From: Pavel Begunkov Date: Thu, 17 Jun 2021 17:14:05 +0000 (+0100) Subject: io_uring: refactor io_get_sequence() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=a3dbdf54da80326fd12bc11ad75ecd699a82374f;p=linux.git io_uring: refactor io_get_sequence() Clean up io_get_sequence() and add a comment describing the magic around sequence correction. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/f55dc409936b8afa4698d24b8677a34d31077ccb.1623949695.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- diff --git a/fs/io_uring.c b/fs/io_uring.c index 474705a97f295..c41e9a925fa2c 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -5993,13 +5993,12 @@ static int io_req_prep_async(struct io_kiocb *req) static u32 io_get_sequence(struct io_kiocb *req) { - struct io_kiocb *pos; - struct io_ring_ctx *ctx = req->ctx; - u32 nr_reqs = 0; + u32 seq = req->ctx->cached_sq_head; - io_for_each_link(pos, req) - nr_reqs++; - return ctx->cached_sq_head - nr_reqs; + /* need original cached_sq_head, but it was increased for each req */ + io_for_each_link(req, req) + seq--; + return seq; } static bool io_drain_req(struct io_kiocb *req)