[PATCH V2 0/3] blk-mq: allow to run queue if queue refcount is held

Ming Lei
2019-04-01T04:42:59Z

Hi,

Since 45a9c9d909b2 ("blk-mq: Fix a use-after-free"), run queue isn't
allowed during cleanup queue even though queue refcount is held.

This change has caused lots of kernel oops triggered in run queue path,
turns out it isn't easy to fix them all.

So move freeing of hw queue resources into hctx's release handler, then
the above issue is fixed. Meantime, this way is safe given freeing hw
queue resource doesn't require tags.

V2:
- moving freeing hw queue resources into hctx's release handler

Ming Lei (3):
blk-mq: free hw queue's resource in hctx's release handler
block: don't drain in-progress dispatch in blk_cleanup_queue()
SCSI: don't grab queue usage counter before run queue

block/blk-core.c | 14 +-------------
block/blk-mq-sysfs.c | 6 ++++++
block/blk-mq.c | 8 ++------
block/blk-mq.h | 2 +-
drivers/scsi/scsi_lib.c | 7 -------
5 files changed, 10 insertions(+), 27 deletions(-)