2 * This file is part of UBIFS.
4 * Copyright (C) 2006-2008 Nokia Corporation.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 * Authors: Adrian Hunter
20 * Artem Bityutskiy (Битюцкий Артём)
24 * This file implements TNC (Tree Node Cache) which caches indexing nodes of
27 * At the moment the locking rules of the TNC tree are quite simple and
28 * straightforward. We just have a mutex and lock it when we traverse the
29 * tree. If a znode is not in memory, we read it from flash while still having
33 #include <linux/crc32.h>
37 * Returned codes of 'matches_name()' and 'fallible_matches_name()' functions.
38 * @NAME_LESS: name corresponding to the first argument is less than second
39 * @NAME_MATCHES: names match
40 * @NAME_GREATER: name corresponding to the second argument is greater than
42 * @NOT_ON_MEDIA: node referred by zbranch does not exist on the media
44 * These constants were introduce to improve readability.
54 * insert_old_idx - record an index node obsoleted since the last commit start.
55 * @c: UBIFS file-system description object
56 * @lnum: LEB number of obsoleted index node
57 * @offs: offset of obsoleted index node
59 * Returns %0 on success, and a negative error code on failure.
61 * For recovery, there must always be a complete intact version of the index on
62 * flash at all times. That is called the "old index". It is the index as at the
63 * time of the last successful commit. Many of the index nodes in the old index
64 * may be dirty, but they must not be erased until the next successful commit
65 * (at which point that index becomes the old index).
67 * That means that the garbage collection and the in-the-gaps method of
68 * committing must be able to determine if an index node is in the old index.
69 * Most of the old index nodes can be found by looking up the TNC using the
70 * 'lookup_znode()' function. However, some of the old index nodes may have
71 * been deleted from the current index or may have been changed so much that
72 * they cannot be easily found. In those cases, an entry is added to an RB-tree.
73 * That is what this function does. The RB-tree is ordered by LEB number and
74 * offset because they uniquely identify the old index node.
76 static int insert_old_idx(struct ubifs_info
*c
, int lnum
, int offs
)
78 struct ubifs_old_idx
*old_idx
, *o
;
79 struct rb_node
**p
, *parent
= NULL
;
81 old_idx
= kmalloc(sizeof(struct ubifs_old_idx
), GFP_NOFS
);
82 if (unlikely(!old_idx
))
87 p
= &c
->old_idx
.rb_node
;
90 o
= rb_entry(parent
, struct ubifs_old_idx
, rb
);
93 else if (lnum
> o
->lnum
)
95 else if (offs
< o
->offs
)
97 else if (offs
> o
->offs
)
100 ubifs_err("old idx added twice!");
105 rb_link_node(&old_idx
->rb
, parent
, p
);
106 rb_insert_color(&old_idx
->rb
, &c
->old_idx
);
111 * insert_old_idx_znode - record a znode obsoleted since last commit start.
112 * @c: UBIFS file-system description object
113 * @znode: znode of obsoleted index node
115 * Returns %0 on success, and a negative error code on failure.
117 int insert_old_idx_znode(struct ubifs_info
*c
, struct ubifs_znode
*znode
)
120 struct ubifs_zbranch
*zbr
;
122 zbr
= &znode
->parent
->zbranch
[znode
->iip
];
124 return insert_old_idx(c
, zbr
->lnum
, zbr
->offs
);
127 return insert_old_idx(c
, c
->zroot
.lnum
,
133 * ins_clr_old_idx_znode - record a znode obsoleted since last commit start.
134 * @c: UBIFS file-system description object
135 * @znode: znode of obsoleted index node
137 * Returns %0 on success, and a negative error code on failure.
139 static int ins_clr_old_idx_znode(struct ubifs_info
*c
,
140 struct ubifs_znode
*znode
)
145 struct ubifs_zbranch
*zbr
;
147 zbr
= &znode
->parent
->zbranch
[znode
->iip
];
149 err
= insert_old_idx(c
, zbr
->lnum
, zbr
->offs
);
158 err
= insert_old_idx(c
, c
->zroot
.lnum
, c
->zroot
.offs
);
169 * destroy_old_idx - destroy the old_idx RB-tree.
170 * @c: UBIFS file-system description object
172 * During start commit, the old_idx RB-tree is used to avoid overwriting index
173 * nodes that were in the index last commit but have since been deleted. This
174 * is necessary for recovery i.e. the old index must be kept intact until the
175 * new index is successfully written. The old-idx RB-tree is used for the
176 * in-the-gaps method of writing index nodes and is destroyed every commit.
178 void destroy_old_idx(struct ubifs_info
*c
)
180 struct rb_node
*this = c
->old_idx
.rb_node
;
181 struct ubifs_old_idx
*old_idx
;
185 this = this->rb_left
;
187 } else if (this->rb_right
) {
188 this = this->rb_right
;
191 old_idx
= rb_entry(this, struct ubifs_old_idx
, rb
);
192 this = rb_parent(this);
194 if (this->rb_left
== &old_idx
->rb
)
195 this->rb_left
= NULL
;
197 this->rb_right
= NULL
;
201 c
->old_idx
= RB_ROOT
;
205 * copy_znode - copy a dirty znode.
206 * @c: UBIFS file-system description object
207 * @znode: znode to copy
209 * A dirty znode being committed may not be changed, so it is copied.
211 static struct ubifs_znode
*copy_znode(struct ubifs_info
*c
,
212 struct ubifs_znode
*znode
)
214 struct ubifs_znode
*zn
;
216 zn
= kmalloc(c
->max_znode_sz
, GFP_NOFS
);
218 return ERR_PTR(-ENOMEM
);
220 memcpy(zn
, znode
, c
->max_znode_sz
);
222 __set_bit(DIRTY_ZNODE
, &zn
->flags
);
223 __clear_bit(COW_ZNODE
, &zn
->flags
);
225 ubifs_assert(!test_bit(OBSOLETE_ZNODE
, &znode
->flags
));
226 __set_bit(OBSOLETE_ZNODE
, &znode
->flags
);
228 if (znode
->level
!= 0) {
230 const int n
= zn
->child_cnt
;
232 /* The children now have new parent */
233 for (i
= 0; i
< n
; i
++) {
234 struct ubifs_zbranch
*zbr
= &zn
->zbranch
[i
];
237 zbr
->znode
->parent
= zn
;
241 atomic_long_inc(&c
->dirty_zn_cnt
);
246 * add_idx_dirt - add dirt due to a dirty znode.
247 * @c: UBIFS file-system description object
248 * @lnum: LEB number of index node
249 * @dirt: size of index node
251 * This function updates lprops dirty space and the new size of the index.
253 static int add_idx_dirt(struct ubifs_info
*c
, int lnum
, int dirt
)
255 c
->calc_idx_sz
-= ALIGN(dirt
, 8);
256 return ubifs_add_dirt(c
, lnum
, dirt
);
260 * dirty_cow_znode - ensure a znode is not being committed.
261 * @c: UBIFS file-system description object
262 * @zbr: branch of znode to check
264 * Returns dirtied znode on success or negative error code on failure.
266 static struct ubifs_znode
*dirty_cow_znode(struct ubifs_info
*c
,
267 struct ubifs_zbranch
*zbr
)
269 struct ubifs_znode
*znode
= zbr
->znode
;
270 struct ubifs_znode
*zn
;
273 if (!test_bit(COW_ZNODE
, &znode
->flags
)) {
274 /* znode is not being committed */
275 if (!test_and_set_bit(DIRTY_ZNODE
, &znode
->flags
)) {
276 atomic_long_inc(&c
->dirty_zn_cnt
);
277 atomic_long_dec(&c
->clean_zn_cnt
);
278 atomic_long_dec(&ubifs_clean_zn_cnt
);
279 err
= add_idx_dirt(c
, zbr
->lnum
, zbr
->len
);
286 zn
= copy_znode(c
, znode
);
287 if (unlikely(IS_ERR(zn
)))
291 err
= insert_old_idx(c
, zbr
->lnum
, zbr
->offs
);
294 err
= add_idx_dirt(c
, zbr
->lnum
, zbr
->len
);
309 * lnc_add - add a leaf node to the leaf node cache.
310 * @c: UBIFS file-system description object
311 * @zbr: zbranch of leaf node
314 * Leaf nodes are non-index nodes directory entry nodes or data nodes. The
315 * purpose of the leaf node cache is to save re-reading the same leaf node over
316 * and over again. Most things are cached by VFS, however the file system must
317 * cache directory entries for readdir and for resolving hash collisions. The
318 * present implementation of the leaf node cache is extremely simple, and
319 * allows for error returns that are not used but that may be needed if a more
320 * complex implementation is created.
322 * Note, this function does not add the @node object to LNC directly, but
323 * allocates a copy of the object and adds the copy to LNC. The reason for this
324 * is that @node has been allocated outside of the TNC subsystem and will be
325 * used with @c->tnc_mutex unlock upon return from the TNC subsystem. But LNC
326 * may be changed at any time, e.g. freed by the shrinker.
328 static int lnc_add(struct ubifs_info
*c
, struct ubifs_zbranch
*zbr
,
333 const struct ubifs_dent_node
*dent
= node
;
335 ubifs_assert(!zbr
->leaf
);
336 ubifs_assert(zbr
->len
!= 0);
337 ubifs_assert(is_hash_key(c
, &zbr
->key
));
339 err
= ubifs_validate_entry(c
, dent
);
342 dbg_dump_node(c
, dent
);
346 lnc_node
= kmalloc(zbr
->len
, GFP_NOFS
);
348 /* We don't have to have the cache, so no error */
351 memcpy(lnc_node
, node
, zbr
->len
);
352 zbr
->leaf
= lnc_node
;
357 * lnc_add_directly - add a leaf node to the leaf-node-cache.
358 * @c: UBIFS file-system description object
359 * @zbr: zbranch of leaf node
362 * This function is similar to 'lnc_add()', but it does not create a copy of
363 * @node but inserts @node to TNC directly.
365 static int lnc_add_directly(struct ubifs_info
*c
, struct ubifs_zbranch
*zbr
,
370 ubifs_assert(!zbr
->leaf
);
371 ubifs_assert(zbr
->len
!= 0);
373 err
= ubifs_validate_entry(c
, node
);
376 dbg_dump_node(c
, node
);
385 * lnc_free - remove a leaf node from the leaf node cache.
