/* Having a writeable /var is necessary for full system functioning.
* If /var isn't writeable, we mount tmpfs over it. While this is
* somewhat outside of ostree's scope, having all /var twiddling
* in one place will make future maintenance easier.
*/
static void
maybe_mount_tmpfs_on_var (void)
{
if (!path_is_on_readonly_fs ("/var"))
return;
if (umount ("/var") < 0 && errno != EINVAL)
warn ("failed to unmount /var prior to mounting tmpfs, mounting over");
if (mount ("tmpfs", "/var", "tmpfs", 0, NULL) < 0)
err (EXIT_FAILURE, "failed to mount tmpfs on /var");
}
/* Having a writeable /var is necessary for full system functioning.
* If /var isn't writeable, we mount tmpfs over it. While this is
* somewhat outside of ostree's scope, having all /var twiddling
* in one place will make future maintenance easier.
*/
static void
maybe_mount_tmpfs_on_var (void)
{
if (!path_is_on_readonly_fs ("/var"))
return;
if (umount ("/var") < 0 && errno != EINVAL)
{
perror ("failed to unmount /var prior to mounting tmpfs, mounting over");
}
if (mount ("tmpfs", "/var", "tmpfs", 0, NULL) < 0)
{
perror ("failed to mount tmpfs on /var");
exit (1);
}
}
int
main(int argc, char *argv[])
{
const char *remounts[] = { "/sysroot", "/etc", "/home", "/root", "/tmp", "/var", NULL };
struct stat stbuf;
int i;
if (path_is_on_readonly_fs ("/"))
{
/* If / isn't writable, don't do any remounts; we don't want
* to clear the readonly flag in that case.
*/
maybe_mount_tmpfs_on_var ();
exit (0);
}
for (i = 0; remounts[i] != NULL; i++)
{
const char *target = remounts[i];
if (lstat (target, &stbuf) < 0)
continue;
/* Silently ignore symbolic links; we expect these to point to
* /sysroot, and thus there isn't a bind mount there.
*/
if (S_ISLNK (stbuf.st_mode))
continue;
if (mount (target, target, NULL, MS_REMOUNT | MS_SILENT, NULL) < 0)
{
/* Also ignore ENINVAL - if the target isn't a mountpoint
* already, then assume things are OK.
*/
if (errno != EINVAL)
{
perrorv ("failed to remount %s", target);
exit (1);
}
}
}
maybe_mount_tmpfs_on_var ();
exit (0);
}
