fs crypto: move per-file encryption from f2fs tree to fs/crypto

This patch adds the renamed functions moved from the f2fs crypto files.

1. definitions for per-file encryption used by ext4 and f2fs.

2. crypto.c for encrypt/decrypt functions
 a. IO preparation:
  - fscrypt_get_ctx / fscrypt_release_ctx
 b. before IOs:
  - fscrypt_encrypt_page
  - fscrypt_decrypt_page
  - fscrypt_zeroout_range
 c. after IOs:
  - fscrypt_decrypt_bio_pages
  - fscrypt_pullback_bio_page
  - fscrypt_restore_control_page

3. policy.c supporting context management.
 a. For ioctls:
  - fscrypt_process_policy
  - fscrypt_get_policy
 b. For context permission
  - fscrypt_has_permitted_context
  - fscrypt_inherit_context

4. keyinfo.c to handle permissions
  - fscrypt_get_encryption_info
  - fscrypt_free_encryption_info

5. fname.c to support filename encryption
 a. general wrapper functions
  - fscrypt_fname_disk_to_usr
  - fscrypt_fname_usr_to_disk
  - fscrypt_setup_filename
  - fscrypt_free_filename

 b. specific filename handling functions
  - fscrypt_fname_alloc_buffer
  - fscrypt_fname_free_buffer

6. Makefile and Kconfig

Cc: Al Viro <viro@ftp.linux.org.uk>
Signed-off-by: Michael Halcrow <mhalcrow@google.com>
Signed-off-by: Ildar Muslukhov <ildarm@google.com>
Signed-off-by: Uday Savagaonkar <savagaon@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/Kconfig

@@ -84,6 +84,8 @@ config MANDATORY_FILE_LOCKING
 
 	  To the best of my knowledge this is dead code that no one cares about.
 
+source "fs/crypto/Kconfig"
+
 source "fs/notify/Kconfig"
 
 source "fs/quota/Kconfig"

fs/Makefile

@@ -30,6 +30,7 @@ obj-$(CONFIG_EVENTFD)		+= eventfd.o
 obj-$(CONFIG_USERFAULTFD)	+= userfaultfd.o
 obj-$(CONFIG_AIO)               += aio.o
 obj-$(CONFIG_FS_DAX)		+= dax.o
+obj-$(CONFIG_FS_ENCRYPTION)	+= crypto/
 obj-$(CONFIG_FILE_LOCKING)      += locks.o
 obj-$(CONFIG_COMPAT)		+= compat.o compat_ioctl.o
 obj-$(CONFIG_BINFMT_AOUT)	+= binfmt_aout.o

fs/crypto/Kconfig

+config FS_ENCRYPTION
+	tristate "FS Encryption (Per-file encryption)"
+	depends on BLOCK
+	select CRYPTO
+	select CRYPTO_AES
+	select CRYPTO_CBC
+	select CRYPTO_ECB
+	select CRYPTO_XTS
+	select CRYPTO_CTS
+	select CRYPTO_CTR
+	select CRYPTO_SHA256
+	select KEYS
+	select ENCRYPTED_KEYS
+	help
+	  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.

fs/crypto/Makefile

+obj-$(CONFIG_FS_ENCRYPTION)	+= fscrypto.o
+
+fscrypto-y := crypto.o fname.o policy.o keyinfo.o

fs/f2fs/Kconfig

@@ -76,15 +76,7 @@ config F2FS_FS_ENCRYPTION
 	bool "F2FS Encryption"
 	depends on F2FS_FS
 	depends on F2FS_FS_XATTR
-	select CRYPTO_AES
-	select CRYPTO_CBC
-	select CRYPTO_ECB
-	select CRYPTO_XTS
-	select CRYPTO_CTS
-	select CRYPTO_CTR
-	select CRYPTO_SHA256
-	select KEYS
-	select ENCRYPTED_KEYS
+	select FS_ENCRYPTION
 	help
 	  Enable encryption of f2fs files and directories.  This
 	  feature is similar to ecryptfs, but it is more memory

fs/f2fs/Makefile

@@ -7,5 +7,3 @@ f2fs-$(CONFIG_F2FS_STAT_FS) += debug.o
 f2fs-$(CONFIG_F2FS_FS_XATTR) += xattr.o
 f2fs-$(CONFIG_F2FS_FS_POSIX_ACL) += acl.o
 f2fs-$(CONFIG_F2FS_IO_TRACE) += trace.o
-f2fs-$(CONFIG_F2FS_FS_ENCRYPTION) += crypto_policy.o crypto.o \
-		crypto_key.o crypto_fname.o

fs/f2fs/data.c

@@ -34,9 +34,9 @@ static void f2fs_read_end_io(struct bio *bio)
 
 	if (f2fs_bio_encrypted(bio)) {
 		if (bio->bi_error) {
-			f2fs_release_crypto_ctx(bio->bi_private);
+			fscrypt_release_ctx(bio->bi_private);
 		} else {
-			f2fs_end_io_crypto_work(bio->bi_private, bio);
+			fscrypt_decrypt_bio_pages(bio->bi_private, bio);
 			return;
 		}
 	}
@@ -64,7 +64,7 @@ static void f2fs_write_end_io(struct bio *bio)
 	bio_for_each_segment_all(bvec, bio, i) {
 		struct page *page = bvec->bv_page;
 
-		f2fs_restore_and_release_control_page(&page);
+		fscrypt_pullback_bio_page(&page, true);
 
 		if (unlikely(bio->bi_error)) {
 			set_bit(AS_EIO, &page->mapping->flags);
@@ -129,16 +129,10 @@ static bool __has_merged_page(struct f2fs_bio_info *io, struct inode *inode,
 
 	bio_for_each_segment_all(bvec, io->bio, i) {
 
-		if (bvec->bv_page->mapping) {
+		if (bvec->bv_page->mapping)
 			target = bvec->bv_page;
-		} else {
-			struct f2fs_crypto_ctx *ctx;
-
-			/* encrypted page */
-			ctx = (struct f2fs_crypto_ctx *)page_private(
-								bvec->bv_page);
-			target = ctx->w.control_page;
-		}
+		else
+			target = fscrypt_control_page(bvec->bv_page);
 
 		if (inode && inode == target->mapping->host)
 			return true;
@@ -220,7 +214,8 @@ void f2fs_flush_merged_bios(struct f2fs_sb_info *sbi)
 int f2fs_submit_page_bio(struct f2fs_io_info *fio)
 {
 	struct bio *bio;
-	struct page *page = fio->encrypted_page ? fio->encrypted_page : fio->page;
+	struct page *page = fio->encrypted_page ?
+			fio->encrypted_page : fio->page;
 
 	trace_f2fs_submit_page_bio(page, fio);
 	f2fs_trace_ios(fio, 0);
@@ -992,12 +987,12 @@ static int f2fs_mpage_readpages(struct address_space *mapping,
 			bio = NULL;
 		}
 		if (bio == NULL) {
-			struct f2fs_crypto_ctx *ctx = NULL;
+			struct fscrypt_ctx *ctx = NULL;
 
 			if (f2fs_encrypted_inode(inode) &&
 					S_ISREG(inode->i_mode)) {
 
-				ctx = f2fs_get_crypto_ctx(inode);
+				ctx = fscrypt_get_ctx(inode);
 				if (IS_ERR(ctx))
 					goto set_error_page;
 
