Illumos #3006

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

diff --git a/module/zfs/zfs_rlock.c b/module/zfs/zfs_rlock.c
index 4f34b37..136972b 100644 (file)
--- a/module/zfs/zfs_rlock.c
+++ b/module/zfs/zfs_rlock.c
@@ -22,6 +22,9 @@
  * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
+/*
+ * Copyright (c) 2012 by Delphix. All rights reserved.
+ */
 
 /*
  * This file contains the code to implement file range locking in
@@ -199,7 +202,7 @@ zfs_range_proxify(avl_tree_t *tree, rl_t *rl)
        rl->r_cnt = 0;
 
        /* create a proxy range lock */
-       proxy = kmem_alloc(sizeof (rl_t), KM_SLEEP);
+       proxy = kmem_alloc(sizeof (rl_t), KM_PUSHPAGE);
        proxy->r_off = rl->r_off;
        proxy->r_len = rl->r_len;
        proxy->r_cnt = 1;
@@ -228,7 +231,7 @@ zfs_range_split(avl_tree_t *tree, rl_t *rl, uint64_t off)
        ASSERT(rl->r_read_wanted == B_FALSE);
 
        /* create the rear proxy range lock */
-       rear = kmem_alloc(sizeof (rl_t), KM_SLEEP);
+       rear = kmem_alloc(sizeof (rl_t), KM_PUSHPAGE);
        rear->r_off = off;
        rear->r_len = rl->r_off + rl->r_len - off;
        rear->r_cnt = rl->r_cnt;
@@ -253,7 +256,7 @@ zfs_range_new_proxy(avl_tree_t *tree, uint64_t off, uint64_t len)
        rl_t *rl;
 
        ASSERT(len);
-       rl = kmem_alloc(sizeof (rl_t), KM_SLEEP);
+       rl = kmem_alloc(sizeof (rl_t), KM_PUSHPAGE);
        rl->r_off = off;
        rl->r_len = len;
        rl->r_cnt = 1;
@@ -486,7 +489,7 @@ zfs_range_unlock_reader(znode_t *zp, rl_t *remove, list_t *free_list)
         */
        if (remove->r_cnt == 1) {
                avl_remove(tree, remove);
-               mutex_exit(&zp->z_range_lock);
+
                if (remove->r_write_wanted)
                        cv_broadcast(&remove->r_wr_cv);
 
@@ -495,9 +498,9 @@ zfs_range_unlock_reader(znode_t *zp, rl_t *remove, list_t *free_list)
 
                list_insert_tail(free_list, remove);
        } else {
-               ASSERT3U(remove->r_cnt, ==, 0);
-               ASSERT3U(remove->r_write_wanted, ==, 0);
-               ASSERT3U(remove->r_read_wanted, ==, 0);
+               ASSERT0(remove->r_cnt);
+               ASSERT0(remove->r_write_wanted);
+               ASSERT0(remove->r_read_wanted);
                /*
                 * Find start proxy representing this reader lock,
                 * then decrement ref count on all proxies
@@ -530,7 +533,6 @@ zfs_range_unlock_reader(znode_t *zp, rl_t *remove, list_t *free_list)
                        }
                }
 
-               mutex_exit(&zp->z_range_lock);
                kmem_free(remove, sizeof (rl_t));
        }
 }
@@ -554,7 +556,6 @@ zfs_range_unlock(rl_t *rl)
        if (rl->r_type == RL_WRITER) {
                /* writer locks can't be shared or split */
                avl_remove(&zp->z_range_avl, rl);
-               mutex_exit(&zp->z_range_lock);
                if (rl->r_write_wanted)
                        cv_broadcast(&rl->r_wr_cv);
 
@@ -569,6 +570,7 @@ zfs_range_unlock(rl_t *rl)
                 */
                zfs_range_unlock_reader(zp, rl, &free_list);
        }
+       mutex_exit(&zp->z_range_lock);
 
        while ((free_rl = list_head(&free_list)) != NULL) {
                list_remove(&free_list, free_rl);
@@ -599,11 +601,13 @@ zfs_range_reduce(rl_t *rl, uint64_t off, uint64_t len)
        mutex_enter(&zp->z_range_lock);
        rl->r_off = off;
        rl->r_len = len;
-       mutex_exit(&zp->z_range_lock);
+
        if (rl->r_write_wanted)
                cv_broadcast(&rl->r_wr_cv);
        if (rl->r_read_wanted)
                cv_broadcast(&rl->r_rd_cv);
+
+       mutex_exit(&zp->z_range_lock);
 }
 
 /*