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* This file is part of UBIFS.
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* Copyright (C) 2006-2008 Nokia Corporation.
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc., 51
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* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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* Authors: Adrian Hunter
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* Artem Bityutskiy (ŠŠøŃŃŃŠŗŠøŠ¹ ŠŃŃŃŠ¼)
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* This file implements TNC (Tree Node Cache) which caches indexing nodes of
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* At the moment the locking rules of the TNC tree are quite simple and
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* straightforward. We just have a mutex and lock it when we traverse the
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* tree. If a znode is not in memory, we read it from flash while still having
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* Returned codes of 'matches_name()' and 'fallible_matches_name()' functions.
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* @NAME_LESS: name corresponding to the first argument is less than second
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* @NAME_MATCHES: names match
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* @NAME_GREATER: name corresponding to the second argument is greater than
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* @NOT_ON_MEDIA: node referred by zbranch does not exist on the media
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* These constants were introduce to improve readability.
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* insert_old_idx - record an index node obsoleted since the last commit start.
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* @c: UBIFS file-system description object
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* @lnum: LEB number of obsoleted index node
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* @offs: offset of obsoleted index node
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* Returns %0 on success, and a negative error code on failure.
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* For recovery, there must always be a complete intact version of the index on
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* flash at all times. That is called the "old index". It is the index as at the
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* time of the last successful commit. Many of the index nodes in the old index
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* may be dirty, but they must not be erased until the next successful commit
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* (at which point that index becomes the old index).
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* That means that the garbage collection and the in-the-gaps method of
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* committing must be able to determine if an index node is in the old index.
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* Most of the old index nodes can be found by looking up the TNC using the
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* 'lookup_znode()' function. However, some of the old index nodes may have
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* been deleted from the current index or may have been changed so much that
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* they cannot be easily found. In those cases, an entry is added to an RB-tree.
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* That is what this function does. The RB-tree is ordered by LEB number and
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* offset because they uniquely identify the old index node.
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static int insert_old_idx(struct ubifs_info *c, int lnum, int offs)
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struct ubifs_old_idx *old_idx, *o;
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struct rb_node **p, *parent = NULL;
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old_idx = kmalloc(sizeof(struct ubifs_old_idx), GFP_NOFS);
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if (unlikely(!old_idx))
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p = &c->old_idx.rb_node;
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o = rb_entry(parent, struct ubifs_old_idx, rb);
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else if (lnum > o->lnum)
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else if (offs < o->offs)
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else if (offs > o->offs)
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ubifs_err("old idx added twice!");
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rb_link_node(&old_idx->rb, parent, p);
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rb_insert_color(&old_idx->rb, &c->old_idx);
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* insert_old_idx_znode - record a znode obsoleted since last commit start.
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* @c: UBIFS file-system description object
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* @znode: znode of obsoleted index node
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* Returns %0 on success, and a negative error code on failure.
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int insert_old_idx_znode(struct ubifs_info *c, struct ubifs_znode *znode)
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struct ubifs_zbranch *zbr;
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zbr = &znode->parent->zbranch[znode->iip];
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return insert_old_idx(c, zbr->lnum, zbr->offs);
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return insert_old_idx(c, c->zroot.lnum,
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* ins_clr_old_idx_znode - record a znode obsoleted since last commit start.
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* @c: UBIFS file-system description object
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* @znode: znode of obsoleted index node
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* Returns %0 on success, and a negative error code on failure.
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static int ins_clr_old_idx_znode(struct ubifs_info *c,
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struct ubifs_znode *znode)
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struct ubifs_zbranch *zbr;
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zbr = &znode->parent->zbranch[znode->iip];
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err = insert_old_idx(c, zbr->lnum, zbr->offs);
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err = insert_old_idx(c, c->zroot.lnum, c->zroot.offs);
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* destroy_old_idx - destroy the old_idx RB-tree.
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* @c: UBIFS file-system description object
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* During start commit, the old_idx RB-tree is used to avoid overwriting index
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* nodes that were in the index last commit but have since been deleted. This
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* is necessary for recovery i.e. the old index must be kept intact until the
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* new index is successfully written. The old-idx RB-tree is used for the
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* in-the-gaps method of writing index nodes and is destroyed every commit.
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void destroy_old_idx(struct ubifs_info *c)
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struct rb_node *this = c->old_idx.rb_node;
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struct ubifs_old_idx *old_idx;
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this = this->rb_left;
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} else if (this->rb_right) {
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this = this->rb_right;
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old_idx = rb_entry(this, struct ubifs_old_idx, rb);
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this = rb_parent(this);
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if (this->rb_left == &old_idx->rb)
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this->rb_left = NULL;
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this->rb_right = NULL;
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c->old_idx = RB_ROOT;
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* copy_znode - copy a dirty znode.
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* @c: UBIFS file-system description object
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* @znode: znode to copy
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* A dirty znode being committed may not be changed, so it is copied.
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static struct ubifs_znode *copy_znode(struct ubifs_info *c,
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struct ubifs_znode *znode)
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struct ubifs_znode *zn;
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zn = kmalloc(c->max_znode_sz, GFP_NOFS);
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return ERR_PTR(-ENOMEM);
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memcpy(zn, znode, c->max_znode_sz);
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__set_bit(DIRTY_ZNODE, &zn->flags);
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__clear_bit(COW_ZNODE, &zn->flags);
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ubifs_assert(!test_bit(OBSOLETE_ZNODE, &znode->flags));
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__set_bit(OBSOLETE_ZNODE, &znode->flags);
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if (znode->level != 0) {
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const int n = zn->child_cnt;
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/* The children now have new parent */
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for (i = 0; i < n; i++) {
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struct ubifs_zbranch *zbr = &zn->zbranch[i];
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zbr->znode->parent = zn;
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atomic_long_inc(&c->dirty_zn_cnt);
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* add_idx_dirt - add dirt due to a dirty znode.
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* @c: UBIFS file-system description object
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* @lnum: LEB number of index node
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* @dirt: size of index node
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* This function updates lprops dirty space and the new size of the index.
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static int add_idx_dirt(struct ubifs_info *c, int lnum, int dirt)
254
c->calc_idx_sz -= ALIGN(dirt, 8);
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return ubifs_add_dirt(c, lnum, dirt);
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* dirty_cow_znode - ensure a znode is not being committed.
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* @c: UBIFS file-system description object
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* @zbr: branch of znode to check
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* Returns dirtied znode on success or negative error code on failure.
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static struct ubifs_znode *dirty_cow_znode(struct ubifs_info *c,
266
struct ubifs_zbranch *zbr)
268
struct ubifs_znode *znode = zbr->znode;
269
struct ubifs_znode *zn;
272
if (!test_bit(COW_ZNODE, &znode->flags)) {
273
/* znode is not being committed */
274
if (!test_and_set_bit(DIRTY_ZNODE, &znode->flags)) {
275
atomic_long_inc(&c->dirty_zn_cnt);
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atomic_long_dec(&c->clean_zn_cnt);
277
atomic_long_dec(&ubifs_clean_zn_cnt);
278
err = add_idx_dirt(c, zbr->lnum, zbr->len);
285
zn = copy_znode(c, znode);
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err = insert_old_idx(c, zbr->lnum, zbr->offs);
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err = add_idx_dirt(c, zbr->lnum, zbr->len);
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* lnc_add - add a leaf node to the leaf node cache.
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* @c: UBIFS file-system description object
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* @zbr: zbranch of leaf node
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* Leaf nodes are non-index nodes directory entry nodes or data nodes. The
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* purpose of the leaf node cache is to save re-reading the same leaf node over
315
* and over again. Most things are cached by VFS, however the file system must
316
* cache directory entries for readdir and for resolving hash collisions. The
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* present implementation of the leaf node cache is extremely simple, and
318
* allows for error returns that are not used but that may be needed if a more
319
* complex implementation is created.
321
* Note, this function does not add the @node object to LNC directly, but
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* allocates a copy of the object and adds the copy to LNC. The reason for this
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* is that @node has been allocated outside of the TNC subsystem and will be
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* used with @c->tnc_mutex unlock upon return from the TNC subsystem. But LNC
325
* may be changed at any time, e.g. freed by the shrinker.
327
static int lnc_add(struct ubifs_info *c, struct ubifs_zbranch *zbr,
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const struct ubifs_dent_node *dent = node;
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ubifs_assert(!zbr->leaf);
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ubifs_assert(zbr->len != 0);
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ubifs_assert(is_hash_key(c, &zbr->key));
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err = ubifs_validate_entry(c, dent);
341
dbg_dump_node(c, dent);
345
lnc_node = kmalloc(zbr->len, GFP_NOFS);
347
/* We don't have to have the cache, so no error */
350
memcpy(lnc_node, node, zbr->len);
351
zbr->leaf = lnc_node;
356
* lnc_add_directly - add a leaf node to the leaf-node-cache.
