Re: [Qemu-devel] [PATCH] file-posix: Consolidate the locking error message

[Eric Blake <eblake@redhat.com>]

On 06/01/2018 04:18 AM, Fam Zheng wrote:
> When hot-plugging a block device fails due to image locking errors,
> users won't see the helpful 'Is another process using the image?'
> message in QMP because currently the error hint is not carried over
> there.
> 
> Even though extending QMP to include hint is a conceivably easy task,
> Libvirt will need some change to consume that data.
> 
> Before that is fully sorted out, let's just do the easy fix by joining
> the two lines.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>   block/file-posix.c         | 10 ++--
>   tests/qemu-iotests/153.out | 99 +++++++++++++-------------------------
>   tests/qemu-iotests/182.out |  3 +-
>   3 files changed, 38 insertions(+), 74 deletions(-)
> 
> diff --git a/block/file-posix.c b/block/file-posix.c
> index 5a602cfe37..03776e13b1 100644
> --- a/block/file-posix.c
> +++ b/block/file-posix.c
> @@ -699,11 +699,10 @@ static int raw_check_lock_bytes(BDRVRawState *s,
>               if (ret) {
>                   char *perm_name = bdrv_perm_names(p);
>                   error_setg(errp,
> -                           "Failed to get \"%s\" lock",
> +                           "Failed to get \"%s\" lock. "
> +                           "Is another process using the image?",

Except that this goes against the error message recommendations that 
Markus has tried to remind people of (in general, using a full-stop in 
error_setg() is frowned on).  Markus, do you have any suggestions?

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org