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From:   Pavel Begunkov <asml.silence@gmail.com>
To:     io-uring@vger.kernel.org
Cc:     Jens Axboe <axboe@kernel.dk>, asml.silence@gmail.com,
        linux-kernel@vger.kernel.org
Subject: [PATCH 11/11] io_uring/rsrc: add lockdep sanity checks
Date:   Thu, 30 Mar 2023 15:53:29 +0100
Message-Id: <d4c9d4791c934fb40e17c69529de78afe241cd6b.1680187408.git.asml.silence@gmail.com>
In-Reply-To: <cover.1680187408.git.asml.silence@gmail.com>
References: <cover.1680187408.git.asml.silence@gmail.com>
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We should hold ->uring_lock while putting nodes with io_put_rsrc_node(),
add a lockdep check for that.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/io_uring.c | 4 ++--
 io_uring/rsrc.c     | 2 +-
 io_uring/rsrc.h     | 6 ++++--
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index beedaf403284..a781b7243b97 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -1002,7 +1002,7 @@ static void __io_req_complete_post(struct io_kiocb *req, unsigned issue_flags)
 
 	if (rsrc_node) {
 		io_ring_submit_lock(ctx, issue_flags);
-		io_put_rsrc_node(rsrc_node);
+		io_put_rsrc_node(ctx, rsrc_node);
 		io_ring_submit_unlock(ctx, issue_flags);
 	}
 }
@@ -1123,7 +1123,7 @@ __cold void io_free_req_tw(struct io_kiocb *req, struct io_tw_state *ts)
 
 	if (req->rsrc_node) {
 		io_tw_lock(ctx, ts);
-		io_put_rsrc_node(req->rsrc_node);
+		io_put_rsrc_node(ctx, req->rsrc_node);
 	}
 	io_dismantle_req(req);
 	io_put_task_remote(req->task, 1);
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 345631091d80..d4bca5e18434 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -236,7 +236,7 @@ void io_rsrc_node_switch(struct io_ring_ctx *ctx,
 
 		atomic_inc(&data_to_kill->refs);
 		/* put master ref */
-		io_put_rsrc_node(rsrc_node);
+		io_put_rsrc_node(ctx, rsrc_node);
 		ctx->rsrc_node = NULL;
 	}
 
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index d1555eaae81a..99f2df4eafa1 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -117,8 +117,10 @@ int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
 int io_register_rsrc(struct io_ring_ctx *ctx, void __user *arg,
 			unsigned int size, unsigned int type);
 
-static inline void io_put_rsrc_node(struct io_rsrc_node *node)
+static inline void io_put_rsrc_node(struct io_ring_ctx *ctx, struct io_rsrc_node *node)
 {
+	lockdep_assert_held(&ctx->uring_lock);
+
 	if (node && !--node->refs)
 		io_rsrc_node_ref_zero(node);
 }
@@ -126,7 +128,7 @@ static inline void io_put_rsrc_node(struct io_rsrc_node *node)
 static inline void io_req_put_rsrc_locked(struct io_kiocb *req,
 					  struct io_ring_ctx *ctx)
 {
-	io_put_rsrc_node(req->rsrc_node);
+	io_put_rsrc_node(ctx, req->rsrc_node);
 }
 
 static inline void io_charge_rsrc_node(struct io_ring_ctx *ctx,
-- 
2.39.1