summaryrefslogtreecommitdiff
path: root/drivers/block
diff options
context:
space:
mode:
authorShaohua Li <shli@fb.com>2017-08-14 15:04:54 -0700
committerJens Axboe <axboe@kernel.dk>2017-08-23 08:54:03 -0600
commitcedcafad8277b3a07e90bf2f68fff5c6b28a183e (patch)
tree6bbd8a28bd9513188b29f1dec567841726053bc6 /drivers/block
parent3bf2bd20734e3e6ffda53719a9c10fb3ee9c5ffa (diff)
nullb: add interface to power on disk
The device created in nullb configfs interface isn't power on by default. After user configures the device, user can do 'echo 1 > xxx/nullb/device_name/power' to power on the device, which will create a disk. the xxx/nullb/device_name/index is the disk index, so if the index is 2, the new created disk should be named as /dev/nullb2. Note, the 'index' is only valid after disk is power on. 'echo 0 > xxx/nullb/device_name/power' will remove the disk. Note, this doesn't remove the device. To remove the device, user should do 'rmdir xxx/nullb/device_name'. Removing the device will remove the disk too. Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/null_blk.c80
1 files changed, 80 insertions, 0 deletions
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index c782492c0099..cf14c46d3462 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -59,9 +59,11 @@ struct nullb_device {
unsigned int blocksize; /* block size */
unsigned int irqmode; /* IRQ completion handler */
unsigned int hw_queue_depth; /* queue depth */
+ unsigned int index; /* index of the disk, only valid with a disk */
bool use_lightnvm; /* register as a LightNVM device */
bool blocking; /* blocking blk-mq device */
bool use_per_node_hctx; /* use per-node allocation for hardware context */
+ bool power; /* power on/off the device */
};
struct nullb {
@@ -193,6 +195,8 @@ MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware contex
static struct nullb_device *null_alloc_dev(void);
static void null_free_dev(struct nullb_device *dev);
+static void null_del_dev(struct nullb *nullb);
+static int null_add_dev(struct nullb_device *dev);
static inline struct nullb_device *to_nullb_device(struct config_item *item)
{
@@ -284,10 +288,50 @@ 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(use_lightnvm, bool);
NULLB_DEVICE_ATTR(blocking, bool);
NULLB_DEVICE_ATTR(use_per_node_hctx, bool);
+static ssize_t nullb_device_power_show(struct config_item *item, char *page)
+{
+ return nullb_device_bool_attr_show(to_nullb_device(item)->power, page);
+}
+
+static ssize_t nullb_device_power_store(struct config_item *item,
+ const char *page, size_t count)
+{
+ struct nullb_device *dev = to_nullb_device(item);
+ bool newp = false;
+ ssize_t ret;
+
+ ret = nullb_device_bool_attr_store(&newp, page, count);
+ if (ret < 0)
+ return ret;
+
+ if (!dev->power && newp) {
+ if (test_and_set_bit(NULLB_DEV_FL_UP, &dev->flags))
+ return count;
+ if (null_add_dev(dev)) {
+ clear_bit(NULLB_DEV_FL_UP, &dev->flags);
+ return -ENOMEM;
+ }
+
+ set_bit(NULLB_DEV_FL_CONFIGURED, &dev->flags);
+ dev->power = newp;
+ } else if (to_nullb_device(item)->power && !newp) {
+ mutex_lock(&lock);
+ dev->power = newp;
+ null_del_dev(dev->nullb);
+ mutex_unlock(&lock);
+ clear_bit(NULLB_DEV_FL_UP, &dev->flags);
+ }
+
+ return count;
+}
+
+CONFIGFS_ATTR(nullb_device_, power);
+
static struct configfs_attribute *nullb_device_attrs[] = {
&nullb_device_attr_size,
&nullb_device_attr_completion_nsec,
@@ -297,9 +341,11 @@ static struct configfs_attribute *nullb_device_attrs[] = {
&nullb_device_attr_blocksize,
&nullb_device_attr_irqmode,
&nullb_device_attr_hw_queue_depth,
+ &nullb_device_attr_index,
&nullb_device_attr_use_lightnvm,
&nullb_device_attr_blocking,
&nullb_device_attr_use_per_node_hctx,
+ &nullb_device_attr_power,
NULL,
};
@@ -335,6 +381,15 @@ config_item *nullb_group_make_item(struct config_group *group, const char *name)
static void
nullb_group_drop_item(struct config_group *group, struct config_item *item)
{
+ struct nullb_device *dev = to_nullb_device(item);
+
+ if (test_and_clear_bit(NULLB_DEV_FL_UP, &dev->flags)) {
+ mutex_lock(&lock);
+ dev->power = false;
+ null_del_dev(dev->nullb);
+ mutex_unlock(&lock);
+ }
+
config_item_put(item);
}
@@ -973,11 +1028,35 @@ static int null_init_tag_set(struct nullb *nullb, struct blk_mq_tag_set *set)
return blk_mq_alloc_tag_set(set);
}
+static void null_validate_conf(struct nullb_device *dev)
+{
+ dev->blocksize = round_down(dev->blocksize, 512);
+ dev->blocksize = clamp_t(unsigned int, dev->blocksize, 512, 4096);
+ if (dev->use_lightnvm && dev->blocksize != 4096)
+ dev->blocksize = 4096;
+
+ if (dev->use_lightnvm && dev->queue_mode != NULL_Q_MQ)
+ dev->queue_mode = NULL_Q_MQ;
+
+ if (dev->queue_mode == NULL_Q_MQ && dev->use_per_node_hctx) {
+ if (dev->submit_queues != nr_online_nodes)
+ dev->submit_queues = nr_online_nodes;
+ } else if (dev->submit_queues > nr_cpu_ids)
+ dev->submit_queues = nr_cpu_ids;
+ else if (dev->submit_queues == 0)
+ dev->submit_queues = 1;
+
+ dev->queue_mode = min_t(unsigned int, dev->queue_mode, NULL_Q_MQ);
+ dev->irqmode = min_t(unsigned int, dev->irqmode, NULL_IRQ_TIMER);
+}
+
static int null_add_dev(struct nullb_device *dev)
{
struct nullb *nullb;
int rv;
+ null_validate_conf(dev);
+
nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, dev->home_node);
if (!nullb) {
rv = -ENOMEM;
@@ -1040,6 +1119,7 @@ static int null_add_dev(struct nullb_device *dev)
mutex_lock(&lock);
nullb->index = nullb_indexes++;
+ dev->index = nullb->index;
mutex_unlock(&lock);
blk_queue_logical_block_size(nullb->q, dev->blocksize);