xfs: add tracepoints to AGF/AGI read operations

To help track down AGI/AGF lock ordering issues, I added these
tracepoints to tell us when an AGI or AGF is read and locked.  With
these we can now determine if the lock ordering goes wrong from
tracing captures.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c
index 14d732f61a41..e87719c5bebe 100644
--- a/fs/xfs/xfs_ialloc.c
+++ b/fs/xfs/xfs_ialloc.c
@@ -40,6 +40,7 @@
 #include "xfs_icreate_item.h"
 #include "xfs_icache.h"
 #include "xfs_dinode.h"
+#include "xfs_trace.h"
 
 
 /*
@@ -1627,8 +1628,9 @@ xfs_read_agi(
 {
         int                     error;
 
-        ASSERT(agno != NULLAGNUMBER);
+        trace_xfs_read_agi(mp, agno);
 
+        ASSERT(agno != NULLAGNUMBER);
         error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
                         XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
                         XFS_FSS_TO_BB(mp, 1), 0, bpp, &xfs_agi_buf_ops);
@@ -1651,6 +1653,8 @@ xfs_ialloc_read_agi(
         struct xfs_perag        *pag;   /* per allocation group data */
         int                     error;
 
+        trace_xfs_ialloc_read_agi(mp, agno);
+
         error = xfs_read_agi(mp, tp, agno, bpp);
         if (error)
                 return error;