On 10/17/18 11:41 AM, Kevin Wolf wrote:
Some block drivers have traditionally changed their node to read-only
mode without asking the user. This behaviour has been marked deprecated
since 2.11, expecting users to provide an explicit read-only=on option.
Now that we have auto-read-only=on, enable these drivers to make use of
the option.
This is the only use of bdrv_set_read_only(), so we can make it a bit
more specific and turn it into a bdrv_apply_auto_read_only() that is
more convenient for drivers to use.
Signed-off-by: Kevin Wolf <kw...@redhat.com>
---
+/*
+ * Called by a driver that can only provide a read-only image.
+ *
+ * Returns 0 if the node is already read-only or it could switch the node to
+ * read-only because BDRV_O_AUTO_RDONLY is set.
+ *
+ * Returns -EACCES if the node is read-write and BDRV_O_AUTO_RDONLY is not set
+ * or bdrv_can_set_read_only() forbids making the node read-only. If @errmsg
+ * is not NULL, it is used as the error message for the Error object.
Works for me.
+++ b/block/rbd.c
@@ -780,16 +780,10 @@ static int qemu_rbd_open(BlockDriverState *bs, QDict
*options, int flags,
/* If we are using an rbd snapshot, we must be r/o, otherwise
* leave as-is */
if (s->snap != NULL) {
- if (!bdrv_is_read_only(bs)) {
- error_report("Opening rbd snapshots without an explicit "
- "read-only=on option is deprecated. Future versions "
- "will refuse to open the image instead of "
- "automatically marking the image read-only.");
- r = bdrv_set_read_only(bs, true, &local_err);
- if (r < 0) {
- error_propagate(errp, local_err);
- goto failed_open;
- }
+ r = bdrv_apply_auto_read_only(bs, "rbd snapshots are read-only", errp);
+ if (r < 0) {
+ rbd_close(s->image);
+ goto failed_open;
That rbd_close() is an independent bugfix. Should probably be split to
a separate commit, or at a minimum called out in the commit message as
intentional.
Actually, is it really needed to prevent a leak, or does the existing
rados_shutdown() in failed_open already implicitly cover the actions of
rbd_close()?
With the RBD issue touched up,
Reviewed-by: Eric Blake <ebl...@redhat.com>
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3266
Virtualization: qemu.org | libvirt.org
