From patchwork Wed Mar 30 10:23:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 12795655 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57F4DC433EF for ; Wed, 30 Mar 2022 10:24:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245327AbiC3K01 (ORCPT ); Wed, 30 Mar 2022 06:26:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245324AbiC3K00 (ORCPT ); Wed, 30 Mar 2022 06:26:26 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F1B1C23F3D3; Wed, 30 Mar 2022 03:24:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 80CFEB81ACC; Wed, 30 Mar 2022 10:24:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DA851C340F2; Wed, 30 Mar 2022 10:24:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648635879; bh=uWsqlbJtgXRCJrJzOEDxeLO3iFvm0oHOpz5qIAsQNu4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DIWHi66FBvyvShB58HpTFUrDAwztcv1hELdmVd7lx9brmMzt2t2hmUaDYYrQve28r BSb0yC3oCINex8/0gqjUsiNYs/QhvmpiCN98ctPRZlwJzG+w7ziI+upJnUkrCtxufI Q7afioFAKmwm0s8TePzIGB6y/bS7PuISMhGApPzAlDNSqV3aClmGK1VvLdQYw8AriM UtoPis2Vka6ADZvJLvsWudFaEsp7awgDG9jczudfGMZecK+zvlMplKNyS0bjMwqz+I 5Kqq5oZ2UeJD1tjtRhTE/FrmYHJG/cOHnpS4XdOuK1PhdG7mpZ98B4umxNmPDcIW3d HFHubVl2SjdMQ== From: Christian Brauner To: Amir Goldstein , Christoph Hellwig , Miklos Szeredi , Al Viro Cc: Christian Brauner , linux-fsdevel@vger.kernel.org, linux-unionfs@vger.kernel.org, Aleksa Sarai , Giuseppe Scrivano , Rodrigo Campos Catelin , Seth Forshee , Luca Bocassi , Lennart Poettering , =?utf-8?q?St=C3=A9phane_Graber?= Subject: [PATCH v2 01/19] fs: add two trivial lookup helpers Date: Wed, 30 Mar 2022 12:23:49 +0200 Message-Id: <20220330102409.1290850-2-brauner@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220330102409.1290850-1-brauner@kernel.org> References: <20220330102409.1290850-1-brauner@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=4649; h=from:subject; bh=uWsqlbJtgXRCJrJzOEDxeLO3iFvm0oHOpz5qIAsQNu4=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMSS56O9u3PK28dFn56N+ZnoXf0dzeWipcqyZWmm7Wllgw/HM qNa9HaUsDGJcDLJiiiwO7Sbhcst5KjYbZWrAzGFlAhnCwMUpABP5FcfI8NC/zexMZVVUx/p75YeW+9 4N21Nxbel7hvZ6rqr5bwynlTH89249Jv+hylCKW/OvxL4zru3ZAokdfUusXinriZc7VObwAwA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Similar to the addition of lookup_one() add a version of lookup_one_unlocked() and lookup_one_positive_unlocked() that take idmapped mounts into account. This is required to port overlay to support idmapped base layers. Cc: Tested-by: Giuseppe Scrivano Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner (Microsoft) Reviewed-by: Christoph Hellwig --- /* v2 */ unchanged --- fs/namei.c | 52 ++++++++++++++++++++++++++++++++++--------- include/linux/namei.h | 2 ++ 2 files changed, 44 insertions(+), 10 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 3f1829b3ab5b..ca2a490a1f6b 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2768,7 +2768,8 @@ struct dentry *lookup_one(struct user_namespace *mnt_userns, const char *name, EXPORT_SYMBOL(lookup_one); /** - * lookup_one_len_unlocked - filesystem helper to lookup single pathname component + * lookup_one_unlocked - filesystem helper to lookup single pathname component + * @mnt_userns: idmapping of the mount the lookup is performed from * @name: pathname component to lookup * @base: base directory to lookup from * @len: maximum length @len should be interpreted to @@ -2779,14 +2780,15 @@ EXPORT_SYMBOL(lookup_one); * Unlike lookup_one_len, it should be called without the parent * i_mutex held, and will take