Re: [fuse-devel] utimensat fails to update ctime

From: Jean-Pierre André
Date: Tue Dec 22 2009 - 05:05:15 EST


Hi all,


OGAWA Hirofumi wrote:
Eric Blake<ebb9@xxxxxxx> writes:

It is likely the issue of libfuse or ntfs-3g. I don't know about ntfs-3g
people at all. So, for now, just Cc: to fuse people.

Which ntfs-3g version are you using ?

utimensat(0, NULL, {UTIME_OMIT, UTIME_NOW}, 0) = 0

Currently ntfs-3g does not set sub-second precision.

There is also a slight problem in the fuse interface :
the time buffer is never passed as NULL, consequently
in some circumstances ntfs-3g cannot decide correctly
over permissions. A permissive action is taken in this
situation.

> From this, "ia_valid" will have "ATTR_CTIME | ATTR_MTIME". And the
request would pass to userland via fuse of kernel part, then it will be
handled by libfuse.

> From quick grep of libfuse and ntfs-3g (would not be latest), ntfs-3g is
using "struct fuse_operations", not "struct fuse_lowlevel_ops".

With the latest ntfs-3g, currently as a release candidate,
you can (optionally) use the low level fuse interface
http://pagesperso-orange.fr/b.andre/advanced-ntfs-3g.html
use the "lowntfs-3g" driver instead of "ntfs-3g"

Hope this helps

Regards

Jean-Pierre



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