[Qemu-devel] [PATCH -V4 06/26] [virtio-9p] coroutines for readlink

[Aneesh Kumar K.V]

From: Venkateswararao Jujjuri (JV) <address@hidden>

Signed-off-by: Venkateswararao Jujjuri "<address@hidden>
Signed-off-by: Aneesh Kumar K.V <address@hidden>
---
 Makefile.objs            |    2 +-
 hw/9pfs/cofs.c           |   44 ++++++++++++++++++++++++++++++++++++++++++++
 hw/9pfs/virtio-9p-coth.h |    1 +
 hw/9pfs/virtio-9p.c      |   27 ++++-----------------------
 hw/9pfs/virtio-9p.h      |    1 -
 5 files changed, 50 insertions(+), 25 deletions(-)
 create mode 100644 hw/9pfs/cofs.c

diff --git a/Makefile.objs b/Makefile.objs
index 9bede68..a534c1c 100644
--- a/Makefile.objs
+++ b/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-$(CONFIG_VIRTFS) += virtio-9p-coth.o
+9pfs-nested-$(CONFIG_VIRTFS) += virtio-9p-coth.o cofs.o
 
 hw-obj-$(CONFIG_REALLY_VIRTFS) += $(addprefix 9pfs/, $(9pfs-nested-y))
 $(addprefix 9pfs/, $(9pfs-nested-y)): QEMU_CFLAGS+=$(GLIB_CFLAGS)
diff --git a/hw/9pfs/cofs.c b/hw/9pfs/cofs.c
new file mode 100644
index 0000000..6bb8b47
--- /dev/null
+++ b/hw/9pfs/cofs.c
@@ -0,0 +1,44 @@
+
+/*
+ * Virtio 9p backend
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Aneesh Kumar K.V <address@hidden>
+ *
+ * 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_readlink(V9fsState *s, V9fsString *path, V9fsString *buf)
+{
+    int err;
+    ssize_t len;
+
+    buf->data = qemu_malloc(PATH_MAX);
+    v9fs_co_run_in_worker(
+        {
+            len = s->ops->readlink(&s->ctx, path->data,
+                                   buf->data, PATH_MAX - 1);
+            if (len > -1) {
+                buf->size = len;
+                buf->data[len] = 0;
+                err = 0;
+            } else {
+                err = -errno;
+            }
+        });
+    if (err) {
+        qemu_free(buf->data);
+        buf->data = NULL;
+        buf->size = 0;
+    }
+    return err;
+}
diff --git a/hw/9pfs/virtio-9p-coth.h b/hw/9pfs/virtio-9p-coth.h
index 9388f9b..94c5147 100644
--- a/hw/9pfs/virtio-9p-coth.h
+++ b/hw/9pfs/virtio-9p-coth.h
@@ -56,4 +56,5 @@ 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 *);
 #endif
diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c
index 63217e9..a68ac3f 100644
--- a/hw/9pfs/virtio-9p.c
+++ b/hw/9pfs/virtio-9p.c
@@ -82,21 +82,6 @@ static int v9fs_do_lstat(V9fsState *s, V9fsString *path, 
struct stat *stbuf)
     return s->ops->lstat(&s->ctx, path->data, stbuf);
 }
 
-static ssize_t v9fs_do_readlink(V9fsState *s, V9fsString *path, V9fsString 
*buf)
-{
-    ssize_t len;
-
-    buf->data = qemu_malloc(1024);
-
-    len = s->ops->readlink(&s->ctx, path->data, buf->data, 1024 - 1);
-    if (len > -1) {
-        buf->size = len;
-        buf->data[len] = 0;
-    }
-
-    return len;
-}
-
 static int v9fs_do_close(V9fsState *s, int fd)
 {
     return s->ops->close(&s->ctx, fd);
@@ -1054,13 +1039,10 @@ static int stat_to_v9stat(V9fsState *s, V9fsString 
*name,
     v9fs_string_null(&v9stat->extension);
 
     if (v9stat->mode & P9_STAT_MODE_SYMLINK) {
-        err = v9fs_do_readlink(s, name, &v9stat->extension);
-        if (err == -1) {
-            err = -errno;
+        err = v9fs_co_readlink(s, name, &v9stat->extension);
+        if (err < 0) {
             return err;
         }
-        v9stat->extension.data[err] = 0;
-        v9stat->extension.size = err;
     } else if (v9stat->mode & P9_STAT_MODE_DEVICE) {
         v9fs_string_sprintf(&v9stat->extension, "%c %u %u",
                 S_ISCHR(stbuf->st_mode) ? 'c' : 'b',
@@ -3599,15 +3581,14 @@ static void v9fs_readlink(void *opaque)
     }
 
     v9fs_string_init(&target);
-    err = v9fs_do_readlink(pdu->s, &fidp->path, &target);
+    err = v9fs_co_readlink(pdu->s, &fidp->path, &target);
     if (err < 0) {
-        err = -errno;
         goto out;
     }
     offset += pdu_marshal(pdu, offset, "s", &target);
     err = offset;
-out:
     v9fs_string_free(&target);
+out:
     complete_pdu(pdu->s, pdu, err);
 }
 
diff --git a/hw/9pfs/virtio-9p.h b/hw/9pfs/virtio-9p.h
index e95b63d..8196da0 100644
--- a/hw/9pfs/virtio-9p.h
+++ b/hw/9pfs/virtio-9p.h
@@ -505,5 +505,4 @@ static inline size_t do_pdu_unpack(void *dst, struct iovec 
*sg, int sg_count,
 }
 
 extern void handle_9p_output(VirtIODevice *vdev, VirtQueue *vq);
-
 #endif
-- 
1.7.4.1