diff options
Diffstat (limited to 'sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_traverse.c')
-rw-r--r-- | sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_traverse.c | 658 |
1 files changed, 658 insertions, 0 deletions
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_traverse.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_traverse.c new file mode 100644 index 0000000..db0869c --- /dev/null +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dmu_traverse.c @@ -0,0 +1,658 @@ +/* + * 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) 2005, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2013 by Delphix. All rights reserved. + */ + +#include <sys/zfs_context.h> +#include <sys/dmu_objset.h> +#include <sys/dmu_traverse.h> +#include <sys/dsl_dataset.h> +#include <sys/dsl_dir.h> +#include <sys/dsl_pool.h> +#include <sys/dnode.h> +#include <sys/spa.h> +#include <sys/zio.h> +#include <sys/dmu_impl.h> +#include <sys/sa.h> +#include <sys/sa_impl.h> +#include <sys/callb.h> +#include <sys/zfeature.h> + +int zfs_pd_blks_max = 100; + +typedef struct prefetch_data { + kmutex_t pd_mtx; + kcondvar_t pd_cv; + int pd_blks_max; + int pd_blks_fetched; + int pd_flags; + boolean_t pd_cancel; + boolean_t pd_exited; +} prefetch_data_t; + +typedef struct traverse_data { + spa_t *td_spa; + uint64_t td_objset; + blkptr_t *td_rootbp; + uint64_t td_min_txg; + zbookmark_t *td_resume; + int td_flags; + prefetch_data_t *td_pfd; + blkptr_cb_t *td_func; + void *td_arg; +} traverse_data_t; + +static int traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp, + uint64_t objset, uint64_t object); +static void prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *, + uint64_t objset, uint64_t object); + +static int +traverse_zil_block(zilog_t *zilog, blkptr_t *bp, void *arg, uint64_t claim_txg) +{ + traverse_data_t *td = arg; + zbookmark_t zb; + + if (BP_IS_HOLE(bp)) + return (0); + + if (claim_txg == 0 && bp->blk_birth >= spa_first_txg(td->td_spa)) + return (0); + + SET_BOOKMARK(&zb, td->td_objset, ZB_ZIL_OBJECT, ZB_ZIL_LEVEL, + bp->blk_cksum.zc_word[ZIL_ZC_SEQ]); + + (void) td->td_func(td->td_spa, zilog, bp, &zb, NULL, td->td_arg); + + return (0); +} + +static int +traverse_zil_record(zilog_t *zilog, lr_t *lrc, void *arg, uint64_t claim_txg) +{ + traverse_data_t *td = arg; + + if (lrc->lrc_txtype == TX_WRITE) { + lr_write_t *lr = (lr_write_t *)lrc; + blkptr_t *bp = &lr->lr_blkptr; + zbookmark_t zb; + + if (BP_IS_HOLE(bp)) + return (0); + + if (claim_txg == 0 || bp->blk_birth < claim_txg) + return (0); + + SET_BOOKMARK(&zb, td->td_objset, lr->lr_foid, + ZB_ZIL_LEVEL, lr->lr_offset / BP_GET_LSIZE(bp)); + + (void) td->td_func(td->td_spa, zilog, bp, &zb, NULL, + td->td_arg); + } + return (0); +} + +static void +traverse_zil(traverse_data_t *td, zil_header_t *zh) +{ + uint64_t claim_txg = zh->zh_claim_txg; + zilog_t *zilog; + + /* + * We only want to visit blocks that have been claimed but not yet + * replayed; plus, in read-only mode, blocks that are already stable. + */ + if (claim_txg == 0 && spa_writeable(td->td_spa)) + return; + + zilog = zil_alloc(spa_get_dsl(td->td_spa)->dp_meta_objset, zh); + + (void) zil_parse(zilog, traverse_zil_block, traverse_zil_record, td, + claim_txg); + + zil_free(zilog); +} + +typedef enum resume_skip { + RESUME_SKIP_ALL, + RESUME_SKIP_NONE, + RESUME_SKIP_CHILDREN +} resume_skip_t; + +/* + * Returns RESUME_SKIP_ALL if td indicates that we are resuming a traversal