@@ -1010,7 +1005,7 @@ static int f2fs_mpage_readpages(struct address_space *mapping,
 				min_t(int, nr_pages, BIO_MAX_PAGES));
 			if (!bio) {
 				if (ctx)
-					f2fs_release_crypto_ctx(ctx);
+					fscrypt_release_ctx(ctx);
 				goto set_error_page;
 			}
 			bio->bi_bdev = bdev;
@@ -1102,7 +1097,7 @@ int do_write_data_page(struct f2fs_io_info *fio)
 		f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode),
 							fio->old_blkaddr);
 
-		fio->encrypted_page = f2fs_encrypt(inode, fio->page);
+		fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page);
 		if (IS_ERR(fio->encrypted_page)) {
 			err = PTR_ERR(fio->encrypted_page);
 			goto out_writepage;
@@ -1608,7 +1603,7 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
 
 		/* avoid symlink page */
 		if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) {
-			err = f2fs_decrypt(page);
+			err = fscrypt_decrypt_page(page);
 			if (err)
 				goto fail;
 		}

fs/f2fs/dir.c

@@ -77,7 +77,7 @@ static unsigned long dir_block_index(unsigned int level,
 }
 
 static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
-				struct f2fs_filename *fname,
+				struct fscrypt_name *fname,
 				f2fs_hash_t namehash,
 				int *max_slots,
 				struct page **res_page)
@@ -103,15 +103,15 @@ static struct f2fs_dir_entry *find_in_block(struct page *dentry_page,
 	return de;
 }
 
-struct f2fs_dir_entry *find_target_dentry(struct f2fs_filename *fname,
+struct f2fs_dir_entry *find_target_dentry(struct fscrypt_name *fname,
 			f2fs_hash_t namehash, int *max_slots,
 			struct f2fs_dentry_ptr *d)
 {
 	struct f2fs_dir_entry *de;
 	unsigned long bit_pos = 0;
 	int max_len = 0;
-	struct f2fs_str de_name = FSTR_INIT(NULL, 0);
-	struct f2fs_str *name = &fname->disk_name;
+	struct fscrypt_str de_name = FSTR_INIT(NULL, 0);
+	struct fscrypt_str *name = &fname->disk_name;
 
 	if (max_slots)
 		*max_slots = 0;
@@ -157,7 +157,7 @@ struct f2fs_dir_entry *find_target_dentry(struct f2fs_filename *fname,
 
 static struct f2fs_dir_entry *find_in_level(struct inode *dir,
 					unsigned int level,
-					struct f2fs_filename *fname,
+					struct fscrypt_name *fname,
 					struct page **res_page)
 {
 	struct qstr name = FSTR_TO_QSTR(&fname->disk_name);
@@ -218,12 +218,12 @@ struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
 	struct f2fs_dir_entry *de = NULL;
 	unsigned int max_depth;
 	unsigned int level;
-	struct f2fs_filename fname;
+	struct fscrypt_name fname;
 	int err;
 
 	*res_page = NULL;
 
-	err = f2fs_fname_setup_filename(dir, child, 1, &fname);
+	err = fscrypt_setup_filename(dir, child, 1, &fname);
 	if (err)
 		return NULL;
 
@@ -251,7 +251,7 @@ struct f2fs_dir_entry *f2fs_find_entry(struct inode *dir,
 			break;
 	}
 out:
-	f2fs_fname_free_filename(&fname);
+	fscrypt_free_filename(&fname);
 	return de;
 }
 
@@ -413,7 +413,7 @@ struct page *init_inode_metadata(struct inode *inode, struct inode *dir,
 			goto put_error;
 
 		if (f2fs_encrypted_inode(dir) && f2fs_may_encrypt(inode)) {
-			err = f2fs_inherit_context(dir, inode, page);
+			err = fscrypt_inherit_context(dir, inode, page, false);
 			if (err)
 				goto put_error;
 		}
@@ -536,11 +536,11 @@ int __f2fs_add_link(struct inode *dir, const struct qstr *name,
 	struct f2fs_dentry_block *dentry_blk = NULL;
 	struct f2fs_dentry_ptr d;
 	struct page *page = NULL;
-	struct f2fs_filename fname;
+	struct fscrypt_name fname;
 	struct qstr new_name;
 	int slots, err;
 
-	err = f2fs_fname_setup_filename(dir, name, 0, &fname);
+	err = fscrypt_setup_filename(dir, name, 0, &fname);
 	if (err)
 		return err;
 
@@ -639,7 +639,7 @@ int __f2fs_add_link(struct inode *dir, const struct qstr *name,
 	kunmap(dentry_page);
 	f2fs_put_page(dentry_page, 1);
 out:
-	f2fs_fname_free_filename(&fname);
+	fscrypt_free_filename(&fname);
 	f2fs_update_time(F2FS_I_SB(dir), REQ_TIME);
 	return err;
 }
@@ -781,12 +781,12 @@ bool f2fs_empty_dir(struct inode *dir)
 }
 
 bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
-				unsigned int start_pos, struct f2fs_str *fstr)
+			unsigned int start_pos, struct fscrypt_str *fstr)
 {
 	unsigned char d_type = DT_UNKNOWN;
 	unsigned int bit_pos;
 	struct f2fs_dir_entry *de = NULL;
-	struct f2fs_str de_name = FSTR_INIT(NULL, 0);
+	struct fscrypt_str de_name = FSTR_INIT(NULL, 0);
 
 	bit_pos = ((unsigned long)ctx->pos % d->max);
 
@@ -820,7 +820,8 @@ bool f2fs_fill_dentries(struct dir_context *ctx, struct f2fs_dentry_ptr *d,
 
 			memcpy(de_name.name, d->filename[bit_pos], de_name.len);
 
