From: Ted Ts'o <tytso@mit.edu>
To: Jeff Moyer <jmoyer@redhat.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
Ibragimov Rinat <ibragimovrinat@mail.ru>,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH][RFC]ext4 on 4k-sector drives without read-modify-write support
Date: Mon, 28 Feb 2011 16:22:21 -0500 [thread overview]
Message-ID: <20110228212221.GH28617@thunk.org> (raw)
In-Reply-To: <x494o7n6f1n.fsf@segfault.boston.devel.redhat.com>
On Mon, Feb 28, 2011 at 04:10:44PM -0500, Jeff Moyer wrote:
> > So it there a reliable way to detect that disk drives that don't have
> > the Read-Modify-Write logic? If that can be reflected up the I/O
> > layer I can have mke2fs enforce that restriction, which currently we
> > only enforce if the logical blocksize is 4k.
>
> That's not enough, I'm afraid. How do you deal with O_DIRECT, for
> example?
The drives do the read/modify/write, so O_DIRECT works fine from the
OS's perspective. There is some risk of torn pages if you get a crash
at the wrong moment, but that's true whenver you have a misaligned
partition. (At least for the drives that do the RMW in the disk
firmware.)
- Ted
next prev parent reply other threads:[~2011-02-28 21:22 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-26 18:24 [PATCH][RFC]ext4 on 4k-sector drives without read-modify-write support Ibragimov Rinat
2011-02-28 14:52 ` Jeff Moyer
2011-02-28 14:58 ` Martin K. Petersen
2011-02-28 18:09 ` Ted Ts'o
2011-02-28 20:19 ` Martin K. Petersen
2011-02-28 21:05 ` Ted Ts'o
2011-02-28 21:10 ` Jeff Moyer
2011-02-28 21:22 ` Ted Ts'o [this message]
2011-02-28 21:57 ` Jeff Moyer
2011-03-01 15:19 ` Martin K. Petersen
2011-02-28 21:20 ` James Bottomley
2011-02-28 21:24 ` Ted Ts'o
2011-02-28 21:23 ` Martin K. Petersen
2011-02-28 22:52 ` [PATCH][RFC]ext4 on 4k-sector drives without read-modify-writesupport Ibragimov Rinat
2011-03-01 22:16 ` Ibragimov Rinat
2011-03-10 17:01 ` Ibragimov Rinat
2011-02-28 17:54 ` [PATCH][RFC]ext4 on 4k-sector drives without read-modify-write support Ibragimov Rinat
2012-09-27 11:41 ` Mike
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