Patch Name: PHKL_26766

Patch Description: s700 10.20 Buffer cache deadlock;write gets VX_ERETRY

Creation Date: 02/05/08

Post Date:  02/06/11

Hardware Platforms - OS Releases:
	s700: 10.20

Products: N/A

Filesets:
	JournalFS.VXFS-BASE-KRN

Automatic Reboot?: Yes

Status: General Release

Critical:
	Yes
	PHKL_26766: HANG

Path Name: /hp-ux_patches/s700/10.X/PHKL_26766

Symptoms:
	PHKL_26766:
	(SR: 8606225321   CR: JAGad94409)
	Applications may hang when accessing a VxFS filesystem.
	The application cannot recover. This occurs only to
	files that are mmap'ed and being written to by
	several processes at the same time.

	PHKL_17206:
	Writing a large mmaped region to a file on Advanced JFS
	gets return error VX_ERETRY (0xf001).

Defect Description:
	PHKL_26766:
	(SR: 8606225321   CR: JAGad94409)
	A deadlock was caused by incorrect ordering of the
	locks in VxFS code.

	Resolution:
	Reorder the locks in VxFS code to remove the deadlock.

	PHKL_17206:
	Advanced JFS initiates direct I/O for large buffer writes.
	When the direct I/O is unsuccessful with a return error
	VX_ERETRY, the code should retry the write using default
	I/O.  A bug in JFS write code misses the checking of
	VX_ERETRY and returns the error to the caller.

	While the symptom is seen only when Advanced JFS is
	installed, the fix is in the base JFS.

SR:
	1653285841 8606225321

Patch Files:
	/usr/conf/lib/libvxfs_base.a(vx_rdwri.o)

what(1) Output:
	/usr/conf/lib/libvxfs_base.a(vx_rdwri.o):
		vx_rdwri.c $Date: 2002/05/08 11:17:34 $ $Revision: 1
			.7.98.30 $ PATCH_10.20 (PHKL_26766)

cksum(1) Output:
	1016779230 35512 /usr/conf/lib/libvxfs_base.a(vx_rdwri.o)

Patch Conflicts: None

Patch Dependencies:
	s700: 10.20: PHKL_16750

Hardware Dependencies: None

Other Dependencies: None

Supersedes:
	PHKL_17206

Equivalent Patches:
	PHKL_19800:
	s700: 11.00

Patch Package Size: 100 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_26766

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

		swinstall -x autoreboot=true -x match_target=true \
			-s /tmp/PHKL_26766.depot

	By default swinstall will archive the original software in
	/var/adm/sw/patch/PHKL_26766.  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_26766.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_26766.depot of=/dev/rmt/0m bs=2k

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