c5 AH |
1706 | goto out; |
1707 | } | |
1708 | ||
16a26b20 SH |
1709 | err = ubifs_node_check_hash(c, buf, zbr->hash); |
1710 | if (err) { | |
1711 | ubifs_bad_hash(c, buf, zbr->hash, zbr->lnum, zbr->offs); | |
1712 | return err; | |
1713 | } | |
1714 | ||
4793e7c5 AH |
1715 | len = le32_to_cpu(ch->len); |
1716 | if (len != zbr->len) { | |
235c362b | 1717 | ubifs_err(c, "bad node length %d, expected %d", len, zbr->len); |
4793e7c5 AH |
1718 | goto out_err; |
1719 | } | |
1720 | ||
1721 | /* Make sure the key of the read node is correct */ | |
1722 | key_read(c, buf + UBIFS_KEY_OFFSET, &key1); | |
1723 | if (!keys_eq(c, &zbr->key, &key1)) { | |
235c362b | 1724 | ubifs_err(c, "bad key in node at LEB %d:%d", |
4793e7c5 | 1725 | zbr->lnum, zbr->offs); |
515315a1 AB |
1726 | dbg_tnck(&zbr->key, "looked for key "); |
1727 | dbg_tnck(&key1, "found node's key "); | |
4793e7c5 AH |
1728 | goto out_err; |
1729 | } | |
1730 | ||
1731 | return 0; | |
1732 | ||
1733 | out_err: | |
1734 | err = -EINVAL; | |
1735 | out: | |
235c362b | 1736 | ubifs_err(c, "bad node at LEB %d:%d", zbr->lnum, zbr->offs); |
edf6be24 | 1737 | ubifs_dump_node(c, buf); |
7c46d0ae | 1738 | dump_stack(); |
4793e7c5 AH |
1739 | return err; |
1740 | } | |
1741 | ||
1742 | /** | |
1743 | * ubifs_tnc_bulk_read - read a number of data nodes in one go. | |
1744 | * @c: UBIFS file-system description object | |
1745 | * @bu: bulk-read parameters and results | |
1746 | * | |
1747 | * This functions reads and validates the data nodes that were identified by the | |
1748 | * 'ubifs_tnc_get_bu_keys()' function. This functions returns %0 on success, | |
1749 | * -EAGAIN to indicate a race with GC, or another negative error code on | |
1750 | * failure. | |
1751 | */ | |
1752 | int ubifs_tnc_bulk_read(struct ubifs_info *c, struct bu_info *bu) | |
1753 | { | |
1754 | int lnum = bu->zbranch[0].lnum, offs = bu->zbranch[0].offs, len, err, i; | |
1755 | struct ubifs_wbuf *wbuf; | |
1756 | void *buf; | |
1757 | ||
1758 | len = bu->zbranch[bu->cnt - 1].offs; | |
1759 | len += bu->zbranch[bu->cnt - 1].len - offs; | |
1760 | if (len > bu->buf_len) { | |
235c362b | 1761 | ubifs_err(c, "buffer too small %d vs %d", bu->buf_len, len); |
4793e7c5 AH |
1762 | return -EINVAL; |
1763 | } | |
1764 | ||
1765 | /* Do the read */ | |
1766 | wbuf = ubifs_get_wbuf(c, lnum); | |
1767 | if (wbuf) | |
1768 | err = read_wbuf(wbuf, bu->buf, len, lnum, offs); | |
1769 | else | |
d304820a | 1770 | err = ubifs_leb_read(c, lnum, bu->buf, offs, len, 0); |
4793e7c5 AH |
1771 | |
1772 | /* Check for a race with GC */ | |
1773 | if (maybe_leb_gced(c, lnum, bu->gc_seq)) | |
1774 | return -EAGAIN; | |
1775 | ||
1776 | if (err && err != -EBADMSG) { | |
235c362b | 1777 | ubifs_err(c, "failed to read from LEB %d:%d, error %d", |
4793e7c5 | 1778 | lnum, offs, err); |
7c46d0ae | 1779 | dump_stack(); |
515315a1 | 1780 | dbg_tnck(&bu->key, "key "); |
4793e7c5 AH |
1781 | return err; |
1782 | } | |
1783 | ||
1784 | /* Validate the nodes read */ | |
1785 | buf = bu->buf; | |
1786 | for (i = 0; i < bu->cnt; i++) { | |
1787 | err = validate_data_node(c, buf, &bu->zbranch[i]); | |
1788 | if (err) | |
1789 | return err; | |
1790 | buf = buf + ALIGN(bu->zbranch[i].len, 8); | |
1791 | } | |
1792 | ||
1793 | return 0; | |
1794 | } | |
1795 | ||
1e51764a AB |
1796 | /** |
1797 | * do_lookup_nm- look up a "hashed" node. | |
1798 | * @c: UBIFS file-system description object | |
1799 | * @key: node key to lookup | |
1800 | * @node: the node is returned here | |
1801 | * @nm: node name | |
1802 | * | |
528e3d17 | 1803 | * This function looks up and reads a node which contains name hash in the key. |
1e51764a AB |
1804 | * Since the hash may have collisions, there may be many nodes with the same |
1805 | * key, so we have to sequentially look to all of them until the needed one is | |
1806 | * found. This function returns zero in case of success, %-ENOENT if the node | |
1807 | * was not found, and a negative error code in case of failure. | |
1808 | */ | |
1809 | static int do_lookup_nm(struct ubifs_info *c, const union ubifs_key *key, | |
f4f61d2c | 1810 | void *node, const struct fscrypt_name *nm) |
1e51764a AB |
1811 | { |
1812 | int found, n, err; | |
1813 | struct ubifs_znode *znode; | |
1e51764a | 1814 | |
35ee314c | 1815 | dbg_tnck(key, "key "); |
1e51764a AB |
1816 | mutex_lock(&c->tnc_mutex); |
1817 | found = ubifs_lookup_level0(c, key, &znode, &n); | |
1818 | if (!found) { | |
1819 | err = -ENOENT; | |
1820 | goto out_unlock; | |
1821 | } else if (found < 0) { | |
1822 | err = found; | |
1823 | goto out_unlock; | |
1824 | } | |
1825 | ||
6eb61d58 | 1826 | ubifs_assert(c, n >= 0); |
1e51764a AB |
1827 | |
1828 | err = resolve_collision(c, key, &znode, &n, nm); | |
1829 | dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n); | |
1830 | if (unlikely(err < 0)) | |
1831 | goto out_unlock; | |
1832 | if (err == 0) { | |
1833 | err = -ENOENT; | |
1834 | goto out_unlock; | |
1835 | } | |
1836 | ||
b91dc981 | 1837 | err = tnc_read_hashed_node(c, &znode->zbranch[n], node); |
1e51764a AB |
1838 | |
1839 | out_unlock: | |
1840 | mutex_unlock(&c->tnc_mutex); | |
1841 | return err; | |
1842 | } | |
1843 | ||
1844 | /** | |
1845 | * ubifs_tnc_lookup_nm - look up a "hashed" node. | |
1846 | * @c: UBIFS file-system description object | |
1847 | * @key: node key to lookup | |
1848 | * @node: the node is returned here | |
1849 | * @nm: node name | |
1850 | * | |
528e3d17 | 1851 | * This function looks up and reads a node which contains name hash in the key. |
1e51764a AB |
1852 | * Since the hash may have collisions, there may be many nodes with the same |
1853 | * key, so we have to sequentially look to all of them until the needed one is | |
1854 | * found. This function returns zero in case of success, %-ENOENT if the node | |
1855 | * was not found, and a negative error code in case of failure. | |
1856 | */ | |
1857 | int ubifs_tnc_lookup_nm(struct ubifs_info *c, const union ubifs_key *key, | |
f4f61d2c | 1858 | void *node, const struct fscrypt_name *nm) |
1e51764a AB |
1859 | { |
1860 | int err, len; | |
1861 | const struct ubifs_dent_node *dent = node; | |
1862 | ||
1863 | /* | |
1864 | * We assume that in most of the cases there are no name collisions and | |
1865 | * 'ubifs_tnc_lookup()' returns us the right direntry. | |
1866 | */ | |
1867 | err = ubifs_tnc_lookup(c, key, node); | |
1868 | if (err) | |
1869 | return err; | |
1870 | ||
1871 | len = le16_to_cpu(dent->nlen); | |
f4f61d2c | 1872 | if (fname_len(nm) == len && !memcmp(dent->name, fname_name(nm), len)) |
1e51764a AB |
1873 | return 0; |
1874 | ||
1875 | /* | |
1876 | * Unluckily, there are hash collisions and we have to iterate over | |
1877 | * them look at each direntry with colliding name hash sequentially. | |
1878 | */ | |
528e3d17 | 1879 | |
1e51764a AB |
1880 | return do_lookup_nm(c, key, node, nm); |
1881 | } | |
1882 | ||
781f675e RW |
1883 | static int search_dh_cookie(struct ubifs_info *c, const union ubifs_key *key, |
1884 | struct ubifs_dent_node *dent, uint32_t cookie, | |
bacfa94b | 1885 | struct ubifs_znode **zn, int *n, int exact) |
528e3d17 | 1886 | { |
781f675e RW |
1887 | int err; |
1888 | struct ubifs_znode *znode = *zn; | |
528e3d17 | 1889 | struct ubifs_zbranch *zbr; |
781f675e | 1890 | union ubifs_key *dkey; |
528e3d17 | 1891 | |
bacfa94b RW |
1892 | if (!exact) { |
1893 | err = tnc_next(c, &znode, n); | |
1894 | if (err) | |
1895 | return err; | |
1896 | } | |
1897 | ||
528e3d17 | 1898 | for (;;) { |
781f675e | 1899 | zbr = &znode->zbranch[*n]; |
528e3d17 RW |
1900 | dkey = &zbr->key; |
1901 | ||
1902 | if (key_inum(c, dkey) != key_inum(c, key) || | |
781f675e | 1903 | key_type(c, dkey) != key_type(c, key)) { |
c877154d | 1904 | return -ENOENT; |
528e3d17 RW |
1905 | } |
1906 | ||
1907 | err = tnc_read_hashed_node(c, zbr, dent); | |
1908 | if (err) | |
c877154d | 1909 | return err; |
528e3d17 RW |
1910 | |
1911 | if (key_hash(c, key) == key_hash(c, dkey) && | |
781f675e RW |
1912 | le32_to_cpu(dent->cookie) == cookie) { |
1913 | *zn = znode; | |
c877154d | 1914 | return 0; |
781f675e | 1915 | } |
781f675e | 1916 | |
c877154d GU |
1917 | err = tnc_next(c, &znode, n); |
1918 | if (err) | |
1919 | return err; | |
