From: Stefan Haberland <sth@linux.vnet.ibm.com>
Date: Mon, 22 May 2017 10:59:11 +0200
Subject: [PATCH] s390/dasd: blk-mq conversion
Git-commit: e443343e509aac82e7281020f25bf8fa0dd46ab7
Patch-mainline: v4.14-rc1
References: bsc#1104967,FATE#325924
Use new blk-mq interfaces. Use multiple queues and also use the block
layer complete helper that finish the IO on the CPU that initiated it.
Reviewed-by: Jan Hoeppner <hoeppner@linux.vnet.ibm.com>
Signed-off-by: Stefan Haberland <sth@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Acked-by: Hannes Reinecke <hare@suse.com>
---
drivers/s390/block/dasd.c | 331 ++++++++++++++++++++-------------------
drivers/s390/block/dasd_devmap.c | 8 +-
drivers/s390/block/dasd_int.h | 19 ++-
3 files changed, 193 insertions(+), 165 deletions(-)
diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c
index 9c97ad1ee121..ea19b4ff87a2 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -62,7 +62,6 @@ MODULE_LICENSE("GPL");
static int dasd_alloc_queue(struct dasd_block *);
static void dasd_setup_queue(struct dasd_block *);
static void dasd_free_queue(struct dasd_block *);
-static void dasd_flush_request_queue(struct dasd_block *);
static int dasd_flush_block_queue(struct dasd_block *);
static void dasd_device_tasklet(struct dasd_device *);
static void dasd_block_tasklet(struct dasd_block *);
@@ -158,7 +157,6 @@ struct dasd_block *dasd_alloc_block(void)
/* open_count = 0 means device online but not in use */
atomic_set(&block->open_count, -1);
- spin_lock_init(&block->request_queue_lock);
atomic_set(&block->tasklet_scheduled, 0);
tasklet_init(&block->tasklet,
(void (*)(unsigned long)) dasd_block_tasklet,
@@ -391,7 +389,6 @@ static int dasd_state_ready_to_basic(struct dasd_device *device)
device->state = DASD_STATE_READY;
return rc;
}
- dasd_flush_request_queue(block);
dasd_destroy_partitions(block);
block->blocks = 0;
block->bp_block = 0;
@@ -1645,8 +1642,10 @@ void dasd_generic_handle_state_change(struct dasd_device *device)
dasd_device_remove_stop_bits(device, DASD_STOPPED_PENDING);
dasd_schedule_device_bh(device);
- if (device->block)
+ if (device->block) {
dasd_schedule_block_bh(device->block);
+ blk_mq_run_hw_queues(device->block->request_queue, true);
+ }
}
EXPORT_SYMBOL_GPL(dasd_generic_handle_state_change);
@@ -2638,6 +2637,7 @@ static void dasd_block_timeout(unsigned long ptr)
dasd_device_remove_stop_bits(block->base, DASD_STOPPED_PENDING);
spin_unlock_irqrestore(get_ccwdev_lock(block->base->cdev), flags);
dasd_schedule_block_bh(block);
+ blk_mq_run_hw_queues(block->request_queue, true);
}
/*
@@ -2677,115 +2677,11 @@ static void __dasd_process_erp(struct dasd_device *device,
erp_fn(cqr);
}
-/*
- * Fetch requests from the block device queue.
- */
-static void __dasd_process_request_queue(struct dasd_block *block)
-{
- struct request_queue *queue;
- struct request *req;
- struct dasd_ccw_req *cqr;
- struct dasd_device *basedev;
- unsigned long flags;
- queue = block->request_queue;
- basedev = block->base;
- /* No queue ? Then there is nothing to do. */
- if (queue == NULL)
- return;
-
- /*
- * We requeue request from the block device queue to the ccw
- * queue only in two states. In state DASD_STATE_READY the
- * partition detection is done and we need to requeue requests
- * for that. State DASD_STATE_ONLINE is normal block device
- * operation.
