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From: "Stefan Bühler" <source@stbuehler.de>
To: Jens Axboe <axboe@kernel.dk>,
	linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: [PATCH v1 1/1] [io_uring] fix handling SQEs requesting NOWAIT
Date: Sat, 27 Apr 2019 20:34:19 +0200	[thread overview]
Message-ID: <20190427183419.5971-1-source@stbuehler.de> (raw)
In-Reply-To: <7bcb0eb3-46d1-70e4-1108-dfd9a348bb7c@stbuehler.de>

Not all request types set REQ_F_FORCE_NONBLOCK when they needed async
punting; reverse logic instead and set REQ_F_NOWAIT if request mustn't
be punted.

Signed-off-by: Stefan Bühler <source@stbuehler.de>
---
 fs/io_uring.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 25632e399a78..77b247b5d10b 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -322,7 +322,7 @@ struct io_kiocb {
 	struct list_head	list;
 	unsigned int		flags;
 	refcount_t		refs;
-#define REQ_F_FORCE_NONBLOCK	1	/* inline submission attempt */
+#define REQ_F_NOWAIT		1	/* must not punt to workers */
 #define REQ_F_IOPOLL_COMPLETED	2	/* polled IO has completed */
 #define REQ_F_FIXED_FILE	4	/* ctx owns file */
 #define REQ_F_SEQ_PREV		8	/* sequential with previous */
@@ -872,11 +872,14 @@ static int io_prep_rw(struct io_kiocb *req, const struct sqe_submit *s,
 	ret = kiocb_set_rw_flags(kiocb, READ_ONCE(sqe->rw_flags));
 	if (unlikely(ret))
 		return ret;
-	/* only force async punt if the sqe didn't ask for NOWAIT */
-	if (force_nonblock && !(kiocb->ki_flags & IOCB_NOWAIT)) {
+
+	/* don't allow async punt if RWF_NOWAIT was requested */
+	if (kiocb->ki_flags & IOCB_NOWAIT)
+		req->flags |= REQ_F_NOWAIT;
+
+	if (force_nonblock)
 		kiocb->ki_flags |= IOCB_NOWAIT;
-		req->flags |= REQ_F_FORCE_NONBLOCK;
-	}
+
 	if (ctx->flags & IORING_SETUP_IOPOLL) {
 		if (!(kiocb->ki_flags & IOCB_DIRECT) ||
 		    !kiocb->ki_filp->f_op->iopoll)
@@ -1535,8 +1538,7 @@ static void io_sq_wq_submit_work(struct work_struct *work)
 		struct sqe_submit *s = &req->submit;
 		const struct io_uring_sqe *sqe = s->sqe;
 
-		/* Ensure we clear previously set forced non-block flag */
-		req->flags &= ~REQ_F_FORCE_NONBLOCK;
+		/* Ensure we clear previously set non-block flag */
 		req->rw.ki_flags &= ~IOCB_NOWAIT;
 
 		ret = 0;
@@ -1722,7 +1724,7 @@ static int io_submit_sqe(struct io_ring_ctx *ctx, struct sqe_submit *s,
 		goto out;
 
 	ret = __io_submit_sqe(ctx, req, s, true);
-	if (ret == -EAGAIN && (req->flags & REQ_F_FORCE_NONBLOCK)) {
+	if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) {
 		struct io_uring_sqe *sqe_copy;
 
 		sqe_copy = kmalloc(sizeof(*sqe_copy), GFP_KERNEL);
-- 
2.20.1


  reply	other threads:[~2019-04-27 18:34 UTC|newest]

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-23 19:06 io_uring: not good enough for release Stefan Bühler
2019-04-23 20:31 ` Jens Axboe
2019-04-23 22:07   ` Jens Axboe
2019-04-24 16:09     ` Jens Axboe
2019-04-27 16:05       ` io_uring: RWF_NOWAIT support Stefan Bühler
2019-04-27 18:34         ` Stefan Bühler [this message]
2019-04-30 15:40           ` [PATCH v1 1/1] [io_uring] fix handling SQEs requesting NOWAIT Jens Axboe
2019-04-27 15:50     ` io_uring: submission error handling Stefan Bühler
2019-04-30 16:02       ` Jens Axboe
2019-04-30 16:15         ` Jens Axboe
2019-04-30 18:15           ` Stefan Bühler
2019-04-30 18:42             ` Jens Axboe
2019-05-01 11:49               ` [PATCH v1 1/1] [io_uring] don't stall on submission errors Stefan Bühler
2019-05-01 12:43                 ` Jens Axboe
2019-04-27 21:07   ` io_uring: closing / release Stefan Bühler
2019-05-11 16:26     ` Stefan Bühler
2019-04-28 15:54   ` io_uring: O_NONBLOCK/IOCB_NOWAIT/RWF_NOWAIT mess Stefan Bühler
2019-05-11 16:34     ` Stefan Bühler
2019-05-11 16:57       ` [PATCH 1/5] fs: RWF flags override default IOCB flags from file flags Stefan Bühler
2019-05-11 16:57         ` [PATCH 2/5] tcp: handle SPLICE_F_NONBLOCK in tcp_splice_read Stefan Bühler
2019-05-11 16:57         ` [PATCH 3/5] pipe: use IOCB_NOWAIT instead of O_NONBLOCK Stefan Bühler
2019-05-11 16:57         ` [PATCH 4/5] socket: " Stefan Bühler
2019-05-11 16:57         ` [PATCH 5/5] io_uring: use FMODE_NOWAIT to detect files supporting IOCB_NOWAIT Stefan Bühler
2019-05-03  9:47   ` [PATCH 1/2] io_uring: restructure io_{read,write} control flow Stefan Bühler
2019-05-03  9:47     ` [PATCH 2/2] io_uring: punt to workers if file doesn't support async Stefan Bühler

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