Re: [PATCH 08/17] Btrfs-progs: Set the root-id for received subvols in btrfs receive

[Wang Shilong <wangsl-fnst@cn.fujitsu.com>]

Hello,

> When an entry was added to the subvol search tree, the root_id was
> always 0 (not set at all) and therefore only the first one was
> added, all the others had been ignored. This commit adds a function
> to retrieve the root_id for a given fd, and this function is used
> to set the root_id before the entry is added.
> 
> Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
> ---
>  cmds-receive.c |  3 +++
>  send-utils.c   | 20 ++++++++++++++++++++
>  send-utils.h   |  1 +
>  3 files changed, 24 insertions(+)
> 
> diff --git a/cmds-receive.c b/cmds-receive.c
> index dc72e9e..eedff13 100644
> --- a/cmds-receive.c
> +++ b/cmds-receive.c
> @@ -125,6 +125,9 @@ static int finish_subvol(struct btrfs_receive *r)
>  		goto out;
>  	}
>  
> +	ret = btrfs_get_root_id(subvol_fd, &r->cur_subvol->root_id);


There has been a function in btrfs-list.c named 'btrfs_list_get_path_rootid'
which does the same things as 'btrfs_get_root_id'.I think you can reuse it.

Thanks,
Wang

> +	if (ret < 0)
> +		goto out;
>  	subvol_uuid_search_add(&r->sus, r->cur_subvol);
>  	r->cur_subvol = NULL;
>  	ret = 0;
> diff --git a/send-utils.c b/send-utils.c
> index 182778a..b2d544c 100644
> --- a/send-utils.c
> +++ b/send-utils.c
> @@ -23,6 +23,26 @@
>  #include "ioctl.h"
>  #include "btrfs-list.h"
>  
> +int btrfs_get_root_id(int fd, u64 *root_id)
> +{
> +	struct btrfs_ioctl_ino_lookup_args ino_args;
> +	int ret;
> +
> +	memset(&ino_args, 0, sizeof(ino_args));
> +	ino_args.objectid = BTRFS_FIRST_FREE_OBJECTID;
> +
> +	/* this ioctl fills in ino_args->treeid */
> +	ret = ioctl(fd, BTRFS_IOC_INO_LOOKUP, &ino_args);
> +	if (ret) {
> +		fprintf(stderr, "ERROR: Failed to lookup root_id - %s\n",
> +			strerror(errno));
> +		return ret;
> +	}
> +
> +	*root_id = ino_args.treeid;
> +	return 0;
> +}
> +
>  static struct rb_node *tree_insert(struct rb_root *root,
>  				   struct subvol_info *si,
>  				   enum subvol_search_type type)
> diff --git a/send-utils.h b/send-utils.h
> index 78abf94..3c8b7b7 100644
> --- a/send-utils.h
> +++ b/send-utils.h
> @@ -61,6 +61,7 @@ struct subvol_uuid_search {
>  	struct rb_root path_subvols;
>  };
>  
> +int btrfs_get_root_id(int fd, u64 *root_id);
>  int subvol_uuid_search_init(int mnt_fd, struct subvol_uuid_search *s);
>  void subvol_uuid_search_finit(struct subvol_uuid_search *s);
>  struct subvol_info *subvol_uuid_search(struct subvol_uuid_search *s,