From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E46891EB5F7; Thu, 10 Apr 2025 13:23:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744291436; cv=none; b=DzQtkL9D12BH+w1mDWUe9ys9pWiYhdnh/gmW8rFeNw2nkoMLd/FYEMpSPsu4hZc7uRYUfpGnH1it7livQTHBj6Q/Du012J9Fe6FgdG3fCQRmx0Kxfxb7xnUN+kx0KMKinJV6sn3hcEXgiOkyMKd1N63CnQD4JB3nexZua2GH+AM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744291436; c=relaxed/simple; bh=35bowL8nZeAUEMUkTdGIDht/faXw5WqatgtW/CTRsXg=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=ic9Q2ZUl05f7559YdorxM0lw7GoJJxMvISyqp5FMS0Q1QIq0TF8igc60dTxkpphWT/pOnqA4sMaA1qiJYgymSv88I4F/3/gkTGMUD9SVS8nKvvSygW/AAOMyYNifjdkIGvtfuXPKKKEhHpUqyT4W2g6ZDMLLZKZbJYLpVN1E6UE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=rRxghqiG; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="rRxghqiG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 96923C4CEE8; Thu, 10 Apr 2025 13:23:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744291434; bh=35bowL8nZeAUEMUkTdGIDht/faXw5WqatgtW/CTRsXg=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=rRxghqiGdl1XAF4NVWbknHnG5h9cvz3NGkhgXsD2JgppigdbzqAkBLipqN0oiagEQ D6JWwn1p9M3kfz/GJtFp2c6T7LrsjuVKMFwylsDXn+oB2nBFYZXR2Y0Sl84mdHM4LG NBj3A0stiagGhOyQ1IK8WzyWqNKeDrmrjv/JgM9Qz/v98dM0xdJV6Apcv+BxCgeK18 G7cLIRoDWQprKHby3OWBXtvhfPtUhXz2N8qP2GMlpZ/XbXectqVw73LPgBuXvOZ6cc rToSWkv3Cq6M6DPa7YBsBIIYLjgdVq9/U2djrmt9Pnw5TbqFy27phjxPULZL7LRml0 AWMhr6E4Ev0xQ== Message-ID: Subject: Re: [PATCH v2 2/2] net: add debugfs files for showing netns refcount tracking info From: Jeff Layton To: Andrew Lunn Cc: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Andrew Morton , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 10 Apr 2025 09:23:52 -0400 In-Reply-To: <91d6d3c60ef5d4ed90418f8a06228767be8a5b1b.camel@kernel.org> References: <20250408-netns-debugfs-v2-0-ca267f51461e@kernel.org> <20250408-netns-debugfs-v2-2-ca267f51461e@kernel.org> <1e717326-8551-419e-b185-5cfb20573b4f@lunn.ch> <91d6d3c60ef5d4ed90418f8a06228767be8a5b1b.camel@kernel.org> Autocrypt: addr=jlayton@kernel.org; prefer-encrypt=mutual; keydata=mQINBE6V0TwBEADXhJg7s8wFDwBMEvn0qyhAnzFLTOCHooMZyx7XO7dAiIhDSi7G1NPxw n8jdFUQMCR/GlpozMFlSFiZXiObE7sef9rTtM68ukUyZM4pJ9l0KjQNgDJ6Fr342Htkjxu/kFV1Wv egyjnSsFt7EGoDjdKqr1TS9syJYFjagYtvWk/UfHlW09X+jOh4vYtfX7iYSx/NfqV3W1D7EDi0PqV T2h6v8i8YqsATFPwO4nuiTmL6I40ZofxVd+9wdRI4Db8yUNA4ZSP2nqLcLtFjClYRBoJvRWvsv4lm 0OX6MYPtv76hka8lW4mnRmZqqx3UtfHX/hF/zH24Gj7A6sYKYLCU3YrI2Ogiu7/ksKcl7goQjpvtV