Re: [PATCH 31/34] vfs: syscall: Add fspick() to select a superblock for reconfiguration [ver #12]

[David Howells]

Alan Jenkins <alan.christopher.jenkins@xxxxxxxxx> wrote:

> Sorry, I guess SB_NOUSER was the wrong word. I was trying find if anything
> stopped things like
> 
> int memfd = memfd_create("foo", 0);
> int fsfd = fspick(memfd, "", FSPICK_EMPTY_PATH);
> 
> fsconfig(fsfd, FSCONFIG_SET_FLAG, "ro", NULL, 0);
> fsconfig(fsfd, FSCONFIG_SET_STRING, "size", "100M", 0);
> fsconfig(fsfd, FSCONFIG_CMD_RECONFIGURE, NULL, NULL, 0);
> 
> So far I'm getting -EBUSY if I try to apply the "ro", -EINVAL if I try to
> apply the "size=100M". But if I don't apply either, then
> FSCONFIG_CMD_RECONFIGURE succeeds.

I should probably check that the picked point is actually a mountpoint.

David