From 49594973fb38283e8c469892fe5eac2942d9bd25 Mon Sep 17 00:00:00 2001
From: "Venkateswararao Jujjuri (JV)" <jvrao@linux.vnet.ibm.com>
Date: Fri, 22 Oct 2010 10:08:45 -0700
Subject: [PATCH] [virtio-9p] Add datasync to server side TFSYNC/RFSYNC for
 dotl

SYNOPSIS
    size[4] Tfsync tag[2] fid[4] datasync[4]

    size[4] Rfsync tag[2]

DESCRIPTION

    The Tfsync transaction transfers ("flushes") all modified in-core data of
    file identified by fid to the disk device (or other  permanent  storage
    device)  where that  file  resides.

    If datasync flag is specified data will be fleshed but does not flush
    modified metadata unless  that  metadata  is  needed  in order to allow a
    subsequent data retrieval to be correctly handled.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
---
 hw/file-op-9p.h      |  2 +-
 hw/virtio-9p-local.c |  8 ++++++--
 hw/virtio-9p.c       | 11 ++++++-----
 3 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/hw/file-op-9p.h b/hw/file-op-9p.h
index 21d60b5855..c7731c2993 100644
--- a/hw/file-op-9p.h
+++ b/hw/file-op-9p.h
@@ -86,7 +86,7 @@ typedef struct FileOperations
     int (*fstat)(FsContext *, int, struct stat *);
     int (*rename)(FsContext *, const char *, const char *);
     int (*truncate)(FsContext *, const char *, off_t);
-    int (*fsync)(FsContext *, int);
+    int (*fsync)(FsContext *, int, int);
     int (*statfs)(FsContext *s, const char *path, struct statfs *stbuf);
     ssize_t (*lgetxattr)(FsContext *, const char *,
                          const char *, void *, size_t);
diff --git a/hw/virtio-9p-local.c b/hw/virtio-9p-local.c
index 0d520201b4..656bfb375b 100644
--- a/hw/virtio-9p-local.c
+++ b/hw/virtio-9p-local.c
@@ -490,9 +490,13 @@ static int local_remove(FsContext *ctx, const char *path)
     return remove(rpath(ctx, path));
 }
 
-static int local_fsync(FsContext *ctx, int fd)
+static int local_fsync(FsContext *ctx, int fd, int datasync)
 {
-    return fsync(fd);
+    if (datasync) {
+        return qemu_fdatasync(fd);
+    } else {
+        return fsync(fd);
+    }
 }
 
 static int local_statfs(FsContext *s, const char *path, struct statfs *stbuf)
diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c
index daade77ed9..7c59988a51 100644
--- a/hw/virtio-9p.c
+++ b/hw/virtio-9p.c
@@ -248,9 +248,9 @@ static int v9fs_do_remove(V9fsState *s, V9fsString *path)
     return s->ops->remove(&s->ctx, path->data);
 }
 
-static int v9fs_do_fsync(V9fsState *s, int fd)
+static int v9fs_do_fsync(V9fsState *s, int fd, int datasync)
 {
-    return s->ops->fsync(&s->ctx, fd);
+    return s->ops->fsync(&s->ctx, fd, datasync);
 }
 
 static int v9fs_do_statfs(V9fsState *s, V9fsString *path, struct statfs *stbuf)
@@ -1868,16 +1868,17 @@ static void v9fs_fsync(V9fsState *s, V9fsPDU *pdu)
     int32_t fid;
     size_t offset = 7;
     V9fsFidState *fidp;
+    int datasync;
     int err;
 
-    pdu_unmarshal(pdu, offset, "d", &fid);
+    pdu_unmarshal(pdu, offset, "dd", &fid, &datasync);
     fidp = lookup_fid(s, fid);
     if (fidp == NULL) {
         err = -ENOENT;
         v9fs_post_do_fsync(s, pdu, err);
         return;
     }
-    err = v9fs_do_fsync(s, fidp->fs.fd);
+    err = v9fs_do_fsync(s, fidp->fs.fd, datasync);
     v9fs_post_do_fsync(s, pdu, err);
 }
 
@@ -3001,7 +3002,7 @@ static void v9fs_wstat(V9fsState *s, V9fsPDU *pdu)
 
     /* do we need to sync the file? */
     if (donttouch_stat(&vs->v9stat)) {
-        err = v9fs_do_fsync(s, vs->fidp->fs.fd);
+        err = v9fs_do_fsync(s, vs->fidp->fs.fd, 0);
         v9fs_wstat_post_fsync(s, vs, err);
         return;
     }