block: fix false warning in bdev_count_inflight_rw()

While bdev_count_inflight is interating all cpus, if some IOs are issued
from traversed cpu and then completed from the cpu that is not traversed
yet:

cpu0
		cpu1
		bdev_count_inflight
		 //for_each_possible_cpu
		 // cpu0 is 0
		 infliht += 0
// issue a io
blk_account_io_start
// cpu0 inflight ++

				cpu2
				// the io is done
				blk_account_io_done
				// cpu2 inflight --
		 // cpu 1 is 0
		 inflight += 0
		 // cpu2 is -1
		 inflight += -1
		 ...

In this case, the total inflight will be -1, causing lots of false
warning. Fix the problem by removing the warning.

Noted there is still a valid warning for nvme-mpath(From Yi) that is not
fixed yet.

Fixes: f5482ee5edb9 ("block: WARN if bdev inflight counter is negative")
Reported-by: Yi Zhang <[email protected]>
Closes: https://lore.kernel.org/linux-block/[email protected]/T/#mae89155a5006463d0a21a4a2c35ae0034b26a339
Reported-and-tested-by: Calvin Owens <[email protected]>
Closes: https://lore.kernel.org/linux-block/[email protected]/T/#m1d935a00070bf95055d0ac84e6075158b08acaef
Reported-by: Dave Chinner <[email protected]>
Closes: https://lore.kernel.org/linux-block/[email protected]/
Signed-off-by: Yu Kuai <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>

0 files changed, 0 insertions, 0 deletions