/**
* 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 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_tnc("key %s", DBGKEY(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("bad key in node at LEB %d:%d",
zbr->lnum, zbr->offs);
dbg_tnc("looked for key %s found node's key %s",
DBGKEY(key), DBGKEY1(&key1));
dbg_dump_node(c, node);
return -EINVAL;
}
return 0;
}
/**
* ubifs_jnl_truncate - update the journal for a truncation.
* @c: UBIFS file-system description object
* @inum: inode number of inode being truncated
* @old_size: old size
* @new_size: new size
*
* When the size of a file decreases due to truncation, a truncation node is
* written, the journal tree is updated, and the last data block is re-written
* if it has been affected.
*
* This function returns %0 in the case of success, and a negative error code in
* case of failure.
*/
int ubifs_jnl_truncate(struct ubifs_info *c, ino_t inum,
loff_t old_size, loff_t new_size)
{
union ubifs_key key, to_key;
struct ubifs_trun_node *trun;
struct ubifs_data_node *uninitialized_var(dn);
int err, dlen, len, lnum, offs, bit, sz;
unsigned int blk;
dbg_jnl("ino %lu, size %lld -> %lld", inum, old_size, new_size);
sz = UBIFS_TRUN_NODE_SZ + UBIFS_MAX_DATA_NODE_SZ * WORST_COMPR_FACTOR;
trun = kmalloc(sz, GFP_NOFS);
if (!trun)
return -ENOMEM;
trun->ch.node_type = UBIFS_TRUN_NODE;
trun_key_init_flash(c, &trun->key, inum);
trun->old_size = cpu_to_le64(old_size);
trun->new_size = cpu_to_le64(new_size);
dlen = new_size & (UBIFS_BLOCK_SIZE - 1);
if (dlen) {
/* Get last data block so it can be truncated */
dn = (void *)trun + ALIGN(UBIFS_TRUN_NODE_SZ, 8);
blk = new_size / UBIFS_BLOCK_SIZE;
data_key_init(c, &key, inum, blk);
dbg_jnl("last block key %s", DBGKEY(&key));
err = ubifs_tnc_lookup(c, &key, dn);
if (err == -ENOENT)
dlen = 0; /* Not found (so it is a hole) */
else if (err)
goto out_free;
else {
if (le32_to_cpu(dn->size) <= dlen)
dlen = 0; /* Nothing to do */
else {
int compr_type = le16_to_cpu(dn->compr_type);
if (compr_type != UBIFS_COMPR_NONE) {
err = recomp_data_node(dn, &dlen);
if (err)
goto out_free;
} else {
dn->size = cpu_to_le32(dlen);
dlen += UBIFS_DATA_NODE_SZ;
}
zero_data_node_unused(dn);
}
}
}
if (dlen)
len = ALIGN(UBIFS_TRUN_NODE_SZ, 8) + dlen;
else
len = UBIFS_TRUN_NODE_SZ;
/* Must make reservation before allocating sequence numbers */
err = make_reservation(c, BASEHD, len);
if (err)
goto out_free;
ubifs_prepare_node(c, trun, UBIFS_TRUN_NODE_SZ, 0);
if (dlen)
ubifs_prepare_node(c, dn, dlen, 0);
err = write_head(c, BASEHD, trun, len, &lnum, &offs, 0);
if (!err)
ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, inum);
release_head(c, BASEHD);
if (err)
goto out_ro;
if (dlen) {
offs += ALIGN(UBIFS_TRUN_NODE_SZ, 8);
err = ubifs_tnc_add(c, &key, lnum, offs, dlen);
if (err)
goto out_ro;
}
err = ubifs_add_dirt(c, lnum, UBIFS_TRUN_NODE_SZ);
if (err)
goto out_ro;
bit = new_size & (UBIFS_BLOCK_SIZE - 1);
blk = new_size / UBIFS_BLOCK_SIZE + (bit ? 1 : 0);
data_key_init(c, &key, inum, blk);
bit = old_size & (UBIFS_BLOCK_SIZE - 1);
blk = old_size / UBIFS_BLOCK_SIZE - (bit ? 0: 1);
data_key_init(c, &to_key, inum, blk);
err = ubifs_tnc_remove_range(c, &key, &to_key);
if (err)
goto out_ro;
finish_reservation(c);
kfree(trun);
return 0;
out_ro:
ubifs_ro_mode(c, err);
finish_reservation(c);
out_free:
kfree(trun);
return err;
}
/**
* read_znode - read an indexing node from flash and fill znode.
