| Message ID | 1423049555-1318-1-git-send-email-luis.henriques@canonical.com |
|---|---|
| State | New |
| Headers | show |
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 28397fc32a85..73d5388bd1f6 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -4963,10 +4963,7 @@ static void rbd_dev_unprobe(struct rbd_device *rbd_dev) { struct rbd_image_header *header; - /* Drop parent reference unless it's already been done (or none) */ - - if (rbd_dev->parent_overlap) - rbd_dev_parent_put(rbd_dev); + rbd_dev_parent_put(rbd_dev); /* Free dynamic fields from the header, then zero it out */
This is a note to let you know that I have just added a patch titled rbd: drop parent_ref in rbd_dev_unprobe() unconditionally to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue This patch is scheduled to be released in version 3.16.7-ckt6. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.16.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 4bb7f1fa74ee64f47a7bfc2c811e126929119d06 Mon Sep 17 00:00:00 2001 From: Ilya Dryomov <idryomov@redhat.com> Date: Mon, 19 Jan 2015 12:06:14 +0300 Subject: rbd: drop parent_ref in rbd_dev_unprobe() unconditionally commit e69b8d414f948c242ad9f3eb2b7e24fba783dbbd upstream. This effectively reverts the last hunk of 392a9dad7e77 ("rbd: detect when clone image is flattened"). The problem with parent_overlap != 0 condition is that it's possible and completely valid to have an image with parent_overlap == 0 whose parent state needs to be cleaned up on unmap. The next commit, which drops the "clone image now standalone" logic, opens up another window of opportunity to hit this, but even without it # cat parent-ref.sh #!/bin/bash rbd create --image-format 2 --size 1 foo rbd snap create foo@snap rbd snap protect foo@snap rbd clone foo@snap bar rbd resize --allow-shrink --size 0 bar rbd resize --size 1 bar DEV=$(rbd map bar) rbd unmap $DEV leaves rbd_device/rbd_spec/etc and rbd_client along with ceph_client hanging around. My thinking behind calling rbd_dev_parent_put() unconditionally is that there shouldn't be any requests in flight at that point in time as we are deep into unmap sequence. Hence, even if rbd_dev_unparent() caused by flatten is delayed by in-flight requests, it will have finished by the time we reach rbd_dev_unprobe() caused by unmap, thus turning unconditional rbd_dev_parent_put() into a no-op. Fixes: http://tracker.ceph.com/issues/10352 Signed-off-by: Ilya Dryomov <idryomov@redhat.com> Reviewed-by: Josh Durgin <jdurgin@redhat.com> Reviewed-by: Alex Elder <elder@linaro.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/block/rbd.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) -- 2.1.4