From a62a3bd9546b91a46bbb74f4b4a49815b64875b1 Mon Sep 17 00:00:00 2001
From: Josef Bacik <josef@toxicpanda.com>
Date: Fri, 9 Sep 2022 17:53:18 -0400
Subject: [PATCH] btrfs: separate out the extent state and extent buffer init
 code

In order to help separate the extent buffer from the extent io tree code
we need to break up the init functions.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/extent-io-tree.h |  4 ++--
 fs/btrfs/extent_io.c      | 21 ++++++++++++++-------
 fs/btrfs/extent_io.h      |  3 +++
 fs/btrfs/super.c          | 17 ++++++++++++-----
 4 files changed, 31 insertions(+), 14 deletions(-)

diff --git a/fs/btrfs/extent-io-tree.h b/fs/btrfs/extent-io-tree.h
index ee2ba4b6e4a1..6c2016db304b 100644
--- a/fs/btrfs/extent-io-tree.h
+++ b/fs/btrfs/extent-io-tree.h
@@ -108,8 +108,8 @@ static inline int lock_extent(struct extent_io_tree *tree, u64 start, u64 end)
 
 int try_lock_extent(struct extent_io_tree *tree, u64 start, u64 end);
 
-int __init extent_io_init(void);
-void __cold extent_io_exit(void);
+int __init extent_state_init_cachep(void);
+void __cold extent_state_free_cachep(void);
 
 u64 count_range_bits(struct extent_io_tree *tree,
 		     u64 *start, u64 search_end,
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index f4481c2212dd..8b2c6f36d8ca 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -230,7 +230,7 @@ static void submit_write_bio(struct extent_page_data *epd, int ret)
 	}
 }
 
-int __init extent_io_init(void)
+int __init extent_state_init_cachep(void)
 {
 	extent_state_cache = kmem_cache_create("btrfs_extent_state",
 			sizeof(struct extent_state), 0,
@@ -238,18 +238,27 @@ int __init extent_io_init(void)
 	if (!extent_state_cache)
 		return -ENOMEM;
 
+	return 0;
+}
+
+int __init extent_buffer_init_cachep(void)
+{
 	extent_buffer_cache = kmem_cache_create("btrfs_extent_buffer",
 			sizeof(struct extent_buffer), 0,
 			SLAB_MEM_SPREAD, NULL);
-	if (!extent_buffer_cache) {
-		kmem_cache_destroy(extent_state_cache);
+	if (!extent_buffer_cache)
 		return -ENOMEM;
-	}
 
 	return 0;
 }
 
-void __cold extent_io_exit(void)
+void __cold extent_state_free_cachep(void)
+{
+	btrfs_extent_state_leak_debug_check();
+	kmem_cache_destroy(extent_state_cache);
+}
+
+void __cold extent_buffer_free_cachep(void)
 {
 	/*
 	 * Make sure all delayed rcu free are flushed before we
@@ -257,8 +266,6 @@ void __cold extent_io_exit(void)
 	 */
 	rcu_barrier();
 	kmem_cache_destroy(extent_buffer_cache);
-	btrfs_extent_state_leak_debug_check();
-	kmem_cache_destroy(extent_state_cache);
 }
 
 /*
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 1c4717669073..a335fbe23bed 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -64,6 +64,9 @@ struct btrfs_fs_info;
 struct io_failure_record;
 struct extent_io_tree;
 
+int __init extent_buffer_init_cachep(void);
+void __cold extent_buffer_free_cachep(void);
+
 typedef void (submit_bio_hook_t)(struct inode *inode, struct bio *bio,
 					 int mirror_num,
 					 enum btrfs_compression_type compress_type);
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index eb0ae7e396ef..be7df8d1d5b8 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2736,13 +2736,17 @@ static int __init init_btrfs_fs(void)
 	if (err)
 		goto free_compress;
 
-	err = extent_io_init();
+	err = extent_state_init_cachep();
 	if (err)
 		goto free_cachep;
 
+	err = extent_buffer_init_cachep();
+	if (err)
+		goto free_extent_cachep;
+
 	err = btrfs_bioset_init();
 	if (err)
-		goto free_extent_io;
+		goto free_eb_cachep;
 
 	err = extent_map_init();
 	if (err)
@@ -2800,8 +2804,10 @@ free_extent_map:
 	extent_map_exit();
 free_bioset:
 	btrfs_bioset_exit();
-free_extent_io:
-	extent_io_exit();
+free_eb_cachep:
+	extent_buffer_free_cachep();
+free_extent_cachep:
+	extent_state_free_cachep();
 free_cachep:
 	btrfs_destroy_cachep();
 free_compress:
@@ -2821,7 +2827,8 @@ static void __exit exit_btrfs_fs(void)
 	ordered_data_exit();
 	extent_map_exit();
 	btrfs_bioset_exit();
-	extent_io_exit();
+	extent_state_free_cachep();
+	extent_buffer_free_cachep();
 	btrfs_interface_exit();
 	unregister_filesystem(&btrfs_fs_type);
 	btrfs_exit_sysfs();