From f9bd67f69af56d712bfd498f5ad9cf7bb177d600 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Thu, 21 Nov 2019 23:21:03 +0300 Subject: [PATCH] io_uring: only !null ptr to io_issue_sqe() Pass only non-null @nxt to io_issue_sqe() and handle it at the caller's side. And propagate it. - kiocb_done() is only called from io_read() and io_write(), which are only called from io_issue_sqe(), so it's @nxt != NULL - io_put_req_find_next() is called either with explicitly non-null local nxt, or from one of the functions in io_issue_sqe() switch (or their callees). Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io_uring.c | 28 ++++++++++++---------------- 1 file changed, 12 insertions(+), 16 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index f6f5871bd7d2..553fa23120e6 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -990,21 +990,13 @@ static void io_free_req(struct io_kiocb *req) * Drop reference to request, return next in chain (if there is one) if this * was the last reference to this request. */ +__attribute__((nonnull)) static void io_put_req_find_next(struct io_kiocb *req, struct io_kiocb **nxtptr) { - struct io_kiocb *nxt = NULL; - - io_req_find_next(req, &nxt); + io_req_find_next(req, nxtptr); if (refcount_dec_and_test(&req->refs)) __io_free_req(req); - - if (nxt) { - if (nxtptr) - *nxtptr = nxt; - else - io_queue_async_work(nxt); - } } static void io_put_req(struct io_kiocb *req) @@ -1488,7 +1480,7 @@ static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret) static void kiocb_done(struct kiocb *kiocb, ssize_t ret, struct io_kiocb **nxt, bool in_async) { - if (in_async && ret >= 0 && nxt && kiocb->ki_complete == io_complete_rw) + if (in_async && ret >= 0 && kiocb->ki_complete == io_complete_rw) *nxt = __io_complete_rw(kiocb, ret); else io_rw_done(kiocb, ret); @@ -2585,6 +2577,7 @@ static int io_req_defer(struct io_kiocb *req) return -EIOCBQUEUED; } +__attribute__((nonnull)) static int io_issue_sqe(struct io_kiocb *req, struct io_kiocb **nxt, bool force_nonblock) { @@ -2901,10 +2894,13 @@ static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req) static void __io_queue_sqe(struct io_kiocb *req) { - struct io_kiocb *nxt = io_prep_linked_timeout(req); + struct io_kiocb *linked_timeout = io_prep_linked_timeout(req); + struct io_kiocb *nxt = NULL; int ret; - ret = io_issue_sqe(req, NULL, true); + ret = io_issue_sqe(req, &nxt, true); + if (nxt) + io_queue_async_work(nxt); /* * We async punt it if the file wasn't marked NOWAIT, or if the file @@ -2940,11 +2936,11 @@ err: /* drop submission reference */ io_put_req(req); - if (nxt) { + if (linked_timeout) { if (!ret) - io_queue_linked_timeout(nxt); + io_queue_linked_timeout(linked_timeout); else - io_put_req(nxt); + io_put_req(linked_timeout); } /* and drop final reference, if we failed */