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9eefe2a2 SR |
1 | /* |
2 | * This file is part of UBIFS. | |
3 | * | |
4 | * Copyright (C) 2006-2008 Nokia Corporation. | |
5 | * | |
ff94bc40 | 6 | * SPDX-License-Identifier: GPL-2.0+ |
9eefe2a2 SR |
7 | * |
8 | * Authors: Adrian Hunter | |
9 | * Artem Bityutskiy (Битюцкий Артём) | |
10 | */ | |
11 | ||
12 | /* | |
13 | * This file implements TNC (Tree Node Cache) which caches indexing nodes of | |
14 | * the UBIFS B-tree. | |
15 | * | |
16 | * At the moment the locking rules of the TNC tree are quite simple and | |
17 | * straightforward. We just have a mutex and lock it when we traverse the | |
18 | * tree. If a znode is not in memory, we read it from flash while still having | |
19 | * the mutex locked. | |
20 | */ | |
21 | ||
ff94bc40 HS |
22 | #ifndef __UBOOT__ |
23 | #include <linux/crc32.h> | |
24 | #include <linux/slab.h> | |
25 | #else | |
26 | #include <linux/compat.h> | |
27 | #include <linux/err.h> | |
28 | #include <linux/stat.h> | |
29 | #endif | |
9eefe2a2 SR |
30 | #include "ubifs.h" |
31 | ||
32 | /* | |
33 | * Returned codes of 'matches_name()' and 'fallible_matches_name()' functions. | |
34 | * @NAME_LESS: name corresponding to the first argument is less than second | |
35 | * @NAME_MATCHES: names match | |
36 | * @NAME_GREATER: name corresponding to the second argument is greater than | |
37 | * first | |
38 | * @NOT_ON_MEDIA: node referred by zbranch does not exist on the media | |
39 | * | |
40 | * These constants were introduce to improve readability. | |
41 | */ | |
42 | enum { | |
43 | NAME_LESS = 0, | |
44 | NAME_MATCHES = 1, | |
45 | NAME_GREATER = 2, | |
46 | NOT_ON_MEDIA = 3, | |
47 | }; | |
48 | ||
49 | /** | |
50 | * insert_old_idx - record an index node obsoleted since the last commit start. | |
51 | * @c: UBIFS file-system description object | |
52 | * @lnum: LEB number of obsoleted index node | |
53 | * @offs: offset of obsoleted index node | |
54 | * | |
55 | * Returns %0 on success, and a negative error code on failure. | |
56 | * | |
57 | * For recovery, there must always be a complete intact version of the index on | |
58 | * flash at all times. That is called the "old index". It is the index as at the | |
59 | * time of the last successful commit. Many of the index nodes in the old index | |
60 | * may be dirty, but they must not be erased until the next successful commit | |
61 | * (at which point that index becomes the old index). | |
62 | * | |
63 | * That means that the garbage collection and the in-the-gaps method of | |
64 | * committing must be able to determine if an index node is in the old index. | |
65 | * Most of the old index nodes can be found by looking up the TNC using the | |
66 | * 'lookup_znode()' function. However, some of the old index nodes may have | |
67 | * been deleted from the current index or may have been changed so much that | |
68 | * they cannot be easily found. In those cases, an entry is added to an RB-tree. | |
69 | * That is what this function does. The RB-tree is ordered by LEB number and | |
70 | * offset because they uniquely identify the old index node. | |
71 | */ | |
72 | static int insert_old_idx(struct ubifs_info *c, int lnum, int offs) | |
73 | { | |
74 | struct ubifs_old_idx *old_idx, *o; | |
75 | struct rb_node **p, *parent = NULL; | |
76 | ||
77 | old_idx = kmalloc(sizeof(struct ubifs_old_idx), GFP_NOFS); | |
78 | if (unlikely(!old_idx)) | |
79 | return -ENOMEM; | |
80 | old_idx->lnum = lnum; | |
81 | old_idx->offs = offs; | |
82 | ||
83 | p = &c->old_idx.rb_node; | |
84 | while (*p) { | |
85 | parent = *p; | |
86 | o = rb_entry(parent, struct ubifs_old_idx, rb); | |
87 | if (lnum < o->lnum) | |
88 | p = &(*p)->rb_left; | |
89 | else if (lnum > o->lnum) | |
90 | p = &(*p)->rb_right; | |
91 | else if (offs < o->offs) | |
92 | p = &(*p)->rb_left; | |
93 | else if (offs > o->offs) | |
94 | p = &(*p)->rb_right; | |
95 | else { | |
0195a7bb | 96 | ubifs_err(c, "old idx added twice!"); |
9eefe2a2 SR |
97 | kfree(old_idx); |
98 | return 0; | |
99 | } | |
100 | } | |
101 | rb_link_node(&old_idx->rb, parent, p); | |
102 | rb_insert_color(&old_idx->rb, &c->old_idx); | |
103 | return 0; | |
104 | } | |
105 | ||
106 | /** | |
107 | * insert_old_idx_znode - record a znode obsoleted since last commit start. | |
108 | * @c: UBIFS file-system description object | |
109 | * @znode: znode of obsoleted index node | |
110 | * | |
111 | * Returns %0 on success, and a negative error code on failure. | |
112 | */ | |
113 | int insert_old_idx_znode(struct ubifs_info *c, struct ubifs_znode *znode) | |
114 | { | |
115 | if (znode->parent) { | |
116 | struct ubifs_zbranch *zbr; | |
117 | ||
118 | zbr = &znode->parent->zbranch[znode->iip]; | |
119 | if (zbr->len) | |
120 | return insert_old_idx(c, zbr->lnum, zbr->offs); | |
121 | } else | |
122 | if (c->zroot.len) | |
123 | return insert_old_idx(c, c->zroot.lnum, | |
124 | c->zroot.offs); | |
125 | return 0; | |
126 | } | |
127 | ||
128 | /** | |
129 | * ins_clr_old_idx_znode - record a znode obsoleted since last commit start. | |
130 | * @c: UBIFS file-system description object | |
131 | * @znode: znode of obsoleted index node | |
132 | * | |
133 | * Returns %0 on success, and a negative error code on failure. | |
134 | */ | |
135 | static int ins_clr_old_idx_znode(struct ubifs_info *c, | |
136 | struct ubifs_znode *znode) | |
137 | { | |
138 | int err; | |
139 | ||
140 | if (znode->parent) { | |
141 | struct ubifs_zbranch *zbr; | |
142 | ||
143 | zbr = &znode->parent->zbranch[znode->iip]; | |
144 | if (zbr->len) { | |
145 | err = insert_old_idx(c, zbr->lnum, zbr->offs); | |
146 | if (err) | |
147 | return err; | |
148 | zbr->lnum = 0; | |
149 | zbr->offs = 0; | |
150 | zbr->len = 0; | |
151 | } | |
152 | } else | |
153 | if (c->zroot.len) { | |
154 | err = insert_old_idx(c, c->zroot.lnum, c->zroot.offs); | |
155 | if (err) | |
156 | return err; | |
157 | c->zroot.lnum = 0; | |
158 | c->zroot.offs = 0; | |
159 | c->zroot.len = 0; | |
160 | } | |
161 | return 0; | |
162 | } | |
163 | ||
164 | /** | |
165 | * destroy_old_idx - destroy the old_idx RB-tree. | |
166 | * @c: UBIFS file-system description object | |
167 | * | |
168 | * During start commit, the old_idx RB-tree is used to avoid overwriting index | |
169 | * nodes that were in the index last commit but have since been deleted. This | |
170 | * is necessary for recovery i.e. the old index must be kept intact until the | |
171 | * new index is successfully written. The old-idx RB-tree is used for the | |
172 | * in-the-gaps method of writing index nodes and is destroyed every commit. | |
173 | */ | |
174 | void destroy_old_idx(struct ubifs_info *c) | |
175 | { | |
ff94bc40 | 176 | struct ubifs_old_idx *old_idx, *n; |
9eefe2a2 | 177 | |
ff94bc40 | 178 | rbtree_postorder_for_each_entry_safe(old_idx, n, &c->old_idx, rb) |
9eefe2a2 | 179 | kfree(old_idx); |
ff94bc40 | 180 | |
9eefe2a2 SR |
181 | c->old_idx = RB_ROOT; |
182 | } | |
183 | ||
184 | /** | |
185 | * copy_znode - copy a dirty znode. | |
186 | * @c: UBIFS file-system description object | |
187 | * @znode: znode to copy | |
188 | * | |
189 | * A dirty znode being committed may not be changed, so it is copied. | |
190 | */ | |
191 | static struct ubifs_znode *copy_znode(struct ubifs_info *c, | |
192 | struct ubifs_znode *znode) | |
193 | { | |
194 | struct ubifs_znode *zn; | |
195 | ||
196 | zn = kmalloc(c->max_znode_sz, GFP_NOFS); | |
197 | if (unlikely(!zn)) | |
198 | return ERR_PTR(-ENOMEM); | |
199 | ||
200 | memcpy(zn, znode, c->max_znode_sz); | |
201 | zn->cnext = NULL; | |
202 | __set_bit(DIRTY_ZNODE, &zn->flags); | |
203 | __clear_bit(COW_ZNODE, &zn->flags); | |
204 | ||
ff94bc40 | 205 | ubifs_assert(!ubifs_zn_obsolete(znode)); |
9eefe2a2 SR |
206 | __set_bit(OBSOLETE_ZNODE, &znode->flags); |
207 | ||
208 | if (znode->level != 0) { | |
209 | int i; | |
210 | const int n = zn->child_cnt; | |
211 | ||
212 | /* The children now have new parent */ | |
213 | for (i = 0; i < n; i++) { | |
214 | struct ubifs_zbranch *zbr = &zn->zbranch[i]; | |
215 | ||
216 | if (zbr->znode) | |
217 | zbr->znode->parent = zn; | |
218 | } | |
219 | } | |
220 | ||
221 | atomic_long_inc(&c->dirty_zn_cnt); | |
222 | return zn; | |
223 | } | |
224 | ||
225 | /** | |
226 | * add_idx_dirt - add dirt due to a dirty znode. | |
227 | * @c: UBIFS file-system description object | |
228 | * @lnum: LEB number of index node | |
229 | * @dirt: size of index node | |
230 | * | |
231 | * This function updates lprops dirty space and the new size of the index. | |
232 | */ | |
233 | static int add_idx_dirt(struct ubifs_info *c, int lnum, int dirt) | |
234 | { | |
235 | c->calc_idx_sz -= ALIGN(dirt, 8); | |
236 | return ubifs_add_dirt(c, lnum, dirt); | |
237 | } | |
238 | ||
239 | /** | |
240 | * dirty_cow_znode - ensure a znode is not being committed. | |
241 | * @c: UBIFS file-system description object | |
242 | * @zbr: branch of znode to check | |
243 | * | |
244 | * Returns dirtied znode on success or negative error code on failure. | |
245 | */ | |
246 | static struct ubifs_znode *dirty_cow_znode(struct ubifs_info *c, | |
247 | struct ubifs_zbranch *zbr) | |
248 | { | |
249 | struct ubifs_znode *znode = zbr->znode; | |
250 | struct ubifs_znode *zn; | |
251 | int err; | |
252 | ||
ff94bc40 | 253 | if (!ubifs_zn_cow(znode)) { |
9eefe2a2 SR |
254 | /* znode is not being committed */ |
255 | if (!test_and_set_bit(DIRTY_ZNODE, &znode->flags)) { | |
256 | atomic_long_inc(&c->dirty_zn_cnt); | |
257 | atomic_long_dec(&c->clean_zn_cnt); | |
258 | atomic_long_dec(&ubifs_clean_zn_cnt); | |
259 | err = add_idx_dirt(c, zbr->lnum, zbr->len); | |
260 | if (unlikely(err)) | |
261 | return ERR_PTR(err); | |
262 | } | |
263 | return znode; | |
264 | } | |
265 | ||
266 | zn = copy_znode(c, znode); | |
267 | if (IS_ERR(zn)) | |
268 | return zn; | |
269 | ||
270 | if (zbr->len) { | |
271 | err = insert_old_idx(c, zbr->lnum, zbr->offs); | |
272 | if (unlikely(err)) | |
273 | return ERR_PTR(err); | |
274 | err = add_idx_dirt(c, zbr->lnum, zbr->len); | |
275 | } else | |
276 | err = 0; | |
277 | ||
278 | zbr->znode = zn; | |
279 | zbr->lnum = 0; | |
280 | zbr->offs = 0; | |
281 | zbr->len = 0; | |
282 | ||
283 | if (unlikely(err)) | |
284 | return ERR_PTR(err); | |
285 | return zn; | |
286 | } | |
287 | ||
288 | /** | |
289 | * lnc_add - add a leaf node to the leaf node cache. | |
290 | * @c: UBIFS file-system description object | |
291 | * @zbr: zbranch of leaf node | |
292 | * @node: leaf node | |
293 | * | |
294 | * Leaf nodes are non-index nodes directory entry nodes or data nodes. The | |
295 | * purpose of the leaf node cache is to save re-reading the same leaf node over | |
296 | * and over again. Most things are cached by VFS, however the file system must | |
297 | * cache directory entries for readdir and for resolving hash collisions. The | |
298 | * present implementation of the leaf node cache is extremely simple, and | |
299 | * allows for error returns that are not used but that may be needed if a more | |
300 | * complex implementation is created. | |
301 | * | |
302 | * Note, this function does not add the @node object to LNC directly, but | |
303 | * allocates a copy of the object and adds the copy to LNC. The reason for this | |
304 | * is that @node has been allocated outside of the TNC subsystem and will be | |
305 | * used with @c->tnc_mutex unlock upon return from the TNC subsystem. But LNC | |
306 | * may be changed at any time, e.g. freed by the shrinker. | |
307 | */ | |
308 | static int lnc_add(struct ubifs_info *c, struct ubifs_zbranch *zbr, | |
309 | const void *node) | |
310 | { | |
311 | int err; | |
312 | void *lnc_node; | |
313 | const struct ubifs_dent_node *dent = node; | |
314 | ||
315 | ubifs_assert(!zbr->leaf); | |
316 | ubifs_assert(zbr->len != 0); | |
317 | ubifs_assert(is_hash_key(c, &zbr->key)); | |
318 | ||
319 | err = ubifs_validate_entry(c, dent); | |
320 | if (err) { | |
ff94bc40 HS |
321 | dump_stack(); |
322 | ubifs_dump_node(c, dent); | |
9eefe2a2 SR |
323 | return err; |
324 | } | |
325 | ||
ff94bc40 | 326 | lnc_node = kmemdup(node, zbr->len, GFP_NOFS); |
9eefe2a2 SR |
327 | if (!lnc_node) |
328 | /* We don't have to have the cache, so no error */ | |
329 | return 0; | |
330 | ||
9eefe2a2 SR |
331 | zbr->leaf = lnc_node; |
332 | return 0; | |
333 | } | |
334 | ||
335 | /** | |
336 | * lnc_add_directly - add a leaf node to the leaf-node-cache. | |
337 | * @c: UBIFS file-system description object | |
338 | * @zbr: zbranch of leaf node | |
339 | * @node: leaf node | |
340 | * | |
341 | * This function is similar to 'lnc_add()', but it does not create a copy of | |
342 | * @node but inserts @node to TNC directly. | |
343 | */ | |
344 | static int lnc_add_directly(struct ubifs_info *c, struct ubifs_zbranch *zbr, | |
345 | void *node) | |
346 | { | |
347 | int err; | |
348 | ||
349 | ubifs_assert(!zbr->leaf); | |
350 | ubifs_assert(zbr->len != 0); | |
351 | ||
352 | err = ubifs_validate_entry(c, node); | |
353 | if (err) { | |
ff94bc40 HS |
354 | dump_stack(); |
355 | ubifs_dump_node(c, node); | |
9eefe2a2 SR |
356 | return err; |
357 | } | |
358 | ||
359 | zbr->leaf = node; | |
360 | return 0; | |
361 | } | |
362 | ||
363 | /** | |
364 | * lnc_free - remove a leaf node from the leaf node cache. | |
365 | * @zbr: zbranch of leaf node | |
366 | * @node: leaf node | |
367 | */ | |
368 | static void lnc_free(struct ubifs_zbranch *zbr) | |
369 | { | |
370 | if (!zbr->leaf) | |
371 | return; | |
372 | kfree(zbr->leaf); | |
373 | zbr->leaf = NULL; | |
374 | } | |
375 | ||
376 | /** | |
377 | * tnc_read_node_nm - read a "hashed" leaf node. | |
378 | * @c: UBIFS file-system description object | |
379 | * @zbr: key and position of the node | |
380 | * @node: node is returned here | |
381 | * | |
382 | * This function reads a "hashed" node defined by @zbr from the leaf node cache | |
383 | * (in it is there) or from the hash media, in which case the node is also | |
384 | * added to LNC. Returns zero in case of success or a negative negative error | |
385 | * code in case of failure. | |
386 | */ | |
387 | static int tnc_read_node_nm(struct ubifs_info *c, struct ubifs_zbranch *zbr, | |
388 | void *node) | |
389 | { | |
390 | int err; | |
391 | ||
392 | ubifs_assert(is_hash_key(c, &zbr->key)); | |
393 | ||
394 | if (zbr->leaf) { | |
395 | /* Read from the leaf node cache */ | |
396 | ubifs_assert(zbr->len != 0); | |
397 | memcpy(node, zbr->leaf, zbr->len); | |
398 | return 0; | |
399 | } | |
400 | ||
401 | err = ubifs_tnc_read_node(c, zbr, node); | |
402 | if (err) | |
403 | return err; | |
404 | ||
405 | /* Add the node to the leaf node cache */ | |
406 | err = lnc_add(c, zbr, node); | |
407 | return err; | |
408 | } | |
409 | ||
410 | /** | |
411 | * try_read_node - read a node if it is a node. | |
412 | * @c: UBIFS file-system description object | |
