From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D152863B8 for ; Mon, 20 Feb 2023 13:57:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 58A96C433EF; Mon, 20 Feb 2023 13:57:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1676901460; bh=roMVyCeTwlxU9CK+65juiWQC6lSxkp+XDcq85zYy9A0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cQxqsXJST03w9E+Kc4Mf5rd/Quefjy8AgJKiAtPRCOb2/nfTBgqtuWr5ObX+foWH7 NSuoT2mAVc4GW3DcMNhgA4aN1HSRIcZ+oLwCgROhdN8kN/ubE8UpPq2EHGz1cYG8ns mqZ1kChsuLmvxKr4/vJbqA7JhChXOEwNIjb1Uqf0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jingbo Xu , Hou Tao , David Howells , Jeff Layton , Sasha Levin Subject: [PATCH 6.1 025/118] fscache: Use clear_and_wake_up_bit() in fscache_create_volume_work() Date: Mon, 20 Feb 2023 14:35:41 +0100 Message-Id: <20230220133601.441009966@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230220133600.368809650@linuxfoundation.org> References: <20230220133600.368809650@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Hou Tao [ Upstream commit 3288666c72568fe1cc7f5c5ae33dfd3ab18004c8 ] fscache_create_volume_work() uses wake_up_bit() to wake up the processes which are waiting for the completion of volume creation. According to comments in wake_up_bit() and waitqueue_active(), an extra smp_mb() is needed to guarantee the memory order between FSCACHE_VOLUME_CREATING flag and waitqueue_active() before invoking wake_up_bit(). Fixing it by using clear_and_wake_up_bit() to add the missing memory barrier. Reviewed-by: Jingbo Xu Signed-off-by: Hou Tao Signed-off-by: David Howells Reviewed-by: Jeff Layton Link: https://lore.kernel.org/r/20230113115211.2895845-3-houtao@huaweicloud.com/ # v3 Signed-off-by: Sasha Levin --- fs/fscache/volume.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/fscache/volume.c b/fs/fscache/volume.c index 903af9d85f8b9..cdf991bdd9def 100644 --- a/fs/fscache/volume.c +++ b/fs/fscache/volume.c @@ -280,8 +280,7 @@ static void fscache_create_volume_work(struct work_struct *work) fscache_end_cache_access(volume->cache, fscache_access_acquire_volume_end); - clear_bit_unlock(FSCACHE_VOLUME_CREATING, &volume->flags); - wake_up_bit(&volume->flags, FSCACHE_VOLUME_CREATING); + clear_and_wake_up_bit(FSCACHE_VOLUME_CREATING, &volume->flags); fscache_put_volume(volume, fscache_volume_put_create_work); } -- 2.39.0