Patch Name: PHKL_17253

Patch Description: s700 10.20 Correct process hangs on ufs inodes

Creation Date: 98/12/22

Post Date:  98/12/24

Hardware Platforms - OS Releases:
	s700: 10.20

Products: N/A

Filesets:
	OS-Core.CORE-KRN

Automatic Reboot?: Yes

Status: General Superseded

Critical:
	Yes
	PHKL_17253: HANG

Path Name: /hp-ux_patches/s700/10.X/PHKL_17253

Symptoms:
	PHKL_17253:
	SR: 5003446260 DTS: JAGaa45712
	Processes reading/writing inodes on a ufs file system may
	sleep (and hang) indefinitely waiting for the inode lock to
	become available.  This problem was introduced in patch
	PHKL_16592.

Defect Description:
	PHKL_17253:
	SR: 5003446260 DTS: JAGaa45712
	The problem is in ip_sharable(), a check to determine
	whether additional read locks can be done.  The check
	incorrectly passes when an inode is ILOCKED and IPAUSED,
	causing these additional read requests to be added.
	These read requests will never be serviced because the
	counts on the inode will be incorrect.
	Resolution:
	The resolution is to correct the ip_sharable() check so
	that read requests are delayed properly in order to keep
	the inode request counts accurate.   This will prevent
	a hang from occurring on these processes.  This change
	is miminal and provides the behavior intended in
	PHKL_16592.

SR:
	5003446260

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

what(1) Output:
	/usr/conf/lib/libufs.a(ufs_inode.o):
		ufs_inode.c $Date: 98/12/22 06:35:59 $ $Revision: 1.
			48.98.19 $ PATCH_10.20 (PHKL_17253)

cksum(1) Output:
	803604963 26044 /usr/conf/lib/libufs.a(ufs_inode.o)

Patch Conflicts: None

Patch Dependencies:
	s700: 10.20: PHKL_16750

Hardware Dependencies: None

Other Dependencies: None

Supersedes: None

Equivalent Patches:
	PHKL_17254:
	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_17253

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

		swinstall -x autoreboot=true -x match_target=true \
			-s /tmp/PHKL_17253.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_17253.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_17253.  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_17253.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_17253.depot of=/dev/rmt/0m bs=2k

Special Installation Instructions:
	This patch depends on base patch PHKL_16750 .
	For successful installation please insure that PHKL_16750
	is in the same depot with PHKL_17253, or PHKL_16750  is
	already installed.