From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Simmons Date: Thu, 27 Feb 2020 16:14:12 -0500 Subject: [lustre-devel] [PATCH 384/622] lustre: obdclass: use RCU to release lu_env_item In-Reply-To: <1582838290-17243-1-git-send-email-jsimmons@infradead.org> References: <1582838290-17243-1-git-send-email-jsimmons@infradead.org> Message-ID: <1582838290-17243-385-git-send-email-jsimmons@infradead.org> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lustre-devel@lists.lustre.org From: Alex Zhuravlev as rhashtable_lookup_fast() is lockless and can find just released objects. Fixes: c678ad5a25 ("lustre: obdclass: put all service's env on the list") WC-bug-id: https://jira.whamcloud.com/browse/LU-12491 Lustre-commit: 87306c22e4b9 ("LU-12491 obdclass: use RCU to release lu_env_item") Signed-off-by: Alex Zhuravlev Reviewed-on: https://review.whamcloud.com/35038 Reviewed-by: Neil Brown Reviewed-by: Shaun Tancheff Reviewed-by: James Simmons Reviewed-by: Oleg Drokin Signed-off-by: James Simmons --- fs/lustre/obdclass/lu_object.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/fs/lustre/obdclass/lu_object.c b/fs/lustre/obdclass/lu_object.c index bafd817..c94911d 100644 --- a/fs/lustre/obdclass/lu_object.c +++ b/fs/lustre/obdclass/lu_object.c @@ -1870,6 +1870,7 @@ struct lu_env_item { struct task_struct *lei_task; /* rhashtable key */ struct rhash_head lei_linkage; struct lu_env *lei_env; + struct rcu_head lei_rcu_head; }; static const struct rhashtable_params lu_env_rhash_params = { @@ -1909,6 +1910,14 @@ int lu_env_add(struct lu_env *env) } EXPORT_SYMBOL(lu_env_add); +static void lu_env_item_free(struct rcu_head *head) +{ + struct lu_env_item *lei; + + lei = container_of(head, struct lu_env_item, lei_rcu_head); + kfree(lei); +} + void lu_env_remove(struct lu_env *env) { struct lu_env_item *lei; @@ -1923,13 +1932,11 @@ void lu_env_remove(struct lu_env *env) } } - rcu_read_lock(); lei = rhashtable_lookup_fast(&lu_env_rhash, &task, lu_env_rhash_params); if (lei && rhashtable_remove_fast(&lu_env_rhash, &lei->lei_linkage, lu_env_rhash_params) == 0) - kfree(lei); - rcu_read_unlock(); + call_rcu(&lei->lei_rcu_head, lu_env_item_free); } EXPORT_SYMBOL(lu_env_remove); -- 1.8.3.1