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| author |   Gioh Kim <gi-oh.kim@cloud.ionos.com> | 2021-04-19 09:37:13 +0200 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2021-04-20 08:59:04 -0600 |
| commit | c77bfa8f5dbd3f8bbb99a751bab00ebcc229a5c5 (patch) | |
| tree | d510b6fca467acbe0e828f25d8a01aaa3c293044 /drivers/block | |
| parent | block/rnbd-srv: Prevent a deadlock generated by accessing sysfs in parallel (diff) | |
| download | linux-dev-c77bfa8f5dbd3f8bbb99a751bab00ebcc229a5c5.tar.xz linux-dev-c77bfa8f5dbd3f8bbb99a751bab00ebcc229a5c5.zip | |
block/rnbd-srv: Remove force_close file after holding a lock
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 <gi-oh.kim@ionos.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Jack Wang <jinpu.wang@ionos.com>
Link: https://lore.kernel.org/r/20210419073722.15351-11-gi-oh.kim@ionos.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/rnbd/rnbd-srv-sysfs.c | 5 | ||||
| -rw-r--r-- | drivers/block/rnbd/rnbd-srv.c | 5 | ||||
| -rw-r--r-- | 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, |