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Diffstat (limited to 'uts/common/fs/zfs/space_map.c')
-rw-r--r--uts/common/fs/zfs/space_map.c616
1 files changed, 616 insertions, 0 deletions
diff --git a/uts/common/fs/zfs/space_map.c b/uts/common/fs/zfs/space_map.c
new file mode 100644
index 000000000000..1ce7b2a3d466
--- /dev/null
+++ b/uts/common/fs/zfs/space_map.c
@@ -0,0 +1,616 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#include <sys/zfs_context.h>
+#include <sys/spa.h>
+#include <sys/dmu.h>
+#include <sys/zio.h>
+#include <sys/space_map.h>
+
+/*
+ * Space map routines.
+ * NOTE: caller is responsible for all locking.
+ */
+static int
+space_map_seg_compare(const void *x1, const void *x2)
+{
+ const space_seg_t *s1 = x1;
+ const space_seg_t *s2 = x2;
+
+ if (s1->ss_start < s2->ss_start) {
+ if (s1->ss_end > s2->ss_start)
+ return (0);
+ return (-1);
+ }
+ if (s1->ss_start > s2->ss_start) {
+ if (s1->ss_start < s2->ss_end)
+ return (0);
+ return (1);
+ }
+ return (0);
+}
+
+void
+space_map_create(space_map_t *sm, uint64_t start, uint64_t size, uint8_t shift,
+ kmutex_t *lp)
+{
+ 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));
+
+ sm->sm_start = start;
+ sm->sm_size = size;
+ sm->sm_shift = shift;
+ sm->sm_lock = lp;
+}
+
+void
+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
+space_map_add(space_map_t *sm, uint64_t start, uint64_t size)
+{
+ avl_index_t where;
+ space_seg_t ssearch, *ss_before, *ss_after, *ss;
+ uint64_t end = start + size;
+ int merge_before, merge_after;
+
+ ASSERT(MUTEX_HELD(sm->sm_lock));
+ VERIFY(size != 0);
+ VERIFY3U(start, >=, sm->sm_start);
+ VERIFY3U(end, <=, sm->sm_start + sm->sm_size);
+ VERIFY(sm->sm_space + size <= sm->sm_size);
+ VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0);
+ VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0);
+
+ ssearch.ss_start = start;
+ ssearch.ss_end = end;
+ ss = avl_find(&sm->sm_root, &ssearch, &where);
+
+ if (ss != NULL && ss->ss_start <= start && ss->ss_end >= end) {
+ zfs_panic_recover("zfs: allocating allocated segment"
+ "(offset=%llu size=%llu)\n",
+ (longlong_t)start, (longlong_t)size);
+ return;
+ }
+
+ /* Make sure we don't overlap with either of our neighbors */
+ VERIFY(ss == NULL);
+
+ ss_before = avl_nearest(&sm->sm_root, where, AVL_BEFORE);
+ ss_after = avl_nearest(&sm->sm_root, where, AVL_AFTER);
+
+ merge_before = (ss_before != NULL && ss_before->ss_end == start);
+ merge_after = (ss_after != NULL && ss_after->ss_start == end);
+
+ 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->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;
+}
+
+void
+space_map_remove(space_map_t *sm, uint64_t start, uint64_t size)
+{
+ avl_index_t where;
+ space_seg_t ssearch, *ss, *newseg;
+ uint64_t end = start + size;
+ int left_over, right_over;
+
+ ASSERT(MUTEX_HELD(sm->sm_lock));
+ VERIFY(size != 0);
+ VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0);
+ VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0);
+
+ ssearch.ss_start = start;
+ ssearch.ss_end = end;
+ ss = avl_find(&sm->sm_root, &ssearch, &where);
+
+ /* Make sure we completely overlap with someone */
+ if (ss == NULL) {
+ zfs_panic_recover("zfs: freeing free segment "
+ "(offset=%llu size=%llu)",
+ (longlong_t)start, (longlong_t)size);
+ return;
+ }
+ VERIFY3U(ss->ss_start, <=, start);
+ VERIFY3U(ss->ss_end, >=, end);
+ VERIFY(sm->sm_space - size <= sm->sm_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->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) {
+ ss->ss_start = end;
+ } 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;
+}
+
+boolean_t
+space_map_contains(space_map_t *sm, uint64_t start, uint64_t size)
+{
+ avl_index_t where;
+ space_seg_t ssearch, *ss;
+ uint64_t end = start + size;
+
+ ASSERT(MUTEX_HELD(sm->sm_lock));
+ VERIFY(size != 0);
+ VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0);
+ VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0);
+
+ ssearch.ss_start = start;
+ ssearch.ss_end = end;
+ ss = avl_find(&sm->sm_root, &ssearch, &where);
+
+ return (ss != NULL && ss->ss_start <= start && ss->ss_end >= end);
+}
+
+void
+space_map_vacate(space_map_t *sm, space_map_func_t *func, space_map_t *mdest)
+{
+ space_seg_t *ss;
+ void *cookie = NULL;
+
+ ASSERT(MUTEX_HELD(sm->sm_lock));
+
+ while ((ss = avl_destroy_nodes(&sm->sm_root, &cookie)) != NULL) {
+ if (func != NULL)
+ func(mdest, ss->ss_start, ss->ss_end - ss->ss_start);
+ kmem_free(ss, sizeof (*ss));
+ }
+ sm->sm_space = 0;
+}
+
+void
+space_map_walk(space_map_t *sm, space_map_func_t *func, space_map_t *mdest)
+{
+ 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))
+ func(mdest, ss->ss_start, ss->ss_end - ss->ss_start);
+}
+
+/*
+ * Wait for any in-progress space_map_load() to complete.
