[PATCH 022/119] xfs: add tracepoints and error injection for deferred extent freeing

["Darrick J. Wong" <darrick.wong@xxxxxxxxxx>]

Add a couple of tracepoints for the deferred extent free operation and
a site for injecting errors while finishing the operation.  This makes
it easier to debug deferred ops and test log redo.

Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
 fs/xfs/libxfs/xfs_alloc.c |    7 +++++++
 fs/xfs/libxfs/xfs_bmap.c  |    2 ++
 fs/xfs/xfs_error.h        |    4 +++-
 fs/xfs/xfs_trace.h        |    5 ++++-
 4 files changed, 16 insertions(+), 2 deletions(-)


diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index c06b463..56c8690 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -2704,6 +2704,13 @@ xfs_free_extent(
 
        ASSERT(len != 0);
 
+       trace_xfs_bmap_free_deferred(mp, agno, 0, agbno, len);
+
+       if (XFS_TEST_ERROR(false, mp,
+                       XFS_ERRTAG_FREE_EXTENT,
+                       XFS_RANDOM_FREE_EXTENT))
+               return -EIO;
+
        error = xfs_free_extent_fix_freelist(tp, agno, &agbp);
        if (error)
                return error;
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 85061a0..3a6d3e3 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -596,6 +596,8 @@ xfs_bmap_add_free(
        new = kmem_zone_alloc(xfs_bmap_free_item_zone, KM_SLEEP);
        new->xbfi_startblock = bno;
        new->xbfi_blockcount = (xfs_extlen_t)len;
+       trace_xfs_bmap_free_defer(mp, XFS_FSB_TO_AGNO(mp, bno), 0,
+                       XFS_FSB_TO_AGBNO(mp, bno), len);
        xfs_defer_add(dfops, XFS_DEFER_OPS_TYPE_FREE, &new->xbfi_list);
 }
 
diff --git a/fs/xfs/xfs_error.h b/fs/xfs/xfs_error.h
index 4ed3042..ee4680e 100644
--- a/fs/xfs/xfs_error.h
+++ b/fs/xfs/xfs_error.h
@@ -90,7 +90,8 @@ extern void xfs_verifier_error(struct xfs_buf *bp);
 #define XFS_ERRTAG_STRATCMPL_IOERR                     19
 #define XFS_ERRTAG_DIOWRITE_IOERR                      20
 #define XFS_ERRTAG_BMAPIFORMAT                         21
-#define XFS_ERRTAG_MAX                                 22
+#define XFS_ERRTAG_FREE_EXTENT                         22
+#define XFS_ERRTAG_MAX                                 23
 
 /*
  * Random factors for above tags, 1 means always, 2 means 1/2 time, etc.
@@ -117,6 +118,7 @@ extern void xfs_verifier_error(struct xfs_buf *bp);
 #define XFS_RANDOM_STRATCMPL_IOERR                     (XFS_RANDOM_DEFAULT/10)
 #define XFS_RANDOM_DIOWRITE_IOERR                      (XFS_RANDOM_DEFAULT/10)
 #define        XFS_RANDOM_BMAPIFORMAT                          
XFS_RANDOM_DEFAULT
+#define XFS_RANDOM_FREE_EXTENT                         1
 
 #ifdef DEBUG
 extern int xfs_error_test_active;
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index 5923014..777a89c 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -2415,9 +2415,12 @@ DEFINE_DEFER_PENDING_EVENT(xfs_defer_pending_cancel);
 DEFINE_DEFER_PENDING_EVENT(xfs_defer_pending_finish);
 DEFINE_DEFER_PENDING_EVENT(xfs_defer_pending_abort);
 
-DEFINE_PHYS_EXTENT_DEFERRED_EVENT(xfs_defer_phys_extent);
 DEFINE_MAP_EXTENT_DEFERRED_EVENT(xfs_defer_map_extent);
 
+#define DEFINE_BMAP_FREE_DEFERRED_EVENT DEFINE_PHYS_EXTENT_DEFERRED_EVENT
+DEFINE_BMAP_FREE_DEFERRED_EVENT(xfs_bmap_free_defer);
+DEFINE_BMAP_FREE_DEFERRED_EVENT(xfs_bmap_free_deferred);
+
 #endif /* _TRACE_XFS_H */
 
 #undef TRACE_INCLUDE_PATH