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Re: [Qemu-devel] [PATCH V15 01/13] quorum: Create quorum.c, add QuorumSi
From: |
Benoît Canet |
Subject: |
Re: [Qemu-devel] [PATCH V15 01/13] quorum: Create quorum.c, add QuorumSingleAIOCB and QuorumAIOCB. |
Date: |
Wed, 5 Feb 2014 14:29:01 +0100 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
Le Tuesday 04 Feb 2014 à 13:57:07 (+0100), Kevin Wolf a écrit :
> Am 03.02.2014 um 22:51 hat Benoît Canet geschrieben:
> > From: Benoît Canet <address@hidden>
> >
> > Signed-off-by: Benoit Canet <address@hidden>
> > Reviewed-by: Max Reitz <address@hidden>
> > ---
> > block/Makefile.objs | 1 +
> > block/quorum.c | 54
> > +++++++++++++++++++++++++++++++++++++++++++++++++++++
> > 2 files changed, 55 insertions(+)
> > create mode 100644 block/quorum.c
> >
> > diff --git a/block/Makefile.objs b/block/Makefile.objs
> > index 4e8c91e..a2650b9 100644
> > --- a/block/Makefile.objs
> > +++ b/block/Makefile.objs
> > @@ -3,6 +3,7 @@ block-obj-y += qcow2.o qcow2-refcount.o qcow2-cluster.o
> > qcow2-snapshot.o qcow2-c
> > block-obj-y += qed.o qed-gencb.o qed-l2-cache.o qed-table.o qed-cluster.o
> > block-obj-y += qed-check.o
> > block-obj-$(CONFIG_VHDX) += vhdx.o vhdx-endian.o vhdx-log.o
> > +block-obj-y += quorum.o
> > block-obj-y += parallels.o blkdebug.o blkverify.o
> > block-obj-y += snapshot.o qapi.o
> > block-obj-$(CONFIG_WIN32) += raw-win32.o win32-aio.o
> > diff --git a/block/quorum.c b/block/quorum.c
> > new file mode 100644
> > index 0000000..17695d6
> > --- /dev/null
> > +++ b/block/quorum.c
> > @@ -0,0 +1,54 @@
> > +/*
> > + * Quorum Block filter
> > + *
> > + * Copyright (C) 2012-2014 Nodalink, EURL.
> > + *
> > + * Author:
> > + * Benoît Canet <address@hidden>
> > + *
> > + * Based on the design and code of blkverify.c (Copyright (C) 2010 IBM,
> > Corp)
> > + * and blkmirror.c (Copyright (C) 2011 Red Hat, Inc).
>
> I think you were planning to respin anyway, so I'll practice my
> nitpicking: The file is called mirror.c, not blkmirror.c.
It's a reference to blkmirror.c by Marcello Tosati. A patch that was never
merged.
https://www.google.fr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CCkQFjAA&url=https%3A%2F%2Flists.gnu.org%2Farchive%2Fhtml%2Fqemu-devel%2F2011-05%2Fmsg02521.html&ei=FzzyUuOBEeSg0QX9jYCgCg&usg=AFQjCNG6W5qbmITacObTAD4ShOZlxky2bA&bvm=bv.60799247,d.d2k
>
> > + *
> > + * This work is licensed under the terms of the GNU GPL, version 2 or
> > later.
> > + * See the COPYING file in the top-level directory.
> > + */
> > +
> > +#include "block/block_int.h"
> > +
> > +typedef struct QuorumAIOCB QuorumAIOCB;
> > +
> > +/* Quorum will create one instance of the following structure per
> > operation it
> > + * performs on its children.
> > + * So for each read/write operation coming from the upper layer there will
> > be
> > + * $children_count QuorumSingleAIOCB.
> > + */
> > +typedef struct QuorumSingleAIOCB {
> > + BlockDriverAIOCB *aiocb;
>
> So this isn't a real AIOCB, but it merely points to one. Perhaps
> something like QuorumChildRequest would be a more precise name?
>
> > + QEMUIOVector qiov;
> > + uint8_t *buf;
>
> The combination of a linear buffer and qiov is unusual. It looks like
> there may be a reason for it (otherwise qemu_iovec_clone() wouldn't
> exist), but I don't understand it yet at this point. Could hint at a
> lack of documentation.
>
> I might back come to this later in the patch series.
>
> > + int ret;
> > + QuorumAIOCB *parent;
> > +} QuorumSingleAIOCB;
> > +
> > +/* Quorum will use the following structure to track progress of each
> > read/write
> > + * operation received by the upper layer.
> > + * This structure hold pointers to the QuorumSingleAIOCB structures
> > instances
> > + * used to do operations on each children and track overall progress.
> > + */
> > +struct QuorumAIOCB {
> > + BlockDriverAIOCB common;
> > +
> > + /* Request metadata */
> > + uint64_t sector_num;
> > + int nb_sectors;
> > +
> > + QEMUIOVector *qiov; /* calling IOV */
> > +
> > + QuorumSingleAIOCB *aios; /* individual AIOs */
> > + int count; /* number of completed AIOCB */
> > + int success_count; /* number of successfully completed AIOCB
> > */
> > + bool *finished; /* completion signal for cancel */
> > +
> > + bool is_read;
> > + int vote_ret;
> > +};
>
> Kevin
- Re: [Qemu-devel] [PATCH V15 03/13] quorum: Add quorum_aio_writev and its dependencies., (continued)
- [Qemu-devel] [PATCH V15 07/13] quorum: Add quorum_getlength()., Benoît Canet, 2014/02/03
- [Qemu-devel] [PATCH V15 05/13] quorum: Add quorum_aio_readv., Benoît Canet, 2014/02/03
- [Qemu-devel] [PATCH V15 08/13] quorum: Add quorum_invalidate_cache()., Benoît Canet, 2014/02/03
- [Qemu-devel] [PATCH V15 10/13] quorum: Add quorum_co_flush()., Benoît Canet, 2014/02/03
- [Qemu-devel] [PATCH V15 11/13] quorum: Implement recursive .bdrv_recurse_is_first_non_filter in quorum., Benoît Canet, 2014/02/03
- [Qemu-devel] [PATCH V15 01/13] quorum: Create quorum.c, add QuorumSingleAIOCB and QuorumAIOCB., Benoît Canet, 2014/02/03
- [Qemu-devel] [PATCH V15 06/13] quorum: Add quorum mechanism., Benoît Canet, 2014/02/03
- [Qemu-devel] [PATCH V15 13/13] quorum: Add unit test., Benoît Canet, 2014/02/03
- [Qemu-devel] [PATCH V15 12/13] quorum: Add quorum_open() and quorum_close()., Benoît Canet, 2014/02/03