386 * @zbr: zbranch of leaf node
389 static void lnc_free(struct ubifs_zbranch
*zbr
)
398 * tnc_read_node_nm - read a "hashed" leaf node.
399 * @c: UBIFS file-system description object
400 * @zbr: key and position of the node
401 * @node: node is returned here
403 * This function reads a "hashed" node defined by @zbr from the leaf node cache
404 * (in it is there) or from the hash media, in which case the node is also
405 * added to LNC. Returns zero in case of success or a negative negative error
406 * code in case of failure.
408 static int tnc_read_node_nm(struct ubifs_info
*c
, struct ubifs_zbranch
*zbr
,
413 ubifs_assert(is_hash_key(c
, &zbr
->key
));
416 /* Read from the leaf node cache */
417 ubifs_assert(zbr
->len
!= 0);
418 memcpy(node
, zbr
->leaf
, zbr
->len
);
422 err
= ubifs_tnc_read_node(c
, zbr
, node
);
426 /* Add the node to the leaf node cache */
427 err
= lnc_add(c
, zbr
, node
);
432 * try_read_node - read a node if it is a node.
433 * @c: UBIFS file-system description object
434 * @buf: buffer to read to
436 * @len: node length (not aligned)
437 * @lnum: LEB number of node to read
438 * @offs: offset of node to read
440 * This function tries to read a node of known type and length, checks it and
441 * stores it in @buf. This function returns %1 if a node is present and %0 if
442 * a node is not present. A negative error code is returned for I/O errors.
443 * This function performs that same function as ubifs_read_node except that
444 * it does not require that there is actually a node present and instead
445 * the return code indicates if a node was read.
447 static int try_read_node(const struct ubifs_info
*c
, void *buf
, int type
,
448 int len
, int lnum
, int offs
)
451 struct ubifs_ch
*ch
= buf
;
452 uint32_t crc
, node_crc
;
454 dbg_io("LEB %d:%d, %s, length %d", lnum
, offs
, dbg_ntype(type
), len
);
456 err
= ubi_read(c
->ubi
, lnum
, buf
, offs
, len
);
458 ubifs_err("cannot read node type %d from LEB %d:%d, error %d",
459 type
, lnum
, offs
, err
);
463 if (le32_to_cpu(ch
->magic
) != UBIFS_NODE_MAGIC
)
466 if (ch
->node_type
!= type
)
469 node_len
= le32_to_cpu(ch
->len
);
473 crc
= crc32(UBIFS_CRC32_INIT
, buf
+ 8, node_len
- 8);
474 node_crc
= le32_to_cpu(ch
->crc
);
482 * fallible_read_node - try to read a leaf node.
483 * @c: UBIFS file-system description object
484 * @key: key of node to read
485 * @zbr: position of node
486 * @node: node returned
488 * This function tries to read a node and returns %1 if the node is read, %0
489 * if the node is not present, and a negative error code in the case of error.
491 static int fallible_read_node(struct ubifs_info
*c
, const union ubifs_key
*key
,
492 struct ubifs_zbranch
*zbr
, void *node
)
496 dbg_tnc("LEB %d:%d, key %s", zbr
->lnum
, zbr
->offs
, DBGKEY(key
));
498 ret
= try_read_node(c
, node
, key_type(c
, key
), zbr
->len
, zbr
->lnum
,
501 union ubifs_key node_key
;
502 struct ubifs_dent_node
*dent
= node
;
504 /* All nodes have key in the same place */
505 key_read(c
, &dent
->key
, &node_key
);
506 if (keys_cmp(c
, key
, &node_key
) != 0)
509 if (ret
== 0 && c
->replaying
)
510 dbg_mnt("dangling branch LEB %d:%d len %d, key %s",
511 zbr
->lnum
, zbr
->offs
, zbr
->len
, DBGKEY(key
));
516 * matches_name - determine if a direntry or xattr entry matches a given name.
517 * @c: UBIFS file-system description object
518 * @zbr: zbranch of dent
521 * This function checks if xentry/direntry referred by zbranch @zbr matches name
522 * @nm. Returns %NAME_MATCHES if it does, %NAME_LESS if the name referred by
523 * @zbr is less than @nm, and %NAME_GREATER if it is greater than @nm. In case
524 * of failure, a negative error code is returned.
526 static int matches_name(struct ubifs_info
*c
, struct ubifs_zbranch
*zbr
,
527 const struct qstr
*nm
)
529 struct ubifs_dent_node
*dent
;
532 /* If possible, match against the dent in the leaf node cache */
534 dent
= kmalloc(zbr
->len
, GFP_NOFS
);
538 err
= ubifs_tnc_read_node(c
, zbr
, dent
);
542 /* Add the node to the leaf node cache */
543 err
= lnc_add_directly(c
, zbr
, dent
);
549 nlen
= le16_to_cpu(dent
->nlen
);
550 err
= memcmp(dent
->name
, nm
->name
, min_t(int, nlen
, nm
->len
));
554 else if (nlen
< nm
->len
)
569 * get_znode - get a TNC znode that may not be loaded yet.
570 * @c: UBIFS file-system description object
571 * @znode: parent znode
572 * @n: znode branch slot number
574 * This function returns the znode or a negative error code.
576 static struct ubifs_znode
*get_znode(struct ubifs_info
*c
,
577 struct ubifs_znode
*znode
, int n
)
579 struct ubifs_zbranch
*zbr
;
581 zbr
= &znode
->zbranch
[n
];
585 znode
= ubifs_load_znode(c
, zbr
, znode
, n
);
590 * tnc_next - find next TNC entry.
591 * @c: UBIFS file-system description object
592 * @zn: znode is passed and returned here
593 * @n: znode branch slot number is passed and returned here
595 * This function returns %0 if the next TNC entry is found, %-ENOENT if there is
596 * no next entry, or a negative error code otherwise.
598 static int tnc_next(struct ubifs_info
*c
, struct ubifs_znode
**zn
, int *n
)
600 struct ubifs_znode
*znode
= *zn
;
604 if (nn
< znode
->child_cnt
) {
609 struct ubifs_znode
*zp
;
616 if (nn
< znode
->child_cnt
) {
617 znode
= get_znode(c
, znode
, nn
);
619 return PTR_ERR(znode
);
620 while (znode
->level
!= 0) {
621 znode
= get_znode(c
, znode
, 0);
623 return PTR_ERR(znode
);
635 * tnc_prev - find previous TNC entry.
636 * @c: UBIFS file-system description object
637 * @zn: znode is returned here
638 * @n: znode branch slot number is passed and returned here
640 * This function returns %0 if the previous TNC entry is found, %-ENOENT if
641 * there is no next entry, or a negative error code otherwise.
643 static int tnc_prev(struct ubifs_info
*c
, struct ubifs_znode
**zn
, int *n
)
645 struct ubifs_znode
*znode
= *zn
;
653 struct ubifs_znode
*zp
;
661 znode
= get_znode(c
, znode
, nn
);
663 return PTR_ERR(znode
);
664 while (znode
->level
!= 0) {
665 nn
= znode
->child_cnt
- 1;
666 znode
= get_znode(c
, znode
, nn
);
668 return PTR_ERR(znode
);
670 nn
= znode
->child_cnt
- 1;
680 * resolve_collision - resolve a collision.
681 * @c: UBIFS file-system description object
682 * @key: key of a directory or extended attribute entry
683 * @zn: znode is returned here
684 * @n: zbranch number is passed and returned here
685 * @nm: name of the entry
687 * This function is called for "hashed" keys to make sure that the found key
688 * really corresponds to the looked up node (directory or extended attribute
689 * entry). It returns %1 and sets @zn and @n if the collision is resolved.
690 * %0 is returned if @nm is not found and @zn and @n are set to the previous
691 * entry, i.e. to the entry after which @nm could follow if it were in TNC.
692 * This means that @n may be set to %-1 if the leftmost key in @zn is the
693 * previous one. A negative error code is returned on failures.
695 static int resolve_collision(struct ubifs_info
*c
, const union ubifs_key
*key
,
696 struct ubifs_znode
**zn
, int *n
,
697 const struct qstr
*nm
)
701 err
= matches_name(c
, &(*zn
)->zbranch
[*n
], nm
);
702 if (unlikely(err
< 0))
704 if (err
== NAME_MATCHES
)
707 if (err
== NAME_GREATER
) {
710 err
= tnc_prev(c
, zn
, n
);
711 if (err
== -ENOENT
) {
712 ubifs_assert(*n
== 0);
718 if (keys_cmp(c
, &(*zn
)->zbranch
[*n
].key
, key
)) {
720 * We have found the branch after which we would
721 * like to insert, but inserting in this znode
722 * may still be wrong. Consider the following 3
723 * znodes, in the case where we are resolving a
724 * collision with Key2.
727 * ----------------------
728 * level 1 | Key0 | Key1 |
729 * -----------------------
731 * znode za | | znode zb
732 * ------------ ------------
733 * level 0 | Key0 | | Key2 |
734 * ------------ ------------
736 * The lookup finds Key2 in znode zb. Lets say
737 * there is no match and the name is greater so
738 * we look left. When we find Key0, we end up
739 * here. If we return now, we will insert into
740 * znode za at slot n = 1. But that is invalid
741 * according to the parent's keys. Key2 must
742 * be inserted into znode zb.
744 * Note, this problem is not relevant for the
745 * case when we go right, because
746 * 'tnc_insert()' would correct the parent key.
748 if (*n
== (*zn
)->child_cnt
- 1) {
749 err
= tnc_next(c
, zn
, n
);
751 /* Should be impossible */
757 ubifs_assert(*n
== 0);
762 err
= matches_name(c
, &(*zn
)->zbranch
[*n
], nm
);
765 if (err
== NAME_LESS
)
767 if (err
== NAME_MATCHES
)
769 ubifs_assert(err
== NAME_GREATER
);
773 struct ubifs_znode
*znode
= *zn
;
777 err
= tnc_next(c
, &znode
, &nn
);
782 if (keys_cmp(c
, &znode
->zbranch
[nn
].key
, key
))
784 err
= matches_name(c
, &znode
->zbranch
[nn
], nm
);
787 if (err
== NAME_GREATER
)
791 if (err
== NAME_MATCHES
)
793 ubifs_assert(err
== NAME_LESS
);
799 * fallible_matches_name - determine if a dent matches a given name.
