| Message ID | 1377757447-23515-3-git-send-email-josh.durgin@inktank.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Reviewed-by: Sage Weil <sage@inktank.com> On Wed, 28 Aug 2013, Josh Durgin wrote: > Without a way to flush the osd client's notify workqueue, a watch > event that is unregistered could continue receiving callbacks > indefinitely. > > Unregistering the event simply means no new notifies are added to the > queue, but there may still be events in the queue that will call the > watch callback for the event. If the queue is flushed after the event > is unregistered, the caller can be sure no more watch callbacks will > occur for the canceled watch. > > Signed-off-by: Josh Durgin <josh.durgin@inktank.com> > --- > include/linux/ceph/osd_client.h | 2 ++ > net/ceph/osd_client.c | 11 +++++++++++ > 2 files changed, 13 insertions(+), 0 deletions(-) > > diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h > index ce6df39..8f47625 100644 > --- a/include/linux/ceph/osd_client.h > +++ b/include/linux/ceph/osd_client.h > @@ -335,6 +335,8 @@ extern int ceph_osdc_wait_request(struct ceph_osd_client *osdc, > struct ceph_osd_request *req); > extern void ceph_osdc_sync(struct ceph_osd_client *osdc); > > +extern void ceph_osdc_flush_notifies(struct ceph_osd_client *osdc); > + > extern int ceph_osdc_readpages(struct ceph_osd_client *osdc, > struct ceph_vino vino, > struct ceph_file_layout *layout, > diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c > index 1606f74..2b4b32a 100644 > --- a/net/ceph/osd_client.c > +++ b/net/ceph/osd_client.c > @@ -2216,6 +2216,17 @@ void ceph_osdc_sync(struct ceph_osd_client *osdc) > EXPORT_SYMBOL(ceph_osdc_sync); > > /* > + * Call all pending notify callbacks - for use after a watch is > + * unregistered, to make sure no more callbacks for it will be invoked > + */ > +extern void ceph_osdc_flush_notifies(struct ceph_osd_client *osdc) > +{ > + flush_workqueue(osdc->notify_wq); > +} > +EXPORT_SYMBOL(ceph_osdc_flush_notifies); > + > + > +/* > * init, shutdown > */ > int ceph_osdc_init(struct ceph_osd_client *osdc, struct ceph_client *client) > -- > 1.7.2.5 > > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 08/29/2013 01:24 AM, Josh Durgin wrote: > Without a way to flush the osd client's notify workqueue, a watch > event that is unregistered could continue receiving callbacks > indefinitely. > > Unregistering the event simply means no new notifies are added to the > queue, but there may still be events in the queue that will call the > watch callback for the event. If the queue is flushed after the event > is unregistered, the caller can be sure no more watch callbacks will > occur for the canceled watch. Looks good. Reviewed-by: Alex Elder <elder@linaro.org> > Signed-off-by: Josh Durgin <josh.durgin@inktank.com> > --- > include/linux/ceph/osd_client.h | 2 ++ > net/ceph/osd_client.c | 11 +++++++++++ > 2 files changed, 13 insertions(+), 0 deletions(-) > > diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h > index ce6df39..8f47625 100644 > --- a/include/linux/ceph/osd_client.h > +++ b/include/linux/ceph/osd_client.h > @@ -335,6 +335,8 @@ extern int ceph_osdc_wait_request(struct ceph_osd_client *osdc, > struct ceph_osd_request *req); > extern void ceph_osdc_sync(struct ceph_osd_client *osdc); > > +extern void ceph_osdc_flush_notifies(struct ceph_osd_client *osdc); > + > extern int ceph_osdc_readpages(struct ceph_osd_client *osdc, > struct ceph_vino vino, > struct ceph_file_layout *layout, > diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c > index 1606f74..2b4b32a 100644 > --- a/net/ceph/osd_client.c > +++ b/net/ceph/osd_client.c > @@ -2216,6 +2216,17 @@ void ceph_osdc_sync(struct ceph_osd_client *osdc) > EXPORT_SYMBOL(ceph_osdc_sync); > > /* > + * Call all pending notify callbacks - for use after a watch is > + * unregistered, to make sure no more callbacks for it will be invoked > + */ > +extern void ceph_osdc_flush_notifies(struct ceph_osd_client *osdc) > +{ > + flush_workqueue(osdc->notify_wq); > +} > +EXPORT_SYMBOL(ceph_osdc_flush_notifies); > + > + > +/* > * init, shutdown > */ > int ceph_osdc_init(struct ceph_osd_client *osdc, struct ceph_client *client) > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/ceph/osd_client.h b/include/linux/ceph/osd_client.h index ce6df39..8f47625 100644 --- a/include/linux/ceph/osd_client.h +++ b/include/linux/ceph/osd_client.h @@ -335,6 +335,8 @@ extern int ceph_osdc_wait_request(struct ceph_osd_client *osdc, struct ceph_osd_request *req); extern void ceph_osdc_sync(struct ceph_osd_client *osdc); +extern void ceph_osdc_flush_notifies(struct ceph_osd_client *osdc); + extern int ceph_osdc_readpages(struct ceph_osd_client *osdc, struct ceph_vino vino, struct ceph_file_layout *layout, diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c index 1606f74..2b4b32a 100644 --- a/net/ceph/osd_client.c +++ b/net/ceph/osd_client.c @@ -2216,6 +2216,17 @@ void ceph_osdc_sync(struct ceph_osd_client *osdc) EXPORT_SYMBOL(ceph_osdc_sync); /* + * Call all pending notify callbacks - for use after a watch is + * unregistered, to make sure no more callbacks for it will be invoked + */ +extern void ceph_osdc_flush_notifies(struct ceph_osd_client *osdc) +{ + flush_workqueue(osdc->notify_wq); +} +EXPORT_SYMBOL(ceph_osdc_flush_notifies); + + +/* * init, shutdown */ int ceph_osdc_init(struct ceph_osd_client *osdc, struct ceph_client *client)
Without a way to flush the osd client's notify workqueue, a watch event that is unregistered could continue receiving callbacks indefinitely. Unregistering the event simply means no new notifies are added to the queue, but there may still be events in the queue that will call the watch callback for the event. If the queue is flushed after the event is unregistered, the caller can be sure no more watch callbacks will occur for the canceled watch. Signed-off-by: Josh Durgin <josh.durgin@inktank.com> --- include/linux/ceph/osd_client.h | 2 ++ net/ceph/osd_client.c | 11 +++++++++++ 2 files changed, 13 insertions(+), 0 deletions(-)