From 94a9174c630c8465ed9e97ecd242993429930c05 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Fri, 26 Nov 2010 14:50:09 -0500 Subject: IB/srp: reduce lock coverage of command completion We only need the lock to cover list and credit manipulations, so push those into srp_remove_req() and update the call chains. We reorder the request removal and command completion in srp_process_rsp() to avoid the SCSI mid-layer sending another command before we've released our request and added any credits returned by the target. This prevents us from returning HOST_BUSY unneccesarily. Signed-off-by: Bart Van Assche [ broken out, small cleanups, and modified to avoid potential extraneous HOST_BUSY returns by David Dillow ] Signed-off-by: David Dillow --- drivers/infiniband/ulp/srp/ib_srp.c | 37 ++++++++++++++----------------------- 1 file changed, 14 insertions(+), 23 deletions(-) (limited to 'drivers/infiniband') diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index e5bd181dbce5..e76fe54faeea 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -549,18 +549,24 @@ static void srp_unmap_data(struct scsi_cmnd *scmnd, scsi_sg_count(scmnd), scmnd->sc_data_direction); } -static void srp_remove_req(struct srp_target_port *target, struct srp_request *req) +static void srp_remove_req(struct srp_target_port *target, + struct srp_request *req, s32 req_lim_delta) { + unsigned long flags; + srp_unmap_data(req->scmnd, target, req); + spin_lock_irqsave(target->scsi_host->host_lock, flags); + target->req_lim += req_lim_delta; req->scmnd = NULL; list_add_tail(&req->list, &target->free_reqs); + spin_unlock_irqrestore(target->scsi_host->host_lock, flags); } static void srp_reset_req(struct srp_target_port *target, struct srp_request *req) { req->scmnd->result = DID_RESET << 16; req->scmnd->scsi_done(req->scmnd); - srp_remove_req(target, req); + srp_remove_req(target, req, 0); } static int srp_reconnect_target(struct srp_target_port *target) @@ -595,13 +601,11 @@ static int srp_reconnect_target(struct srp_target_port *target) while (ib_poll_cq(target->send_cq, 1, &wc) > 0) ; /* nothing */ - spin_lock_irq(target->scsi_host->host_lock); for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) { struct srp_request *req = &target->req_ring[i]; if (req->scmnd) srp_reset_req(target, req); } - spin_unlock_irq(target->scsi_host->host_lock); INIT_LIST_HEAD(&target->free_tx); for (i = 0; i < SRP_SQ_SIZE; ++i) @@ -914,15 +918,12 @@ static void srp_process_rsp(struct srp_target_port *target, struct srp_rsp *rsp) struct srp_request *req; struct scsi_cmnd *scmnd; unsigned long flags; - s32 delta; - - delta = (s32) be32_to_cpu(rsp->req_lim_delta); - - spin_lock_irqsave(target->scsi_host->host_lock, flags); - - target->req_lim += delta; if (unlikely(rsp->tag & SRP_TAG_TSK_MGMT)) { + spin_lock_irqsave(target->scsi_host->host_lock, flags); + target->req_lim += be32_to_cpu(rsp->req_lim_delta); + spin_unlock_irqrestore(target->scsi_host->host_lock, flags); + target->tsk_mgmt_status = -1; if (be32_to_cpu(rsp->resp_data_len) >= 4) target->tsk_mgmt_status = rsp->data[3]; @@ -948,12 +949,10 @@ static void srp_process_rsp(struct srp_target_port *target, struct srp_rsp *rsp) else if (rsp->flags & (SRP_RSP_FLAG_DIOVER | SRP_RSP_FLAG_DIUNDER)) scsi_set_resid(scmnd, be32_to_cpu(rsp->data_in_res_cnt)); + srp_remove_req(target, req, be32_to_cpu(rsp->req_lim_delta)); scmnd->host_scribble = NULL; scmnd->scsi_done(scmnd); - srp_remove_req(target, req); } - - spin_unlock_irqrestore(target->scsi_host->host_lock, flags); } static int srp_response_common(struct srp_target_port *target, s32 req_delta, @@ -1498,18 +1497,14 @@ static int srp_abort(struct scsi_cmnd *scmnd) SRP_TSK_ABORT_TASK)) return FAILED; - spin_lock_irq(target->scsi_host->host_lock); - if (req->scmnd) { if (!target->tsk_mgmt_status) { - srp_remove_req(target, req); + srp_remove_req(target, req, 0); scmnd->result = DID_ABORT << 16; } else ret = FAILED; } - spin_unlock_irq(target->scsi_host->host_lock); - return ret; } @@ -1528,16 +1523,12 @@ static int srp_reset_device(struct scsi_cmnd *scmnd) if (target->tsk_mgmt_status) return FAILED; - spin_lock_irq(target->scsi_host->host_lock); - for (i = 0; i < SRP_CMD_SQ_SIZE; ++i) { struct srp_request *req = &target->req_ring[i]; if (req->scmnd && req->scmnd->device == scmnd->device) srp_reset_req(target, req); } - spin_unlock_irq(target->scsi_host->host_lock); - return SUCCESS; } -- cgit v1.2.2