800 * @c: UBIFS file-system description object
801 * @zbr: zbranch of dent
804 * This is a "fallible" version of 'matches_name()' function which does not
805 * panic if the direntry/xentry referred by @zbr does not exist on the media.
807 * This function checks if xentry/direntry referred by zbranch @zbr matches name
808 * @nm. Returns %NAME_MATCHES it does, %NAME_LESS if the name referred by @zbr
809 * is less than @nm, %NAME_GREATER if it is greater than @nm, and @NOT_ON_MEDIA
810 * if xentry/direntry referred by @zbr does not exist on the media. A negative
811 * error code is returned in case of failure.
813 static int fallible_matches_name(struct ubifs_info
*c
,
814 struct ubifs_zbranch
*zbr
,
815 const struct qstr
*nm
)
817 struct ubifs_dent_node
*dent
;
820 /* If possible, match against the dent in the leaf node cache */
822 dent
= kmalloc(zbr
->len
, GFP_NOFS
);
826 err
= fallible_read_node(c
, &zbr
->key
, zbr
, dent
);
830 /* The node was not present */
834 ubifs_assert(err
== 1);
836 err
= lnc_add_directly(c
, zbr
, dent
);
842 nlen
= le16_to_cpu(dent
->nlen
);
843 err
= memcmp(dent
->name
, nm
->name
, min_t(int, nlen
, nm
->len
));
847 else if (nlen
< nm
->len
)
862 * fallible_resolve_collision - resolve a collision even if nodes are missing.
863 * @c: UBIFS file-system description object
865 * @zn: znode is returned here
866 * @n: branch number is passed and returned here
867 * @nm: name of directory entry
868 * @adding: indicates caller is adding a key to the TNC
870 * This is a "fallible" version of the 'resolve_collision()' function which
871 * does not panic if one of the nodes referred to by TNC does not exist on the
872 * media. This may happen when replaying the journal if a deleted node was
873 * Garbage-collected and the commit was not done. A branch that refers to a node
874 * that is not present is called a dangling branch. The following are the return
875 * codes for this function:
876 * o if @nm was found, %1 is returned and @zn and @n are set to the found
878 * o if we are @adding and @nm was not found, %0 is returned;
879 * o if we are not @adding and @nm was not found, but a dangling branch was
880 * found, then %1 is returned and @zn and @n are set to the dangling branch;
881 * o a negative error code is returned in case of failure.
883 static int fallible_resolve_collision(struct ubifs_info
*c
,
884 const union ubifs_key
*key
,
885 struct ubifs_znode
**zn
, int *n
,
886 const struct qstr
*nm
, int adding
)
888 struct ubifs_znode
*o_znode
= NULL
, *znode
= *zn
;
889 int uninitialized_var(o_n
), err
, cmp
, unsure
= 0, nn
= *n
;
891 cmp
= fallible_matches_name(c
, &znode
->zbranch
[nn
], nm
);
892 if (unlikely(cmp
< 0))
894 if (cmp
== NAME_MATCHES
)
896 if (cmp
== NOT_ON_MEDIA
) {
900 * We are unlucky and hit a dangling branch straight away.
901 * Now we do not really know where to go to find the needed
902 * branch - to the left or to the right. Well, let's try left.
906 unsure
= 1; /* Remove a dangling branch wherever it is */
908 if (cmp
== NAME_GREATER
|| unsure
) {
911 err
= tnc_prev(c
, zn
, n
);
912 if (err
== -ENOENT
) {
913 ubifs_assert(*n
== 0);
919 if (keys_cmp(c
, &(*zn
)->zbranch
[*n
].key
, key
)) {
920 /* See comments in 'resolve_collision()' */
921 if (*n
== (*zn
)->child_cnt
- 1) {
922 err
= tnc_next(c
, zn
, n
);
924 /* Should be impossible */
930 ubifs_assert(*n
== 0);
935 err
= fallible_matches_name(c
, &(*zn
)->zbranch
[*n
], nm
);
938 if (err
== NAME_MATCHES
)
940 if (err
== NOT_ON_MEDIA
) {
947 if (err
== NAME_LESS
)
954 if (cmp
== NAME_LESS
|| unsure
) {
959 err
= tnc_next(c
, &znode
, &nn
);
964 if (keys_cmp(c
, &znode
->zbranch
[nn
].key
, key
))
966 err
= fallible_matches_name(c
, &znode
->zbranch
[nn
], nm
);
969 if (err
== NAME_GREATER
)
973 if (err
== NAME_MATCHES
)
975 if (err
== NOT_ON_MEDIA
) {
982 /* Never match a dangling branch when adding */
983 if (adding
|| !o_znode
)
986 dbg_mnt("dangling match LEB %d:%d len %d %s",
987 o_znode
->zbranch
[o_n
].lnum
, o_znode
->zbranch
[o_n
].offs
,
988 o_znode
->zbranch
[o_n
].len
, DBGKEY(key
));
995 * matches_position - determine if a zbranch matches a given position.
996 * @zbr: zbranch of dent
997 * @lnum: LEB number of dent to match
998 * @offs: offset of dent to match
1000 * This function returns %1 if @lnum:@offs matches, and %0 otherwise.
1002 static int matches_position(struct ubifs_zbranch
*zbr
, int lnum
, int offs
)
1004 if (zbr
->lnum
== lnum
&& zbr
->offs
== offs
)
1011 * resolve_collision_directly - resolve a collision directly.
1012 * @c: UBIFS file-system description object
1013 * @key: key of directory entry
1014 * @zn: znode is passed and returned here
1015 * @n: zbranch number is passed and returned here
1016 * @lnum: LEB number of dent node to match
1017 * @offs: offset of dent node to match
1019 * This function is used for "hashed" keys to make sure the found directory or
1020 * extended attribute entry node is what was looked for. It is used when the
1021 * flash address of the right node is known (@lnum:@offs) which makes it much
1022 * easier to resolve collisions (no need to read entries and match full
1023 * names). This function returns %1 and sets @zn and @n if the collision is
1024 * resolved, %0 if @lnum:@offs is not found and @zn and @n are set to the
1025 * previous directory entry. Otherwise a negative error code is returned.
1027 static int resolve_collision_directly(struct ubifs_info
*c
,
1028 const union ubifs_key
*key
,
1029 struct ubifs_znode
**zn
, int *n
,
1032 struct ubifs_znode
*znode
;
1037 if (matches_position(&znode
->zbranch
[nn
], lnum
, offs
))
1042 err
= tnc_prev(c
, &znode
, &nn
);
1047 if (keys_cmp(c
, &znode
->zbranch
[nn
].key
, key
))
1049 if (matches_position(&znode
->zbranch
[nn
], lnum
, offs
)) {
1060 err
= tnc_next(c
, &znode
, &nn
);
1065 if (keys_cmp(c
, &znode
->zbranch
[nn
].key
, key
))
1069 if (matches_position(&znode
->zbranch
[nn
], lnum
, offs
))
1075 * dirty_cow_bottom_up - dirty a znode and its ancestors.
1076 * @c: UBIFS file-system description object
1077 * @znode: znode to dirty
1079 * If we do not have a unique key that resides in a znode, then we cannot
1080 * dirty that znode from the top down (i.e. by using lookup_level0_dirty)
1081 * This function records the path back to the last dirty ancestor, and then
1082 * dirties the znodes on that path.
1084 static struct ubifs_znode
*dirty_cow_bottom_up(struct ubifs_info
*c
,
1085 struct ubifs_znode
*znode
)
1087 struct ubifs_znode
*zp
;
1088 int *path
= c
->bottom_up_buf
, p
= 0;
1090 ubifs_assert(c
->zroot
.znode
);
1091 ubifs_assert(znode
);
1092 if (c
->zroot
.znode
->level
> BOTTOM_UP_HEIGHT
) {
1093 kfree(c
->bottom_up_buf
);
1094 c
->bottom_up_buf
= kmalloc(c
->zroot
.znode
->level
* sizeof(int),
1096 if (!c
->bottom_up_buf
)
1097 return ERR_PTR(-ENOMEM
);
1098 path
= c
->bottom_up_buf
;
1100 if (c
->zroot
.znode
->level
) {
1101 /* Go up until parent is dirty */
1109 ubifs_assert(p
< c
->zroot
.znode
->level
);
1111 if (!zp
->cnext
&& ubifs_zn_dirty(znode
))
1117 /* Come back down, dirtying as we go */
1119 struct ubifs_zbranch
*zbr
;
1123 ubifs_assert(path
[p
- 1] >= 0);
1124 ubifs_assert(path
[p
- 1] < zp
->child_cnt
);
1125 zbr
= &zp
->zbranch
[path
[--p
]];
1126 znode
= dirty_cow_znode(c
, zbr
);
1128 ubifs_assert(znode
== c
->zroot
.znode
);
1129 znode
= dirty_cow_znode(c
, &c
->zroot
);
1131 if (unlikely(IS_ERR(znode
)) || !p
)
1133 ubifs_assert(path
[p
- 1] >= 0);
1134 ubifs_assert(path
[p
- 1] < znode
->child_cnt
);
1135 znode
= znode
->zbranch
[path
[p
- 1]].znode
;
1142 * ubifs_lookup_level0 - search for zero-level znode.
1143 * @c: UBIFS file-system description object
1144 * @key: key to lookup
1145 * @zn: znode is returned here
1146 * @n: znode branch slot number is returned here
1148 * This function looks up the TNC tree and search for zero-level znode which
1149 * refers key @key. The found zero-level znode is returned in @zn. There are 3
1151 * o exact match, i.e. the found zero-level znode contains key @key, then %1
1152 * is returned and slot number of the matched branch is stored in @n;
1153 * o not exact match, which means that zero-level znode does not contain
1154 * @key, then %0 is returned and slot number of the closed branch is stored
1156 * o @key is so small that it is even less than the lowest key of the
1157 * leftmost zero-level node, then %0 is returned and %0 is stored in @n.
1159 * Note, when the TNC tree is traversed, some znodes may be absent, then this
1160 * function reads corresponding indexing nodes and inserts them to TNC. In
1161 * case of failure, a negative error code is returned.
