Index: qemu/block/raw-posix.c
===================================================================
--- qemu.orig/block/raw-posix.c
+++ qemu/block/raw-posix.c
@@ -276,6 +276,39 @@ static int raw_open(BlockDriverState *bs
      return raw_open_common(bs, filename, flags, 0);
  }

+static int raw_reopen(BlockDriverState *bs, int flags)
+{
+    BDRVRawState *s = bs->opaque;
+    int new_fd;
+    int ret = 0;
+
+    /* Handle request for toggling O_DIRECT */
+    if ((bs->open_flags | BDRV_O_NOCACHE) ^
+        (flags | BDRV_O_NOCACHE))
+    {
+        if ((new_fd = dup(s->fd)) <=  0) {
+            return -1;
+        }
+
+        if ((ret = fcntl_setfl(new_fd, flags)) < 0) {
+            close(new_fd);
+            return ret;
+        }
+
+        /* Set new flags, so replace old fd with new one */
+        close(s->fd);
+        s->fd = new_fd;
+        s->open_flags = flags;
+        bs->open_flags = flags;
+    }
+
+    /*
+     * TBD: handle O_DSYNC and other flags for which image
+     * file has to be reopened
+     */
+    return 0;
+}
+
  /* XXX: use host sector size if necessary with:
  #ifdef DIOCGSECTORSIZE
          {
@@ -886,6 +919,7 @@ static BlockDriver bdrv_file = {
      .instance_size = sizeof(BDRVRawState),
      .bdrv_probe = NULL, /* no probe for protocols */
      .bdrv_file_open = raw_open,
+    .bdrv_reopen = raw_reopen,
      .bdrv_read = raw_read,
      .bdrv_write = raw_write,
      .bdrv_close = raw_close,
Index: qemu/block.c
===================================================================
--- qemu.orig/block.c
+++ qemu/block.c
@@ -687,20 +687,33 @@ int bdrv_reopen(BlockDriverState *bs, in
          qerror_report(QERR_DATA_SYNC_FAILED, bs->device_name);
          return ret;
      }
-    open_flags = bs->open_flags;
-    bdrv_close(bs);

-    ret = bdrv_open(bs, bs->filename, bdrv_flags, drv);
-    if (ret < 0) {
-        /* Reopen failed. Try to open with original flags */
-        qerror_report(QERR_REOPEN_FILE_FAILED, bs->filename);
-        ret = bdrv_open(bs, bs->filename, open_flags, drv);
+    /* Use driver specific reopen() if available */
+    if (drv->bdrv_reopen) {
+        if ((ret = drv->bdrv_reopen(bs, bdrv_flags)) < 0) {
+            qerror_report(QERR_REOPEN_FILE_FAILED, bs->filename);
+            return ret;
+        }
+    } else {
+        /* Use reopen procedure common for drivers */
+        open_flags = bs->open_flags;
+        bdrv_close(bs);
+
+        ret = bdrv_open(bs, bs->filename, bdrv_flags, drv);
          if (ret < 0) {
-            /* Reopen failed with orig and modified flags */
-            abort();
+            /*
+             * Reopen failed. Try to open with original flags
+            */
+            qerror_report(QERR_REOPEN_FILE_FAILED, bs->filename);
+            ret = bdrv_open(bs, bs->filename, open_flags, drv);
+            if (ret < 0) {
+                /*
+                 * Reopen with orig and modified flags failed
+                 */
+                abort();
+            }
          }
      }
-
      return ret;
  }

Index: qemu/block_int.h
===================================================================
--- qemu.orig/block_int.h
+++ qemu/block_int.h
@@ -54,6 +54,7 @@ struct BlockDriver {
      int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char 
*filename);
      int (*bdrv_probe_device)(const char *filename);
      int (*bdrv_open)(BlockDriverState *bs, int flags);
+    int (*bdrv_reopen)(BlockDriverState *bs, int flags);
      int (*bdrv_file_open)(BlockDriverState *bs, const char *filename, 
int flags);