[v4] btrfs: send: add support for fs-verity

Message ID	0561e8a33f991fa15053054b7b089d176fde6523.1660596577.git.boris@bur.io (mailing list archive)
State	Not Applicable
Headers	show Return-Path: <linux-fscrypt-owner@kernel.org> Feedback-ID: i083147f8:Fastmail From: Boris Burkov <boris@bur.io> To: linux-btrfs@vger.kernel.org, kernel-team@fb.com, linux-fscrypt@vger.kernel.org Subject: [PATCH v4] btrfs: send: add support for fs-verity Date: Mon, 15 Aug 2022 13:54:28 -0700 Message-Id: <0561e8a33f991fa15053054b7b089d176fde6523.1660596577.git.boris@bur.io> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	[v4] btrfs: send: add support for fs-verity \| expand [v4] btrfs: send: add support for fs-verity

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 51c480439263..7c55af4aa048 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -4106,6 +4106,7 @@ static inline int btrfs_defrag_cancelled(struct btrfs_fs_info *fs_info) extern const struct fsverity_operations btrfs_verityops; int btrfs_drop_verity_items(struct btrfs_inode *inode); +int btrfs_get_verity_descriptor(struct inode *inode, void *buf, size_t buf_size); BTRFS_SETGET_FUNCS(verity_descriptor_encryption, struct btrfs_verity_descriptor_item, encryption, 8); @@ -4123,6 +4124,11 @@ static inline int btrfs_drop_verity_items(struct btrfs_inode *inode) return 0; } +static inline int btrfs_get_verity_descriptor(struct inode *inode, void *buf, size_t buf_size) +{ + return -EPERM; +} + #endif /* Sanity test specific functions */ diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index e7671afcee4f..9e8679848d54 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -3,6 +3,7 @@ * Copyright (C) 2012 Alexander Block. All rights reserved. */ +#include "linux/compiler_attributes.h" #include <linux/bsearch.h> #include <linux/fs.h> #include <linux/file.h> @@ -15,6 +16,7 @@ #include <linux/string.h> #include <linux/compat.h> #include <linux/crc32c.h> +#include <linux/fsverity.h> #include "send.h" #include "ctree.h" @@ -127,6 +129,8 @@ struct send_ctx { bool cur_inode_new_gen; bool cur_inode_deleted; bool ignore_cur_inode; + bool cur_inode_needs_verity; + void *verity_descriptor; u64 send_progress; @@ -624,6 +628,7 @@ static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len) return tlv_put(sctx, attr, &__tmp, sizeof(__tmp)); \ } +TLV_PUT_DEFINE_INT(8) TLV_PUT_DEFINE_INT(32) TLV_PUT_DEFINE_INT(64) @@ -4886,6 +4891,79 @@ static int process_all_new_xattrs(struct send_ctx *sctx) return ret; } +static int send_verity(struct send_ctx *sctx, struct fs_path *path, + struct fsverity_descriptor *desc) +{ + int ret; + + ret = begin_cmd(sctx, BTRFS_SEND_C_ENABLE_VERITY); + if (ret < 0) + goto out; + + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, path); + TLV_PUT_U8(sctx, BTRFS_SEND_A_VERITY_ALGORITHM, le8_to_cpu(desc->hash_algorithm)); + TLV_PUT_U32(sctx, BTRFS_SEND_A_VERITY_BLOCK_SIZE, 1U << le8_to_cpu(desc->log_blocksize)); + TLV_PUT(sctx, BTRFS_SEND_A_VERITY_SALT_DATA, desc->salt, le8_to_cpu(desc->salt_size)); + TLV_PUT(sctx, BTRFS_SEND_A_VERITY_SIG_DATA, desc->signature, le32_to_cpu(desc->sig_size)); + + ret = send_cmd(sctx); + +tlv_put_failure: +out: + return ret; +} + +static int process_verity(struct send_ctx *sctx) +{ + int ret = 0; + struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; + struct inode *inode; + struct fs_path *p; + + inode = btrfs_iget(fs_info->sb, sctx->cur_ino, sctx->send_root); + if (IS_ERR(inode)) + return PTR_ERR(inode); + + ret = btrfs_get_verity_descriptor(inode, NULL, 0); + if (ret < 0) + goto iput; + + if (ret > FS_VERITY_MAX_DESCRIPTOR_SIZE) { + ret = -EMSGSIZE; + goto iput; + } + if (!sctx->verity_descriptor) { + sctx->verity_descriptor = kvmalloc(FS_VERITY_MAX_DESCRIPTOR_SIZE, GFP_KERNEL); + if (!sctx->verity_descriptor) { + ret = -ENOMEM; + goto iput; + } + } + + ret = btrfs_get_verity_descriptor(inode, sctx->verity_descriptor, ret); + if (ret < 0) + goto iput; + + p = fs_path_alloc(); + if (!p) { + ret = -ENOMEM; + goto iput; + } + ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); + if (ret < 0) + goto free_path; + + ret = send_verity(sctx, p, sctx->verity_descriptor); + if (ret < 0) + goto free_path; + +free_path: + fs_path_free(p); +iput: + iput(inode); + return ret; +} + static inline u64 max_send_read_size(const struct send_ctx *sctx) { return sctx->send_max_size - SZ_16K; @@ -6377,6 +6455,11 @@ static int finish_inode_if_needed(struct send_ctx *sctx, int at_end) if (ret < 0) goto out; } + if (sctx->cur_inode_needs_verity) { + ret = process_verity(sctx); + if (ret < 0) + goto out; + } ret = send_capabilities(sctx); if (ret < 0) @@ -6785,6 +6868,18 @@ static int changed_extent(struct send_ctx *sctx, return ret; } +static int changed_verity(struct send_ctx *sctx, + enum btrfs_compare_tree_result result) +{ + int ret = 0; + + if (!sctx->cur_inode_new_gen && !sctx->cur_inode_deleted) { + if (result == BTRFS_COMPARE_TREE_NEW) + sctx->cur_inode_needs_verity = true; + } + return ret; +} + static int dir_changed(struct send_ctx *sctx, u64 dir) { u64 orig_gen, new_gen; @@ -6939,6 +7034,9 @@ static int changed_cb(struct btrfs_path *left_path, ret = changed_xattr(sctx, result); else if (key->type == BTRFS_EXTENT_DATA_KEY) ret = changed_extent(sctx, result); + else if (key->type == BTRFS_VERITY_DESC_ITEM_KEY && + key->offset == 0) + ret = changed_verity(sctx, result); } out: @@ -8036,6 +8134,7 @@ long btrfs_ioctl_send(struct inode *inode, struct btrfs_ioctl_send_args *arg) kvfree(sctx->clone_roots); kfree(sctx->send_buf_pages); kvfree(sctx->send_buf); + kvfree(sctx->verity_descriptor); name_cache_free(sctx); diff --git a/fs/btrfs/send.h b/fs/btrfs/send.h index 4bb4e6a638cb..0a4537775e0c 100644 --- a/fs/btrfs/send.h +++ b/fs/btrfs/send.h @@ -92,8 +92,11 @@ enum btrfs_send_cmd { BTRFS_SEND_C_ENCODED_WRITE = 25, BTRFS_SEND_C_MAX_V2 = 25, + /* Version 3 */ + BTRFS_SEND_C_ENABLE_VERITY = 26, + BTRFS_SEND_C_MAX_V3 = 26, /* End */ - BTRFS_SEND_C_MAX = 25, + BTRFS_SEND_C_MAX = 26, }; /* attributes in send stream */ @@ -160,8 +163,14 @@ enum { BTRFS_SEND_A_ENCRYPTION = 31, BTRFS_SEND_A_MAX_V2 = 31, - /* End */ - BTRFS_SEND_A_MAX = 31, + /* Version 3 */ + BTRFS_SEND_A_VERITY_ALGORITHM = 32, + BTRFS_SEND_A_VERITY_BLOCK_SIZE = 33, + BTRFS_SEND_A_VERITY_SALT_DATA = 34, + BTRFS_SEND_A_VERITY_SIG_DATA = 35, + BTRFS_SEND_A_MAX_V3 = 35, + + __BTRFS_SEND_A_MAX = 35, }; long btrfs_ioctl_send(struct inode *inode, struct btrfs_ioctl_send_args *arg); diff --git a/fs/btrfs/verity.c b/fs/btrfs/verity.c index 90eb5c2830a9..ee00e33c309e 100644 --- a/fs/btrfs/verity.c +++ b/fs/btrfs/verity.c @@ -659,8 +659,7 @@ static int btrfs_end_enable_verity(struct file *filp, const void *desc, * * Returns the size on success or a negative error code on failure. */ -static int btrfs_get_verity_descriptor(struct inode *inode, void *buf, - size_t buf_size) +int btrfs_get_verity_descriptor(struct inode *inode, void *buf, size_t buf_size) { u64 true_size; int ret = 0; diff --git a/fs/verity/fsverity_private.h b/fs/verity/fsverity_private.h index 629785c95007..dbe1ce5b450a 100644 --- a/fs/verity/fsverity_private.h +++ b/fs/verity/fsverity_private.h @@ -70,8 +70,6 @@ struct fsverity_info { const struct inode *inode; }; -/* Arbitrary limit to bound the kmalloc() size. Can be changed. */ -#define FS_VERITY_MAX_DESCRIPTOR_SIZE 16384 #define FS_VERITY_MAX_SIGNATURE_SIZE (FS_VERITY_MAX_DESCRIPTOR_SIZE - \ sizeof(struct fsverity_descriptor)) diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h index 7af030fa3c36..40f14e5fed9d 100644 --- a/include/linux/fsverity.h +++ b/include/linux/fsverity.h @@ -22,6 +22,9 @@ */ #define FS_VERITY_MAX_DIGEST_SIZE SHA512_DIGEST_SIZE +/* Arbitrary limit to bound the kmalloc() size. Can be changed. */ +#define FS_VERITY_MAX_DESCRIPTOR_SIZE 16384 + /* Verity operations for filesystems */ struct fsverity_operations {

[v4] btrfs: send: add support for fs-verity

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