Re: [Qemu-devel] [PATCH] savevm: create snapshot failed when id_str already exits

[Stefan Hajnoczi <stefanha@gmail.com>]

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On Thu, Mar 12, 2015 at 11:29:38PM +0800, Yi Wang wrote:
> How about this?
> 
> From 913cf2cd04167b7f6b892ac1ab405a617d886b97 Mon Sep 17 00:00:00 2001
> From: Yi Wang <up2wing@gmail.com>
> Date: Thu, 12 Mar 2015 22:54:42 +0800
> Subject: [PATCH] savevm: create snapshot failed when id_str already exists
> 
> The command "virsh create" will fail in such condition: vm has two
> disks: vda and vdb. vda has snapshot s1 with id "1", vdb doesn't have
> s1 but has snapshot s2 with id "1"。When we want to run command "virsh
> create s1", del_existing_snapshots() only deletes s1 in vda, and
> bdrv_snapshot_create() tries to create vdb's snapshot s1 with id "1",
> but id "1" alreay exists in vdb with name "s2"!
> 
> The simplest way is call find_new_snapshot_id() unconditionally.
> 
> Signed-off-by: Yi Wang <up2wing@gmail.com>
> ---
>  block/qcow2-snapshot.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/block/qcow2-snapshot.c b/block/qcow2-snapshot.c
> index 5b3903c..cb00f56 100644
> --- a/block/qcow2-snapshot.c
> +++ b/block/qcow2-snapshot.c
> @@ -351,10 +351,8 @@ int qcow2_snapshot_create(BlockDriverState *bs,
> QEMUSnapshotInfo *sn_info)
> 
>      memset(sn, 0, sizeof(*sn));
> 
> -    /* Generate an ID if it wasn't passed */
> -    if (sn_info->id_str[0] == '\0') {
> -        find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str));
> -    }
> +    /* Generate an ID */
> +    find_new_snapshot_id(bs, sn_info->id_str, sizeof(sn_info->id_str));
> 
>      /* Check that the ID is unique */
>      if (find_snapshot_by_id_and_name(bs, sn_info->id_str, NULL) >= 0) {
> -- 
> 1.9.5.msysgit.0

Thanks, I've applied the patch to the block-next branch for QEMU 2.4:
https://github.com/stefanha/qemu/commits/block-next

Please send future patches as separate top-level email threads using
git-send-email(1).  I missed this reply since it was not a new email
thread.  git-am(1) refuses to apply the patch because of line-wrapping
in your email, I had to fix that manually.

Also, please stick to ASCII characters when possible.  Your patch
description uses the Chinese full stop (句號).  I had to manually edit
the patch because git-am(1) refuses to apply a copy-pasted patch without
explicit character encoding information.

Stefan

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