linux-kernel - [PATCH 3.2 099/164] ext4: bail out from make_indexed

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Date:	Fri, 12 Dec 2014 06:14:25 +0000
From:	Ben Hutchings <ben@...adent.org.uk>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:	akpm@...ux-foundation.org, "Jan Kara" <jack@...e.cz>,
	"Theodore Ts'o" <tytso@....edu>
Subject: [PATCH 3.2 099/164] ext4: bail out from make_indexed_dir() on
 first error

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

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

From: Jan Kara <jack@...e.cz>

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@...e.cz>
Signed-off-by: Theodore Ts'o <tytso@....edu>
[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@...adent.org.uk>
---
--- 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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