block: Allow changing 'discard' on reopen

'discard' is one of the basic BlockdevOptions available for all
drivers, but it's not handled by bdrv_reopen_prepare() so any attempt
to change it results in an error:

   (qemu) qemu-io virtio0 "reopen -o discard=on"
   Cannot change the option 'discard'

Since there's no reason why we shouldn't allow changing it and the
implementation is simple let's just do it.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Alberto Garcia 2018-09-06 12:37:08 +03:00 committed by Kevin Wolf
parent 8d3245750b
commit 593b307197

11
block.c
View File

@ -3156,6 +3156,7 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
BlockDriver *drv;
QemuOpts *opts;
QDict *orig_reopen_opts;
char *discard = NULL;
bool read_only;
assert(reopen_state != NULL);
@ -3178,6 +3179,15 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
update_flags_from_options(&reopen_state->flags, opts);
discard = qemu_opt_get_del(opts, "discard");
if (discard != NULL) {
if (bdrv_parse_discard_flags(discard, &reopen_state->flags) != 0) {
error_setg(errp, "Invalid discard option");
ret = -EINVAL;
goto error;
}
}
/* All other options (including node-name and driver) must be unchanged.
* Put them back into the QDict, so that they are checked at the end
* of this function. */
@ -3291,6 +3301,7 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue,
error:
qemu_opts_del(opts);
qobject_unref(orig_reopen_opts);
g_free(discard);
return ret;
}