diff options
Diffstat (limited to 'qemu/roms/u-boot/fs/ubifs/tnc.c')
| -rw-r--r-- | qemu/roms/u-boot/fs/ubifs/tnc.c | 2767 |
1 files changed, 0 insertions, 2767 deletions
diff --git a/qemu/roms/u-boot/fs/ubifs/tnc.c b/qemu/roms/u-boot/fs/ubifs/tnc.c deleted file mode 100644 index ccda9387b..000000000 --- a/qemu/roms/u-boot/fs/ubifs/tnc.c +++ /dev/null @@ -1,2767 +0,0 @@ -/* - * This file is part of UBIFS. - * - * Copyright (C) 2006-2008 Nokia Corporation. - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 as published by - * the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * - * You should have received a copy of the GNU General Public License along with - * this program; if not, write to the Free Software Foundation, Inc., 51 - * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA - * - * Authors: Adrian Hunter - * Artem Bityutskiy (Битюцкий Артём) - */ - -/* - * This file implements TNC (Tree Node Cache) which caches indexing nodes of - * the UBIFS B-tree. - * - * At the moment the locking rules of the TNC tree are quite simple and - * straightforward. We just have a mutex and lock it when we traverse the - * tree. If a znode is not in memory, we read it from flash while still having - * the mutex locked. - */ - -#include "ubifs.h" - -/* - * Returned codes of 'matches_name()' and 'fallible_matches_name()' functions. - * @NAME_LESS: name corresponding to the first argument is less than second - * @NAME_MATCHES: names match - * @NAME_GREATER: name corresponding to the second argument is greater than - * first - * @NOT_ON_MEDIA: node referred by zbranch does not exist on the media - * - * These constants were introduce to improve readability. - */ -enum { - NAME_LESS = 0, - NAME_MATCHES = 1, - NAME_GREATER = 2, - NOT_ON_MEDIA = 3, -}; - -/** - * insert_old_idx - record an index node obsoleted since the last commit start. - * @c: UBIFS file-system description object - * @lnum: LEB number of obsoleted index node - * @offs: offset of obsoleted index node - * - * Returns %0 on success, and a negative error code on failure. - * - * For recovery, there must always be a complete intact version of the index on - * flash at all times. That is called the "old index". It is the index as at the - * time of the last successful commit. Many of the index nodes in the old index - * may be dirty, but they must not be erased until the next successful commit - * (at which point that index becomes the old index). - * - * That means that the garbage collection and the in-the-gaps method of - * committing must be able to determine if an index node is in the old index. - * Most of the old index nodes can be found by looking up the TNC using the - * 'lookup_znode()' function. However, some of the old index nodes may have - * been deleted from the current index or may have been changed so much that - * they cannot be easily found. In those cases, an entry is added to an RB-tree. - * That is what this function does. The RB-tree is ordered by LEB number and - * offset because they uniquely identify the old index node. - */ -static int insert_old_idx(struct ubifs_info *c, int lnum, int offs) -{ - struct ubifs_old_idx *old_idx, *o; - struct rb_node **p, *parent = NULL; - - old_idx = kmalloc(sizeof(struct ubifs_old_idx), GFP_NOFS); - if (unlikely(!old_idx)) - return -ENOMEM; - old_idx->lnum = lnum; - old_idx->offs = offs; - - p = &c->old_idx.rb_node; - while (*p) { - parent = *p; - o = rb_entry(parent, struct ubifs_old_idx, rb); - if (lnum < o->lnum) - p = &(*p)->rb_left; - else if (lnum > o->lnum) - p = &(*p)->rb_right; - else if (offs < o->offs) - p = &(*p)->rb_left; - else if (offs > o->offs) - p = &(*p)->rb_right; - else { - ubifs_err("old idx added twice!"); - kfree(old_idx); - return 0; - } - } - rb_link_node(&old_idx->rb, parent, p); - rb_insert_color(&old_idx->rb, &c->old_idx); - return 0; -} - -/** - * insert_old_idx_znode - record a znode obsoleted since last commit start. - * @c: UBIFS file-system description object - * @znode: znode of obsoleted index node - * - * Returns %0 on success, and a negative error code on failure. - */ -int insert_old_idx_znode(struct ubifs_info *c, struct ubifs_znode *znode) -{ - if (znode->parent) { - struct ubifs_zbranch *zbr; - - zbr = &znode->parent->zbranch[znode->iip]; - if (zbr->len) - return insert_old_idx(c, zbr->lnum, zbr->offs); - } else - if (c->zroot.len) - return insert_old_idx(c, c->zroot.lnum, - c->zroot.offs); - return 0; -} - -/** - * ins_clr_old_idx_znode - record a znode obsoleted since last commit start. - * @c: UBIFS file-system description object - * @znode: znode of obsoleted index node - * - * Returns %0 on success, and a negative error code on failure. - */ -static int ins_clr_old_idx_znode(struct ubifs_info *c, - struct ubifs_znode *znode) -{ - int err; - - if (znode->parent) { - struct ubifs_zbranch *zbr; - - zbr = &znode->parent->zbranch[znode->iip]; - if (zbr->len) { - err = insert_old_idx(c, zbr->lnum, zbr->offs); - if (err) - return err; - zbr->lnum = 0; - zbr->offs = 0; - zbr->len = 0; - } - } else - if (c->zroot.len) { - err = insert_old_idx(c, c->zroot.lnum, c->zroot.offs); - if (err) - return err; - c->zroot.lnum = 0; - c->zroot.offs = 0; - c->zroot.len = 0; - } - return 0; -} - -/** - * destroy_old_idx - destroy the old_idx RB-tree. - * @c: UBIFS file-system description object - * - * During start commit, the old_idx RB-tree is used to avoid overwriting index - * nodes that were in the index last commit but have since been deleted. This - * is necessary for recovery i.e. the old index must be kept intact until the - * new index is successfully written. The old-idx RB-tree is used for the - * in-the-gaps method of writing index nodes and is destroyed every commit. - */ -void destroy_old_idx(struct ubifs_info *c) -{ - struct rb_node *this = c->old_idx.rb_node; - struct ubifs_old_idx *old_idx; - - while (this) { - if (this->rb_left) { - this = this->rb_left; - continue; - } else if (this->rb_right) { - this = this->rb_right; - continue; - } - old_idx = rb_entry(this, struct ubifs_old_idx, rb); - this = rb_parent(this); - if (this) { - if (this->rb_left == &old_idx->rb) - this->rb_left = NULL; - else - this->rb_right = NULL; - } - kfree(old_idx); - } - c->old_idx = RB_ROOT; -} - -/** - * copy_znode - copy a dirty znode. - * @c: UBIFS file-system description object - * @znode: znode to copy - * - * A dirty znode being committed may not be changed, so it is copied. - */ -static struct ubifs_znode *copy_znode(struct ubifs_info *c, - struct ubifs_znode *znode) -{ - struct ubifs_znode *zn; - - zn = kmalloc(c->max_znode_sz, GFP_NOFS); - if (unlikely(!zn)) - return ERR_PTR(-ENOMEM); - - memcpy(zn, znode, c->max_znode_sz); - zn->cnext = NULL; - __set_bit(DIRTY_ZNODE, &zn->flags); - __clear_bit(COW_ZNODE, &zn->flags); - - ubifs_assert(!test_bit(OBSOLETE_ZNODE, &znode->flags)); - __set_bit(OBSOLETE_ZNODE, &znode->flags); - - if (znode->level != 0) { - int i; - const int n = zn->child_cnt; - - /* The children now have new parent */ - for (i = 0; i < n; i++) { - struct ubifs_zbranch *zbr = &zn->zbranch[i]; - - if (zbr->znode) - zbr->znode->parent = zn; - } - } - - atomic_long_inc(&c->dirty_zn_cnt); - return zn; -} - -/** - * add_idx_dirt - add dirt due to a dirty znode. - * @c: UBIFS file-system description object - * @lnum: LEB number of index node - * @dirt: size of index node - * - * This function updates lprops dirty space and the new size of the index. - */ -static int add_idx_dirt(struct ubifs_info *c, int lnum, int dirt) -{ - c->calc_idx_sz -= ALIGN(dirt, 8); - return ubifs_add_dirt(c, lnum, dirt); -} - -/** - * dirty_cow_znode - ensure a znode is not being committed. - * @c: UBIFS file-system description object - * @zbr: branch of znode to check - * - * Returns dirtied znode on success or negative error code on failure. - */ -static struct ubifs_znode *dirty_cow_znode(struct ubifs_info *c, - struct ubifs_zbranch *zbr) -{ - struct ubifs_znode *znode = zbr->znode; - struct ubifs_znode *zn; - int err; - - if (!test_bit(COW_ZNODE, &znode->flags)) { - /* znode is not being committed */ - if (!test_and_set_bit(DIRTY_ZNODE, &znode->flags)) { - atomic_long_inc(&c->dirty_zn_cnt); - atomic_long_dec(&c->clean_zn_cnt); - atomic_long_dec(&ubifs_clean_zn_cnt); - err = add_idx_dirt(c, zbr->lnum, zbr->len); - if (unlikely(err)) - return ERR_PTR(err); - } - return znode; - } - - zn = copy_znode(c, znode); - if (IS_ERR(zn)) - return zn; - - if (zbr->len) { - err = insert_old_idx(c, zbr->lnum, zbr->offs); - if (unlikely(err)) - return ERR_PTR(err); - err = add_idx_dirt(c, zbr->lnum, zbr->len); - } else - err = 0; - - zbr->znode = zn; - zbr->lnum = 0; - zbr->offs = 0; - zbr->len = 0; - - if (unlikely(err)) - return ERR_PTR(err); - return zn; -} - -/** - * lnc_add - add a leaf node to the leaf node cache. - * @c: UBIFS file-system description object - * @zbr: zbranch of leaf node - * @node: leaf node - * - * Leaf nodes are non-index nodes directory entry nodes or data nodes. The - * purpose of the leaf node cache is to save re-reading the same leaf node over - * and over again. Most things are cached by VFS, however the file system must - * cache directory entries for readdir and for resolving hash collisions. The - * present implementation