413 | * @buf: buffer to read to | |
414 | * @type: node type | |
415 | * @len: node length (not aligned) | |
416 | * @lnum: LEB number of node to read | |
417 | * @offs: offset of node to read | |
418 | * | |
419 | * This function tries to read a node of known type and length, checks it and | |
420 | * stores it in @buf. This function returns %1 if a node is present and %0 if | |
421 | * a node is not present. A negative error code is returned for I/O errors. | |
422 | * This function performs that same function as ubifs_read_node except that | |
423 | * it does not require that there is actually a node present and instead | |
424 | * the return code indicates if a node was read. | |
425 | * | |
426 | * Note, this function does not check CRC of data nodes if @c->no_chk_data_crc | |
427 | * is true (it is controlled by corresponding mount option). However, if | |
ff94bc40 HS |
428 | * @c->mounting or @c->remounting_rw is true (we are mounting or re-mounting to |
429 | * R/W mode), @c->no_chk_data_crc is ignored and CRC is checked. This is | |
430 | * because during mounting or re-mounting from R/O mode to R/W mode we may read | |
431 | * journal nodes (when replying the journal or doing the recovery) and the | |
432 | * journal nodes may potentially be corrupted, so checking is required. | |
9eefe2a2 SR |
433 | */ |
434 | static int try_read_node(const struct ubifs_info *c, void *buf, int type, | |
435 | int len, int lnum, int offs) | |
436 | { | |
437 | int err, node_len; | |
438 | struct ubifs_ch *ch = buf; | |
439 | uint32_t crc, node_crc; | |
440 | ||
441 | dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len); | |
442 | ||
ff94bc40 | 443 | err = ubifs_leb_read(c, lnum, buf, offs, len, 1); |
9eefe2a2 | 444 | if (err) { |
0195a7bb | 445 | ubifs_err(c, "cannot read node type %d from LEB %d:%d, error %d", |
9eefe2a2 SR |
446 | type, lnum, offs, err); |
447 | return err; | |
448 | } | |
449 | ||
450 | if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC) | |
451 | return 0; | |
452 | ||
453 | if (ch->node_type != type) | |
454 | return 0; | |
455 | ||
456 | node_len = le32_to_cpu(ch->len); | |
457 | if (node_len != len) | |
458 | return 0; | |
459 | ||
ff94bc40 HS |
460 | if (type == UBIFS_DATA_NODE && c->no_chk_data_crc && !c->mounting && |
461 | !c->remounting_rw) | |
9eefe2a2 SR |
462 | return 1; |
463 | ||
464 | crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8); | |
465 | node_crc = le32_to_cpu(ch->crc); | |
466 | if (crc != node_crc) | |
467 | return 0; | |
468 | ||
469 | return 1; | |
470 | } | |
471 | ||
472 | /** | |
473 | * fallible_read_node - try to read a leaf node. | |
474 | * @c: UBIFS file-system description object | |
475 | * @key: key of node to read | |
476 | * @zbr: position of node | |
477 | * @node: node returned | |
478 | * | |
479 | * This function tries to read a node and returns %1 if the node is read, %0 | |
480 | * if the node is not present, and a negative error code in the case of error. | |
481 | */ | |
482 | static int fallible_read_node(struct ubifs_info *c, const union ubifs_key *key, | |
483 | struct ubifs_zbranch *zbr, void *node) | |
484 | { | |
485 | int ret; | |
486 | ||
ff94bc40 | 487 | dbg_tnck(key, "LEB %d:%d, key ", zbr->lnum, zbr->offs); |
9eefe2a2 SR |
488 | |
489 | ret = try_read_node(c, node, key_type(c, key), zbr->len, zbr->lnum, | |
490 | zbr->offs); | |
491 | if (ret == 1) { | |
492 | union ubifs_key node_key; | |
493 | struct ubifs_dent_node *dent = node; | |
494 | ||
495 | /* All nodes have key in the same place */ | |
496 | key_read(c, &dent->key, &node_key); | |
497 | if (keys_cmp(c, key, &node_key) != 0) | |
498 | ret = 0; | |
499 | } | |
500 | if (ret == 0 && c->replaying) | |
ff94bc40 HS |
501 | dbg_mntk(key, "dangling branch LEB %d:%d len %d, key ", |
502 | zbr->lnum, zbr->offs, zbr->len); | |
9eefe2a2 SR |
503 | return ret; |
504 | } | |
505 | ||
506 | /** | |
507 | * matches_name - determine if a direntry or xattr entry matches a given name. | |
508 | * @c: UBIFS file-system description object | |
509 | * @zbr: zbranch of dent | |
510 | * @nm: name to match | |
511 | * | |
512 | * This function checks if xentry/direntry referred by zbranch @zbr matches name | |
513 | * @nm. Returns %NAME_MATCHES if it does, %NAME_LESS if the name referred by | |
514 | * @zbr is less than @nm, and %NAME_GREATER if it is greater than @nm. In case | |
515 | * of failure, a negative error code is returned. | |
516 | */ | |
517 | static int matches_name(struct ubifs_info *c, struct ubifs_zbranch *zbr, | |
518 | const struct qstr *nm) | |
519 | { | |
520 | struct ubifs_dent_node *dent; | |
521 | int nlen, err; | |
522 | ||
523 | /* If possible, match against the dent in the leaf node cache */ | |
524 | if (!zbr->leaf) { | |
525 | dent = kmalloc(zbr->len, GFP_NOFS); | |
526 | if (!dent) | |
527 | return -ENOMEM; | |
528 | ||
529 | err = ubifs_tnc_read_node(c, zbr, dent); | |
530 | if (err) | |
531 | goto out_free; | |
532 | ||
533 | /* Add the node to the leaf node cache */ | |
534 | err = lnc_add_directly(c, zbr, dent); | |
535 | if (err) | |
536 | goto out_free; | |
537 | } else | |
538 | dent = zbr->leaf; | |
539 | ||
540 | nlen = le16_to_cpu(dent->nlen); | |
541 | err = memcmp(dent->name, nm->name, min_t(int, nlen, nm->len)); | |
542 | if (err == 0) { | |
543 | if (nlen == nm->len) | |
544 | return NAME_MATCHES; | |
545 | else if (nlen < nm->len) | |
546 | return NAME_LESS; | |
547 | else | |
548 | return NAME_GREATER; | |
549 | } else if (err < 0) | |
550 | return NAME_LESS; | |
551 | else | |
552 | return NAME_GREATER; | |
553 | ||
554 | out_free: | |
555 | kfree(dent); | |
556 | return err; | |
557 | } | |
558 | ||
559 | /** | |
560 | * get_znode - get a TNC znode that may not be loaded yet. | |
561 | * @c: UBIFS file-system description object | |
562 | * @znode: parent znode | |
563 | * @n: znode branch slot number | |
564 | * | |
565 | * This function returns the znode or a negative error code. | |
566 | */ | |
567 | static struct ubifs_znode *get_znode(struct ubifs_info *c, | |
568 | struct ubifs_znode *znode, int n) | |
569 | { | |
570 | struct ubifs_zbranch *zbr; | |
571 | ||
572 | zbr = &znode->zbranch[n]; | |
573 | if (zbr->znode) | |
574 | znode = zbr->znode; | |
575 | else | |
576 | znode = ubifs_load_znode(c, zbr, znode, n); | |
577 | return znode; | |
578 | } | |
579 | ||
580 | /** | |
581 | * tnc_next - find next TNC entry. | |
582 | * @c: UBIFS file-system description object | |
583 | * @zn: znode is passed and returned here | |
584 | * @n: znode branch slot number is passed and returned here | |
585 | * | |
586 | * This function returns %0 if the next TNC entry is found, %-ENOENT if there is | |
587 | * no next entry, or a negative error code otherwise. | |
588 | */ | |
589 | static int tnc_next(struct ubifs_info *c, struct ubifs_znode **zn, int *n) | |
590 | { | |
591 | struct ubifs_znode *znode = *zn; | |
592 | int nn = *n; | |
593 | ||
594 | nn += 1; | |
595 | if (nn < znode->child_cnt) { | |
596 | *n = nn; | |
597 | return 0; | |
598 | } | |
599 | while (1) { | |
600 | struct ubifs_znode *zp; | |
601 | ||
602 | zp = znode->parent; | |
603 | if (!zp) | |
604 | return -ENOENT; | |
605 | nn = znode->iip + 1; | |
606 | znode = zp; | |
607 | if (nn < znode->child_cnt) { | |
608 | znode = get_znode(c, znode, nn); | |
609 | if (IS_ERR(znode)) | |
610 | return PTR_ERR(znode); | |
611 | while (znode->level != 0) { | |
612 | znode = get_znode(c, znode, 0); | |
613 | if (IS_ERR(znode)) | |
614 | return PTR_ERR(znode); | |
615 | } | |
616 | nn = 0; | |
617 | break; | |
618 | } | |
619 | } | |
620 | *zn = znode; | |
621 | *n = nn; | |
622 | return 0; | |
623 | } | |
624 | ||
625 | /** | |
626 | * tnc_prev - find previous TNC entry. | |
627 | * @c: UBIFS file-system description object | |
628 | * @zn: znode is returned here | |
629 | * @n: znode branch slot number is passed and returned here | |
630 | * | |
631 | * This function returns %0 if the previous TNC entry is found, %-ENOENT if | |
632 | * there is no next entry, or a negative error code otherwise. | |
633 | */ | |
634 | static int tnc_prev(struct ubifs_info *c, struct ubifs_znode **zn, int *n) | |
635 | { | |
636 | struct ubifs_znode *znode = *zn; | |
637 | int nn = *n; | |
638 | ||
639 | if (nn > 0) { | |
640 | *n = nn - 1; | |
641 | return 0; | |
642 | } | |
643 | while (1) { | |
644 | struct ubifs_znode *zp; | |
645 | ||
646 | zp = znode->parent; | |
647 | if (!zp) | |
648 | return -ENOENT; | |
649 | nn = znode->iip - 1; | |
650 | znode = zp; | |
651 | if (nn >= 0) { | |
652 | znode = get_znode(c, znode, nn); | |
653 | if (IS_ERR(znode)) | |
654 | return PTR_ERR(znode); | |
655 | while (znode->level != 0) { | |
656 | nn = znode->child_cnt - 1; | |
657 | znode = get_znode(c, znode, nn); | |
658 | if (IS_ERR(znode)) | |
659 | return PTR_ERR(znode); | |
660 | } | |
661 | nn = znode->child_cnt - 1; | |
662 | break; | |
663 | } | |
664 | } | |
665 | *zn = znode; | |
666 | *n = nn; | |
667 | return 0; | |
668 | } | |
669 | ||
670 | /** | |
671 | * resolve_collision - resolve a collision. | |
672 | * @c: UBIFS file-system description object | |
673 | * @key: key of a directory or extended attribute entry | |
674 | * @zn: znode is returned here | |
675 | * @n: zbranch number is passed and returned here | |
676 | * @nm: name of the entry | |
677 | * | |
678 | * This function is called for "hashed" keys to make sure that the found key | |
679 | * really corresponds to the looked up node (directory or extended attribute | |
680 | * entry). It returns %1 and sets @zn and @n if the collision is resolved. | |
681 | * %0 is returned if @nm is not found and @zn and @n are set to the previous | |
682 | * entry, i.e. to the entry after which @nm could follow if it were in TNC. | |
683 | * This means that @n may be set to %-1 if the leftmost key in @zn is the | |
684 | * previous one. A negative error code is returned on failures. | |
685 | */ | |
686 | static int resolve_collision(struct ubifs_info *c, const union ubifs_key *key, | |
687 | struct ubifs_znode **zn, int *n, | |
688 | const struct qstr *nm) | |
689 | { | |
690 | int err; | |
691 | ||
692 | err = matches_name(c, &(*zn)->zbranch[*n], nm); | |
693 | if (unlikely(err < 0)) | |
694 | return err; | |
695 | if (err == NAME_MATCHES) | |
696 | return 1; | |
697 | ||
698 | if (err == NAME_GREATER) { | |
699 | /* Look left */ | |
700 | while (1) { | |
701 | err = tnc_prev(c, zn, n); | |
702 | if (err == -ENOENT) { | |
703 | ubifs_assert(*n == 0); | |
704 | *n = -1; | |
705 | return 0; | |
706 | } | |
707 | if (err < 0) | |
708 | return err; | |
709 | if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) { | |
710 | /* | |
711 | * We have found the branch after which we would | |
712 | * like to insert, but inserting in this znode | |
713 | * may still be wrong. Consider the following 3 | |
714 | * znodes, in the case where we are resolving a | |
715 | * collision with Key2. | |
716 | * | |
717 | * znode zp | |
718 | * ---------------------- | |
719 | * level 1 | Key0 | Key1 | | |
720 | * ----------------------- | |
721 | * | | | |
722 | * znode za | | znode zb | |
723 | * ------------ ------------ | |
724 | * level 0 | Key0 | | Key2 | | |
725 | * ------------ ------------ | |
726 | * | |
727 | * The lookup finds Key2 in znode zb. Lets say | |
728 | * there is no match and the name is greater so | |
729 | * we look left. When we find Key0, we end up | |
730 | * here. If we return now, we will insert into | |
731 | * znode za at slot n = 1. But that is invalid | |
732 | * according to the parent's keys. Key2 must | |
733 | * be inserted into znode zb. | |
734 | * | |
735 | * Note, this problem is not relevant for the | |
736 | * case when we go right, because | |
737 | * 'tnc_insert()' would correct the parent key. | |
738 | */ | |
739 | if (*n == (*zn)->child_cnt - 1) { | |
740 | err = tnc_next(c, zn, n); | |
741 | if (err) { | |
742 | /* Should be impossible */ | |
743 | ubifs_assert(0); | |
744 | if (err == -ENOENT) | |
745 | err = -EINVAL; | |
746 | return err; | |
747 | } | |
748 | ubifs_assert(*n == 0); | |
749 | *n = -1; | |
750 | } | |
751 | return 0; | |
752 | } | |
753 | err = matches_name(c, &(*zn)->zbranch[*n], nm); | |
754 | if (err < 0) | |
755 | return err; | |
756 | if (err == NAME_LESS) | |
757 | return 0; | |
758 | if (err == NAME_MATCHES) | |
759 | return 1; | |
760 | ubifs_assert(err == NAME_GREATER); | |
761 | } | |
762 | } else { | |
763 | int nn = *n; | |
764 | struct ubifs_znode *znode = *zn; | |
765 | ||
766 | /* Look right */ | |
767 | while (1) { | |
768 | err = tnc_next(c, &znode, &nn); | |
769 | if (err == -ENOENT) | |
770 | return 0; | |
771 | if (err < 0) | |
772 | return err; | |
773 | if (keys_cmp(c, &znode->zbranch[nn].key, key)) | |
774 | return 0; | |
775 | err = matches_name(c, &znode->zbranch[nn], nm); | |
776 | if (err < 0) | |
777 | return err; | |
778 | if (err == NAME_GREATER) | |
779 | return 0; | |
780 | *zn = znode; | |
781 | *n = nn; | |
782 | if (err == NAME_MATCHES) | |
783 | return 1; | |
784 | ubifs_assert(err == NAME_LESS); | |
785 | } | |
786 | } | |
787 | } | |
788 | ||
789 | /** | |
790 | * fallible_matches_name - determine if a dent matches a given name. | |
791 | * @c: UBIFS file-system description object | |
792 | * @zbr: zbranch of dent | |
793 | * @nm: name to match | |
794 | * | |
795 | * This is a "fallible" version of 'matches_name()' function which does not | |
796 | * panic if the direntry/xentry referred by @zbr does not exist on the media. | |
797 | * | |
798 | * This function checks if xentry/direntry referred by zbranch @zbr matches name | |
799 | * @nm. Returns %NAME_MATCHES it does, %NAME_LESS if the name referred by @zbr | |
800 | * is less than @nm, %NAME_GREATER if it is greater than @nm, and @NOT_ON_MEDIA | |
801 | * if xentry/direntry referred by @zbr does not exist on the media. A negative | |
802 | * error code is returned in case of failure. | |
803 | */ | |
804 | static int fallible_matches_name(struct ubifs_info *c, | |
805 | struct ubifs_zbranch *zbr, | |
806 | const struct qstr *nm) | |
807 | { | |
808 | struct ubifs_dent_node *dent; | |
809 | int nlen, err; | |
810 | ||
811 | /* If possible, match against the dent in the leaf node cache */ | |
812 | if (!zbr->leaf) { | |
813 | dent = kmalloc(zbr->len, GFP_NOFS); | |
814 | if (!dent) | |
815 | return -ENOMEM; | |
816 | ||
817 | err = fallible_read_node(c, &zbr->key, zbr, dent); | |
818 | if (err < 0) | |
819 | goto out_free; | |
820 | if (err == 0) { | |
821 | /* The node was not present */ | |
822 | err = NOT_ON_MEDIA; | |
823 | goto out_free; | |
824 | } | |
825 | ubifs_assert(err == 1); | |
826 | ||
827 | err = lnc_add_directly(c, zbr, dent); | |
828 | if (err) | |
829 | goto out_free; | |
830 | } else | |
831 | dent = zbr->leaf; | |
832 | ||
833 | nlen = le16_to_cpu(dent->nlen); | |
