After a transport layer occurred, periodically try to reconnect to the target until the dev_loss timer expires. Protect the callback functions that can be invoked from inside the SCSI EH against concurrent invocation with srp_reconnect_rport() via the rport mutex. Change the default dev_loss_tmo from 60s into 600s to give the reconnect mechanism a chance to kick in.
Signed-off-by: Bart Van Assche <[email protected]> Acked-by: David Dillow <[email protected]> Cc: Roland Dreier <[email protected]> Cc: Vu Pham <[email protected]> Cc: Sebastian Riemer <[email protected]> --- Documentation/ABI/stable/sysfs-transport-srp | 8 +++++ drivers/infiniband/ulp/srp/ib_srp.c | 52 ++++++++++++++++++++++++---- 2 files changed, 54 insertions(+), 6 deletions(-) diff --git a/Documentation/ABI/stable/sysfs-transport-srp b/Documentation/ABI/stable/sysfs-transport-srp index 178a44d..21bd480 100644 --- a/Documentation/ABI/stable/sysfs-transport-srp +++ b/Documentation/ABI/stable/sysfs-transport-srp @@ -30,6 +30,14 @@ Contact: [email protected] Description: 16-byte local SRP port identifier in hexadecimal format. An example: 4c:49:4e:55:58:20:56:49:4f:00:00:00:00:00:00:00. +What: /sys/class/srp_remote_ports/port-<h>:<n>/reconnect_delay +Date: December 1, 2013 +KernelVersion: 3.12 +Contact: [email protected], [email protected] +Description: Number of seconds the SCSI layer will wait after a reconnect + attempt failed before retrying. Setting this attribute to + "off" will disable time-based reconnecting. + What: /sys/class/srp_remote_ports/port-<h>:<n>/roles Date: June 27, 2007 KernelVersion: 2.6.24 diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index ceb84b6..4be3eb8 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -88,6 +88,11 @@ MODULE_PARM_DESC(topspin_workarounds, static struct kernel_param_ops srp_tmo_ops; +static int srp_reconnect_delay = 10; +module_param_cb(reconnect_delay, &srp_tmo_ops, &srp_reconnect_delay, + S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(reconnect_delay, "Time between successive reconnect attempts"); + static int srp_fast_io_fail_tmo = 15; module_param_cb(fast_io_fail_tmo, &srp_tmo_ops, &srp_fast_io_fail_tmo, S_IRUGO | S_IWUSR); @@ -96,7 +101,7 @@ MODULE_PARM_DESC(fast_io_fail_tmo, " layer error and failing all I/O. \"off\" means that this" " functionality is disabled."); -static int srp_dev_loss_tmo = 60; +static int srp_dev_loss_tmo = 600; module_param_cb(dev_loss_tmo, &srp_tmo_ops, &srp_dev_loss_tmo, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(dev_loss_tmo, @@ -144,10 +149,14 @@ static int srp_tmo_set(const char *val, const struct kernel_param *kp) } else { tmo = -1; } - if (kp->arg == &srp_fast_io_fail_tmo) - res = srp_tmo_valid(tmo, srp_dev_loss_tmo); + if (kp->arg == &srp_reconnect_delay) + res = srp_tmo_valid(tmo, srp_fast_io_fail_tmo, + srp_dev_loss_tmo); + else if (kp->arg == &srp_fast_io_fail_tmo) + res = srp_tmo_valid(srp_reconnect_delay, tmo, srp_dev_loss_tmo); else - res = srp_tmo_valid(srp_fast_io_fail_tmo, tmo); + res = srp_tmo_valid(srp_reconnect_delay, srp_fast_io_fail_tmo, + tmo); if (res) goto out; *(int *)kp->arg = tmo; @@ -1426,18 +1435,29 @@ static void srp_send_completion(struct ib_cq *cq, void *target_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_request *req; struct srp_iu *iu; struct srp_cmd *cmd; struct ib_device *dev; unsigned long flags; int len, result; + 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); result = srp_chkready(target->rport); if (unlikely(result)) { scmnd->result = result; scmnd->scsi_done(scmnd); - return 0; + goto unlock_rport; } spin_lock_irqsave(&target->lock, flags); @@ -1482,6 +1502,10 @@ static int srp_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd) goto err_unmap; } +unlock_rport: + if (in_scsi_eh) + mutex_unlock(&rport->mutex); + return 0; err_unmap: @@ -1496,6 +1520,9 @@ err_iu: err_unlock: spin_unlock_irqrestore(&target->lock, flags); + if (in_scsi_eh) + mutex_unlock(&rport->mutex); + return SCSI_MLQUEUE_HOST_BUSY; } @@ -1780,6 +1807,7 @@ static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event) static int srp_send_tsk_mgmt(struct srp_target_port *target, u64 req_tag, unsigned int lun, u8 func) { + struct srp_rport *rport = target->rport; struct ib_device *dev = target->srp_host->srp_dev->dev; struct srp_iu *iu; struct srp_tsk_mgmt *tsk_mgmt; @@ -1789,12 +1817,20 @@ static int srp_send_tsk_mgmt(struct srp_target_port *target, init_completion(&target->tsk_mgmt_done); + /* + * Lock the rport mutex to avoid that srp_create_target_ib() is + * invoked while a task management function is being sent. + */ + mutex_lock(&rport->mutex); spin_lock_irq(&target->lock); iu = __srp_get_tx_iu(target, SRP_IU_TSK_MGMT); spin_unlock_irq(&target->lock); - if (!iu) + if (!iu) { + mutex_unlock(&rport->mutex); + return -1; + } ib_dma_sync_single_for_cpu(dev, iu->dma, sizeof *tsk_mgmt, DMA_TO_DEVICE); @@ -1811,8 +1847,11 @@ static int srp_send_tsk_mgmt(struct srp_target_port *target, DMA_TO_DEVICE); if (srp_post_send(target, iu, sizeof *tsk_mgmt)) { srp_put_tx_iu(target, iu, SRP_IU_TSK_MGMT); + mutex_unlock(&rport->mutex); + return -1; } + mutex_unlock(&rport->mutex); if (!wait_for_completion_timeout(&target->tsk_mgmt_done, msecs_to_jiffies(SRP_ABORT_TIMEOUT_MS))) @@ -2713,6 +2752,7 @@ static void srp_remove_one(struct ib_device *device) static struct srp_function_template ib_srp_transport_functions = { .has_rport_state = true, .reset_timer_if_blocked = true, + .reconnect_delay = &srp_reconnect_delay, .fast_io_fail_tmo = &srp_fast_io_fail_tmo, .dev_loss_tmo = &srp_dev_loss_tmo, .reconnect = srp_rport_reconnect, -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
