bcachefs: BCH_FSCK_ERR_snapshot_key_missing_inode_snapshot

We're going to be doing some snapshot deletion performance improvements,
and those will strictly require that if an extent/dirent/xattr is
present, an inode is present in that snapshot ID.

We already check for this, but we don't repair it on disk: this patch
adds that repair and turns it into a real fsck_err().

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

diff --git a/fs/bcachefs/fsck.c b/fs/bcachefs/fsck.c
index 1daa3d970919e0b8ef0ff9bbc0ce03796ad649e7..942a03d060743c32cc7ec1bd85fdb2cb6c347369 100644 (file)
--- a/fs/bcachefs/fsck.c
+++ b/fs/bcachefs/fsck.c
@@ -907,9 +907,9 @@ static int get_visible_inodes(struct btree_trans *trans,
 }
 
 static struct inode_walker_entry *
-lookup_inode_for_snapshot(struct bch_fs *c, struct inode_walker *w, struct bkey_s_c k)
+lookup_inode_for_snapshot(struct btree_trans *trans, struct inode_walker *w, struct bkey_s_c k)
 {
-       bool is_whiteout = k.k->type == KEY_TYPE_whiteout;
+       struct bch_fs *c = trans->c;
 
        struct inode_walker_entry *i;
        __darray_for_each(w->inodes, i)
@@ -920,34 +920,63 @@ lookup_inode_for_snapshot(struct bch_fs *c, struct inode_walker *w, struct bkey_
 found:
        BUG_ON(k.k->p.snapshot > i->inode.bi_snapshot);
 
-       if (k.k->p.snapshot != i->inode.bi_snapshot && !is_whiteout) {
-               struct inode_walker_entry new = *i;
-
-               new.inode.bi_snapshot   = k.k->p.snapshot;
-               new.count               = 0;
-               new.i_size              = 0;
-
-               struct printbuf buf = PRINTBUF;
-               bch2_bkey_val_to_text(&buf, c, k);
+       struct printbuf buf = PRINTBUF;
+       int ret = 0;
 
-               bch_info(c, "have key for inode %llu:%u but have inode in ancestor snapshot %u\n"
+       if (fsck_err_on(k.k->p.snapshot != i->inode.bi_snapshot,
+                       trans, snapshot_key_missing_inode_snapshot,
+                        "have key for inode %llu:%u but have inode in ancestor snapshot %u\n"
                         "unexpected because we should always update the inode when we update a key in that inode\n"
                         "%s",
-                        w->last_pos.inode, k.k->p.snapshot, i->inode.bi_snapshot, buf.buf);
-               printbuf_exit(&buf);
+                        w->last_pos.inode, k.k->p.snapshot, i->inode.bi_snapshot,
+                        (bch2_bkey_val_to_text(&buf, c, k),
+                         buf.buf))) {
+               struct bch_inode_unpacked new = i->inode;
+               struct bkey_i whiteout;
+
+               new.bi_snapshot = k.k->p.snapshot;
+
+               if (!i->whiteout) {
+                       ret = __bch2_fsck_write_inode(trans, &new);
+               } else {
+                       bkey_init(&whiteout.k);
+                       whiteout.k.type = KEY_TYPE_whiteout;
+                       whiteout.k.p = SPOS(0, i->inode.bi_inum, i->inode.bi_snapshot);
+                       ret = bch2_btree_insert_nonextent(trans, BTREE_ID_inodes,
+                                                         &whiteout,
+                                                         BTREE_UPDATE_internal_snapshot_node);
+               }
+
+               if (ret)
+                       goto fsck_err;
+
+               ret = bch2_trans_commit(trans, NULL, NULL, 0);
+               if (ret)
+                       goto fsck_err;
+
+               struct inode_walker_entry new_entry = *i;
+
+               new_entry.inode.bi_snapshot     = k.k->p.snapshot;
+               new_entry.count                 = 0;
+               new_entry.i_size                = 0;
 
                while (i > w->inodes.data && i[-1].inode.bi_snapshot > k.k->p.snapshot)
                        --i;
 
                size_t pos = i - w->inodes.data;
-               int ret = darray_insert_item(&w->inodes, pos, new);
+               ret = darray_insert_item(&w->inodes, pos, new_entry);
                if (ret)
-                       return ERR_PTR(ret);
+                       goto fsck_err;
 
-               i = w->inodes.data + pos;
+               ret = -BCH_ERR_transaction_restart_nested;
+               goto fsck_err;
        }
 
+       printbuf_exit(&buf);
        return i;
+fsck_err:
+       printbuf_exit(&buf);
+       return ERR_PTR(ret);
 }
 
 static struct inode_walker_entry *walk_inode(struct btree_trans *trans,
@@ -962,7 +991,7 @@ static struct inode_walker_entry *walk_inode(struct btree_trans *trans,
 
        w->last_pos = k.k->p;
 
-       return lookup_inode_for_snapshot(trans->c, w, k);
+       return lookup_inode_for_snapshot(trans, w, k);
 }
 
 /*