X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=module%2Fzfs%2Fspace_map.c;fp=module%2Fzfs%2Fspace_map.c;h=1cdacc81da95a053b11b27aaa80101e30ad3954d;hb=fb5f0bc83330c8a0236c4d34a23723ac1974971a;hp=0a1fd59eaba67c2c32f664bebfdbe53531115da5;hpb=42bcb36c8987b0b11411ce6cf8339694b624a17c;p=zfs.git diff --git a/module/zfs/space_map.c b/module/zfs/space_map.c index 0a1fd59..1cdacc8 100644 --- a/module/zfs/space_map.c +++ b/module/zfs/space_map.c @@ -23,8 +23,6 @@ * 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 @@ -180,7 +181,7 @@ space_map_remove(space_map_t *sm, uint64_t start, uint64_t size) 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 +221,10 @@ 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); } /* @@ -504,3 +456,131 @@ 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_SLEEP); + 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); +}