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path: root/drivers/md/dm-cache-target.c
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Diffstat (limited to 'drivers/md/dm-cache-target.c')
-rw-r--r--drivers/md/dm-cache-target.c54
1 files changed, 40 insertions, 14 deletions
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index df44b60e66f2..516f9c922bb2 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -151,6 +151,9 @@ struct cache {
atomic_t nr_migrations;
wait_queue_head_t migration_wait;
+ wait_queue_head_t quiescing_wait;
+ atomic_t quiescing_ack;
+
/*
* cache_size entries, dirty if set
*/
@@ -742,8 +745,9 @@ static void cell_defer(struct cache *cache, struct dm_bio_prison_cell *cell,
static void cleanup_migration(struct dm_cache_migration *mg)
{
- dec_nr_migrations(mg->cache);
+ struct cache *cache = mg->cache;
free_migration(mg);
+ dec_nr_migrations(cache);
}
static void migration_failure(struct dm_cache_migration *mg)
@@ -1340,34 +1344,51 @@ static void writeback_some_dirty_blocks(struct cache *cache)
/*----------------------------------------------------------------
* Main worker loop
*--------------------------------------------------------------*/
-static void start_quiescing(struct cache *cache)
+static bool is_quiescing(struct cache *cache)
{
+ int r;
unsigned long flags;
spin_lock_irqsave(&cache->lock, flags);
- cache->quiescing = 1;
+ r = cache->quiescing;
spin_unlock_irqrestore(&cache->lock, flags);
+
+ return r;
}
-static void stop_quiescing(struct cache *cache)
+static void ack_quiescing(struct cache *cache)
+{
+ if (is_quiescing(cache)) {
+ atomic_inc(&cache->quiescing_ack);
+ wake_up(&cache->quiescing_wait);
+ }
+}
+
+static void wait_for_quiescing_ack(struct cache *cache)
+{
+ wait_event(cache->quiescing_wait, atomic_read(&cache->quiescing_ack));
+}
+
+static void start_quiescing(struct cache *cache)
{
unsigned long flags;
spin_lock_irqsave(&cache->lock, flags);
- cache->quiescing = 0;
+ cache->quiescing = true;
spin_unlock_irqrestore(&cache->lock, flags);
+
+ wait_for_quiescing_ack(cache);
}
-static bool is_quiescing(struct cache *cache)
+static void stop_quiescing(struct cache *cache)
{
- int r;
unsigned long flags;
spin_lock_irqsave(&cache->lock, flags);
- r = cache->quiescing;
+ cache->quiescing = false;
spin_unlock_irqrestore(&cache->lock, flags);
- return r;
+ atomic_set(&cache->quiescing_ack, 0);
}
static void wait_for_migrations(struct cache *cache)
@@ -1414,16 +1435,15 @@ static void do_worker(struct work_struct *ws)
struct cache *cache = container_of(ws, struct cache, worker);
do {
- if (!is_quiescing(cache))
+ if (!is_quiescing(cache)) {
+ writeback_some_dirty_blocks(cache);
+ process_deferred_writethrough_bios(cache);
process_deferred_bios(cache);
+ }
process_migrations(cache, &cache->quiesced_migrations, issue_copy);
process_migrations(cache, &cache->completed_migrations, complete_migration);
- writeback_some_dirty_blocks(cache);
-
- process_deferred_writethrough_bios(cache);
-
if (commit_if_needed(cache)) {
process_deferred_flush_bios(cache, false);
@@ -1436,6 +1456,9 @@ static void do_worker(struct work_struct *ws)
process_migrations(cache, &cache->need_commit_migrations,
migration_success_post_commit);
}
+
+ ack_quiescing(cache);
+
} while (more_work(cache));
}
@@ -1998,6 +2021,9 @@ static int cache_create(struct cache_args *ca, struct cache **result)
atomic_set(&cache->nr_migrations, 0);
init_waitqueue_head(&cache->migration_wait);
+ init_waitqueue_head(&cache->quiescing_wait);
+ atomic_set(&cache->quiescing_ack, 0);
+
r = -ENOMEM;
cache->nr_dirty = 0;
cache->dirty_bitset = alloc_bitset(from_cblock(cache->cache_size));