diff options
Diffstat (limited to 'fs/xfs/scrub/scrub.h')
-rw-r--r-- | fs/xfs/scrub/scrub.h | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/fs/xfs/scrub/scrub.h b/fs/xfs/scrub/scrub.h index 391027047146..4e7e3edb6350 100644 --- a/fs/xfs/scrub/scrub.h +++ b/fs/xfs/scrub/scrub.h @@ -8,6 +8,49 @@ struct xfs_scrub; +struct xchk_relax { + unsigned long next_resched; + unsigned int resched_nr; + bool interruptible; +}; + +/* Yield to the scheduler at most 10x per second. */ +#define XCHK_RELAX_NEXT (jiffies + (HZ / 10)) + +#define INIT_XCHK_RELAX \ + (struct xchk_relax){ \ + .next_resched = XCHK_RELAX_NEXT, \ + .resched_nr = 0, \ + .interruptible = true, \ + } + +/* + * Relax during a scrub operation and exit if there's a fatal signal pending. + * + * If preemption is disabled, we need to yield to the scheduler every now and + * then so that we don't run afoul of the soft lockup watchdog or RCU stall + * detector. cond_resched calls are somewhat expensive (~5ns) so we want to + * ratelimit this to 10x per second. Amortize the cost of the other checks by + * only doing it once every 100 calls. + */ +static inline int xchk_maybe_relax(struct xchk_relax *widget) +{ + /* Amortize the cost of scheduling and checking signals. */ + if (likely(++widget->resched_nr < 100)) + return 0; + widget->resched_nr = 0; + + if (unlikely(widget->next_resched <= jiffies)) { + cond_resched(); + widget->next_resched = XCHK_RELAX_NEXT; + } + + if (widget->interruptible && fatal_signal_pending(current)) + return -EINTR; + + return 0; +} + /* * Standard flags for allocating memory within scrub. NOFS context is * configured by the process allocation scope. Scrub and repair must be able @@ -123,6 +166,9 @@ struct xfs_scrub { */ unsigned int sick_mask; + /* next time we want to cond_resched() */ + struct xchk_relax relax; + /* State tracking for single-AG operations. */ struct xchk_ag sa; }; @@ -167,6 +213,24 @@ struct xfs_scrub_subord *xchk_scrub_create_subord(struct xfs_scrub *sc, unsigned int subtype); void xchk_scrub_free_subord(struct xfs_scrub_subord *sub); +/* + * We /could/ terminate a scrub/repair operation early. If we're not + * in a good place to continue (fatal signal, etc.) then bail out. + * Note that we're careful not to make any judgements about *error. + */ +static inline bool +xchk_should_terminate( + struct xfs_scrub *sc, + int *error) +{ + if (xchk_maybe_relax(&sc->relax)) { + if (*error == 0) + *error = -EINTR; + return true; + } + return false; +} + /* Metadata scrubbers */ int xchk_tester(struct xfs_scrub *sc); int xchk_superblock(struct xfs_scrub *sc); |