357
* @c: UBIFS file-system description object
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* @zbr: zbranch of leaf node
361
* This function is similar to 'lnc_add()', but it does not create a copy of
362
* @node but inserts @node to TNC directly.
364
static int lnc_add_directly(struct ubifs_info *c, struct ubifs_zbranch *zbr,
369
ubifs_assert(!zbr->leaf);
370
ubifs_assert(zbr->len != 0);
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err = ubifs_validate_entry(c, node);
375
dbg_dump_node(c, node);
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* lnc_free - remove a leaf node from the leaf node cache.
385
* @zbr: zbranch of leaf node
388
static void lnc_free(struct ubifs_zbranch *zbr)
397
* tnc_read_node_nm - read a "hashed" leaf node.
398
* @c: UBIFS file-system description object
399
* @zbr: key and position of the node
400
* @node: node is returned here
402
* This function reads a "hashed" node defined by @zbr from the leaf node cache
403
* (in it is there) or from the hash media, in which case the node is also
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* added to LNC. Returns zero in case of success or a negative negative error
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* code in case of failure.
407
static int tnc_read_node_nm(struct ubifs_info *c, struct ubifs_zbranch *zbr,
412
ubifs_assert(is_hash_key(c, &zbr->key));
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/* Read from the leaf node cache */
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ubifs_assert(zbr->len != 0);
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memcpy(node, zbr->leaf, zbr->len);
421
err = ubifs_tnc_read_node(c, zbr, node);
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/* Add the node to the leaf node cache */
426
err = lnc_add(c, zbr, node);
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* try_read_node - read a node if it is a node.
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* @c: UBIFS file-system description object
433
* @buf: buffer to read to
435
* @len: node length (not aligned)
436
* @lnum: LEB number of node to read
437
* @offs: offset of node to read
439
* This function tries to read a node of known type and length, checks it and
440
* stores it in @buf. This function returns %1 if a node is present and %0 if
441
* a node is not present. A negative error code is returned for I/O errors.
442
* This function performs that same function as ubifs_read_node except that
443
* it does not require that there is actually a node present and instead
444
* the return code indicates if a node was read.
446
* Note, this function does not check CRC of data nodes if @c->no_chk_data_crc
447
* is true (it is controlled by corresponding mount option). However, if
448
* @c->always_chk_crc is true, @c->no_chk_data_crc is ignored and CRC is always
451
static int try_read_node(const struct ubifs_info *c, void *buf, int type,
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int len, int lnum, int offs)
455
struct ubifs_ch *ch = buf;
456
uint32_t crc, node_crc;
458
dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len);
460
err = ubi_read(c->ubi, lnum, buf, offs, len);
462
ubifs_err("cannot read node type %d from LEB %d:%d, error %d",
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type, lnum, offs, err);
467
if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC)
470
if (ch->node_type != type)
473
node_len = le32_to_cpu(ch->len);
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if (type == UBIFS_DATA_NODE && !c->always_chk_crc && c->no_chk_data_crc)
480
crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8);
481
node_crc = le32_to_cpu(ch->crc);
489
* fallible_read_node - try to read a leaf node.
490
* @c: UBIFS file-system description object
491
* @key: key of node to read
492
* @zbr: position of node
493
* @node: node returned
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* This function tries to read a node and returns %1 if the node is read, %0
496
* if the node is not present, and a negative error code in the case of error.
498
static int fallible_read_node(struct ubifs_info *c, const union ubifs_key *key,
499
struct ubifs_zbranch *zbr, void *node)
503
dbg_tnc("LEB %d:%d, key %s", zbr->lnum, zbr->offs, DBGKEY(key));
505
ret = try_read_node(c, node, key_type(c, key), zbr->len, zbr->lnum,
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union ubifs_key node_key;
509
struct ubifs_dent_node *dent = node;
511
/* All nodes have key in the same place */
512
key_read(c, &dent->key, &node_key);
513
if (keys_cmp(c, key, &node_key) != 0)
516
if (ret == 0 && c->replaying)
517
dbg_mnt("dangling branch LEB %d:%d len %d, key %s",
518
zbr->lnum, zbr->offs, zbr->len, DBGKEY(key));
523
* matches_name - determine if a direntry or xattr entry matches a given name.
524
* @c: UBIFS file-system description object
525
* @zbr: zbranch of dent
528
* This function checks if xentry/direntry referred by zbranch @zbr matches name
529
* @nm. Returns %NAME_MATCHES if it does, %NAME_LESS if the name referred by
530
* @zbr is less than @nm, and %NAME_GREATER if it is greater than @nm. In case
531
* of failure, a negative error code is returned.
533
static int matches_name(struct ubifs_info *c, struct ubifs_zbranch *zbr,
534
const struct qstr *nm)
536
struct ubifs_dent_node *dent;
539
/* If possible, match against the dent in the leaf node cache */
541
dent = kmalloc(zbr->len, GFP_NOFS);
545
err = ubifs_tnc_read_node(c, zbr, dent);
549
/* Add the node to the leaf node cache */
550
err = lnc_add_directly(c, zbr, dent);
556
nlen = le16_to_cpu(dent->nlen);
557
err = memcmp(dent->name, nm->name, min_t(int, nlen, nm->len));
561
else if (nlen < nm->len)
576
* get_znode - get a TNC znode that may not be loaded yet.
577
* @c: UBIFS file-system description object
578
* @znode: parent znode
579
* @n: znode branch slot number
581
* This function returns the znode or a negative error code.
583
static struct ubifs_znode *get_znode(struct ubifs_info *c,
584
struct ubifs_znode *znode, int n)
586
struct ubifs_zbranch *zbr;
588
zbr = &znode->zbranch[n];
592
znode = ubifs_load_znode(c, zbr, znode, n);
597
* tnc_next - find next TNC entry.
598
* @c: UBIFS file-system description object
599
* @zn: znode is passed and returned here
600
* @n: znode branch slot number is passed and returned here
602
* This function returns %0 if the next TNC entry is found, %-ENOENT if there is
603
* no next entry, or a negative error code otherwise.
605
static int tnc_next(struct ubifs_info *c, struct ubifs_znode **zn, int *n)
607
struct ubifs_znode *znode = *zn;
611
if (nn < znode->child_cnt) {
616
struct ubifs_znode *zp;
623
if (nn < znode->child_cnt) {
624
znode = get_znode(c, znode, nn);
626
return PTR_ERR(znode);
627
while (znode->level != 0) {
628
znode = get_znode(c, znode, 0);
630
return PTR_ERR(znode);
642
* tnc_prev - find previous TNC entry.
643
* @c: UBIFS file-system description object
644
* @zn: znode is returned here
645
* @n: znode branch slot number is passed and returned here
647
* This function returns %0 if the previous TNC entry is found, %-ENOENT if
648
* there is no next entry, or a negative error code otherwise.
650
static int tnc_prev(struct ubifs_info *c, struct ubifs_znode **zn, int *n)
652
struct ubifs_znode *znode = *zn;
660
struct ubifs_znode *zp;
668
znode = get_znode(c, znode, nn);
670
return PTR_ERR(znode);
671
while (znode->level != 0) {
672
nn = znode->child_cnt - 1;
673
znode = get_znode(c, znode, nn);
675
return PTR_ERR(znode);
677
nn = znode->child_cnt - 1;
687
* resolve_collision - resolve a collision.
688
* @c: UBIFS file-system description object
689
* @key: key of a directory or extended attribute entry
690
* @zn: znode is returned here
691
* @n: zbranch number is passed and returned here
692
* @nm: name of the entry
694
* This function is called for "hashed" keys to make sure that the found key
695
* really corresponds to the looked up node (directory or extended attribute
696
* entry). It returns %1 and sets @zn and @n if the collision is resolved.
697
* %0 is returned if @nm is not found and @zn and @n are set to the previous
698
* entry, i.e. to the entry after which @nm could follow if it were in TNC.
699
* This means that @n may be set to %-1 if the leftmost key in @zn is the
700
* previous one. A negative error code is returned on failures.
702
static int resolve_collision(struct ubifs_info *c, const union ubifs_key *key,
703
struct ubifs_znode **zn, int *n,
704
const struct qstr *nm)
708
err = matches_name(c, &(*zn)->zbranch[*n], nm);
709
if (unlikely(err < 0))
711
if (err == NAME_MATCHES)
714
if (err == NAME_GREATER) {
717
err = tnc_prev(c, zn, n);
718
if (err == -ENOENT) {
719
ubifs_assert(*n == 0);
725
if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) {
727
* We have found the branch after which we would
728
* like to insert, but inserting in this znode
729
* may still be wrong. Consider the following 3
730
* znodes, in the case where we are resolving a
731
* collision with Key2.
