commit df2a6f29a5019707d69f6eeb30cf792841cae5aa
author Paolo Bonzini <pbonzini@redhat.com> Wed Sep 04 19:00:21 2013 +0200
committer Stefan Hajnoczi <stefanha@redhat.com> Fri Sep 06 15:25:08 2013 +0200
tree 196a71f34402aae6cfded4d54d65df548b24483a
parent e641c1e81e54fc14908ff6785ef7d51e42c2e1bb

block: keep bs->total_sectors up to date even for growable block devices

If a BlockDriverState is growable, after every write we need to
check if bs->total_sectors might have changed.  With this change,
bdrv_getlength does not need anymore a system call.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

block.c

diff --git a/block.c b/block.c
index 905bf34..d9a3a7f 100644
--- a/block.c
+++ b/block.c
@@ -2739,6 +2739,9 @@
     if (bs->wr_highest_sector < sector_num + nb_sectors - 1) {
         bs->wr_highest_sector = sector_num + nb_sectors - 1;
     }
+    if (bs->growable && ret >= 0) {
+        bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors);
+    }
 
     tracked_request_end(&req);
 
@@ -2813,7 +2816,7 @@
     if (!drv)
         return -ENOMEDIUM;
 
-    if (bs->growable || bdrv_dev_has_removable_media(bs)) {
+    if (bdrv_dev_has_removable_media(bs)) {
         if (drv->bdrv_getlength) {
             return drv->bdrv_getlength(bs);
         }