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authorJens Axboe <jens.axboe@oracle.com>2008-01-29 14:51:59 +0100
committerJens Axboe <jens.axboe@oracle.com>2008-01-29 21:55:07 +0100
commit8324aa91d1e11a1fc25f209687a0b2e6c2ed47d0 (patch)
treec63753df94b741d328840edabde74462591ca0b3 /block/blk-sysfs.c
parenta168ee84c90b39ece357da127ab388f2f64db19c (diff)
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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 <jens.axboe@oracle.com>
Diffstat (limited to 'block/blk-sysfs.c')
-rw-r--r--block/blk-sysfs.c298
1 files changed, 298 insertions, 0 deletions
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
new file mode 100644
index 00000000000..d9b9afab345
--- /dev/null
+++ b/block/blk-sysfs.c
@@ -0,0 +1,298 @@
+/*
+ * Functions related to sysfs handling
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/blktrace_api.h>
+
+#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);
+ }
+}