X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=module%2Fzfs%2Fspace_map.c;h=9c0cdb6beeccd947c47773d043a311dd6081b8bc;hb=1c24b699b0c7590e135f4701b50a4c933ebe0499;hp=0a1fd59eaba67c2c32f664bebfdbe53531115da5;hpb=172bb4bd5e4afef721dd4d2972d8680d983f144b;p=zfs.git diff --git a/module/zfs/space_map.c b/module/zfs/space_map.c index 0a1fd59..9c0cdb6 100644 --- a/module/zfs/space_map.c +++ b/module/zfs/space_map.c @@ -19,12 +19,10 @@ * CDDL HEADER END */ /* - * Copyright 2008 Sun Microsystems, Inc. All rights reserved. + * Copyright 2009 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ -#pragma ident "%Z%%M% %I% %E% SMI" - #include #include #include @@ -60,6 +58,8 @@ space_map_create(space_map_t *sm, uint64_t start, uint64_t size, uint8_t shift, { bzero(sm, sizeof (*sm)); + cv_init(&sm->sm_load_cv, NULL, CV_DEFAULT, NULL); + avl_create(&sm->sm_root, space_map_seg_compare, sizeof (space_seg_t), offsetof(struct space_seg, ss_node)); @@ -75,6 +75,7 @@ space_map_destroy(space_map_t *sm) ASSERT(!sm->sm_loaded && !sm->sm_loading); VERIFY3U(sm->sm_space, ==, 0); avl_destroy(&sm->sm_root); + cv_destroy(&sm->sm_load_cv); } void @@ -115,19 +116,33 @@ space_map_add(space_map_t *sm, uint64_t start, uint64_t size) if (merge_before && merge_after) { avl_remove(&sm->sm_root, ss_before); + if (sm->sm_pp_root) { + avl_remove(sm->sm_pp_root, ss_before); + avl_remove(sm->sm_pp_root, ss_after); + } ss_after->ss_start = ss_before->ss_start; kmem_free(ss_before, sizeof (*ss_before)); + ss = ss_after; } else if (merge_before) { ss_before->ss_end = end; + if (sm->sm_pp_root) + avl_remove(sm->sm_pp_root, ss_before); + ss = ss_before; } else if (merge_after) { ss_after->ss_start = start; + if (sm->sm_pp_root) + avl_remove(sm->sm_pp_root, ss_after); + ss = ss_after; } else { - ss = kmem_alloc(sizeof (*ss), KM_SLEEP); + ss = kmem_alloc(sizeof (*ss), KM_PUSHPAGE); ss->ss_start = start; ss->ss_end = end; avl_insert(&sm->sm_root, ss, where); } + if (sm->sm_pp_root) + avl_add(sm->sm_pp_root, ss); + sm->sm_space += size; } @@ -162,12 +177,17 @@ space_map_remove(space_map_t *sm, uint64_t start, uint64_t size) left_over = (ss->ss_start != start); right_over = (ss->ss_end != end); + if (sm->sm_pp_root) + avl_remove(sm->sm_pp_root, ss); + if (left_over && right_over) { - newseg = kmem_alloc(sizeof (*newseg), KM_SLEEP); + newseg = kmem_alloc(sizeof (*newseg), KM_PUSHPAGE); newseg->ss_start = end; newseg->ss_end = ss->ss_end; ss->ss_end = start; avl_insert_here(&sm->sm_root, newseg, ss, AVL_AFTER); + if (sm->sm_pp_root) + avl_add(sm->sm_pp_root, newseg); } else if (left_over) { ss->ss_end = start; } else if (right_over) { @@ -175,12 +195,16 @@ space_map_remove(space_map_t *sm, uint64_t start, uint64_t size) } else { avl_remove(&sm->sm_root, ss); kmem_free(ss, sizeof (*ss)); + ss = NULL; } + if (sm->sm_pp_root && ss != NULL) + avl_add(sm->sm_pp_root, ss); + sm->sm_space -= size; } -int +boolean_t space_map_contains(space_map_t *sm, uint64_t start, uint64_t size) { avl_index_t where; @@ -220,59 +244,10 @@ space_map_walk(space_map_t *sm, space_map_func_t *func, space_map_t *mdest) { space_seg_t *ss; - for (ss = avl_first(&sm->sm_root); ss; ss = AVL_NEXT(&sm->sm_root, ss)) - func(mdest, ss->ss_start, ss->ss_end - ss->ss_start); -} - -void -space_map_excise(space_map_t *sm, uint64_t start, uint64_t size) -{ - avl_tree_t *t = &sm->sm_root; - avl_index_t where; - space_seg_t *ss, search; - uint64_t end = start + size; - uint64_t rm_start, rm_end; - ASSERT(MUTEX_HELD(sm->sm_lock)); - search.ss_start = start; - search.ss_end = start; - - for (;;) { - ss = avl_find(t, &search, &where); - - if (ss == NULL) - ss = avl_nearest(t, where, AVL_AFTER); - - if (ss == NULL || ss->ss_start >= end) - break; - - rm_start = MAX(ss->ss_start, start); - rm_end = MIN(ss->ss_end, end); - - space_map_remove(sm, rm_start, rm_end - rm_start); - } -} - -/* - * Replace smd with the union of smd and sms. - */ -void -space_map_union(space_map_t *smd, space_map_t *sms) -{ - avl_tree_t *t = &sms->sm_root; - space_seg_t *ss; - - ASSERT(MUTEX_HELD(smd->sm_lock)); - - /* - * For each source segment, remove any intersections with the - * destination, then add the source segment to the destination. - */ - for (ss = avl_first(t); ss != NULL; ss = AVL_NEXT(t, ss)) { - space_map_excise(smd, ss->ss_start, ss->ss_end - ss->ss_start); - space_map_add(smd, ss->ss_start, ss->ss_end - ss->ss_start); - } + for (ss = avl_first(&sm->sm_root); ss; ss = AVL_NEXT(&sm->sm_root, ss)) + func(mdest, ss->ss_start, ss->ss_end - ss->ss_start); } /* @@ -283,8 +258,10 @@ space_map_load_wait(space_map_t *sm) { ASSERT(MUTEX_HELD(sm->sm_lock)); - while (sm->sm_loading) + while (sm->sm_loading) { + ASSERT(!sm->sm_loaded); cv_wait(&sm->sm_load_cv, sm->sm_lock); + } } /* @@ -301,11 +278,8 @@ space_map_load(space_map_t *sm, space_map_ops_t *ops, uint8_t maptype, int error = 0; ASSERT(MUTEX_HELD(sm->sm_lock)); - - space_map_load_wait(sm); - - if (sm->sm_loaded) - return (0); + ASSERT(!sm->sm_loaded); + ASSERT(!sm->sm_loading); sm->sm_loading = B_TRUE; end = smo->smo_objsize; @@ -336,7 +310,8 @@ space_map_load(space_map_t *sm, space_map_ops_t *ops, uint8_t maptype, smo->smo_object, offset, size); mutex_exit(sm->sm_lock); - error = dmu_read(os, smo->smo_object, offset, size, entry_map); + error = dmu_read(os, smo->smo_object, offset, size, entry_map, + DMU_READ_PREFETCH); mutex_enter(sm->sm_lock); if (error != 0) break; @@ -390,6 +365,13 @@ space_map_unload(space_map_t *sm) } uint64_t +space_map_maxsize(space_map_t *sm) +{ + ASSERT(sm->sm_ops != NULL); + return (sm->sm_ops->smop_max(sm)); +} + +uint64_t space_map_alloc(space_map_t *sm, uint64_t size) { uint64_t start; @@ -504,3 +486,131 @@ space_map_truncate(space_map_obj_t *smo, objset_t *os, dmu_tx_t *tx) smo->smo_objsize = 0; smo->smo_alloc = 0; } + +/* + * Space map reference trees. + * + * A space map is a collection of integers. Every integer is either + * in the map, or it's not. A space map reference tree generalizes + * the idea: it allows its members to have arbitrary reference counts, + * as opposed to the