Add bdrv_flush_all()

This patch adds a bdrv_flush_all() function.  It's necessary to ensure that all
IO operations have been flushed to disk before completely a live migration.

N.B. we don't actually use this now.  We really should flush the block drivers
using an live savevm callback to avoid unnecessary guest down time.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5432 c046a42c-6fe2-441c-8c8c-71466251a162

block.c

@@ -895,6 +895,16 @@ void bdrv_flush(BlockDriverState *bs)
         bdrv_flush(bs->backing_hd);
 }
 
+void bdrv_flush_all(void)
+{
+    BlockDriverState *bs;
+
+    for (bs = bdrv_first; bs != NULL; bs = bs->next)
+        if (bs->drv && !bdrv_is_read_only(bs) && 
+            (!bdrv_is_removable(bs) || bdrv_is_inserted(bs)))
+            bdrv_flush(bs);
+}
+
 /*
  * Returns true iff the specified sector is present in the disk image. Drivers
  * not implementing the functionality are assumed to not support backing files,

block.h

@@ -93,6 +93,8 @@ int qemu_key_check(BlockDriverState *bs, const char *name);
 
 /* Ensure contents are flushed to disk.  */
 void bdrv_flush(BlockDriverState *bs);
+void bdrv_flush_all(void);
+
 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
 	int *pnum);