FreeBSD: Clean up zfsdev_close to match Linux

Resolve some oddities in zfsdev_close() which could result in a
panic and were not present in the equivalent function for Linux.

- Remove unused definition ZFS_MIN_MINOR
- FreeBSD: Simplify zfsdev state destruction
- Assert zs_minor is valid in zfsdev_close
- Make locking around zfsdev state match Linux

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ryan Moeller <ryan@iXsystems.com>
Closes #11720

diff --git a/include/sys/zfs_ioctl.h b/include/sys/zfs_ioctl.h
index afae576ea21a0b2b8ddfca169a82f5e31b7d3df6..8834c52990d0279a55b6dfcc2c436592fde1f58b 100644 (file)
--- a/include/sys/zfs_ioctl.h
+++ b/include/sys/zfs_ioctl.h
@@ -525,7 +525,6 @@ typedef struct zfs_useracct {
 } zfs_useracct_t;
 
 #define        ZFSDEV_MAX_MINOR        (1 << 16)
-#define        ZFS_MIN_MINOR   (ZFSDEV_MAX_MINOR + 1)
 
 #define        ZPOOL_EXPORT_AFTER_SPLIT 0x1
 

diff --git a/module/os/freebsd/zfs/kmod_core.c b/module/os/freebsd/zfs/kmod_core.c
index c11d4dbcf660c3e4c8d06dbb1a722e82b15bd907..d5ba0d93a56924064642a08dd11e0a56a4711af1 100644 (file)
--- a/module/os/freebsd/zfs/kmod_core.c
+++ b/module/os/freebsd/zfs/kmod_core.c
@@ -182,23 +182,21 @@ out:
 static void
 zfsdev_close(void *data)
 {
-       zfsdev_state_t *zs, *zsp = data;
+       zfsdev_state_t *zs = data;
+
+       ASSERT(zs != NULL);
 
        mutex_enter(&zfsdev_state_lock);
-       for (zs = zfsdev_state_list; zs != NULL; zs = zs->zs_next) {
-               if (zs == zsp)
-                       break;
-       }
-       if (zs == NULL || zs->zs_minor <= 0) {
-               mutex_exit(&zfsdev_state_lock);
-               return;
-       }
+
+       ASSERT(zs->zs_minor != 0);
+
        zs->zs_minor = -1;
        zfs_onexit_destroy(zs->zs_onexit);
        zfs_zevent_destroy(zs->zs_zevent);
-       mutex_exit(&zfsdev_state_lock);
        zs->zs_onexit = NULL;
        zs->zs_zevent = NULL;
+
+       mutex_exit(&zfsdev_state_lock);
 }
 
 static int