On Sat, Mar 21, 2026 at 07:54:39AM +0000, shuo chen wrote:

The unlock_buffer and clear_and_wake_up_bit call same the three function in the same sequence: 1.clear_bit_unlock 2.smp_mb__after_atomic 3.wake_up_bit

So why don't unlock_buffer write the fllowing: void unlock_buffer(struct buffer_head *bh) { clear_and_wake_up_bit(BH_Lock,&bh->b_state); }

Probably not the answer you want, but the `unlock_buffer()` has been written the way it is back in `fc9b52cd8f5f4`, in 2008. And the `clear_and_wake_up_bit()` function has been introduced only in `8236b0ae31c83`, in 2018 (10 years later). So, the root answer to your question is: the function didn't exist to be used back then. Judging from the commit message at `8236b0ae31c83` I would make the educated guess that they are semantically identical, but I don't have enough knowledge to make such a claim firmly. Maybe the semantics is the same, order doesn't matter and everyone just missed it. But maybe nobody changed because order changes semantics, I don't know. --- Sincerely, Agatha Isabelle Moreira C Developer | agatha.dev Sourcehut: https://sr.ht/~devlavender/