Previously, we can't map same device name from different sessions
due to the limitation of sysfs naming mechanism.
root@clt2:~# ls -l /sys/class/rnbd-client/ctl/devices/
total 0
lrwxrwxrwx 1 root 0 Sep 2 16:31 !dev!nullb1 -> ../../../block/rnbd0
We only use the device name in above, which caused device with
the same name can't be mapped from another server. To address
the issue, the sessname is appended to the node to differentiate
where the device comes from.
Also, we need to check if the pathname is existed in a specific
session instead of search it in global sess_list.
Signed-off-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Gioh Kim <gi-oh.kim@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Reviewed-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
During map_device if the given session exists, then the path parameter is
not used. In such a case, the path parameter is redundant.
This commit makes the path parameter optional for map_device. When the
path parameter is not given, if the session exists then that is used to
establish the rtrs connection.
If the session does not exist, and the path parameter is also missing,
then map_device fails.
Signed-off-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
module_is_live function is only defined when CONFIG_MODULES is enabled.
Use try_module_get instead to check whether the module is being removed.
When module unload and manuall unmapping is happening in parallel, we can
try removing the symlink twice: rnbd_client_exit
vs. rnbd_clt_unmap_dev_store.
This is probably not the best way to deal with this race in general, but
for now this fixes the compilation issue when CONFIG_MODULES is disabled
and has no functional impact. Regression tests passed.
Fixes: 1eb54f8f5d ("block/rnbd: client: sysfs interface functions")
Link: https://lore.kernel.org/r/20200521185909.457245-1-danil.kipnis@cloud.ionos.com
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Suggested-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
This is the sysfs interface to rnbd block devices on client side:
/sys/class/rnbd-client/ctl/
|- map_device
| *** maps remote device
|
|- devices/
*** all mapped devices
/sys/block/rnbd<N>/rnbd/
|- unmap_device
| *** unmaps device
|
|- state
| *** device state
|
|- session
| *** session name
|
|- mapping_path
*** path of the dev that was mapped on server
Link: https://lore.kernel.org/r/20200511135131.27580-19-danil.kipnis@cloud.ionos.com
Signed-off-by: Danil Kipnis <danil.kipnis@cloud.ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Guoqing Jiang