diff options
| -rw-r--r-- | drivers/block/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/block/null_blk.c | 210 |
2 files changed, 210 insertions, 1 deletions
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig index 8ddc98279c8f..5dd62a8c4d60 100644 --- a/drivers/block/Kconfig +++ b/drivers/block/Kconfig @@ -17,6 +17,7 @@ if BLK_DEV config BLK_DEV_NULL_BLK tristate "Null test block driver" + depends on CONFIGFS_FS config BLK_DEV_FD tristate "Normal floppy disk support" diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index 73938cde11f3..c782492c0099 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -1,3 +1,7 @@ +/* + * Add configfs and memory store: Kyungchan Koh <kkc6196@fb.com> and + * Shaohua Li <shli@fb.com> + */ #include <linux/module.h> #include <linux/moduleparam.h> @@ -9,6 +13,7 @@ #include <linux/blk-mq.h> #include <linux/hrtimer.h> #include <linux/lightnvm.h> +#include <linux/configfs.h> struct nullb_cmd { struct list_head list; @@ -30,8 +35,21 @@ struct nullb_queue { struct nullb_cmd *cmds; }; +/* + * Status flags for nullb_device. + * + * CONFIGURED: Device has been configured and turned on. Cannot reconfigure. + * UP: Device is currently on and visible in userspace. + */ +enum nullb_device_flags { + NULLB_DEV_FL_CONFIGURED = 0, + NULLB_DEV_FL_UP = 1, +}; + struct nullb_device { struct nullb *nullb; + struct config_item item; + unsigned long flags; /* device flags */ unsigned long size; /* device size in MB */ unsigned long completion_nsec; /* time in ns to complete a request */ @@ -173,6 +191,185 @@ static bool g_use_per_node_hctx; module_param_named(use_per_node_hctx, g_use_per_node_hctx, bool, S_IRUGO); MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false"); +static struct nullb_device *null_alloc_dev(void); +static void null_free_dev(struct nullb_device *dev); + +static inline struct nullb_device *to_nullb_device(struct config_item *item) +{ + return item ? container_of(item, struct nullb_device, item) : NULL; +} + +static inline ssize_t nullb_device_uint_attr_show(unsigned int val, char *page) +{ + return snprintf(page, PAGE_SIZE, "%u\n", val); +} + +static inline ssize_t nullb_device_ulong_attr_show(unsigned long val, + char *page) +{ + return snprintf(page, PAGE_SIZE, "%lu\n", val); +} + +static inline ssize_t nullb_device_bool_attr_show(bool val, char *page) +{ + return snprintf(page, PAGE_SIZE, "%u\n", val); +} + +static ssize_t nullb_device_uint_attr_store(unsigned int *val, + const char *page, size_t count) +{ + unsigned int tmp; + int result; + + result = kstrtouint(page, 0, &tmp); + if (result) + return result; + + *val = tmp; + return count; +} + +static ssize_t nullb_device_ulong_attr_store(unsigned long *val, + const char *page, size_t count) +{ + int result; + unsigned long tmp; + + result = kstrtoul(page, 0, &tmp); + if (result) + return result; + + *val = tmp; + return count; +} + +static ssize_t nullb_device_bool_attr_store(bool *val, const char *page, + size_t count) +{ + bool tmp; + int result; + + result = kstrtobool(page, &tmp); + if (result) + return result; + + *val = tmp; + return count; +} + +/* The following macro should only be used with TYPE = {uint, ulong, bool}. */ +#define NULLB_DEVICE_ATTR(NAME, TYPE) \ +static ssize_t \ +nullb_device_##NAME##_show(struct config_item *item, char *page) \ +{ \ + return nullb_device_##TYPE##_attr_show( \ + to_nullb_device(item)->NAME, page); \ +} \ +static ssize_t \ +nullb_device_##NAME##_store(struct config_item *item, const char *page, \ + size_t count) \ +{ \ + if (test_bit(NULLB_DEV_FL_CONFIGURED, &to_nullb_device(item)->flags)) \ + return -EBUSY; \ + return nullb_device_##TYPE##_attr_store( \ + &to_nullb_device(item)->NAME, page, 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(use_lightnvm, bool); +NULLB_DEVICE_ATTR(blocking, bool); +NULLB_DEVICE_ATTR(use_per_node_hctx, bool); + +static struct configfs_attribute *nullb_device_attrs[] = { + &nullb_device_attr_size, + &nullb_device_attr_completion_nsec, + &nullb_device_attr_submit_queues, + &nullb_device_attr_home_node, + &nullb_device_attr_queue_mode, + &nullb_device_attr_blocksize, + &nullb_device_attr_irqmode, + &nullb_device_attr_hw_queue_depth, + &nullb_device_attr_use_lightnvm, + &nullb_device_attr_blocking, + &nullb_device_attr_use_per_node_hctx, + NULL, +}; + +static void nullb_device_release(struct config_item *item) +{ + null_free_dev(to_nullb_device(item)); +} + +static struct configfs_item_operations nullb_device_ops = { + .release = nullb_device_release, +}; + +static struct config_item_type nullb_device_type = { + .ct_item_ops = &nullb_device_ops, + .ct_attrs = nullb_device_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct +config_item *nullb_group_make_item(struct config_group *group, const char *name) +{ + struct nullb_device *dev; + + dev = null_alloc_dev(); + if (!dev) + return ERR_PTR(-ENOMEM); + + config_item_init_type_name(&dev->item, name, &nullb_device_type); + + return &dev->item; +} + +static void +nullb_group_drop_item(struct config_group *group, struct config_item *item) +{ + config_item_put(item); +} + +static ssize_t memb_group_features_show(struct config_item *item, char *page) +{ + return snprintf(page, PAGE_SIZE, "\n"); +} + +CONFIGFS_ATTR_RO(memb_group_, features); + +static struct configfs_attribute *nullb_group_attrs[] = { + &memb_group_attr_features, + NULL, +}; + +static struct configfs_group_operations nullb_group_ops = { + .make_item = nullb_group_make_item, + .drop_item = nullb_group_drop_item, +}; + +static struct config_item_type nullb_group_type = { + .ct_group_ops = &nullb_group_ops, + .ct_attrs = nullb_group_attrs, + .ct_owner = THIS_MODULE, +}; + +static struct configfs_subsystem nullb_subsys = { + .su_group = { + .cg_item = { + .ci_namebuf = "nullb", + .ci_type = &nullb_group_type, + }, + }, +}; + static struct nullb_device *null_alloc_dev(void) { struct nullb_device *dev; @@ -919,12 +1116,19 @@ static int __init null_init(void) return ret; } + config_group_init(&nullb_subsys.su_group); + mutex_init(&nullb_subsys.su_mutex); + + ret = configfs_register_subsystem(&nullb_subsys); + if (ret) + goto err_tagset; + mutex_init(&lock); null_major = register_blkdev(0, "nullb"); if (null_major < 0) { ret = null_major; - goto err_tagset; + goto err_conf; } if (g_use_lightnvm) { @@ -961,6 +1165,8 @@ err_dev: kmem_cache_destroy(ppa_cache); err_ppa: unregister_blkdev(null_major, "nullb"); +err_conf: + configfs_unregister_subsystem(&nullb_subsys); err_tagset: if (g_queue_mode == NULL_Q_MQ && shared_tags) blk_mq_free_tag_set(&tag_set); @@ -971,6 +1177,8 @@ static void __exit null_exit(void) { struct nullb *nullb; + configfs_unregister_subsystem(&nullb_subsys); + unregister_blkdev(null_major, "nullb"); mutex_lock(&lock); |