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Date: Tue, 18 Jun 2013 16:09:39 +0200
From: Stefan Hajnoczi <stefanha@gmail.com>
Message-ID: <20130618140939.GN7649@stefanha-thinkpad.redhat.com>
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In-Reply-To: <1371209999-15579-8-git-send-email-xiawenc@linux.vnet.ibm.com>
Subject: Re: [Qemu-devel] [PATCH V2 07/12] qmp: add internal snapshot
 support in qmp_transaction
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To: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Cc: kwolf@redhat.com, phrdina@redhat.com, famz@redhat.com, armbru@redhat.com, qemu-devel@nongnu.org, lcapitulino@redhat.com, stefanha@redhat.com, pbonzini@redhat.com, dietmar@proxmox.com

On Fri, Jun 14, 2013 at 07:39:54PM +0800, Wenchao Xia wrote:
> +    /* Forbid having a name similar to id, empty name is also forbidden. */
> +    if (!snapshot_name_wellformed(name)) {
> +        error_setg(errp, "Name %s on device %s is not a valid one",

Please use '%s' instead of just %s for arguments in error messages.
This will make the message easier to understand, especially when name is
empty.  It's also consistent with the rest of blockdev.c.

> +                   name, device);
> +        return;
> +    }
> +
> +    /* 3. take the snapshot */
> +    sn1 = &state->sn;
> +    pstrcpy(sn1->name, sizeof(sn1->name), name);
> +    qemu_gettimeofday(&tv);
> +    sn1->date_sec = tv.tv_sec;
> +    sn1->date_nsec = tv.tv_usec * 1000;
> +    /* not good to use vm_clock in block layer, but that is what we can do now,
> +       or drop it later, since it is an emulater concept. */

It's appropriate here and blockdev.c is emulator code, so you can drop
the comment.