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 X-Spam-Level: X-Spam-Status: No, score=-20.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5A8C5C07E9D for ; Mon, 19 Jul 2021 11:11:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 49BB561164 for ; Mon, 19 Jul 2021 11:11:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236638AbhGSKaw (ORCPT ); Mon, 19 Jul 2021 06:30:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:59616 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236565AbhGSKav (ORCPT ); Mon, 19 Jul 2021 06:30:51 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 293F3610FB; Mon, 19 Jul 2021 11:11:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626693091; bh=jrsTlB5aH/oGmwuzPWogVfh8GOFsiWt44Xhk1ytIt+s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uYKW8PgHDB1atflqo+MD1UpxMdoq53iRhiLT2N7vitaRh2ZLIAegL4kL7HUjcxNEE arlXvswDHDSJk81aozI41Dtvb7dex9vPk8cc/esCKqDGwazN5IV5GNS0vqp7kZXzOJ NxdjdTyfVbXEbI1JXG0et9aCqtulHQOcIgI4W4m6N6nRhBPB5LyknGxtzIJ6akYk4z BbaoqtN85AGsMFdDHfduKMDJAtA95t5Rx7DywW6T2TyVdAvJiu6JOt4fpJNkdAmvWx BeqxSTEWsYAHoAXeM4M4gBhDmGXioXYeCDxZa2eLE/WqCTtkRv+9utw6jPFfL9U8HN 9Q+c1SCW7lJQg== From: Christian Brauner To: Christoph Hellwig , Chris Mason , Josef Bacik , David Sterba , Al Viro Cc: linux-btrfs@vger.kernel.org, Christian Brauner , Christoph Hellwig Subject: [PATCH v2 13/21] btrfs/inode: allow idmapped BTRFS_IOC_{SNAP,SUBVOL}_CREATE{_V2} ioctl Date: Mon, 19 Jul 2021 13:10:44 +0200 Message-Id: <20210719111052.1626299-14-brauner@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210719111052.1626299-1-brauner@kernel.org> References: <20210719111052.1626299-1-brauner@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=8169; h=from:subject; bh=Qd/ossu19EBjuNoVKBILraaqsYqlGubb3Nx4OcwJeds=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMSR8jd3mkcoqo632lyFBaWrF8VTr+XJ/wo+qm0x8ErLilKHA 8uk9HaUsDGJcDLJiiiwO7Sbhcst5KjYbZWrAzGFlAhnCwMUpABP5e4nhn9mP5aF/yhe8cnDse7TK7k HMLInqA7xZsjujcsy+pbWGRjIyXL49o0gz1XLp5qWT1PZWy8dxSXX4WUUL3Prj1tFXxbKOGwA= X-Developer-Key: i=christian.brauner@ubuntu.com; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Christian Brauner Creating subvolumes and snapshots is one of the core features of btrfs and is even available to unprivileged users. Make it possible to use subvolume and snapshot creation on idmapped mounts. This is a fairly straightforward operation since all the permission checking helpers are already capable of handling idmapped mounts. So we just need to pass down the mount's userns. Cc: Chris Mason Cc: Josef Bacik Cc: Christoph Hellwig Cc: David Sterba Cc: linux-btrfs@vger.kernel.org Signed-off-by: Christian Brauner --- /* v2 */ unchanged --- fs/btrfs/ctree.h | 3 ++- fs/btrfs/inode.c | 5 +++-- fs/btrfs/ioctl.c | 48 ++++++++++++++++++++++++++++-------------------- 3 files changed, 33 insertions(+), 23 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index e5e53e592d4f..ee1876571b3f 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3145,7 +3145,8 @@ int btrfs_set_extent_delalloc(struct btrfs_inode *inode, u64 start, u64 end, struct extent_state **cached_state); int btrfs_create_subvol_root(struct btrfs_trans_handle *trans, struct btrfs_root *new_root, - struct btrfs_root *parent_root); + struct btrfs_root *parent_root, + struct user_namespace *mnt_userns); void btrfs_set_delalloc_extent(struct inode *inode, struct extent_state *state, unsigned *bits); void btrfs_clear_delalloc_extent(struct inode *inode, diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index a2a36a45998e..84f732b062dd 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8940,7 +8940,8 @@ static int btrfs_truncate(struct inode *inode, bool skip_writeback) */ int btrfs_create_subvol_root(struct btrfs_trans_handle *trans, struct btrfs_root *new_root, - struct btrfs_root *parent_root) + struct btrfs_root *parent_root, + struct user_namespace *mnt_userns) { struct inode *inode; int err; @@ -8951,7 +8952,7 @@ int btrfs_create_subvol_root(struct btrfs_trans_handle *trans, if (err < 0) return err; - inode = btrfs_new_inode(trans, new_root, &init_user_ns, NULL, "..", 2, + inode = btrfs_new_inode(trans, new_root, mnt_userns, NULL, "..", 2, ino, ino, S_IFDIR | (~current_umask() & S_IRWXUGO), &index); diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 7a6a886df7c4..be52891ba571 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -492,8 +492,8 @@ int __pure btrfs_is_empty_uuid(u8 *uuid) return 1; } -static noinline int create_subvol(struct inode *dir, - struct dentry *dentry, +static noinline int create_subvol(struct user_namespace *mnt_userns, + struct inode *dir, struct dentry *dentry, const char *name, int namelen, struct btrfs_qgroup_inherit *inherit) { @@ -638,7 +638,7 @@ static noinline int create_subvol(struct inode *dir, goto fail; } - ret = btrfs_create_subvol_root(trans, new_root, root); + ret = btrfs_create_subvol_root(trans, new_root, root, mnt_userns); btrfs_put_root(new_root); if (ret) { /* We potentially lose an unused inode item here */ @@ -864,15 +864,16 @@ static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir) } /* copy of may_create in fs/namei.c() */ -static inline int btrfs_may_create(struct inode *dir, struct dentry *child) +static inline int btrfs_may_create(struct user_namespace *mnt_userns, + struct inode *dir, struct dentry *child) { if (d_really_is_positive(child)) return -EEXIST; if (IS_DEADDIR(dir)) return -ENOENT; - if (!fsuidgid_has_mapping(dir->i_sb, &init_user_ns)) + if (!fsuidgid_has_mapping(dir->i_sb, mnt_userns)) return -EOVERFLOW; - return inode_permission(&init_user_ns, dir, MAY_WRITE | MAY_EXEC); + return inode_permission(mnt_userns, dir, MAY_WRITE | MAY_EXEC); } /* @@ -881,6 +882,7 @@ static inline int btrfs_may_create(struct inode *dir, struct dentry *child) * inside this filesystem so it's quite a bit simpler. */ static noinline int btrfs_mksubvol(const struct path *parent, + struct user_namespace *mnt_userns, const char *name, int namelen, struct btrfs_root *snap_src, bool readonly, @@ -895,12 +897,13 @@ static noinline int btrfs_mksubvol(const struct path *parent, if (error == -EINTR) return error; - dentry = lookup_one_len(name, parent->dentry, namelen); + dentry = lookup_mapped_one_len(mnt_userns, name, + parent->dentry, namelen); error = PTR_ERR(dentry); if (IS_ERR(dentry)) goto out_unlock; - error = btrfs_may_create(dir, dentry); + error = btrfs_may_create(mnt_userns, dir, dentry); if (error) goto out_dput; @@ -922,7 +925,7 @@ static noinline int btrfs_mksubvol(const struct path *parent, if (snap_src) error = create_snapshot(snap_src, dir, dentry, readonly, inherit); else - error = create_subvol(dir, dentry, name, namelen, inherit); + error = create_subvol(mnt_userns, dir, dentry, name, namelen, inherit); if (!error) fsnotify_mkdir(dir, dentry); @@ -936,6 +939,7 @@ static noinline int btrfs_mksubvol(const struct path *parent, } static noinline int btrfs_mksnapshot(const struct path *parent, + struct user_namespace *mnt_userns, const char *name, int namelen, struct btrfs_root *root, bool readonly, @@ -965,7 +969,7 @@ static noinline int btrfs_mksnapshot(const struct path *parent, btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1); - ret = btrfs_mksubvol(parent, name, namelen, + ret = btrfs_mksubvol(parent, mnt_userns, name, namelen, root, readonly, inherit); out: if (snapshot_force_cow) @@ -1794,6 +1798,7 @@ static noinline int btrfs_ioctl_resize(struct file *file, } static noinline int __btrfs_ioctl_snap_create(struct file *file, + struct user_namespace *mnt_userns, const char *name, unsigned long fd, int subvol, bool readonly, struct btrfs_qgroup_inherit *inherit) @@ -1821,8 +1826,8 @@ static noinline int __btrfs_ioctl_snap_create(struct file *file, } if (subvol) { - ret = btrfs_mksubvol(&file->f_path, name, namelen, - NULL, readonly, inherit); + ret = btrfs_mksubvol(&file->f_path, mnt_userns, name, + namelen, NULL, readonly, inherit); } else { struct fd src = fdget(fd); struct inode *src_inode; @@ -1836,16 +1841,17 @@ static noinline int __btrfs_ioctl_snap_create(struct file *file, btrfs_info(BTRFS_I(file_inode(file))->root->fs_info, "Snapshot src from another FS"); ret = -EXDEV; - } else if (!inode_owner_or_capable(&init_user_ns, src_inode)) { + } else if (!inode_owner_or_capable(mnt_userns, src_inode)) { /* * Subvolume creation is not restricted, but snapshots * are limited to own subvolumes only */ ret = -EPERM; } else { - ret = btrfs_mksnapshot(&file->f_path, name, namelen, - BTRFS_I(src_inode)->root, - readonly, inherit); + ret = btrfs_mksnapshot(&file->f_path, mnt_userns, + name, namelen, + BTRFS_I(src_inode)->root, + readonly, inherit); } fdput(src); } @@ -1869,8 +1875,9 @@ static noinline int btrfs_ioctl_snap_create(struct file *file, return PTR_ERR(vol_args); vol_args->name[BTRFS_PATH_NAME_MAX] = '\0'; - ret = __btrfs_ioctl_snap_create(file, vol_args->name, vol_args->fd, - subvol, false, NULL); + ret = __btrfs_ioctl_snap_create(file, file_mnt_user_ns(file), + vol_args->name, vol_args->fd, subvol, + false, NULL); kfree(vol_args); return ret; @@ -1928,8 +1935,9 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file, } } - ret = __btrfs_ioctl_snap_create(file, vol_args->name, vol_args->fd, - subvol, readonly, inherit); + ret = __btrfs_ioctl_snap_create(file, file_mnt_user_ns(file), + vol_args->name, vol_args->fd, subvol, + readonly, inherit); if (ret) goto free_inherit; free_inherit: -- 2.30.2