From patchwork Tue Aug 8 17:12:07 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sweet Tea Dorminy X-Patchwork-Id: 13346785 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 AB147C41513 for ; Tue, 8 Aug 2023 18:54:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229997AbjHHSyw (ORCPT ); Tue, 8 Aug 2023 14:54:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46298 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234372AbjHHSyd (ORCPT ); Tue, 8 Aug 2023 14:54:33 -0400 Received: from box.fidei.email (box.fidei.email [IPv6:2605:2700:0:2:a800:ff:feba:dc44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6E89B6A3B8; Tue, 8 Aug 2023 10:12:33 -0700 (PDT) Received: from authenticated-user (box.fidei.email [71.19.144.250]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by box.fidei.email (Postfix) with ESMTPSA id 06EB283440; Tue, 8 Aug 2023 13:12:32 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=dorminy.me; s=mail; t=1691514753; bh=FJrLZI11Ai0Wipo6ZqqWSD3xYlfiGD92yFyPBuB597I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=W5/T3O3c9n4XGuEyVJ2i/rL8a+u1fjKNUb+XnfoszCiSuA0CM2z5aPQeuUv6PpOVW 0Y28S0AezxdHM7dbglE8+WPxXMKZGMNtIuaJSFYilzyMFiD1MXbgNhSPe6RVcF0SKF lSAyFipcTcMsiXohdlXc5+L1iFPAmrROVfzH+kbkGfeuowe1OTd7Lj5DclL0RB5i07 WzHdCwT6mcoRi3kMxZO0H9L3WE85LK6diRUp2YB9B9ixe9oGvFFzNjnoVgKVshVB+X AamDZVN0PeQDFWyjjUaHZa4gn+xSG3uhxkI9sXYWQqFcT5+WC5o21ggWyhTrreo76x 1gATH0kKOWgkw== From: Sweet Tea Dorminy To: Chris Mason , Josef Bacik , David Sterba , "Theodore Y . Ts'o" , Jaegeuk Kim , kernel-team@meta.com, linux-btrfs@vger.kernel.org, linux-fscrypt@vger.kernel.org, Eric Biggers Cc: Omar Sandoval , Sweet Tea Dorminy Subject: [PATCH v3 05/17] btrfs: add inode encryption contexts Date: Tue, 8 Aug 2023 13:12:07 -0400 Message-ID: In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org From: Omar Sandoval In order to store encryption information for directories, symlinks, etc., fscrypt stores a context item with each encrypted non-regular inode. fscrypt provides an arbitrary blob for the filesystem to store, and it does not clearly fit into an existing structure, so this goes in a new item type. Signed-off-by: Omar Sandoval Signed-off-by: Sweet Tea Dorminy --- fs/btrfs/fscrypt.c | 118 ++++++++++++++++++++++++++++++++ fs/btrfs/fscrypt.h | 2 + fs/btrfs/inode.c | 19 +++++ fs/btrfs/ioctl.c | 8 ++- include/uapi/linux/btrfs_tree.h | 10 +++ 5 files changed, 155 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/fscrypt.c b/fs/btrfs/fscrypt.c index 3a53dc59c1e4..d09d42210f37 100644 --- a/fs/btrfs/fscrypt.c +++ b/fs/btrfs/fscrypt.c @@ -1,8 +1,126 @@ // SPDX-License-Identifier: GPL-2.0 +#include #include "ctree.h" +#include "accessors.h" +#include "btrfs_inode.h" +#include "disk-io.h" +#include "fs.h" #include "fscrypt.h" +#include "ioctl.h" +#include "messages.h" +#include "transaction.h" +#include "xattr.h" + +static int btrfs_fscrypt_get_context(struct inode *inode, void *ctx, size_t len) +{ + struct btrfs_key key = { + .objectid = btrfs_ino(BTRFS_I(inode)), + .type = BTRFS_FSCRYPT_CTX_ITEM_KEY, + .offset = 0, + }; + struct btrfs_path *path; + struct extent_buffer *leaf; + unsigned long ptr; + int ret; + + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + ret = btrfs_search_slot(NULL, BTRFS_I(inode)->root, &key, path, 0, 0); + if (ret) { + len = -ENOENT; + goto out; + } + + leaf = path->nodes[0]; + ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); + /* fscrypt provides max context length, but it could be less */ + len = min_t(size_t, len, btrfs_item_size(leaf, path->slots[0])); + read_extent_buffer(leaf, ctx, ptr, len); + +out: + btrfs_free_path(path); + return len; +} + +static void btrfs_fscrypt_update_context(struct btrfs_path *path, + const void *ctx, size_t len) +{ + struct extent_buffer *leaf = path->nodes[0]; + unsigned long ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); + + len = min_t(size_t, len, btrfs_item_size(leaf, path->slots[0])); + write_extent_buffer(leaf, ctx, ptr, len); + btrfs_mark_buffer_dirty(leaf); +} + +static int btrfs_fscrypt_set_context(struct inode *inode, const void *ctx, + size_t len, void *fs_data) +{ + struct btrfs_trans_handle *trans = fs_data; + struct btrfs_key key = { + .objectid = btrfs_ino(BTRFS_I(inode)), + .type = BTRFS_FSCRYPT_CTX_ITEM_KEY, + .offset = 0, + }; + struct btrfs_path *path; + int ret; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + if (!trans) + trans = btrfs_start_transaction(BTRFS_I(inode)->root, 1); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + ret = btrfs_search_slot(trans, BTRFS_I(inode)->root, &key, path, 0, 1); + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + return ret; + } + + if (ret > 0) { + btrfs_release_path(path); + ret = btrfs_insert_empty_item(trans, BTRFS_I(inode)->root, path, &key, len); + if (ret) { + btrfs_abort_transaction(trans, ret); + return ret; + } + } + + btrfs_fscrypt_update_context(path, ctx, len); + + if (fs_data) + return ret; + + BTRFS_I(inode)->flags |= BTRFS_INODE_ENCRYPT; + btrfs_sync_inode_flags_to_i_flags(inode); + inode_inc_iversion(inode); + inode->i_ctime = current_time(inode); + ret = btrfs_update_inode(trans, BTRFS_I(inode)->root, BTRFS_I(inode)); + if (!ret) { + btrfs_end_transaction(trans); + return ret; + } + + btrfs_abort_transaction(trans, ret); + btrfs_end_transaction(trans); + return ret; +} + +static bool btrfs_fscrypt_empty_dir(struct inode *inode) +{ + return inode->i_size == BTRFS_EMPTY_DIR_SIZE; +} const struct fscrypt_operations btrfs_fscrypt_ops = { + .get_context = btrfs_fscrypt_get_context, + .set_context = btrfs_fscrypt_set_context, + .empty_dir = btrfs_fscrypt_empty_dir, .key_prefix = "btrfs:" }; diff --git a/fs/btrfs/fscrypt.h b/fs/btrfs/fscrypt.h index 7f4e6888bd43..80adb7e56826 100644 --- a/fs/btrfs/fscrypt.h +++ b/fs/btrfs/fscrypt.h @@ -5,6 +5,8 @@ #include +#include "fs.h" + extern const struct fscrypt_operations btrfs_fscrypt_ops; #endif /* BTRFS_FSCRYPT_H */ diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 49ee05ecc03a..0d0f6f7f0d27 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -62,6 +62,7 @@ #include "defrag.h" #include "dir-item.h" #include "file-item.h" +#include "fscrypt.h" #include "uuid-tree.h" #include "ioctl.h" #include "file.h" @@ -6055,6 +6056,9 @@ int btrfs_new_inode_prepare(struct btrfs_new_inode_args *args, struct inode *inode = args->inode; int ret; + if (fscrypt_is_nokey_name(args->dentry)) + return -ENOKEY; + if (!args->orphan) { ret = fscrypt_setup_filename(dir, &args->dentry->d_name, 0, &args->fname); @@ -6090,6 +6094,9 @@ int btrfs_new_inode_prepare(struct btrfs_new_inode_args *args, if (dir->i_security) (*trans_num_items)++; #endif + /* 1 to add fscrypt item, but only for encrypted non-regular files */ + if (args->encrypt && !S_ISREG(inode->i_mode)) + (*trans_num_items)++; if (args->orphan) { /* 1 to add orphan item */ (*trans_num_items)++; @@ -6268,6 +6275,11 @@ int btrfs_create_new_inode(struct btrfs_trans_handle *trans, inode->i_ctime = inode->i_mtime; BTRFS_I(inode)->i_otime = inode->i_mtime; + if (args->encrypt) { + BTRFS_I(inode)->flags |= BTRFS_INODE_ENCRYPT; + btrfs_sync_inode_flags_to_i_flags(inode); + } + /* * We're going to fill the inode item now, so at this point the inode * must be fully initialized. @@ -6342,6 +6354,13 @@ int btrfs_create_new_inode(struct btrfs_trans_handle *trans, goto discard; } } + if (args->encrypt && !S_ISREG(inode->i_mode)) { + ret = fscrypt_set_context(inode, trans); + if (ret) { + btrfs_abort_transaction(trans, ret); + goto discard; + } + } inode_tree_add(BTRFS_I(inode)); diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index a895d105464b..05984e5448b4 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -156,6 +156,8 @@ static unsigned int btrfs_inode_flags_to_fsflags(struct btrfs_inode *binode) iflags |= FS_DIRSYNC_FL; if (flags & BTRFS_INODE_NODATACOW) iflags |= FS_NOCOW_FL; + if (flags & BTRFS_INODE_ENCRYPT) + iflags |= FS_ENCRYPT_FL; if (ro_flags & BTRFS_INODE_RO_VERITY) iflags |= FS_VERITY_FL; @@ -185,12 +187,14 @@ void btrfs_sync_inode_flags_to_i_flags(struct inode *inode) new_fl |= S_NOATIME; if (binode->flags & BTRFS_INODE_DIRSYNC) new_fl |= S_DIRSYNC; + if (binode->flags & BTRFS_INODE_ENCRYPT) + new_fl |= S_ENCRYPTED; if (binode->ro_flags & BTRFS_INODE_RO_VERITY) new_fl |= S_VERITY; set_mask_bits(&inode->i_flags, S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC | - S_VERITY, new_fl); + S_VERITY | S_ENCRYPTED, new_fl); } /* @@ -203,7 +207,7 @@ static int check_fsflags(unsigned int old_flags, unsigned int flags) FS_NOATIME_FL | FS_NODUMP_FL | \ FS_SYNC_FL | FS_DIRSYNC_FL | \ FS_NOCOMP_FL | FS_COMPR_FL | - FS_NOCOW_FL)) + FS_NOCOW_FL | FS_ENCRYPT_FL)) return -EOPNOTSUPP; /* COMPR and NOCOMP on new/old are valid */ diff --git a/include/uapi/linux/btrfs_tree.h b/include/uapi/linux/btrfs_tree.h index ab38d0f411fa..029af0aeb65d 100644 --- a/include/uapi/linux/btrfs_tree.h +++ b/include/uapi/linux/btrfs_tree.h @@ -161,6 +161,8 @@ #define BTRFS_VERITY_DESC_ITEM_KEY 36 #define BTRFS_VERITY_MERKLE_ITEM_KEY 37 +#define BTRFS_FSCRYPT_CTX_ITEM_KEY 41 + #define BTRFS_ORPHAN_ITEM_KEY 48 /* reserve 2-15 close to the inode for later flexibility */ @@ -399,6 +401,7 @@ static inline __u8 btrfs_dir_flags_to_ftype(__u8 flags) #define BTRFS_INODE_NOATIME (1U << 9) #define BTRFS_INODE_DIRSYNC (1U << 10) #define BTRFS_INODE_COMPRESS (1U << 11) +#define BTRFS_INODE_ENCRYPT (1U << 12) #define BTRFS_INODE_ROOT_ITEM_INIT (1U << 31) @@ -415,6 +418,7 @@ static inline __u8 btrfs_dir_flags_to_ftype(__u8 flags) BTRFS_INODE_NOATIME | \ BTRFS_INODE_DIRSYNC | \ BTRFS_INODE_COMPRESS | \ + BTRFS_INODE_ENCRYPT | \ BTRFS_INODE_ROOT_ITEM_INIT) #define BTRFS_INODE_RO_VERITY (1U << 0) @@ -1016,6 +1020,12 @@ enum { BTRFS_NR_FILE_EXTENT_TYPES = 3, }; +enum { + BTRFS_ENCRYPTION_NONE, + BTRFS_ENCRYPTION_FSCRYPT, + BTRFS_NR_ENCRYPTION_TYPES, +}; + struct btrfs_file_extent_item { /* * transaction id that created this extent