From 8c130827f417da791edb919df8cac56af30a1489 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Mon, 22 Mar 2021 01:58:32 +0000 Subject: io_uring: don't alter iopoll reissue fail ret code When reissue_prep failed in io_complete_rw_iopoll(), we change return code to -EIO to prevent io_iopoll_complete() from doing resubmission. Mark requests with a new flag (i.e. REQ_F_DONT_REISSUE) instead and retain the original return value. It also removes io_rw_reissue() from io_iopoll_complete() that will be used later. Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io_uring.c | 41 ++++++++++++++++------------------------- 1 file changed, 16 insertions(+), 25 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index a3a0348ab6eb..9362c9228540 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -696,6 +696,7 @@ enum { REQ_F_LTIMEOUT_ACTIVE_BIT, REQ_F_COMPLETE_INLINE_BIT, REQ_F_REISSUE_BIT, + REQ_F_DONT_REISSUE_BIT, /* keep async read/write and isreg together and in order */ REQ_F_ASYNC_READ_BIT, REQ_F_ASYNC_WRITE_BIT, @@ -741,6 +742,8 @@ enum { REQ_F_COMPLETE_INLINE = BIT(REQ_F_COMPLETE_INLINE_BIT), /* caller should reissue async */ REQ_F_REISSUE = BIT(REQ_F_REISSUE_BIT), + /* don't attempt request reissue, see io_rw_reissue() */ + REQ_F_DONT_REISSUE = BIT(REQ_F_DONT_REISSUE_BIT), /* supports async reads */ REQ_F_ASYNC_READ = BIT(REQ_F_ASYNC_READ_BIT), /* supports async writes */ @@ -1016,7 +1019,6 @@ static struct fixed_rsrc_ref_node *alloc_fixed_rsrc_ref_node( struct io_ring_ctx *ctx); static void io_ring_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc); -static bool io_rw_reissue(struct io_kiocb *req); static void io_cqring_fill_event(struct io_kiocb *req, long res); static void io_put_req(struct io_kiocb *req); static void io_put_req_deferred(struct io_kiocb *req, int nr); @@ -2253,10 +2255,12 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events, req = list_first_entry(done, struct io_kiocb, inflight_entry); list_del(&req->inflight_entry); - if (READ_ONCE(req->result) == -EAGAIN) { + if (READ_ONCE(req->result) == -EAGAIN && + !(req->flags & REQ_F_DONT_REISSUE)) { req->iopoll_completed = 0; - if (io_rw_reissue(req)) - continue; + req_ref_get(req); + io_queue_async_work(req); + continue; } if (req->flags & REQ_F_BUFFER_SELECTED) @@ -2471,24 +2475,6 @@ static bool io_rw_should_reissue(struct io_kiocb *req) } #endif -static bool io_rw_reissue(struct io_kiocb *req) -{ -#ifdef CONFIG_BLOCK - if (!io_rw_should_reissue(req)) - return false; - - lockdep_assert_held(&req->ctx->uring_lock); - - if (io_resubmit_prep(req)) { - req_ref_get(req); - io_queue_async_work(req); - return true; - } - req_set_fail_links(req); -#endif - return false; -} - static void __io_complete_rw(struct io_kiocb *req, long res, long res2, unsigned int issue_flags) { @@ -2527,15 +2513,17 @@ static void io_complete_rw_iopoll(struct kiocb *kiocb, long res, long res2) iov_iter_revert(&rw->iter, req->result - iov_iter_count(&rw->iter)); else if (!io_resubmit_prep(req)) - res = -EIO; + req->flags |= REQ_F_DONT_REISSUE; } #endif if (kiocb->ki_flags & IOCB_WRITE) kiocb_end_write(req); - if (res != -EAGAIN && res != req->result) + if (res != -EAGAIN && res != req->result) { + req->flags |= REQ_F_DONT_REISSUE; req_set_fail_links(req); + } WRITE_ONCE(req->result, res); /* order with io_iopoll_complete() checking ->result */ @@ -2776,7 +2764,10 @@ static void kiocb_done(struct kiocb *kiocb, ssize_t ret, if (check_reissue && req->flags & REQ_F_REISSUE) { req->flags &= ~REQ_F_REISSUE; - if (!io_rw_reissue(req)) { + if (!io_resubmit_prep(req)) { + req_ref_get(req); + io_queue_async_work(req); + } else { int cflags = 0; req_set_fail_links(req); -- cgit