]> git.proxmox.com Git - mirror_zfs.git/commitdiff
Linux compat 4.18: check_disk_size_change()
authorBrian Behlendorf <behlendorf1@llnl.gov>
Fri, 15 Jun 2018 22:05:21 +0000 (15:05 -0700)
committerGitHub <noreply@github.com>
Fri, 15 Jun 2018 22:05:21 +0000 (15:05 -0700)
Added support for the bops->check_events() interface which was
added in the 2.6.38 kernel to replace bops->media_changed().
Fully implementing this functionality allows the volume resize
code to rely on revalidate_disk(), which is the preferred
mechanism, and removes the need to use check_disk_size_change().

In order for bops->check_events() to lookup the zvol_state_t
stored in the disk->private_data the zvol_state_lock needs to
be held.  Since the check events interface may poll the mutex
has been converted to a rwlock for better concurrently.  The
rwlock need only be taken as a writer in the zvol_free() path
when disk->private_data is set to NULL.

The configure checks for the block_device_operations structure
were consolidated in a single kernel-block-device-operations.m4
file.

The ZFS_AC_KERNEL_BDEV_BLOCK_DEVICE_OPERATIONS configure checks
and assoicated dead code was removed.  This interface was added
to the 2.6.28 kernel which predates the oldest supported 2.6.32
kernel and will therefore always be available.

Updated maximum Linux version in META file.  The 4.17 kernel
was released on 2018-06-03 and ZoL is compatible with the
finalized kernel.

Reviewed-by: Boris Protopopov <boris.protopopov@actifio.com>
Reviewed-by: Sara Hartse <sara.hartse@delphix.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #7611

META
config/kernel-bdev-block-device-operations.m4 [deleted file]
config/kernel-block-device-operations-release-void.m4 [deleted file]
config/kernel-block-device-operations.m4 [new file with mode: 0644]
config/kernel.m4
include/linux/blkdev_compat.h
module/zfs/zvol.c

diff --git a/META b/META
index f0ef3487e1ceb21b16f2d14b674cea8e368c42ed..6d58f475326248a82b9860635d2c88d359b8307d 100644 (file)
--- a/META
+++ b/META
@@ -6,5 +6,5 @@ Release:       1
 Release-Tags:  relext
 License:       CDDL
 Author:        OpenZFS on Linux
-Linux-Maximum: 4.16
+Linux-Maximum: 4.17
 Linux-Minimum: 2.6.32
diff --git a/config/kernel-bdev-block-device-operations.m4 b/config/kernel-bdev-block-device-operations.m4
deleted file mode 100644 (file)
index faacc19..0000000
+++ /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="$tmp_flags"
-])
diff --git a/config/kernel-block-device-operations-release-void.m4 b/config/kernel-block-device-operations-release-void.m4
deleted file mode 100644 (file)
index a73f858..0000000
+++ /dev/null
@@ -1,29 +0,0 @@
-dnl #
-dnl # 3.10.x API change
-dnl #
-AC_DEFUN([ZFS_AC_KERNEL_BLOCK_DEVICE_OPERATIONS_RELEASE_VOID], [
-       AC_MSG_CHECKING([whether block_device_operations.release is void])
-       tmp_flags="$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 (file)
index 0000000..5f2811c
--- /dev/null
@@ -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"
+])
index 8151cdc224e327acd89aadd558f2d978b54fc96d..d5b69d68260e3a6d177aafc0c62833f51fcb96b8 100644 (file)
@@ -40,7 +40,7 @@ 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
index c42cdd37a47b216e6e0b0a020bda22868845190f..27a4743c0fadf858ccbcb2c5abe834d9920ad63e 100644 (file)
@@ -33,6 +33,7 @@
 #include <linux/elevator.h>
 #include <linux/backing-dev.h>
 #include <linux/hdreg.h>
+#include <linux/msdos_fs.h>    /* for SECTOR_* */
 
 #ifndef HAVE_FMODE_T
 typedef unsigned __bitwise__ fmode_t;
index 97b2e4d7803ed38219f0806c1e5c03fc246f0c6e..ecba516fcc0d836a56f4b97947db19838b12ca22 100644 (file)
@@ -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);
@@ -1131,7 +1104,7 @@ zvol_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb, 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));
@@ -1143,7 +1116,7 @@ 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);
 }
@@ -1159,8 +1132,8 @@ 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)
@@ -1238,8 +1211,8 @@ 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);
 
@@ -1361,9 +1334,7 @@ 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
@@ -1372,7 +1343,7 @@ 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));
        }
 
@@ -1396,7 +1367,7 @@ 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));
@@ -1414,11 +1385,18 @@ 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)
@@ -1439,9 +1417,7 @@ 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);
@@ -1465,7 +1441,7 @@ 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));
@@ -1491,7 +1467,7 @@ 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:
@@ -1531,23 +1507,62 @@ 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)
 {
-       zvol_state_t *zv = disk->private_data;
+       rw_enter(&zvol_state_lock, RW_READER);
 
-       ASSERT(zv && zv->zv_open_count > 0);
+       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);
+       }
 
-       zv->zv_changed = 0;
-       set_capacity(zv->zv_disk, zv->zv_volsize >> 9);
+       rw_exit(&zvol_state_lock);
 
        return (0);
 }
@@ -1564,7 +1579,7 @@ 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);
 
@@ -1597,68 +1612,20 @@ 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
@@ -1711,6 +1678,10 @@ 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
@@ -1755,7 +1726,6 @@ 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);
@@ -1882,9 +1852,9 @@ 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);
@@ -1901,7 +1871,7 @@ 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));
@@ -2141,7 +2111,7 @@ 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);
@@ -2166,15 +2136,15 @@ 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)
@@ -2185,11 +2155,9 @@ 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);
@@ -2208,7 +2176,7 @@ 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);
@@ -2228,7 +2196,10 @@ 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);
@@ -2239,7 +2210,7 @@ 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);
@@ -2260,7 +2231,7 @@ 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);
@@ -2288,7 +2259,7 @@ 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 {
@@ -2665,7 +2636,7 @@ 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,
@@ -2702,7 +2673,7 @@ 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));
@@ -2719,7 +2690,7 @@ 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);
 }