Re: [PATCH V3 7/9] fsverity: Remove filesystem specific build config option

[Eric Biggers <ebiggers@kernel.org>]

On Sat, Dec 08, 2018 at 12:21:42PM +0530, Chandan Rajendra wrote:
> In order to have a common code base for fsverity "post read" processing
> for all filesystems which support fsverity, this commit removes
> filesystem specific build config option (e.g. CONFIG_EXT4_FS_VERITY)
> and replaces it with a build option (i.e. CONFIG_FS_VERITY) whose
> value affects all the filesystems making use of fsverity.
> 
> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>

Reviewed-by: Eric Biggers <ebiggers@google.com>

> ---
>  Documentation/filesystems/fsverity.rst |  4 ++--
>  fs/ext4/Kconfig                        | 20 --------------------
>  fs/ext4/ext4.h                         |  2 --
>  fs/ext4/readpage.c                     |  4 ++--
>  fs/ext4/super.c                        |  6 +++---
>  fs/ext4/sysfs.c                        |  4 ++--
>  fs/f2fs/Kconfig                        | 20 --------------------
>  fs/f2fs/data.c                         |  2 +-
>  fs/f2fs/f2fs.h                         |  2 --
>  fs/f2fs/super.c                        |  6 +++---
>  fs/f2fs/sysfs.c                        |  4 ++--
>  fs/verity/Kconfig                      |  3 ++-
>  fs/verity/fsverity_private.h           |  1 -
>  include/linux/fs.h                     |  4 ++--
>  include/linux/fsverity.h               |  7 +++----
>  15 files changed, 22 insertions(+), 67 deletions(-)
> 
> diff --git a/Documentation/filesystems/fsverity.rst b/Documentation/filesystems/fsverity.rst
> index d633fc0567bd..bb208dad10d9 100644
> --- a/Documentation/filesystems/fsverity.rst
> +++ b/Documentation/filesystems/fsverity.rst
> @@ -279,7 +279,7 @@ ext4
>  
>  ext4 supports fs-verity since kernel version TODO.
>  
> -CONFIG_EXT4_FS_VERITY must be enabled in the kernel config.  Also, the
> +CONFIG_FS_VERITY must be enabled in the kernel config.  Also, the
>  filesystem must have been formatted with ``-O verity``, or had
>  ``tune2fs -O verity`` run on it.  These require e2fsprogs v1.44.4-2 or
>  later.  This e2fsprogs version is also required for e2fsck to
> @@ -306,7 +306,7 @@ f2fs
>  
>  f2fs supports fs-verity since kernel version TODO.
>  
> -CONFIG_F2FS_FS_VERITY must be enabled in the kernel config.  Also, the
> +CONFIG_FS_VERITY must be enabled in the kernel config.  Also, the
>  filesystem must have been formatted with ``-O verity``.  This requires
>  f2fs-tools v1.11.0 or later.
>  
> diff --git a/fs/ext4/Kconfig b/fs/ext4/Kconfig
> index e1002bbf35bf..031e5a82d556 100644
> --- a/fs/ext4/Kconfig
> +++ b/fs/ext4/Kconfig
> @@ -96,26 +96,6 @@ config EXT4_FS_SECURITY
>  	  If you are not using a security module that requires using
>  	  extended attributes for file security labels, say N.
>  
> -config EXT4_FS_VERITY
> -	bool "Ext4 Verity"
> -	depends on EXT4_FS
> -	select FS_VERITY
> -	help
> -	  This option enables fs-verity for ext4.  fs-verity is the
> -	  dm-verity mechanism implemented at the file level.  Userspace
> -	  can append a Merkle tree (hash tree) to a file, then enable
> -	  fs-verity on the file.  ext4 will then transparently verify
> -	  any data read from the file against the Merkle tree.  The file
> -	  is also made read-only.
> -
> -	  This serves as an integrity check, but the availability of the
> -	  Merkle tree root hash also allows efficiently supporting
> -	  various use cases where normally the whole file would need to
> -	  be hashed at once, such as auditing and authenticity
> -	  verification (appraisal).
> -
> -	  If unsure, say N.