-			ret = f2fs_fname_disk_to_usr(d->inode, &de->hash_code,
+			ret = fscrypt_fname_disk_to_usr(d->inode,
+						(u32)de->hash_code, 0,
 						&de_name, fstr);
 			kfree(de_name.name);
 			if (ret < 0)
@@ -849,16 +850,15 @@ static int f2fs_readdir(struct file *file, struct dir_context *ctx)
 	struct file_ra_state *ra = &file->f_ra;
 	unsigned int n = ((unsigned long)ctx->pos / NR_DENTRY_IN_BLOCK);
 	struct f2fs_dentry_ptr d;
-	struct f2fs_str fstr = FSTR_INIT(NULL, 0);
+	struct fscrypt_str fstr = FSTR_INIT(NULL, 0);
 	int err = 0;
 
 	if (f2fs_encrypted_inode(inode)) {
-		err = f2fs_get_encryption_info(inode);
+		err = fscrypt_get_encryption_info(inode);
 		if (err)
 			return err;
 
-		err = f2fs_fname_crypto_alloc_buffer(inode, F2FS_NAME_LEN,
-								&fstr);
+		err = fscrypt_fname_alloc_buffer(inode, F2FS_NAME_LEN, &fstr);
 		if (err < 0)
 			return err;
 	}
@@ -898,14 +898,14 @@ static int f2fs_readdir(struct file *file, struct dir_context *ctx)
 		f2fs_put_page(dentry_page, 1);
 	}
 out:
-	f2fs_fname_crypto_free_buffer(&fstr);
+	fscrypt_fname_free_buffer(&fstr);
 	return err;
 }
 
 static int f2fs_dir_open(struct inode *inode, struct file *filp)
 {
 	if (f2fs_encrypted_inode(inode))
-		return f2fs_get_encryption_info(inode) ? -EACCES : 0;
+		return fscrypt_get_encryption_info(inode) ? -EACCES : 0;
 	return 0;
 }
 

fs/f2fs/f2fs.h

@@ -22,6 +22,7 @@
 #include <linux/vmalloc.h>
 #include <linux/bio.h>
 #include <linux/blkdev.h>
+#include <linux/fscrypto.h>
 
 #ifdef CONFIG_F2FS_CHECK_FS
 #define f2fs_bug_on(sbi, condition)	BUG_ON(condition)
@@ -231,12 +232,9 @@ static inline bool __has_cursum_space(struct f2fs_journal *journal,
 #define F2FS_IOC_WRITE_CHECKPOINT	_IO(F2FS_IOCTL_MAGIC, 7)
 #define F2FS_IOC_DEFRAGMENT		_IO(F2FS_IOCTL_MAGIC, 8)
 
-#define F2FS_IOC_SET_ENCRYPTION_POLICY					\
-		_IOR('f', 19, struct f2fs_encryption_policy)
-#define F2FS_IOC_GET_ENCRYPTION_PWSALT					\
-		_IOW('f', 20, __u8[16])
-#define F2FS_IOC_GET_ENCRYPTION_POLICY					\
-		_IOW('f', 21, struct f2fs_encryption_policy)
+#define F2FS_IOC_SET_ENCRYPTION_POLICY	FS_IOC_SET_ENCRYPTION_POLICY
+#define F2FS_IOC_GET_ENCRYPTION_POLICY	FS_IOC_GET_ENCRYPTION_POLICY
+#define F2FS_IOC_GET_ENCRYPTION_PWSALT	FS_IOC_GET_ENCRYPTION_PWSALT
 
 /*
  * should be same as XFS_IOC_GOINGDOWN.
@@ -266,25 +264,6 @@ struct f2fs_defragment {
  * For INODE and NODE manager
  */
 /* for directory operations */
-struct f2fs_str {
-	unsigned char *name;
-	u32 len;
-};
-
-struct f2fs_filename {
-	const struct qstr *usr_fname;
-	struct f2fs_str disk_name;
-	f2fs_hash_t hash;
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
-	struct f2fs_str crypto_buf;
-#endif
-};
-
-#define FSTR_INIT(n, l)		{ .name = n, .len = l }
-#define FSTR_TO_QSTR(f)		QSTR_INIT((f)->name, (f)->len)
-#define fname_name(p)		((p)->disk_name.name)
-#define fname_len(p)		((p)->disk_name.len)
-
 struct f2fs_dentry_ptr {
 	struct inode *inode;
 	const void *bitmap;
@@ -412,15 +391,6 @@ struct f2fs_map_blocks {
 #define file_enc_name(inode)	is_file(inode, FADVISE_ENC_NAME_BIT)
 #define file_set_enc_name(inode) set_file(inode, FADVISE_ENC_NAME_BIT)
 
-/* Encryption algorithms */
-#define F2FS_ENCRYPTION_MODE_INVALID		0
-#define F2FS_ENCRYPTION_MODE_AES_256_XTS	1
-#define F2FS_ENCRYPTION_MODE_AES_256_GCM	2
-#define F2FS_ENCRYPTION_MODE_AES_256_CBC	3
-#define F2FS_ENCRYPTION_MODE_AES_256_CTS	4
-
-#include "f2fs_crypto.h"
-
 #define DEF_DIR_LEVEL		0
 
 struct f2fs_inode_info {
@@ -444,13 +414,7 @@ struct f2fs_inode_info {
 	struct list_head dirty_list;	/* linked in global dirty list */
 	struct list_head inmem_pages;	/* inmemory pages managed by f2fs */
 	struct mutex inmem_lock;	/* lock for inmemory pages */
-
 	struct extent_tree *extent_tree;	/* cached extent_tree entry */
-
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
-	/* Encryption params */
-	struct f2fs_crypt_info *i_crypt_info;
-#endif
 };
 
 static inline void get_extent_info(struct extent_info *ext,
@@ -1741,10 +1705,10 @@ struct dentry *f2fs_get_parent(struct dentry *child);
 extern unsigned char f2fs_filetype_table[F2FS_FT_MAX];
 void set_de_type(struct f2fs_dir_entry *, umode_t);
 
