[PATCH 5.12 0/4] random 5.12 bits

[PATCH 5.12 0/4] random 5.12 bits

[Pavel Begunkov]

1/4 is a fix.
Others may make slightly easier looking for ->io_uring usages.

Pavel Begunkov (4):
  io_uring: choose right tctx->io_wq for try cancel
  io_uring: inline io_req_clean_work()
  io_uring: inline __io_queue_async_work()
  io_uring: remove extra in_idle wake up

 fs/io_uring.c | 44 +++++++++++++++-----------------------------
 1 file changed, 15 insertions(+), 29 deletions(-)

-- 
2.24.0

[PATCH 1/4] io_uring: choose right tctx->io_wq for try cancel

[Pavel Begunkov]

When we cancel SQPOLL, @task in io_uring_try_cancel_requests() will
differ from current. Use the right tctx from passed in @task, and don't
forget that it can be NULL when the io_uring ctx exits.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 0c363529a836..34d0fd4a933b 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8615,7 +8615,8 @@ static void io_uring_try_cancel_requests(struct io_ring_ctx *ctx,
 					 struct files_struct *files)
 {
 	struct io_task_cancel cancel = { .task = task, .files = files, };
-	struct io_uring_task *tctx = current->io_uring;
+	struct task_struct *tctx_task = task ?: current;
+	struct io_uring_task *tctx = tctx_task->io_uring;
 
 	while (1) {
 		enum io_wq_cancel cret;
-- 
2.24.0

[PATCH 2/4] io_uring: inline io_req_clean_work()

[Pavel Begunkov]

Inline io_req_clean_work(), less code and easier to analyse
tctx dependencies and refs usage.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c | 30 +++++++++++++-----------------
 1 file changed, 13 insertions(+), 17 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 34d0fd4a933b..3d8c99c46127 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1167,22 +1167,6 @@ static bool req_need_defer(struct io_kiocb *req, u32 seq)
 	return false;
 }
 
-static void io_req_clean_work(struct io_kiocb *req)
-{
-	if (req->flags & REQ_F_INFLIGHT) {
-		struct io_ring_ctx *ctx = req->ctx;
-		struct io_uring_task *tctx = req->task->io_uring;
-		unsigned long flags;
-
-		spin_lock_irqsave(&ctx->inflight_lock, flags);
-		list_del(&req->inflight_entry);
-		spin_unlock_irqrestore(&ctx->inflight_lock, flags);
-		req->flags &= ~REQ_F_INFLIGHT;
-		if (atomic_read(&tctx->in_idle))
-			wake_up(&tctx->wait);
-	}
-}
-
 static void io_req_track_inflight(struct io_kiocb *req)
 {
 	struct io_ring_ctx *ctx = req->ctx;
@@ -1671,7 +1655,19 @@ static void io_dismantle_req(struct io_kiocb *req)
 		io_put_file(req, req->file, (req->flags & REQ_F_FIXED_FILE));
 	if (req->fixed_rsrc_refs)
 		percpu_ref_put(req->fixed_rsrc_refs);
-	io_req_clean_work(req);
+
+	if (req->flags & REQ_F_INFLIGHT) {
+		struct io_ring_ctx *ctx = req->ctx;
+		struct io_uring_task *tctx = req->task->io_uring;
+		unsigned long flags;
+
+		spin_lock_irqsave(&ctx->inflight_lock, flags);
+		list_del(&req->inflight_entry);
+		spin_unlock_irqrestore(&ctx->inflight_lock, flags);
+		req->flags &= ~REQ_F_INFLIGHT;
+		if (atomic_read(&tctx->in_idle))
+			wake_up(&tctx->wait);
+	}
 }
 
 static inline void io_put_task(struct task_struct *task, int nr)
-- 
2.24.0

[PATCH 3/4] io_uring: inline __io_queue_async_work()

[Pavel Begunkov]

__io_queue_async_work() is only called from io_queue_async_work(),
inline it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 3d8c99c46127..411323dc43bb 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1205,7 +1205,7 @@ static void io_prep_async_link(struct io_kiocb *req)
 		io_prep_async_work(cur);
 }
 
-static struct io_kiocb *__io_queue_async_work(struct io_kiocb *req)
+static void io_queue_async_work(struct io_kiocb *req)
 {
 	struct io_ring_ctx *ctx = req->ctx;
 	struct io_kiocb *link = io_prep_linked_timeout(req);
@@ -1216,18 +1216,9 @@ static struct io_kiocb *__io_queue_async_work(struct io_kiocb *req)
 
 	trace_io_uring_queue_async_work(ctx, io_wq_is_hashed(&req->work), req,
 					&req->work, req->flags);
-	io_wq_enqueue(tctx->io_wq, &req->work);
-	return link;
-}
-
-static void io_queue_async_work(struct io_kiocb *req)
-{
-	struct io_kiocb *link;
-
 	/* init ->work of the whole link before punting */
 	io_prep_async_link(req);
-	link = __io_queue_async_work(req);
-
+	io_wq_enqueue(tctx->io_wq, &req->work);
 	if (link)
 		io_queue_linked_timeout(link);
 }
-- 
2.24.0

[PATCH 4/4] io_uring: remove extra in_idle wake up

[Pavel Begunkov]

io_dismantle_req() is always followed by io_put_task(), which already do
proper in_idle wake ups, so we can skip waking the owner task in
io_dismantle_req(). The rules are simpler now, do io_put_task() shortly
after ending a request, and it will be fine.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 411323dc43bb..e9215477426d 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1649,18 +1649,16 @@ static void io_dismantle_req(struct io_kiocb *req)
 
 	if (req->flags & REQ_F_INFLIGHT) {
 		struct io_ring_ctx *ctx = req->ctx;
-		struct io_uring_task *tctx = req->task->io_uring;
 		unsigned long flags;
 
 		spin_lock_irqsave(&ctx->inflight_lock, flags);
 		list_del(&req->inflight_entry);
 		spin_unlock_irqrestore(&ctx->inflight_lock, flags);
 		req->flags &= ~REQ_F_INFLIGHT;
-		if (atomic_read(&tctx->in_idle))
-			wake_up(&tctx->wait);
 	}
 }
 
+/* must to be called somewhat shortly after putting a request */
 static inline void io_put_task(struct task_struct *task, int nr)
 {
 	struct io_uring_task *tctx = task->io_uring;
-- 
2.24.0

Re: [PATCH 5.12 0/4] random 5.12 bits

[Jens Axboe]

On 3/1/21 11:20 AM, Pavel Begunkov wrote:
> 1/4 is a fix.
> Others may make slightly easier looking for ->io_uring usages.
> 
> Pavel Begunkov (4):
>   io_uring: choose right tctx->io_wq for try cancel
>   io_uring: inline io_req_clean_work()
>   io_uring: inline __io_queue_async_work()
>   io_uring: remove extra in_idle wake up
> 
>  fs/io_uring.c | 44 +++++++++++++++-----------------------------
>  1 file changed, 15 insertions(+), 29 deletions(-)

Looks good, applied.

-- 
Jens Axboe