* Use is subject to license terms.
*/
-#pragma ident "%Z%%M% %I% %E% SMI"
-
#include <sys/zfs_context.h>
#include <sys/spa.h>
#include <sys/dmu.h>
{
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));
ASSERT(!sm->sm_loaded && !sm->sm_loading);
VERIFY3U(sm->sm_space, ==, 0);
avl_destroy(&sm->sm_root);
+ cv_destroy(&sm->sm_load_cv);
}
void
sm->sm_space -= size;
}
-int
+boolean_t
space_map_contains(space_map_t *sm, uint64_t start, uint64_t size)
{
avl_index_t where;
{
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);
}
/*
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);
+}
git://git.camperquake.de / zfs.git / blobdiff