nbd: Don't crash when server reports NBD_CMD_READ failure
commit08ace1d75372b57c5ab56aea02c71cdda4b58fdf
authorEric Blake <eblake@redhat.com>
Sun, 12 Nov 2017 01:39:36 +0000 (11 19:39 -0600)
committerEric Blake <eblake@redhat.com>
Fri, 17 Nov 2017 14:02:45 +0000 (17 08:02 -0600)
tree19d69a0088efc3bb85f0469798faeb25efc5331c
parentfec035a53fa15c4c8c4e62bfef56a35df4161e38
nbd: Don't crash when server reports NBD_CMD_READ failure

If a server fails a read, for example with EIO, but the connection
is still live, then we would crash trying to print a non-existent
error message in nbd_client_co_preadv().  For consistency, also
change the error printout in nbd_read_reply_entry(), although that
instance does not crash.  Bug introduced in commit f140e300.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20171112013936.5942-1-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
block/nbd-client.c