Linux RAID subsystem development
 help / color / mirror / Atom feed
From: Guoqing Jiang <gqjiang@suse.com>
To: linux-raid@vger.kernel.org
Cc: shli@fb.com, Guoqing Jiang <gqjiang@suse.com>
Subject: [PATCH V2 06/10] md-cluster: protect md_find_rdev_nr_rcu with rcu lock
Date: Fri, 12 Aug 2016 13:42:39 +0800	[thread overview]
Message-ID: <1470980563-26062-7-git-send-email-gqjiang@suse.com> (raw)
In-Reply-To: <1470980563-26062-1-git-send-email-gqjiang@suse.com>

We need to use rcu_read_lock/unlock to avoid potential
race.

Reported-by: Shaohua Li <shli@fb.com>
Reviewed-by: NeilBrown <neilb@suse.com>
Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
---
 drivers/md/md-cluster.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/md/md-cluster.c b/drivers/md/md-cluster.c
index ea2699e..8972413 100644
--- a/drivers/md/md-cluster.c
+++ b/drivers/md/md-cluster.c
@@ -486,9 +486,10 @@ static void process_metadata_update(struct mddev *mddev, struct cluster_msg *msg
 
 static void process_remove_disk(struct mddev *mddev, struct cluster_msg *msg)
 {
-	struct md_rdev *rdev = md_find_rdev_nr_rcu(mddev,
-						   le32_to_cpu(msg->raid_slot));
+	struct md_rdev *rdev;
 
+	rcu_read_lock();
+	rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));
 	if (rdev) {
 		set_bit(ClusterRemove, &rdev->flags);
 		set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
@@ -497,18 +498,21 @@ static void process_remove_disk(struct mddev *mddev, struct cluster_msg *msg)
 	else
 		pr_warn("%s: %d Could not find disk(%d) to REMOVE\n",
 			__func__, __LINE__, le32_to_cpu(msg->raid_slot));
+	rcu_read_unlock();
 }
 
 static void process_readd_disk(struct mddev *mddev, struct cluster_msg *msg)
 {
-	struct md_rdev *rdev = md_find_rdev_nr_rcu(mddev,
-						   le32_to_cpu(msg->raid_slot));
+	struct md_rdev *rdev;
 
+	rcu_read_lock();
+	rdev = md_find_rdev_nr_rcu(mddev, le32_to_cpu(msg->raid_slot));
 	if (rdev && test_bit(Faulty, &rdev->flags))
 		clear_bit(Faulty, &rdev->flags);
 	else
 		pr_warn("%s: %d Could not find disk(%d) which is faulty",
 			__func__, __LINE__, le32_to_cpu(msg->raid_slot));
+	rcu_read_unlock();
 }
 
 static int process_recvd_msg(struct mddev *mddev, struct cluster_msg *msg)
-- 
2.6.2


  parent reply	other threads:[~2016-08-12  5:42 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-12  5:42 [PATCH V2 00/10] The latest changes for md-cluster Guoqing Jiang
2016-08-12  5:42 ` [PATCH V2 01/10] md-cluster: call md_kick_rdev_from_array once ack failed Guoqing Jiang
2016-08-12  5:42 ` [PATCH V2 02/10] md-cluster: use FORCEUNLOCK in lockres_free Guoqing Jiang
2016-08-12  5:42 ` [PATCH V2 03/10] md-cluster: remove some unnecessary dlm_unlock_sync Guoqing Jiang
2016-08-12  5:42 ` [PATCH V2 04/10] md: changes for MD_STILL_CLOSED flag Guoqing Jiang
2016-08-12  5:42 ` [PATCH V2 05/10] md-cluster: clean related infos of cluster Guoqing Jiang
2016-08-12  5:42 ` Guoqing Jiang [this message]
2016-08-12  5:42 ` [PATCH V2 07/10] md: remove obsolete ret in md_start_sync Guoqing Jiang
2016-08-12  5:42 ` [PATCH V2 08/10] md-cluster: convert the completion to wait queue Guoqing Jiang
2016-08-12  5:42 ` [PATCH V2 09/10] md-cluster: introduce dlm_lock_sync_interruptible to fix tasks hang Guoqing Jiang
2016-08-12  5:42 ` [PATCH V2 10/10] md-cluster: make resync lock also could be interruptted Guoqing Jiang
2016-08-17  1:49 ` [PATCH V2 00/10] The latest changes for md-cluster Shaohua Li

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=1470980563-26062-7-git-send-email-gqjiang@suse.com \
    --to=gqjiang@suse.com \
    --cc=linux-raid@vger.kernel.org \
    --cc=shli@fb.com \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox