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

Youling Tang
2024-07-09T01:12:26Z

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);
sb->s_shrink->seeks = 0;
c->vfs_sb = sb;
strscpy(sb->s_id, c->name, sizeof(sb->s_id));
--
2.34.1