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>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 321760d..5b19760 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2028,6 +2028,8 @@
 
 	return ext4_filetype_table[filetype];
 }
+extern int ext4_check_all_de(struct inode *dir, struct buffer_head *bh,
+			     void *buf, int buf_size);
 
 /* fsync.c */
 extern int ext4_sync_file(struct file *, loff_t, loff_t, int);