2019-09-05 23:04:35

by Vivek Goyal

[permalink] [raw]
Subject: [PATCH 18/18] virtiofs: Remove TODO item from virtio_fs_free_devs()

virtio_fs_free_devs() is now called from ->kill_sb(). By this time
all device queues have been quiesced. I am assuming that while
->kill_sb() is in progress, another mount instance will wait for
it to finish (sb->s_umount mutex provides mutual exclusion).

W.r.t ->remove path, we should be fine as we are not touching vdev
or virtqueues. And we have reference on virtio_fs object, so we know
rest of the data structures are valid.

So I can't see the need of any additional locking yet.

Signed-off-by: Vivek Goyal <[email protected]>
---
fs/fuse/virtio_fs.c | 2 --
1 file changed, 2 deletions(-)

diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index eadaea6eb8e2..61aa3eba7b22 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -200,8 +200,6 @@ static void virtio_fs_free_devs(struct virtio_fs *fs)
{
unsigned int i;

- /* TODO lock */
-
for (i = 0; i < fs->nvqs; i++) {
struct virtio_fs_vq *fsvq = &fs->vqs[i];

--
2.20.1


2019-09-06 17:38:16

by Stefan Hajnoczi

[permalink] [raw]
Subject: Re: [PATCH 18/18] virtiofs: Remove TODO item from virtio_fs_free_devs()

On Thu, Sep 05, 2019 at 03:48:59PM -0400, Vivek Goyal wrote:
> virtio_fs_free_devs() is now called from ->kill_sb(). By this time
> all device queues have been quiesced. I am assuming that while
> ->kill_sb() is in progress, another mount instance will wait for
> it to finish (sb->s_umount mutex provides mutual exclusion).
>
> W.r.t ->remove path, we should be fine as we are not touching vdev
> or virtqueues. And we have reference on virtio_fs object, so we know
> rest of the data structures are valid.
>
> So I can't see the need of any additional locking yet.
>
> Signed-off-by: Vivek Goyal <[email protected]>
> ---
> fs/fuse/virtio_fs.c | 2 --
> 1 file changed, 2 deletions(-)

Reviewed-by: Stefan Hajnoczi <[email protected]>


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