> -
>  config EXT4_DEBUG
>  	bool "EXT4 debugging support"
>  	depends on EXT4_FS
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 64bf9fb7ef18..bff8d639dd0c 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -41,8 +41,6 @@
>  #endif
>  
>  #include <linux/fscrypt.h>
> -
> -#define __FS_HAS_VERITY IS_ENABLED(CONFIG_EXT4_FS_VERITY)
>  #include <linux/fsverity.h>
>  
>  #include <linux/compiler.h>
> diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c
> index 2c037df629dd..8717ac0a5bb2 100644
> --- a/fs/ext4/readpage.c
> +++ b/fs/ext4/readpage.c
> @@ -158,7 +158,7 @@ static struct bio_post_read_ctx *get_bio_post_read_ctx(struct inode *inode,
>  
>  	if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode))
>  		post_read_steps |= 1 << STEP_DECRYPT;
> -#ifdef CONFIG_EXT4_FS_VERITY
> +#ifdef CONFIG_FS_VERITY
>  	if (inode->i_verity_info != NULL &&
>  	    (index < ((i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT)))
>  		post_read_steps |= 1 << STEP_VERITY;
> @@ -205,7 +205,7 @@ static void mpage_end_io(struct bio *bio)
>  
>  static inline loff_t ext4_readpage_limit(struct inode *inode)
>  {
> -#ifdef CONFIG_EXT4_FS_VERITY
> +#ifdef CONFIG_FS_VERITY
>  	if (IS_VERITY(inode)) {
>  		if (inode->i_verity_info)
>  			/* limit to end of metadata region */
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 35ed3c48f8d2..0d169de59f76 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -1316,7 +1316,7 @@ static const struct fscrypt_operations ext4_cryptops = {
>  };
>  #endif
>  
> -#ifdef CONFIG_EXT4_FS_VERITY
> +#ifdef CONFIG_FS_VERITY
>  static int ext4_set_verity(struct inode *inode, loff_t data_i_size)
>  {
>  	int err;
> @@ -1402,7 +1402,7 @@ static const struct fsverity_operations ext4_verityops = {
>  	.set_verity		= ext4_set_verity,
>  	.get_metadata_end	= ext4_get_metadata_end,
>  };
> -#endif /* CONFIG_EXT4_FS_VERITY */
> +#endif /* CONFIG_FS_VERITY */
>  
>  #ifdef CONFIG_QUOTA
>  static const char * const quotatypes[] = INITQFNAMES;
> @@ -4235,7 +4235,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
>  #ifdef CONFIG_FS_ENCRYPTION
>  	sb->s_cop = &ext4_cryptops;
>  #endif
> -#ifdef CONFIG_EXT4_FS_VERITY
> +#ifdef CONFIG_FS_VERITY
>  	sb->s_vop = &ext4_verityops;
>  #endif
>  #ifdef CONFIG_QUOTA
> diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
> index 8bc915452a38..6fa0f47c3180 100644
> --- a/fs/ext4/sysfs.c
> +++ b/fs/ext4/sysfs.c
> @@ -227,7 +227,7 @@ EXT4_ATTR_FEATURE(meta_bg_resize);
>  #ifdef CONFIG_FS_ENCRYPTION
>  EXT4_ATTR_FEATURE(encryption);
>  #endif
> -#ifdef CONFIG_EXT4_FS_VERITY
> +#ifdef CONFIG_FS_VERITY
>  EXT4_ATTR_FEATURE(verity);
>  #endif
>  EXT4_ATTR_FEATURE(metadata_csum_seed);
> @@ -239,7 +239,7 @@ static struct attribute *ext4_feat_attrs[] = {
>  #ifdef CONFIG_FS_ENCRYPTION
>  	ATTR_LIST(encryption),
>  #endif
> -#ifdef CONFIG_EXT4_FS_VERITY
> +#ifdef CONFIG_FS_VERITY
>  	ATTR_LIST(verity),
>  #endif
>  	ATTR_LIST(metadata_csum_seed),
> diff --git a/fs/f2fs/Kconfig b/fs/f2fs/Kconfig
> index a5a1a381fcf1..e57cc754d543 100644
> --- a/fs/f2fs/Kconfig
> +++ b/fs/f2fs/Kconfig
> @@ -71,26 +71,6 @@ config F2FS_CHECK_FS
>  
>  	  If you want to improve the performance, say N.
