From 8324aa91d1e11a1fc25f209687a0b2e6c2ed47d0 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 29 Jan 2008 14:51:59 +0100 Subject: block: split tag and sysfs handling from blk-core.c Seperates the tag and sysfs handling from ll_rw_blk. Signed-off-by: Jens Axboe --- block/blk-sysfs.c | 298 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 298 insertions(+) create mode 100644 block/blk-sysfs.c (limited to 'block/blk-sysfs.c') diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c new file mode 100644 index 000000000000..d9b9afab3456 --- /dev/null +++ b/block/blk-sysfs.c @@ -0,0 +1,298 @@ +/* + * Functions related to sysfs handling + */ +#include +#include +#include +#include +#include + +#include "blk.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 int var, char *page) +{ + return sprintf(page, "%d\n", var); +} + +static ssize_t +queue_var_store(unsigned long *var, const char *page, size_t count) +{ + char *p = (char *) page; + + *var = simple_strtoul(p, &p, 10); + 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) +{ + struct request_list *rl = &q->rq; + unsigned long nr; + int ret = queue_var_store(&nr, page, count); + if (nr < BLKDEV_MIN_RQ) + nr = BLKDEV_MIN_RQ; + + spin_lock_irq(q->queue_lock); + q->nr_requests = nr; + blk_queue_congestion_threshold(q); + + if (rl->count[READ] >= queue_congestion_on_threshold(q)) + blk_set_queue_congested(q, READ); + else if (rl->count[READ] < queue_congestion_off_threshold(q)) + blk_clear_queue_congested(q, READ); + + if (rl->count[WRITE] >= queue_congestion_on_threshold(q)) + blk_set_queue_congested(q, WRITE); + else if (rl->count[WRITE] < queue_congestion_off_threshold(q)) + blk_clear_queue_congested(q, WRITE); + + if (rl->count[READ] >= q->nr_requests) { + blk_set_queue_full(q, READ); + } else if (rl->count[READ]+1 <= q->nr_requests) { + blk_clear_queue_full(q, READ); + wake_up(&rl->wait[READ]); + } + + if (rl->count[WRITE] >= q->nr_requests) { + blk_set_queue_full(q, WRITE); + } else if (rl->count[WRITE]+1 <= q->nr_requests) { + blk_clear_queue_full(q, WRITE); + wake_up(&rl->wait[WRITE]); + } + spin_unlock_irq(q->queue_lock); + return ret; +} + +static ssize_t queue_ra_show(struct request_queue *q, char *page) +{ + int 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); + + spin_lock_irq(q->queue_lock); + q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10); + spin_unlock_irq(q->queue_lock); + + return ret; +} + +static ssize_t queue_max_sectors_show(struct request_queue *q, char *page) +{ + int max_sectors_kb = q->max_sectors >> 1; + + return queue_var_show(max_sectors_kb, (page)); +} + +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 = q->max_hw_sectors >> 1, + page_kb = 1 << (PAGE_CACHE_SHIFT - 10); + ssize_t ret = queue_var_store(&max_sectors_kb, page, count); + + if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb) + return -EINVAL; + /* + * Take the queue lock to update the readahead and max_sectors + * values synchronously: + */ + spin_lock_irq(q->queue_lock); + q->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 = q->max_hw_sectors >> 1; + + return queue_var_show(max_hw_sectors_kb, (page)); +} + + +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_iosched_entry = { + .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR }, + .show = elv_iosched_show, + .store = elv_iosched_store, +}; + +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_iosched_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 (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) { + 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 = container_of(kobj, struct request_queue, kobj); + + ssize_t res; + + if (!entry->store) + return -EIO; + mutex_lock(&q->sysfs_lock); + if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) { + mutex_unlock(&q->sysfs_lock); + return -ENOENT; + } + res = entry->store(q, page, length); + mutex_unlock(&q->sysfs_lock); + return res; +} + +/** + * blk_cleanup_queue: - release a &struct request_queue when it is no longer needed + * @kobj: the kobj belonging of the request queue to be released + * + * Description: + * blk_cleanup_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. + * + * Caveat: + * Hopefully the low level driver will have finished any + * outstanding requests first... + **/ +static void blk_release_queue(struct kobject *kobj) +{ + struct request_queue *q = + container_of(kobj, struct request_queue, kobj); + struct request_list *rl = &q->rq; + + blk_sync_queue(q); + + if (rl->rq_pool) + mempool_destroy(rl->rq_pool); + + if (q->queue_tags) + __blk_queue_free_tags(q); + + blk_trace_shutdown(q); + + bdi_destroy(&q->backing_dev_info); + kmem_cache_free(blk_requestq_cachep, q); +} + +static 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 request_queue *q = disk->queue; + + if (!q || !q->request_fn) + return -ENXIO; + + ret = kobject_add(&q->kobj, kobject_get(&disk->dev.kobj), + "%s", "queue"); + if (ret < 0) + return ret; + + kobject_uevent(&q->kobj, KOBJ_ADD); + + ret = elv_register_queue(q); + if (ret) { + kobject_uevent(&q->kobj, KOBJ_REMOVE); + kobject_del(&q->kobj); + return ret; + } + + return 0; +} + +void blk_unregister_queue(struct gendisk *disk) +{ + struct request_queue *q = disk->queue; + + if (q && q->request_fn) { + elv_unregister_queue(q); + + kobject_uevent(&q->kobj, KOBJ_REMOVE); + kobject_del(&q->kobj); + kobject_put(&disk->dev.kobj); + } +} -- cgit v1.2.3