fscrypt: remove filesystem specific build config option

In order to have a common code base for fscrypt "post read" processing
for all filesystems which support encryption, this commit removes
filesystem specific build config option (e.g. CONFIG_EXT4_FS_ENCRYPTION)
and replaces it with a build option (i.e. CONFIG_FS_ENCRYPTION) whose
value affects all the filesystems making use of fscrypt.

Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>

Documentation/filesystems/fscrypt.rst

@@ -343,9 +343,9 @@ FS_IOC_SET_ENCRYPTION_POLICY can fail with the following errors:
 - ``ENOTEMPTY``: the file is unencrypted and is a nonempty directory
 - ``ENOTTY``: this type of filesystem does not implement encryption
 - ``EOPNOTSUPP``: the kernel was not configured with encryption
-  support for this filesystem, or the filesystem superblock has not
+  support for filesystems, or the filesystem superblock has not
   had encryption enabled on it.  (For example, to use encryption on an
-  ext4 filesystem, CONFIG_EXT4_ENCRYPTION must be enabled in the
+  ext4 filesystem, CONFIG_FS_ENCRYPTION must be enabled in the
   kernel config, and the superblock must have had the "encrypt"
   feature flag enabled using ``tune2fs -O encrypt`` or ``mkfs.ext4 -O
   encrypt``.)

arch/mips/configs/generic_defconfig

@@ -59,7 +59,7 @@ CONFIG_HID_MONTEREY=y
 CONFIG_EXT4_FS=y
 CONFIG_EXT4_FS_POSIX_ACL=y
 CONFIG_EXT4_FS_SECURITY=y
-CONFIG_EXT4_ENCRYPTION=y
+CONFIG_FS_ENCRYPTION=y
 CONFIG_FANOTIFY=y
 CONFIG_FUSE_FS=y
 CONFIG_CUSE=y

arch/nds32/configs/defconfig

@@ -74,7 +74,7 @@ CONFIG_GENERIC_PHY=y
 CONFIG_EXT4_FS=y
 CONFIG_EXT4_FS_POSIX_ACL=y
 CONFIG_EXT4_FS_SECURITY=y
-CONFIG_EXT4_ENCRYPTION=y
+CONFIG_FS_ENCRYPTION=y
 CONFIG_FUSE_FS=y
 CONFIG_MSDOS_FS=y
 CONFIG_VFAT_FS=y

arch/s390/configs/debug_defconfig

@@ -500,7 +500,6 @@ CONFIG_S390_AP_IOMMU=y
 CONFIG_EXT4_FS=y
 CONFIG_EXT4_FS_POSIX_ACL=y
 CONFIG_EXT4_FS_SECURITY=y
-CONFIG_EXT4_ENCRYPTION=y
 CONFIG_JBD2_DEBUG=y
 CONFIG_JFS_FS=m
 CONFIG_JFS_POSIX_ACL=y
@@ -520,6 +519,7 @@ CONFIG_BTRFS_DEBUG=y
 CONFIG_NILFS2_FS=m
 CONFIG_FS_DAX=y
 CONFIG_EXPORTFS_BLOCK_OPS=y
+CONFIG_FS_ENCRYPTION=y
 CONFIG_FANOTIFY=y
 CONFIG_FANOTIFY_ACCESS_PERMISSIONS=y
 CONFIG_QUOTA_NETLINK_INTERFACE=y

arch/s390/configs/performance_defconfig

@@ -497,7 +497,6 @@ CONFIG_S390_AP_IOMMU=y
 CONFIG_EXT4_FS=y
 CONFIG_EXT4_FS_POSIX_ACL=y
 CONFIG_EXT4_FS_SECURITY=y
-CONFIG_EXT4_ENCRYPTION=y
 CONFIG_JBD2_DEBUG=y
 CONFIG_JFS_FS=m
 CONFIG_JFS_POSIX_ACL=y
@@ -515,6 +514,7 @@ CONFIG_BTRFS_FS_POSIX_ACL=y
 CONFIG_NILFS2_FS=m
 CONFIG_FS_DAX=y
 CONFIG_EXPORTFS_BLOCK_OPS=y
+CONFIG_FS_ENCRYPTION=y
 CONFIG_FANOTIFY=y
 CONFIG_FANOTIFY_ACCESS_PERMISSIONS=y
 CONFIG_QUOTA_NETLINK_INTERFACE=y

