diff --git a/config/kernel-bdev-block-device-operations.m4 b/config/kernel-bdev-block-device-operations.m4
deleted file mode 100644
index faacc195d..000000000
--- a/config/kernel-bdev-block-device-operations.m4
+++ /dev/null
@@ -1,34 +0,0 @@
-dnl #
-dnl # 2.6.x API change
-dnl #
-AC_DEFUN([ZFS_AC_KERNEL_BDEV_BLOCK_DEVICE_OPERATIONS], [
-	AC_MSG_CHECKING([block device operation prototypes])
-	tmp_flags="$EXTRA_KCFLAGS"
-	EXTRA_KCFLAGS="${NO_UNUSED_BUT_SET_VARIABLE}"
-	ZFS_LINUX_TRY_COMPILE([
-		#include <linux/blkdev.h>
-
-		int blk_open(struct block_device *bdev, fmode_t mode)
-		    { return 0; }
-		int blk_ioctl(struct block_device *bdev, fmode_t mode,
-		    unsigned x, unsigned long y) { return 0; }
-		int blk_compat_ioctl(struct block_device * bdev, fmode_t mode,
-		    unsigned x, unsigned long y) { return 0; }
-
-		static const struct block_device_operations
-		    bops __attribute__ ((unused)) = {
-			.open		= blk_open,
-			.release	= NULL,
-			.ioctl		= blk_ioctl,
-			.compat_ioctl	= blk_compat_ioctl,
-		};
-	],[
-	],[
-		AC_MSG_RESULT(struct block_device)
-		AC_DEFINE(HAVE_BDEV_BLOCK_DEVICE_OPERATIONS, 1,
-		          [struct block_device_operations use bdevs])
-	],[
-		AC_MSG_RESULT(struct inode)
-	])
-	EXTRA_KCFLAGS="$tmp_flags"
-])
diff --git a/config/kernel-block-device-operations-release-void.m4 b/config/kernel-block-device-operations-release-void.m4
deleted file mode 100644
index a73f85872..000000000
--- a/config/kernel-block-device-operations-release-void.m4
+++ /dev/null
@@ -1,29 +0,0 @@
-dnl #
-dnl # 3.10.x API change
-dnl #
-AC_DEFUN([ZFS_AC_KERNEL_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID], [
-	AC_MSG_CHECKING([whether block_device_operations.release is void])
-	tmp_flags="$EXTRA_KCFLAGS"
-	EXTRA_KCFLAGS="${NO_UNUSED_BUT_SET_VARIABLE}"
-	ZFS_LINUX_TRY_COMPILE([
-		#include <linux/blkdev.h>
-
-		void blk_release(struct gendisk *g, fmode_t mode) { return; }
-
-		static const struct block_device_operations
-		    bops __attribute__ ((unused)) = {
-			.open		= NULL,
-			.release	= blk_release,
-			.ioctl		= NULL,
-			.compat_ioctl	= NULL,
-		};
-	],[
-	],[
-		AC_MSG_RESULT(void)
-		AC_DEFINE(HAVE_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID, 1,
-		          [struct block_device_operations.release returns void])
-	],[
-		AC_MSG_RESULT(int)
-	])
-	EXTRA_KCFLAGS="$tmp_flags"
-])
diff --git a/config/kernel-block-device-operations.m4 b/config/kernel-block-device-operations.m4
new file mode 100644
