Re: [PATCH 2/2] bcachefs: Add support for FS_IOC_GETFSSYSFSPATH

Hongbo Li
2024-07-09T02:27:15Z

On 2024/7/9 10:11, Youling Tang wrote:
> On 09/07/2024 10:04, Hongbo Li wrote:
>>
>>
>> On 2024/7/9 9:11, Youling Tang wrote:
>>> From: Kent Overstreet <kent.overstreet@linux.dev>
>>>
>>> [TEST]:
>>> ```
>>> $ cat ioctl_getsysfspath.c
>>>   #include <stdio.h>
>>>   #include <stdlib.h>
>>>   #include <fcntl.h>
>>>   #include <sys/ioctl.h>
>>>   #include <linux/fs.h>
>>>   #include <unistd.h>
>>>
>>>   int main(int argc, char *argv[]) {
>>>       int fd;
>>>       struct fs_sysfs_path sysfs_path = {};
>>>
>>>       if (argc != 2) {
>>>           fprintf(stderr, "Usage: %s <path_to_file_or_directory>\n",
>>> argv[0]);
>>>           exit(EXIT_FAILURE);
>>>       }
>>>
>>>       fd = open(argv[1], O_RDONLY);
>>>       if (fd == -1) {
>>>           perror("open");
>>>           exit(EXIT_FAILURE);
>>>       }
>>>
>>>       if (ioctl(fd, FS_IOC_GETFSSYSFSPATH, &sysfs_path) == -1) {
>>>           perror("ioctl FS_IOC_GETFSSYSFSPATH");
>>>           close(fd);
>>>           exit(EXIT_FAILURE);
>>>       }
>>>
>>>       printf("FS_IOC_GETFSSYSFSPATH: %s\n", sysfs_path.name);
>>>       close(fd);
>>>       return 0;
>>>   }
>>>
>>> $ gcc ioctl_getsysfspath.c
>>> $ sudo bcachefs format /dev/sda
>>> $ sudo mount.bcachefs /dev/sda /mnt
>>> $ sudo ./a.out /mnt
>>>    FS_IOC_GETFSSYSFSPATH: bcachefs/c380b4ab-fbb6-41d2-b805-7a89cae9cadb
>>> ```
>>>
>>> Original patch link:
>>> [1]:
>>> https://lore.kernel.org/all/20240207025624.1019754-8-kent.overstreet@linux.dev/
>>>
>>> Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
>>> Signed-off-by: Youling Tang <youling.tang@linux.dev>
>>> ---
>>>   fs/bcachefs/fs.c | 1 +
>>>   1 file changed, 1 insertion(+)
>>>
>>> diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c
>>> index 011ee5075a52..8699770398d1 100644
>>> --- a/fs/bcachefs/fs.c
>>> +++ b/fs/bcachefs/fs.c
>>> @@ -1978,6 +1978,7 @@ static int bch2_fs_get_tree(struct fs_context *fc)
>>>       sb->s_time_min        = div_s64(S64_MIN,
>>> c->sb.time_units_per_sec) + 1;
>>>       sb->s_time_max        = div_s64(S64_MAX,
>>> c->sb.time_units_per_sec);
>>>       super_set_uuid(sb, c->sb.user_uuid.b, sizeof(c->sb.user_uuid));
>>> +    super_set_sysfs_name_uuid(sb);
>>
>> Reviewed-by: Hongbo Li <lihongbo22@huawei.com>
>>
>> It's quite strange that other commits have been merged, but the ones
>> for bcachefs have not been merged.
> Because bcachefs was not upstream at the time, [1] described the following:
>   Note, I dropped the bcachefs changes because they're not upstream yet.
>   But once this is a stable branch you can just pull in vfs.uuid and rely
>   on that.
>
Got it! Thank you!

Thanks,
Hongbo
> [1]:
> https://lore.kernel.org/all/20240208-wecken-nutzen-3df1102a39b2@brauner/
>
> Thanks,
> Youling.