-struct f2fs_dir_entry *find_target_dentry(struct f2fs_filename *,
+struct f2fs_dir_entry *find_target_dentry(struct fscrypt_name *,
 			f2fs_hash_t, int *, struct f2fs_dentry_ptr *);
 bool f2fs_fill_dentries(struct dir_context *, struct f2fs_dentry_ptr *,
-			unsigned int, struct f2fs_str *);
+			unsigned int, struct fscrypt_str *);
 void do_make_empty_dir(struct inode *, struct inode *,
 			struct f2fs_dentry_ptr *);
 struct page *init_inode_metadata(struct inode *, struct inode *,
@@ -2120,7 +2084,7 @@ int f2fs_convert_inline_inode(struct inode *);
 int f2fs_write_inline_data(struct inode *, struct page *);
 bool recover_inline_data(struct inode *, struct page *);
 struct f2fs_dir_entry *find_in_inline_dir(struct inode *,
-				struct f2fs_filename *, struct page **);
+				struct fscrypt_name *, struct page **);
 struct f2fs_dir_entry *f2fs_parent_inline_dir(struct inode *, struct page **);
 int make_empty_inline_dir(struct inode *inode, struct inode *, struct page *);
 int f2fs_add_inline_entry(struct inode *, const struct qstr *, struct inode *,
@@ -2129,7 +2093,7 @@ void f2fs_delete_inline_entry(struct f2fs_dir_entry *, struct page *,
 						struct inode *, struct inode *);
 bool f2fs_empty_inline_dir(struct inode *);
 int f2fs_read_inline_dir(struct file *, struct dir_context *,
-						struct f2fs_str *);
+						struct fscrypt_str *);
 int f2fs_inline_data_fiemap(struct inode *,
 		struct fiemap_extent_info *, __u64, __u64);
 
@@ -2159,13 +2123,9 @@ void destroy_extent_cache(void);
 /*
  * crypto support
  */
-static inline int f2fs_encrypted_inode(struct inode *inode)
+static inline bool f2fs_encrypted_inode(struct inode *inode)
 {
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
 	return file_is_encrypt(inode);
-#else
-	return 0;
-#endif
 }
 
 static inline void f2fs_set_encrypted_inode(struct inode *inode)
@@ -2177,20 +2137,12 @@ static inline void f2fs_set_encrypted_inode(struct inode *inode)
 
 static inline bool f2fs_bio_encrypted(struct bio *bio)
 {
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
-	return unlikely(bio->bi_private != NULL);
-#else
-	return false;
-#endif
+	return bio->bi_private != NULL;
 }
 
 static inline int f2fs_sb_has_crypto(struct super_block *sb)
 {
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
 	return F2FS_HAS_FEATURE(sb, F2FS_FEATURE_ENCRYPT);
-#else
-	return 0;
-#endif
 }
 
 static inline bool f2fs_may_encrypt(struct inode *inode)
@@ -2204,86 +2156,28 @@ static inline bool f2fs_may_encrypt(struct inode *inode)
 #endif
 }
 
-/* crypto_policy.c */
-int f2fs_is_child_context_consistent_with_parent(struct inode *,
-							struct inode *);
-int f2fs_inherit_context(struct inode *, struct inode *, struct page *);
-int f2fs_process_policy(const struct f2fs_encryption_policy *, struct inode *);
-int f2fs_get_policy(struct inode *, struct f2fs_encryption_policy *);
-
-/* crypt.c */
-extern struct kmem_cache *f2fs_crypt_info_cachep;
-bool f2fs_valid_contents_enc_mode(uint32_t);
-uint32_t f2fs_validate_encryption_key_size(uint32_t, uint32_t);
-struct f2fs_crypto_ctx *f2fs_get_crypto_ctx(struct inode *);
-void f2fs_release_crypto_ctx(struct f2fs_crypto_ctx *);
-struct page *f2fs_encrypt(struct inode *, struct page *);
-int f2fs_decrypt(struct page *);
-void f2fs_end_io_crypto_work(struct f2fs_crypto_ctx *, struct bio *);
-
-/* crypto_key.c */
-void f2fs_free_encryption_info(struct inode *, struct f2fs_crypt_info *);
-int _f2fs_get_encryption_info(struct inode *inode);
-
-/* crypto_fname.c */
-bool f2fs_valid_filenames_enc_mode(uint32_t);
-u32 f2fs_fname_crypto_round_up(u32, u32);
-unsigned f2fs_fname_encrypted_size(struct inode *, u32);
-int f2fs_fname_crypto_alloc_buffer(struct inode *, u32, struct f2fs_str *);
-int f2fs_fname_disk_to_usr(struct inode *, f2fs_hash_t *,
-			const struct f2fs_str *, struct f2fs_str *);
-int f2fs_fname_usr_to_disk(struct inode *, const struct qstr *,
-			struct f2fs_str *);
-
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
-void f2fs_restore_and_release_control_page(struct page **);
-void f2fs_restore_control_page(struct page *);
-
-int __init f2fs_init_crypto(void);
-int f2fs_crypto_initialize(void);
-void f2fs_exit_crypto(void);
-
-int f2fs_has_encryption_key(struct inode *);
-
-static inline int f2fs_get_encryption_info(struct inode *inode)
-{
-	struct f2fs_crypt_info *ci = F2FS_I(inode)->i_crypt_info;
-
-	if (!ci ||
-		(ci->ci_keyring_key &&
-		 (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) |
-					       (1 << KEY_FLAG_REVOKED) |
-					       (1 << KEY_FLAG_DEAD)))))
-		return _f2fs_get_encryption_info(inode);
-	return 0;
-}
-
-void f2fs_fname_crypto_free_buffer(struct f2fs_str *);
-int f2fs_fname_setup_filename(struct inode *, const struct qstr *,
-				int lookup, struct f2fs_filename *);
-void f2fs_fname_free_filename(struct f2fs_filename *);
-#else
-static inline void f2fs_restore_and_release_control_page(struct page **p) { }
-static inline void f2fs_restore_control_page(struct page *p) { }
-
-static inline int __init f2fs_init_crypto(void) { return 0; }
-static inline void f2fs_exit_crypto(void) { }
-
-static inline int f2fs_has_encryption_key(struct inode *i) { return 0; }
-static inline int f2fs_get_encryption_info(struct inode *i) { return 0; }
-static inline void f2fs_fname_crypto_free_buffer(struct f2fs_str *p) { }
-
-static inline int f2fs_fname_setup_filename(struct inode *dir,
-					const struct qstr *iname,
-					int lookup, struct f2fs_filename *fname)
-{
-	memset(fname, 0, sizeof(struct f2fs_filename));
-	fname->usr_fname = iname;
-	fname->disk_name.name = (unsigned char *)iname->name;
-	fname->disk_name.len = iname->len;
-	return 0;
-}
-
-static inline void f2fs_fname_free_filename(struct f2fs_filename *fname) { }
+#ifndef CONFIG_F2FS_FS_ENCRYPTION
+#define fscrypt_set_d_op(i)
+#define fscrypt_get_ctx			fscrypt_notsupp_get_ctx
+#define fscrypt_release_ctx		fscrypt_notsupp_release_ctx
+#define fscrypt_encrypt_page		fscrypt_notsupp_encrypt_page
+#define fscrypt_decrypt_page		fscrypt_notsupp_decrypt_page
+#define fscrypt_decrypt_bio_pages	fscrypt_notsupp_decrypt_bio_pages
+#define fscrypt_pullback_bio_page	fscrypt_notsupp_pullback_bio_page
+#define fscrypt_restore_control_page	fscrypt_notsupp_restore_control_page
+#define fscrypt_zeroout_range		fscrypt_notsupp_zeroout_range
+#define fscrypt_process_policy		fscrypt_notsupp_process_policy
+#define fscrypt_get_policy		fscrypt_notsupp_get_policy
+#define fscrypt_has_permitted_context	fscrypt_notsupp_has_permitted_context
+#define fscrypt_inherit_context		fscrypt_notsupp_inherit_context
+#define fscrypt_get_encryption_info	fscrypt_notsupp_get_encryption_info
+#define fscrypt_put_encryption_info	fscrypt_notsupp_put_encryption_info
+#define fscrypt_setup_filename		fscrypt_notsupp_setup_filename
+#define fscrypt_free_filename		fscrypt_notsupp_free_filename
+#define fscrypt_fname_encrypted_size	fscrypt_notsupp_fname_encrypted_size
+#define fscrypt_fname_alloc_buffer	fscrypt_notsupp_fname_alloc_buffer
+#define fscrypt_fname_free_buffer	fscrypt_notsupp_fname_free_buffer
+#define fscrypt_fname_disk_to_usr	fscrypt_notsupp_fname_disk_to_usr
+#define fscrypt_fname_usr_to_disk	fscrypt_notsupp_fname_usr_to_disk
 #endif
 #endif

