From 2ef82d24f445e82f80e235f44eb9d1bc933e3670 Mon Sep 17 00:00:00 2001 From: Dexuan Cui Date: Wed, 16 Jul 2014 00:00:45 -0700 Subject: [PATCH] Drivers: hv: hv_fcopy: fix a race condition for SMP guest We should schedule the 5s "timer work" before starting the data transfer, otherwise, the data transfer code may finish so fast on another virtual cpu that when the code(fcopy_write()) trying to cancel the 5s "timer work" can occasionally fail because the "timer work" may haven't been scheduled yet and as a result the fcopy process will be aborted wrongly by fcopy_work_func() in 5s. Thank Liz Zhang for the initial investigation on the bug. This addresses https://bugzilla.redhat.com/show_bug.cgi?id=1118123 Tested-by: Liz Zhang Cc: Haiyang Zhang Cc: stable@vger.kernel.org Signed-off-by: Dexuan Cui Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- drivers/hv/hv_fcopy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hv/hv_fcopy.c b/drivers/hv/hv_fcopy.c index eaaa3d843b80..23b2ce294c4c 100644 --- a/drivers/hv/hv_fcopy.c +++ b/drivers/hv/hv_fcopy.c @@ -246,8 +246,8 @@ void hv_fcopy_onchannelcallback(void *context) /* * Send the information to the user-level daemon. */ - fcopy_send_data(); schedule_delayed_work(&fcopy_work, 5*HZ); + fcopy_send_data(); return; } icmsghdr->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE; -- 2.20.1