Linux-Doc Archive on lore.kernel.org
 help / color / Atom feed
From: Gioh Kim <gi-oh.kim@ionos.com>
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 <gi-oh.kim@cloud.ionos.com>,
	Gioh Kim <gi-oh.kim@ionos.com>
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> (raw)
In-Reply-To: <20210419073722.15351-1-gi-oh.kim@ionos.com>

From: Gioh Kim <gi-oh.kim@cloud.ionos.com>

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>
---
 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


  parent reply index

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-19  7:37 [PATCHv5 for-next 00/19] Misc update for rnbd Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 01/19] MAINTAINERS: Change maintainer for rnbd module Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 02/19] Documentation/sysfs-block-rnbd: Add descriptions for remap_device and resize Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 03/19] block/rnbd-clt: Remove some arguments from insert_dev_if_not_exists_devpath Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 04/19] block/rnbd-clt: Remove some arguments from rnbd_client_setup_device Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 05/19] block/rnbd-clt: Move add_disk(dev->gd) to rnbd_clt_setup_gen_disk Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 06/19] block/rnbd: Kill rnbd_clt_destroy_default_group Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 07/19] block/rnbd: Kill destroy_device_cb Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 08/19] block/rnbd-clt: Replace {NO_WAIT,WAIT} with RTRS_PERMIT_{WAIT,NOWAIT} Gioh Kim
2021-04-19  7:46   ` Leon Romanovsky
2021-04-19  7:37 ` [PATCHv5 for-next 09/19] block/rnbd-srv: Prevent a deadlock generated by accessing sysfs in parallel Gioh Kim
2021-04-19  7:37 ` Gioh Kim [this message]
2021-04-19  7:37 ` [PATCHv5 for-next 11/19] block/rnbd-clt: Improve find_or_create_sess() return check Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 12/19] block/rnbd-clt: Fix missing a memory free when unloading the module Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 13/19] block/rnbd-clt: Support polling mode for IO latency optimization Gioh Kim
2021-04-19  7:47   ` Leon Romanovsky
2021-04-19  7:37 ` [PATCHv5 for-next 14/19] Documentation/ABI/rnbd-clt: Add description for nr_poll_queues Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 15/19] block/rnbd-srv: Remove unused arguments of rnbd_srv_rdma_ev Gioh Kim
2021-04-19  7:47   ` Leon Romanovsky
2021-04-19  7:37 ` [PATCHv5 for-next 16/19] block/rnbd-clt: Generate kobject_uevent when the rnbd device state changes Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 17/19] block/rnbd-clt: Remove max_segment_size Gioh Kim
2021-04-19  7:47   ` Leon Romanovsky
2021-04-19  7:37 ` [PATCHv5 for-next 18/19] block/rnbd-clt-sysfs: Remove copy buffer overlap in rnbd_clt_get_path_name Gioh Kim
2021-04-19  7:37 ` [PATCHv5 for-next 19/19] block/rnbd: Use strscpy instead of strlcpy Gioh Kim
2021-04-19 17:54 ` [PATCHv5 for-next 00/19] Misc update for rnbd Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210419073722.15351-11-gi-oh.kim@ionos.com \
    --to=gi-oh.kim@ionos.com \
    --cc=akinobu.mita@gmail.com \
    --cc=axboe@kernel.dk \
    --cc=bvanassche@acm.org \
    --cc=corbet@lwn.net \
    --cc=gi-oh.kim@cloud.ionos.com \
    --cc=haris.iqbal@ionos.com \
    --cc=hch@infradead.org \
    --cc=jinpu.wang@ionos.com \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=sagi@grimberg.me \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Doc Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-doc/0 linux-doc/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-doc linux-doc/ https://lore.kernel.org/linux-doc \
		linux-doc@vger.kernel.org
	public-inbox-index linux-doc

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-doc


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git