Patch-ID# 104764-01
Keywords: disk cache buffer write asynchronous fragment
Synopsis: SunOS 4.1.3_U1: POINT PATCH for async writes and disk corruption     
Date: Mar/21/97

Solaris Release: 1.1.1A

SunOS Release: 4.1.3_U1A

Unbundled Product: 

Unbundled Release: 

	SPECIAL NOTE:
	As a point patch, this fix is not currently scheduled nor
	will necessarily be approved for integration in a future
	SunOS release.  This patch is not intended for general use.

Relevant Architectures: sparc
    NOTE: sun4(all)

BugId's fixed with this patch: 1243247

Changes incorporated in this version: 

Patches accumulated and obsoleted by this patch: 

Patches which conflict with this patch: 

Patches required with this patch: 

Obsoleted by: 

Files included with this patch:  ufs_inode.o

Problem Description: 

Bug 1243247
There is a  a race if the pages for the inode are synced when
the inode is being marked inactive in iinactive().
This causes file corruption.  If these pages are not synced 
in iinactive, the  problem is not seen.

This fix would have some performance effect on machine with
less memory configuration. The performance impact could be seen
when the system is low on memory i.e freemem < lotsfree. 

Patch Installation Instructions: 

1) As root, make a backup of the original ufs_inode.o
   mv /sys/`arch -k`/OBJ/ufs_inode.o /sys/`arch -k`/OBJ/ufs_inode.o.fcs
  
2) Copy the new file from the patch directory:
   cp ufs_inode.o /sys/`arch -k`/OBJ
  
3) Build a new kernel and reboot the system.  Please refer to the
   System and Network Administration manual for details on building
   a custom kernel.