btrfs: move btrfs_pinned_by_swapfile prototype into volumes.h

[ Upstream commit c2e79e865b ]

This is defined in volumes.c, move the prototype into volumes.h.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 6bfe3959b0 ("btrfs: compare the correct fsid/metadata_uuid in btrfs_validate_super")
Signed-off-by: Sasha Levin <sashal@kernel.org>

fs/btrfs/ctree.h

@@ -536,8 +536,6 @@ struct btrfs_swapfile_pin {
 	int bg_extent_count;
 };
 
-bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr);
-
 enum {
 	BTRFS_FS_BARRIER,
 	BTRFS_FS_CLOSING_START,

fs/btrfs/volumes.h

@@ -622,4 +622,6 @@ const char *btrfs_bg_type_to_raid_name(u64 flags);
 int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
 int btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical);
 
+bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr);
+
 #endif