forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
502 lines
13 KiB
502 lines
13 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* This file is part of UBIFS. |
|
* |
|
* Copyright (C) 2006-2008 Nokia Corporation. |
|
* |
|
* Authors: Adrian Hunter |
|
* Artem Bityutskiy (Битюцкий Артём) |
|
*/ |
|
|
|
/* |
|
* This file contains miscelanious TNC-related functions shared betweend |
|
* different files. This file does not form any logically separate TNC |
|
* sub-system. The file was created because there is a lot of TNC code and |
|
* putting it all in one file would make that file too big and unreadable. |
|
*/ |
|
|
|
#include "ubifs.h" |
|
|
|
/** |
|
* ubifs_tnc_levelorder_next - next TNC tree element in levelorder traversal. |
|
* @c: UBIFS file-system description object |
|
* @zr: root of the subtree to traverse |
|
* @znode: previous znode |
|
* |
|
* This function implements levelorder TNC traversal. The LNC is ignored. |
|
* Returns the next element or %NULL if @znode is already the last one. |
|
*/ |
|
struct ubifs_znode *ubifs_tnc_levelorder_next(const struct ubifs_info *c, |
|
struct ubifs_znode *zr, |
|
struct ubifs_znode *znode) |
|
{ |
|
int level, iip, level_search = 0; |
|
struct ubifs_znode *zn; |
|
|
|
ubifs_assert(c, zr); |
|
|
|
if (unlikely(!znode)) |
|
return zr; |
|
|
|
if (unlikely(znode == zr)) { |
|
if (znode->level == 0) |
|
return NULL; |
|
return ubifs_tnc_find_child(zr, 0); |
|
} |
|
|
|
level = znode->level; |
|
|
|
iip = znode->iip; |
|
while (1) { |
|
ubifs_assert(c, znode->level <= zr->level); |
|
|
|
/* |
|
* First walk up until there is a znode with next branch to |
|
* look at. |
|
*/ |
|
while (znode->parent != zr && iip >= znode->parent->child_cnt) { |
|
znode = znode->parent; |
|
iip = znode->iip; |
|
} |
|
|
|
if (unlikely(znode->parent == zr && |
|
iip >= znode->parent->child_cnt)) { |
|
/* This level is done, switch to the lower one */ |
|
level -= 1; |
|
if (level_search || level < 0) |
|
/* |
|
* We were already looking for znode at lower |
|
* level ('level_search'). As we are here |
|
* again, it just does not exist. Or all levels |
|
* were finished ('level < 0'). |
|
*/ |
|
return NULL; |
|
|
|
level_search = 1; |
|
iip = -1; |
|
znode = ubifs_tnc_find_child(zr, 0); |
|
ubifs_assert(c, znode); |
|
} |
|
|
|
/* Switch to the next index */ |
|
zn = ubifs_tnc_find_child(znode->parent, iip + 1); |
|
if (!zn) { |
|
/* No more children to look at, we have walk up */ |
|
iip = znode->parent->child_cnt; |
|
continue; |
|
} |
|
|
|
/* Walk back down to the level we came from ('level') */ |
|
while (zn->level != level) { |
|
znode = zn; |
|
zn = ubifs_tnc_find_child(zn, 0); |
|
if (!zn) { |
|
/* |
|
* This path is not too deep so it does not |
|
* reach 'level'. Try next path. |
|
*/ |
|
iip = znode->iip; |
|
break; |
|
} |
|
} |
|
|
|
if (zn) { |
|
ubifs_assert(c, zn->level >= 0); |
|
return zn; |
|
} |
|
} |
|
} |
|
|
|
/** |
|
* ubifs_search_zbranch - search znode branch. |
|
* @c: UBIFS file-system description object |
|
* @znode: znode to search in |
|
* @key: key to search for |
|
* @n: znode branch slot number is returned here |
|
* |
|
* This is a helper function which search branch with key @key in @znode using |
|
* binary search. The result of the search may be: |
|
* o exact match, then %1 is returned, and the slot number of the branch is |
|
* stored in @n; |
|
* o no exact match, then %0 is returned and the slot number of the left |
|
* closest branch is returned in @n; the slot if all keys in this znode are |
|
