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SubjectRe: [PATCH V1] fuse: Set fuse request error upon fuse abort connection
Hi Miklos,

Did you get a chance to look on the below change ?
could you please review and provide your comments if any.

Thanks and Regards,
Pradeep

On 2021-04-16 19:49, Pradeep P V K wrote:
> There is a minor race in setting the fuse out request error
> between fuse_abort_conn() and fuse_dev_do_read() as explained
> below.
>
> Thread-1 Thread-2
> ======== ========
> ->fuse_simple_request() ->shutdown
> ->__fuse_request_send()
> ->queue_request() ->fuse_abort_conn()
> ->fuse_dev_do_read() ->acquire(fpq->lock)
> ->wait_for(fpq->lock) ->set err to all req's in fpq->io
> ->release(fpq->lock)
> ->acquire(fpq->lock)
> ->add req to fpq->io
>
> The above scenario may cause Thread-1 request to add into
> fpq->io list after Thread-2 sets -ECONNABORTED err to all
> its requests in fpq->io list. This leaves Thread-1 request
> with unset err and this further misleads as a completed
> request without an err set upon request_end().
>
> Handle this by setting the err appropriately.
>
> Signed-off-by: Pradeep P V K <pragalla@codeaurora.org>
> ---
> fs/fuse/dev.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> index a5ceccc..102c56f 100644
> --- a/fs/fuse/dev.c
> +++ b/fs/fuse/dev.c
> @@ -1283,6 +1283,7 @@ static ssize_t fuse_dev_do_read(struct fuse_dev
> *fud, struct file *file,
> clear_bit(FR_LOCKED, &req->flags);
> if (!fpq->connected) {
> err = fc->aborted ? -ECONNABORTED : -ENODEV;
> + req->out.h.error = err;
> goto out_end;
> }
> if (err) {

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