1163 int ubifs_lookup_level0(struct ubifs_info
*c
, const union ubifs_key
*key
,
1164 struct ubifs_znode
**zn
, int *n
)
1167 struct ubifs_znode
*znode
;
1168 unsigned long time
= get_seconds();
1170 dbg_tnc("search key %s", DBGKEY(key
));
1172 znode
= c
->zroot
.znode
;
1173 if (unlikely(!znode
)) {
1174 znode
= ubifs_load_znode(c
, &c
->zroot
, NULL
, 0);
1176 return PTR_ERR(znode
);
1182 struct ubifs_zbranch
*zbr
;
1184 exact
= ubifs_search_zbranch(c
, znode
, key
, n
);
1186 if (znode
->level
== 0)
1191 zbr
= &znode
->zbranch
[*n
];
1199 /* znode is not in TNC cache, load it from the media */
1200 znode
= ubifs_load_znode(c
, zbr
, znode
, *n
);
1202 return PTR_ERR(znode
);
1206 if (exact
|| !is_hash_key(c
, key
) || *n
!= -1) {
1207 dbg_tnc("found %d, lvl %d, n %d", exact
, znode
->level
, *n
);
1212 * Here is a tricky place. We have not found the key and this is a
1213 * "hashed" key, which may collide. The rest of the code deals with
1214 * situations like this:
1218 * | 3 | 5 | | 6 | 7 | (x)
1220 * Or more a complex example:
1224 * | 1 | 3 | | 5 | 8 |
1226 * | 5 | 5 | | 6 | 7 | (x)
1228 * In the examples, if we are looking for key "5", we may reach nodes
1229 * marked with "(x)". In this case what we have do is to look at the
1230 * left and see if there is "5" key there. If there is, we have to
1233 * Note, this whole situation is possible because we allow to have
1234 * elements which are equivalent to the next key in the parent in the
1235 * children of current znode. For example, this happens if we split a
1236 * znode like this: | 3 | 5 | 5 | 6 | 7 |, which results in something
1240 * | 3 | 5 | | 5 | 6 | 7 |
1242 * And this becomes what is at the first "picture" after key "5" marked
1243 * with "^" is removed. What could be done is we could prohibit
1244 * splitting in the middle of the colliding sequence. Also, when
1245 * removing the leftmost key, we would have to correct the key of the
1246 * parent node, which would introduce additional complications. Namely,
1247 * if we changed the the leftmost key of the parent znode, the garbage
1248 * collector would be unable to find it (GC is doing this when GC'ing
1249 * indexing LEBs). Although we already have an additional RB-tree where
1250 * we save such changed znodes (see 'ins_clr_old_idx_znode()') until
1251 * after the commit. But anyway, this does not look easy to implement
1252 * so we did not try this.
1254 err
= tnc_prev(c
, &znode
, n
);
1255 if (err
== -ENOENT
) {
1256 dbg_tnc("found 0, lvl %d, n -1", znode
->level
);
1260 if (unlikely(err
< 0))
1262 if (keys_cmp(c
, key
, &znode
->zbranch
[*n
].key
)) {
1263 dbg_tnc("found 0, lvl %d, n -1", znode
->level
);
1268 dbg_tnc("found 1, lvl %d, n %d", znode
->level
, *n
);
1274 * lookup_level0_dirty - search for zero-level znode dirtying.
1275 * @c: UBIFS file-system description object
1276 * @key: key to lookup
1277 * @zn: znode is returned here
1278 * @n: znode branch slot number is returned here
1280 * This function looks up the TNC tree and search for zero-level znode which
1281 * refers key @key. The found zero-level znode is returned in @zn. There are 3
1283 * o exact match, i.e. the found zero-level znode contains key @key, then %1
1284 * is returned and slot number of the matched branch is stored in @n;
1285 * o not exact match, which means that zero-level znode does not contain @key
1286 * then %0 is returned and slot number of the closed branch is stored in
1288 * o @key is so small that it is even less than the lowest key of the
1289 * leftmost zero-level node, then %0 is returned and %-1 is stored in @n.
1291 * Additionally all znodes in the path from the root to the located zero-level
1292 * znode are marked as dirty.
1294 * Note, when the TNC tree is traversed, some znodes may be absent, then this
1295 * function reads corresponding indexing nodes and inserts them to TNC. In
1296 * case of failure, a negative error code is returned.
1298 static int lookup_level0_dirty(struct ubifs_info
*c
, const union ubifs_key
*key
,
1299 struct ubifs_znode
**zn
, int *n
)
1302 struct ubifs_znode
*znode
;
1303 unsigned long time
= get_seconds();
1305 dbg_tnc("search and dirty key %s", DBGKEY(key
));
1307 znode
= c
->zroot
.znode
;
1308 if (unlikely(!znode
)) {
1309 znode
= ubifs_load_znode(c
, &c
->zroot
, NULL
, 0);
1311 return PTR_ERR(znode
);
1314 znode
= dirty_cow_znode(c
, &c
->zroot
);
1316 return PTR_ERR(znode
);
1321 struct ubifs_zbranch
*zbr
;
1323 exact
= ubifs_search_zbranch(c
, znode
, key
, n
);
1325 if (znode
->level
== 0)
1330 zbr
= &znode
->zbranch
[*n
];
1334 znode
= dirty_cow_znode(c
, zbr
);
1336 return PTR_ERR(znode
);
1340 /* znode is not in TNC cache, load it from the media */
1341 znode
= ubifs_load_znode(c
, zbr
, znode
, *n
);
1343 return PTR_ERR(znode
);
1344 znode
= dirty_cow_znode(c
, zbr
);
1346 return PTR_ERR(znode
);
1350 if (exact
|| !is_hash_key(c
, key
) || *n
!= -1) {
1351 dbg_tnc("found %d, lvl %d, n %d", exact
, znode
->level
, *n
);
1356 * See huge comment at 'lookup_level0_dirty()' what is the rest of the
1359 err
= tnc_prev(c
, &znode
, n
);
1360 if (err
== -ENOENT
) {
1362 dbg_tnc("found 0, lvl %d, n -1", znode
->level
);
1365 if (unlikely(err
< 0))
1367 if (keys_cmp(c
, key
, &znode
->zbranch
[*n
].key
)) {
1369 dbg_tnc("found 0, lvl %d, n -1", znode
->level
);
1373 if (znode
->cnext
|| !ubifs_zn_dirty(znode
)) {
1374 znode
= dirty_cow_bottom_up(c
, znode
);
1376 return PTR_ERR(znode
);
1379 dbg_tnc("found 1, lvl %d, n %d", znode
->level
, *n
);
1385 * maybe_leb_gced - determine if a LEB may have been garbage collected.
1386 * @c: UBIFS file-system description object
1388 * @gc_seq1: garbage collection sequence number
1390 * This function determines if @lnum may have been garbage collected since
1391 * sequence number @gc_seq1. If it may have been then %1 is returned, otherwise
1394 static int maybe_leb_gced(struct ubifs_info
*c
, int lnum
, int gc_seq1
)
1396 int gc_seq2
, gced_lnum
;
1398 gced_lnum
= c
->gced_lnum
;
1400 gc_seq2
= c
->gc_seq
;
1401 /* Same seq means no GC */
1402 if (gc_seq1
== gc_seq2
)
1404 /* Different by more than 1 means we don't know */
1405 if (gc_seq1
+ 1 != gc_seq2
)
1408 * We have seen the sequence number has increased by 1. Now we need to
1409 * be sure we read the right LEB number, so read it again.
1412 if (gced_lnum
!= c
->gced_lnum
)
1414 /* Finally we can check lnum */
1415 if (gced_lnum
== lnum
)
1421 * ubifs_tnc_locate - look up a file-system node and return it and its location.
1422 * @c: UBIFS file-system description object
1423 * @key: node key to lookup
1424 * @node: the node is returned here
1425 * @lnum: LEB number is returned here
1426 * @offs: offset is returned here
1428 * This function look up and reads node with key @key. The caller has to make
1429 * sure the @node buffer is large enough to fit the node. Returns zero in case
1430 * of success, %-ENOENT if the node was not found, and a negative error code in
1431 * case of failure. The node location can be returned in @lnum and @offs.
1433 int ubifs_tnc_locate(struct ubifs_info
*c
, const union ubifs_key
*key
,
1434 void *node
, int *lnum
, int *offs
)
1436 int found
, n
, err
, safely
= 0, gc_seq1
;
1437 struct ubifs_znode
*znode
;
1438 struct ubifs_zbranch zbr
, *zt
;
1441 mutex_lock(&c
->tnc_mutex
);
1442 found
= ubifs_lookup_level0(c
, key
, &znode
, &n
);
1446 } else if (found
< 0) {
1450 zt
= &znode
->zbranch
[n
];
1455 if (is_hash_key(c
, key
)) {
1457 * In this case the leaf node cache gets used, so we pass the
1458 * address of the zbranch and keep the mutex locked
1460 err
= tnc_read_node_nm(c
, zt
, node
);
1464 err
= ubifs_tnc_read_node(c
, zt
, node
);
1467 /* Drop the TNC mutex prematurely and race with garbage collection */
1468 zbr
= znode
->zbranch
[n
];
1469 gc_seq1
= c
->gc_seq
;
1470 mutex_unlock(&c
->tnc_mutex
);
1472 if (ubifs_get_wbuf(c
, zbr
.lnum
)) {
1473 /* We do not GC journal heads */
1474 err
= ubifs_tnc_read_node(c
, &zbr
, node
);
1478 err
= fallible_read_node(c
, key
, &zbr
, node
);
1479 if (maybe_leb_gced(c
, zbr
.lnum
, gc_seq1
)) {
1481 * The node may have been GC'ed out from under us so try again
1482 * while keeping the TNC mutex locked.
1490 mutex_unlock(&c
->tnc_mutex
);
1495 * do_lookup_nm- look up a "hashed" node.
1496 * @c: UBIFS file-system description object
1497 * @key: node key to lookup
1498 * @node: the node is returned here
1501 * This function look up and reads a node which contains name hash in the key.
1502 * Since the hash may have collisions, there may be many nodes with the same
1503 * key, so we have to sequentially look to all of them until the needed one is
1504 * found. This function returns zero in case of success, %-ENOENT if the node
1505 * was not found, and a negative error code in case of failure.