1920 | } | |
781f675e RW |
1921 | } |
1922 | ||
1923 | static int do_lookup_dh(struct ubifs_info *c, const union ubifs_key *key, | |
1924 | struct ubifs_dent_node *dent, uint32_t cookie) | |
1925 | { | |
1926 | int n, err; | |
1927 | struct ubifs_znode *znode; | |
1928 | union ubifs_key start_key; | |
1929 | ||
6eb61d58 | 1930 | ubifs_assert(c, is_hash_key(c, key)); |
781f675e RW |
1931 | |
1932 | lowest_dent_key(c, &start_key, key_inum(c, key)); | |
1933 | ||
1934 | mutex_lock(&c->tnc_mutex); | |
1935 | err = ubifs_lookup_level0(c, &start_key, &znode, &n); | |
1936 | if (unlikely(err < 0)) | |
1937 | goto out_unlock; | |
1938 | ||
bacfa94b | 1939 | err = search_dh_cookie(c, key, dent, cookie, &znode, &n, err); |
781f675e | 1940 | |
528e3d17 RW |
1941 | out_unlock: |
1942 | mutex_unlock(&c->tnc_mutex); | |
1943 | return err; | |
1944 | } | |
1945 | ||
1946 | /** | |
1947 | * ubifs_tnc_lookup_dh - look up a "double hashed" node. | |
1948 | * @c: UBIFS file-system description object | |
1949 | * @key: node key to lookup | |
1950 | * @node: the node is returned here | |
1951 | * @cookie: node cookie for collision resolution | |
1952 | * | |
1953 | * This function looks up and reads a node which contains name hash in the key. | |
1954 | * Since the hash may have collisions, there may be many nodes with the same | |
1955 | * key, so we have to sequentially look to all of them until the needed one | |
1956 | * with the same cookie value is found. | |
1957 | * This function returns zero in case of success, %-ENOENT if the node | |
1958 | * was not found, and a negative error code in case of failure. | |
1959 | */ | |
1960 | int ubifs_tnc_lookup_dh(struct ubifs_info *c, const union ubifs_key *key, | |
1961 | void *node, uint32_t cookie) | |
1962 | { | |
1963 | int err; | |
1964 | const struct ubifs_dent_node *dent = node; | |
1965 | ||
d63d61c1 RW |
1966 | if (!c->double_hash) |
1967 | return -EOPNOTSUPP; | |
1968 | ||
528e3d17 RW |
1969 | /* |
1970 | * We assume that in most of the cases there are no name collisions and | |
1971 | * 'ubifs_tnc_lookup()' returns us the right direntry. | |
1972 | */ | |
1973 | err = ubifs_tnc_lookup(c, key, node); | |
1974 | if (err) | |
1975 | return err; | |
1976 | ||
1977 | if (le32_to_cpu(dent->cookie) == cookie) | |
1978 | return 0; | |
1979 | ||
1980 | /* | |
1981 | * Unluckily, there are hash collisions and we have to iterate over | |
1982 | * them look at each direntry with colliding name hash sequentially. | |
1983 | */ | |
1984 | return do_lookup_dh(c, key, node, cookie); | |
1985 | } | |
1986 | ||
1e51764a AB |
1987 | /** |
1988 | * correct_parent_keys - correct parent znodes' keys. | |
1989 | * @c: UBIFS file-system description object | |
1990 | * @znode: znode to correct parent znodes for | |
1991 | * | |
1992 | * This is a helper function for 'tnc_insert()'. When the key of the leftmost | |
1993 | * zbranch changes, keys of parent znodes have to be corrected. This helper | |
1994 | * function is called in such situations and corrects the keys if needed. | |
1995 | */ | |
1996 | static void correct_parent_keys(const struct ubifs_info *c, | |
1997 | struct ubifs_znode *znode) | |
1998 | { | |
1999 | union ubifs_key *key, *key1; | |
2000 | ||
6eb61d58 RW |
2001 | ubifs_assert(c, znode->parent); |
2002 | ubifs_assert(c, znode->iip == 0); | |
1e51764a AB |
2003 | |
2004 | key = &znode->zbranch[0].key; | |
2005 | key1 = &znode->parent->zbranch[0].key; | |
2006 | ||
2007 | while (keys_cmp(c, key, key1) < 0) { | |
2008 | key_copy(c, key, key1); | |
2009 | znode = znode->parent; | |
2010 | znode->alt = 1; | |
2011 | if (!znode->parent || znode->iip) | |
2012 | break; | |
2013 | key1 = &znode->parent->zbranch[0].key; | |
2014 | } | |
2015 | } | |
2016 | ||
2017 | /** | |
2018 | * insert_zbranch - insert a zbranch into a znode. | |
6eb61d58 | 2019 | * @c: UBIFS file-system description object |
1e51764a AB |
2020 | * @znode: znode into which to insert |
2021 | * @zbr: zbranch to insert | |
2022 | * @n: slot number to insert to | |
2023 | * | |
2024 | * This is a helper function for 'tnc_insert()'. UBIFS does not allow "gaps" in | |
2025 | * znode's array of zbranches and keeps zbranches consolidated, so when a new | |
2026 | * zbranch has to be inserted to the @znode->zbranches[]' array at the @n-th | |
2027 | * slot, zbranches starting from @n have to be moved right. | |
2028 | */ | |
6eb61d58 | 2029 | static void insert_zbranch(struct ubifs_info *c, struct ubifs_znode *znode, |
1e51764a AB |
2030 | const struct ubifs_zbranch *zbr, int n) |
2031 | { | |
2032 | int i; | |
2033 | ||
6eb61d58 | 2034 | ubifs_assert(c, ubifs_zn_dirty(znode)); |
1e51764a AB |
2035 | |
2036 | if (znode->level) { | |
2037 | for (i = znode->child_cnt; i > n; i--) { | |
2038 | znode->zbranch[i] = znode->zbranch[i - 1]; | |
2039 | if (znode->zbranch[i].znode) | |
2040 | znode->zbranch[i].znode->iip = i; | |
2041 | } | |
2042 | if (zbr->znode) | |
2043 | zbr->znode->iip = n; | |
2044 | } else | |
2045 | for (i = znode->child_cnt; i > n; i--) | |
2046 | znode->zbranch[i] = znode->zbranch[i - 1]; | |
2047 | ||
2048 | znode->zbranch[n] = *zbr; | |
2049 | znode->child_cnt += 1; | |
2050 | ||
2051 | /* | |
2052 | * After inserting at slot zero, the lower bound of the key range of | |
2053 | * this znode may have changed. If this znode is subsequently split | |
2054 | * then the upper bound of the key range may change, and furthermore | |
2055 | * it could change to be lower than the original lower bound. If that | |
2056 | * happens, then it will no longer be possible to find this znode in the | |
2057 | * TNC using the key from the index node on flash. That is bad because | |
2058 | * if it is not found, we will assume it is obsolete and may overwrite | |
2059 | * it. Then if there is an unclean unmount, we will start using the | |
2060 | * old index which will be broken. | |
2061 | * | |
2062 | * So we first mark znodes that have insertions at slot zero, and then | |
2063 | * if they are split we add their lnum/offs to the old_idx tree. | |
2064 | */ | |
2065 | if (n == 0) | |
2066 | znode->alt = 1; | |
2067 | } | |
2068 | ||
2069 | /** | |
2070 | * tnc_insert - insert a node into TNC. | |
2071 | * @c: UBIFS file-system description object | |
2072 | * @znode: znode to insert into | |
2073 | * @zbr: branch to insert | |
2074 | * @n: slot number to insert new zbranch to | |
2075 | * | |
2076 | * This function inserts a new node described by @zbr into znode @znode. If | |
2077 | * znode does not have a free slot for new zbranch, it is split. Parent znodes | |
2078 | * are splat as well if needed. Returns zero in case of success or a negative | |
2079 | * error code in case of failure. | |
2080 | */ | |
2081 | static int tnc_insert(struct ubifs_info *c, struct ubifs_znode *znode, | |
2082 | struct ubifs_zbranch *zbr, int n) | |
2083 | { | |
2084 | struct ubifs_znode *zn, *zi, *zp; | |
2085 | int i, keep, move, appending = 0; | |
2242c689 | 2086 | union ubifs_key *key = &zbr->key, *key1; |
1e51764a | 2087 | |
6eb61d58 | 2088 | ubifs_assert(c, n >= 0 && n <= c->fanout); |
1e51764a AB |
2089 | |
2090 | /* Implement naive insert for now */ | |
2091 | again: | |
2092 | zp = znode->parent; | |
2093 | if (znode->child_cnt < c->fanout) { | |
6eb61d58 | 2094 | ubifs_assert(c, n != c->fanout); |
515315a1 | 2095 | dbg_tnck(key, "inserted at %d level %d, key ", n, znode->level); |
1e51764a | 2096 | |
6eb61d58 | 2097 | insert_zbranch(c, znode, zbr, n); |
1e51764a AB |
2098 | |
2099 | /* Ensure parent's key is correct */ | |
2100 | if (n == 0 && zp && znode->iip == 0) | |
2101 | correct_parent_keys(c, znode); | |
2102 | ||
2103 | return 0; | |
2104 | } | |
2105 | ||
2106 | /* | |
2107 | * Unfortunately, @znode does not have more empty slots and we have to | |
2108 | * split it. | |
2109 | */ | |
515315a1 | 2110 | dbg_tnck(key, "splitting level %d, key ", znode->level); |
1e51764a AB |
2111 | |
2112 | if (znode->alt) | |
2113 | /* | |
2114 | * We can no longer be sure of finding this znode by key, so we | |
2115 | * record it in the old_idx tree. | |
2116 | */ | |
2117 | ins_clr_old_idx_znode(c, znode); | |
2118 | ||
2119 | zn = kzalloc(c->max_znode_sz, GFP_NOFS); | |
2120 | if (!zn) | |