YrOOI5VGLHge0awt7bhMCTM9KAfPc+xL/ZxAMVWd3NCk5SamL2cE99UWgtvNOIYU8m6EjTLhsj8sn VluJH0/RcxEeFbnSaswVChNSGa7mXJrTR22lRL6ZPjdMgS2Km90haWPRc8Wolcz07Y2se0xpGVLEQ cDEsvv5IMmeMe1/qLZ6NaVkNuL3WOXvxaVT9USW1+/SGipO2IpKJjeDZfehlB/kpfF24+RrK+seQf CBYyUE8QJpvTZyfUHNYldXlrjO6n5MdOempLqWpfOmcGkwnyNRBR46g/jf8KnPRwXs509yAqDB6sE LZH+yWr9LQZEwARAQABtCVKZWZmIExheXRvbiA8amxheXRvbkBwb29jaGllcmVkcy5uZXQ+iQI7BB MBAgAlAhsDBgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAUCTpXWPAIZAQAKCRAADmhBGVaCFc65D/4 gBLNMHopQYgG/9RIM3kgFCCQV0pLv0hcg1cjr+bPI5f1PzJoOVi9s0wBDHwp8+vtHgYhM54yt43uI 7Htij0RHFL5eFqoVT4TSfAg2qlvNemJEOY0e4daljjmZM7UtmpGs9NN0r9r50W82eb5Kw5bc/r0km R/arUS2st+ecRsCnwAOj6HiURwIgfDMHGPtSkoPpu3DDp/cjcYUg3HaOJuTjtGHFH963B+f+hyQ2B rQZBBE76ErgTDJ2Db9Ey0kw7VEZ4I2nnVUY9B5dE2pJFVO5HJBMp30fUGKvwaKqYCU2iAKxdmJXRI ONb7dSde8LqZahuunPDMZyMA5+mkQl7kpIpR6kVDIiqmxzRuPeiMP7O2FCUlS2DnJnRVrHmCljLkZ Wf7ZUA22wJpepBligemtSRSbqCyZ3B48zJ8g5B8xLEntPo/NknSJaYRvfEQqGxgk5kkNWMIMDkfQO lDSXZvoxqU9wFH/9jTv1/6p8dHeGM0BsbBLMqQaqnWiVt5mG92E1zkOW69LnoozE6Le+12DsNW7Rj iR5K+27MObjXEYIW7FIvNN/TQ6U1EOsdxwB8o//Yfc3p2QqPr5uS93SDDan5ehH59BnHpguTc27Xi QQZ9EGiieCUx6Zh2ze3X2UW9YNzE15uKwkkuEIj60NvQRmEDfweYfOfPVOueC+iFifbQgSmVmZiBM YXl0b24gPGpsYXl0b25AcmVkaGF0LmNvbT6JAjgEEwECACIFAk6V0q0CGwMGCwkIBwMCBhUIAgkKC wQWAgMBAh4BAheAAAoJEAAOaEEZVoIViKUQALpvsacTMWWOd7SlPFzIYy2/fjvKlfB/Xs4YdNcf9q LqF+lk2RBUHdR/dGwZpvw/OLmnZ8TryDo2zXVJNWEEUFNc7wQpl3i78r6UU/GUY/RQmOgPhs3epQC 3PMJj4xFx+VuVcf/MXgDDdBUHaCTT793hyBeDbQuciARDJAW24Q1RCmjcwWIV/pgrlFa4lAXsmhoa c8UPc82Ijrs6ivlTweFf16VBc4nSLX5FB3ls7S5noRhm5/Zsd4PGPgIHgCZcPgkAnU1S/A/rSqf3F LpU+CbVBDvlVAnOq9gfNF+QiTlOHdZVIe4gEYAU3CUjbleywQqV02BKxPVM0C5/oVjMVx3bri75n1 TkBYGmqAXy9usCkHIsG5CBHmphv9MHmqMZQVsxvCzfnI5IO1+7MoloeeW/lxuyd0pU88dZsV/riHw 87i2GJUJtVlMl5IGBNFpqoNUoqmvRfEMeXhy/kUX4Xc03I1coZIgmwLmCSXwx9MaCPFzV/dOOrju2 xjO+2sYyB5BNtxRqUEyXglpujFZqJxxau7E0eXoYgoY9gtFGsspzFkVNntamVXEWVVgzJJr/EWW0y +jNd54MfPRqH+eCGuqlnNLktSAVz1MvVRY1dxUltSlDZT7P2bUoMorIPu8p7ZCg9dyX1+9T6Muc5d Hxf/BBP/ir+3e8JTFQBFOiLNdFtB9KZWZmIExheXRvbiA8amxheXRvbkBzYW1iYS5vcmc+iQI4BBM BAgAiBQJOldK9AhsDBgsJCAcDAgYVCAIJCgsEFgIDAQIeAQIXgAAKCRAADmhBGVaCFWgWD/0ZRi4h N9FK2BdQs9RwNnFZUr7JidAWfCrs37XrA/56olQl3ojn0fQtrP4DbTmCuh0SfMijB24psy1GnkPep naQ6VRf7Dxg/Y8muZELSOtsv2CKt3/02J1BBitrkkqmHyni5fLLYYg6fub0T/8Kwo1qGPdu1hx2BQ RERYtQ/S5d/T0cACdlzi6w8rs5f09hU9Tu4qV1JLKmBTgUWKN969HPRkxiojLQziHVyM/weR5Reu6 FZVNuVBGqBD+sfk/c98VJHjsQhYJijcsmgMb1NohAzwrBKcSGKOWJToGEO/1RkIN8tqGnYNp2G+aR 685D0chgTl1WzPRM6mFG1+n2b2RR95DxumKVpwBwdLPoCkI24JkeDJ7lXSe3uFWISstFGt0HL8Eew