From: Christoph Hellwig <hch@infradead.org>
To: Douglas Gilbert <dgilbert@interlog.com>
Cc: Christoph Hellwig <hch@infradead.org>,
linux-scsi@vger.kernel.org, linux-ide@vger.kernel.org,
linux-kernel@vger.kernel.org, liml@rtr.ca, jens.axboe@oracle.com,
matthew@wil.cx, dwmw2@infradead.org
Subject: Re: [PATCH 4/7] sd: add support for WRITE SAME (16) with unmap bit
Date: Sat, 29 Aug 2009 21:05:00 -0400 [thread overview]
Message-ID: <20090830010500.GA24395@infradead.org> (raw)
In-Reply-To: <4A99CB2F.9000000@interlog.com>
On Sat, Aug 29, 2009 at 08:43:27PM -0400, Douglas Gilbert wrote:
>> + if (buffer[14] & 0x80)
>> + sdkp->thin_provisioning = 1;
>> +
>
> So you are checking the TPE bit (Thin Provisioning Enabled) but
> not the TPRZ bit (Thin Provisioning Read Zeros). Shouldn't
> there also be a sdkp->thin_provisioning_read_zeros bit defined
> in struct scsi_disk?
>
> Is your application well defined when TPRZ==0 ?
Filesystems do not care if these blocks are in a defined state, as
they must never return the content of uninitilized blocks to userspace.
Now if we do want to support discard through raid arrays we might start
to care, and will have check the TPRZ bit.
next prev parent reply other threads:[~2009-08-30 1:05 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-08-29 23:03 [PATCH 0/7] discard support revisited Christoph Hellwig
2009-08-29 23:03 ` [PATCH 1/7] Make DISCARD_BARRIER and DISCARD_NOBARRIER writes instead of reads Christoph Hellwig
2009-09-03 17:52 ` David Woodhouse
2009-09-03 17:56 ` Matthew Wilcox
2009-08-29 23:03 ` [PATCH 2/7] block: use blkdev_issue_discard in blk_ioctl_discard Christoph Hellwig
2009-09-01 9:06 ` Steven Whitehouse
2009-09-11 22:26 ` Christoph Hellwig
2009-09-14 9:40 ` Jens Axboe
2009-08-29 23:03 ` [PATCH 3/7] block: discard may need to allocate pages Christoph Hellwig
2009-08-29 23:03 ` [PATCH 4/7] sd: add support for WRITE SAME (16) with unmap bit Christoph Hellwig
2009-08-30 0:43 ` Douglas Gilbert
2009-08-30 1:05 ` Christoph Hellwig [this message]
2009-08-30 2:43 ` Douglas Gilbert
2009-08-30 2:48 ` Christoph Hellwig
2009-08-30 11:12 ` Sergei Shtylyov
2009-08-30 17:14 ` Christoph Hellwig
2009-08-29 23:03 ` [PATCH 5/7] libata: Add support for TRIM Christoph Hellwig
2009-08-29 23:03 ` [PATCH 6/7] block: allow large discard requests Christoph Hellwig
2009-08-30 2:49 ` Mark Lord
2009-08-30 2:50 ` Matthew Wilcox
2009-08-30 2:52 ` Mark Lord
2009-08-30 2:56 ` Christoph Hellwig
2009-08-29 23:03 ` [PATCH 7/7] xfs: add batches discard support Christoph Hellwig
2009-08-29 23:37 ` [PATCH 0/7] discard support revisited Matthew Wilcox
2009-08-30 2:15 ` Christoph Hellwig
2009-08-30 3:03 ` Matthew Wilcox
2009-08-30 20:17 ` James Bottomley
2009-08-30 21:42 ` Matthew Wilcox
2009-08-30 22:48 ` Christoph Hellwig
2009-09-02 19:46 ` Matthew Wilcox
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