xfs: embed the pagb_list array in the perag structure

Now that the perag structure is allocated memory rather than held in
an array, we don't need to have the busy extent array external to
the structure. Embed it into the perag structure to avoid needing an
extra allocation when setting up.
Signed-off-by: NDave Chinner <david@fromorbit.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAlex Elder <aelder@sgi.com>

fs/xfs/xfs_ag.h

@@ -187,14 +187,8 @@ typedef struct xfs_perag_busy {
 /*
  * Per-ag incore structure, copies of information in agf and agi,
  * to improve the performance of allocation group selection.
- *
- * pick sizes which fit in allocation buckets well
  */
-#if (BITS_PER_LONG == 32)
-#define XFS_PAGB_NUM_SLOTS	84
-#elif (BITS_PER_LONG == 64)
 #define XFS_PAGB_NUM_SLOTS	128
-#endif
 
 typedef struct xfs_perag {
 	struct xfs_mount *pag_mount;	/* owner filesystem */
@@ -212,8 +206,6 @@ typedef struct xfs_perag {
 	__uint32_t	pagf_btreeblks;	/* # of blocks held in AGF btrees */
 	xfs_agino_t	pagi_freecount;	/* number of free inodes */
 	xfs_agino_t	pagi_count;	/* number of allocated inodes */
-	int		pagb_count;	/* pagb slots in use */
-	xfs_perag_busy_t *pagb_list;	/* unstable blocks */
 
 	/*
 	 * Inode allocation search lookup optimisation.
@@ -232,6 +224,8 @@ typedef struct xfs_perag {
 	rwlock_t	pag_ici_lock;	/* incore inode lock */
 	struct radix_tree_root pag_ici_root;	/* incore inode cache root */
 #endif
+	int		pagb_count;	/* pagb slots in use */
+	xfs_perag_busy_t pagb_list[XFS_PAGB_NUM_SLOTS];	/* unstable blocks */
 } xfs_perag_t;
 
 /*

fs/xfs/xfs_alloc.c

@@ -2200,8 +2200,8 @@ xfs_alloc_read_agf(
 		pag->pagf_levels[XFS_BTNUM_CNTi] =
 			be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]);
 		spin_lock_init(&pag->pagb_lock);
-		pag->pagb_list = kmem_zalloc(XFS_PAGB_NUM_SLOTS *
-					sizeof(xfs_perag_busy_t), KM_SLEEP);
+		pag->pagb_count = 0;
+		memset(pag->pagb_list, 0, sizeof(pag->pagb_list));
 		pag->pagf_init = 1;
 	}
 #ifdef DEBUG

fs/xfs/xfs_mount.c

@@ -247,10 +247,9 @@ xfs_free_perag(
 	for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
 		spin_lock(&mp->m_perag_lock);
 		pag = radix_tree_delete(&mp->m_perag_tree, agno);
+		ASSERT(pag);
 		ASSERT(atomic_read(&pag->pag_ref) == 0);
 		spin_unlock(&mp->m_perag_lock);
-		ASSERT(pag);
-		kmem_free(pag->pagb_list);
 		kmem_free(pag);
 	}
 }