[PATCH 5.10 03/54] io_uring: dont iterate io_uring_cancel_files()

Greg Kroah-Hartman
2021-02-11T16:28:09Z

From: Pavel Begunkov <asml.silence@gmail.com>

[ Upstream commit b52fda00dd9df8b4a6de5784df94f9617f6133a1 ]

io_uring_cancel_files() guarantees to cancel all matching requests,
that's not necessary to do that in a loop. Move it up in the callchain
into io_uring_cancel_task_requests().

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/io_uring.c | 34 ++++++++++++----------------------
1 file changed, 12 insertions(+), 22 deletions(-)

--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8654,16 +8654,10 @@ static void io_cancel_defer_files(struct
}
}

-/*
- * Returns true if we found and killed one or more files pinning requests
- */
-static bool io_uring_cancel_files(struct io_ring_ctx *ctx,
+static void io_uring_cancel_files(struct io_ring_ctx *ctx,
struct task_struct *task,
struct files_struct *files)
{
- if (list_empty_careful(&ctx->inflight_list))
- return false;
-
while (!list_empty_careful(&ctx->inflight_list)) {
struct io_kiocb *cancel_req = NULL, *req;
DEFINE_WAIT(wait);
@@ -8698,8 +8692,6 @@ static bool io_uring_cancel_files(struct
schedule();
finish_wait(&ctx->inflight_wait, &wait);
}
-
- return true;
}

static bool io_cancel_task_cb(struct io_wq_work *work, void *data)
@@ -8710,15 +8702,12 @@ static bool io_cancel_task_cb(struct io_
return io_task_match(req, task);
}

-static bool __io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
- struct task_struct *task,
- struct files_struct *files)
+static void __io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
+ struct task_struct *task)
{
- bool ret;
-
- ret = io_uring_cancel_files(ctx, task, files);
- if (!files) {
+ while (1) {
enum io_wq_cancel cret;
+ bool ret = false;

cret = io_wq_cancel_cb(ctx->io_wq, io_cancel_task_cb, task, true);
if (cret != IO_WQ_CANCEL_NOTFOUND)
@@ -8734,9 +8723,11 @@ static bool __io_uring_cancel_task_reque

ret |= io_poll_remove_all(ctx, task);
ret |= io_kill_timeouts(ctx, task);
+ if (!ret)
+ break;
+ io_run_task_work();
+ cond_resched();
}
-
- return ret;
}

static void io_disable_sqo_submit(struct io_ring_ctx *ctx)
@@ -8771,11 +8762,10 @@ static void io_uring_cancel_task_request

io_cancel_defer_files(ctx, task, files);
io_cqring_overflow_flush(ctx, true, task, files);
+ io_uring_cancel_files(ctx, task, files);

- while (__io_uring_cancel_task_requests(ctx, task, files)) {
- io_run_task_work();
- cond_resched();
- }
+ if (!files)
+ __io_uring_cancel_task_requests(ctx, task);

if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
atomic_dec(&task->io_uring->in_idle);