834 | err = memcmp(dent->name, nm->name, min_t(int, nlen, nm->len)); | |
835 | if (err == 0) { | |
836 | if (nlen == nm->len) | |
837 | return NAME_MATCHES; | |
838 | else if (nlen < nm->len) | |
839 | return NAME_LESS; | |
840 | else | |
841 | return NAME_GREATER; | |
842 | } else if (err < 0) | |
843 | return NAME_LESS; | |
844 | else | |
845 | return NAME_GREATER; | |
846 | ||
847 | out_free: | |
848 | kfree(dent); | |
849 | return err; | |
850 | } | |
851 | ||
852 | /** | |
853 | * fallible_resolve_collision - resolve a collision even if nodes are missing. | |
854 | * @c: UBIFS file-system description object | |
855 | * @key: key | |
856 | * @zn: znode is returned here | |
857 | * @n: branch number is passed and returned here | |
858 | * @nm: name of directory entry | |
859 | * @adding: indicates caller is adding a key to the TNC | |
860 | * | |
861 | * This is a "fallible" version of the 'resolve_collision()' function which | |
862 | * does not panic if one of the nodes referred to by TNC does not exist on the | |
863 | * media. This may happen when replaying the journal if a deleted node was | |
864 | * Garbage-collected and the commit was not done. A branch that refers to a node | |
865 | * that is not present is called a dangling branch. The following are the return | |
866 | * codes for this function: | |
867 | * o if @nm was found, %1 is returned and @zn and @n are set to the found | |
868 | * branch; | |
869 | * o if we are @adding and @nm was not found, %0 is returned; | |
870 | * o if we are not @adding and @nm was not found, but a dangling branch was | |
871 | * found, then %1 is returned and @zn and @n are set to the dangling branch; | |
872 | * o a negative error code is returned in case of failure. | |
873 | */ | |
874 | static int fallible_resolve_collision(struct ubifs_info *c, | |
875 | const union ubifs_key *key, | |
876 | struct ubifs_znode **zn, int *n, | |
877 | const struct qstr *nm, int adding) | |
878 | { | |
879 | struct ubifs_znode *o_znode = NULL, *znode = *zn; | |
880 | int uninitialized_var(o_n), err, cmp, unsure = 0, nn = *n; | |
881 | ||
882 | cmp = fallible_matches_name(c, &znode->zbranch[nn], nm); | |
883 | if (unlikely(cmp < 0)) | |
884 | return cmp; | |
885 | if (cmp == NAME_MATCHES) | |
886 | return 1; | |
887 | if (cmp == NOT_ON_MEDIA) { | |
888 | o_znode = znode; | |
889 | o_n = nn; | |
890 | /* | |
891 | * We are unlucky and hit a dangling branch straight away. | |
892 | * Now we do not really know where to go to find the needed | |
893 | * branch - to the left or to the right. Well, let's try left. | |
894 | */ | |
895 | unsure = 1; | |
896 | } else if (!adding) | |
897 | unsure = 1; /* Remove a dangling branch wherever it is */ | |
898 | ||
899 | if (cmp == NAME_GREATER || unsure) { | |
900 | /* Look left */ | |
901 | while (1) { | |
902 | err = tnc_prev(c, zn, n); | |
903 | if (err == -ENOENT) { | |
904 | ubifs_assert(*n == 0); | |
905 | *n = -1; | |
906 | break; | |
907 | } | |
908 | if (err < 0) | |
909 | return err; | |
910 | if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) { | |
911 | /* See comments in 'resolve_collision()' */ | |
912 | if (*n == (*zn)->child_cnt - 1) { | |
913 | err = tnc_next(c, zn, n); | |
914 | if (err) { | |
915 | /* Should be impossible */ | |
916 | ubifs_assert(0); | |
917 | if (err == -ENOENT) | |
918 | err = -EINVAL; | |
919 | return err; | |
920 | } | |
921 | ubifs_assert(*n == 0); | |
922 | *n = -1; | |
923 | } | |
924 | break; | |
925 | } | |
926 | err = fallible_matches_name(c, &(*zn)->zbranch[*n], nm); | |
927 | if (err < 0) | |
928 | return err; | |
929 | if (err == NAME_MATCHES) | |
930 | return 1; | |
931 | if (err == NOT_ON_MEDIA) { | |
932 | o_znode = *zn; | |
933 | o_n = *n; | |
934 | continue; | |
935 | } | |
936 | if (!adding) | |
937 | continue; | |
938 | if (err == NAME_LESS) | |
939 | break; | |
940 | else | |
941 | unsure = 0; | |
942 | } | |
943 | } | |
944 | ||
945 | if (cmp == NAME_LESS || unsure) { | |
946 | /* Look right */ | |
947 | *zn = znode; | |
948 | *n = nn; | |
949 | while (1) { | |
950 | err = tnc_next(c, &znode, &nn); | |
951 | if (err == -ENOENT) | |
952 | break; | |
953 | if (err < 0) | |
954 | return err; | |
955 | if (keys_cmp(c, &znode->zbranch[nn].key, key)) | |
956 | break; | |
957 | err = fallible_matches_name(c, &znode->zbranch[nn], nm); | |
958 | if (err < 0) | |
959 | return err; | |
960 | if (err == NAME_GREATER) | |
961 | break; | |
962 | *zn = znode; | |
963 | *n = nn; | |
964 | if (err == NAME_MATCHES) | |
965 | return 1; | |
966 | if (err == NOT_ON_MEDIA) { | |
967 | o_znode = znode; | |
968 | o_n = nn; | |
969 | } | |
970 | } | |
971 | } | |
972 | ||
973 | /* Never match a dangling branch when adding */ | |
974 | if (adding || !o_znode) | |
975 | return 0; | |
976 | ||
ff94bc40 | 977 | dbg_mntk(key, "dangling match LEB %d:%d len %d key ", |
9eefe2a2 | 978 | o_znode->zbranch[o_n].lnum, o_znode->zbranch[o_n].offs, |
ff94bc40 | 979 | o_znode->zbranch[o_n].len); |
9eefe2a2 SR |
980 | *zn = o_znode; |
981 | *n = o_n; | |
982 | return 1; | |
983 | } | |
984 | ||
985 | /** | |
986 | * matches_position - determine if a zbranch matches a given position. | |
987 | * @zbr: zbranch of dent | |
988 | * @lnum: LEB number of dent to match | |
989 | * @offs: offset of dent to match | |
990 | * | |
991 | * This function returns %1 if @lnum:@offs matches, and %0 otherwise. | |
992 | */ | |
993 | static int matches_position(struct ubifs_zbranch *zbr, int lnum, int offs) | |
994 | { | |
995 | if (zbr->lnum == lnum && zbr->offs == offs) | |
996 | return 1; | |
997 | else | |
998 | return 0; | |
999 | } | |
1000 | ||
1001 | /** | |
1002 | * resolve_collision_directly - resolve a collision directly. | |
1003 | * @c: UBIFS file-system description object | |
1004 | * @key: key of directory entry | |
1005 | * @zn: znode is passed and returned here | |
1006 | * @n: zbranch number is passed and returned here | |
1007 | * @lnum: LEB number of dent node to match | |
1008 | * @offs: offset of dent node to match | |
1009 | * | |
1010 | * This function is used for "hashed" keys to make sure the found directory or | |
1011 | * extended attribute entry node is what was looked for. It is used when the | |
1012 | * flash address of the right node is known (@lnum:@offs) which makes it much | |
1013 | * easier to resolve collisions (no need to read entries and match full | |
1014 | * names). This function returns %1 and sets @zn and @n if the collision is | |
1015 | * resolved, %0 if @lnum:@offs is not found and @zn and @n are set to the | |
1016 | * previous directory entry. Otherwise a negative error code is returned. | |
1017 | */ | |
1018 | static int resolve_collision_directly(struct ubifs_info *c, | |
1019 | const union ubifs_key *key, | |
1020 | struct ubifs_znode **zn, int *n, | |
1021 | int lnum, int offs) | |
1022 | { | |
1023 | struct ubifs_znode *znode; | |
1024 | int nn, err; | |
1025 | ||
1026 | znode = *zn; | |
1027 | nn = *n; | |
1028 | if (matches_position(&znode->zbranch[nn], lnum, offs)) | |
1029 | return 1; | |
1030 | ||
1031 | /* Look left */ | |
1032 | while (1) { | |
1033 | err = tnc_prev(c, &znode, &nn); | |
1034 | if (err == -ENOENT) | |
1035 | break; | |
1036 | if (err < 0) | |
1037 | return err; | |
1038 | if (keys_cmp(c, &znode->zbranch[nn].key, key)) | |
1039 | break; | |
1040 | if (matches_position(&znode->zbranch[nn], lnum, offs)) { | |
1041 | *zn = znode; | |
1042 | *n = nn; | |
1043 | return 1; | |
1044 | } | |
1045 | } | |
1046 | ||
1047 | /* Look right */ | |
1048 | znode = *zn; | |
1049 | nn = *n; | |
1050 | while (1) { | |
1051 | err = tnc_next(c, &znode, &nn); | |
1052 | if (err == -ENOENT) | |
1053 | return 0; | |
1054 | if (err < 0) | |
1055 | return err; | |
1056 | if (keys_cmp(c, &znode->zbranch[nn].key, key)) | |
1057 | return 0; | |
1058 | *zn = znode; | |
1059 | *n = nn; | |
1060 | if (matches_position(&znode->zbranch[nn], lnum, offs)) | |
1061 | return 1; | |
1062 | } | |
1063 | } | |
1064 | ||
1065 | /** | |
1066 | * dirty_cow_bottom_up - dirty a znode and its ancestors. | |
1067 | * @c: UBIFS file-system description object | |
1068 | * @znode: znode to dirty | |
1069 | * | |
1070 | * If we do not have a unique key that resides in a znode, then we cannot | |
1071 | * dirty that znode from the top down (i.e. by using lookup_level0_dirty) | |
1072 | * This function records the path back to the last dirty ancestor, and then | |
1073 | * dirties the znodes on that path. | |
1074 | */ | |
1075 | static struct ubifs_znode *dirty_cow_bottom_up(struct ubifs_info *c, | |
1076 | struct ubifs_znode *znode) | |
1077 | { | |
1078 | struct ubifs_znode *zp; | |
1079 | int *path = c->bottom_up_buf, p = 0; | |
1080 | ||
1081 | ubifs_assert(c->zroot.znode); | |
1082 | ubifs_assert(znode); | |
1083 | if (c->zroot.znode->level > BOTTOM_UP_HEIGHT) { | |
1084 | kfree(c->bottom_up_buf); | |
1085 | c->bottom_up_buf = kmalloc(c->zroot.znode->level * sizeof(int), | |
1086 | GFP_NOFS); | |
1087 | if (!c->bottom_up_buf) | |
1088 | return ERR_PTR(-ENOMEM); | |
1089 | path = c->bottom_up_buf; | |
1090 | } | |
1091 | if (c->zroot.znode->level) { | |
1092 | /* Go up until parent is dirty */ | |
1093 | while (1) { | |
1094 | int n; | |
1095 | ||
1096 | zp = znode->parent; | |
1097 | if (!zp) | |
1098 | break; | |
1099 | n = znode->iip; | |
1100 | ubifs_assert(p < c->zroot.znode->level); | |
1101 | path[p++] = n; | |
1102 | if (!zp->cnext && ubifs_zn_dirty(znode)) | |
1103 | break; | |
1104 | znode = zp; | |
1105 | } | |
1106 | } | |
1107 | ||
1108 | /* Come back down, dirtying as we go */ | |
1109 | while (1) { | |
1110 | struct ubifs_zbranch *zbr; | |
1111 | ||
1112 | zp = znode->parent; | |
1113 | if (zp) { | |
1114 | ubifs_assert(path[p - 1] >= 0); | |
1115 | ubifs_assert(path[p - 1] < zp->child_cnt); | |
1116 | zbr = &zp->zbranch[path[--p]]; | |
1117 | znode = dirty_cow_znode(c, zbr); | |
1118 | } else { | |
1119 | ubifs_assert(znode == c->zroot.znode); | |
1120 | znode = dirty_cow_znode(c, &c->zroot); | |
1121 | } | |
1122 | if (IS_ERR(znode) || !p) | |
1123 | break; | |
1124 | ubifs_assert(path[p - 1] >= 0); | |
1125 | ubifs_assert(path[p - 1] < znode->child_cnt); | |
1126 | znode = znode->zbranch[path[p - 1]].znode; | |
1127 | } | |
1128 | ||
1129 | return znode; | |
1130 | } | |
1131 | ||
1132 | /** | |
1133 | * ubifs_lookup_level0 - search for zero-level znode. | |
1134 | * @c: UBIFS file-system description object | |
1135 | * @key: key to lookup | |
1136 | * @zn: znode is returned here | |
1137 | * @n: znode branch slot number is returned here | |
1138 | * | |
1139 | * This function looks up the TNC tree and search for zero-level znode which | |
1140 | * refers key @key. The found zero-level znode is returned in @zn. There are 3 | |
1141 | * cases: | |
1142 | * o exact match, i.e. the found zero-level znode contains key @key, then %1 | |
1143 | * is returned and slot number of the matched branch is stored in @n; | |
1144 | * o not exact match, which means that zero-level znode does not contain | |
ff94bc40 HS |
1145 | * @key, then %0 is returned and slot number of the closest branch is stored |
1146 | * in @n; | |
9eefe2a2 SR |
1147 | * o @key is so small that it is even less than the lowest key of the |
1148 | * leftmost zero-level node, then %0 is returned and %0 is stored in @n. | |
1149 | * | |
1150 | * Note, when the TNC tree is traversed, some znodes may be absent, then this | |
1151 | * function reads corresponding indexing nodes and inserts them to TNC. In | |
1152 | * case of failure, a negative error code is returned. | |
1153 | */ | |
1154 | int ubifs_lookup_level0(struct ubifs_info *c, const union ubifs_key *key, | |
1155 | struct ubifs_znode **zn, int *n) | |
1156 | { | |
1157 | int err, exact; | |
1158 | struct ubifs_znode *znode; | |
1159 | unsigned long time = get_seconds(); | |
1160 | ||
ff94bc40 HS |
1161 | dbg_tnck(key, "search key "); |
1162 | ubifs_assert(key_type(c, key) < UBIFS_INVALID_KEY); | |
9eefe2a2 SR |
1163 | |
1164 | znode = c->zroot.znode; | |
1165 | if (unlikely(!znode)) { | |
1166 | znode = ubifs_load_znode(c, &c->zroot, NULL, 0); | |
1167 | if (IS_ERR(znode)) | |
1168 | return PTR_ERR(znode); | |
1169 | } | |
1170 | ||
1171 | znode->time = time; | |
1172 | ||
1173 | while (1) { | |
1174 | struct ubifs_zbranch *zbr; | |
1175 | ||
1176 | exact = ubifs_search_zbranch(c, znode, key, n); | |
1177 | ||
1178 | if (znode->level == 0) | |
1179 | break; | |
1180 | ||
1181 | if (*n < 0) | |
1182 | *n = 0; | |
1183 | zbr = &znode->zbranch[*n]; | |
1184 | ||
1185 | if (zbr->znode) { | |
1186 | znode->time = time; | |
1187 | znode = zbr->znode; | |
1188 | continue; | |
1189 | } | |
1190 | ||
1191 | /* znode is not in TNC cache, load it from the media */ | |
1192 | znode = ubifs_load_znode(c, zbr, znode, *n); | |
1193 | if (IS_ERR(znode)) | |
1194 | return PTR_ERR(znode); | |
1195 | } | |
1196 | ||
1197 | *zn = znode; | |
1198 | if (exact || !is_hash_key(c, key) || *n != -1) { | |
1199 | dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n); | |
1200 | return exact; | |
1201 | } | |
1202 | ||
1203 | /* | |
1204 | * Here is a tricky place. We have not found the key and this is a | |
1205 | * "hashed" key, which may collide. The rest of the code deals with | |
1206 | * situations like this: | |
1207 | * | |
1208 | * | 3 | 5 | | |
1209 | * / \ | |
1210 | * | 3 | 5 | | 6 | 7 | (x) | |
1211 | * | |
1212 | * Or more a complex example: | |
1213 | * | |
1214 | * | 1 | 5 | | |
1215 | * / \ | |
1216 | * | 1 | 3 | | 5 | 8 | | |
1217 | * \ / | |
1218 | * | 5 | 5 | | 6 | 7 | (x) | |
1219 | * | |
1220 | * In the examples, if we are looking for key "5", we may reach nodes | |
1221 | * marked with "(x)". In this case what we have do is to look at the | |
1222 | * left and see if there is "5" key there. If there is, we have to | |
1223 | * return it. | |
1224 | * | |
1225 | * Note, this whole situation is possible because we allow to have | |
1226 | * elements which are equivalent to the next key in the parent in the | |
1227 | * children of current znode. For example, this happens if we split a | |
1228 | * znode like this: | 3 | 5 | 5 | 6 | 7 |, which results in something | |
1229 | * like this: | |
1230 | * | 3 | 5 | | |
1231 | * / \ | |
1232 | * | 3 | 5 | | 5 | 6 | 7 | | |
1233 | * ^ | |
1234 | * And this becomes what is at the first "picture" after key "5" marked | |
1235 | * with "^" is removed. What could be done is we could prohibit | |
1236 | * splitting in the middle of the colliding sequence. Also, when | |
1237 | * removing the leftmost key, we would have to correct the key of the | |
1238 | * parent node, which would introduce additional complications. Namely, | |
ff94bc40 | 1239 | * if we changed the leftmost key of the parent znode, the garbage |
9eefe2a2 SR |
1240 | * collector would be unable to find it (GC is doing this when GC'ing |