2121 | return -ENOMEM; | |
2122 | zn->parent = zp; | |
2123 | zn->level = znode->level; | |
2124 | ||
2125 | /* Decide where to split */ | |
2242c689 AH |
2126 | if (znode->level == 0 && key_type(c, key) == UBIFS_DATA_KEY) { |
2127 | /* Try not to split consecutive data keys */ | |
2128 | if (n == c->fanout) { | |
2129 | key1 = &znode->zbranch[n - 1].key; | |
2130 | if (key_inum(c, key1) == key_inum(c, key) && | |
2131 | key_type(c, key1) == UBIFS_DATA_KEY) | |
2132 | appending = 1; | |
2133 | } else | |
2134 | goto check_split; | |
2135 | } else if (appending && n != c->fanout) { | |
2136 | /* Try not to split consecutive data keys */ | |
2137 | appending = 0; | |
2138 | check_split: | |
2139 | if (n >= (c->fanout + 1) / 2) { | |
2140 | key1 = &znode->zbranch[0].key; | |
2141 | if (key_inum(c, key1) == key_inum(c, key) && | |
2142 | key_type(c, key1) == UBIFS_DATA_KEY) { | |
2143 | key1 = &znode->zbranch[n].key; | |
2144 | if (key_inum(c, key1) != key_inum(c, key) || | |
2145 | key_type(c, key1) != UBIFS_DATA_KEY) { | |
2146 | keep = n; | |
2147 | move = c->fanout - keep; | |
2148 | zi = znode; | |
2149 | goto do_split; | |
2150 | } | |
2151 | } | |
2152 | } | |
1e51764a AB |
2153 | } |
2154 | ||
2155 | if (appending) { | |
2156 | keep = c->fanout; | |
2157 | move = 0; | |
2158 | } else { | |
2159 | keep = (c->fanout + 1) / 2; | |
2160 | move = c->fanout - keep; | |
2161 | } | |
2162 | ||
2163 | /* | |
2164 | * Although we don't at present, we could look at the neighbors and see | |
2165 | * if we can move some zbranches there. | |
2166 | */ | |
2167 | ||
2168 | if (n < keep) { | |
2169 | /* Insert into existing znode */ | |
2170 | zi = znode; | |
2171 | move += 1; | |
2172 | keep -= 1; | |
2173 | } else { | |
2174 | /* Insert into new znode */ | |
2175 | zi = zn; | |
2176 | n -= keep; | |
2177 | /* Re-parent */ | |
2178 | if (zn->level != 0) | |
2179 | zbr->znode->parent = zn; | |
2180 | } | |
2181 | ||
2242c689 AH |
2182 | do_split: |
2183 | ||
1e51764a AB |
2184 | __set_bit(DIRTY_ZNODE, &zn->flags); |
2185 | atomic_long_inc(&c->dirty_zn_cnt); | |
2186 | ||
2187 | zn->child_cnt = move; | |
2188 | znode->child_cnt = keep; | |
2189 | ||
2190 | dbg_tnc("moving %d, keeping %d", move, keep); | |
2191 | ||
2192 | /* Move zbranch */ | |
2193 | for (i = 0; i < move; i++) { | |
2194 | zn->zbranch[i] = znode->zbranch[keep + i]; | |
2195 | /* Re-parent */ | |
2196 | if (zn->level != 0) | |
2197 | if (zn->zbranch[i].znode) { | |
2198 | zn->zbranch[i].znode->parent = zn; | |
2199 | zn->zbranch[i].znode->iip = i; | |
2200 | } | |
2201 | } | |
2202 | ||
2203 | /* Insert new key and branch */ | |
515315a1 | 2204 | dbg_tnck(key, "inserting at %d level %d, key ", n, zn->level); |
1e51764a | 2205 | |
6eb61d58 | 2206 | insert_zbranch(c, zi, zbr, n); |
1e51764a AB |
2207 | |
2208 | /* Insert new znode (produced by spitting) into the parent */ | |
2209 | if (zp) { | |
2242c689 AH |
2210 | if (n == 0 && zi == znode && znode->iip == 0) |
2211 | correct_parent_keys(c, znode); | |
2212 | ||
1e51764a AB |
2213 | /* Locate insertion point */ |
2214 | n = znode->iip + 1; | |
1e51764a AB |
2215 | |
2216 | /* Tail recursion */ | |
2217 | zbr->key = zn->zbranch[0].key; | |
2218 | zbr->znode = zn; | |
2219 | zbr->lnum = 0; | |
2220 | zbr->offs = 0; | |
2221 | zbr->len = 0; | |
2222 | znode = zp; | |
2223 | ||
2224 | goto again; | |
2225 | } | |
2226 | ||
2227 | /* We have to split root znode */ | |
2228 | dbg_tnc("creating new zroot at level %d", znode->level + 1); | |
2229 | ||
2230 | zi = kzalloc(c->max_znode_sz, GFP_NOFS); | |
2231 | if (!zi) | |
2232 | return -ENOMEM; | |
2233 | ||
2234 | zi->child_cnt = 2; | |
2235 | zi->level = znode->level + 1; | |
2236 | ||
2237 | __set_bit(DIRTY_ZNODE, &zi->flags); | |
2238 | atomic_long_inc(&c->dirty_zn_cnt); | |
2239 | ||
2240 | zi->zbranch[0].key = znode->zbranch[0].key; | |
2241 | zi->zbranch[0].znode = znode; | |
2242 | zi->zbranch[0].lnum = c->zroot.lnum; | |
2243 | zi->zbranch[0].offs = c->zroot.offs; | |
2244 | zi->zbranch[0].len = c->zroot.len; | |
2245 | zi->zbranch[1].key = zn->zbranch[0].key; | |
2246 | zi->zbranch[1].znode = zn; | |
2247 | ||
2248 | c->zroot.lnum = 0; | |
2249 | c->zroot.offs = 0; | |
2250 | c->zroot.len = 0; | |
2251 | c->zroot.znode = zi; | |
2252 | ||
2253 | zn->parent = zi; | |
2254 | zn->iip = 1; | |
2255 | znode->parent = zi; | |
2256 | znode->iip = 0; | |
2257 | ||
2258 | return 0; | |
2259 | } | |
2260 | ||
2261 | /** | |
2262 | * ubifs_tnc_add - add a node to TNC. | |
2263 | * @c: UBIFS file-system description object | |
2264 | * @key: key to add | |
2265 | * @lnum: LEB number of node | |
2266 | * @offs: node offset | |
2267 | * @len: node length | |
823838a4 | 2268 | * @hash: The hash over the node |
1e51764a AB |
2269 | * |
2270 | * This function adds a node with key @key to TNC. The node may be new or it may | |
2271 | * obsolete some existing one. Returns %0 on success or negative error code on | |
2272 | * failure. | |
2273 | */ | |
2274 | int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum, | |
823838a4 | 2275 | int offs, int len, const u8 *hash) |
1e51764a AB |
2276 | { |
2277 | int found, n, err = 0; | |
2278 | struct ubifs_znode *znode; | |
2279 | ||
2280 | mutex_lock(&c->tnc_mutex); | |
515315a1 | 2281 | dbg_tnck(key, "%d:%d, len %d, key ", lnum, offs, len); |
1e51764a AB |
2282 | found = lookup_level0_dirty(c, key, &znode, &n); |
2283 | if (!found) { | |
2284 | struct ubifs_zbranch zbr; | |
2285 | ||
2286 | zbr.znode = NULL; | |
2287 | zbr.lnum = lnum; | |
2288 | zbr.offs = offs; | |
2289 | zbr.len = len; | |
823838a4 | 2290 | ubifs_copy_hash(c, hash, zbr.hash); |
1e51764a AB |
2291 | key_copy(c, key, &zbr.key); |
2292 | err = tnc_insert(c, znode, &zbr, n + 1); | |
2293 | } else if (found == 1) { | |
2294 | struct ubifs_zbranch *zbr = &znode->zbranch[n]; | |
2295 | ||
2296 | lnc_free(zbr); | |
2297 | err = ubifs_add_dirt(c, zbr->lnum, zbr->len); | |
2298 | zbr->lnum = lnum; | |
2299 | zbr->offs = offs; | |
2300 | zbr->len = len; | |
823838a4 | 2301 | ubifs_copy_hash(c, hash, zbr->hash); |
1e51764a AB |
2302 | } else |
2303 | err = found; | |
2304 | if (!err) | |
2305 | err = dbg_check_tnc(c, 0); | |
2306 | mutex_unlock(&c->tnc_mutex); | |
2307 | ||
2308 | return err; | |
2309 | } | |
2310 | ||
2311 | /** | |
2312 | * ubifs_tnc_replace - replace a node in the TNC only if the old node is found. | |
2313 | * @c: UBIFS file-system description object | |
2314 | * @key: key to add | |
2315 | * @old_lnum: LEB number of old node | |
2316 | * @old_offs: old node offset | |
2317 | * @lnum: LEB number of node | |
2318 | * @offs: node offset | |
2319 | * @len: node length | |
2320 | * | |
2321 | * This function replaces a node with key @key in the TNC only if the old node | |
2322 | * is found. This function is called by garbage collection when node are moved. | |
2323 | * Returns %0 on success or negative error code on failure. | |
2324 | */ | |
2325 | int ubifs_tnc_replace(struct ubifs_info *c, const union ubifs_key *key, | |
2326 | int old_lnum, int old_offs, int lnum, int offs, int len) | |
2327 | { | |
2328 | int found, n, err = 0; | |
2329 | struct ubifs_znode *znode; | |
2330 | ||
2331 | mutex_lock(&c->tnc_mutex); | |
515315a1 AB |
2332 | dbg_tnck(key, "old LEB %d:%d, new LEB %d:%d, len %d, key ", old_lnum, |
2333 | old_offs, lnum, offs, len); | |
1e51764a AB |
2334 | found = lookup_level0_dirty(c, key, &znode, &n); |
2335 | if (found < 0) { | |
2336 | err = found; | |
2337 | goto out_unlock; | |
2338 | } | |
2339 | ||
2340 | if (found == 1) { | |
2341 | struct ubifs_zbranch *zbr = &znode->zbranch[n]; | |
2342 | ||
2343 | found = 0; | |
2344 | if (zbr->lnum == old_lnum && zbr->offs == old_offs) { | |
2345 | lnc_free(zbr); | |
2346 | err = ubifs_add_dirt(c, zbr->lnum, zbr->len); | |
2347 | if (err) | |
2348 | goto out_unlock; | |
2349 | zbr->lnum = lnum; | |
2350 | zbr->offs = offs; | |
2351 | zbr->len = len; | |
2352 | found = 1; | |
2353 | } else if (is_hash_key(c, key)) { | |
2354 | found = resolve_collision_directly(c, key, &znode, &n, | |
2355 | old_lnum, old_offs); | |
2356 | dbg_tnc("rc returned %d, znode %p, n %d, LEB %d:%d", | |
2357 | found, znode, n, old_lnum, old_offs); | |
2358 | if (found < 0) { | |
