diff options
Diffstat (limited to 'block/blk-sysfs.c')
| -rw-r--r-- | block/blk-sysfs.c | 612 |
1 files changed, 612 insertions, 0 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c new file mode 100644 index 000000000..2b8fd302f --- /dev/null +++ b/block/blk-sysfs.c @@ -0,0 +1,612 @@ +/* + * Functions related to sysfs handling + */ +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/bio.h> +#include <linux/blkdev.h> +#include <linux/blktrace_api.h> +#include <linux/blk-mq.h> + +#include "blk.h" +#include "blk-cgroup.h" +#include "blk-mq.h" + +struct queue_sysfs_entry { + struct attribute attr; + ssize_t (*show)(struct request_queue *, char *); + ssize_t (*store)(struct request_queue *, const char *, size_t); +}; + +static ssize_t +queue_var_show(unsigned long var, char *page) +{ + return sprintf(page, "%lu\n", var); +} + +static ssize_t +queue_var_store(unsigned long *var, const char *page, size_t count) +{ + int err; + unsigned long v; + + err = kstrtoul(page, 10, &v); + if (err || v > UINT_MAX) + return -EINVAL; + + *var = v; + + return count; +} + +static ssize_t queue_requests_show(struct request_queue *q, char *page) +{ + return queue_var_show(q->nr_requests, (page)); +} + +static ssize_t +queue_requests_store(struct request_queue *q, const char *page, size_t count) +{ + unsigned long nr; + int ret, err; + + if (!q->request_fn && !q->mq_ops) + return -EINVAL; + + ret = queue_var_store(&nr, page, count); + if (ret < 0) + return ret; + + if (nr < BLKDEV_MIN_RQ) + nr = BLKDEV_MIN_RQ; + + if (q->request_fn) + err = blk_update_nr_requests(q, nr); + else + err = blk_mq_update_nr_requests(q, nr); + + if (err) + return err; + + return ret; +} + +static ssize_t queue_ra_show(struct request_queue *q, char *page) +{ + unsigned long ra_kb = q->backing_dev_info.ra_pages << + (PAGE_CACHE_SHIFT - 10); + + return queue_var_show(ra_kb, (page)); +} + +static ssize_t +queue_ra_store(struct request_queue *q, const char *page, size_t count) +{ + unsigned long ra_kb; + ssize_t ret = queue_var_store(&ra_kb, page, count); + + if (ret < 0) + return ret; + + q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10); + + return ret; +} + +static ssize_t queue_max_sectors_show(struct request_queue *q, char *page) +{ + int max_sectors_kb = queue_max_sectors(q) >> 1; + + return queue_var_show(max_sectors_kb, (page)); +} + +static ssize_t queue_max_segments_show(struct request_queue *q, char *page) +{ + return queue_var_show(queue_max_segments(q), (page)); +} + +static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page) +{ + return queue_var_show(q->limits.max_integrity_segments, (page)); +} + +static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page) +{ + if (blk_queue_cluster(q)) + return queue_var_show(queue_max_segment_size(q), (page)); + + return queue_var_show(PAGE_CACHE_SIZE, (page)); +} + +static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page) +{ + return queue_var_show(queue_logical_block_size(q), page); +} + +static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page) +{ + return queue_var_show(queue_physical_block_size(q), page); +} + +static ssize_t queue_io_min_show(struct request_queue *q, char *page) +{ + return queue_var_show(queue_io_min(q), page); +} + +static ssize_t queue_io_opt_show(struct request_queue *q, char *page) +{ + return queue_var_show(queue_io_opt(q), page); +} + +static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page) +{ + return queue_var_show(q->limits.discard_granularity, page); +} + +static ssize_t queue_discard_max_show(struct request_queue *q, char *page) +{ + return sprintf(page, "%llu\n", + (unsigned long long)q->limits.max_discard_sectors << 9); +} + +static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page) +{ + return queue_var_show(queue_discard_zeroes_data(q), page); +} + +static ssize_t queue_write_same_max_show(struct request_queue *q, char *page) +{ + return sprintf(page, "%llu\n", + (unsigned long long)q->limits.max_write_same_sectors << 9); +} + + +static ssize_t +queue_max_sectors_store(struct request_queue *q, const char *page, size_t