Illumos #3552, #3564

[zfs.git] / module / zfs / space_map.c

diff --git a/module/zfs/space_map.c b/module/zfs/space_map.c
index 1ce7b2a..a031f3a 100644 (file)
--- a/module/zfs/space_map.c
+++ b/module/zfs/space_map.c
@@ -22,6 +22,9 @@
  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
+/*
+ * Copyright (c) 2012 by Delphix. All rights reserved.
+ */
 
 #include <sys/zfs_context.h>
 #include <sys/spa.h>
@@ -29,6 +32,23 @@
 #include <sys/zio.h>
 #include <sys/space_map.h>
 
+static kmem_cache_t *space_seg_cache;
+
+void
+space_map_init(void)
+{
+       ASSERT(space_seg_cache == NULL);
+       space_seg_cache = kmem_cache_create("space_seg_cache",
+           sizeof (space_seg_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
+}
+
+void
+space_map_fini(void)
+{
+       kmem_cache_destroy(space_seg_cache);
+       space_seg_cache = NULL;
+}
+
 /*
  * Space map routines.
  * NOTE: caller is responsible for all locking.
@@ -73,7 +93,7 @@ void
 space_map_destroy(space_map_t *sm)
 {
        ASSERT(!sm->sm_loaded && !sm->sm_loading);
-       VERIFY3U(sm->sm_space, ==, 0);
+       VERIFY0(sm->sm_space);
        avl_destroy(&sm->sm_root);
        cv_destroy(&sm->sm_load_cv);
 }
@@ -87,6 +107,7 @@ space_map_add(space_map_t *sm, uint64_t start, uint64_t size)
        int merge_before, merge_after;
 
        ASSERT(MUTEX_HELD(sm->sm_lock));
+       VERIFY(!sm->sm_condensing);
        VERIFY(size != 0);
        VERIFY3U(start, >=, sm->sm_start);
        VERIFY3U(end, <=, sm->sm_start + sm->sm_size);
@@ -121,7 +142,7 @@ space_map_add(space_map_t *sm, uint64_t start, uint64_t size)
                        avl_remove(sm->sm_pp_root, ss_after);
                }
                ss_after->ss_start = ss_before->ss_start;
-               kmem_free(ss_before, sizeof (*ss_before));
+               kmem_cache_free(space_seg_cache, ss_before);
                ss = ss_after;
        } else if (merge_before) {
                ss_before->ss_end = end;
@@ -134,7 +155,7 @@ space_map_add(space_map_t *sm, uint64_t start, uint64_t size)
                        avl_remove(sm->sm_pp_root, ss_after);
                ss = ss_after;
        } else {
-               ss = kmem_alloc(sizeof (*ss), KM_SLEEP);
+               ss = kmem_cache_alloc(space_seg_cache, KM_PUSHPAGE);
                ss->ss_start = start;
                ss->ss_end = end;
                avl_insert(&sm->sm_root, ss, where);
@@ -155,6 +176,7 @@ space_map_remove(space_map_t *sm, uint64_t start, uint64_t size)
        int left_over, right_over;
 
        ASSERT(MUTEX_HELD(sm->sm_lock));
+       VERIFY(!sm->sm_condensing);
        VERIFY(size != 0);
        VERIFY(P2PHASE(start, 1ULL << sm->sm_shift) == 0);
        VERIFY(P2PHASE(size, 1ULL << sm->sm_shift) == 0);
@@ -181,7 +203,7 @@ space_map_remove(space_map_t *sm, uint64_t start, uint64_t size)
                avl_remove(sm->sm_pp_root, ss);
 
        if (left_over && right_over) {
-               newseg = kmem_alloc(sizeof (*newseg), KM_SLEEP);
+               newseg = kmem_cache_alloc(space_seg_cache, KM_PUSHPAGE);
                newseg->ss_start = end;
                newseg->ss_end = ss->ss_end;
                ss->ss_end = start;
@@ -194,7 +216,7 @@ space_map_remove(space_map_t *sm, uint64_t start, uint64_t size)
                ss->ss_start = end;
        } else {
                avl_remove(&sm->sm_root, ss);
-               kmem_free(ss, sizeof (*ss));
+               kmem_cache_free(space_seg_cache, ss);
                ss = NULL;
        }
 
