[libvirt] [PATCH 2/2] storage: fix build with musl libc

[Michal Privoznik]

On 10/16/19 1:22 PM, casantos at redhat.com wrote:
> From: Carlos Santos <casantos at redhat.com>
> 
> On musl _PATH_MOUNTED is defined in paths.h, not in mntent.h, which
> causes compilation errors:
> 
> storage/storage_backend_fs.c: In function 'virStorageBackendFileSystemIsMounted':
> storage/storage_backend_fs.c:255:23: error: '_PATH_MOUNTED' undeclared (first use in this function); did you mean 'XPATH_POINT'?
>       if ((mtab = fopen(_PATH_MOUNTED, "r")) == NULL) {
>                         ^~~~~~~~~~~~~
>                         XPATH_POINT
> 
> Fix this including paths.h if _PATH_MOUNTED is still not defined after
> including mntent.h. This also works with glibc and uClibc-ng.
> 
> Signed-off-by: Carlos Santos <casantos at redhat.com>
> ---
>   src/storage/storage_backend_fs.c       | 3 +++
>   src/storage/storage_backend_vstorage.c | 3 +++
>   2 files changed, 6 insertions(+)
> 
> diff --git a/src/storage/storage_backend_fs.c b/src/storage/storage_backend_fs.c
> index ed677058ed..fafe2745cc 100644
> --- a/src/storage/storage_backend_fs.c
> +++ b/src/storage/storage_backend_fs.c
> @@ -42,6 +42,9 @@ VIR_LOG_INIT("storage.storage_backend_fs");
>   #if WITH_STORAGE_FS
>   
>   # include <mntent.h>
> +#ifndef _PATH_MOUNTED
> +# include <paths.h>
> +#endif

Well, in fact glibc has the _PATH_MOUNTED defined in paths.h too but 
only thanks to mntent.h including paths.h (to define deprecated MOUNTED 
macro) we are not hitting error there. Therefore, we can and should 
always include paths.h. IOW, those ifndef-s can be dropped.

>   
>   struct _virNetfsDiscoverState {
>       const char *host;
> diff --git a/src/storage/storage_backend_vstorage.c b/src/storage/storage_backend_vstorage.c
> index cec21dccbf..685f78a22f 100644
> --- a/src/storage/storage_backend_vstorage.c
> +++ b/src/storage/storage_backend_vstorage.c
> @@ -7,6 +7,9 @@
>   #include "virlog.h"
>   #include "virstring.h"
>   #include <mntent.h>
> +#ifndef _PATH_MOUNTED
> +#include <paths.h>
> +#endif
>   #include <pwd.h>
>   #include <grp.h>
>   #include "storage_util.h"
> 

Michal