* greater than @key, then %-1 is returned in @n. |
|
*/ |
|
int ubifs_search_zbranch(const struct ubifs_info *c, |
|
const struct ubifs_znode *znode, |
|
const union ubifs_key *key, int *n) |
|
{ |
|
int beg = 0, end = znode->child_cnt, mid; |
|
int cmp; |
|
const struct ubifs_zbranch *zbr = &znode->zbranch[0]; |
|
|
|
ubifs_assert(c, end > beg); |
|
|
|
while (end > beg) { |
|
mid = (beg + end) >> 1; |
|
cmp = keys_cmp(c, key, &zbr[mid].key); |
|
if (cmp > 0) |
|
beg = mid + 1; |
|
else if (cmp < 0) |
|
end = mid; |
|
else { |
|
*n = mid; |
|
return 1; |
|
} |
|
} |
|
|
|
*n = end - 1; |
|
|
|
/* The insert point is after *n */ |
|
ubifs_assert(c, *n >= -1 && *n < znode->child_cnt); |
|
if (*n == -1) |
|
ubifs_assert(c, keys_cmp(c, key, &zbr[0].key) < 0); |
|
else |
|
ubifs_assert(c, keys_cmp(c, key, &zbr[*n].key) > 0); |
|
if (*n + 1 < znode->child_cnt) |
|
ubifs_assert(c, keys_cmp(c, key, &zbr[*n + 1].key) < 0); |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_postorder_first - find first znode to do postorder tree traversal. |
|
* @znode: znode to start at (root of the sub-tree to traverse) |
|
* |
|
* Find the lowest leftmost znode in a subtree of the TNC tree. The LNC is |
|
* ignored. |
|
*/ |
|
struct ubifs_znode *ubifs_tnc_postorder_first(struct ubifs_znode *znode) |
|
{ |
|
if (unlikely(!znode)) |
|
return NULL; |
|
|
|
while (znode->level > 0) { |
|
struct ubifs_znode *child; |
|
|
|
child = ubifs_tnc_find_child(znode, 0); |
|
if (!child) |
|
return znode; |
|
znode = child; |
|
} |
|
|
|
return znode; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_postorder_next - next TNC tree element in postorder traversal. |
|
* @c: UBIFS file-system description object |
|
* @znode: previous znode |
|
* |
|
* This function implements postorder TNC traversal. The LNC is ignored. |
|
* Returns the next element or %NULL if @znode is already the last one. |
|
*/ |
|
struct ubifs_znode *ubifs_tnc_postorder_next(const struct ubifs_info *c, |
|
struct ubifs_znode *znode) |
|
{ |
|
struct ubifs_znode *zn; |
|
|
|
ubifs_assert(c, znode); |
|
if (unlikely(!znode->parent)) |
|
return NULL; |
|
|
|
/* Switch to the next index in the parent */ |
|
zn = ubifs_tnc_find_child(znode->parent, znode->iip + 1); |
|
if (!zn) |
|
/* This is in fact the last child, return parent */ |
|
return znode->parent; |
|
|
|
/* Go to the first znode in this new subtree */ |
|
return ubifs_tnc_postorder_first(zn); |
|
} |
|
|
|
/** |
|
* ubifs_destroy_tnc_subtree - destroy all znodes connected to a subtree. |
|
* @c: UBIFS file-system description object |
|
* @znode: znode defining subtree to destroy |
|
* |
|
* This function destroys subtree of the TNC tree. Returns number of clean |
|
* znodes in the subtree. |
|
*/ |
|
long ubifs_destroy_tnc_subtree(const struct ubifs_info *c, |
|
struct ubifs_znode *znode) |
|
{ |
|
struct ubifs_znode *zn = ubifs_tnc_postorder_first(znode); |
|
long clean_freed = 0; |
|
int n; |
|
|
|
ubifs_assert(c, zn); |
|
while (1) { |
|
for (n = 0; n < zn->child_cnt; n++) { |
|
if (!zn->zbranch[n].znode) |
|
continue; |
|
|
|
if (zn->level > 0 && |
|
!ubifs_zn_dirty(zn->zbranch[n].znode)) |
|
clean_freed += 1; |
|
|
|
cond_resched(); |
|
kfree(zn->zbranch[n].znode); |
|
} |
|
|
|
if (zn == znode) { |
|
if (!ubifs_zn_dirty(zn)) |
|
clean_freed += 1; |
|
kfree(zn); |
|
return clean_freed; |
|
} |
|
|
|
zn = ubifs_tnc_postorder_next(c, zn); |
|
} |
|
} |
|
|
|
/** |
|
* read_znode - read an indexing node from flash and fill znode. |
|
* @c: UBIFS file-system description object |
|
