diff options
Diffstat (limited to 'module/zfs/dmu_traverse.c')
| -rw-r--r-- | module/zfs/dmu_traverse.c | 107 |
1 files changed, 97 insertions, 10 deletions
diff --git a/module/zfs/dmu_traverse.c b/module/zfs/dmu_traverse.c index 376f60f82..980c1aa2f 100644 --- a/module/zfs/dmu_traverse.c +++ b/module/zfs/dmu_traverse.c @@ -20,6 +20,7 @@ */ /* * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2012 by Delphix. All rights reserved. */ #include <sys/zfs_context.h> @@ -53,6 +54,7 @@ typedef struct traverse_data { 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; @@ -128,6 +130,54 @@ traverse_zil(traverse_data_t *td, zil_header_t *zh) 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); + ASSERT3U(zb->zb_level, ==, 0); + bcopy(zb, td->td_resume, sizeof (*td->td_resume)); +} + static int traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp, arc_buf_t *pbuf, blkptr_t *bp, const zbookmark_t *zb) @@ -137,8 +187,20 @@ traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp, 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 (BP_IS_HOLE(bp)) { err = td->td_func(td->td_spa, NULL, NULL, pbuf, zb, dnp, td->td_arg); return (err); @@ -164,8 +226,10 @@ traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp, td->td_arg); if (err == TRAVERSE_VISIT_NO_CHILDREN) return (0); - if (err) - return (err); + if (err == ERESTART) + pause = B_TRUE; /* handle pausing at a common point */ + if (err != 0) + goto post; } if (BP_GET_LEVEL(bp) > 0) { @@ -253,9 +317,18 @@ traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp, if (buf) (void) arc_buf_remove_ref(buf, &buf); +post: if (err == 0 && lasterr == 0 && (td->td_flags & TRAVERSE_POST)) { err = td->td_func(td->td_spa, NULL, bp, pbuf, 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); @@ -353,22 +426,27 @@ traverse_prefetch_thread(void *arg) * 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_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; zbookmark_t *czb; int err; + ASSERT(ds == NULL || objset == ds->ds_object); + ASSERT(!(flags & TRAVERSE_PRE) || !(flags & TRAVERSE_POST)); + td = kmem_alloc(sizeof(traverse_data_t), KM_PUSHPAGE); pd = kmem_zalloc(sizeof(prefetch_data_t), KM_PUSHPAGE); czb = kmem_alloc(sizeof(zbookmark_t), KM_PUSHPAGE); td->td_spa = spa; - td->td_objset = ds ? ds->ds_object : 0; + 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; @@ -424,8 +502,17 @@ 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)); + 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)); } /* @@ -442,8 +529,8 @@ traverse_pool(spa_t *spa, uint64_t txg_start, int flags, boolean_t hard = (flags & TRAVERSE_HARD); /* visit the MOS */ - err = traverse_impl(spa, NULL, spa_get_rootblkptr(spa), - txg_start, flags, func, arg); + err = traverse_impl(spa, NULL, 0, spa_get_rootblkptr(spa), + txg_start, NULL, flags, func, arg); if (err) return (err); |