| Message ID | 20220517095534.15288-1-idryomov@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | libceph: fix misleading ceph_osdc_cancel_request() comment | expand |
On 5/17/22 5:55 PM, Ilya Dryomov wrote: > cancel_request() never guaranteed that after its return the OSD > client would be completely done with the OSD request. The callback > (if specified) can still be invoked and a ref can still be held. > > Signed-off-by: Ilya Dryomov <idryomov@gmail.com> > --- > net/ceph/osd_client.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c > index 4b88f2a4a6e2..9d82bb42e958 100644 > --- a/net/ceph/osd_client.c > +++ b/net/ceph/osd_client.c > @@ -4591,8 +4591,13 @@ int ceph_osdc_start_request(struct ceph_osd_client *osdc, > EXPORT_SYMBOL(ceph_osdc_start_request); > > /* > - * Unregister a registered request. The request is not completed: > - * ->r_result isn't set and __complete_request() isn't called. > + * Unregister request. If @req was registered, it isn't completed: > + * r_result isn't set and __complete_request() isn't invoked. > + * > + * If @req wasn't registered, this call may have raced with > + * handle_reply(), in which case r_result would already be set and > + * __complete_request() would be getting invoked, possibly even > + * concurrently with this call. > */ > void ceph_osdc_cancel_request(struct ceph_osd_request *req) > { Reviewed-by: Xiubo Li <xiubli@redhat.com>
On Tue, 2022-05-17 at 11:55 +0200, Ilya Dryomov wrote: > cancel_request() never guaranteed that after its return the OSD > client would be completely done with the OSD request. The callback > (if specified) can still be invoked and a ref can still be held. > > Signed-off-by: Ilya Dryomov <idryomov@gmail.com> > --- > net/ceph/osd_client.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) > > diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c > index 4b88f2a4a6e2..9d82bb42e958 100644 > --- a/net/ceph/osd_client.c > +++ b/net/ceph/osd_client.c > @@ -4591,8 +4591,13 @@ int ceph_osdc_start_request(struct ceph_osd_client *osdc, > EXPORT_SYMBOL(ceph_osdc_start_request); > > /* > - * Unregister a registered request. The request is not completed: > - * ->r_result isn't set and __complete_request() isn't called. > + * Unregister request. If @req was registered, it isn't completed: > + * r_result isn't set and __complete_request() isn't invoked. > + * > + * If @req wasn't registered, this call may have raced with > + * handle_reply(), in which case r_result would already be set and > + * __complete_request() would be getting invoked, possibly even > + * concurrently with this call. > */ > void ceph_osdc_cancel_request(struct ceph_osd_request *req) > { Reviewed-by: Jeff Layton <jlayton@kernel.org>
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c index 4b88f2a4a6e2..9d82bb42e958 100644 --- a/net/ceph/osd_client.c +++ b/net/ceph/osd_client.c @@ -4591,8 +4591,13 @@ int ceph_osdc_start_request(struct ceph_osd_client *osdc, EXPORT_SYMBOL(ceph_osdc_start_request); /* - * Unregister a registered request. The request is not completed: - * ->r_result isn't set and __complete_request() isn't called. + * Unregister request. If @req was registered, it isn't completed: + * r_result isn't set and __complete_request() isn't invoked. + * + * If @req wasn't registered, this call may have raced with + * handle_reply(), in which case r_result would already be set and + * __complete_request() would be getting invoked, possibly even + * concurrently with this call. */ void ceph_osdc_cancel_request(struct ceph_osd_request *req) {
cancel_request() never guaranteed that after its return the OSD client would be completely done with the OSD request. The callback (if specified) can still be invoked and a ref can still be held. Signed-off-by: Ilya Dryomov <idryomov@gmail.com> --- net/ceph/osd_client.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)