We forbid polling, writing and reading when the file were detached, this may
complex the user in several cases:
- when guest pass some buffers to vhost/qemu and then disable some queues,
vhost/qemu needs to to its own cleanup which is complex. We can do this simply
by allowing a user can still write to an disabled queue to handle this. And
user can still do read but just nothing returned.
- align the polling behavior with macvtap which never fails when the queue is
created. this can simplify the polling errors handling of its user (e.g vhost)
Signed-off-by: Jason Wang <jasow...@redhat.com>
---
drivers/net/tun.c | 18 +++++++++++-------
1 files changed, 11 insertions(+), 7 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index af372d0..eb68937 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -307,7 +307,7 @@ static void tun_flow_update(struct tun_struct *tun, u32
rxhash,
rcu_read_lock();
- if (tun->numqueues == 1)
+ if (tun->numqueues == 1 || queue_index >= tun->numqueues)
goto unlock;
e = tun_flow_find(head, rxhash);
@@ -406,21 +406,21 @@ static void __tun_detach(struct tun_file *tfile, bool
clean)
tun = rtnl_dereference(tfile->tun);
- if (tun) {
+ if (tun && !tfile->detached) {
u16 index = tfile->queue_index;
BUG_ON(index >= tun->numqueues);
dev = tun->dev;
rcu_assign_pointer(tun->tfiles[index],
tun->tfiles[tun->numqueues - 1]);
- rcu_assign_pointer(tfile->tun, NULL);
ntfile = rtnl_dereference(tun->tfiles[index]);
ntfile->queue_index = index;
--tun->numqueues;
- if (clean)
+ if (clean) {
+ rcu_assign_pointer(tfile->tun, NULL);
sock_put(&tfile->sk);
- else
+ } else
tun_disable_queue(tun, tfile);
synchronize_net();
@@ -465,6 +465,10 @@ static void tun_detach_all(struct net_device *dev)
rcu_assign_pointer(tfile->tun, NULL);
--tun->numqueues;
}
+ list_for_each_entry(tfile, &tun->disabled, next) {
+ wake_up_all(&tfile->wq.wait);
+ rcu_assign_pointer(tfile->tun, NULL);
+ }
BUG_ON(tun->numqueues != 0);
synchronize_net();
@@ -491,7 +495,7 @@ static int tun_attach(struct tun_struct *tun, struct file
*file)
int err;
err = -EINVAL;
- if (rtnl_dereference(tfile->tun))
+ if (rtnl_dereference(tfile->tun) && !tfile->detached)
goto out;
err = -EBUSY;
@@ -1795,7 +1799,7 @@ static int tun_set_queue(struct file *file, struct ifreq
*ifr)
ret = tun_attach(tun, file);
} else if (ifr->ifr_flags & IFF_DETACH_QUEUE) {
tun = rtnl_dereference(tfile->tun);
- if (!tun || !(tun->flags & TUN_TAP_MQ))
+ if (!tun || !(tun->flags & TUN_TAP_MQ) || tfile->detached)
ret = -EINVAL;
else
__tun_detach(tfile, false);
--
1.7.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