2359 | err = found; | |
2360 | goto out_unlock; | |
2361 | } | |
2362 | ||
2363 | if (found) { | |
2364 | /* Ensure the znode is dirtied */ | |
2365 | if (znode->cnext || !ubifs_zn_dirty(znode)) { | |
f92b9826 AB |
2366 | znode = dirty_cow_bottom_up(c, znode); |
2367 | if (IS_ERR(znode)) { | |
2368 | err = PTR_ERR(znode); | |
2369 | goto out_unlock; | |
2370 | } | |
1e51764a AB |
2371 | } |
2372 | zbr = &znode->zbranch[n]; | |
2373 | lnc_free(zbr); | |
2374 | err = ubifs_add_dirt(c, zbr->lnum, | |
2375 | zbr->len); | |
2376 | if (err) | |
2377 | goto out_unlock; | |
2378 | zbr->lnum = lnum; | |
2379 | zbr->offs = offs; | |
2380 | zbr->len = len; | |
2381 | } | |
2382 | } | |
2383 | } | |
2384 | ||
2385 | if (!found) | |
2386 | err = ubifs_add_dirt(c, lnum, len); | |
2387 | ||
2388 | if (!err) | |
2389 | err = dbg_check_tnc(c, 0); | |
2390 | ||
2391 | out_unlock: | |
2392 | mutex_unlock(&c->tnc_mutex); | |
2393 | return err; | |
2394 | } | |
2395 | ||
2396 | /** | |
2397 | * ubifs_tnc_add_nm - add a "hashed" node to TNC. | |
2398 | * @c: UBIFS file-system description object | |
2399 | * @key: key to add | |
2400 | * @lnum: LEB number of node | |
2401 | * @offs: node offset | |
2402 | * @len: node length | |
823838a4 | 2403 | * @hash: The hash over the node |
1e51764a AB |
2404 | * @nm: node name |
2405 | * | |
2406 | * This is the same as 'ubifs_tnc_add()' but it should be used with keys which | |
2407 | * may have collisions, like directory entry keys. | |
2408 | */ | |
2409 | int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key, | |
823838a4 | 2410 | int lnum, int offs, int len, const u8 *hash, |
f4f61d2c | 2411 | const struct fscrypt_name *nm) |
1e51764a AB |
2412 | { |
2413 | int found, n, err = 0; | |
2414 | struct ubifs_znode *znode; | |
2415 | ||
2416 | mutex_lock(&c->tnc_mutex); | |
35ee314c | 2417 | dbg_tnck(key, "LEB %d:%d, key ", lnum, offs); |
1e51764a AB |
2418 | found = lookup_level0_dirty(c, key, &znode, &n); |
2419 | if (found < 0) { | |
2420 | err = found; | |
2421 | goto out_unlock; | |
2422 | } | |
2423 | ||
2424 | if (found == 1) { | |
2425 | if (c->replaying) | |
2426 | found = fallible_resolve_collision(c, key, &znode, &n, | |
2427 | nm, 1); | |
2428 | else | |
2429 | found = resolve_collision(c, key, &znode, &n, nm); | |
2430 | dbg_tnc("rc returned %d, znode %p, n %d", found, znode, n); | |
2431 | if (found < 0) { | |
2432 | err = found; | |
2433 | goto out_unlock; | |
2434 | } | |
2435 | ||
2436 | /* Ensure the znode is dirtied */ | |
2437 | if (znode->cnext || !ubifs_zn_dirty(znode)) { | |
f92b9826 AB |
2438 | znode = dirty_cow_bottom_up(c, znode); |
2439 | if (IS_ERR(znode)) { | |
2440 | err = PTR_ERR(znode); | |
2441 | goto out_unlock; | |
2442 | } | |
1e51764a AB |
2443 | } |
2444 | ||
2445 | if (found == 1) { | |
2446 | struct ubifs_zbranch *zbr = &znode->zbranch[n]; | |
2447 | ||
2448 | lnc_free(zbr); | |
2449 | err = ubifs_add_dirt(c, zbr->lnum, zbr->len); | |
2450 | zbr->lnum = lnum; | |
2451 | zbr->offs = offs; | |
2452 | zbr->len = len; | |
823838a4 | 2453 | ubifs_copy_hash(c, hash, zbr->hash); |
1e51764a AB |
2454 | goto out_unlock; |
2455 | } | |
2456 | } | |
2457 | ||
2458 | if (!found) { | |
2459 | struct ubifs_zbranch zbr; | |
2460 | ||
2461 | zbr.znode = NULL; | |
2462 | zbr.lnum = lnum; | |
2463 | zbr.offs = offs; | |
2464 | zbr.len = len; | |
823838a4 | 2465 | ubifs_copy_hash(c, hash, zbr.hash); |
1e51764a AB |
2466 | key_copy(c, key, &zbr.key); |
2467 | err = tnc_insert(c, znode, &zbr, n + 1); | |
2468 | if (err) | |
2469 | goto out_unlock; | |
2470 | if (c->replaying) { | |
2471 | /* | |
2472 | * We did not find it in the index so there may be a | |
2473 | * dangling branch still in the index. So we remove it | |
2474 | * by passing 'ubifs_tnc_remove_nm()' the same key but | |
2475 | * an unmatchable name. | |
2476 | */ | |
f4f61d2c | 2477 | struct fscrypt_name noname = { .disk_name = { .name = "", .len = 1 } }; |
1e51764a AB |
2478 | |
2479 | err = dbg_check_tnc(c, 0); | |
2480 | mutex_unlock(&c->tnc_mutex); | |
2481 | if (err) | |
2482 | return err; | |
2483 | return ubifs_tnc_remove_nm(c, key, &noname); | |
2484 | } | |
2485 | } | |
2486 | ||
2487 | out_unlock: | |
2488 | if (!err) | |
2489 | err = dbg_check_tnc(c, 0); | |
2490 | mutex_unlock(&c->tnc_mutex); | |
2491 | return err; | |
2492 | } | |
2493 | ||
2494 | /** | |
2495 | * tnc_delete - delete a znode form TNC. | |
2496 | * @c: UBIFS file-system description object | |
2497 | * @znode: znode to delete from | |
2498 | * @n: zbranch slot number to delete | |
2499 | * | |
2500 | * This function deletes a leaf node from @n-th slot of @znode. Returns zero in | |
2501 | * case of success and a negative error code in case of failure. | |
2502 | */ | |
2503 | static int tnc_delete(struct ubifs_info *c, struct ubifs_znode *znode, int n) | |
2504 | { | |
2505 | struct ubifs_zbranch *zbr; | |
2506 | struct ubifs_znode *zp; | |
2507 | int i, err; | |
2508 | ||
2509 | /* Delete without merge for now */ | |
6eb61d58 RW |
2510 | ubifs_assert(c, znode->level == 0); |
2511 | ubifs_assert(c, n >= 0 && n < c->fanout); | |
515315a1 | 2512 | dbg_tnck(&znode->zbranch[n].key, "deleting key "); |
1e51764a AB |
2513 | |
2514 | zbr = &znode->zbranch[n]; | |
2515 | lnc_free(zbr); | |
2516 | ||
2517 | err = ubifs_add_dirt(c, zbr->lnum, zbr->len); | |
2518 | if (err) { | |
edf6be24 | 2519 | ubifs_dump_znode(c, znode); |
1e51764a AB |
2520 | return err; |
2521 | } | |
2522 | ||
2523 | /* We do not "gap" zbranch slots */ | |
2524 | for (i = n; i < znode->child_cnt - 1; i++) | |
2525 | znode->zbranch[i] = znode->zbranch[i + 1]; | |
2526 | znode->child_cnt -= 1; | |
2527 | ||
2528 | if (znode->child_cnt > 0) | |
2529 | return 0; | |
2530 | ||
2531 | /* | |
2532 | * This was the last zbranch, we have to delete this znode from the | |
2533 | * parent. | |
2534 | */ | |
2535 | ||
2536 | do { | |
6eb61d58 RW |
2537 | ubifs_assert(c, !ubifs_zn_obsolete(znode)); |
2538 | ubifs_assert(c, ubifs_zn_dirty(znode)); | |
1e51764a AB |
2539 | |
2540 | zp = znode->parent; | |
2541 | n = znode->iip; | |
2542 | ||
2543 | atomic_long_dec(&c->dirty_zn_cnt); | |
2544 | ||
2545 | err = insert_old_idx_znode(c, znode); | |
2546 | if (err) | |
2547 | return err; | |
2548 | ||
2549 | if (znode->cnext) { | |
2550 | __set_bit(OBSOLETE_ZNODE, &znode->flags); | |
2551 | atomic_long_inc(&c->clean_zn_cnt); | |
2552 | atomic_long_inc(&ubifs_clean_zn_cnt); | |
2553 | } else | |
2554 | kfree(znode); | |
2555 | znode = zp; | |
2556 | } while (znode->child_cnt == 1); /* while removing last child */ | |
2557 | ||
2558 | /* Remove from znode, entry n - 1 */ | |
2559 | znode->child_cnt -= 1; | |
6eb61d58 | 2560 | ubifs_assert(c, znode->level != 0); |
1e51764a AB |
2561 | for (i = n; i < znode->child_cnt; i++) { |
2562 | znode->zbranch[i] = znode->zbranch[i + 1]; | |
2563 | if (znode->zbranch[i].znode) | |
2564 | znode->zbranch[i].znode->iip = i; | |
2565 | } | |
2566 | ||
2567 | /* | |
2568 | * If this is the root and it has only 1 child then | |
2569 | * collapse the tree. | |
2570 | */ | |
2571 | if (!znode->parent) { | |
2572 | while (znode->child_cnt == 1 && znode->level != 0) { | |
2573 | zp = znode; | |
2574 | zbr = &znode->zbranch[0]; | |
2575 | znode = get_znode(c, znode, 0); | |
2576 | if (IS_ERR(znode)) | |
2577 | return PTR_ERR(znode); | |
2578 | znode = dirty_cow_znode(c, zbr); | |
2579 | if (IS_ERR(znode)) | |
2580 | return PTR_ERR(znode); | |
2581 | znode->parent = NULL; | |
2582 | znode->iip = 0; | |
2583 | if (c->zroot.len) { | |
2584 | err = insert_old_idx(c, c->zroot.lnum, | |
2585 | c->zroot.offs); | |
2586 | if (err) | |
2587 | return err; | |
2588 | } | |
2589 | c->zroot.lnum = zbr->lnum; | |
2590 | c->zroot.offs = zbr->offs; | |
2591 | c->zroot.len = zbr->len; | |
2592 | c->zroot.znode = znode; | |
6eb61d58 RW |
2593 | ubifs_assert(c, !ubifs_zn_obsolete(zp)); |
2594 | ubifs_assert(c, ubifs_zn_dirty(zp)); | |
1e51764a AB |
2595 | atomic_long_dec(&c->dirty_zn_cnt); |
2596 | ||
2597 | if (zp->cnext) { | |
2598 | __set_bit(OBSOLETE_ZNODE, &zp->flags); | |
2599 | atomic_long_inc(&c->clean_zn_cnt); | |
2600 | atomic_long_inc(&ubifs_clean_zn_cnt); | |
2601 | } else | |
2602 | kfree(zp); | |
2603 | } | |
2604 | } | |
2605 | ||