* @zzbr: the zbranch describing the node to read |
|
* @znode: znode to read to |
|
* |
|
* This function reads an indexing node from the flash media and fills znode |
|
* with the read data. Returns zero in case of success and a negative error |
|
* code in case of failure. The read indexing node is validated and if anything |
|
* is wrong with it, this function prints complaint messages and returns |
|
* %-EINVAL. |
|
*/ |
|
static int read_znode(struct ubifs_info *c, struct ubifs_zbranch *zzbr, |
|
struct ubifs_znode *znode) |
|
{ |
|
int lnum = zzbr->lnum; |
|
int offs = zzbr->offs; |
|
int len = zzbr->len; |
|
int i, err, type, cmp; |
|
struct ubifs_idx_node *idx; |
|
|
|
idx = kmalloc(c->max_idx_node_sz, GFP_NOFS); |
|
if (!idx) |
|
return -ENOMEM; |
|
|
|
err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs); |
|
if (err < 0) { |
|
kfree(idx); |
|
return err; |
|
} |
|
|
|
err = ubifs_node_check_hash(c, idx, zzbr->hash); |
|
if (err) { |
|
ubifs_bad_hash(c, idx, zzbr->hash, lnum, offs); |
|
kfree(idx); |
|
return err; |
|
} |
|
|
|
znode->child_cnt = le16_to_cpu(idx->child_cnt); |
|
znode->level = le16_to_cpu(idx->level); |
|
|
|
dbg_tnc("LEB %d:%d, level %d, %d branch", |
|
lnum, offs, znode->level, znode->child_cnt); |
|
|
|
if (znode->child_cnt > c->fanout || znode->level > UBIFS_MAX_LEVELS) { |
|
ubifs_err(c, "current fanout %d, branch count %d", |
|
c->fanout, znode->child_cnt); |
|
ubifs_err(c, "max levels %d, znode level %d", |
|
UBIFS_MAX_LEVELS, znode->level); |
|
err = 1; |
|
goto out_dump; |
|
} |
|
|
|
for (i = 0; i < znode->child_cnt; i++) { |
|
struct ubifs_branch *br = ubifs_idx_branch(c, idx, i); |
|
struct ubifs_zbranch *zbr = &znode->zbranch[i]; |
|
|
|
key_read(c, &br->key, &zbr->key); |
|
zbr->lnum = le32_to_cpu(br->lnum); |
|
zbr->offs = le32_to_cpu(br->offs); |
|
zbr->len = le32_to_cpu(br->len); |
|
ubifs_copy_hash(c, ubifs_branch_hash(c, br), zbr->hash); |
|
zbr->znode = NULL; |
|
|
|
/* Validate branch */ |
|
|
|
if (zbr->lnum < c->main_first || |
|
zbr->lnum >= c->leb_cnt || zbr->offs < 0 || |
|
zbr->offs + zbr->len > c->leb_size || zbr->offs & 7) { |
|
ubifs_err(c, "bad branch %d", i); |
|
err = 2; |
|
goto out_dump; |
|
} |
|
|
|
switch (key_type(c, &zbr->key)) { |
|
case UBIFS_INO_KEY: |
|
case UBIFS_DATA_KEY: |
|
case UBIFS_DENT_KEY: |
|
case UBIFS_XENT_KEY: |
|
break; |
|
default: |
|
ubifs_err(c, "bad key type at slot %d: %d", |
|
i, key_type(c, &zbr->key)); |
|
err = 3; |
|
goto out_dump; |
|
} |
|
|
|
if (znode->level) |
|
continue; |
|
|
|
type = key_type(c, &zbr->key); |
|
if (c->ranges[type].max_len == 0) { |
|
if (zbr->len != c->ranges[type].len) { |
|
ubifs_err(c, "bad target node (type %d) length (%d)", |
|
type, zbr->len); |
|
ubifs_err(c, "have to be %d", c->ranges[type].len); |
|
err = 4; |
|
goto out_dump; |
|
} |
|
} else if (zbr->len < c->ranges[type].min_len || |
|
zbr->len > c->ranges[type].max_len) { |
|
ubifs_err(c, "bad target node (type %d) length (%d)", |
|
type, zbr->len); |
|
ubifs_err(c, "have to be in range of %d-%d", |
|
c->ranges[type].min_len, |
|
c->ranges[type].max_len); |
|
err = 5; |
|
goto out_dump; |
|
} |
|
} |
|
|
|
/* |
|
* Ensure that the next key is greater or equivalent to the |
|
* previous one. |
|
*/ |
|
for (i = 0; i < znode->child_cnt - 1; i++) { |
|
const union ubifs_key *key1, *key2; |
|
|
|
key1 = &znode->zbranch[i].key; |
|
key2 = &znode->zbranch[i + 1].key; |
|
|
|
cmp = keys_cmp(c, key1, key2); |
|
if (cmp > 0) { |
|
ubifs_err(c, "bad key order (keys %d and %d)", i, i + 1); |
|
err = 6; |
|
