block: Unhash a zone write plug only if needed

[linux-block.git] / block / blk-zoned.c

diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index 78557f810f1d9c0769fb0922392ce33fe093ad74..2f61ba56dad27b293c030069c8defa396659c1ee 100644 (file)
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -476,29 +476,6 @@ static bool disk_insert_zone_wplug(struct gendisk *disk,
        return true;
 }
 
-static void disk_remove_zone_wplug(struct gendisk *disk,
-                                  struct blk_zone_wplug *zwplug)
-{
-       unsigned long flags;
-
-       spin_lock_irqsave(&disk->zone_wplugs_lock, flags);
-       zwplug->flags |= BLK_ZONE_WPLUG_UNHASHED;
-       atomic_dec(&zwplug->ref);
-       hlist_del_init_rcu(&zwplug->node);
-       spin_unlock_irqrestore(&disk->zone_wplugs_lock, flags);
-}
-
-static inline bool disk_should_remove_zone_wplug(struct gendisk *disk,
-                                                struct blk_zone_wplug *zwplug)
-{
-       /* If the zone is still busy, the plug cannot be removed. */
-       if (zwplug->flags & BLK_ZONE_WPLUG_BUSY)
-               return false;
-
-       /* We can remove zone write plugs for zones that are empty or full. */
-       return !zwplug->wp_offset || zwplug->wp_offset >= disk->zone_capacity;
-}
-
 static struct blk_zone_wplug *disk_get_zone_wplug(struct gendisk *disk,
                                                  sector_t sector)
 {
@@ -534,11 +511,43 @@ static inline void disk_put_zone_wplug(struct blk_zone_wplug *zwplug)
        if (atomic_dec_and_test(&zwplug->ref)) {
                WARN_ON_ONCE(!bio_list_empty(&zwplug->bio_list));
                WARN_ON_ONCE(!list_empty(&zwplug->link));
+               WARN_ON_ONCE(!(zwplug->flags & BLK_ZONE_WPLUG_UNHASHED));
 
                call_rcu(&zwplug->rcu_head, disk_free_zone_wplug_rcu);
        }
 }
 
+static inline bool disk_should_remove_zone_wplug(struct gendisk *disk,
+                                                struct blk_zone_wplug *zwplug)
+{
+       /* If the zone is still busy, the plug cannot be removed. */
+       if (zwplug->flags & BLK_ZONE_WPLUG_BUSY)
+               return false;
+
+       /* We can remove zone write plugs for zones that are empty or full. */
+       return !zwplug->wp_offset || zwplug->wp_offset >= disk->zone_capacity;
+}
+
+static void disk_remove_zone_wplug(struct gendisk *disk,
+                                  struct blk_zone_wplug *zwplug)
+{
+       unsigned long flags;
+
+       /* If the zone write plug was already removed, we have nothing to do. */
+       if (zwplug->flags & BLK_ZONE_WPLUG_UNHASHED)
+               return;
+
+       /*
+        * Mark the zone write plug as unhashed and drop the extra reference we
+        * took when the plug was inserted in the hash table.
+        */
+       zwplug->flags |= BLK_ZONE_WPLUG_UNHASHED;
+       spin_lock_irqsave(&disk->zone_wplugs_lock, flags);
+       hlist_del_init_rcu(&zwplug->node);
+       spin_unlock_irqrestore(&disk->zone_wplugs_lock, flags);
+       disk_put_zone_wplug(zwplug);
+}
+
 static void blk_zone_wplug_bio_work(struct work_struct *work);
 
 /*