2606 | return 0; | |
2607 | } | |
2608 | ||
2609 | /** | |
2610 | * ubifs_tnc_remove - remove an index entry of a node. | |
2611 | * @c: UBIFS file-system description object | |
2612 | * @key: key of node | |
2613 | * | |
2614 | * Returns %0 on success or negative error code on failure. | |
2615 | */ | |
2616 | int ubifs_tnc_remove(struct ubifs_info *c, const union ubifs_key *key) | |
2617 | { | |
2618 | int found, n, err = 0; | |
2619 | struct ubifs_znode *znode; | |
2620 | ||
2621 | mutex_lock(&c->tnc_mutex); | |
515315a1 | 2622 | dbg_tnck(key, "key "); |
1e51764a AB |
2623 | found = lookup_level0_dirty(c, key, &znode, &n); |
2624 | if (found < 0) { | |
2625 | err = found; | |
2626 | goto out_unlock; | |
2627 | } | |
2628 | if (found == 1) | |
2629 | err = tnc_delete(c, znode, n); | |
2630 | if (!err) | |
2631 | err = dbg_check_tnc(c, 0); | |
2632 | ||
2633 | out_unlock: | |
2634 | mutex_unlock(&c->tnc_mutex); | |
2635 | return err; | |
2636 | } | |
2637 | ||
2638 | /** | |
2639 | * ubifs_tnc_remove_nm - remove an index entry for a "hashed" node. | |
2640 | * @c: UBIFS file-system description object | |
2641 | * @key: key of node | |
2642 | * @nm: directory entry name | |
2643 | * | |
2644 | * Returns %0 on success or negative error code on failure. | |
2645 | */ | |
2646 | int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key, | |
f4f61d2c | 2647 | const struct fscrypt_name *nm) |
1e51764a AB |
2648 | { |
2649 | int n, err; | |
2650 | struct ubifs_znode *znode; | |
2651 | ||
2652 | mutex_lock(&c->tnc_mutex); | |
35ee314c | 2653 | dbg_tnck(key, "key "); |
1e51764a AB |
2654 | err = lookup_level0_dirty(c, key, &znode, &n); |
2655 | if (err < 0) | |
2656 | goto out_unlock; | |
2657 | ||
2658 | if (err) { | |
2659 | if (c->replaying) | |
2660 | err = fallible_resolve_collision(c, key, &znode, &n, | |
2661 | nm, 0); | |
2662 | else | |
2663 | err = resolve_collision(c, key, &znode, &n, nm); | |
2664 | dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n); | |
2665 | if (err < 0) | |
2666 | goto out_unlock; | |
2667 | if (err) { | |
2668 | /* Ensure the znode is dirtied */ | |
2669 | if (znode->cnext || !ubifs_zn_dirty(znode)) { | |
c4361570 AB |
2670 | znode = dirty_cow_bottom_up(c, znode); |
2671 | if (IS_ERR(znode)) { | |
2672 | err = PTR_ERR(znode); | |
2673 | goto out_unlock; | |
2674 | } | |
1e51764a AB |
2675 | } |
2676 | err = tnc_delete(c, znode, n); | |
2677 | } | |
2678 | } | |
2679 | ||
2680 | out_unlock: | |
2681 | if (!err) | |
2682 | err = dbg_check_tnc(c, 0); | |
2683 | mutex_unlock(&c->tnc_mutex); | |
2684 | return err; | |
2685 | } | |
2686 | ||
781f675e RW |
2687 | /** |
2688 | * ubifs_tnc_remove_dh - remove an index entry for a "double hashed" node. | |
2689 | * @c: UBIFS file-system description object | |
2690 | * @key: key of node | |
2691 | * @cookie: node cookie for collision resolution | |
2692 | * | |
2693 | * Returns %0 on success or negative error code on failure. | |
2694 | */ | |
2695 | int ubifs_tnc_remove_dh(struct ubifs_info *c, const union ubifs_key *key, | |
2696 | uint32_t cookie) | |
2697 | { | |
2698 | int n, err; | |
2699 | struct ubifs_znode *znode; | |
2700 | struct ubifs_dent_node *dent; | |
2701 | struct ubifs_zbranch *zbr; | |
2702 | ||
2703 | if (!c->double_hash) | |
2704 | return -EOPNOTSUPP; | |
2705 | ||
2706 | mutex_lock(&c->tnc_mutex); | |
2707 | err = lookup_level0_dirty(c, key, &znode, &n); | |
2708 | if (err <= 0) | |
2709 | goto out_unlock; | |
2710 | ||
2711 | zbr = &znode->zbranch[n]; | |
2712 | dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS); | |
2713 | if (!dent) { | |
2714 | err = -ENOMEM; | |
2715 | goto out_unlock; | |
2716 | } | |
2717 | ||
2718 | err = tnc_read_hashed_node(c, zbr, dent); | |
2719 | if (err) | |
2720 | goto out_free; | |
2721 | ||
2722 | /* If the cookie does not match, we're facing a hash collision. */ | |
2723 | if (le32_to_cpu(dent->cookie) != cookie) { | |
2724 | union ubifs_key start_key; | |
2725 | ||
2726 | lowest_dent_key(c, &start_key, key_inum(c, key)); | |
2727 | ||
2728 | err = ubifs_lookup_level0(c, &start_key, &znode, &n); | |
2729 | if (unlikely(err < 0)) | |
2730 | goto out_free; | |
2731 | ||
bacfa94b | 2732 | err = search_dh_cookie(c, key, dent, cookie, &znode, &n, err); |
781f675e RW |
2733 | if (err) |
2734 | goto out_free; | |
2735 | } | |
2736 | ||
2737 | if (znode->cnext || !ubifs_zn_dirty(znode)) { | |
2738 | znode = dirty_cow_bottom_up(c, znode); | |
2739 | if (IS_ERR(znode)) { | |
2740 | err = PTR_ERR(znode); | |
2741 | goto out_free; | |
2742 | } | |
2743 | } | |
2744 | err = tnc_delete(c, znode, n); | |
2745 | ||
2746 | out_free: | |
2747 | kfree(dent); | |
2748 | out_unlock: | |
2749 | if (!err) | |
2750 | err = dbg_check_tnc(c, 0); | |
2751 | mutex_unlock(&c->tnc_mutex); | |
2752 | return err; | |
2753 | } | |
2754 | ||
1e51764a AB |
2755 | /** |
2756 | * key_in_range - determine if a key falls within a range of keys. | |
2757 | * @c: UBIFS file-system description object | |
2758 | * @key: key to check | |
2759 | * @from_key: lowest key in range | |
2760 | * @to_key: highest key in range | |
2761 | * | |
2762 | * This function returns %1 if the key is in range and %0 otherwise. | |
2763 | */ | |
2764 | static int key_in_range(struct ubifs_info *c, union ubifs_key *key, | |
2765 | union ubifs_key *from_key, union ubifs_key *to_key) | |
2766 | { | |
2767 | if (keys_cmp(c, key, from_key) < 0) | |
2768 | return 0; | |
2769 | if (keys_cmp(c, key, to_key) > 0) | |
2770 | return 0; | |
2771 | return 1; | |
2772 | } | |
2773 | ||
2774 | /** | |
2775 | * ubifs_tnc_remove_range - remove index entries in range. | |
2776 | * @c: UBIFS file-system description object | |
2777 | * @from_key: lowest key to remove | |
2778 | * @to_key: highest key to remove | |
2779 | * | |
2780 | * This function removes index entries starting at @from_key and ending at | |
2781 | * @to_key. This function returns zero in case of success and a negative error | |
2782 | * code in case of failure. | |
2783 | */ | |
2784 | int ubifs_tnc_remove_range(struct ubifs_info *c, union ubifs_key *from_key, | |
2785 | union ubifs_key *to_key) | |
2786 | { | |
2787 | int i, n, k, err = 0; | |
2788 | struct ubifs_znode *znode; | |
2789 | union ubifs_key *key; | |
2790 | ||
2791 | mutex_lock(&c->tnc_mutex); | |
2792 | while (1) { | |
2793 | /* Find first level 0 znode that contains keys to remove */ | |
2794 | err = ubifs_lookup_level0(c, from_key, &znode, &n); | |
2795 | if (err < 0) | |
2796 | goto out_unlock; | |
2797 | ||
2798 | if (err) | |
2799 | key = from_key; | |
2800 | else { | |
2801 | err = tnc_next(c, &znode, &n); | |
2802 | if (err == -ENOENT) { | |
2803 | err = 0; | |
2804 | goto out_unlock; | |
2805 | } | |
2806 | if (err < 0) | |
2807 | goto out_unlock; | |
2808 | key = &znode->zbranch[n].key; | |
2809 | if (!key_in_range(c, key, from_key, to_key)) { | |
2810 | err = 0; | |
2811 | goto out_unlock; | |
2812 | } | |
2813 | } | |
2814 | ||
2815 | /* Ensure the znode is dirtied */ | |
2816 | if (znode->cnext || !ubifs_zn_dirty(znode)) { | |
f92b9826 AB |
2817 | znode = dirty_cow_bottom_up(c, znode); |
2818 | if (IS_ERR(znode)) { | |
2819 | err = PTR_ERR(znode); | |
2820 | goto out_unlock; | |
2821 | } | |
1e51764a AB |
2822 | } |
2823 | ||
2824 | /* Remove all keys in range except the first */ | |
2825 | for (i = n + 1, k = 0; i < znode->child_cnt; i++, k++) { | |
2826 | key = &znode->zbranch[i].key; | |
2827 | if (!key_in_range(c, key, from_key, to_key)) | |
2828 | break; | |
2829 | lnc_free(&znode->zbranch[i]); | |
2830 | err = ubifs_add_dirt(c, znode->zbranch[i].lnum, | |
2831 | znode->zbranch[i].len); | |
2832 | if (err) { | |
edf6be24 | 2833 | ubifs_dump_znode(c, znode); |
1e51764a AB |
2834 | goto out_unlock; |
2835 | } | |
515315a1 | 2836 | dbg_tnck(key, "removing key "); |
1e51764a AB |
2837 | } |
2838 | if (k) { | |
2839 | for (i = n + 1 + k; i < znode->child_cnt; i++) | |
2840 | znode->zbranch[i - k] = znode->zbranch[i]; | |
2841 | znode->child_cnt -= k; | |
2842 | } | |
2843 | ||
2844 | /* Now delete the first */ | |
2845 | err = tnc_delete(c, znode, n); | |
2846 | if (err) | |
2847 | goto out_unlock; | |
2848 | } | |
2849 | ||
2850 | out_unlock: | |
2851 | if (!err) | |