- */
- if (basedev->state < DASD_STATE_READY) {
- while ((req = blk_fetch_request(block->request_queue)))
- __blk_end_request_all(req, BLK_STS_IOERR);
- return;
- }
-
- /*
- * if device is stopped do not fetch new requests
- * except failfast is active which will let requests fail
- * immediately in __dasd_block_start_head()
- */
- if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST))
- return;
-
- /* Now we try to fetch requests from the request queue */
- while ((req = blk_peek_request(queue))) {
- if (basedev->features & DASD_FEATURE_READONLY &&
- rq_data_dir(req) == WRITE) {
- DBF_DEV_EVENT(DBF_ERR, basedev,
- "Rejecting write request %p",
- req);
- blk_start_request(req);
- __blk_end_request_all(req, BLK_STS_IOERR);
- continue;
- }
- if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
- (basedev->features & DASD_FEATURE_FAILFAST ||
- blk_noretry_request(req))) {
- DBF_DEV_EVENT(DBF_ERR, basedev,
- "Rejecting failfast request %p",
- req);
- blk_start_request(req);
- __blk_end_request_all(req, BLK_STS_TIMEOUT);
- continue;
- }
- cqr = basedev->discipline->build_cp(basedev, block, req);
- if (IS_ERR(cqr)) {
- if (PTR_ERR(cqr) == -EBUSY)
- break; /* normal end condition */
- if (PTR_ERR(cqr) == -ENOMEM)
- break; /* terminate request queue loop */
- if (PTR_ERR(cqr) == -EAGAIN) {
- /*
- * The current request cannot be build right
- * now, we have to try later. If this request
- * is the head-of-queue we stop the device
- * for 1/2 second.
- */
- if (!list_empty(&block->ccw_queue))
- break;
- spin_lock_irqsave(
- get_ccwdev_lock(basedev->cdev), flags);
- dasd_device_set_stop_bits(basedev,
- DASD_STOPPED_PENDING);
- spin_unlock_irqrestore(
- get_ccwdev_lock(basedev->cdev), flags);
- dasd_block_set_timer(block, HZ/2);
- break;
- }
- DBF_DEV_EVENT(DBF_ERR, basedev,
- "CCW creation failed (rc=%ld) "
- "on request %p",
- PTR_ERR(cqr), req);
- blk_start_request(req);
- __blk_end_request_all(req, BLK_STS_IOERR);
- continue;
- }
- /*
- * Note: callback is set to dasd_return_cqr_cb in
- * __dasd_block_start_head to cover erp requests as well
- */
- cqr->callback_data = (void *) req;
- cqr->status = DASD_CQR_FILLED;
- req->completion_data = cqr;
- blk_start_request(req);
- list_add_tail(&cqr->blocklist, &block->ccw_queue);
- INIT_LIST_HEAD(&cqr->devlist);
- dasd_profile_start(block, cqr, req);
- }
-}
-
static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
{
struct request *req;
- int status;
blk_status_t error = BLK_STS_OK;
+ int status;
req = (struct request *) cqr->callback_data;
dasd_profile_end(cqr->block, cqr, req);
@@ -2809,7 +2705,19 @@ static void __dasd_cleanup_cqr(struct dasd_ccw_req *cqr)
break;
}
}
- __blk_end_request_all(req, error);
+
+ /*
+ * We need to take care for ETIMEDOUT errors here since the
+ * complete callback does not get called in this case.
+ * Take care of all errors here and avoid additional code to
+ * transfer the error value to the complete callback.
