Re: [Qemu-devel] [PATCH 07/13] 9p: darwin: Properly translate AT_REMOVEDIR flag

[Greg Kurz <groug@kaod.org>]

On Sat, 26 May 2018 01:23:09 -0400
keno@juliacomputing.com wrote:

> From: Keno Fischer <keno@alumni.harvard.edu>
> 
> This code relied on P9_DOTL_AT_REMOVEDIR and AT_REMOVEDIR having the same
> numerical value, but on Darwin, they do not.
> 
> Signed-off-by: Keno Fischer <keno@juliacomputing.com>
> ---
>  hw/9pfs/9p-local.c | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
> index 6e0b2e8..c55ea25 100644
> --- a/hw/9pfs/9p-local.c
> +++ b/hw/9pfs/9p-local.c
> @@ -1376,7 +1376,17 @@ static int local_unlinkat(FsContext *ctx, V9fsPath *dir,
>          return -1;
>      }
>  
> -    ret = local_unlinkat_common(ctx, dirfd, name, flags);
> +    if ((flags & ~P9_DOTL_AT_REMOVEDIR) != 0) {

The != 0 isn't needed but...

> +        errno = EINVAL;
> +        return -1;

... I'm more concerned about this new error path. How can this happen ?

> +    }
> +
> +    size_t rflags = 0;

Please declare this at the beginning of the function.

> +    if (flags & P9_DOTL_AT_REMOVEDIR) {
> +        rflags |= AT_REMOVEDIR;
> +    }
> +
> +    ret = local_unlinkat_common(ctx, dirfd, name, rflags);
>      close_preserve_errno(dirfd);
>      return ret;
>  }