libceph: add function to ensure notifies are complete

commit dd935f44a40f8fb02aff2cc0df2269c92422df1c upstream.

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>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Josh Durgin 2013-08-28 21:43:09 -07:00 committed by Greg Kroah-Hartman
parent dd932ee7a2
commit a2e5951b11
2 changed files with 13 additions and 0 deletions

View File

@ -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,

View File

@ -2208,6 +2208,17 @@ 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
*/