+ */
+ if (error) {
+ blk_mq_end_request(req, error);
+ blk_mq_run_hw_queues(req->q, true);
+ } else {
+ blk_mq_complete_request(req);
+ }
}
/*
@@ -2938,27 +2846,30 @@ static void dasd_block_tasklet(struct dasd_block *block)
struct list_head final_queue;
struct list_head *l, *n;
struct dasd_ccw_req *cqr;
+ struct dasd_queue *dq;
atomic_set(&block->tasklet_scheduled, 0);
INIT_LIST_HEAD(&final_queue);
- spin_lock(&block->queue_lock);
+ spin_lock_irq(&block->queue_lock);
/* Finish off requests on ccw queue */
__dasd_process_block_ccw_queue(block, &final_queue);
- spin_unlock(&block->queue_lock);
+ spin_unlock_irq(&block->queue_lock);
+
/* Now call the callback function of requests with final status */
- spin_lock_irq(&block->request_queue_lock);
list_for_each_safe(l, n, &final_queue) {
cqr = list_entry(l, struct dasd_ccw_req, blocklist);
+ dq = cqr->dq;
+ spin_lock_irq(&dq->lock);
list_del_init(&cqr->blocklist);
__dasd_cleanup_cqr(cqr);
+ spin_unlock_irq(&dq->lock);
}
- spin_lock(&block->queue_lock);
- /* Get new request from the block device request queue */
- __dasd_process_request_queue(block);
+
+ spin_lock_irq(&block->queue_lock);
/* Now check if the head of the ccw queue needs to be started. */
__dasd_block_start_head(block);
- spin_unlock(&block->queue_lock);
- spin_unlock_irq(&block->request_queue_lock);
+ spin_unlock_irq(&block->queue_lock);
+
if (waitqueue_active(&shutdown_waitq))
wake_up(&shutdown_waitq);
dasd_put_device(block->base);
@@ -2977,14 +2888,13 @@ static int _dasd_requeue_request(struct dasd_ccw_req *cqr)
{
struct dasd_block *block = cqr->block;
struct request *req;
- unsigned long flags;
if (!block)
return -EINVAL;
- spin_lock_irqsave(&block->request_queue_lock, flags);
+ spin_lock_irq(&cqr->dq->lock);
req = (struct request *) cqr->callback_data;
- blk_requeue_request(block->request_queue, req);
- spin_unlock_irqrestore(&block->request_queue_lock, flags);
+ blk_mq_requeue_request(req, false);
+ spin_unlock_irq(&cqr->dq->lock);
return 0;
}
@@ -2999,6 +2909,7 @@ static int dasd_flush_block_queue(struct dasd_block *block)
struct dasd_ccw_req *cqr, *n;
int rc, i;
struct list_head flush_queue;
+ unsigned long flags;
INIT_LIST_HEAD(&flush_queue);
spin_lock_bh(&block->queue_lock);
@@ -3037,11 +2948,11 @@ static int dasd_flush_block_queue(struct dasd_block *block)
goto restart_cb;
}
/* call the callback function */
- spin_lock_irq(&block->request_queue_lock);
+ spin_lock_irqsave(&cqr->dq->lock, flags);
cqr->endclk = get_tod_clock();
list_del_init(&cqr->blocklist);
__dasd_cleanup_cqr(cqr);
- spin_unlock_irq(&block->request_queue_lock);
+ spin_unlock_irqrestore(&cqr->dq->lock, flags);
}
return rc;
}
@@ -3069,42 +2980,114 @@ EXPORT_SYMBOL(dasd_schedule_block_bh);
/*
* Dasd request queue function. Called from ll_rw_blk.c
*/
