From 73ee5d8672871bd69077ca71e7208a36bfa6343c Mon Sep 17 00:00:00 2001 From: Brian King Date: Thu, 17 Jun 2010 13:55:13 -0500 Subject: [PATCH] [SCSI] ibmvfc: Fix soft lockup on resume This fixes a softlockup seen on resume. During resume, the CRQ must be reenabled. However, the H_ENABLE_CRQ hcall used to do this may return H_BUSY or H_LONG_BUSY. When this happens, the caller is expected to retry later. Normally the H_ENABLE_CRQ succeeds relatively soon. However, we have seen cases where this can take long enough to see softlockup warnings. This patch changes a simple loop, which was causing the softlockup, to a loop at task level which sleeps between retries rather than simply spinning. Signed-off-by: Brian King Signed-off-by: James Bottomley --- drivers/scsi/ibmvscsi/ibmvfc.c | 81 ++++++++++++++++++++++------------ drivers/scsi/ibmvscsi/ibmvfc.h | 2 + 2 files changed, 56 insertions(+), 27 deletions(-) diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c index fef49521cbc..d6fcb3f4396 100644 --- a/drivers/scsi/ibmvscsi/ibmvfc.c +++ b/drivers/scsi/ibmvscsi/ibmvfc.c @@ -504,12 +504,23 @@ static void ibmvfc_set_host_action(struct ibmvfc_host *vhost, if (vhost->action == IBMVFC_HOST_ACTION_ALLOC_TGTS) vhost->action = action; break; - case IBMVFC_HOST_ACTION_LOGO: case IBMVFC_HOST_ACTION_INIT: case IBMVFC_HOST_ACTION_TGT_DEL: + switch (vhost->action) { + case IBMVFC_HOST_ACTION_RESET: + case IBMVFC_HOST_ACTION_REENABLE: + break; + default: + vhost->action = action; + break; + }; + break; + case IBMVFC_HOST_ACTION_LOGO: case IBMVFC_HOST_ACTION_QUERY_TGTS: case IBMVFC_HOST_ACTION_TGT_DEL_FAILED: case IBMVFC_HOST_ACTION_NONE: + case IBMVFC_HOST_ACTION_RESET: + case IBMVFC_HOST_ACTION_REENABLE: default: vhost->action = action; break; @@ -641,7 +652,7 @@ static int ibmvfc_send_crq_init_complete(struct ibmvfc_host *vhost) **/ static void ibmvfc_release_crq_queue(struct ibmvfc_host *vhost) { - long rc; + long rc = 0; struct vio_dev *vdev = to_vio_dev(vhost->dev); struct ibmvfc_crq_queue *crq = &vhost->crq; @@ -649,6 +660,8 @@ static void ibmvfc_release_crq_queue(struct ibmvfc_host *vhost) free_irq(vdev->irq, vhost); tasklet_kill(&vhost->tasklet); do { + if (rc) + msleep(100); rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address); } while (rc == H_BUSY || H_IS_LONG_BUSY(rc)); @@ -667,11 +680,13 @@ static void ibmvfc_release_crq_queue(struct ibmvfc_host *vhost) **/ static int ibmvfc_reenable_crq_queue(struct ibmvfc_host *vhost) { - int rc; + int rc = 0; struct vio_dev *vdev = to_vio_dev(vhost->dev); /* Re-enable the CRQ */ do { + if (rc) + msleep(100); rc = plpar_hcall_norets(H_ENABLE_CRQ, vdev->unit_address); } while (rc == H_IN_PROGRESS || rc == H_BUSY || H_IS_LONG_BUSY(rc)); @@ -690,15 +705,19 @@ static int ibmvfc_reenable_crq_queue(struct ibmvfc_host *vhost) **/ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost) { - int rc; + int rc = 0; + unsigned long flags; struct vio_dev *vdev = to_vio_dev(vhost->dev); struct ibmvfc_crq_queue *crq = &vhost->crq; /* Close the CRQ */ do { + if (rc) + msleep(100); rc = plpar_hcall_norets(H_FREE_CRQ, vdev->unit_address); } while (rc == H_BUSY || H_IS_LONG_BUSY(rc)); + spin_lock_irqsave(vhost->host->host_lock, flags); vhost->state = IBMVFC_NO_CRQ; vhost->logged_in = 0; ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_NONE); @@ -716,6 +735,7 @@ static int ibmvfc_reset_crq(struct ibmvfc_host *vhost) dev_warn(vhost->dev, "Partner adapter not ready\n"); else if (rc != 0) dev_warn(vhost->dev, "Couldn't register crq (rc=%d)\n", rc); + spin_unlock_irqrestore(vhost->host->host_lock, flags); return rc; } @@ -821,17 +841,9 @@ static void ibmvfc_purge_requests(struct ibmvfc_host *vhost, int error_code) **/ static void ibmvfc_hard_reset_host(struct