734
* ----------------------
735
* level 1 | Key0 | Key1 |
736
* -----------------------
738
* znode za | | znode zb
739
* ------------ ------------
740
* level 0 | Key0 | | Key2 |
741
* ------------ ------------
743
* The lookup finds Key2 in znode zb. Lets say
744
* there is no match and the name is greater so
745
* we look left. When we find Key0, we end up
746
* here. If we return now, we will insert into
747
* znode za at slot n = 1. But that is invalid
748
* according to the parent's keys. Key2 must
749
* be inserted into znode zb.
751
* Note, this problem is not relevant for the
752
* case when we go right, because
753
* 'tnc_insert()' would correct the parent key.
755
if (*n == (*zn)->child_cnt - 1) {
756
err = tnc_next(c, zn, n);
758
/* Should be impossible */
764
ubifs_assert(*n == 0);
769
err = matches_name(c, &(*zn)->zbranch[*n], nm);
772
if (err == NAME_LESS)
774
if (err == NAME_MATCHES)
776
ubifs_assert(err == NAME_GREATER);
780
struct ubifs_znode *znode = *zn;
784
err = tnc_next(c, &znode, &nn);
789
if (keys_cmp(c, &znode->zbranch[nn].key, key))
791
err = matches_name(c, &znode->zbranch[nn], nm);
794
if (err == NAME_GREATER)
798
if (err == NAME_MATCHES)
800
ubifs_assert(err == NAME_LESS);
806
* fallible_matches_name - determine if a dent matches a given name.
807
* @c: UBIFS file-system description object
808
* @zbr: zbranch of dent
811
* This is a "fallible" version of 'matches_name()' function which does not
812
* panic if the direntry/xentry referred by @zbr does not exist on the media.
814
* This function checks if xentry/direntry referred by zbranch @zbr matches name
815
* @nm. Returns %NAME_MATCHES it does, %NAME_LESS if the name referred by @zbr
816
* is less than @nm, %NAME_GREATER if it is greater than @nm, and @NOT_ON_MEDIA
817
* if xentry/direntry referred by @zbr does not exist on the media. A negative
818
* error code is returned in case of failure.
820
static int fallible_matches_name(struct ubifs_info *c,
821
struct ubifs_zbranch *zbr,
822
const struct qstr *nm)
824
struct ubifs_dent_node *dent;
827
/* If possible, match against the dent in the leaf node cache */
829
dent = kmalloc(zbr->len, GFP_NOFS);
833
err = fallible_read_node(c, &zbr->key, zbr, dent);
837
/* The node was not present */
841
ubifs_assert(err == 1);
843
err = lnc_add_directly(c, zbr, dent);
849
nlen = le16_to_cpu(dent->nlen);
850
err = memcmp(dent->name, nm->name, min_t(int, nlen, nm->len));
854
else if (nlen < nm->len)
869
* fallible_resolve_collision - resolve a collision even if nodes are missing.
870
* @c: UBIFS file-system description object
872
* @zn: znode is returned here
873
* @n: branch number is passed and returned here
874
* @nm: name of directory entry
875
* @adding: indicates caller is adding a key to the TNC
877
* This is a "fallible" version of the 'resolve_collision()' function which
878
* does not panic if one of the nodes referred to by TNC does not exist on the
879
* media. This may happen when replaying the journal if a deleted node was
880
* Garbage-collected and the commit was not done. A branch that refers to a node
881
* that is not present is called a dangling branch. The following are the return
882
* codes for this function:
883
* o if @nm was found, %1 is returned and @zn and @n are set to the found
885
* o if we are @adding and @nm was not found, %0 is returned;
886
* o if we are not @adding and @nm was not found, but a dangling branch was
887
* found, then %1 is returned and @zn and @n are set to the dangling branch;
888
* o a negative error code is returned in case of failure.
890
static int fallible_resolve_collision(struct ubifs_info *c,
891
const union ubifs_key *key,
892
struct ubifs_znode **zn, int *n,
893
const struct qstr *nm, int adding)
895
struct ubifs_znode *o_znode = NULL, *znode = *zn;
896
int uninitialized_var(o_n), err, cmp, unsure = 0, nn = *n;
898
cmp = fallible_matches_name(c, &znode->zbranch[nn], nm);
899
if (unlikely(cmp < 0))
901
if (cmp == NAME_MATCHES)
903
if (cmp == NOT_ON_MEDIA) {
907
* We are unlucky and hit a dangling branch straight away.
908
* Now we do not really know where to go to find the needed
909
* branch - to the left or to the right. Well, let's try left.
913
unsure = 1; /* Remove a dangling branch wherever it is */
915
if (cmp == NAME_GREATER || unsure) {
918
err = tnc_prev(c, zn, n);
919
if (err == -ENOENT) {
920
ubifs_assert(*n == 0);
926
if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) {
927
/* See comments in 'resolve_collision()' */
928
if (*n == (*zn)->child_cnt - 1) {
929
err = tnc_next(c, zn, n);
931
/* Should be impossible */
937
ubifs_assert(*n == 0);
942
err = fallible_matches_name(c, &(*zn)->zbranch[*n], nm);
945
if (err == NAME_MATCHES)
947
if (err == NOT_ON_MEDIA) {
954
if (err == NAME_LESS)
961
if (cmp == NAME_LESS || unsure) {
966
err = tnc_next(c, &znode, &nn);
971
if (keys_cmp(c, &znode->zbranch[nn].key, key))
973
err = fallible_matches_name(c, &znode->zbranch[nn], nm);
976
if (err == NAME_GREATER)
980
if (err == NAME_MATCHES)
982
if (err == NOT_ON_MEDIA) {
989
/* Never match a dangling branch when adding */
990
if (adding || !o_znode)
993
dbg_mnt("dangling match LEB %d:%d len %d %s",
994
o_znode->zbranch[o_n].lnum, o_znode->zbranch[o_n].offs,
995
o_znode->zbranch[o_n].len, DBGKEY(key));
1002
* matches_position - determine if a zbranch matches a given position.
1003
* @zbr: zbranch of dent
1004
* @lnum: LEB number of dent to match
1005
* @offs: offset of dent to match
1007
* This function returns %1 if @lnum:@offs matches, and %0 otherwise.
1009
static int matches_position(struct ubifs_zbranch *zbr, int lnum, int offs)
1011
if (zbr->lnum == lnum && zbr->offs == offs)
1018
* resolve_collision_directly - resolve a collision directly.
1019
* @c: UBIFS file-system description object
1020
* @key: key of directory entry
1021
* @zn: znode is passed and returned here
1022
* @n: zbranch number is passed and returned here
1023
* @lnum: LEB number of dent node to match
1024
* @offs: offset of dent node to match
1026
* This function is used for "hashed" keys to make sure the found directory or
1027
* extended attribute entry node is what was looked for. It is used when the
1028
* flash address of the right node is known (@lnum:@offs) which makes it much
1029
* easier to resolve collisions (no need to read entries and match full
1030
* names). This function returns %1 and sets @zn and @n if the collision is
1031
* resolved, %0 if @lnum:@offs is not found and @zn and @n are set to the
1032
* previous directory entry. Otherwise a negative error code is returned.
1034
static int resolve_collision_directly(struct ubifs_info *c,
1035
const union ubifs_key *key,
1036
struct ubifs_znode **zn, int *n,
1039
struct ubifs_znode *znode;
1044
if (matches_position(&znode->zbranch[nn], lnum, offs))
1049
err = tnc_prev(c, &znode, &nn);
1054
if (keys_cmp(c, &znode->zbranch[nn].key, key))
1056
if (matches_position(&znode->zbranch[nn], lnum, offs)) {
1067
err = tnc_next(c, &znode, &nn);
1072
if (keys_cmp(c, &znode->zbranch[nn].key, key))
1076
if (matches_position(&znode->zbranch[nn], lnum, offs))
1082
* dirty_cow_bottom_up - dirty a znode and its ancestors.
1083
* @c: UBIFS file-system description object
1084
* @znode: znode to dirty
1086
* If we do not have a unique key that resides in a znode, then we cannot
1087
* dirty that znode from the top down (i.e. by using lookup_level0_dirty)
1088
* This function records the path back to the last dirty ancestor, and then
1089
* dirties the znodes on that path.
1091
static struct ubifs_znode *dirty_cow_bottom_up(struct ubifs_info *c,
1092
struct ubifs_znode *znode)
1094
struct ubifs_znode *zp;
1095
int *path = c->bottom_up_buf, p = 0;
1097
ubifs_assert(c->zroot.znode);
1098
ubifs_assert(znode);
1099
if (c->zroot.znode->level > BOTTOM_UP_HEIGHT) {
1100
kfree(c->bottom_up_buf);
1101
c->bottom_up_buf = kmalloc(c->zroot.znode->level * sizeof(int),
1103
if (!c->bottom_up_buf)
1104
return ERR_PTR(-ENOMEM);
1105
path = c->bottom_up_buf;
1107
if (c->zroot.znode->level) {
1108
/* Go up until parent is dirty */
1116
ubifs_assert(p < c->zroot.znode->level);
1118
if (!zp->cnext && ubifs_zn_dirty(znode))
1124
/* Come back down, dirtying as we go */
1126
struct ubifs_zbranch *zbr;
1130
ubifs_assert(path[p - 1] >= 0);
1131
ubifs_assert(path[p - 1] < zp->child_cnt);
1132
zbr = &zp->zbranch[path[--p]];
1133
znode = dirty_cow_znode(c, zbr);
1135
ubifs_assert(znode == c->zroot.znode);
1136
znode = dirty_cow_znode(c, &c->zroot);
1138
if (IS_ERR(znode) || !p)
1140
ubifs_assert(path[p - 1] >= 0);
1141
ubifs_assert(path[p - 1] < znode->child_cnt);
1142
znode = znode->zbranch[path[p - 1]].znode;
1149
* ubifs_lookup_level0 - search for zero-level znode.
