From: Josef Bacik <josef@toxicpanda.com>
Date: Thu, 20 Jun 2019 15:37:50 -0400
Subject: btrfs: export the caching control helpers
Git-commit: e3cb339fa5ca57cfa5429bf3da548331dce93038
Patch-mainline: v5.4-rc1
References: bsc#1165949

Man a lot of people use this stuff.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Acked-by: Nikolay Borisov <nborisov@suse.com>
---
 fs/btrfs/block-group.h |  3 +++
 fs/btrfs/extent-tree.c | 36 ++++++++++++++++++------------------
 2 files changed, 21 insertions(+), 18 deletions(-)

diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h
index 7069bcfc5e8f..3f8b6ffefb8a 100644
--- a/fs/btrfs/block-group.h
+++ b/fs/btrfs/block-group.h
@@ -170,6 +170,9 @@ void btrfs_wait_block_group_cache_progress(struct btrfs_block_group_cache *cache
 int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache);
 int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
 			    int load_cache_only);
+void btrfs_put_caching_control(struct btrfs_caching_control *ctl);
+struct btrfs_caching_control *btrfs_get_caching_control(
+		struct btrfs_block_group_cache *cache);
 
 static inline int btrfs_block_group_cache_done(
 		struct btrfs_block_group_cache *cache)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 2d92f103fa2b..dab8e90237cd 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -182,8 +182,8 @@ static int exclude_super_stripes(struct btrfs_block_group_cache *cache)
 	return 0;
 }
 
-static struct btrfs_caching_control *
-get_caching_control(struct btrfs_block_group_cache *cache)
+struct btrfs_caching_control *btrfs_get_caching_control(
+		struct btrfs_block_group_cache *cache)
 {
 	struct btrfs_caching_control *ctl;
 
@@ -199,7 +199,7 @@ get_caching_control(struct btrfs_block_group_cache *cache)
 	return ctl;
 }
 
-static void put_caching_control(struct btrfs_caching_control *ctl)
+void btrfs_put_caching_control(struct btrfs_caching_control *ctl)
 {
 	if (refcount_dec_and_test(&ctl->count))
 		kfree(ctl);
@@ -455,7 +455,7 @@ static noinline void caching_thread(struct btrfs_work *work)
 
 	wake_up(&caching_ctl->wait);
 
-	put_caching_control(caching_ctl);
+	btrfs_put_caching_control(caching_ctl);
 	btrfs_put_block_group(block_group);
 }
 
@@ -504,7 +504,7 @@ int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
 		schedule();
 
 		finish_wait(&ctl->wait, &wait);
-		put_caching_control(ctl);
+		btrfs_put_caching_control(ctl);
 		spin_lock(&cache->lock);
 	}
 
@@ -557,7 +557,7 @@ int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
 
 		wake_up(&caching_ctl->wait);
 		if (ret == 1) {
-			put_caching_control(caching_ctl);
+			btrfs_put_caching_control(caching_ctl);
 			btrfs_free_excluded_extents(cache);
 			return 0;
 		}
@@ -579,7 +579,7 @@ int btrfs_cache_block_group(struct btrfs_block_group_cache *cache,
 	}
 
 	if (load_cache_only) {
-		put_caching_control(caching_ctl);
+		btrfs_put_caching_control(caching_ctl);
 		return 0;
 	}
 
@@ -4153,7 +4153,7 @@ static int __exclude_logged_extent(struct btrfs_fs_info *fs_info,
 		return -EINVAL;
 
 	btrfs_cache_block_group(block_group, 0);
-	caching_ctl = get_caching_control(block_group);
+	caching_ctl = btrfs_get_caching_control(block_group);
 
 	if (!caching_ctl) {
 		/* Logic error */
@@ -4183,7 +4183,7 @@ static int __exclude_logged_extent(struct btrfs_fs_info *fs_info,
 		}
 out_lock:
 		mutex_unlock(&caching_ctl->mutex);
-		put_caching_control(caching_ctl);
+		btrfs_put_caching_control(caching_ctl);
 	}
 	btrfs_put_block_group(block_group);
 	return ret;
@@ -4306,7 +4306,7 @@ void btrfs_prepare_extent_commit(struct btrfs_fs_info *fs_info)
 		if (btrfs_block_group_cache_done(cache)) {
 			cache->last_byte_to_unpin = (u64)-1;
 			list_del_init(&caching_ctl->list);
-			put_caching_control(caching_ctl);
+			btrfs_put_caching_control(caching_ctl);
 		} else {
 			cache->last_byte_to_unpin = caching_ctl->progress;
 		}
@@ -4937,14 +4937,14 @@ void btrfs_wait_block_group_cache_progress(struct btrfs_block_group_cache *cache
 {
 	struct btrfs_caching_control *caching_ctl;
 
-	caching_ctl = get_caching_control(cache);
+	caching_ctl = btrfs_get_caching_control(cache);
 	if (!caching_ctl)
 		return;
 
 	wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache) ||
 		   (cache->free_space_ctl->free_space >= num_bytes));
 
-	put_caching_control(caching_ctl);
+	btrfs_put_caching_control(caching_ctl);
 }
 
 int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
@@ -4952,14 +4952,14 @@ int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
 	struct btrfs_caching_control *caching_ctl;
 	int ret = 0;
 
-	caching_ctl = get_caching_control(cache);
+	caching_ctl = btrfs_get_caching_control(cache);
 	if (!caching_ctl)
 		return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0;
 
 	wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache));
 	if (cache->cached == BTRFS_CACHE_ERROR)
 		ret = -EIO;
-	put_caching_control(caching_ctl);
+	btrfs_put_caching_control(caching_ctl);
 	return ret;
 }
 
@@ -7482,7 +7482,7 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info)
 		caching_ctl = list_entry(info->caching_block_groups.next,
 					 struct btrfs_caching_control, list);
 		list_del(&caching_ctl->list);
-		put_caching_control(caching_ctl);
+		btrfs_put_caching_control(caching_ctl);
 	}
 	up_write(&info->commit_root_sem);
 
@@ -8202,7 +8202,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 	}
 
 	if (block_group->has_caching_ctl)
-		caching_ctl = get_caching_control(block_group);
+		caching_ctl = btrfs_get_caching_control(block_group);
 	if (block_group->cached == BTRFS_CACHE_STARTED)
 		btrfs_wait_block_group_cache_done(block_group);
 	if (block_group->has_caching_ctl) {
@@ -8223,8 +8223,8 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
 		up_write(&fs_info->commit_root_sem);
 		if (caching_ctl) {
 			/* Once for the caching bgs list and once for us. */
-			put_caching_control(caching_ctl);
-			put_caching_control(caching_ctl);
+			btrfs_put_caching_control(caching_ctl);
+			btrfs_put_caching_control(caching_ctl);
 		}
 	}