/* * 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include 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; int td_flags; prefetch_data_t *td_pfd; blkptr_cb_t *td_func; void *td_arg; } traverse_data_t; typedef struct traverse_visitbp_data { /* Function arguments */ traverse_data_t *tv_td; const dnode_phys_t *tv_dnp; arc_buf_t *tv_pbuf; blkptr_t *tv_bp; const zbookmark_t *tv_zb; /* Local variables */ prefetch_data_t *tv_pd; zbookmark_t tv_czb; arc_buf_t *tv_buf; boolean_t tv_hard; objset_phys_t *tv_osp; dnode_phys_t *tv_ldnp; blkptr_t *tv_cbp; uint32_t tv_flags; int tv_err; int tv_lasterr; int tv_i; int tv_epb; int tv_depth; } traverse_visitbp_data_t; static inline int traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp, arc_buf_t *pbuf, blkptr_t *bp, const zbookmark_t *zb); static int traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp, arc_buf_t *buf, 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->blk_birth == 0) 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, NULL, &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->blk_birth == 0) 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, NULL, &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); } #define TRAVERSE_VISITBP_MAX_DEPTH 20 static void __traverse_visitbp_init(traverse_visitbp_data_t *tv, traverse_data_t *td, const dnode_phys_t *dnp, arc_buf_t *pbuf, blkptr_t *bp, const zbookmark_t *zb, int depth) { tv->tv_td = td; tv->tv_dnp = dnp; tv->tv_pbuf = pbuf; tv->tv_bp = bp; tv->tv_zb = zb; tv->tv_err = 0; tv->tv_lasterr = 0; tv->tv_buf = NULL; tv->tv_pd = td->td_pfd; tv->tv_hard = td->td_flags & TRAVERSE_HARD; tv->tv_flags = ARC_WAIT; tv->tv_depth = depth; } static noinline int __traverse_visitbp(traverse_visitbp_data_t *tv) { ASSERT3S(tv->tv_depth, <, TRAVERSE_VISITBP_MAX_DEPTH); if (tv->tv_bp->blk_birth == 0) { tv->tv_err = tv->tv_td->td_func(tv->tv_td->td_spa, NULL, NULL, tv->tv_pbuf, tv->tv_zb, tv->tv_dnp, tv->tv_td->td_arg); return (tv->tv_err); } if (tv->tv_bp->blk_birth <= tv->tv_td->td_min_txg) return (0); if (tv->tv_pd && !tv->tv_pd->pd_exited && ((tv->tv_pd->pd_flags & TRAVERSE_PREFETCH_DATA) || BP_GET_TYPE(tv->tv_bp) == DMU_OT_DNODE || BP_GET_LEVEL(tv->tv_bp) > 0)) { mutex_enter(&tv->tv_pd->pd_mtx); ASSERT(tv->tv_pd->pd_blks_fetched >= 0); while (tv->tv_pd->pd_blks_fetched == 0 && !tv->tv_pd->pd_exited) cv_wait(&tv->tv_pd->pd_cv, &tv->tv_pd->pd_mtx); tv->tv_pd->pd_blks_fetched--; cv_broadcast(&tv->tv_pd->pd_cv); mutex_exit(&tv->tv_pd->pd_mtx); } if (tv->tv_td->td_flags & TRAVERSE_PRE) { tv->tv_err = tv->tv_td->td_func(tv->tv_td->td_spa, NULL, tv->tv_bp, tv->tv_pbuf, tv->tv_zb, tv->tv_dnp, tv->tv_td->td_arg); if (tv->tv_err == TRAVERSE_VISIT_NO_CHILDREN) return (0); if (tv->tv_err) return (tv->tv_err); } if (BP_GET_LEVEL(tv->tv_bp) > 0) { tv->tv_epb = BP_GET_LSIZE(tv->tv_bp) >> SPA_BLKPTRSHIFT; tv->tv_err = dsl_read(NULL, tv->tv_td->td_spa, tv->tv_bp, tv->tv_pbuf, arc_getbuf_func, &tv->tv_buf, ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &tv->tv_flags, tv->tv_zb); if (tv->tv_err) return (tv->tv_err); /* recursively visitbp() blocks below this */ tv->tv_cbp = tv->tv_buf->b_data; for (tv->tv_i = 0; tv->tv_i < tv->tv_epb; tv->tv_i++, tv->tv_cbp++) { SET_BOOKMARK(&tv->tv_czb, tv->tv_zb->zb_objset, tv->tv_zb->zb_object, tv->tv_zb->zb_level - 1, tv->tv_zb->zb_blkid * tv->tv_epb + tv->tv_i); __traverse_visitbp_init(tv + 1, tv->tv_td, tv->tv_dnp, tv->tv_buf, tv->tv_cbp, &tv->tv_czb, tv->tv_depth + 1); tv->tv_err = __traverse_visitbp(tv + 1); if (tv->tv_err) { if (!tv->tv_hard) break; tv->tv_lasterr = tv->tv_err; } } } else if (BP_GET_TYPE(tv->tv_bp) == DMU_OT_DNODE) { tv->tv_epb = BP_GET_LSIZE(tv->tv_bp) >> DNODE_SHIFT; tv->tv_err = dsl_read(NULL, tv->tv_td->td_spa, tv->tv_bp, tv->tv_pbuf, arc_getbuf_func, &tv->tv_buf, ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &tv->tv_flags, tv->tv_zb); if (tv->tv_err) return (tv->tv_err); /* recursively visitbp() blocks below this */ tv->tv_dnp = tv->tv_buf->b_data; for (tv->tv_i = 0; tv->tv_i < tv->tv_epb; tv->tv_i++, tv->tv_dnp++) { tv->tv_err = traverse_dnode(tv->tv_td, tv->tv_dnp, tv->tv_buf, tv->tv_zb->zb_objset, tv->tv_zb->zb_blkid * tv->tv_epb + tv->tv_i); if (tv->tv_err) { if (!tv->tv_hard) break; tv->tv_lasterr = tv->tv_err; } } } else if (BP_GET_TYPE(tv->tv_bp) == DMU_OT_OBJSET) { tv->tv_err = dsl_read_nolock(NULL, tv->tv_td->td_spa, tv->tv_bp, arc_getbuf_func, &tv->tv_buf, ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &tv->tv_flags, tv->tv_zb); if (tv->tv_err) return (tv->tv_err); tv->tv_osp = tv->tv_buf->b_data; tv->tv_ldnp = &tv->tv_osp->os_meta_dnode; tv->tv_err = traverse_dnode(tv->tv_td, tv->tv_ldnp, tv->tv_buf, tv->tv_zb->zb_objset, DMU_META_DNODE_OBJECT); if (tv->tv_err && tv->tv_hard) { tv->tv_lasterr = tv->tv_err; tv->tv_err = 0; } if (tv->tv_err == 0 && arc_buf_size(tv->tv_buf) >= sizeof (objset_phys_t)) { tv->tv_ldnp = &tv->tv_osp->os_userused_dnode; tv->tv_err = traverse_dnode(tv->tv_td, tv->tv_ldnp, tv->tv_buf, tv->tv_zb->zb_objset, DMU_USERUSED_OBJECT); } if (tv->tv_err && tv->tv_hard) { tv->tv_lasterr = tv->tv_err; tv->tv_err = 0; } if (tv->tv_err == 0 && arc_buf_size(tv->tv_buf) >= sizeof (objset_phys_t)) { tv->tv_ldnp = &tv->tv_osp->os_groupused_dnode; tv->tv_err = traverse_dnode(tv->tv_td, tv->tv_ldnp, tv->tv_buf, tv->tv_zb->zb_objset, DMU_GROUPUSED_OBJECT); } } if (tv->tv_buf) (void) arc_buf_remove_ref(tv->tv_buf, &tv->tv_buf); if (tv->tv_err == 0 && tv->tv_lasterr == 0 && (tv->tv_td->td_flags & TRAVERSE_POST)) { tv->tv_err = tv->tv_td->td_func(tv->tv_td->td_spa, NULL, tv->tv_bp, tv->tv_pbuf, tv->tv_zb, tv->tv_dnp, tv->tv_td->td_arg); } return (tv->tv_err != 0 ? tv->tv_err : tv->tv_lasterr); } /* * Due to limited stack space recursive functions are frowned upon in * the Linux kernel. However, they often are the most elegant solution * to a problem. The following code preserves the recursive function * traverse_visitbp() but moves the local variables AND function * arguments to the heap to minimize the stack frame size. Enough * space is initially allocated on the