Commits
Bart Van Assche committed 48396e80fb6
RDMA/srp: Rework SCSI device reset handling
Since .scsi_done() must only be called after scsi_queue_rq() has
finished, make sure that the SRP initiator driver does not call
.scsi_done() while scsi_queue_rq() is in progress. Although
invoking sg_reset -d while I/O is in progress works fine with kernel
v4.20 and before, that is not the case with kernel v5.0-rc1. This
patch avoids that the following crash is triggered with kernel
v5.0-rc1:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000138
CPU: 0 PID: 360 Comm: kworker/0:1H Tainted: G B 5.0.0-rc1-dbg+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
Workqueue: kblockd blk_mq_run_work_fn
RIP: 0010:blk_mq_dispatch_rq_list+0x116/0xb10
Call Trace:
blk_mq_sched_dispatch_requests+0x2f7/0x300
__blk_mq_run_hw_queue+0xd6/0x180
blk_mq_run_work_fn+0x27/0x30
process_one_work+0x4f1/0xa20
worker_thread+0x67/0x5b0
kthread+0x1cf/0x1f0
ret_from_fork+0x24/0x30
Cc: <stable@vger.kernel.org>
Fixes: 94a9174c630c ("IB/srp: reduce lock coverage of command completion")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>