index 000000000..5f2811c15
--- /dev/null
+++ b/config/kernel-block-device-operations.m4
@@ -0,0 +1,57 @@
+dnl #
+dnl # 2.6.38 API change
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS], [
+	AC_MSG_CHECKING([whether bops->check_events() exists])
+	tmp_flags="$EXTRA_KCFLAGS"
+	EXTRA_KCFLAGS="${NO_UNUSED_BUT_SET_VARIABLE}"
+	ZFS_LINUX_TRY_COMPILE([
+		#include <linux/blkdev.h>
+
+		unsigned int blk_check_events(struct gendisk *disk,
+		    unsigned int clearing) { return (0); }
+
+		static const struct block_device_operations
+		    bops __attribute__ ((unused)) = {
+			.check_events	= blk_check_events,
+		};
+	],[
+	],[
+		AC_MSG_RESULT(yes)
+		AC_DEFINE(HAVE_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS, 1,
+		    [bops->check_events() exists])
+	],[
+		AC_MSG_RESULT(no)
+	])
+	EXTRA_KCFLAGS="$tmp_flags"
+])
+
+dnl #
+dnl # 3.10.x API change
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID], [
+	AC_MSG_CHECKING([whether bops->release() is void])
+	tmp_flags="$EXTRA_KCFLAGS"
+	EXTRA_KCFLAGS="${NO_UNUSED_BUT_SET_VARIABLE}"
+	ZFS_LINUX_TRY_COMPILE([
+		#include <linux/blkdev.h>
+
+		void blk_release(struct gendisk *g, fmode_t mode) { return; }
+
+		static const struct block_device_operations
+		    bops __attribute__ ((unused)) = {
+			.open		= NULL,
+			.release	= blk_release,
+			.ioctl		= NULL,
+			.compat_ioctl	= NULL,
+		};
+	],[
+	],[
+		AC_MSG_RESULT(void)
+		AC_DEFINE(HAVE_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID, 1,
+		          [bops->release() returns void])
+	],[
+		AC_MSG_RESULT(int)
+	])
+	EXTRA_KCFLAGS="$tmp_flags"
+])
diff --git a/config/kernel.m4 b/config/kernel.m4
index 375e4b79a..c7ca260c5 100644
--- a/config/kernel.m4
+++ b/config/kernel.m4
@@ -12,7 +12,7 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
 	ZFS_AC_KERNEL_CURRENT_BIO_TAIL
 	ZFS_AC_KERNEL_SUPER_USER_NS
 	ZFS_AC_KERNEL_SUBMIT_BIO
-	ZFS_AC_KERNEL_BDEV_BLOCK_DEVICE_OPERATIONS
+	ZFS_AC_KERNEL_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS
 	ZFS_AC_KERNEL_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID
 	ZFS_AC_KERNEL_TYPE_FMODE_T
 	ZFS_AC_KERNEL_3ARG_BLKDEV_GET
diff --git a/include/linux/blkdev_compat.h b/include/linux/blkdev_compat.h
index f99980ab3..27f056626 100644
--- a/include/linux/blkdev_compat.h
+++ b/include/linux/blkdev_compat.h
@@ -32,6 +32,7 @@
 #include <linux/blkdev.h>
 #include <linux/elevator.h>
 #include <linux/backing-dev.h>
+#include <linux/msdos_fs.h>	/* for SECTOR_* */
 
