#include <linux/dm-io.h>
#include <linux/dm-kcopyd.h>
#include <linux/list.h>
+#include <linux/rculist.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
+#include <linux/rbtree.h>
#define DM_MSG_PREFIX "thin"
unsigned ref_count;
spinlock_t lock;
- struct bio_list deferred_bios;
struct bio_list deferred_flush_bios;
struct list_head prepared_mappings;
struct list_head prepared_discards;
-
- struct bio_list retry_on_resume_list;
+ struct list_head active_thins;
struct dm_deferred_set *shared_read_ds;
struct dm_deferred_set *all_io_ds;
* Target context for a thin.
*/
struct thin_c {
+ struct list_head list;
struct dm_dev *pool_dev;
struct dm_dev *origin_dev;
dm_thin_id dev_id;
struct pool *pool;
struct dm_thin_device *td;
bool requeue_mode:1;
+ spinlock_t lock;
+ struct bio_list deferred_bio_list;
+ struct bio_list retry_on_resume_list;
+ struct rb_root sort_bio_list; /* sorted list of deferred bios */
};
/*----------------------------------------------------------------*/
struct pool *pool = tc->pool;
unsigned long flags;
- spin_lock_irqsave(&pool->lock, flags);
- dm_cell_release_no_holder(pool->prison, cell, &pool->deferred_bios);
- spin_unlock_irqrestore(&pool->lock, flags);
+ spin_lock_irqsave(&tc->lock, flags);
+ dm_cell_release_no_holder(pool->prison, cell, &tc->deferred_bio_list);
+ spin_unlock_irqrestore(&tc->lock, flags);
wake_worker(pool);
}
struct dm_deferred_entry *shared_read_entry;
struct dm_deferred_entry *all_io_entry;
struct dm_thin_new_mapping *overwrite_mapping;
+ struct rb_node rb_node;
};
static void requeue_bio_list(struct thin_c *tc, struct bio_list *master)
bio_list_init(&bios);
- spin_lock_irqsave(&tc->pool->lock, flags);
+ spin_lock_irqsave(&tc->lock, flags);
bio_list_merge(&bios, master);
bio_list_init(master);
- spin_unlock_irqrestore(&tc->pool->lock, flags);
+ spin_unlock_irqrestore(&tc->lock, flags);
- while ((bio = bio_list_pop(&bios))) {
- struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
-
- if (h->tc == tc)
- bio_endio(bio, DM_ENDIO_REQUEUE);
- else
- bio_list_add(master, bio);
- }
+ while ((bio = bio_list_pop(&bios)))
+ bio_endio(bio, DM_ENDIO_REQUEUE);
}
static void requeue_io(struct thin_c *tc)
{
- struct pool *pool = tc->pool;
-
- requeue_bio_list(tc, &pool->deferred_bios);
- requeue_bio_list(tc, &pool->retry_on_resume_list);
+ requeue_bio_list(tc, &tc->deferred_bio_list);
+ requeue_bio_list(tc, &tc->retry_on_resume_list);
}
-static void error_retry_list(struct pool *pool)
+static void error_thin_retry_list(struct thin_c *tc)
{
struct bio *bio;
unsigned long flags;
bio_list_init(&bios);
- spin_lock_irqsave(&pool->lock, flags);
- bio_list_merge(&bios, &pool->retry_on_resume_list);
- bio_list_init(&pool->retry_on_resume_list);
- spin_unlock_irqrestore(&pool->lock, flags);
+ spin_lock_irqsave(&tc->lock, flags);
+ bio_list_merge(&bios, &tc->retry_on_resume_list);
+ bio_list_init(&tc->retry_on_resume_list);
+ spin_unlock_irqrestore(&tc->lock, flags);
while ((bio = bio_list_pop(&bios)))
bio_io_error(bio);
}
+static void error_retry_list(struct pool *pool)
+{
+ struct thin_c *tc;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(tc, &pool->active_thins, list)
+ error_thin_retry_list(tc);
+ rcu_read_unlock();
+}
+
/*
* This section of code contains the logic for processing a thin device's IO.
