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| author | Lars Ellenberg <lars.ellenberg@linbit.com> | 2017-05-11 10:21:46 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-05-11 10:04:30 -0600 |
| commit | a00ebd1cf12c378a1d4f7a1d6daf1d76c1eaad82 (patch) | |
| tree | 98edd7dd6a0d901d705fe94374c983eda5524798 /drivers/block/drbd | |
| parent | ed6565e734249ef021d5c13ba34c167eb4e42f62 (diff) | |
| download | linux-a00ebd1cf12c378a1d4f7a1d6daf1d76c1eaad82.tar.gz linux-a00ebd1cf12c378a1d4f7a1d6daf1d76c1eaad82.tar.xz | |
drbd: fix request leak introduced by locking/atomic, kref: Kill kref_sub()
When killing kref_sub(), the unconditional additional kref_get()
was not properly paired with the necessary kref_put(), causing
a leak of struct drbd_requests (~ 224 Bytes) per submitted bio,
and breaking DRBD in general, as the destructor of those "drbd_requests"
does more than just the mempoll_free().
Fixes: bdfafc4ffdd2 ("locking/atomic, kref: Kill kref_sub()")
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Cc: stable@vger.kernel.org # v4.11
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/block/drbd')
| -rw-r--r-- | drivers/block/drbd/drbd_req.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index b5730e17b455..656624314f0d 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -315,24 +315,32 @@ void drbd_req_complete(struct drbd_request *req, struct bio_and_error *m) } /* still holds resource->req_lock */ -static int drbd_req_put_completion_ref(struct drbd_request *req, struct bio_and_error *m, int put) +static void drbd_req_put_completion_ref(struct drbd_request *req, struct bio_and_error *m, int put) { struct drbd_device *device = req->device; D_ASSERT(device, m || (req->rq_state & RQ_POSTPONED)); + if (!put) + return; + if (!atomic_sub_and_test(put, &req->completion_ref)) - return 0; + return; drbd_req_complete(req, m); + /* local completion may still come in later, + * we need to keep the req object around. */ + if (req->rq_state & RQ_LOCAL_ABORTED) + return; + if (req->rq_state & RQ_POSTPONED) { /* don't destroy the req object just yet, * but queue it for retry */ drbd_restart_request(req); - return 0; + return; } - return 1; + kref_put(&req->kref, drbd_req_destroy); } static void set_if_null_req_next(struct drbd_peer_device *peer_device, struct drbd_request *req) @@ -519,12 +527,8 @@ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m, if (req->i.waiting) wake_up(&device->misc_wait); - if (c_put) { - if (drbd_req_put_completion_ref(req, m, c_put)) - kref_put(&req->kref, drbd_req_destroy); - } else { - kref_put(&req->kref, drbd_req_destroy); - } + drbd_req_put_completion_ref(req, m, c_put); + kref_put(&req->kref, drbd_req_destroy); } static void drbd_report_io_error(struct drbd_device *device, struct drbd_request *req) @@ -1366,8 +1370,7 @@ nodata: } out: - if (drbd_req_put_completion_ref(req, &m, 1)) - kref_put(&req->kref, drbd_req_destroy); + drbd_req_put_completion_ref(req, &m, 1); spin_unlock_irq(&resource->req_lock); /* Even though above is a kref_put(), this is safe. |