btrfs: extend btrfs_dir_item type to store encryption status

For directories with encrypted files/filenames, we need to store a flag
indicating this fact. There's no room in other fields, so we'll need to
borrow a bit from dir_type. Since it's now a combination of type and
flags, we rename it to dir_flags to reflect its new usage.

The new flag, FT_ENCRYPTED, indicates a directory containing encrypted
data, which is orthogonal to file type; therefore, add the new
flag, and make conversion from directory type to file type strip the
flag.

As the file types almost never change we can afford to use the bits.
Actual usage will be guarded behind an incompat bit, this patch only
adds the support for later use by fscrypt.
Signed-off-by: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/accessors.h

@@ -484,14 +484,25 @@ BTRFS_SETGET_FUNCS(root_ref_name_len, struct btrfs_root_ref, name_len, 16);
 
 /* struct btrfs_dir_item */
 BTRFS_SETGET_FUNCS(dir_data_len, struct btrfs_dir_item, data_len, 16);
-BTRFS_SETGET_FUNCS(dir_type, struct btrfs_dir_item, type, 8);
+BTRFS_SETGET_FUNCS(dir_flags, struct btrfs_dir_item, type, 8);
 BTRFS_SETGET_FUNCS(dir_name_len, struct btrfs_dir_item, name_len, 16);
 BTRFS_SETGET_FUNCS(dir_transid, struct btrfs_dir_item, transid, 64);
-BTRFS_SETGET_STACK_FUNCS(stack_dir_type, struct btrfs_dir_item, type, 8);
+BTRFS_SETGET_STACK_FUNCS(stack_dir_flags, struct btrfs_dir_item, type, 8);
 BTRFS_SETGET_STACK_FUNCS(stack_dir_data_len, struct btrfs_dir_item, data_len, 16);
 BTRFS_SETGET_STACK_FUNCS(stack_dir_name_len, struct btrfs_dir_item, name_len, 16);
 BTRFS_SETGET_STACK_FUNCS(stack_dir_transid, struct btrfs_dir_item, transid, 64);
 
+static inline u8 btrfs_dir_ftype(const struct extent_buffer *eb,
+				 const struct btrfs_dir_item *item)
+{
+	return btrfs_dir_flags_to_ftype(btrfs_dir_flags(eb, item));
+}
+
+static inline u8 btrfs_stack_dir_ftype(const struct btrfs_dir_item *item)
+{
+	return btrfs_dir_flags_to_ftype(btrfs_stack_dir_flags(item));
+}
+
 static inline void btrfs_dir_item_key(const struct extent_buffer *eb,
 				      const struct btrfs_dir_item *item,
 				      struct btrfs_disk_key *key)

fs/btrfs/delayed-inode.c

@@ -1416,7 +1416,7 @@ void btrfs_balance_delayed_items(struct btrfs_fs_info *fs_info)
 int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
 				   const char *name, int name_len,
 				   struct btrfs_inode *dir,
-				   struct btrfs_disk_key *disk_key, u8 type,
+				   struct btrfs_disk_key *disk_key, u8 flags,
 				   u64 index)
 {
 	struct btrfs_fs_info *fs_info = trans->fs_info;
@@ -1447,7 +1447,7 @@ int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
 	btrfs_set_stack_dir_transid(dir_item, trans->transid);
 	btrfs_set_stack_dir_data_len(dir_item, 0);
 	btrfs_set_stack_dir_name_len(dir_item, name_len);
-	btrfs_set_stack_dir_type(dir_item, type);
+	btrfs_set_stack_dir_flags(dir_item, flags);
 	memcpy((char *)(dir_item + 1), name, name_len);
 
 	data_len = delayed_item->data_len + sizeof(struct btrfs_item);
@@ -1757,7 +1757,7 @@ int btrfs_readdir_delayed_dir_index(struct dir_context *ctx,
 		name = (char *)(di + 1);
 		name_len = btrfs_stack_dir_name_len(di);
 
-		d_type = fs_ftype_to_dtype(di->type);
+		d_type = fs_ftype_to_dtype(btrfs_dir_flags_to_ftype(di->type));
 		btrfs_disk_key_to_cpu(&location, &di->location);
 
 		over = !dir_emit(ctx, name, name_len,

fs/btrfs/delayed-inode.h

@@ -113,7 +113,7 @@ static inline void btrfs_init_delayed_root(
 int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
 				   const char *name, int name_len,
 				   struct btrfs_inode *dir,
-				   struct btrfs_disk_key *disk_key, u8 type,
+				   struct btrfs_disk_key *disk_key, u8 flags,
 				   u64 index);
 