* Much of the code depends on pool object resources (lists, workqueues, etc)
struct pool *pool = tc->pool;
unsigned long flags;
- spin_lock_irqsave(&pool->lock, flags);
- cell_release(pool, cell, &pool->deferred_bios);
- spin_unlock_irqrestore(&tc->pool->lock, flags);
+ spin_lock_irqsave(&tc->lock, flags);
+ cell_release(pool, cell, &tc->deferred_bio_list);
+ spin_unlock_irqrestore(&tc->lock, flags);
wake_worker(pool);
}
struct pool *pool = tc->pool;
unsigned long flags;
- spin_lock_irqsave(&pool->lock, flags);
- cell_release_no_holder(pool, cell, &pool->deferred_bios);
- spin_unlock_irqrestore(&pool->lock, flags);
+ spin_lock_irqsave(&tc->lock, flags);
+ cell_release_no_holder(pool, cell, &tc->deferred_bio_list);
+ spin_unlock_irqrestore(&tc->lock, flags);
wake_worker(pool);
}
{
struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
struct thin_c *tc = h->tc;
- struct pool *pool = tc->pool;
unsigned long flags;
- spin_lock_irqsave(&pool->lock, flags);
- bio_list_add(&pool->retry_on_resume_list, bio);
- spin_unlock_irqrestore(&pool->lock, flags);
+ spin_lock_irqsave(&tc->lock, flags);
+ bio_list_add(&tc->retry_on_resume_list, bio);
+ spin_unlock_irqrestore(&tc->lock, flags);
}
static bool should_error_unserviceable_bio(struct pool *pool)
jiffies > pool->last_commit_jiffies + COMMIT_PERIOD;
}
-static void process_deferred_bios(struct pool *pool)
+#define thin_pbd(node) rb_entry((node), struct dm_thin_endio_hook, rb_node)
+#define thin_bio(pbd) dm_bio_from_per_bio_data((pbd), sizeof(struct dm_thin_endio_hook))
+
+static void __thin_bio_rb_add(struct thin_c *tc, struct bio *bio)
+{
+ struct rb_node **rbp, *parent;
+ struct dm_thin_endio_hook *pbd;
+ sector_t bi_sector = bio->bi_iter.bi_sector;
+
+ rbp = &tc->sort_bio_list.rb_node;
+ parent = NULL;
+ while (*rbp) {
+ parent = *rbp;
+ pbd = thin_pbd(parent);
+
+ if (bi_sector < thin_bio(pbd)->bi_iter.bi_sector)
+ rbp = &(*rbp)->rb_left;
+ else
+ rbp = &(*rbp)->rb_right;
+ }
+
+ pbd = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
+ rb_link_node(&pbd->rb_node, parent, rbp);
+ rb_insert_color(&pbd->rb_node, &tc->sort_bio_list);
+}
+
+static void __extract_sorted_bios(struct thin_c *tc)
+{
+ struct rb_node *node;
+ struct dm_thin_endio_hook *pbd;
+ struct bio *bio;
+
+ for (node = rb_first(&tc->sort_bio_list); node; node = rb_next(node)) {
+ pbd = thin_pbd(node);
+ bio = thin_bio(pbd);
+
+ bio_list_add(&tc->deferred_bio_list, bio);
+ rb_erase(&pbd->rb_node, &tc->sort_bio_list);
+ }
+
+ WARN_ON(!RB_EMPTY_ROOT(&tc->sort_bio_list));
+}
+
+static void __sort_thin_deferred_bios(struct thin_c *tc)
+{
+ struct bio *bio;
+ struct bio_list bios;
+
+ bio_list_init(&bios);
+ bio_list_merge(&bios, &tc->deferred_bio_list);
+ bio_list_init(&tc->deferred_bio_list);
+
+ /* Sort deferred_bio_list using rb-tree */
+ while ((bio = bio_list_pop(&bios)))
+ __thin_bio_rb_add(tc, bio);
+
+ /*
+ * Transfer the sorted bios in sort_bio_list back to
+ * deferred_bio_list to allow lockless submission of
+ * all bios.
