linux-kernel - [PATCH 3/3] io_uring: Convert advanced XArray uses to the normal API

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Date:   Fri,  9 Oct 2020 13:49:53 +0100
From:   "Matthew Wilcox (Oracle)" <willy@...radead.org>
To:     Jens Axboe <axboe@...nel.dk>
Cc:     "Matthew Wilcox (Oracle)" <willy@...radead.org>,
        linux-fsdevel@...r.kernel.org, io-uring@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Pavel Begunkov <asml.silence@...il.com>
Subject: [PATCH 3/3] io_uring: Convert advanced XArray uses to the normal API

There are no bugs here that I've spotted, it's just easier to use the
normal API and there are no performance advantages to using the more
verbose advanced API.

Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
---
 fs/io_uring.c | 14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index bcef6210bf67..1a894df526da 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8615,27 +8615,17 @@ static int io_uring_add_task_file(struct file *file)
 static void io_uring_del_task_file(struct file *file)
 {
 	struct io_uring_task *tctx = current->io_uring;
-	XA_STATE(xas, &tctx->xa, (unsigned long) file);
 
 	if (tctx->last == file)
 		tctx->last = NULL;
-
-	xas_lock(&xas);
-	file = xas_store(&xas, NULL);
-	xas_unlock(&xas);
-
+	file = xa_erase(&tctx->xa, (unsigned long)file);
 	if (file)
 		fput(file);
 }
 
 static void __io_uring_attempt_task_drop(struct file *file)
 {
-	XA_STATE(xas, &current->io_uring->xa, (unsigned long) file);
-	struct file *old;
-
-	rcu_read_lock();
-	old = xas_load(&xas);
-	rcu_read_unlock();
+	struct file *old = xa_load(&current->io_uring->xa, (unsigned long)file);
 
 	if (old == file)
 		io_uring_del_task_file(file);
-- 
2.28.0