Uma Krishnan 32a9ae415b scsi: cxlflash: Acquire semaphore before invoking ioctl services ... When a superpipe process that makes use of virtual LUNs is terminated or killed abruptly, there is a possibility that the cxlflash driver could hang and deprive other operations on the adapter. The release fop registered to be invoked on a context close, detaches every LUN associated with the context. The underlying service to detach the LUN assumes it has been called with the read semaphore held, and releases the semaphore before any operation that could be time consuming. When invoked without holding the read semaphore, an opportunity is created for the semaphore's count to become negative when it is temporarily released during one of these potential lengthy operations. This negative count results in subsequent acquisition attempts taking forever, leading to the hang. To support the current design point of holding the semaphore on the ioctl() paths, the release fop should acquire it before invoking any ioctl services. Signed-off-by: Uma Krishnan <ukrishn@linux.vnet.ibm.com> Acked-by: Matthew R. Ochs <mrochs@linux.vnet.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>		2018-05-18 11:22:10 -04:00
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backend.h
common.h
cxl_hw.c
Kconfig
lunmgt.c
main.c
main.h
Makefile
ocxl_hw.c
ocxl_hw.h
sislite.h
superpipe.c	scsi: cxlflash: Acquire semaphore before invoking ioctl services	2018-05-18 11:22:10 -04:00
superpipe.h
vlun.c
vlun.h