goto out_dump; |
|
} else if (cmp == 0 && !is_hash_key(c, key1)) { |
|
/* These can only be keys with colliding hash */ |
|
ubifs_err(c, "keys %d and %d are not hashed but equivalent", |
|
i, i + 1); |
|
err = 7; |
|
goto out_dump; |
|
} |
|
} |
|
|
|
kfree(idx); |
|
return 0; |
|
|
|
out_dump: |
|
ubifs_err(c, "bad indexing node at LEB %d:%d, error %d", lnum, offs, err); |
|
ubifs_dump_node(c, idx, c->max_idx_node_sz); |
|
kfree(idx); |
|
return -EINVAL; |
|
} |
|
|
|
/** |
|
* ubifs_load_znode - load znode to TNC cache. |
|
* @c: UBIFS file-system description object |
|
* @zbr: znode branch |
|
* @parent: znode's parent |
|
* @iip: index in parent |
|
* |
|
* This function loads znode pointed to by @zbr into the TNC cache and |
|
* returns pointer to it in case of success and a negative error code in case |
|
* of failure. |
|
*/ |
|
struct ubifs_znode *ubifs_load_znode(struct ubifs_info *c, |
|
struct ubifs_zbranch *zbr, |
|
struct ubifs_znode *parent, int iip) |
|
{ |
|
int err; |
|
struct ubifs_znode *znode; |
|
|
|
ubifs_assert(c, !zbr->znode); |
|
/* |
|
* A slab cache is not presently used for znodes because the znode size |
|
* depends on the fanout which is stored in the superblock. |
|
*/ |
|
znode = kzalloc(c->max_znode_sz, GFP_NOFS); |
|
if (!znode) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
err = read_znode(c, zbr, znode); |
|
if (err) |
|
goto out; |
|
|
|
atomic_long_inc(&c->clean_zn_cnt); |
|
|
|
/* |
|
* Increment the global clean znode counter as well. It is OK that |
|
* global and per-FS clean znode counters may be inconsistent for some |
|
* short time (because we might be preempted at this point), the global |
|
* one is only used in shrinker. |
|
*/ |
|
atomic_long_inc(&ubifs_clean_zn_cnt); |
|
|
|
zbr->znode = znode; |
|
znode->parent = parent; |
|
znode->time = ktime_get_seconds(); |
|
znode->iip = iip; |
|
|
|
return znode; |
|
|
|
out: |
|
kfree(znode); |
|
return ERR_PTR(err); |
|
} |
|
|
|
/** |
|
* ubifs_tnc_read_node - read a leaf node from the flash media. |
|
* @c: UBIFS file-system description object |
|
* @zbr: key and position of the node |
|
* @node: node is returned here |
|
* |
|
* This function reads a node defined by @zbr from the flash media. Returns |
|
* zero in case of success or a negative error code in case of failure. |
|
*/ |
|
int ubifs_tnc_read_node(struct ubifs_info *c, struct ubifs_zbranch *zbr, |
|
void *node) |
|
{ |
|
union ubifs_key key1, *key = &zbr->key; |
|
int err, type = key_type(c, key); |
|
struct ubifs_wbuf *wbuf; |
|
|
|
/* |
|
* 'zbr' has to point to on-flash node. The node may sit in a bud and |
|
* may even be in a write buffer, so we have to take care about this. |
|
*/ |
|
wbuf = ubifs_get_wbuf(c, zbr->lnum); |
|
if (wbuf) |
|
err = ubifs_read_node_wbuf(wbuf, node, type, zbr->len, |
|
zbr->lnum, zbr->offs); |
|
else |
|
err = ubifs_read_node(c, node, type, zbr->len, zbr->lnum, |
|
zbr->offs); |
|
|
|
if (err) { |
|
dbg_tnck(key, "key "); |
|
return err; |
|
} |
|
|
|
/* Make sure the key of the read node is correct */ |
|
key_read(c, node + UBIFS_KEY_OFFSET, &key1); |
|
if (!keys_eq(c, key, &key1)) { |
|
ubifs_err(c, "bad key in node at LEB %d:%d", |
|
zbr->lnum, zbr->offs); |
|
dbg_tnck(key, "looked for key "); |
|
dbg_tnck(&key1, "but found node's key "); |
|
ubifs_dump_node(c, node, zbr->len); |
|
return -EINVAL; |
|
} |
|
|
|
err = ubifs_node_check_hash(c, node, zbr->hash); |
|
if (err) { |
|
ubifs_bad_hash(c, node, zbr->hash, zbr->lnum, zbr->offs); |
|
return err; |
|
} |
|
|
|
return 0; |
|
}
|
|
|