diff mbox

[v4,2.1,3/4] virtio-blk: Treat read/write beyond end as invalid

Message ID 1404925652-17986-4-git-send-email-armbru@redhat.com
State New
Headers show

Commit Message

Markus Armbruster July 9, 2014, 5:07 p.m. UTC 
The block layer fails such reads and writes just fine.  However, they
then get treated like valid operations that fail: the error action
gets executed.  Unwanted; reporting the error to the guest is the only
sensible action.

Reject them before passing them to the block layer.  This bypasses the
error action and I/O accounting.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
---
 hw/block/virtio-blk.c | 7 +++++++
 1 file changed, 7 insertions(+)
diff mbox

Patch

diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index 53d6f92..8a2cff2 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -291,12 +291,19 @@  static void virtio_blk_handle_flush(VirtIOBlockReq *req, MultiReqBuffer *mrb)
 static bool virtio_blk_sect_range_ok(VirtIOBlock *dev,
                                      uint64_t sector, size_t size)
 {
+    uint64_t nb_sectors = size >> BDRV_SECTOR_BITS;
+    uint64_t total_sectors;
+
     if (sector & dev->sector_mask) {
         return false;
     }
     if (size % dev->conf->logical_block_size) {
         return false;
     }
+    bdrv_get_geometry(dev->bs, &total_sectors);
+    if (sector > total_sectors || nb_sectors > total_sectors - sector) {
+        return false;
+    }
     return true;
 }