block: Improve driver whitelist checks

The main intent of this patch is to consolidate the whitelist checks to
a single point in the code instead of spreading it everywhere. This adds
a nicer error message for read-only whitelisting, too, in places where
it was still missing.

The patch also contains a bonus bug fix: By finding the format first in
bdrv_open() and then independently checking against the whitelist only
later, we avoid the case that use of a non-whitelisted format results in
probing rather than an error message. Previously, this could happen when
using the driver=... option.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
This commit is contained in:
Kevin Wolf 2013-10-10 11:45:55 +02:00
parent 00c49b21e7
commit 8f94a6e40e
2 changed files with 9 additions and 9 deletions

10
block.c
View file

@ -769,7 +769,11 @@ static int bdrv_open_common(BlockDriverState *bs, BlockDriverState *file,
bs->read_only = !(open_flags & BDRV_O_RDWR);
if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) {
error_setg(errp, "Driver '%s' is not whitelisted", drv->format_name);
error_setg(errp,
!bs->read_only && bdrv_is_whitelisted(drv, true)
? "Driver '%s' can only be used for read-only devices"
: "Driver '%s' is not whitelisted",
drv->format_name);
return -ENOTSUP;
}
@ -881,7 +885,7 @@ int bdrv_file_open(BlockDriverState **pbs, const char *filename,
/* Find the right block driver */
drvname = qdict_get_try_str(options, "driver");
if (drvname) {
drv = bdrv_find_whitelisted_format(drvname, !(flags & BDRV_O_RDWR));
drv = bdrv_find_format(drvname);
if (!drv) {
error_setg(errp, "Unknown driver '%s'", drvname);
}
@ -1123,7 +1127,7 @@ int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
/* Find the right image format driver */
drvname = qdict_get_try_str(options, "driver");
if (drvname) {
drv = bdrv_find_whitelisted_format(drvname, !(flags & BDRV_O_RDWR));
drv = bdrv_find_format(drvname);
qdict_del(options, "driver");
}

View file

@ -468,13 +468,9 @@ static DriveInfo *blockdev_init(QemuOpts *all_opts,
return NULL;
}
drv = bdrv_find_whitelisted_format(buf, ro);
drv = bdrv_find_format(buf);
if (!drv) {
if (!ro && bdrv_find_whitelisted_format(buf, !ro)) {
error_report("'%s' can be only used as read-only device.", buf);
} else {
error_report("'%s' invalid format", buf);
}
error_report("'%s' invalid format", buf);
return NULL;
}
}