of the leaf node cache is extremely simple, and - * allows for error returns that are not used but that may be needed if a more - * complex implementation is created. - * - * Note, this function does not add the @node object to LNC directly, but - * allocates a copy of the object and adds the copy to LNC. The reason for this - * is that @node has been allocated outside of the TNC subsystem and will be - * used with @c->tnc_mutex unlock upon return from the TNC subsystem. But LNC - * may be changed at any time, e.g. freed by the shrinker. - */ -static int lnc_add(struct ubifs_info *c, struct ubifs_zbranch *zbr, - const void *node) -{ - int err; - void *lnc_node; - const struct ubifs_dent_node *dent = node; - - ubifs_assert(!zbr->leaf); - ubifs_assert(zbr->len != 0); - ubifs_assert(is_hash_key(c, &zbr->key)); - - err = ubifs_validate_entry(c, dent); - if (err) { - dbg_dump_stack(); - dbg_dump_node(c, dent); - return err; - } - - lnc_node = kmalloc(zbr->len, GFP_NOFS); - if (!lnc_node) - /* We don't have to have the cache, so no error */ - return 0; - - memcpy(lnc_node, node, zbr->len); - zbr->leaf = lnc_node; - return 0; -} - - /** - * lnc_add_directly - add a leaf node to the leaf-node-cache. - * @c: UBIFS file-system description object - * @zbr: zbranch of leaf node - * @node: leaf node - * - * This function is similar to 'lnc_add()', but it does not create a copy of - * @node but inserts @node to TNC directly. - */ -static int lnc_add_directly(struct ubifs_info *c, struct ubifs_zbranch *zbr, - void *node) -{ - int err; - - ubifs_assert(!zbr->leaf); - ubifs_assert(zbr->len != 0); - - err = ubifs_validate_entry(c, node); - if (err) { - dbg_dump_stack(); - dbg_dump_node(c, node); - return err; - } - - zbr->leaf = node; - return 0; -} - -/** - * lnc_free - remove a leaf node from the leaf node cache. - * @zbr: zbranch of leaf node - * @node: leaf node - */ -static void lnc_free(struct ubifs_zbranch *zbr) -{ - if (!zbr->leaf) - return; - kfree(zbr->leaf); - zbr->leaf = NULL; -} - -/** - * tnc_read_node_nm - read a "hashed" leaf node. - * @c: UBIFS file-system description object - * @zbr: key and position of the node - * @node: node is returned here - * - * This function reads a "hashed" node defined by @zbr from the leaf node cache - * (in it is there) or from the hash media, in which case the node is also - * added to LNC. Returns zero in case of success or a negative negative error - * code in case of failure. - */ -static int tnc_read_node_nm(struct ubifs_info *c, struct ubifs_zbranch *zbr, - void *node) -{ - int err; - - ubifs_assert(is_hash_key(c, &zbr->key)); - - if (zbr->leaf) { - /* Read from the leaf node cache */ - ubifs_assert(zbr->len != 0); - memcpy(node, zbr->leaf, zbr->len); - return 0; - } - - err = ubifs_tnc_read_node(c, zbr, node); - if (err) - return err; - - /* Add the node to the leaf node cache */ - err = lnc_add(c, zbr, node); - return err; -} - -/** - * try_read_node - read a node if it is a node. - * @c: UBIFS file-system description object - * @buf: buffer to read to - * @type: node type - * @len: node length (not aligned) - * @lnum: LEB number of node to read - * @offs: offset of node to read - * - * This function tries to read a node of known type and length, checks it and - * stores it in @buf. This function returns %1 if a node is present and %0 if - * a node is not present. A negative error code is returned for I/O errors. - * This function performs that same function as ubifs_read_node except that - * it does not require that there is actually a node present and instead - * the return code indicates if a node was read. - * - * Note, this function does not check CRC of data nodes if @c->no_chk_data_crc - * is true (it is controlled by corresponding mount option). However, if - * @c->always_chk_crc is true, @c->no_chk_data_crc is ignored and CRC is always - * checked. - */ -static int try_read_node(const struct ubifs_info *c, void *buf, int type, - int len, int lnum, int offs) -{ - int err, node_len; - struct ubifs_ch *ch = buf; - uint32_t crc, node_crc; - - dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len); - - err = ubi_read(c->ubi, lnum, buf, offs, len); - if (err) { - ubifs_err("cannot read node type %d from LEB %d:%d, error %d", - type, lnum, offs, err); - return err; - } - - if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC) - return 0; - - if (ch->node_type != type) - return 0; - - node_len = le32_to_cpu(ch->len); - if (node_len != len) - return 0; - - if (type == UBIFS_DATA_NODE && !c->always_chk_crc && c->no_chk_data_crc) - return 1; - - crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8); - node_crc = le32_to_cpu(ch->crc); - if (crc != node_crc) - return 0; - - return 1; -} - -/** - * fallible_read_node - try to read a leaf node. - * @c: UBIFS file-system description object - * @key: key of node to read - * @zbr: position of node - * @node: node returned - * - * This function tries to read a node and returns %1 if the node is read, %0 - * if the node is not present, and a negative error code in the case of error. - */ -static int fallible_read_node(struct ubifs_info *c, const union ubifs_key *key, - struct ubifs_zbranch *zbr, void *node) -{ - int ret; - - dbg_tnc("LEB %d:%d, key %s", zbr->lnum, zbr->offs, DBGKEY(key)); - - ret = try_read_node(c, node, key_type(c, key), zbr->len, zbr->lnum, - zbr->offs); - if (ret == 1) { - union ubifs_key node_key; - struct ubifs_dent_node *dent = node; - - /* All nodes have key in the same place */ - key_read(c, &dent->key, &node_key); - if (keys_cmp(c, key, &node_key) != 0) - ret = 0; - } - if (ret == 0 && c->replaying) - dbg_mnt("dangling branch LEB %d:%d len %d, key %s", - zbr->lnum, zbr->offs, zbr->len, DBGKEY(key)); - return ret; -} - -/** - * matches_name - determine if a direntry or xattr entry matches a given name. - * @c: UBIFS file-system description object - * @zbr: zbranch of dent - * @nm: name to match - * - * This function checks if xentry/direntry referred by zbranch @zbr matches name - * @nm. Returns %NAME_MATCHES if it does, %NAME_LESS if the name referred by - * @zbr is less than @nm, and %NAME_GREATER if it is greater than @nm. In case - * of failure, a negative error code is returned. - */ -static int matches_name(struct ubifs_info *c, struct ubifs_zbranch *zbr, - const struct qstr *nm) -{ - struct ubifs_dent_node *dent; - int nlen, err; - - /* If possible, match against the dent in the leaf node cache */ - if (!zbr->leaf) { - dent = kmalloc(zbr->len, GFP_NOFS); - if (!dent) - return -ENOMEM; - - err = ubifs_tnc_read_node(c, zbr, dent); - if (err) - goto out_free; - - /* Add the node to the leaf node cache */ - err = lnc_add_directly(c, zbr, dent); - if (err) - goto out_free; - } else - dent = zbr->leaf; - - nlen = le16_to_cpu(dent->nlen); - err = memcmp(dent->name, nm->name, min_t(int, nlen, nm->len)); - if (err == 0) { - if (nlen == nm->len) - return NAME_MATCHES; - else if (nlen < nm->len) - return NAME_LESS; - else - return NAME_GREATER; - } else if (err < 0) - return NAME_LESS; - else - return NAME_GREATER; - -out_free: - kfree(dent); - return err; -} - -/** - * get_znode - get a TNC znode that may not be loaded yet. - * @c: UBIFS file-system description object - * @znode: parent znode - * @n: znode branch slot number - * - * This function returns the znode or a negative error code. - */ -static struct ubifs_znode *get_znode(struct ubifs_info *c, - struct ubifs_znode *znode, int n) -{ - struct ubifs_zbranch *zbr; - - zbr = &znode->zbranch[n]; - if (zbr->znode) - znode = zbr->znode; - else - znode = ubifs_load_znode(c, zbr, znode, n); - return znode; -} - -/** - * tnc_next - find next TNC entry. - * @c: UBIFS file-system description object - * @zn: znode is passed and returned here - * @n: znode branch slot number is passed and returned here - * - * This function returns %0 if the next TNC entry is found, %-ENOENT if there is - * no next entry, or a negative error code otherwise. - */ -static int tnc_next(struct ubifs_info *c, struct ubifs_znode **zn, int *n) -{ - struct ubifs_znode *znode = *zn; - int nn = *n; - - nn += 1; - if (nn < znode->child_cnt) { - *n = nn; - return 0; - } - while (1) { - struct ubifs_znode *zp; - - zp = znode->parent; - if (!zp) - return -ENOENT; - nn = znode->iip + 1; - znode = zp; - if (nn < znode->child_cnt) { - znode = get_znode(c, znode, nn); - if (IS_ERR(znode)) - return PTR_ERR(znode); - while (znode->level != 0) { - znode = get_znode(c, znode, 0); - if (IS_ERR(znode)) - return PTR_ERR(znode); - } - nn = 0; - break; - } - } - *zn = znode; - *n = nn; - return 0; -} - -/** - * tnc_prev - find previous TNC entry. - * @c: UBIFS file-system description object - * @zn: znode is returned here - * @n: znode branch slot number is passed and returned here - * - * This function returns %0 if the previous TNC entry is found, %-ENOENT if - * there is no next entry, or a negative error code otherwise. - */ -static int tnc_prev(struct ubifs_info *c, struct ubifs_znode **zn, int *n) -{ - struct ubifs_znode *znode = *zn; - int nn = *n; - - if (nn > 0) { - *n = nn - 1; - return 0; - } - while (1) { - struct ubifs_znode *zp; - - zp = znode->parent; - if (!zp) - return -ENOENT; - nn = znode->iip - 1; - znode = zp; - if (nn >= 