and + * the block indicated by zb does not need to be visited at all. Returns + * RESUME_SKIP_CHILDREN if we are resuming a post traversal and we reach the + * resume point. This indicates that this block should be visited but not its + * children (since they must have been visited in a previous traversal). + * Otherwise returns RESUME_SKIP_NONE. + */ +static resume_skip_t +resume_skip_check(traverse_data_t *td, const dnode_phys_t *dnp, + const zbookmark_t *zb) +{ + if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume)) { + /* + * If we already visited this bp & everything below, + * don't bother doing it again. + */ + if (zbookmark_is_before(dnp, zb, td->td_resume)) + return (RESUME_SKIP_ALL); + + /* + * If we found the block we're trying to resume from, zero + * the bookmark out to indicate that we have resumed. + */ + ASSERT3U(zb->zb_object, <=, td->td_resume->zb_object); + if (bcmp(zb, td->td_resume, sizeof (*zb)) == 0) { + bzero(td->td_resume, sizeof (*zb)); + if (td->td_flags & TRAVERSE_POST) + return (RESUME_SKIP_CHILDREN); + } + } + return (RESUME_SKIP_NONE); +} + +static void +traverse_pause(traverse_data_t *td, const zbookmark_t *zb) +{ + ASSERT(td->td_resume != NULL); + ASSERT0(zb->zb_level); + bcopy(zb, td->td_resume, sizeof (*td->td_resume)); +} + +static void +traverse_prefetch_metadata(traverse_data_t *td, + const blkptr_t *bp, const zbookmark_t *zb) +{ + uint32_t flags = ARC_NOWAIT | ARC_PREFETCH; + + if (!(td->td_flags & TRAVERSE_PREFETCH_METADATA)) + return; + /* + * If we are in the process of resuming, don't prefetch, because + * some children will not be needed (and in fact may have already + * been freed). + */ + if (td->td_resume != NULL && !ZB_IS_ZERO(td->td_resume)) + return; + if (BP_IS_HOLE(bp) || bp->blk_birth <= td->td_min_txg) + return; + if (BP_GET_LEVEL(bp) == 0 && BP_GET_TYPE(bp) != DMU_OT_DNODE) + return; + + (void) arc_read(NULL, td->td_spa, bp, NULL, NULL, + ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb); +} + +static int +traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp, + const blkptr_t *bp, const zbookmark_t *zb) +{ + zbookmark_t czb; + int err = 0, lasterr = 0; + arc_buf_t *buf = NULL; + prefetch_data_t *pd = td->td_pfd; + boolean_t hard = td->td_flags & TRAVERSE_HARD; + boolean_t pause = B_FALSE; + + switch (resume_skip_check(td, dnp, zb)) { + case RESUME_SKIP_ALL: + return (0); + case RESUME_SKIP_CHILDREN: + goto post; + case RESUME_SKIP_NONE: + break; + default: + ASSERT(0); + } + + if (bp->blk_birth == 0) { + if (spa_feature_is_active(td->td_spa, SPA_FEATURE_HOLE_BIRTH)) { + /* + * Since this block has a birth time of 0 it must be a + * hole created before the SPA_FEATURE_HOLE_BIRTH + * feature was enabled. If SPA_FEATURE_HOLE_BIRTH + * was enabled before the min_txg for this traveral we + * know the hole must have been created before the + * min_txg for this traveral, so we can skip it. If + * SPA_FEATURE_HOLE_BIRTH was enabled after the min_txg + * for this traveral we cannot tell if the hole was + * created before or after the min_txg for this + * traversal, so we cannot skip it. + */ + uint64_t hole_birth_enabled_txg; + VERIFY(spa_feature_enabled_txg(td->td_spa, + SPA_FEATURE_HOLE_BIRTH, &hole_birth_enabled_txg)); + if (hole_birth_enabled_txg < td->td_min_txg) + return (0); + } + } else if (bp->blk_birth <= td->td_min_txg) { + return (0); + } + + if (BP_IS_HOLE(bp)) { + err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg); + return (err); + } + + if (pd && !pd->pd_exited && + ((pd->pd_flags & TRAVERSE_PREFETCH_DATA) || + BP_GET_TYPE(bp) == DMU_OT_DNODE || BP_GET_LEVEL(bp) > 0)) { + mutex_enter(&pd->pd_mtx); + ASSERT(pd->pd_blks_fetched >= 0); + while (pd->pd_blks_fetched == 0 && !pd->pd_exited) + cv_wait(&pd->pd_cv, &pd->pd_mtx); + pd->pd_blks_fetched--; + cv_broadcast(&pd->pd_cv); + mutex_exit(&pd->pd_mtx); + } + + if (td->td_flags & TRAVERSE_PRE) { + err = td->td_func(td->td_spa, NULL, bp, zb, dnp, + td->td_arg); + if (err == TRAVERSE_VISIT_NO_CHILDREN) + return (0); + if (err == ERESTART) + pause = B_TRUE; /* handle pausing at a common point */ + if (err != 0) + goto post; + } + + 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, td->td_spa, bp, arc_getbuf_func, &buf, + ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb); + if (err != 0) + return (err); + cbp = buf->b_data; + + for (i = 0; i < epb; i++) { + SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object, + zb->zb_level - 1, + zb->zb_blkid * epb + i); + traverse_prefetch_metadata(td, &cbp[i], &czb); + } + + /* recursively visitbp() blocks below this */ + for (i = 0; i < epb; i++) { + SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object, + zb->zb_level - 1, + zb->zb_blkid * epb + i); + err = traverse_visitbp(td, dnp, &cbp[i], &czb); + if (err != 0) { + if (!hard) + break; + lasterr = err; + } + } + } else if (BP_GET_TYPE(bp) == DMU_OT_DNODE) { + uint32_t flags = ARC_WAIT; + int i; + int epb = BP_GET_LSIZE(bp) >> DNODE_SHIFT; + + err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf, + ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb); + if (err != 0) + return (err); + dnp = buf->b_data; + + for (i = 0; i < epb; i++) { + prefetch_dnode_metadata(td, &dnp[i], zb->zb_objset, + zb->zb_blkid * epb + i); + } + + /* recursively visitbp() blocks below this */ + for (i = 0; i < epb; i++) { + err = traverse_dnode(td, &dnp[i], zb->zb_objset, + zb->zb_blkid * epb + i); + if (err != 0) { + if (!hard) + break; + lasterr = err; + } + } + } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) { + uint32_t flags = ARC_WAIT; + objset_phys_t *osp; + dnode_phys_t *dnp; + + err = arc_read(NULL, td->td_spa, bp, arc_getbuf_func, &buf, + ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb); + if (err != 0) + return (err); + + osp = buf->b_data; + dnp = &osp->os_meta_dnode; + prefetch_dnode_metadata(td, dnp, zb->zb_objset, + DMU_META_DNODE_OBJECT); + if (arc_buf_size(buf) >= sizeof (objset_phys_t)) { + prefetch_dnode_metadata(td, &osp->os_groupused_dnode, + zb->zb_objset, DMU_GROUPUSED_OBJECT); + prefetch_dnode_metadata(td, &osp->os_userused_dnode, + zb->zb_objset, DMU_USERUSED_OBJECT); + } + + err = traverse_dnode(td, dnp, zb->zb_objset, + DMU_META_DNODE_OBJECT); + if (err && hard) { + lasterr = err; + err = 0; + } + if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) { + dnp = &osp->os_groupused_dnode; + err = traverse_dnode(td, dnp, zb->zb_objset, + DMU_GROUPUSED_OBJECT); + } + if (err && hard) { + lasterr = err; + err = 0; + } + if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) { + dnp = &osp->os_userused_dnode; + err = traverse_dnode(td, dnp, zb->zb_objset, + DMU_USERUSED_OBJECT); + } + } + + if (buf) + (void) arc_buf_remove_ref(buf, &buf); + +post: + if (err == 0 && (td->td_flags & TRAVERSE_POST)) { + err = td->td_func(td->td_spa, NULL, bp, zb, dnp, td->td_arg); + if (err == ERESTART) + pause = B_TRUE; + } + + if (pause && td->td_resume != NULL) { + ASSERT3U(err, ==, ERESTART); + ASSERT(!hard); + traverse_pause(td, zb); + } + + return (err != 0 ? err : lasterr); +} + +static void +prefetch_dnode_metadata(traverse_data_t *td, const dnode_phys_t *dnp, + uint64_t objset, uint64_t object) +{ + int j; + zbookmark_t czb; + + for (j = 0; j < dnp->dn_nblkptr; j++) { + SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j); + traverse_prefetch_metadata(td, &dnp->dn_blkptr[j], &czb); + } + + if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { + SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID); + traverse_prefetch_metadata(td, &dnp->dn_spill, &czb); + } +} + +static int +traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp, + uint64_t objset, uint64_t object) +{ + int j, err = 0, lasterr = 0; + zbookmark_t czb; + boolean_t hard = (td->td_flags & TRAVERSE_HARD); + + for (j = 0; j < dnp->dn_nblkptr; j++) { + SET_BOOKMARK(&czb, objset, object, dnp->dn_nlevels - 1, j); + err = traverse_visitbp(td, dnp, &dnp->dn_blkptr[j], &czb); + if (err != 0) { + if (!hard) + break; + lasterr = err; + } + } + + if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { + SET_BOOKMARK(&czb, objset, object, 0, DMU_SPILL_BLKID); + err = traverse_visitbp(td, dnp, &dnp->dn_spill, &czb); + if (err != 0) { + if (!hard) + return (err); + lasterr = err; + } + } + return (err != 0 ? err : lasterr); +} + +/* ARGSUSED */ +static int +traverse_prefetcher(spa_t *spa, zilog_t *zilog, const blkptr_t *bp, + const zbookmark_t *zb, const dnode_phys_t *dnp, void *arg) +{ + prefetch_data_t *pfd = arg; + uint32_t aflags = ARC_NOWAIT | ARC_PREFETCH; + + ASSERT(pfd->pd_blks_fetched >= 0); + if (pfd->pd_cancel) + return (SET_ERROR(EINTR)); + + if (BP_IS_HOLE(bp) || BP_IS_EMBEDDED(bp) || + !((pfd->pd_flags & TRAVERSE_PREFETCH_DATA) || + BP_GET_TYPE(bp) == DMU_OT_DNODE || BP_GET_LEVEL(bp) > 0) || + BP_GET_TYPE(bp) == DMU_OT_INTENT_LOG) + return (0); + + mutex_enter(&pfd->pd_mtx); + while (!pfd->pd_cancel && pfd->pd_blks_fetched >= pfd->pd_blks_max) + cv_wait(&pfd->pd_cv, &pfd->pd_mtx); + pfd->pd_blks_fetched++; + cv_broadcast(&pfd->pd_cv); + mutex_exit(&pfd->pd_mtx); + + (void) arc_read(NULL, spa, bp, NULL, NULL, ZIO_PRIORITY_ASYNC_READ, + ZIO_FLAG_CANFAIL | ZIO_FLAG_SPECULATIVE, &aflags, zb); + + return (0); +} + +static void +traverse_prefetch_thread(void *arg) +{ + traverse_data_t *td_main = arg; + traverse_data_t td = *td_main; + zbookmark_t czb; + + td.td_func = traverse_prefetcher; + td.td_arg = td_main->td_pfd; + td.td_pfd = NULL; + + SET_BOOKMARK(&czb, td.td_objset, + ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID); + (void) traverse_visitbp(&td, NULL, td.td_rootbp, &czb); + + mutex_enter(&td_main->td_pfd->pd_mtx); + td_main->td_pfd->pd_exited = B_TRUE; + cv_broadcast(&td_main->td_pfd->pd_cv); + mutex_exit(&td_main->td_pfd->pd_mtx); +} + +/* + * NB: dataset must not be changing on-disk (eg, is a snapshot or we are + * in syncing context). + */ +static int +traverse_impl(spa_t *spa, dsl_dataset_t *ds, uint64_t objset, blkptr_t *rootbp, + uint64_t txg_start, zbookmark_t *resume, int flags, + blkptr_cb_t func, void *arg) +{ + traverse_data_t td; + prefetch_data_t pd = { 0 }; + zbookmark_t czb; + int err; + + ASSERT(ds == NULL || objset == ds->ds_object); + ASSERT(!(flags & TRAVERSE_PRE) || !(flags & TRAVERSE_POST)); + + /* + * The data prefetching mechanism (the prefetch thread) is incompatible + * with resuming from a bookmark. + */ + ASSERT(resume == NULL || !