Re: [d_path 0/7] Fixes to d_path: Respin

Andreas Gruenbacher
2007-04-20T11:45:04Z

On Friday 20 April 2007 11:30, Alan Cox wrote:
> > As far as I can see, glibc internally looks at /proc/mounts (or else
> > mtab) to find out where tmpfs is mounted for opening files there, and to
> > look up filesystem information for statfs(), while accessing that path,
> > too. Fstatfs() also looks into the same files, but it only matches by
> > filesystem type, so this is only a very unreliable heuristic, anyway.
> >
> > So judging from that, glibc users should be fine.
>
> So glibc does use it and you will change behaviour

Not for statfs(), shm_open(), and sem_open().

Possibly for fstatfs(): fstatfs() has no way of looking up mount points per
path name in /proc/mounts, and so it resorts to mapping from the numeric
statfs->f_type to the filesystem name (e.g., "ext3"), looks up the first
mount point with that name, and sets the statfs->f_flag flags based on that
entry. This field may change from one arbitrary value to another.

Andreas