fscrypt: rename DCACHE_ENCRYPTED_NAME to DCACHE_NOKEY_NAME

Originally we used the term "encrypted name" or "ciphertext name" to
mean the encoded filename that is shown when an encrypted directory is
listed without its key.  But these terms are ambiguous since they also
mean the filename stored on-disk.  "Encrypted name" is especially
ambiguous since it could also be understood to mean "this filename is
encrypted on-disk", similar to "encrypted file".

So we've started calling these encoded names "no-key names" instead.

Therefore, rename DCACHE_ENCRYPTED_NAME to DCACHE_NOKEY_NAME to avoid
confusion about what this flag means.

Link: https://lore.kernel.org/r/20200924042624.98439-3-ebiggers@kernel.orgSigned-off-by: Eric Biggers <ebiggers@google.com>

fs/crypto/fname.c

@@ -541,7 +541,7 @@ static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags)
 	 * reverting to no-key names without evicting the directory's inode
 	 * -- which implies eviction of the dentries in the directory.
 	 */
-	if (!(dentry->d_flags & DCACHE_ENCRYPTED_NAME))
+	if (!(dentry->d_flags & DCACHE_NOKEY_NAME))
 		return 1;
 
 	/*

fs/crypto/hooks.c

@@ -61,7 +61,7 @@ int __fscrypt_prepare_link(struct inode *inode, struct inode *dir,
 		return err;
 
 	/* ... in case we looked up no-key name before key was added */
-	if (dentry->d_flags & DCACHE_ENCRYPTED_NAME)
+	if (dentry->d_flags & DCACHE_NOKEY_NAME)
 		return -ENOKEY;
 
 	if (!fscrypt_has_permitted_context(dir, inode))
@@ -86,8 +86,7 @@ int __fscrypt_prepare_rename(struct inode *old_dir, struct dentry *old_dentry,
 		return err;
 
 	/* ... in case we looked up no-key name(s) before key was added */
-	if ((old_dentry->d_flags | new_dentry->d_flags) &
-	    DCACHE_ENCRYPTED_NAME)
+	if ((old_dentry->d_flags | new_dentry->d_flags) & DCACHE_NOKEY_NAME)
 		return -ENOKEY;
 
 	if (old_dir != new_dir) {
@@ -116,7 +115,7 @@ int __fscrypt_prepare_lookup(struct inode *dir, struct dentry *dentry,
 
 	if (fname->is_nokey_name) {
 		spin_lock(&dentry->d_lock);
-		dentry->d_flags |= DCACHE_ENCRYPTED_NAME;
+		dentry->d_flags |= DCACHE_NOKEY_NAME;
 		spin_unlock(&dentry->d_lock);
 		d_set_d_op(dentry, &fscrypt_d_ops);
 	}

include/linux/dcache.h

@@ -213,7 +213,7 @@ struct dentry_operations {
 
 #define DCACHE_MAY_FREE			0x00800000
 #define DCACHE_FALLTHRU			0x01000000 /* Fall through to lower layer */
-#define DCACHE_ENCRYPTED_NAME		0x02000000 /* Encrypted name (dir key was unavailable) */
+#define DCACHE_NOKEY_NAME		0x02000000 /* Encrypted name encoded without key */
 #define DCACHE_OP_REAL			0x04000000
 
 #define DCACHE_PAR_LOOKUP		0x10000000 /* being looked up (with parent locked shared) */

include/linux/fscrypt.h

@@ -100,15 +100,15 @@ static inline bool fscrypt_needs_contents_encryption(const struct inode *inode)
 }
 
 /*
- * When d_splice_alias() moves a directory's encrypted alias to its decrypted
- * alias as a result of the encryption key being added, DCACHE_ENCRYPTED_NAME
- * must be cleared.  Note that we don't have to support arbitrary moves of this
- * flag because fscrypt doesn't allow encrypted aliases to be the source or
- * target of a rename().
+ * When d_splice_alias() moves a directory's no-key alias to its plaintext alias
+ * as a result of the encryption key being added, DCACHE_NOKEY_NAME must be
+ * cleared.  Note that we don't have to support arbitrary moves of this flag
+ * because fscrypt doesn't allow no-key names to be the source or target of a
+ * rename().
  */
 static inline void fscrypt_handle_d_move(struct dentry *dentry)
 {
-	dentry->d_flags &= ~DCACHE_ENCRYPTED_NAME;
+	dentry->d_flags &= ~DCACHE_NOKEY_NAME;
 }
 
 /* crypto.c */