Illumos #3306, #3321

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

diff --git a/module/zfs/dbuf.c b/module/zfs/dbuf.c
index eba719c..205abaa 100644 (file)
--- a/module/zfs/dbuf.c
+++ b/module/zfs/dbuf.c
@@ -21,6 +21,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
+ * Copyright (c) 2012 by Delphix. All rights reserved.
  */
 
 #include <sys/zfs_context.h>
@@ -260,7 +261,7 @@ dbuf_is_metadata(dmu_buf_impl_t *db)
                boolean_t is_metadata;
 
                DB_DNODE_ENTER(db);
-               is_metadata = dmu_ot[DB_DNODE(db)->dn_type].ot_metadata;
+               is_metadata = DMU_OT_IS_METADATA(DB_DNODE(db)->dn_type);
                DB_DNODE_EXIT(db);
 
                return (is_metadata);
@@ -298,7 +299,7 @@ retry:
 #if defined(_KERNEL) && defined(HAVE_SPL)
        /* Large allocations which do not require contiguous pages
         * should be using vmem_alloc() in the linux kernel */
-       h->hash_table = vmem_zalloc(hsize * sizeof (void *), KM_SLEEP);
+       h->hash_table = vmem_zalloc(hsize * sizeof (void *), KM_PUSHPAGE);
 #else
        h->hash_table = kmem_zalloc(hsize * sizeof (void *), KM_NOSLEEP);
 #endif
@@ -1719,7 +1720,7 @@ dbuf_create(dnode_t *dn, uint8_t level, uint64_t blkid,
        ASSERT(RW_LOCK_HELD(&dn->dn_struct_rwlock));
        ASSERT(dn->dn_type != DMU_OT_NONE);
 
-       db = kmem_cache_alloc(dbuf_cache, KM_SLEEP);
+       db = kmem_cache_alloc(dbuf_cache, KM_PUSHPAGE);
 
        db->db_objset = os;
        db->db.db_object = dn->dn_object;
@@ -2019,7 +2020,7 @@ dbuf_hold_impl(dnode_t *dn, uint8_t level, uint64_t blkid, int fail_sparse,
        int error;
 
        dh = kmem_zalloc(sizeof(struct dbuf_hold_impl_data) *
-           DBUF_HOLD_IMPL_MAX_DEPTH, KM_SLEEP);
+           DBUF_HOLD_IMPL_MAX_DEPTH, KM_PUSHPAGE);
        __dbuf_hold_impl_init(dh, dn, level, blkid, fail_sparse, tag, dbp, 0);
 
        error = __dbuf_hold_impl(dh);
@@ -2188,7 +2189,24 @@ dbuf_rele_and_unlock(dmu_buf_impl_t *db, void *tag)
                        dbuf_evict(db);
                } else {
                        VERIFY(arc_buf_remove_ref(db->db_buf, db) == 0);
-                       if (!DBUF_IS_CACHEABLE(db))
+
+                       /*
+                        * A dbuf will be eligible for eviction if either the
+                        * 'primarycache' property is set or a duplicate
+                        * copy of this buffer is already cached in the arc.
+                        *
+                        * In the case of the 'primarycache' a buffer
+                        * is considered for eviction if it matches the
+                        * criteria set in the property.
+                        *
+                        * To decide if our buffer is considered a
+                        * duplicate, we must call into the arc to determine
+                        * if multiple buffers are referencing the same
+                        * block on-disk. If so, then we simply evict
+                        * ourselves.
+                        */
+                       if (!DBUF_IS_CACHEABLE(db) ||
+                           arc_buf_eviction_needed(db->db_buf))
                                dbuf_clear(db);
                        else
                                mutex_exit(&db->db_mtx);
@@ -2846,6 +2864,7 @@ EXPORT_SYMBOL(dmu_buf_will_dirty);
 EXPORT_SYMBOL(dmu_buf_will_not_fill);
 EXPORT_SYMBOL(dmu_buf_will_fill);
 EXPORT_SYMBOL(dmu_buf_fill_done);
+EXPORT_SYMBOL(dmu_buf_rele);
 EXPORT_SYMBOL(dbuf_assign_arcbuf);
 EXPORT_SYMBOL(dbuf_clear);
 EXPORT_SYMBOL(dbuf_prefetch);