count) +{ + unsigned long max_sectors_kb, + max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1, + page_kb = 1 << (PAGE_CACHE_SHIFT - 10); + ssize_t ret = queue_var_store(&max_sectors_kb, page, count); + + if (ret < 0) + return ret; + + if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb) + return -EINVAL; + + spin_lock_irq(q->queue_lock); + q->limits.max_sectors = max_sectors_kb << 1; + spin_unlock_irq(q->queue_lock); + + return ret; +} + +static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page) +{ + int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1; + + return queue_var_show(max_hw_sectors_kb, (page)); +} + +#define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \ +static ssize_t \ +queue_show_##name(struct request_queue *q, char *page) \ +{ \ + int bit; \ + bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \ + return queue_var_show(neg ? !bit : bit, page); \ +} \ +static ssize_t \ +queue_store_##name(struct request_queue *q, const char *page, size_t count) \ +{ \ + unsigned long val; \ + ssize_t ret; \ + ret = queue_var_store(&val, page, count); \ + if (ret < 0) \ + return ret; \ + if (neg) \ + val = !val; \ + \ + spin_lock_irq(q->queue_lock); \ + if (val) \ + queue_flag_set(QUEUE_FLAG_##flag, q); \ + else \ + queue_flag_clear(QUEUE_FLAG_##flag, q); \ + spin_unlock_irq(q->queue_lock); \ + return ret; \ +} + +QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1); +QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0); +QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0); +#undef QUEUE_SYSFS_BIT_FNS + +static ssize_t queue_nomerges_show(struct request_queue *q, char *page) +{ + return queue_var_show((blk_queue_nomerges(q) << 1) | + blk_queue_noxmerges(q), page); +} + +static ssize_t queue_nomerges_store(struct request_queue *q, const char *page, + size_t count) +{ + unsigned long nm; + ssize_t ret = queue_var_store(&nm, page, count); + + if (ret < 0) + return ret; + + spin_lock_irq(q->queue_lock); + queue_flag_clear(QUEUE_FLAG_NOMERGES, q); + queue_flag_clear(QUEUE_FLAG_NOXMERGES, q); + if (nm == 2) + queue_flag_set(QUEUE_FLAG_NOMERGES, q); + else if (nm) + queue_flag_set(QUEUE_FLAG_NOXMERGES, q); + spin_unlock_irq(q->queue_lock); + + return ret; +} + +static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page) +{ + bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags); + bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags); + + return queue_var_show(set << force, page); +} + +static ssize_t +queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count) +{ + ssize_t ret = -EINVAL; +#ifdef CONFIG_SMP + unsigned long val; + + ret = queue_var_store(&val, page, count); + if (ret < 0) + return ret; + + spin_lock_irq(q->queue_lock); + if (val == 2) { + queue_flag_set(QUEUE_FLAG_SAME_COMP, q); + queue_flag_set(QUEUE_FLAG_SAME_FORCE, q); + } else if (val == 1) { + queue_flag_set(QUEUE_FLAG_SAME_COMP, q); + queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); + } else if (val == 0) { + queue_flag_clear(QUEUE_FLAG_SAME_COMP, q); + queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q); + } + spin_unlock_irq(q->queue_lock); +#endif + return ret; +} + +static struct queue_sysfs_entry queue_requests_entry = { + .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR }, + .show = queue_requests_show, + .store = queue_requests_store, +}; + +static struct queue_sysfs_entry queue_ra_entry = { + .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR }, + .show = queue_ra_show, + .store = queue_ra_store, +}; + +static struct queue_sysfs_entry queue_max_sectors_entry = { + .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR }, + .show = queue_max_sectors_show, + .store = queue_max_sectors_store, +}; + +static struct queue_sysfs_entry queue_max_hw_sectors_entry = { + .