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[95.90.238.229]) by smtp.googlemail.com with ESMTPSA id g22sm8701833ejz.46.2021.04.19.00.37.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Apr 2021 00:37:56 -0700 (PDT) From: Gioh Kim To: linux-block@vger.kernel.org, linux-doc@vger.kernel.org Cc: axboe@kernel.dk, akinobu.mita@gmail.com, corbet@lwn.net, hch@infradead.org, sagi@grimberg.me, bvanassche@acm.org, haris.iqbal@ionos.com, jinpu.wang@ionos.com, Gioh Kim , Gioh Kim Subject: [PATCHv5 for-next 10/19] block/rnbd-srv: Remove force_close file after holding a lock Date: Mon, 19 Apr 2021 09:37:13 +0200 Message-Id: <20210419073722.15351-11-gi-oh.kim@ionos.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210419073722.15351-1-gi-oh.kim@ionos.com> References: <20210419073722.15351-1-gi-oh.kim@ionos.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org From: Gioh Kim We changed the rnbd_srv_sess_dev_force_close to use try-lock because rnbd_srv_sess_dev_force_close and process_msg_close can generate a deadlock. Now rnbd_srv_sess_dev_force_close would do nothing if it fails to get the lock. So removing the force_close file should be moved to after the lock. Or the force_close file is removed but the others are not removed. Signed-off-by: Gioh Kim Signed-off-by: Md Haris Iqbal Signed-off-by: Jack Wang --- drivers/block/rnbd/rnbd-srv-sysfs.c | 5 +---- drivers/block/rnbd/rnbd-srv.c | 5 ++++- drivers/block/rnbd/rnbd-srv.h | 3 ++- 3 files changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/block/rnbd/rnbd-srv-sysfs.c b/drivers/block/rnbd/rnbd-srv-sysfs.c index 05ffe488ddc6..acf5fced11ef 100644 --- a/drivers/block/rnbd/rnbd-srv-sysfs.c +++ b/drivers/block/rnbd/rnbd-srv-sysfs.c @@ -147,10 +147,7 @@ static ssize_t rnbd_srv_dev_session_force_close_store(struct kobject *kobj, } rnbd_srv_info(sess_dev, "force close requested\n"); - - /* first remove sysfs itself to avoid deadlock */ - sysfs_remove_file_self(&sess_dev->kobj, &attr->attr); - rnbd_srv_sess_dev_force_close(sess_dev); + rnbd_srv_sess_dev_force_close(sess_dev, attr); return count; } diff --git a/drivers/block/rnbd/rnbd-srv.c b/drivers/block/rnbd/rnbd-srv.c index 1549a6361630..a9bb414f7442 100644 --- a/drivers/block/rnbd/rnbd-srv.c +++ b/drivers/block/rnbd/rnbd-srv.c @@ -329,7 +329,8 @@ static int rnbd_srv_link_ev(struct rtrs_srv *rtrs, } } -void rnbd_srv_sess_dev_force_close(struct rnbd_srv_sess_dev *sess_dev) +void rnbd_srv_sess_dev_force_close(struct rnbd_srv_sess_dev *sess_dev, + struct kobj_attribute *attr) { struct rnbd_srv_session *sess = sess_dev->sess; @@ -337,6 +338,8 @@ void rnbd_srv_sess_dev_force_close(struct rnbd_srv_sess_dev *sess_dev) /* It is already started to close by client's close message. */ if (!mutex_trylock(&sess->lock)) return; + /* first remove sysfs itself to avoid deadlock */ + sysfs_remove_file_self(&sess_dev->kobj, &attr->attr); rnbd_srv_destroy_dev_session_sysfs(sess_dev); mutex_unlock(&sess->lock); } diff --git a/drivers/block/rnbd/rnbd-srv.h b/drivers/block/rnbd/rnbd-srv.h index b157371c25ed..98ddc31eb408 100644 --- a/drivers/block/rnbd/rnbd-srv.h +++ b/drivers/block/rnbd/rnbd-srv.h @@ -64,7 +64,8 @@ struct rnbd_srv_sess_dev { enum rnbd_access_mode access_mode; }; -void rnbd_srv_sess_dev_force_close(struct rnbd_srv_sess_dev *sess_dev); +void rnbd_srv_sess_dev_force_close(struct rnbd_srv_sess_dev *sess_dev, + struct kobj_attribute *attr); /* rnbd-srv-sysfs.c */ int rnbd_srv_create_dev_sysfs(struct rnbd_srv_dev *dev, -- 2.25.1