@@ -224,6 +246,20 @@ space_map_contains(space_map_t *sm, uint64_t start, uint64_t size)
 }
 
 void
+space_map_swap(space_map_t **msrc, space_map_t **mdst)
+{
+       space_map_t *sm;
+
+       ASSERT(MUTEX_HELD((*msrc)->sm_lock));
+       ASSERT0((*mdst)->sm_space);
+       ASSERT0(avl_numnodes(&(*mdst)->sm_root));
+
+       sm = *msrc;
+       *msrc = *mdst;
+       *mdst = sm;
+}
+
+void
 space_map_vacate(space_map_t *sm, space_map_func_t *func, space_map_t *mdest)
 {
        space_seg_t *ss;
@@ -234,7 +270,7 @@ space_map_vacate(space_map_t *sm, space_map_func_t *func, space_map_t *mdest)
        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));
+               kmem_cache_free(space_seg_cache, ss);
        }
        sm->sm_space = 0;
 }
@@ -286,7 +322,7 @@ space_map_load(space_map_t *sm, space_map_ops_t *ops, uint8_t maptype,
        space = smo->smo_alloc;
 
        ASSERT(sm->sm_ops == NULL);
-       VERIFY3U(sm->sm_space, ==, 0);
+       VERIFY0(sm->sm_space);
 
        if (maptype == SM_FREE) {
                space_map_add(sm, sm->sm_start, sm->sm_size);
@@ -404,9 +440,9 @@ 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;
+       avl_tree_t *t = &sm->sm_root;
        space_seg_t *ss;
-       uint64_t bufsize, start, size, run_len;
+       uint64_t bufsize, start, size, run_len, total, sm_space, nodes;
        uint64_t *entry, *entry_map, *entry_map_end;
 
        ASSERT(MUTEX_HELD(sm->sm_lock));
@@ -435,11 +471,14 @@ space_map_sync(space_map_t *sm, uint8_t 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) {
+       total = 0;
+       nodes = avl_numnodes(&sm->sm_root);
+       sm_space = sm->sm_space;
+       for (ss = avl_first(t); ss != NULL; ss = AVL_NEXT(t, ss)) {
                size = ss->ss_end - ss->ss_start;
                start = (ss->ss_start - sm->sm_start) >> sm->sm_shift;
 
-               sm->sm_space -= size;
+               total += size;
                size >>= sm->sm_shift;
 
                while (size) {
@@ -461,7 +500,6 @@ space_map_sync(space_map_t *sm, uint8_t maptype,
                        start += run_len;
                        size -= run_len;
                }
-               kmem_free(ss, sizeof (*ss));
        }
 
        if (entry != entry_map) {
@@ -473,9 +511,15 @@ space_map_sync(space_map_t *sm, uint8_t maptype,
                smo->smo_objsize += size;
        }
 
-       zio_buf_free(entry_map, bufsize);
+       /*
+        * Ensure that the space_map's accounting wasn't changed
+        * while we were in the middle of writing it out.
+        */
+       VERIFY3U(nodes, ==, avl_numnodes(&sm->sm_root));
+       VERIFY3U(sm->sm_space, ==, sm_space);
+       VERIFY3U(sm->sm_space, ==, total);
 
-       VERIFY3U(sm->sm_space, ==, 0);
+       zio_buf_free(entry_map, bufsize);
 }
 
 void
@@ -551,7 +595,7 @@ 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 = kmem_alloc(sizeof (*sr), KM_PUSHPAGE);
        sr->sr_offset = offset;
        sr->sr_refcnt = refcnt;