+ */
+ __extract_sorted_bios(tc);
+}
+
+static void process_thin_deferred_bios(struct thin_c *tc)
{
+ struct pool *pool = tc->pool;
unsigned long flags;
struct bio *bio;
struct bio_list bios;
+ struct blk_plug plug;
+
+ if (tc->requeue_mode) {
+ requeue_bio_list(tc, &tc->deferred_bio_list);
+ return;
+ }
bio_list_init(&bios);
- spin_lock_irqsave(&pool->lock, flags);
- bio_list_merge(&bios, &pool->deferred_bios);
- bio_list_init(&pool->deferred_bios);
- spin_unlock_irqrestore(&pool->lock, flags);
+ spin_lock_irqsave(&tc->lock, flags);
- while ((bio = bio_list_pop(&bios))) {
- struct dm_thin_endio_hook *h = dm_per_bio_data(bio, sizeof(struct dm_thin_endio_hook));
- struct thin_c *tc = h->tc;
+ if (bio_list_empty(&tc->deferred_bio_list)) {
+ spin_unlock_irqrestore(&tc->lock, flags);
+ return;
+ }
- if (tc->requeue_mode) {
- bio_endio(bio, DM_ENDIO_REQUEUE);
- continue;
- }
+ __sort_thin_deferred_bios(tc);
+
+ bio_list_merge(&bios, &tc->deferred_bio_list);
+ bio_list_init(&tc->deferred_bio_list);
+ spin_unlock_irqrestore(&tc->lock, flags);
+
+ blk_start_plug(&plug);
+ while ((bio = bio_list_pop(&bios))) {
/*
* If we've got no free new_mapping structs, and processing
* this bio might require one, we pause until there are some
* prepared mappings to process.
*/
if (ensure_next_mapping(pool)) {
- spin_lock_irqsave(&pool->lock, flags);
- bio_list_merge(&pool->deferred_bios, &bios);
- spin_unlock_irqrestore(&pool->lock, flags);
-
+ spin_lock_irqsave(&tc->lock, flags);
+ bio_list_add(&tc->deferred_bio_list, bio);
+ bio_list_merge(&tc->deferred_bio_list, &bios);
+ spin_unlock_irqrestore(&tc->lock, flags);
break;
}
else
pool->process_bio(tc, bio);
}
+ blk_finish_plug(&plug);
+}
+
+static void process_deferred_bios(struct pool *pool)
+{
+ unsigned long flags;
+ struct bio *bio;
+ struct bio_list bios;
+ struct thin_c *tc;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(tc, &pool->active_thins, list)
+ process_thin_deferred_bios(tc);
+ rcu_read_unlock();
/*
* If there are any deferred flush bios, we must commit
unsigned long flags;
struct pool *pool = tc->pool;
- spin_lock_irqsave(&pool->lock, flags);
- bio_list_add(&pool->deferred_bios, bio);
- spin_unlock_irqrestore(&pool->lock, flags);
+ spin_lock_irqsave(&tc->lock, flags);
+ bio_list_add(&tc->deferred_bio_list, bio);
+ spin_unlock_irqrestore(&tc->lock, flags);
wake_worker(pool);
}
static int pool_is_congested(struct dm_target_callbacks *cb, int bdi_bits)
{
- int r;
- unsigned long flags;
struct pool_c *pt = container_of(cb, struct pool_c, callbacks);
+ struct request_queue *q;
- spin_lock_irqsave(&pt->pool->lock, flags);
- r = !bio_list_empty(&pt->pool->retry_on_resume_list);
- spin_unlock_irqrestore(&pt->pool->lock, flags);
+ if (get_pool_mode(pt->pool) == PM_OUT_OF_DATA_SPACE)
+ return 1;
- if (!r) {
- struct request_queue *q = bdev_get_queue(pt->data_dev->bdev);
- r = bdi_congested(&q->backing_dev_info, bdi_bits);
