From: Darrick J. Wong Date: Wed, 12 Apr 2023 02:00:00 +0000 (-0700) Subject: xfs: scrub should use ECHRNG to signal that the drain is needed X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=88accf17226733088923635b580779a3c86b6f23;p=linux.git xfs: scrub should use ECHRNG to signal that the drain is needed In the previous patch, we added jump labels to the intent drain code so that regular filesystem operations need not pay the price of checking for someone (scrub) waiting on intents to drain from some part of the filesystem when that someone isn't running. However, I observed that xfs/285 now spends a lot more time pushing the AIL from the inode btree scrubber than it used to. This is because the inobt scrubber will try push the AIL to try to get logged inode cores written to the filesystem when it sees a weird discrepancy between the ondisk inode and the inobt records. This AIL push is triggered when the setup function sees TRY_HARDER is set; and the requisite EDEADLOCK return is initiated when the discrepancy is seen. The solution to this performance slow down is to use a different result code (ECHRNG) for scrub code to signal that it needs to wait for deferred intent work items to drain out of some part of the filesystem. When this happens, set a new scrub state flag (XCHK_NEED_DRAIN) so that setup functions will activate the jump label. Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner --- diff --git a/fs/xfs/scrub/btree.c b/fs/xfs/scrub/btree.c index e54c1cfe64bf3..626282dbe2e37 100644 --- a/fs/xfs/scrub/btree.c +++ b/fs/xfs/scrub/btree.c @@ -36,6 +36,7 @@ __xchk_btree_process_error( switch (*error) { case -EDEADLOCK: + case -ECHRNG: /* Used to restart an op with deadlock avoidance. */ trace_xchk_deadlock_retry(sc->ip, sc->sm, *error); break; diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c index 87649facbbdef..dcfe66044d4ae 100644 --- a/fs/xfs/scrub/common.c +++ b/fs/xfs/scrub/common.c @@ -75,6 +75,7 @@ __xchk_process_error( case 0: return true; case -EDEADLOCK: + case -ECHRNG: /* Used to restart an op with deadlock avoidance. */ trace_xchk_deadlock_retry( sc->ip ? sc->ip : XFS_I(file_inode(sc->file)), @@ -130,6 +131,7 @@ __xchk_fblock_process_error( case 0: return true; case -EDEADLOCK: + case -ECHRNG: /* Used to restart an op with deadlock avoidance. */ trace_xchk_deadlock_retry(sc->ip, sc->sm, *error); break; @@ -488,7 +490,7 @@ xchk_perag_drain_and_lock( } if (!(sc->flags & XCHK_FSGATES_DRAIN)) - return -EDEADLOCK; + return -ECHRNG; error = xfs_perag_intent_drain(sa->pag); if (error == -ERESTARTSYS) error = -EINTR; diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h index 4714e8a43094c..83b1a392930a5 100644 --- a/fs/xfs/scrub/common.h +++ b/fs/xfs/scrub/common.h @@ -161,7 +161,7 @@ void xchk_start_reaping(struct xfs_scrub *sc); */ static inline bool xchk_need_intent_drain(struct xfs_scrub *sc) { - return sc->flags & XCHK_TRY_HARDER; + return sc->flags & XCHK_NEED_DRAIN; } void xchk_fsgates_enable(struct xfs_scrub *sc, unsigned int scrub_fshooks); diff --git a/fs/xfs/scrub/dabtree.c b/fs/xfs/scrub/dabtree.c index c392c0765e5ca..82b150d3b8b70 100644 --- a/fs/xfs/scrub/dabtree.c +++ b/fs/xfs/scrub/dabtree.c @@ -39,6 +39,7 @@ xchk_da_process_error( switch (*error) { case -EDEADLOCK: + case -ECHRNG: /* Used to restart an op with deadlock avoidance. */ trace_xchk_deadlock_retry(sc->ip, sc->sm, *error); break; diff --git a/fs/xfs/scrub/repair.c b/fs/xfs/scrub/repair.c index b800341aae691..ab0758308f573 100644 --- a/fs/xfs/scrub/repair.c +++ b/fs/xfs/scrub/repair.c @@ -60,6 +60,9 @@ xrep_attempt( sc->sm->sm_flags &= ~XFS_SCRUB_FLAGS_OUT; sc->flags |= XREP_ALREADY_FIXED; return -EAGAIN; + case -ECHRNG: + sc->flags |= XCHK_NEED_DRAIN; + return -EAGAIN; case -EDEADLOCK: /* Tell the caller to try again having grabbed all the locks. */ if (!(sc->flags & XCHK_TRY_HARDER)) { diff --git a/fs/xfs/scrub/scrub.c b/fs/xfs/scrub/scrub.c index bd5d4357cd64c..787a9096ddef6 100644 --- a/fs/xfs/scrub/scrub.c +++ b/fs/xfs/scrub/scrub.c @@ -510,6 +510,8 @@ retry_op: error = sc->ops->setup(sc); if (error == -EDEADLOCK && !(sc->flags & XCHK_TRY_HARDER)) goto try_harder; + if (error == -ECHRNG && !(sc->flags & XCHK_NEED_DRAIN)) + goto need_drain; if (error) goto out_teardown; @@ -517,6 +519,8 @@ retry_op: error = sc->ops->scrub(sc); if (error == -EDEADLOCK && !(sc->flags & XCHK_TRY_HARDER)) goto try_harder; + if (error == -ECHRNG && !(sc->flags & XCHK_NEED_DRAIN)) + goto need_drain; if (error || (sm->sm_flags & XFS_SCRUB_OFLAG_INCOMPLETE)) goto out_teardown; @@ -575,6 +579,12 @@ out: error = 0; } return error; +need_drain: + error = xchk_teardown(sc, 0); + if (error) + goto out_sc; + sc->flags |= XCHK_NEED_DRAIN; + goto retry_op; try_harder: /* * Scrubbers return -EDEADLOCK to mean 'try harder'. Tear down diff --git a/fs/xfs/scrub/scrub.h b/fs/xfs/scrub/scrub.h index 4fdb6017f8206..d85c3b883b4ce 100644 --- a/fs/xfs/scrub/scrub.h +++ b/fs/xfs/scrub/scrub.h @@ -98,6 +98,7 @@ struct xfs_scrub { #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 304c55192c908..68efd6fda61c1 100644 --- a/fs/xfs/scrub/trace.h +++ b/fs/xfs/scrub/trace.h @@ -100,6 +100,7 @@ TRACE_DEFINE_ENUM(XFS_SCRUB_TYPE_FSCOUNTERS); { 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" } DECLARE_EVENT_CLASS(xchk_class,