>  
> -config F2FS_FS_VERITY
> -	bool "F2FS Verity"
> -	depends on F2FS_FS
> -	select FS_VERITY
> -	help
> -	  This option enables fs-verity for f2fs.  fs-verity is the
> -	  dm-verity mechanism implemented at the file level.  Userspace
> -	  can append a Merkle tree (hash tree) to a file, then enable
> -	  fs-verity on the file.  f2fs will then transparently verify
> -	  any data read from the file against the Merkle tree.  The file
> -	  is also made read-only.
> -
> -	  This serves as an integrity check, but the availability of the
> -	  Merkle tree root hash also allows efficiently supporting
> -	  various use cases where normally the whole file would need to
> -	  be hashed at once, such as auditing and authenticity
> -	  verification (appraisal).
> -
> -	  If unsure, say N.
> -
>  config F2FS_IO_TRACE
>  	bool "F2FS IO tracer"
>  	depends on F2FS_FS
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 844ec573263e..83b59b985894 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -610,7 +610,7 @@ static struct bio *f2fs_grab_read_bio(struct inode *inode, block_t blkaddr,
>  
>  	if (f2fs_encrypted_file(inode))
>  		post_read_steps |= 1 << STEP_DECRYPT;
> -#ifdef CONFIG_F2FS_FS_VERITY
> +#ifdef CONFIG_FS_VERITY
>  	if (inode->i_verity_info != NULL &&
>  	    (first_idx < ((i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT)))
>  		post_read_steps |= 1 << STEP_VERITY;
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 54bd93c7b630..7161918042e7 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -25,8 +25,6 @@
>  #include <crypto/hash.h>
>  
>  #include <linux/fscrypt.h>
> -
> -#define __FS_HAS_VERITY IS_ENABLED(CONFIG_F2FS_FS_VERITY)
>  #include <linux/fsverity.h>
>  
>  #ifdef CONFIG_F2FS_CHECK_FS
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index 73320202bd01..4a67b901eefc 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -2197,7 +2197,7 @@ static const struct fscrypt_operations f2fs_cryptops = {
>  };
>  #endif
>  
> -#ifdef CONFIG_F2FS_FS_VERITY
> +#ifdef CONFIG_FS_VERITY
>  static int f2fs_set_verity(struct inode *inode, loff_t data_i_size)
>  {
>  	int err;
> @@ -2223,7 +2223,7 @@ static const struct fsverity_operations f2fs_verityops = {
>  	.set_verity		= f2fs_set_verity,
>  	.get_metadata_end	= f2fs_get_metadata_end,
>  };
> -#endif /* CONFIG_F2FS_FS_VERITY */
> +#endif /* CONFIG_FS_VERITY */
>  
>  static struct inode *f2fs_nfs_get_inode(struct super_block *sb,
>  		u64 ino, u32 generation)
> @@ -3147,7 +3147,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
>  #ifdef CONFIG_FS_ENCRYPTION
>  	sb->s_cop = &f2fs_cryptops;
>  #endif
> -#ifdef CONFIG_F2FS_FS_VERITY
> +#ifdef CONFIG_FS_VERITY
>  	sb->s_vop = &f2fs_verityops;
>  #endif
>  	sb->s_xattr = f2fs_xattr_handlers;
> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
> index 737677655bc0..949e6d87f4e3 100644
> --- a/fs/f2fs/sysfs.c
> +++ b/fs/f2fs/sysfs.c
> @@ -444,7 +444,7 @@ F2FS_FEATURE_RO_ATTR(flexible_inline_xattr, FEAT_FLEXIBLE_INLINE_XATTR);
>  F2FS_FEATURE_RO_ATTR(quota_ino, FEAT_QUOTA_INO);
>  F2FS_FEATURE_RO_ATTR(inode_crtime, FEAT_INODE_CRTIME);
>  F2FS_FEATURE_RO_ATTR(lost_found, FEAT_LOST_FOUND);
> -#ifdef CONFIG_F2FS_FS_VERITY
> +#ifdef CONFIG_FS_VERITY
>  F2FS_FEATURE_RO_ATTR(verity, FEAT_VERITY);
>  #endif
>  F2FS_FEATURE_RO_ATTR(sb_checksum, FEAT_SB_CHECKSUM);
> @@ -507,7 +507,7 @@ static struct attribute *f2fs_feat_attrs[] = {
>  	ATTR_LIST(quota_ino),
>  	ATTR_LIST(inode_crtime),
>  	ATTR_LIST(lost_found),
> -#ifdef CONFIG_F2FS_FS_VERITY
> +#ifdef CONFIG_FS_VERITY
>  	ATTR_LIST(verity),
>  #endif
>  	ATTR_LIST(sb_checksum),
> diff --git a/fs/verity/Kconfig b/fs/verity/Kconfig
> index a7470a2e4892..6d9437a432cd 100644
> --- a/fs/verity/Kconfig
> +++ b/fs/verity/Kconfig
> @@ -1,5 +1,5 @@
>  config FS_VERITY
> -	tristate "FS Verity (read-only file-based authenticity protection)"
> +	bool "FS Verity (read-only file-based authenticity protection)"
>  	select CRYPTO
>  	# SHA-256 is selected as it's intended to be the default hash algorithm.
