diff options
| -rw-r--r-- | fs/ubifs/recovery.c | 70 |
1 files changed, 23 insertions, 47 deletions
diff --git a/fs/ubifs/recovery.c b/fs/ubifs/recovery.c index fe3b364..7444650 100644 --- a/fs/ubifs/recovery.c +++ b/fs/ubifs/recovery.c @@ -418,59 +418,35 @@ static void clean_buf(const struct ubifs_info *c, void **buf, int lnum, * @lnum: LEB number of the LEB from which @buf was read * @offs: offset from which @buf was read * - * This function scans @buf for more nodes and returns %0 is a node is found and - * %1 if no more nodes are found. + * This function ensures that the corrupted node at @offs is the last thing + * written to a LEB. This function returns %1 if more data is not found and + * %0 if more data is found. */ static int no_more_nodes(const struct ubifs_info *c, void *buf, int len, int lnum, int offs) { - int skip, next_offs = 0; + struct ubifs_ch *ch = buf; + int skip, dlen = le32_to_cpu(ch->len); - if (len > UBIFS_DATA_NODE_SZ) { - struct ubifs_ch *ch = buf; - int dlen = le32_to_cpu(ch->len); - - if (ch->node_type == UBIFS_DATA_NODE && dlen >= UBIFS_CH_SZ && - dlen <= UBIFS_MAX_DATA_NODE_SZ) - /* The corrupt node looks like a data node */ - next_offs = ALIGN(offs + dlen, 8); - } - - if (c->min_io_size == 1) - skip = 8; - else - skip = ALIGN(offs + 1, c->min_io_size) - offs; - - offs += skip; - buf += skip; - len -= skip; - while (len > 8) { - struct ubifs_ch *ch = buf; - uint32_t magic = le32_to_cpu(ch->magic); - int ret; - - if (magic == UBIFS_NODE_MAGIC) { - ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1); - if (ret == SCANNED_A_NODE || ret > 0) { - /* - * There is a small chance this is just data in - * a data node, so check that possibility. e.g. - * this is part of a file that itself contains - * a UBIFS image. - */ - if (next_offs && offs + le32_to_cpu(ch->len) <= - next_offs) - continue; - dbg_rcvry("unexpected node at %d:%d", lnum, - offs); - return 0; - } - } - offs += 8; - buf += 8; - len -= 8; + /* Check for empty space after the corrupt node's common header */ + skip = ALIGN(offs + UBIFS_CH_SZ, c->min_io_size) - offs; + if (is_empty(buf + skip, len - skip)) + return 1; + /* + * The area after the common header size is not empty, so the common + * header must be intact. Check it. + */ + if (ubifs_check_node(c, buf, lnum, offs, 1, 0) != -EUCLEAN) { + dbg_rcvry("unexpected bad common header at %d:%d", lnum, offs); + return 0; } - return 1; + /* Now we know the corrupt node's length we can skip over it */ + skip = ALIGN(offs + dlen, c->min_io_size) - offs; + /* After which there should be empty space */ + if (is_empty(buf + skip, len - skip)) + return 1; + dbg_rcvry("unexpected data at %d:%d", lnum, offs + skip); + return 0; } /** |