Bug 9635

Summary: Unaligned accesses in xfs_file_readdir
Product: File System Reporter: Dustin Marquess (jailbird)
Component: XFSAssignee: XFS Guru (xfs-masters)
Severity: normal CC: bunk, mingo
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 2.6.24-rc6 Subsystem:
Regression: Yes Bisected commit-id:
Bug Depends on:    
Bug Blocks: 9243    
Attachments: partial revert of commit 041388b54
attempted XFS fix, take #2
Christoph Hellwig's patch

Description Dustin Marquess 2007-12-25 17:47:27 UTC
Most recent kernel where this bug did not occur: 2.6.23
Distribution: Debian/lenny
Hardware Environment: API CS20D (2 x 833Mhz EV68AL Alpha CPUs)
Software Environment: 

Linux sky 2.6.24-rc6-mm1 #1 SMP Mon Dec 24 00:24:38 CST 2007 alpha GNU/Linux
Gnu C                  4.2.3
Gnu make               3.81
binutils               2.18.20071027
util-linux             2.13
mount                  2.13
module-init-tools      3.3-pre11
e2fsprogs              1.40.2
xfsprogs               2.9.4
Linux C Library        2.7
Dynamic linker (ldd)   2.7
Procps                 3.2.7
Net-tools              1.60
Console-tools          0.2.3
Sh-utils               5.97
udev                   114
Modules Loaded         xt_multiport xt_state ip6table_mangle ip6table_filter ip6_tables iptable_mangle iptable_filter adm9240 hwmon_vid loop i2c_ali1535 i2c_ali15x3 i2c_core sd_mod ide_cd_mod cdrom generic sym53c8xx e100 scsi_transport_spi alim15x3 mii scsi_mod ide_core

(Note: -mm1 compile, however bug was introduced in 2.6.24-rc6 patch, not -mm1)

Problem Description:

kernel unaligned acc    : 270990 (pc=fffffc00011855f4,va=fffffc007e39204b)

From System.map:

fffffc0001185480 t xfs_file_readdir
fffffc0001185650 t xfs_hack_filldir

Steps to reproduce:

Boot.  ls a directory on a XFS filesystem.

Seems to be caused by the major xfs_file.c changes in the 2.6.24-rc6 patch.
Comment 1 Ingo Molnar 2008-01-01 12:25:35 UTC
Created attachment 14248 [details]
partial revert of commit 041388b54

Does the attached patch make any difference? It's a partial revert of one of the XFS changes in -rc6. (NOTE: i'm not an XFS expert so this could easily be the wrong patch.)
Comment 2 Ingo Molnar 2008-01-01 12:27:42 UTC
Created attachment 14249 [details]
attempted XFS fix, take #2
Comment 3 Dustin Marquess 2008-01-01 14:03:58 UTC
I'll take a look at that.

Christoph Hellwig <hch@lst.de> posted a patch to the XFS list that seems to fix it.  I'll attach it here.  I definitely not an expert, so I'll let somebody else decide which fix is "better".
Comment 4 Dustin Marquess 2008-01-01 14:04:47 UTC
Created attachment 14255 [details]
Christoph Hellwig's patch
Comment 5 Ingo Molnar 2008-01-02 02:46:58 UTC
ah, ok - disregard my patch then.
Comment 6 Adrian Bunk 2008-01-11 12:32:24 UTC
Fix is now as commit aea6ad0ce5e215ce99fe9e3edd9268f696862d8f in Linus' tree.