How to understand statements on FIFO j->pin in bch_journal_next

["Wang Sheng-Hui" <shhuiw@xxxxxxxxxxx>]

Hi,

Sorry to trouble you.

I noticed some statements in the function:
---------------------------------------------------------
void bch_journal_next(struct journal *j)
{
    atomic_t p = { 1 };
    ...
    BUG_ON(!fifo_push(&j->pin, p));
    atomic_set(&fifo_back(&j->pin), 1);

    ...

fifo_push would add atomic_t {1} to the back of the FIFO, while next
atomic_set would set the back element of FIFO to 1, which is atomic_t {1}.

I wonder why there is additional atomic_set statement ?

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Regards,
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