fs/crypto/Kconfig

@@ -1,5 +1,5 @@
 config FS_ENCRYPTION
-	tristate "FS Encryption (Per-file encryption)"
+	bool "FS Encryption (Per-file encryption)"
 	select CRYPTO
 	select CRYPTO_AES
 	select CRYPTO_CBC
@@ -12,4 +12,5 @@ config FS_ENCRYPTION
 	  Enable encryption of files and directories.  This
 	  feature is similar to ecryptfs, but it is more memory
 	  efficient since it avoids caching the encrypted and
-	  decrypted pages in the page cache.
+	  decrypted pages in the page cache.  Currently Ext4,
+	  F2FS and UBIFS make use of this feature.

fs/crypto/fscrypt_private.h

@@ -12,7 +12,6 @@
 #ifndef _FSCRYPT_PRIVATE_H
 #define _FSCRYPT_PRIVATE_H
 
-#define __FS_HAS_ENCRYPTION 1
 #include <linux/fscrypt.h>
 #include <crypto/hash.h>
 

fs/ext4/Kconfig

@@ -96,21 +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_ENCRYPTION
-	bool "Ext4 Encryption"
-	depends on EXT4_FS
-	select FS_ENCRYPTION
-	help
-	  Enable encryption of ext4 files and directories.  This
-	  feature is similar to ecryptfs, but it is more memory
-	  efficient since it avoids caching the encrypted and
-	  decrypted pages in the page cache.
-
-config EXT4_FS_ENCRYPTION
-	bool
-	default y
-	depends on EXT4_ENCRYPTION
-
 config EXT4_DEBUG
 	bool "EXT4 debugging support"
 	depends on EXT4_FS

fs/ext4/dir.c

@@ -283,9 +283,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
 done:
 	err = 0;
 errout:
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
 	fscrypt_fname_free_buffer(&fstr);
-#endif
 	brelse(bh);
 	return err;
 }

fs/ext4/ext4.h

@@ -40,7 +40,6 @@
 #include <linux/compat.h>
 #endif
 
-#define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_EXT4_FS_ENCRYPTION)
 #include <linux/fscrypt.h>
 
 #include <linux/compiler.h>
@@ -1326,7 +1325,7 @@ struct ext4_super_block {
 #define EXT4_MF_FS_ABORTED		0x0002	/* Fatal error detected */
 #define EXT4_MF_TEST_DUMMY_ENCRYPTION	0x0004
 
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 #define DUMMY_ENCRYPTION_ENABLED(sbi) (unlikely((sbi)->s_mount_flags & \
 						EXT4_MF_TEST_DUMMY_ENCRYPTION))
 #else
@@ -2051,7 +2050,7 @@ struct ext4_filename {
 	const struct qstr *usr_fname;
 	struct fscrypt_str disk_name;
 	struct dx_hash_info hinfo;
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 	struct fscrypt_str crypto_buf;
 #endif
 };
@@ -2279,7 +2278,7 @@ extern unsigned ext4_free_clusters_after_init(struct super_block *sb,
 					      struct ext4_group_desc *gdp);
 ext4_fsblk_t ext4_inode_to_goal_block(struct inode *);
 
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 static inline int ext4_fname_setup_filename(struct inode *dir,
 			const struct qstr *iname,
 			int lookup, struct ext4_filename *fname)

fs/ext4/inode.c

@@ -1150,7 +1150,7 @@ int do_journal_get_write_access(handle_t *handle,
 	return ret;
 }
 
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
 				  get_block_t *get_block)
 {
@@ -1302,7 +1302,7 @@ retry_journal:
 	/* In case writeback began while the page was unlocked */
 	wait_for_stable_page(page);
 
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 	if (ext4_should_dioread_nolock(inode))
 		ret = ext4_block_write_begin(page, pos, len,
 					     ext4_get_block_unwritten);
@@ -3104,7 +3104,7 @@ retry_journal:
 	/* In case writeback began while the page was unlocked */
 	wait_for_stable_page(page);
 
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 	ret = ext4_block_write_begin(page, pos, len,
 				     ext4_da_get_block_prep);
 #else
@@ -3879,7 +3879,7 @@ static ssize_t ext4_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
 	loff_t offset = iocb->ki_pos;
 	ssize_t ret;
 
