From: Bart Van Assche <bvanassche@acm.org>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, Christoph Hellwig <hch@lst.de>,
Bart Van Assche <bvanassche@acm.org>,
Christoph Hellwig <hch@infradead.org>,
Ming Lei <ming.lei@redhat.com>, Hannes Reinecke <hare@suse.com>,
Johannes Thumshirn <jthumshirn@suse.de>
Subject: [PATCH 8/8] null_blk: Enable modifying 'submit_queues' after an instance has been configured
Date: Mon, 30 Sep 2019 16:00:47 -0700 [thread overview]
Message-ID: <20190930230047.44113-9-bvanassche@acm.org> (raw)
In-Reply-To: <20190930230047.44113-1-bvanassche@acm.org>
This patch makes it possible to test blk_mq_update_nr_hw_queues() from
inside a VM.
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/block/null_blk_main.c | 75 +++++++++++++++++++++++------------
1 file changed, 50 insertions(+), 25 deletions(-)
diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c
index f5747cfd806f..f5e0dffb4624 100644
--- a/drivers/block/null_blk_main.c
+++ b/drivers/block/null_blk_main.c
@@ -227,7 +227,7 @@ static ssize_t nullb_device_uint_attr_store(unsigned int *val,
int result;
result = kstrtouint(page, 0, &tmp);
- if (result)
+ if (result < 0)
return result;
*val = tmp;
@@ -241,7 +241,7 @@ static ssize_t nullb_device_ulong_attr_store(unsigned long *val,
unsigned long tmp;
result = kstrtoul(page, 0, &tmp);
- if (result)
+ if (result < 0)
return result;
*val = tmp;
@@ -255,7 +255,7 @@ static ssize_t nullb_device_bool_attr_store(bool *val, const char *page,
int result;
result = kstrtobool(page, &tmp);
- if (result)
+ if (result < 0)
return result;
*val = tmp;
@@ -263,7 +263,7 @@ static ssize_t nullb_device_bool_attr_store(bool *val, const char *page,
}
/* The following macro should only be used with TYPE = {uint, ulong, bool}. */
-#define NULLB_DEVICE_ATTR(NAME, TYPE) \
+#define NULLB_DEVICE_ATTR(NAME, TYPE, APPLY) \
static ssize_t \
nullb_device_##NAME##_show(struct config_item *item, char *page) \
{ \
@@ -274,32 +274,57 @@ static ssize_t \
nullb_device_##NAME##_store(struct config_item *item, const char *page, \
size_t count) \
{ \
+ int (*apply_fn)(struct nullb_device *dev, TYPE new_value) = APPLY; \
struct nullb_device *dev = to_nullb_device(item); \
+ TYPE new_value; \
+ int ret; \
\
- if (test_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags)) \
- return -EBUSY; \
- return nullb_device_##TYPE##_attr_store(&dev->NAME, page, count); \
+ ret = nullb_device_##TYPE##_attr_store(&new_value, page, count); \
+ if (ret < 0) \
+ return ret; \
+ if (apply_fn) \
+ ret = apply_fn(dev, new_value); \
+ else if (test_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags)) \
+ ret = -EBUSY; \
+ if (ret < 0) \
+ return ret; \
+ dev->NAME = new_value; \
+ return count; \
} \
CONFIGFS_ATTR(nullb_device_, NAME);
-NULLB_DEVICE_ATTR(size, ulong);
-NULLB_DEVICE_ATTR(completion_nsec, ulong);
-NULLB_DEVICE_ATTR(submit_queues, uint);