1150
* @c: UBIFS file-system description object
1151
* @key: key to lookup
1152
* @zn: znode is returned here
1153
* @n: znode branch slot number is returned here
1155
* This function looks up the TNC tree and search for zero-level znode which
1156
* refers key @key. The found zero-level znode is returned in @zn. There are 3
1158
* o exact match, i.e. the found zero-level znode contains key @key, then %1
1159
* is returned and slot number of the matched branch is stored in @n;
1160
* o not exact match, which means that zero-level znode does not contain
1161
* @key, then %0 is returned and slot number of the closed branch is stored
1163
* o @key is so small that it is even less than the lowest key of the
1164
* leftmost zero-level node, then %0 is returned and %0 is stored in @n.
1166
* Note, when the TNC tree is traversed, some znodes may be absent, then this
1167
* function reads corresponding indexing nodes and inserts them to TNC. In
1168
* case of failure, a negative error code is returned.
1170
int ubifs_lookup_level0(struct ubifs_info *c, const union ubifs_key *key,
1171
struct ubifs_znode **zn, int *n)
1174
struct ubifs_znode *znode;
1175
unsigned long time = get_seconds();
1177
dbg_tnc("search key %s", DBGKEY(key));
1179
znode = c->zroot.znode;
1180
if (unlikely(!znode)) {
1181
znode = ubifs_load_znode(c, &c->zroot, NULL, 0);
1183
return PTR_ERR(znode);
1189
struct ubifs_zbranch *zbr;
1191
exact = ubifs_search_zbranch(c, znode, key, n);
1193
if (znode->level == 0)
1198
zbr = &znode->zbranch[*n];
1206
/* znode is not in TNC cache, load it from the media */
1207
znode = ubifs_load_znode(c, zbr, znode, *n);
1209
return PTR_ERR(znode);
1213
if (exact || !is_hash_key(c, key) || *n != -1) {
1214
dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n);
1219
* Here is a tricky place. We have not found the key and this is a
1220
* "hashed" key, which may collide. The rest of the code deals with
1221
* situations like this:
1225
* | 3 | 5 | | 6 | 7 | (x)
1227
* Or more a complex example:
1231
* | 1 | 3 | | 5 | 8 |
1233
* | 5 | 5 | | 6 | 7 | (x)
1235
* In the examples, if we are looking for key "5", we may reach nodes
1236
* marked with "(x)". In this case what we have do is to look at the
1237
* left and see if there is "5" key there. If there is, we have to
1240
* Note, this whole situation is possible because we allow to have
1241
* elements which are equivalent to the next key in the parent in the
1242
* children of current znode. For example, this happens if we split a
1243
* znode like this: | 3 | 5 | 5 | 6 | 7 |, which results in something
1247
* | 3 | 5 | | 5 | 6 | 7 |
1249
* And this becomes what is at the first "picture" after key "5" marked
1250
* with "^" is removed. What could be done is we could prohibit
1251
* splitting in the middle of the colliding sequence. Also, when
1252
* removing the leftmost key, we would have to correct the key of the
1253
* parent node, which would introduce additional complications. Namely,
1254
* if we changed the the leftmost key of the parent znode, the garbage
1255
* collector would be unable to find it (GC is doing this when GC'ing
1256
* indexing LEBs). Although we already have an additional RB-tree where
1257
* we save such changed znodes (see 'ins_clr_old_idx_znode()') until
1258
* after the commit. But anyway, this does not look easy to implement
1259
* so we did not try this.
1261
err = tnc_prev(c, &znode, n);
1262
if (err == -ENOENT) {
1263
dbg_tnc("found 0, lvl %d, n -1", znode->level);
1267
if (unlikely(err < 0))
1269
if (keys_cmp(c, key, &znode->zbranch[*n].key)) {
1270
dbg_tnc("found 0, lvl %d, n -1", znode->level);
1275
dbg_tnc("found 1, lvl %d, n %d", znode->level, *n);
1281
* lookup_level0_dirty - search for zero-level znode dirtying.
1282
* @c: UBIFS file-system description object
1283
* @key: key to lookup
1284
* @zn: znode is returned here
1285
* @n: znode branch slot number is returned here
1287
* This function looks up the TNC tree and search for zero-level znode which
1288
* refers key @key. The found zero-level znode is returned in @zn. There are 3
1290
* o exact match, i.e. the found zero-level znode contains key @key, then %1
1291
* is returned and slot number of the matched branch is stored in @n;
1292
* o not exact match, which means that zero-level znode does not contain @key
1293
* then %0 is returned and slot number of the closed branch is stored in
1295
* o @key is so small that it is even less than the lowest key of the
1296
* leftmost zero-level node, then %0 is returned and %-1 is stored in @n.
1298
* Additionally all znodes in the path from the root to the located zero-level
1299
* znode are marked as dirty.
1301
* Note, when the TNC tree is traversed, some znodes may be absent, then this
1302
* function reads corresponding indexing nodes and inserts them to TNC. In
1303
* case of failure, a negative error code is returned.
1305
static int lookup_level0_dirty(struct ubifs_info *c, const union ubifs_key *key,
1306
struct ubifs_znode **zn, int *n)
1309
struct ubifs_znode *znode;
1310
unsigned long time = get_seconds();
1312
dbg_tnc("search and dirty key %s", DBGKEY(key));
1314
znode = c->zroot.znode;
1315
if (unlikely(!znode)) {
1316
znode = ubifs_load_znode(c, &c->zroot, NULL, 0);
1318
return PTR_ERR(znode);
1321
znode = dirty_cow_znode(c, &c->zroot);
1323
return PTR_ERR(znode);
1328
struct ubifs_zbranch *zbr;
1330
exact = ubifs_search_zbranch(c, znode, key, n);
1332
if (znode->level == 0)
1337
zbr = &znode->zbranch[*n];
1341
znode = dirty_cow_znode(c, zbr);
1343
return PTR_ERR(znode);
1347
/* znode is not in TNC cache, load it from the media */
1348
znode = ubifs_load_znode(c, zbr, znode, *n);
1350
return PTR_ERR(znode);
1351
znode = dirty_cow_znode(c, zbr);
1353
return PTR_ERR(znode);
1357
if (exact || !is_hash_key(c, key) || *n != -1) {
1358
dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n);
1363
* See huge comment at 'lookup_level0_dirty()' what is the rest of the
1366
err = tnc_prev(c, &znode, n);
1367
if (err == -ENOENT) {
1369
dbg_tnc("found 0, lvl %d, n -1", znode->level);
1372
if (unlikely(err < 0))
1374
if (keys_cmp(c, key, &znode->zbranch[*n].key)) {
1376
dbg_tnc("found 0, lvl %d, n -1", znode->level);
1380
if (znode->cnext || !ubifs_zn_dirty(znode)) {
1381
znode = dirty_cow_bottom_up(c, znode);
1383
return PTR_ERR(znode);
1386
dbg_tnc("found 1, lvl %d, n %d", znode->level, *n);
1392
* maybe_leb_gced - determine if a LEB may have been garbage collected.
1393
* @c: UBIFS file-system description object
1395
* @gc_seq1: garbage collection sequence number
1397
* This function determines if @lnum may have been garbage collected since
1398
* sequence number @gc_seq1. If it may have been then %1 is returned, otherwise
1401
static int maybe_leb_gced(struct ubifs_info *c, int lnum, int gc_seq1)
1404
* No garbage collection in the read-only U-Boot implementation
1410
* ubifs_tnc_locate - look up a file-system node and return it and its location.
1411
* @c: UBIFS file-system description object
1412
* @key: node key to lookup
1413
* @node: the node is returned here
1414
* @lnum: LEB number is returned here
1415
* @offs: offset is returned here
1417
* This function look up and reads node with key @key. The caller has to make
1418
* sure the @node buffer is large enough to fit the node. Returns zero in case
1419
* of success, %-ENOENT if the node was not found, and a negative error code in
1420
* case of failure. The node location can be returned in @lnum and @offs.
