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;