btrfs: migrate the delalloc space stuff to it's own home

We have code for data and metadata reservations for delalloc.  There's
quite a bit of code here, and it's used in a lot of places so I've
separated it out to it's own file.  inode.c and file.c are already
pretty large, and this code is complicated enough to live in its own
space.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/Makefile

@@ -11,7 +11,7 @@ btrfs-y += super.o ctree.o extent-tree.o print-tree.o root-tree.o dir-item.o \
 	   compression.o delayed-ref.o relocation.o delayed-inode.o scrub.o \
 	   reada.o backref.o ulist.o qgroup.o send.o dev-replace.o raid56.o \
 	   uuid-tree.o props.o free-space-tree.o tree-checker.o space-info.o \
-	   block-rsv.o
+	   block-rsv.o delalloc-space.o
 
 btrfs-$(CONFIG_BTRFS_FS_POSIX_ACL) += acl.o
 btrfs-$(CONFIG_BTRFS_FS_CHECK_INTEGRITY) += check-integrity.o

fs/btrfs/ctree.h

@@ -2758,16 +2758,6 @@ enum btrfs_chunk_alloc_enum {
 
 int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags,
 		      enum btrfs_chunk_alloc_enum force);
-int btrfs_alloc_data_chunk_ondemand(struct btrfs_inode *inode, u64 bytes);
-int btrfs_check_data_free_space(struct inode *inode,
-			struct extent_changeset **reserved, u64 start, u64 len);
-void btrfs_free_reserved_data_space(struct inode *inode,
-			struct extent_changeset *reserved, u64 start, u64 len);
-void btrfs_delalloc_release_space(struct inode *inode,
-				  struct extent_changeset *reserved,
-				  u64 start, u64 len, bool qgroup_free);
-void btrfs_free_reserved_data_space_noquota(struct inode *inode, u64 start,
-					    u64 len);
 int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
 				     struct btrfs_block_rsv *rsv,
 				     int nitems, bool use_global_rsv);
@@ -2777,10 +2767,6 @@ void btrfs_delalloc_release_extents(struct btrfs_inode *inode, u64 num_bytes,
 				    bool qgroup_free);
 
 int btrfs_delalloc_reserve_metadata(struct btrfs_inode *inode, u64 num_bytes);
-void btrfs_delalloc_release_metadata(struct btrfs_inode *inode, u64 num_bytes,
-				     bool qgroup_free);
-int btrfs_delalloc_reserve_space(struct inode *inode,
-			struct extent_changeset **reserved, u64 start, u64 len);
 int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache);
 void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache);
 void btrfs_put_block_group_cache(struct btrfs_fs_info *info);

fs/btrfs/delalloc-space.h

+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef BTRFS_DELALLOC_SPACE_H
+#define BTRFS_DELALLOC_SPACE_H
+
+struct extent_changeset;
+
+int btrfs_alloc_data_chunk_ondemand(struct btrfs_inode *inode, u64 bytes);
+int btrfs_check_data_free_space(struct inode *inode,
+			struct extent_changeset **reserved, u64 start, u64 len);
+void btrfs_free_reserved_data_space(struct inode *inode,
+			struct extent_changeset *reserved, u64 start, u64 len);
+void btrfs_delalloc_release_space(struct inode *inode,
+				  struct extent_changeset *reserved,
+				  u64 start, u64 len, bool qgroup_free);
+void btrfs_free_reserved_data_space_noquota(struct inode *inode, u64 start,
+					    u64 len);
+void btrfs_delalloc_release_metadata(struct btrfs_inode *inode, u64 num_bytes,
+				     bool qgroup_free);
+int btrfs_delalloc_reserve_space(struct inode *inode,
+			struct extent_changeset **reserved, u64 start, u64 len);
+
+#endif /* BTRFS_DELALLOC_SPACE_H */

fs/btrfs/file.c

@@ -26,6 +26,7 @@
 #include "volumes.h"
 #include "qgroup.h"
 #include "compression.h"
+#include "delalloc-space.h"
 
 static struct kmem_cache *btrfs_inode_defrag_cachep;
 /*

fs/btrfs/free-space-cache.c

@@ -19,6 +19,7 @@
 #include "inode-map.h"
 #include "volumes.h"
 #include "space-info.h"
+#include "delalloc-space.h"
 
 #define BITS_PER_BITMAP		(PAGE_SIZE * 8UL)
 #define MAX_CACHE_BYTES_PER_GIG	SZ_32K

fs/btrfs/inode-map.c

@@ -11,6 +11,7 @@
 #include "free-space-cache.h"
 #include "inode-map.h"
 #include "transaction.h"
+#include "delalloc-space.h"
 
 static int caching_kthread(void *data)
 {

fs/btrfs/inode.c

@@ -47,6 +47,7 @@
 #include "props.h"
 #include "qgroup.h"
 #include "dedupe.h"
+#include "delalloc-space.h"
 
 struct btrfs_iget_args {
 	struct btrfs_key *location;

fs/btrfs/ioctl.c

@@ -44,6 +44,7 @@
 #include "tree-log.h"
 #include "compression.h"
 #include "space-info.h"
+#include "delalloc-space.h"
 
 #ifdef CONFIG_64BIT
 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI

fs/btrfs/ordered-data.c

@@ -13,6 +13,7 @@
 #include "extent_io.h"
 #include "disk-io.h"
 #include "compression.h"
+#include "delalloc-space.h"
 
 static struct kmem_cache *btrfs_ordered_extent_cache;
 

fs/btrfs/relocation.c

@@ -20,6 +20,7 @@
 #include "inode-map.h"
 #include "qgroup.h"
 #include "print-tree.h"
+#include "delalloc-space.h"
 
 /*
  * backref_node, mapping_node and tree_block start with this