- }
-
- return r;
+ q = bdev_get_queue(pt->data_dev->bdev);
+ return bdi_congested(&q->backing_dev_info, bdi_bits);
}
-static void __requeue_bios(struct pool *pool)
+static void requeue_bios(struct pool *pool)
{
- bio_list_merge(&pool->deferred_bios, &pool->retry_on_resume_list);
- bio_list_init(&pool->retry_on_resume_list);
+ unsigned long flags;
+ struct thin_c *tc;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(tc, &pool->active_thins, list) {
+ spin_lock_irqsave(&tc->lock, flags);
+ bio_list_merge(&tc->deferred_bio_list, &tc->retry_on_resume_list);
+ bio_list_init(&tc->retry_on_resume_list);
+ spin_unlock_irqrestore(&tc->lock, flags);
+ }
+ rcu_read_unlock();
}
/*----------------------------------------------------------------
INIT_WORK(&pool->worker, do_worker);
INIT_DELAYED_WORK(&pool->waker, do_waker);
spin_lock_init(&pool->lock);
- bio_list_init(&pool->deferred_bios);
bio_list_init(&pool->deferred_flush_bios);
INIT_LIST_HEAD(&pool->prepared_mappings);
INIT_LIST_HEAD(&pool->prepared_discards);
+ INIT_LIST_HEAD(&pool->active_thins);
pool->low_water_triggered = false;
- bio_list_init(&pool->retry_on_resume_list);
pool->shared_read_ds = dm_deferred_set_create();
if (!pool->shared_read_ds) {
spin_lock_irqsave(&pool->lock, flags);
pool->low_water_triggered = false;
- __requeue_bios(pool);
spin_unlock_irqrestore(&pool->lock, flags);
+ requeue_bios(pool);
do_waker(&pool->waker.work);
}
.name = "thin-pool",
.features = DM_TARGET_SINGLETON | DM_TARGET_ALWAYS_WRITEABLE |
DM_TARGET_IMMUTABLE,
- .version = {1, 11, 0},
+ .version = {1, 12, 0},
.module = THIS_MODULE,
.ctr = pool_ctr,
.dtr = pool_dtr,
static void thin_dtr(struct dm_target *ti)
{
struct thin_c *tc = ti->private;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tc->pool->lock, flags);
+ list_del_rcu(&tc->list);
+ spin_unlock_irqrestore(&tc->pool->lock, flags);
+ synchronize_rcu();
mutex_lock(&dm_thin_pool_table.mutex);
r = -ENOMEM;
goto out_unlock;
}
+ spin_lock_init(&tc->lock);
+ bio_list_init(&tc->deferred_bio_list);
+ bio_list_init(&tc->retry_on_resume_list);
+ tc->sort_bio_list = RB_ROOT;
if (argc == 3) {
r = dm_get_device(ti, argv[2], FMODE_READ, &origin_dev);
mutex_unlock(&dm_thin_pool_table.mutex);
+ spin_lock(&tc->pool->lock);
+ list_add_tail_rcu(&tc->list, &tc->pool->active_thins);
+ spin_unlock(&tc->pool->lock);
+ /*
+ * This synchronize_rcu() call is needed here otherwise we risk a
+ * wake_worker() call finding no bios to process (because the newly
+ * added tc isn't yet visible). So this reduces latency since we
+ * aren't then dependent on the periodic commit to wake_worker().
+ */
+ synchronize_rcu();
+
return 0;
bad_target_max_io_len:
static struct target_type thin_target = {
.name = "thin",
- .version = {1, 11, 0},
+ .version = {1, 12, 0},
.module = THIS_MODULE,
.ctr = thin_ctr,
.dtr = thin_dtr,
projects / firefly-linux-kernel-4.4.55.git / blobdiff