X-Git-Url: https://git.camperquake.de/gitweb.cgi?a=blobdiff_plain;f=module%2Fzfs%2Fzfs_rlock.c;h=136972b32d03dc7bb9554939b641234efb26e040;hb=64d7b6cf75e52a4698d9bdec61745573c39d2e5a;hp=9362fb4e82b0de88f68e482eca759d98bb614526;hpb=3c4988c83e4f278cd6c8076f6cdb8e4858d05840;p=zfs.git

diff --git a/module/zfs/zfs_rlock.c b/module/zfs/zfs_rlock.c
index 9362fb4..136972b 100644
--- 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;
@@ -426,7 +429,7 @@ zfs_range_lock(znode_t *zp, uint64_t off, uint64_t len, rl_type_t type)
 
 	ASSERT(type == RL_READER || type == RL_WRITER || type == RL_APPEND);
 
-	new = kmem_alloc(sizeof (rl_t), KM_SLEEP);
+	new = kmem_alloc(sizeof (rl_t), KM_PUSHPAGE);
 	new->r_zp = zp;
 	new->r_off = off;
 	if (len + off < off)	/* overflow */
@@ -453,11 +456,25 @@ zfs_range_lock(znode_t *zp, uint64_t off, uint64_t len, rl_type_t type)
 	return (new);
 }
 
+static void
+zfs_range_free(void *arg)
+{
+	rl_t *rl = arg;
+
+	if (rl->r_write_wanted)
+		cv_destroy(&rl->r_wr_cv);
+
+	if (rl->r_read_wanted)
+		cv_destroy(&rl->r_rd_cv);
+
+	kmem_free(rl, sizeof (rl_t));
+}
+
 /*
  * Unlock a reader lock
  */
 static void
-zfs_range_unlock_reader(znode_t *zp, rl_t *remove)
+zfs_range_unlock_reader(znode_t *zp, rl_t *remove, list_t *free_list)
 {
 	avl_tree_t *tree = &zp->z_range_avl;
 	rl_t *rl, *next = NULL;
@@ -472,18 +489,18 @@ zfs_range_unlock_reader(znode_t *zp, rl_t *remove)
 	 */
 	if (remove->r_cnt == 1) {
 		avl_remove(tree, remove);
-		if (remove->r_write_wanted) {
+
+		if (remove->r_write_wanted)
 			cv_broadcast(&remove->r_wr_cv);
-			cv_destroy(&remove->r_wr_cv);
-		}
-		if (remove->r_read_wanted) {
+
+		if (remove->r_read_wanted)
 			cv_broadcast(&remove->r_rd_cv);
-			cv_destroy(&remove->r_rd_cv);
-		}
+
+		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
@@ -505,19 +522,19 @@ zfs_range_unlock_reader(znode_t *zp, rl_t *remove)
 			rl->r_cnt--;
 			if (rl->r_cnt == 0) {
 				avl_remove(tree, rl);
-				if (rl->r_write_wanted) {
+
+				if (rl->r_write_wanted)
 					cv_broadcast(&rl->r_wr_cv);
-					cv_destroy(&rl->r_wr_cv);
-				}
-				if (rl->r_read_wanted) {
+
+				if (rl->r_read_wanted)
 					cv_broadcast(&rl->r_rd_cv);
-					cv_destroy(&rl->r_rd_cv);
-				}
-				kmem_free(rl, sizeof (rl_t));
+
+				list_insert_tail(free_list, rl);
 			}
 		}
+
+		kmem_free(remove, sizeof (rl_t));
 	}
-	kmem_free(remove, sizeof (rl_t));
 }
 
 /*
@@ -527,33 +544,40 @@ void
 zfs_range_unlock(rl_t *rl)
 {
 	znode_t *zp = rl->r_zp;
+	list_t free_list;
+	rl_t *free_rl;
 
 	ASSERT(rl->r_type == RL_WRITER || rl->r_type == RL_READER);
 	ASSERT(rl->r_cnt == 1 || rl->r_cnt == 0);
 	ASSERT(!rl->r_proxy);
+	list_create(&free_list, sizeof(rl_t), offsetof(rl_t, rl_node));
 
 	mutex_enter(&zp->z_range_lock);
 	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) {
+		if (rl->r_write_wanted)
 			cv_broadcast(&rl->r_wr_cv);
-			cv_destroy(&rl->r_wr_cv);
-		}
-		if (rl->r_read_wanted) {
+
+		if (rl->r_read_wanted)
 			cv_broadcast(&rl->r_rd_cv);
-			cv_destroy(&rl->r_rd_cv);
-		}
-		kmem_free(rl, sizeof (rl_t));
+
+		list_insert_tail(&free_list, rl);
 	} else {
 		/*
 		 * lock may be shared, let zfs_range_unlock_reader()
-		 * release the lock and free the rl_t
+		 * release the zp->z_range_lock lock and free the rl_t
 		 */
-		zfs_range_unlock_reader(zp, rl);
-		mutex_exit(&zp->z_range_lock);
+		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);
+		zfs_range_free(free_rl);
+	}
+
+	list_destroy(&free_list);
 }
 
 /*
@@ -577,11 +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);
 }
 
 /*