[PATCH v3 09/17] hw/9pfs: Add a helper qemu_stat_blksize()

[Bin Meng]

As Windows host does not have stat->st_blksize field, we use the one
we calculated in init_win32_root_directory().

Add a helper qemu_stat_blksize() and use it to avoid direct access to
stat->st_blksize.

Co-developed-by: Guohuai Shi <guohuai....@windriver.com>
Signed-off-by: Bin Meng <bin.m...@windriver.com>
---

 hw/9pfs/9p-util.h       | 12 ++++++++++++
 hw/9pfs/9p-util-win32.c |  7 +++++++
 hw/9pfs/9p.c            | 13 ++++++++++++-
 3 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/hw/9pfs/9p-util.h b/hw/9pfs/9p-util.h
index b8e5c037a2..ff16e74f5d 100644
--- a/hw/9pfs/9p-util.h
+++ b/hw/9pfs/9p-util.h
@@ -131,6 +131,7 @@ int openat_dir(int dirfd, const char *name);
 int openat_file(int dirfd, const char *name, int flags, mode_t mode);
 off_t qemu_dirent_off_win32(void *s, void *fs);
 uint64_t qemu_stat_rdev_win32(void *fs_ctx);
+uint64_t qemu_stat_blksize_win32(void *fs_ctx);
 #endif
 
 static inline void close_preserve_errno(int fd)
@@ -258,6 +259,17 @@ static inline uint64_t qemu_stat_rdev(const struct stat 
*stbuf, void *fs_ctx)
 #endif
 }
 
+static inline uint64_t qemu_stat_blksize(const struct stat *stbuf, void 
*fs_ctx)
+{
+#if defined(CONFIG_LINUX) || defined(CONFIG_DARWIN)
+    return stbuf->st_blksize;
+#elif defined(CONFIG_WIN32)
+    return qemu_stat_blksize_win32(fs_ctx);
+#else
+#error Missing qemu_stat_blksize() implementation for this host system
+#endif
+}
+
 /*
  * As long as mknodat is not available on macOS, this workaround
  * using pthread_fchdir_np is needed. qemu_mknodat is defined in
diff --git a/hw/9pfs/9p-util-win32.c b/hw/9pfs/9p-util-win32.c
index 54c10069b9..07e1fcc4f1 100644
--- a/hw/9pfs/9p-util-win32.c
+++ b/hw/9pfs/9p-util-win32.c
@@ -954,3 +954,10 @@ uint64_t qemu_stat_rdev_win32(void *fs_ctx)
 
     return rdev;
 }
+
+uint64_t qemu_stat_blksize_win32(void *fs_ctx)
+{
+    LocalData *data = ((FsContext *)fs_ctx)->private;
+
+    return data ? (uint64_t)data->block_size : 0;
+}
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
index 36916fe581..def85a57fa 100644
--- a/hw/9pfs/9p.c
+++ b/hw/9pfs/9p.c
@@ -1335,12 +1335,14 @@ static int32_t blksize_to_iounit(const V9fsPDU *pdu, 
int32_t blksize)
 
 static int32_t stat_to_iounit(const V9fsPDU *pdu, const struct stat *stbuf)
 {
-    return blksize_to_iounit(pdu, stbuf->st_blksize);
+    return blksize_to_iounit(pdu, qemu_stat_blksize(stbuf, &pdu->s->ctx));
 }
 
 static int stat_to_v9stat_dotl(V9fsPDU *pdu, const struct stat *stbuf,
                                 V9fsStatDotl *v9lstat)
 {
+    dev_t rdev = qemu_stat_rdev(stbuf, &pdu->s->ctx);
+
     memset(v9lstat, 0, sizeof(*v9lstat));
 
     v9lstat->st_mode = stbuf->st_mode;
@@ -1350,7 +1352,16 @@ static int stat_to_v9stat_dotl(V9fsPDU *pdu, const 
struct stat *stbuf,
     v9lstat->st_rdev = host_dev_to_dotl_dev(rdev);
     v9lstat->st_size = stbuf->st_size;
     v9lstat->st_blksize = stat_to_iounit(pdu, stbuf);
+#if defined(CONFIG_LINUX) || defined(CONFIG_DARWIN)
     v9lstat->st_blocks = stbuf->st_blocks;
+#elif defined(CONFIG_WIN32)
+    if (v9lstat->st_blksize == 0) {
+        v9lstat->st_blocks = 0;
+    } else {
+        v9lstat->st_blocks = ROUND_UP(v9lstat->st_size / v9lstat->st_blksize,
+                                      v9lstat->st_blksize);
+    }
+#endif
     v9lstat->st_atime_sec = stbuf->st_atime;
     v9lstat->st_mtime_sec = stbuf->st_mtime;
     v9lstat->st_ctime_sec = stbuf->st_ctime;
-- 
2.25.1