fs/f2fs/f2fs_crypto.h

-/*
- * linux/fs/f2fs/f2fs_crypto.h
- *
- * Copied from linux/fs/ext4/ext4_crypto.h
- *
- * Copyright (C) 2015, Google, Inc.
- *
- * This contains encryption header content for f2fs
- *
- * Written by Michael Halcrow, 2015.
- * Modified by Jaegeuk Kim, 2015.
- */
-#ifndef _F2FS_CRYPTO_H
-#define _F2FS_CRYPTO_H
-
-#include <linux/fs.h>
-
-#define F2FS_KEY_DESCRIPTOR_SIZE	8
-
-/* Policy provided via an ioctl on the topmost directory */
-struct f2fs_encryption_policy {
-	char version;
-	char contents_encryption_mode;
-	char filenames_encryption_mode;
-	char flags;
-	char master_key_descriptor[F2FS_KEY_DESCRIPTOR_SIZE];
-} __attribute__((__packed__));
-
-#define F2FS_ENCRYPTION_CONTEXT_FORMAT_V1	1
-#define F2FS_KEY_DERIVATION_NONCE_SIZE		16
-
-#define F2FS_POLICY_FLAGS_PAD_4		0x00
-#define F2FS_POLICY_FLAGS_PAD_8		0x01
-#define F2FS_POLICY_FLAGS_PAD_16	0x02
-#define F2FS_POLICY_FLAGS_PAD_32	0x03
-#define F2FS_POLICY_FLAGS_PAD_MASK	0x03
-#define F2FS_POLICY_FLAGS_VALID		0x03
-
-/**
- * Encryption context for inode
- *
- * Protector format:
- *  1 byte: Protector format (1 = this version)
- *  1 byte: File contents encryption mode
- *  1 byte: File names encryption mode
- *  1 byte: Flags
- *  8 bytes: Master Key descriptor
- *  16 bytes: Encryption Key derivation nonce
- */
-struct f2fs_encryption_context {
-	char format;
-	char contents_encryption_mode;
-	char filenames_encryption_mode;
-	char flags;
-	char master_key_descriptor[F2FS_KEY_DESCRIPTOR_SIZE];
-	char nonce[F2FS_KEY_DERIVATION_NONCE_SIZE];
-} __attribute__((__packed__));
-
-/* Encryption parameters */
-#define F2FS_XTS_TWEAK_SIZE 16
-#define F2FS_AES_128_ECB_KEY_SIZE 16
-#define F2FS_AES_256_GCM_KEY_SIZE 32
-#define F2FS_AES_256_CBC_KEY_SIZE 32
-#define F2FS_AES_256_CTS_KEY_SIZE 32
-#define F2FS_AES_256_XTS_KEY_SIZE 64
-#define F2FS_MAX_KEY_SIZE 64
-
-#define F2FS_KEY_DESC_PREFIX "f2fs:"
-#define F2FS_KEY_DESC_PREFIX_SIZE 5
-
-struct f2fs_encryption_key {
-	__u32 mode;
-	char raw[F2FS_MAX_KEY_SIZE];
-	__u32 size;
-} __attribute__((__packed__));
-
-struct f2fs_crypt_info {
-	char		ci_data_mode;
-	char		ci_filename_mode;
-	char		ci_flags;
-	struct crypto_ablkcipher *ci_ctfm;
-	struct key	*ci_keyring_key;
-	char		ci_master_key[F2FS_KEY_DESCRIPTOR_SIZE];
-};
-
-#define F2FS_CTX_REQUIRES_FREE_ENCRYPT_FL             0x00000001
-#define F2FS_WRITE_PATH_FL			      0x00000002
-
-struct f2fs_crypto_ctx {
-	union {
-		struct {
-			struct page *bounce_page;       /* Ciphertext page */
-			struct page *control_page;      /* Original page  */
-		} w;
-		struct {
-			struct bio *bio;
-			struct work_struct work;
-		} r;
-		struct list_head free_list;     /* Free list */
-	};
-	char flags;                      /* Flags */
-};
-
-struct f2fs_completion_result {
-	struct completion completion;
-	int res;
-};
-
-#define DECLARE_F2FS_COMPLETION_RESULT(ecr) \
-	struct f2fs_completion_result ecr = { \
-		COMPLETION_INITIALIZER((ecr).completion), 0 }
-
-static inline int f2fs_encryption_key_size(int mode)
-{
-	switch (mode) {
-	case F2FS_ENCRYPTION_MODE_AES_256_XTS:
-		return F2FS_AES_256_XTS_KEY_SIZE;
-	case F2FS_ENCRYPTION_MODE_AES_256_GCM:
-		return F2FS_AES_256_GCM_KEY_SIZE;
-	case F2FS_ENCRYPTION_MODE_AES_256_CBC:
-		return F2FS_AES_256_CBC_KEY_SIZE;
-	case F2FS_ENCRYPTION_MODE_AES_256_CTS:
-		return F2FS_AES_256_CTS_KEY_SIZE;
-	default:
-		BUG();
-	}
-	return 0;
-}
-
-#define F2FS_FNAME_NUM_SCATTER_ENTRIES	4
-#define F2FS_CRYPTO_BLOCK_SIZE		16
-#define F2FS_FNAME_CRYPTO_DIGEST_SIZE	32
-
-/**
- * For encrypted symlinks, the ciphertext length is stored at the beginning
- * of the string in little-endian format.
- */
-struct f2fs_encrypted_symlink_data {
-	__le16 len;
-	char encrypted_path[1];
-} __attribute__((__packed__));
-
-/**
- * This function is used to calculate the disk space required to
- * store a filename of length l in encrypted symlink format.
- */
-static inline u32 encrypted_symlink_data_len(u32 l)
-{
-	return (l + sizeof(struct f2fs_encrypted_symlink_data) - 1);
-}
-#endif	/* _F2FS_CRYPTO_H */

