[PATCH 8/8] io_uring: kill not used anymore inflight_lock

[Pavel Begunkov <asml.silence@gmail.com>]

ctx->inflight_lock now doesn't protect anything that should be protected
-- tctx->inflight_files is atomic, and inflight list is gone. Time to
eradicate it.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 134ea0e3373d..a678920b1c8d 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -377,8 +377,6 @@ struct io_ring_ctx {
 		struct hlist_head	*cancel_hash;
 		unsigned		cancel_hash_bits;
 		bool			poll_multi_file;
-
-		spinlock_t		inflight_lock;
 	} ____cacheline_aligned_in_smp;
 
 	struct delayed_work		file_put_work;
@@ -1303,7 +1301,6 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
 	INIT_LIST_HEAD(&ctx->iopoll_list);
 	INIT_LIST_HEAD(&ctx->defer_list);
 	INIT_LIST_HEAD(&ctx->timeout_list);
-	spin_lock_init(&ctx->inflight_lock);
 	INIT_DELAYED_WORK(&ctx->file_put_work, io_file_put_work);
 	init_llist_head(&ctx->file_put_llist);
 	return ctx;
@@ -1433,7 +1430,6 @@ static bool io_grab_identity(struct io_kiocb *req)
 {
 	const struct io_op_def *def = &io_op_defs[req->opcode];
 	struct io_identity *id = req->work.identity;
-	struct io_ring_ctx *ctx = req->ctx;
 
 	if (def->work_flags & IO_WQ_WORK_FSIZE) {
 		if (id->fsize != rlimit(RLIMIT_FSIZE))
@@ -1491,9 +1487,7 @@ static bool io_grab_identity(struct io_kiocb *req)
 		get_nsproxy(id->nsproxy);
 		req->flags |= REQ_F_INFLIGHT;
 
-		spin_lock_irq(&ctx->inflight_lock);
 		atomic_inc(&current->io_uring->inflight_files);
-		spin_unlock_irq(&ctx->inflight_lock);
 		req->work.flags |= IO_WQ_WORK_FILES;
 	}
 
@@ -6088,15 +6082,11 @@ static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 
 static void io_req_drop_files(struct io_kiocb *req)
 {
-	struct io_ring_ctx *ctx = req->ctx;
 	struct io_uring_task *tctx = req->task->io_uring;
-	unsigned long flags;
 
 	put_files_struct(req->work.identity->files);
 	put_nsproxy(req->work.identity->nsproxy);
-	spin_lock_irqsave(&ctx->inflight_lock, flags);
 	atomic_dec(&tctx->inflight_files);
-	spin_unlock_irqrestore(&ctx->inflight_lock, flags);
 	req->flags &= ~REQ_F_INFLIGHT;
 	req->work.flags &= ~IO_WQ_WORK_FILES;
 	if (atomic_read(&tctx->in_idle))
-- 
2.24.0