[PATCH 7/9] btrfs: separate out the extent buffer init code

[Josef Bacik <josef@toxicpanda.com>]

We want to move this into it's own file, so separate out the init/exit
code for setting up the extent_buffer cache.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/extent_io.c | 36 +++++++++++++++++++-----------------
 fs/btrfs/extent_io.h |  2 ++
 fs/btrfs/super.c     |  9 ++++++++-
 3 files changed, 29 insertions(+), 18 deletions(-)

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 80c105b78bbf..d8acf5df35e7 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -135,32 +135,30 @@ static int __must_check flush_write_bio(struct extent_page_data *epd)
 
 int __init extent_io_init(void)
 {
-	extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
-			sizeof(struct extent_buffer), 0,
-			SLAB_MEM_SPREAD, NULL);
-	if (!extent_buffer_cache)
-		return -ENOMEM;
-
 	if (bioset_init(&btrfs_bioset, BIO_POOL_SIZE,
 			offsetof(struct btrfs_io_bio, bio),
 			BIOSET_NEED_BVECS))
-		goto free_buffer_cache;
+		return -ENOMEM;
 
-	if (bioset_integrity_create(&btrfs_bioset, BIO_POOL_SIZE))
-		goto free_bioset;
+	if (bioset_integrity_create(&btrfs_bioset, BIO_POOL_SIZE)) {
+		bioset_exit(&btrfs_bioset);
+		return -ENOMEM;
+	}
 
 	return 0;
+}
 
-free_bioset:
-	bioset_exit(&btrfs_bioset);
-
-free_buffer_cache:
-	kmem_cache_destroy(extent_buffer_cache);
-	extent_buffer_cache = NULL;
-	return -ENOMEM;
+int __init extent_buffer_init(void)
+{
+	extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
+			sizeof(struct extent_buffer), 0,
+			SLAB_MEM_SPREAD, NULL);
+	if (!extent_buffer_cache)
+		return -ENOMEM;
+	return 0;
 }
 
-void __cold extent_io_exit(void)
+void __cold extent_buffer_exit(void)
 {
 	btrfs_extent_buffer_leak_debug_check();
 
@@ -170,6 +168,10 @@ void __cold extent_io_exit(void)
 	 */
 	rcu_barrier();
 	kmem_cache_destroy(extent_buffer_cache);
+}
+
+void __cold extent_io_exit(void)
+{
 	bioset_exit(&btrfs_bioset);
 }
 
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index e22045cef89b..e2246956e544 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -332,4 +332,6 @@ bool find_lock_delalloc_range(struct inode *inode,
 #endif
 struct extent_buffer *alloc_test_extent_buffer(struct btrfs_fs_info *fs_info,
 					       u64 start);
+int __init extent_buffer_init(void);
+void __cold extent_buffer_exit(void);
 #endif
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 843015b9a11e..7207bb39f236 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2360,10 +2360,14 @@ static int __init init_btrfs_fs(void)
 	if (err)
 		goto free_cachep;
 
-	err = extent_state_cache_init();
+	err = extent_buffer_init();
 	if (err)
 		goto free_extent_io;
 
+	err = extent_state_cache_init();
+	if (err)
+		goto free_extent_buffer;
+
 	err = extent_map_init();
 	if (err)
 		goto free_extent_state_cache;
@@ -2428,6 +2432,8 @@ static int __init init_btrfs_fs(void)
 	extent_map_exit();
 free_extent_state_cache:
 	extent_state_cache_exit();
+free_extent_buffer:
+	extent_buffer_exit();
 free_extent_io:
 	extent_io_exit();
 free_cachep:
@@ -2449,6 +2455,7 @@ static void __exit exit_btrfs_fs(void)
 	ordered_data_exit();
 	extent_map_exit();
 	extent_state_cache_exit();
+	extent_buffer_exit();
 	extent_io_exit();
 	btrfs_interface_exit();
 	btrfs_end_io_wq_exit();
-- 
2.21.0