On 13.07.20 г. 15:28 ч., Johannes Thumshirn wrote:
> Add retrieval of the filesystem's generation to the fsinfo ioctl. This is
> driven by setting the BTRFS_FS_INFO_FLAG_GENERATION flag in
> btrfs_ioctl_fs_info_args::flags.
>
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
Reviewed-by: Nikolay Borisov <nborisov@xxxxxxxx>
> ---
> fs/btrfs/ioctl.c | 5 +++++
> include/uapi/linux/btrfs.h | 6 +++++-
> 2 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 3a566cf71fc6..f1b433ec09e8 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -3247,6 +3247,11 @@ static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
> fi_args->flags |= BTRFS_FS_INFO_FLAG_CSUM_INFO;
> }
>
> + if (flags_in & BTRFS_FS_INFO_FLAG_GENERATION) {
> + fi_args->generation = fs_info->generation;
> + fi_args->flags |= BTRFS_FS_INFO_FLAG_GENERATION;
> + }
> +
> if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
> ret = -EFAULT;
>
> diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
> index b3e0af77642f..b8373723eb4a 100644
> --- a/include/uapi/linux/btrfs.h
> +++ b/include/uapi/linux/btrfs.h
> @@ -250,6 +250,9 @@ struct btrfs_ioctl_dev_info_args {
> /* Request information about checksum type and size */
> #define BTRFS_FS_INFO_FLAG_CSUM_INFO (1 << 0)
>
> +/* Request information about filesystem generation */
> +#define BTRFS_FS_INFO_FLAG_GENERATION (1 << 1)
> +
> struct btrfs_ioctl_fs_info_args {
> __u64 max_id; /* out */
> __u64 num_devices; /* out */
> @@ -261,7 +264,8 @@ struct btrfs_ioctl_fs_info_args {
> __u16 csum_type; /* out */
> __u16 csum_size; /* out */
> __u64 flags; /* in/out */
> - __u8 reserved[968]; /* pad to 1k */
> + __u64 generation; /* out */
> + __u8 reserved[960]; /* pad to 1k */
> };
>
>
>
