X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=module%2Fzfs%2Fdmu_traverse.c;h=980c1aa2f8222f0acb959e2bb134ef2e5f587c79;hb=5853fe790d1df58c5dd85ea52c5e165b6d43013c;hp=775bb83583787313835ce2d83241d64a6ce87ab6;hpb=c28b227942b421ebdc03c9df9a012642fb517223;p=zfs.git diff --git a/module/zfs/dmu_traverse.c b/module/zfs/dmu_traverse.c index 775bb83..980c1aa 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 @@ -53,37 +54,13 @@ 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; 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); @@ -153,191 +130,208 @@ traverse_zil(traverse_data_t *td, zil_header_t *zh) zil_free(zilog); } -#define TRAVERSE_VISITBP_MAX_DEPTH 20 +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_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) +traverse_pause(traverse_data_t *td, const zbookmark_t *zb) { - 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; + ASSERT(td->td_resume != NULL); + ASSERT3U(zb->zb_level, ==, 0); + bcopy(zb, td->td_resume, sizeof (*td->td_resume)); } -static noinline int -__traverse_visitbp(traverse_visitbp_data_t *tv) +static int +traverse_visitbp(traverse_data_t *td, const dnode_phys_t *dnp, + arc_buf_t *pbuf, blkptr_t *bp, const zbookmark_t *zb) { - ASSERT3S(tv->tv_depth, <, TRAVERSE_VISITBP_MAX_DEPTH); + 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 (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 (BP_IS_HOLE(bp)) { + err = td->td_func(td->td_spa, NULL, NULL, pbuf, zb, dnp, + td->td_arg); + return (err); } - if (tv->tv_bp->blk_birth <= tv->tv_td->td_min_txg) + if (bp->blk_birth <= 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 (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 (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) + if (td->td_flags & TRAVERSE_PRE) { + err = td->td_func(td->td_spa, NULL, bp, pbuf, zb, dnp, + td->td_arg); + if (err == TRAVERSE_VISIT_NO_CHILDREN) return (0); - if (tv->tv_err) - return (tv->tv_err); + if (err == ERESTART) + pause = B_TRUE; /* handle pausing at a common point */ + if (err != 0) + goto post; } - if (BP_GET_LEVEL(tv->tv_bp) > 0) { - tv->tv_epb = BP_GET_LSIZE(tv->tv_bp) >> SPA_BLKPTRSHIFT; + if (BP_GET_LEVEL(bp) > 0) { + uint32_t flags = ARC_WAIT; + int i; + blkptr_t *cbp; + int epb = BP_GET_LSIZE(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); + err = dsl_read(NULL, td->td_spa, bp, pbuf, + arc_getbuf_func, &buf, + ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb); + if (err) + return (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) + cbp = buf->b_data; + for (i = 0; i < epb; i++, cbp++) { + SET_BOOKMARK(&czb, zb->zb_objset, zb->zb_object, + zb->zb_level - 1, + zb->zb_blkid * epb + i); + err = traverse_visitbp(td, dnp, buf, cbp, &czb); + if (err) { + if (!hard) break; - tv->tv_lasterr = tv->tv_err; + lasterr = 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); + } 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 = dsl_read(NULL, td->td_spa, bp, pbuf, + arc_getbuf_func, &buf, + ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb); + if (err) + return (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) + dnp = buf->b_data; + for (i = 0; i < epb; i++, dnp++) { + err = traverse_dnode(td, dnp, buf, zb->zb_objset, + zb->zb_blkid * epb + i); + if (err) { + if (!hard) break; - tv->tv_lasterr = tv->tv_err; + lasterr = 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; + } else if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) { + uint32_t flags = ARC_WAIT; + objset_phys_t *osp; + dnode_phys_t *dnp; + + err = dsl_read_nolock(NULL, td->td_spa, bp, + arc_getbuf_func, &buf, + ZIO_PRIORITY_ASYNC_READ, ZIO_FLAG_CANFAIL, &flags, zb); + if (err) + return (err); + + osp = buf->b_data; + dnp = &osp->os_meta_dnode; + err = traverse_dnode(td, dnp, buf, zb->zb_objset, + DMU_META_DNODE_OBJECT); + if (err && hard) { + lasterr = err; + 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, + if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) { + dnp = &osp->os_userused_dnode; + err = traverse_dnode(td, dnp, buf, zb->zb_objset, DMU_USERUSED_OBJECT); } - if (tv->tv_err && tv->tv_hard) { - tv->tv_lasterr = tv->tv_err; - tv->tv_err = 0; + if (err && hard) { + lasterr = err; + 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, + if (err == 0 && arc_buf_size(buf) >= sizeof (objset_phys_t)) { + dnp = &osp->os_groupused_dnode; + err = traverse_dnode(td, dnp, buf, zb->zb_objset, DMU_GROUPUSED_OBJECT); } } - if (tv->tv_buf) - (void) arc_buf_remove_ref(tv->tv_buf, &tv->tv_buf); + if (buf) + (void) arc_buf_remove_ref(buf, &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); +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; } - 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); + if (pause && td->td_resume != NULL) { + ASSERT3U(err, ==, ERESTART); + ASSERT(!hard); + traverse_pause(td, zb); + } - return (error); + return (err != 0 ? err : lasterr); } static int @@ -432,22 +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; - 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); + 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; @@ -503,8 +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)); } /* @@ -521,8 +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); @@ -571,4 +579,7 @@ traverse_pool(spa_t *spa, uint64_t txg_start, int flags, #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