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>
diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index bcf1652..9eab2df 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -2294,6 +2294,8 @@
{
int error;
+ trace_xfs_read_agf(mp, agno);
+
ASSERT(agno != NULLAGNUMBER);
error = xfs_trans_read_buf(
mp, tp, mp->m_ddev_targp,
@@ -2324,8 +2326,9 @@
struct xfs_perag *pag; /* per allocation group data */
int error;
- ASSERT(agno != NULLAGNUMBER);
+ trace_xfs_alloc_read_agf(mp, agno);
+ ASSERT(agno != NULLAGNUMBER);
error = xfs_read_agf(mp, tp, agno,
(flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0,
bpp);