1507 static int do_lookup_nm(struct ubifs_info
*c
, const union ubifs_key
*key
,
1508 void *node
, const struct qstr
*nm
)
1511 struct ubifs_znode
*znode
;
1513 dbg_tnc("name '%.*s' key %s", nm
->len
, nm
->name
, DBGKEY(key
));
1514 mutex_lock(&c
->tnc_mutex
);
1515 found
= ubifs_lookup_level0(c
, key
, &znode
, &n
);
1519 } else if (found
< 0) {
1524 ubifs_assert(n
>= 0);
1526 err
= resolve_collision(c
, key
, &znode
, &n
, nm
);
1527 dbg_tnc("rc returned %d, znode %p, n %d", err
, znode
, n
);
1528 if (unlikely(err
< 0))
1535 err
= tnc_read_node_nm(c
, &znode
->zbranch
[n
], node
);
1538 mutex_unlock(&c
->tnc_mutex
);
1543 * ubifs_tnc_lookup_nm - look up a "hashed" node.
1544 * @c: UBIFS file-system description object
1545 * @key: node key to lookup
1546 * @node: the node is returned here
1549 * This function look up and reads a node which contains name hash in the key.
1550 * Since the hash may have collisions, there may be many nodes with the same
1551 * key, so we have to sequentially look to all of them until the needed one is
1552 * found. This function returns zero in case of success, %-ENOENT if the node
1553 * was not found, and a negative error code in case of failure.
1555 int ubifs_tnc_lookup_nm(struct ubifs_info
*c
, const union ubifs_key
*key
,
1556 void *node
, const struct qstr
*nm
)
1559 const struct ubifs_dent_node
*dent
= node
;
1562 * We assume that in most of the cases there are no name collisions and
1563 * 'ubifs_tnc_lookup()' returns us the right direntry.
1565 err
= ubifs_tnc_lookup(c
, key
, node
);
1569 len
= le16_to_cpu(dent
->nlen
);
1570 if (nm
->len
== len
&& !memcmp(dent
->name
, nm
->name
, len
))
1574 * Unluckily, there are hash collisions and we have to iterate over
1575 * them look at each direntry with colliding name hash sequentially.
1577 return do_lookup_nm(c
, key
, node
, nm
);
1581 * correct_parent_keys - correct parent znodes' keys.
1582 * @c: UBIFS file-system description object
1583 * @znode: znode to correct parent znodes for
1585 * This is a helper function for 'tnc_insert()'. When the key of the leftmost
1586 * zbranch changes, keys of parent znodes have to be corrected. This helper
1587 * function is called in such situations and corrects the keys if needed.
1589 static void correct_parent_keys(const struct ubifs_info
*c
,
1590 struct ubifs_znode
*znode
)
1592 union ubifs_key
*key
, *key1
;
1594 ubifs_assert(znode
->parent
);
1595 ubifs_assert(znode
->iip
== 0);
1597 key
= &znode
->zbranch
[0].key
;
1598 key1
= &znode
->parent
->zbranch
[0].key
;
1600 while (keys_cmp(c
, key
, key1
) < 0) {
1601 key_copy(c
, key
, key1
);
1602 znode
= znode
->parent
;
1604 if (!znode
->parent
|| znode
->iip
)
1606 key1
= &znode
->parent
->zbranch
[0].key
;
1611 * insert_zbranch - insert a zbranch into a znode.
1612 * @znode: znode into which to insert
1613 * @zbr: zbranch to insert
1614 * @n: slot number to insert to
1616 * This is a helper function for 'tnc_insert()'. UBIFS does not allow "gaps" in
1617 * znode's array of zbranches and keeps zbranches consolidated, so when a new
1618 * zbranch has to be inserted to the @znode->zbranches[]' array at the @n-th
1619 * slot, zbranches starting from @n have to be moved right.
1621 static void insert_zbranch(struct ubifs_znode
*znode
,
1622 const struct ubifs_zbranch
*zbr
, int n
)
1626 ubifs_assert(ubifs_zn_dirty(znode
));
1629 for (i
= znode
->child_cnt
; i
> n
; i
--) {
1630 znode
->zbranch
[i
] = znode
->zbranch
[i
- 1];
1631 if (znode
->zbranch
[i
].znode
)
1632 znode
->zbranch
[i
].znode
->iip
= i
;
1635 zbr
->znode
->iip
= n
;
1637 for (i
= znode
->child_cnt
; i
> n
; i
--)
1638 znode
->zbranch
[i
] = znode
->zbranch
[i
- 1];
1640 znode
->zbranch
[n
] = *zbr
;
1641 znode
->child_cnt
+= 1;
1644 * After inserting at slot zero, the lower bound of the key range of
1645 * this znode may have changed. If this znode is subsequently split
1646 * then the upper bound of the key range may change, and furthermore
1647 * it could change to be lower than the original lower bound. If that
1648 * happens, then it will no longer be possible to find this znode in the
1649 * TNC using the key from the index node on flash. That is bad because
1650 * if it is not found, we will assume it is obsolete and may overwrite
1651 * it. Then if there is an unclean unmount, we will start using the
1652 * old index which will be broken.
1654 * So we first mark znodes that have insertions at slot zero, and then
1655 * if they are split we add their lnum/offs to the old_idx tree.
1662 * tnc_insert - insert a node into TNC.
1663 * @c: UBIFS file-system description object
1664 * @znode: znode to insert into
1665 * @zbr: branch to insert
1666 * @n: slot number to insert new zbranch to
1668 * This function inserts a new node described by @zbr into znode @znode. If
1669 * znode does not have a free slot for new zbranch, it is split. Parent znodes
1670 * are splat as well if needed. Returns zero in case of success or a negative
1671 * error code in case of failure.
1673 static int tnc_insert(struct ubifs_info
*c
, struct ubifs_znode
*znode
,
1674 struct ubifs_zbranch
*zbr
, int n
)
1676 struct ubifs_znode
*zn
, *zi
, *zp
;
1677 int i
, keep
, move
, appending
= 0;
1678 union ubifs_key
*key
= &zbr
->key
;
1680 ubifs_assert(n
>= 0 && n
<= c
->fanout
);
1682 /* Implement naive insert for now */
1685 if (znode
->child_cnt
< c
->fanout
) {
1686 ubifs_assert(n
!= c
->fanout
);
1687 dbg_tnc("inserted at %d level %d, key %s", n
, znode
->level
,
1690 insert_zbranch(znode
, zbr
, n
);
1692 /* Ensure parent's key is correct */
1693 if (n
== 0 && zp
&& znode
->iip
== 0)
1694 correct_parent_keys(c
, znode
);
1700 * Unfortunately, @znode does not have more empty slots and we have to
1703 dbg_tnc("splitting level %d, key %s", znode
->level
, DBGKEY(key
));
1707 * We can no longer be sure of finding this znode by key, so we
1708 * record it in the old_idx tree.
1710 ins_clr_old_idx_znode(c
, znode
);
1712 zn
= kzalloc(c
->max_znode_sz
, GFP_NOFS
);
1716 zn
->level
= znode
->level
;
1718 /* Decide where to split */
1719 if (znode
->level
== 0 && n
== c
->fanout
&&
1720 key_type(c
, key
) == UBIFS_DATA_KEY
) {
1721 union ubifs_key
*key1
;
1724 * If this is an inode which is being appended - do not split
1725 * it because no other zbranches can be inserted between
1726 * zbranches of consecutive data nodes anyway.
1728 key1
= &znode
->zbranch
[n
- 1].key
;
1729 if (key_inum(c
, key1
) == key_inum(c
, key
) &&
1730 key_type(c
, key1
) == UBIFS_DATA_KEY
&&
1731 key_block(c
, key1
) == key_block(c
, key
) - 1)
1739 keep
= (c
->fanout
+ 1) / 2;
1740 move
= c
->fanout
- keep
;
1744 * Although we don't at present, we could look at the neighbors and see
1745 * if we can move some zbranches there.
1749 /* Insert into existing znode */
1754 /* Insert into new znode */
1759 zbr
->znode
->parent
= zn
;
1762 __set_bit(DIRTY_ZNODE
, &zn
->flags
);
1763 atomic_long_inc(&c
->dirty_zn_cnt
);
1765 zn
->child_cnt
= move
;
1766 znode
->child_cnt
= keep
;
1768 dbg_tnc("moving %d, keeping %d", move
, keep
);
1771 for (i
= 0; i
< move
; i
++) {
1772 zn
->zbranch
[i
] = znode
->zbranch
[keep
+ i
];
1775 if (zn
->zbranch
[i
].znode
) {
1776 zn
->zbranch
[i
].znode
->parent
= zn
;
1777 zn
->zbranch
[i
].znode
->iip
= i
;
1781 /* Insert new key and branch */
1782 dbg_tnc("inserting at %d level %d, key %s", n
, zn
->level
, DBGKEY(key
));
1784 insert_zbranch(zi
, zbr
, n
);
1786 /* Insert new znode (produced by spitting) into the parent */
1789 /* Locate insertion point */
1791 if (appending
&& n
!= c
->fanout
)
1794 if (i
== 0 && zi
== znode
&& znode
->iip
== 0)
1795 correct_parent_keys(c
, znode
);
1797 /* Tail recursion */
1798 zbr
->key
= zn
->zbranch
[0].key
;
1808 /* We have to split root znode */
1809 dbg_tnc("creating new zroot at level %d", znode
->level
+ 1);
1811 zi
= kzalloc(c
->max_znode_sz
, GFP_NOFS
);
1816 zi
->level
= znode
->level
+ 1;
1818 __set_bit(DIRTY_ZNODE
, &zi
->flags
);
1819 atomic_long_inc(&c
->dirty_zn_cnt
);
1821 zi
->zbranch
[0].key
= znode
->zbranch
[0].key
;
1822 zi
->zbranch
[0].znode
= znode
;
1823 zi
->zbranch
[0].lnum
= c
->zroot
.lnum
;
1824 zi
->zbranch
[0].offs
= c
->zroot
.offs
;
1825 zi
->zbranch
[0].len
= c
->zroot
.len
;
1826 zi
->zbranch
[1].key
= zn
->zbranch
[0].key
;
1827 zi
->zbranch
[1].znode
= zn
;
1832 c
->zroot
.znode
= zi
;
1843 * ubifs_tnc_add - add a node to TNC.