fs/f2fs/file.c

@@ -421,7 +421,7 @@ static int f2fs_file_mmap(struct file *file, struct vm_area_struct *vma)
 	int err;
 
 	if (f2fs_encrypted_inode(inode)) {
-		err = f2fs_get_encryption_info(inode);
+		err = fscrypt_get_encryption_info(inode);
 		if (err)
 			return 0;
 		if (!f2fs_encrypted_inode(inode))
@@ -443,10 +443,10 @@ static int f2fs_file_open(struct inode *inode, struct file *filp)
 	int ret = generic_file_open(inode, filp);
 
 	if (!ret && f2fs_encrypted_inode(inode)) {
-		ret = f2fs_get_encryption_info(inode);
+		ret = fscrypt_get_encryption_info(inode);
 		if (ret)
 			return -EACCES;
-		if (!f2fs_encrypted_inode(inode))
+		if (!fscrypt_has_encryption_key(inode))
 			return -ENOKEY;
 	}
 	return ret;
@@ -526,7 +526,8 @@ static int truncate_partial_data_page(struct inode *inode, u64 from,
 truncate_out:
 	f2fs_wait_on_page_writeback(page, DATA, true);
 	zero_user(page, offset, PAGE_CACHE_SIZE - offset);
-	if (!cache_only || !f2fs_encrypted_inode(inode) || !S_ISREG(inode->i_mode))
+	if (!cache_only || !f2fs_encrypted_inode(inode) ||
+					!S_ISREG(inode->i_mode))
 		set_page_dirty(page);
 	f2fs_put_page(page, 1);
 	return 0;
@@ -674,7 +675,7 @@ int f2fs_setattr(struct dentry *dentry, struct iattr *attr)
 
 	if (attr->ia_valid & ATTR_SIZE) {
 		if (f2fs_encrypted_inode(inode) &&
-				f2fs_get_encryption_info(inode))
+				fscrypt_get_encryption_info(inode))
 			return -EACCES;
 
 		if (attr->ia_size <= i_size_read(inode)) {
@@ -1529,39 +1530,30 @@ static bool uuid_is_nonzero(__u8 u[16])
 
 static int f2fs_ioc_set_encryption_policy(struct file *filp, unsigned long arg)
 {
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
-	struct f2fs_encryption_policy policy;
+	struct fscrypt_policy policy;
 	struct inode *inode = file_inode(filp);
 
-	if (copy_from_user(&policy, (struct f2fs_encryption_policy __user *)arg,
+	if (copy_from_user(&policy, (struct fscrypt_policy __user *)arg,
 							sizeof(policy)))
 		return -EFAULT;
 
 	f2fs_update_time(F2FS_I_SB(inode), REQ_TIME);
-	return f2fs_process_policy(&policy, inode);
-#else
-	return -EOPNOTSUPP;
-#endif
+	return fscrypt_process_policy(inode, &policy);
 }
 
 static int f2fs_ioc_get_encryption_policy(struct file *filp, unsigned long arg)
 {
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
-	struct f2fs_encryption_policy policy;
+	struct fscrypt_policy policy;
 	struct inode *inode = file_inode(filp);
 	int err;
 
-	err = f2fs_get_policy(inode, &policy);
+	err = fscrypt_get_policy(inode, &policy);
 	if (err)
 		return err;
 
-	if (copy_to_user((struct f2fs_encryption_policy __user *)arg, &policy,
-							sizeof(policy)))
+	if (copy_to_user((struct fscrypt_policy __user *)arg, &policy, sizeof(policy)))
 		return -EFAULT;
 	return 0;
-#else
-	return -EOPNOTSUPP;
-#endif
 }
 
 static int f2fs_ioc_get_encryption_pwsalt(struct file *filp, unsigned long arg)
@@ -1873,8 +1865,8 @@ static ssize_t f2fs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	ssize_t ret;
 
 	if (f2fs_encrypted_inode(inode) &&
-				!f2fs_has_encryption_key(inode) &&
-				f2fs_get_encryption_info(inode))
+				!fscrypt_has_encryption_key(inode) &&
+				fscrypt_get_encryption_info(inode))
 		return -EACCES;
 
 	inode_lock(inode);

fs/f2fs/inline.c

@@ -277,7 +277,7 @@ bool recover_inline_data(struct inode *inode, struct page *npage)
 }
 
 struct f2fs_dir_entry *find_in_inline_dir(struct inode *dir,
-			struct f2fs_filename *fname, struct page **res_page)
+			struct fscrypt_name *fname, struct page **res_page)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
 	struct f2fs_inline_dentry *inline_dentry;
@@ -535,7 +535,7 @@ bool f2fs_empty_inline_dir(struct inode *dir)
 }
 
 int f2fs_read_inline_dir(struct file *file, struct dir_context *ctx,
-				struct f2fs_str *fstr)
+				struct fscrypt_str *fstr)
 {
 	struct inode *inode = file_inode(file);
 	struct f2fs_inline_dentry *inline_dentry = NULL;

fs/f2fs/inode.c

@@ -389,10 +389,7 @@ void f2fs_evict_inode(struct inode *inode)
 		}
 	}
 out_clear:
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
-	if (fi->i_crypt_info)
-		f2fs_free_encryption_info(inode, fi->i_crypt_info);
-#endif
+	fscrypt_put_encryption_info(inode, NULL);
 	clear_inode(inode);
 }
 

fs/f2fs/namei.c

@@ -169,7 +169,7 @@ static int f2fs_link(struct dentry *old_dentry, struct inode *dir,
 	int err;
 
 	if (f2fs_encrypted_inode(dir) &&
-		!f2fs_is_child_context_consistent_with_parent(dir, inode))
+			!fscrypt_has_permitted_context(dir, inode))
 		return -EPERM;
 
 	f2fs_balance_fs(sbi, true);
@@ -352,20 +352,20 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct inode *inode;
 	size_t len = strlen(symname);
-	struct f2fs_str disk_link = FSTR_INIT((char *)symname, len + 1);
-	struct f2fs_encrypted_symlink_data *sd = NULL;
+	struct fscrypt_str disk_link = FSTR_INIT((char *)symname, len + 1);
+	struct fscrypt_symlink_data *sd = NULL;
 	int err;
 
 	if (f2fs_encrypted_inode(dir)) {
-		err = f2fs_get_encryption_info(dir);
+		err = fscrypt_get_encryption_info(dir);
 		if (err)
 			return err;
 
