ext4: check inline directory before converting

Before converting an inline directory to a regular directory, check
the directory entries to make sure they're not obviously broken.
This helps us to avoid a BUG_ON if one of the dirents is trashed.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>

1 files changed, 12 insertions, 0 deletions

diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 141b6acbc51c..bea662bd0ca6 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -1172,6 +1172,18 @@ static int ext4_convert_inline_data_nolock(handle_t *handle,
 	if (error < 0)
 		goto out;
 
+	/*
+	 * Make sure the inline directory entries pass checks before we try to
+	 * convert them, so that we avoid touching stuff that needs fsck.
+	 */
+	if (S_ISDIR(inode->i_mode)) {
+		error = ext4_check_all_de(inode, iloc->bh,
+					buf + EXT4_INLINE_DOTDOT_SIZE,
+					inline_size - EXT4_INLINE_DOTDOT_SIZE);
+		if (error)
+			goto out;
+	}
+
 	error = ext4_destroy_inline_data_nolock(handle, inode);
 	if (error)
 		goto out;