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 	if (IS_ENCRYPTED(inode) && S_ISREG(inode->i_mode))
 		return 0;
 #endif

fs/ext4/ioctl.c

@@ -210,7 +210,7 @@ journal_err_out:
 	return err;
 }
 
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 static int uuid_is_zero(__u8 u[16])
 {
 	int	i;
@@ -978,7 +978,7 @@ resizefs_out:
 		return fscrypt_ioctl_set_policy(filp, (const void __user *)arg);
 
 	case EXT4_IOC_GET_ENCRYPTION_PWSALT: {
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 		int err, err2;
 		struct ext4_sb_info *sbi = EXT4_SB(sb);
 		handle_t *handle;

fs/ext4/namei.c

@@ -612,7 +612,7 @@ static struct stats dx_show_leaf(struct inode *dir,
 		{
 			if (show_names)
 			{
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 				int len;
 				char *name;
 				struct fscrypt_str fname_crypto_str =
@@ -984,7 +984,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 	top = (struct ext4_dir_entry_2 *) ((char *) de +
 					   dir->i_sb->s_blocksize -
 					   EXT4_DIR_REC_LEN(0));
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 	/* Check if the directory is encrypted */
 	if (IS_ENCRYPTED(dir)) {
 		err = fscrypt_get_encryption_info(dir);
@@ -1047,7 +1047,7 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 	}
 errout:
 	brelse(bh);
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 	fscrypt_fname_free_buffer(&fname_crypto_str);
 #endif
 	return count;
@@ -1267,7 +1267,7 @@ static inline bool ext4_match(const struct ext4_filename *fname,
 
 	f.usr_fname = fname->usr_fname;
 	f.disk_name = fname->disk_name;
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 	f.crypto_buf = fname->crypto_buf;
 #endif
 	return fscrypt_match_name(&f, de->name, de->name_len);
@@ -1498,7 +1498,7 @@ static struct buffer_head * ext4_dx_find_entry(struct inode *dir,
 	ext4_lblk_t block;
 	int retval;
 
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 	*res_dir = NULL;
 #endif
 	frame = dx_probe(fname, dir, NULL, frames);

fs/ext4/page-io.c

@@ -66,7 +66,7 @@ static void ext4_finish_bio(struct bio *bio)
 
 	bio_for_each_segment_all(bvec, bio, i) {
 		struct page *page = bvec->bv_page;
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 		struct page *data_page = NULL;
 #endif
 		struct buffer_head *bh, *head;
@@ -78,7 +78,7 @@ static void ext4_finish_bio(struct bio *bio)
 		if (!page)
 			continue;
 
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 		if (!page->mapping) {
 			/* The bounce data pages are unmapped. */
 			data_page = page;
@@ -111,7 +111,7 @@ static void ext4_finish_bio(struct bio *bio)
 		bit_spin_unlock(BH_Uptodate_Lock, &head->b_state);
 		local_irq_restore(flags);
 		if (!under_io) {
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 			if (data_page)
 				fscrypt_restore_control_page(data_page);
 #endif

fs/ext4/readpage.c

@@ -49,7 +49,7 @@
 
 static inline bool ext4_bio_encrypted(struct bio *bio)
 {
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 	return unlikely(bio->bi_private != NULL);
 #else
 	return false;

fs/ext4/super.c

@@ -1232,7 +1232,7 @@ static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
 	return try_to_free_buffers(page);
 }
 
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
 {
 	return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
@@ -1922,7 +1922,7 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
 		*journal_ioprio =
 			IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, arg);
 	} else if (token == Opt_test_dummy_encryption) {
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 		sbi->s_mount_flags |= EXT4_MF_TEST_DUMMY_ENCRYPTION;
 		ext4_msg(sb, KERN_WARNING,
 			 "Test dummy encryption mode enabled");
@@ -4167,7 +4167,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_op = &ext4_sops;
 	sb->s_export_op = &ext4_export_ops;
 	sb->s_xattr = ext4_xattr_handlers;
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 	sb->s_cop = &ext4_cryptops;
 #endif
 #ifdef CONFIG_QUOTA