-NULLB_DEVICE_ATTR(home_node, uint);
-NULLB_DEVICE_ATTR(queue_mode, uint);
-NULLB_DEVICE_ATTR(blocksize, uint);
-NULLB_DEVICE_ATTR(irqmode, uint);
-NULLB_DEVICE_ATTR(hw_queue_depth, uint);
-NULLB_DEVICE_ATTR(index, uint);
-NULLB_DEVICE_ATTR(blocking, bool);
-NULLB_DEVICE_ATTR(use_per_node_hctx, bool);
-NULLB_DEVICE_ATTR(memory_backed, bool);
-NULLB_DEVICE_ATTR(discard, bool);
-NULLB_DEVICE_ATTR(mbps, uint);
-NULLB_DEVICE_ATTR(cache_size, ulong);
-NULLB_DEVICE_ATTR(zoned, bool);
-NULLB_DEVICE_ATTR(zone_size, ulong);
-NULLB_DEVICE_ATTR(zone_nr_conv, uint);
+static int nullb_apply_submit_queues(struct nullb_device *dev,
+ unsigned int submit_queues)
+{
+ struct nullb *nullb = dev->nullb;
+ struct blk_mq_tag_set *set;
+
+ if (!nullb)
+ return 0;
+
+ set = nullb->tag_set;
+ blk_mq_update_nr_hw_queues(set, submit_queues);
+ return set->nr_hw_queues == submit_queues ? 0 : -ENOMEM;
+}
+
+NULLB_DEVICE_ATTR(size, ulong, NULL);
+NULLB_DEVICE_ATTR(completion_nsec, ulong, NULL);
+NULLB_DEVICE_ATTR(submit_queues, uint, nullb_apply_submit_queues);
+NULLB_DEVICE_ATTR(home_node, uint, NULL);
+NULLB_DEVICE_ATTR(queue_mode, uint, NULL);
+NULLB_DEVICE_ATTR(blocksize, uint, NULL);
+NULLB_DEVICE_ATTR(irqmode, uint, NULL);
+NULLB_DEVICE_ATTR(hw_queue_depth, uint, NULL);
+NULLB_DEVICE_ATTR(index, uint, NULL);
+NULLB_DEVICE_ATTR(blocking, bool, NULL);
+NULLB_DEVICE_ATTR(use_per_node_hctx, bool, NULL);
+NULLB_DEVICE_ATTR(memory_backed, bool, NULL);
+NULLB_DEVICE_ATTR(discard, bool, NULL);
+NULLB_DEVICE_ATTR(mbps, uint, NULL);
+NULLB_DEVICE_ATTR(cache_size, ulong, NULL);
+NULLB_DEVICE_ATTR(zoned, bool, NULL);
+NULLB_DEVICE_ATTR(zone_size, ulong, NULL);
+NULLB_DEVICE_ATTR(zone_nr_conv, uint, NULL);
static ssize_t nullb_device_power_show(struct config_item *item, char *page)
{
--
2.23.0.444.g18eeb5a265-goog
next prev parent reply other threads:[~2019-09-30 23:01 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-30 23:00 [PATCH 0/8] Block layer patches for kernel v5.5 Bart Van Assche
2019-09-30 23:00 ` [PATCH 1/8] block: Fix three kernel-doc warnings Bart Van Assche
2019-09-30 23:00 ` [PATCH 2/8] block: Fix writeback throttling W=1 compiler warnings Bart Van Assche
2019-09-30 23:00 ` [PATCH 3/8] block: Remove request_queue.nr_queues Bart Van Assche
2019-09-30 23:00 ` [PATCH 4/8] block: Remove "dying" checks from sysfs callbacks Bart Van Assche
2019-09-30 23:00 ` [PATCH 5/8] block: Reduce sysfs_lock locking inside blk_cleanup_queue() Bart Van Assche
2019-09-30 23:00 ` [PATCH 6/8] block: Document all members of blk_mq_tag_set and bkl_mq_queue_map Bart Van Assche
2019-09-30 23:00 ` [PATCH 7/8] null_blk: Improve nullb_device_##NAME##_store() readability Bart Van Assche
2019-09-30 23:00 ` Bart Van Assche [this message]
2019-10-02 3:28 ` [PATCH 0/8] Block layer patches for kernel v5.5 Jens Axboe
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