stack for 16 levels of recursion. * This change does ugly-up-the-code but it reduces the worst case * usage from roughly 2496 bytes to 576 bytes on x86_64 archs. */ static int traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp, arc_buf_t *pbuf, blkptr_t *bp, const zbookmark_t *zb) { traverse_visitbp_data_t *tv; int error; tv = kmem_zalloc(sizeof(traverse_visitbp_data_t) * TRAVERSE_VISITBP_MAX_DEPTH, KM_SLEEP); __traverse_visitbp_init(tv, td, dnp, pbuf, bp, zb, 0); error = __traverse_visitbp(tv); kmem_free(tv, sizeof(traverse_visitbp_data_t) * TRAVERSE_VISITBP_MAX_DEPTH); return (error); } static int traverse_dnode(traverse_data_t *td, const dnode_phys_t *dnp, arc_buf_t *buf, 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, buf, (blkptr_t *)&dnp->dn_blkptr[j], &czb); if (err) { 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, buf, (blkptr_t *)&dnp->dn_spill, &czb); if (err) { 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, arc_buf_t *pbuf, 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 (EINTR); if (bp == NULL || !((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) dsl_read(NULL, spa, bp, pbuf, 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, 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, blkptr_t *rootbp, uint64_t txg_start, int flags, blkptr_cb_t func, void *arg) { traverse_data_t *td; prefetch_data_t *pd; zbookmark_t *czb; int err; td = kmem_alloc(sizeof(traverse_data_t), KM_SLEEP); pd = kmem_zalloc(sizeof(prefetch_data_t), KM_SLEEP); czb = kmem_alloc(sizeof(zbookmark_t), KM_SLEEP); td->td_spa = spa; td->td_objset = ds ? ds->ds_object : 0; td->td_rootbp = rootbp; td->td_min_txg = txg_start; 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)) { objset_t *os; err = dmu_objset_from_ds(ds, &os); if (err) return (err); traverse_zil(td, &os->os_zil_header); } if (!(flags & TRAVERSE_PREFETCH) || 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, 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); kmem_free(czb, sizeof(zbookmark_t)); kmem_free(pd, sizeof(struct prefetch_data)); kmem_free(td, sizeof(struct traverse_data)); 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_phys->ds_bp, txg_start, 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, spa_get_rootblkptr(spa), txg_start, flags, func, arg); if (err) 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) { if (!hard) return (err); lasterr = err; continue; } if (doi.doi_type == DMU_OT_DSL_DATASET) { dsl_dataset_t *ds; uint64_t txg = txg_start; rw_enter(&dp->dp_config_rwlock, RW_READER); err = dsl_dataset_hold_obj(dp, obj, FTAG, &ds); rw_exit(&dp->dp_config_rwlock); if (err) { 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) { if (!hard) return (err); lasterr = err; } } } if (err == ESRCH) err = 0; return (err != 0 ? err : lasterr); } #if defined(_KERNEL) && defined(HAVE_SPL) EXPORT_SYMBOL(traverse_dataset); EXPORT_SYMBOL(traverse_pool); module_param(zfs_pd_blks_max, int, 0644); MODULE_PARM_DESC(zfs_pd_blks_max, "Max number of blocks to prefetch"); #endif