-static void do_dasd_request(struct request_queue *queue)
+static blk_status_t do_dasd_request(struct blk_mq_hw_ctx *hctx,
+ const struct blk_mq_queue_data *qd)
{
- struct dasd_block *block;
+ struct dasd_block *block = hctx->queue->queuedata;
+ struct dasd_queue *dq = hctx->driver_data;
+ struct request *req = qd->rq;
+ struct dasd_device *basedev;
+ struct dasd_ccw_req *cqr;
+ blk_status_t rc = BLK_STS_OK;
+
+ basedev = block->base;
+ spin_lock_irq(&dq->lock);
+ if (basedev->state < DASD_STATE_READY) {
+ DBF_DEV_EVENT(DBF_ERR, basedev,
+ "device not ready for request %p", req);
+ rc = BLK_STS_IOERR;
+ goto out;
+ }
+
+ /*
+ * if device is stopped do not fetch new requests
+ * except failfast is active which will let requests fail
+ * immediately in __dasd_block_start_head()
+ */
+ if (basedev->stopped && !(basedev->features & DASD_FEATURE_FAILFAST)) {
+ DBF_DEV_EVENT(DBF_ERR, basedev,
+ "device stopped request %p", req);
+ rc = BLK_STS_RESOURCE;
+ goto out;
+ }
+
+ if (basedev->features & DASD_FEATURE_READONLY &&
+ rq_data_dir(req) == WRITE) {
+ DBF_DEV_EVENT(DBF_ERR, basedev,
+ "Rejecting write request %p", req);
+ rc = BLK_STS_IOERR;
+ goto out;
+ }
- block = queue->queuedata;
+ if (test_bit(DASD_FLAG_ABORTALL, &basedev->flags) &&
+ (basedev->features & DASD_FEATURE_FAILFAST ||
+ blk_noretry_request(req))) {
+ DBF_DEV_EVENT(DBF_ERR, basedev,
+ "Rejecting failfast request %p", req);
+ rc = BLK_STS_IOERR;
+ goto out;
+ }
+
+ cqr = basedev->discipline->build_cp(basedev, block, req);
+ if (IS_ERR(cqr)) {
+ if (PTR_ERR(cqr) == -EBUSY ||
+ PTR_ERR(cqr) == -ENOMEM ||
+ PTR_ERR(cqr) == -EAGAIN) {
+ rc = BLK_STS_RESOURCE;
+ goto out;
+ }
+ DBF_DEV_EVENT(DBF_ERR, basedev,
+ "CCW creation failed (rc=%ld) on request %p",
+ PTR_ERR(cqr), req);
+ rc = BLK_STS_IOERR;
+ goto out;
+ }
+ /*
+ * Note: callback is set to dasd_return_cqr_cb in
+ * __dasd_block_start_head to cover erp requests as well
+ */
+ cqr->callback_data = req;
+ cqr->status = DASD_CQR_FILLED;
+ cqr->dq = dq;
+ req->completion_data = cqr;
+ blk_mq_start_request(req);
spin_lock(&block->queue_lock);
- /* Get new request from the block device request queue */
- __dasd_process_request_queue(block);
- /* Now check if the head of the ccw queue needs to be started. */
- __dasd_block_start_head(block);
+ list_add_tail(&cqr->blocklist, &block->ccw_queue);
+ INIT_LIST_HEAD(&cqr->devlist);
+ dasd_profile_start(block, cqr, req);
+ dasd_schedule_block_bh(block);
spin_unlock(&block->queue_lock);
+
+out:
+ spin_unlock_irq(&dq->lock);
+ return rc;
}
/*
* Block timeout callback, called from the block layer
*
- * request_queue lock is held on entry.
- *
* Return values:
* BLK_EH_RESET_TIMER if the request should be left running
* BLK_EH_NOT_HANDLED if the request is handled or terminated
* by the driver.