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO }, + .show = queue_max_hw_sectors_show, +}; + +static struct queue_sysfs_entry queue_max_segments_entry = { + .attr = {.name = "max_segments", .mode = S_IRUGO }, + .show = queue_max_segments_show, +}; + +static struct queue_sysfs_entry queue_max_integrity_segments_entry = { + .attr = {.name = "max_integrity_segments", .mode = S_IRUGO }, + .show = queue_max_integrity_segments_show, +}; + +static struct queue_sysfs_entry queue_max_segment_size_entry = { + .attr = {.name = "max_segment_size", .mode = S_IRUGO }, + .show = queue_max_segment_size_show, +}; + +static struct queue_sysfs_entry queue_iosched_entry = { + .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR }, + .show = elv_iosched_show, + .store = elv_iosched_store, +}; + +static struct queue_sysfs_entry queue_hw_sector_size_entry = { + .attr = {.name = "hw_sector_size", .mode = S_IRUGO }, + .show = queue_logical_block_size_show, +}; + +static struct queue_sysfs_entry queue_logical_block_size_entry = { + .attr = {.name = "logical_block_size", .mode = S_IRUGO }, + .show = queue_logical_block_size_show, +}; + +static struct queue_sysfs_entry queue_physical_block_size_entry = { + .attr = {.name = "physical_block_size", .mode = S_IRUGO }, + .show = queue_physical_block_size_show, +}; + +static struct queue_sysfs_entry queue_io_min_entry = { + .attr = {.name = "minimum_io_size", .mode = S_IRUGO }, + .show = queue_io_min_show, +}; + +static struct queue_sysfs_entry queue_io_opt_entry = { + .attr = {.name = "optimal_io_size", .mode = S_IRUGO }, + .show = queue_io_opt_show, +}; + +static struct queue_sysfs_entry queue_discard_granularity_entry = { + .attr = {.name = "discard_granularity", .mode = S_IRUGO }, + .show = queue_discard_granularity_show, +}; + +static struct queue_sysfs_entry queue_discard_max_entry = { + .attr = {.name = "discard_max_bytes", .mode = S_IRUGO }, + .show = queue_discard_max_show, +}; + +static struct queue_sysfs_entry queue_discard_zeroes_data_entry = { + .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO }, + .show = queue_discard_zeroes_data_show, +}; + +static struct queue_sysfs_entry queue_write_same_max_entry = { + .attr = {.name = "write_same_max_bytes", .mode = S_IRUGO }, + .show = queue_write_same_max_show, +}; + +static struct queue_sysfs_entry queue_nonrot_entry = { + .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR }, + .show = queue_show_nonrot, + .store = queue_store_nonrot, +}; + +static struct queue_sysfs_entry queue_nomerges_entry = { + .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR }, + .show = queue_nomerges_show, + .store = queue_nomerges_store, +}; + +static struct queue_sysfs_entry queue_rq_affinity_entry = { + .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR }, + .show = queue_rq_affinity_show, + .store = queue_rq_affinity_store, +}; + +static struct queue_sysfs_entry queue_iostats_entry = { + .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR }, + .show = queue_show_iostats, + .store = queue_store_iostats, +}; + +static struct queue_sysfs_entry queue_random_entry = { + .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR }, + .show = queue_show_random, + .store = queue_store_random, +}; + +static struct attribute *default_attrs[] = { + &queue_requests_entry.attr, + &queue_ra_entry.attr, + &queue_max_hw_sectors_entry.attr, + &queue_max_sectors_entry.attr, + &queue_max_segments_entry.attr, + &queue_max_integrity_segments_entry.attr, + &queue_max_segment_size_entry.attr, + &queue_iosched_entry.attr, + &queue_hw_sector_size_entry.attr, + &queue_logical_block_size_entry.attr, + &queue_physical_block_size_entry.attr, + &queue_io_min_entry.attr, + &queue_io_opt_entry.attr, + &queue_discard_granularity_entry.attr, + &queue_discard_max_entry.attr, + &queue_discard_zeroes_data_entry.attr, + &queue_write_same_max_entry.attr, + &queue_nonrot_entry.attr, + &queue_nomerges_entry.attr, + &queue_rq_affinity_entry.attr, + &queue_iostats_entry.attr, + &queue_random_entry.attr, + NULL, +}; + +#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr) + +static ssize_t +queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page) +{ + struct queue_sysfs_entry *entry = to_queue(attr); + struct request_queue *q = + container_of(kobj, struct request_queue, kobj); + ssize_t res; + + if (!entry->show) + return -EIO; + mutex_lock(&q->sysfs_lock); + if (blk_queue_dying(q)) { + mutex_unlock(&q->sysfs_lock); + return -ENOENT; + } + res = entry->show(q, page); + mutex_unlock(&q->sysfs_lock); + return res; +} + +static ssize_t +queue_attr_store(struct kobject *kobj, struct attribute *attr, + const char *page, size_t length) +{ + struct queue_sysfs_entry *entry = to_queue(attr); + struct request_queue *q; + ssize_t res; + + if (!entry->store) + return -EIO; + + q = container_of(kobj, struct request_queue, kobj); + mutex_lock(&q->sysfs_lock); + if (blk_queue_dying(q)) { + mutex_unlock(&q->sysfs_lock); + return -ENOENT; + } + res = entry->store(q, page, length); + mutex_unlock(&q->sysfs_lock); + return res; +} + +static void blk_free_queue_rcu(struct rcu_head *rcu_head) +{ + struct request_queue *q = container_of(rcu_head, struct request_queue, + rcu_head); + kmem_cache_free(blk_requestq_cachep, q); +} + +/** + * blk_release_queue: - release a &struct request_queue when it is no longer needed + * @kobj: the kobj belonging to the request queue to be released + * + * Description: + * blk_release_queue is the pair to blk_init_queue() or + * blk_queue_make_request(). It should be called when a request queue is + * being released; typically when a block device is being de-registered. + * Currently, its primary task it to free all the &struct request + * structures that were allocated to the queue and the queue itself. + * + * Note: + * The low level driver must have finished any outstanding requests first + * via blk_cleanup_queue(). + **/ +static void blk_release_queue(struct kobject *kobj) +{ + struct request_queue *q = + container_of(kobj, struct request_queue, kobj); + + blkcg_exit_queue(q); + + if (q->elevator) { + spin_lock_irq(q->queue_lock); + ioc_clear_queue(q); + spin_unlock_irq(q->queue_lock); + elevator_exit(q->elevator); + } + + blk_exit_rl(&q->root_rl); + + if (q->queue_tags) + __blk_queue_free_tags(q); + + if (!q->mq_ops) + blk_free_flush_queue(q->fq); + else + blk_mq_release(q); + + blk_trace_shutdown(q); + + ida_simple_remove(&blk_queue_ida, q->id); + call_rcu(&q->rcu_head, blk_free_queue_rcu); +} + +static const struct sysfs_ops queue_sysfs_ops = { + .show = queue_attr_show, + .store = queue_attr_store, +}; + +struct kobj_type blk_queue_ktype = { + .sysfs_ops = &queue_sysfs_ops, + .default_attrs = default_attrs, + .release = blk_release_queue, +}; + +int blk_register_queue(struct gendisk *disk) +{ + int ret; + struct device *dev = disk_to_dev(disk); + struct request_queue *q = disk->queue; + + if (WARN_ON(!q)) + return -ENXIO; + + /* + * SCSI probing may synchronously create and destroy a lot of + * request_queues for non-existent devices. Shutting down a fully + * functional queue takes measureable wallclock time as RCU grace + * periods are involved. To avoid excessive latency in these + * cases, a request_queue starts out in a degraded mode which is + * faster to shut down and is made fully functional here as + * request_queues for non-existent devices never get registered. + */ + if (!blk_queue_init_done(q)) { + queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q); + blk_queue_bypass_end(q); + if (q->mq_ops) + blk_mq_finish_init(q); + } + + ret = blk_trace_init_sysfs(dev); + if (ret) + return ret; + + ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue"); + if (ret < 0) { + blk_trace_remove_sysfs(dev); + return ret; + } + + kobject_uevent(&q->kobj, KOBJ_ADD); + + if (q->mq_ops) + blk_mq_register_disk(disk); + + if (!q->request_fn) + return 0; + + ret = elv_register_queue(q); + if (ret) { + kobject_uevent(&q->kobj, KOBJ_REMOVE); + kobject_del(&q->kobj); + blk_trace_remove_sysfs(dev); + kobject_put(&dev->kobj); + return ret; + } + + return 0; +} + +void blk_unregister_queue(struct gendisk *disk) +{ + struct request_queue *q = disk->queue; + + if (WARN_ON(!q)) + return; + + if (q->mq_ops) + blk_mq_unregister_disk(disk); + + if (q->request_fn) + elv_unregister_queue(q); + + kobject_uevent(&q->kobj, KOBJ_REMOVE); + kobject_del(&q->kobj); + blk_trace_remove_sysfs(disk_to_dev(disk)); + kobject_put(&disk_to_dev(disk)->kobj); +} |