From: Paolo Bonzini <pbonzini@redhat.com>
Date: Thu, 9 Aug 2012 14:07:21 +0000 (+0200)
Subject: blockdev: flip default cache mode from writethrough to writeback
X-Git-Tag: v1.2.0-rc0~35^2~4
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1f212b9d3edd8679bafd3bcf0301795206438724;p=thirdparty%2Fqemu.git

blockdev: flip default cache mode from writethrough to writeback

Now all major device models (IDE, SCSI, virtio) can choose between
writethrough and writeback at run-time, and virtio will even revert
to writethrough if the guest is not capable of sending flushes.  So
we can change the default to writeback at last.

Tested, for lack of a better idea, with a breakpoint on bdrv_open
and all cache choices one by one.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---

diff --git a/blockdev.c b/blockdev.c
index 8669142704b..7c83baa353c 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -377,6 +377,7 @@ DriveInfo *drive_init(QemuOpts *opts, int default_to_scsi)
 	}
     }
 
+    bdrv_flags |= BDRV_O_CACHE_WB;
     if ((buf = qemu_opt_get(opts, "cache")) != NULL) {
         if (bdrv_parse_cache_flags(buf, &bdrv_flags) != 0) {
             error_report("invalid cache option");