Don't use O_TRUNC when opening QEMU logfiles

SELinux wants all log files opened with O_APPEND. When
running non-root though, libvirtd likes to use O_TRUNC
to avoid log files growing in size indefinitely. Instead
of using O_TRUNC though, we can use O_APPEND and then
call ftruncate() which keeps SELinux happier.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
(cherry picked from commit 639d5c4966)
This commit is contained in:
Daniel P. Berrange 2012-09-21 10:37:53 +01:00 committed by Cole Robinson
parent f4e3a2afa5
commit a8ad93965f

View File

@ -1446,12 +1446,22 @@ qemuDomainOpenLogHelper(struct qemud_driver *driver,
{
char *logfile;
int fd = -1;
bool trunc = false;
if (virAsprintf(&logfile, "%s/%s.log", driver->logDir, vm->def->name) < 0) {
virReportOOMError();
return -1;
}
/* To make SELinux happy we always need to open in append mode.
* So we fake O_TRUNC by calling ftruncate after open instead
*/
if (oflags & O_TRUNC) {
oflags &= ~O_TRUNC;
oflags |= O_APPEND;
trunc = true;
}
if ((fd = open(logfile, oflags, mode)) < 0) {
virReportSystemError(errno, _("failed to create logfile %s"),
logfile);
@ -1463,6 +1473,13 @@ qemuDomainOpenLogHelper(struct qemud_driver *driver,
VIR_FORCE_CLOSE(fd);
goto cleanup;
}
if (trunc &&
ftruncate(fd, 0) < 0) {
virReportSystemError(errno, _("failed to truncate %s"),
logfile);
VIR_FORCE_CLOSE(fd);
goto cleanup;
}
cleanup:
VIR_FREE(logfile);