+ */
+void
+space_map_load_wait(space_map_t *sm)
+{
+ ASSERT(MUTEX_HELD(sm->sm_lock));
+
+ while (sm->sm_loading) {
+ ASSERT(!sm->sm_loaded);
+ cv_wait(&sm->sm_load_cv, sm->sm_lock);
+ }
+}
+
+/*
+ * Note: space_map_load() will drop sm_lock across dmu_read() calls.
+ * The caller must be OK with this.
+ */
+int
+space_map_load(space_map_t *sm, space_map_ops_t *ops, uint8_t maptype,
+ space_map_obj_t *smo, objset_t *os)
+{
+ uint64_t *entry, *entry_map, *entry_map_end;
+ uint64_t bufsize, size, offset, end, space;
+ uint64_t mapstart = sm->sm_start;
+ int error = 0;
+
+ ASSERT(MUTEX_HELD(sm->sm_lock));
+ ASSERT(!sm->sm_loaded);
+ ASSERT(!sm->sm_loading);
+
+ sm->sm_loading = B_TRUE;
+ end = smo->smo_objsize;
+ space = smo->smo_alloc;
+
+ ASSERT(sm->sm_ops == NULL);
+ VERIFY3U(sm->sm_space, ==, 0);
+
+ if (maptype == SM_FREE) {
+ space_map_add(sm, sm->sm_start, sm->sm_size);
+ space = sm->sm_size - space;
+ }
+
+ bufsize = 1ULL << SPACE_MAP_BLOCKSHIFT;
+ entry_map = zio_buf_alloc(bufsize);
+
+ mutex_exit(sm->sm_lock);
+ if (end > bufsize)
+ dmu_prefetch(os, smo->smo_object, bufsize, end - bufsize);
+ mutex_enter(sm->sm_lock);
+
+ for (offset = 0; offset < end; offset += bufsize) {
+ size = MIN(end - offset, bufsize);
+ VERIFY(P2PHASE(size, sizeof (uint64_t)) == 0);
+ VERIFY(size != 0);
+
+ dprintf("object=%llu offset=%llx size=%llx\n",
+ smo->smo_object, offset, size);
+
+ mutex_exit(sm->sm_lock);
+ error = dmu_read(os, smo->smo_object, offset, size, entry_map,
+ DMU_READ_PREFETCH);
+ mutex_enter(sm->sm_lock);
+ if (error != 0)
+ break;
+
+ entry_map_end = entry_map + (size / sizeof (uint64_t));
+ for (entry = entry_map; entry < entry_map_end; entry++) {
+ uint64_t e = *entry;
+
+ if (SM_DEBUG_DECODE(e)) /* Skip debug entries */
+ continue;
+
+ (SM_TYPE_DECODE(e) == maptype ?
