[PATCH 3.2 099/164] ext4: bail out from make_indexed_dir() on first error

From: Ben Hutchings
Date: Fri Dec 12 2014 - 01:36:48 EST


3.2.65-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Jan Kara <jack@xxxxxxx>

commit 6050d47adcadbb53582434d919ed7f038d936712 upstream.

When ext4_handle_dirty_dx_node() or ext4_handle_dirty_dirent_node()
fail, there's really something wrong with the fs and there's no point in
continuing further. Just return error from make_indexed_dir() in that
case. Also initialize frames array so that if we return early due to
error, dx_release() doesn't try to dereference uninitialized memory
(which could happen also due to error in do_split()).

Coverity-id: 741300
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
[bwh: Backported to 3.2:
- We have ext4_handle_dirty_metadata() not
ext4_handle_dirty_{dx,dirent}_node()]
- do_split() returns errors by reference not with ERR_PTR()]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1408,31 +1408,38 @@ static int make_indexed_dir(handle_t *ha
hinfo.hash_version += EXT4_SB(dir->i_sb)->s_hash_unsigned;
hinfo.seed = EXT4_SB(dir->i_sb)->s_hash_seed;
ext4fs_dirhash(name, namelen, &hinfo);
+ memset(frames, 0, sizeof(frames));
frame = frames;
frame->entries = entries;
frame->at = entries;
frame->bh = bh;
bh = bh2;

- ext4_handle_dirty_metadata(handle, dir, frame->bh);
- ext4_handle_dirty_metadata(handle, dir, bh);
+ retval = ext4_handle_dirty_metadata(handle, dir, frame->bh);
+ if (retval)
+ goto out_frames;
+ retval = ext4_handle_dirty_metadata(handle, dir, bh);
+ if (retval)
+ goto out_frames;

de = do_split(handle,dir, &bh, frame, &hinfo, &retval);
if (!de) {
- /*
- * Even if the block split failed, we have to properly write
- * out all the changes we did so far. Otherwise we can end up
- * with corrupted filesystem.
- */
- ext4_mark_inode_dirty(handle, dir);
- dx_release(frames);
- return retval;
+ goto out_frames;
}
dx_release(frames);

retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
brelse(bh);
return retval;
+out_frames:
+ /*
+ * Even if the block split failed, we have to properly write
+ * out all the changes we did so far. Otherwise we can end up
+ * with corrupted filesystem.
+ */
+ ext4_mark_inode_dirty(handle, dir);
+ dx_release(frames);
+ return retval;
}

/*

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