 int btrfs_delete_delayed_dir_index(struct btrfs_trans_handle *trans,

fs/btrfs/dir-item.c

@@ -83,7 +83,7 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans,
 	leaf = path->nodes[0];
 	btrfs_cpu_key_to_disk(&disk_key, &location);
 	btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
-	btrfs_set_dir_type(leaf, dir_item, BTRFS_FT_XATTR);
+	btrfs_set_dir_flags(leaf, dir_item, BTRFS_FT_XATTR);
 	btrfs_set_dir_name_len(leaf, dir_item, name_len);
 	btrfs_set_dir_transid(leaf, dir_item, trans->transid);
 	btrfs_set_dir_data_len(leaf, dir_item, data_len);
@@ -140,9 +140,12 @@ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans,
 		goto out_free;
 	}
 
+	if (IS_ENCRYPTED(&dir->vfs_inode))
+		type |= BTRFS_FT_ENCRYPTED;
+
 	leaf = path->nodes[0];
 	btrfs_set_dir_item_key(leaf, dir_item, &disk_key);
-	btrfs_set_dir_type(leaf, dir_item, type);
+	btrfs_set_dir_flags(leaf, dir_item, type);
 	btrfs_set_dir_data_len(leaf, dir_item, 0);
 	btrfs_set_dir_name_len(leaf, dir_item, name->len);
 	btrfs_set_dir_transid(leaf, dir_item, trans->transid);

fs/btrfs/inode.c

@@ -5597,7 +5597,7 @@ static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
 			   location->objectid, location->type, location->offset);
 	}
 	if (!ret)
-		*type = btrfs_dir_type(path->nodes[0], di);
+		*type = btrfs_dir_ftype(path->nodes[0], di);
 out:
 	fscrypt_free_filename(&fname);
 	btrfs_free_path(path);
@@ -6046,6 +6046,7 @@ static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
 	btrfs_for_each_slot(root, &key, &found_key, path, ret) {
 		struct dir_entry *entry;
 		struct extent_buffer *leaf = path->nodes[0];
+		u8 ftype;
 
 		if (found_key.objectid != key.objectid)
 			break;
@@ -6069,13 +6070,13 @@ static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
 			goto again;
 		}
 
+		ftype = btrfs_dir_flags_to_ftype(btrfs_dir_flags(leaf, di));
 		entry = addr;
-		put_unaligned(name_len, &entry->name_len);
 		name_ptr = (char *)(entry + 1);
-		read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
-				   name_len);
-		put_unaligned(fs_ftype_to_dtype(btrfs_dir_type(leaf, di)),
-				&entry->type);
+		read_extent_buffer(leaf, name_ptr,
+				   (unsigned long)(di + 1), name_len);
+		put_unaligned(name_len, &entry->name_len);
+		put_unaligned(fs_ftype_to_dtype(ftype), &entry->type);
 		btrfs_dir_item_key_to_cpu(leaf, di, &location);
 		put_unaligned(location.objectid, &entry->ino);
 		put_unaligned(found_key.offset, &entry->offset);

fs/btrfs/print-tree.c

@@ -242,9 +242,9 @@ void btrfs_print_leaf(struct extent_buffer *l)
 		case BTRFS_DIR_ITEM_KEY:
 			di = btrfs_item_ptr(l, i, struct btrfs_dir_item);
 			btrfs_dir_item_key_to_cpu(l, di, &found_key);
-			pr_info("\t\tdir oid %llu type %u\n",
+			pr_info("\t\tdir oid %llu flags %u\n",
 				found_key.objectid,
-				btrfs_dir_type(l, di));
+				btrfs_dir_flags(l, di));
 			break;
 		case BTRFS_ROOT_ITEM_KEY:
 			ri = btrfs_item_ptr(l, i, struct btrfs_root_item);

fs/btrfs/send.c

@@ -1094,7 +1094,7 @@ static int iterate_dir_item(struct btrfs_root *root, struct btrfs_path *path,
 		data_len = btrfs_dir_data_len(eb, di);
 		btrfs_dir_item_key_to_cpu(eb, di, &di_key);
 
