Tyrel Datwyler 2149aa5830 scsi: ibmvscsi: Fix potential race after loss of transport ... [ Upstream commit 665e0224a3 ] After a loss of transport due to an adapter migration or crash/disconnect from the host partner there is a tiny window where we can race adjusting the request_limit of the adapter. The request limit is atomically increased/decreased to track the number of inflight requests against the allowed limit of our VIOS partner. After a transport loss we set the request_limit to zero to reflect this state. However, there is a window where the adapter may attempt to queue a command because the transport loss event hasn't been fully processed yet and request_limit is still greater than zero. The hypercall to send the event will fail and the error path will increment the request_limit as a result. If the adapter processes the transport event prior to this increment the request_limit becomes out of sync with the adapter state and can result in SCSI commands being submitted on the now reset connection prior to an SRP Login resulting in a protocol violation. Fix this race by protecting request_limit with the host lock when changing the value via atomic_set() to indicate no transport. Link: https://lore.kernel.org/r/20201025001355.4527-1-tyreld@linux.ibm.com Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>		2020-11-10 12:37:30 +01:00
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Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
ibmvfc.c	scsi: ibmvfc: Fix error return in ibmvfc_probe()	2020-10-29 09:58:07 +01:00
ibmvfc.h	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156	2019-05-30 11:26:35 -07:00
ibmvscsi.c	scsi: ibmvscsi: Fix potential race after loss of transport	2020-11-10 12:37:30 +01:00
ibmvscsi.h	SCSI misc on 20190709	2019-07-11 15:14:01 -07:00