(flags & TRAVERSE_PREFETCH_DATA)); + + td.td_spa = spa; + td.td_objset = objset; + td.td_rootbp = rootbp; + td.td_min_txg = txg_start; + td.td_resume = resume; + td.td_func = func; + td.td_arg = arg; + td.td_pfd = &pd; + td.td_flags = flags; + + pd.pd_blks_max = zfs_pd_blks_max; + pd.pd_flags = flags; + mutex_init(&pd.pd_mtx, NULL, MUTEX_DEFAULT, NULL); + cv_init(&pd.pd_cv, NULL, CV_DEFAULT, NULL); + + /* See comment on ZIL traversal in dsl_scan_visitds. */ + if (ds != NULL && !dsl_dataset_is_snapshot(ds) && !BP_IS_HOLE(rootbp)) { + uint32_t flags = ARC_WAIT; + objset_phys_t *osp; + arc_buf_t *buf; + + err = arc_read(NULL, td.td_spa, rootbp, + arc_getbuf_func, &buf, + ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, NULL); + if (err != 0) + return (err); + + osp = buf->b_data; + traverse_zil(&td, &osp->os_zil_header); + (void) arc_buf_remove_ref(buf, &buf); + } + + if (!(flags & TRAVERSE_PREFETCH_DATA) || + 0 == taskq_dispatch(system_taskq, traverse_prefetch_thread, + &td, TQ_NOQUEUE)) + pd.pd_exited = B_TRUE; + + SET_BOOKMARK(&czb, td.td_objset, + ZB_ROOT_OBJECT, ZB_ROOT_LEVEL, ZB_ROOT_BLKID); + err = traverse_visitbp(&td, NULL, rootbp, &czb); + + mutex_enter(&pd.pd_mtx); + pd.pd_cancel = B_TRUE; + cv_broadcast(&pd.pd_cv); + while (!pd.pd_exited) + cv_wait(&pd.pd_cv, &pd.pd_mtx); + mutex_exit(&pd.pd_mtx); + + mutex_destroy(&pd.pd_mtx); + cv_destroy(&pd.pd_cv); + + return (err); +} + +/* + * NB: dataset must not be changing on-disk (eg, is a snapshot or we are + * in syncing context). + */ +int +traverse_dataset(dsl_dataset_t *ds, uint64_t txg_start, int flags, + blkptr_cb_t func, void *arg) +{ + return (traverse_impl(ds->ds_dir->dd_pool->dp_spa, ds, ds->ds_object, + &ds->ds_phys->ds_bp, txg_start, NULL, flags, func, arg)); +} + +int +traverse_dataset_destroyed(spa_t *spa, blkptr_t *blkptr, + uint64_t txg_start, zbookmark_t *resume, int flags, + blkptr_cb_t func, void *arg) +{ + return (traverse_impl(spa, NULL, ZB_DESTROYED_OBJSET, + blkptr, txg_start, resume, flags, func, arg)); +} + +/* + * NB: pool must not be changing on-disk (eg, from zdb or sync context). + */ +int +traverse_pool(spa_t *spa, uint64_t txg_start, int flags, + blkptr_cb_t func, void *arg) +{ + int err, lasterr = 0; + uint64_t obj; + dsl_pool_t *dp = spa_get_dsl(spa); + objset_t *mos = dp->dp_meta_objset; + boolean_t hard = (flags & TRAVERSE_HARD); + + /* visit the MOS */ + err = traverse_impl(spa, NULL, 0, spa_get_rootblkptr(spa), + txg_start, NULL, flags, func, arg); + if (err != 0) + return (err); + + /* visit each dataset */ + for (obj = 1; err == 0 || (err != ESRCH && hard); + err = dmu_object_next(mos, &obj, FALSE, txg_start)) { + dmu_object_info_t doi; + + err = dmu_object_info(mos, obj, &doi); + if (err != 0) { + if (!hard) + return (err); + lasterr = err; + continue; + } + + if (doi.doi_bonus_type == DMU_OT_DSL_DATASET) { + dsl_dataset_t *ds; + uint64_t txg = txg_start; + + dsl_pool_config_enter(dp, FTAG); + err = dsl_dataset_hold_obj(dp, obj, FTAG, &ds); + dsl_pool_config_exit(dp, FTAG); + if (err != 0) { + if (!hard) + return (err); + lasterr = err; + continue; + } + if (ds->ds_phys->ds_prev_snap_txg > txg) + txg = ds->ds_phys->ds_prev_snap_txg; + err = traverse_dataset(ds, txg, flags, func, arg); + dsl_dataset_rele(ds, FTAG); + if (err != 0) { + if (!hard) + return (err); + lasterr = err; + } + } + } + if (err == ESRCH) + err = 0; + return (err != 0 ? err : lasterr); +} |