on 13/11/2010 13:06 Martin Matuska said the following: > No, this is not good for us. Solaris does not allow "mounting" of > snapshots on any vnode, like we do. Solaris has them only in > .zfs/snapshots. This allows us to have read-only mounts without even > mounting the parent zfs. > > Before v15 we have been happy with that code and had no issues :-) > > I have a very simple testcase where just fixing the VFS_RELE breaks our > forced unmount. Let's say we use the correct VFS_RELE in zfs_vfsops.c: > VFS_RELE(vfsp->mnt_vnodecovered->v_vfsp); > > Now let's say you have a mounted filesystem (e.g. md) under /mnt: > /dev/md5 on /mnt (ufs, local) > > # mkdir /mnt/test > # mount -t zfs t...@t2 /mnt/test > # umount -f /mnt > > Now you will hang because the second VFS_HOLD.
Hang here would be bad, I agree. But I think that the umount shouldn't succeed either, in this case. > So I stick to my opinion > that this "extra protection" is more a problem than a solution in our > case and it should be commented out. -- Andriy Gapon _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"