-		if (btrfs_dir_type(eb, di) == BTRFS_FT_XATTR) {
+		if (btrfs_dir_ftype(eb, di) == BTRFS_FT_XATTR) {
 			if (name_len > XATTR_NAME_MAX) {
 				ret = -ENAMETOOLONG;
 				goto out;

fs/btrfs/tree-checker.c

@@ -531,7 +531,7 @@ static int check_dir_item(struct extent_buffer *leaf,
 		}
 
 		/* dir type check */
-		dir_type = btrfs_dir_type(leaf, di);
+		dir_type = btrfs_dir_ftype(leaf, di);
 		if (unlikely(dir_type >= BTRFS_FT_MAX)) {
 			dir_item_err(leaf, slot,
 			"invalid dir item type, have %u expect [0, %u)",

fs/btrfs/tree-log.c

@@ -1799,7 +1799,7 @@ static int delete_conflicting_dir_entry(struct btrfs_trans_handle *trans,
 					struct btrfs_path *path,
 					struct btrfs_dir_item *dst_di,
 					const struct btrfs_key *log_key,
-					u8 log_type,
+					u8 log_flags,
 					bool exists)
 {
 	struct btrfs_key found_key;
@@ -1809,7 +1809,7 @@ static int delete_conflicting_dir_entry(struct btrfs_trans_handle *trans,
 	if (found_key.objectid == log_key->objectid &&
 	    found_key.type == log_key->type &&
 	    found_key.offset == log_key->offset &&
-	    btrfs_dir_type(path->nodes[0], dst_di) == log_type)
+	    btrfs_dir_flags(path->nodes[0], dst_di) == log_flags)
 		return 1;
 
 	/*
@@ -1853,7 +1853,7 @@ static noinline int replay_one_name(struct btrfs_trans_handle *trans,
 	struct btrfs_key log_key;
 	struct btrfs_key search_key;
 	struct inode *dir;
-	u8 log_type;
+	u8 log_flags;
 	bool exists;
 	int ret;
 	bool update_size = true;
@@ -1867,7 +1867,7 @@ static noinline int replay_one_name(struct btrfs_trans_handle *trans,
 	if (ret)
 		goto out;
 
-	log_type = btrfs_dir_type(eb, di);
+	log_flags = btrfs_dir_flags(eb, di);
 	btrfs_dir_item_key_to_cpu(eb, di, &log_key);
 	ret = btrfs_lookup_inode(trans, root, path, &log_key, 0);
 	btrfs_release_path(path);
@@ -1883,8 +1883,8 @@ static noinline int replay_one_name(struct btrfs_trans_handle *trans,
 		goto out;
 	} else if (dir_dst_di) {
 		ret = delete_conflicting_dir_entry(trans, BTRFS_I(dir), path,
-						   dir_dst_di, &log_key, log_type,
-						   exists);
+						   dir_dst_di, &log_key,
+						   log_flags, exists);
 		if (ret < 0)
 			goto out;
 		dir_dst_matches = (ret == 1);
@@ -1901,7 +1901,7 @@ static noinline int replay_one_name(struct btrfs_trans_handle *trans,
 	} else if (index_dst_di) {
 		ret = delete_conflicting_dir_entry(trans, BTRFS_I(dir), path,
 						   index_dst_di, &log_key,
-						   log_type, exists);
+						   log_flags, exists);
 		if (ret < 0)
 			goto out;
 		index_dst_matches = (ret == 1);
@@ -2010,7 +2010,7 @@ static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
 	 * to ever delete the parent directory has it would result in stale
 	 * dentries that can never be deleted.
 	 */
-	if (ret == 1 && btrfs_dir_type(eb, di) != BTRFS_FT_DIR) {
+	if (ret == 1 && btrfs_dir_ftype(eb, di) != BTRFS_FT_DIR) {
 		struct btrfs_path *fixup_path;
 		struct btrfs_key di_key;
 
@@ -5452,7 +5452,7 @@ static int log_new_dir_dentries(struct btrfs_trans_handle *trans,
 			}
 
 			di = btrfs_item_ptr(leaf, i, struct btrfs_dir_item);
-			type = btrfs_dir_type(leaf, di);
+			type = btrfs_dir_ftype(leaf, di);
 			if (btrfs_dir_transid(leaf, di) < trans->transid)
 				continue;
 			btrfs_dir_item_key_to_cpu(leaf, di, &di_key);
@@ -6292,7 +6292,7 @@ static int log_new_delayed_dentries(struct btrfs_trans_handle *trans,
 			continue;
 		}
 
-		if (btrfs_stack_dir_type(dir_item) == BTRFS_FT_DIR)
+		if (btrfs_stack_dir_ftype(dir_item) == BTRFS_FT_DIR)
 			log_mode = LOG_INODE_ALL;
 
 		ctx->log_new_dentries = false;

include/uapi/linux/btrfs_tree.h

@@ -376,6 +376,13 @@ enum btrfs_csum_type {
 #define BTRFS_FT_SYMLINK	7
 #define BTRFS_FT_XATTR		8
 #define BTRFS_FT_MAX		9
+/* Directory contains encrypted data */
+#define BTRFS_FT_ENCRYPTED	0x80
+
+static inline __u8 btrfs_dir_flags_to_ftype(__u8 flags)
+{
+	return flags & ~BTRFS_FT_ENCRYPTED;
+}
 
 /*
  * Inode flags