On 4/22/21 7:02 PM, Kevin Wolf wrote: > This is a partial revert of commits 77542d43149 and bc79c87bcde. > > Usually, an error during initialisation means that the configuration was > wrong. Reconnecting won't make the error go away, but just turn the > error condition into an endless loop. Avoid this and return errors > again. > > Additionally, calling vhost_user_blk_disconnect() from the chardev event > handler could result in use-after-free because none of the > initialisation code expects that the device could just go away in the
TIL initialisation wording. > middle. So removing the call fixes crashes in several places. > > For example, using a num-queues setting that is incompatible with the > backend would result in a crash like this (dereferencing dev->opaque, > which is already NULL): > > #0 0x0000555555d0a4bd in vhost_user_read_cb (source=0x5555568f4690, > condition=(G_IO_IN | G_IO_HUP), opaque=0x7fffffffcbf0) at > ../hw/virtio/vhost-user.c:313 > #1 0x0000555555d950d3 in qio_channel_fd_source_dispatch > (source=0x555557c3f750, callback=0x555555d0a478 <vhost_user_read_cb>, > user_data=0x7fffffffcbf0) at ../io/channel-watch.c:84 > #2 0x00007ffff7b32a9f in g_main_context_dispatch () at > /lib64/libglib-2.0.so.0 > #3 0x00007ffff7b84a98 in g_main_context_iterate.constprop () at > /lib64/libglib-2.0.so.0 > #4 0x00007ffff7b32163 in g_main_loop_run () at /lib64/libglib-2.0.so.0 > #5 0x0000555555d0a724 in vhost_user_read (dev=0x555557bc62f8, > msg=0x7fffffffcc50) at ../hw/virtio/vhost-user.c:402 > #6 0x0000555555d0ee6b in vhost_user_get_config (dev=0x555557bc62f8, > config=0x555557bc62ac "", config_len=60) at ../hw/virtio/vhost-user.c:2133 > #7 0x0000555555d56d46 in vhost_dev_get_config (hdev=0x555557bc62f8, > config=0x555557bc62ac "", config_len=60) at ../hw/virtio/vhost.c:1566 > #8 0x0000555555cdd150 in vhost_user_blk_device_realize (dev=0x555557bc60b0, > errp=0x7fffffffcf90) at ../hw/block/vhost-user-blk.c:510 > #9 0x0000555555d08f6d in virtio_device_realize (dev=0x555557bc60b0, > errp=0x7fffffffcff0) at ../hw/virtio/virtio.c:3660 > > Signed-off-by: Kevin Wolf <kw...@redhat.com> > --- > hw/block/vhost-user-blk.c | 54 ++++++++++----------------------------- > 1 file changed, 13 insertions(+), 41 deletions(-)