 #ifndef HAVE_FMODE_T
 typedef unsigned __bitwise__ fmode_t;
diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c
index ffa5fac7c..03f956302 100644
--- a/module/zfs/zvol.c
+++ b/module/zfs/zvol.c
@@ -99,7 +99,7 @@ unsigned long zvol_max_discard_blocks = 16384;
 unsigned int zvol_volmode = ZFS_VOLMODE_GEOM;
 
 static taskq_t *zvol_taskq;
-static kmutex_t zvol_state_lock;
+static krwlock_t zvol_state_lock;
 static list_t zvol_state_list;
 
 #define	ZVOL_HT_SIZE	1024
@@ -176,17 +176,17 @@ zvol_find_by_dev(dev_t dev)
 {
 	zvol_state_t *zv;
 
-	mutex_enter(&zvol_state_lock);
+	rw_enter(&zvol_state_lock, RW_READER);
 	for (zv = list_head(&zvol_state_list); zv != NULL;
 	    zv = list_next(&zvol_state_list, zv)) {
 		mutex_enter(&zv->zv_state_lock);
 		if (zv->zv_dev == dev) {
-			mutex_exit(&zvol_state_lock);
+			rw_exit(&zvol_state_lock);
 			return (zv);
 		}
 		mutex_exit(&zv->zv_state_lock);
 	}
-	mutex_exit(&zvol_state_lock);
+	rw_exit(&zvol_state_lock);
 
 	return (NULL);
 }
@@ -204,7 +204,7 @@ zvol_find_by_name_hash(const char *name, uint64_t hash, int mode)
 	zvol_state_t *zv;
 	struct hlist_node *p = NULL;
 
-	mutex_enter(&zvol_state_lock);
+	rw_enter(&zvol_state_lock, RW_READER);
 	hlist_for_each(p, ZVOL_HT_HEAD(hash)) {
 		zv = hlist_entry(p, zvol_state_t, zv_hlink);
 		mutex_enter(&zv->zv_state_lock);
@@ -227,12 +227,12 @@ zvol_find_by_name_hash(const char *name, uint64_t hash, int mode)
 				    strncmp(zv->zv_name, name, MAXNAMELEN)
 				    == 0);
 			}
-			mutex_exit(&zvol_state_lock);
+			rw_exit(&zvol_state_lock);
 			return (zv);
 		}
 		mutex_exit(&zv->zv_state_lock);
 	}
-	mutex_exit(&zvol_state_lock);
+	rw_exit(&zvol_state_lock);
 
 	return (NULL);
 }
@@ -339,24 +339,6 @@ zvol_get_stats(objset_t *os, nvlist_t *nv)
 	return (SET_ERROR(error));
 }
 
-static void
-zvol_size_changed(zvol_state_t *zv, uint64_t volsize)
-{
-	struct block_device *bdev;
-
-	ASSERT(MUTEX_HELD(&zv->zv_state_lock));
-
-	bdev = bdget_disk(zv->zv_disk, 0);
-	if (bdev == NULL)
-		return;
-
-	set_capacity(zv->zv_disk, volsize >> 9);
-	zv->zv_volsize = volsize;
-	check_disk_size_change(zv->zv_disk, bdev);
-
-	bdput(bdev);
-}
-
 /*
  * Sanity check volume size.
  */
@@ -409,31 +391,17 @@ zvol_update_volsize(uint64_t volsize, objset_t *os)
 	return (error);
 }
 
-static int
-zvol_update_live_volsize(zvol_state_t *zv, uint64_t volsize)
-{
-	zvol_size_changed(zv, volsize);
-
-	/*
-	 * We should post a event here describing the expansion.  However,
-	 * the zfs_ereport_post() interface doesn't nicely support posting
-	 * events for zvols, it assumes events relate to vdevs or zios.
-	 */
-
-	return (0);
-}
-
 /*
- * Set ZFS_PROP_VOLSIZE set entry point.
+ * Set ZFS_PROP_VOLSIZE set entry point.  Note that modifying the volume
+ * size will result in a udev "change" event being generated.
  */
 int
 zvol_set_volsize(const char *name, uint64_t volsize)
 {
-	zvol_state_t *zv = NULL;
 	objset_t *os = NULL;
-	int error;
-	dmu_object_info_t *doi;
+	struct gendisk *disk = NULL;
 	uint64_t readonly;
+	int error;
 	boolean_t owned = B_FALSE;
 
 	error = dsl_prop_get_integer(name,
@@ -443,7 +411,7 @@ zvol_set_volsize(const char *name, uint64_t volsize)
 	if (readonly)
 		return (SET_ERROR(EROFS));
 
-	zv = zvol_find_by_name(name, RW_READER);
+	zvol_state_t *zv = zvol_find_by_name(name, RW_READER);
 
 	ASSERT(zv == NULL || (MUTEX_HELD(&zv->zv_state_lock) &&
 	    RW_READ_HELD(&zv->zv_suspend_lock)));
@@ -464,16 +432,18 @@ zvol_set_volsize(const char *name, uint64_t volsize)
 		os = zv->zv_objset;
 	}
 
