diff options
author | Alex Elder <elder@inktank.com> | 2012-10-09 03:37:30 (GMT) |
---|---|---|
committer | Alex Elder <elder@inktank.com> | 2012-10-10 04:59:52 (GMT) |
commit | 588377d6199034c36d335e7df5818b731fea072c (patch) | |
tree | 95efb0eac7f7376395ca3f282e79a5123138c79d /Documentation/static-keys.txt | |
parent | 6285bc231277419255f3498d3eb5ddc9f8e7fe79 (diff) | |
download | linux-588377d6199034c36d335e7df5818b731fea072c.tar.xz |
rbd: reset BACKOFF if unable to re-queue
If ceph_fault() is unable to queue work after a delay, it sets the
BACKOFF connection flag so con_work() will attempt to do so.
In con_work(), when BACKOFF is set, if queue_delayed_work() doesn't
result in newly-queued work, it simply ignores this condition and
proceeds as if no backoff delay were desired. There are two
problems with this--one of which is a bug.
The first problem is simply that the intended behavior is to back
off, and if we aren't able queue the work item to run after a delay
we're not doing that.
The only reason queue_delayed_work() won't queue work is if the
provided work item is already queued. In the messenger, this
means that con_work() is already scheduled to be run again. So
if we simply set the BACKOFF flag again when this occurs, we know
the next con_work() call will again attempt to hold off activity
on the connection until after the delay.
The second problem--the bug--is a leak of a reference count. If
queue_delayed_work() returns 0 in con_work(), con->ops->put() drops
the connection reference held on entry to con_work(). However,
processing is (was) allowed to continue, and at the end of the
function a second con->ops->put() is called.
This patch fixes both problems.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Diffstat (limited to 'Documentation/static-keys.txt')
0 files changed, 0 insertions, 0 deletions