block/rnbd-srv: don't free the device on a sysfs error

rnbd_srv_create_dev_sysfs() drops the only kobject reference on its
error paths, and the release function frees the rnbd_srv_dev.
process_msg_open() keeps using it and ends in destroy_device() with a
list_del() and a second kfree(). This doesn't need memory pressure: a
client opening a device while its last mapping goes away gets -EEXIST
from kobject_add() against the old directory.

Only undo kobject_add() on failure and leave the reference to
destroy_device(). Initialise the kobject once, the next open retries.

Fixes: 8cee532f469b ("block/rnbd: server: sysfs interface functions")
Fixes: d3a95ccaaf4d ("block/rnbd: call kobject_put in the failure path")
Cc: "Md. Haris Iqbal" <haris.iqbal@ionos.com>
Cc: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Link: https://patch.msgid.link/20261028164415.1262013-17-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>

0 files changed, 0 insertions, 0 deletions