Re: [PATCH v3 2/4] util: introduce qemu_open and qemu_create with error reporting

[Eric Blake]

On 7/24/20 8:25 AM, Daniel P. Berrangé wrote:
> This introduces two new helper metohds
>
>    int qemu_open(const char *name, int flags, Error **errp);
>    int qemu_create(const char *name, int flags, mode_t mode, Error **errp);
>
> Note that with this design we no longer require or even accept the
> O_CREAT flag. Avoiding overloading the two distinct operations
> means we can avoid variable arguments which would prevent 'errp' from
> being the last argument. It also gives us a guarantee that the 'mode' is
> given when creating files, avoiding a latent security bug.

I like it.

> Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> ---
>   include/qemu/osdep.h |  6 ++++
>   util/osdep.c         | 78 ++++++++++++++++++++++++++++++++++++--------
>   2 files changed, 71 insertions(+), 13 deletions(-)
>
> diff --git a/include/qemu/osdep.h b/include/qemu/osdep.h
> index 3a16e58932..ca24ebe211 100644
> --- a/include/qemu/osdep.h
> +++ b/include/qemu/osdep.h
> @@ -494,7 +494,13 @@ int qemu_madvise(void *addr, size_t len, int advice);
>   int qemu_mprotect_rwx(void *addr, size_t size);
>   int qemu_mprotect_none(void *addr, size_t size);
>   
> +/*
> + * Don't introduce new usage of this function, prefer the following
> + * qemu_open/qemu_create that take a "Error **errp"

s/a /an /

Reviewed-by: Eric Blake <eblake@redhat.com>

--
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org