diff options
| -rw-r--r-- | fs/ext4/extents.c | 144 |
1 files changed, 86 insertions, 58 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 77146b8..96264b2 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -92,36 +92,6 @@ static void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb) ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff); } -static int ext4_ext_check_header(const char *function, struct inode *inode, - struct ext4_extent_header *eh) -{ - const char *error_msg = NULL; - - if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { - error_msg = "invalid magic"; - goto corrupted; - } - if (unlikely(eh->eh_max == 0)) { - error_msg = "invalid eh_max"; - goto corrupted; - } - if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { - error_msg = "invalid eh_entries"; - goto corrupted; - } - return 0; - -corrupted: - ext4_error(inode->i_sb, function, - "bad header in inode #%lu: %s - magic %x, " - "entries %u, max %u, depth %u", - inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic), - le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), - le16_to_cpu(eh->eh_depth)); - - return -EIO; -} - static handle_t *ext4_ext_journal_restart(handle_t *handle, int needed) { int err; @@ -270,6 +240,70 @@ static int ext4_ext_space_root_idx(struct inode *inode) return size; } +static int +ext4_ext_max_entries(struct inode *inode, int depth) +{ + int max; + + if (depth == ext_depth(inode)) { + if (depth == 0) + max = ext4_ext_space_root(inode); + else + max = ext4_ext_space_root_idx(inode); + } else { + if (depth == 0) + max = ext4_ext_space_block(inode); + else + max = ext4_ext_space_block_idx(inode); + } + + return max; +} + +static int __ext4_ext_check_header(const char *function, struct inode *inode, + struct ext4_extent_header *eh, + int depth) +{ + const char *error_msg; + int max = 0; + + if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { + error_msg = "invalid magic"; + goto corrupted; + } + if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) { + error_msg = "unexpected eh_depth"; + goto corrupted; + } + if (unlikely(eh->eh_max == 0)) { + error_msg = "invalid eh_max"; + goto corrupted; + } + max = ext4_ext_max_entries(inode, depth); + if (unlikely(le16_to_cpu(eh->eh_max) > max)) { + error_msg = "too large eh_max"; + goto corrupted; + } + if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { + error_msg = "invalid eh_entries"; + goto corrupted; + } + return 0; + +corrupted: + ext4_error(inode->i_sb, function, + "bad header in inode #%lu: %s - magic %x, " + "entries %u, max %u(%u), depth %u(%u)", + inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic), + le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), + max, le16_to_cpu(eh->eh_depth), depth); + + return -EIO; +} + +#define ext4_ext_check_header(inode, eh, depth) \ + __ext4_ext_check_header(__FUNCTION__, inode, eh, depth) + #ifdef EXT_DEBUG static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) { @@ -330,6 +364,7 @@ static void ext4_ext_drop_refs(struct ext4_ext_path *path) /* * ext4_ext_binsearch_idx: * binary search for the closest index of the given block + * the header must be checked before calling this */ static void ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int block) @@ -337,9 +372,6 @@ ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int bloc struct ext4_extent_header *eh = path->p_hdr; struct ext4_extent_idx *r, *l, *m; - BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC); - BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max)); - BUG_ON(le16_to_cpu(eh->eh_entries) <= 0); ext_debug("binsearch for %d(idx): ", block); @@ -389,6 +421,7 @@ ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int bloc /* * ext4_ext_binsearch: * binary search for closest extent of the given block + * the header must be checked before calling this */ static void ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block) @@ -396,9 +429,6 @@ ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block) struct ext4_extent_header *eh = path->p_hdr; struct ext4_extent *r, *l, *m; - BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC); - BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max)); - if (eh->eh_entries == 0) { /* * this leaf is empty: @@ -469,11 +499,10 @@ ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path) short int depth, i, ppos = 0, alloc = 0; eh = ext_inode_hdr(inode); - BUG_ON(eh == NULL); - if (ext4_ext_check_header(__FUNCTION__, inode, eh)) + depth = ext_depth(inode); + if (ext4_ext_check_header(inode, eh, depth)) return ERR_PTR(-EIO); - i = depth = ext_depth(inode); /* account possible depth increase */ if (!path) { @@ -485,10 +514,12 @@ ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path) } path[0].p_hdr = eh; + i = depth; /* walk through the tree */ while (i) { ext_debug("depth %d: num %d, max %d\n", ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); + ext4_ext_binsearch_idx(inode, path + ppos, block); path[ppos].p_block = idx_pblock(path[ppos].p_idx); path[ppos].p_depth = i; @@ -505,7 +536,7 @@ ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path) path[ppos].p_hdr = eh; i--; - if (ext4_ext_check_header(__FUNCTION__, inode, eh)) + if (ext4_ext_check_header(inode, eh, i)) goto err; } @@ -514,9 +545,6 @@ ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path) path[ppos].p_ext = NULL; path[ppos].p_idx = NULL; - if (ext4_ext_check_header(__FUNCTION__, inode, eh)) - goto err; - /* find extent */ ext4_ext_binsearch(inode, path + ppos, block); @@ -1738,13 +1766,12 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, unsigned uninitialized = 0; struct ext4_extent *ex; + /* the header must be checked already in ext4_ext_remove_space() */ ext_debug("truncate since %lu in leaf\n", start); if (!path[depth].p_hdr) path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); eh = path[depth].p_hdr; BUG_ON(eh == NULL); - BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max)); - BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC); /* find where to start removing */ ex = EXT_LAST_EXTENT(eh); @@ -1898,7 +1925,7 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start) return -ENOMEM; } path[0].p_hdr = ext_inode_hdr(inode); - if (ext4_ext_check_header(__FUNCTION__, inode, path[0].p_hdr)) { + if (ext4_ext_check_header(inode, path[0].p_hdr, depth)) { err = -EIO; goto out; } @@ -1919,17 +1946,8 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start) if (!path[i].p_hdr) { ext_debug("initialize header\n"); path[i].p_hdr = ext_block_hdr(path[i].p_bh); - if (ext4_ext_check_header(__FUNCTION__, inode, - path[i].p_hdr)) { - err = -EIO; - goto out; - } } - BUG_ON(le16_to_cpu(path[i].p_hdr->eh_entries) - > le16_to_cpu(path[i].p_hdr->eh_max)); - BUG_ON(path[i].p_hdr->eh_magic != EXT4_EXT_MAGIC); - if (!path[i].p_idx) { /* this level hasn't been touched yet */ path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr); @@ -1946,17 +1964,27 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start) i, EXT_FIRST_INDEX(path[i].p_hdr), path[i].p_idx); if (ext4_ext_more_to_rm(path + i)) { + struct buffer_head *bh; /* go to the next level */ ext_debug("move to level %d (block %llu)\n", i + 1, idx_pblock(path[i].p_idx)); memset(path + i + 1, 0, sizeof(*path)); - path[i+1].p_bh = - sb_bread(sb, idx_pblock(path[i].p_idx)); - if (!path[i+1].p_bh) { + bh = sb_bread(sb, idx_pblock(path[i].p_idx)); + if (!bh) { /* should we reset i_size? */ err = -EIO; break; } + if (WARN_ON(i + 1 > depth)) { + err = -EIO; + break; + } + if (ext4_ext_check_header(inode, ext_block_hdr(bh), + depth - i - 1)) { + err = -EIO; + break; + } + path[i + 1].p_bh = bh; /* save actual number of indexes since this * number is changed at the next iteration */ |