-		if (!f2fs_encrypted_inode(dir))
+		if (!fscrypt_has_encryption_key(dir))
 			return -EPERM;
 
-		disk_link.len = (f2fs_fname_encrypted_size(dir, len) +
-				sizeof(struct f2fs_encrypted_symlink_data));
+		disk_link.len = (fscrypt_fname_encrypted_size(dir, len) +
+				sizeof(struct fscrypt_symlink_data));
 	}
 
 	if (disk_link.len > dir->i_sb->s_blocksize)
@@ -393,7 +393,7 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
 
 	if (f2fs_encrypted_inode(inode)) {
 		struct qstr istr = QSTR_INIT(symname, len);
-		struct f2fs_str ostr;
+		struct fscrypt_str ostr;
 
 		sd = kzalloc(disk_link.len, GFP_NOFS);
 		if (!sd) {
@@ -401,18 +401,18 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
 			goto err_out;
 		}
 
-		err = f2fs_get_encryption_info(inode);
+		err = fscrypt_get_encryption_info(inode);
 		if (err)
 			goto err_out;
 
-		if (!f2fs_encrypted_inode(inode)) {
+		if (!fscrypt_has_encryption_key(inode)) {
 			err = -EPERM;
 			goto err_out;
 		}
 
 		ostr.name = sd->encrypted_path;
 		ostr.len = disk_link.len;
-		err = f2fs_fname_usr_to_disk(inode, &istr, &ostr);
+		err = fscrypt_fname_usr_to_disk(inode, &istr, &ostr);
 		if (err < 0)
 			goto err_out;
 
@@ -593,7 +593,7 @@ static int __f2fs_tmpfile(struct inode *dir, struct dentry *dentry,
 static int f2fs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
 {
 	if (f2fs_encrypted_inode(dir)) {
-		int err = f2fs_get_encryption_info(dir);
+		int err = fscrypt_get_encryption_info(dir);
 		if (err)
 			return err;
 	}
@@ -623,8 +623,7 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
 	int err = -ENOENT;
 
 	if ((old_dir != new_dir) && f2fs_encrypted_inode(new_dir) &&
-		!f2fs_is_child_context_consistent_with_parent(new_dir,
-							old_inode)) {
+			!fscrypt_has_permitted_context(new_dir, old_inode)) {
 		err = -EPERM;
 		goto out;
 	}
@@ -805,10 +804,8 @@ static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
 
 	if ((f2fs_encrypted_inode(old_dir) || f2fs_encrypted_inode(new_dir)) &&
 			(old_dir != new_dir) &&
-		(!f2fs_is_child_context_consistent_with_parent(new_dir,
-								old_inode) ||
-		!f2fs_is_child_context_consistent_with_parent(old_dir,
-								new_inode)))
+			(!fscrypt_has_permitted_context(new_dir, old_inode) ||
+			 !fscrypt_has_permitted_context(old_dir, new_inode)))
 		return -EPERM;
 
 	old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
@@ -970,16 +967,15 @@ static int f2fs_rename2(struct inode *old_dir, struct dentry *old_dentry,
 	return f2fs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
 }
 
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
 static const char *f2fs_encrypted_get_link(struct dentry *dentry,
 					   struct inode *inode,
 					   struct delayed_call *done)
 {
 	struct page *cpage = NULL;
 	char *caddr, *paddr = NULL;
-	struct f2fs_str cstr = FSTR_INIT(NULL, 0);
-	struct f2fs_str pstr = FSTR_INIT(NULL, 0);
-	struct f2fs_encrypted_symlink_data *sd;
+	struct fscrypt_str cstr = FSTR_INIT(NULL, 0);
+	struct fscrypt_str pstr = FSTR_INIT(NULL, 0);
+	struct fscrypt_symlink_data *sd;
 	loff_t size = min_t(loff_t, i_size_read(inode), PAGE_SIZE - 1);
 	u32 max_size = inode->i_sb->s_blocksize;
 	int res;
@@ -987,7 +983,7 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry,
 	if (!dentry)
 		return ERR_PTR(-ECHILD);
 
-	res = f2fs_get_encryption_info(inode);
+	res = fscrypt_get_encryption_info(inode);
 	if (res)
 		return ERR_PTR(res);
 
@@ -998,7 +994,7 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry,
 	caddr[size] = 0;
 
 	/* Symlink is encrypted */
-	sd = (struct f2fs_encrypted_symlink_data *)caddr;
+	sd = (struct fscrypt_symlink_data *)caddr;
 	cstr.name = sd->encrypted_path;
 	cstr.len = le16_to_cpu(sd->len);
 
@@ -1014,17 +1010,16 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry,
 		goto errout;
 	}
 
-	if ((cstr.len + sizeof(struct f2fs_encrypted_symlink_data) - 1) >
-								max_size) {
+	if ((cstr.len + sizeof(struct fscrypt_symlink_data) - 1) > max_size) {
 		/* Symlink data on the disk is corrupted */
 		res = -EIO;
 		goto errout;
 	}
-	res = f2fs_fname_crypto_alloc_buffer(inode, cstr.len, &pstr);
+	res = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr);
 	if (res)
 		goto errout;
 
-	res = f2fs_fname_disk_to_usr(inode, NULL, &cstr, &pstr);
+	res = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr);
 	if (res < 0)
 		goto errout;
 
@@ -1037,7 +1032,7 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry,
 	set_delayed_call(done, kfree_link, paddr);
 	return paddr;
 errout:
-	f2fs_fname_crypto_free_buffer(&pstr);
+	fscrypt_fname_free_buffer(&pstr);
 	page_cache_release(cpage);
 	return ERR_PTR(res);
 }
@@ -1054,7 +1049,6 @@ const struct inode_operations f2fs_encrypted_symlink_inode_operations = {
 	.removexattr	= generic_removexattr,
 #endif
 };
-#endif
 
 const struct inode_operations f2fs_dir_inode_operations = {
 	.create		= f2fs_create,

fs/f2fs/super.c

@@ -470,10 +470,6 @@ static struct inode *f2fs_alloc_inode(struct super_block *sb)
 
