Patch Name: PHKL_11637

Patch Description: s700 10.20 system hang: LVM/VxFS deadlock; CD-ROM lockup

Creation Date: 97/07/03

Post Date:  97/07/12

Hardware Platforms - OS Releases:
	s700: 10.20

Products: N/A

Filesets:
	OS-Core.CORE-KRN

Automatic Reboot?: Yes

Status: General Superseded

Critical:
	No (superseded patches were critical)
	PHKL_9909: HANG

Path Name: /hp-ux_patches/s700/10.X/PHKL_11637

Symptoms:
	PHKL_11637:
	CDROM drive remains locked when system is rebooted.

	PHKL_9909:
	A deadlock can occur on system running LVM, JFS and HFS.
	The hang was introduced by one process running lvmerge
	on HFS logical volumes and another process running umount
	on a JFS logical volume. This deadlock can only occur
	with the following scenario:

	(1). Process A is running a lvmerge or a lvsplit on a HFS
	     logical volume

	(2). Process B is running a mount, umount or sync on a JFS
	     logical volume.

Defect Description:
	PHKL_11637:
	Mount an HFS file system from the CDROM drive then
	reboot the system without unmounting the file system.
	When the system comes up, the CDROM draw will remain locked.

	PHKL_9909:
	A deadlock resulted from a process running lvmerge on HFS
	logical volumes, and another process running umount on a
	JFS logical volume. The umount process grabs the JFS
	update sleep lock (used to serialize JFS syncs/mounts/
	umounts), calls spec_close to close the device we are
	unmounting, and eventually gets to a LVM close routine
	which is sleeping waiting to acquire the LVM volume-group
	lock. The lvmerge process is holding the LVM volume-group
	lock and proceeds to call freeze_and_sync_fs_dev() to
	freeze and sync the file system associated with the
	device. The routine ufs_freeze() is first called which in
	turn calls walk_and_freeze_fs() without a pointer to a
	vfs structure. This proves faulty since update() is
	now called without a vfsp and will proceed to try and sync
	every mounted file system instead of just the file system
	being frozen. So we proceeded to try and sync a JFS file
	system which first tries to grab the JFS update sleep
	lock, and a deadlock occurs. This problem can be
	reproduced by having one process running a lvsplit or
	lvmerge on a HFS logical volume, and another process
	running a mount, umount or sync on a JFS logical volume.

	The fix for this problem is to pass the vfsp to
	walk_and_freeze_fs() from ufs_freeze() instead of the
	do_sync argument. The routine walk_and_freeze_fs()
	now uses vfsp when it calls update().

SR:
	5003328237 5003361766

Patch Files:
	/usr/conf/lib/libufs.a(ufs_vfsops.o)

what(1) Output:
	/usr/conf/lib/libufs.a(ufs_vfsops.o):
		ufs_vfsops.c  $Date: 97/07/02 12:36:26 $ $Revision:
			1.20.98.11 $ PATCH_10.20 (PHKL_11637)

cksum(1) Output:
	1217969789 20424 /usr/conf/lib/libufs.a(ufs_vfsops.o)

Patch Conflicts: None

Patch Dependencies: None

Hardware Dependencies: None

Other Dependencies: None

Supersedes:
	PHKL_9909

Equivalent Patches:
	PHKL_11636:
	s800: 10.20

Patch Package Size: 80 KBytes

Installation Instructions:
	Please review all instructions and the Hewlett-Packard
	SupportLine User Guide or your Hewlett-Packard support terms
	and conditions for precautions, scope of license,
	restrictions, and, limitation of liability and warranties,
	before installing this patch.
	------------------------------------------------------------
	1. Back up your system before installing a patch.

	2. Login as root.

	3. Copy the patch to the /tmp directory.

	4. Move to the /tmp directory and unshar the patch:

		cd /tmp
		sh PHKL_11637

	5a. For a standalone system, run swinstall to install the
	    patch:

		swinstall -x autoreboot=true -x match_target=true \
			-s /tmp/PHKL_11637.depot

	5b. For a homogeneous NFS Diskless cluster run swcluster on the
	    server to install the patch on the server and the clients:

		swcluster -i -b

	    This will invoke swcluster in the interactive mode and
	    force all clients to be shut down.

	    WARNING: All cluster clients must be shut down prior to the
		     patch installation.  Installing the patch while the
		     clients are booted is unsupported and can lead to
		     serious problems.

	    The swcluster command will invoke an swinstall session in which
	    you must specify:

		alternate root path  -  default is /export/shared_root/OS_700
		source depot path    -  /tmp/PHKL_11637.depot

	    To complete the installation, select the patch by choosing
	    "Actions -> Match What Target Has" and then "Actions -> Install"
	    from the Menubar.

	5c. For a heterogeneous NFS Diskless cluster:

		- run swinstall on the server as in step 5a to install
		  the patch on the cluster server.

		- run swcluster on the server as in step 5b to install
		  the patch on the cluster clients.

	By default swinstall will archive the original software in
	/var/adm/sw/patch/PHKL_11637.  If you do not wish to retain a
	copy of the original software, you can create an empty file
	named /var/adm/sw/patch/PATCH_NOSAVE.

	Warning: If this file exists when a patch is installed, the
	         patch cannot be deinstalled.  Please be careful
		 when using this feature.

	It is recommended that you move the PHKL_11637.text file to
	/var/adm/sw/patch for future reference.

	To put this patch on a magnetic tape and install from the
	tape drive, use the command:

		dd if=/tmp/PHKL_11637.depot of=/dev/rmt/0m bs=2k

Special Installation Instructions: None