From: Eric Sandeen <sandeen@redhat.com>
To: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Ric Wheeler <ricwheeler@gmail.com>,
Lukas Czerner <lczerner@redhat.com>,
Andreas Dilger <adilger.kernel@dilger.ca>,
linux-ext4@vger.kernel.org, tytso@mit.edu
Subject: Re: [PATCH] e2fsck: Discard free data and inode blocks.
Date: Fri, 22 Oct 2010 13:23:36 -0500 [thread overview]
Message-ID: <4CC1D6A8.6080000@redhat.com> (raw)
In-Reply-To: <yq18w1qp3bl.fsf@sermon.lab.mkp.net>
Martin K. Petersen wrote:
>>>>>> "Ric" == Ric Wheeler <ricwheeler@gmail.com> writes:
>
>>> so we're not depending on it zeroing blocks, we're just depending on
>>> it advertising correctly whether or not it -does- zero.
>
> If the relevant bits are set (ATA: DRAT and RZAT, SCSI: TPRZ) we'll set
> the bdev's discard_zeroes_data flag.
>
> [root@test ~]# lsscsi | grep SSD | awk '{ print $7 }'
> /dev/sde
> [root@test ~]# grep . /sys/block/sde/queue/discard_zeroes_data
> 1
>
> The relevant ioctl is BLKDISCARDZEROES.
which is what that patch I pointed to uses, BTW...
I really think it's on firm footing here, we're not assuming
discard == zeroed data, we are checking whether the drive
reports exactly that behavior ...
-Eric
next prev parent reply other threads:[~2010-10-22 18:23 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-10-21 14:15 [PATCH] e2fsck: Discard free data and inode blocks Lukas Czerner
2010-10-21 18:07 ` Andreas Dilger
2010-10-22 9:12 ` Lukas Czerner
2010-10-22 11:30 ` Ric Wheeler
2010-10-22 11:43 ` Lukas Czerner
2010-10-22 14:12 ` Ric Wheeler
2010-10-22 14:32 ` Lukas Czerner
2010-10-22 14:46 ` Ric Wheeler
2010-10-22 15:37 ` Eric Sandeen
2010-10-22 15:41 ` Ric Wheeler
2010-10-22 17:03 ` Martin K. Petersen
2010-10-22 17:14 ` Ric Wheeler
2010-10-22 17:29 ` Martin K. Petersen
2010-10-22 18:23 ` Eric Sandeen [this message]
2010-10-22 17:50 ` Andreas Dilger
2010-10-22 18:01 ` Lukas Czerner
2010-10-22 18:17 ` Andreas Dilger
2010-10-22 18:23 ` Ric Wheeler
2010-10-22 21:19 ` Martin K. Petersen
2010-10-22 18:29 ` Eric Sandeen
2010-10-22 21:01 ` Martin K. Petersen
2010-10-22 18:00 ` Andreas Dilger
2010-10-22 18:27 ` Eric Sandeen
2010-10-22 18:31 ` Lukas Czerner
-- strict thread matches above, loose matches on Subject: below --
2010-10-11 10:37 Lukas Czerner
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