P8RuGC8s5h7Ct91HMNQTbjgA+Vi1foWUVXpEintAKgoywaIDlJfTZIl6Ew8ETN/7DLy8bXYgq0Xzh aKg3CnOUuGQV5/nl4OAX/3jocT5Cz/OtAiNYj5mLPeL5z2ZszjoCAH6caqsF2oLyAnLqRgDgR+wTQ T6gMhr2IRsl+cp8gPHBwQ4uZMb+X00c/Amm9VfviT+BI7B66cnC7Zv6Gvmtu2rEjWDGWPqUgccB7h dMKnKDthkA227/82tYoFiFMb/NwtgGrn5n2vwJyKN6SEoygGrNt0SI84y6hEVbQlSmVmZiBMYXl0b 24gPGpsYXl0b25AcHJpbWFyeWRhdGEuY29tPokCOQQTAQIAIwUCU4xmKQIbAwcLCQgHAwIBBhUIAg kKCwQWAgMBAh4BAheAAAoJEAAOaEEZVoIV1H0P/j4OUTwFd7BBbpoSp695qb6HqCzWMuExsp8nZjr uymMaeZbGr3OWMNEXRI1FWNHMtcMHWLP/RaDqCJil28proO+PQ/yPhsr2QqJcW4nr91tBrv/MqItu AXLYlsgXqp4BxLP67bzRJ1Bd2x0bWXurpEXY//VBOLnODqThGEcL7jouwjmnRh9FTKZfBDpFRaEfD FOXIfAkMKBa/c9TQwRpx2DPsl3eFWVCNuNGKeGsirLqCxUg5kWTxEorROppz9oU4HPicL6rRH22Ce 6nOAON2vHvhkUuO3GbffhrcsPD4DaYup4ic+DxWm+DaSSRJ+e1yJvwi6NmQ9P9UAuLG93S2MdNNbo sZ9P8k2mTOVKMc+GooI9Ve/vH8unwitwo7ORMVXhJeU6Q0X7zf3SjwDq2lBhn1DSuTsn2DbsNTiDv qrAaCvbsTsw+SZRwF85eG67eAwouYk+dnKmp1q57LDKMyzysij2oDKbcBlwB/TeX16p8+LxECv51a sjS9TInnipssssUDrHIvoTTXWcz7Y5wIngxDFwT8rPY3EggzLGfK5Zx2Q5S/N0FfmADmKknG/D8qG IcJE574D956tiUDKN4I+/g125ORR1v7bP+OIaayAvq17RP+qcAqkxc0x8iCYVCYDouDyNvWPGRhbL UO7mlBpjW9jK9e2fvZY9iw3QzIPGKtClKZWZmIExheXRvbiA8amVmZi5sYXl0b25AcHJpbWFyeWRh dGEuY29tPokCOQQTAQIAIwUCU4xmUAIbAwcLCQgHAwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJEAAOa EEZVoIVzJoQALFCS6n/FHQS+hIzHIb56JbokhK0AFqoLVzLKzrnaeXhE5isWcVg0eoV2oTScIwUSU apy94if69tnUo4Q7YNt8/6yFM6hwZAxFjOXR0ciGE3Q+Z1zi49Ox51yjGMQGxlakV9ep4sV/d5a50 M+LFTmYSAFp6HY23JN9PkjVJC4PUv5DYRbOZ6Y1+TfXKBAewMVqtwT1Y+LPlfmI8dbbbuUX/kKZ5d dhV2736fgyfpslvJKYl0YifUOVy4D1G/oSycyHkJG78OvX4JKcf2kKzVvg7/Rnv+AueCfFQ6nGwPn 0P91I7TEOC4XfZ6a1K3uTp4fPPs1Wn75X7K8lzJP/p8lme40uqwAyBjk+IA5VGd+CVRiyJTpGZwA0 jwSYLyXboX+Dqm9pSYzmC9+/AE7lIgpWj+3iNisp1SWtHc4pdtQ5EU2SEz8yKvDbD0lNDbv4ljI7e flPsvN6vOrxz24mCliEco5DwhpaaSnzWnbAPXhQDWb/lUgs/JNk8dtwmvWnqCwRqElMLVisAbJmC0 BhZ/Ab4sph3EaiZfdXKhiQqSGdK4La3OTJOJYZphPdGgnkvDV9Pl1QZ0ijXQrVIy3zd6VCNaKYq7B AKidn5g/2Q8oio9Tf4XfdZ9dtwcB+bwDJFgvvDYaZ5bI3ln4V3EyW5i2NfXazz/GA/I/ZtbsigCFc 8ftCBKZWZmIExheXRvbiA8amxheXRvbkBrZXJuZWwub3JnPokCOAQTAQIAIgUCWe8u6AIbAwYLCQg HAwIGFQgCCQoLBBYCAwECHgECF4AACgkQAA5oQRlWghUuCg/+Lb/xGxZD2Q1oJVAE37uW308UpVSD 2tAMJUvFTdDbfe3zKlPDTuVsyNsALBGclPLagJ5ZTP+Vp2irAN9uwBuacBOTtmOdz4ZN2tdvNgozz uxp4CHBDVzAslUi2idy+xpsp47DWPxYFIRP3M8QG/aNW052LaPc0cedYxp8+9eiVUNpxF4SiU4i9J DfX/sn9XcfoVZIxMpCRE750zvJvcCUz9HojsrMQ1NFc7MFT1z3MOW2/RlzPcog7xvR5ENPH19ojRD CHqumUHRry+RF0lH00clzX/W8OrQJZtoBPXv9ahka/Vp7kEulcBJr1cH5Wz/WprhsIM7U9pse1f1g Yy9YbXtWctUz8uvDR7shsQxAhX3qO7DilMtuGo1v97I/Kx4gXQ52syh/w6EBny71CZrOgD6kJwPVV