-	doi = kmem_alloc(sizeof (dmu_object_info_t), KM_SLEEP);
+	dmu_object_info_t *doi = kmem_alloc(sizeof (*doi), KM_SLEEP);
 
 	if ((error = dmu_object_info(os, ZVOL_OBJ, doi)) ||
 	    (error = zvol_check_volsize(volsize, doi->doi_data_block_size)))
 		goto out;
 
 	error = zvol_update_volsize(volsize, os);
-
-	if (error == 0 && zv != NULL)
-		error = zvol_update_live_volsize(zv, volsize);
+	if (error == 0 && zv != NULL) {
+		zv->zv_volsize = volsize;
+		zv->zv_changed = 1;
+		disk = zv->zv_disk;
+	}
 out:
 	kmem_free(doi, sizeof (dmu_object_info_t));
 
@@ -488,6 +458,9 @@ out:
 	if (zv != NULL)
 		mutex_exit(&zv->zv_state_lock);
 
+	if (disk != NULL)
+		revalidate_disk(disk);
+
 	return (SET_ERROR(error));
 }
 
@@ -543,8 +516,8 @@ zvol_set_volblocksize(const char *name, uint64_t volblocksize)
 	if (zv == NULL)
 		return (SET_ERROR(ENXIO));
 
-	ASSERT(MUTEX_HELD(&zv->zv_state_lock) &&
-	    RW_READ_HELD(&zv->zv_suspend_lock));
+	ASSERT(MUTEX_HELD(&zv->zv_state_lock));
+	ASSERT(RW_READ_HELD(&zv->zv_suspend_lock));
 
 	if (zv->zv_flags & ZVOL_RDONLY) {
 		mutex_exit(&zv->zv_state_lock);
@@ -1120,7 +1093,7 @@ zvol_get_data(void *arg, lr_write_t *lr, char *buf, zio_t *zio)
 static void
 zvol_insert(zvol_state_t *zv)
 {
-	ASSERT(MUTEX_HELD(&zvol_state_lock));
+	ASSERT(RW_WRITE_HELD(&zvol_state_lock));
 	ASSERT3U(MINOR(zv->zv_dev) & ZVOL_MINOR_MASK, ==, 0);
 	list_insert_head(&zvol_state_list, zv);
 	hlist_add_head(&zv->zv_hlink, ZVOL_HT_HEAD(zv->zv_hash));
@@ -1132,7 +1105,7 @@ zvol_insert(zvol_state_t *zv)
 static void
 zvol_remove(zvol_state_t *zv)
 {
-	ASSERT(MUTEX_HELD(&zvol_state_lock));
+	ASSERT(RW_WRITE_HELD(&zvol_state_lock));
 	list_remove(&zvol_state_list, zv);
 	hlist_del(&zv->zv_hlink);
 }
@@ -1148,8 +1121,8 @@ zvol_setup_zv(zvol_state_t *zv)
 	uint64_t ro;
 	objset_t *os = zv->zv_objset;
 
-	ASSERT(MUTEX_HELD(&zv->zv_state_lock) &&
-	    RW_LOCK_HELD(&zv->zv_suspend_lock));
+	ASSERT(MUTEX_HELD(&zv->zv_state_lock));
+	ASSERT(RW_LOCK_HELD(&zv->zv_suspend_lock));
 
 	error = dsl_prop_get_integer(zv->zv_name, "readonly", &ro, NULL);
 	if (error)
@@ -1227,8 +1200,8 @@ zvol_suspend(const char *name)
 		return (NULL);
 
 	/* block all I/O, release in zvol_resume. */
-	ASSERT(MUTEX_HELD(&zv->zv_state_lock) &&
-	    RW_WRITE_HELD(&zv->zv_suspend_lock));
+	ASSERT(MUTEX_HELD(&zv->zv_state_lock));
+	ASSERT(RW_WRITE_HELD(&zv->zv_suspend_lock));
 
 	atomic_inc(&zv->zv_suspend_ref);
 