1422
int ubifs_tnc_locate(struct ubifs_info *c, const union ubifs_key *key,
1423
void *node, int *lnum, int *offs)
1425
int found, n, err, safely = 0, gc_seq1;
1426
struct ubifs_znode *znode;
1427
struct ubifs_zbranch zbr, *zt;
1430
mutex_lock(&c->tnc_mutex);
1431
found = ubifs_lookup_level0(c, key, &znode, &n);
1435
} else if (found < 0) {
1439
zt = &znode->zbranch[n];
1444
if (is_hash_key(c, key)) {
1446
* In this case the leaf node cache gets used, so we pass the
1447
* address of the zbranch and keep the mutex locked
1449
err = tnc_read_node_nm(c, zt, node);
1453
err = ubifs_tnc_read_node(c, zt, node);
1456
/* Drop the TNC mutex prematurely and race with garbage collection */
1457
zbr = znode->zbranch[n];
1458
gc_seq1 = c->gc_seq;
1459
mutex_unlock(&c->tnc_mutex);
1461
err = fallible_read_node(c, key, &zbr, node);
1462
if (err <= 0 || maybe_leb_gced(c, zbr.lnum, gc_seq1)) {
1464
* The node may have been GC'ed out from under us so try again
1465
* while keeping the TNC mutex locked.
1473
mutex_unlock(&c->tnc_mutex);
1478
* ubifs_tnc_get_bu_keys - lookup keys for bulk-read.
1479
* @c: UBIFS file-system description object
1480
* @bu: bulk-read parameters and results
1482
* Lookup consecutive data node keys for the same inode that reside
1483
* consecutively in the same LEB. This function returns zero in case of success
1484
* and a negative error code in case of failure.
1486
* Note, if the bulk-read buffer length (@bu->buf_len) is known, this function
1487
* makes sure bulk-read nodes fit the buffer. Otherwise, this function prepares
1488
* maximum possible amount of nodes for bulk-read.
1490
int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu)
1492
int n, err = 0, lnum = -1, uninitialized_var(offs);
1493
int uninitialized_var(len);
1494
unsigned int block = key_block(c, &bu->key);
1495
struct ubifs_znode *znode;
1501
mutex_lock(&c->tnc_mutex);
1502
/* Find first key */
1503
err = ubifs_lookup_level0(c, &bu->key, &znode, &n);
1508
len = znode->zbranch[n].len;
1509
/* The buffer must be big enough for at least 1 node */
1510
if (len > bu->buf_len) {
1515
bu->zbranch[bu->cnt++] = znode->zbranch[n];
1517
lnum = znode->zbranch[n].lnum;
1518
offs = ALIGN(znode->zbranch[n].offs + len, 8);
1521
struct ubifs_zbranch *zbr;
1522
union ubifs_key *key;
1523
unsigned int next_block;
1526
err = tnc_next(c, &znode, &n);
1529
zbr = &znode->zbranch[n];
1531
/* See if there is another data key for this file */
1532
if (key_inum(c, key) != key_inum(c, &bu->key) ||
1533
key_type(c, key) != UBIFS_DATA_KEY) {
1538
/* First key found */
1540
offs = ALIGN(zbr->offs + zbr->len, 8);
1542
if (len > bu->buf_len) {
1548
* The data nodes must be in consecutive positions in
1551
if (zbr->lnum != lnum || zbr->offs != offs)
1553
offs += ALIGN(zbr->len, 8);
1554
len = ALIGN(len, 8) + zbr->len;
1555
/* Must not exceed buffer length */
1556
if (len > bu->buf_len)
1559
/* Allow for holes */
1560
next_block = key_block(c, key);
1561
bu->blk_cnt += (next_block - block - 1);
1562
if (bu->blk_cnt >= UBIFS_MAX_BULK_READ)
1566
bu->zbranch[bu->cnt++] = *zbr;
1568
/* See if we have room for more */
1569
if (bu->cnt >= UBIFS_MAX_BULK_READ)
1571
if (bu->blk_cnt >= UBIFS_MAX_BULK_READ)
1575
if (err == -ENOENT) {
1579
bu->gc_seq = c->gc_seq;
1580
mutex_unlock(&c->tnc_mutex);
1584
* An enormous hole could cause bulk-read to encompass too many
1585
* page cache pages, so limit the number here.
1587
if (bu->blk_cnt > UBIFS_MAX_BULK_READ)
1588
bu->blk_cnt = UBIFS_MAX_BULK_READ;
1590
* Ensure that bulk-read covers a whole number of page cache
1593
if (UBIFS_BLOCKS_PER_PAGE == 1 ||
1594
!(bu->blk_cnt & (UBIFS_BLOCKS_PER_PAGE - 1)))
1597
/* At the end of file we can round up */
1598
bu->blk_cnt += UBIFS_BLOCKS_PER_PAGE - 1;
1601
/* Exclude data nodes that do not make up a whole page cache page */
1602
block = key_block(c, &bu->key) + bu->blk_cnt;
1603
block &= ~(UBIFS_BLOCKS_PER_PAGE - 1);
1605
if (key_block(c, &bu->zbranch[bu->cnt - 1].key) < block)
1613
* validate_data_node - validate data nodes for bulk-read.
1614
* @c: UBIFS file-system description object
1615
* @buf: buffer containing data node to validate
1616
* @zbr: zbranch of data node to validate
1618
* This functions returns %0 on success or a negative error code on failure.
1620
static int validate_data_node(struct ubifs_info *c, void *buf,
1621
struct ubifs_zbranch *zbr)
1623
union ubifs_key key1;
1624
struct ubifs_ch *ch = buf;
1627
if (ch->node_type != UBIFS_DATA_NODE) {
1628
ubifs_err("bad node type (%d but expected %d)",
1629
ch->node_type, UBIFS_DATA_NODE);
1633
err = ubifs_check_node(c, buf, zbr->lnum, zbr->offs, 0, 0);
1635
ubifs_err("expected node type %d", UBIFS_DATA_NODE);
1639
len = le32_to_cpu(ch->len);
1640
if (len != zbr->len) {
1641
ubifs_err("bad node length %d, expected %d", len, zbr->len);
1645
/* Make sure the key of the read node is correct */
1646
key_read(c, buf + UBIFS_KEY_OFFSET, &key1);
1647
if (!keys_eq(c, &zbr->key, &key1)) {
1648
ubifs_err("bad key in node at LEB %d:%d",
1649
zbr->lnum, zbr->offs);
1650
dbg_tnc("looked for key %s found node's key %s",
1651
DBGKEY(&zbr->key), DBGKEY1(&key1));
1660
ubifs_err("bad node at LEB %d:%d", zbr->lnum, zbr->offs);
1661
dbg_dump_node(c, buf);
1667
* ubifs_tnc_bulk_read - read a number of data nodes in one go.
1668
* @c: UBIFS file-system description object
1669
* @bu: bulk-read parameters and results
1671
* This functions reads and validates the data nodes that were identified by the
1672
* 'ubifs_tnc_get_bu_keys()' function. This functions returns %0 on success,
1673
* -EAGAIN to indicate a race with GC, or another negative error code on
1676
int ubifs_tnc_bulk_read(struct ubifs_info *c, struct bu_info *bu)
1678
int lnum = bu->zbranch[0].lnum, offs = bu->zbranch[0].offs, len, err, i;
1681
len = bu->zbranch[bu->cnt - 1].offs;
1682
len += bu->zbranch[bu->cnt - 1].len - offs;
1683
if (len > bu->buf_len) {
1684
ubifs_err("buffer too small %d vs %d", bu->buf_len, len);
1689
err = ubi_read(c->ubi, lnum, bu->buf, offs, len);
1691
/* Check for a race with GC */
1692
if (maybe_leb_gced(c, lnum, bu->gc_seq))
1695
if (err && err != -EBADMSG) {
1696
ubifs_err("failed to read from LEB %d:%d, error %d",
1699
dbg_tnc("key %s", DBGKEY(&bu->key));
1703
/* Validate the nodes read */
1705
for (i = 0; i < bu->cnt; i++) {
1706
err = validate_data_node(c, buf, &bu->zbranch[i]);
1709
buf = buf + ALIGN(bu->zbranch[i].len, 8);
1716
* do_lookup_nm- look up a "hashed" node.
1717
* @c: UBIFS file-system description object
1718
* @key: node key to lookup
1719
* @node: the node is returned here
1722
* This function look up and reads a node which contains name hash in the key.
1723
* Since the hash may have collisions, there may be many nodes with the same
1724
* key, so we have to sequentially look to all of them until the needed one is
1725
* found. This function returns zero in case of success, %-ENOENT if the node
1726
* was not found, and a negative error code in case of failure.
