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Message-Id: <20201012132634.639060575@linuxfoundation.org>
Date: Mon, 12 Oct 2020 15:27:00 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Coly Li <colyli@...e.de>,
Chaitanya Kulkarni <chaitanya.kulkarni@....com>,
Christoph Hellwig <hch@....de>, Hannes Reinecke <hare@...e.de>,
Jan Kara <jack@...e.com>, Jens Axboe <axboe@...nel.dk>,
Mikhail Skorzhinskii <mskorzhinskiy@...arflare.com>,
Philipp Reisner <philipp.reisner@...bit.com>,
Sagi Grimberg <sagi@...mberg.me>,
Vlastimil Babka <vbabka@...e.com>,
"David S. Miller" <davem@...emloft.net>
Subject: [PATCH 5.4 37/85] nvme-tcp: check page by sendpage_ok() before calling kernel_sendpage()
From: Coly Li <colyli@...e.de>
commit 7d4194abfc4de13a2663c7fee6891de8360f7a52 upstream.
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 <colyli@...e.de>
Cc: Chaitanya Kulkarni <chaitanya.kulkarni@....com>
Cc: Christoph Hellwig <hch@....de>
Cc: Hannes Reinecke <hare@...e.de>
Cc: Jan Kara <jack@...e.com>
Cc: Jens Axboe <axboe@...nel.dk>
Cc: Mikhail Skorzhinskii <mskorzhinskiy@...arflare.com>
Cc: Philipp Reisner <philipp.reisner@...bit.com>
Cc: Sagi Grimberg <sagi@...mberg.me>
Cc: Vlastimil Babka <vbabka@...e.com>
Cc: stable@...r.kernel.org
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
drivers/nvme/host/tcp.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -861,12 +861,11 @@ static int nvme_tcp_try_send_data(struct
else
flags |= MSG_MORE;
- /* 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)
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