meson: handle fuse versions with buggy dt_type handling

Link: libfuse/libfuse#591
Signed-off-by: Christian Brauner (Microsoft) <christian.brauner@ubuntu.com>

meson.build

@@ -150,11 +150,17 @@ libfuse = dependency('fuse3', required: false)
 if libfuse.found()
     conf.set10('HAVE_FUSE3', true)
     conf.set('FUSE_USE_VERSION', 35)
+    if libfuse.version().version_compare('>=3.10.3')
+	conf.set10('HAVE_FUSE_RETURNS_DT_TYPE', true)
+    else
+	conf.set10('HAVE_FUSE_RETURNS_DT_TYPE', false)
+    endif
 else
     libfuse = dependency('fuse', version: '>= 2.6')
     if libfuse.found()
         conf.set10('HAVE_FUSE', true)
         conf.set('FUSE_USE_VERSION', 26)
+	conf.set10('HAVE_FUSE_RETURNS_DT_TYPE', true)
     endif
 endif
 

src/bindings.c

@@ -939,7 +939,9 @@ static void __attribute__((destructor)) lxcfs_exit(void)
 void *lxcfs_fuse_init(struct fuse_conn_info *conn, void *data)
 {
 	struct fuse_context *fc = fuse_get_context();
+#if HAVE_FUSE_RETURNS_DT_TYPE
 	can_use_sys_cpu = true;
+#endif
 	has_versioned_opts = true;
 	return fc->private_data;
 }

src/lxcfs_fuse_compat.h

@@ -12,7 +12,11 @@
 #include "memory_utils.h"
 
 #ifdef HAVE_FUSE3
-#define DIR_FILLER(F,B,N,S,O) F(B,N,S,O,FUSE_FILL_DIR_PLUS)
+  #if HAVE_FUSE_RETURNS_DT_TYPE
+    #define DIR_FILLER(F,B,N,S,O) F(B,N,S,O,FUSE_FILL_DIR_PLUS)
+  #else
+    #define DIR_FILLER(F,B,N,S,O) F(B,N,S,O,0)
+  #endif
 #else
 #define DIR_FILLER(F,B,N,S,O) F(B,N,S,O)
 #endif
@@ -26,19 +30,22 @@ static inline int dir_filler(fuse_fill_dir_t filler, void *buf,
 static inline int dirent_filler(fuse_fill_dir_t filler, const char *path,
 				const char *name, void *buf, off_t off)
 {
+#if HAVE_FUSE_RETURNS_DT_TYPE
 	__do_closedir DIR *dirp = NULL;
 	struct stat st;
 
 	dirp = opendir(path);
 	if (dirp && !fstatat(dirfd(dirp), name, &st, AT_SYMLINK_NOFOLLOW))
 		return DIR_FILLER(filler, buf, name, &st, off);
+#endif
 
 	return DIR_FILLER(filler, buf, name, NULL, off);
 }
 
 static inline int dirent_fillerat(fuse_fill_dir_t filler, DIR *dp,
 				  struct dirent *dentry, void *buf, off_t off)
 {
+#if HAVE_FUSE_RETURNS_DT_TYPE
 	struct stat st;
 	int ret;
 
@@ -51,18 +58,23 @@ static inline int dirent_fillerat(fuse_fill_dir_t filler, DIR *dp,
 	}
 
 	return DIR_FILLER(filler, buf, dentry->d_name, &st, off);
+#else
+	return DIR_FILLER(filler, buf, dentry->d_name, NULL, off);
+#endif
 }
 static inline int dir_fillerat(fuse_fill_dir_t filler, DIR *dp,
 			       const char *name, void *buf, off_t off)
 {
+#if HAVE_FUSE_RETURNS_DT_TYPE
 	struct stat st;
 	int ret;
 
 	ret = fstatat(dirfd(dp), name, &st, AT_SYMLINK_NOFOLLOW);
-	if (ret)
-		return DIR_FILLER(filler, buf, name, NULL, off);
+	if (!ret)
+		return DIR_FILLER(filler, buf, name, &st, off);
+#endif
 
-	return DIR_FILLER(filler, buf, name, &st, off);
+	return DIR_FILLER(filler, buf, name, NULL, off);
 }
 
 #endif /* __LXCFS_FUSE_COMPAT_H */