Reference counters are preferred to use refcount_t instead of atomic_t. This is because the implementation of refcount_t can prevent overflows and detect possible use-after-free. So convert atomic_t ref counters to refcount_t.
Signed-off-by: Chuhong Yuan <[email protected]> --- drivers/block/drbd/drbd_int.h | 3 ++- drivers/block/drbd/drbd_main.c | 4 ++-- drivers/block/drbd/drbd_req.c | 16 ++++++++-------- 3 files changed, 12 insertions(+), 11 deletions(-) diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h index ddbf56014c51..d5167a7a87db 100644 --- a/drivers/block/drbd/drbd_int.h +++ b/drivers/block/drbd/drbd_int.h @@ -30,6 +30,7 @@ #include <linux/genhd.h> #include <linux/idr.h> #include <linux/dynamic_debug.h> +#include <linux/refcount.h> #include <net/tcp.h> #include <linux/lru_cache.h> #include <linux/prefetch.h> @@ -354,7 +355,7 @@ struct drbd_request { /* once it hits 0, we may complete the master_bio */ - atomic_t completion_ref; + refcount_t completion_ref; /* once it hits 0, we may destroy this drbd_request object */ struct kref kref; diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c index 9bd4ddd12b25..37746708ee84 100644 --- a/drivers/block/drbd/drbd_main.c +++ b/drivers/block/drbd/drbd_main.c @@ -2295,14 +2295,14 @@ static void do_retry(struct work_struct *ws) bool expected; expected = - expect(atomic_read(&req->completion_ref) == 0) && + expect(refcount_read(&req->completion_ref) == 0) && expect(req->rq_state & RQ_POSTPONED) && expect((req->rq_state & RQ_LOCAL_PENDING) == 0 || (req->rq_state & RQ_LOCAL_ABORTED) != 0); if (!expected) drbd_err(device, "req=%p completion_ref=%d rq_state=%x\n", - req, atomic_read(&req->completion_ref), + req, refcount_read(&req->completion_ref), req->rq_state); /* We still need to put one kref associated with the diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c index f86cea4c0f8d..cb5d573e7ea2 100644 --- a/drivers/block/drbd/drbd_req.c +++ b/drivers/block/drbd/drbd_req.c @@ -69,7 +69,7 @@ static struct drbd_request *drbd_req_new(struct drbd_device *device, struct bio INIT_LIST_HEAD(&req->req_pending_local); /* one reference to be put by __drbd_make_request */ - atomic_set(&req->completion_ref, 1); + refcount_set(&req->completion_ref, 1); /* one kref as long as completion_ref > 0 */ kref_init(&req->kref); return req; @@ -95,11 +95,11 @@ void drbd_req_destroy(struct kref *kref) const unsigned s = req->rq_state; if ((req->master_bio && !(s & RQ_POSTPONED)) || - atomic_read(&req->completion_ref) || + refcount_read(&req->completion_ref) || (s & RQ_LOCAL_PENDING) || ((s & RQ_NET_MASK) && !(s & RQ_NET_DONE))) { drbd_err(device, "drbd_req_destroy: Logic BUG rq_state = 0x%x, completion_ref = %d\n", - s, atomic_read(&req->completion_ref)); + s, refcount_read(&req->completion_ref)); return; } @@ -315,7 +315,7 @@ static void drbd_req_put_completion_ref(struct drbd_request *req, struct bio_and if (!put) return; - if (!atomic_sub_and_test(put, &req->completion_ref)) + if (!refcount_sub_and_test(put, &req->completion_ref)) return; drbd_req_complete(req, m); @@ -440,15 +440,15 @@ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m, kref_get(&req->kref); if (!(s & RQ_LOCAL_PENDING) && (set & RQ_LOCAL_PENDING)) - atomic_inc(&req->completion_ref); + refcount_inc(&req->completion_ref); if (!(s & RQ_NET_PENDING) && (set & RQ_NET_PENDING)) { inc_ap_pending(device); - atomic_inc(&req->completion_ref); + refcount_inc(&req->completion_ref); } if (!(s & RQ_NET_QUEUED) && (set & RQ_NET_QUEUED)) { - atomic_inc(&req->completion_ref); + refcount_inc(&req->completion_ref); set_if_null_req_next(peer_device, req); } @@ -466,7 +466,7 @@ static void mod_rq_state(struct drbd_request *req, struct bio_and_error *m, } if (!(s & RQ_COMPLETION_SUSP) && (set & RQ_COMPLETION_SUSP)) - atomic_inc(&req->completion_ref); + refcount_inc(&req->completion_ref); /* progress: put references */ -- 2.20.1