@@ -1349,9 +1322,7 @@ zvol_open(struct block_device *bdev, fmode_t flag)
 	int error = 0;
 	boolean_t drop_suspend = B_TRUE;
 
-	ASSERT(!MUTEX_HELD(&zvol_state_lock));
-
-	mutex_enter(&zvol_state_lock);
+	rw_enter(&zvol_state_lock, RW_READER);
 	/*
 	 * Obtain a copy of private_data under the zvol_state_lock to make
 	 * sure that either the result of zvol free code path setting
@@ -1360,7 +1331,7 @@ zvol_open(struct block_device *bdev, fmode_t flag)
 	 */
 	zv = bdev->bd_disk->private_data;
 	if (zv == NULL) {
-		mutex_exit(&zvol_state_lock);
+		rw_exit(&zvol_state_lock);
 		return (SET_ERROR(-ENXIO));
 	}
 
@@ -1384,7 +1355,7 @@ zvol_open(struct block_device *bdev, fmode_t flag)
 	} else {
 		drop_suspend = B_FALSE;
 	}
-	mutex_exit(&zvol_state_lock);
+	rw_exit(&zvol_state_lock);
 
 	ASSERT(MUTEX_HELD(&zv->zv_state_lock));
 	ASSERT(zv->zv_open_count != 0 || RW_READ_HELD(&zv->zv_suspend_lock));
@@ -1402,11 +1373,18 @@ zvol_open(struct block_device *bdev, fmode_t flag)
 
 	zv->zv_open_count++;
 
+	mutex_exit(&zv->zv_state_lock);
+	if (drop_suspend)
+		rw_exit(&zv->zv_suspend_lock);
+
 	check_disk_change(bdev);
 
+	return (0);
+
 out_open_count:
 	if (zv->zv_open_count == 0)
 		zvol_last_close(zv);
+
 out_mutex:
 	mutex_exit(&zv->zv_state_lock);
 	if (drop_suspend)
@@ -1427,9 +1405,7 @@ zvol_release(struct gendisk *disk, fmode_t mode)
 	zvol_state_t *zv;
 	boolean_t drop_suspend = B_TRUE;
 
-	ASSERT(!MUTEX_HELD(&zvol_state_lock));
-
-	mutex_enter(&zvol_state_lock);
+	rw_enter(&zvol_state_lock, RW_READER);
 	zv = disk->private_data;
 
 	mutex_enter(&zv->zv_state_lock);
@@ -1453,7 +1429,7 @@ zvol_release(struct gendisk *disk, fmode_t mode)
 	} else {
 		drop_suspend = B_FALSE;
 	}
-	mutex_exit(&zvol_state_lock);
+	rw_exit(&zvol_state_lock);
 
 	ASSERT(MUTEX_HELD(&zv->zv_state_lock));
 	ASSERT(zv->zv_open_count != 1 || RW_READ_HELD(&zv->zv_suspend_lock));
@@ -1479,7 +1455,7 @@ zvol_ioctl(struct block_device *bdev, fmode_t mode,
 	zvol_state_t *zv = bdev->bd_disk->private_data;
 	int error = 0;
 
-	ASSERT(zv && zv->zv_open_count > 0);
+	ASSERT3U(zv->zv_open_count, >, 0);
 
 	switch (cmd) {
 	case BLKFLSBUF:
@@ -1519,23 +1495,62 @@ zvol_compat_ioctl(struct block_device *bdev, fmode_t mode,
 #define	zvol_compat_ioctl	NULL
 #endif
 
