bcachefs: fix bch2_inum_snapshot_to_path()

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/namei.c b/fs/bcachefs/namei.c
index bd093ce56ad9b9452e7660b5b246a04ad2349211..a84b69d6caef7861c2acc1c55350bdddbbf88467 100644 (file)
--- a/fs/bcachefs/namei.c
+++ b/fs/bcachefs/namei.c
@@ -609,29 +609,39 @@ static inline void reverse_bytes(void *b, size_t n)
        }
 }
 
-/* XXX: we don't yet attempt to print paths when we don't know the subvol */
-int bch2_inum_to_path(struct btree_trans *trans, subvol_inum inum, struct printbuf *path)
+static int __bch2_inum_to_path(struct btree_trans *trans,
+                              u32 subvol, u64 inum, u32 snapshot,
+                              struct printbuf *path)
 {
        unsigned orig_pos = path->pos;
        int ret = 0;
 
-       while (!subvol_inum_eq(inum, BCACHEFS_ROOT_SUBVOL_INUM)) {
+       while (true) {
+               if (!snapshot) {
+                       ret = bch2_subvolume_get_snapshot(trans, subvol, &snapshot);
+                       if (ret)
+                               goto disconnected;
+               }
+
                struct bch_inode_unpacked inode;
-               ret = bch2_inode_find_by_inum_trans(trans, inum, &inode);
+               ret = bch2_inode_find_by_inum_snapshot(trans, inum, snapshot, &inode, 0);
                if (ret)
                        goto disconnected;
 
+               if (inode.bi_subvol == BCACHEFS_ROOT_SUBVOL &&
+                   inode.bi_inum == BCACHEFS_ROOT_INO)
+                       break;
+
                if (!inode.bi_dir && !inode.bi_dir_offset) {
                        ret = -BCH_ERR_ENOENT_inode_no_backpointer;
                        goto disconnected;
                }
 
-               inum = parent_inum(inum, &inode);
-
-               u32 snapshot;
-               ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
-               if (ret)
-                       goto disconnected;
+               inum = inode.bi_dir;
+               if (inode.bi_parent_subvol) {
+                       subvol = inode.bi_parent_subvol;
+                       snapshot = 0;
+               }
 
                struct btree_iter d_iter;
                struct bkey_s_c_dirent d = bch2_bkey_get_iter_typed(trans, &d_iter,
@@ -668,22 +678,18 @@ disconnected:
        goto out;
 }
 
+int bch2_inum_to_path(struct btree_trans *trans,
+                     subvol_inum inum,
+                     struct printbuf *path)
+{
+       return __bch2_inum_to_path(trans, inum.subvol, inum.inum, 0, path);
+}
+
 int bch2_inum_snapshot_to_path(struct btree_trans *trans, u64 inum, u32 snapshot,
                               snapshot_id_list *snapshot_overwrites,
                               struct printbuf *path)
 {
-       u32 subvol = bch2_snapshot_oldest_subvol(trans->c, snapshot, snapshot_overwrites);
-       int ret = 0;
-
-       if (subvol) {
-               ret = bch2_inum_to_path(trans, (subvol_inum) { subvol, inum }, path);
-               if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
-                       return ret;
-       }
-
-       if (!subvol || ret)
-               prt_printf(path, "inum %llu:%u", inum, snapshot);
-       return 0;
+       return __bch2_inum_to_path(trans, 0, inum, snapshot, path);
 }
 
 /* fsck */