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From: Jens Axboe <axboe@kernel.dk>
To: io-uring@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org, Jens Axboe <axboe@kernel.dk>
Subject: [PATCH 07/10] io-wq: add support for uncancellable work
Date: Fri, 13 Dec 2019 11:36:29 -0700	[thread overview]
Message-ID: <20191213183632.19441-8-axboe@kernel.dk> (raw)
In-Reply-To: <20191213183632.19441-1-axboe@kernel.dk>

Not all work can be cancelled, some of it we may need to guarantee
that it runs to completion. Allow the caller to set IO_WQ_WORK_NO_CANCEL
on work that must not be cancelled. Note that the caller work function
must also check for IO_WQ_WORK_NO_CANCEL on work that is marked
IO_WQ_WORK_CANCEL.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 fs/io-wq.c    | 8 +++++++-
 fs/io-wq.h    | 1 +
 fs/io_uring.c | 5 ++++-
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/fs/io-wq.c b/fs/io-wq.c
index 90c4978781fb..d0303ad17347 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -453,6 +453,10 @@ static void io_worker_handle_work(struct io_worker *worker)
 		}
 		if (!worker->creds)
 			worker->creds = override_creds(wq->creds);
+		/*
+		 * OK to set IO_WQ_WORK_CANCEL even for uncancellable work,
+		 * the worker function will do the right thing.
+		 */
 		if (test_bit(IO_WQ_BIT_CANCEL, &wq->state))
 			work->flags |= IO_WQ_WORK_CANCEL;
 		if (worker->mm)
@@ -829,6 +833,7 @@ static bool io_work_cancel(struct io_worker *worker, void *cancel_data)
 	 */
 	spin_lock_irqsave(&worker->lock, flags);
 	if (worker->cur_work &&
+	    !(worker->cur_work->flags & IO_WQ_WORK_NO_CANCEL) &&
 	    data->cancel(worker->cur_work, data->caller_data)) {
 		send_sig(SIGINT, worker->task, 1);
 		ret = true;
@@ -903,7 +908,8 @@ static bool io_wq_worker_cancel(struct io_worker *worker, void *data)
 		return false;
 
 	spin_lock_irqsave(&worker->lock, flags);
-	if (worker->cur_work == work) {
+	if (worker->cur_work == work &&
+	    !(worker->cur_work->flags & IO_WQ_WORK_NO_CANCEL)) {
 		send_sig(SIGINT, worker->task, 1);
 		ret = true;
 	}
diff --git a/fs/io-wq.h b/fs/io-wq.h
index fb993b2bd0ef..f0a016c4ee9c 100644
--- a/fs/io-wq.h
+++ b/fs/io-wq.h
@@ -12,6 +12,7 @@ enum {
 	IO_WQ_WORK_UNBOUND	= 32,
 	IO_WQ_WORK_INTERNAL	= 64,
 	IO_WQ_WORK_CB		= 128,
+	IO_WQ_WORK_NO_CANCEL	= 256,
 
 	IO_WQ_HASH_SHIFT	= 24,	/* upper 8 bits are used for hash key */
 };
diff --git a/fs/io_uring.c b/fs/io_uring.c
index db79ac79d80e..132f887ef18d 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3153,8 +3153,11 @@ static void io_wq_submit_work(struct io_wq_work **workptr)
 	/* Ensure we clear previously set non-block flag */
 	req->rw.ki_flags &= ~IOCB_NOWAIT;
 
-	if (work->flags & IO_WQ_WORK_CANCEL)
+	/* if NO_CANCEL is set, we must still run the work */
+	if ((work->flags & (IO_WQ_WORK_CANCEL|IO_WQ_WORK_NO_CANCEL)) ==
+				IO_WQ_WORK_CANCEL) {
 		ret = -ECANCELED;
+	}
 
 	if (!ret) {
 		req->has_user = (work->flags & IO_WQ_WORK_HAS_MM) != 0;
-- 
2.24.1


  parent reply	other threads:[~2019-12-13 20:40 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-13 18:36 [PATCHSET 0/10] io_uring items for 5.6 Jens Axboe
2019-12-13 18:36 ` [PATCH 01/10] io_uring: add support for fallocate() Jens Axboe
2019-12-13 18:36 ` [PATCH 02/10] io_uring: remove 'sqe' parameter to the OP helpers that take it Jens Axboe
2019-12-13 18:36 ` [PATCH 03/10] fs: add namei support for doing a non-blocking path lookup Jens Axboe
2019-12-27  0:42   ` Al Viro
2019-12-27  5:05     ` Jens Axboe
2019-12-27  5:25       ` Jens Axboe
2019-12-27 15:45         ` Jens Axboe
2019-12-28 19:03           ` Jens Axboe
2019-12-13 18:36 ` [PATCH 04/10] fs: make build_open_flags() available internally Jens Axboe
2019-12-13 18:36 ` [PATCH 05/10] io_uring: add support for IORING_OP_OPENAT Jens Axboe
2019-12-13 18:36 ` [PATCH 06/10] fs: move filp_close() outside of __close_fd_get_file() Jens Axboe
2019-12-16 19:27   ` Jann Horn
2019-12-16 19:39     ` Jens Axboe
2019-12-13 18:36 ` Jens Axboe [this message]
2019-12-13 18:36 ` [PATCH 08/10] io_uring: add support for IORING_OP_CLOSE Jens Axboe
2019-12-13 18:36 ` [PATCH 09/10] io_uring: use u64_to_user_ptr() consistently Jens Axboe
2019-12-13 18:36 ` [PATCH 10/10] io_uring: avoid ring quiesce for fixed file set unregister and update Jens Axboe

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