xfs: refactor buffer cancellation table allocation

Move the code that allocates and frees the buffer cancellation tables
used by log recovery into the file that actually uses the tables.  This
is a precursor to some cleanups and a memory leak fix.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/libxfs/xfs_log_recover.h

@@ -110,12 +110,6 @@ struct xlog_recover {
 
 #define ITEM_TYPE(i)	(*(unsigned short *)(i)->ri_buf[0].i_addr)
 
-/*
- * This is the number of entries in the l_buf_cancel_table used during
- * recovery.
- */
-#define	XLOG_BC_TABLE_SIZE	64
-
 #define	XLOG_RECOVER_CRCPASS	0
 #define	XLOG_RECOVER_PASS1	1
 #define	XLOG_RECOVER_PASS2	2
@@ -128,5 +122,13 @@ int xlog_recover_iget(struct xfs_mount *mp, xfs_ino_t ino,
 		struct xfs_inode **ipp);
 void xlog_recover_release_intent(struct xlog *log, unsigned short intent_type,
 		uint64_t intent_id);
+void xlog_alloc_buf_cancel_table(struct xlog *log);
+void xlog_free_buf_cancel_table(struct xlog *log);
+
+#ifdef DEBUG
+void xlog_check_buf_cancel_table(struct xlog *log);
+#else
+#define xlog_check_buf_cancel_table(log) do { } while (0)
+#endif
 
 #endif	/* __XFS_LOG_RECOVER_H__ */

fs/xfs/xfs_buf_item_recover.c

@@ -23,6 +23,15 @@
 #include "xfs_dir2.h"
 #include "xfs_quota.h"
 
+/*
+ * This is the number of entries in the l_buf_cancel_table used during
+ * recovery.
+ */
+#define	XLOG_BC_TABLE_SIZE	64
+
+#define XLOG_BUF_CANCEL_BUCKET(log, blkno) \
+	((log)->l_buf_cancel_table + ((uint64_t)blkno % XLOG_BC_TABLE_SIZE))
+
 /*
  * This structure is used during recovery to record the buf log items which
  * have been canceled and should not be replayed.
@@ -993,3 +1002,41 @@ const struct xlog_recover_item_ops xlog_buf_item_ops = {
 	.commit_pass1		= xlog_recover_buf_commit_pass1,
 	.commit_pass2		= xlog_recover_buf_commit_pass2,
 };
+
+#ifdef DEBUG
+void
+xlog_check_buf_cancel_table(
+	struct xlog	*log)
+{
+	int		i;
+
+	for (i = 0; i < XLOG_BC_TABLE_SIZE; i++)
+		ASSERT(list_empty(&log->l_buf_cancel_table[i]));
+}
+#endif
+
+void
+xlog_alloc_buf_cancel_table(
+	struct xlog	*log)
+{
+	int		i;
+
+	ASSERT(log->l_buf_cancel_table == NULL);
+
+	log->l_buf_cancel_table = kmem_zalloc(XLOG_BC_TABLE_SIZE *
+						 sizeof(struct list_head),
+						 0);
+	for (i = 0; i < XLOG_BC_TABLE_SIZE; i++)
+		INIT_LIST_HEAD(&log->l_buf_cancel_table[i]);
+}
+
+void
+xlog_free_buf_cancel_table(
+	struct xlog	*log)
+{
+	if (!log->l_buf_cancel_table)
+		return;
+
+	kmem_free(log->l_buf_cancel_table);
+	log->l_buf_cancel_table = NULL;
+}

fs/xfs/xfs_log_priv.h

@@ -428,9 +428,6 @@ struct xlog {
 	struct rw_semaphore	l_incompat_users;
 };
 
-#define XLOG_BUF_CANCEL_BUCKET(log, blkno) \
-	((log)->l_buf_cancel_table + ((uint64_t)blkno % XLOG_BC_TABLE_SIZE))
-
 /*
  * Bits for operational state
  */

fs/xfs/xfs_log_recover.c

@@ -3223,45 +3223,31 @@ xlog_do_log_recovery(
 	xfs_daddr_t	head_blk,
 	xfs_daddr_t	tail_blk)
 {
-	int		error, i;
+	int		error;
 
 	ASSERT(head_blk != tail_blk);
 
 	/*
 	 * First do a pass to find all of the cancelled buf log items.
 	 * Store them in the buf_cancel_table for use in the second pass.
 	 */
-	log->l_buf_cancel_table = kmem_zalloc(XLOG_BC_TABLE_SIZE *
-						 sizeof(struct list_head),
-						 0);
-	for (i = 0; i < XLOG_BC_TABLE_SIZE; i++)
-		INIT_LIST_HEAD(&log->l_buf_cancel_table[i]);
+	xlog_alloc_buf_cancel_table(log);
 
 	error = xlog_do_recovery_pass(log, head_blk, tail_blk,
 				      XLOG_RECOVER_PASS1, NULL);
-	if (error != 0) {
-		kmem_free(log->l_buf_cancel_table);
-		log->l_buf_cancel_table = NULL;
-		return error;
-	}
+	if (error != 0)
+		goto out_cancel;
+
 	/*
 	 * Then do a second pass to actually recover the items in the log.
 	 * When it is complete free the table of buf cancel items.
 	 */
 	error = xlog_do_recovery_pass(log, head_blk, tail_blk,
 				      XLOG_RECOVER_PASS2, NULL);
-#ifdef DEBUG
-	if (!error) {
-		int	i;
-
-		for (i = 0; i < XLOG_BC_TABLE_SIZE; i++)
-			ASSERT(list_empty(&log->l_buf_cancel_table[i]));
-	}
-#endif	/* DEBUG */
-
-	kmem_free(log->l_buf_cancel_table);
-	log->l_buf_cancel_table = NULL;
-
+	if (!error)
+		xlog_check_buf_cancel_table(log);
+out_cancel:
+	xlog_free_buf_cancel_table(log);
 	return error;
 }