tree fce5a8414513e8b4c7587d7f8f711e278b8b89ee
parent a25e3726b32c746c0098125d4c7463bb84df72bb
author NeilBrown <neilb@suse.de> 1574909803 +1100
committer J. Bruce Fields <bfields@redhat.com> 1575143992 -0500

nfsd: check for EBUSY from vfs_rmdir/vfs_unink.

vfs_rmdir and vfs_unlink can return -EBUSY if the
target is a mountpoint.  This currently gets passed to
nfserrno() by nfsd_unlink(), and that results in a WARNing,
which is not user-friendly.

Possibly the best NFSv4 error is NFS4ERR_FILE_OPEN, because
there is a sense in which the object is currently in use
by some other task.  The Linux NFSv4 client will map this
back to EBUSY, which is an added benefit.

For NFSv3, the best we can do is probably NFS3ERR_ACCES, which isn't
true, but is not less true than the other options.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>