From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 36A71CCFA0D for ; Wed, 5 Nov 2025 10:34:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=dF9AB2hHwwy3EWP2w3CZaHyaORf+Miu82PxVJshLJGw=; b=xbr3iWOGkJONqDqPd6EdcucCbY 2Sk0m/ecNs43dXOZZCA5YR31tG66GgDO31gEKQ6NjFywF6fH+vqF/eQBei1bfkUzamOmJ84DJ/mVW 85sfWLr/0Y1jVTv25Ob56OH5gML7oSR5rbm+Q2+DnK2U7mYp1EelQvRJTDpDQ4JqhBIkIM8JJ8JPf y3UDSYidyXd4fPhERP7ZPE0HFbtKPOCVDCF41txsKtLlICsZYWXys5huox6ki6z4KArERBOLUkbWF OmT+5fNFBxlIWxh03QT1JzQ6YnqmynNhMaQ5Dz/XyG6/FnpyAgSXy38AWd27ez9dMlOJ4sTCw1lhE yHffREhw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vGaq9-0000000DTgr-2B6m; Wed, 05 Nov 2025 10:34:09 +0000 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vGaq6-0000000DTf5-2k5R for linux-nvme@lists.infradead.org; Wed, 05 Nov 2025 10:34:07 +0000 Received: from pps.filterd (m0360072.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 5A55R8tF021943; Wed, 5 Nov 2025 10:34:02 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=pp1; bh=dF9AB2hHwwy3EWP2w 3CZaHyaORf+Miu82PxVJshLJGw=; b=itjMWuF1bkIdzOZEsujmPcZoLfbXsW/x4 JQvcF5Ldsb1zQJHKXdQcyRNx0FZdZ2o9JMBr8xPIA7fXofXrX5ASFiEJZa6hkPTe qekX+81ZfqxnO060SHRDg8JmCXhPY3Cf4qbKJSNPD9cGEzDNDqPuWD36BIGpJqop VasLVOhH1OoIulW41e8//uZ0hY4Z7lSkvmi+K3bbgAJVQ4uKcCIWMmgUBceU413x MwIbSy4tgKbPdL/I11/cb3d94cs3+BDX8rI8R40AwYH+minc40wZJQV2gUmdmKeT lf6Utaqp0qNGthc2rXOB/B2Q/R4WwlqOtpl5erLPs39K7oz3th53w== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4a59v20aap-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 05 Nov 2025 10:34:02 +0000 (GMT) Received: from m0360072.ppops.net (m0360072.ppops.net [127.0.0.1]) by pps.reinject (8.18.1.12/8.18.0.8) with ESMTP id 5A5AY1mx020495; Wed, 5 Nov 2025 10:34:01 GMT Received: from ppma23.wdc07v.mail.ibm.com (5d.69.3da9.ip4.static.sl-reverse.com [169.61.105.93]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4a59v20aam-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 05 Nov 2025 10:34:01 +0000 (GMT) Received: from pps.filterd (ppma23.wdc07v.mail.ibm.com [127.0.0.1]) by ppma23.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 5A57tnfS009855; Wed, 5 Nov 2025 10:34:01 GMT Received: from smtprelay03.fra02v.mail.ibm.com ([9.218.2.224]) by ppma23.wdc07v.mail.ibm.com (PPS) with ESMTPS id 4a5x1kfg6w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 05 Nov 2025 10:34:01 +0000 Received: from smtpav07.fra02v.mail.ibm.com (smtpav07.fra02v.mail.ibm.com [10.20.54.106]) by smtprelay03.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 5A5AXw9H55837062 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 5 Nov 2025 10:33:58 GMT Received: from smtpav07.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B78C22004D; Wed, 5 Nov 2025 10:33:58 +0000 (GMT) Received: from smtpav07.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id ABB4120043; Wed, 5 Nov 2025 10:33:56 +0000 (GMT) Received: from li-c9696b4c-3419-11b2-a85c-f9edc3bf8a84.in.ibm.com (unknown [9.109.198.245]) by smtpav07.fra02v.mail.ibm.com (Postfix) with ESMTP; Wed, 5 Nov 2025 10:33:56 +0000 (GMT) From: Nilay Shroff To: linux-nvme@lists.infradead.org Cc: hare@suse.de, hch@lst.de, kbusch@kernel.org, sagi@grimberg.me, dwagner@suse.de, axboe@kernel.dk, kanie@linux.alibaba.com, gjoyce@ibm.com Subject: [RFC PATCHv5 3/7] nvme: add generic debugfs support Date: Wed, 5 Nov 2025 16:03:22 +0530 Message-ID: <20251105103347.86059-4-nilay@linux.ibm.