Bug 646498

Summary:	[6.0] write system call returns with 0 when it should return with EFBIG.
Product:	Red Hat Enterprise Linux 6	Reporter:	Debbie Johnson <dejohnso>
Component:	kernel	Assignee:	Eric Sandeen <esandeen>
Status:	CLOSED ERRATA	QA Contact:	Petr Beňas <pbenas>
Severity:	high	Docs Contact:
Priority:	medium
Version:	6.0	CC:	jwest, kzhang, ndoane, pbenas, pstehlik
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Linux
Whiteboard:
Fixed In Version:	kernel-2.6.32-91.el6	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:
Clones:	703094 (view as bug list)		Environment:
Last Closed:	2011-05-23 20:27:24 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	703094

Description Debbie Johnson 2010-10-25 13:46:39 UTC

Description of problem:
[6.0] write system call returns with 0 when it should return with EFBIG.

Version-Release number of selected component (if applicable):
V6.0

How reproducible:


By running the following reproducer(Step to Reproduce), we can confirm that the
write system call returns with 0 when it should return the error EFBIG.

This fix is already included in 2.6.36-rc1.
(http://marc.info/?l=git-commits-head&m=128121851624648&w=2)
Please apply it.

Version-Release number of selected component:
Red Hat Enterprise Linux Version Number: RHEL6
Release Number: 6.0rc
Architecture: x86_64
Kernel Version: 2.6.32-71.el6
Related Package Version: kernel
Related Middleware / Application: None 

Step to Reproduce:
-------------------------------------------------------------------------------
#!/bin/sh

/bin/dd if=/dev/zero of=./img bs=1k count=1 seek=1024k > /dev/null 2>&1
/sbin/mkfs.ext3 -Fq ./img
/bin/mount -o loop -t ext4 ./img /mnt
/bin/touch /mnt/file
/usr/bin/strace /bin/dd if=/dev/zero of=/mnt/file conv=notrunc bs=1k count=1 \
seek=$((2194719883264/1024)) 2>&1 | /bin/egrep "write.* 1024\) = "
/bin/umount /mnt
exit
-------------------------------------------------------------------------------
Run this script.

Actual Results:
write system call returns with 0 in this case.

Expected Results:
write system call returns with EFBIG in this case.

Comment 2 Eric Sandeen 2010-11-22 19:39:12 UTC

Just as a general note, using the ext4 driver for ext3 filesystems in RHEL6 is not recommended.  We can fix this, but it's not the preferred mode of operation.

Comment 3 Eric Sandeen 2010-11-22 19:49:25 UTC

Upstream commit:

commit d889dc8382c4d71b6d538b7b13777bc1ec51df10
Author: Toshiyuki Okajima <toshi.okajima.com>
Date:   Tue Jul 27 11:56:07 2010 -0400

    ext4: fix EFBIG edge case when writing to large non-extent file
    
    By running the following reproducer, we can confirm that the write
    system call returns with 0 when it should return the error EFBIG.
    
    #!/bin/sh
    
    /bin/dd if=/dev/zero of=./img bs=1k count=1 seek=1024k > /dev/null 2>&1
    /sbin/mkfs.ext3 -Fq ./img
    /bin/mount -o loop -t ext4 ./img /mnt
    /bin/touch /mnt/file
    strace /bin/dd if=/dev/zero of=/mnt/file conv=notrunc bs=1k count=1 seek=$((2194719883264/1024)) 2>&1 | /bin/egrep "w
    /bin/umount /mnt
    exit
    
    Signed-off-by: Toshiyuki Okajima <toshi.okajima.com>
    Signed-off-by: "Theodore Ts'o" <tytso>
    Cc: Eric Sandeen <sandeen>

Comment 5 RHEL Program Management 2010-11-23 18:49:27 UTC

This request was evaluated by Red Hat Product Management for inclusion
in a Red Hat Enterprise Linux maintenance release. Product Management has 
requested further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed 
products. This request is not yet committed for inclusion in an Update release.

Comment 6 Aristeu Rozanski 2010-12-15 16:06:19 UTC

Patch(es) available on kernel-2.6.32-91.el6

Comment 10 Petr Beňas 2011-01-19 13:47:11 UTC

Reproduced in 2.6.32-90.el6 and verified in 2.6.32-91.el6.

Comment 12 errata-xmlrpc 2011-05-23 20:27:24 UTC

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHSA-2011-0542.html