xfs: rename xfs_get_perag

xfs_get_perag is really getting the perag that an inode belongs to
based on it's inode number. Convert the use of this function to just
get the perag from a provided ag number.  Use this new function to
obtain the per-ag structure when traversing the per AG inode trees
for sync and reclaim.

Signed-off-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
diff --git a/fs/xfs/linux-2.6/xfs_sync.c b/fs/xfs/linux-2.6/xfs_sync.c
index 0f90bfe..cc964fa 100644
--- a/fs/xfs/linux-2.6/xfs_sync.c
+++ b/fs/xfs/linux-2.6/xfs_sync.c
@@ -90,14 +90,13 @@
 STATIC int
 xfs_inode_ag_walk(
 	struct xfs_mount	*mp,
-	xfs_agnumber_t		ag,
+	struct xfs_perag	*pag,
 	int			(*execute)(struct xfs_inode *ip,
 					   struct xfs_perag *pag, int flags),
 	int			flags,
 	int			tag,
 	int			exclusive)
 {
-	struct xfs_perag	*pag = &mp->m_perag[ag];
 	uint32_t		first_index;
 	int			last_error = 0;
 	int			skipped;
@@ -141,8 +140,6 @@
 		delay(1);
 		goto restart;
 	}
-
-	xfs_put_perag(mp, pag);
 	return last_error;
 }
 
@@ -160,10 +157,16 @@
 	xfs_agnumber_t		ag;
 
 	for (ag = 0; ag < mp->m_sb.sb_agcount; ag++) {
-		if (!mp->m_perag[ag].pag_ici_init)
+		struct xfs_perag	*pag;
+
+		pag = xfs_perag_get(mp, ag);
+		if (!pag->pag_ici_init) {
+			xfs_perag_put(pag);
 			continue;
-		error = xfs_inode_ag_walk(mp, ag, execute, flags, tag,
+		}
+		error = xfs_inode_ag_walk(mp, pag, execute, flags, tag,
 						exclusive);
+		xfs_perag_put(pag);
 		if (error) {
 			last_error = error;
 			if (error == EFSCORRUPTED)
@@ -690,16 +693,17 @@
 xfs_inode_set_reclaim_tag(
 	xfs_inode_t	*ip)
 {
-	xfs_mount_t	*mp = ip->i_mount;
-	xfs_perag_t	*pag = xfs_get_perag(mp, ip->i_ino);
+	struct xfs_mount *mp = ip->i_mount;
+	struct xfs_perag *pag;
 
+	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
 	read_lock(&pag->pag_ici_lock);
 	spin_lock(&ip->i_flags_lock);
 	__xfs_inode_set_reclaim_tag(pag, ip);
 	__xfs_iflags_set(ip, XFS_IRECLAIMABLE);
 	spin_unlock(&ip->i_flags_lock);
 	read_unlock(&pag->pag_ici_lock);
-	xfs_put_perag(mp, pag);
+	xfs_perag_put(pag);
 }
 
 void
diff --git a/fs/xfs/xfs_iget.c b/fs/xfs/xfs_iget.c
index 155e798..e281eb4 100644
--- a/fs/xfs/xfs_iget.c
+++ b/fs/xfs/xfs_iget.c
@@ -374,7 +374,7 @@
 		return EINVAL;
 
 	/* get the perag structure and ensure that it's inode capable */
-	pag = xfs_get_perag(mp, ino);
+	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ino));
 	if (!pag->pagi_inodeok)
 		return EINVAL;
 	ASSERT(pag->pag_ici_init);
@@ -398,7 +398,7 @@
 		if (error)
 			goto out_error_or_again;
 	}
-	xfs_put_perag(mp, pag);
+	xfs_perag_put(pag);
 
 	*ipp = ip;
 
@@ -417,7 +417,7 @@
 		delay(1);
 		goto again;
 	}
-	xfs_put_perag(mp, pag);
+	xfs_perag_put(pag);
 	return error;
 }
 
@@ -488,12 +488,12 @@
 	 * added to the tree assert that it's been there before to catch
 	 * problems with the inode life time early on.
 	 */
-	pag = xfs_get_perag(mp, ip->i_ino);
+	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
 	write_lock(&pag->pag_ici_lock);
 	if (!radix_tree_delete(&pag->pag_ici_root, agino))
 		ASSERT(0);
 	write_unlock(&pag->pag_ici_lock);
-	xfs_put_perag(mp, pag);
+	xfs_perag_put(pag);
 
 	/*
 	 * Here we do an (almost) spurious inode lock in order to coordinate
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index ef77fd8..bd3d816 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1946,8 +1946,9 @@
 	xfs_inode_t		*ip, **ip_found;
 	xfs_inode_log_item_t	*iip;
 	xfs_log_item_t		*lip;
-	xfs_perag_t		*pag = xfs_get_perag(mp, inum);
+	struct xfs_perag	*pag;
 
+	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, inum));
 	if (mp->m_sb.sb_blocksize >= XFS_INODE_CLUSTER_SIZE(mp)) {
 		blks_per_cluster = 1;
 		ninodes = mp->m_sb.sb_inopblock;
@@ -2088,7 +2089,7 @@
 	}
 
 	kmem_free(ip_found);
-	xfs_put_perag(mp, pag);
+	xfs_perag_put(pag);
 }
 
 /*
@@ -2675,7 +2676,7 @@
 	xfs_buf_t	*bp)
 {
 	xfs_mount_t		*mp = ip->i_mount;
-	xfs_perag_t		*pag = xfs_get_perag(mp, ip->i_ino);
+	struct xfs_perag	*pag;
 	unsigned long		first_index, mask;
 	unsigned long		inodes_per_cluster;
 	int			ilist_size;
@@ -2686,6 +2687,7 @@
 	int			bufwasdelwri;
 	int			i;
 
+	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
 	ASSERT(pag->pagi_inodeok);
 	ASSERT(pag->pag_ici_init);
 
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 1df7e45..f8a68a2 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -386,14 +386,14 @@
 /*
  * perag get/put wrappers for eventual ref counting
  */
-static inline xfs_perag_t *
-xfs_get_perag(struct xfs_mount *mp, xfs_ino_t ino)
+static inline struct xfs_perag *
+xfs_perag_get(struct xfs_mount *mp, xfs_agnumber_t agno)
 {
-	return &mp->m_perag[XFS_INO_TO_AGNO(mp, ino)];
+	return &mp->m_perag[agno];
 }
 
 static inline void
-xfs_put_perag(struct xfs_mount *mp, xfs_perag_t *pag)
+xfs_perag_put(struct xfs_perag *pag)
 {
 	/* nothing to see here, move along */
 }