>  	# To avoid bloat, other wanted algorithms must be selected explicitly.
> @@ -23,6 +23,7 @@ config FS_VERITY
>  	  the contents may actually be needed.  Also, fs-verity verifies
>  	  data each time it is paged back in, which provides better
>  	  protection against malicious disks vs. an ahead-of-time hash.
> +	  Currently Ext4 and F2FS make use of this feature.
>  
>  	  If unsure, say N.
>  
> diff --git a/fs/verity/fsverity_private.h b/fs/verity/fsverity_private.h
> index 4b39d0a5544b..a7acb98ac42e 100644
> --- a/fs/verity/fsverity_private.h
> +++ b/fs/verity/fsverity_private.h
> @@ -15,7 +15,6 @@
>  #define pr_fmt(fmt) "fs-verity: " fmt
>  
>  #include <crypto/sha.h>
> -#define __FS_HAS_VERITY 1
>  #include <linux/fsverity.h>
>  
>  /*
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index de602d9f8d0e..1583b861a225 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -704,7 +704,7 @@ struct inode {
>  	struct fscrypt_info	*i_crypt_info;
>  #endif
>  
> -#if IS_ENABLED(CONFIG_FS_VERITY)
> +#ifdef CONFIG_FS_VERITY
>  	struct fsverity_info	*i_verity_info;
>  #endif
>  
> @@ -1407,7 +1407,7 @@ struct super_block {
>  #ifdef CONFIG_FS_ENCRYPTION
>  	const struct fscrypt_operations	*s_cop;
>  #endif
> -#if IS_ENABLED(CONFIG_FS_VERITY)
> +#ifdef CONFIG_FS_VERITY
>  	const struct fsverity_operations *s_vop;
>  #endif
>  	struct hlist_bl_head	s_roots;	/* alternate root dentries for NFS */
> diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h
> index c30c4f6ed411..ea8c418bd7d5 100644
> --- a/include/linux/fsverity.h
> +++ b/include/linux/fsverity.h
> @@ -19,8 +19,7 @@ struct fsverity_operations {
>  	int (*get_metadata_end)(struct inode *inode, loff_t *metadata_end_ret);
>  };
>  
> -#if __FS_HAS_VERITY
> -
> +#ifdef CONFIG_FS_VERITY
>  /* ioctl.c */
>  extern int fsverity_ioctl_enable(struct file *filp, const void __user *arg);
>  extern int fsverity_ioctl_measure(struct file *filp, void __user *arg);
> @@ -42,7 +41,7 @@ static inline bool fsverity_check_hole(struct inode *inode, struct page *page)
>  	return inode->i_verity_info == NULL || fsverity_verify_page(page);
>  }
>  
> -#else /* !__FS_HAS_VERITY */
> +#else  /* ! CONFIG_FS_VERITY */
>  
>  /* ioctl.c */
>  
> @@ -107,6 +106,6 @@ static inline bool fsverity_check_hole(struct inode *inode, struct page *page)
>  	return true;
>  }
>  
> -#endif	/* !__FS_HAS_VERITY */
> +#endif	/* ! CONFIG_FS_VERITY */
>  
>  #endif	/* _LINUX_FSVERITY_H */
> -- 
> 2.19.1
>