[libvirt] [PATCH 3/6] storage: fs: Don't attempt directory creation if it already exists

[Peter Krempa]

On Mon, Apr 27, 2015 at 16:48:41 -0400, Cole Robinson wrote:
> The current code attempts to handle this, but it only catches mkdir
> failing with EEXIST. However if say trying to build /tmp for an
> unprivileged qemu:///session, mkdir will fail with EPERM.
> 
> Rather than catch any errors, just don't attempt mkdir if the directory
> already exists.
> ---
>  src/util/virfile.c | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/src/util/virfile.c b/src/util/virfile.c
> index 87d121d..23a1655 100644
> --- a/src/util/virfile.c
> +++ b/src/util/virfile.c
> @@ -2289,12 +2289,13 @@ virDirCreateNoFork(const char *path,
>      int ret = 0;
>      struct stat st;
>  
> -    if ((mkdir(path, mode) < 0)
> -        && !((errno == EEXIST) && (flags & VIR_DIR_CREATE_ALLOW_EXIST))) {
> -        ret = -errno;
> -        virReportSystemError(errno, _("failed to create directory '%s'"),
> -                             path);
> -        goto error;
> +    if (!(flags & VIR_DIR_CREATE_ALLOW_EXIST) || !virFileExists(path)) {

De Morgan's law allows to optimize this into a more readable form:
        if (!(virFileExists(path) && (flags & VIR_DIR_CREATE_ALLOW_EXIST))) {

It's one set of parentheses more but it's readable.

> +        if (mkdir(path, mode) < 0) {
> +            ret = -errno;
> +            virReportSystemError(errno, _("failed to create directory '%s'"),
> +                                 path);
> +            goto error;
> +        }

ACK with the condition made human readable.

Peter
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: Digital signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20150428/5d99056e/attachment-0001.sig>