+/*
+ * Linux 2.6.38 preferred interface.
+ */
+#ifdef HAVE_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS
+static unsigned int
+zvol_check_events(struct gendisk *disk, unsigned int clearing)
+{
+	unsigned int mask = 0;
+
+	rw_enter(&zvol_state_lock, RW_READER);
+
+	zvol_state_t *zv = disk->private_data;
+	if (zv != NULL) {
+		mutex_enter(&zv->zv_state_lock);
+		mask = zv->zv_changed ? DISK_EVENT_MEDIA_CHANGE : 0;
+		zv->zv_changed = 0;
+		mutex_exit(&zv->zv_state_lock);
+	}
+
+	rw_exit(&zvol_state_lock);
+
+	return (mask);
+}
+#else
 static int zvol_media_changed(struct gendisk *disk)
 {
+	int changed = 0;
+
+	rw_enter(&zvol_state_lock, RW_READER);
+
 	zvol_state_t *zv = disk->private_data;
+	if (zv != NULL) {
+		mutex_enter(&zv->zv_state_lock);
+		changed = zv->zv_changed;
+		zv->zv_changed = 0;
+		mutex_exit(&zv->zv_state_lock);
+	}
 
-	ASSERT(zv && zv->zv_open_count > 0);
+	rw_exit(&zvol_state_lock);
 
-	return (zv->zv_changed);
+	return (changed);
 }
+#endif
 
 static int zvol_revalidate_disk(struct gendisk *disk)
 {
+	rw_enter(&zvol_state_lock, RW_READER);
+
 	zvol_state_t *zv = disk->private_data;
+	if (zv != NULL) {
+		mutex_enter(&zv->zv_state_lock);
+		set_capacity(zv->zv_disk, zv->zv_volsize >> SECTOR_BITS);
+		mutex_exit(&zv->zv_state_lock);
+	}
 
-	ASSERT(zv && zv->zv_open_count > 0);
-
-	zv->zv_changed = 0;
-	set_capacity(zv->zv_disk, zv->zv_volsize >> 9);
+	rw_exit(&zvol_state_lock);
 
 	return (0);
 }
@@ -1552,7 +1567,7 @@ zvol_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 	zvol_state_t *zv = bdev->bd_disk->private_data;
 	sector_t sectors;
 
-	ASSERT(zv && zv->zv_open_count > 0);
+	ASSERT3U(zv->zv_open_count, >, 0);
 
 	sectors = get_capacity(zv->zv_disk);
 
@@ -1585,68 +1600,20 @@ zvol_probe(dev_t dev, int *part, void *arg)
 	return (kobj);
 }
 
-#ifdef HAVE_BDEV_BLOCK_DEVICE_OPERATIONS
 static struct block_device_operations zvol_ops = {
 	.open			= zvol_open,
 	.release		= zvol_release,
 	.ioctl			= zvol_ioctl,
 	.compat_ioctl		= zvol_compat_ioctl,
-	.media_changed		= zvol_media_changed,
-	.revalidate_disk	= zvol_revalidate_disk,
-	.getgeo			= zvol_getgeo,
-	.owner			= THIS_MODULE,
-};
-
-#else /* HAVE_BDEV_BLOCK_DEVICE_OPERATIONS */
-
-static int
-zvol_open_by_inode(struct inode *inode, struct file *file)
-{
-	return (zvol_open(inode->i_bdev, file->f_mode));
-}
-
-static int
-zvol_release_by_inode(struct inode *inode, struct file *file)
-{
-	return (zvol_release(inode->i_bdev->bd_disk, file->f_mode));
-}
-
-static int
-zvol_ioctl_by_inode(struct inode *inode, struct file *file,
-    unsigned int cmd, unsigned long arg)
-{
-	if (file == NULL || inode == NULL)
-		return (SET_ERROR(-EINVAL));
-
-	return (zvol_ioctl(inode->i_bdev, file->f_mode, cmd, arg));
-}
-
-#ifdef CONFIG_COMPAT
-static long
-zvol_compat_ioctl_by_inode(struct file *file,
-    unsigned int cmd, unsigned long arg)
-{
-	if (file == NULL)
-		return (SET_ERROR(-EINVAL));
-
-	return (zvol_compat_ioctl(file->f_dentry->d_inode->i_bdev,
-	    file->f_mode, cmd, arg));
-}
+#ifdef HAVE_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS
+	.check_events		= zvol_check_events,
 #else
-#define	zvol_compat_ioctl_by_inode	NULL
-#endif
-
-static struct block_device_operations zvol_ops = {
-	.open			= zvol_open_by_inode,
-	.release		= zvol_release_by_inode,
-	.ioctl			= zvol_ioctl_by_inode,
-	.compat_ioctl		= zvol_compat_ioctl_by_inode,
 	.media_changed		= zvol_media_changed,
+#endif
 	.revalidate_disk	= zvol_revalidate_disk,
 	.getgeo			= zvol_getgeo,
 	.owner			= THIS_MODULE,
 };
-#endif /* HAVE_BDEV_BLOCK_DEVICE_OPERATIONS */
 