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251105103347.86059-1-nilay@linux.ibm.com> References: <20251105103347.86059-1-nilay@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-GUID: CpC0rOF2OFRHOV9r2A6VC01xdcxiuucG X-Proofpoint-ORIG-GUID: A3I3py6FtrJgelHWW6j_xm4CiVD9Du8O X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUxMTAxMDAyMSBTYWx0ZWRfXxxprNFdvnzRY eHgXEVt1zKVVf1t+zIpJmqME1TZjZ5g4AAphwgrmcfvSDXZmdLIgXMX4TJhfTLelf2qLitvzSJM XUetCTUTInsYJSDNQIJaalfEsi3u+y8LiKIL93AUEmrWMyx9xxdreEC4jhdAsUtbdM/+O9q7MFg ul1e4NA/5cOFgU5F6WdQBm6JSt4grisMBMepV8mrkrjakUcaAhtGftlyX0lf/1uNonpPrmqsYnt QGn1cCB4zwvqX7EfrvPV1w5rpdFLrrQYNgzmCBB7LrQ2uYtjGYoFtfzkg7vSpWMcXoFK92ZUloz uuAbI62+rUEaI9nbyKJ+da0Lv/fT++l0YPsrfSRb/9c90CWGNC80A3wOuNfuouqTphSEPdIHWFf BOwaGHoNwJOPyNh1fzbmUMRbpFLbdg== X-Authority-Analysis: v=2.4 cv=H8HWAuYi c=1 sm=1 tr=0 ts=690b281a cx=c_pps a=3Bg1Hr4SwmMryq2xdFQyZA==:117 a=3Bg1Hr4SwmMryq2xdFQyZA==:17 a=6UeiqGixMTsA:10 a=VkNPw1HP01LnGYTKEx00:22 a=VnNF1IyMAAAA:8 a=RurgEnbhPsFkkpbWVXEA:9 a=cPQSjfK2_nFv0Q5t_7PE:22 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.9,FMLib:17.12.100.49 definitions=2025-11-05_04,2025-11-03_03,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 phishscore=0 lowpriorityscore=0 priorityscore=1501 adultscore=0 impostorscore=0 clxscore=1015 bulkscore=0 suspectscore=0 malwarescore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2510240000 definitions=main-2511010021 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251105_023406_824692_B01D3082 X-CRM114-Status: GOOD ( 24.20 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org Add generic infrastructure for creating and managing debugfs files in the NVMe module. This introduces helper APIs that allow NVMe drivers to register and unregister debugfs entries, along with a reusable attribute structure for defining new debugfs files. The implementation uses seq_file interfaces to safely expose per-NS and per-NS-head statistics, while supporting both simple show callbacks and full seq_operations. Reviewed-by: Hannes Reinecke Signed-off-by: Nilay Shroff --- drivers/nvme/host/Makefile | 2 +- drivers/nvme/host/core.c | 3 + drivers/nvme/host/debugfs.c | 138 ++++++++++++++++++++++++++++++++++ drivers/nvme/host/multipath.c | 2 + drivers/nvme/host/nvme.h | 10 +++ 5 files changed, 154 insertions(+), 1 deletion(-) create mode 100644 drivers/nvme/host/debugfs.c diff --git a/drivers/nvme/host/Makefile b/drivers/nvme/host/Makefile index 6414ec968f99..7962dfc3b2ad 100644 --- a/drivers/nvme/host/Makefile +++ b/drivers/nvme/host/Makefile @@ -10,7 +10,7 @@ obj-$(CONFIG_NVME_FC) += nvme-fc.o obj-$(CONFIG_NVME_TCP) += nvme-tcp.o obj-$(CONFIG_NVME_APPLE) += nvme-apple.o -nvme-core-y += core.o ioctl.o sysfs.o pr.o +nvme-core-y += core.o ioctl.o sysfs.o pr.o debugfs.o nvme-core-$(CONFIG_NVME_VERBOSE_ERRORS) += constants.o nvme-core-$(CONFIG_TRACING) += trace.o nvme-core-$(CONFIG_NVME_MULTIPATH) += multipath.o diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 47f375c63d2d..c15dfcaf3de2 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -4187,6 +4187,8 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, struct nvme_ns_info *info) if (device_add_disk(ctrl->device, ns->disk, nvme_ns_attr_groups)) goto out_cleanup_ns_from_list; + nvme_debugfs_register(ns->disk); + if (!nvme_ns_head_multipath(ns->head)) nvme_add_ns_cdev(ns); @@ -4276,6 +4278,7 @@ static void nvme_ns_remove(struct nvme_ns *ns) nvme_mpath_remove_sysfs_link(ns); + nvme_debugfs_unregister(ns->disk); del_gendisk(ns->disk); mutex_lock(&ns->ctrl->namespaces_lock); diff --git a/drivers/nvme/host/debugfs.c b/drivers/nvme/host/debugfs.c new file mode 100644 index 000000000000..6bb57c4b5c3b --- /dev/null +++ b/drivers/nvme/host/debugfs.