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| author | Eric Sandeen <sandeen@redhat.com> | 2009-03-11 01:18:47 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2009-03-11 01:18:47 +0300 |
| commit | 395a87bfefbc400011417e9eaae33169f9f036c0 (patch) | |
| tree | 1f0d0f85f33166c9d6187102573a683c27d3e849 /fs/ext4 | |
| parent | 041b62374c7fedc11a8a1eeda2868612d3d1436c (diff) | |
| download | linux-395a87bfefbc400011417e9eaae33169f9f036c0.tar.xz | |
ext4: fix header check in ext4_ext_search_right() for deep extent trees.
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>
Diffstat (limited to 'fs/ext4')
| -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 e2eab196875f..e0aa4fe4f596 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -1122,7 +1122,8 @@ 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; @@ -1179,7 +1180,8 @@ got_index: 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; } |