xfs: disable reaping in fscounters scrub

The fscounters scrub code doesn't work properly because it cannot
quiesce updates to the percpu counters in the filesystem, hence it
returns false corruption reports.  This has been fixed properly in
one of the online repair patchsets that are under review by replacing
the xchk_disable_reaping calls with an exclusive filesystem freeze.
Disabling background gc isn't sufficient to fix the problem.

In other words, scrub doesn't need to call xfs_inodegc_stop, which is
just as well since it wasn't correct to allow scrub to call
xfs_inodegc_start when something else could be calling xfs_inodegc_stop
(e.g. trying to freeze the filesystem).

Neuter the scrubber for now, and remove the xchk_*_reaping functions.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
index 9aa79665c6080538c72a24ece5166cbff9d8086c..7a20256be969a45c716f7cdf54f23a048c15d4ba 100644 (file)
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -1164,32 +1164,6 @@ xchk_metadata_inode_forks(
        return 0;
 }
 
-/* Pause background reaping of resources. */
-void
-xchk_stop_reaping(
-       struct xfs_scrub        *sc)
-{
-       sc->flags |= XCHK_REAPING_DISABLED;
-       xfs_blockgc_stop(sc->mp);
-       xfs_inodegc_stop(sc->mp);
-}
-
-/* Restart background reaping of resources. */
-void
-xchk_start_reaping(
-       struct xfs_scrub        *sc)
-{
-       /*
-        * Readonly filesystems do not perform inactivation or speculative
-        * preallocation, so there's no need to restart the workers.
-        */
-       if (!xfs_is_readonly(sc->mp)) {
-               xfs_inodegc_start(sc->mp);
-               xfs_blockgc_start(sc->mp);
-       }
-       sc->flags &= ~XCHK_REAPING_DISABLED;
-}
-
 /*
  * Enable filesystem hooks (i.e. runtime code patching) before starting a scrub
  * operation.  Callers must not hold any locks that intersect with the CPU

diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h
index 18b5f2b62f13620113f23a14f8819980d5ed34e4..791235cd9b0083e6b43c560cd469789b8a90c7ec 100644 (file)
--- a/fs/xfs/scrub/common.h
+++ b/fs/xfs/scrub/common.h
@@ -156,8 +156,6 @@ static inline bool xchk_skip_xref(struct xfs_scrub_metadata *sm)
 }
 
 int xchk_metadata_inode_forks(struct xfs_scrub *sc);
-void xchk_stop_reaping(struct xfs_scrub *sc);
-void xchk_start_reaping(struct xfs_scrub *sc);
 
 /*
  * Setting up a hook to wait for intents to drain is costly -- we have to take

diff --git a/fs/xfs/scrub/fscounters.c b/fs/xfs/scrub/fscounters.c
index faa315be7978d4f11715c8c90ea76595f68104a9..e382a35e98d88c81396c33830290039749b6ba6a 100644 (file)
--- a/fs/xfs/scrub/fscounters.c
+++ b/fs/xfs/scrub/fscounters.c
@@ -150,13 +150,6 @@ xchk_setup_fscounters(
        if (error)
                return error;
 
-       /*
-        * Pause background reclaim while we're scrubbing to reduce the
-        * likelihood of background perturbations to the counters throwing off
-        * our calculations.
-        */
-       xchk_stop_reaping(sc);
-
        return xchk_trans_alloc(sc, 0);
 }
 
@@ -453,6 +446,12 @@ xchk_fscounters(
        if (frextents > mp->m_sb.sb_rextents)
                xchk_set_corrupt(sc);
 
+       /*
+        * XXX: We can't quiesce percpu counter updates, so exit early.
+        * This can be re-enabled when we gain exclusive freeze functionality.
+        */
+       return 0;
+
        /*
         * If ifree exceeds icount by more than the minimum variance then
         * something's probably wrong with the counters.

diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c
index 02819bedc5b1589e9bc94d4c85d7806f871455c0..3d98f604765e17d8af7e0504ba3dafeb8cdc5b46 100644 (file)
--- a/fs/xfs/scrub/scrub.c
+++ b/fs/xfs/scrub/scrub.c
@@ -186,8 +186,6 @@ xchk_teardown(
        }
        if (sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR)
                mnt_drop_write_file(sc->file);
-       if (sc->flags & XCHK_REAPING_DISABLED)
-               xchk_start_reaping(sc);
        if (sc->buf) {
                if (sc->buf_cleanup)
                        sc->buf_cleanup(sc->buf);

diff --git a/fs/xfs/scrub/scrub.h b/fs/xfs/scrub/scrub.h
index e71903474cd794cf90541103926258399bd3feb3..b38e93830ddea2b011ab57a7f900f540a6106e24 100644 (file)
--- a/fs/xfs/scrub/scrub.h
+++ b/fs/xfs/scrub/scrub.h
@@ -106,7 +106,6 @@ struct xfs_scrub {
 
 /* XCHK state flags grow up from zero, XREP state flags grown down from 2^31 */
 #define XCHK_TRY_HARDER                (1 << 0)  /* can't get resources, try again */
-#define XCHK_REAPING_DISABLED  (1 << 1)  /* background block reaping paused */
 #define XCHK_FSGATES_DRAIN     (1 << 2)  /* defer ops draining enabled */
 #define XCHK_NEED_DRAIN                (1 << 3)  /* scrub needs to drain defer ops */
 #define XREP_ALREADY_FIXED     (1 << 31) /* checking our repair work */

diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
index 68efd6fda61c15db6fa29c9e89597157584356c7..b3894daeb86a96f10f4d1201a569a494978e62a6 100644 (file)
--- a/fs/xfs/scrub/trace.h
+++ b/fs/xfs/scrub/trace.h
@@ -98,7 +98,6 @@ TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_FSCOUNTERS);
 
 #define XFS_SCRUB_STATE_STRINGS \
        { XCHK_TRY_HARDER,                      "try_harder" }, \
-       { XCHK_REAPING_DISABLED,                "reaping_disabled" }, \
        { XCHK_FSGATES_DRAIN,                   "fsgates_drain" }, \
        { XCHK_NEED_DRAIN,                      "need_drain" }, \
        { XREP_ALREADY_FIXED,                   "already_fixed" }