This patch fixes utimensat() to make its behavior consistent
with that of utime()/utimes() when dealing with files marked
immutable and append-only.
The current utimensat() implementation also returns EPERM if
'times' is non-NULL and the tv_nsec fields are both UTIME_NOW.
For consistency, the
(times != NULL && times[0].tv_nsec == UTIME_NOW &&
times[1].tv_nsec == UTIME_NOW)
case should be treated like the traditional utimes() case where
'times' is NULL. That is, the call should succeed for a file
marked append-only and should give the error EACCES if the file
is marked as immutable.
The simple way to do this is to set 'times' to NULL
if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW).
This is also the natural approach, since POSIX.1 semantics consider the
times == {{x, UTIME_NOW}, {y, UTIME_NOW}}
to be exactly equivalent to the case for
times == NULL.
(Thanks to Miklos for pointing this out.)
Patch 3 in this series relies on the simplification provided
by this patch.
CC: Miklos Szeredi <miklos@szeredi.hu>
CC: Al Viro <viro@zeniv.linux.org.uk>
CC: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
--- linux-2.6.26-rc4/fs/utimes.c 2008-06-03 22:47:07.000000000 +0200
+++ linux-2.6.26-rc4-utimensat-fix-v4/fs/utimes.c 2008-06-03 22:59:55.000000000 +0200
@@ -102,6 +102,10 @@
if (error)
goto dput_and_out;
+ if (times && times[0].tv_nsec == UTIME_NOW &&
+ times[1].tv_nsec == UTIME_NOW)
+ times = NULL;
+
/* Don't worry, the checks are done in inode_change_ok() */
newattrs.ia_valid = ATTR_CTIME | ATTR_MTIME | ATTR_ATIME;
if (times) {
--
