hw/9pfs: Add yield support for readdir related coroutines

This include readdir, telldir, seekdir, rewinddir.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

Makefile.objs

@@ -305,7 +305,7 @@ hw-obj-$(CONFIG_SOUND) += $(sound-obj-y)
 9pfs-nested-$(CONFIG_VIRTFS) = virtio-9p.o virtio-9p-debug.o
 9pfs-nested-$(CONFIG_VIRTFS) +=  virtio-9p-local.o virtio-9p-xattr.o
 9pfs-nested-$(CONFIG_VIRTFS) +=   virtio-9p-xattr-user.o virtio-9p-posix-acl.o
-9pfs-nested-$(CONFIG_VIRTFS) += virtio-9p-coth.o cofs.o
+9pfs-nested-$(CONFIG_VIRTFS) += virtio-9p-coth.o cofs.o codir.o
 
 hw-obj-$(CONFIG_REALLY_VIRTFS) += $(addprefix 9pfs/, $(9pfs-nested-y))
 $(addprefix 9pfs/, $(9pfs-nested-y)): QEMU_CFLAGS+=$(GLIB_CFLAGS)

hw/9pfs/codir.c

@@ -0,0 +1,66 @@
+
+/*
+ * Virtio 9p backend
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "fsdev/qemu-fsdev.h"
+#include "qemu-thread.h"
+#include "qemu-coroutine.h"
+#include "virtio-9p-coth.h"
+
+int v9fs_co_readdir(V9fsState *s, V9fsFidState *fidp, struct dirent **dent)
+{
+    int err;
+
+    v9fs_co_run_in_worker(
+        {
+            errno = 0;
+            /*FIXME!! need to switch to readdir_r */
+            *dent = s->ops->readdir(&s->ctx, fidp->fs.dir);
+            if (!*dent && errno) {
+                err = -errno;
+            } else {
+                err = 0;
+            }
+        });
+    return err;
+}
+
+off_t v9fs_co_telldir(V9fsState *s, V9fsFidState *fidp)
+{
+    off_t err;
+
+    v9fs_co_run_in_worker(
+        {
+            err = s->ops->telldir(&s->ctx, fidp->fs.dir);
+            if (err < 0) {
+                err = -errno;
+            }
+        });
+    return err;
+}
+
+void v9fs_co_seekdir(V9fsState *s, V9fsFidState *fidp, off_t offset)
+{
+    v9fs_co_run_in_worker(
+        {
+            s->ops->seekdir(&s->ctx, fidp->fs.dir, offset);
+        });
+}
+
+void v9fs_co_rewinddir(V9fsState *s, V9fsFidState *fidp)
+{
+    v9fs_co_run_in_worker(
+        {
+            s->ops->rewinddir(&s->ctx, fidp->fs.dir);
+        });
+}

hw/9pfs/virtio-9p-coth.h

@@ -57,4 +57,9 @@ typedef struct V9fsThPool {
 extern void co_run_in_worker_bh(void *);
 extern int v9fs_init_worker_threads(void);
 extern int v9fs_co_readlink(V9fsState *, V9fsString *, V9fsString *);
+extern int v9fs_co_readdir(V9fsState *, V9fsFidState *,
+                           struct dirent **);
+extern off_t v9fs_co_telldir(V9fsState *, V9fsFidState *);
+extern void v9fs_co_seekdir(V9fsState *, V9fsFidState *, off_t);
+extern void v9fs_co_rewinddir(V9fsState *, V9fsFidState *);
 #endif