Andy Lutomirski <[email protected]> wrote:
> > Whilst I'm at it, do we want the option of doing the equivalent of
> > mountat()? I.e. offering the option to open all the device files used by
> > a superblock with dfd and AT_* flags in combination with the filename?
> >
>
> Isn’t that more or less what I was suggesting? I suggested dfd and path and
> I also suggested just an fd and letting the caller open the file itself.
Do we need AT_* flags? There are three that we could use:
AT_SYMLINK_NOFOLLOW
AT_NO_AUTOMOUNT
AT_EMPTY_PATH
AT_EMPTY_PATH I can see, but I don't see it as likely that we'd want to use
the other two for selecting a source? Note that we can always do:
fsfd = fsopen("ext4");
sfd = open("/dev/", O_PATH);
fsconfig(fsfd, fsconfig_set_path, "journal_path", "sda1", sfd);
or:
fsfd = fsopen("ext4");
sfd = open("/dev/sda1", O_PATH);
fsconfig(fsfd, fsconfig_set_path_empty, "journal_path", "", sfd);
or:
fsfd = fsopen("ext4");
jfd = open("/dev/sda1", O_RDWR);
fsconfig(fsfd, fsconfig_set_fd, "journal_path", NULL, jfd);
assuming the open on the latter doesn't exclude the use by the filesystem.
This way I don't need a second syscall or a 6-arg syscall to handle path
specification.
David
