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 18B8A25EF9C; Tue, 11 Nov 2025 01:41:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762825278; cv=none; b=RfSRYHvPNrCsRmdX7cWYL5leYGMKBAROaeJT0LotyHpkeEEMQ9ZLYnIk3HTdu8QsI5QeoBZ+1BB10+QeiLYpzrXtthui9M2ZvRsSD98udf2ErRNfQELjikhd+Uq1UNIWGqrBbPUHsnxdhb9l4dqCDYy46diZhV2g8XP5zdrY5DA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762825278; c=relaxed/simple; bh=FVbny0FRXhGt0nX/v/dx6gIcYbp9YCn3BlwKqKAntJ8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=m/C2xCtinaBMuyuYQ5DG1fZ9hfxKYq3FX2z9Cv/uwnjJtl6I+sFnLm3dSWllvMcKHAADEj4QO5bRvro9Fg3nSRYeQFS7vQYtnGGryQoRoyb0XW21wOKb6ZN4edb97wxdl2a2JKhjGSELgh/3Xw9s56GiyXpTLm5AI1Gv5S5EsJM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=TMDT+2rL; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="TMDT+2rL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 72795C113D0; Tue, 11 Nov 2025 01:41:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1762825277; bh=FVbny0FRXhGt0nX/v/dx6gIcYbp9YCn3BlwKqKAntJ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TMDT+2rLAZGFBznyz/tOSIxYKbaSYjo/eukhrNN8m985ha3sERtEllwOzez58JPj2 jOeIARpIbFbj6pn4itn7+vact7jzawKpgfxYCR/amiACRqdu4OtUbfFNDTQMCbWGRY CMYa/T6xkVPuLgzoFuTJBUV99qcpFyuX4nZIQyBs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Viacheslav Dubeyko , Alex Markuze , Ilya Dryomov , Sasha Levin Subject: [PATCH 6.17 735/849] ceph: refactor wake_up_bit() pattern of calling Date: Tue, 11 Nov 2025 09:45:05 +0900 Message-ID: <20251111004554.209138683@linuxfoundation.org> X-Mailer: git-send-email 2.51.2 In-Reply-To: <20251111004536.460310036@linuxfoundation.org> References: <20251111004536.460310036@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Viacheslav Dubeyko [ Upstream commit 53db6f25ee47cb1265141d31562604e56146919a ] The wake_up_bit() is called in ceph_async_unlink_cb(), wake_async_create_waiters(), and ceph_finish_async_create(). It makes sense to switch on clear_bit() function, because it makes the code much cleaner and easier to understand. More important rework is the adding of smp_mb__after_atomic() memory barrier after the bit modification and before wake_up_bit() call. It can prevent potential race condition of accessing the modified bit in other threads. Luckily, clear_and_wake_up_bit() already implements the required functionality pattern: static inline void clear_and_wake_up_bit(int bit, unsigned long *word) { clear_bit_unlock(bit, word); /* See wake_up_bit() for which memory barrier you need to use. */ smp_mb__after_atomic(); wake_up_bit(word, bit); } Signed-off-by: Viacheslav Dubeyko Reviewed-by: Alex Markuze Signed-off-by: Ilya Dryomov Signed-off-by: Sasha Levin --- fs/ceph/dir.c | 3 +-- fs/ceph/file.c | 6 ++---- 2 files changed, 3 insertions(+), 6 deletions(-) diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c index 32973c62c1a23..d18c0eaef9b7e 100644 --- a/fs/ceph/dir.c +++ b/fs/ceph/dir.c @@ -1260,8 +1260,7 @@ static void ceph_async_unlink_cb(struct ceph_mds_client *mdsc, spin_unlock(&fsc->async_unlink_conflict_lock); spin_lock(&dentry->d_lock); - di->flags &= ~CEPH_DENTRY_ASYNC_UNLINK; - wake_up_bit(&di->flags, CEPH_DENTRY_ASYNC_UNLINK_BIT); + clear_and_wake_up_bit(CEPH_DENTRY_ASYNC_UNLINK_BIT, &di->flags); spin_unlock(&dentry->d_lock); synchronize_rcu(); diff --git a/fs/ceph/file.c b/fs/ceph/file.c index 978acd3d4b329..d7b943feb9320 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -579,8 +579,7 @@ static void wake_async_create_waiters(struct inode *inode, spin_lock(&ci->i_ceph_lock); if (ci->i_ceph_flags & CEPH_I_ASYNC_CREATE) { - ci->i_ceph_flags &= ~CEPH_I_ASYNC_CREATE; - wake_up_bit(&ci->i_ceph_flags, CEPH_ASYNC_CREATE_BIT); + clear_and_wake_up_bit(CEPH_ASYNC_CREATE_BIT, &ci->i_ceph_flags); if (ci->i_ceph_flags & CEPH_I_ASYNC_CHECK_CAPS) { ci->i_ceph_flags &= ~CEPH_I_ASYNC_CHECK_CAPS; @@ -762,8 +761,7 @@ static int ceph_finish_async_create(struct inode *dir, struct inode *inode, } spin_lock(&dentry->d_lock); - di->flags &= ~CEPH_DENTRY_ASYNC_CREATE; - wake_up_bit(&di->flags, CEPH_DENTRY_ASYNC_CREATE_BIT); + clear_and_wake_up_bit(CEPH_DENTRY_ASYNC_CREATE_BIT, &di->flags); spin_unlock(&dentry->d_lock); return ret; -- 2.51.0