Description of problem:

When booting into rescue mode from CD/DVD, anaconda will load install.img twice from the install media, causing noticeable delay unnecessarily. 

Version-Release number of selected component (if applicable):

anaconda-13.21.176


How reproducible:

Every time.

Steps to Reproduce:
1. Boot into rescue mode from CD/DVD
2. check /tmp/anaconda.log
3.
  
Actual results:

# cat /tmp/anaconda.log
14:42:27,548 INFO    : kernel command line: initrd=initrd.img rescue BOOT_IMAGE=vmlinuz

14:42:27,548 DEBUG   : readNetInfo /tmp/s390net not found, early return
14:42:27,548 INFO    : anaconda version 13.21.176 on x86_64 starting
14:42:30,709 DEBUG   : Saving module ipv6
14:42:30,709 DEBUG   : Saving module iscsi_ibft
14:42:30,709 DEBUG   : Saving module iscsi_boot_sysfs
14:42:30,709 DEBUG   : Saving module pcspkr
14:42:30,709 DEBUG   : Saving module edd
14:42:30,709 DEBUG   : Saving module iscsi_tcp
14:42:30,709 DEBUG   : Saving module libiscsi_tcp
14:42:30,709 DEBUG   : Saving module libiscsi
14:42:30,709 DEBUG   : Saving module scsi_transport_iscsi
14:42:30,709 DEBUG   : Saving module squashfs
14:42:30,709 DEBUG   : Saving module cramfs
14:42:30,710 DEBUG   : probing buses
14:42:30,728 DEBUG   : waiting for hardware to initialize
14:42:34,845 INFO    : Trying to detect vendor driver discs
14:42:35,207 DEBUG   : probing buses
14:42:35,226 DEBUG   : waiting for hardware to initialize
14:42:38,611 INFO    : trying to mount CD device /dev/sr0 on /mnt/stage2
14:42:38,614 INFO    : drive status is CDS_DISC_OK
14:42:38,679 INFO    : transferring /mnt/stage2/images/install.img to /tmp
14:43:25,451 INFO    : mounted loopback device /mnt/runtime on /dev/loop0 as /tmp/install.img
14:43:25,451 INFO    : Looking for updates in /mnt/stage2/images/updates.img
14:43:25,451 INFO    : Looking for product in /mnt/stage2/images/product.img
14:43:25,769 INFO    : mounted loopback device /tmp/product-disk on /dev/loop7 as /mnt/stage2/images/product.img
14:43:26,467 INFO    : umounting loopback /tmp/product-disk /dev/loop7
14:43:26,526 DEBUG   : This appears to be a boot.iso.
14:43:26,527 INFO    : umounting loopback /mnt/runtime /dev/loop0
14:43:41,272 DEBUG   : going to set language to en_US.UTF-8
14:43:41,272 INFO    : setting language to en_US.UTF-8
14:43:41,280 INFO    : 53 keymaps are available
14:43:44,551 INFO    : starting STEP_METHOD
14:43:56,653 INFO    : starting STEP_STAGE2
14:43:56,653 INFO    : trying to mount CD device /dev/sr0 on /mnt/stage2
14:43:56,656 INFO    : drive status is CDS_DISC_OK
14:43:56,861 INFO    : transferring /mnt/stage2/images/install.img to /tmp
14:44:43,634 INFO    : mounted loopback device /mnt/runtime on /dev/loop0 as /tmp/install.img
14:44:43,634 INFO    : Looking for updates in /mnt/stage2/images/updates.img
14:44:43,634 INFO    : Looking for product in /mnt/stage2/images/product.img
14:44:43,928 INFO    : mounted loopback device /tmp/product-disk on /dev/loop7 as /mnt/stage2/images/product.img
14:44:44,613 INFO    : umounting loopback /tmp/product-disk /dev/loop7
14:44:44,672 INFO    : got stage2 at url cdrom:///dev/sr0:/mnt/stage2
14:44:44,723 INFO    : Loading SELinux policy
14:44:45,188 INFO    : getting ready to spawn shell now
14:44:45,492 INFO    : Running anaconda script /usr/bin/anaconda
14:44:48,125 INFO    : using only installclass Red Hat Enterprise Linux Server
14:44:48,132 INFO    : created new libuser.conf at /tmp/libuser.v_4WVb with instPath="/mnt/sysimage"




Expected results:

Stage2 image (install.img) is only loaded once...


Additional info:

Problem would seem to be in loader.c, where the call to "findAnacondaCD("/mnt/stage2")" will unmount the CD before returning, if rescue mode is selected. 
So, the check for ".discinfo" file will fail causing unmount of the /mnt/runtime, and the install.img to get loaded again from the CD...

...
   /* Before anything else, see if there's a CD/DVD with a stage2 image on
     * it.  However if stage2= was given, use that value as an override here.
     * That will also then bypass any method selection UI in loader.
     */
    if (!FL_ASKMETHOD(flags)) {
        url = findAnacondaCD("/mnt/stage2");
        if (url) {
            /* This is specific to RHEL, which does not have the mirror system
             * set up like Fedora does.  If the CD/DVD doesn't have packages,
             * then it's a boot.iso and we still need to prompt for the
             * installation source.
             */

            if (!access("/mnt/stage2/.discinfo", R_OK) || FL_RESCUE(flags)) {
                skipLangKbd = 1;
                flags |= LOADER_FLAGS_NOPASS;

                setStage2LocFromCmdline(url, loaderData);
                skipMethodDialog = 1;

                logMessage(INFO, "Detected stage 2 image on CD (url: %s)", url);
                winStatus(50, 3, _("Media Detected"),
                          _("Found local installation media"), 0);
                sleep(3);
                newtPopWindow();
            }
            else {
                logMessage(DEBUGLVL, "This appears to be a boot.iso.");
                umountStage2();
                free(url);
                url = NULL;
            }
        }
...