1844 * @c: UBIFS file-system description object
1846 * @lnum: LEB number of node
1847 * @offs: node offset
1850 * This function adds a node with key @key to TNC. The node may be new or it may
1851 * obsolete some existing one. Returns %0 on success or negative error code on
1854 int ubifs_tnc_add(struct ubifs_info
*c
, const union ubifs_key
*key
, int lnum
,
1857 int found
, n
, err
= 0;
1858 struct ubifs_znode
*znode
;
1860 mutex_lock(&c
->tnc_mutex
);
1861 dbg_tnc("%d:%d, len %d, key %s", lnum
, offs
, len
, DBGKEY(key
));
1862 found
= lookup_level0_dirty(c
, key
, &znode
, &n
);
1864 struct ubifs_zbranch zbr
;
1870 key_copy(c
, key
, &zbr
.key
);
1871 err
= tnc_insert(c
, znode
, &zbr
, n
+ 1);
1872 } else if (found
== 1) {
1873 struct ubifs_zbranch
*zbr
= &znode
->zbranch
[n
];
1876 err
= ubifs_add_dirt(c
, zbr
->lnum
, zbr
->len
);
1883 err
= dbg_check_tnc(c
, 0);
1884 mutex_unlock(&c
->tnc_mutex
);
1890 * ubifs_tnc_replace - replace a node in the TNC only if the old node is found.
1891 * @c: UBIFS file-system description object
1893 * @old_lnum: LEB number of old node
1894 * @old_offs: old node offset
1895 * @lnum: LEB number of node
1896 * @offs: node offset
1899 * This function replaces a node with key @key in the TNC only if the old node
1900 * is found. This function is called by garbage collection when node are moved.
1901 * Returns %0 on success or negative error code on failure.
1903 int ubifs_tnc_replace(struct ubifs_info
*c
, const union ubifs_key
*key
,
1904 int old_lnum
, int old_offs
, int lnum
, int offs
, int len
)
1906 int found
, n
, err
= 0;
1907 struct ubifs_znode
*znode
;
1909 mutex_lock(&c
->tnc_mutex
);
1910 dbg_tnc("old LEB %d:%d, new LEB %d:%d, len %d, key %s", old_lnum
,
1911 old_offs
, lnum
, offs
, len
, DBGKEY(key
));
1912 found
= lookup_level0_dirty(c
, key
, &znode
, &n
);
1919 struct ubifs_zbranch
*zbr
= &znode
->zbranch
[n
];
1922 if (zbr
->lnum
== old_lnum
&& zbr
->offs
== old_offs
) {
1924 err
= ubifs_add_dirt(c
, zbr
->lnum
, zbr
->len
);
1931 } else if (is_hash_key(c
, key
)) {
1932 found
= resolve_collision_directly(c
, key
, &znode
, &n
,
1933 old_lnum
, old_offs
);
1934 dbg_tnc("rc returned %d, znode %p, n %d, LEB %d:%d",
1935 found
, znode
, n
, old_lnum
, old_offs
);
1942 /* Ensure the znode is dirtied */
1943 if (znode
->cnext
|| !ubifs_zn_dirty(znode
)) {
1944 znode
= dirty_cow_bottom_up(c
,
1946 if (IS_ERR(znode
)) {
1947 err
= PTR_ERR(znode
);
1951 zbr
= &znode
->zbranch
[n
];
1953 err
= ubifs_add_dirt(c
, zbr
->lnum
,
1965 err
= ubifs_add_dirt(c
, lnum
, len
);
1968 err
= dbg_check_tnc(c
, 0);
1971 mutex_unlock(&c
->tnc_mutex
);
1976 * ubifs_tnc_add_nm - add a "hashed" node to TNC.
1977 * @c: UBIFS file-system description object
1979 * @lnum: LEB number of node
1980 * @offs: node offset
1984 * This is the same as 'ubifs_tnc_add()' but it should be used with keys which
1985 * may have collisions, like directory entry keys.
1987 int ubifs_tnc_add_nm(struct ubifs_info
*c
, const union ubifs_key
*key
,
1988 int lnum
, int offs
, int len
, const struct qstr
*nm
)
1990 int found
, n
, err
= 0;
1991 struct ubifs_znode
*znode
;
1993 mutex_lock(&c
->tnc_mutex
);
1994 dbg_tnc("LEB %d:%d, name '%.*s', key %s", lnum
, offs
, nm
->len
, nm
->name
,
1996 found
= lookup_level0_dirty(c
, key
, &znode
, &n
);
2004 found
= fallible_resolve_collision(c
, key
, &znode
, &n
,
2007 found
= resolve_collision(c
, key
, &znode
, &n
, nm
);
2008 dbg_tnc("rc returned %d, znode %p, n %d", found
, znode
, n
);
2014 /* Ensure the znode is dirtied */
2015 if (znode
->cnext
|| !ubifs_zn_dirty(znode
)) {
2016 znode
= dirty_cow_bottom_up(c
, znode
);
2017 if (IS_ERR(znode
)) {
2018 err
= PTR_ERR(znode
);
2024 struct ubifs_zbranch
*zbr
= &znode
->zbranch
[n
];
2027 err
= ubifs_add_dirt(c
, zbr
->lnum
, zbr
->len
);
2036 struct ubifs_zbranch zbr
;
2042 key_copy(c
, key
, &zbr
.key
);
2043 err
= tnc_insert(c
, znode
, &zbr
, n
+ 1);
2048 * We did not find it in the index so there may be a
2049 * dangling branch still in the index. So we remove it
2050 * by passing 'ubifs_tnc_remove_nm()' the same key but
2051 * an unmatchable name.
2053 struct qstr noname
= { .len
= 0, .name
= "" };
2055 err
= dbg_check_tnc(c
, 0);
2056 mutex_unlock(&c
->tnc_mutex
);
2059 return ubifs_tnc_remove_nm(c
, key
, &noname
);
2065 err
= dbg_check_tnc(c
, 0);
2066 mutex_unlock(&c
->tnc_mutex
);
2071 * tnc_delete - delete a znode form TNC.
2072 * @c: UBIFS file-system description object
2073 * @znode: znode to delete from
2074 * @n: zbranch slot number to delete
2076 * This function deletes a leaf node from @n-th slot of @znode. Returns zero in
2077 * case of success and a negative error code in case of failure.
2079 static int tnc_delete(struct ubifs_info
*c
, struct ubifs_znode
*znode
, int n
)
2081 struct ubifs_zbranch
*zbr
;
2082 struct ubifs_znode
*zp
;
2085 /* Delete without merge for now */
2086 ubifs_assert(znode
->level
== 0);
2087 ubifs_assert(n
>= 0 && n
< c
->fanout
);
2088 dbg_tnc("deleting %s", DBGKEY(&znode
->zbranch
[n
].key
));
2090 zbr
= &znode
->zbranch
[n
];
2093 err
= ubifs_add_dirt(c
, zbr
->lnum
, zbr
->len
);
2095 dbg_dump_znode(c
, znode
);
2099 /* We do not "gap" zbranch slots */
2100 for (i
= n
; i
< znode
->child_cnt
- 1; i
++)
2101 znode
->zbranch
[i
] = znode
->zbranch
[i
+ 1];
2102 znode
->child_cnt
-= 1;
2104 if (znode
->child_cnt
> 0)
2108 * This was the last zbranch, we have to delete this znode from the
2113 ubifs_assert(!test_bit(OBSOLETE_ZNODE
, &znode
->flags
));
2114 ubifs_assert(ubifs_zn_dirty(znode
));
2119 atomic_long_dec(&c
->dirty_zn_cnt
);
2121 err
= insert_old_idx_znode(c
, znode
);
2126 __set_bit(OBSOLETE_ZNODE
, &znode
->flags
);
2127 atomic_long_inc(&c
->clean_zn_cnt
);
2128 atomic_long_inc(&ubifs_clean_zn_cnt
);
2132 } while (znode
->child_cnt
== 1); /* while removing last child */
2134 /* Remove from znode, entry n - 1 */
2135 znode
->child_cnt
-= 1;
2136 ubifs_assert(znode
->level
!= 0);
2137 for (i
= n
; i
< znode
->child_cnt
; i
++) {
2138 znode
->zbranch
[i
] = znode
->zbranch
[i
+ 1];
2139 if (znode
->zbranch
[i
].znode
)
2140 znode
->zbranch
[i
].znode
->iip
= i
;
2144 * If this is the root and it has only 1 child then
2145 * collapse the tree.
2147 if (!znode
->parent
) {
2148 while (znode
->child_cnt
== 1 && znode
->level
!= 0) {
2150 zbr
= &znode
->zbranch
[0];
2151 znode
= get_znode(c
, znode
, 0);
2153 return PTR_ERR(znode
);
2154 znode
= dirty_cow_znode(c
, zbr
);
2156 return PTR_ERR(znode
);
2157 znode
->parent
= NULL
;
2160 err
= insert_old_idx(c
, c
->zroot
.lnum
,
2165 c
->zroot
.lnum
= zbr
->lnum
;
2166 c
->zroot
.offs
= zbr
->offs
;
2167 c
->zroot
.len
= zbr
->len
;
2168 c
->zroot
.znode
= znode
;
2169 ubifs_assert(!test_bit(OBSOLETE_ZNODE
,
2171 ubifs_assert(test_bit(DIRTY_ZNODE
, &zp
->flags
));
2172 atomic_long_dec(&c
->dirty_zn_cnt
);
2175 __set_bit(OBSOLETE_ZNODE
, &zp
->flags
);
2176 atomic_long_inc(&c
->clean_zn_cnt
);
2177 atomic_long_inc(&ubifs_clean_zn_cnt
);
2187 * ubifs_tnc_remove - remove an index entry of a node.
2188 * @c: UBIFS file-system description object
2191 * Returns %0 on success or negative error code on failure.
2193 int ubifs_tnc_remove(struct ubifs_info
*c
, const union ubifs_key
*key
)
2195 int found
, n
, err
= 0;
2196 struct ubifs_znode
*znode
;
2198 mutex_lock(&c
->tnc_mutex
);
2199 dbg_tnc("key %s", DBGKEY(key
));
2200 found
= lookup_level0_dirty(c
, key
, &znode
, &n
);
2206 err
= tnc_delete(c
, znode
, n
);
2208 err
= dbg_check_tnc(c
, 0);
2211 mutex_unlock(&c
->tnc_mutex
);
2216 * ubifs_tnc_remove_nm - remove an index entry for a "hashed" node.
2217 * @c: UBIFS file-system description object
2219 * @nm: directory entry name
2221 * Returns %0 on success or negative error code on failure.