2852 | err = dbg_check_tnc(c, 0); | |
2853 | mutex_unlock(&c->tnc_mutex); | |
2854 | return err; | |
2855 | } | |
2856 | ||
2857 | /** | |
2858 | * ubifs_tnc_remove_ino - remove an inode from TNC. | |
2859 | * @c: UBIFS file-system description object | |
2860 | * @inum: inode number to remove | |
2861 | * | |
2862 | * This function remove inode @inum and all the extended attributes associated | |
2863 | * with the anode from TNC and returns zero in case of success or a negative | |
2864 | * error code in case of failure. | |
2865 | */ | |
2866 | int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum) | |
2867 | { | |
2868 | union ubifs_key key1, key2; | |
2869 | struct ubifs_dent_node *xent, *pxent = NULL; | |
f4f61d2c | 2870 | struct fscrypt_name nm = {0}; |
1e51764a | 2871 | |
e84461ad | 2872 | dbg_tnc("ino %lu", (unsigned long)inum); |
1e51764a AB |
2873 | |
2874 | /* | |
2875 | * Walk all extended attribute entries and remove them together with | |
2876 | * corresponding extended attribute inodes. | |
2877 | */ | |
2878 | lowest_xent_key(c, &key1, inum); | |
2879 | while (1) { | |
2880 | ino_t xattr_inum; | |
2881 | int err; | |
2882 | ||
2883 | xent = ubifs_tnc_next_ent(c, &key1, &nm); | |
2884 | if (IS_ERR(xent)) { | |
2885 | err = PTR_ERR(xent); | |
2886 | if (err == -ENOENT) | |
2887 | break; | |
2888 | return err; | |
2889 | } | |
2890 | ||
2891 | xattr_inum = le64_to_cpu(xent->inum); | |
e84461ad AB |
2892 | dbg_tnc("xent '%s', ino %lu", xent->name, |
2893 | (unsigned long)xattr_inum); | |
1e51764a | 2894 | |
272eda82 RW |
2895 | ubifs_evict_xattr_inode(c, xattr_inum); |
2896 | ||
f4f61d2c RW |
2897 | fname_name(&nm) = xent->name; |
2898 | fname_len(&nm) = le16_to_cpu(xent->nlen); | |
1e51764a AB |
2899 | err = ubifs_tnc_remove_nm(c, &key1, &nm); |
2900 | if (err) { | |
2901 | kfree(xent); | |
2902 | return err; | |
2903 | } | |
2904 | ||
2905 | lowest_ino_key(c, &key1, xattr_inum); | |
2906 | highest_ino_key(c, &key2, xattr_inum); | |
2907 | err = ubifs_tnc_remove_range(c, &key1, &key2); | |
2908 | if (err) { | |
2909 | kfree(xent); | |
2910 | return err; | |
2911 | } | |
2912 | ||
2913 | kfree(pxent); | |
2914 | pxent = xent; | |
2915 | key_read(c, &xent->key, &key1); | |
2916 | } | |
2917 | ||
2918 | kfree(pxent); | |
2919 | lowest_ino_key(c, &key1, inum); | |
2920 | highest_ino_key(c, &key2, inum); | |
2921 | ||
2922 | return ubifs_tnc_remove_range(c, &key1, &key2); | |
2923 | } | |
2924 | ||
2925 | /** | |
2926 | * ubifs_tnc_next_ent - walk directory or extended attribute entries. | |
2927 | * @c: UBIFS file-system description object | |
2928 | * @key: key of last entry | |
2929 | * @nm: name of last entry found or %NULL | |
2930 | * | |
2931 | * This function finds and reads the next directory or extended attribute entry | |
2932 | * after the given key (@key) if there is one. @nm is used to resolve | |
2933 | * collisions. | |
2934 | * | |
2935 | * If the name of the current entry is not known and only the key is known, | |
2936 | * @nm->name has to be %NULL. In this case the semantics of this function is a | |
2937 | * little bit different and it returns the entry corresponding to this key, not | |
2938 | * the next one. If the key was not found, the closest "right" entry is | |
2939 | * returned. | |
2940 | * | |
2941 | * If the fist entry has to be found, @key has to contain the lowest possible | |
2942 | * key value for this inode and @name has to be %NULL. | |
2943 | * | |
2944 | * This function returns the found directory or extended attribute entry node | |
2945 | * in case of success, %-ENOENT is returned if no entry was found, and a | |
2946 | * negative error code is returned in case of failure. | |
2947 | */ | |
2948 | struct ubifs_dent_node *ubifs_tnc_next_ent(struct ubifs_info *c, | |
2949 | union ubifs_key *key, | |
f4f61d2c | 2950 | const struct fscrypt_name *nm) |
1e51764a AB |
2951 | { |
2952 | int n, err, type = key_type(c, key); | |
2953 | struct ubifs_znode *znode; | |
2954 | struct ubifs_dent_node *dent; | |
2955 | struct ubifs_zbranch *zbr; | |
2956 | union ubifs_key *dkey; | |
2957 | ||
35ee314c | 2958 | dbg_tnck(key, "key "); |
6eb61d58 | 2959 | ubifs_assert(c, is_hash_key(c, key)); |
1e51764a AB |
2960 | |
2961 | mutex_lock(&c->tnc_mutex); | |
2962 | err = ubifs_lookup_level0(c, key, &znode, &n); | |
2963 | if (unlikely(err < 0)) | |
2964 | goto out_unlock; | |
2965 | ||
f4f61d2c | 2966 | if (fname_len(nm) > 0) { |
1e51764a AB |
2967 | if (err) { |
2968 | /* Handle collisions */ | |
1cb51a15 RW |
2969 | if (c->replaying) |
2970 | err = fallible_resolve_collision(c, key, &znode, &n, | |
2971 | nm, 0); | |
2972 | else | |
2973 | err = resolve_collision(c, key, &znode, &n, nm); | |
1e51764a AB |
2974 | dbg_tnc("rc returned %d, znode %p, n %d", |
2975 | err, znode, n); | |
2976 | if (unlikely(err < 0)) | |
2977 | goto out_unlock; | |
2978 | } | |
2979 | ||
2980 | /* Now find next entry */ | |
2981 | err = tnc_next(c, &znode, &n); | |
2982 | if (unlikely(err)) | |
2983 | goto out_unlock; | |
2984 | } else { | |
2985 | /* | |
2986 | * The full name of the entry was not given, in which case the | |
2987 | * behavior of this function is a little different and it | |
2988 | * returns current entry, not the next one. | |
2989 | */ | |
2990 | if (!err) { | |
2991 | /* | |
2992 | * However, the given key does not exist in the TNC | |
2993 | * tree and @znode/@n variables contain the closest | |
2994 | * "preceding" element. Switch to the next one. | |
2995 | */ | |
2996 | err = tnc_next(c, &znode, &n); | |
2997 | if (err) | |
2998 | goto out_unlock; | |
2999 | } | |
3000 | } | |
3001 | ||
3002 | zbr = &znode->zbranch[n]; | |
3003 | dent = kmalloc(zbr->len, GFP_NOFS); | |
3004 | if (unlikely(!dent)) { | |
3005 | err = -ENOMEM; | |
3006 | goto out_unlock; | |
3007 | } | |
3008 | ||
3009 | /* | |
3010 | * The above 'tnc_next()' call could lead us to the next inode, check | |
3011 | * this. | |
3012 | */ | |
3013 | dkey = &zbr->key; | |
3014 | if (key_inum(c, dkey) != key_inum(c, key) || | |
3015 | key_type(c, dkey) != type) { | |
3016 | err = -ENOENT; | |
3017 | goto out_free; | |
3018 | } | |
3019 | ||
b91dc981 | 3020 | err = tnc_read_hashed_node(c, zbr, dent); |
1e51764a AB |
3021 | if (unlikely(err)) |
3022 | goto out_free; | |
3023 | ||
3024 | mutex_unlock(&c->tnc_mutex); | |
3025 | return dent; | |
3026 | ||
3027 | out_free: | |
3028 | kfree(dent); | |
3029 | out_unlock: | |
3030 | mutex_unlock(&c->tnc_mutex); | |
3031 | return ERR_PTR(err); | |
3032 | } | |
3033 | ||
3034 | /** | |
3035 | * tnc_destroy_cnext - destroy left-over obsolete znodes from a failed commit. | |
3036 | * @c: UBIFS file-system description object | |
3037 | * | |
3038 | * Destroy left-over obsolete znodes from a failed commit. | |
3039 | */ | |
3040 | static void tnc_destroy_cnext(struct ubifs_info *c) | |
3041 | { | |
3042 | struct ubifs_znode *cnext; | |
3043 | ||
3044 | if (!c->cnext) | |
3045 | return; | |
6eb61d58 | 3046 | ubifs_assert(c, c->cmt_state == COMMIT_BROKEN); |
1e51764a AB |
3047 | cnext = c->cnext; |
3048 | do { | |
3049 | struct ubifs_znode *znode = cnext; | |
3050 | ||
3051 | cnext = cnext->cnext; | |
f42eed7c | 3052 | if (ubifs_zn_obsolete(znode)) |
1e51764a AB |
3053 | kfree(znode); |
3054 | } while (cnext && cnext != c->cnext); | |
3055 | } | |
3056 | ||
3057 | /** | |
3058 | * ubifs_tnc_close - close TNC subsystem and free all related resources. | |
3059 | * @c: UBIFS file-system description object | |
3060 | */ | |
3061 | void ubifs_tnc_close(struct ubifs_info *c) | |
3062 | { | |
1e51764a AB |
3063 | tnc_destroy_cnext(c); |
3064 | if (c->zroot.znode) { | |
380347e9 | 3065 | long n, freed; |
83707237 | 3066 | |
83707237 | 3067 | n = atomic_long_read(&c->clean_zn_cnt); |
6eb61d58 RW |
3068 | freed = ubifs_destroy_tnc_subtree(c, c->zroot.znode); |
3069 | ubifs_assert(c, freed == n); | |
83707237 | 3070 | atomic_long_sub(n, &ubifs_clean_zn_cnt); |
1e51764a AB |
3071 | } |
3072 | kfree(c->gap_lebs); | |
3073 | kfree(c->ilebs); | |
3074 | destroy_old_idx(c); | |
3075 | } | |
3076 | ||
3077 | /** | |
3078 | * left_znode - get the znode to the left. | |
3079 | * @c: UBIFS file-system description object | |
3080 | * @znode: znode | |
3081 | * | |
