From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shaohua Li Subject: [PATCH 2/2] raid5-cache: fix lockdep warning Date: Wed, 16 Nov 2016 17:20:19 -0800 Message-ID: <29709f0fbd66cef1d743a78be112305976eb4880.1479345454.git.shli@fb.com> References: <5d6f023fb1d1398317d07f02634f90b055e26f4b.1479345454.git.shli@fb.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <5d6f023fb1d1398317d07f02634f90b055e26f4b.1479345454.git.shli@fb.com> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org Cc: songliubraving@fb.com, neilb@suse.com List-Id: linux-raid.ids lockdep reports warning of the rcu_dereference usage. Using normal rdev access pattern to avoid the warning. Signed-off-by: Shaohua Li --- drivers/md/raid5-cache.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 641dec8..fe62578 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -987,16 +987,28 @@ static int r5l_recovery_flush_one_stripe(struct r5l_log *log, continue; /* in case device is broken */ + rcu_read_lock(); rdev = rcu_dereference(conf->disks[disk_index].rdev); - if (rdev) + if (rdev) { + atomic_inc(&rdev->nr_pending); + rcu_read_unlock(); sync_page_io(rdev, stripe_sect, PAGE_SIZE, sh->dev[disk_index].page, REQ_OP_WRITE, 0, false); + rdev_dec_pending(rdev, rdev->mddev); + rcu_read_lock(); + } rrdev = rcu_dereference(conf->disks[disk_index].replacement); - if (rrdev) + if (rrdev) { + atomic_inc(&rrdev->nr_pending); + rcu_read_unlock(); sync_page_io(rrdev, stripe_sect, PAGE_SIZE, sh->dev[disk_index].page, REQ_OP_WRITE, 0, false); + rdev_dec_pending(rrdev, rrdev->mddev); + rcu_read_lock(); + } + rcu_read_unlock(); } raid5_release_stripe(sh); return 0; -- 2.9.3