2223 int ubifs_tnc_remove_nm(struct ubifs_info
*c
, const union ubifs_key
*key
,
2224 const struct qstr
*nm
)
2227 struct ubifs_znode
*znode
;
2229 mutex_lock(&c
->tnc_mutex
);
2230 dbg_tnc("%.*s, key %s", nm
->len
, nm
->name
, DBGKEY(key
));
2231 err
= lookup_level0_dirty(c
, key
, &znode
, &n
);
2237 err
= fallible_resolve_collision(c
, key
, &znode
, &n
,
2240 err
= resolve_collision(c
, key
, &znode
, &n
, nm
);
2241 dbg_tnc("rc returned %d, znode %p, n %d", err
, znode
, n
);
2245 /* Ensure the znode is dirtied */
2246 if (znode
->cnext
|| !ubifs_zn_dirty(znode
)) {
2247 znode
= dirty_cow_bottom_up(c
, znode
);
2248 if (IS_ERR(znode
)) {
2249 err
= PTR_ERR(znode
);
2253 err
= tnc_delete(c
, znode
, n
);
2259 err
= dbg_check_tnc(c
, 0);
2260 mutex_unlock(&c
->tnc_mutex
);
2265 * key_in_range - determine if a key falls within a range of keys.
2266 * @c: UBIFS file-system description object
2267 * @key: key to check
2268 * @from_key: lowest key in range
2269 * @to_key: highest key in range
2271 * This function returns %1 if the key is in range and %0 otherwise.
2273 static int key_in_range(struct ubifs_info
*c
, union ubifs_key
*key
,
2274 union ubifs_key
*from_key
, union ubifs_key
*to_key
)
2276 if (keys_cmp(c
, key
, from_key
) < 0)
2278 if (keys_cmp(c
, key
, to_key
) > 0)
2284 * ubifs_tnc_remove_range - remove index entries in range.
2285 * @c: UBIFS file-system description object
2286 * @from_key: lowest key to remove
2287 * @to_key: highest key to remove
2289 * This function removes index entries starting at @from_key and ending at
2290 * @to_key. This function returns zero in case of success and a negative error
2291 * code in case of failure.
2293 int ubifs_tnc_remove_range(struct ubifs_info
*c
, union ubifs_key
*from_key
,
2294 union ubifs_key
*to_key
)
2296 int i
, n
, k
, err
= 0;
2297 struct ubifs_znode
*znode
;
2298 union ubifs_key
*key
;
2300 mutex_lock(&c
->tnc_mutex
);
2302 /* Find first level 0 znode that contains keys to remove */
2303 err
= ubifs_lookup_level0(c
, from_key
, &znode
, &n
);
2310 err
= tnc_next(c
, &znode
, &n
);
2311 if (err
== -ENOENT
) {
2317 key
= &znode
->zbranch
[n
].key
;
2318 if (!key_in_range(c
, key
, from_key
, to_key
)) {
2324 /* Ensure the znode is dirtied */
2325 if (znode
->cnext
|| !ubifs_zn_dirty(znode
)) {
2326 znode
= dirty_cow_bottom_up(c
, znode
);
2327 if (IS_ERR(znode
)) {
2328 err
= PTR_ERR(znode
);
2333 /* Remove all keys in range except the first */
2334 for (i
= n
+ 1, k
= 0; i
< znode
->child_cnt
; i
++, k
++) {
2335 key
= &znode
->zbranch
[i
].key
;
2336 if (!key_in_range(c
, key
, from_key
, to_key
))
2338 lnc_free(&znode
->zbranch
[i
]);
2339 err
= ubifs_add_dirt(c
, znode
->zbranch
[i
].lnum
,
2340 znode
->zbranch
[i
].len
);
2342 dbg_dump_znode(c
, znode
);
2345 dbg_tnc("removing %s", DBGKEY(key
));
2348 for (i
= n
+ 1 + k
; i
< znode
->child_cnt
; i
++)
2349 znode
->zbranch
[i
- k
] = znode
->zbranch
[i
];
2350 znode
->child_cnt
-= k
;
2353 /* Now delete the first */
2354 err
= tnc_delete(c
, znode
, n
);
2361 err
= dbg_check_tnc(c
, 0);
2362 mutex_unlock(&c
->tnc_mutex
);
2367 * ubifs_tnc_remove_ino - remove an inode from TNC.
2368 * @c: UBIFS file-system description object
2369 * @inum: inode number to remove
2371 * This function remove inode @inum and all the extended attributes associated
2372 * with the anode from TNC and returns zero in case of success or a negative
2373 * error code in case of failure.
2375 int ubifs_tnc_remove_ino(struct ubifs_info
*c
, ino_t inum
)
2377 union ubifs_key key1
, key2
;
2378 struct ubifs_dent_node
*xent
, *pxent
= NULL
;
2379 struct qstr nm
= { .name
= NULL
};
2381 dbg_tnc("ino %lu", inum
);
2384 * Walk all extended attribute entries and remove them together with
2385 * corresponding extended attribute inodes.
2387 lowest_xent_key(c
, &key1
, inum
);
2392 xent
= ubifs_tnc_next_ent(c
, &key1
, &nm
);
2394 err
= PTR_ERR(xent
);
2400 xattr_inum
= le64_to_cpu(xent
->inum
);
2401 dbg_tnc("xent '%s', ino %lu", xent
->name
, xattr_inum
);
2403 nm
.name
= xent
->name
;
2404 nm
.len
= le16_to_cpu(xent
->nlen
);
2405 err
= ubifs_tnc_remove_nm(c
, &key1
, &nm
);
2411 lowest_ino_key(c
, &key1
, xattr_inum
);
2412 highest_ino_key(c
, &key2
, xattr_inum
);
2413 err
= ubifs_tnc_remove_range(c
, &key1
, &key2
);
2421 key_read(c
, &xent
->key
, &key1
);
2425 lowest_ino_key(c
, &key1
, inum
);
2426 highest_ino_key(c
, &key2
, inum
);
2428 return ubifs_tnc_remove_range(c
, &key1
, &key2
);
2432 * ubifs_tnc_next_ent - walk directory or extended attribute entries.
2433 * @c: UBIFS file-system description object
2434 * @key: key of last entry
2435 * @nm: name of last entry found or %NULL
2437 * This function finds and reads the next directory or extended attribute entry
2438 * after the given key (@key) if there is one. @nm is used to resolve
2441 * If the name of the current entry is not known and only the key is known,
2442 * @nm->name has to be %NULL. In this case the semantics of this function is a
2443 * little bit different and it returns the entry corresponding to this key, not
2444 * the next one. If the key was not found, the closest "right" entry is
2447 * If the fist entry has to be found, @key has to contain the lowest possible
2448 * key value for this inode and @name has to be %NULL.
2450 * This function returns the found directory or extended attribute entry node
2451 * in case of success, %-ENOENT is returned if no entry was found, and a
2452 * negative error code is returned in case of failure.
2454 struct ubifs_dent_node
*ubifs_tnc_next_ent(struct ubifs_info
*c
,
2455 union ubifs_key
*key
,
2456 const struct qstr
*nm
)
2458 int n
, err
, type
= key_type(c
, key
);
2459 struct ubifs_znode
*znode
;
2460 struct ubifs_dent_node
*dent
;
2461 struct ubifs_zbranch
*zbr
;
2462 union ubifs_key
*dkey
;
2464 dbg_tnc("%s %s", nm
->name
? (char *)nm
->name
: "(lowest)", DBGKEY(key
));
2465 ubifs_assert(is_hash_key(c
, key
));
2467 mutex_lock(&c
->tnc_mutex
);
2468 err
= ubifs_lookup_level0(c
, key
, &znode
, &n
);
2469 if (unlikely(err
< 0))
2474 /* Handle collisions */
2475 err
= resolve_collision(c
, key
, &znode
, &n
, nm
);
2476 dbg_tnc("rc returned %d, znode %p, n %d",
2478 if (unlikely(err
< 0))
2482 /* Now find next entry */
2483 err
= tnc_next(c
, &znode
, &n
);
2488 * The full name of the entry was not given, in which case the
2489 * behavior of this function is a little different and it
2490 * returns current entry, not the next one.
2494 * However, the given key does not exist in the TNC
2495 * tree and @znode/@n variables contain the closest
2496 * "preceding" element. Switch to the next one.
2498 err
= tnc_next(c
, &znode
, &n
);
2504 zbr
= &znode
->zbranch
[n
];
2505 dent
= kmalloc(zbr
->len
, GFP_NOFS
);
2506 if (unlikely(!dent
)) {
2512 * The above 'tnc_next()' call could lead us to the next inode, check
2516 if (key_inum(c
, dkey
) != key_inum(c
, key
) ||
2517 key_type(c
, dkey
) != type
) {
2522 err
= tnc_read_node_nm(c
, zbr
, dent
);
2526 mutex_unlock(&c
->tnc_mutex
);
2532 mutex_unlock(&c
->tnc_mutex
);
2533 return ERR_PTR(err
);
2537 * tnc_destroy_cnext - destroy left-over obsolete znodes from a failed commit.
2538 * @c: UBIFS file-system description object
2540 * Destroy left-over obsolete znodes from a failed commit.
2542 static void tnc_destroy_cnext(struct ubifs_info
*c
)
2544 struct ubifs_znode
*cnext
;
2548 ubifs_assert(c
->cmt_state
== COMMIT_BROKEN
);
2551 struct ubifs_znode
*znode
= cnext
;
2553 cnext
= cnext
->cnext
;
2554 if (test_bit(OBSOLETE_ZNODE
, &znode
->flags
))
2556 } while (cnext
&& cnext
!= c
->cnext
);
2560 * ubifs_tnc_close - close TNC subsystem and free all related resources.
2561 * @c: UBIFS file-system description object
2563 void ubifs_tnc_close(struct ubifs_info
*c
)
2567 tnc_destroy_cnext(c
);
2568 if (c
->zroot
.znode
) {
2569 clean_freed
= ubifs_destroy_tnc_subtree(c
->zroot
.znode
);
2570 atomic_long_sub(clean_freed
, &ubifs_clean_zn_cnt
);
2578 * left_znode - get the znode to the left.
2579 * @c: UBIFS file-system description object
2582 * This function returns a pointer to the znode to the left of @znode or NULL if
2583 * there is not one. A negative error code is returned on failure.
