bcachefs: Add support for dirents that point to subvolumes

Dirents currently always point to inodes. Subvolumes add a new type of
dirent, with d_type DT_SUBVOL, that instead points to an entry in the
subvolumes btree, and the subvolume has a pointer to the root inode.

This patch adds bch2_dirent_read_target() to get the inode (and
potentially subvolume) a dirent points to, and changes existing code to
use that instead of reading from d_inum directly.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

1 files changed, 13 insertions, 1 deletions

diff --git a/fs/bcachefs/dirent.h b/fs/bcachefs/dirent.h
index c14f6029e1c9..3cd05a2454e1 100644
--- a/fs/bcachefs/dirent.h
+++ b/fs/bcachefs/dirent.h
@@ -37,6 +37,17 @@ int bch2_dirent_delete_at(struct btree_trans *,
 			  const struct bch_hash_info *,
 			  struct btree_iter *);
 
+int __bch2_dirent_read_target(struct btree_trans *, struct bkey_s_c_dirent,
+			      u32 *, u32 *, u64 *, bool);
+
+int bch2_dirent_read_target(struct btree_trans *,
+			    struct bkey_s_c_dirent, u64 *);
+
+static inline unsigned vfs_d_type(unsigned type)
+{
+	return type == DT_SUBVOL ? DT_DIR : type;
+}
+
 enum bch_rename_mode {
 	BCH_RENAME,
 	BCH_RENAME_OVERWRITE,
@@ -52,7 +63,8 @@ int bch2_dirent_rename(struct btree_trans *,
 
 int __bch2_dirent_lookup_trans(struct btree_trans *, struct btree_iter *, u64,
 			   const struct bch_hash_info *,
-			   const struct qstr *, unsigned);
+			   const struct qstr *, u64 *,
+			   unsigned);
 u64 bch2_dirent_lookup(struct bch_fs *, u64, const struct bch_hash_info *,
 		       const struct qstr *);