0) { - znode = get_znode(c, znode, nn); - if (IS_ERR(znode)) - return PTR_ERR(znode); - while (znode->level != 0) { - nn = znode->child_cnt - 1; - znode = get_znode(c, znode, nn); - if (IS_ERR(znode)) - return PTR_ERR(znode); - } - nn = znode->child_cnt - 1; - break; - } - } - *zn = znode; - *n = nn; - return 0; -} - -/** - * resolve_collision - resolve a collision. - * @c: UBIFS file-system description object - * @key: key of a directory or extended attribute entry - * @zn: znode is returned here - * @n: zbranch number is passed and returned here - * @nm: name of the entry - * - * This function is called for "hashed" keys to make sure that the found key - * really corresponds to the looked up node (directory or extended attribute - * entry). It returns %1 and sets @zn and @n if the collision is resolved. - * %0 is returned if @nm is not found and @zn and @n are set to the previous - * entry, i.e. to the entry after which @nm could follow if it were in TNC. - * This means that @n may be set to %-1 if the leftmost key in @zn is the - * previous one. A negative error code is returned on failures. - */ -static int resolve_collision(struct ubifs_info *c, const union ubifs_key *key, - struct ubifs_znode **zn, int *n, - const struct qstr *nm) -{ - int err; - - err = matches_name(c, &(*zn)->zbranch[*n], nm); - if (unlikely(err < 0)) - return err; - if (err == NAME_MATCHES) - return 1; - - if (err == NAME_GREATER) { - /* Look left */ - while (1) { - err = tnc_prev(c, zn, n); - if (err == -ENOENT) { - ubifs_assert(*n == 0); - *n = -1; - return 0; - } - if (err < 0) - return err; - if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) { - /* - * We have found the branch after which we would - * like to insert, but inserting in this znode - * may still be wrong. Consider the following 3 - * znodes, in the case where we are resolving a - * collision with Key2. - * - * znode zp - * ---------------------- - * level 1 | Key0 | Key1 | - * ----------------------- - * | | - * znode za | | znode zb - * ------------ ------------ - * level 0 | Key0 | | Key2 | - * ------------ ------------ - * - * The lookup finds Key2 in znode zb. Lets say - * there is no match and the name is greater so - * we look left. When we find Key0, we end up - * here. If we return now, we will insert into - * znode za at slot n = 1. But that is invalid - * according to the parent's keys. Key2 must - * be inserted into znode zb. - * - * Note, this problem is not relevant for the - * case when we go right, because - * 'tnc_insert()' would correct the parent key. - */ - if (*n == (*zn)->child_cnt - 1) { - err = tnc_next(c, zn, n); - if (err) { - /* Should be impossible */ - ubifs_assert(0); - if (err == -ENOENT) - err = -EINVAL; - return err; - } - ubifs_assert(*n == 0); - *n = -1; - } - return 0; - } - err = matches_name(c, &(*zn)->zbranch[*n], nm); - if (err < 0) - return err; - if (err == NAME_LESS) - return 0; - if (err == NAME_MATCHES) - return 1; - ubifs_assert(err == NAME_GREATER); - } - } else { - int nn = *n; - struct ubifs_znode *znode = *zn; - - /* Look right */ - while (1) { - err = tnc_next(c, &znode, &nn); - if (err == -ENOENT) - return 0; - if (err < 0) - return err; - if (keys_cmp(c, &znode->zbranch[nn].key, key)) - return 0; - err = matches_name(c, &znode->zbranch[nn], nm); - if (err < 0) - return err; - if (err == NAME_GREATER) - return 0; - *zn = znode; - *n = nn; - if (err == NAME_MATCHES) - return 1; - ubifs_assert(err == NAME_LESS); - } - } -} - -/** - * fallible_matches_name - determine if a dent matches a given name. - * @c: UBIFS file-system description object - * @zbr: zbranch of dent - * @nm: name to match - * - * This is a "fallible" version of 'matches_name()' function which does not - * panic if the direntry/xentry referred by @zbr does not exist on the media. - * - * This function checks if xentry/direntry referred by zbranch @zbr matches name - * @nm. Returns %NAME_MATCHES it does, %NAME_LESS if the name referred by @zbr - * is less than @nm, %NAME_GREATER if it is greater than @nm, and @NOT_ON_MEDIA - * if xentry/direntry referred by @zbr does not exist on the media. A negative - * error code is returned in case of failure. - */ -static int fallible_matches_name(struct ubifs_info *c, - struct ubifs_zbranch *zbr, - const struct qstr *nm) -{ - struct ubifs_dent_node *dent; - int nlen, err; - - /* If possible, match against the dent in the leaf node cache */ - if (!zbr->leaf) { - dent = kmalloc(zbr->len, GFP_NOFS); - if (!dent) - return -ENOMEM; - - err = fallible_read_node(c, &zbr->key, zbr, dent); - if (err < 0) - goto out_free; - if (err == 0) { - /* The node was not present */ - err = NOT_ON_MEDIA; - goto out_free; - } - ubifs_assert(err == 1); - - err = lnc_add_directly(c, zbr, dent); - if (err) - goto out_free; - } else - dent = zbr->leaf; - - nlen = le16_to_cpu(dent->nlen); - err = memcmp(dent->name, nm->name, min_t(int, nlen, nm->len)); - if (err == 0) { - if (nlen == nm->len) - return NAME_MATCHES; - else if (nlen < nm->len) - return NAME_LESS; - else - return NAME_GREATER; - } else if (err < 0) - return NAME_LESS; - else - return NAME_GREATER; - -out_free: - kfree(dent); - return err; -} - -/** - * fallible_resolve_collision - resolve a collision even if nodes are missing. - * @c: UBIFS file-system description object - * @key: key - * @zn: znode is returned here - * @n: branch number is passed and returned here - * @nm: name of directory entry - * @adding: indicates caller is adding a key to the TNC - * - * This is a "fallible" version of the 'resolve_collision()' function which - * does not panic if one of the nodes referred to by TNC does not exist on the - * media. This may happen when replaying the journal if a deleted node was - * Garbage-collected and the commit was not done. A branch that refers to a node - * that is not present is called a dangling branch. The following are the return - * codes for this function: - * o if @nm was found, %1 is returned and @zn and @n are set to the found - * branch; - * o if we are @adding and @nm was not found, %0 is returned; - * o if we are not @adding and @nm was not found, but a dangling branch was - * found, then %1 is returned and @zn and @n are set to the dangling branch; - * o a negative error code is returned in case of failure. - */ -static int fallible_resolve_collision(struct ubifs_info *c, - const union ubifs_key *key, - struct ubifs_znode **zn, int *n, - const struct qstr *nm, int adding) -{ - struct ubifs_znode *o_znode = NULL, *znode = *zn; - int uninitialized_var(o_n), err, cmp, unsure = 0, nn = *n; - - cmp = fallible_matches_name(c, &znode->zbranch[nn], nm); - if (unlikely(cmp < 0)) - return cmp; - if (cmp == NAME_MATCHES) - return 1; - if (cmp == NOT_ON_MEDIA) { - o_znode = znode; - o_n = nn; - /* - * We are unlucky and hit a dangling branch straight away. - * Now we do not really know where to go to find the needed - * branch - to the left or to the right. Well, let's try left. - */ - unsure = 1; - } else if (!adding) - unsure = 1; /* Remove a dangling branch wherever it is */ - - if (cmp == NAME_GREATER || unsure) { - /* Look left */ - while (1) { - err = tnc_prev(c, zn, n); - if (err == -ENOENT) { - ubifs_assert(*n == 0); - *n = -1; - break; - } - if (err < 0) - return err; - if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) { - /* See comments in 'resolve_collision()' */ - if (*n == (*zn)->child_cnt - 1) { - err = tnc_next(c, zn, n); - if (err) { - /* Should be impossible */ - ubifs_assert(0); - if (err == -ENOENT) - err = -EINVAL; - return err; - } - ubifs_assert(*n == 0); - *n = -1; - } - break; - } - err = fallible_matches_name(c, &(*zn)->zbranch[*n], nm); - if (err < 0) - return err; - if (err == NAME_MATCHES) - return 1; - if (err == NOT_ON_MEDIA) { - o_znode = *zn; - o_n = *n; - continue; - } - if (!adding) - continue; - if (err == NAME_LESS) - break; - else - unsure = 0; - } - } - - if (cmp == NAME_LESS || unsure) { - /* Look right */ - *zn = znode; - *n = nn; - while (1) { - err = tnc_next(c, &znode, &nn); - if (err == -ENOENT) - break; - if (err < 0) - return err; - if (keys_cmp(c, &znode->zbranch[nn].key, key)) - break; - err = fallible_matches_name(c, &znode->zbranch[nn], nm); - if (err < 0) - return err; - if (err == NAME_GREATER) - break; - *zn = znode; - *n = nn; - if (err == NAME_MATCHES) - return 1; - if (err == NOT_ON_MEDIA) { - o_znode = znode; - o_n = nn; - } - } - } - - /* Never match a dangling branch when adding */ - if (adding || !o_znode) - return 0; - - dbg_mnt("dangling match LEB %d:%d len %d %s", - o_znode->zbranch[o_n].lnum, o_znode->zbranch[o_n].offs, - o_znode->zbranch[o_n].len, DBGKEY(key)); - *zn = o_znode; - *n = o_n; - return 1; -} - -/** - * matches_position - determine if a zbranch matches a given position. - * @zbr: zbranch of dent - * @lnum: LEB number of dent to match - * @offs: offset of dent to match - * - * This function returns %1 if @lnum:@offs matches, and %0 otherwise. - */ -static int matches_position(struct ubifs_zbranch *zbr, int lnum, int offs) -{ - if (zbr->lnum == lnum && zbr->offs == offs) - return 1; - else - return 0; -} - -/** - * resolve_collision_directly - resolve a collision directly. - * @c: UBIFS file-system description object - * @key: key of