xfs: Convert filestreams code to use per-ag get/put routines

Use xfs_perag_get() and xfs_perag_put() in the filestreams code.

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/xfs_filestream.c b/fs/xfs/xfs_filestream.c
index a631e14..e61f2aa 100644
--- a/fs/xfs/xfs_filestream.c
+++ b/fs/xfs/xfs_filestream.c
@@ -140,6 +140,7 @@
 	int		flags,
 	xfs_extlen_t	minlen)
 {
+	int		streams, max_streams;
 	int		err, trylock, nscan;
 	xfs_extlen_t	longest, free, minfree, maxfree = 0;
 	xfs_agnumber_t	ag, max_ag = NULLAGNUMBER;
@@ -155,15 +156,15 @@
 	trylock = XFS_ALLOC_FLAG_TRYLOCK;
 
 	for (nscan = 0; 1; nscan++) {
-
-		TRACE_AG_SCAN(mp, ag, xfs_filestream_peek_ag(mp, ag));
-
-		pag = mp->m_perag + ag;
+		pag = xfs_perag_get(mp, ag);
+		TRACE_AG_SCAN(mp, ag, atomic_read(&pag->pagf_fstrms));
 
 		if (!pag->pagf_init) {
 			err = xfs_alloc_pagf_init(mp, NULL, ag, trylock);
-			if (err && !trylock)
+			if (err && !trylock) {
+				xfs_perag_put(pag);
 				return err;
+			}
 		}
 
 		/* Might fail sometimes during the 1st pass with trylock set. */
@@ -173,6 +174,7 @@
 		/* Keep track of the AG with the most free blocks. */
 		if (pag->pagf_freeblks > maxfree) {
 			maxfree = pag->pagf_freeblks;
+			max_streams = atomic_read(&pag->pagf_fstrms);
 			max_ag = ag;
 		}
 
@@ -195,6 +197,8 @@
 
 			/* Break out, retaining the reference on the AG. */
 			free = pag->pagf_freeblks;
+			streams = atomic_read(&pag->pagf_fstrms);
+			xfs_perag_put(pag);
 			*agp = ag;
 			break;
 		}
@@ -202,6 +206,7 @@
 		/* Drop the reference on this AG, it's not usable. */
 		xfs_filestream_put_ag(mp, ag);
 next_ag:
+		xfs_perag_put(pag);
 		/* Move to the next AG, wrapping to AG 0 if necessary. */
 		if (++ag >= mp->m_sb.sb_agcount)
 			ag = 0;
@@ -229,6 +234,7 @@
 		if (max_ag != NULLAGNUMBER) {
 			xfs_filestream_get_ag(mp, max_ag);
 			TRACE_AG_PICK1(mp, max_ag, maxfree);
+			streams = max_streams;
 			free = maxfree;
 			*agp = max_ag;
 			break;
@@ -240,8 +246,7 @@
 		return 0;
 	}
 
-	TRACE_AG_PICK2(mp, startag, *agp, xfs_filestream_peek_ag(mp, *agp),
-			free, nscan, flags);
+	TRACE_AG_PICK2(mp, startag, *agp, streams, free, nscan, flags);
 
 	return 0;
 }