1728
static int do_lookup_nm(struct ubifs_info *c, const union ubifs_key *key,
1729
void *node, const struct qstr *nm)
1732
struct ubifs_znode *znode;
1734
dbg_tnc("name '%.*s' key %s", nm->len, nm->name, DBGKEY(key));
1735
mutex_lock(&c->tnc_mutex);
1736
found = ubifs_lookup_level0(c, key, &znode, &n);
1740
} else if (found < 0) {
1745
ubifs_assert(n >= 0);
1747
err = resolve_collision(c, key, &znode, &n, nm);
1748
dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n);
1749
if (unlikely(err < 0))
1756
err = tnc_read_node_nm(c, &znode->zbranch[n], node);
1759
mutex_unlock(&c->tnc_mutex);
1764
* ubifs_tnc_lookup_nm - look up a "hashed" node.
1765
* @c: UBIFS file-system description object
1766
* @key: node key to lookup
1767
* @node: the node is returned here
1770
* This function look up and reads a node which contains name hash in the key.
1771
* Since the hash may have collisions, there may be many nodes with the same
1772
* key, so we have to sequentially look to all of them until the needed one is
1773
* found. This function returns zero in case of success, %-ENOENT if the node
1774
* was not found, and a negative error code in case of failure.
1776
int ubifs_tnc_lookup_nm(struct ubifs_info *c, const union ubifs_key *key,
1777
void *node, const struct qstr *nm)
1780
const struct ubifs_dent_node *dent = node;
1783
* We assume that in most of the cases there are no name collisions and
1784
* 'ubifs_tnc_lookup()' returns us the right direntry.
1786
err = ubifs_tnc_lookup(c, key, node);
1790
len = le16_to_cpu(dent->nlen);
1791
if (nm->len == len && !memcmp(dent->name, nm->name, len))
1795
* Unluckily, there are hash collisions and we have to iterate over
1796
* them look at each direntry with colliding name hash sequentially.
1798
return do_lookup_nm(c, key, node, nm);
1802
* correct_parent_keys - correct parent znodes' keys.
1803
* @c: UBIFS file-system description object
1804
* @znode: znode to correct parent znodes for
1806
* This is a helper function for 'tnc_insert()'. When the key of the leftmost
1807
* zbranch changes, keys of parent znodes have to be corrected. This helper
1808
* function is called in such situations and corrects the keys if needed.
1810
static void correct_parent_keys(const struct ubifs_info *c,
1811
struct ubifs_znode *znode)
1813
union ubifs_key *key, *key1;
1815
ubifs_assert(znode->parent);
1816
ubifs_assert(znode->iip == 0);
1818
key = &znode->zbranch[0].key;
1819
key1 = &znode->parent->zbranch[0].key;
1821
while (keys_cmp(c, key, key1) < 0) {
1822
key_copy(c, key, key1);
1823
znode = znode->parent;
1825
if (!znode->parent || znode->iip)
1827
key1 = &znode->parent->zbranch[0].key;
1832
* insert_zbranch - insert a zbranch into a znode.
1833
* @znode: znode into which to insert
1834
* @zbr: zbranch to insert
1835
* @n: slot number to insert to
1837
* This is a helper function for 'tnc_insert()'. UBIFS does not allow "gaps" in
1838
* znode's array of zbranches and keeps zbranches consolidated, so when a new
1839
* zbranch has to be inserted to the @znode->zbranches[]' array at the @n-th
1840
* slot, zbranches starting from @n have to be moved right.
1842
static void insert_zbranch(struct ubifs_znode *znode,
1843
const struct ubifs_zbranch *zbr, int n)
1847
ubifs_assert(ubifs_zn_dirty(znode));
1850
for (i = znode->child_cnt; i > n; i--) {
1851
znode->zbranch[i] = znode->zbranch[i - 1];
1852
if (znode->zbranch[i].znode)
1853
znode->zbranch[i].znode->iip = i;
1856
zbr->znode->iip = n;
1858
for (i = znode->child_cnt; i > n; i--)
1859
znode->zbranch[i] = znode->zbranch[i - 1];
1861
znode->zbranch[n] = *zbr;
1862
znode->child_cnt += 1;
1865
* After inserting at slot zero, the lower bound of the key range of
1866
* this znode may have changed. If this znode is subsequently split
1867
* then the upper bound of the key range may change, and furthermore
1868
* it could change to be lower than the original lower bound. If that
1869
* happens, then it will no longer be possible to find this znode in the
1870
* TNC using the key from the index node on flash. That is bad because
1871
* if it is not found, we will assume it is obsolete and may overwrite
1872
* it. Then if there is an unclean unmount, we will start using the
1873
* old index which will be broken.
1875
* So we first mark znodes that have insertions at slot zero, and then
1876
* if they are split we add their lnum/offs to the old_idx tree.
1883
* tnc_insert - insert a node into TNC.
1884
* @c: UBIFS file-system description object
1885
* @znode: znode to insert into
1886
* @zbr: branch to insert
1887
* @n: slot number to insert new zbranch to
1889
* This function inserts a new node described by @zbr into znode @znode. If
1890
* znode does not have a free slot for new zbranch, it is split. Parent znodes
1891
* are splat as well if needed. Returns zero in case of success or a negative
1892
* error code in case of failure.
1894
static int tnc_insert(struct ubifs_info *c, struct ubifs_znode *znode,
1895
struct ubifs_zbranch *zbr, int n)
1897
struct ubifs_znode *zn, *zi, *zp;
1898
int i, keep, move, appending = 0;
1899
union ubifs_key *key = &zbr->key, *key1;
1901
ubifs_assert(n >= 0 && n <= c->fanout);
1903
/* Implement naive insert for now */
1906
if (znode->child_cnt < c->fanout) {
1907
ubifs_assert(n != c->fanout);
1908
dbg_tnc("inserted at %d level %d, key %s", n, znode->level,
1911
insert_zbranch(znode, zbr, n);
1913
/* Ensure parent's key is correct */
1914
if (n == 0 && zp && znode->iip == 0)
1915
correct_parent_keys(c, znode);
1921
* Unfortunately, @znode does not have more empty slots and we have to
1924
dbg_tnc("splitting level %d, key %s", znode->level, DBGKEY(key));
1928
* We can no longer be sure of finding this znode by key, so we
1929
* record it in the old_idx tree.
1931
ins_clr_old_idx_znode(c, znode);
1933
zn = kzalloc(c->max_znode_sz, GFP_NOFS);
1937
zn->level = znode->level;
1939
/* Decide where to split */
1940
if (znode->level == 0 && key_type(c, key) == UBIFS_DATA_KEY) {
1941
/* Try not to split consecutive data keys */
1942
if (n == c->fanout) {
1943
key1 = &znode->zbranch[n - 1].key;
1944
if (key_inum(c, key1) == key_inum(c, key) &&
1945
key_type(c, key1) == UBIFS_DATA_KEY)
1949
} else if (appending && n != c->fanout) {
1950
/* Try not to split consecutive data keys */
1953
if (n >= (c->fanout + 1) / 2) {
1954
key1 = &znode->zbranch[0].key;
1955
if (key_inum(c, key1) == key_inum(c, key) &&
1956
key_type(c, key1) == UBIFS_DATA_KEY) {
1957
key1 = &znode->zbranch[n].key;
1958
if (key_inum(c, key1) != key_inum(c, key) ||
1959
key_type(c, key1) != UBIFS_DATA_KEY) {
1961
move = c->fanout - keep;
1973
keep = (c->fanout + 1) / 2;
1974
move = c->fanout - keep;
1978
* Although we don't at present, we could look at the neighbors and see
1979
* if we can move some zbranches there.
1983
/* Insert into existing znode */
1988
/* Insert into new znode */
1993
zbr->znode->parent = zn;
1998
__set_bit(DIRTY_ZNODE, &zn->flags);
1999
atomic_long_inc(&c->dirty_zn_cnt);
2001
zn->child_cnt = move;
2002
znode->child_cnt = keep;
2004
dbg_tnc("moving %d, keeping %d", move, keep);
2007
for (i = 0; i < move; i++) {
2008
zn->zbranch[i] = znode->zbranch[keep + i];
2011
if (zn->zbranch[i].znode) {
2012
zn->zbranch[i].znode->parent = zn;
2013
zn->zbranch[i].znode->iip = i;
2017
/* Insert new key and branch */
2018
dbg_tnc("inserting at %d level %d, key %s", n, zn->level, DBGKEY(key));
2020
insert_zbranch(zi, zbr, n);
2022
/* Insert new znode (produced by spitting) into the parent */
2024
if (n == 0 && zi == znode && znode->iip == 0)
2025
correct_parent_keys(c, znode);
2027
/* Locate insertion point */
2030
/* Tail recursion */
2031
zbr->key = zn->zbranch[0].key;
2041
/* We have to split root znode */
2042
dbg_tnc("creating new zroot at level %d", znode->level + 1);
2044
zi = kzalloc(c->max_znode_sz, GFP_NOFS);
2049
zi->level = znode->level + 1;
2051
__set_bit(DIRTY_ZNODE, &zi->flags);
2052
atomic_long_inc(&c->dirty_zn_cnt);
2054
zi->zbranch[0].key = znode->zbranch[0].key;
2055
zi->zbranch[0].znode = znode;
2056
zi->zbranch[0].lnum = c->zroot.lnum;
2057
zi->zbranch[0].offs = c->zroot.offs;
2058
zi->zbranch[0].len = c->zroot.len;
2059
zi->zbranch[1].key = zn->zbranch[0].key;
2060
zi->zbranch[1].znode = zn;
2065
c->zroot.znode = zi;
2076
* ubifs_tnc_add - add a node to TNC.
