Patch Name: PHKL_11717

Patch Description: s700 10.20 Fix for deadlock with Advanced VxFS snapshot buf

Creation Date: 97/07/09

Post Date:  97/07/16

Hardware Platforms - OS Releases:
	s700: 10.20

Products:
	HP OnLineJFS (Advanced VxFS) B.10.20

Filesets:
	AdvJournalFS.VXFS-ADV-KRN OS-Core.CORE-KRN

Automatic Reboot?: Yes

Status: General Superseded

Critical:
	Yes
	PHKL_11717: HANG

Path Name: /hp-ux_patches/s700/10.X/PHKL_11717

Symptoms:
	PHKL_11717:
	The original problem was customer see deadlock when doing
	backup activity, or in other words, system hang.

Defect Description:
	PHKL_11717:
	The problem was that stealbuffer will grab all the buffers
	it can before finishing the steal and if it hit a dirty
	buffer, it will try to flush that buffer out.  Unfortunately
	if that buffer is vxfs snapshot buffer, the flushing out of
	the content may sometime depend on getting other buffers
	that may in turn being grabbed by stealbuffer routine.
	Basically, the scenario looks like stealbuffer is sleeping
	on the same buffer it already has.

SR:
	1653213413

Patch Files:
	/usr/conf/lib/libhp-ux.a(dbc_bio.o)
	/usr/conf/lib/libvxfs_adv.a(vx_snap.o)

what(1) Output:
	/usr/conf/lib/libhp-ux.a(dbc_bio.o):
		dbc_bio.c $Date: 97/07/09 15:09:41 $ $Revision: 1.6.
			98.5 $ PATCH_10.20 (PHKL_11717)
	/usr/conf/lib/libvxfs_adv.a(vx_snap.o):
		vx_snap.c $Date: 97/07/09 15:06:50 $ $Revision: 1.7.
			98.8 $ PATCH_10.20 (PHKL_11717)

cksum(1) Output:
	4289132443 5272 /usr/conf/lib/libhp-ux.a(dbc_bio.o)
	783963738 12564 /usr/conf/lib/libvxfs_adv.a(vx_snap.o)

Patch Conflicts: None

Patch Dependencies: None

Hardware Dependencies: None

Other Dependencies: None

Supersedes: None

Equivalent Patches:
	PHKL_11721:
	s800: 10.20

Patch Package Size: 70 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_11717

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

		swinstall -x autoreboot=true -x match_target=true \
			-s /tmp/PHKL_11717.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_11717.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_11717.  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_11717.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_11717.depot of=/dev/rmt/0m bs=2k

Special Installation Instructions: None