 /*
  * Allocate memory for a new zvol_state_t and setup the required
@@ -1699,6 +1666,10 @@ zvol_alloc(dev_t dev, const char *name)
 	rw_init(&zv->zv_suspend_lock, NULL, RW_DEFAULT, NULL);
 
 	zv->zv_disk->major = zvol_major;
+#ifdef HAVE_BLOCK_DEVICE_OPERATIONS_CHECK_EVENTS
+	zv->zv_disk->events = DISK_EVENT_MEDIA_CHANGE;
+#endif
+
 	if (volmode == ZFS_VOLMODE_DEV) {
 		/*
 		 * ZFS_VOLMODE_DEV disable partitioning on ZVOL devices: set
@@ -1743,7 +1714,6 @@ zvol_free(void *arg)
 {
 	zvol_state_t *zv = arg;
 
-	ASSERT(!MUTEX_HELD(&zvol_state_lock));
 	ASSERT(!RW_LOCK_HELD(&zv->zv_suspend_lock));
 	ASSERT(!MUTEX_HELD(&zv->zv_state_lock));
 	ASSERT(zv->zv_open_count == 0);
@@ -1870,9 +1840,9 @@ out_doi:
 	kmem_free(doi, sizeof (dmu_object_info_t));
 
 	if (error == 0) {
-		mutex_enter(&zvol_state_lock);
+		rw_enter(&zvol_state_lock, RW_WRITER);
 		zvol_insert(zv);
-		mutex_exit(&zvol_state_lock);
+		rw_exit(&zvol_state_lock);
 		add_disk(zv->zv_disk);
 	} else {
 		ida_simple_remove(&zvol_ida, idx);
@@ -1889,7 +1859,7 @@ zvol_rename_minor(zvol_state_t *zv, const char *newname)
 {
 	int readonly = get_disk_ro(zv->zv_disk);
 
-	ASSERT(MUTEX_HELD(&zvol_state_lock));
+	ASSERT(RW_LOCK_HELD(&zvol_state_lock));
 	ASSERT(MUTEX_HELD(&zv->zv_state_lock));
 
 	strlcpy(zv->zv_name, newname, sizeof (zv->zv_name));
@@ -2129,7 +2099,7 @@ zvol_remove_minors_impl(const char *name)
 	list_create(&free_list, sizeof (zvol_state_t),
 	    offsetof(zvol_state_t, zv_next));
 
-	mutex_enter(&zvol_state_lock);
+	rw_enter(&zvol_state_lock, RW_WRITER);
 
 	for (zv = list_head(&zvol_state_list); zv != NULL; zv = zv_next) {
 		zv_next = list_next(&zvol_state_list, zv);
@@ -2154,15 +2124,15 @@ zvol_remove_minors_impl(const char *name)
 			zvol_remove(zv);
 
 			/*
-			 * clear this while holding zvol_state_lock so
-			 * zvol_open won't open it
+			 * Cleared while holding zvol_state_lock as a writer
+			 * which will prevent zvol_open() from opening it.
 			 */
 			zv->zv_disk->private_data = NULL;
 
 			/* Drop zv_state_lock before zvol_free() */
 			mutex_exit(&zv->zv_state_lock);
 
