Vitaly Kuznetsov d7f2fbafb4 Drivers: hv: vmbus: serialize Offer and Rescind offer ... Commit 4b2f9abea5 ("staging: hv: convert channel_mgmt.c to not call osd_schedule_callback")' was written under an assumption that we never receive Rescind offer while we're still processing the initial Offer request. However, the issue we fixed in 04a258c162 could be caused by this assumption not always being true. In particular, we need to protect against the following: 1) Receiving a Rescind offer after we do queue_work() for processing an Offer request and before we actually enter vmbus_process_offer(). work.func points to vmbus_process_offer() at this moment and in vmbus_onoffer_rescind() we do another queue_work() without a check so we'll enter vmbus_process_offer() twice. 2) Receiving a Rescind offer after we enter vmbus_process_offer() and especially after we set >state = CHANNEL_OPEN_STATE. Many things can go wrong in that case, e.g. we can call free_channel() while we're still using it. Implement the required protection by changing work->func at the very end of vmbus_process_offer() and checking work->func in vmbus_onoffer_rescind(). In case we receive rescind offer during or before vmbus_process_offer() is done we set rescind flag to true and we check it at the end of vmbus_process_offer() so such offer will not get lost. Suggested-by: Radim Krčmář <rkrcmar@redhat.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2015-01-25 09:18:01 -08:00
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channel.c	Drivers: hv: rename sc_lock to the more generic lock	2015-01-25 09:18:00 -08:00
channel_mgmt.c	Drivers: hv: vmbus: serialize Offer and Rescind offer	2015-01-25 09:18:01 -08:00
connection.c	Drivers: hv: vmbus: Use get_cpu() to get the current CPU	2015-01-12 05:04:10 -08:00
hv.c	Drivers: hv: vmbus: Implement a clockevent device	2015-01-25 09:17:57 -08:00
hv_balloon.c	Drivers: hv: hv_balloon: Don't post pressure status from interrupt context	2015-01-25 09:17:57 -08:00
hv_fcopy.c	hv: hv_fcopy: drop the obsolete message on transfer failure	2015-01-25 09:17:58 -08:00
hv_kvp.c	Drivers: hv: kvp,vss: Fast propagation of userspace communication failure	2014-11-26 19:00:32 -08:00
hv_snapshot.c	Drivers: hv: kvp,vss: Fast propagation of userspace communication failure	2014-11-26 19:00:32 -08:00
hv_util.c	Drivers: hv: util: Fix a bug in the KVP code	2014-07-09 14:34:35 -07:00
hyperv_vmbus.h	Drivers: hv: vmbus: Implement a clockevent device	2015-01-25 09:17:57 -08:00
Kconfig	x86: Make Linux guest support optional	2013-03-04 13:14:25 -08:00
Makefile	Drivers: hv: Implement the file copy service	2014-02-18 10:53:48 -08:00
ring_buffer.c	Drivers: hv: vmbus: Enable interrupt driven flow control	2014-09-23 23:31:22 -07:00
vmbus_drv.c	Drivers: hv: vmbus: Implement a clockevent device	2015-01-25 09:17:57 -08:00