ocfs2: annotate flexible array members with __counted_by_le()

Annotate flexible array members of 'struct ocfs2_extent_list',
'struct ocfs2_chain_list', 'struct ocfs2_truncate_log',
'struct ocfs2_dx_entry_list', 'ocfs2_refcount_list' and
'struct ocfs2_xattr_header' with '__counted_by_le()'
attribute to improve array bounds checking when
CONFIG_UBSAN_BOUNDS is enabled.

[[e-mail]: fix __counted_by_le() usage in ocfs2_expand_inline_dx_root()]
Link: https://lkml.kernel.org/r/[e-mail]
Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Dmitry Antipov <[e-mail]>
Reviewed-by: Joseph Qi <[e-mail]>
Reviewed-by: Heming Zhao <[e-mail]>
Cc: Mark Fasheh <[e-mail]>
Cc: Joel Becker <[e-mail]>
Cc: Junxiao Bi <[e-mail]>
Cc: Changwei Ge <[e-mail]>
Cc: Jun Piao <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

fs/ocfs2/dir.c

···
 	}
 
 	dx_root->dr_flags &= ~OCFS2_DX_FLAG_INLINE;
-	memset(&dx_root->dr_list, 0, osb->sb->s_blocksize -
-	       offsetof(struct ocfs2_dx_root_block, dr_list));
+
+	dx_root->dr_list.l_tree_depth = 0;
 	dx_root->dr_list.l_count =
 		cpu_to_le16(ocfs2_extent_recs_per_dx_root(osb->sb));
+	dx_root->dr_list.l_next_free_rec = 0;
+	memset(&dx_root->dr_list.l_recs, 0,
+	       osb->sb->s_blocksize -
+	       (offsetof(struct ocfs2_dx_root_block, dr_list) +
+		offsetof(struct ocfs2_extent_list, l_recs)));
 
 	/* This should never fail considering we start with an empty
 	 * dx_root. */

fs/ocfs2/ocfs2_fs.h

···
 	__le16 l_reserved1;
 	__le64 l_reserved2;		/* Pad to
 					   sizeof(ocfs2_extent_rec) */
-/*10*/	struct ocfs2_extent_rec l_recs[];	/* Extent records */
+					/* Extent records */
+/*10*/	struct ocfs2_extent_rec l_recs[] __counted_by_le(l_count);
 };
 
 /*
···
 	__le16 cl_count;		/* Total chains in this list */
 	__le16 cl_next_free_rec;	/* Next unused chain slot */
 	__le64 cl_reserved1;
-/*10*/	struct ocfs2_chain_rec cl_recs[];	/* Chain records */
+					/* Chain records */
+/*10*/	struct ocfs2_chain_rec cl_recs[] __counted_by_le(cl_count);
 };
 
 /*
···
 /*00*/	__le16 tl_count;		/* Total records in this log */
 	__le16 tl_used;			/* Number of records in use */
 	__le32 tl_reserved1;
-/*08*/	struct ocfs2_truncate_rec tl_recs[];	/* Truncate records */
+					/* Truncate records */
+/*08*/	struct ocfs2_truncate_rec tl_recs[] __counted_by_le(tl_count);
 };
 
 /*
···
 					 * possible in de_entries */
 	__le16		de_num_used;	/* Current number of
 					 * de_entries entries */
-	struct	ocfs2_dx_entry		de_entries[];	/* Indexed dir entries
-							 * in a packed array of
-							 * length de_num_used */
+					/* Indexed dir entries in a packed
+					 * array of length de_num_used.
+					 */
+	struct	ocfs2_dx_entry		de_entries[] __counted_by_le(de_count);
 };
 
 #define OCFS2_DX_FLAG_INLINE	0x01
···
 	__le16 rl_used;		/* Current number of used records */
 	__le32 rl_reserved2;
 	__le64 rl_reserved1;	/* Pad to sizeof(ocfs2_refcount_record) */
-/*10*/	struct ocfs2_refcount_rec rl_recs[];	/* Refcount records */
+				/* Refcount records */
+/*10*/	struct ocfs2_refcount_rec rl_recs[] __counted_by_le(rl_count);
 };
 
 
···
 						    buckets.  A block uses
 						    xb_check and sets
 						    this field to zero.) */
-	struct ocfs2_xattr_entry xh_entries[]; /* xattr entry list. */
+						/* xattr entry list. */
+	struct ocfs2_xattr_entry xh_entries[] __counted_by_le(xh_count);
 };
 
 /*