On Fri, Sep 06, 2019 at 01:00:09PM +0100, Stefan Hajnoczi wrote:
> On Thu, Sep 05, 2019 at 03:48:55PM -0400, Vivek Goyal wrote:
> > diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
> > index 85e2dcad68c1..04e2c000d63f 100644
> > --- a/fs/fuse/fuse_i.h
> > +++ b/fs/fuse/fuse_i.h
> > @@ -479,6 +479,11 @@ struct fuse_iqueue_ops {
> > */
> > void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq)
> > __releases(fiq->waitq.lock);
> > +
> > + /**
> > + * Put a reference on fiq_priv.
>
> I'm a bit confused about fiq->priv's role in this. The callback takes
> struct fuse_iqueue *fiq as the argument, not void *priv, so it could
> theoretically do more than just release priv.
>
> I think one of the following would be clearer:
>
> /**
> * Drop a reference to fiq->priv.
> */
> void (*put_priv)(void *priv);
>
> Or:
>
> /**
> * Clean up when fuse_iqueue is destroyed.
> */
> void (*release)(struct fuse_iqueue *fiq);
>
> In the second case fuse_conn_put() shouldn't check fiq->priv.
Hi Stefan,
I like using ->release() method sounds better. Here is the updated patch.
This also changes the next patch, so will post that as well.
Thanks
Vivek
Subject: virtiofs: Add a fuse_iqueue operation to put() reference
Soon I will make virtio_fs object reference counted, where reference will
be taken by device as well as by fuse_conn (fuse_conn->fuse_iqueue->fiq_priv).
When fuse_connection is going away, it should put its reference on virtio_fs
object.
So add a fuse_iqueue method which can be used to call into virtio_fs to
put the reference on the object (fiq_priv).
Signed-off-by: Vivek Goyal <vgo...@redhat.com>
---
fs/fuse/fuse_i.h | 5 +++++
fs/fuse/inode.c | 4 ++++
2 files changed, 9 insertions(+)
Index: rhvgoyal-linux-fuse/fs/fuse/fuse_i.h
===================================================================
--- rhvgoyal-linux-fuse.orig/fs/fuse/fuse_i.h 2019-09-06 08:46:41.846086544
-0400
+++ rhvgoyal-linux-fuse/fs/fuse/fuse_i.h 2019-09-06 09:24:32.752245246
-0400
@@ -479,6 +479,11 @@ struct fuse_iqueue_ops {
*/
void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq)
__releases(fiq->waitq.lock);
+
+ /**
+ * Cleanup up when fuse_iqueue is destroyed
+ */
+ void (*release)(struct fuse_iqueue *fiq);
};
/** /dev/fuse input queue operations */
Index: rhvgoyal-linux-fuse/fs/fuse/inode.c
===================================================================
--- rhvgoyal-linux-fuse.orig/fs/fuse/inode.c 2019-09-06 08:46:41.847086544
-0400
+++ rhvgoyal-linux-fuse/fs/fuse/inode.c 2019-09-06 09:24:32.754245246 -0400
@@ -631,8 +631,12 @@ EXPORT_SYMBOL_GPL(fuse_conn_init);
void fuse_conn_put(struct fuse_conn *fc)
{
if (refcount_dec_and_test(&fc->count)) {
+ struct fuse_iqueue *fiq = &fc->iq;
+
if (fc->destroy_req)
fuse_request_free(fc->destroy_req);
+ if (fiq->ops->release)
+ fiq->ops->release(fiq);
put_pid_ns(fc->pid_ns);
put_user_ns(fc->user_ns);
fc->release(fc);