*/
-enum blk_eh_timer_return dasd_times_out(struct request *req)
+enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved)
{
struct dasd_ccw_req *cqr = req->completion_data;
struct dasd_block *block = req->q->queuedata;
struct dasd_device *device;
+ unsigned long flags;
int rc = 0;
if (!cqr)
return BLK_EH_NOT_HANDLED;
+ spin_lock_irqsave(&cqr->dq->lock, flags);
device = cqr->startdev ? cqr->startdev : block->base;
- if (!device->blk_timeout)
+ if (!device->blk_timeout) {
+ spin_unlock_irqrestore(&cqr->dq->lock, flags);
return BLK_EH_RESET_TIMER;
+ }
DBF_DEV_EVENT(DBF_WARNING, device,
" dasd_times_out cqr %p status %x",
cqr, cqr->status);
@@ -3154,19 +3137,64 @@ enum blk_eh_timer_return dasd_times_out(struct request *req)
}
dasd_schedule_block_bh(block);
spin_unlock(&block->queue_lock);
+ spin_unlock_irqrestore(&cqr->dq->lock, flags);
return rc ? BLK_EH_RESET_TIMER : BLK_EH_NOT_HANDLED;
}
+static int dasd_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
+ unsigned int idx)
+{
+ struct dasd_queue *dq = kzalloc(sizeof(*dq), GFP_KERNEL);
+
+ if (!dq)
+ return -ENOMEM;
+
+ spin_lock_init(&dq->lock);
+ hctx->driver_data = dq;
+
+ return 0;
+}
+
+static void dasd_exit_hctx(struct blk_mq_hw_ctx *hctx, unsigned int idx)
+{
+ kfree(hctx->driver_data);
+ hctx->driver_data = NULL;
+}
+
+static void dasd_request_done(struct request *req)
+{
+ blk_mq_end_request(req, 0);
+ blk_mq_run_hw_queues(req->q, true);
+}
+
+static struct blk_mq_ops dasd_mq_ops = {
+ .queue_rq = do_dasd_request,
+ .complete = dasd_request_done,
+ .timeout = dasd_times_out,
+ .init_hctx = dasd_init_hctx,
+ .exit_hctx = dasd_exit_hctx,
+};
+
/*
* Allocate and initialize request queue and default I/O scheduler.
*/
static int dasd_alloc_queue(struct dasd_block *block)
{
- block->request_queue = blk_init_queue(do_dasd_request,
- &block->request_queue_lock);
- if (block->request_queue == NULL)
- return -ENOMEM;
+ int rc;
+
+ block->tag_set.ops = &dasd_mq_ops;
+ block->tag_set.nr_hw_queues = DASD_NR_HW_QUEUES;
+ block->tag_set.queue_depth = DASD_MAX_LCU_DEV * DASD_REQ_PER_DEV;
+ block->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
+
+ rc = blk_mq_alloc_tag_set(&block->tag_set);
+ if (rc)
+ return rc;
+
+ block->request_queue = blk_mq_init_queue(&block->tag_set);
+ if (IS_ERR(block->request_queue))
+ return PTR_ERR(block->request_queue);
block->request_queue->queuedata = block;
@@ -3229,26 +3257,11 @@ static void dasd_free_queue(struct dasd_block *block)
{
if (block->request_queue) {
blk_cleanup_queue(block->request_queue);
+ blk_mq_free_tag_set(&block->tag_set);
block->request_queue = NULL;
}
}
-/*
- * Flush request on the request queue.
