[Qemu-devel] [PATCH 45/46] qed: honor BDRV_O_INCOMING for incoming live migration

[Kevin Wolf <kwolf@redhat.com>]

From: Benoît Canet <benoit.canet@gmail.com>

>From original commit with Patchwork-id: 31108 by
Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

"The QED image format includes a file header bit to mark images dirty.
QED normally checks dirty images on open and fixes inconsistent
metadata.  This is undesirable during live migration since the dirty bit
may be set if the source host is modifying the image file.  The check
should be postponed until migration completes.

Skip operations that modify the image file if the BDRV_O_INCOMING flag
is set."

Signed-off-by: Benoit Canet <benoit.canet@gmail.com>
Reviewed-by: Stefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qed.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/block/qed.c b/block/qed.c
index a5e9d57..aea2772 100644
--- a/block/qed.c
+++ b/block/qed.c
@@ -450,7 +450,7 @@ static int bdrv_qed_open(BlockDriverState *bs, int flags)
      * feature is no longer valid.
      */
     if ((s->header.autoclear_features & ~QED_AUTOCLEAR_FEATURE_MASK) != 0 &&
-        !bdrv_is_read_only(bs->file)) {
+        !bdrv_is_read_only(bs->file) && !(flags & BDRV_O_INCOMING)) {
         s->header.autoclear_features &= QED_AUTOCLEAR_FEATURE_MASK;
 
         ret = qed_write_header_sync(s);
@@ -477,7 +477,8 @@ static int bdrv_qed_open(BlockDriverState *bs, int flags)
          * potentially inconsistent images to be opened read-only.  This can
          * aid data recovery from an otherwise inconsistent image.
          */
-        if (!bdrv_is_read_only(bs->file)) {
+        if (!bdrv_is_read_only(bs->file) &&
+            !(flags & BDRV_O_INCOMING)) {
             BdrvCheckResult result = {0};
 
             ret = qed_check(s, &result, true);
-- 
1.7.6.5