diff options
| author | Eric Sandeen <sandeen@redhat.com> | 2009-06-02 08:09:14 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-06-11 20:01:38 -0700 |
| commit | 2f99429dd64583792c5dffbb6af3ce9d67f71016 (patch) | |
| tree | e940c3f343ebc76fc611c1d43b8fe020a8eb1dc8 | |
| parent | fccb0272b539368be564a8d09ae4b71134a237d3 (diff) | |
ext4: fix header check in ext4_ext_search_right() for deep extent trees.
(cherry picked from commit 395a87bfefbc400011417e9eaae33169f9f036c0)
The ext4_ext_search_right() function is confusing; it uses a
"depth" variable which is 0 at the root and maximum at the leaves,
but the on-disk metadata uses a "depth" (actually eh_depth) which
is opposite: maximum at the root, and 0 at the leaves.
The ext4_ext_check_header() function is given a depth and checks
the header agaisnt that depth; it expects the on-disk semantics,
but we are giving it the opposite in the while loop in this
function. We should be giving it the on-disk notion of "depth"
which we can get from (p_depth - depth) - and if you look, the last
(more commonly hit) call to ext4_ext_check_header() does just this.
Sending in the wrong depth results in (incorrect) messages
about corruption:
EXT4-fs error (device sdb1): ext4_ext_search_right: bad header
in inode #2621457: unexpected eh_depth - magic f30a, entries 340,
max 340(0), depth 1(2)
http://bugzilla.kernel.org/show_bug.cgi?id=12821
Reported-by: David Dindorp <ddi@dubex.dk>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | fs/ext4/extents.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index b24d3c53f20..acb98c9db48 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -1118,7 +1118,8 @@ ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path, struct ext4_extent_idx *ix; struct ext4_extent *ex; ext4_fsblk_t block; - int depth, ee_len; + int depth; /* Note, NOT eh_depth; depth from top of tree */ + int ee_len; BUG_ON(path == NULL); depth = path->p_depth; @@ -1177,7 +1178,8 @@ ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path, if (bh == NULL) return -EIO; eh = ext_block_hdr(bh); - if (ext4_ext_check_header(inode, eh, depth)) { + /* subtract from p_depth to get proper eh_depth */ + if (ext4_ext_check_header(inode, eh, path->p_depth - depth)) { put_bh(bh); return -EIO; } |