2077
* @c: UBIFS file-system description object
2079
* @lnum: LEB number of node
2080
* @offs: node offset
2083
* This function adds a node with key @key to TNC. The node may be new or it may
2084
* obsolete some existing one. Returns %0 on success or negative error code on
2087
int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum,
2090
int found, n, err = 0;
2091
struct ubifs_znode *znode;
2093
mutex_lock(&c->tnc_mutex);
2094
dbg_tnc("%d:%d, len %d, key %s", lnum, offs, len, DBGKEY(key));
2095
found = lookup_level0_dirty(c, key, &znode, &n);
2097
struct ubifs_zbranch zbr;
2103
key_copy(c, key, &zbr.key);
2104
err = tnc_insert(c, znode, &zbr, n + 1);
2105
} else if (found == 1) {
2106
struct ubifs_zbranch *zbr = &znode->zbranch[n];
2109
err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
2116
err = dbg_check_tnc(c, 0);
2117
mutex_unlock(&c->tnc_mutex);
2123
* ubifs_tnc_replace - replace a node in the TNC only if the old node is found.
2124
* @c: UBIFS file-system description object
2126
* @old_lnum: LEB number of old node
2127
* @old_offs: old node offset
2128
* @lnum: LEB number of node
2129
* @offs: node offset
2132
* This function replaces a node with key @key in the TNC only if the old node
2133
* is found. This function is called by garbage collection when node are moved.
2134
* Returns %0 on success or negative error code on failure.
2136
int ubifs_tnc_replace(struct ubifs_info *c, const union ubifs_key *key,
2137
int old_lnum, int old_offs, int lnum, int offs, int len)
2139
int found, n, err = 0;
2140
struct ubifs_znode *znode;
2142
mutex_lock(&c->tnc_mutex);
2143
dbg_tnc("old LEB %d:%d, new LEB %d:%d, len %d, key %s", old_lnum,
2144
old_offs, lnum, offs, len, DBGKEY(key));
2145
found = lookup_level0_dirty(c, key, &znode, &n);
2152
struct ubifs_zbranch *zbr = &znode->zbranch[n];
2155
if (zbr->lnum == old_lnum && zbr->offs == old_offs) {
2157
err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
2164
} else if (is_hash_key(c, key)) {
2165
found = resolve_collision_directly(c, key, &znode, &n,
2166
old_lnum, old_offs);
2167
dbg_tnc("rc returned %d, znode %p, n %d, LEB %d:%d",
2168
found, znode, n, old_lnum, old_offs);
2175
/* Ensure the znode is dirtied */
2176
if (znode->cnext || !ubifs_zn_dirty(znode)) {
2177
znode = dirty_cow_bottom_up(c, znode);
2178
if (IS_ERR(znode)) {
2179
err = PTR_ERR(znode);
2183
zbr = &znode->zbranch[n];
2185
err = ubifs_add_dirt(c, zbr->lnum,
2197
err = ubifs_add_dirt(c, lnum, len);
2200
err = dbg_check_tnc(c, 0);
2203
mutex_unlock(&c->tnc_mutex);
2208
* ubifs_tnc_add_nm - add a "hashed" node to TNC.
2209
* @c: UBIFS file-system description object
2211
* @lnum: LEB number of node
2212
* @offs: node offset
2216
* This is the same as 'ubifs_tnc_add()' but it should be used with keys which
2217
* may have collisions, like directory entry keys.
2219
int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key,
2220
int lnum, int offs, int len, const struct qstr *nm)
2222
int found, n, err = 0;
2223
struct ubifs_znode *znode;
2225
mutex_lock(&c->tnc_mutex);
2226
dbg_tnc("LEB %d:%d, name '%.*s', key %s", lnum, offs, nm->len, nm->name,
2228
found = lookup_level0_dirty(c, key, &znode, &n);
2236
found = fallible_resolve_collision(c, key, &znode, &n,
2239
found = resolve_collision(c, key, &znode, &n, nm);
2240
dbg_tnc("rc returned %d, znode %p, n %d", found, znode, n);
2246
/* Ensure the znode is dirtied */
2247
if (znode->cnext || !ubifs_zn_dirty(znode)) {
2248
znode = dirty_cow_bottom_up(c, znode);
2249
if (IS_ERR(znode)) {
2250
err = PTR_ERR(znode);
2256
struct ubifs_zbranch *zbr = &znode->zbranch[n];
2259
err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
2268
struct ubifs_zbranch zbr;
2274
key_copy(c, key, &zbr.key);
2275
err = tnc_insert(c, znode, &zbr, n + 1);
2280
* We did not find it in the index so there may be a
2281
* dangling branch still in the index. So we remove it
2282
* by passing 'ubifs_tnc_remove_nm()' the same key but
2283
* an unmatchable name.
2285
struct qstr noname = { .len = 0, .name = "" };
2287
err = dbg_check_tnc(c, 0);
2288
mutex_unlock(&c->tnc_mutex);
2291
return ubifs_tnc_remove_nm(c, key, &noname);
2297
err = dbg_check_tnc(c, 0);
2298
mutex_unlock(&c->tnc_mutex);
2303
* tnc_delete - delete a znode form TNC.
2304
* @c: UBIFS file-system description object
2305
* @znode: znode to delete from
2306
* @n: zbranch slot number to delete
2308
* This function deletes a leaf node from @n-th slot of @znode. Returns zero in
2309
* case of success and a negative error code in case of failure.
2311
static int tnc_delete(struct ubifs_info *c, struct ubifs_znode *znode, int n)
2313
struct ubifs_zbranch *zbr;
2314
struct ubifs_znode *zp;
2317
/* Delete without merge for now */
2318
ubifs_assert(znode->level == 0);
2319
ubifs_assert(n >= 0 && n < c->fanout);
2320
dbg_tnc("deleting %s", DBGKEY(&znode->zbranch[n].key));
2322
zbr = &znode->zbranch[n];
2325
err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
2327
dbg_dump_znode(c, znode);
2331
/* We do not "gap" zbranch slots */
2332
for (i = n; i < znode->child_cnt - 1; i++)
2333
znode->zbranch[i] = znode->zbranch[i + 1];
2334
znode->child_cnt -= 1;
2336
if (znode->child_cnt > 0)
2340
* This was the last zbranch, we have to delete this znode from the
2345
ubifs_assert(!test_bit(OBSOLETE_ZNODE, &znode->flags));
2346
ubifs_assert(ubifs_zn_dirty(znode));
2351
atomic_long_dec(&c->dirty_zn_cnt);
2353
err = insert_old_idx_znode(c, znode);
2358
__set_bit(OBSOLETE_ZNODE, &znode->flags);
2359
atomic_long_inc(&c->clean_zn_cnt);
2360
atomic_long_inc(&ubifs_clean_zn_cnt);
2364
} while (znode->child_cnt == 1); /* while removing last child */
2366
/* Remove from znode, entry n - 1 */
2367
znode->child_cnt -= 1;
2368
ubifs_assert(znode->level != 0);
2369
for (i = n; i < znode->child_cnt; i++) {
2370
znode->zbranch[i] = znode->zbranch[i + 1];
2371
if (znode->zbranch[i].znode)
2372
znode->zbranch[i].znode->iip = i;
2376
* If this is the root and it has only 1 child then
2377
* collapse the tree.
2379
if (!znode->parent) {
2380
while (znode->child_cnt == 1 && znode->level != 0) {
2382
zbr = &znode->zbranch[0];
2383
znode = get_znode(c, znode, 0);
2385
return PTR_ERR(znode);
2386
znode = dirty_cow_znode(c, zbr);
2388
return PTR_ERR(znode);
2389
znode->parent = NULL;
2392
err = insert_old_idx(c, c->zroot.lnum,
2397
c->zroot.lnum = zbr->lnum;
2398
c->zroot.offs = zbr->offs;
2399
c->zroot.len = zbr->len;
2400
c->zroot.znode = znode;
2401
ubifs_assert(!test_bit(OBSOLETE_ZNODE,
2403
ubifs_assert(test_bit(DIRTY_ZNODE, &zp->flags));
2404
atomic_long_dec(&c->dirty_zn_cnt);
2407
__set_bit(OBSOLETE_ZNODE, &zp->flags);
2408
atomic_long_inc(&c->clean_zn_cnt);
2409
atomic_long_inc(&ubifs_clean_zn_cnt);
2419
* ubifs_tnc_remove - remove an index entry of a node.
2420
* @c: UBIFS file-system description object
2423
* Returns %0 on success or negative error code on failure.