AaM1LRC28muq91WCFhs/nzHozpbzcheyGtMUI2Ao4K6mnY+3zIuXPygZMFr9KXE6fF7HzKxKuZMJO aEZCiDOq0anx6FmOzs5E6Jqdpo/mtI8beK+BE7Va6ni7YrQlnT0i3vaTVMTiCThbqsB20VrbMjlhp f8lfK1XVNbRq/R7GZ9zHESlsa35ha60yd/j3pu5hT2xyy8krV8vGhHvnJ1XRMJBAB/UYb6FyC7S+m QZIQXVeAA+smfTT0tDrisj1U5x6ZB9b3nBg65kc= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.54.3 (3.54.3-1.fc41) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Thu, 2025-04-10 at 09:08 -0400, Jeff Layton wrote: > On Thu, 2025-04-10 at 14:36 +0200, Andrew Lunn wrote: > > On Tue, Apr 08, 2025 at 09:36:38AM -0400, Jeff Layton wrote: > > > CONFIG_NET_NS_REFCNT_TRACKER currently has no convenient way to displ= ay > > > its tracking info. Add a new net_ns directory under the debugfs > > > ref_tracker directory. Create a directory in there for every netns, w= ith > > > refcnt and notrefcnt files that show the currently tracked active and > > > passive references. > >=20 > > I think most if not all of this should be moved into the tracker > > sources, there is very little which is netdev specific.=20 > >=20 >=20 > Fair enough. I can move most of this into helpers in ref_tracker.c. >=20 > > >=20 > > > Signed-off-by: Jeff Layton > > > --- > > > net/core/net_namespace.c | 151 +++++++++++++++++++++++++++++++++++++= ++++++++++ > > > 1 file changed, 151 insertions(+) > > >=20 > > > diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c > > > index 4303f2a4926243e2c0ff0c0387383cd8e0658019..7e9dc487f46d656ee4ae3= d6d18d35bb2aba2b176 100644 > > > --- a/net/core/net_namespace.c > > > +++ b/net/core/net_namespace.c > > > @@ -1512,3 +1512,154 @@ const struct proc_ns_operations netns_operati= ons =3D { > > > .owner =3D netns_owner, > > > }; > > > #endif > > > + > > > +#ifdef CONFIG_DEBUG_FS > > > +#ifdef CONFIG_NET_NS_REFCNT_TRACKER > > > + > > > +#include > > > + > > > +static struct dentry *ns_ref_tracker_dir; > > > +static unsigned int ns_debug_net_id; > > > + > > > +struct ns_debug_net { > > > + struct dentry *netdir; > > > + struct dentry *refcnt; > > > + struct dentry *notrefcnt; > > > +}; > > > + > > > +#define MAX_NS_DEBUG_BUFSIZE (32 * PAGE_SIZE) > > > + > > > +static int > > > +ns_debug_tracker_show(struct seq_file *f, void *v) > > > +{ > > > + struct ref_tracker_dir *tracker =3D f->private; > > > + int len, bufsize =3D PAGE_SIZE; > > > + char *buf; > > > + > > > + for (;;) { > > > + buf =3D kvmalloc(bufsize, GFP_KERNEL); > > > + if (!buf) > > > + return -ENOMEM; > > > + > > > + len =3D ref_tracker_dir_snprint(tracker, buf, bufsize); > > > + if (len < bufsize) > > > + break; > > > + > > > + kvfree(buf); > > > + bufsize *=3D 2; > > > + if (bufsize > MAX_NS_DEBUG_BUFSIZE) > > > + return -ENOBUFS; > >=20 > > Maybe consider storing bufsize between calls to dump the tracker? I > > guess you then have about the correct size for most calls, and from > > looking at len, you can decide to downsize it if needed. > >=20 >=20 > Eric had a proposed change to make ref_tracker_dir_snprint() not sit > with hard IRQs disabled for so long. That involved passing back a > needed size, so I might rather integrate this into that change. >=20 > > > +static int > > > +ns_debug_init_net(struct net *net) > > > +{ > > > + struct ns_debug_net *dnet =3D net_generic(net, ns_debug_net_id); > > > + char name[11]; /* 10 decimal digits + NULL term */ > > > + int len; > > > + > > > + len =3D snprintf(name, sizeof(name), "%u", net->ns.inum); > > > + if (len >=3D sizeof(name)) > > > + return -EOVERFLOW; > > > + > > > + dnet->netdir =3D debugfs_create_dir(name, ns_ref_tracker_dir); > > > + if (IS_ERR(dnet->netdir)) > > > + return PTR_ERR(dnet->netdir); > >=20 > > As i pointed out before, the tracker already has a name. Is that name > > useless? Not specific enough? Rather than having two names, maybe > > change the name to make it useful. Once it has a usable name, you > > should be able to push more code into the core. > >=20 >=20 > I don't understand which name you mean. >=20 > This patch creates a ref_tracker/net_ns dir and then creates > directories under that that have names that match the net namespace > inode numbers as displayed in /proc//ns/net symlink. Those > directories hold two files "refcnt" and "notrefcnt" that display the > different trackers. >=20 > It's not clear to me what you'd like to see changed in that scheme. Oh, ok. I guess you mean these names? ref_tracker_dir_init(&net->refcnt_tracker, 128, "net refcnt"); ref_tracker_dir_init(&net->notrefcnt_tracker, 128, "net notrefcnt")= ; Two problems there: 1/ they have an embedded space in the name which is just painful. Maybe we = can replace those with underscores? 2/ they aren't named in a per-net namespace way I guess we could do something like these nested dirs: debug ref_tracker net_refcnt net_notrefcnt ...and then create files under the net_* directories that match the netns ID's. That's what I was trying to ask when I asked about the directory structure in the last set. How do you want the directory structure laid out? --=20 Jeff Layton