On 2017-06-02 13:21, Vladimir Sementsov-Ogievskiy wrote:
Add format driver handler, which should mark loaded read-only
bitmaps as 'IN_USE' in the image and unset read_only field in
corresponding BdrvDirtyBitmap's.
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
block.c | 17 +++++++++++++++++
include/block/block_int.h | 7 +++++++
2 files changed, 24 insertions(+)
diff --git a/block.c b/block.c
index 04af7697dc..161db9e32a 100644
--- a/block.c
+++ b/block.c
@@ -2946,12 +2946,16 @@ void bdrv_reopen_commit(BDRVReopenState
*reopen_state)
{
BlockDriver *drv;
BlockDriverState *bs;
+ bool old_can_write, new_can_write;
assert(reopen_state != NULL);
bs = reopen_state->bs;
drv = bs->drv;
assert(drv != NULL);
+ old_can_write =
+ !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) &
BDRV_O_INACTIVE);
+
/* If there are any driver level actions to take */
if (drv->bdrv_reopen_commit) {
drv->bdrv_reopen_commit(reopen_state);
@@ -2965,6 +2969,19 @@ void bdrv_reopen_commit(BDRVReopenState
*reopen_state)
bs->read_only = !(reopen_state->flags & BDRV_O_RDWR);
bdrv_refresh_limits(bs, NULL);
+
+ new_can_write =
+ !bdrv_is_read_only(bs) && !(bdrv_get_flags(bs) &
BDRV_O_INACTIVE);
+ if (!old_can_write && new_can_write &&
drv->bdrv_reopen_bitmaps_rw) {
+ Error *local_err = NULL;
+ if (drv->bdrv_reopen_bitmaps_rw(bs, &local_err) < 0) {
+ /* This is not fatal, bitmaps just left read-only, so
all following
+ * writes will fail. User can remove read-only bitmaps
to unblock
+ * writes.
+ */
In a sense, it pretty much is fatal. We were asked to make the image
non-read-only but we failed because it effectively still is read-only.
But I can't think of anything better, and you're right, removing the
bitmaps would resolve the situation. This would require the user to know
that updating the bitmaps was the issue, and local_err may not actually
reflect that.
+ error_report_err(local_err);
So I'd prepend this with something like "$node_name: Failed to make
dirty bitmaps writable", and maybe append a hint like "Removing all
persistent dirty bitmaps from this node will allow writing to it".