Re: [PATCH v8 02/27] block: Fixes nfs compiling error on msys2/mingw

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 9/13/20 12:44 AM, 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, so we use consistence st_size instead.
> 
> Signed-off-by: Yonggang Luo <luoyonggang@gmail.com>
> ---
>  block/nfs.c | 26 ++++++++++++++++++++++----
>  1 file changed, 22 insertions(+), 4 deletions(-)
> 
> diff --git a/block/nfs.c b/block/nfs.c
> index 61a249a9fc..98b48f363b 100644
> --- a/block/nfs.c
> +++ b/block/nfs.c
> @@ -24,7 +24,9 @@
>  
>  #include "qemu/osdep.h"
>  
> +#if !defined(_WIN32)
>  #include <poll.h>
> +#endif
>  #include "qemu/config-file.h"
>  #include "qemu/error-report.h"
>  #include "qapi/error.h"
> @@ -51,6 +53,12 @@
>  #define QEMU_NFS_MAX_PAGECACHE_SIZE (8388608 / NFS_BLKSIZE)
>  #define QEMU_NFS_MAX_DEBUG_LEVEL 2
>  
> +#if defined (_WIN32)
> +#define nfs_stat __stat64
> +#else
> +#define nfs_stat stat
> +#endif
> +
>  typedef struct NFSClient {
>      struct nfs_context *context;
>      struct nfsfh *fh;
> @@ -58,7 +66,9 @@ typedef struct NFSClient {
>      bool has_zero_init;
>      AioContext *aio_context;
>      QemuMutex mutex;
> +#if !defined (_WIN32)
>      blkcnt_t st_blocks;

What about adding a "typedef off_t blkcnt_t;" or
similar typedef instead? Then no need to #ifdef
the st_blocks uses.

> +#endif
>      bool cache_used;
>      NFSServer *server;
>      char *path;
> @@ -70,7 +80,7 @@ typedef struct NFSRPC {
>      int ret;
>      int complete;
>      QEMUIOVector *iov;
> -    struct stat *st;
> +    struct nfs_stat *st;
>      Coroutine *co;
>      NFSClient *client;
>  } NFSRPC;
> @@ -419,7 +429,7 @@ static int64_t nfs_client_open(NFSClient *client, BlockdevOptionsNfs *opts,
>                                 int flags, int open_flags, Error **errp)
>  {
>      int64_t ret = -EINVAL;
> -    struct stat st;
> +    struct nfs_stat st;
>      char *file = NULL, *strp = NULL;
>  
>      qemu_mutex_init(&client->mutex);
> @@ -545,7 +555,9 @@ static int64_t nfs_client_open(NFSClient *client, BlockdevOptionsNfs *opts,
>      }
>  
>      ret = DIV_ROUND_UP(st.st_size, BDRV_SECTOR_SIZE);
> +#if !defined (_WIN32)
>      client->st_blocks = st.st_blocks;
> +#endif
>      client->has_zero_init = S_ISREG(st.st_mode);
>      *strp = '/';
>      goto out;
> @@ -706,6 +718,7 @@ static int nfs_has_zero_init(BlockDriverState *bs)
>      return client->has_zero_init;
>  }
>  
> +#if !defined (_WIN32)
>  /* Called (via nfs_service) with QemuMutex held.  */
>  static void
>  nfs_get_allocated_file_size_cb(int ret, struct nfs_context *nfs, void *data,
> @@ -729,7 +742,7 @@ static int64_t nfs_get_allocated_file_size(BlockDriverState *bs)
>  {
>      NFSClient *client = bs->opaque;
>      NFSRPC task = {0};
> -    struct stat st;
> +    struct nfs_stat st;
>  
>      if (bdrv_is_read_only(bs) &&
>          !(bs->open_flags & BDRV_O_NOCACHE)) {
> @@ -748,6 +761,7 @@ static int64_t nfs_get_allocated_file_size(BlockDriverState *bs)
>  
>      return (task.ret < 0 ? task.ret : st.st_blocks * 512);
>  }
> +#endif
>  
>  static int coroutine_fn
>  nfs_file_co_truncate(BlockDriverState *bs, int64_t offset, bool exact,
> @@ -778,7 +792,7 @@ static int nfs_reopen_prepare(BDRVReopenState *state,
>                                BlockReopenQueue *queue, Error **errp)
>  {
>      NFSClient *client = state->bs->opaque;
> -    struct stat st;
> +    struct nfs_stat st;
>      int ret = 0;
>  
>      if (state->flags & BDRV_O_RDWR && bdrv_is_read_only(state->bs)) {
> @@ -800,7 +814,9 @@ static int nfs_reopen_prepare(BDRVReopenState *state,
>                         nfs_get_error(client->context));
>              return ret;
>          }
> +#if !defined (_WIN32)
>          client->st_blocks = st.st_blocks;
> +#endif
>      }
>  
>      return 0;
> @@ -869,7 +885,9 @@ static BlockDriver bdrv_nfs = {
>      .create_opts                    = &nfs_create_opts,
>  
>      .bdrv_has_zero_init             = nfs_has_zero_init,
> +#if !defined (_WIN32)
>      .bdrv_get_allocated_file_size   = nfs_get_allocated_file_size,
> +#endif
>      .bdrv_co_truncate               = nfs_file_co_truncate,
>  
>      .bdrv_file_open                 = nfs_file_open,
>