Jan Kara f1b43174a0 rq-qos: fix missed wake-ups in rq_qos_throttle try two ... Commit 545fbd0775ba ("rq-qos: fix missed wake-ups in rq_qos_throttle") tried to fix a problem that a process could be sleeping in rq_qos_wait() without anyone to wake it up. However the fix is not complete and the following can still happen: CPU1 (waiter1) CPU2 (waiter2) CPU3 (waker) rq_qos_wait() rq_qos_wait() acquire_inflight_cb() -> fails acquire_inflight_cb() -> fails completes IOs, inflight decreased prepare_to_wait_exclusive() prepare_to_wait_exclusive() has_sleeper = !wq_has_single_sleeper() -> true as there are two sleepers has_sleeper = !wq_has_single_sleeper() -> true io_schedule() io_schedule() Deadlock as now there's nobody to wakeup the two waiters. The logic automatically blocking when there are already sleepers is really subtle and the only way to make it work reliably is that we check whether there are some waiters in the queue when adding ourselves there. That way, we are guaranteed that at least the first process to enter the wait queue will recheck the waiting condition before going to sleep and thus guarantee forward progress. UPSTREAM COMMIT: 11c7aa0ddea8611007768d3e6b58d45dc60a19e1 Fixes: 545fbd0775ba ("rq-qos: fix missed wake-ups in rq_qos_throttle") CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20210607112613.25344-1-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk>		2022-04-12 16:58:30 +08:00
..
partitions	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
Kconfig	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
Kconfig.iosched	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
Makefile	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
badblocks.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
bfq-cgroup.c	bfq: fix blkio cgroup leakage v4	2021-03-16 16:35:01 +08:00
bfq-iosched.c	bfq: Avoid false bfq queue merging	2021-04-12 12:52:11 +08:00
bfq-iosched.h	bfq: fix blkio cgroup leakage v4	2021-03-16 16:35:01 +08:00
bfq-wf2q.c	bfq: fix blkio cgroup leakage v4	2021-03-16 16:35:01 +08:00
bio-integrity.c	block: release bip in a right way in error path	2021-03-16 16:31:28 +08:00
bio.c	block: fix zero ioutil if io stall or disk enter blocked state	2022-04-06 16:56:35 +08:00
blk-cgroup.c	block: fix zero ioutil if io stall or disk enter blocked state	2022-04-06 16:56:35 +08:00
blk-core.c	Revert "Revert "block: end bio with BLK_STS_AGAIN in case of non-mq devs and REQ_NOWAIT""	2021-04-12 12:51:49 +08:00
blk-exec.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-flush.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-integrity.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-ioc.c	block: Fix use-after-free issue accessing struct io_cq	2021-03-16 16:25:58 +08:00
blk-iocost.c	blk-iocost: ioc_pd_free() shouldn't assume irq disabled	2021-03-16 16:35:42 +08:00
blk-iolatency.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-lib.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-map.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-merge.c	block: recalculate segment count for multi-segment discards correctly	2021-04-12 12:53:31 +08:00
blk-mq-cpumap.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-mq-debugfs-zoned.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-mq-debugfs.c	blk-mq-debugfs: update blk_queue_flag_name[] accordingly for new flags	2021-03-16 16:31:47 +08:00
blk-mq-debugfs.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-mq-pci.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-mq-rdma.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-mq-sched.c	blk-mq: order adding requests to hctx->dispatch and checking SCHED_RESTART	2021-03-16 16:35:09 +08:00
blk-mq-sched.h	block: only call sched requeue_request() for scheduled requests	2021-03-16 16:36:14 +08:00
blk-mq-sysfs.c	blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue	2021-03-16 16:38:30 +08:00
blk-mq-tag.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-mq-tag.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-mq-virtio.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-mq.c	block: fix inflight statistics of part0	2022-04-06 16:56:29 +08:00
blk-mq.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-pm.c	scsi: block: Fix a race in the runtime power management code	2021-03-16 16:43:51 +08:00
blk-pm.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-rq-qos.c	rq-qos: fix missed wake-ups in rq_qos_throttle try two	2022-04-12 16:58:30 +08:00
blk-rq-qos.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-settings.c	blk-settings: align max_sectors on "logical_block_size" boundary	2021-04-12 12:52:32 +08:00
blk-softirq.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-stat.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-stat.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-sysfs.c	blk-mq: move cancel of hctx->run_work to the front of blk_exit_queue	2021-03-16 16:38:30 +08:00
blk-throttle.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-timeout.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-wbt.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-wbt.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
blk-zoned.c	block: Simplify REQ_OP_ZONE_RESET_ALL handling	2021-03-16 16:42:25 +08:00
blk.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
bounce.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
bsg-lib.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
bsg.c	bsg: free the request before return error code	2021-04-12 12:52:19 +08:00
cmdline-parser.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
compat_ioctl.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
elevator.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
genhd.c	block: fix zero ioutil if io stall or disk enter blocked state	2022-04-06 16:56:35 +08:00
ioctl.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
ioprio.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
kyber-iosched.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
mq-deadline.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
opal_proto.h	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
partition-generic.c	block: fix zero ioutil if io stall or disk enter blocked state	2022-04-06 16:56:35 +08:00
scsi_ioctl.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
sed-opal.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00
t10-pi.c	Init Repo base on linux 5.4.32 long term, and add base tlinux kernel interfaces.	2021-03-16 11:01:34 +08:00