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>

1 files changed, 25 insertions, 31 deletions

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index b3c423a645bc..3bddd9f657e5 100644
--- a/fs/f2fs/namei.c
+++ b/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 @@ out:
 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;
 	}
@@ -804,11 +803,9 @@ static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
 	int err = -ENOENT;
 
 	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)))
+			(old_dir != new_dir) &&
+			(!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,