 	/* Will be used by directory only */
 	fi->i_dir_level = F2FS_SB(sb)->dir_level;
-
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
-	fi->i_crypt_info = NULL;
-#endif
 	return &fi->vfs_inode;
 }
 
@@ -507,11 +503,7 @@ static int f2fs_drop_inode(struct inode *inode)
 
 			sb_end_intwrite(inode->i_sb);
 
-#ifdef CONFIG_F2FS_FS_ENCRYPTION
-			if (F2FS_I(inode)->i_crypt_info)
-				f2fs_free_encryption_info(inode,
-					F2FS_I(inode)->i_crypt_info);
-#endif
+			fscrypt_put_encryption_info(inode, NULL);
 			spin_lock(&inode->i_lock);
 			atomic_dec(&inode->i_count);
 		}
@@ -891,6 +883,41 @@ static struct super_operations f2fs_sops = {
 	.remount_fs	= f2fs_remount,
 };
 
+#ifdef CONFIG_F2FS_FS_ENCRYPTION
+static int f2fs_get_context(struct inode *inode, void *ctx, size_t len)
+{
+	return f2fs_getxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION,
+				F2FS_XATTR_NAME_ENCRYPTION_CONTEXT,
+				ctx, len, NULL);
+}
+
+static int f2fs_set_context(struct inode *inode, const void *ctx, size_t len,
+							void *fs_data)
+{
+	return f2fs_setxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION,
+				F2FS_XATTR_NAME_ENCRYPTION_CONTEXT,
+				ctx, len, fs_data, XATTR_CREATE);
+}
+
+static unsigned f2fs_max_namelen(struct inode *inode)
+{
+	return S_ISLNK(inode->i_mode) ?
+			inode->i_sb->s_blocksize : F2FS_NAME_LEN;
+}
+
+static struct fscrypt_operations f2fs_cryptops = {
+	.get_context	= f2fs_get_context,
+	.set_context	= f2fs_set_context,
+	.is_encrypted	= f2fs_encrypted_inode,
+	.empty_dir	= f2fs_empty_dir,
+	.max_namelen	= f2fs_max_namelen,
+};
+#else
+static struct fscrypt_operations f2fs_cryptops = {
+	.is_encrypted	= f2fs_encrypted_inode,
+};
+#endif
+
 static struct inode *f2fs_nfs_get_inode(struct super_block *sb,
 		u64 ino, u32 generation)
 {
@@ -1314,6 +1341,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
 	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
 
 	sb->s_op = &f2fs_sops;
+	sb->s_cop = &f2fs_cryptops;
 	sb->s_xattr = f2fs_xattr_handlers;
 	sb->s_export_op = &f2fs_export_ops;
 	sb->s_magic = F2FS_SUPER_MAGIC;
@@ -1619,13 +1647,9 @@ static int __init init_f2fs_fs(void)
 		err = -ENOMEM;
 		goto free_extent_cache;
 	}
-	err = f2fs_init_crypto();
-	if (err)
-		goto free_kset;
-
 	err = register_shrinker(&f2fs_shrinker_info);
 	if (err)
-		goto free_crypto;
+		goto free_kset;
 
 	err = register_filesystem(&f2fs_fs_type);
 	if (err)
@@ -1640,8 +1664,6 @@ static int __init init_f2fs_fs(void)
 	unregister_filesystem(&f2fs_fs_type);
 free_shrinker:
 	unregister_shrinker(&f2fs_shrinker_info);
-free_crypto:
-	f2fs_exit_crypto();
 free_kset:
 	kset_unregister(f2fs_kset);
 free_extent_cache:
@@ -1664,7 +1686,6 @@ static void __exit exit_f2fs_fs(void)
 	f2fs_destroy_root_stats();
 	unregister_shrinker(&f2fs_shrinker_info);
 	unregister_filesystem(&f2fs_fs_type);
-	f2fs_exit_crypto();
 	destroy_extent_cache();
 	destroy_checkpoint_caches();
 	destroy_segment_manager_caches();

include/linux/dcache.h

@@ -228,6 +228,8 @@ struct dentry_operations {
 #define DCACHE_FALLTHRU			0x01000000 /* Fall through to lower layer */
 #define DCACHE_OP_SELECT_INODE		0x02000000 /* Unioned entry: dcache op selects inode */
 
+#define DCACHE_ENCRYPTED_WITH_KEY	0x04000000 /* dir is encrypted with a valid key */
+
 extern seqlock_t rename_lock;
 
 /*

include/linux/fs.h

@@ -53,6 +53,8 @@ struct swap_info_struct;
 struct seq_file;
 struct workqueue_struct;
 struct iov_iter;
+struct fscrypt_info;
+struct fscrypt_operations;
 
 extern void __init inode_init(void);
 extern void __init inode_init_early(void);
@@ -678,6 +680,10 @@ struct inode {
 	struct hlist_head	i_fsnotify_marks;
 #endif
 
+#if IS_ENABLED(CONFIG_FS_ENCRYPTION)
+	struct fscrypt_info	*i_crypt_info;
+#endif
+
 	void			*i_private; /* fs or device private pointer */
 };
 
@@ -1323,6 +1329,8 @@ struct super_block {
 #endif
 	const struct xattr_handler **s_xattr;
 
+	const struct fscrypt_operations	*s_cop;
+
 	struct hlist_bl_head	s_anon;		/* anonymous dentries for (nfs) exporting */
 	struct list_head	s_mounts;	/* list of mounts; _not_ for fs use */
 	struct block_device	*s_bdev;

include/uapi/linux/fs.h

@@ -246,6 +246,24 @@ struct fsxattr {
 #define FS_IOC_FSGETXATTR		_IOR ('X', 31, struct fsxattr)
 #define FS_IOC_FSSETXATTR		_IOW ('X', 32, struct fsxattr)
 
+/*
+ * File system encryption support
+ */
+/* Policy provided via an ioctl on the topmost directory */
+#define FS_KEY_DESCRIPTOR_SIZE	8
+
+struct fscrypt_policy {
+	__u8 version;
+	__u8 contents_encryption_mode;
+	__u8 filenames_encryption_mode;
+	__u8 flags;
+	__u8 master_key_descriptor[FS_KEY_DESCRIPTOR_SIZE];
+} __packed;
+
+#define FS_IOC_SET_ENCRYPTION_POLICY	_IOR('f', 19, struct fscrypt_policy)
+#define FS_IOC_GET_ENCRYPTION_PWSALT	_IOW('f', 20, __u8[16])
+#define FS_IOC_GET_ENCRYPTION_POLICY	_IOW('f', 21, struct fscrypt_policy)
+
 /*
  * Inode flags (FS_IOC_GETFLAGS / FS_IOC_SETFLAGS)
  *