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Date: Fri, 1 Feb 2008 10:28:04 -0800 From: Andrew Morton <akpm@...ux-foundation.org> To: "linux-ext4@...r.kernel.org" <linux-ext4@...r.kernel.org> Cc: bugme-daemon@...zilla.kernel.org, Joerg-Cyril.Hoehle@...ystems.com Subject: Re: [Bug 9866] New: chattr sticky behaviour and Orlov block allocator On Fri, 1 Feb 2008 07:25:09 -0800 (PST) bugme-daemon@...zilla.kernel.org wrote: > http://bugzilla.kernel.org/show_bug.cgi?id=9866 > > Summary: chattr sticky behaviour and Orlov block allocator > Product: File System > Version: 2.5 > KernelVersion: 2.6.22 > Platform: All > OS/Version: Linux > Tree: Mainline > Status: NEW > Severity: normal > Priority: P1 > Component: ext3 > AssignedTo: akpm@...l.org > ReportedBy: Joerg-Cyril.Hoehle@...ystems.com > > > Latest working kernel version: 2.6.22 > Earliest failing kernel version: 2.6.18 (oldest tested) > Distribution: Ubuntu Gutsy > Hardware Environment: Fujitsu Siemens C1110 laptop > Software Environment: chattr 1.40.2 (12-Jul-2007), mke2fs 1.40.2 (12-Jul-2007) > Problem Description: > Some file attributes have sticky behaviour in ext2/3 whereas I believe > it should not. Namely, a directory marked with chattr +T serves "to be > the top of directory hierarchies for the purposes of the Orlov block > allocator", as the manpage says. > > It seems wrong that subdirectories stickily inherit the +T flag: they > are obviously not top-level! Even files get the T attribute this way, > even though the chattr manpages only documents it for directories. > > References: > http://lwn.net/Articles/14633/ > http://lwn.net/Articles/14447/ Theodore Ts'o ext3 patch > http://en.wikipedia.org/wiki/Orlov_block_allocator > > > Steps to reproduce: > The following shows the sticky behaviour: > $ mkdir tests > chattr -V +T tests > chattr 1.40.2 (12-Jul-2007) > Flags von tests wie folgt gesetzt: ----------------T- > $ mkdir tests/src > $ cp -dp /etc/fstab tests/src > $ lsattr . tests tests/src > ----------------T- ./tests > ----------------T- tests/src > ----------------T- tests/src/fstab > > I verified (using cp -dpr and ls -lifR) that indeed, the inherited T > attribute causes all subdirectories to be created in inodes far apart > (like with mount -o remount,oldalloc), whereas the Orlov allocator > normally would put the directories next to each other. My expectation > is that only e.g. /home/user{1,2,3,4,5,6} should be created spread > out, whereas each user home's contents would be next each other > (/home/user1/{foo,bar,etc}). > > The effect of this bug makes chattr +T unusable, because Orlov > optimization is de facto eliminated. > > Regards, > Jörg Höhle > > > -- > Configure bugmail: http://bugzilla.kernel.org/userprefs.cgi?tab=email > ------- You are receiving this mail because: ------- > You are the assignee for the bug, or are watching the assignee. - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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