2425
int ubifs_tnc_remove(struct ubifs_info *c, const union ubifs_key *key)
2427
int found, n, err = 0;
2428
struct ubifs_znode *znode;
2430
mutex_lock(&c->tnc_mutex);
2431
dbg_tnc("key %s", DBGKEY(key));
2432
found = lookup_level0_dirty(c, key, &znode, &n);
2438
err = tnc_delete(c, znode, n);
2440
err = dbg_check_tnc(c, 0);
2443
mutex_unlock(&c->tnc_mutex);
2448
* ubifs_tnc_remove_nm - remove an index entry for a "hashed" node.
2449
* @c: UBIFS file-system description object
2451
* @nm: directory entry name
2453
* Returns %0 on success or negative error code on failure.
2455
int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key,
2456
const struct qstr *nm)
2459
struct ubifs_znode *znode;
2461
mutex_lock(&c->tnc_mutex);
2462
dbg_tnc("%.*s, key %s", nm->len, nm->name, DBGKEY(key));
2463
err = lookup_level0_dirty(c, key, &znode, &n);
2469
err = fallible_resolve_collision(c, key, &znode, &n,
2472
err = resolve_collision(c, key, &znode, &n, nm);
2473
dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n);
2477
/* Ensure the znode is dirtied */
2478
if (znode->cnext || !ubifs_zn_dirty(znode)) {
2479
znode = dirty_cow_bottom_up(c, znode);
2480
if (IS_ERR(znode)) {
2481
err = PTR_ERR(znode);
2485
err = tnc_delete(c, znode, n);
2491
err = dbg_check_tnc(c, 0);
2492
mutex_unlock(&c->tnc_mutex);
2497
* key_in_range - determine if a key falls within a range of keys.
2498
* @c: UBIFS file-system description object
2499
* @key: key to check
2500
* @from_key: lowest key in range
2501
* @to_key: highest key in range
2503
* This function returns %1 if the key is in range and %0 otherwise.
2505
static int key_in_range(struct ubifs_info *c, union ubifs_key *key,
2506
union ubifs_key *from_key, union ubifs_key *to_key)
2508
if (keys_cmp(c, key, from_key) < 0)
2510
if (keys_cmp(c, key, to_key) > 0)
2516
* ubifs_tnc_remove_range - remove index entries in range.
2517
* @c: UBIFS file-system description object
2518
* @from_key: lowest key to remove
2519
* @to_key: highest key to remove
2521
* This function removes index entries starting at @from_key and ending at
2522
* @to_key. This function returns zero in case of success and a negative error
2523
* code in case of failure.
2525
int ubifs_tnc_remove_range(struct ubifs_info *c, union ubifs_key *from_key,
2526
union ubifs_key *to_key)
2528
int i, n, k, err = 0;
2529
struct ubifs_znode *znode;
2530
union ubifs_key *key;
2532
mutex_lock(&c->tnc_mutex);
2534
/* Find first level 0 znode that contains keys to remove */
2535
err = ubifs_lookup_level0(c, from_key, &znode, &n);
2542
err = tnc_next(c, &znode, &n);
2543
if (err == -ENOENT) {
2549
key = &znode->zbranch[n].key;
2550
if (!key_in_range(c, key, from_key, to_key)) {
2556
/* Ensure the znode is dirtied */
2557
if (znode->cnext || !ubifs_zn_dirty(znode)) {
2558
znode = dirty_cow_bottom_up(c, znode);
2559
if (IS_ERR(znode)) {
2560
err = PTR_ERR(znode);
2565
/* Remove all keys in range except the first */
2566
for (i = n + 1, k = 0; i < znode->child_cnt; i++, k++) {
2567
key = &znode->zbranch[i].key;
2568
if (!key_in_range(c, key, from_key, to_key))
2570
lnc_free(&znode->zbranch[i]);
2571
err = ubifs_add_dirt(c, znode->zbranch[i].lnum,
2572
znode->zbranch[i].len);
2574
dbg_dump_znode(c, znode);
2577
dbg_tnc("removing %s", DBGKEY(key));
2580
for (i = n + 1 + k; i < znode->child_cnt; i++)
2581
znode->zbranch[i - k] = znode->zbranch[i];
2582
znode->child_cnt -= k;
2585
/* Now delete the first */
2586
err = tnc_delete(c, znode, n);
2593
err = dbg_check_tnc(c, 0);
2594
mutex_unlock(&c->tnc_mutex);
2599
* ubifs_tnc_remove_ino - remove an inode from TNC.
2600
* @c: UBIFS file-system description object
2601
* @inum: inode number to remove
2603
* This function remove inode @inum and all the extended attributes associated
2604
* with the anode from TNC and returns zero in case of success or a negative
2605
* error code in case of failure.
2607
int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum)
2609
union ubifs_key key1, key2;
2610
struct ubifs_dent_node *xent, *pxent = NULL;
2611
struct qstr nm = { .name = NULL };
2613
dbg_tnc("ino %lu", (unsigned long)inum);
2616
* Walk all extended attribute entries and remove them together with
2617
* corresponding extended attribute inodes.
2619
lowest_xent_key(c, &key1, inum);
2624
xent = ubifs_tnc_next_ent(c, &key1, &nm);
2626
err = PTR_ERR(xent);
2632
xattr_inum = le64_to_cpu(xent->inum);
2633
dbg_tnc("xent '%s', ino %lu", xent->name,
2634
(unsigned long)xattr_inum);
2636
nm.name = (char *)xent->name;
2637
nm.len = le16_to_cpu(xent->nlen);
2638
err = ubifs_tnc_remove_nm(c, &key1, &nm);
2644
lowest_ino_key(c, &key1, xattr_inum);
2645
highest_ino_key(c, &key2, xattr_inum);
2646
err = ubifs_tnc_remove_range(c, &key1, &key2);
2654
key_read(c, &xent->key, &key1);
2658
lowest_ino_key(c, &key1, inum);
2659
highest_ino_key(c, &key2, inum);
2661
return ubifs_tnc_remove_range(c, &key1, &key2);
2665
* ubifs_tnc_next_ent - walk directory or extended attribute entries.
2666
* @c: UBIFS file-system description object
2667
* @key: key of last entry
2668
* @nm: name of last entry found or %NULL
2670
* This function finds and reads the next directory or extended attribute entry
2671
* after the given key (@key) if there is one. @nm is used to resolve
2674
* If the name of the current entry is not known and only the key is known,
2675
* @nm->name has to be %NULL. In this case the semantics of this function is a
2676
* little bit different and it returns the entry corresponding to this key, not
2677
* the next one. If the key was not found, the closest "right" entry is
2680
* If the fist entry has to be found, @key has to contain the lowest possible
2681
* key value for this inode and @name has to be %NULL.
2683
* This function returns the found directory or extended attribute entry node
2684
* in case of success, %-ENOENT is returned if no entry was found, and a
2685
* negative error code is returned in case of failure.
2687
struct ubifs_dent_node *ubifs_tnc_next_ent(struct ubifs_info *c,
2688
union ubifs_key *key,
2689
const struct qstr *nm)
2691
int n, err, type = key_type(c, key);
2692
struct ubifs_znode *znode;
2693
struct ubifs_dent_node *dent;
2694
struct ubifs_zbranch *zbr;
2695
union ubifs_key *dkey;
2697
dbg_tnc("%s %s", nm->name ? (char *)nm->name : "(lowest)", DBGKEY(key));
2698
ubifs_assert(is_hash_key(c, key));
2700
mutex_lock(&c->tnc_mutex);
2701
err = ubifs_lookup_level0(c, key, &znode, &n);
2702
if (unlikely(err < 0))
2707
/* Handle collisions */
2708
err = resolve_collision(c, key, &znode, &n, nm);
2709
dbg_tnc("rc returned %d, znode %p, n %d",
2711
if (unlikely(err < 0))
2715
/* Now find next entry */
2716
err = tnc_next(c, &znode, &n);
2721
* The full name of the entry was not given, in which case the
2722
* behavior of this function is a little different and it
2723
* returns current entry, not the next one.
2727
* However, the given key does not exist in the TNC
2728
* tree and @znode/@n variables contain the closest
2729
* "preceding" element. Switch to the next one.
2731
err = tnc_next(c, &znode, &n);
2737
zbr = &znode->zbranch[n];
2738
dent = kmalloc(zbr->len, GFP_NOFS);
2739
if (unlikely(!dent)) {
2745
* The above 'tnc_next()' call could lead us to the next inode, check
2749
if (key_inum(c, dkey) != key_inum(c, key) ||
2750
key_type(c, dkey) != type) {
2755
err = tnc_read_node_nm(c, zbr, dent);
2759
mutex_unlock(&c->tnc_mutex);
2765
mutex_unlock(&c->tnc_mutex);
2766
return ERR_PTR(err);
added
removed
fs/ubifs/tnc.c
