[RFC PATCH v1] block: avoid to call .bi_end_io() recursively

There were reports about heavy stack use by recursive calling .bi_end_io().[1][2][3] Also these patches[1] [2] [3] were posted for addressing the issue. And the idea is basically similar, all serializes the recursive calling of .bi_end_io() by percpu list. This patch still takes the same idea,

[RFC PATCH v1] block: avoid to call .bi_end_io() recursively

There were reports about heavy stack use by recursive calling .bi_end_io().[1][2][3] Also these patches[1] [2] [3] were posted for addressing the issue. And the idea is basically similar, all serializes the recursive calling of .bi_end_io() by percpu list. This patch still takes the same idea,