btrfs: rename btrfs_get_block_group_info and make it static

The function btrfs_get_block_group_info() was introduced by the
commit 5af3e8cc ("Btrfs: make filesystem read-only when submitting
 barrier fails") which used it in disk-io.c.

However, the function is only called in ioctl.c now.
Its parameter type btrfs_ioctl_space_info* is only for ioctl.

So, make it static and rename it to be original name
get_block_group_info.

No functional change.
Signed-off-by: NSu Yue <suy.fnst@cn.fujitsu.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/ctree.h

@@ -3267,8 +3267,6 @@ int btrfs_is_empty_uuid(u8 *uuid);
 int btrfs_defrag_file(struct inode *inode, struct file *file,
 		      struct btrfs_ioctl_defrag_range_args *range,
 		      u64 newer_than, unsigned long max_pages);
-void btrfs_get_block_group_info(struct list_head *groups_list,
-				struct btrfs_ioctl_space_info *space);
 void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
 			       struct btrfs_ioctl_balance_args *bargs);
 ssize_t btrfs_dedupe_file_range(struct file *src_file, u64 loff, u64 olen,

fs/btrfs/ioctl.c

@@ -4007,8 +4007,8 @@ static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
 	return ret;
 }
 
-void btrfs_get_block_group_info(struct list_head *groups_list,
-				struct btrfs_ioctl_space_info *space)
+static void get_block_group_info(struct list_head *groups_list,
+				 struct btrfs_ioctl_space_info *space)
 {
 	struct btrfs_block_group_cache *block_group;
 
@@ -4124,8 +4124,8 @@ static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
 		down_read(&info->groups_sem);
 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
 			if (!list_empty(&info->block_groups[c])) {
-				btrfs_get_block_group_info(
-					&info->block_groups[c], &space);
+				get_block_group_info(&info->block_groups[c],
+						     &space);
 				memcpy(dest, &space, sizeof(space));
 				dest++;
 				space_args.total_spaces++;