fs/ext4/sysfs.c

@@ -224,7 +224,7 @@ static struct attribute *ext4_attrs[] = {
 EXT4_ATTR_FEATURE(lazy_itable_init);
 EXT4_ATTR_FEATURE(batched_discard);
 EXT4_ATTR_FEATURE(meta_bg_resize);
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 EXT4_ATTR_FEATURE(encryption);
 #endif
 EXT4_ATTR_FEATURE(metadata_csum_seed);
@@ -233,7 +233,7 @@ static struct attribute *ext4_feat_attrs[] = {
 	ATTR_LIST(lazy_itable_init),
 	ATTR_LIST(batched_discard),
 	ATTR_LIST(meta_bg_resize),
-#ifdef CONFIG_EXT4_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 	ATTR_LIST(encryption),
 #endif
 	ATTR_LIST(metadata_csum_seed),

fs/f2fs/Kconfig

@@ -3,6 +3,7 @@ config F2FS_FS
 	depends on BLOCK
 	select CRYPTO
 	select CRYPTO_CRC32
+	select F2FS_FS_XATTR if FS_ENCRYPTION
 	help
 	  F2FS is based on Log-structured File System (LFS), which supports
 	  versatile "flash-friendly" features. The design has been focused on
@@ -70,17 +71,6 @@ config F2FS_CHECK_FS
 
 	  If you want to improve the performance, say N.
 
-config F2FS_FS_ENCRYPTION
-	bool "F2FS Encryption"
-	depends on F2FS_FS
-	depends on F2FS_FS_XATTR
-	select FS_ENCRYPTION
-	help
-	  Enable encryption of f2fs files and directories.  This
-	  feature is similar to ecryptfs, but it is more memory
-	  efficient since it avoids caching the encrypted and
-	  decrypted pages in the page cache.
-
 config F2FS_IO_TRACE
 	bool "F2FS IO tracer"
 	depends on F2FS_FS

fs/f2fs/f2fs.h

@@ -24,7 +24,6 @@
 #include <linux/quotaops.h>
 #include <crypto/hash.h>
 
-#define __FS_HAS_ENCRYPTION IS_ENABLED(CONFIG_F2FS_FS_ENCRYPTION)
 #include <linux/fscrypt.h>
 
 #ifdef CONFIG_F2FS_CHECK_FS
@@ -1137,7 +1136,7 @@ enum fsync_mode {
 	FSYNC_MODE_NOBARRIER,	/* fsync behaves nobarrier based on posix */
 };
 
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 #define DUMMY_ENCRYPTION_ENABLED(sbi) \
 			(unlikely(F2FS_OPTION(sbi).test_dummy_encryption))
 #else
@@ -3470,7 +3469,7 @@ static inline bool f2fs_encrypted_file(struct inode *inode)
 
 static inline void f2fs_set_encrypted_inode(struct inode *inode)
 {
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 	file_set_encrypt(inode);
 	f2fs_set_inode_flags(inode);
 #endif
@@ -3549,7 +3548,7 @@ static inline void set_opt_mode(struct f2fs_sb_info *sbi, unsigned int mt)
 
 static inline bool f2fs_may_encrypt(struct inode *inode)
 {
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 	umode_t mode = inode->i_mode;
 
 	return (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode));

fs/f2fs/super.c

@@ -757,7 +757,7 @@ static int parse_options(struct super_block *sb, char *options)
 			kvfree(name);
 			break;
 		case Opt_test_dummy_encryption:
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 			if (!f2fs_sb_has_encrypt(sbi)) {
 				f2fs_msg(sb, KERN_ERR, "Encrypt feature is off");
 				return -EINVAL;
@@ -1390,7 +1390,7 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
 		seq_printf(seq, ",whint_mode=%s", "user-based");
 	else if (F2FS_OPTION(sbi).whint_mode == WHINT_MODE_FS)
 		seq_printf(seq, ",whint_mode=%s", "fs-based");
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 	if (F2FS_OPTION(sbi).test_dummy_encryption)
 		seq_puts(seq, ",test_dummy_encryption");
 #endif
@@ -2154,7 +2154,7 @@ static const struct super_operations f2fs_sops = {
 	.remount_fs	= f2fs_remount,
 };
 
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 static int f2fs_get_context(struct inode *inode, void *ctx, size_t len)
 {
 	return f2fs_getxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION,
@@ -3116,7 +3116,7 @@ try_onemore:
 #endif
 
 	sb->s_op = &f2fs_sops;
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
+#ifdef CONFIG_FS_ENCRYPTION
 	sb->s_cop = &f2fs_cryptops;
 #endif
 	sb->s_xattr = f2fs_xattr_handlers;