1241 | * indexing LEBs). Although we already have an additional RB-tree where | |
1242 | * we save such changed znodes (see 'ins_clr_old_idx_znode()') until | |
1243 | * after the commit. But anyway, this does not look easy to implement | |
1244 | * so we did not try this. | |
1245 | */ | |
1246 | err = tnc_prev(c, &znode, n); | |
1247 | if (err == -ENOENT) { | |
1248 | dbg_tnc("found 0, lvl %d, n -1", znode->level); | |
1249 | *n = -1; | |
1250 | return 0; | |
1251 | } | |
1252 | if (unlikely(err < 0)) | |
1253 | return err; | |
1254 | if (keys_cmp(c, key, &znode->zbranch[*n].key)) { | |
1255 | dbg_tnc("found 0, lvl %d, n -1", znode->level); | |
1256 | *n = -1; | |
1257 | return 0; | |
1258 | } | |
1259 | ||
1260 | dbg_tnc("found 1, lvl %d, n %d", znode->level, *n); | |
1261 | *zn = znode; | |
1262 | return 1; | |
1263 | } | |
1264 | ||
1265 | /** | |
1266 | * lookup_level0_dirty - search for zero-level znode dirtying. | |
1267 | * @c: UBIFS file-system description object | |
1268 | * @key: key to lookup | |
1269 | * @zn: znode is returned here | |
1270 | * @n: znode branch slot number is returned here | |
1271 | * | |
1272 | * This function looks up the TNC tree and search for zero-level znode which | |
1273 | * refers key @key. The found zero-level znode is returned in @zn. There are 3 | |
1274 | * cases: | |
1275 | * o exact match, i.e. the found zero-level znode contains key @key, then %1 | |
1276 | * is returned and slot number of the matched branch is stored in @n; | |
1277 | * o not exact match, which means that zero-level znode does not contain @key | |
1278 | * then %0 is returned and slot number of the closed branch is stored in | |
1279 | * @n; | |
1280 | * o @key is so small that it is even less than the lowest key of the | |
1281 | * leftmost zero-level node, then %0 is returned and %-1 is stored in @n. | |
1282 | * | |
1283 | * Additionally all znodes in the path from the root to the located zero-level | |
1284 | * znode are marked as dirty. | |
1285 | * | |
1286 | * Note, when the TNC tree is traversed, some znodes may be absent, then this | |
1287 | * function reads corresponding indexing nodes and inserts them to TNC. In | |
1288 | * case of failure, a negative error code is returned. | |
1289 | */ | |
1290 | static int lookup_level0_dirty(struct ubifs_info *c, const union ubifs_key *key, | |
1291 | struct ubifs_znode **zn, int *n) | |
1292 | { | |
1293 | int err, exact; | |
1294 | struct ubifs_znode *znode; | |
1295 | unsigned long time = get_seconds(); | |
1296 | ||
ff94bc40 | 1297 | dbg_tnck(key, "search and dirty key "); |
9eefe2a2 SR |
1298 | |
1299 | znode = c->zroot.znode; | |
1300 | if (unlikely(!znode)) { | |
1301 | znode = ubifs_load_znode(c, &c->zroot, NULL, 0); | |
1302 | if (IS_ERR(znode)) | |
1303 | return PTR_ERR(znode); | |
1304 | } | |
1305 | ||
1306 | znode = dirty_cow_znode(c, &c->zroot); | |
1307 | if (IS_ERR(znode)) | |
1308 | return PTR_ERR(znode); | |
1309 | ||
1310 | znode->time = time; | |
1311 | ||
1312 | while (1) { | |
1313 | struct ubifs_zbranch *zbr; | |
1314 | ||
1315 | exact = ubifs_search_zbranch(c, znode, key, n); | |
1316 | ||
1317 | if (znode->level == 0) | |
1318 | break; | |
1319 | ||
1320 | if (*n < 0) | |
1321 | *n = 0; | |
1322 | zbr = &znode->zbranch[*n]; | |
1323 | ||
1324 | if (zbr->znode) { | |
1325 | znode->time = time; | |
1326 | znode = dirty_cow_znode(c, zbr); | |
1327 | if (IS_ERR(znode)) | |
1328 | return PTR_ERR(znode); | |
1329 | continue; | |
1330 | } | |
1331 | ||
1332 | /* znode is not in TNC cache, load it from the media */ | |
1333 | znode = ubifs_load_znode(c, zbr, znode, *n); | |
1334 | if (IS_ERR(znode)) | |
1335 | return PTR_ERR(znode); | |
1336 | znode = dirty_cow_znode(c, zbr); | |
1337 | if (IS_ERR(znode)) | |
1338 | return PTR_ERR(znode); | |
1339 | } | |
1340 | ||
1341 | *zn = znode; | |
1342 | if (exact || !is_hash_key(c, key) || *n != -1) { | |
1343 | dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n); | |
1344 | return exact; | |
1345 | } | |
1346 | ||
1347 | /* | |
1348 | * See huge comment at 'lookup_level0_dirty()' what is the rest of the | |
1349 | * code. | |
1350 | */ | |
1351 | err = tnc_prev(c, &znode, n); | |
1352 | if (err == -ENOENT) { | |
1353 | *n = -1; | |
1354 | dbg_tnc("found 0, lvl %d, n -1", znode->level); | |
1355 | return 0; | |
1356 | } | |
1357 | if (unlikely(err < 0)) | |
1358 | return err; | |
1359 | if (keys_cmp(c, key, &znode->zbranch[*n].key)) { | |
1360 | *n = -1; | |
1361 | dbg_tnc("found 0, lvl %d, n -1", znode->level); | |
1362 | return 0; | |
1363 | } | |
1364 | ||
1365 | if (znode->cnext || !ubifs_zn_dirty(znode)) { | |
1366 | znode = dirty_cow_bottom_up(c, znode); | |
1367 | if (IS_ERR(znode)) | |
1368 | return PTR_ERR(znode); | |
1369 | } | |
1370 | ||
1371 | dbg_tnc("found 1, lvl %d, n %d", znode->level, *n); | |
1372 | *zn = znode; | |
1373 | return 1; | |
1374 | } | |
1375 | ||
1376 | /** | |
1377 | * maybe_leb_gced - determine if a LEB may have been garbage collected. | |
1378 | * @c: UBIFS file-system description object | |
1379 | * @lnum: LEB number | |
1380 | * @gc_seq1: garbage collection sequence number | |
1381 | * | |
1382 | * This function determines if @lnum may have been garbage collected since | |
1383 | * sequence number @gc_seq1. If it may have been then %1 is returned, otherwise | |
1384 | * %0 is returned. | |
1385 | */ | |
1386 | static int maybe_leb_gced(struct ubifs_info *c, int lnum, int gc_seq1) | |
1387 | { | |
ff94bc40 HS |
1388 | #ifndef __UBOOT__ |
1389 | int gc_seq2, gced_lnum; | |
1390 | ||
1391 | gced_lnum = c->gced_lnum; | |
1392 | smp_rmb(); | |
1393 | gc_seq2 = c->gc_seq; | |
1394 | /* Same seq means no GC */ | |
1395 | if (gc_seq1 == gc_seq2) | |
1396 | return 0; | |
1397 | /* Different by more than 1 means we don't know */ | |
1398 | if (gc_seq1 + 1 != gc_seq2) | |
1399 | return 1; | |
9eefe2a2 | 1400 | /* |
ff94bc40 HS |
1401 | * We have seen the sequence number has increased by 1. Now we need to |
1402 | * be sure we read the right LEB number, so read it again. | |
9eefe2a2 | 1403 | */ |
ff94bc40 HS |
1404 | smp_rmb(); |
1405 | if (gced_lnum != c->gced_lnum) | |
1406 | return 1; | |
1407 | /* Finally we can check lnum */ | |
1408 | if (gced_lnum == lnum) | |
1409 | return 1; | |
1410 | #else | |
1411 | /* No garbage collection in the read-only U-Boot implementation */ | |
1412 | #endif | |
9eefe2a2 SR |
1413 | return 0; |
1414 | } | |
1415 | ||
1416 | /** | |
1417 | * ubifs_tnc_locate - look up a file-system node and return it and its location. | |
1418 | * @c: UBIFS file-system description object | |
1419 | * @key: node key to lookup | |
1420 | * @node: the node is returned here | |
1421 | * @lnum: LEB number is returned here | |
1422 | * @offs: offset is returned here | |
1423 | * | |
ff94bc40 | 1424 | * This function looks up and reads node with key @key. The caller has to make |
9eefe2a2 SR |
1425 | * sure the @node buffer is large enough to fit the node. Returns zero in case |
1426 | * of success, %-ENOENT if the node was not found, and a negative error code in | |
1427 | * case of failure. The node location can be returned in @lnum and @offs. | |
1428 | */ | |
1429 | int ubifs_tnc_locate(struct ubifs_info *c, const union ubifs_key *key, | |
1430 | void *node, int *lnum, int *offs) | |
1431 | { | |
1432 | int found, n, err, safely = 0, gc_seq1; | |
1433 | struct ubifs_znode *znode; | |
1434 | struct ubifs_zbranch zbr, *zt; | |
1435 | ||
1436 | again: | |
1437 | mutex_lock(&c->tnc_mutex); | |
1438 | found = ubifs_lookup_level0(c, key, &znode, &n); | |
1439 | if (!found) { | |
1440 | err = -ENOENT; | |
1441 | goto out; | |
1442 | } else if (found < 0) { | |
1443 | err = found; | |
1444 | goto out; | |
1445 | } | |
1446 | zt = &znode->zbranch[n]; | |
1447 | if (lnum) { | |
1448 | *lnum = zt->lnum; | |
1449 | *offs = zt->offs; | |
1450 | } | |
1451 | if (is_hash_key(c, key)) { | |
1452 | /* | |
1453 | * In this case the leaf node cache gets used, so we pass the | |
1454 | * address of the zbranch and keep the mutex locked | |
1455 | */ | |
1456 | err = tnc_read_node_nm(c, zt, node); | |
1457 | goto out; | |
1458 | } | |
1459 | if (safely) { | |
1460 | err = ubifs_tnc_read_node(c, zt, node); | |
1461 | goto out; | |
1462 | } | |
1463 | /* Drop the TNC mutex prematurely and race with garbage collection */ | |
1464 | zbr = znode->zbranch[n]; | |
1465 | gc_seq1 = c->gc_seq; | |
1466 | mutex_unlock(&c->tnc_mutex); | |
1467 | ||
ff94bc40 HS |
1468 | if (ubifs_get_wbuf(c, zbr.lnum)) { |
1469 | /* We do not GC journal heads */ | |
1470 | err = ubifs_tnc_read_node(c, &zbr, node); | |
1471 | return err; | |
1472 | } | |
1473 | ||
9eefe2a2 SR |
1474 | err = fallible_read_node(c, key, &zbr, node); |
1475 | if (err <= 0 || maybe_leb_gced(c, zbr.lnum, gc_seq1)) { | |
1476 | /* | |
1477 | * The node may have been GC'ed out from under us so try again | |
1478 | * while keeping the TNC mutex locked. | |
1479 | */ | |
1480 | safely = 1; | |
1481 | goto again; | |
1482 | } | |
1483 | return 0; | |
1484 | ||
1485 | out: | |
1486 | mutex_unlock(&c->tnc_mutex); | |
1487 | return err; | |
1488 | } | |
1489 | ||
1490 | /** | |
1491 | * ubifs_tnc_get_bu_keys - lookup keys for bulk-read. | |
1492 | * @c: UBIFS file-system description object | |
1493 | * @bu: bulk-read parameters and results | |
1494 | * | |
1495 | * Lookup consecutive data node keys for the same inode that reside | |
1496 | * consecutively in the same LEB. This function returns zero in case of success | |
1497 | * and a negative error code in case of failure. | |
1498 | * | |
1499 | * Note, if the bulk-read buffer length (@bu->buf_len) is known, this function | |
1500 | * makes sure bulk-read nodes fit the buffer. Otherwise, this function prepares | |
1501 | * maximum possible amount of nodes for bulk-read. | |
1502 | */ | |
1503 | int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu) | |
1504 | { | |
1505 | int n, err = 0, lnum = -1, uninitialized_var(offs); | |
1506 | int uninitialized_var(len); | |
1507 | unsigned int block = key_block(c, &bu->key); | |
1508 | struct ubifs_znode *znode; | |
1509 | ||
1510 | bu->cnt = 0; | |
1511 | bu->blk_cnt = 0; | |
1512 | bu->eof = 0; | |
1513 | ||
1514 | mutex_lock(&c->tnc_mutex); | |
1515 | /* Find first key */ | |
1516 | err = ubifs_lookup_level0(c, &bu->key, &znode, &n); | |
1517 | if (err < 0) | |
1518 | goto out; | |
1519 | if (err) { | |
1520 | /* Key found */ | |
1521 | len = znode->zbranch[n].len; | |
1522 | /* The buffer must be big enough for at least 1 node */ | |
1523 | if (len > bu->buf_len) { | |
1524 | err = -EINVAL; | |
1525 | goto out; | |
1526 | } | |
1527 | /* Add this key */ | |
1528 | bu->zbranch[bu->cnt++] = znode->zbranch[n]; | |
1529 | bu->blk_cnt += 1; | |
1530 | lnum = znode->zbranch[n].lnum; | |
1531 | offs = ALIGN(znode->zbranch[n].offs + len, 8); | |
1532 | } | |
1533 | while (1) { | |
1534 | struct ubifs_zbranch *zbr; | |
1535 | union ubifs_key *key; | |
1536 | unsigned int next_block; | |
1537 | ||
1538 | /* Find next key */ | |
1539 | err = tnc_next(c, &znode, &n); | |
1540 | if (err) | |
1541 | goto out; | |
1542 | zbr = &znode->zbranch[n]; | |
1543 | key = &zbr->key; | |
1544 | /* See if there is another data key for this file */ | |
1545 | if (key_inum(c, key) != key_inum(c, &bu->key) || | |
1546 | key_type(c, key) != UBIFS_DATA_KEY) { | |
1547 | err = -ENOENT; | |
1548 | goto out; | |
1549 | } | |
1550 | if (lnum < 0) { | |
1551 | /* First key found */ | |
1552 | lnum = zbr->lnum; | |
1553 | offs = ALIGN(zbr->offs + zbr->len, 8); | |
1554 | len = zbr->len; | |
1555 | if (len > bu->buf_len) { | |
1556 | err = -EINVAL; | |
1557 | goto out; | |
1558 | } | |
1559 | } else { | |
1560 | /* | |
1561 | * The data nodes must be in consecutive positions in | |
1562 | * the same LEB. | |
1563 | */ | |
1564 | if (zbr->lnum != lnum || zbr->offs != offs) | |
1565 | goto out; | |
1566 | offs += ALIGN(zbr->len, 8); | |
1567 | len = ALIGN(len, 8) + zbr->len; | |
1568 | /* Must not exceed buffer length */ | |
1569 | if (len > bu->buf_len) | |
1570 | goto out; | |
1571 | } | |
1572 | /* Allow for holes */ | |
1573 | next_block = key_block(c, key); | |
1574 | bu->blk_cnt += (next_block - block - 1); | |
1575 | if (bu->blk_cnt >= UBIFS_MAX_BULK_READ) | |
1576 | goto out; | |
1577 | block = next_block; | |
1578 | /* Add this key */ | |
1579 | bu->zbranch[bu->cnt++] = *zbr; | |
1580 | bu->blk_cnt += 1; | |
1581 | /* See if we have room for more */ | |
1582 | if (bu->cnt >= UBIFS_MAX_BULK_READ) | |
1583 | goto out; | |
1584 | if (bu->blk_cnt >= UBIFS_MAX_BULK_READ) | |
1585 | goto out; | |
1586 | } | |
1587 | out: | |
1588 | if (err == -ENOENT) { | |
1589 | bu->eof = 1; | |
1590 | err = 0; | |
1591 | } | |
1592 | bu->gc_seq = c->gc_seq; | |
1593 | mutex_unlock(&c->tnc_mutex); | |
1594 | if (err) | |
1595 | return err; | |
1596 | /* | |
1597 | * An enormous hole could cause bulk-read to encompass too many | |
1598 | * page cache pages, so limit the number here. | |
1599 | */ | |
1600 | if (bu->blk_cnt > UBIFS_MAX_BULK_READ) | |
1601 | bu->blk_cnt = UBIFS_MAX_BULK_READ; | |
1602 | /* | |
1603 | * Ensure that bulk-read covers a whole number of page cache | |
1604 | * pages. | |
1605 | */ | |
1606 | if (UBIFS_BLOCKS_PER_PAGE == 1 || | |
1607 | !(bu->blk_cnt & (UBIFS_BLOCKS_PER_PAGE - 1))) | |
1608 | return 0; | |
1609 | if (bu->eof) { | |
1610 | /* At the end of file we can round up */ | |
1611 | bu->blk_cnt += UBIFS_BLOCKS_PER_PAGE - 1; | |
1612 | return 0; | |
1613 | } | |
1614 | /* Exclude data nodes that do not make up a whole page cache page */ | |
1615 | block = key_block(c, &bu->key) + bu->blk_cnt; | |
1616 | block &= ~(UBIFS_BLOCKS_PER_PAGE - 1); | |
1617 | while (bu->cnt) { | |
1618 | if (key_block(c, &bu->zbranch[bu->cnt - 1].key) < block) | |
1619 | break; | |
1620 | bu->cnt -= 1; | |
1621 | } | |
1622 | return 0; | |
1623 | } | |
1624 | ||
ff94bc40 HS |
1625 | /** |
1626 | * read_wbuf - bulk-read from a LEB with a wbuf. | |
1627 | * @wbuf: wbuf that may overlap the read | |
1628 | * @buf: buffer into which to read | |
1629 | * @len: read length | |
1630 | * @lnum: LEB number from which to read | |
1631 | * @offs: offset from which to read | |
1632 | * | |
1633 | * This functions returns %0 on success or a negative error code on failure. | |
1634 | */ | |
1635 | static int read_wbuf(struct ubifs_wbuf *wbuf, void *buf, int len, int lnum, | |
1636 | int offs) | |
1637 | { | |
1638 | const struct ubifs_info *c = wbuf->c; | |
1639 | int rlen, overlap; | |
1640 | ||
1641 | dbg_io("LEB %d:%d, length %d", lnum, offs, len); | |
1642 | ubifs_assert(wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0); | |
1643 | ubifs_assert(!(offs & 7) && offs < c->leb_size); | |
1644 | ubifs_assert(offs + len <= c->leb_size); | |
1645 | ||
1646 | spin_lock(&wbuf->lock); | |
1647 | overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs); | |
