[Qemu-devel] [PATCH -V3 09/32] virtio-9p: Implement P9_TWRITE

["Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>]

From: Anthony Liguori <aliguori@us.ibm.com>

This gets write to file to work

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
 hw/virtio-9p-local.c |    7 ++++
 hw/virtio-9p.c       |   97 ++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 102 insertions(+), 2 deletions(-)

diff --git a/hw/virtio-9p-local.c b/hw/virtio-9p-local.c
index d77ecc2..c5d1db3 100644
--- a/hw/virtio-9p-local.c
+++ b/hw/virtio-9p-local.c
@@ -129,6 +129,12 @@ static off_t local_lseek(void *opaque, int fd, off_t offset, int whence)
     return lseek(fd, offset, whence);
 }
 
+static ssize_t local_writev(void *opaque, int fd, const struct iovec *iov,
+			    int iovcnt)
+{
+    return writev(fd, iov, iovcnt);
+}
+
 static V9fsPosixFileOperations ops = {
     .lstat = local_lstat,
     .setuid = local_setuid,
@@ -143,6 +149,7 @@ static V9fsPosixFileOperations ops = {
     .seekdir = local_seekdir,
     .readv = local_readv,
     .lseek = local_lseek,
+    .writev = local_writev,
 };
 
 V9fsPosixFileOperations *virtio_9p_init_local(const char *path)
diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
index 3ac6255..bc26d66 100644
--- a/hw/virtio-9p.c
+++ b/hw/virtio-9p.c
@@ -168,6 +168,12 @@ static off_t posix_lseek(V9fsState *s, int fd, off_t offset, int whence)
     return s->ops->lseek(s->ops->opaque, fd, offset, whence);
 }
 
+static int posix_writev(V9fsState *s, int fd, const struct iovec *iov,
+                       int iovcnt)
+{
+    return s->ops->writev(s->ops->opaque, fd, iov, iovcnt);
+}
+
 static void v9fs_string_init(V9fsString *str)
 {
     str->data = NULL;
@@ -1319,10 +1325,97 @@ out:
     complete_pdu(s, pdu, err);
 }
 
+typedef struct V9fsWriteState {
+    V9fsPDU *pdu;
+    size_t offset;
+    int32_t fid;
+    int32_t len;
+    int32_t count;
+    int32_t total;
+    int64_t off;
+    V9fsFidState *fidp;
+    struct iovec iov[128]; /* FIXME: bad, bad, bad */
+    struct iovec *sg;
+    int cnt;
+} V9fsWriteState;
+
+static void v9fs_write_post_writev(V9fsState *s, V9fsWriteState *vs,
+                                   ssize_t err)
+{
+    BUG_ON(vs->len < 0);
+    vs->total += vs->len;
+    vs->sg = adjust_sg(vs->sg, vs->len, &vs->cnt);
+    if (vs->total < vs->count && vs->len > 0) {
+        do {
+            if (0)
+                print_sg(vs->sg, vs->cnt);
+            vs->len =  posix_writev(s, vs->fidp->fd, vs->sg, vs->cnt);
+        } while (vs->len == -1 && errno == EINTR);
+        v9fs_write_post_writev(s, vs, err);
+    }
+    vs->offset += pdu_marshal(vs->pdu, vs->offset, "d", vs->total);
+
+    err = vs->offset;
+    complete_pdu(s, vs->pdu, err);
+    qemu_free(vs);
+}
+
+static void v9fs_write_post_lseek(V9fsState *s, V9fsWriteState *vs, ssize_t err)
+{
+    BUG_ON(err == -1);
+
+    vs->sg = cap_sg(vs->sg, vs->count, &vs->cnt);
+
+    if (vs->total < vs->count) {
+        do {
+            if (0)
+                print_sg(vs->sg, vs->cnt);
+            vs->len = posix_writev(s, vs->fidp->fd, vs->sg, vs->cnt);
+        } while (vs->len == -1 && errno == EINTR);
+
+        v9fs_write_post_writev(s, vs, err);
+        return;
+    }
+
+    complete_pdu(s, vs->pdu, err);
+    qemu_free(vs);
+}
+
 static void v9fs_write(V9fsState *s, V9fsPDU *pdu)
 {
-    if (debug_9p_pdu)
-        pprint_pdu(pdu);
+    V9fsWriteState *vs;
+    ssize_t err;
+
+    vs = qemu_malloc(sizeof(*vs));
+
+    vs->pdu = pdu;
+    vs->offset = 7;
+    vs->sg = vs->iov;
+    vs->total = 0;
+    vs->len = 0;
+
+    pdu_unmarshal(vs->pdu, vs->offset, "dqdv", &vs->fid, &vs->off, &vs->count,
+                    vs->sg, &vs->cnt);
+
+    vs->fidp = lookup_fid(s, vs->fid);
+    if (vs->fidp == NULL) {
+        err = -EINVAL;
+        goto out;
+    }
+
+    if (vs->fidp->fd == -1) {
+        err = -EINVAL;
+        goto out;
+    }
+
+    err = posix_lseek(s, vs->fidp->fd, vs->off, SEEK_SET);
+
+    v9fs_write_post_lseek(s, vs, err);
+    return;
+
+out:
+    complete_pdu(s, vs->pdu, err);
+    qemu_free(vs);
 }
 
 static void v9fs_create(V9fsState *s, V9fsPDU *pdu)
-- 
1.7.0.2.323.g0d092