2585 static struct ubifs_znode
*left_znode(struct ubifs_info
*c
,
2586 struct ubifs_znode
*znode
)
2588 int level
= znode
->level
;
2591 int n
= znode
->iip
- 1;
2593 /* Go up until we can go left */
2594 znode
= znode
->parent
;
2598 /* Now go down the rightmost branch to 'level' */
2599 znode
= get_znode(c
, znode
, n
);
2602 while (znode
->level
!= level
) {
2603 n
= znode
->child_cnt
- 1;
2604 znode
= get_znode(c
, znode
, n
);
2615 * right_znode - get the znode to the right.
2616 * @c: UBIFS file-system description object
2619 * This function returns a pointer to the znode to the right of @znode or NULL
2620 * if there is not one. A negative error code is returned on failure.
2622 static struct ubifs_znode
*right_znode(struct ubifs_info
*c
,
2623 struct ubifs_znode
*znode
)
2625 int level
= znode
->level
;
2628 int n
= znode
->iip
+ 1;
2630 /* Go up until we can go right */
2631 znode
= znode
->parent
;
2634 if (n
< znode
->child_cnt
) {
2635 /* Now go down the leftmost branch to 'level' */
2636 znode
= get_znode(c
, znode
, n
);
2639 while (znode
->level
!= level
) {
2640 znode
= get_znode(c
, znode
, 0);
2651 * lookup_znode - find a particular indexing node from TNC.
2652 * @c: UBIFS file-system description object
2653 * @key: index node key to lookup
2654 * @level: index node level
2655 * @lnum: index node LEB number
2656 * @offs: index node offset
2658 * This function searches an indexing node by its first key @key and its
2659 * address @lnum:@offs. It looks up the indexing tree by pulling all indexing
2660 * nodes it traverses to TNC. This function is called fro indexing nodes which
2661 * were found on the media by scanning, for example when garbage-collecting or
2662 * when doing in-the-gaps commit. This means that the indexing node which is
2663 * looked for does not have to have exactly the same leftmost key @key, because
2664 * the leftmost key may have been changed, in which case TNC will contain a
2665 * dirty znode which still refers the same @lnum:@offs. This function is clever
2666 * enough to recognize such indexing nodes.
2668 * Note, if a znode was deleted or changed too much, then this function will
2669 * not find it. For situations like this UBIFS has the old index RB-tree
2670 * (indexed by @lnum:@offs).
2672 * This function returns a pointer to the znode found or %NULL if it is not
2673 * found. A negative error code is returned on failure.
2675 static struct ubifs_znode
*lookup_znode(struct ubifs_info
*c
,
2676 union ubifs_key
*key
, int level
,
2679 struct ubifs_znode
*znode
, *zn
;
2683 * The arguments have probably been read off flash, so don't assume
2687 return ERR_PTR(-EINVAL
);
2689 /* Get the root znode */
2690 znode
= c
->zroot
.znode
;
2692 znode
= ubifs_load_znode(c
, &c
->zroot
, NULL
, 0);
2696 /* Check if it is the one we are looking for */
2697 if (c
->zroot
.lnum
== lnum
&& c
->zroot
.offs
== offs
)
2699 /* Descend to the parent level i.e. (level + 1) */
2700 if (level
>= znode
->level
)
2703 ubifs_search_zbranch(c
, znode
, key
, &n
);
2706 * We reached a znode where the leftmost key is greater
2707 * than the key we are searching for. This is the same
2708 * situation as the one described in a huge comment at
2709 * the end of the 'ubifs_lookup_level0()' function. And
2710 * for exactly the same reasons we have to try to look
2711 * left before giving up.
2713 znode
= left_znode(c
, znode
);
2718 ubifs_search_zbranch(c
, znode
, key
, &n
);
2719 ubifs_assert(n
>= 0);
2721 if (znode
->level
== level
+ 1)
2723 znode
= get_znode(c
, znode
, n
);
2727 /* Check if the child is the one we are looking for */
2728 if (znode
->zbranch
[n
].lnum
== lnum
&& znode
->zbranch
[n
].offs
== offs
)
2729 return get_znode(c
, znode
, n
);
2730 /* If the key is unique, there is nowhere else to look */
2731 if (!is_hash_key(c
, key
))
2734 * The key is not unique and so may be also in the znodes to either
2741 /* Move one branch to the left */
2745 znode
= left_znode(c
, znode
);
2750 n
= znode
->child_cnt
- 1;
2753 if (znode
->zbranch
[n
].lnum
== lnum
&&
2754 znode
->zbranch
[n
].offs
== offs
)
2755 return get_znode(c
, znode
, n
);
2756 /* Stop if the key is less than the one we are looking for */
2757 if (keys_cmp(c
, &znode
->zbranch
[n
].key
, key
) < 0)
2760 /* Back to the middle */
2765 /* Move one branch to the right */
2766 if (++n
>= znode
->child_cnt
) {
2767 znode
= right_znode(c
, znode
);
2775 if (znode
->zbranch
[n
].lnum
== lnum
&&
2776 znode
->zbranch
[n
].offs
== offs
)
2777 return get_znode(c
, znode
, n
);
2778 /* Stop if the key is greater than the one we are looking for */
2779 if (keys_cmp(c
, &znode
->zbranch
[n
].key
, key
) > 0)
2786 * is_idx_node_in_tnc - determine if an index node is in the TNC.
2787 * @c: UBIFS file-system description object
2788 * @key: key of index node
2789 * @level: index node level
2790 * @lnum: LEB number of index node
2791 * @offs: offset of index node
2793 * This function returns %0 if the index node is not referred to in the TNC, %1
2794 * if the index node is referred to in the TNC and the corresponding znode is
2795 * dirty, %2 if an index node is referred to in the TNC and the corresponding
2796 * znode is clean, and a negative error code in case of failure.
2798 * Note, the @key argument has to be the key of the first child. Also note,
2799 * this function relies on the fact that 0:0 is never a valid LEB number and
2800 * offset for a main-area node.
2802 int is_idx_node_in_tnc(struct ubifs_info
*c
, union ubifs_key
*key
, int level
,
2805 struct ubifs_znode
*znode
;
2807 znode
= lookup_znode(c
, key
, level
, lnum
, offs
);
2811 return PTR_ERR(znode
);
2813 return ubifs_zn_dirty(znode
) ? 1 : 2;
2817 * is_leaf_node_in_tnc - determine if a non-indexing not is in the TNC.
2818 * @c: UBIFS file-system description object
2820 * @lnum: node LEB number
2821 * @offs: node offset
2823 * This function returns %1 if the node is referred to in the TNC, %0 if it is
2824 * not, and a negative error code in case of failure.
2826 * Note, this function relies on the fact that 0:0 is never a valid LEB number
2827 * and offset for a main-area node.
2829 static int is_leaf_node_in_tnc(struct ubifs_info
*c
, union ubifs_key
*key
,
2832 struct ubifs_zbranch
*zbr
;
2833 struct ubifs_znode
*znode
, *zn
;
2834 int n
, found
, err
, nn
;
2835 const int unique
= !is_hash_key(c
, key
);
2837 found
= ubifs_lookup_level0(c
, key
, &znode
, &n
);
2839 return found
; /* Error code */
2842 zbr
= &znode
->zbranch
[n
];
2843 if (lnum
== zbr
->lnum
&& offs
== zbr
->offs
)
2844 return 1; /* Found it */
2848 * Because the key is not unique, we have to look left
2855 err
= tnc_prev(c
, &znode
, &n
);
2860 if (keys_cmp(c
, key
, &znode
->zbranch
[n
].key
))
2862 zbr
= &znode
->zbranch
[n
];
2863 if (lnum
== zbr
->lnum
&& offs
== zbr
->offs
)
2864 return 1; /* Found it */
2870 err
= tnc_next(c
, &znode
, &n
);
2876 if (keys_cmp(c
, key
, &znode
->zbranch
[n
].key
))
2878 zbr
= &znode
->zbranch
[n
];
2879 if (lnum
== zbr
->lnum
&& offs
== zbr
->offs
)
2880 return 1; /* Found it */
2886 * ubifs_tnc_has_node - determine whether a node is in the TNC.
2887 * @c: UBIFS file-system description object
2889 * @level: index node level (if it is an index node)
2890 * @lnum: node LEB number
2891 * @offs: node offset
2892 * @is_idx: non-zero if the node is an index node
2894 * This function returns %1 if the node is in the TNC, %0 if it is not, and a
2895 * negative error code in case of failure. For index nodes, @key has to be the
2896 * key of the first child. An index node is considered to be in the TNC only if
2897 * the corresponding znode is clean or has not been loaded.
2899 int ubifs_tnc_has_node(struct ubifs_info
*c
, union ubifs_key
*key
, int level
,
2900 int lnum
, int offs
, int is_idx
)
2904 mutex_lock(&c
->tnc_mutex
);
2906 err
= is_idx_node_in_tnc(c
, key
, level
, lnum
, offs
);
2910 /* The index node was found but it was dirty */
2913 /* The index node was found and it was clean */
2918 err
= is_leaf_node_in_tnc(c
, key
, lnum
, offs
);
2921 mutex_unlock(&c
->tnc_mutex
);
2926 * ubifs_dirty_idx_node - dirty an index node.
2927 * @c: UBIFS file-system description object
2928 * @key: index node key
2929 * @level: index node level
2930 * @lnum: index node LEB number
2931 * @offs: index node offset
2933 * This function loads and dirties an index node so that it can be garbage
2934 * collected. The @key argument has to be the key of the first child. This
2935 * function relies on the fact that 0:0 is never a valid LEB number and offset
2936 * for a main-area node. Returns %0 on success and a negative error code on
2939 int ubifs_dirty_idx_node(struct ubifs_info
*c
, union ubifs_key
*key
, int level
,
2942 struct ubifs_znode
*znode
;
2945 mutex_lock(&c
->tnc_mutex
);
2946 znode
= lookup_znode(c
, key
, level
, lnum
, offs
);
2949 if (IS_ERR(znode
)) {
2950 err
= PTR_ERR(znode
);
2953 znode
= dirty_cow_bottom_up(c
, znode
);
2954 if (IS_ERR(znode
)) {
2955 err
= PTR_ERR(znode
);
2960 mutex_unlock(&c
->tnc_mutex
);