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>

2 files changed, 36 insertions, 10 deletions

diff --git a/fs/xfs/xfs_filestream.c b/fs/xfs/xfs_filestream.c
index a631e1451abb..e61f2aa088a9 100644
--- a/fs/xfs/xfs_filestream.c
+++ b/fs/xfs/xfs_filestream.c
@@ -140,6 +140,7 @@ _xfs_filestream_pick_ag(
         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 @@ _xfs_filestream_pick_ag(
         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 @@ _xfs_filestream_pick_ag(
                 /* 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 @@ _xfs_filestream_pick_ag(
 
                         /* 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 @@ _xfs_filestream_pick_ag(
                 /* 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 @@ next_ag:
                 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 @@ next_ag:
                 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;
 }
diff --git a/fs/xfs/xfs_filestream.h b/fs/xfs/xfs_filestream.h
index 4aba67c5f64f..58378b2ea033 100644
--- a/fs/xfs/xfs_filestream.h
+++ b/fs/xfs/xfs_filestream.h
@@ -79,12 +79,21 @@ extern ktrace_t *xfs_filestreams_trace_buf;
  * the cache that reference per-ag array elements that have since been
  * reallocated.
  */
+/*
+ * xfs_filestream_peek_ag is only used in tracing code
+ */
 static inline int
 xfs_filestream_peek_ag(
         xfs_mount_t     *mp,
         xfs_agnumber_t  agno)
 {
-        return atomic_read(&mp->m_perag[agno].pagf_fstrms);
+        struct xfs_perag *pag;
+        int             ret;
+
+        pag = xfs_perag_get(mp, agno);
+        ret = atomic_read(&pag->pagf_fstrms);
+        xfs_perag_put(pag);
+        return ret;
 }
 
 static inline int
@@ -92,7 +101,13 @@ xfs_filestream_get_ag(
         xfs_mount_t     *mp,
         xfs_agnumber_t  agno)
 {
-        return atomic_inc_return(&mp->m_perag[agno].pagf_fstrms);
+        struct xfs_perag *pag;
+        int             ret;
+
+        pag = xfs_perag_get(mp, agno);
+        ret = atomic_inc_return(&pag->pagf_fstrms);
+        xfs_perag_put(pag);
+        return ret;
 }
 
 static inline int
@@ -100,7 +115,13 @@ xfs_filestream_put_ag(
         xfs_mount_t     *mp,
         xfs_agnumber_t  agno)
 {
-        return atomic_dec_return(&mp->m_perag[agno].pagf_fstrms);
+        struct xfs_perag *pag;
+        int             ret;
+
+        pag = xfs_perag_get(mp, agno);
+        ret = atomic_dec_return(&pag->pagf_fstrms);
+        xfs_perag_put(pag);
+        return ret;
 }
 
 /* allocation selection flags */