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2025 IBM Corporation + * Nilay Shroff + */ + +#include +#include + +#include "nvme.h" + +struct nvme_debugfs_attr { + const char *name; + umode_t mode; + int (*show)(void *data, struct seq_file *m); + ssize_t (*write)(void *data, const char __user *buf, size_t count, + loff_t *ppos); + const struct seq_operations *seq_ops; +}; + +struct nvme_debugfs_ctx { + void *data; + struct nvme_debugfs_attr *attr; + int srcu_idx; +}; + +static int nvme_debugfs_show(struct seq_file *m, void *v) +{ + struct nvme_debugfs_ctx *ctx = m->private; + void *data = ctx->data; + struct nvme_debugfs_attr *attr = ctx->attr; + + return attr->show(data, m); +} + +static int nvme_debugfs_open(struct inode *inode, struct file *file) +{ + void *data = inode->i_private; + struct nvme_debugfs_attr *attr = debugfs_get_aux(file); + struct nvme_debugfs_ctx *ctx; + struct seq_file *m; + int ret; + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (WARN_ON_ONCE(!ctx)) + return -ENOMEM; + + ctx->data = data; + ctx->attr = attr; + + if (attr->seq_ops) { + ret = seq_open(file, attr->seq_ops); + if (ret) { + kfree(ctx); + return ret; + } + m = file->private_data; + m->private = ctx; + return ret; + } + + if (WARN_ON_ONCE(!attr->show)) { + kfree(ctx); + return -EPERM; + } + + return single_open(file, nvme_debugfs_show, ctx); +} + +static ssize_t nvme_debugfs_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct seq_file *m = file->private_data; + struct nvme_debugfs_ctx *ctx = m->private; + struct nvme_debugfs_attr *attr = ctx->attr; + + if (!attr->write) + return -EPERM; + + return attr->write(ctx->data, buf, count, ppos); +} + +static int nvme_debugfs_release(struct inode *inode, struct file *file) +{ + struct seq_file *m = file->private_data; + struct nvme_debugfs_ctx *ctx = m->private; + struct nvme_debugfs_attr *attr = ctx->attr; + int ret; + + if (attr->seq_ops) + ret = seq_release(inode, file); + else + ret = single_release(inode, file); + + kfree(ctx); + return ret; +} + +static const struct file_operations nvme_debugfs_fops = { + .owner = THIS_MODULE, + .open = nvme_debugfs_open, + .read = seq_read, + .write = nvme_debugfs_write, + .llseek = seq_lseek, + .release = nvme_debugfs_release, +}; + + +static const struct nvme_debugfs_attr nvme_mpath_debugfs_attrs[] = { + {}, +}; + +static const struct nvme_debugfs_attr nvme_ns_debugfs_attrs[] = { + {}, +}; + +static void nvme_debugfs_create_files(struct request_queue *q, + const struct nvme_debugfs_attr *attr, void *data) +{ + if (WARN_ON_ONCE(!q->debugfs_dir)) + return; + + for (; attr->name; attr++) + debugfs_create_file_aux(attr->name, attr->mode, q->debugfs_dir, + data, (void *)attr, &nvme_debugfs_fops); +} + +void nvme_debugfs_register(struct gendisk *disk) +{ + const struct nvme_debugfs_attr *attr; + + if (nvme_disk_is_ns_head(disk)) + attr = nvme_mpath_debugfs_attrs; + else + attr = nvme_ns_debugfs_attrs; + + nvme_debugfs_create_files(disk->queue, attr, disk->private_data); +} diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 55dc28375662..047dd9da9cbf 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -1086,6 +1086,7 @@ static void nvme_remove_head(struct nvme_ns_head *head) nvme_cdev_del(&head->cdev, &head->cdev_device); synchronize_srcu(&head->srcu); + nvme_debugfs_unregister(head->disk); del_gendisk(head->disk); } nvme_put_ns_head(head); @@ -1192,6 +1193,7 @@ static void nvme_mpath_set_live(struct nvme_ns *ns) } nvme_add_ns_head_cdev(head); kblockd_schedule_work(&head->partition_scan_work); + nvme_debugfs_register(head->disk); } nvme_mpath_add_sysfs_link(ns->head); diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index 715c7053054c..1c1ec2a7f9ad 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -1000,6 +1000,16 @@ static inline int nvme_data_dir(const enum req_op op) return NVME_STAT_OTHER; } +void nvme_debugfs_register(struct gendisk *disk); +static inline void nvme_debugfs_unregister(struct gendisk *disk) +{ + /* + * Nothing to do for now. When the request queue is unregistered, + * all files under q->debugfs_dir are recursively deleted. + * This is just a placeholder; the compiler will optimize it out. + */ +} + #ifdef CONFIG_NVME_MULTIPATH static inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl) { -- 2.51.0