Patch "io_uring: Convert advanced XArray uses to the normal API" has been added to the 5.8-stable tree

[<gregkh@xxxxxxxxxxxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    io_uring: Convert advanced XArray uses to the normal API

to the 5.8-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     io_uring-convert-advanced-xarray-uses-to-the-normal-api.patch
and it can be found in the queue-5.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From foo@baz Thu Oct 29 01:16:54 PM CET 2020
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Date: Fri, 9 Oct 2020 13:49:53 +0100
Subject: io_uring: Convert advanced XArray uses to the normal API

From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>

commit 5e2ed8c4f45093698855b1f45cdf43efbf6dd498 upstream.

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@xxxxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 fs/io_uring.c |   14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7958,27 +7958,17 @@ static int io_uring_add_task_file(struct
 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);


Patches currently in stable-queue which might be from willy@xxxxxxxxxxxxx are

queue-5.8/io_uring-convert-advanced-xarray-uses-to-the-normal-api.patch
queue-5.8/io_uring-fix-xarray-usage-in-io_uring_add_task_file.patch
queue-5.8/io_uring-fix-use-of-xarray-in-__io_uring_files_cancel.patch