From 7d4194abfc4de13a2663c7fee6891de8360f7a52 Mon Sep 17 00:00:00 2001 From: Coly Li Date: Fri, 2 Oct 2020 16:27:30 +0800 Subject: nvme-tcp: check page by sendpage_ok() before calling kernel_sendpage() Currently nvme_tcp_try_send_data() doesn't use kernel_sendpage() to send slab pages. But for pages allocated by __get_free_pages() without __GFP_COMP, which also have refcount as 0, they are still sent by kernel_sendpage() to remote end, this is problematic. The new introduced helper sendpage_ok() checks both PageSlab tag and page_count counter, and returns true if the checking page is OK to be sent by kernel_sendpage(). This patch fixes the page checking issue of nvme_tcp_try_send_data() with sendpage_ok(). If sendpage_ok() returns true, send this page by kernel_sendpage(), otherwise use sock_no_sendpage to handle this page. Signed-off-by: Coly Li Cc: Chaitanya Kulkarni Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Jan Kara Cc: Jens Axboe Cc: Mikhail Skorzhinskii Cc: Philipp Reisner Cc: Sagi Grimberg Cc: Vlastimil Babka Cc: stable@vger.kernel.org Signed-off-by: David S. Miller --- drivers/nvme/host/tcp.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 8f4f29f18b8c..d6a3e1487354 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -913,12 +913,11 @@ static int nvme_tcp_try_send_data(struct nvme_tcp_request *req) else flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST; - /* can't zcopy slab pages */ - if (unlikely(PageSlab(page))) { - ret = sock_no_sendpage(queue->sock, page, offset, len, + if (sendpage_ok(page)) { + ret = kernel_sendpage(queue->sock, page, offset, len, flags); } else { - ret = kernel_sendpage(queue->sock, page, offset, len, + ret = sock_no_sendpage(queue->sock, page, offset, len, flags); } if (ret <= 0) -- cgit v1.2.3