From 4fa3c019640ef776e393345ed35d9ec5c51aa3c1 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Thu, 28 Feb 2013 12:07:48 +0100 Subject: s390/scm_blk: suspend writes Stop writing to scm after certain error conditions such as a concurrent firmware upgrade. Resume to normal state once scm_blk_set_available is called (due to an scm availability notification). Reviewed-by: Peter Oberparleiter Signed-off-by: Sebastian Ott Signed-off-by: Peter Oberparleiter Signed-off-by: Martin Schwidefsky --- drivers/s390/block/scm_blk.c | 61 ++++++++++++++++++++++++++++++++++++++++---- drivers/s390/block/scm_blk.h | 2 ++ 2 files changed, 58 insertions(+), 5 deletions(-) (limited to 'drivers/s390/block') diff --git a/drivers/s390/block/scm_blk.c b/drivers/s390/block/scm_blk.c index d9c7e940fa3..5ac9c935c15 100644 --- a/drivers/s390/block/scm_blk.c +++ b/drivers/s390/block/scm_blk.c @@ -135,6 +135,11 @@ static const struct block_device_operations scm_blk_devops = { .release = scm_release, }; +static bool scm_permit_request(struct scm_blk_dev *bdev, struct request *req) +{ + return rq_data_dir(req) != WRITE || bdev->state != SCM_WR_PROHIBIT; +} + static void scm_request_prepare(struct scm_request *scmrq) { struct scm_blk_dev *bdev = scmrq->bdev; @@ -222,6 +227,10 @@ static void scm_blk_request(struct request_queue *rq) if (req->cmd_type != REQ_TYPE_FS) continue; + if (!scm_permit_request(bdev, req)) { + scm_ensure_queue_restart(bdev); + return; + } scmrq = scm_request_fetch(); if (!scmrq) { SCM_LOG(5, "no request"); @@ -285,6 +294,38 @@ void scm_blk_irq(struct scm_device *scmdev, void *data, int error) tasklet_hi_schedule(&bdev->tasklet); } +static void scm_blk_handle_error(struct scm_request *scmrq) +{ + struct scm_blk_dev *bdev = scmrq->bdev; + unsigned long flags; + + if (scmrq->error != -EIO) + goto restart; + + /* For -EIO the response block is valid. */ + switch (scmrq->aob->response.eqc) { + case EQC_WR_PROHIBIT: + spin_lock_irqsave(&bdev->lock, flags); + if (bdev->state != SCM_WR_PROHIBIT) + pr_info("%lu: Write access to the SCM increment is suspended\n", + (unsigned long) bdev->scmdev->address); + bdev->state = SCM_WR_PROHIBIT; + spin_unlock_irqrestore(&bdev->lock, flags); + goto requeue; + default: + break; + } + +restart: + if (!scm_start_aob(scmrq->aob)) + return; + +requeue: + spin_lock_irqsave(&bdev->rq_lock, flags); + scm_request_requeue(scmrq); + spin_unlock_irqrestore(&bdev->rq_lock, flags); +} + static void scm_blk_tasklet(struct scm_blk_dev *bdev) { struct scm_request *scmrq; @@ -298,11 +339,8 @@ static void scm_blk_tasklet(struct scm_blk_dev *bdev) spin_unlock_irqrestore(&bdev->lock, flags); if (scmrq->error && scmrq->retries-- > 0) { - if (scm_start_aob(scmrq->aob)) { - spin_lock_irqsave(&bdev->rq_lock, flags); - scm_request_requeue(scmrq); - spin_unlock_irqrestore(&bdev->rq_lock, flags); - } + scm_blk_handle_error(scmrq); + /* Request restarted or requeued, handle next. */ spin_lock_irqsave(&bdev->lock, flags); continue; @@ -336,6 +374,7 @@ int scm_blk_dev_setup(struct scm_blk_dev *bdev, struct scm_device *scmdev) } bdev->scmdev = scmdev; + bdev->state = SCM_OPER; spin_lock_init(&bdev->rq_lock); spin_lock_init(&bdev->lock); INIT_LIST_HEAD(&bdev->finished_requests); @@ -400,6 +439,18 @@ void scm_blk_dev_cleanup(struct scm_blk_dev *bdev) put_disk(bdev->gendisk); } +void scm_blk_set_available(struct scm_blk_dev *bdev) +{ + unsigned long flags; + + spin_lock_irqsave(&bdev->lock, flags); + if (bdev->state == SCM_WR_PROHIBIT) + pr_info("%lu: Write access to the SCM increment is restored\n", + (unsigned long) bdev->scmdev->address); + bdev->state = SCM_OPER; + spin_unlock_irqrestore(&bdev->lock, flags); +} + static int __init scm_blk_init(void) { int ret = -EINVAL; diff --git a/drivers/s390/block/scm_blk.h b/drivers/s390/block/scm_blk.h index 3c1ccf49464..8b387b32fd6 100644 --- a/drivers/s390/block/scm_blk.h +++ b/drivers/s390/block/scm_blk.h @@ -21,6 +21,7 @@ struct scm_blk_dev { spinlock_t rq_lock; /* guard the request queue */ spinlock_t lock; /* guard the rest of the blockdev */ atomic_t queued_reqs; + enum {SCM_OPER, SCM_WR_PROHIBIT} state; struct list_head finished_requests; #ifdef CONFIG_SCM_BLOCK_CLUSTER_WRITE struct list_head cluster_list; @@ -48,6 +49,7 @@ struct scm_request { int scm_blk_dev_setup(struct scm_blk_dev *, struct scm_device *); void scm_blk_dev_cleanup(struct scm_blk_dev *); +void scm_blk_set_available(struct scm_blk_dev *); void scm_blk_irq(struct scm_device *, void *, int); void scm_request_finish(struct scm_request *); -- cgit v1.2.3