On Tue, Jul 25, 2023 at 12:15:40PM +0100, Daniel P. Berrangé wrote:
On Tue, Jul 25, 2023 at 01:11:55PM +0200, Stefano Garzarella wrote:
qemu_open() in blkio_virtio_blk_common_open() is used to open the
character device (e.g. /dev/vhost-vdpa-0 or /dev/vfio/vfio) or in
the future eventually the unix socket.
In all these cases we cannot open the path in read-only mode,
when the `read-only` option of blockdev is on, because the exchange
of IOCTL commands for example will fail.
In order to open the device read-only, we have to use the `read-only`
property of the libblkio driver as we already do in blkio_file_open().
Fixes: cad2ccc395 ("block/blkio: use qemu_open() to support fd passing for
virtio-blk")
Reported-by: Qing Wang <qinw...@redhat.com>
Signed-off-by: Stefano Garzarella <sgarz...@redhat.com>
---
block/blkio.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)
diff --git a/block/blkio.c b/block/blkio.c
index 1798648134..fe9bf8ea5f 100644
--- a/block/blkio.c
+++ b/block/blkio.c
@@ -686,15 +686,7 @@ static int blkio_virtio_blk_common_open(BlockDriverState
*bs,
* layer through the "/dev/fdset/N" special path.
*/
if (fd_supported) {
- int open_flags;
-
- if (flags & BDRV_O_RDWR) {
- open_flags = O_RDWR;
- } else {
- open_flags = O_RDONLY;
- }
-
- fd = qemu_open(path, open_flags, errp);
I'd suggest taking the paragraph from the commit message explaining why
it is correct to hardcode O_RDWR and putting it into a comment here.
Ack, I'd also add:
Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=2225439
in the commit message.
I'll fix in v2.
Thanks,
Stefano
+ fd = qemu_open(path, O_RDWR, errp);
if (fd < 0) {
return -EINVAL;
}
--
2.41.0
With regards,
Daniel
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