* @c: UBIFS file-system description object
* @lnum: LEB of the indexing node to read
* @offs: node offset
* @len: node length
* @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, int lnum, int offs, int len,
struct ubifs_znode *znode)
{
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;
}
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) {
dbg_err("current fanout %d, branch count %d",
c->fanout, znode->child_cnt);
dbg_err("max levels %d, znode level %d",
UBIFS_MAX_LEVELS, znode->level);
err = 1;
goto out_dump;
}
for (i = 0; i < znode->child_cnt; i++) {
const 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);
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) {
dbg_err("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:
dbg_msg("bad key type at slot %d: %s", i,
DBGKEY(&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) {
dbg_err("bad target node (type %d) length (%d)",
type, zbr->len);
dbg_err("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) {
dbg_err("bad target node (type %d) length (%d)",
type, zbr->len);
dbg_err("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) {
dbg_err("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 */
dbg_err("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("bad indexing node at LEB %d:%d, error %d", lnum, offs, err);
dbg_dump_node(c, idx);
kfree(idx);
return -EINVAL;
}
/**
* ubifs_jnl_write_data - write a data node to the journal.
* @c: UBIFS file-system description object
* @inode: inode the data node belongs to
* @key: node key
* @buf: buffer to write
* @len: data length (must not exceed %UBIFS_BLOCK_SIZE)
*
* This function writes a data node to the journal. Returns %0 if the data node
* was successfully written, and a negative error code in case of failure.
*/
int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode,
const union ubifs_key *key, const void *buf, int len)
{
int err, lnum, offs, compr_type, out_len;
int dlen = UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE * WORST_COMPR_FACTOR;
const struct ubifs_inode *ui = ubifs_inode(inode);
struct ubifs_data_node *data;
dbg_jnl("ino %lu, blk %u, len %d, key %s", key_ino(c, key),
key_block(c, key), len, DBGKEY(key));
ubifs_assert(len <= UBIFS_BLOCK_SIZE);
data = kmalloc(dlen, GFP_NOFS);
if (!data)
return -ENOMEM;
data->ch.node_type = UBIFS_DATA_NODE;
key_write(c, key, &data->key);
data->size = cpu_to_le32(len);
zero_data_node_unused(data);
if (!(ui->flags && UBIFS_COMPR_FL))
/* Compression is disabled for this inode */
compr_type = UBIFS_COMPR_NONE;
else
compr_type = ui->compr_type;
out_len = dlen - UBIFS_DATA_NODE_SZ;
ubifs_compress(buf, len, &data->data, &out_len, &compr_type);
ubifs_assert(out_len <= UBIFS_BLOCK_SIZE);
dlen = UBIFS_DATA_NODE_SZ + out_len;
data->compr_type = cpu_to_le16(compr_type);
/* Make reservation before allocating sequence numbers */
err = make_reservation(c, DATAHD, dlen);
if (err)
goto out_free;
err = write_node(c, DATAHD, data, dlen, &lnum, &offs);
if (!err)
ubifs_wbuf_add_ino_nolock(&c->jheads[DATAHD].wbuf,
key_ino(c, key));
release_head(c, DATAHD);
if (err)
goto out_ro;
err = ubifs_tnc_add(c, key, lnum, offs, dlen);
if (err)
goto out_ro;
finish_reservation(c);
kfree(data);
return 0;
out_ro:
ubifs_ro_mode(c, err);
finish_reservation(c);
out_free:
kfree(data);
return err;
}
