hw/9pfs/9p-synth: added directory for readdir test

This will provide the following virtual files by the 9pfs
synth driver:

  - /ReadDirDir/ReadDirFile99
  - /ReadDirDir/ReadDirFile98
  ...
  - /ReadDirDir/ReadDirFile1
  - /ReadDirDir/ReadDirFile0

This virtual directory and its virtual 100 files will be
used by the upcoming 9pfs readdir tests.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <5408c28c8de25dd575b745cef63bf785305ccef2.1579567020.git.qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>

hw/9pfs/9p-synth.c

@@ -578,6 +578,25 @@ static int synth_init(FsContext *ctx, Error **errp)
                                        NULL, v9fs_synth_qtest_flush_write,
                                        ctx);
         assert(!ret);
+
+        /* Directory for READDIR test */
+        {
+            V9fsSynthNode *dir = NULL;
+            ret = qemu_v9fs_synth_mkdir(
+                NULL, 0700, QTEST_V9FS_SYNTH_READDIR_DIR, &dir
+            );
+            assert(!ret);
+            for (i = 0; i < QTEST_V9FS_SYNTH_READDIR_NFILES; ++i) {
+                char *name = g_strdup_printf(
+                    QTEST_V9FS_SYNTH_READDIR_FILE, i
+                );
+                ret = qemu_v9fs_synth_add_file(
+                    dir, 0, name, NULL, NULL, ctx
+                );
+                assert(!ret);
+                g_free(name);
+            }
+        }
     }
 
     return 0;

hw/9pfs/9p-synth.h

@@ -55,6 +55,11 @@ int qemu_v9fs_synth_add_file(V9fsSynthNode *parent, int mode,
 #define QTEST_V9FS_SYNTH_LOPEN_FILE "LOPEN"
 #define QTEST_V9FS_SYNTH_WRITE_FILE "WRITE"
 
+/* for READDIR test */
+#define QTEST_V9FS_SYNTH_READDIR_DIR "ReadDirDir"
+#define QTEST_V9FS_SYNTH_READDIR_FILE "ReadDirFile%d"
+#define QTEST_V9FS_SYNTH_READDIR_NFILES 100
+
 /* Any write to the "FLUSH" file is handled one byte at a time by the
  * backend. If the byte is zero, the backend returns success (ie, 1),
  * otherwise it forces the server to try again forever. Thus allowing