1648 | if (!overlap) { | |
1649 | /* We may safely unlock the write-buffer and read the data */ | |
1650 | spin_unlock(&wbuf->lock); | |
1651 | return ubifs_leb_read(c, lnum, buf, offs, len, 0); | |
1652 | } | |
1653 | ||
1654 | /* Don't read under wbuf */ | |
1655 | rlen = wbuf->offs - offs; | |
1656 | if (rlen < 0) | |
1657 | rlen = 0; | |
1658 | ||
1659 | /* Copy the rest from the write-buffer */ | |
1660 | memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen); | |
1661 | spin_unlock(&wbuf->lock); | |
1662 | ||
1663 | if (rlen > 0) | |
1664 | /* Read everything that goes before write-buffer */ | |
1665 | return ubifs_leb_read(c, lnum, buf, offs, rlen, 0); | |
1666 | ||
1667 | return 0; | |
1668 | } | |
1669 | ||
9eefe2a2 SR |
1670 | /** |
1671 | * validate_data_node - validate data nodes for bulk-read. | |
1672 | * @c: UBIFS file-system description object | |
1673 | * @buf: buffer containing data node to validate | |
1674 | * @zbr: zbranch of data node to validate | |
1675 | * | |
1676 | * This functions returns %0 on success or a negative error code on failure. | |
1677 | */ | |
1678 | static int validate_data_node(struct ubifs_info *c, void *buf, | |
1679 | struct ubifs_zbranch *zbr) | |
1680 | { | |
1681 | union ubifs_key key1; | |
1682 | struct ubifs_ch *ch = buf; | |
1683 | int err, len; | |
1684 | ||
1685 | if (ch->node_type != UBIFS_DATA_NODE) { | |
0195a7bb | 1686 | ubifs_err(c, "bad node type (%d but expected %d)", |
9eefe2a2 SR |
1687 | ch->node_type, UBIFS_DATA_NODE); |
1688 | goto out_err; | |
1689 | } | |
1690 | ||
1691 | err = ubifs_check_node(c, buf, zbr->lnum, zbr->offs, 0, 0); | |
1692 | if (err) { | |
0195a7bb | 1693 | ubifs_err(c, "expected node type %d", UBIFS_DATA_NODE); |
9eefe2a2 SR |
1694 | goto out; |
1695 | } | |
1696 | ||
1697 | len = le32_to_cpu(ch->len); | |
1698 | if (len != zbr->len) { | |
0195a7bb | 1699 | ubifs_err(c, "bad node length %d, expected %d", len, zbr->len); |
9eefe2a2 SR |
1700 | goto out_err; |
1701 | } | |
1702 | ||
1703 | /* Make sure the key of the read node is correct */ | |
1704 | key_read(c, buf + UBIFS_KEY_OFFSET, &key1); | |
1705 | if (!keys_eq(c, &zbr->key, &key1)) { | |
0195a7bb | 1706 | ubifs_err(c, "bad key in node at LEB %d:%d", |
9eefe2a2 | 1707 | zbr->lnum, zbr->offs); |
ff94bc40 HS |
1708 | dbg_tnck(&zbr->key, "looked for key "); |
1709 | dbg_tnck(&key1, "found node's key "); | |
9eefe2a2 SR |
1710 | goto out_err; |
1711 | } | |
1712 | ||
1713 | return 0; | |
1714 | ||
1715 | out_err: | |
1716 | err = -EINVAL; | |
1717 | out: | |
0195a7bb | 1718 | ubifs_err(c, "bad node at LEB %d:%d", zbr->lnum, zbr->offs); |
ff94bc40 HS |
1719 | ubifs_dump_node(c, buf); |
1720 | dump_stack(); | |
9eefe2a2 SR |
1721 | return err; |
1722 | } | |
1723 | ||
1724 | /** | |
1725 | * ubifs_tnc_bulk_read - read a number of data nodes in one go. | |
1726 | * @c: UBIFS file-system description object | |
1727 | * @bu: bulk-read parameters and results | |
1728 | * | |
1729 | * This functions reads and validates the data nodes that were identified by the | |
1730 | * 'ubifs_tnc_get_bu_keys()' function. This functions returns %0 on success, | |
1731 | * -EAGAIN to indicate a race with GC, or another negative error code on | |
1732 | * failure. | |
1733 | */ | |
1734 | int ubifs_tnc_bulk_read(struct ubifs_info *c, struct bu_info *bu) | |
1735 | { | |
1736 | int lnum = bu->zbranch[0].lnum, offs = bu->zbranch[0].offs, len, err, i; | |
ff94bc40 | 1737 | struct ubifs_wbuf *wbuf; |
9eefe2a2 SR |
1738 | void *buf; |
1739 | ||
1740 | len = bu->zbranch[bu->cnt - 1].offs; | |
1741 | len += bu->zbranch[bu->cnt - 1].len - offs; | |
1742 | if (len > bu->buf_len) { | |
0195a7bb | 1743 | ubifs_err(c, "buffer too small %d vs %d", bu->buf_len, len); |
9eefe2a2 SR |
1744 | return -EINVAL; |
1745 | } | |
1746 | ||
1747 | /* Do the read */ | |
ff94bc40 HS |
1748 | wbuf = ubifs_get_wbuf(c, lnum); |
1749 | if (wbuf) | |
1750 | err = read_wbuf(wbuf, bu->buf, len, lnum, offs); | |
1751 | else | |
1752 | err = ubifs_leb_read(c, lnum, bu->buf, offs, len, 0); | |
9eefe2a2 SR |
1753 | |
1754 | /* Check for a race with GC */ | |
1755 | if (maybe_leb_gced(c, lnum, bu->gc_seq)) | |
1756 | return -EAGAIN; | |
1757 | ||
1758 | if (err && err != -EBADMSG) { | |
0195a7bb | 1759 | ubifs_err(c, "failed to read from LEB %d:%d, error %d", |
9eefe2a2 | 1760 | lnum, offs, err); |
ff94bc40 HS |
1761 | dump_stack(); |
1762 | dbg_tnck(&bu->key, "key "); | |
9eefe2a2 SR |
1763 | return err; |
1764 | } | |
1765 | ||
1766 | /* Validate the nodes read */ | |
1767 | buf = bu->buf; | |
1768 | for (i = 0; i < bu->cnt; i++) { | |
1769 | err = validate_data_node(c, buf, &bu->zbranch[i]); | |
1770 | if (err) | |
1771 | return err; | |
1772 | buf = buf + ALIGN(bu->zbranch[i].len, 8); | |
1773 | } | |
1774 | ||
1775 | return 0; | |
1776 | } | |
1777 | ||
1778 | /** | |
1779 | * do_lookup_nm- look up a "hashed" node. | |
1780 | * @c: UBIFS file-system description object | |
1781 | * @key: node key to lookup | |
1782 | * @node: the node is returned here | |
1783 | * @nm: node name | |
1784 | * | |
1785 | * This function look up and reads a node which contains name hash in the key. | |
1786 | * Since the hash may have collisions, there may be many nodes with the same | |
1787 | * key, so we have to sequentially look to all of them until the needed one is | |
1788 | * found. This function returns zero in case of success, %-ENOENT if the node | |
1789 | * was not found, and a negative error code in case of failure. | |
1790 | */ | |
1791 | static int do_lookup_nm(struct ubifs_info *c, const union ubifs_key *key, | |
1792 | void *node, const struct qstr *nm) | |
1793 | { | |
1794 | int found, n, err; | |
1795 | struct ubifs_znode *znode; | |
1796 | ||
ff94bc40 | 1797 | dbg_tnck(key, "name '%.*s' key ", nm->len, nm->name); |
9eefe2a2 SR |
1798 | mutex_lock(&c->tnc_mutex); |
1799 | found = ubifs_lookup_level0(c, key, &znode, &n); | |
1800 | if (!found) { | |
1801 | err = -ENOENT; | |
1802 | goto out_unlock; | |
1803 | } else if (found < 0) { | |
1804 | err = found; | |
1805 | goto out_unlock; | |
1806 | } | |
1807 | ||
1808 | ubifs_assert(n >= 0); | |
1809 | ||
1810 | err = resolve_collision(c, key, &znode, &n, nm); | |
1811 | dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n); | |
1812 | if (unlikely(err < 0)) | |
1813 | goto out_unlock; | |
1814 | if (err == 0) { | |
1815 | err = -ENOENT; | |
1816 | goto out_unlock; | |
1817 | } | |
1818 | ||
1819 | err = tnc_read_node_nm(c, &znode->zbranch[n], node); | |
1820 | ||
1821 | out_unlock: | |
1822 | mutex_unlock(&c->tnc_mutex); | |
1823 | return err; | |
1824 | } | |
1825 | ||
1826 | /** | |
1827 | * ubifs_tnc_lookup_nm - look up a "hashed" node. | |
1828 | * @c: UBIFS file-system description object | |
1829 | * @key: node key to lookup | |
1830 | * @node: the node is returned here | |
1831 | * @nm: node name | |
1832 | * | |
1833 | * This function look up and reads a node which contains name hash in the key. | |
1834 | * Since the hash may have collisions, there may be many nodes with the same | |
1835 | * key, so we have to sequentially look to all of them until the needed one is | |
1836 | * found. This function returns zero in case of success, %-ENOENT if the node | |
1837 | * was not found, and a negative error code in case of failure. | |
1838 | */ | |
1839 | int ubifs_tnc_lookup_nm(struct ubifs_info *c, const union ubifs_key *key, | |
1840 | void *node, const struct qstr *nm) | |
1841 | { | |
1842 | int err, len; | |
1843 | const struct ubifs_dent_node *dent = node; | |
1844 | ||
1845 | /* | |
1846 | * We assume that in most of the cases there are no name collisions and | |
1847 | * 'ubifs_tnc_lookup()' returns us the right direntry. | |
1848 | */ | |
1849 | err = ubifs_tnc_lookup(c, key, node); | |
1850 | if (err) | |
1851 | return err; | |
1852 | ||
1853 | len = le16_to_cpu(dent->nlen); | |
1854 | if (nm->len == len && !memcmp(dent->name, nm->name, len)) | |
1855 | return 0; | |
1856 | ||
1857 | /* | |
1858 | * Unluckily, there are hash collisions and we have to iterate over | |
1859 | * them look at each direntry with colliding name hash sequentially. | |
1860 | */ | |
1861 | return do_lookup_nm(c, key, node, nm); | |
1862 | } | |
1863 | ||
1864 | /** | |
1865 | * correct_parent_keys - correct parent znodes' keys. | |
1866 | * @c: UBIFS file-system description object | |
1867 | * @znode: znode to correct parent znodes for | |
1868 | * | |
1869 | * This is a helper function for 'tnc_insert()'. When the key of the leftmost | |
1870 | * zbranch changes, keys of parent znodes have to be corrected. This helper | |
1871 | * function is called in such situations and corrects the keys if needed. | |
1872 | */ | |
1873 | static void correct_parent_keys(const struct ubifs_info *c, | |
1874 | struct ubifs_znode *znode) | |
1875 | { | |
1876 | union ubifs_key *key, *key1; | |
1877 | ||
1878 | ubifs_assert(znode->parent); | |
1879 | ubifs_assert(znode->iip == 0); | |
1880 | ||
1881 | key = &znode->zbranch[0].key; | |
1882 | key1 = &znode->parent->zbranch[0].key; | |
1883 | ||
1884 | while (keys_cmp(c, key, key1) < 0) { | |
1885 | key_copy(c, key, key1); | |
1886 | znode = znode->parent; | |
1887 | znode->alt = 1; | |
1888 | if (!znode->parent || znode->iip) | |
1889 | break; | |
1890 | key1 = &znode->parent->zbranch[0].key; | |
1891 | } | |
1892 | } | |
1893 | ||
1894 | /** | |
1895 | * insert_zbranch - insert a zbranch into a znode. | |
1896 | * @znode: znode into which to insert | |
1897 | * @zbr: zbranch to insert | |
1898 | * @n: slot number to insert to | |
1899 | * | |
1900 | * This is a helper function for 'tnc_insert()'. UBIFS does not allow "gaps" in | |
1901 | * znode's array of zbranches and keeps zbranches consolidated, so when a new | |
1902 | * zbranch has to be inserted to the @znode->zbranches[]' array at the @n-th | |
1903 | * slot, zbranches starting from @n have to be moved right. | |
1904 | */ | |
1905 | static void insert_zbranch(struct ubifs_znode *znode, | |
1906 | const struct ubifs_zbranch *zbr, int n) | |
1907 | { | |
1908 | int i; | |
1909 | ||
1910 | ubifs_assert(ubifs_zn_dirty(znode)); | |
1911 | ||
1912 | if (znode->level) { | |
1913 | for (i = znode->child_cnt; i > n; i--) { | |
1914 | znode->zbranch[i] = znode->zbranch[i - 1]; | |
1915 | if (znode->zbranch[i].znode) | |
1916 | znode->zbranch[i].znode->iip = i; | |
1917 | } | |
1918 | if (zbr->znode) | |
1919 | zbr->znode->iip = n; | |
1920 | } else | |
1921 | for (i = znode->child_cnt; i > n; i--) | |
1922 | znode->zbranch[i] = znode->zbranch[i - 1]; | |
1923 | ||
1924 | znode->zbranch[n] = *zbr; | |
1925 | znode->child_cnt += 1; | |
1926 | ||
1927 | /* | |
1928 | * After inserting at slot zero, the lower bound of the key range of | |
1929 | * this znode may have changed. If this znode is subsequently split | |
1930 | * then the upper bound of the key range may change, and furthermore | |
1931 | * it could change to be lower than the original lower bound. If that | |
1932 | * happens, then it will no longer be possible to find this znode in the | |
1933 | * TNC using the key from the index node on flash. That is bad because | |
1934 | * if it is not found, we will assume it is obsolete and may overwrite | |
1935 | * it. Then if there is an unclean unmount, we will start using the | |
1936 | * old index which will be broken. | |
1937 | * | |
1938 | * So we first mark znodes that have insertions at slot zero, and then | |
1939 | * if they are split we add their lnum/offs to the old_idx tree. | |
1940 | */ | |
1941 | if (n == 0) | |
1942 | znode->alt = 1; | |
1943 | } | |
1944 | ||
1945 | /** | |
1946 | * tnc_insert - insert a node into TNC. | |
1947 | * @c: UBIFS file-system description object | |
1948 | * @znode: znode to insert into | |
1949 | * @zbr: branch to insert | |
1950 | * @n: slot number to insert new zbranch to | |
1951 | * | |
1952 | * This function inserts a new node described by @zbr into znode @znode. If | |
1953 | * znode does not have a free slot for new zbranch, it is split. Parent znodes | |
1954 | * are splat as well if needed. Returns zero in case of success or a negative | |
1955 | * error code in case of failure. | |
1956 | */ | |
1957 | static int tnc_insert(struct ubifs_info *c, struct ubifs_znode *znode, | |
1958 | struct ubifs_zbranch *zbr, int n) | |
1959 | { | |
1960 | struct ubifs_znode *zn, *zi, *zp; | |
1961 | int i, keep, move, appending = 0; | |
1962 | union ubifs_key *key = &zbr->key, *key1; | |
1963 | ||
1964 | ubifs_assert(n >= 0 && n <= c->fanout); | |
1965 | ||
1966 | /* Implement naive insert for now */ | |
1967 | again: | |
1968 | zp = znode->parent; | |
1969 | if (znode->child_cnt < c->fanout) { | |
1970 | ubifs_assert(n != c->fanout); | |
ff94bc40 | 1971 | dbg_tnck(key, "inserted at %d level %d, key ", n, znode->level); |
9eefe2a2 SR |
1972 | |
1973 | insert_zbranch(znode, zbr, n); | |
1974 | ||
1975 | /* Ensure parent's key is correct */ | |
1976 | if (n == 0 && zp && znode->iip == 0) | |
1977 | correct_parent_keys(c, znode); | |
1978 | ||
1979 | return 0; | |
1980 | } | |
1981 | ||
1982 | /* | |
1983 | * Unfortunately, @znode does not have more empty slots and we have to | |
1984 | * split it. | |
1985 | */ | |
ff94bc40 | 1986 | dbg_tnck(key, "splitting level %d, key ", znode->level); |
9eefe2a2 SR |
1987 | |
1988 | if (znode->alt) | |
1989 | /* | |
1990 | * We can no longer be sure of finding this znode by key, so we | |
1991 | * record it in the old_idx tree. | |
1992 | */ | |
1993 | ins_clr_old_idx_znode(c, znode); | |
1994 | ||
1995 | zn = kzalloc(c->max_znode_sz, GFP_NOFS); | |
1996 | if (!zn) | |
1997 | return -ENOMEM; | |
1998 | zn->parent = zp; | |
1999 | zn->level = znode->level; | |
2000 | ||
2001 | /* Decide where to split */ | |
2002 | if (znode->level == 0 && key_type(c, key) == UBIFS_DATA_KEY) { | |
2003 | /* Try not to split consecutive data keys */ | |
2004 | if (n == c->fanout) { | |
2005 | key1 = &znode->zbranch[n - 1].key; | |
2006 | if (key_inum(c, key1) == key_inum(c, key) && | |
2007 | key_type(c, key1) == UBIFS_DATA_KEY) | |
2008 | appending = 1; | |
2009 | } else | |
2010 | goto check_split; | |
2011 | } else if (appending && n != c->fanout) { | |
2012 | /* Try not to split consecutive data keys */ | |
2013 | appending = 0; | |
2014 | check_split: | |
2015 | if (n >= (c->fanout + 1) / 2) { | |
2016 | key1 = &znode->zbranch[0].key; | |
2017 | if (key_inum(c, key1) == key_inum(c, key) && | |
2018 | key_type(c, key1) == UBIFS_DATA_KEY) { | |
2019 | key1 = &znode->zbranch[n].key; | |
2020 | if (key_inum(c, key1) != key_inum(c, key) || | |
2021 | key_type(c, key1) != UBIFS_DATA_KEY) { | |
2022 | keep = n; | |
2023 | move = c->fanout - keep; | |
2024 | zi = znode; | |
2025 | goto do_split; | |
2026 | } | |
2027 | } | |
2028 | } | |
2029 | } | |
2030 | ||
2031 | if (appending) { | |
2032 | keep = c->fanout; | |
