From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-188.mta0.migadu.com (out-188.mta0.migadu.com [91.218.175.188]) (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 4BD30292918 for ; Thu, 25 Dec 2025 23:21:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766704902; cv=none; b=JifL+2m9F+z+nrIuxiPpUU/IWtH/nqssjyE3VhIAXwz6mKmQjWJK0wNXPNOHiDYR5+fO5t9L6HExHqGV9oHKwQ//oczP8wlW9zkflJOgEZxrsnLW5RvXKYSHyvGgan1SwgwODETNyHrK5rgXi4LABZ0H04I6MeJu18pFDy/uINw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766704902; c=relaxed/simple; bh=eHc/9h6653MgzBLH8SGSWdotekhAKEDDGV2/8yjGhjg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=r2IrAVdUqMQhmlfRyTKhDshPOMrpNzZleQBbnm3FzevRDN0HcuWB0uBucpI9pHLCbxcWIsnEhvYhLuejBxCD0S+fpHj1s63RLaXqZVlg5R/4qoNrs1g/QCxeeNsC+YG8aGcUAqCzYWrI8D13G7fgFpESGADHudhcl0I4/vwKDmA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=vbIrljY9; arc=none smtp.client-ip=91.218.175.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="vbIrljY9" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1766704898; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HNWA2wy5x9qmESizAoWxNjF5HTjl76WyG9bV89v6wkc=; b=vbIrljY9Mm8NiHjnoyWxvDlzPBU2XDS3DgZXbUz8CnkO/r1IXynRdZ8/R1sxe1r4/n2nhn grLSA4DBmRv8k2SMke7G7nnY2fKRze3XDs+LQhTS4HCHZYnjRzuCWi6jsah7qfHMH6W3nv sqCjwirvPFv+S3Obsz/ngB7fVRGsvVw= From: Shakeel Butt To: Andrew Morton Cc: Johannes Weiner , Michal Hocko , Roman Gushchin , Muchun Song , SeongJae Park , Meta kernel team , linux-mm@kvack.org, cgroups@vger.kernel.org, damon@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH 3/8] memcg: mem_cgroup_get_from_ino() returns NULL on error Date: Thu, 25 Dec 2025 15:21:11 -0800 Message-ID: <20251225232116.294540-4-shakeel.butt@linux.dev> In-Reply-To: <20251225232116.294540-1-shakeel.butt@linux.dev> References: <20251225232116.294540-1-shakeel.butt@linux.dev> Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Change mem_cgroup_get_from_ino() to return NULL on error instead of ERR_PTR values. This simplifies the API: NULL indicates failure, and a valid pointer indicates success with a CSS reference held that the caller must release via mem_cgroup_put(). Signed-off-by: Shakeel Butt --- mm/memcontrol.c | 6 ++---- mm/shrinker_debug.c | 2 +- 2 files changed, 3 insertions(+), 5 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index e85816960e38..92beb74482fa 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3624,17 +3624,15 @@ struct mem_cgroup *mem_cgroup_get_from_ino(unsigned long ino) { struct cgroup *cgrp; struct cgroup_subsys_state *css; - struct mem_cgroup *memcg; + struct mem_cgroup *memcg = NULL; cgrp = cgroup_get_from_id(ino); if (IS_ERR(cgrp)) - return ERR_CAST(cgrp); + return NULL; css = cgroup_get_e_css(cgrp, &memory_cgrp_subsys); if (css) memcg = container_of(css, struct mem_cgroup, css); - else - memcg = ERR_PTR(-ENOENT); cgroup_put(cgrp); diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c index 20eaee3e97f7..8aaeb8f5c3af 100644 --- a/mm/shrinker_debug.c +++ b/mm/shrinker_debug.c @@ -130,7 +130,7 @@ static ssize_t shrinker_debugfs_scan_write(struct file *file, if (shrinker->flags & SHRINKER_MEMCG_AWARE) { memcg = mem_cgroup_get_from_ino(ino); - if (!memcg || IS_ERR(memcg)) + if (!memcg) return -ENOENT; if (!mem_cgroup_online(memcg)) { -- 2.47.3