directory entry - * @zn: znode is passed and returned here - * @n: zbranch number is passed and returned here - * @lnum: LEB number of dent node to match - * @offs: offset of dent node to match - * - * This function is used for "hashed" keys to make sure the found directory or - * extended attribute entry node is what was looked for. It is used when the - * flash address of the right node is known (@lnum:@offs) which makes it much - * easier to resolve collisions (no need to read entries and match full - * names). This function returns %1 and sets @zn and @n if the collision is - * resolved, %0 if @lnum:@offs is not found and @zn and @n are set to the - * previous directory entry. Otherwise a negative error code is returned. - */ -static int resolve_collision_directly(struct ubifs_info *c, - const union ubifs_key *key, - struct ubifs_znode **zn, int *n, - int lnum, int offs) -{ - struct ubifs_znode *znode; - int nn, err; - - znode = *zn; - nn = *n; - if (matches_position(&znode->zbranch[nn], lnum, offs)) - return 1; - - /* Look left */ - while (1) { - err = tnc_prev(c, &znode, &nn); - if (err == -ENOENT) - break; - if (err < 0) - return err; - if (keys_cmp(c, &znode->zbranch[nn].key, key)) - break; - if (matches_position(&znode->zbranch[nn], lnum, offs)) { - *zn = znode; - *n = nn; - return 1; - } - } - - /* Look right */ - znode = *zn; - nn = *n; - while (1) { - err = tnc_next(c, &znode, &nn); - if (err == -ENOENT) - return 0; - if (err < 0) - return err; - if (keys_cmp(c, &znode->zbranch[nn].key, key)) - return 0; - *zn = znode; - *n = nn; - if (matches_position(&znode->zbranch[nn], lnum, offs)) - return 1; - } -} - -/** - * dirty_cow_bottom_up - dirty a znode and its ancestors. - * @c: UBIFS file-system description object - * @znode: znode to dirty - * - * If we do not have a unique key that resides in a znode, then we cannot - * dirty that znode from the top down (i.e. by using lookup_level0_dirty) - * This function records the path back to the last dirty ancestor, and then - * dirties the znodes on that path. - */ -static struct ubifs_znode *dirty_cow_bottom_up(struct ubifs_info *c, - struct ubifs_znode *znode) -{ - struct ubifs_znode *zp; - int *path = c->bottom_up_buf, p = 0; - - ubifs_assert(c->zroot.znode); - ubifs_assert(znode); - if (c->zroot.znode->level > BOTTOM_UP_HEIGHT) { - kfree(c->bottom_up_buf); - c->bottom_up_buf = kmalloc(c->zroot.znode->level * sizeof(int), - GFP_NOFS); - if (!c->bottom_up_buf) - return ERR_PTR(-ENOMEM); - path = c->bottom_up_buf; - } - if (c->zroot.znode->level) { - /* Go up until parent is dirty */ - while (1) { - int n; - - zp = znode->parent; - if (!zp) - break; - n = znode->iip; - ubifs_assert(p < c->zroot.znode->level); - path[p++] = n; - if (!zp->cnext && ubifs_zn_dirty(znode)) - break; - znode = zp; - } - } - - /* Come back down, dirtying as we go */ - while (1) { - struct ubifs_zbranch *zbr; - - zp = znode->parent; - if (zp) { - ubifs_assert(path[p - 1] >= 0); - ubifs_assert(path[p - 1] < zp->child_cnt); - zbr = &zp->zbranch[path[--p]]; - znode = dirty_cow_znode(c, zbr); - } else { - ubifs_assert(znode == c->zroot.znode); - znode = dirty_cow_znode(c, &c->zroot); - } - if (IS_ERR(znode) || !p) - break; - ubifs_assert(path[p - 1] >= 0); - ubifs_assert(path[p - 1] < znode->child_cnt); - znode = znode->zbranch[path[p - 1]].znode; - } - - return znode; -} - -/** - * ubifs_lookup_level0 - search for zero-level znode. - * @c: UBIFS file-system description object - * @key: key to lookup - * @zn: znode is returned here - * @n: znode branch slot number is returned here - * - * This function looks up the TNC tree and search for zero-level znode which - * refers key @key. The found zero-level znode is returned in @zn. There are 3 - * cases: - * o exact match, i.e. the found zero-level znode contains key @key, then %1 - * is returned and slot number of the matched branch is stored in @n; - * o not exact match, which means that zero-level znode does not contain - * @key, then %0 is returned and slot number of the closed branch is stored - * in @n; - * o @key is so small that it is even less than the lowest key of the - * leftmost zero-level node, then %0 is returned and %0 is stored in @n. - * - * Note, when the TNC tree is traversed, some znodes may be absent, then this - * function reads corresponding indexing nodes and inserts them to TNC. In - * case of failure, a negative error code is returned. - */ -int ubifs_lookup_level0(struct ubifs_info *c, const union ubifs_key *key, - struct ubifs_znode **zn, int *n) -{ - int err, exact; - struct ubifs_znode *znode; - unsigned long time = get_seconds(); - - dbg_tnc("search key %s", DBGKEY(key)); - - znode = c->zroot.znode; - if (unlikely(!znode)) { - znode = ubifs_load_znode(c, &c->zroot, NULL, 0); - if (IS_ERR(znode)) - return PTR_ERR(znode); - } - - znode->time = time; - - while (1) { - struct ubifs_zbranch *zbr; - - exact = ubifs_search_zbranch(c, znode, key, n); - - if (znode->level == 0) - break; - - if (*n < 0) - *n = 0; - zbr = &znode->zbranch[*n]; - - if (zbr->znode) { - znode->time = time; - znode = zbr->znode; - continue; - } - - /* znode is not in TNC cache, load it from the media */ - znode = ubifs_load_znode(c, zbr, znode, *n); - if (IS_ERR(znode)) - return PTR_ERR(znode); - } - - *zn = znode; - if (exact || !is_hash_key(c, key) || *n != -1) { - dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n); - return exact; - } - - /* - * Here is a tricky place. We have not found the key and this is a - * "hashed" key, which may collide. The rest of the code deals with - * situations like this: - * - * | 3 | 5 | - * / \ - * | 3 | 5 | | 6 | 7 | (x) - * - * Or more a complex example: - * - * | 1 | 5 | - * / \ - * | 1 | 3 | | 5 | 8 | - * \ / - * | 5 | 5 | | 6 | 7 | (x) - * - * In the examples, if we are looking for key "5", we may reach nodes - * marked with "(x)". In this case what we have do is to look at the - * left and see if there is "5" key there. If there is, we have to - * return it. - * - * Note, this whole situation is possible because we allow to have - * elements which are equivalent to the next key in the parent in the - * children of current znode. For example, this happens if we split a - * znode like this: | 3 | 5 | 5 | 6 | 7 |, which results in something - * like this: - * | 3 | 5 | - * / \ - * | 3 | 5 | | 5 | 6 | 7 | - * ^ - * And this becomes what is at the first "picture" after key "5" marked - * with "^" is removed. What could be done is we could prohibit - * splitting in the middle of the colliding sequence. Also, when - * removing the leftmost key, we would have to correct the key of the - * parent node, which would introduce additional complications. Namely, - * if we changed the the leftmost key of the parent znode, the garbage - * collector would be unable to find it (GC is doing this when GC'ing - * indexing LEBs). Although we already have an additional RB-tree where - * we save such changed znodes (see 'ins_clr_old_idx_znode()') until - * after the commit. But anyway, this does not look easy to implement - * so we did not try this. - */ - err = tnc_prev(c, &znode, n); - if (err == -ENOENT) { - dbg_tnc("found 0, lvl %d, n -1", znode->level); - *n = -1; - return 0; - } - if (unlikely(err < 0)) - return err; - if (keys_cmp(c, key, &znode->zbranch[*n].key)) { - dbg_tnc("found 0, lvl %d, n -1", znode->level); - *n = -1; - return 0; - } - - dbg_tnc("found 1, lvl %d, n %d", znode->level, *n); - *zn = znode; - return 1; -} - -/** - * lookup_level0_dirty - search for zero-level znode dirtying. - * @c: UBIFS file-system description object - * @key: key to lookup - * @zn: znode is returned here - * @n: znode branch slot number is returned here - * - * This function looks up the TNC tree and search for zero-level znode which - * refers key @key. The found zero-level znode is returned in @zn. There are 3 - * cases: - * o exact match, i.e. the found zero-level znode contains key @key, then %1 - * is returned and slot number of the matched branch is stored in @n; - * o not exact match, which means that zero-level znode does not contain @key - * then %0 is returned and slot number of the closed branch is stored in - * @n; - * o @key is so small that it is even less than the lowest key of the - * leftmost zero-level node, then %0 is returned and %-1 is stored in @n. - * - * Additionally all znodes in the path from the root to the located zero-level - * znode are marked as dirty. - * - * Note, when the TNC tree is traversed, some znodes may be absent, then this - * function reads corresponding indexing nodes and inserts them to TNC. In - * case of failure, a negative error code is returned. - */ -static int lookup_level0_dirty(struct ubifs_info *c, const union ubifs_key *key, - struct ubifs_znode **zn, int *n) -{ - int err, exact; - struct ubifs_znode *znode; - unsigned long time = get_seconds(); - - dbg_tnc("search and dirty key %s", DBGKEY(key)); - - znode = c->zroot.znode; - if (unlikely(!znode)) { - znode = ubifs_load_znode(c, &c->zroot, NULL, 0); - if (IS_ERR(znode)) - return PTR_ERR(znode); - } - - znode = dirty_cow_znode(c, &c->zroot); - if (IS_ERR(znode)) - return PTR_ERR(znode); - - znode->time = time; - - while (1) { - struct ubifs_zbranch *zbr; - - exact = ubifs_search_zbranch(c, znode, key, n); - - if (znode->level == 0) - break; - - if (*n < 0) - *n = 0; - zbr = &znode->zbranch[*n]; - - if (zbr->znode) { - znode->time = time; - znode = dirty_cow_znode(c, zbr); - if (IS_ERR(znode)) - return PTR_ERR(znode); - continue; - } - - /* znode is not in TNC cache, load it from the media */ - znode = ubifs_load_znode(c, zbr, znode, *n); - if (IS_ERR(znode)) - return PTR_ERR(znode); - znode = dirty_cow_znode(c, zbr); - if (IS_ERR(znode)) - return PTR_ERR(znode); - } - - *zn = znode; - if (exact || !is_hash_key(c, key) || *n != -1) { - dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n); - return exact; - } - - /* - * See huge comment at 'lookup_level0_dirty()' what is the rest of the - * code. - */ - err = tnc_prev(c, &znode, n); - if (err == -ENOENT) { - *n = -1; - dbg_tnc("found 0, lvl %d, n -1", znode->level); - return 0; - } - if (unlikely(err < 0)) - return err; - if (keys_cmp(c, key, &znode->zbranch[*n].key)) { - *n = -1; - dbg_tnc("found 0, lvl %d, n -1", znode->level); - return 0; - } - - if (znode->cnext || !ubifs_zn_dirty(znode)) { - znode = dirty_cow_bottom_up(c, znode); - if (IS_ERR(znode)) - return PTR_ERR(znode); - } - - dbg_tnc("found 1, lvl %d, n %d", znode->level, *n); - *zn = znode; - return 1; -} - -/** - * maybe_leb_gced - determine if a LEB may have been garbage collected. - * @c: UBIFS file-system description object - * @lnum: LEB number - * @gc_seq1: garbage collection sequence number - * - * This function determines if @lnum may have been garbage collected since - * sequence number @gc_seq1. If it may have been then %1 is returned, otherwise - * %0 is returned. - */ -static int maybe_leb_gced(struct ubifs_info *c, int lnum, int gc_seq1) -{ - /* - * No garbage collection in the read-only U-Boot implementation - */ - return 0; -} - -/** - * ubifs_tnc_locate - look up a file-system node and return it and its location. - * @c: UBIFS file-system description object - * @key: node key to lookup - * @node: the node is returned here - * @lnum: LEB number is returned here - * @offs: offset is returned here - * - * This function look up and reads node with key @key. The caller has to make - * sure the @node buffer is large enough to fit the node. Returns zero in case - * of success, %-ENOENT if the node was not found, and a negative error code in - * case of failure. The node location can be returned in @lnum and @offs. - */ -int ubifs_tnc_locate(struct ubifs_info *c, const union ubifs_key *key, - void *node, int *lnum, int *offs) -{ - int found, n, err, safely = 0, gc_seq1; - struct ubifs_znode *znode; - struct ubifs_zbranch zbr, *zt; - -again: - mutex_lock(&c->tnc_mutex); - found = ubifs_lookup_level0(c, key, &znode, &n); - if (!found) { - err = -ENOENT; - goto out; - } else if (found < 0) { - err = found; - goto out; - } - zt = &znode->zbranch[n]; - if (lnum) { - *lnum = zt->lnum; - *offs = zt->offs; - } - if (is_hash_key(c, key)) { - /* - * In this case the leaf node cache gets used, so we pass the - * address of the zbranch and keep the mutex locked - */ - err = tnc_read_node_nm(c, zt, node); - goto out; - } - if (safely) { - err = ubifs_tnc_read_node(c, zt, node); - goto out; - } - /* Drop the TNC mutex prematurely and race with garbage collection */ - zbr = znode->zbranch[n]; - gc_seq1 = c->gc_seq; - mutex_unlock(&c->tnc_mutex); - - err = fallible_read_node(c, key, &zbr, node); - if (err <= 0 || maybe_leb_gced(c, zbr.lnum, gc_seq1)) { - /* - * The node may have been GC'ed out from under us so try again - * while keeping the TNC mutex locked. - */ - safely = 1; - goto again; - } - return 0; - -out: - mutex_unlock(&c->tnc_mutex); - return err; -} - -/** - * ubifs_tnc_get_bu_keys - lookup keys for bulk-read. - * @c: UBIFS file-system description object - * @bu: bulk-read parameters and results - * - * Lookup consecutive data node keys for the same inode that reside - * consecutively in the same LEB. This function returns zero in case of success - * and a negative error code in case of failure. - * - * Note, if the bulk-read buffer length (@bu->buf_len) is known, this function - * makes sure bulk-read nodes fit the buffer. Otherwise, this function prepares - * maximum possible amount of nodes for bulk-read. - */ -int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu) -{ - int n, err = 0, lnum = -1, uninitialized_var(offs); - int uninitialized_var(len); - unsigned int block = key_block(c, &bu->key); - struct ubifs_znode *znode; - - bu->cnt = 0; - bu->blk_cnt = 0; - bu->eof = 0; - - mutex_lock(&c->tnc_mutex); - /* Find first key */ - err = ubifs_lookup_level0(c, &bu->key, &znode, &n); - if (err < 0) - goto out; - if (err) { - /* Key found */ - len = znode->zbranch[n].len; - /* The buffer must be big enough for at least 1 node */ - if (len > bu->buf_len) { - err = -EINVAL; - goto out; - } - /* Add this key */ - bu->zbranch[bu->cnt++] = znode->zbranch[n]; - bu->blk_cnt += 1; - lnum = znode->zbranch[n].lnum; - offs = ALIGN(znode->zbranch[n].offs + len, 8); - } - while (1) { - struct ubifs_zbranch *zbr; - union ubifs_key *key; - unsigned int next_block; - - /* Find next key */ - err = tnc_next(c, &znode, &n); - if (err) - goto out; - zbr = &znode->zbranch[n]; - key = &zbr->key; - /* See if there is another data key for this file */ - if (key_inum(c, key) != key_inum(c, &bu->key) || - key_type(c, key) != UBIFS_DATA_KEY) { - err = -ENOENT; - goto out; - } - if (lnum < 0) { - /* First key found */ - lnum = zbr->lnum; - offs = ALIGN(zbr->offs + zbr->len, 8); - len = zbr->len; - if (len > bu->buf_len) { - err = -EINVAL; - goto out; - } - } else { - /* - * The data nodes must be in consecutive positions in - * the same LEB. - */ - if (zbr->lnum != lnum || zbr->offs != offs) - goto out; - offs += ALIGN(zbr->len, 8); - len = ALIGN(len, 8) + zbr->len; - /* Must not exceed buffer length */ - if (len > bu->buf_len) - goto out; - } - /* Allow for holes */ - next_block = key_block(c, key); - bu->blk_cnt += (next_block - block - 1); - if (bu->blk_cnt >= UBIFS_MAX_BULK_READ) - goto out; - block = next_block; - /* Add this key */ - bu->zbranch[bu->cnt++] = *zbr; - bu->blk_cnt += 1; - /* See if we have room for more */ - if (bu->cnt >= UBIFS_MAX_BULK_READ) - goto out; - if (bu->blk_cnt >= UBIFS_MAX_BULK_READ) - goto out; - } -out: - if (err == -ENOENT) { - bu->eof = 1; - err = 0; - } - bu->gc_seq = c->gc_seq; - mutex_unlock(&c->tnc_mutex); - if (err) - return err; - /* - * An enormous hole could cause bulk-read to encompass too many - * page cache pages, so limit the number here. - */ - if (bu->blk_cnt > UBIFS_MAX_BULK_READ) - bu->blk_cnt = UBIFS_MAX_BULK_READ; - /* - * Ensure that bulk-read covers a whole number of page cache - * pages. - */ - if (UBIFS_BLOCKS_PER_PAGE == 1 || - !(bu->blk_cnt & (UBIFS_BLOCKS_PER_PAGE - 1))) - return 0; - if (bu->eof) { - /* At the end of file we can round up */ - bu->blk_cnt += UBIFS_BLOCKS_PER_PAGE - 1; - return 0; - } - /* Exclude data nodes that do not make up a whole page cache page */ - block = key_block(c, &bu->key) + bu->blk_cnt; - block &= ~(UBIFS_BLOCKS_PER_PAGE - 1); - while (bu->cnt) { - if (key_block(c, &bu->zbranch[bu->cnt - 1].key) < block) - break; - bu->cnt -= 1; - } - return 0; -} - -/** - * validate_data_node - validate data nodes for bulk-read. - * @c: UBIFS file-system description object - * @buf: buffer containing data node to validate - * @zbr: zbranch of data node to validate - * - * This functions returns %0 on success or a negative error code on failure. - */ -static int validate_data_node(struct ubifs_info *c, void *buf, - struct ubifs_zbranch *zbr) -{ - union ubifs_key key1; - struct ubifs_ch *ch = buf; - int err, len; - - if (ch->node_type != UBIFS_DATA_NODE) { - ubifs_err("bad node type (%d but expected %d)", - ch->node_type, UBIFS_DATA_NODE); - goto out_err; - } - - err = ubifs_check_node(c, buf, zbr->lnum, zbr->offs, 0, 0); - if (err) { - ubifs_err("expected node type %d", UBIFS_DATA_NODE); - goto out; - } - - len = le32_to_cpu(ch->len); - if (len != zbr->len) { - ubifs_err("bad node length %d, expected %d", len, zbr->len); - goto out_err; - } - - /* Make sure the key of the read node is correct */ - key_read(c, buf + UBIFS_KEY_OFFSET, &key1); - if (!keys_eq(c, &zbr->key, &key1)) { - ubifs_err("bad key in node at LEB %d:%d", - zbr->lnum, zbr->offs); - dbg_tnc("looked for key %s found node's key %s", - DBGKEY(&zbr->key), DBGKEY1(&key1)); - goto out_err; - } - - return 0; - -out_err: - err = -EINVAL; -out: - ubifs_err("bad node at LEB %d:%d", zbr->lnum, zbr->offs); - dbg_dump_node(c, buf); - dbg_dump_stack(); - return err; -} - -/** - * ubifs_tnc_bulk_read - read a number of data nodes in one go. - * @c: UBIFS file-system description object - * @bu: bulk-read parameters and results - * - * This functions reads and validates the data nodes that were identified by the - * 'ubifs_tnc_get_bu_keys()' function. This functions returns %0 on success, - * -EAGAIN to indicate a race with GC, or another negative error code on - * failure. - */ -int ubifs_tnc_bulk_read(struct ubifs_info *c, struct bu_info *bu) -{ - int lnum = bu->zbranch[0].lnum, offs = bu->zbranch[0].offs, len, err, i; - void *buf; - - len = bu->zbranch[bu->cnt - 1].offs; - len += bu->zbranch[bu->cnt - 1].len - offs; - if (len > bu->buf_len) { - ubifs_err("buffer too small %d vs %d", bu->buf_len, len); - return -EINVAL; - } - - /* Do the read */ - err = ubi_read(c->ubi, lnum, bu->buf, offs, len); - - /* Check for a race with GC */ - if (maybe_leb_gced(c, lnum, bu->gc_seq)) - return -EAGAIN; - - if (err && err != -EBADMSG) { - ubifs_err("failed to read from LEB %d:%d, error %d", - lnum, offs, err); - dbg_dump_stack(); - dbg_tnc("key %s", DBGKEY(&bu->key)); - return err; - } - - /* Validate the nodes read */ - buf = bu->buf; - for (i = 0; i < bu->cnt; i++) { - err = validate_data_node(c, buf, &bu->zbranch[i]); - if (err) - return err; - buf = buf + ALIGN(bu->zbranch[i].len, 8); - } - - return 0; -} - -/** - * do_lookup_nm- look up a "hashed" node. - * @c: UBIFS file-system description object - * @key: node key to lookup - * @node: the node is returned here - * @nm: node name - * - * This function look up and reads a node which contains name hash in the key. - * Since the hash may have collisions, there may be many nodes with the same - * key, so we have to sequentially look to all of them until the needed one is - * found. This function returns zero in case of success, %-ENOENT if the node - * was not found, and a negative error code in case of failure. - */ -static int do_lookup_nm(struct ubifs_info *c, const union ubifs_key *key, - void *node, const struct qstr *nm) -{ - int found, n, err; - struct ubifs_znode *znode; - - dbg_tnc("name '%.*s' key %s", nm->len, nm->name, DBGKEY(key)); - mutex_lock(&c->tnc_mutex); - found = ubifs_lookup_level0(c, key, &znode, &n); - if (!found) { - err = -ENOENT; - goto out_unlock; - } else if (found < 0) { - err = found; - goto out_unlock; - } - - ubifs_assert(n >= 0); - - err = resolve_collision(c, key, &znode, &n, nm); - dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n); - if (unlikely(err < 0)) - goto out_unlock; - if (err == 0) { - err = -ENOENT; - goto out_unlock; - } - - err = tnc_read_node_nm(c, &znode->zbranch[n], node); - -out_unlock: - mutex_unlock(&c->tnc_mutex); - return err; -} - -/** - * ubifs_tnc_lookup_nm - look up a "hashed" node. - * @c: UBIFS file-system description object - * @key: node key to lookup - * @node: the node is returned here - * @nm: node name - * - * This function look up and reads a node which contains name hash in the key. - * Since the hash may have collisions, there may be many nodes with the same - * key, so we have to sequentially look to all of them until the needed one is - * found. This function returns zero in case of success, %-ENOENT if the node - * was not found, and a negative error code in case of failure. - */ -int ubifs_tnc_lookup_nm(struct ubifs_info *c, const union ubifs_key *key, - void *node, const struct qstr *nm) -{ - int err, len; - const struct ubifs_dent_node *dent = node; - - /* - * We assume that in most of the cases there are no name collisions and - * 'ubifs_tnc_lookup()' returns us the right direntry. - */ - err = ubifs_tnc_lookup(c, key, node); - if (err) - return err; - - len = le16_to_cpu(dent->nlen); - if (nm->len == len && !memcmp(dent->name, nm->name, len)) - return 0; - - /* - * Unluckily, there are hash collisions and we have to iterate over - * them look at each direntry with colliding name hash sequentially. - */ - return do_lookup_nm(c, key, node, nm); -} - -/** - * correct_parent_keys - correct parent znodes' keys. - * @c: UBIFS file-system description object - * @znode: znode to correct parent znodes for - * - * This is a helper function for 'tnc_insert()'. When the key of the leftmost - * zbranch changes, keys of parent znodes have to be corrected. This helper - * function is called in such situations and corrects the keys if needed. - */ -static void correct_parent_keys(const struct ubifs_info *c, - struct ubifs_znode *znode) -{ - union ubifs_key *key, *key1; - - ubifs_assert(znode->parent); - ubifs_assert(znode->iip == 0); - - key = &znode->zbranch[0].key; - key1 = &znode->parent->zbranch[0].key; - - while (keys_cmp(c, key, key1) < 0) { - key_copy(c, key, key1); - znode = znode->parent; - znode->alt = 1; - if (!znode->parent || znode->iip) - break; - key1 = &znode->parent->zbranch[0].key; - } -} - -/** - * insert_zbranch - insert a zbranch into a znode. - * @znode: znode into which to insert - * @zbr: zbranch to insert - * @n: slot number to insert to - * - * This is a helper function for 'tnc_insert()'. UBIFS does not allow "gaps" in - * znode's array of zbranches and keeps zbranches consolidated, so when a new - * zbranch has to be inserted to the @znode->zbranches[]' array at the @n-th - * slot, zbranches starting from @n have to be moved right. - */ -static void insert_zbranch(struct ubifs_znode *znode, - const struct ubifs_zbranch *zbr, int n) -{ - int i; - - ubifs_assert(ubifs_zn_dirty(znode)); - - if (znode->level) { - for (i = znode->child_cnt; i > n; i--) { - znode->zbranch[i] = znode->zbranch[i - 1]; - if (znode->zbranch[i].znode) - znode->zbranch[i].znode->iip = i; - } - if (zbr->znode) - zbr->znode->iip = n; - } else - for (i = znode->child_cnt; i > n; i--) - znode->zbranch[i] = znode->zbranch[i - 1]; - - znode->zbranch[n] = *zbr; - znode->child_cnt += 1; - - /* - * After inserting at slot zero, the lower bound of the key range of - * this znode may have changed. If this znode is subsequently split - * then the upper bound of the key range may change, and furthermore - * it could change to be lower than the original lower bound. If that - * happens, then it will no longer be possible to find this znode in the - * TNC using the key from the index node on flash. That is bad because - * if it is not found, we will assume it is obsolete and may overwrite - * it. Then if there is an unclean unmount, we will start using the - * old index which will be broken. - * - * So we first mark znodes that have insertions at slot zero, and then - * if they are split we add their lnum/offs to the old_idx tree. - */ - if (n == 0) - znode->alt = 1; -} - -/** - * tnc_insert - insert a node into TNC. - * @c: UBIFS file-system description object - * @znode: znode to insert into - * @zbr: branch to insert - * @n: slot number to insert new zbranch to - * - * This function inserts a new node described by @zbr into znode @znode. If - * znode does not have a free slot for new zbranch, it is split. Parent znodes - * are splat as well if needed. Returns zero in case of success or a negative - * error code in case of failure. - */ -static int tnc_insert(struct ubifs_info *c, struct ubifs_znode *znode, - struct ubifs_zbranch *zbr, int n) -{ - struct ubifs_znode *zn, *zi, *zp; - int i, keep, move, appending = 0; - union ubifs_key *key = &zbr->key, *key1; - - ubifs_assert(n >= 0 && n <= c->fanout); - - /* Implement naive insert for now */ -again: - zp = znode->parent; - if (znode->child_cnt < c->fanout) { - ubifs_assert(n != c->fanout); - dbg_tnc("inserted at %d level %d, key %s", n, znode->level, - DBGKEY(key)); - - insert_zbranch(znode, zbr, n); - - /* Ensure parent's key is correct */ - if (n == 0 && zp && znode->iip == 0) - correct_parent_keys(c, znode); - - return 0; - } - - /* - * Unfortunately, @znode does not have more empty slots and we have to - * split it. - */ - dbg_tnc("splitting level %d, key %s", znode->level, DBGKEY(key)); - - if (znode->alt) - /* - * We can no longer be sure of finding this znode by key, so we - * record it in the old_idx tree. - */ - ins_clr_old_idx_znode(c, znode); - - zn = kzalloc(c->max_znode_sz, GFP_NOFS); - if (!zn) - return -ENOMEM; - zn->parent = zp; - zn->level = znode->level; - - /* Decide where to split */ - if (znode->level == 0 && key_type(c, key) == UBIFS_DATA_KEY) { - /* Try not to split consecutive data keys */ - if (n == c->fanout) { - key1 = &znode->zbranch[n - 1].key; - if (key_inum(c, key1) == key_inum(c, key) && - key_type(c, key1) == UBIFS_DATA_KEY) - appending = 1; - } else - goto check_split; - } else if (appending && n != c->fanout) { - /* Try not to split consecutive data keys */ - appending = 0; -check_split: - if (n >= (c->fanout + 1) / 2) { - key1 = &znode->zbranch[0].key; - if (key_inum(c, key1) == key_inum(c, key) && - key_type(c, key1) == UBIFS_DATA_KEY) { - key1 = &znode->zbranch[n].key; - if (key_inum(c, key1) != key_inum(c, key) || - key_type(c, key1) != UBIFS_DATA_KEY) { - keep = n; - move = c->fanout - keep; - zi = znode; - goto do_split; - } - } - } - } - - if (appending) { - keep = c->fanout; - move = 0; - } else { - keep = (c->fanout + 1) / 2; - move = c->fanout - keep; - } - - /* - * Although we don't at present, we could look at the neighbors and see - * if we can move some zbranches there. - */ - - if (n < keep) { - /* Insert into existing znode */ - zi = znode; - move += 1; - keep -= 1; - } else { - /* Insert into new znode */ - zi = zn; - n -= keep; - /* Re-parent */ - if (zn->level != 0) - zbr->znode->parent = zn; - } - -do_split: - - __set_bit(DIRTY_ZNODE, &zn->flags); - atomic_long_inc(&c->dirty_zn_cnt); - - zn->child_cnt = move; - znode->child_cnt = keep; - - dbg_tnc("moving %d, keeping %d", move, keep); - - /* Move zbranch */ - for (i = 0; i < move; i++) { - zn->zbranch[i] = znode->zbranch[keep + i]; - /* Re-parent */ - if (zn->level != 0) - if (zn->zbranch[i].znode) { - zn->zbranch[i].znode->parent = zn; - zn->zbranch[i].znode->iip = i; - } - } - - /* Insert new key and branch */ - dbg_tnc("inserting at %d level %d, key %s", n, zn->level, DBGKEY(key)); - - insert_zbranch(zi, zbr, n); - - /* Insert new znode (produced by spitting) into the parent */ - if (zp) { - if (n == 0 && zi == znode && znode->iip == 0) - correct_parent_keys(c, znode); - - /* Locate insertion point */ - n = znode->iip + 1; - - /* Tail recursion */ - zbr->key = zn->zbranch[0].key; - zbr->znode = zn; - zbr->lnum = 0; - zbr->offs = 0; - zbr->len = 0; - znode = zp; - - goto again; - } - - /* We have to split root znode */ - dbg_tnc("creating new zroot at level %d", znode->level + 1); - - zi = kzalloc(c->max_znode_sz, GFP_NOFS); - if (!zi) - return -ENOMEM; - - zi->child_cnt = 2; - zi->level = znode->level + 1; - - __set_bit(DIRTY_ZNODE, &zi->flags); - atomic_long_inc(&c->dirty_zn_cnt); - - zi->zbranch[0].key = znode->zbranch[0].key; - zi->zbranch[0].znode = znode; - zi->zbranch[0].lnum = c->zroot.lnum; - zi->zbranch[0].offs = c->zroot.offs; - zi->zbranch[0].len = c->zroot.len; - zi->zbranch[1].key = zn->zbranch[0].key; - zi->zbranch[1].znode = zn; - - c->zroot.lnum = 0; - c->zroot.offs = 0; - c->zroot.len = 0; - c->zroot.znode = zi; - - zn->parent = zi; - zn->iip = 1; - znode->parent = zi; - znode->iip = 0; - - return 0; -} - -/** - * ubifs_tnc_add - add a node to TNC. - * @c: UBIFS file-system description object - * @key: key to add - * @lnum: LEB number of node - * @offs: node offset - * @len: node length - * - * This function adds a node with key @key to TNC. The node may be new or it may - * obsolete some existing one. Returns %0 on success or negative error code on - * failure. - */ -int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum, - int offs, int len) -{ - int found, n, err = 0; - struct ubifs_znode *znode; - - mutex_lock(&c->tnc_mutex); - dbg_tnc("%d:%d, len %d, key %s", lnum, offs, len, DBGKEY(key)); - found = lookup_level0_dirty(c, key, &znode, &n); - if (!found) { - struct ubifs_zbranch zbr; - - zbr.znode = NULL; - zbr.lnum = lnum; - zbr.offs = offs; - zbr.len = len; - key_copy(c, key, &zbr.key); - err = tnc_insert(c, znode, &zbr, n + 1); - } else if (found == 1) { - struct ubifs_zbranch *zbr = &znode->zbranch[n]; - - lnc_free(zbr); - err = ubifs_add_dirt(c, zbr->lnum, zbr->len); - zbr->lnum = lnum; - zbr->offs = offs; - zbr->len = len; - } else - err = found; - if (!err) - err = dbg_check_tnc(c, 0); - mutex_unlock(&c->tnc_mutex); - - return err; -} - -/** - * ubifs_tnc_replace - replace a node in the TNC only if the old node is found. - * @c: UBIFS file-system description object - * @key: key to add - * @old_lnum: LEB number of old node - * @old_offs: old node offset - * @lnum: LEB number of node - * @offs: node offset - * @len: node length - * - * This function replaces a node with key @key in the TNC only if the old node - * is found. This function is called by garbage collection when node are moved. - * Returns %0 on success or negative error code on failure. - */ -int ubifs_tnc_replace(struct ubifs_info *c, const union ubifs_key *key, - int old_lnum, int old_offs, int lnum, int offs, int len) -{ - int found, n, err = 0; - struct ubifs_znode *znode; - - mutex_lock(&c->tnc_mutex); - dbg_tnc("old LEB %d:%d, new LEB %d:%d, len %d, key %s", old_lnum, - old_offs, lnum, offs, len, DBGKEY(key)); - found = lookup_level0_dirty(c, key, &znode, &n); - if (found < 0) { - err = found; - goto out_unlock; - } - - if (found == 1) { - struct ubifs_zbranch *zbr = &znode->zbranch[n]; - - found = 0; - if (zbr->lnum == old_lnum && zbr->offs == old_offs) { - lnc_free(zbr); - err = ubifs_add_dirt(c, zbr->lnum, zbr->len); - if (err) - goto out_unlock; - zbr->lnum = lnum; - zbr->offs = offs; - zbr->len = len; - found = 1; - } else if (is_hash_key(c, key)) { - found = resolve_collision_directly(c, key, &znode, &n, - old_lnum, old_offs); - dbg_tnc("rc returned %d, znode %p, n %d, LEB %d:%d", - found, znode, n, old_lnum, old_offs); - if (found < 0) { - err = found; - goto out_unlock; - } - - if (found) { - /* Ensure the znode is dirtied */ - if (znode->cnext || !ubifs_zn_dirty(znode)) { - znode = dirty_cow_bottom_up(c, znode); - if (IS_ERR(znode)) { - err = PTR_ERR(znode); - goto out_unlock; - } - } - zbr = &znode->zbranch[n]; - lnc_free(zbr); - err = ubifs_add_dirt(c, zbr->lnum, - zbr->len); - if (err) - goto out_unlock; - zbr->lnum = lnum; - zbr->offs = offs; - zbr->len = len; - } - } - } - - if (!found) - err = ubifs_add_dirt(c, lnum, len); - - if (!err) - err = dbg_check_tnc(c, 0); - -out_unlock: - mutex_unlock(&c->tnc_mutex); - return err; -} - -/** - * ubifs_tnc_add_nm - add a "hashed" node to TNC. - * @c: UBIFS file-system description object - * @key: key to add - * @lnum: LEB number of node - * @offs: node offset - * @len: node length - * @nm: node name - * - * This is the same as 'ubifs_tnc_add()' but it should be used with keys which - * may have collisions, like directory entry keys. - */ -int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key, - int lnum, int offs, int len, const struct qstr *nm) -{ - int found, n, err = 0; - struct ubifs_znode *znode; - - mutex_lock(&c->tnc_mutex); - dbg_tnc("LEB %d:%d, name '%.*s', key %s", lnum, offs, nm->len, nm->name, - DBGKEY(key)); - found = lookup_level0_dirty(c, key, &znode, &n); - if (found < 0) { - err = found; - goto out_unlock; - } - - if (found == 1) { - if (c->replaying) - found = fallible_resolve_collision(c, key, &znode, &n, - nm, 1); - else - found = resolve_collision(c, key, &znode, &n, nm); - dbg_tnc("rc returned %d, znode %p, n %d", found, znode, n); - if (found < 0) { - err = found; - goto out_unlock; - } - - /* Ensure the znode is dirtied */ - if (znode->cnext || !ubifs_zn_dirty(znode)) { - znode = dirty_cow_bottom_up(c, znode); - if (IS_ERR(znode)) { - err = PTR_ERR(znode); - goto out_unlock; - } - } - - if (found == 1) { - struct ubifs_zbranch *zbr = &znode->zbranch[n]; - - lnc_free(zbr); - err = ubifs_add_dirt(c, zbr->lnum, zbr->len); - zbr->lnum = lnum; - zbr->offs = offs; - zbr->len = len; - goto out_unlock; - } - } - - if (!found) { - struct ubifs_zbranch zbr; - - zbr.znode = NULL; - zbr.lnum = lnum; - zbr.offs = offs; - zbr.len = len; - key_copy(c, key, &zbr.key); - err = tnc_insert(c, znode, &zbr, n + 1); - if (err) - goto out_unlock; - if (c->replaying) { - /* - * We did not find it in the index so there may be a - * dangling branch still in the index. So we remove it - * by passing 'ubifs_tnc_remove_nm()' the same key but - * an unmatchable name. - */ - struct qstr noname = { .len = 0, .name = "" }; - - err = dbg_check_tnc(c, 0); - mutex_unlock(&c->tnc_mutex); - if (err) - return err; - return ubifs_tnc_remove_nm(c, key, &noname); - } - } - -out_unlock: - if (!err) - err = dbg_check_tnc(c, 0); - mutex_unlock(&c->tnc_mutex); - return err; -} - -/** - * tnc_delete - delete a znode form TNC. - * @c: UBIFS file-system description object - * @znode: znode to delete from - * @n: zbranch slot number to delete - * - * This function deletes a leaf node from @n-th slot of @znode. Returns zero in - * case of success and a negative error code in case of failure. - */ -static int tnc_delete(struct ubifs_info *c, struct ubifs_znode *znode, int n) -{ - struct ubifs_zbranch *zbr; - struct ubifs_znode *zp; - int i, err; - - /* Delete without merge for now */ - ubifs_assert(znode->level == 0); - ubifs_assert(n >= 0 && n < c->fanout); - dbg_tnc("deleting %s", DBGKEY(&znode->zbranch[n].key)); - - zbr = &znode->zbranch[n]; - lnc_free(zbr); - - err = ubifs_add_dirt(c, zbr->lnum, zbr->len); - if (err) { - dbg_dump_znode(c, znode); - return err; - } - - /* We do not "gap" zbranch slots */ - for (i = n; i < znode->child_cnt - 1; i++) - znode->zbranch[i] = znode->zbranch[i + 1]; - znode->child_cnt -= 1; - - if (znode->child_cnt > 0) - return 0; - - /* - * This was the last zbranch, we have to delete this znode from the - * parent. - */ - - do { - ubifs_assert(!test_bit(OBSOLETE_ZNODE, &znode->flags)); - ubifs_assert(ubifs_zn_dirty(znode)); - - zp = znode->parent; - n = znode->iip; - - atomic_long_dec(&c->dirty_zn_cnt); - - err = insert_old_idx_znode(c, znode); - if (err) - return err; - - if (znode->cnext) { - __set_bit(OBSOLETE_ZNODE, &znode->flags); - atomic_long_inc(&c->clean_zn_cnt); - atomic_long_inc(&ubifs_clean_zn_cnt); - } else - kfree(znode); - znode = zp; - } while (znode->child_cnt == 1); /* while removing last child */ - - /* Remove from znode, entry n - 1 */ - znode->child_cnt -= 1; - ubifs_assert(znode->level != 0); - for (i = n; i < znode->child_cnt; i++) { - znode->zbranch[i] = znode->zbranch[i + 1]; - if (znode->zbranch[i].znode) - znode->zbranch[i].znode->iip = i; - } - - /* - * If this is the root and it has only 1 child then - * collapse the tree. - */ - if (!znode->parent) { - while (znode->child_cnt == 1 && znode->level != 0) { - zp = znode; - zbr = &znode->zbranch[0]; - znode = get_znode(c, znode, 0); - if (IS_ERR(znode)) - return PTR_ERR(znode); - znode = dirty_cow_znode(c, zbr); - if (IS_ERR(znode)) - return PTR_ERR(znode); - znode->parent = NULL; - znode->iip = 0; - if (c->zroot.len) { - err = insert_old_idx(c, c->zroot.lnum, - c->zroot.offs); - if (err) - return err; - } - c->zroot.lnum = zbr->lnum; - c->zroot.offs = zbr->offs; - c->zroot.len = zbr->len; - c->zroot.znode = znode; - ubifs_assert(!test_bit(OBSOLETE_ZNODE, - &zp->flags)); - ubifs_assert(test_bit(DIRTY_ZNODE, &zp->flags)); - atomic_long_dec(&c->dirty_zn_cnt); - - if (zp->cnext) { - __set_bit(OBSOLETE_ZNODE, &zp->flags); - atomic_long_inc(&c->clean_zn_cnt); - atomic_long_inc(&ubifs_clean_zn_cnt); - } else - kfree(zp); - } - } - - return 0; -} - -/** - * ubifs_tnc_remove - remove an index entry of a node. - * @c: UBIFS file-system description object - * @key: key of node - * - * Returns %0 on success or negative error code on failure. - */ -int ubifs_tnc_remove(struct ubifs_info *c, const union ubifs_key *key) -{ - int found, n, err = 0; - struct ubifs_znode *znode; - - mutex_lock(&c->tnc_mutex); - dbg_tnc("key %s", DBGKEY(key)); - found = lookup_level0_dirty(c, key, &znode, &n); - if (found < 0) { - err = found; - goto out_unlock; - } - if (found == 1) - err = tnc_delete(c, znode, n); - if (!err) - err = dbg_check_tnc(c, 0); - -out_unlock: - mutex_unlock(&c->tnc_mutex); - return err; -} - -/** - * ubifs_tnc_remove_nm - remove an index entry for a "hashed" node. - * @c: UBIFS file-system description object - * @key: key of node - * @nm: directory entry name - * - * Returns %0 on success or negative error code on failure. - */ -int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key, - const struct qstr *nm) -{ - int n, err; - struct ubifs_znode *znode; - - mutex_lock(&c->tnc_mutex); - dbg_tnc("%.*s, key %s", nm->len, nm->name, DBGKEY(key)); - err = lookup_level0_dirty(c, key, &znode, &n); - if (err < 0) - goto out_unlock; - - if (err) { - if (c->replaying) - err = fallible_resolve_collision(c, key, &znode, &n, - nm, 0); - else - err = resolve_collision(c, key, &znode, &n, nm); - dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n); - if (err < 0) - goto out_unlock; - if (err) { - /* Ensure the znode is dirtied */ - if (znode->cnext || !ubifs_zn_dirty(znode)) { - znode = dirty_cow_bottom_up(c, znode); - if (IS_ERR(znode)) { - err = PTR_ERR(znode); - goto out_unlock; - } - } - err = tnc_delete(c, znode, n); - } - } - -out_unlock: - if (!err) - err = dbg_check_tnc(c, 0); - mutex_unlock(&c->tnc_mutex); - return err; -} - -/** - * key_in_range - determine if a key falls within a range of keys. - * @c: UBIFS file-system description object - * @key: key to check - * @from_key: lowest key in range - * @to_key: highest key in range - * - * This function returns %1 if the key is in range and %0 otherwise. - */ -static int key_in_range(struct ubifs_info *c, union ubifs_key *key, - union ubifs_key *from_key, union ubifs_key *to_key) -{ - if (keys_cmp(c, key, from_key) < 0) - return 0; - if (keys_cmp(c, key, to_key) > 0) - return 0; - return 1; -} - -/** - * ubifs_tnc_remove_range - remove index entries in range. - * @c: UBIFS file-system description object - * @from_key: lowest key to remove - * @to_key: highest key to remove - * - * This function removes index entries starting at @from_key and ending at - * @to_key. This function returns zero in case of success and a negative error - * code in case of failure. - */ -int ubifs_tnc_remove_range(struct ubifs_info *c, union ubifs_key *from_key, - union ubifs_key *to_key) -{ - int i, n, k, err = 0; - struct ubifs_znode *znode; - union ubifs_key *key; - - mutex_lock(&c->tnc_mutex); - while (1) { - /* Find first level 0 znode that contains keys to remove */ - err = ubifs_lookup_level0(c, from_key, &znode, &n); - if (err < 0) - goto out_unlock; - - if (err) - key = from_key; - else { - err = tnc_next(c, &znode, &n); - if (err == -ENOENT) { - err = 0; - goto out_unlock; - } - if (err < 0) - goto out_unlock; - key = &znode->zbranch[n].key; - if (!key_in_range(c, key, from_key, to_key)) { - err = 0; - goto out_unlock; - } - } - - /* Ensure the znode is dirtied */ - if (znode->cnext || !ubifs_zn_dirty(znode)) { - znode = dirty_cow_bottom_up(c, znode); - if (IS_ERR(znode)) { - err = PTR_ERR(znode); - goto out_unlock; - } - } - - /* Remove all keys in range except the first */ - for (i = n + 1, k = 0; i < znode->child_cnt; i++, k++) { - key = &znode->zbranch[i].key; - if (!key_in_range(c, key, from_key, to_key)) - break; - lnc_free(&znode->zbranch[i]); - err = ubifs_add_dirt(c, znode->zbranch[i].lnum, - znode->zbranch[i].len); - if (err) { - dbg_dump_znode(c, znode); - goto out_unlock; - } - dbg_tnc("removing %s", DBGKEY(key)); - } - if (k) { - for (i = n + 1 + k; i < znode->child_cnt; i++) - znode->zbranch[i - k] = znode->zbranch[i]; - znode->child_cnt -= k; - } - - /* Now delete the first */ - err = tnc_delete(c, znode, n); - if (err) - goto out_unlock; - } - -out_unlock: - if (!err) - err = dbg_check_tnc(c, 0); - mutex_unlock(&c->tnc_mutex); - return err; -} - -/** - * ubifs_tnc_remove_ino - remove an inode from TNC. - * @c: UBIFS file-system description object - * @inum: inode number to remove - * - * This function remove inode @inum and all the extended attributes associated - * with the anode from TNC and returns zero in case of success or a negative - * error code in case of failure. - */ -int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum) -{ - union ubifs_key key1, key2; - struct ubifs_dent_node *xent, *pxent = NULL; - struct qstr nm = { .name = NULL }; - - dbg_tnc("ino %lu", (unsigned long)inum); - - /* - * Walk all extended attribute entries and remove them together with - * corresponding extended attribute inodes. - */ - lowest_xent_key(c, &key1, inum); - while (1) { - ino_t xattr_inum; - int err; - - xent = ubifs_tnc_next_ent(c, &key1, &nm); - if (IS_ERR(xent)) { - err = PTR_ERR(xent); - if (err == -ENOENT) - break; - return err; - } - - xattr_inum = le64_to_cpu(xent->inum); - dbg_tnc("xent '%s', ino %lu", xent->name, - (unsigned long)xattr_inum); - - nm.name = (char *)xent->name; - nm.len = le16_to_cpu(xent->nlen); - err = ubifs_tnc_remove_nm(c, &key1, &nm); - if (err) { - kfree(xent); - return err; - } - - lowest_ino_key(c, &key1, xattr_inum); - highest_ino_key(c, &key2, xattr_inum); - err = ubifs_tnc_remove_range(c, &key1, &key2); - if (err) { - kfree(xent); - return err; - } - - kfree(pxent); - pxent = xent; - key_read(c, &xent->key, &key1); - } - - kfree(pxent); - lowest_ino_key(c, &key1, inum); - highest_ino_key(c, &key2, inum); - - return ubifs_tnc_remove_range(c, &key1, &key2); -} - -/** - * ubifs_tnc_next_ent - walk directory or extended attribute entries. - * @c: UBIFS file-system description object - * @key: key of last entry - * @nm: name of last entry found or %NULL - * - * This function finds and reads the next directory or extended attribute entry - * after the given key (@key) if there is one. @nm is used to resolve - * collisions. - * - * If the name of the current entry is not known and only the key is known, - * @nm->name has to be %NULL. In this case the semantics of this function is a - * little bit different and it returns the entry corresponding to this key, not - * the next one. If the key was not found, the closest "right" entry is - * returned. - * - * If the fist entry has to be found, @key has to contain the lowest possible - * key value for this inode and @name has to be %NULL. - * - * This function returns the found directory or extended attribute entry node - * in case of success, %-ENOENT is returned if no entry was found, and a - * negative error code is returned in case of failure. - */ -struct ubifs_dent_node *ubifs_tnc_next_ent(struct ubifs_info *c, - union ubifs_key *key, - const struct qstr *nm) -{ - int n, err, type = key_type(c, key); - struct ubifs_znode *znode; - struct ubifs_dent_node *dent; - struct ubifs_zbranch *zbr; - union ubifs_key *dkey; - - dbg_tnc("%s %s", nm->name ? (char *)nm->name : "(lowest)", DBGKEY(key)); - ubifs_assert(is_hash_key(c, key)); - - mutex_lock(&c->tnc_mutex); - err = ubifs_lookup_level0(c, key, &znode, &n); - if (unlikely(err < 0)) - goto out_unlock; - - if (nm->name) { - if (err) { - /* Handle collisions */ - err = resolve_collision(c, key, &znode, &n, nm); - dbg_tnc("rc returned %d, znode %p, n %d", - err, znode, n); - if (unlikely(err < 0)) - goto out_unlock; - } - - /* Now find next entry */ - err = tnc_next(c, &znode, &n); - if (unlikely(err)) - goto out_unlock; - } else { - /* - * The full name of the entry was not given, in which case the - * behavior of this function is a little different and it - * returns current entry, not the next one. - */ - if (!err) { - /* - * However, the given key does not exist in the TNC - * tree and @znode/@n variables contain the closest - * "preceding" element. Switch to the next one. - */ - err = tnc_next(c, &znode, &n); - if (err) - goto out_unlock; - } - } - - zbr = &znode->zbranch[n]; - dent = kmalloc(zbr->len, GFP_NOFS); - if (unlikely(!dent)) { - err = -ENOMEM; - goto out_unlock; - } - - /* - * The above 'tnc_next()' call could lead us to the next inode, check - * this. - */ - dkey = &zbr->key; - if (key_inum(c, dkey) != key_inum(c, key) || - key_type(c, dkey) != type) { - err = -ENOENT; - goto out_free; - } - - err = tnc_read_node_nm(c, zbr, dent); - if (unlikely(err)) - goto out_free; - - mutex_unlock(&c->tnc_mutex); - return dent; - -out_free: - kfree(dent); -out_unlock: - mutex_unlock(&c->tnc_mutex); - return ERR_PTR(err); -} |