implicit reference count of 0 or 1 in a space map. + * This representation comes in handy when computing the union or + * intersection of multiple space maps. For example, the union of + * N space maps is the subset of the reference tree with refcnt >= 1. + * The intersection of N space maps is the subset with refcnt >= N. + * + * [It's very much like a Fourier transform. Unions and intersections + * are hard to perform in the 'space map domain', so we convert the maps + * into the 'reference count domain', where it's trivial, then invert.] + * + * vdev_dtl_reassess() uses computations of this form to determine + * DTL_MISSING and DTL_OUTAGE for interior vdevs -- e.g. a RAID-Z vdev + * has an outage wherever refcnt >= vdev_nparity + 1, and a mirror vdev + * has an outage wherever refcnt >= vdev_children. + */ +static int +space_map_ref_compare(const void *x1, const void *x2) +{ + const space_ref_t *sr1 = x1; + const space_ref_t *sr2 = x2; + + if (sr1->sr_offset < sr2->sr_offset) + return (-1); + if (sr1->sr_offset > sr2->sr_offset) + return (1); + + if (sr1 < sr2) + return (-1); + if (sr1 > sr2) + return (1); + + return (0); +} + +void +space_map_ref_create(avl_tree_t *t) +{ + avl_create(t, space_map_ref_compare, + sizeof (space_ref_t), offsetof(space_ref_t, sr_node)); +} + +void +space_map_ref_destroy(avl_tree_t *t) +{ + space_ref_t *sr; + void *cookie = NULL; + + while ((sr = avl_destroy_nodes(t, &cookie)) != NULL) + kmem_free(sr, sizeof (*sr)); + + avl_destroy(t); +} + +static void +space_map_ref_add_node(avl_tree_t *t, uint64_t offset, int64_t refcnt) +{ + space_ref_t *sr; + + sr = kmem_alloc(sizeof (*sr), KM_PUSHPAGE); + sr->sr_offset = offset; + sr->sr_refcnt = refcnt; + + avl_add(t, sr); +} + +void +space_map_ref_add_seg(avl_tree_t *t, uint64_t start, uint64_t end, + int64_t refcnt) +{ + space_map_ref_add_node(t, start, refcnt); + space_map_ref_add_node(t, end, -refcnt); +} + +/* + * Convert (or add) a space map into a reference tree. + */ +void +space_map_ref_add_map(avl_tree_t *t, space_map_t *sm, int64_t refcnt) +{ + space_seg_t *ss; + + ASSERT(MUTEX_HELD(sm->sm_lock)); + + for (ss = avl_first(&sm->sm_root); ss; ss = AVL_NEXT(&sm->sm_root, ss)) + space_map_ref_add_seg(t, ss->ss_start, ss->ss_end, refcnt); +} + +/* + * Convert a reference tree into a space map. The space map will contain + * all members of the reference tree for which refcnt >= minref. + */ +void +space_map_ref_generate_map(avl_tree_t *t, space_map_t *sm, int64_t minref) +{ + uint64_t start = -1ULL; + int64_t refcnt = 0; + space_ref_t *sr; + + ASSERT(MUTEX_HELD(sm->sm_lock)); + + space_map_vacate(sm, NULL, NULL); + + for (sr = avl_first(t); sr != NULL; sr = AVL_NEXT(t, sr)) { + refcnt += sr->sr_refcnt; + if (refcnt >= minref) { + if (start == -1ULL) { + start = sr->sr_offset; + } + } else { + if (start != -1ULL) { + uint64_t end = sr->sr_offset; + ASSERT(start <= end); + if (end > start) + space_map_add(sm, start, end - start); + start = -1ULL; + } + } + } + ASSERT(refcnt == 0); + ASSERT(start == -1ULL); +}