-			/* try parallel zv_free, if failed do it in place */
+			/* Try parallel zv_free, if failed do it in place */
 			t = taskq_dispatch(system_taskq, zvol_free, zv,
 			    TQ_SLEEP);
 			if (t == TASKQID_INVALID)
@@ -2173,11 +2143,9 @@ zvol_remove_minors_impl(const char *name)
 			mutex_exit(&zv->zv_state_lock);
 		}
 	}
-	mutex_exit(&zvol_state_lock);
+	rw_exit(&zvol_state_lock);
 
-	/*
-	 * Drop zvol_state_lock before calling zvol_free()
-	 */
+	/* Drop zvol_state_lock before calling zvol_free() */
 	while ((zv = list_head(&free_list)) != NULL) {
 		list_remove(&free_list, zv);
 		zvol_free(zv);
@@ -2196,7 +2164,7 @@ zvol_remove_minor_impl(const char *name)
 	if (zvol_inhibit_dev)
 		return;
 
-	mutex_enter(&zvol_state_lock);
+	rw_enter(&zvol_state_lock, RW_WRITER);
 
 	for (zv = list_head(&zvol_state_list); zv != NULL; zv = zv_next) {
 		zv_next = list_next(&zvol_state_list, zv);
@@ -2216,7 +2184,10 @@ zvol_remove_minor_impl(const char *name)
 			}
 			zvol_remove(zv);
 
-			/* clear this so zvol_open won't open it */
+			/*
+			 * Cleared while holding zvol_state_lock as a writer
+			 * which will prevent zvol_open() from opening it.
+			 */
 			zv->zv_disk->private_data = NULL;
 
 			mutex_exit(&zv->zv_state_lock);
@@ -2227,7 +2198,7 @@ zvol_remove_minor_impl(const char *name)
 	}
 
 	/* Drop zvol_state_lock before calling zvol_free() */
-	mutex_exit(&zvol_state_lock);
+	rw_exit(&zvol_state_lock);
 
 	if (zv != NULL)
 		zvol_free(zv);
@@ -2248,7 +2219,7 @@ zvol_rename_minors_impl(const char *oldname, const char *newname)
 	oldnamelen = strlen(oldname);
 	newnamelen = strlen(newname);
 
-	mutex_enter(&zvol_state_lock);
+	rw_enter(&zvol_state_lock, RW_READER);
 
 	for (zv = list_head(&zvol_state_list); zv != NULL; zv = zv_next) {
 		zv_next = list_next(&zvol_state_list, zv);
@@ -2276,7 +2247,7 @@ zvol_rename_minors_impl(const char *oldname, const char *newname)
 		mutex_exit(&zv->zv_state_lock);
 	}
 
-	mutex_exit(&zvol_state_lock);
+	rw_exit(&zvol_state_lock);
 }
 
 typedef struct zvol_snapdev_cb_arg {
@@ -2653,7 +2624,7 @@ zvol_init(void)
 
 	list_create(&zvol_state_list, sizeof (zvol_state_t),
 	    offsetof(zvol_state_t, zv_next));
-	mutex_init(&zvol_state_lock, NULL, MUTEX_DEFAULT, NULL);
+	rw_init(&zvol_state_lock, NULL, RW_DEFAULT, NULL);
 	ida_init(&zvol_ida);
 
 	zvol_taskq = taskq_create(ZVOL_DRIVER, threads, maxclsyspri,
@@ -2690,7 +2661,7 @@ out_taskq:
 	taskq_destroy(zvol_taskq);
 out:
 	ida_destroy(&zvol_ida);
-	mutex_destroy(&zvol_state_lock);
+	rw_destroy(&zvol_state_lock);
 	list_destroy(&zvol_state_list);
 
 	return (SET_ERROR(error));
@@ -2707,7 +2678,7 @@ zvol_fini(void)
 
 	taskq_destroy(zvol_taskq);
 	list_destroy(&zvol_state_list);
-	mutex_destroy(&zvol_state_lock);
+	rw_destroy(&zvol_state_lock);
 
 	ida_destroy(&zvol_ida);
 }