diff options
Diffstat (limited to 'sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c')
| -rw-r--r-- | sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c | 1764 |
1 files changed, 1764 insertions, 0 deletions
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c new file mode 100644 index 0000000..0d0fd74 --- /dev/null +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_scan.c @@ -0,0 +1,1764 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ +/* + * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2013 by Delphix. All rights reserved. + */ + +#include <sys/dsl_scan.h> +#include <sys/dsl_pool.h> +#include <sys/dsl_dataset.h> +#include <sys/dsl_prop.h> +#include <sys/dsl_dir.h> +#include <sys/dsl_synctask.h> +#include <sys/dnode.h> +#include <sys/dmu_tx.h> +#include <sys/dmu_objset.h> +#include <sys/arc.h> +#include <sys/zap.h> +#include <sys/zio.h> +#include <sys/zfs_context.h> +#include <sys/fs/zfs.h> +#include <sys/zfs_znode.h> +#include <sys/spa_impl.h> +#include <sys/vdev_impl.h> +#include <sys/zil_impl.h> +#include <sys/zio_checksum.h> +#include <sys/ddt.h> +#include <sys/sa.h> +#include <sys/sa_impl.h> +#include <sys/zfeature.h> +#ifdef _KERNEL +#include <sys/zfs_vfsops.h> +#endif + +typedef int (scan_cb_t)(dsl_pool_t *, const blkptr_t *, const zbookmark_t *); + +static scan_cb_t dsl_scan_defrag_cb; +static scan_cb_t dsl_scan_scrub_cb; +static scan_cb_t dsl_scan_remove_cb; +static void dsl_scan_cancel_sync(void *, dmu_tx_t *); +static void dsl_scan_sync_state(dsl_scan_t *, dmu_tx_t *tx); + +unsigned int zfs_top_maxinflight = 32; /* maximum I/Os per top-level */ +unsigned int zfs_resilver_delay = 2; /* number of ticks to delay resilver */ +unsigned int zfs_scrub_delay = 4; /* number of ticks to delay scrub */ +unsigned int zfs_scan_idle = 50; /* idle window in clock ticks */ + +unsigned int zfs_scan_min_time_ms = 1000; /* min millisecs to scrub per txg */ +unsigned int zfs_free_min_time_ms = 1000; /* min millisecs to free per txg */ +unsigned int zfs_resilver_min_time_ms = 3000; /* min millisecs to resilver + per txg */ +boolean_t zfs_no_scrub_io = B_FALSE; /* set to disable scrub i/o */ +boolean_t zfs_no_scrub_prefetch = B_FALSE; /* set to disable srub prefetching */ + +SYSCTL_DECL(_vfs_zfs); +SYSCTL_UINT(_vfs_zfs, OID_AUTO, top_maxinflight, CTLFLAG_RWTUN, + &zfs_top_maxinflight, 0, "Maximum I/Os per top-level vdev"); +SYSCTL_UINT(_vfs_zfs, OID_AUTO, resilver_delay, CTLFLAG_RWTUN, + &zfs_resilver_delay, 0, "Number of ticks to delay resilver"); +SYSCTL_UINT(_vfs_zfs, OID_AUTO, scrub_delay, CTLFLAG_RWTUN, + &zfs_scrub_delay, 0, "Number of ticks to delay scrub"); +SYSCTL_UINT(_vfs_zfs, OID_AUTO, scan_idle, CTLFLAG_RWTUN, + &zfs_scan_idle, 0, "Idle scan window in clock ticks"); +SYSCTL_UINT(_vfs_zfs, OID_AUTO, scan_min_time_ms, CTLFLAG_RWTUN, + &zfs_scan_min_time_ms, 0, "Min millisecs to scrub per txg"); +SYSCTL_UINT(_vfs_zfs, OID_AUTO, free_min_time_ms, CTLFLAG_RWTUN, + &zfs_free_min_time_ms, 0, "Min millisecs to free per txg"); +SYSCTL_UINT(_vfs_zfs, OID_AUTO, resilver_min_time_ms, CTLFLAG_RWTUN, + &zfs_resilver_min_time_ms, 0, "Min millisecs to resilver per txg"); +SYSCTL_INT(_vfs_zfs, OID_AUTO, no_scrub_io, CTLFLAG_RWTUN, + &zfs_no_scrub_io, 0, "Disable scrub I/O"); +SYSCTL_INT(_vfs_zfs, OID_AUTO, no_scrub_prefetch, CTLFLAG_RWTUN, + &zfs_no_scrub_prefetch, 0, "Disable scrub prefetching"); + +enum ddt_class zfs_scrub_ddt_class_max = DDT_CLASS_DUPLICATE; + +#define DSL_SCAN_IS_SCRUB_RESILVER(scn) \ + ((scn)->scn_phys.scn_func == POOL_SCAN_SCRUB || \ + (scn)->scn_phys.scn_func == POOL_SCAN_RESILVER) + +extern int zfs_txg_timeout; + +/* the order has to match pool_scan_type */ +static scan_cb_t *scan_funcs[POOL_SCAN_FUNCS] = { + NULL, + dsl_scan_scrub_cb, /* POOL_SCAN_SCRUB */ + dsl_scan_scrub_cb, /* POOL_SCAN_RESILVER */ +}; + +int +dsl_scan_init(dsl_pool_t *dp, uint64_t txg) +{ + int err; + dsl_scan_t *scn; + spa_t *spa = dp->dp_spa; + uint64_t f; + + scn = dp->dp_scan = kmem_zalloc(sizeof (dsl_scan_t), KM_SLEEP); + scn->scn_dp = dp; + + /* + * It's possible that we're resuming a scan after a reboot so + * make sure that the scan_async_destroying flag is initialized + * appropriately. + */ + ASSERT(!scn->scn_async_destroying); + scn->scn_async_destroying = spa_feature_is_active(dp->dp_spa, + SPA_FEATURE_ASYNC_DESTROY); + + err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, + "scrub_func", sizeof (uint64_t), 1, &f); + if (err == 0) { + /* + * There was an old-style scrub in progress. Restart a + * new-style scrub from the beginning. + */ + scn->scn_restart_txg = txg; + zfs_dbgmsg("old-style scrub was in progress; " + "restarting new-style scrub in txg %llu", + scn->scn_restart_txg); + + /* + * Load the queue obj from the old location so that it + * can be freed by dsl_scan_done(). + */ + (void) zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, + "scrub_queue", sizeof (uint64_t), 1, + &scn->scn_phys.scn_queue_obj); + } else { + err = zap_lookup(dp->dp_meta_objset, DMU_POOL_DIRECTORY_OBJECT, + DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS, + &scn->scn_phys); + if (err == ENOENT) + return (0); + else if (err) + return (err); + + if (scn->scn_phys.scn_state == DSS_SCANNING && + spa_prev_software_version(dp->dp_spa) < SPA_VERSION_SCAN) { + /* + * A new-type scrub was in progress on an old + * pool, and the pool was accessed by old + * software. Restart from the beginning, since + * the old software may have changed the pool in + * the meantime. + */ + scn->scn_restart_txg = txg; + zfs_dbgmsg("new-style scrub was modified " + "by old software; restarting in txg %llu", + scn->scn_restart_txg); + } + } + + spa_scan_stat_init(spa); + return (0); +} + +void +dsl_scan_fini(dsl_pool_t *dp) +{ + if (dp->dp_scan) { + kmem_free(dp->dp_scan, sizeof (dsl_scan_t)); + dp->dp_scan = NULL; + } +} + +/* ARGSUSED */ +static int +dsl_scan_setup_check(void *arg, dmu_tx_t *tx) +{ + dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; + + if (scn->scn_phys.scn_state == DSS_SCANNING) + return (SET_ERROR(EBUSY)); + + return (0); +} + +static void +dsl_scan_setup_sync(void *arg, dmu_tx_t *tx) +{ + dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; + pool_scan_func_t *funcp = arg; + dmu_object_type_t ot = 0; + dsl_pool_t *dp = scn->scn_dp; + spa_t *spa = dp->dp_spa; + + ASSERT(scn->scn_phys.scn_state != DSS_SCANNING); + ASSERT(*funcp > POOL_SCAN_NONE && *funcp < POOL_SCAN_FUNCS); + bzero(&scn->scn_phys, sizeof (scn->scn_phys)); + scn->scn_phys.scn_func = *funcp; + scn->scn_phys.scn_state = DSS_SCANNING; + scn->scn_phys.scn_min_txg = 0; + scn->scn_phys.scn_max_txg = tx->tx_txg; + scn->scn_phys.scn_ddt_class_max = DDT_CLASSES - 1; /* the entire DDT */ + scn->scn_phys.scn_start_time = gethrestime_sec(); + scn->scn_phys.scn_errors = 0; + scn->scn_phys.scn_to_examine = spa->spa_root_vdev->vdev_stat.vs_alloc; + scn->scn_restart_txg = 0; + scn->scn_done_txg = 0; + spa_scan_stat_init(spa); + + if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { + scn->scn_phys.scn_ddt_class_max = zfs_scrub_ddt_class_max; + + /* rewrite all disk labels */ + vdev_config_dirty(spa->spa_root_vdev); + + if (vdev_resilver_needed(spa->spa_root_vdev, + &scn->scn_phys.scn_min_txg, &scn->scn_phys.scn_max_txg)) { + spa_event_notify(spa, NULL, ESC_ZFS_RESILVER_START); + } else { + spa_event_notify(spa, NULL, ESC_ZFS_SCRUB_START); + } + + spa->spa_scrub_started = B_TRUE; + /* + * If this is an incremental scrub, limit the DDT scrub phase + * to just the auto-ditto class (for correctness); the rest + * of the scrub should go faster using top-down pruning. + */ + if (scn->scn_phys.scn_min_txg > TXG_INITIAL) + scn->scn_phys.scn_ddt_class_max = DDT_CLASS_DITTO; + + } + + /* back to the generic stuff */ + + if (dp->dp_blkstats == NULL) { + dp->dp_blkstats = + kmem_alloc(sizeof (zfs_all_blkstats_t), KM_SLEEP); + } + bzero(dp->dp_blkstats, sizeof (zfs_all_blkstats_t)); + + if (spa_version(spa) < SPA_VERSION_DSL_SCRUB) + ot = DMU_OT_ZAP_OTHER; + + scn->scn_phys.scn_queue_obj = zap_create(dp->dp_meta_objset, + ot ? ot : DMU_OT_SCAN_QUEUE, DMU_OT_NONE, 0, tx); + + dsl_scan_sync_state(scn, tx); + + spa_history_log_internal(spa, "scan setup", tx, + "func=%u mintxg=%llu maxtxg=%llu", + *funcp, scn->scn_phys.scn_min_txg, scn->scn_phys.scn_max_txg); +} + +/* ARGSUSED */ +static void +dsl_scan_done(dsl_scan_t *scn, boolean_t complete, dmu_tx_t *tx) +{ + static const char *old_names[] = { + "scrub_bookmark", + "scrub_ddt_bookmark", + "scrub_ddt_class_max", + "scrub_queue", + "scrub_min_txg", + "scrub_max_txg", + "scrub_func", + "scrub_errors", + NULL + }; + + dsl_pool_t *dp = scn->scn_dp; + spa_t *spa = dp->dp_spa; + int i; + + /* Remove any remnants of an old-style scrub. */ + for (i = 0; old_names[i]; i++) { + (void) zap_remove(dp->dp_meta_objset, + DMU_POOL_DIRECTORY_OBJECT, old_names[i], tx); + } + + if (scn->scn_phys.scn_queue_obj != 0) { + VERIFY(0 == dmu_object_free(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, tx)); + scn->scn_phys.scn_queue_obj = 0; + } + + /* + * If we were "restarted" from a stopped state, don't bother + * with anything else. + */ + if (scn->scn_phys.scn_state != DSS_SCANNING) + return; + + if (complete) + scn->scn_phys.scn_state = DSS_FINISHED; + else + scn->scn_phys.scn_state = DSS_CANCELED; + + spa_history_log_internal(spa, "scan done", tx, + "complete=%u", complete); + + if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { + mutex_enter(&spa->spa_scrub_lock); + while (spa->spa_scrub_inflight > 0) { + cv_wait(&spa->spa_scrub_io_cv, + &spa->spa_scrub_lock); + } + mutex_exit(&spa->spa_scrub_lock); + spa->spa_scrub_started = B_FALSE; + spa->spa_scrub_active = B_FALSE; + + /* + * If the scrub/resilver completed, update all DTLs to + * reflect this. Whether it succeeded or not, vacate + * all temporary scrub DTLs. + */ + vdev_dtl_reassess(spa->spa_root_vdev, tx->tx_txg, + complete ? scn->scn_phys.scn_max_txg : 0, B_TRUE); + if (complete) { + spa_event_notify(spa, NULL, scn->scn_phys.scn_min_txg ? + ESC_ZFS_RESILVER_FINISH : ESC_ZFS_SCRUB_FINISH); + } + spa_errlog_rotate(spa); + + /* + * We may have finished replacing a device. + * Let the async thread assess this and handle the detach. + */ + spa_async_request(spa, SPA_ASYNC_RESILVER_DONE); + } + + scn->scn_phys.scn_end_time = gethrestime_sec(); +} + +/* ARGSUSED */ +static int +dsl_scan_cancel_check(void *arg, dmu_tx_t *tx) +{ + dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; + + if (scn->scn_phys.scn_state != DSS_SCANNING) + return (SET_ERROR(ENOENT)); + return (0); +} + +/* ARGSUSED */ +static void +dsl_scan_cancel_sync(void *arg, dmu_tx_t *tx) +{ + dsl_scan_t *scn = dmu_tx_pool(tx)->dp_scan; + + dsl_scan_done(scn, B_FALSE, tx); + dsl_scan_sync_state(scn, tx); +} + +int +dsl_scan_cancel(dsl_pool_t *dp) +{ + return (dsl_sync_task(spa_name(dp->dp_spa), dsl_scan_cancel_check, + dsl_scan_cancel_sync, NULL, 3)); +} + +static void dsl_scan_visitbp(blkptr_t *bp, + const zbookmark_t *zb, dnode_phys_t *dnp, arc_buf_t *pbuf, + dsl_dataset_t *ds, dsl_scan_t *scn, dmu_objset_type_t ostype, + dmu_tx_t *tx); +static void dsl_scan_visitdnode(dsl_scan_t *, dsl_dataset_t *ds, + dmu_objset_type_t ostype, + dnode_phys_t *dnp, arc_buf_t *buf, uint64_t object, dmu_tx_t *tx); + +void +dsl_free(dsl_pool_t *dp, uint64_t txg, const blkptr_t *bp) +{ + zio_free(dp->dp_spa, txg, bp); +} + +void +dsl_free_sync(zio_t *pio, dsl_pool_t *dp, uint64_t txg, const blkptr_t *bpp) +{ + ASSERT(dsl_pool_sync_context(dp)); + zio_nowait(zio_free_sync(pio, dp->dp_spa, txg, bpp, BP_GET_PSIZE(bpp), + pio->io_flags)); +} + +static uint64_t +dsl_scan_ds_maxtxg(dsl_dataset_t *ds) +{ + uint64_t smt = ds->ds_dir->dd_pool->dp_scan->scn_phys.scn_max_txg; + if (dsl_dataset_is_snapshot(ds)) + return (MIN(smt, ds->ds_phys->ds_creation_txg)); + return (smt); +} + +static void +dsl_scan_sync_state(dsl_scan_t *scn, dmu_tx_t *tx) +{ + VERIFY0(zap_update(scn->scn_dp->dp_meta_objset, + DMU_POOL_DIRECTORY_OBJECT, + DMU_POOL_SCAN, sizeof (uint64_t), SCAN_PHYS_NUMINTS, + &scn->scn_phys, tx)); +} + +static boolean_t +dsl_scan_check_pause(dsl_scan_t *scn, const zbookmark_t *zb) +{ + uint64_t elapsed_nanosecs; + unsigned int mintime; + + /* we never skip user/group accounting objects */ + if (zb && (int64_t)zb->zb_object < 0) + return (B_FALSE); + + if (scn->scn_pausing) + return (B_TRUE); /* we're already pausing */ + + if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark)) + return (B_FALSE); /* we're resuming */ + + /* We only know how to resume from level-0 blocks. */ + if (zb && zb->zb_level != 0) + return (B_FALSE); + + mintime = (scn->scn_phys.scn_func == POOL_SCAN_RESILVER) ? + zfs_resilver_min_time_ms : zfs_scan_min_time_ms; + elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time; + if (elapsed_nanosecs / NANOSEC > zfs_txg_timeout || + (NSEC2MSEC(elapsed_nanosecs) > mintime && + txg_sync_waiting(scn->scn_dp)) || + spa_shutting_down(scn->scn_dp->dp_spa)) { + if (zb) { + dprintf("pausing at bookmark %llx/%llx/%llx/%llx\n", + (longlong_t)zb->zb_objset, + (longlong_t)zb->zb_object, + (longlong_t)zb->zb_level, + (longlong_t)zb->zb_blkid); + scn->scn_phys.scn_bookmark = *zb; + } + dprintf("pausing at DDT bookmark %llx/%llx/%llx/%llx\n", + (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_class, + (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_type, + (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_checksum, + (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_cursor); + scn->scn_pausing = B_TRUE; + return (B_TRUE); + } + return (B_FALSE); +} + +typedef struct zil_scan_arg { + dsl_pool_t *zsa_dp; + zil_header_t *zsa_zh; +} zil_scan_arg_t; + +/* ARGSUSED */ +static int +dsl_scan_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) +{ + zil_scan_arg_t *zsa = arg; + dsl_pool_t *dp = zsa->zsa_dp; + dsl_scan_t *scn = dp->dp_scan; + zil_header_t *zh = zsa->zsa_zh; + zbookmark_t zb; + + if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) + return (0); + + /* + * One block ("stubby") can be allocated a long time ago; we + * want to visit that one because it has been allocated + * (on-disk) even if it hasn't been claimed (even though for + * scrub there's nothing to do to it). + */ + if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(dp->dp_spa)) + return (0); + + SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET], + ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); + + VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb)); + return (0); +} + +/* ARGSUSED */ +static int +dsl_scan_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg) +{ + if (lrc->lrc_txtype == TX_WRITE) { + zil_scan_arg_t *zsa = arg; + dsl_pool_t *dp = zsa->zsa_dp; + dsl_scan_t *scn = dp->dp_scan; + zil_header_t *zh = zsa->zsa_zh; + lr_write_t *lr = (lr_write_t *)lrc; + blkptr_t *bp = &lr->lr_blkptr; + zbookmark_t zb; + + if (BP_IS_HOLE(bp) || + bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) + return (0); + + /* + * birth can be < claim_txg if this record's txg is + * already txg sync'ed (but this log block contains + * other records that are not synced) + */ + if (claim_txg == 0 || bp->blk_birth < claim_txg) + return (0); + + SET_BOOKMARK(&zb, zh->zh_log.blk_cksum.zc_word[ZIL_ZC_OBJSET], + lr->lr_foid, ZB_ZIL_LEVEL, + lr->lr_offset / BP_GET_LSIZE(bp)); + + VERIFY(0 == scan_funcs[scn->scn_phys.scn_func](dp, bp, &zb)); + } + return (0); +} + +static void +dsl_scan_zil(dsl_pool_t *dp, zil_header_t *zh) +{ + uint64_t claim_txg = zh->zh_claim_txg; + zil_scan_arg_t zsa = { dp, zh }; + zilog_t *zilog; + + /* + * We only want to visit blocks that have been claimed but not yet + * replayed (or, in read-only mode, blocks that *would* be claimed). + */ + if (claim_txg == 0 && spa_writeable(dp->dp_spa)) + return; + + zilog = zil_alloc(dp->dp_meta_objset, zh); + + (void) zil_parse(zilog, dsl_scan_zil_block, dsl_scan_zil_record, &zsa, + claim_txg); + + zil_free(zilog); +} + +/* ARGSUSED */ +static void +dsl_scan_prefetch(dsl_scan_t *scn, arc_buf_t *buf, blkptr_t *bp, + uint64_t objset, uint64_t object, uint64_t blkid) +{ + zbookmark_t czb; + uint32_t flags = ARC_NOWAIT | ARC_PREFETCH; + + if (zfs_no_scrub_prefetch) + return; + + if (BP_IS_HOLE(bp) || bp->blk_birth <= scn->scn_phys.scn_min_txg || + (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE)) + return; + + SET_BOOKMARK(&czb, objset, object, BP_GET_LEVEL(bp), blkid); + + (void) arc_read(scn->scn_zio_root, scn->scn_dp->dp_spa, bp, + NULL, NULL, ZIO_PRIORITY_ASYNC_READ, + ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD, &flags, &czb); +} + +static boolean_t +dsl_scan_check_resume(dsl_scan_t *scn, const dnode_phys_t *dnp, + const zbookmark_t *zb) +{ + /* + * We never skip over user/group accounting objects (obj<0) + */ + if (!ZB_IS_ZERO(&scn->scn_phys.scn_bookmark) && + (int64_t)zb->zb_object >= 0) { + /* + * If we already visited this bp & everything below (in + * a prior txg sync), don't bother doing it again. + */ + if (zbookmark_is_before(dnp, zb, &scn->scn_phys.scn_bookmark)) + return (B_TRUE); + + /* + * If we found the block we're trying to resume from, or + * we went past it to a different object, zero it out to + * indicate that it's OK to start checking for pausing + * again. + */ + if (bcmp(zb, &scn->scn_phys.scn_bookmark, sizeof (*zb)) == 0 || + zb->zb_object > scn->scn_phys.scn_bookmark.zb_object) { + dprintf("resuming at %llx/%llx/%llx/%llx\n", + (longlong_t)zb->zb_objset, + (longlong_t)zb->zb_object, + (longlong_t)zb->zb_level, + (longlong_t)zb->zb_blkid); + bzero(&scn->scn_phys.scn_bookmark, sizeof (*zb)); + } + } + return (B_FALSE); +} + +/* + * Return nonzero on i/o error. + * Return new buf to write out in *bufp. + */ +static int +dsl_scan_recurse(dsl_scan_t *scn, dsl_dataset_t *ds, dmu_objset_type_t ostype, + dnode_phys_t *dnp, const blkptr_t *bp, + const zbookmark_t *zb, dmu_tx_t *tx, arc_buf_t **bufp) +{ + dsl_pool_t *dp = scn->scn_dp; + int zio_flags = ZIO_FLAG_CANFAIL | ZIO_FLAG_SCAN_THREAD; + int err; + + if (BP_GET_LEVEL(bp) > 0) { + uint32_t flags = ARC_WAIT; + int i; + blkptr_t *cbp; + int epb = BP_GET_LSIZE(bp) >> SPA_BLKPTRSHIFT; + + err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, bufp, + ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); + if (err) { + scn->scn_phys.scn_errors++; + return (err); + } + for (i = 0, cbp = (*bufp)->b_data; i < epb; i++, cbp++) { + dsl_scan_prefetch(scn, *bufp, cbp, zb->zb_objset, + zb->zb_object, zb->zb_blkid * epb + i); + } + for (i = 0, cbp = (*bufp)->b_data; i < epb; i++, cbp++) { + zbookmark_t czb; + + SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object, + zb->zb_level - 1, + zb->zb_blkid * epb + i); + dsl_scan_visitbp(cbp, &czb, dnp, + *bufp, ds, scn, ostype, tx); + } + } else if (BP_GET_TYPE(bp) == DMU_OT_USERGROUP_USED) { + uint32_t flags = ARC_WAIT; + + err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, bufp, + ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); + if (err) { + scn->scn_phys.scn_errors++; + return (err); + } + } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) { + uint32_t flags = ARC_WAIT; + dnode_phys_t *cdnp; + int i, j; + int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT; + + err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, bufp, + ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); + if (err) { + scn->scn_phys.scn_errors++; + return (err); + } + for (i = 0, cdnp = (*bufp)->b_data; i < epb; i++, cdnp++) { + for (j = 0; j < cdnp->dn_nblkptr; j++) { + blkptr_t *cbp = &cdnp->dn_blkptr[j]; + dsl_scan_prefetch(scn, *bufp, cbp, + zb->zb_objset, zb->zb_blkid * epb + i, j); + } + } + for (i = 0, cdnp = (*bufp)->b_data; i < epb; i++, cdnp++) { + dsl_scan_visitdnode(scn, ds, ostype, + cdnp, *bufp, zb->zb_blkid * epb + i, tx); + } + + } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) { + uint32_t flags = ARC_WAIT; + objset_phys_t *osp; + + err = arc_read(NULL, dp->dp_spa, bp, arc_getbuf_func, bufp, + ZIO_PRIORITY_ASYNC_READ, zio_flags, &flags, zb); + if (err) { + scn->scn_phys.scn_errors++; + return (err); + } + + osp = (*bufp)->b_data; + + dsl_scan_visitdnode(scn, ds, osp->os_type, + &osp->os_meta_dnode, *bufp, DMU_META_DNODE_OBJECT, tx); + + if (OBJSET_BUF_HAS_USERUSED(*bufp)) { + /* + * We also always visit user/group accounting + * objects, and never skip them, even if we are + * pausing. This is necessary so that the space + * deltas from this txg get integrated. + */ + dsl_scan_visitdnode(scn, ds, osp->os_type, + &osp->os_groupused_dnode, *bufp, + DMU_GROUPUSED_OBJECT, tx); + dsl_scan_visitdnode(scn, ds, osp->os_type, + &osp->os_userused_dnode, *bufp, + DMU_USERUSED_OBJECT, tx); + } + } + + return (0); +} + +static void +dsl_scan_visitdnode(dsl_scan_t *scn, dsl_dataset_t *ds, + dmu_objset_type_t ostype, dnode_phys_t *dnp, arc_buf_t *buf, + uint64_t object, dmu_tx_t *tx) +{ + int j; + + for (j = 0; j < dnp->dn_nblkptr; j++) { + zbookmark_t czb; + + SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object, + dnp->dn_nlevels - 1, j); + dsl_scan_visitbp(&dnp->dn_blkptr[j], + &czb, dnp, buf, ds, scn, ostype, tx); + } + + if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { + zbookmark_t czb; + SET_BOOKMARK(&czb, ds ? ds->ds_object : 0, object, + 0, DMU_SPILL_BLKID); + dsl_scan_visitbp(&dnp->dn_spill, + &czb, dnp, buf, ds, scn, ostype, tx); + } +} + +/* + * The arguments are in this order because mdb can only print the + * first 5; we want them to be useful. + */ +static void +dsl_scan_visitbp(blkptr_t *bp, const zbookmark_t *zb, + dnode_phys_t *dnp, arc_buf_t *pbuf, + dsl_dataset_t *ds, dsl_scan_t *scn, dmu_objset_type_t ostype, + dmu_tx_t *tx) +{ + dsl_pool_t *dp = scn->scn_dp; + arc_buf_t *buf = NULL; + blkptr_t bp_toread = *bp; + + /* ASSERT(pbuf == NULL || arc_released(pbuf)); */ + + if (dsl_scan_check_pause(scn, zb)) + return; + + if (dsl_scan_check_resume(scn, dnp, zb)) + return; + + if (BP_IS_HOLE(bp)) + return; + + scn->scn_visited_this_txg++; + + dprintf_bp(bp, + "visiting ds=%p/%llu zb=%llx/%llx/%llx/%llx buf=%p bp=%p", + ds, ds ? ds->ds_object : 0, + zb->zb_objset, zb->zb_object, zb->zb_level, zb->zb_blkid, + pbuf, bp); + + if (bp->blk_birth <= scn->scn_phys.scn_cur_min_txg) + return; + + if (dsl_scan_recurse(scn, ds, ostype, dnp, &bp_toread, zb, tx, + &buf) != 0) + return; + + /* + * If dsl_scan_ddt() has aready visited this block, it will have + * already done any translations or scrubbing, so don't call the + * callback again. + */ + if (ddt_class_contains(dp->dp_spa, + scn->scn_phys.scn_ddt_class_max, bp)) { + ASSERT(buf == NULL); + return; + } + + /* + * If this block is from the future (after cur_max_txg), then we + * are doing this on behalf of a deleted snapshot, and we will + * revisit the future block on the next pass of this dataset. + * Don't scan it now unless we need to because something + * under it was modified. + */ + if (BP_PHYSICAL_BIRTH(bp) <= scn->scn_phys.scn_cur_max_txg) { + scan_funcs[scn->scn_phys.scn_func](dp, bp, zb); + } + if (buf) + (void) arc_buf_remove_ref(buf, &buf); +} + +static void +dsl_scan_visit_rootbp(dsl_scan_t *scn, dsl_dataset_t *ds, blkptr_t *bp, + dmu_tx_t *tx) +{ + zbookmark_t zb; + + SET_BOOKMARK(&zb, ds ? ds->ds_object : DMU_META_OBJSET, + ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID); + dsl_scan_visitbp(bp, &zb, NULL, NULL, + ds, scn, DMU_OST_NONE, tx); + + dprintf_ds(ds, "finished scan%s", ""); +} + +void +dsl_scan_ds_destroyed(dsl_dataset_t *ds, dmu_tx_t *tx) +{ + dsl_pool_t *dp = ds->ds_dir->dd_pool; + dsl_scan_t *scn = dp->dp_scan; + uint64_t mintxg; + + if (scn->scn_phys.scn_state != DSS_SCANNING) + return; + + if (scn->scn_phys.scn_bookmark.zb_objset == ds->ds_object) { + if (dsl_dataset_is_snapshot(ds)) { + /* Note, scn_cur_{min,max}_txg stays the same. */ + scn->scn_phys.scn_bookmark.zb_objset = + ds->ds_phys->ds_next_snap_obj; + zfs_dbgmsg("destroying ds %llu; currently traversing; " + "reset zb_objset to %llu", + (u_longlong_t)ds->ds_object, + (u_longlong_t)ds->ds_phys->ds_next_snap_obj); + scn->scn_phys.scn_flags |= DSF_VISIT_DS_AGAIN; + } else { + SET_BOOKMARK(&scn->scn_phys.scn_bookmark, + ZB_DESTROYED_OBJSET, 0, 0, 0); + zfs_dbgmsg("destroying ds %llu; currently traversing; " + "reset bookmark to -1,0,0,0", + (u_longlong_t)ds->ds_object); + } + } else if (zap_lookup_int_key(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, ds->ds_object, &mintxg) == 0) { + ASSERT3U(ds->ds_phys->ds_num_children, <=, 1); + VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, ds->ds_object, tx)); + if (dsl_dataset_is_snapshot(ds)) { + /* + * We keep the same mintxg; it could be > + * ds_creation_txg if the previous snapshot was + * deleted too. + */ + VERIFY(zap_add_int_key(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, + ds->ds_phys->ds_next_snap_obj, mintxg, tx) == 0); + zfs_dbgmsg("destroying ds %llu; in queue; " + "replacing with %llu", + (u_longlong_t)ds->ds_object, + (u_longlong_t)ds->ds_phys->ds_next_snap_obj); + } else { + zfs_dbgmsg("destroying ds %llu; in queue; removing", + (u_longlong_t)ds->ds_object); + } + } else { + zfs_dbgmsg("destroying ds %llu; ignoring", + (u_longlong_t)ds->ds_object); + } + + /* + * dsl_scan_sync() should be called after this, and should sync + * out our changed state, but just to be safe, do it here. + */ + dsl_scan_sync_state(scn, tx); +} + +void +dsl_scan_ds_snapshotted(dsl_dataset_t *ds, dmu_tx_t *tx) +{ + dsl_pool_t *dp = ds->ds_dir->dd_pool; + dsl_scan_t *scn = dp->dp_scan; + uint64_t mintxg; + + if (scn->scn_phys.scn_state != DSS_SCANNING) + return; + + ASSERT(ds->ds_phys->ds_prev_snap_obj != 0); + + if (scn->scn_phys.scn_bookmark.zb_objset == ds->ds_object) { + scn->scn_phys.scn_bookmark.zb_objset = + ds->ds_phys->ds_prev_snap_obj; + zfs_dbgmsg("snapshotting ds %llu; currently traversing; " + "reset zb_objset to %llu", + (u_longlong_t)ds->ds_object, + (u_longlong_t)ds->ds_phys->ds_prev_snap_obj); + } else if (zap_lookup_int_key(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, ds->ds_object, &mintxg) == 0) { + VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, ds->ds_object, tx)); + VERIFY(zap_add_int_key(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, + ds->ds_phys->ds_prev_snap_obj, mintxg, tx) == 0); + zfs_dbgmsg("snapshotting ds %llu; in queue; " + "replacing with %llu", + (u_longlong_t)ds->ds_object, + (u_longlong_t)ds->ds_phys->ds_prev_snap_obj); + } + dsl_scan_sync_state(scn, tx); +} + +void +dsl_scan_ds_clone_swapped(dsl_dataset_t *ds1, dsl_dataset_t *ds2, dmu_tx_t *tx) +{ + dsl_pool_t *dp = ds1->ds_dir->dd_pool; + dsl_scan_t *scn = dp->dp_scan; + uint64_t mintxg; + + if (scn->scn_phys.scn_state != DSS_SCANNING) + return; + + if (scn->scn_phys.scn_bookmark.zb_objset == ds1->ds_object) { + scn->scn_phys.scn_bookmark.zb_objset = ds2->ds_object; + zfs_dbgmsg("clone_swap ds %llu; currently traversing; " + "reset zb_objset to %llu", + (u_longlong_t)ds1->ds_object, + (u_longlong_t)ds2->ds_object); + } else if (scn->scn_phys.scn_bookmark.zb_objset == ds2->ds_object) { + scn->scn_phys.scn_bookmark.zb_objset = ds1->ds_object; + zfs_dbgmsg("clone_swap ds %llu; currently traversing; " + "reset zb_objset to %llu", + (u_longlong_t)ds2->ds_object, + (u_longlong_t)ds1->ds_object); + } + + if (zap_lookup_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj, + ds1->ds_object, &mintxg) == 0) { + int err; + + ASSERT3U(mintxg, ==, ds1->ds_phys->ds_prev_snap_txg); + ASSERT3U(mintxg, ==, ds2->ds_phys->ds_prev_snap_txg); + VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, ds1->ds_object, tx)); + err = zap_add_int_key(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, ds2->ds_object, mintxg, tx); + VERIFY(err == 0 || err == EEXIST); + if (err == EEXIST) { + /* Both were there to begin with */ + VERIFY(0 == zap_add_int_key(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, + ds1->ds_object, mintxg, tx)); + } + zfs_dbgmsg("clone_swap ds %llu; in queue; " + "replacing with %llu", + (u_longlong_t)ds1->ds_object, + (u_longlong_t)ds2->ds_object); + } else if (zap_lookup_int_key(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, ds2->ds_object, &mintxg) == 0) { + ASSERT3U(mintxg, ==, ds1->ds_phys->ds_prev_snap_txg); + ASSERT3U(mintxg, ==, ds2->ds_phys->ds_prev_snap_txg); + VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, ds2->ds_object, tx)); + VERIFY(0 == zap_add_int_key(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, ds1->ds_object, mintxg, tx)); + zfs_dbgmsg("clone_swap ds %llu; in queue; " + "replacing with %llu", + (u_longlong_t)ds2->ds_object, + (u_longlong_t)ds1->ds_object); + } + + dsl_scan_sync_state(scn, tx); +} + +struct enqueue_clones_arg { + dmu_tx_t *tx; + uint64_t originobj; +}; + +/* ARGSUSED */ +static int +enqueue_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg) +{ + struct enqueue_clones_arg *eca = arg; + dsl_dataset_t *ds; + int err; + dsl_scan_t *scn = dp->dp_scan; + + if (hds->ds_dir->dd_phys->dd_origin_obj != eca->originobj) + return (0); + + err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds); + if (err) + return (err); + + while (ds->ds_phys->ds_prev_snap_obj != eca->originobj) { + dsl_dataset_t *prev; + err = dsl_dataset_hold_obj(dp, + ds->ds_phys->ds_prev_snap_obj, FTAG, &prev); + + dsl_dataset_rele(ds, FTAG); + if (err) + return (err); + ds = prev; + } + VERIFY(zap_add_int_key(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, ds->ds_object, + ds->ds_phys->ds_prev_snap_txg, eca->tx) == 0); + dsl_dataset_rele(ds, FTAG); + return (0); +} + +static void +dsl_scan_visitds(dsl_scan_t *scn, uint64_t dsobj, dmu_tx_t *tx) +{ + dsl_pool_t *dp = scn->scn_dp; + dsl_dataset_t *ds; + objset_t *os; + + VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); + + if (dmu_objset_from_ds(ds, &os)) + goto out; + + /* + * Only the ZIL in the head (non-snapshot) is valid. Even though + * snapshots can have ZIL block pointers (which may be the same + * BP as in the head), they must be ignored. So we traverse the + * ZIL here, rather than in scan_recurse(), because the regular + * snapshot block-sharing rules don't apply to it. + */ + if (DSL_SCAN_IS_SCRUB_RESILVER(scn) && !dsl_dataset_is_snapshot(ds)) + dsl_scan_zil(dp, &os->os_zil_header); + + /* + * Iterate over the bps in this ds. + */ + dmu_buf_will_dirty(ds->ds_dbuf, tx); + dsl_scan_visit_rootbp(scn, ds, &ds->ds_phys->ds_bp, tx); + + char *dsname = kmem_alloc(ZFS_MAXNAMELEN, KM_SLEEP); + dsl_dataset_name(ds, dsname); + zfs_dbgmsg("scanned dataset %llu (%s) with min=%llu max=%llu; " + "pausing=%u", + (longlong_t)dsobj, dsname, + (longlong_t)scn->scn_phys.scn_cur_min_txg, + (longlong_t)scn->scn_phys.scn_cur_max_txg, + (int)scn->scn_pausing); + kmem_free(dsname, ZFS_MAXNAMELEN); + + if (scn->scn_pausing) + goto out; + + /* + * We've finished this pass over this dataset. + */ + + /* + * If we did not completely visit this dataset, do another pass. + */ + if (scn->scn_phys.scn_flags & DSF_VISIT_DS_AGAIN) { + zfs_dbgmsg("incomplete pass; visiting again"); + scn->scn_phys.scn_flags &= ~DSF_VISIT_DS_AGAIN; + VERIFY(zap_add_int_key(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, ds->ds_object, + scn->scn_phys.scn_cur_max_txg, tx) == 0); + goto out; + } + + /* + * Add descendent datasets to work queue. + */ + if (ds->ds_phys->ds_next_snap_obj != 0) { + VERIFY(zap_add_int_key(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, ds->ds_phys->ds_next_snap_obj, + ds->ds_phys->ds_creation_txg, tx) == 0); + } + if (ds->ds_phys->ds_num_children > 1) { + boolean_t usenext = B_FALSE; + if (ds->ds_phys->ds_next_clones_obj != 0) { + uint64_t count; + /* + * A bug in a previous version of the code could + * cause upgrade_clones_cb() to not set + * ds_next_snap_obj when it should, leading to a + * missing entry. Therefore we can only use the + * next_clones_obj when its count is correct. + */ + int err = zap_count(dp->dp_meta_objset, + ds->ds_phys->ds_next_clones_obj, &count); + if (err == 0 && + count == ds->ds_phys->ds_num_children - 1) + usenext = B_TRUE; + } + + if (usenext) { + VERIFY0(zap_join_key(dp->dp_meta_objset, + ds->ds_phys->ds_next_clones_obj, + scn->scn_phys.scn_queue_obj, + ds->ds_phys->ds_creation_txg, tx)); + } else { + struct enqueue_clones_arg eca; + eca.tx = tx; + eca.originobj = ds->ds_object; + + VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, + enqueue_clones_cb, &eca, DS_FIND_CHILDREN)); + } + } + +out: + dsl_dataset_rele(ds, FTAG); +} + +/* ARGSUSED */ +static int +enqueue_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg) +{ + dmu_tx_t *tx = arg; + dsl_dataset_t *ds; + int err; + dsl_scan_t *scn = dp->dp_scan; + + err = dsl_dataset_hold_obj(dp, hds->ds_object, FTAG, &ds); + if (err) + return (err); + + while (ds->ds_phys->ds_prev_snap_obj != 0) { + dsl_dataset_t *prev; + err = dsl_dataset_hold_obj(dp, ds->ds_phys->ds_prev_snap_obj, + FTAG, &prev); + if (err) { + dsl_dataset_rele(ds, FTAG); + return (err); + } + + /* + * If this is a clone, we don't need to worry about it for now. + */ + if (prev->ds_phys->ds_next_snap_obj != ds->ds_object) { + dsl_dataset_rele(ds, FTAG); + dsl_dataset_rele(prev, FTAG); + return (0); + } + dsl_dataset_rele(ds, FTAG); + ds = prev; + } + + VERIFY(zap_add_int_key(dp->dp_meta_objset, scn->scn_phys.scn_queue_obj, + ds->ds_object, ds->ds_phys->ds_prev_snap_txg, tx) == 0); + dsl_dataset_rele(ds, FTAG); + return (0); +} + +/* + * Scrub/dedup interaction. + * + * If there are N references to a deduped block, we don't want to scrub it + * N times -- ideally, we should scrub it exactly once. + * + * We leverage the fact that the dde's replication class (enum ddt_class) + * is ordered from highest replication class (DDT_CLASS_DITTO) to lowest + * (DDT_CLASS_UNIQUE) so that we may walk the DDT in that order. + * + * To prevent excess scrubbing, the scrub begins by walking the DDT + * to find all blocks with refcnt > 1, and scrubs each of these once. + * Since there are two replication classes which contain blocks with + * refcnt > 1, we scrub the highest replication class (DDT_CLASS_DITTO) first. + * Finally the top-down scrub begins, only visiting blocks with refcnt == 1. + * + * There would be nothing more to say if a block's refcnt couldn't change + * during a scrub, but of course it can so we must account for changes + * in a block's replication class. + * + * Here's an example of what can occur: + * + * If a block has refcnt > 1 during the DDT scrub phase, but has refcnt == 1 + * when visited during the top-down scrub phase, it will be scrubbed twice. + * This negates our scrub optimization, but is otherwise harmless. + * + * If a block has refcnt == 1 during the DDT scrub phase, but has refcnt > 1 + * on each visit during the top-down scrub phase, it will never be scrubbed. + * To catch this, ddt_sync_entry() notifies the scrub code whenever a block's + * reference class transitions to a higher level (i.e DDT_CLASS_UNIQUE to + * DDT_CLASS_DUPLICATE); if it transitions from refcnt == 1 to refcnt > 1 + * while a scrub is in progress, it scrubs the block right then. + */ +static void +dsl_scan_ddt(dsl_scan_t *scn, dmu_tx_t *tx) +{ + ddt_bookmark_t *ddb = &scn->scn_phys.scn_ddt_bookmark; + ddt_entry_t dde = { 0 }; + int error; + uint64_t n = 0; + + while ((error = ddt_walk(scn->scn_dp->dp_spa, ddb, &dde)) == 0) { + ddt_t *ddt; + + if (ddb->ddb_class > scn->scn_phys.scn_ddt_class_max) + break; + dprintf("visiting ddb=%llu/%llu/%llu/%llx\n", + (longlong_t)ddb->ddb_class, + (longlong_t)ddb->ddb_type, + (longlong_t)ddb->ddb_checksum, + (longlong_t)ddb->ddb_cursor); + + /* There should be no pending changes to the dedup table */ + ddt = scn->scn_dp->dp_spa->spa_ddt[ddb->ddb_checksum]; + ASSERT(avl_first(&ddt->ddt_tree) == NULL); + + dsl_scan_ddt_entry(scn, ddb->ddb_checksum, &dde, tx); + n++; + + if (dsl_scan_check_pause(scn, NULL)) + break; + } + + zfs_dbgmsg("scanned %llu ddt entries with class_max = %u; pausing=%u", + (longlong_t)n, (int)scn->scn_phys.scn_ddt_class_max, + (int)scn->scn_pausing); + + ASSERT(error == 0 || error == ENOENT); + ASSERT(error != ENOENT || + ddb->ddb_class > scn->scn_phys.scn_ddt_class_max); +} + +/* ARGSUSED */ +void +dsl_scan_ddt_entry(dsl_scan_t *scn, enum zio_checksum checksum, + ddt_entry_t *dde, dmu_tx_t *tx) +{ + const ddt_key_t *ddk = &dde->dde_key; + ddt_phys_t *ddp = dde->dde_phys; + blkptr_t bp; + zbookmark_t zb = { 0 }; + + if (scn->scn_phys.scn_state != DSS_SCANNING) + return; + + for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) { + if (ddp->ddp_phys_birth == 0 || + ddp->ddp_phys_birth > scn->scn_phys.scn_max_txg) + continue; + ddt_bp_create(checksum, ddk, ddp, &bp); + + scn->scn_visited_this_txg++; + scan_funcs[scn->scn_phys.scn_func](scn->scn_dp, &bp, &zb); + } +} + +static void +dsl_scan_visit(dsl_scan_t *scn, dmu_tx_t *tx) +{ + dsl_pool_t *dp = scn->scn_dp; + zap_cursor_t zc; + zap_attribute_t za; + + if (scn->scn_phys.scn_ddt_bookmark.ddb_class <= + scn->scn_phys.scn_ddt_class_max) { + scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg; + scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg; + dsl_scan_ddt(scn, tx); + if (scn->scn_pausing) + return; + } + + if (scn->scn_phys.scn_bookmark.zb_objset == DMU_META_OBJSET) { + /* First do the MOS & ORIGIN */ + + scn->scn_phys.scn_cur_min_txg = scn->scn_phys.scn_min_txg; + scn->scn_phys.scn_cur_max_txg = scn->scn_phys.scn_max_txg; + dsl_scan_visit_rootbp(scn, NULL, + &dp->dp_meta_rootbp, tx); + spa_set_rootblkptr(dp->dp_spa, &dp->dp_meta_rootbp); + if (scn->scn_pausing) + return; + + if (spa_version(dp->dp_spa) < SPA_VERSION_DSL_SCRUB) { + VERIFY0(dmu_objset_find_dp(dp, dp->dp_root_dir_obj, + enqueue_cb, tx, DS_FIND_CHILDREN)); + } else { + dsl_scan_visitds(scn, + dp->dp_origin_snap->ds_object, tx); + } + ASSERT(!scn->scn_pausing); + } else if (scn->scn_phys.scn_bookmark.zb_objset != + ZB_DESTROYED_OBJSET) { + /* + * If we were paused, continue from here. Note if the + * ds we were paused on was deleted, the zb_objset may + * be -1, so we will skip this and find a new objset + * below. + */ + dsl_scan_visitds(scn, scn->scn_phys.scn_bookmark.zb_objset, tx); + if (scn->scn_pausing) + return; + } + + /* + * In case we were paused right at the end of the ds, zero the + * bookmark so we don't think that we're still trying to resume. + */ + bzero(&scn->scn_phys.scn_bookmark, sizeof (zbookmark_t)); + + /* keep pulling things out of the zap-object-as-queue */ + while (zap_cursor_init(&zc, dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj), + zap_cursor_retrieve(&zc, &za) == 0) { + dsl_dataset_t *ds; + uint64_t dsobj; + + dsobj = strtonum(za.za_name, NULL); + VERIFY3U(0, ==, zap_remove_int(dp->dp_meta_objset, + scn->scn_phys.scn_queue_obj, dsobj, tx)); + + /* Set up min/max txg */ + VERIFY3U(0, ==, dsl_dataset_hold_obj(dp, dsobj, FTAG, &ds)); + if (za.za_first_integer != 0) { + scn->scn_phys.scn_cur_min_txg = + MAX(scn->scn_phys.scn_min_txg, + za.za_first_integer); + } else { + scn->scn_phys.scn_cur_min_txg = + MAX(scn->scn_phys.scn_min_txg, + ds->ds_phys->ds_prev_snap_txg); + } + scn->scn_phys.scn_cur_max_txg = dsl_scan_ds_maxtxg(ds); + dsl_dataset_rele(ds, FTAG); + + dsl_scan_visitds(scn, dsobj, tx); + zap_cursor_fini(&zc); + if (scn->scn_pausing) + return; + } + zap_cursor_fini(&zc); +} + +static boolean_t +dsl_scan_free_should_pause(dsl_scan_t *scn) +{ + uint64_t elapsed_nanosecs; + + if (zfs_recover) + return (B_FALSE); + + elapsed_nanosecs = gethrtime() - scn->scn_sync_start_time; + return (elapsed_nanosecs / NANOSEC > zfs_txg_timeout || + (NSEC2MSEC(elapsed_nanosecs) > zfs_free_min_time_ms && + txg_sync_waiting(scn->scn_dp)) || + spa_shutting_down(scn->scn_dp->dp_spa)); +} + +static int +dsl_scan_free_block_cb(void *arg, const blkptr_t *bp, dmu_tx_t *tx) +{ + dsl_scan_t *scn = arg; + + if (!scn->scn_is_bptree || + (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_OBJSET)) { + if (dsl_scan_free_should_pause(scn)) + return (SET_ERROR(ERESTART)); + } + + zio_nowait(zio_free_sync(scn->scn_zio_root, scn->scn_dp->dp_spa, + dmu_tx_get_txg(tx), bp, BP_GET_PSIZE(bp), 0)); + dsl_dir_diduse_space(tx->tx_pool->dp_free_dir, DD_USED_HEAD, + -bp_get_dsize_sync(scn->scn_dp->dp_spa, bp), + -BP_GET_PSIZE(bp), -BP_GET_UCSIZE(bp), tx); + scn->scn_visited_this_txg++; + return (0); +} + +boolean_t +dsl_scan_active(dsl_scan_t *scn) +{ + spa_t *spa = scn->scn_dp->dp_spa; + uint64_t used = 0, comp, uncomp; + + if (spa->spa_load_state != SPA_LOAD_NONE) + return (B_FALSE); + if (spa_shutting_down(spa)) + return (B_FALSE); + if (scn->scn_phys.scn_state == DSS_SCANNING || + scn->scn_async_destroying) + return (B_TRUE); + + if (spa_version(scn->scn_dp->dp_spa) >= SPA_VERSION_DEADLISTS) { + (void) bpobj_space(&scn->scn_dp->dp_free_bpobj, + &used, &comp, &uncomp); + } + return (used != 0); +} + +void +dsl_scan_sync(dsl_pool_t *dp, dmu_tx_t *tx) +{ + dsl_scan_t *scn = dp->dp_scan; + spa_t *spa = dp->dp_spa; + int err; + + /* + * Check for scn_restart_txg before checking spa_load_state, so + * that we can restart an old-style scan while the pool is being + * imported (see dsl_scan_init). + */ + if (scn->scn_restart_txg != 0 && + scn->scn_restart_txg <= tx->tx_txg) { + pool_scan_func_t func = POOL_SCAN_SCRUB; + dsl_scan_done(scn, B_FALSE, tx); + if (vdev_resilver_needed(spa->spa_root_vdev, NULL, NULL)) + func = POOL_SCAN_RESILVER; + zfs_dbgmsg("restarting scan func=%u txg=%llu", + func, tx->tx_txg); + dsl_scan_setup_sync(&func, tx); + } + + if (!dsl_scan_active(scn) || + spa_sync_pass(dp->dp_spa) > 1) + return; + + scn->scn_visited_this_txg = 0; + scn->scn_pausing = B_FALSE; + scn->scn_sync_start_time = gethrtime(); + spa->spa_scrub_active = B_TRUE; + + /* + * First process the free list. If we pause the free, don't do + * any scanning. This ensures that there is no free list when + * we are scanning, so the scan code doesn't have to worry about + * traversing it. + */ + if (spa_version(dp->dp_spa) >= SPA_VERSION_DEADLISTS) { + scn->scn_is_bptree = B_FALSE; + scn->scn_zio_root = zio_root(dp->dp_spa, NULL, + NULL, ZIO_FLAG_MUSTSUCCEED); + err = bpobj_iterate(&dp->dp_free_bpobj, + dsl_scan_free_block_cb, scn, tx); + VERIFY3U(0, ==, zio_wait(scn->scn_zio_root)); + + if (err == 0 && spa_feature_is_active(spa, + SPA_FEATURE_ASYNC_DESTROY)) { + ASSERT(scn->scn_async_destroying); + scn->scn_is_bptree = B_TRUE; + scn->scn_zio_root = zio_root(dp->dp_spa, NULL, + NULL, ZIO_FLAG_MUSTSUCCEED); + err = bptree_iterate(dp->dp_meta_objset, + dp->dp_bptree_obj, B_TRUE, dsl_scan_free_block_cb, + scn, tx); + VERIFY0(zio_wait(scn->scn_zio_root)); + + if (err == 0) { + /* finished; deactivate async destroy feature */ + spa_feature_decr(spa, SPA_FEATURE_ASYNC_DESTROY, + tx); + ASSERT(!spa_feature_is_active(spa, + SPA_FEATURE_ASYNC_DESTROY)); + VERIFY0(zap_remove(dp->dp_meta_objset, + DMU_POOL_DIRECTORY_OBJECT, + DMU_POOL_BPTREE_OBJ, tx)); + VERIFY0(bptree_free(dp->dp_meta_objset, + dp->dp_bptree_obj, tx)); + dp->dp_bptree_obj = 0; + scn->scn_async_destroying = B_FALSE; + } + } + if (scn->scn_visited_this_txg) { + zfs_dbgmsg("freed %llu blocks in %llums from " + "free_bpobj/bptree txg %llu", + (longlong_t)scn->scn_visited_this_txg, + (longlong_t) + NSEC2MSEC(gethrtime() - scn->scn_sync_start_time), + (longlong_t)tx->tx_txg); + scn->scn_visited_this_txg = 0; + /* + * Re-sync the ddt so that we can further modify + * it when doing bprewrite. + */ + ddt_sync(spa, tx->tx_txg); + } + if (err == ERESTART) + return; + /* finished; verify that space accounting went to zero */ + ASSERT0(dp->dp_free_dir->dd_phys->dd_used_bytes); + ASSERT0(dp->dp_free_dir->dd_phys->dd_compressed_bytes); + ASSERT0(dp->dp_free_dir->dd_phys->dd_uncompressed_bytes); + } + + if (scn->scn_phys.scn_state != DSS_SCANNING) + return; + + if (scn->scn_done_txg == tx->tx_txg) { + ASSERT(!scn->scn_pausing); + /* finished with scan. */ + zfs_dbgmsg("txg %llu scan complete", tx->tx_txg); + dsl_scan_done(scn, B_TRUE, tx); + ASSERT3U(spa->spa_scrub_inflight, ==, 0); + dsl_scan_sync_state(scn, tx); + return; + } + + if (scn->scn_phys.scn_ddt_bookmark.ddb_class <= + scn->scn_phys.scn_ddt_class_max) { + zfs_dbgmsg("doing scan sync txg %llu; " + "ddt bm=%llu/%llu/%llu/%llx", + (longlong_t)tx->tx_txg, + (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_class, + (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_type, + (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_checksum, + (longlong_t)scn->scn_phys.scn_ddt_bookmark.ddb_cursor); + ASSERT(scn->scn_phys.scn_bookmark.zb_objset == 0); + ASSERT(scn->scn_phys.scn_bookmark.zb_object == 0); + ASSERT(scn->scn_phys.scn_bookmark.zb_level == 0); + ASSERT(scn->scn_phys.scn_bookmark.zb_blkid == 0); + } else { + zfs_dbgmsg("doing scan sync txg %llu; bm=%llu/%llu/%llu/%llu", + (longlong_t)tx->tx_txg, + (longlong_t)scn->scn_phys.scn_bookmark.zb_objset, + (longlong_t)scn->scn_phys.scn_bookmark.zb_object, + (longlong_t)scn->scn_phys.scn_bookmark.zb_level, + (longlong_t)scn->scn_phys.scn_bookmark.zb_blkid); + } + + scn->scn_zio_root = zio_root(dp->dp_spa, NULL, + NULL, ZIO_FLAG_CANFAIL); + dsl_pool_config_enter(dp, FTAG); + dsl_scan_visit(scn, tx); + dsl_pool_config_exit(dp, FTAG); + (void) zio_wait(scn->scn_zio_root); + scn->scn_zio_root = NULL; + + zfs_dbgmsg("visited %llu blocks in %llums", + (longlong_t)scn->scn_visited_this_txg, + (longlong_t)NSEC2MSEC(gethrtime() - scn->scn_sync_start_time)); + + if (!scn->scn_pausing) { + scn->scn_done_txg = tx->tx_txg + 1; + zfs_dbgmsg("txg %llu traversal complete, waiting till txg %llu", + tx->tx_txg, scn->scn_done_txg); + } + + if (DSL_SCAN_IS_SCRUB_RESILVER(scn)) { + mutex_enter(&spa->spa_scrub_lock); + while (spa->spa_scrub_inflight > 0) { + cv_wait(&spa->spa_scrub_io_cv, + &spa->spa_scrub_lock); + } + mutex_exit(&spa->spa_scrub_lock); + } + + dsl_scan_sync_state(scn, tx); +} + +/* + * This will start a new scan, or restart an existing one. + */ +void +dsl_resilver_restart(dsl_pool_t *dp, uint64_t txg) +{ + if (txg == 0) { + dmu_tx_t *tx; + tx = dmu_tx_create_dd(dp->dp_mos_dir); + VERIFY(0 == dmu_tx_assign(tx, TXG_WAIT)); + + txg = dmu_tx_get_txg(tx); + dp->dp_scan->scn_restart_txg = txg; + dmu_tx_commit(tx); + } else { + dp->dp_scan->scn_restart_txg = txg; + } + zfs_dbgmsg("restarting resilver txg=%llu", txg); +} + +boolean_t +dsl_scan_resilvering(dsl_pool_t *dp) +{ + return (dp->dp_scan->scn_phys.scn_state == DSS_SCANNING && + dp->dp_scan->scn_phys.scn_func == POOL_SCAN_RESILVER); +} + +/* + * scrub consumers + */ + +static void +count_block(zfs_all_blkstats_t *zab, const blkptr_t *bp) +{ + int i; + + /* + * If we resume after a reboot, zab will be NULL; don't record + * incomplete stats in that case. + */ + if (zab == NULL) + return; + + for (i = 0; i < 4; i++) { + int l = (i < 2) ? BP_GET_LEVEL(bp) : DN_MAX_LEVELS; + int t = (i & 1) ? BP_GET_TYPE(bp) : DMU_OT_TOTAL; + if (t & DMU_OT_NEWTYPE) + t = DMU_OT_OTHER; + zfs_blkstat_t *zb = &zab->zab_type[l][t]; + int equal; + + zb->zb_count++; + zb->zb_asize += BP_GET_ASIZE(bp); + zb->zb_lsize += BP_GET_LSIZE(bp); + zb->zb_psize += BP_GET_PSIZE(bp); + zb->zb_gangs += BP_COUNT_GANG(bp); + + switch (BP_GET_NDVAS(bp)) { + case 2: + if (DVA_GET_VDEV(&bp->blk_dva[0]) == + DVA_GET_VDEV(&bp->blk_dva[1])) + zb->zb_ditto_2_of_2_samevdev++; + break; + case 3: + equal = (DVA_GET_VDEV(&bp->blk_dva[0]) == + DVA_GET_VDEV(&bp->blk_dva[1])) + + (DVA_GET_VDEV(&bp->blk_dva[0]) == + DVA_GET_VDEV(&bp->blk_dva[2])) + + (DVA_GET_VDEV(&bp->blk_dva[1]) == + DVA_GET_VDEV(&bp->blk_dva[2])); + if (equal == 1) + zb->zb_ditto_2_of_3_samevdev++; + else if (equal == 3) + zb->zb_ditto_3_of_3_samevdev++; + break; + } + } +} + +static void +dsl_scan_scrub_done(zio_t *zio) +{ + spa_t *spa = zio->io_spa; + + zio_data_buf_free(zio->io_data, zio->io_size); + + mutex_enter(&spa->spa_scrub_lock); + spa->spa_scrub_inflight--; + cv_broadcast(&spa->spa_scrub_io_cv); + + if (zio->io_error && (zio->io_error != ECKSUM || + !(zio->io_flags & ZIO_FLAG_SPECULATIVE))) { + spa->spa_dsl_pool->dp_scan->scn_phys.scn_errors++; + } + mutex_exit(&spa->spa_scrub_lock); +} + +static int +dsl_scan_scrub_cb(dsl_pool_t *dp, + const blkptr_t *bp, const zbookmark_t *zb) +{ + dsl_scan_t *scn = dp->dp_scan; + size_t size = BP_GET_PSIZE(bp); + spa_t *spa = dp->dp_spa; + uint64_t phys_birth = BP_PHYSICAL_BIRTH(bp); + boolean_t needs_io; + int zio_flags = ZIO_FLAG_SCAN_THREAD | ZIO_FLAG_RAW | ZIO_FLAG_CANFAIL; + unsigned int scan_delay = 0; + + if (phys_birth <= scn->scn_phys.scn_min_txg || + phys_birth >= scn->scn_phys.scn_max_txg) + return (0); + + count_block(dp->dp_blkstats, bp); + + if (BP_IS_EMBEDDED(bp)) + return (0); + + ASSERT(DSL_SCAN_IS_SCRUB_RESILVER(scn)); + if (scn->scn_phys.scn_func == POOL_SCAN_SCRUB) { + zio_flags |= ZIO_FLAG_SCRUB; + needs_io = B_TRUE; + scan_delay = zfs_scrub_delay; + } else { + ASSERT3U(scn->scn_phys.scn_func, ==, POOL_SCAN_RESILVER); + zio_flags |= ZIO_FLAG_RESILVER; + needs_io = B_FALSE; + scan_delay = zfs_resilver_delay; + } + + /* If it's an intent log block, failure is expected. */ + if (zb->zb_level == ZB_ZIL_LEVEL) + zio_flags |= ZIO_FLAG_SPECULATIVE; + + for (int d = 0; d < BP_GET_NDVAS(bp); d++) { + vdev_t *vd = vdev_lookup_top(spa, + DVA_GET_VDEV(&bp->blk_dva[d])); + + /* + * Keep track of how much data we've examined so that + * zpool(1M) status can make useful progress reports. + */ + scn->scn_phys.scn_examined += DVA_GET_ASIZE(&bp->blk_dva[d]); + spa->spa_scan_pass_exam += DVA_GET_ASIZE(&bp->blk_dva[d]); + + /* if it's a resilver, this may not be in the target range */ + if (!needs_io) { + if (DVA_GET_GANG(&bp->blk_dva[d])) { + /* + * Gang members may be spread across multiple + * vdevs, so the best estimate we have is the + * scrub range, which has already been checked. + * XXX -- it would be better to change our + * allocation policy to ensure that all + * gang members reside on the same vdev. + */ + needs_io = B_TRUE; + } else { + needs_io = vdev_dtl_contains(vd, DTL_PARTIAL, + phys_birth, 1); + } + } + } + + if (needs_io && !zfs_no_scrub_io) { + vdev_t *rvd = spa->spa_root_vdev; + uint64_t maxinflight = rvd->vdev_children * + MAX(zfs_top_maxinflight, 1); + void *data = zio_data_buf_alloc(size); + + mutex_enter(&spa->spa_scrub_lock); + while (spa->spa_scrub_inflight >= maxinflight) + cv_wait(&spa->spa_scrub_io_cv, &spa->spa_scrub_lock); + spa->spa_scrub_inflight++; + mutex_exit(&spa->spa_scrub_lock); + + /* + * If we're seeing recent (zfs_scan_idle) "important" I/Os + * then throttle our workload to limit the impact of a scan. + */ + if (ddi_get_lbolt64() - spa->spa_last_io <= zfs_scan_idle) + delay(MAX((int)scan_delay, 0)); + + zio_nowait(zio_read(NULL, spa, bp, data, size, + dsl_scan_scrub_done, NULL, ZIO_PRIORITY_SCRUB, + zio_flags, zb)); + } + + /* do not relocate this block */ + return (0); +} + +int +dsl_scan(dsl_pool_t *dp, pool_scan_func_t func) +{ + spa_t *spa = dp->dp_spa; + + /* + * Purge all vdev caches and probe all devices. We do this here + * rather than in sync context because this requires a writer lock + * on the spa_config lock, which we can't do from sync context. The + * spa_scrub_reopen flag indicates that vdev_open() should not + * attempt to start another scrub. + */ + spa_vdev_state_enter(spa, SCL_NONE); + spa->spa_scrub_reopen = B_TRUE; + vdev_reopen(spa->spa_root_vdev); + spa->spa_scrub_reopen = B_FALSE; + (void) spa_vdev_state_exit(spa, NULL, 0); + + return (dsl_sync_task(spa_name(spa), dsl_scan_setup_check, + dsl_scan_setup_sync, &func, 0)); +} |