3082 | * This function returns a pointer to the znode to the left of @znode or NULL if | |
3083 | * there is not one. A negative error code is returned on failure. | |
3084 | */ | |
3085 | static struct ubifs_znode *left_znode(struct ubifs_info *c, | |
3086 | struct ubifs_znode *znode) | |
3087 | { | |
3088 | int level = znode->level; | |
3089 | ||
3090 | while (1) { | |
3091 | int n = znode->iip - 1; | |
3092 | ||
3093 | /* Go up until we can go left */ | |
3094 | znode = znode->parent; | |
3095 | if (!znode) | |
3096 | return NULL; | |
3097 | if (n >= 0) { | |
3098 | /* Now go down the rightmost branch to 'level' */ | |
3099 | znode = get_znode(c, znode, n); | |
3100 | if (IS_ERR(znode)) | |
3101 | return znode; | |
3102 | while (znode->level != level) { | |
3103 | n = znode->child_cnt - 1; | |
3104 | znode = get_znode(c, znode, n); | |
3105 | if (IS_ERR(znode)) | |
3106 | return znode; | |
3107 | } | |
3108 | break; | |
3109 | } | |
3110 | } | |
3111 | return znode; | |
3112 | } | |
3113 | ||
3114 | /** | |
3115 | * right_znode - get the znode to the right. | |
3116 | * @c: UBIFS file-system description object | |
3117 | * @znode: znode | |
3118 | * | |
3119 | * This function returns a pointer to the znode to the right of @znode or NULL | |
3120 | * if there is not one. A negative error code is returned on failure. | |
3121 | */ | |
3122 | static struct ubifs_znode *right_znode(struct ubifs_info *c, | |
3123 | struct ubifs_znode *znode) | |
3124 | { | |
3125 | int level = znode->level; | |
3126 | ||
3127 | while (1) { | |
3128 | int n = znode->iip + 1; | |
3129 | ||
3130 | /* Go up until we can go right */ | |
3131 | znode = znode->parent; | |
3132 | if (!znode) | |
3133 | return NULL; | |
3134 | if (n < znode->child_cnt) { | |
3135 | /* Now go down the leftmost branch to 'level' */ | |
3136 | znode = get_znode(c, znode, n); | |
3137 | if (IS_ERR(znode)) | |
3138 | return znode; | |
3139 | while (znode->level != level) { | |
3140 | znode = get_znode(c, znode, 0); | |
3141 | if (IS_ERR(znode)) | |
3142 | return znode; | |
3143 | } | |
3144 | break; | |
3145 | } | |
3146 | } | |
3147 | return znode; | |
3148 | } | |
3149 | ||
3150 | /** | |
3151 | * lookup_znode - find a particular indexing node from TNC. | |
3152 | * @c: UBIFS file-system description object | |
3153 | * @key: index node key to lookup | |
3154 | * @level: index node level | |
3155 | * @lnum: index node LEB number | |
3156 | * @offs: index node offset | |
3157 | * | |
3158 | * This function searches an indexing node by its first key @key and its | |
3159 | * address @lnum:@offs. It looks up the indexing tree by pulling all indexing | |
ba2f48f7 | 3160 | * nodes it traverses to TNC. This function is called for indexing nodes which |
1e51764a AB |
3161 | * were found on the media by scanning, for example when garbage-collecting or |
3162 | * when doing in-the-gaps commit. This means that the indexing node which is | |
3163 | * looked for does not have to have exactly the same leftmost key @key, because | |
3164 | * the leftmost key may have been changed, in which case TNC will contain a | |
3165 | * dirty znode which still refers the same @lnum:@offs. This function is clever | |
3166 | * enough to recognize such indexing nodes. | |
3167 | * | |
3168 | * Note, if a znode was deleted or changed too much, then this function will | |
3169 | * not find it. For situations like this UBIFS has the old index RB-tree | |
3170 | * (indexed by @lnum:@offs). | |
3171 | * | |
3172 | * This function returns a pointer to the znode found or %NULL if it is not | |
3173 | * found. A negative error code is returned on failure. | |
3174 | */ | |
3175 | static struct ubifs_znode *lookup_znode(struct ubifs_info *c, | |
3176 | union ubifs_key *key, int level, | |
3177 | int lnum, int offs) | |
3178 | { | |
3179 | struct ubifs_znode *znode, *zn; | |
3180 | int n, nn; | |
3181 | ||
6eb61d58 | 3182 | ubifs_assert(c, key_type(c, key) < UBIFS_INVALID_KEY); |
ba2f48f7 | 3183 | |
1e51764a AB |
3184 | /* |
3185 | * The arguments have probably been read off flash, so don't assume | |
3186 | * they are valid. | |
3187 | */ | |
3188 | if (level < 0) | |
3189 | return ERR_PTR(-EINVAL); | |
3190 | ||
3191 | /* Get the root znode */ | |
3192 | znode = c->zroot.znode; | |
3193 | if (!znode) { | |
3194 | znode = ubifs_load_znode(c, &c->zroot, NULL, 0); | |
3195 | if (IS_ERR(znode)) | |
3196 | return znode; | |
3197 | } | |
3198 | /* Check if it is the one we are looking for */ | |
3199 | if (c->zroot.lnum == lnum && c->zroot.offs == offs) | |
3200 | return znode; | |
3201 | /* Descend to the parent level i.e. (level + 1) */ | |
3202 | if (level >= znode->level) | |
3203 | return NULL; | |
3204 | while (1) { | |
3205 | ubifs_search_zbranch(c, znode, key, &n); | |
3206 | if (n < 0) { | |
3207 | /* | |
3208 | * We reached a znode where the leftmost key is greater | |
3209 | * than the key we are searching for. This is the same | |
3210 | * situation as the one described in a huge comment at | |
3211 | * the end of the 'ubifs_lookup_level0()' function. And | |
3212 | * for exactly the same reasons we have to try to look | |
3213 | * left before giving up. | |
3214 | */ | |
3215 | znode = left_znode(c, znode); | |
3216 | if (!znode) | |
3217 | return NULL; | |
3218 | if (IS_ERR(znode)) | |
3219 | return znode; | |
3220 | ubifs_search_zbranch(c, znode, key, &n); | |
6eb61d58 | 3221 | ubifs_assert(c, n >= 0); |
1e51764a AB |
3222 | } |
3223 | if (znode->level == level + 1) | |
3224 | break; | |
3225 | znode = get_znode(c, znode, n); | |
3226 | if (IS_ERR(znode)) | |
3227 | return znode; | |
3228 | } | |
3229 | /* Check if the child is the one we are looking for */ | |
3230 | if (znode->zbranch[n].lnum == lnum && znode->zbranch[n].offs == offs) | |
3231 | return get_znode(c, znode, n); | |
3232 | /* If the key is unique, there is nowhere else to look */ | |
3233 | if (!is_hash_key(c, key)) | |
3234 | return NULL; | |
3235 | /* | |
3236 | * The key is not unique and so may be also in the znodes to either | |
3237 | * side. | |
3238 | */ | |
3239 | zn = znode; | |
3240 | nn = n; | |
3241 | /* Look left */ | |
3242 | while (1) { | |
3243 | /* Move one branch to the left */ | |
3244 | if (n) | |
3245 | n -= 1; | |
3246 | else { | |
3247 | znode = left_znode(c, znode); | |
3248 | if (!znode) | |
3249 | break; | |
3250 | if (IS_ERR(znode)) | |
3251 | return znode; | |
3252 | n = znode->child_cnt - 1; | |
3253 | } | |
3254 | /* Check it */ | |
3255 | if (znode->zbranch[n].lnum == lnum && | |
3256 | znode->zbranch[n].offs == offs) | |
3257 | return get_znode(c, znode, n); | |
3258 | /* Stop if the key is less than the one we are looking for */ | |
3259 | if (keys_cmp(c, &znode->zbranch[n].key, key) < 0) | |
3260 | break; | |
3261 | } | |
3262 | /* Back to the middle */ | |
3263 | znode = zn; | |
3264 | n = nn; | |
3265 | /* Look right */ | |
3266 | while (1) { | |
3267 | /* Move one branch to the right */ | |
3268 | if (++n >= znode->child_cnt) { | |
3269 | znode = right_znode(c, znode); | |
3270 | if (!znode) | |
3271 | break; | |
3272 | if (IS_ERR(znode)) | |
3273 | return znode; | |
3274 | n = 0; | |
3275 | } | |
3276 | /* Check it */ | |
3277 | if (znode->zbranch[n].lnum == lnum && | |
3278 | znode->zbranch[n].offs == offs) | |
3279 | return get_znode(c, znode, n); | |
3280 | /* Stop if the key is greater than the one we are looking for */ | |
3281 | if (keys_cmp(c, &znode->zbranch[n].key, key) > 0) | |
3282 | break; | |
3283 | } | |
3284 | return NULL; | |
3285 | } | |
3286 | ||
3287 | /** | |
3288 | * is_idx_node_in_tnc - determine if an index node is in the TNC. | |
3289 | * @c: UBIFS file-system description object | |
3290 | * @key: key of index node | |
3291 | * @level: index node level | |
3292 | * @lnum: LEB number of index node | |
3293 | * @offs: offset of index node | |
3294 | * | |
3295 | * This function returns %0 if the index node is not referred to in the TNC, %1 | |
3296 | * if the index node is referred to in the TNC and the corresponding znode is | |
3297 | * dirty, %2 if an index node is referred to in the TNC and the corresponding | |
3298 | * znode is clean, and a negative error code in case of failure. | |
3299 | * | |
3300 | * Note, the @key argument has to be the key of the first child. Also note, | |
