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

Youling Tang
2024-07-09T02:11:41Z

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.

[1]:
https://lore.kernel.org/all/20240208-wecken-nutzen-3df1102a39b2@brauner/

Thanks,
Youling.