Re: [PATCH v2 1/2] block: Fixes nfs compiling error on msys2/mingw

[Max Reitz <mreitz@redhat.com>]

On 13.10.20 02:15, Yonggang Luo wrote:
> These compiling errors are fixed:
> ../block/nfs.c:27:10: fatal error: poll.h: No such file or directory
>     27 | #include <poll.h>
>        |          ^~~~~~~~
> compilation terminated.
> 
> ../block/nfs.c:63:5: error: unknown type name 'blkcnt_t'
>     63 |     blkcnt_t st_blocks;
>        |     ^~~~~~~~
> ../block/nfs.c: In function 'nfs_client_open':
> ../block/nfs.c:550:27: error: 'struct _stat64' has no member named 'st_blocks'
>    550 |     client->st_blocks = st.st_blocks;
>        |                           ^
> ../block/nfs.c: In function 'nfs_get_allocated_file_size':
> ../block/nfs.c:751:41: error: 'struct _stat64' has no member named 'st_blocks'
>    751 |     return (task.ret < 0 ? task.ret : st.st_blocks * 512);
>        |                                         ^
> ../block/nfs.c: In function 'nfs_reopen_prepare':
> ../block/nfs.c:805:31: error: 'struct _stat64' has no member named 'st_blocks'
>    805 |         client->st_blocks = st.st_blocks;
>        |                               ^
> ../block/nfs.c: In function 'nfs_get_allocated_file_size':
> ../block/nfs.c:752:1: error: control reaches end of non-void function [-Werror=return-type]
>    752 | }
>        | ^
> 
> On msys2/mingw, there is no st_blocks in struct _stat64 yet, we disable the usage of it
> on msys2/mingw, and create a typedef long long blkcnt_t; for further implementation
> 
> Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
> ---
>   block/nfs.c | 15 +++++++++++++++
>   1 file changed, 15 insertions(+)
> 
> diff --git a/block/nfs.c b/block/nfs.c
> index f86e660374..cf8795fb49 100644
> --- a/block/nfs.c
> +++ b/block/nfs.c

[...]

> @@ -51,6 +53,10 @@
>   #define QEMU_NFS_MAX_PAGECACHE_SIZE (8388608 / NFS_BLKSIZE)
>   #define QEMU_NFS_MAX_DEBUG_LEVEL 2
>   
> +#if defined(_WIN32)
> +typedef long long blkcnt_t;

This makes me uneasy.  Is there a guarantee that this type will never be 
defined in a mingw environment (which would then result in a new compile 
error)?

Can’t we just give NFSClient.st_blocks a different type, i.e. uint64_t?

Apart from that, looks good to me.