3301 | * this function relies on the fact that 0:0 is never a valid LEB number and | |
3302 | * offset for a main-area node. | |
3303 | */ | |
3304 | int is_idx_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, int level, | |
3305 | int lnum, int offs) | |
3306 | { | |
3307 | struct ubifs_znode *znode; | |
3308 | ||
3309 | znode = lookup_znode(c, key, level, lnum, offs); | |
3310 | if (!znode) | |
3311 | return 0; | |
3312 | if (IS_ERR(znode)) | |
3313 | return PTR_ERR(znode); | |
3314 | ||
3315 | return ubifs_zn_dirty(znode) ? 1 : 2; | |
3316 | } | |
3317 | ||
3318 | /** | |
3319 | * is_leaf_node_in_tnc - determine if a non-indexing not is in the TNC. | |
3320 | * @c: UBIFS file-system description object | |
3321 | * @key: node key | |
3322 | * @lnum: node LEB number | |
3323 | * @offs: node offset | |
3324 | * | |
3325 | * This function returns %1 if the node is referred to in the TNC, %0 if it is | |
3326 | * not, and a negative error code in case of failure. | |
3327 | * | |
3328 | * Note, this function relies on the fact that 0:0 is never a valid LEB number | |
3329 | * and offset for a main-area node. | |
3330 | */ | |
3331 | static int is_leaf_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, | |
3332 | int lnum, int offs) | |
3333 | { | |
3334 | struct ubifs_zbranch *zbr; | |
3335 | struct ubifs_znode *znode, *zn; | |
3336 | int n, found, err, nn; | |
3337 | const int unique = !is_hash_key(c, key); | |
3338 | ||
3339 | found = ubifs_lookup_level0(c, key, &znode, &n); | |
3340 | if (found < 0) | |
3341 | return found; /* Error code */ | |
3342 | if (!found) | |
3343 | return 0; | |
3344 | zbr = &znode->zbranch[n]; | |
3345 | if (lnum == zbr->lnum && offs == zbr->offs) | |
3346 | return 1; /* Found it */ | |
3347 | if (unique) | |
3348 | return 0; | |
3349 | /* | |
3350 | * Because the key is not unique, we have to look left | |
3351 | * and right as well | |
3352 | */ | |
3353 | zn = znode; | |
3354 | nn = n; | |
3355 | /* Look left */ | |
3356 | while (1) { | |
3357 | err = tnc_prev(c, &znode, &n); | |
3358 | if (err == -ENOENT) | |
3359 | break; | |
3360 | if (err) | |
3361 | return err; | |
3362 | if (keys_cmp(c, key, &znode->zbranch[n].key)) | |
3363 | break; | |
3364 | zbr = &znode->zbranch[n]; | |
3365 | if (lnum == zbr->lnum && offs == zbr->offs) | |
3366 | return 1; /* Found it */ | |
3367 | } | |
3368 | /* Look right */ | |
3369 | znode = zn; | |
3370 | n = nn; | |
3371 | while (1) { | |
3372 | err = tnc_next(c, &znode, &n); | |
3373 | if (err) { | |
3374 | if (err == -ENOENT) | |
3375 | return 0; | |
3376 | return err; | |
3377 | } | |
3378 | if (keys_cmp(c, key, &znode->zbranch[n].key)) | |
3379 | break; | |
3380 | zbr = &znode->zbranch[n]; | |
3381 | if (lnum == zbr->lnum && offs == zbr->offs) | |
3382 | return 1; /* Found it */ | |
3383 | } | |
3384 | return 0; | |
3385 | } | |
3386 | ||
3387 | /** | |
3388 | * ubifs_tnc_has_node - determine whether a node is in the TNC. | |
3389 | * @c: UBIFS file-system description object | |
3390 | * @key: node key | |
3391 | * @level: index node level (if it is an index node) | |
3392 | * @lnum: node LEB number | |
3393 | * @offs: node offset | |
3394 | * @is_idx: non-zero if the node is an index node | |
3395 | * | |
3396 | * This function returns %1 if the node is in the TNC, %0 if it is not, and a | |
3397 | * negative error code in case of failure. For index nodes, @key has to be the | |
3398 | * key of the first child. An index node is considered to be in the TNC only if | |
3399 | * the corresponding znode is clean or has not been loaded. | |
3400 | */ | |
3401 | int ubifs_tnc_has_node(struct ubifs_info *c, union ubifs_key *key, int level, | |
3402 | int lnum, int offs, int is_idx) | |
3403 | { | |
3404 | int err; | |
3405 | ||
3406 | mutex_lock(&c->tnc_mutex); | |
3407 | if (is_idx) { | |
3408 | err = is_idx_node_in_tnc(c, key, level, lnum, offs); | |
3409 | if (err < 0) | |
3410 | goto out_unlock; | |
3411 | if (err == 1) | |
3412 | /* The index node was found but it was dirty */ | |
3413 | err = 0; | |
3414 | else if (err == 2) | |
3415 | /* The index node was found and it was clean */ | |
3416 | err = 1; | |
3417 | else | |
3418 | BUG_ON(err != 0); | |
3419 | } else | |
3420 | err = is_leaf_node_in_tnc(c, key, lnum, offs); | |
3421 | ||
3422 | out_unlock: | |
3423 | mutex_unlock(&c->tnc_mutex); | |
3424 | return err; | |
3425 | } | |
3426 | ||
3427 | /** | |
3428 | * ubifs_dirty_idx_node - dirty an index node. | |
3429 | * @c: UBIFS file-system description object | |
3430 | * @key: index node key | |
3431 | * @level: index node level | |
3432 | * @lnum: index node LEB number | |
3433 | * @offs: index node offset | |
3434 | * | |
3435 | * This function loads and dirties an index node so that it can be garbage | |
3436 | * collected. The @key argument has to be the key of the first child. This | |
3437 | * function relies on the fact that 0:0 is never a valid LEB number and offset | |
3438 | * for a main-area node. Returns %0 on success and a negative error code on | |
3439 | * failure. | |
3440 | */ | |
3441 | int ubifs_dirty_idx_node(struct ubifs_info *c, union ubifs_key *key, int level, | |
3442 | int lnum, int offs) | |
3443 | { | |
3444 | struct ubifs_znode *znode; | |
3445 | int err = 0; | |
3446 | ||
3447 | mutex_lock(&c->tnc_mutex); | |
3448 | znode = lookup_znode(c, key, level, lnum, offs); | |
3449 | if (!znode) | |
3450 | goto out_unlock; | |
3451 | if (IS_ERR(znode)) { | |
3452 | err = PTR_ERR(znode); | |
3453 | goto out_unlock; | |
3454 | } | |
3455 | znode = dirty_cow_bottom_up(c, znode); | |
3456 | if (IS_ERR(znode)) { | |
3457 | err = PTR_ERR(znode); | |
3458 | goto out_unlock; | |
3459 | } | |
3460 | ||
3461 | out_unlock: | |
3462 | mutex_unlock(&c->tnc_mutex); | |
3463 | return err; | |
3464 | } | |
e3c3efc2 | 3465 | |
e3c3efc2 AB |
3466 | /** |
3467 | * dbg_check_inode_size - check if inode size is correct. | |
3468 | * @c: UBIFS file-system description object | |
3469 | * @inum: inode number | |
3470 | * @size: inode size | |
3471 | * | |
3472 | * This function makes sure that the inode size (@size) is correct and it does | |
3473 | * not have any pages beyond @size. Returns zero if the inode is OK, %-EINVAL | |
3474 | * if it has a data page beyond @size, and other negative error code in case of | |
3475 | * other errors. | |
3476 | */ | |
3477 | int dbg_check_inode_size(struct ubifs_info *c, const struct inode *inode, | |
3478 | loff_t size) | |
3479 | { | |
3480 | int err, n; | |
3481 | union ubifs_key from_key, to_key, *key; | |
3482 | struct ubifs_znode *znode; | |
3483 | unsigned int block; | |
3484 | ||
3485 | if (!S_ISREG(inode->i_mode)) | |
3486 | return 0; | |
2b1844a8 | 3487 | if (!dbg_is_chk_gen(c)) |
e3c3efc2 AB |
3488 | return 0; |
3489 | ||
3490 | block = (size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT; | |
3491 | data_key_init(c, &from_key, inode->i_ino, block); | |
3492 | highest_data_key(c, &to_key, inode->i_ino); | |
3493 | ||
3494 | mutex_lock(&c->tnc_mutex); | |
3495 | err = ubifs_lookup_level0(c, &from_key, &znode, &n); | |
3496 | if (err < 0) | |
3497 | goto out_unlock; | |
3498 | ||
3499 | if (err) { | |
e3c3efc2 AB |
3500 | key = &from_key; |
3501 | goto out_dump; | |
3502 | } | |
3503 | ||
3504 | err = tnc_next(c, &znode, &n); | |
3505 | if (err == -ENOENT) { | |
3506 | err = 0; | |
3507 | goto out_unlock; | |
3508 | } | |
3509 | if (err < 0) | |
3510 | goto out_unlock; | |
3511 | ||
6eb61d58 | 3512 | ubifs_assert(c, err == 0); |
e3c3efc2 AB |
3513 | key = &znode->zbranch[n].key; |
3514 | if (!key_in_range(c, key, &from_key, &to_key)) | |
3515 | goto out_unlock; | |
3516 | ||
3517 | out_dump: | |
3518 | block = key_block(c, key); | |
235c362b | 3519 | ubifs_err(c, "inode %lu has size %lld, but there are data at offset %lld", |
515315a1 AB |
3520 | (unsigned long)inode->i_ino, size, |
3521 | ((loff_t)block) << UBIFS_BLOCK_SHIFT); | |
4315fb40 | 3522 | mutex_unlock(&c->tnc_mutex); |
edf6be24 | 3523 | ubifs_dump_inode(c, inode); |
7c46d0ae | 3524 | dump_stack(); |
4315fb40 | 3525 | return -EINVAL; |
e3c3efc2 AB |
3526 | |
3527 | out_unlock: | |
3528 | mutex_unlock(&c->tnc_mutex); | |
3529 | return err; | |
3530 | } |