From: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Mon, 17 May 2010 16:46:04 +0000 (-0700)
Subject: block: Add SG_IO device check in refresh_total_sectors()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=396759ad4ad5289623eb7e1993c433ad4e7b13a1;p=qemu.git

block: Add SG_IO device check in refresh_total_sectors()

This patch adds a special case check for scsi-generic devices in
refresh_total_sectors() to skip the subsequent BlockDriver->bdrv_getlength()
that will be returning -ESPIPE from block/raw-posic.c:raw_getlength() for
BlockDriverState->sg=1 devices.

Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---

diff --git a/block.c b/block.c
index 6a95768e81..0b0966c571 100644
--- a/block.c
+++ b/block.c
@@ -361,6 +361,10 @@ static int refresh_total_sectors(BlockDriverState *bs, int64_t hint)
 {
     BlockDriver *drv = bs->drv;
 
+    /* Do not attempt drv->bdrv_getlength() on scsi-generic devices */
+    if (bs->sg)
+        return 0;
+
     /* query actual device if possible, otherwise just trust the hint */
     if (drv->bdrv_getlength) {
         int64_t length = drv->bdrv_getlength(bs);