ibmvfc_host *vhost) { - int rc; - - scsi_block_requests(vhost->host); ibmvfc_purge_requests(vhost, DID_ERROR); - if ((rc = ibmvfc_reset_crq(vhost)) || - (rc = ibmvfc_send_crq_init(vhost)) || - (rc = vio_enable_interrupts(to_vio_dev(vhost->dev)))) { - dev_err(vhost->dev, "Error after reset rc=%d\n", rc); - ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD); - } else - ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN); + ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN); + ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_RESET); } /** @@ -2606,22 +2618,13 @@ static void ibmvfc_handle_crq(struct ibmvfc_crq *crq, struct ibmvfc_host *vhost) dev_info(vhost->dev, "Re-enabling adapter\n"); vhost->client_migrated = 1; ibmvfc_purge_requests(vhost, DID_REQUEUE); - if ((rc = ibmvfc_reenable_crq_queue(vhost)) || - (rc = ibmvfc_send_crq_init(vhost))) { - ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD); - dev_err(vhost->dev, "Error after enable (rc=%ld)\n", rc); - } else - ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN); + ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN); + ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_REENABLE); } else { dev_err(vhost->dev, "Virtual adapter failed (rc=%d)\n", crq->format); - ibmvfc_purge_requests(vhost, DID_ERROR); - if ((rc = ibmvfc_reset_crq(vhost)) || - (rc = ibmvfc_send_crq_init(vhost))) { - ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD); - dev_err(vhost->dev, "Error after reset (rc=%ld)\n", rc); - } else - ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN); + ibmvfc_link_down(vhost, IBMVFC_LINK_DOWN); + ibmvfc_set_host_action(vhost, IBMVFC_HOST_ACTION_RESET); } return; case IBMVFC_CRQ_CMD_RSP: @@ -4123,6 +4126,8 @@ static int __ibmvfc_work_to_do(struct ibmvfc_host *vhost) case IBMVFC_HOST_ACTION_TGT_DEL: case IBMVFC_HOST_ACTION_TGT_DEL_FAILED: case IBMVFC_HOST_ACTION_QUERY: + case IBMVFC_HOST_ACTION_RESET: + case IBMVFC_HOST_ACTION_REENABLE: default: break; }; @@ -4220,6 +4225,7 @@ static void ibmvfc_do_work(struct ibmvfc_host *vhost) struct ibmvfc_target *tgt; unsigned long flags; struct fc_rport *rport; + int rc; ibmvfc_log_ae(vhost, vhost->events_to_log); spin_lock_irqsave(vhost->host->host_lock, flags); @@ -4229,6 +4235,27 @@ static void ibmvfc_do_work(struct ibmvfc_host *vhost) case IBMVFC_HOST_ACTION_LOGO_WAIT: case IBMVFC_HOST_ACTION_INIT_WAIT: break; + case IBMVFC_HOST_ACTION_RESET: + vhost->action = IBMVFC_HOST_ACTION_TGT_DEL; + spin_unlock_irqrestore(vhost->host->host_lock, flags); + rc = ibmvfc_reset_crq(vhost); + spin_lock_irqsave(vhost->host->host_lock, flags); + if (rc || (rc = ibmvfc_send_crq_init(vhost)) || + (rc = vio_enable_interrupts(to_vio_dev(vhost->dev)))) { + ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD); + dev_err(vhost->dev, "Error after reset (rc=%d)\n", rc); + } + break; + case IBMVFC_HOST_ACTION_REENABLE: + vhost->action = IBMVFC_HOST_ACTION_TGT_DEL; + spin_unlock_irqrestore(vhost->host->host_lock, flags); + rc = ibmvfc_reenable_crq_queue(vhost); + spin_lock_irqsave(vhost->host->host_lock, flags); + if (rc || (rc = ibmvfc_send_crq_init(vhost))) { + ibmvfc_link_down(vhost, IBMVFC_LINK_DEAD); + dev_err(vhost->dev, "Error after enable (rc=%d)\n", rc); + } + break; case IBMVFC_HOST_ACTION_LOGO: vhost->job_step(vhost); break; diff --git a/drivers/scsi/ibmvscsi/ibmvfc.h b/drivers/scsi/ibmvscsi/ibmvfc.h index 7e9742764e4..2010d73aca8 100644 --- a/drivers/scsi/ibmvscsi/ibmvfc.h +++ b/drivers/scsi/ibmvscsi/ibmvfc.h @@ -649,6 +649,8 @@ struct ibmvfc_event_pool { enum ibmvfc_host_action { IBMVFC_HOST_ACTION_NONE = 0, + IBMVFC_HOST_ACTION_RESET, + IBMVFC_HOST_ACTION_REENABLE, IBMVFC_HOST_ACTION_LOGO, IBMVFC_HOST_ACTION_LOGO_WAIT, IBMVFC_HOST_ACTION_INIT, -- 2.39.3