Fix a pair of conditions in which a concurrent umount can cause
NULL pointer dereferences:
* zfs_sb_teardown - prevent a NULL dereference by not calling
dmu_objset_pool with a null z_os.
* zfs_resume_fs - don't try to unmount with a null z_os. This
change makes the ZoL code more consistent
with both Illumos and FreeBSD.
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1543
- * Drain the iput_taskq to ensure all active references to the
+ * If someone has not already unmounted this file system,
+ * drain the iput_taskq to ensure all active references to the
* zfs_sb_t have been handled only then can it be safely destroyed.
*/
* zfs_sb_t have been handled only then can it be safely destroyed.
*/
- taskq_wait(dsl_pool_iput_taskq(dmu_objset_pool(zsb->z_os)));
+ if (zsb->z_os)
+ taskq_wait(dsl_pool_iput_taskq(dmu_objset_pool(zsb->z_os)));
/*
* Close the zil. NB: Can't close the zil while zfs_inactive
/*
* Close the zil. NB: Can't close the zil while zfs_inactive
- * Since we couldn't reopen zfs_sb_t, force
- * unmount this file system.
+ * Since we couldn't reopen zfs_sb_t or, setup the
+ * sa framework, force unmount this file system.
- (void) zfs_umount(zsb->z_sb);
+ if (zsb->z_os)
+ (void) zfs_umount(zsb->z_sb);