2033 | move = 0; | |
2034 | } else { | |
2035 | keep = (c->fanout + 1) / 2; | |
2036 | move = c->fanout - keep; | |
2037 | } | |
2038 | ||
2039 | /* | |
2040 | * Although we don't at present, we could look at the neighbors and see | |
2041 | * if we can move some zbranches there. | |
2042 | */ | |
2043 | ||
2044 | if (n < keep) { | |
2045 | /* Insert into existing znode */ | |
2046 | zi = znode; | |
2047 | move += 1; | |
2048 | keep -= 1; | |
2049 | } else { | |
2050 | /* Insert into new znode */ | |
2051 | zi = zn; | |
2052 | n -= keep; | |
2053 | /* Re-parent */ | |
2054 | if (zn->level != 0) | |
2055 | zbr->znode->parent = zn; | |
2056 | } | |
2057 | ||
2058 | do_split: | |
2059 | ||
2060 | __set_bit(DIRTY_ZNODE, &zn->flags); | |
2061 | atomic_long_inc(&c->dirty_zn_cnt); | |
2062 | ||
2063 | zn->child_cnt = move; | |
2064 | znode->child_cnt = keep; | |
2065 | ||
2066 | dbg_tnc("moving %d, keeping %d", move, keep); | |
2067 | ||
2068 | /* Move zbranch */ | |
2069 | for (i = 0; i < move; i++) { | |
2070 | zn->zbranch[i] = znode->zbranch[keep + i]; | |
2071 | /* Re-parent */ | |
2072 | if (zn->level != 0) | |
2073 | if (zn->zbranch[i].znode) { | |
2074 | zn->zbranch[i].znode->parent = zn; | |
2075 | zn->zbranch[i].znode->iip = i; | |
2076 | } | |
2077 | } | |
2078 | ||
2079 | /* Insert new key and branch */ | |
ff94bc40 | 2080 | dbg_tnck(key, "inserting at %d level %d, key ", n, zn->level); |
9eefe2a2 SR |
2081 | |
2082 | insert_zbranch(zi, zbr, n); | |
2083 | ||
2084 | /* Insert new znode (produced by spitting) into the parent */ | |
2085 | if (zp) { | |
2086 | if (n == 0 && zi == znode && znode->iip == 0) | |
2087 | correct_parent_keys(c, znode); | |
2088 | ||
2089 | /* Locate insertion point */ | |
2090 | n = znode->iip + 1; | |
2091 | ||
2092 | /* Tail recursion */ | |
2093 | zbr->key = zn->zbranch[0].key; | |
2094 | zbr->znode = zn; | |
2095 | zbr->lnum = 0; | |
2096 | zbr->offs = 0; | |
2097 | zbr->len = 0; | |
2098 | znode = zp; | |
2099 | ||
2100 | goto again; | |
2101 | } | |
2102 | ||
2103 | /* We have to split root znode */ | |
2104 | dbg_tnc("creating new zroot at level %d", znode->level + 1); | |
2105 | ||
2106 | zi = kzalloc(c->max_znode_sz, GFP_NOFS); | |
2107 | if (!zi) | |
2108 | return -ENOMEM; | |
2109 | ||
2110 | zi->child_cnt = 2; | |
2111 | zi->level = znode->level + 1; | |
2112 | ||
2113 | __set_bit(DIRTY_ZNODE, &zi->flags); | |
2114 | atomic_long_inc(&c->dirty_zn_cnt); | |
2115 | ||
2116 | zi->zbranch[0].key = znode->zbranch[0].key; | |
2117 | zi->zbranch[0].znode = znode; | |
2118 | zi->zbranch[0].lnum = c->zroot.lnum; | |
2119 | zi->zbranch[0].offs = c->zroot.offs; | |
2120 | zi->zbranch[0].len = c->zroot.len; | |
2121 | zi->zbranch[1].key = zn->zbranch[0].key; | |
2122 | zi->zbranch[1].znode = zn; | |
2123 | ||
2124 | c->zroot.lnum = 0; | |
2125 | c->zroot.offs = 0; | |
2126 | c->zroot.len = 0; | |
2127 | c->zroot.znode = zi; | |
2128 | ||
2129 | zn->parent = zi; | |
2130 | zn->iip = 1; | |
2131 | znode->parent = zi; | |
2132 | znode->iip = 0; | |
2133 | ||
2134 | return 0; | |
2135 | } | |
2136 | ||
2137 | /** | |
2138 | * ubifs_tnc_add - add a node to TNC. | |
2139 | * @c: UBIFS file-system description object | |
2140 | * @key: key to add | |
2141 | * @lnum: LEB number of node | |
2142 | * @offs: node offset | |
2143 | * @len: node length | |
2144 | * | |
2145 | * This function adds a node with key @key to TNC. The node may be new or it may | |
2146 | * obsolete some existing one. Returns %0 on success or negative error code on | |
2147 | * failure. | |
2148 | */ | |
2149 | int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum, | |
2150 | int offs, int len) | |
2151 | { | |
2152 | int found, n, err = 0; | |
2153 | struct ubifs_znode *znode; | |
2154 | ||
2155 | mutex_lock(&c->tnc_mutex); | |
ff94bc40 | 2156 | dbg_tnck(key, "%d:%d, len %d, key ", lnum, offs, len); |
9eefe2a2 SR |
2157 | found = lookup_level0_dirty(c, key, &znode, &n); |
2158 | if (!found) { | |
2159 | struct ubifs_zbranch zbr; | |
2160 | ||
2161 | zbr.znode = NULL; | |
2162 | zbr.lnum = lnum; | |
2163 | zbr.offs = offs; | |
2164 | zbr.len = len; | |
2165 | key_copy(c, key, &zbr.key); | |
2166 | err = tnc_insert(c, znode, &zbr, n + 1); | |
2167 | } else if (found == 1) { | |
2168 | struct ubifs_zbranch *zbr = &znode->zbranch[n]; | |
2169 | ||
2170 | lnc_free(zbr); | |
2171 | err = ubifs_add_dirt(c, zbr->lnum, zbr->len); | |
2172 | zbr->lnum = lnum; | |
2173 | zbr->offs = offs; | |
2174 | zbr->len = len; | |
2175 | } else | |
2176 | err = found; | |
2177 | if (!err) | |
2178 | err = dbg_check_tnc(c, 0); | |
2179 | mutex_unlock(&c->tnc_mutex); | |
2180 | ||
2181 | return err; | |
2182 | } | |
2183 | ||
2184 | /** | |
2185 | * ubifs_tnc_replace - replace a node in the TNC only if the old node is found. | |
2186 | * @c: UBIFS file-system description object | |
2187 | * @key: key to add | |
2188 | * @old_lnum: LEB number of old node | |
2189 | * @old_offs: old node offset | |
2190 | * @lnum: LEB number of node | |
2191 | * @offs: node offset | |
2192 | * @len: node length | |
2193 | * | |
2194 | * This function replaces a node with key @key in the TNC only if the old node | |
2195 | * is found. This function is called by garbage collection when node are moved. | |
2196 | * Returns %0 on success or negative error code on failure. | |
2197 | */ | |
2198 | int ubifs_tnc_replace(struct ubifs_info *c, const union ubifs_key *key, | |
2199 | int old_lnum, int old_offs, int lnum, int offs, int len) | |
2200 | { | |
2201 | int found, n, err = 0; | |
2202 | struct ubifs_znode *znode; | |
2203 | ||
2204 | mutex_lock(&c->tnc_mutex); | |
ff94bc40 HS |
2205 | dbg_tnck(key, "old LEB %d:%d, new LEB %d:%d, len %d, key ", old_lnum, |
2206 | old_offs, lnum, offs, len); | |
9eefe2a2 SR |
2207 | found = lookup_level0_dirty(c, key, &znode, &n); |
2208 | if (found < 0) { | |
2209 | err = found; | |
2210 | goto out_unlock; | |
2211 | } | |
2212 | ||
2213 | if (found == 1) { | |
2214 | struct ubifs_zbranch *zbr = &znode->zbranch[n]; | |
2215 | ||
2216 | found = 0; | |
2217 | if (zbr->lnum == old_lnum && zbr->offs == old_offs) { | |
2218 | lnc_free(zbr); | |
2219 | err = ubifs_add_dirt(c, zbr->lnum, zbr->len); | |
2220 | if (err) | |
2221 | goto out_unlock; | |
2222 | zbr->lnum = lnum; | |
2223 | zbr->offs = offs; | |
2224 | zbr->len = len; | |
2225 | found = 1; | |
2226 | } else if (is_hash_key(c, key)) { | |
2227 | found = resolve_collision_directly(c, key, &znode, &n, | |
2228 | old_lnum, old_offs); | |
2229 | dbg_tnc("rc returned %d, znode %p, n %d, LEB %d:%d", | |
2230 | found, znode, n, old_lnum, old_offs); | |
2231 | if (found < 0) { | |
2232 | err = found; | |
2233 | goto out_unlock; | |
2234 | } | |
2235 | ||
2236 | if (found) { | |
2237 | /* Ensure the znode is dirtied */ | |
2238 | if (znode->cnext || !ubifs_zn_dirty(znode)) { | |
2239 | znode = dirty_cow_bottom_up(c, znode); | |
2240 | if (IS_ERR(znode)) { | |
2241 | err = PTR_ERR(znode); | |
2242 | goto out_unlock; | |
2243 | } | |
2244 | } | |
2245 | zbr = &znode->zbranch[n]; | |
2246 | lnc_free(zbr); | |
2247 | err = ubifs_add_dirt(c, zbr->lnum, | |
2248 | zbr->len); | |
2249 | if (err) | |
2250 | goto out_unlock; | |
2251 | zbr->lnum = lnum; | |
2252 | zbr->offs = offs; | |
2253 | zbr->len = len; | |
2254 | } | |
2255 | } | |
2256 | } | |
2257 | ||
2258 | if (!found) | |
2259 | err = ubifs_add_dirt(c, lnum, len); | |
2260 | ||
2261 | if (!err) | |
2262 | err = dbg_check_tnc(c, 0); | |
2263 | ||
2264 | out_unlock: | |
2265 | mutex_unlock(&c->tnc_mutex); | |
2266 | return err; | |
2267 | } | |
2268 | ||
2269 | /** | |
2270 | * ubifs_tnc_add_nm - add a "hashed" node to TNC. | |
2271 | * @c: UBIFS file-system description object | |
2272 | * @key: key to add | |
2273 | * @lnum: LEB number of node | |
2274 | * @offs: node offset | |
2275 | * @len: node length | |
2276 | * @nm: node name | |
2277 | * | |
2278 | * This is the same as 'ubifs_tnc_add()' but it should be used with keys which | |
2279 | * may have collisions, like directory entry keys. | |
2280 | */ | |
2281 | int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key, | |
2282 | int lnum, int offs, int len, const struct qstr *nm) | |
2283 | { | |
2284 | int found, n, err = 0; | |
2285 | struct ubifs_znode *znode; | |
2286 | ||
2287 | mutex_lock(&c->tnc_mutex); | |
ff94bc40 HS |
2288 | dbg_tnck(key, "LEB %d:%d, name '%.*s', key ", |
2289 | lnum, offs, nm->len, nm->name); | |
9eefe2a2 SR |
2290 | found = lookup_level0_dirty(c, key, &znode, &n); |
2291 | if (found < 0) { | |
2292 | err = found; | |
2293 | goto out_unlock; | |
2294 | } | |
2295 | ||
2296 | if (found == 1) { | |
2297 | if (c->replaying) | |
2298 | found = fallible_resolve_collision(c, key, &znode, &n, | |
2299 | nm, 1); | |
2300 | else | |
2301 | found = resolve_collision(c, key, &znode, &n, nm); | |
2302 | dbg_tnc("rc returned %d, znode %p, n %d", found, znode, n); | |
2303 | if (found < 0) { | |
2304 | err = found; | |
2305 | goto out_unlock; | |
2306 | } | |
2307 | ||
2308 | /* Ensure the znode is dirtied */ | |
2309 | if (znode->cnext || !ubifs_zn_dirty(znode)) { | |
2310 | znode = dirty_cow_bottom_up(c, znode); | |
2311 | if (IS_ERR(znode)) { | |
2312 | err = PTR_ERR(znode); | |
2313 | goto out_unlock; | |
2314 | } | |
2315 | } | |
2316 | ||
2317 | if (found == 1) { | |
2318 | struct ubifs_zbranch *zbr = &znode->zbranch[n]; | |
2319 | ||
2320 | lnc_free(zbr); | |
2321 | err = ubifs_add_dirt(c, zbr->lnum, zbr->len); | |
2322 | zbr->lnum = lnum; | |
2323 | zbr->offs = offs; | |
2324 | zbr->len = len; | |
2325 | goto out_unlock; | |
2326 | } | |
2327 | } | |
2328 | ||
2329 | if (!found) { | |
2330 | struct ubifs_zbranch zbr; | |
2331 | ||
2332 | zbr.znode = NULL; | |
2333 | zbr.lnum = lnum; | |
2334 | zbr.offs = offs; | |
2335 | zbr.len = len; | |
2336 | key_copy(c, key, &zbr.key); | |
2337 | err = tnc_insert(c, znode, &zbr, n + 1); | |
2338 | if (err) | |
2339 | goto out_unlock; | |
2340 | if (c->replaying) { | |
2341 | /* | |
2342 | * We did not find it in the index so there may be a | |
2343 | * dangling branch still in the index. So we remove it | |
2344 | * by passing 'ubifs_tnc_remove_nm()' the same key but | |
2345 | * an unmatchable name. | |
2346 | */ | |
ff94bc40 | 2347 | struct qstr noname = { .name = "" }; |
9eefe2a2 SR |
2348 | |
2349 | err = dbg_check_tnc(c, 0); | |
2350 | mutex_unlock(&c->tnc_mutex); | |
2351 | if (err) | |
2352 | return err; | |
2353 | return ubifs_tnc_remove_nm(c, key, &noname); | |
2354 | } | |
2355 | } | |
2356 | ||
2357 | out_unlock: | |
2358 | if (!err) | |
2359 | err = dbg_check_tnc(c, 0); | |
2360 | mutex_unlock(&c->tnc_mutex); | |
2361 | return err; | |
2362 | } | |
2363 | ||
2364 | /** | |
2365 | * tnc_delete - delete a znode form TNC. | |
2366 | * @c: UBIFS file-system description object | |
2367 | * @znode: znode to delete from | |
2368 | * @n: zbranch slot number to delete | |
2369 | * | |
2370 | * This function deletes a leaf node from @n-th slot of @znode. Returns zero in | |
2371 | * case of success and a negative error code in case of failure. | |
2372 | */ | |
2373 | static int tnc_delete(struct ubifs_info *c, struct ubifs_znode *znode, int n) | |
2374 | { | |
2375 | struct ubifs_zbranch *zbr; | |
2376 | struct ubifs_znode *zp; | |
2377 | int i, err; | |
2378 | ||
2379 | /* Delete without merge for now */ | |
2380 | ubifs_assert(znode->level == 0); | |
2381 | ubifs_assert(n >= 0 && n < c->fanout); | |
ff94bc40 | 2382 | dbg_tnck(&znode->zbranch[n].key, "deleting key "); |
9eefe2a2 SR |
2383 | |
2384 | zbr = &znode->zbranch[n]; | |
2385 | lnc_free(zbr); | |
2386 | ||
2387 | err = ubifs_add_dirt(c, zbr->lnum, zbr->len); | |
2388 | if (err) { | |
ff94bc40 | 2389 | ubifs_dump_znode(c, znode); |
9eefe2a2 SR |
2390 | return err; |
2391 | } | |
2392 | ||
2393 | /* We do not "gap" zbranch slots */ | |
2394 | for (i = n; i < znode->child_cnt - 1; i++) | |
2395 | znode->zbranch[i] = znode->zbranch[i + 1]; | |
2396 | znode->child_cnt -= 1; | |
2397 | ||
2398 | if (znode->child_cnt > 0) | |
2399 | return 0; | |
2400 | ||
2401 | /* | |
2402 | * This was the last zbranch, we have to delete this znode from the | |
2403 | * parent. | |
2404 | */ | |
2405 | ||
2406 | do { | |
ff94bc40 | 2407 | ubifs_assert(!ubifs_zn_obsolete(znode)); |
9eefe2a2 SR |
2408 | ubifs_assert(ubifs_zn_dirty(znode)); |
2409 | ||
2410 | zp = znode->parent; | |
2411 | n = znode->iip; | |
2412 | ||
2413 | atomic_long_dec(&c->dirty_zn_cnt); | |
2414 | ||
2415 | err = insert_old_idx_znode(c, znode); | |
2416 | if (err) | |
2417 | return err; | |
2418 | ||
2419 | if (znode->cnext) { | |
2420 | __set_bit(OBSOLETE_ZNODE, &znode->flags); | |
2421 | atomic_long_inc(&c->clean_zn_cnt); | |
2422 | atomic_long_inc(&ubifs_clean_zn_cnt); | |
2423 | } else | |
2424 | kfree(znode); | |
2425 | znode = zp; | |
2426 | } while (znode->child_cnt == 1); /* while removing last child */ | |
2427 | ||
2428 | /* Remove from znode, entry n - 1 */ | |
2429 | znode->child_cnt -= 1; | |
2430 | ubifs_assert(znode->level != 0); | |
2431 | for (i = n; i < znode->child_cnt; i++) { | |
2432 | znode->zbranch[i] = znode->zbranch[i + 1]; | |
2433 | if (znode->zbranch[i].znode) | |
2434 | znode->zbranch[i].znode->iip = i; | |
2435 | } | |
2436 | ||
2437 | /* | |
2438 | * If this is the root and it has only 1 child then | |
2439 | * collapse the tree. | |
2440 | */ | |
2441 | if (!znode->parent) { | |
2442 | while (znode->child_cnt == 1 && znode->level != 0) { | |
2443 | zp = znode; | |
2444 | zbr = &znode->zbranch[0]; | |
2445 | znode = get_znode(c, znode, 0); | |
2446 | if (IS_ERR(znode)) | |
2447 | return PTR_ERR(znode); | |
2448 | znode = dirty_cow_znode(c, zbr); | |
2449 | if (IS_ERR(znode)) | |
2450 | return PTR_ERR(znode); | |
2451 | znode->parent = NULL; | |
2452 | znode->iip = 0; | |
2453 | if (c->zroot.len) { | |
2454 | err = insert_old_idx(c, c->zroot.lnum, | |
2455 | c->zroot.offs); | |
2456 | if (err) | |
2457 | return err; | |
2458 | } | |
2459 | c->zroot.lnum = zbr->lnum; | |
2460 | c->zroot.offs = zbr->offs; | |
2461 | c->zroot.len = zbr->len; | |
2462 | c->zroot.znode = znode; | |
ff94bc40 HS |
2463 | ubifs_assert(!ubifs_zn_obsolete(zp)); |
2464 | ubifs_assert(ubifs_zn_dirty(zp)); | |
9eefe2a2 SR |
2465 | atomic_long_dec(&c->dirty_zn_cnt); |
2466 | ||
2467 | if (zp->cnext) { | |
2468 | __set_bit(OBSOLETE_ZNODE, &zp->flags); | |
2469 | atomic_long_inc(&c->clean_zn_cnt); | |
2470 | atomic_long_inc(&ubifs_clean_zn_cnt); | |
2471 | } else | |
2472 | kfree(zp); | |
2473 | } | |
2474 | } | |
2475 | ||
2476 | return 0; | |
2477 | } | |
2478 | ||
2479 | /** | |
2480 | * ubifs_tnc_remove - remove an index entry of a node. | |
2481 | * @c: UBIFS file-system description object | |
2482 | * @key: key of node | |
2483 | * | |
2484 | * Returns %0 on success or negative error code on failure. | |
2485 | */ | |
2486 | int ubifs_tnc_remove(struct ubifs_info *c, const union ubifs_key *key) | |
