From: Chuck Lever <chuck.lever@xxxxxxxxxx> [ Upstream commit 13a9a9d74d4d9689ad65938966dbc66386063648 ] On platforms that implement flush_dcache_page(), a large NFS WRITE triggers the WARN_ONCE in bvec_iter_advance(): Sep 20 14:01:05 klimt.1015granger.net kernel: Attempted to advance past end of bvec iter Sep 20 14:01:05 klimt.1015granger.net kernel: WARNING: CPU: 0 PID: 1032 at include/linux/bvec.h:101 bvec_iter_advance.isra.0+0xa7/0x158 [sunrpc] Sep 20 14:01:05 klimt.1015granger.net kernel: Call Trace: Sep 20 14:01:05 klimt.1015granger.net kernel: svc_tcp_recvfrom+0x60c/0x12c7 [sunrpc] Sep 20 14:01:05 klimt.1015granger.net kernel: ? bvec_iter_advance.isra.0+0x158/0x158 [sunrpc] Sep 20 14:01:05 klimt.1015granger.net kernel: ? del_timer_sync+0x4b/0x55 Sep 20 14:01:05 klimt.1015granger.net kernel: ? test_bit+0x1d/0x27 [sunrpc] Sep 20 14:01:05 klimt.1015granger.net kernel: svc_recv+0x1193/0x15e4 [sunrpc] Sep 20 14:01:05 klimt.1015granger.net kernel: ? try_to_freeze.isra.0+0x6f/0x6f [sunrpc] Sep 20 14:01:05 klimt.1015granger.net kernel: ? refcount_sub_and_test.constprop.0+0x13/0x40 [sunrpc] Sep 20 14:01:05 klimt.1015granger.net kernel: ? svc_xprt_put+0x1e/0x29f [sunrpc] Sep 20 14:01:05 klimt.1015granger.net kernel: ? svc_send+0x39f/0x3c1 [sunrpc] Sep 20 14:01:05 klimt.1015granger.net kernel: nfsd+0x282/0x345 [nfsd] Sep 20 14:01:05 klimt.1015granger.net kernel: ? __kthread_parkme+0x74/0xba Sep 20 14:01:05 klimt.1015granger.net kernel: kthread+0x2ad/0x2bc Sep 20 14:01:05 klimt.1015granger.net kernel: ? nfsd_destroy+0x124/0x124 [nfsd] Sep 20 14:01:05 klimt.1015granger.net kernel: ? test_bit+0x1d/0x27 Sep 20 14:01:05 klimt.1015granger.net kernel: ? kthread_mod_delayed_work+0x115/0x115 Sep 20 14:01:05 klimt.1015granger.net kernel: ret_from_fork+0x22/0x30 Reported-by: He Zhe <zhe.he@xxxxxxxxxxxxx> Fixes: ca07eda33e01 ("SUNRPC: Refactor svc_recvfrom()") Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/sunrpc/svcsock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index c537272f9c7ed..183d2465df7a3 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -228,7 +228,7 @@ static int svc_one_sock_name(struct svc_sock *svsk, char *buf, int remaining) static void svc_flush_bvec(const struct bio_vec *bvec, size_t size, size_t seek) { struct bvec_iter bi = { - .bi_size = size, + .bi_size = size + seek, }; struct bio_vec bv; -- 2.25.1