From: Paolo Bonzini <pbonzini@redhat.com>
To: Eric Blake <eblake@redhat.com>, Fam Zheng <famz@redhat.com>
Cc: qemu-devel@nongnu.org, Kevin Wolf <kwolf@redhat.com>,
qemu-block@nongnu.org, Max Reitz <mreitz@redhat.com>,
"nbd-general@lists.sourceforge.net"
<nbd-general@lists.sourceforge.net>
Subject: Re: [Qemu-devel] [PATCH v5 13/14] nbd: Implement NBD_CMD_WRITE_ZEROES on server
Date: Tue, 19 Jul 2016 17:45:39 +0200 [thread overview]
Message-ID: <aad94967-fd7b-4377-ad40-3f07d67b5c32@redhat.com> (raw)
In-Reply-To: <578E4708.5080308@redhat.com>
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On 19/07/2016 17:28, Eric Blake wrote:
>> If I'm reading the NBD proto.md correctly, this is not enough if
>> NBD_CMD_FLAG_NO_HOLE is specified. We probably need to use a zeroed buffer with
>> blk_pwrite, or pass a new flag (BDRV_RED_NO_HOLE) to blk_pwrite_zeroes to
>> enforce the bdrv_driver_pwritev() branch in bdrv_co_do_pwrite_zeroes().
I agree with Eric's interpretation. It's a bit weird to have the
direction inverted, but I'm not sure I see the ambiguity. Can you explain?
Paolo
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next prev parent reply other threads:[~2016-07-19 15:45 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-19 4:07 [Qemu-devel] [PATCH for-2.7 v5 00/14] nbd: efficient write zeroes Eric Blake
2016-07-19 4:07 ` [Qemu-devel] [PATCH v5 01/14] nbd: Fix bad flag detection on server Eric Blake
2016-07-19 4:07 ` [Qemu-devel] [PATCH v5 02/14] nbd: Add qemu-nbd -D for human-readable description Eric Blake
2016-07-19 4:07 ` [Qemu-devel] [PATCH v5 03/14] nbd: Limit nbdflags to 16 bits Eric Blake
2016-07-19 4:07 ` [Qemu-devel] [PATCH v5 04/14] nbd: Treat flags vs. command type as separate fields Eric Blake
2016-07-19 4:07 ` [Qemu-devel] [PATCH v5 05/14] nbd: Share common reply-sending code in server Eric Blake
2016-07-19 5:10 ` Fam Zheng
2016-07-19 14:52 ` Eric Blake
2016-07-20 4:39 ` Fam Zheng
2016-07-19 4:07 ` [Qemu-devel] [PATCH v5 06/14] nbd: Send message along with server NBD_REP_ERR errors Eric Blake
2016-07-19 5:15 ` Fam Zheng
2016-10-11 15:12 ` Eric Blake
2016-07-19 4:07 ` [Qemu-devel] [PATCH v5 07/14] nbd: Share common option-sending code in client Eric Blake
2016-07-19 5:31 ` Fam Zheng
2016-07-19 4:07 ` [Qemu-devel] [PATCH v5 08/14] nbd: Let server know when client gives up negotiation Eric Blake
2016-07-19 4:07 ` [Qemu-devel] [PATCH v5 09/14] nbd: Let client skip portions of server reply Eric Blake
2016-07-19 4:07 ` [Qemu-devel] [PATCH v5 10/14] nbd: Less allocation during NBD_OPT_LIST Eric Blake
2016-07-19 4:07 ` [Qemu-devel] [PATCH v5 11/14] nbd: Support shorter handshake Eric Blake
2016-07-19 4:07 ` [Qemu-devel] [PATCH v5 12/14] nbd: Improve server handling of shutdown requests Eric Blake
2016-07-19 4:08 ` [Qemu-devel] [PATCH v5 13/14] nbd: Implement NBD_CMD_WRITE_ZEROES on server Eric Blake
2016-07-19 6:21 ` Fam Zheng
2016-07-19 15:28 ` Eric Blake
2016-07-19 15:45 ` Paolo Bonzini [this message]
2016-07-20 3:34 ` Fam Zheng
2016-07-20 3:47 ` Eric Blake
2016-07-20 4:37 ` Fam Zheng
2016-07-20 7:09 ` Paolo Bonzini
2016-07-20 7:38 ` Fam Zheng
2016-07-20 8:16 ` Paolo Bonzini
2016-07-20 9:04 ` Fam Zheng
2016-07-20 9:19 ` [Qemu-devel] semantics of FIEMAP without FIEMAP_FLAG_SYNC (was Re: [PATCH v5 13/14] nbd: Implement NBD_CMD_WRITE_ZEROES on server) Paolo Bonzini
2016-07-20 12:30 ` Dave Chinner
2016-07-20 13:35 ` Niels de Vos
2016-07-21 11:43 ` Dave Chinner
2016-07-21 12:31 ` Pádraig Brady
2016-07-21 13:15 ` Dave Chinner
2016-07-20 13:40 ` Paolo Bonzini
2016-07-21 12:41 ` Dave Chinner
2016-07-21 13:01 ` Pádraig Brady
2016-07-21 14:23 ` Paolo Bonzini
2016-07-22 8:58 ` Dave Chinner
2016-07-22 10:41 ` Paolo Bonzini
2018-02-15 16:40 ` Vladimir Sementsov-Ogievskiy
2018-02-15 16:42 ` Paolo Bonzini
2018-04-18 14:25 ` Vladimir Sementsov-Ogievskiy
2018-04-18 14:41 ` [Qemu-devel] semantics of FIEMAP without FIEMAP_FLAG_SYNC Eric Blake
2016-08-18 13:50 ` [Qemu-devel] [PATCH v5 13/14] nbd: Implement NBD_CMD_WRITE_ZEROES on server Vladimir Sementsov-Ogievskiy
2016-08-18 13:52 ` Paolo Bonzini
2016-07-19 4:08 ` [Qemu-devel] [PATCH v5 14/14] nbd: Implement NBD_CMD_WRITE_ZEROES on client Eric Blake
2016-07-19 6:24 ` Fam Zheng
2016-07-19 15:31 ` Eric Blake
2016-07-19 6:33 ` [Qemu-devel] [PATCH for-2.7 v5 00/14] nbd: efficient write zeroes Fam Zheng
2016-07-19 8:53 ` Paolo Bonzini
2016-07-19 15:33 ` Eric Blake
2016-07-19 15:41 ` Paolo Bonzini
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