From: Bart Van Assche bvanassche@acm.org
[ Upstream commit fd56141244066a6a21ef458670071c58b6402035 ]
The previous patch guarantees that srp_queuecommand() does not get invoked while reconnecting occurs. Hence remove the code from srp_queuecommand() that prevents command queueing while reconnecting. This patch avoids that the following can appear in the kernel log:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:747 in_atomic(): 1, irqs_disabled(): 0, pid: 5600, name: scsi_eh_9 1 lock held by scsi_eh_9/5600: #0: (rcu_read_lock){....}, at: [<00000000cbb798c7>] __blk_mq_run_hw_queue+0xf1/0x1e0 Preemption disabled at: [<00000000139badf2>] __blk_mq_delay_run_hw_queue+0x78/0xf0 CPU: 9 PID: 5600 Comm: scsi_eh_9 Tainted: G W 4.15.0-rc4-dbg+ #1 Hardware name: Dell Inc. PowerEdge R720/0VWT90, BIOS 2.5.4 01/22/2016 Call Trace: dump_stack+0x67/0x99 ___might_sleep+0x16a/0x250 [ib_srp] __mutex_lock+0x46/0x9d0 srp_queuecommand+0x356/0x420 [ib_srp] scsi_dispatch_cmd+0xf6/0x3f0 scsi_queue_rq+0x4a8/0x5f0 blk_mq_dispatch_rq_list+0x73/0x440 blk_mq_sched_dispatch_requests+0x109/0x1a0 __blk_mq_run_hw_queue+0x131/0x1e0 __blk_mq_delay_run_hw_queue+0x9a/0xf0 blk_mq_run_hw_queue+0xc0/0x1e0 blk_mq_start_hw_queues+0x2c/0x40 scsi_run_queue+0x18e/0x2d0 scsi_run_host_queues+0x22/0x40 scsi_error_handler+0x18d/0x5f0 kthread+0x11c/0x140 ret_from_fork+0x24/0x30
Reviewed-by: Hannes Reinecke hare@suse.com Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Laurence Oberman loberman@redhat.com Cc: Jason Gunthorpe jgg@mellanox.com Cc: Leon Romanovsky leonro@mellanox.com Cc: Doug Ledford dledford@redhat.com Signed-off-by: Bart Van Assche bvanassche@acm.org Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/infiniband/ulp/srp/ib_srp.c | 21 ++------------------- 1 file changed, 2 insertions(+), 19 deletions(-)
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index 3dbc3ed263c21..9a70267244e1a 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -2057,7 +2057,6 @@ static void srp_send_completion(struct ib_cq *cq, void *ch_ptr) static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) { struct srp_target_port *target = host_to_target(shost); - struct srp_rport *rport = target->rport; struct srp_rdma_ch *ch; struct srp_request *req; struct srp_iu *iu; @@ -2067,16 +2066,6 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) u32 tag; u16 idx; int len, ret; - const bool in_scsi_eh = !in_interrupt() && current == shost->ehandler; - - /* - * The SCSI EH thread is the only context from which srp_queuecommand() - * can get invoked for blocked devices (SDEV_BLOCK / - * SDEV_CREATED_BLOCK). Avoid racing with srp_reconnect_rport() by - * locking the rport mutex if invoked from inside the SCSI EH. - */ - if (in_scsi_eh) - mutex_lock(&rport->mutex);
scmnd->result = srp_chkready(target->rport); if (unlikely(scmnd->result)) @@ -2138,13 +2127,7 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) goto err_unmap; }
- ret = 0; - -unlock_rport: - if (in_scsi_eh) - mutex_unlock(&rport->mutex); - - return ret; + return 0;
err_unmap: srp_unmap_data(scmnd, ch, req); @@ -2166,7 +2149,7 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) ret = SCSI_MLQUEUE_HOST_BUSY; }
- goto unlock_rport; + return ret; }
/*