- */
-static void dasd_flush_request_queue(struct dasd_block *block)
-{
- struct request *req;
-
- if (!block->request_queue)
- return;
-
- spin_lock_irq(&block->request_queue_lock);
- while ((req = blk_fetch_request(block->request_queue)))
- __blk_end_request_all(req, BLK_STS_IOERR);
- spin_unlock_irq(&block->request_queue_lock);
-}
-
static int dasd_open(struct block_device *bdev, fmode_t mode)
{
struct dasd_device *base;
@@ -3744,8 +3757,10 @@ int dasd_generic_path_operational(struct dasd_device *device)
return 1;
}
dasd_schedule_device_bh(device);
- if (device->block)
+ if (device->block) {
dasd_schedule_block_bh(device->block);
+ blk_mq_run_hw_queues(device->block->request_queue, true);
+ }
if (!device->stopped)
wake_up(&generic_waitq);
@@ -4008,8 +4023,10 @@ int dasd_generic_restore_device(struct ccw_device *cdev)
*/
device->stopped |= DASD_UNRESUMED_PM;
- if (device->block)
+ if (device->block) {
dasd_schedule_block_bh(device->block);
+ blk_mq_run_hw_queues(device->block->request_queue, true);
+ }
clear_bit(DASD_FLAG_SUSPENDED, &device->flags);
dasd_put_device(device);
diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c
index e38042ce94e6..c95a4784c191 100644
--- a/drivers/s390/block/dasd_devmap.c
+++ b/drivers/s390/block/dasd_devmap.c
@@ -1326,7 +1326,7 @@ dasd_timeout_store(struct device *dev, struct device_attribute *attr,
{
struct dasd_device *device;
struct request_queue *q;
- unsigned long val, flags;
+ unsigned long val;
device = dasd_device_from_cdev(to_ccwdev(dev));
if (IS_ERR(device) || !device->block)
@@ -1342,16 +1342,10 @@ dasd_timeout_store(struct device *dev, struct device_attribute *attr,
dasd_put_device(device);
return -ENODEV;
}
- spin_lock_irqsave(&device->block->request_queue_lock, flags);
- if (!val)
- blk_queue_rq_timed_out(q, NULL);
- else
- blk_queue_rq_timed_out(q, dasd_times_out);
device->blk_timeout = val;
blk_queue_rq_timeout(q, device->blk_timeout * HZ);
- spin_unlock_irqrestore(&device->block->request_queue_lock, flags);
dasd_put_device(device);
return count;
diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index f9e25fc03d6b..db470bd10175 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -56,6 +56,7 @@
#include <asm/dasd.h>
#include <asm/idals.h>
#include <linux/bitops.h>
+#include <linux/blk-mq.h>
/* DASD discipline magic */
#define DASD_ECKD_MAGIC 0xC5C3D2C4
@@ -185,6 +186,7 @@ struct dasd_ccw_req {
char status; /* status of this request */
short retries; /* A retry counter */
unsigned long flags; /* flags of this request */
+ struct dasd_queue *dq;
/* ... and how */
unsigned long starttime; /* jiffies time of request start */
@@ -248,6 +250,16 @@ struct dasd_ccw_req {
#define DASD_CQR_SUPPRESS_IL 6 /* Suppress 'Incorrect Length' error */
#define DASD_CQR_SUPPRESS_CR 7 /* Suppress 'Command Reject' error */
+/*
+ * There is no reliable way to determine the number of available CPUs on
+ * LPAR but there is no big performance difference between 1 and the
+ * maximum CPU number.
+ * 64 is a good trade off performance wise.
+ */
+#define DASD_NR_HW_QUEUES 64
+#define DASD_MAX_LCU_DEV 256
+#define DASD_REQ_PER_DEV 4
+
/* Signature for error recovery functions. */
typedef struct dasd_ccw_req *(*dasd_erp_fn_t) (struct dasd_ccw_req *);
@@ -539,6 +551,7 @@ struct dasd_block {
struct gendisk *gdp;
struct request_queue *request_queue;
spinlock_t request_queue_lock;
+ struct blk_mq_tag_set tag_set;
struct block_device *bdev;
atomic_t open_count;
@@ -563,6 +576,10 @@ struct dasd_attention_data {
__u8 lpum;
};
+struct dasd_queue {
+ spinlock_t lock;
+};
+
/* reasons why device (ccw_device_start) was stopped */
#define DASD_STOPPED_NOT_ACC 1 /* not accessible */
#define DASD_STOPPED_QUIESCE 2 /* Quiesced */
@@ -731,7 +748,7 @@ void dasd_free_device(struct dasd_device *);
struct dasd_block *dasd_alloc_block(void);
void dasd_free_block(struct dasd_block *);
-enum blk_eh_timer_return dasd_times_out(struct request *req);
+enum blk_eh_timer_return dasd_times_out(struct request *req, bool reserved);
void dasd_enable_device(struct dasd_device *);
void dasd_set_target_state(struct dasd_device *, int);
--
2.16.4