From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-113.freemail.mail.aliyun.com (out30-113.freemail.mail.aliyun.com [115.124.30.113]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3D0562F360A for ; Wed, 22 Jul 2026 12:49:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.113 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784724586; cv=none; b=L4lMByZeso9psGnO0IrFQQGZchngRRUmn+T2SDmEiwvwlxJ7v4WZbBkHmV4v9DpoUCifnT/+Q226kqG0uhmmexfFE1LpI22dVGb4Lw2jmbcsSPsk8YLgffX7rENIOlnD1lUuBEAlzrPBUbYD+gGx3ex9oeHGvWmAiPbqavHEWRc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784724586; c=relaxed/simple; bh=cxHikLnOINPUdEmPCdbaVwlYo6YTatvM/crhEXy5RTI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=C5wG2+AHTCnxK6M0TIWwO4lpLOP6jl191mdVqwDRcV9cTGk0+CQAVI5DTLOQ1bwbxb303rGx7ztnIQDPPRBK7KgW7EiZkzUg1LroiCLB9/MR2muRDppPPb535oWKONAy1yhqRpkd9/Gub6SmP6mbnfbetuEinwQG21ui9B2IYuI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=xzPTGsZR; arc=none smtp.client-ip=115.124.30.113 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="xzPTGsZR" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1784724576; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=PEqRa9WNHp2UTn+NgMgPVbwjvcuLfhIBSAHM6BSit+0=; b=xzPTGsZRWDTgXCjPIK1l3UgAY/cDx1QdsfAovwve6FgfXs/DhHSFHZ54QlEQuu8w4rX7JYCjhTGm3IonftpsdARJ1xtsZBupy72ivhC+IyScjEMmM7HTVYmqDHhk/KHSxEbsk1ahnkMH2kEVMBHxvbE/RZA/FL7EgO0pBDYSEPI= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R111e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033037033178;MF=joseph.qi@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0X7dMO6v_1784724575; Received: from localhost(mailfrom:joseph.qi@linux.alibaba.com fp:SMTPD_---0X7dMO6v_1784724575 cluster:ay36) by smtp.aliyun-inc.com; Wed, 22 Jul 2026 20:49:35 +0800 From: Joseph Qi To: Andrew Morton , Mark Fasheh , Joel Becker , Heming Zhao Cc: ocfs2-devel@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/3] ocfs2: cluster: avoid lock order inversion in o2hb_region_pin() from drop_item Date: Wed, 22 Jul 2026 20:49:32 +0800 Message-Id: <20260722124933.430554-3-joseph.qi@linux.alibaba.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20260722124933.430554-1-joseph.qi@linux.alibaba.com> References: <20260722124933.430554-1-joseph.qi@linux.alibaba.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit o2hb_heartbeat_group_drop_item() is called from configfs rmdir with the parent directory's inode_lock held. It calls o2hb_region_pin() -> o2nm_depend_item() -> configfs_depend_item(), which acquires the configfs root inode_lock. This creates a parent -> root inode_lock nesting that could deadlock against paths taking root -> parent (e.g. subsystem unregistration). Fix this by using configfs_depend_item_unlocked() when o2hb_region_pin() is called from a configfs callback context. This variant skips the root inode_lock when caller and target are in the same subsystem, which is safe because VFS already holds a lock preventing unregistration. Add o2nm_depend_item_unlocked() wrapper and a from_callback parameter to o2hb_region_pin() to select the appropriate variant. Fixes: 58a3158a5d17 ("ocfs2/cluster: Pin/unpin o2hb regions") Signed-off-by: Joseph Qi --- fs/ocfs2/cluster/heartbeat.c | 17 ++++++++++------- fs/ocfs2/cluster/nodemanager.c | 6 ++++++ fs/ocfs2/cluster/nodemanager.h | 1 + 3 files changed, 17 insertions(+), 7 deletions(-) diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c index 5ca1d9c0c6575..b9395835523e2 100644 --- a/fs/ocfs2/cluster/heartbeat.c +++ b/fs/ocfs2/cluster/heartbeat.c @@ -146,7 +146,7 @@ static unsigned int o2hb_dependent_users; * In global heartbeat mode, we pin/unpin all o2hb regions. This solution * works for both file system and userdlm domains. */ -static int o2hb_region_pin(const char *region_uuid); +static int o2hb_region_pin(const char *region_uuid, bool from_callback); static void o2hb_region_unpin(const char *region_uuid); /* Only sets a new threshold if there are no active regions. @@ -2188,7 +2188,7 @@ static void o2hb_heartbeat_group_drop_item(struct config_group *group, if (bitmap_weight(o2hb_quorum_region_bitmap, O2NM_MAX_REGIONS) <= O2HB_PIN_CUT_OFF) - o2hb_region_pin(NULL); + o2hb_region_pin(NULL, true); unlock: spin_unlock(&o2hb_live_lock); @@ -2330,7 +2330,7 @@ EXPORT_SYMBOL_GPL(o2hb_setup_callback); * In local, we only pin the matching region. In global we pin all the active * regions. */ -static int o2hb_region_pin(const char *region_uuid) +static int o2hb_region_pin(const char *region_uuid, bool from_callback) { int ret = 0, found; struct o2hb_region *reg, *pinned; @@ -2385,7 +2385,10 @@ static int o2hb_region_pin(const char *region_uuid) spin_unlock(&o2hb_live_lock); /* Ignore ENOENT only for local hb (userdlm domain) */ - ret = o2nm_depend_item(&pinned->hr_item); + if (from_callback) + ret = o2nm_depend_item_unlocked(&pinned->hr_item); + else + ret = o2nm_depend_item(&pinned->hr_item); spin_lock(&o2hb_live_lock); if (!ret) { @@ -2483,8 +2486,8 @@ static int o2hb_region_inc_user(const char *region_uuid) /* local heartbeat */ if (!o2hb_global_heartbeat_active()) { - ret = o2hb_region_pin(region_uuid); - goto unlock; + ret = o2hb_region_pin(region_uuid, false); + goto unlock; } /* @@ -2497,7 +2500,7 @@ static int o2hb_region_inc_user(const char *region_uuid) if (bitmap_weight(o2hb_quorum_region_bitmap, O2NM_MAX_REGIONS) <= O2HB_PIN_CUT_OFF) - ret = o2hb_region_pin(NULL); + ret = o2hb_region_pin(NULL, false); unlock: spin_unlock(&o2hb_live_lock); diff --git a/fs/ocfs2/cluster/nodemanager.c b/fs/ocfs2/cluster/nodemanager.c index e1f8f577ce5d6..ebdf0bdbb8c69 100644 --- a/fs/ocfs2/cluster/nodemanager.c +++ b/fs/ocfs2/cluster/nodemanager.c @@ -778,6 +778,12 @@ int o2nm_depend_item(struct config_item *item) return configfs_depend_item(&o2nm_cluster_group.cs_subsys, item); } +int o2nm_depend_item_unlocked(struct config_item *item) +{ + return configfs_depend_item_unlocked(&o2nm_cluster_group.cs_subsys, + item); +} + void o2nm_undepend_item(struct config_item *item) { configfs_undepend_item(item); diff --git a/fs/ocfs2/cluster/nodemanager.h b/fs/ocfs2/cluster/nodemanager.h index 39006005427b6..ca3483fb54504 100644 --- a/fs/ocfs2/cluster/nodemanager.h +++ b/fs/ocfs2/cluster/nodemanager.h @@ -64,6 +64,7 @@ void o2nm_node_get(struct o2nm_node *node); void o2nm_node_put(struct o2nm_node *node); int o2nm_depend_item(struct config_item *item); +int o2nm_depend_item_unlocked(struct config_item *item); void o2nm_undepend_item(struct config_item *item); int o2nm_depend_node(u8 node_num); void o2nm_undepend_node(u8 node_num); -- 2.39.3