[PATCH -next 2/2] ubifs: add support for FS_IOC_GETFSSYSFSPATH

[Zhihao Cheng]

在 2024/8/26 17:17, Hongbo Li 写道:
> In commit ae8c51175730 ("fs: add FS_IOC_GETFSSYSFSPATH"), a
> new fs ioctl was introduced to standardize exporting data from
> sysfs across filesystems. The returned path will always be of the
> form "$FSTYP/$SYSFS_IDENTIFIER", where the sysfs identifier may
> be a UUID or a device name.
> 
> The ubifs is a file system based on char device, and the common
> method to fill s_sysfs_name (super_set_sysfs_name_bdev) is
> unavialable. So in order to support FS_IOC_GETFSSYSFSPATH ioctl,
> we fill the s_sysfs_name with ubi_volume_info member which keeps
> the format defined in macro UBIFS_DFS_DIR_NAME by using
> super_set_sysfs_name_generic.
> 
> That's for ubifs, it will output "ubifs/<dev>".
> 
> ```
> $ ./ioctl_getfssysfs_path /mnt/ubifs/testfile
> path: ubifs/ubi0_0
> 
> $ ls /sys/fs/ubifs/ubi0_0/
> errors_crc  errors_magic  errors_node
> ```
> 
> Signed-off-by: Hongbo Li <lihongbo22 at huawei.com>
> ---
>   fs/ubifs/super.c | 2 ++
>   1 file changed, 2 insertions(+)

Reviewed-by: Zhihao Cheng <chengzhihao1 at huawei.com>
> 
> diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
> index 291583005dd1..cb26b8b27ef6 100644
> --- a/fs/ubifs/super.c
> +++ b/fs/ubifs/super.c
> @@ -2249,6 +2249,8 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
>   	}
>   
>   	super_set_uuid(sb, c->uuid, sizeof(c->uuid));
> +	super_set_sysfs_name_generic(sb, UBIFS_DFS_DIR_NAME,
> +				     c->vi.ubi_num, c->vi.vol_id);
>   
>   	mutex_unlock(&c->umount_mutex);
>   	return 0;
>