+ space_map_add : space_map_remove)(sm,
+ (SM_OFFSET_DECODE(e) << sm->sm_shift) + mapstart,
+ SM_RUN_DECODE(e) << sm->sm_shift);
+ }
+ }
+
+ if (error == 0) {
+ VERIFY3U(sm->sm_space, ==, space);
+
+ sm->sm_loaded = B_TRUE;
+ sm->sm_ops = ops;
+ if (ops != NULL)
+ ops->smop_load(sm);
+ } else {
+ space_map_vacate(sm, NULL, NULL);
+ }
+
+ zio_buf_free(entry_map, bufsize);
+
+ sm->sm_loading = B_FALSE;
+
+ cv_broadcast(&sm->sm_load_cv);
+
+ return (error);
+}
+
+void
+space_map_unload(space_map_t *sm)
+{
+ ASSERT(MUTEX_HELD(sm->sm_lock));
+
+ if (sm->sm_loaded && sm->sm_ops != NULL)
+ sm->sm_ops->smop_unload(sm);
+
+ sm->sm_loaded = B_FALSE;
+ sm->sm_ops = NULL;
+
+ space_map_vacate(sm, NULL, NULL);
+}
+
+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;
+
+ start = sm->sm_ops->smop_alloc(sm, size);
+ if (start != -1ULL)
+ space_map_remove(sm, start, size);
+ return (start);
+}
+
+void
+space_map_claim(space_map_t *sm, uint64_t start, uint64_t size)
+{
+ sm->sm_ops->smop_claim(sm, start, size);
+ space_map_remove(sm, start, size);
+}
+
+void
+space_map_free(space_map_t *sm, uint64_t start, uint64_t size)
+{
+ space_map_add(sm, start, size);
+ sm->sm_ops->smop_free(sm, start, size);
+}
+
+/*
+ * Note: space_map_sync() will drop sm_lock across dmu_write() calls.
+ */
+void
+space_map_sync(space_map_t *sm, uint8_t maptype,
+ space_map_obj_t *smo, objset_t *os, dmu_tx_t *tx)
+{
+ spa_t *spa = dmu_objset_spa(os);
+ void *cookie = NULL;
+ space_seg_t *ss;
+ uint64_t bufsize, start, size, run_len;
+ uint64_t *entry, *entry_map, *entry_map_end;
+
+ ASSERT(MUTEX_HELD(sm->sm_lock));
+
+ if (sm->sm_space == 0)
+ return;
+
+ dprintf("object %4llu, txg %llu, pass %d, %c, count %lu, space %llx\n",
+ smo->smo_object, dmu_tx_get_txg(tx), spa_sync_pass(spa),
+ maptype == SM_ALLOC ? 'A' : 'F', avl_numnodes(&sm->sm_root),
+ sm->sm_space);
+
+ if (maptype == SM_ALLOC)
+ smo->smo_alloc += sm->sm_space;
+ else
+ smo->smo_alloc -= sm->sm_space;
+
+ bufsize = (8 + avl_numnodes(&sm->sm_root)) * sizeof (uint64_t);
+ bufsize = MIN(bufsize, 1ULL << SPACE_MAP_BLOCKSHIFT);
+ entry_map = zio_buf_alloc(bufsize);
+ entry_map_end = entry_map + (bufsize / sizeof (uint64_t));
+ entry = entry_map;
+
+ *entry++ = SM_DEBUG_ENCODE(1) |
+ SM_DEBUG_ACTION_ENCODE(maptype) |
+ SM_DEBUG_SYNCPASS_ENCODE(spa_sync_pass(spa)) |
+ SM_DEBUG_TXG_ENCODE(dmu_tx_get_txg(tx));
+
+ while ((ss = avl_destroy_nodes(&sm->sm_root, &cookie)) != NULL) {
+ size = ss->ss_end - ss->ss_start;
+ start = (ss->ss_start - sm->sm_start) >> sm->sm_shift;
+
+ sm->sm_space -= size;
+ size >>= sm->sm_shift;
+
+ while (size) {
+ run_len = MIN(size, SM_RUN_MAX);
+
+ if (entry == entry_map_end) {
+ mutex_exit(sm->sm_lock);
+ dmu_write(os, smo->smo_object, smo->smo_objsize,
+ bufsize, entry_map, tx);
+ mutex_enter(sm->sm_lock);
+ smo->smo_objsize += bufsize;
+ entry = entry_map;
+ }
+
+ *entry++ = SM_OFFSET_ENCODE(start) |
+ SM_TYPE_ENCODE(maptype) |
+ SM_RUN_ENCODE(run_len);
+
+ start += run_len;
+ size -= run_len;
+ }
+ kmem_free(ss, sizeof (*ss));
+ }
+
+ if (entry != entry_map) {
+ size = (entry - entry_map) * sizeof (uint64_t);
+ mutex_exit(sm->sm_lock);
+ dmu_write(os, smo->smo_object, smo->smo_objsize,
+ size, entry_map, tx);
+ mutex_enter(sm->sm_lock);
+ smo->smo_objsize += size;
+ }
+
+ zio_buf_free(entry_map, bufsize);
+
+ VERIFY3U(sm->sm_space, ==, 0);
+}
+
+void
+space_map_truncate(space_map_obj_t *smo, objset_t *os, dmu_tx_t *tx)
+{
+ VERIFY(dmu_free_range(os, smo->smo_object, 0, -1ULL, tx) == 0);
+
+ 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);
+}
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