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From: Kirill Tkhai <ktkhai@virtuozzo.com>
To: miklos@szeredi.hu, ktkhai@virtuozzo.com, linux-fsdevel@vger.kernel.org
Subject: [PATCH 3/6] fuse: Underline congestion_threshold and max_background may be read w/o fc->lock
Date: Mon, 27 Aug 2018 18:29:29 +0300	[thread overview]
Message-ID: <153538376941.18303.12286472696863147895.stgit@localhost.localdomain> (raw)
In-Reply-To: <153538208536.18303.10732945923322972743.stgit@localhost.localdomain>

Since they are of unsigned int type, it's allowed to read them
unlocked during reporting to userspace. Let's underline this fact
with READ_ONCE() macroses.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
---
 fs/fuse/control.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/fuse/control.c b/fs/fuse/control.c
index e09b9cd9c3fc..c7290625e171 100644
--- a/fs/fuse/control.c
+++ b/fs/fuse/control.c
@@ -107,7 +107,7 @@ static ssize_t fuse_conn_max_background_read(struct file *file,
 	if (!fc)
 		return 0;
 
-	val = fc->max_background;
+	val = READ_ONCE(fc->max_background);
 	fuse_conn_put(fc);
 
 	return fuse_conn_limit_read(file, buf, len, ppos, val);
@@ -144,7 +144,7 @@ static ssize_t fuse_conn_congestion_threshold_read(struct file *file,
 	if (!fc)
 		return 0;
 
-	val = fc->congestion_threshold;
+	val = READ_ONCE(fc->congestion_threshold);
 	fuse_conn_put(fc);
 
 	return fuse_conn_limit_read(file, buf, len, ppos, val);

  parent reply	other threads:[~2018-08-27 19:16 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-27 15:29 [PATCH 0/6] Extract bg queue logic out fuse_conn::lock Kirill Tkhai
2018-08-27 15:29 ` [PATCH 1/6] fuse: Use list_first_entry() in flush_bg_queue() Kirill Tkhai
2018-08-27 15:29 ` [PATCH 2/6] fuse: Move clear_bit() up in request_end() Kirill Tkhai
2018-08-27 15:29 ` Kirill Tkhai [this message]
2018-08-27 15:29 ` [PATCH 4/6] fuse: Lock fc->lock during changing num_background and congestion_threshold Kirill Tkhai
2018-08-27 15:29 ` [PATCH 5/6] fs: Introduce fuse_conn::bg_lock Kirill Tkhai
2018-08-27 15:29 ` [PATCH 6/6] fuse: Do not take fuse_conn::lock on fuse_request_send_background() Kirill Tkhai
2018-09-26 12:25   ` Miklos Szeredi
2018-09-26 15:18     ` Kirill Tkhai
2018-09-27  8:37       ` Kirill Tkhai
2018-09-27 11:25         ` Miklos Szeredi
2018-09-11 10:14 ` [PATCH 0/6] Extract bg queue logic out fuse_conn::lock Kirill Tkhai
2018-10-01  9:23   ` Miklos Szeredi

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