the i_mutex itself if necessary. */ -struct dentry *lookup_one_len_unlocked(const char *name, - struct dentry *base, int len) +struct dentry *lookup_one_unlocked(struct user_namespace *mnt_userns, + const char *name, struct dentry *base, + int len) { struct qstr this; int err; struct dentry *ret; - err = lookup_one_common(&init_user_ns, name, base, len, &this); + err = lookup_one_common(mnt_userns, name, base, len, &this); if (err) return ERR_PTR(err); @@ -2795,6 +2797,41 @@ struct dentry *lookup_one_len_unlocked(const char *name, ret = lookup_slow(&this, base, 0); return ret; } +EXPORT_SYMBOL(lookup_one_unlocked); + +/* + * Like lookup_positive_unlocked() but takes a mount's idmapping into account. + */ +struct dentry *lookup_one_positive_unlocked(struct user_namespace *mnt_userns, + const char *name, + struct dentry *base, int len) +{ + struct dentry *ret = lookup_one_unlocked(mnt_userns, name, base, len); + if (!IS_ERR(ret) && d_flags_negative(smp_load_acquire(&ret->d_flags))) { + dput(ret); + ret = ERR_PTR(-ENOENT); + } + return ret; +} +EXPORT_SYMBOL(lookup_one_positive_unlocked); + +/** + * lookup_one_len_unlocked - filesystem helper to lookup single pathname component + * @name: pathname component to lookup + * @base: base directory to lookup from + * @len: maximum length @len should be interpreted to + * + * Note that this routine is purely a helper for filesystem usage and should + * not be called by generic code. + * + * Unlike lookup_one_len, it should be called without the parent + * i_mutex held, and will take the i_mutex itself if necessary. + */ +struct dentry *lookup_one_len_unlocked(const char *name, + struct dentry *base, int len) +{ + return lookup_one_unlocked(&init_user_ns, name, base, len); +} EXPORT_SYMBOL(lookup_one_len_unlocked); /* @@ -2808,12 +2845,7 @@ EXPORT_SYMBOL(lookup_one_len_unlocked); struct dentry *lookup_positive_unlocked(const char *name, struct dentry *base, int len) { - struct dentry *ret = lookup_one_len_unlocked(name, base, len); - if (!IS_ERR(ret) && d_flags_negative(smp_load_acquire(&ret->d_flags))) { - dput(ret); - ret = ERR_PTR(-ENOENT); - } - return ret; + return lookup_one_positive_unlocked(&init_user_ns, name, base, len); } EXPORT_SYMBOL(lookup_positive_unlocked); diff --git a/include/linux/namei.h b/include/linux/namei.h index e89329bb3134..759b996b9e1a 100644 --- a/include/linux/namei.h +++ b/include/linux/namei.h @@ -69,6 +69,8 @@ extern struct dentry *lookup_one_len(const char *, struct dentry *, int); extern struct dentry *lookup_one_len_unlocked(const char *, struct dentry *, int); extern struct dentry *lookup_positive_unlocked(const char *, struct dentry *, int); struct dentry *lookup_one(struct user_namespace *, const char *, struct dentry *, int); +struct dentry *lookup_one_unlocked(struct user_namespace *, const char *, struct dentry *, int); +struct dentry *lookup_one_positive_unlocked(struct user_namespace *, const char *, struct dentry *, int); extern int follow_down_one(struct path *); extern int follow_down(struct path *); From patchwork Wed Mar 30 10:23:50 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christian Brauner X-Patchwork-Id: 12795656 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A3E0FC433F5 for ; Wed, 30 Mar 2022 10:24:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245331AbiC3K0e (ORCPT ); Wed, 30 Mar 2022 06:26:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56854 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245328AbiC3K0d (ORCPT ); Wed, 30 Mar 2022 06:26:33 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1505125845F; Wed, 30 Mar 2022 03:24:49 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B5C2FB81B81; Wed, 30 Mar 2022 10:24:47 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B0AA2C340F2; Wed, 30 Mar 2022 10:24:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648635886; bh=OSUBEDpFtUGq1zuxnlsi16HS8t/VIhTkz+CQ1B058IQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BhhPlREa10kimGl9t1e9Ch7hkVaBD6kQ0MtJ5vieSnhQ5AVN8+cNOqIPbZYeGcil0 hfGmS8gHBGi9lpxDksE6ibsn821bjXsXEx3HqOGil0hngm3I2KsyTtTbgpUHl29yxt Zijw1KGC9V7yjZ599CjlLk7pZQNFoKKXYR689csXVRSHXjhTrFRrg8en5JrVzVH5xE wwP3ImY+73F6A1glvGiYWvrAYmzwSW18O21XIRTBQ1yoP/l5NgRJNU3mauyoT5dKD4 uCDU1Pxeo5Iz1SQKFIp97EtDaMY/wdgEbDmicsreq8ZEkmQ/UKTat+Pzl8CSLG5nH6 vKM1NOA8DVmEQ== From: Christian Brauner To: Amir Goldstein , Christoph Hellwig , Miklos Szeredi , Al Viro Cc: Christian Brauner , linux-fsdevel@vger.kernel.org, linux-unionfs@vger.kernel.org, Aleksa Sarai , Giuseppe Scrivano , Rodrigo Campos Catelin , Seth Forshee , Luca Bocassi , Lennart Poettering , =?utf-8?q?St=C3=A9phane_Graber?= , stable@vger.kernel.org Subject: [PATCH v2 02/19] exportfs: support idmapped mounts Date: Wed, 30 Mar 2022 12:23:50 +0200 Message-Id: <20220330102409.1290850-3-brauner@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220330102409.1290850-1-brauner@kernel.org> References: <20220330102409.1290850-1-brauner@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1859; h=from:subject; bh=OSUBEDpFtUGq1zuxnlsi16HS8t/VIhTkz+CQ1B058IQ=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMSS56O/WVbrO1aAgL1AsGdBTeJ39xv4nBjfcdFuTq+9P2P3V 1/R3RykLgxgXg6yYIotDu0m43HKeis1GmRowc1iZQIYwcHEKwETez2D4K3DswhtWtzd5yZ8Xrnhh7q 7DtPTHTq7fX+Ms+GOuXza6ksPwv1I9S/Hq+sRDRRHL/zInNKfIPr+y0nLpx5c9TWfPnOedxQgA X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Make the two locations where exportfs helpers check permission to lookup a given inode idmapped mount aware by switching it to the lookup_one() helper. This is a bugfix for the open_by_handle_at() system call which doesn't take idmapped mounts into account currently. It's not tied to a specific commit so we'll just Cc stable. In addition this is required to support idmapped base layers in overlay. The overlay filesystem uses exportfs to encode and decode file handles for its index=on mount option and when nfs_export=on. Cc: Cc: Tested-by: Giuseppe Scrivano Reviewed-by: Amir Goldstein Signed-off-by: Christian Brauner (Microsoft) Reviewed-by: Christoph Hellwig --- /* v2 */ unchanged --- fs/exportfs/expfs.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c index 0106eba46d5a..3ef80d000e13 100644 --- a/fs/exportfs/expfs.c +++ b/fs/exportfs/expfs.c @@ -145,7 +145,7 @@ static struct dentry *reconnect_one(struct vfsmount *mnt, if (err) goto out_err; dprintk("%s: found name: %s\n", __func__, nbuf); - tmp = lookup_one_len_unlocked(nbuf, parent, strlen(nbuf)); + tmp = lookup_one_unlocked(mnt_user_ns(mnt), nbuf, parent, strlen(nbuf)); if (IS_ERR(tmp)) { dprintk("%s: lookup failed: %d\n", __func__, PTR_ERR(tmp)); err = PTR_ERR(tmp); @@ -525,7 +525,8 @@ exportfs_decode_fh_raw(struct vfsmount *mnt, struct fid *fid, int fh_len, } inode_lock(target_dir->d_inode); - nresult = lookup_one_len(nbuf, target_dir, strlen(nbuf)); + nresult = lookup_one(mnt_user_ns(mnt), nbuf, + target_dir, strlen(nbuf)); if (!IS_ERR(nresult)) { if (unlikely(nresult->d_inode != result->d_inode)) { dput(nresult);