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System crashes when sg_reset is executed in a loop. CPU: 13 PID: 7073 Comm: sg_reset Tainted: G E 4.8.0-rc1+ #4 RIP: 0010:[<ffffffffa0825370>] [<ffffffffa0825370>] beiscsi_eh_device_reset+0x160/0x520 [be2iscsi] Call Trace: [<ffffffff814c7c77>] ? scsi_host_alloc_command+0x47/0xc0 [<ffffffff814caafa>] scsi_try_bus_device_reset+0x2a/0x50 [<ffffffff814cb46e>] scsi_ioctl_reset+0x13e/0x260 [<ffffffff814ca477>] scsi_ioctl+0x137/0x3d0 [<ffffffffa05e4ba2>] sg_ioctl+0x572/0xc20 [sg] [<ffffffff8123f627>] do_vfs_ioctl+0xa7/0x5d0 The accesses to beiscsi_io_task is being protected in device reset handler with frwd_lock but the freeing of task can happen under back_lock. Hold the reference of iscsi_task till invalidation completes. This prevents use of ICD when invalidation of that ICD is being processed. Use frwd_lock for iscsi_tasks looping and back_lock to access beiscsi_io_task structures. Rewrite mgmt_invalidation_icds to handle allocation and freeing of IOCTL buffer in one place. Signed-off-by: Jitendra Bhivare <jitendra.bhivare@broadcom.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.