2487 | { | |
2488 | int found, n, err = 0; | |
2489 | struct ubifs_znode *znode; | |
2490 | ||
2491 | mutex_lock(&c->tnc_mutex); | |
ff94bc40 | 2492 | dbg_tnck(key, "key "); |
9eefe2a2 SR |
2493 | found = lookup_level0_dirty(c, key, &znode, &n); |
2494 | if (found < 0) { | |
2495 | err = found; | |
2496 | goto out_unlock; | |
2497 | } | |
2498 | if (found == 1) | |
2499 | err = tnc_delete(c, znode, n); | |
2500 | if (!err) | |
2501 | err = dbg_check_tnc(c, 0); | |
2502 | ||
2503 | out_unlock: | |
2504 | mutex_unlock(&c->tnc_mutex); | |
2505 | return err; | |
2506 | } | |
2507 | ||
2508 | /** | |
2509 | * ubifs_tnc_remove_nm - remove an index entry for a "hashed" node. | |
2510 | * @c: UBIFS file-system description object | |
2511 | * @key: key of node | |
2512 | * @nm: directory entry name | |
2513 | * | |
2514 | * Returns %0 on success or negative error code on failure. | |
2515 | */ | |
2516 | int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key, | |
2517 | const struct qstr *nm) | |
2518 | { | |
2519 | int n, err; | |
2520 | struct ubifs_znode *znode; | |
2521 | ||
2522 | mutex_lock(&c->tnc_mutex); | |
ff94bc40 | 2523 | dbg_tnck(key, "%.*s, key ", nm->len, nm->name); |
9eefe2a2 SR |
2524 | err = lookup_level0_dirty(c, key, &znode, &n); |
2525 | if (err < 0) | |
2526 | goto out_unlock; | |
2527 | ||
2528 | if (err) { | |
2529 | if (c->replaying) | |
2530 | err = fallible_resolve_collision(c, key, &znode, &n, | |
2531 | nm, 0); | |
2532 | else | |
2533 | err = resolve_collision(c, key, &znode, &n, nm); | |
2534 | dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n); | |
2535 | if (err < 0) | |
2536 | goto out_unlock; | |
2537 | if (err) { | |
2538 | /* Ensure the znode is dirtied */ | |
2539 | if (znode->cnext || !ubifs_zn_dirty(znode)) { | |
ff94bc40 HS |
2540 | znode = dirty_cow_bottom_up(c, znode); |
2541 | if (IS_ERR(znode)) { | |
2542 | err = PTR_ERR(znode); | |
2543 | goto out_unlock; | |
2544 | } | |
9eefe2a2 SR |
2545 | } |
2546 | err = tnc_delete(c, znode, n); | |
2547 | } | |
2548 | } | |
2549 | ||
2550 | out_unlock: | |
2551 | if (!err) | |
2552 | err = dbg_check_tnc(c, 0); | |
2553 | mutex_unlock(&c->tnc_mutex); | |
2554 | return err; | |
2555 | } | |
2556 | ||
2557 | /** | |
2558 | * key_in_range - determine if a key falls within a range of keys. | |
2559 | * @c: UBIFS file-system description object | |
2560 | * @key: key to check | |
2561 | * @from_key: lowest key in range | |
2562 | * @to_key: highest key in range | |
2563 | * | |
2564 | * This function returns %1 if the key is in range and %0 otherwise. | |
2565 | */ | |
2566 | static int key_in_range(struct ubifs_info *c, union ubifs_key *key, | |
2567 | union ubifs_key *from_key, union ubifs_key *to_key) | |
2568 | { | |
2569 | if (keys_cmp(c, key, from_key) < 0) | |
2570 | return 0; | |
2571 | if (keys_cmp(c, key, to_key) > 0) | |
2572 | return 0; | |
2573 | return 1; | |
2574 | } | |
2575 | ||
2576 | /** | |
2577 | * ubifs_tnc_remove_range - remove index entries in range. | |
2578 | * @c: UBIFS file-system description object | |
2579 | * @from_key: lowest key to remove | |
2580 | * @to_key: highest key to remove | |
2581 | * | |
2582 | * This function removes index entries starting at @from_key and ending at | |
2583 | * @to_key. This function returns zero in case of success and a negative error | |
2584 | * code in case of failure. | |
2585 | */ | |
2586 | int ubifs_tnc_remove_range(struct ubifs_info *c, union ubifs_key *from_key, | |
2587 | union ubifs_key *to_key) | |
2588 | { | |
2589 | int i, n, k, err = 0; | |
2590 | struct ubifs_znode *znode; | |
2591 | union ubifs_key *key; | |
2592 | ||
2593 | mutex_lock(&c->tnc_mutex); | |
2594 | while (1) { | |
2595 | /* Find first level 0 znode that contains keys to remove */ | |
2596 | err = ubifs_lookup_level0(c, from_key, &znode, &n); | |
2597 | if (err < 0) | |
2598 | goto out_unlock; | |
2599 | ||
2600 | if (err) | |
2601 | key = from_key; | |
2602 | else { | |
2603 | err = tnc_next(c, &znode, &n); | |
2604 | if (err == -ENOENT) { | |
2605 | err = 0; | |
2606 | goto out_unlock; | |
2607 | } | |
2608 | if (err < 0) | |
2609 | goto out_unlock; | |
2610 | key = &znode->zbranch[n].key; | |
2611 | if (!key_in_range(c, key, from_key, to_key)) { | |
2612 | err = 0; | |
2613 | goto out_unlock; | |
2614 | } | |
2615 | } | |
2616 | ||
2617 | /* Ensure the znode is dirtied */ | |
2618 | if (znode->cnext || !ubifs_zn_dirty(znode)) { | |
2619 | znode = dirty_cow_bottom_up(c, znode); | |
2620 | if (IS_ERR(znode)) { | |
2621 | err = PTR_ERR(znode); | |
2622 | goto out_unlock; | |
2623 | } | |
2624 | } | |
2625 | ||
2626 | /* Remove all keys in range except the first */ | |
2627 | for (i = n + 1, k = 0; i < znode->child_cnt; i++, k++) { | |
2628 | key = &znode->zbranch[i].key; | |
2629 | if (!key_in_range(c, key, from_key, to_key)) | |
2630 | break; | |
2631 | lnc_free(&znode->zbranch[i]); | |
2632 | err = ubifs_add_dirt(c, znode->zbranch[i].lnum, | |
2633 | znode->zbranch[i].len); | |
2634 | if (err) { | |
ff94bc40 | 2635 | ubifs_dump_znode(c, znode); |
9eefe2a2 SR |
2636 | goto out_unlock; |
2637 | } | |
ff94bc40 | 2638 | dbg_tnck(key, "removing key "); |
9eefe2a2 SR |
2639 | } |
2640 | if (k) { | |
2641 | for (i = n + 1 + k; i < znode->child_cnt; i++) | |
2642 | znode->zbranch[i - k] = znode->zbranch[i]; | |
2643 | znode->child_cnt -= k; | |
2644 | } | |
2645 | ||
2646 | /* Now delete the first */ | |
2647 | err = tnc_delete(c, znode, n); | |
2648 | if (err) | |
2649 | goto out_unlock; | |
2650 | } | |
2651 | ||
2652 | out_unlock: | |
2653 | if (!err) | |
2654 | err = dbg_check_tnc(c, 0); | |
2655 | mutex_unlock(&c->tnc_mutex); | |
2656 | return err; | |
2657 | } | |
2658 | ||
2659 | /** | |
2660 | * ubifs_tnc_remove_ino - remove an inode from TNC. | |
2661 | * @c: UBIFS file-system description object | |
2662 | * @inum: inode number to remove | |
2663 | * | |
2664 | * This function remove inode @inum and all the extended attributes associated | |
2665 | * with the anode from TNC and returns zero in case of success or a negative | |
2666 | * error code in case of failure. | |
2667 | */ | |
2668 | int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum) | |
2669 | { | |
2670 | union ubifs_key key1, key2; | |
2671 | struct ubifs_dent_node *xent, *pxent = NULL; | |
2672 | struct qstr nm = { .name = NULL }; | |
2673 | ||
2674 | dbg_tnc("ino %lu", (unsigned long)inum); | |
2675 | ||
2676 | /* | |
2677 | * Walk all extended attribute entries and remove them together with | |
2678 | * corresponding extended attribute inodes. | |
2679 | */ | |
2680 | lowest_xent_key(c, &key1, inum); | |
2681 | while (1) { | |
2682 | ino_t xattr_inum; | |
2683 | int err; | |
2684 | ||
2685 | xent = ubifs_tnc_next_ent(c, &key1, &nm); | |
2686 | if (IS_ERR(xent)) { | |
2687 | err = PTR_ERR(xent); | |
2688 | if (err == -ENOENT) | |
2689 | break; | |
2690 | return err; | |
2691 | } | |
2692 | ||
2693 | xattr_inum = le64_to_cpu(xent->inum); | |
2694 | dbg_tnc("xent '%s', ino %lu", xent->name, | |
2695 | (unsigned long)xattr_inum); | |
2696 | ||
ff94bc40 | 2697 | nm.name = xent->name; |
9eefe2a2 SR |
2698 | nm.len = le16_to_cpu(xent->nlen); |
2699 | err = ubifs_tnc_remove_nm(c, &key1, &nm); | |
2700 | if (err) { | |
2701 | kfree(xent); | |
2702 | return err; | |
2703 | } | |
2704 | ||
2705 | lowest_ino_key(c, &key1, xattr_inum); | |
2706 | highest_ino_key(c, &key2, xattr_inum); | |
2707 | err = ubifs_tnc_remove_range(c, &key1, &key2); | |
2708 | if (err) { | |
2709 | kfree(xent); | |
2710 | return err; | |
2711 | } | |
2712 | ||
2713 | kfree(pxent); | |
2714 | pxent = xent; | |
2715 | key_read(c, &xent->key, &key1); | |
2716 | } | |
2717 | ||
2718 | kfree(pxent); | |
2719 | lowest_ino_key(c, &key1, inum); | |
2720 | highest_ino_key(c, &key2, inum); | |
2721 | ||
2722 | return ubifs_tnc_remove_range(c, &key1, &key2); | |
2723 | } | |
2724 | ||
2725 | /** | |
2726 | * ubifs_tnc_next_ent - walk directory or extended attribute entries. | |
2727 | * @c: UBIFS file-system description object | |
2728 | * @key: key of last entry | |
2729 | * @nm: name of last entry found or %NULL | |
2730 | * | |
2731 | * This function finds and reads the next directory or extended attribute entry | |
2732 | * after the given key (@key) if there is one. @nm is used to resolve | |
2733 | * collisions. | |
2734 | * | |
2735 | * If the name of the current entry is not known and only the key is known, | |
2736 | * @nm->name has to be %NULL. In this case the semantics of this function is a | |
2737 | * little bit different and it returns the entry corresponding to this key, not | |
2738 | * the next one. If the key was not found, the closest "right" entry is | |
2739 | * returned. | |
2740 | * | |
2741 | * If the fist entry has to be found, @key has to contain the lowest possible | |
2742 | * key value for this inode and @name has to be %NULL. | |
2743 | * | |
2744 | * This function returns the found directory or extended attribute entry node | |
2745 | * in case of success, %-ENOENT is returned if no entry was found, and a | |
2746 | * negative error code is returned in case of failure. | |
2747 | */ | |
2748 | struct ubifs_dent_node *ubifs_tnc_next_ent(struct ubifs_info *c, | |
2749 | union ubifs_key *key, | |
2750 | const struct qstr *nm) | |
2751 | { | |
2752 | int n, err, type = key_type(c, key); | |
2753 | struct ubifs_znode *znode; | |
2754 | struct ubifs_dent_node *dent; | |
2755 | struct ubifs_zbranch *zbr; | |
2756 | union ubifs_key *dkey; | |
2757 | ||
ff94bc40 | 2758 | dbg_tnck(key, "%s ", nm->name ? (char *)nm->name : "(lowest)"); |
9eefe2a2 SR |
2759 | ubifs_assert(is_hash_key(c, key)); |
2760 | ||
2761 | mutex_lock(&c->tnc_mutex); | |
2762 | err = ubifs_lookup_level0(c, key, &znode, &n); | |
2763 | if (unlikely(err < 0)) | |
2764 | goto out_unlock; | |
2765 | ||
2766 | if (nm->name) { | |
2767 | if (err) { | |
2768 | /* Handle collisions */ | |
2769 | err = resolve_collision(c, key, &znode, &n, nm); | |
2770 | dbg_tnc("rc returned %d, znode %p, n %d", | |
2771 | err, znode, n); | |
2772 | if (unlikely(err < 0)) | |
2773 | goto out_unlock; | |
2774 | } | |
2775 | ||
2776 | /* Now find next entry */ | |
2777 | err = tnc_next(c, &znode, &n); | |
2778 | if (unlikely(err)) | |
2779 | goto out_unlock; | |
2780 | } else { | |
2781 | /* | |
2782 | * The full name of the entry was not given, in which case the | |
2783 | * behavior of this function is a little different and it | |
2784 | * returns current entry, not the next one. | |
2785 | */ | |
2786 | if (!err) { | |
2787 | /* | |
2788 | * However, the given key does not exist in the TNC | |
2789 | * tree and @znode/@n variables contain the closest | |
2790 | * "preceding" element. Switch to the next one. | |
2791 | */ | |
2792 | err = tnc_next(c, &znode, &n); | |
2793 | if (err) | |
2794 | goto out_unlock; | |
2795 | } | |
2796 | } | |
2797 | ||
2798 | zbr = &znode->zbranch[n]; | |
2799 | dent = kmalloc(zbr->len, GFP_NOFS); | |
2800 | if (unlikely(!dent)) { | |
2801 | err = -ENOMEM; | |
2802 | goto out_unlock; | |
2803 | } | |
2804 | ||
2805 | /* | |
2806 | * The above 'tnc_next()' call could lead us to the next inode, check | |
2807 | * this. | |
2808 | */ | |
2809 | dkey = &zbr->key; | |
2810 | if (key_inum(c, dkey) != key_inum(c, key) || | |
2811 | key_type(c, dkey) != type) { | |
2812 | err = -ENOENT; | |
2813 | goto out_free; | |
2814 | } | |
2815 | ||
2816 | err = tnc_read_node_nm(c, zbr, dent); | |
2817 | if (unlikely(err)) | |
2818 | goto out_free; | |
2819 | ||
2820 | mutex_unlock(&c->tnc_mutex); | |
2821 | return dent; | |
2822 | ||
2823 | out_free: | |
2824 | kfree(dent); | |
2825 | out_unlock: | |
2826 | mutex_unlock(&c->tnc_mutex); | |
2827 | return ERR_PTR(err); | |
2828 | } | |
ff94bc40 | 2829 | |
ff94bc40 HS |
2830 | /** |
2831 | * tnc_destroy_cnext - destroy left-over obsolete znodes from a failed commit. | |
2832 | * @c: UBIFS file-system description object | |
2833 | * | |
2834 | * Destroy left-over obsolete znodes from a failed commit. | |
2835 | */ | |
2836 | static void tnc_destroy_cnext(struct ubifs_info *c) | |
2837 | { | |
2838 | struct ubifs_znode *cnext; | |
2839 | ||
2840 | if (!c->cnext) | |
2841 | return; | |
2842 | ubifs_assert(c->cmt_state == COMMIT_BROKEN); | |
2843 | cnext = c->cnext; | |
2844 | do { | |
2845 | struct ubifs_znode *znode = cnext; | |
2846 | ||
2847 | cnext = cnext->cnext; | |
2848 | if (ubifs_zn_obsolete(znode)) | |
2849 | kfree(znode); | |
2850 | } while (cnext && cnext != c->cnext); | |
2851 | } | |
2852 | ||
2853 | /** | |
2854 | * ubifs_tnc_close - close TNC subsystem and free all related resources. | |
2855 | * @c: UBIFS file-system description object | |
2856 | */ | |
2857 | void ubifs_tnc_close(struct ubifs_info *c) | |
2858 | { | |
2859 | tnc_destroy_cnext(c); | |
2860 | if (c->zroot.znode) { | |
0195a7bb | 2861 | long n, freed; |
ff94bc40 | 2862 | |
ff94bc40 | 2863 | n = atomic_long_read(&c->clean_zn_cnt); |
0195a7bb HS |
2864 | freed = ubifs_destroy_tnc_subtree(c->zroot.znode); |
2865 | ubifs_assert(freed == n); | |
ff94bc40 HS |
2866 | atomic_long_sub(n, &ubifs_clean_zn_cnt); |
2867 | } | |
2868 | kfree(c->gap_lebs); | |
2869 | kfree(c->ilebs); | |
2870 | destroy_old_idx(c); | |
2871 | } | |
ff94bc40 HS |
2872 | |
2873 | /** | |
2874 | * left_znode - get the znode to the left. | |
2875 | * @c: UBIFS file-system description object | |
2876 | * @znode: znode | |
2877 | * | |
2878 | * This function returns a pointer to the znode to the left of @znode or NULL if | |
2879 | * there is not one. A negative error code is returned on failure. | |
2880 | */ | |
2881 | static struct ubifs_znode *left_znode(struct ubifs_info *c, | |
2882 | struct ubifs_znode *znode) | |
2883 | { | |
2884 | int level = znode->level; | |
2885 | ||
2886 | while (1) { | |
2887 | int n = znode->iip - 1; | |
2888 | ||
2889 | /* Go up until we can go left */ | |
2890 | znode = znode->parent; | |
2891 | if (!znode) | |
2892 | return NULL; | |
2893 | if (n >= 0) { | |
2894 | /* Now go down the rightmost branch to 'level' */ | |
2895 | znode = get_znode(c, znode, n); | |
2896 | if (IS_ERR(znode)) | |
2897 | return znode; | |
2898 | while (znode->level != level) { | |
2899 | n = znode->child_cnt - 1; | |
2900 | znode = get_znode(c, znode, n); | |
2901 | if (IS_ERR(znode)) | |
2902 | return znode; | |
2903 | } | |
2904 | break; | |
2905 | } | |
2906 | } | |
2907 | return znode; | |
2908 | } | |
2909 | ||
2910 | /** | |
2911 | * right_znode - get the znode to the right. | |
2912 | * @c: UBIFS file-system description object | |
2913 | * @znode: znode | |
2914 | * | |
2915 | * This function returns a pointer to the znode to the right of @znode or NULL | |
2916 | * if there is not one. A negative error code is returned on failure. | |
2917 | */ | |
2918 | static struct ubifs_znode *right_znode(struct ubifs_info *c, | |
