On 4/24/25 17:21, Ming Lei wrote:
Both adding/deleting disk code are reader of `nr_hw_queues`, so we can't allow them in-progress when updating nr_hw_queues, kernel panic and kasan has been reported in [1]. Prevent adding/deleting disk during updating nr_hw_queues by adding rw_semaphore to tagset, write lock is grabbed in blk_mq_update_nr_hw_queues(), and read lock is acquired when adding/deleting disk. Also mark GFP_NOIO allocation scope for adding/deleting disk because blk_mq_update_nr_hw_queues() is part of some driver's error handler. This way avoids lot of trouble. Suggested-by: Nilay Shroff <nilay@xxxxxxxxxxxxx> Reported-by: Nilay Shroff <nilay@xxxxxxxxxxxxx> Closes: https://lore.kernel.org/linux-block/a5896cdb-a59a-4a37-9f99-20522f5d2987@xxxxxxxxxxxxx/ Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> --- block/blk-mq.c | 4 ++ block/genhd.c | 94 +++++++++++++++++++++++++++++++----------- include/linux/blk-mq.h | 3 ++ 3 files changed, 78 insertions(+), 23 deletions(-)
Reviewed-by: Hannes Reinecke <hare@xxxxxxx> Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@xxxxxxx +49 911 74053 688 SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich
