[XFS] Ensure that when we unlock a log item when there is someone waiting

for log space, we give at least one thread a chance to flush
metadata and free more log space.

SGI Modid: 2.5.x-xfs:slinx:149321a6

fs/xfs/xfs_inode.c

@@ -3003,9 +3003,7 @@ xfs_iflush(
 	 * see if other inodes can be gathered into this write
 	 */
 
-#ifdef DEBUG
-	ip->i_chash->chl_buf = bp;		/* inode clustering debug */
-#endif
+	ip->i_chash->chl_buf = bp;
 
 	ch = XFS_CHASH(mp, ip->i_blkno);
 	s = mutex_spinlock(&ch->ch_lock);

fs/xfs/xfs_inode.h

@@ -192,9 +192,7 @@ typedef struct xfs_chashlist {
 	struct xfs_inode	*chl_ip;
 	xfs_daddr_t		chl_blkno;	/* starting block number of
 						 * the cluster */
-#ifdef DEBUG
-	struct xfs_buf		*chl_buf;	/* debug: the inode buffer */
-#endif
+	struct xfs_buf		*chl_buf;	/* the inode buffer */
 } xfs_chashlist_t;
 
 typedef struct xfs_chash {

fs/xfs/xfs_log.c

@@ -794,8 +794,9 @@ xfs_log_move_tail(xfs_mount_t	*mp,
 		do {
 			ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
 
-			if (free_bytes < tic->t_unit_res)
+			if (free_bytes < tic->t_unit_res && tail_lsn != 1)
 				break;
+			tail_lsn = 0;
 			free_bytes -= tic->t_unit_res;
 			sv_signal(&tic->t_sema);
 			tic = tic->t_next;
@@ -814,8 +815,9 @@ xfs_log_move_tail(xfs_mount_t	*mp,
 				need_bytes = tic->t_unit_res*tic->t_cnt;
 			else
 				need_bytes = tic->t_unit_res;
-			if (free_bytes < need_bytes)
+			if (free_bytes < need_bytes && tail_lsn != 1)
 				break;
+			tail_lsn = 0;
 			free_bytes -= need_bytes;
 			sv_signal(&tic->t_sema);
 			tic = tic->t_next;

fs/xfs/xfsidbg.c

@@ -4883,13 +4883,8 @@ xfsidbg_xchashlist(xfs_chashlist_t *chl)
 	xfs_inode_t	*ip;
 
 	while (chl != NULL) {
-#ifdef DEBUG
-		kdb_printf("hashlist inode 0x%p blkno %Ld buf 0x%p",
-		       chl->chl_ip, chl->chl_blkno, chl->chl_buf);
-#else
-		kdb_printf("hashlist inode 0x%p blkno %lld",
-		       chl->chl_ip, (long long) chl->chl_blkno);
-#endif
+		kdb_printf("hashlist inode 0x%p blkno %lld buf 0x%p",
+		       chl->chl_ip, (long long) chl->chl_blkno, chl->chl_buf);
 
 		kdb_printf("\n");