Date: Wed, 26 Feb 2020 15:59:46 +0000 (UTC) From: Alexander Motin <mav@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r358339 - head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs Message-ID: <202002261559.01QFxk27041511@repo.freebsd.org>
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Author: mav Date: Wed Feb 26 15:59:46 2020 New Revision: 358339 URL: https://svnweb.freebsd.org/changeset/base/358339 Log: MFZoL: Fix issue with scanning dedup blocks as scan ends This patch fixes an issue discovered by ztest where dsl_scan_ddt_entry() could add I/Os to the dsl scan queues between when the scan had finished all required work and when the scan was marked as complete. This caused the scan to spin indefinitely without ending. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Serapheim Dimitropoulos <serapheim.dimitro@delphix.com> Reviewed-by: Matthew Ahrens <mahrens@delphix.com> Signed-off-by: Tom Caputi <tcaputi@datto.com> Closes #8010 zfsonlinux/zfs@5e0bd0ae056e26de36dee3c199c6fcff8f14ee15 MFC after: 1 week Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c Modified: head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c ============================================================================== --- head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c Wed Feb 26 15:56:07 2020 (r358338) +++ head/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c Wed Feb 26 15:59:46 2020 (r358339) @@ -2365,6 +2365,20 @@ dsl_scan_ddt_entry(dsl_scan_t *scn, enum zio_checksum if (!dsl_scan_is_running(scn)) return; + /* + * This function is special because it is the only thing + * that can add scan_io_t's to the vdev scan queues from + * outside dsl_scan_sync(). For the most part this is ok + * as long as it is called from within syncing context. + * However, dsl_scan_sync() expects that no new sio's will + * be added between when all the work for a scan is done + * and the next txg when the scan is actually marked as + * completed. This check ensures we do not issue new sio's + * during this period. + */ + if (scn->scn_done_txg != 0) + return; + for (p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { if (ddp->ddp_phys_birth == 0 || ddp->ddp_phys_birth > scn->scn_phys.scn_max_txg) @@ -3416,6 +3430,8 @@ dsl_scan_sync(dsl_pool_t *dp, dmu_tx_t *tx) (longlong_t)tx->tx_txg); } } else if (scn->scn_is_sorted && scn->scn_bytes_pending != 0) { + ASSERT(scn->scn_clearing); + /* need to issue scrubbing IOs from per-vdev queues */ scn->scn_zio_root = zio_root(dp->dp_spa, NULL, NULL, ZIO_FLAG_CANFAIL);
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