2919 | struct ubifs_znode *znode) | |
2920 | { | |
2921 | int level = znode->level; | |
2922 | ||
2923 | while (1) { | |
2924 | int n = znode->iip + 1; | |
2925 | ||
2926 | /* Go up until we can go right */ | |
2927 | znode = znode->parent; | |
2928 | if (!znode) | |
2929 | return NULL; | |
2930 | if (n < znode->child_cnt) { | |
2931 | /* Now go down the leftmost branch to 'level' */ | |
2932 | znode = get_znode(c, znode, n); | |
2933 | if (IS_ERR(znode)) | |
2934 | return znode; | |
2935 | while (znode->level != level) { | |
2936 | znode = get_znode(c, znode, 0); | |
2937 | if (IS_ERR(znode)) | |
2938 | return znode; | |
2939 | } | |
2940 | break; | |
2941 | } | |
2942 | } | |
2943 | return znode; | |
2944 | } | |
2945 | ||
2946 | /** | |
2947 | * lookup_znode - find a particular indexing node from TNC. | |
2948 | * @c: UBIFS file-system description object | |
2949 | * @key: index node key to lookup | |
2950 | * @level: index node level | |
2951 | * @lnum: index node LEB number | |
2952 | * @offs: index node offset | |
2953 | * | |
2954 | * This function searches an indexing node by its first key @key and its | |
2955 | * address @lnum:@offs. It looks up the indexing tree by pulling all indexing | |
2956 | * nodes it traverses to TNC. This function is called for indexing nodes which | |
2957 | * were found on the media by scanning, for example when garbage-collecting or | |
2958 | * when doing in-the-gaps commit. This means that the indexing node which is | |
2959 | * looked for does not have to have exactly the same leftmost key @key, because | |
2960 | * the leftmost key may have been changed, in which case TNC will contain a | |
2961 | * dirty znode which still refers the same @lnum:@offs. This function is clever | |
2962 | * enough to recognize such indexing nodes. | |
2963 | * | |
2964 | * Note, if a znode was deleted or changed too much, then this function will | |
2965 | * not find it. For situations like this UBIFS has the old index RB-tree | |
2966 | * (indexed by @lnum:@offs). | |
2967 | * | |
2968 | * This function returns a pointer to the znode found or %NULL if it is not | |
2969 | * found. A negative error code is returned on failure. | |
2970 | */ | |
2971 | static struct ubifs_znode *lookup_znode(struct ubifs_info *c, | |
2972 | union ubifs_key *key, int level, | |
2973 | int lnum, int offs) | |
2974 | { | |
2975 | struct ubifs_znode *znode, *zn; | |
2976 | int n, nn; | |
2977 | ||
2978 | ubifs_assert(key_type(c, key) < UBIFS_INVALID_KEY); | |
2979 | ||
2980 | /* | |
2981 | * The arguments have probably been read off flash, so don't assume | |
2982 | * they are valid. | |
2983 | */ | |
2984 | if (level < 0) | |
2985 | return ERR_PTR(-EINVAL); | |
2986 | ||
2987 | /* Get the root znode */ | |
2988 | znode = c->zroot.znode; | |
2989 | if (!znode) { | |
2990 | znode = ubifs_load_znode(c, &c->zroot, NULL, 0); | |
2991 | if (IS_ERR(znode)) | |
2992 | return znode; | |
2993 | } | |
2994 | /* Check if it is the one we are looking for */ | |
2995 | if (c->zroot.lnum == lnum && c->zroot.offs == offs) | |
2996 | return znode; | |
2997 | /* Descend to the parent level i.e. (level + 1) */ | |
2998 | if (level >= znode->level) | |
2999 | return NULL; | |
3000 | while (1) { | |
3001 | ubifs_search_zbranch(c, znode, key, &n); | |
3002 | if (n < 0) { | |
3003 | /* | |
3004 | * We reached a znode where the leftmost key is greater | |
3005 | * than the key we are searching for. This is the same | |
3006 | * situation as the one described in a huge comment at | |
3007 | * the end of the 'ubifs_lookup_level0()' function. And | |
3008 | * for exactly the same reasons we have to try to look | |
3009 | * left before giving up. | |
3010 | */ | |
3011 | znode = left_znode(c, znode); | |
3012 | if (!znode) | |
3013 | return NULL; | |
3014 | if (IS_ERR(znode)) | |
3015 | return znode; | |
3016 | ubifs_search_zbranch(c, znode, key, &n); | |
3017 | ubifs_assert(n >= 0); | |
3018 | } | |
3019 | if (znode->level == level + 1) | |
3020 | break; | |
3021 | znode = get_znode(c, znode, n); | |
3022 | if (IS_ERR(znode)) | |
3023 | return znode; | |
3024 | } | |
3025 | /* Check if the child is the one we are looking for */ | |
3026 | if (znode->zbranch[n].lnum == lnum && znode->zbranch[n].offs == offs) | |
3027 | return get_znode(c, znode, n); | |
3028 | /* If the key is unique, there is nowhere else to look */ | |
3029 | if (!is_hash_key(c, key)) | |
3030 | return NULL; | |
3031 | /* | |
3032 | * The key is not unique and so may be also in the znodes to either | |
3033 | * side. | |
3034 | */ | |
3035 | zn = znode; | |
3036 | nn = n; | |
3037 | /* Look left */ | |
3038 | while (1) { | |
3039 | /* Move one branch to the left */ | |
3040 | if (n) | |
3041 | n -= 1; | |
3042 | else { | |
3043 | znode = left_znode(c, znode); | |
3044 | if (!znode) | |
3045 | break; | |
3046 | if (IS_ERR(znode)) | |
3047 | return znode; | |
3048 | n = znode->child_cnt - 1; | |
3049 | } | |
3050 | /* Check it */ | |
3051 | if (znode->zbranch[n].lnum == lnum && | |
3052 | znode->zbranch[n].offs == offs) | |
3053 | return get_znode(c, znode, n); | |
3054 | /* Stop if the key is less than the one we are looking for */ | |
3055 | if (keys_cmp(c, &znode->zbranch[n].key, key) < 0) | |
3056 | break; | |
3057 | } | |
3058 | /* Back to the middle */ | |
3059 | znode = zn; | |
3060 | n = nn; | |
3061 | /* Look right */ | |
3062 | while (1) { | |
3063 | /* Move one branch to the right */ | |
3064 | if (++n >= znode->child_cnt) { | |
3065 | znode = right_znode(c, znode); | |
3066 | if (!znode) | |
3067 | break; | |
3068 | if (IS_ERR(znode)) | |
3069 | return znode; | |
3070 | n = 0; | |
3071 | } | |
3072 | /* Check it */ | |
3073 | if (znode->zbranch[n].lnum == lnum && | |
3074 | znode->zbranch[n].offs == offs) | |
3075 | return get_znode(c, znode, n); | |
3076 | /* Stop if the key is greater than the one we are looking for */ | |
3077 | if (keys_cmp(c, &znode->zbranch[n].key, key) > 0) | |
3078 | break; | |
3079 | } | |
3080 | return NULL; | |
3081 | } | |
3082 | ||
3083 | /** | |
3084 | * is_idx_node_in_tnc - determine if an index node is in the TNC. | |
3085 | * @c: UBIFS file-system description object | |
3086 | * @key: key of index node | |
3087 | * @level: index node level | |
3088 | * @lnum: LEB number of index node | |
3089 | * @offs: offset of index node | |
3090 | * | |
3091 | * This function returns %0 if the index node is not referred to in the TNC, %1 | |
3092 | * if the index node is referred to in the TNC and the corresponding znode is | |
3093 | * dirty, %2 if an index node is referred to in the TNC and the corresponding | |
3094 | * znode is clean, and a negative error code in case of failure. | |
3095 | * | |
3096 | * Note, the @key argument has to be the key of the first child. Also note, | |
3097 | * this function relies on the fact that 0:0 is never a valid LEB number and | |
3098 | * offset for a main-area node. | |
3099 | */ | |
3100 | int is_idx_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, int level, | |
3101 | int lnum, int offs) | |
3102 | { | |
3103 | struct ubifs_znode *znode; | |
3104 | ||
3105 | znode = lookup_znode(c, key, level, lnum, offs); | |
3106 | if (!znode) | |
3107 | return 0; | |
3108 | if (IS_ERR(znode)) | |
3109 | return PTR_ERR(znode); | |
3110 | ||
3111 | return ubifs_zn_dirty(znode) ? 1 : 2; | |
3112 | } | |
3113 | ||
3114 | /** | |
3115 | * is_leaf_node_in_tnc - determine if a non-indexing not is in the TNC. | |
3116 | * @c: UBIFS file-system description object | |
3117 | * @key: node key | |
3118 | * @lnum: node LEB number | |
3119 | * @offs: node offset | |
3120 | * | |
3121 | * This function returns %1 if the node is referred to in the TNC, %0 if it is | |
3122 | * not, and a negative error code in case of failure. | |
3123 | * | |
3124 | * Note, this function relies on the fact that 0:0 is never a valid LEB number | |
3125 | * and offset for a main-area node. | |
3126 | */ | |
3127 | static int is_leaf_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, | |
3128 | int lnum, int offs) | |
3129 | { | |
3130 | struct ubifs_zbranch *zbr; | |
3131 | struct ubifs_znode *znode, *zn; | |
3132 | int n, found, err, nn; | |
3133 | const int unique = !is_hash_key(c, key); | |
3134 | ||
3135 | found = ubifs_lookup_level0(c, key, &znode, &n); | |
3136 | if (found < 0) | |
3137 | return found; /* Error code */ | |
3138 | if (!found) | |
3139 | return 0; | |
3140 | zbr = &znode->zbranch[n]; | |
3141 | if (lnum == zbr->lnum && offs == zbr->offs) | |
3142 | return 1; /* Found it */ | |
3143 | if (unique) | |
3144 | return 0; | |
3145 | /* | |
3146 | * Because the key is not unique, we have to look left | |
3147 | * and right as well | |
3148 | */ | |
3149 | zn = znode; | |
3150 | nn = n; | |
3151 | /* Look left */ | |
3152 | while (1) { | |
3153 | err = tnc_prev(c, &znode, &n); | |
3154 | if (err == -ENOENT) | |
3155 | break; | |
3156 | if (err) | |
3157 | return err; | |
3158 | if (keys_cmp(c, key, &znode->zbranch[n].key)) | |
3159 | break; | |
3160 | zbr = &znode->zbranch[n]; | |
3161 | if (lnum == zbr->lnum && offs == zbr->offs) | |
3162 | return 1; /* Found it */ | |
3163 | } | |
3164 | /* Look right */ | |
3165 | znode = zn; | |
3166 | n = nn; | |
3167 | while (1) { | |
3168 | err = tnc_next(c, &znode, &n); | |
3169 | if (err) { | |
3170 | if (err == -ENOENT) | |
3171 | return 0; | |
3172 | return err; | |
3173 | } | |
3174 | if (keys_cmp(c, key, &znode->zbranch[n].key)) | |
3175 | break; | |
3176 | zbr = &znode->zbranch[n]; | |
3177 | if (lnum == zbr->lnum && offs == zbr->offs) | |
3178 | return 1; /* Found it */ | |
3179 | } | |
3180 | return 0; | |
3181 | } | |
3182 | ||
3183 | /** | |
3184 | * ubifs_tnc_has_node - determine whether a node is in the TNC. | |
3185 | * @c: UBIFS file-system description object | |
3186 | * @key: node key | |
3187 | * @level: index node level (if it is an index node) | |
3188 | * @lnum: node LEB number | |
3189 | * @offs: node offset | |
3190 | * @is_idx: non-zero if the node is an index node | |
3191 | * | |
3192 | * This function returns %1 if the node is in the TNC, %0 if it is not, and a | |
3193 | * negative error code in case of failure. For index nodes, @key has to be the | |
3194 | * key of the first child. An index node is considered to be in the TNC only if | |
3195 | * the corresponding znode is clean or has not been loaded. | |
3196 | */ | |
3197 | int ubifs_tnc_has_node(struct ubifs_info *c, union ubifs_key *key, int level, | |
3198 | int lnum, int offs, int is_idx) | |
3199 | { | |
3200 | int err; | |
3201 | ||
3202 | mutex_lock(&c->tnc_mutex); | |
3203 | if (is_idx) { | |
3204 | err = is_idx_node_in_tnc(c, key, level, lnum, offs); | |
3205 | if (err < 0) | |
3206 | goto out_unlock; | |
3207 | if (err == 1) | |
3208 | /* The index node was found but it was dirty */ | |
3209 | err = 0; | |
3210 | else if (err == 2) | |
3211 | /* The index node was found and it was clean */ | |
3212 | err = 1; | |
3213 | else | |
3214 | BUG_ON(err != 0); | |
3215 | } else | |
3216 | err = is_leaf_node_in_tnc(c, key, lnum, offs); | |
3217 | ||
3218 | out_unlock: | |
3219 | mutex_unlock(&c->tnc_mutex); | |
3220 | return err; | |
3221 | } | |
3222 | ||
3223 | /** | |
3224 | * ubifs_dirty_idx_node - dirty an index node. | |
3225 | * @c: UBIFS file-system description object | |
3226 | * @key: index node key | |
3227 | * @level: index node level | |
3228 | * @lnum: index node LEB number | |
3229 | * @offs: index node offset | |
3230 | * | |
3231 | * This function loads and dirties an index node so that it can be garbage | |
3232 | * collected. The @key argument has to be the key of the first child. This | |
3233 | * function relies on the fact that 0:0 is never a valid LEB number and offset | |
3234 | * for a main-area node. Returns %0 on success and a negative error code on | |
3235 | * failure. | |
3236 | */ | |
3237 | int ubifs_dirty_idx_node(struct ubifs_info *c, union ubifs_key *key, int level, | |
3238 | int lnum, int offs) | |
3239 | { | |
3240 | struct ubifs_znode *znode; | |
3241 | int err = 0; | |
3242 | ||
3243 | mutex_lock(&c->tnc_mutex); | |
3244 | znode = lookup_znode(c, key, level, lnum, offs); | |
3245 | if (!znode) | |
3246 | goto out_unlock; | |
3247 | if (IS_ERR(znode)) { | |
3248 | err = PTR_ERR(znode); | |
3249 | goto out_unlock; | |
3250 | } | |
3251 | znode = dirty_cow_bottom_up(c, znode); | |
3252 | if (IS_ERR(znode)) { | |
3253 | err = PTR_ERR(znode); | |
3254 | goto out_unlock; | |
3255 | } | |
3256 | ||
3257 | out_unlock: | |
3258 | mutex_unlock(&c->tnc_mutex); | |
3259 | return err; | |
3260 | } | |
3261 | ||
3262 | /** | |
3263 | * dbg_check_inode_size - check if inode size is correct. | |
3264 | * @c: UBIFS file-system description object | |
3265 | * @inum: inode number | |
3266 | * @size: inode size | |
3267 | * | |
3268 | * This function makes sure that the inode size (@size) is correct and it does | |
3269 | * not have any pages beyond @size. Returns zero if the inode is OK, %-EINVAL | |
3270 | * if it has a data page beyond @size, and other negative error code in case of | |
3271 | * other errors. | |
3272 | */ | |
3273 | int dbg_check_inode_size(struct ubifs_info *c, const struct inode *inode, | |
3274 | loff_t size) | |
3275 | { | |
3276 | int err, n; | |
3277 | union ubifs_key from_key, to_key, *key; | |
3278 | struct ubifs_znode *znode; | |
3279 | unsigned int block; | |
3280 | ||
3281 | if (!S_ISREG(inode->i_mode)) | |
3282 | return 0; | |
3283 | if (!dbg_is_chk_gen(c)) | |
3284 | return 0; | |
3285 | ||
3286 | block = (size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT; | |
3287 | data_key_init(c, &from_key, inode->i_ino, block); | |
3288 | highest_data_key(c, &to_key, inode->i_ino); | |
3289 | ||
3290 | mutex_lock(&c->tnc_mutex); | |
3291 | err = ubifs_lookup_level0(c, &from_key, &znode, &n); | |
3292 | if (err < 0) | |
3293 | goto out_unlock; | |
3294 | ||
3295 | if (err) { | |
ff94bc40 HS |
3296 | key = &from_key; |
3297 | goto out_dump; | |
3298 | } | |
3299 | ||
3300 | err = tnc_next(c, &znode, &n); | |
3301 | if (err == -ENOENT) { | |
3302 | err = 0; | |
3303 | goto out_unlock; | |
3304 | } | |
3305 | if (err < 0) | |
3306 | goto out_unlock; | |
3307 | ||
3308 | ubifs_assert(err == 0); | |
3309 | key = &znode->zbranch[n].key; | |
3310 | if (!key_in_range(c, key, &from_key, &to_key)) | |
3311 | goto out_unlock; | |
3312 | ||
3313 | out_dump: | |
3314 | block = key_block(c, key); | |
0195a7bb | 3315 | ubifs_err(c, "inode %lu has size %lld, but there are data at offset %lld", |
ff94bc40 HS |
3316 | (unsigned long)inode->i_ino, size, |
3317 | ((loff_t)block) << UBIFS_BLOCK_SHIFT); | |
3318 | mutex_unlock(&c->tnc_mutex); | |
3319 | ubifs_dump_inode(c, inode); | |
3320 | dump_stack(); | |
3321 | return -EINVAL; | |
3322 | ||
3323 | out_unlock: | |
3324 | mutex_unlock(&c->tnc_mutex); | |
3325 | return err; | |
3326 | } |