From f3181a10e13ac55e18958d7c48cba6f925c71483 Mon Sep 17 00:00:00 2001 From: Faisal Latif Date: Fri, 21 Nov 2008 20:50:55 -0600 Subject: [PATCH] RDMA/nes: Check cqp_avail_reqs is empty after locking the list Between the first empty list check and locking the list, the list can change. Check it again after it is locked to make sure the list is still not empty. Signed-off-by: Faisal Latif Signed-off-by: Chien Tung Signed-off-by: Roland Dreier --- drivers/infiniband/hw/nes/nes_utils.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/hw/nes/nes_utils.c b/drivers/infiniband/hw/nes/nes_utils.c index fb8cbd71a2ef..5611a73d5831 100644 --- a/drivers/infiniband/hw/nes/nes_utils.c +++ b/drivers/infiniband/hw/nes/nes_utils.c @@ -540,11 +540,14 @@ struct nes_cqp_request *nes_get_cqp_request(struct nes_device *nesdev) if (!list_empty(&nesdev->cqp_avail_reqs)) { spin_lock_irqsave(&nesdev->cqp.lock, flags); - cqp_request = list_entry(nesdev->cqp_avail_reqs.next, + if (!list_empty(&nesdev->cqp_avail_reqs)) { + cqp_request = list_entry(nesdev->cqp_avail_reqs.next, struct nes_cqp_request, list); - list_del_init(&cqp_request->list); + list_del_init(&cqp_request->list); + } spin_unlock_irqrestore(&nesdev->cqp.lock, flags); - } else { + } + if (cqp_request == NULL) { cqp_request = kzalloc(sizeof(struct nes_cqp_request), GFP_KERNEL); if (cqp_request) { cqp_request->dynamic = 1; -- 2.39.5