From 4e17aaab54359fa2cdeb0080c822a08f2980f979 Mon Sep 17 00:00:00 2001 From: Stefan Roesch Date: Thu, 16 Jun 2022 14:22:18 -0700 Subject: [PATCH] io_uring: Add support for async buffered writes This enables the async buffered writes for the filesystems that support async buffered writes in io-uring. Buffered writes are enabled for blocks that are already in the page cache or can be acquired with noio. Signed-off-by: Stefan Roesch Link: https://lore.kernel.org/r/20220616212221.2024518-12-shr@fb.com [axboe: adapt to 5.20 branch] Signed-off-by: Jens Axboe --- io_uring/rw.c | 29 ++++++++++++++++++++++++----- 1 file changed, 24 insertions(+), 5 deletions(-) diff --git a/io_uring/rw.c b/io_uring/rw.c index c50a0d66d67a..4d4ca6389876 100644 --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -641,7 +641,7 @@ static inline int io_iter_do_read(struct io_rw *rw, struct iov_iter *iter) return -EINVAL; } -static bool need_read_all(struct io_kiocb *req) +static bool need_complete_io(struct io_kiocb *req) { return req->flags & REQ_F_ISREG || S_ISBLK(file_inode(req->file)->i_mode); @@ -775,7 +775,7 @@ int io_read(struct io_kiocb *req, unsigned int issue_flags) kfree(iovec); return IOU_ISSUE_SKIP_COMPLETE; } else if (ret == req->cqe.res || ret <= 0 || !force_nonblock || - (req->flags & REQ_F_NOWAIT) || !need_read_all(req)) { + (req->flags & REQ_F_NOWAIT) || !need_complete_io(req)) { /* read all, failed, already did sync or don't want to retry */ goto done; } @@ -870,9 +870,10 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags) if (unlikely(!io_file_supports_nowait(req))) goto copy_iov; - /* file path doesn't support NOWAIT for non-direct_IO */ - if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) && - (req->flags & REQ_F_ISREG)) + /* File path supports NOWAIT for non-direct_IO only for block devices. */ + if (!(kiocb->ki_flags & IOCB_DIRECT) && + !(kiocb->ki_filp->f_mode & FMODE_BUF_WASYNC) && + (req->flags & REQ_F_ISREG)) goto copy_iov; kiocb->ki_flags |= IOCB_NOWAIT; @@ -928,6 +929,24 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags) /* IOPOLL retry should happen for io-wq threads */ if (ret2 == -EAGAIN && (req->ctx->flags & IORING_SETUP_IOPOLL)) goto copy_iov; + + if (ret2 != req->cqe.res && ret2 >= 0 && need_complete_io(req)) { + struct io_async_rw *rw; + + /* This is a partial write. The file pos has already been + * updated, setup the async struct to complete the request + * in the worker. Also update bytes_done to account for + * the bytes already written. + */ + iov_iter_save_state(&s->iter, &s->iter_state); + ret = io_setup_async_rw(req, iovec, s, true); + + rw = req->async_data; + if (rw) + rw->bytes_done += ret2; + + return ret ? ret : -EAGAIN; + } done: ret = kiocb_done(req, ret2, issue_flags); } else { -- 2.39.5