From 75c668cdd6ca05dd9c7138a5a080c0088d72cf51 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Thu, 4 Feb 2021 13:52:05 +0000 Subject: [PATCH] io_uring: treat NONBLOCK and RWF_NOWAIT similarly Make decision making of whether we need to retry read/write similar for O_NONBLOCK and RWF_NOWAIT. Set REQ_F_NOWAIT when either is specified and use it for all relevant checks. Also fix resubmitting NOWAIT requests via io_rw_reissue(). Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io_uring.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index bbf8ea83..ce2ea3f 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2734,7 +2734,9 @@ static bool io_rw_reissue(struct io_kiocb *req, long res) if (res != -EAGAIN && res != -EOPNOTSUPP) return false; mode = file_inode(req->file)->i_mode; - if ((!S_ISBLK(mode) && !S_ISREG(mode)) || io_wq_current_is_worker()) + if (!S_ISBLK(mode) && !S_ISREG(mode)) + return false; + if ((req->flags & REQ_F_NOWAIT) || io_wq_current_is_worker()) return false; lockdep_assert_held(&req->ctx->uring_lock); @@ -2907,16 +2909,17 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe) { struct io_ring_ctx *ctx = req->ctx; struct kiocb *kiocb = &req->rw.kiocb; + struct file *file = req->file; unsigned ioprio; int ret; - if (S_ISREG(file_inode(req->file)->i_mode)) + if (S_ISREG(file_inode(file)->i_mode)) req->flags |= REQ_F_ISREG; kiocb->ki_pos = READ_ONCE(sqe->off); - if (kiocb->ki_pos == -1 && !(req->file->f_mode & FMODE_STREAM)) { + if (kiocb->ki_pos == -1 && !(file->f_mode & FMODE_STREAM)) { req->flags |= REQ_F_CUR_POS; - kiocb->ki_pos = req->file->f_pos; + kiocb->ki_pos = file->f_pos; } kiocb->ki_hint = ki_hint_validate(file_write_hint(kiocb->ki_filp)); kiocb->ki_flags = iocb_flags(kiocb->ki_filp); @@ -2924,6 +2927,10 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (unlikely(ret)) return ret; + /* don't allow async punt for O_NONBLOCK or RWF_NOWAIT */ + if ((kiocb->ki_flags & IOCB_NOWAIT) || (file->f_flags & O_NONBLOCK)) + req->flags |= REQ_F_NOWAIT; + ioprio = READ_ONCE(sqe->ioprio); if (ioprio) { ret = ioprio_check_cap(ioprio); @@ -2934,10 +2941,6 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe) } else kiocb->ki_ioprio = get_current_ioprio(); - /* don't allow async punt if RWF_NOWAIT was requested */ - if (kiocb->ki_flags & IOCB_NOWAIT) - req->flags |= REQ_F_NOWAIT; - if (ctx->flags & IORING_SETUP_IOPOLL) { if (!(kiocb->ki_flags & IOCB_DIRECT) || !kiocb->ki_filp->f_op->iopoll) @@ -3546,15 +3549,14 @@ static int io_read(struct io_kiocb *req, bool force_nonblock, /* IOPOLL retry should happen for io-wq threads */ if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL)) goto done; - /* no retry on NONBLOCK marked file */ - if (req->file->f_flags & O_NONBLOCK) + /* no retry on NONBLOCK nor RWF_NOWAIT */ + if (req->flags & REQ_F_NOWAIT) goto done; /* some cases will consume bytes even on error returns */ iov_iter_revert(iter, io_size - iov_iter_count(iter)); ret = 0; } else if (ret <= 0 || ret == io_size || !force_nonblock || - (req->file->f_flags & O_NONBLOCK) || - !(req->flags & REQ_F_ISREG)) { + (req->flags & REQ_F_NOWAIT) || !(req->flags & REQ_F_ISREG)) { /* read all, failed, already did sync or don't want to retry */ goto done; } @@ -3675,8 +3677,8 @@ static int io_write(struct io_kiocb *req, bool force_nonblock, */ if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT)) ret2 = -EAGAIN; - /* no retry on NONBLOCK marked file */ - if (ret2 == -EAGAIN && (req->file->f_flags & O_NONBLOCK)) + /* no retry on NONBLOCK nor RWF_NOWAIT */ + if (ret2 == -EAGAIN && (req->flags & REQ_F_NOWAIT)) goto done; if (!force_nonblock || ret2 != -EAGAIN) { /* IOPOLL retry should happen for io-wq threads */ -- 2.7.4