Spdk/lib/bdev/raid
Shuhei Matsumoto 284aca9e36 bdev/raid: Fix race issue among multiple threads to free RAID bdev
The following issue was observed.

The first thread returned the last IO channel and the second thread
then removed the first base device, but raid_bdev_cleanup() was
called before raid_bdev_destroy_cb() was called.

raid_bdev_destroy_cb() was accessed to the raid bdev already freed
by raid_bdev_cleanup() and caused segmentation fault.

The call sequence was as follows:

The first thread:
 spdk_put_io_channel() -> ch->destroy_cb -> raid_bdev_destroy_cb
-> access raid bdev

The second thread:
 raid_bdev_remove_base_devices() -> raid_bdev_deconfigure() ->
spdk_bdev_unregister() -> spdk_io_device_unregister() ->
spdk_bdev_destroy_cb() -> raid_bdev_destruct() -> raid_bdev_cleanup()
-> free raid bdev

The fix is to hold number of created channels in struct
raid_bdev_io_channel and use it in raid_bdev_destroy_cb().

Bdev layer, IO device/channel layer, and NVMe-oF layer  already
process this case correctly.

    Fixes #884.

Reported-by: yidong0635 <dongx.yi@intel.com>

Change-Id: Ie9d61bdddca479ce7f491ff9a08db45e71f16a8d
Signed-off-by: yidong0635 <dongx.yi@intel.com>
Signed-off-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/463249
Reviewed-by: Broadcom SPDK FC-NVMe CI <spdk-ci.pdl@broadcom.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Seth Howell <seth.howell@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
2019-08-12 04:20:15 +00:00
..
bdev_raid_rpc.c bdev/raid/rpc: try to break lines after 100 characters 2019-08-05 23:12:49 +00:00
bdev_raid.c bdev/raid: Fix race issue among multiple threads to free RAID bdev 2019-08-12 04:20:15 +00:00
bdev_raid.h bdev/raid: Fix race issue among multiple threads to free RAID bdev 2019-08-12 04:20:15 +00:00
Makefile bdev: remove "v" prefix from vbdev library names 2018-11-01 21:25:55 +00:00