blockdev: Fix drive_add for drives without media
Watch this:
(qemu) drive_add 0 if=none
(qemu) info block
none0: type=hd removable=0 [not inserted]
(qemu) drive_del none0
Segmentation fault (core dumped)
add_init_drive() is confused about drive_init()'s failure modes, and
cleans up when it shouldn't. This leaves the DriveInfo with member
opts dangling. drive_del attempts to free it, and dies.
drive_init() behaves as follows:
* If it created a drive with media, it returns its DriveInfo.
* If it created a drive without media, it clears *fatal_error and
returns NULL.
* If it couldn't create a drive, it sets *fatal_error and returns
NULL.
Of its three callers:
* drive_init_func() is correct.
* usb_msd_init() assumes drive_init() failed when it returns NULL.
This is correct only because it always passes option "file", and
"drive without media" can't happen then.
* add_init_drive() assumes drive_init() failed when it returns NULL.
This is incorrect.
Clean up drive_init() to return NULL on failure and only on failure.
Drop its parameter fatal_error.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/vl.c b/vl.c
index f86724f..ce5708b 100644
--- a/vl.c
+++ b/vl.c
@@ -631,13 +631,8 @@
static int drive_init_func(QemuOpts *opts, void *opaque)
{
int *use_scsi = opaque;
- int fatal_error = 0;
- if (drive_init(opts, *use_scsi, &fatal_error) == NULL) {
- if (fatal_error)
- return 1;
- }
- return 0;
+ return drive_init(opts, *use_scsi) == NULL;
}
static int drive_enable_snapshot(QemuOpts *opts, void *opaque)
@@ -666,7 +661,7 @@
if (snapshot) {
drive_enable_snapshot(opts, NULL);
}
- if (drive_init_func(opts, &use_scsi)) {
+ if (!drive_init(opts, use_scsi)) {
exit(1);
}
}
