bcachefs: bch2_indirect_extent_missing_error() prints path, not just inode number

We want all error messages converted to print paths, not just inode
numbers - users want this information, and it speeds up debugging too.

Auditing and converting all error messages is going to be a big project,
so for the moment we're just doing this incrementally.

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

5 files changed, 51 insertions, 8 deletions

diff --git a/fs/bcachefs/error.c b/fs/bcachefs/error.c
index 038da6a61f6b..14cfcfa39590 100644
--- a/fs/bcachefs/error.c
+++ b/fs/bcachefs/error.c
@@ -535,7 +535,6 @@ int bch2_inum_err_msg_trans(struct btree_trans *trans, struct printbuf *out, sub
 	u32 restart_count = trans->restart_count;
 	int ret = 0;
 
-	/* XXX: we don't yet attempt to print paths when we don't know the subvol */
 	if (inum.subvol)
 		ret = lockrestart_do(trans, bch2_inum_to_path(trans, inum, out));
 	if (!inum.subvol || ret)
@@ -562,3 +561,34 @@ void bch2_inum_offset_err_msg(struct bch_fs *c, struct printbuf *out,
 {
 	bch2_trans_run(c, bch2_inum_offset_err_msg_trans(trans, out, inum, offset));
 }
+
+int bch2_inum_snap_err_msg_trans(struct btree_trans *trans, struct printbuf *out,
+				 struct bpos pos)
+{
+	u32 restart_count = trans->restart_count;
+	struct bch_fs *c = trans->c;
+	int ret = 0;
+
+	if (!bch2_snapshot_is_leaf(c, pos.snapshot))
+		prt_str(out, "(multiple snapshots) ");
+
+	subvol_inum inum = {
+		.subvol	= bch2_snapshot_tree_oldest_subvol(c, pos.snapshot),
+		.inum	= pos.inode,
+	};
+
+	if (inum.subvol)
+		ret = lockrestart_do(trans, bch2_inum_to_path(trans, inum, out));
+	if (!inum.subvol || ret)
+		prt_printf(out, "inum %llu:%u", pos.inode, pos.snapshot);
+
+	return trans_was_restarted(trans, restart_count);
+}
+
+int bch2_inum_snap_offset_err_msg_trans(struct btree_trans *trans, struct printbuf *out,
+					struct bpos pos)
+{
+	int ret = bch2_inum_snap_err_msg_trans(trans, out, pos);
+	prt_printf(out, " offset %llu: ", pos.offset << 8);
+	return ret;
+}
diff --git a/fs/bcachefs/error.h b/fs/bcachefs/error.h
index 7acf2a27ca28..95cf48a31dbf 100644
--- a/fs/bcachefs/error.h
+++ b/fs/bcachefs/error.h
@@ -244,4 +244,7 @@ int bch2_inum_offset_err_msg_trans(struct btree_trans *, struct printbuf *, subv
 void bch2_inum_err_msg(struct bch_fs *, struct printbuf *, subvol_inum);
 void bch2_inum_offset_err_msg(struct bch_fs *, struct printbuf *, subvol_inum, u64);
 
+int bch2_inum_snap_err_msg_trans(struct btree_trans *, struct printbuf *, struct bpos);
+int bch2_inum_snap_offset_err_msg_trans(struct btree_trans *, struct printbuf *, struct bpos);
+
 #endif /* _BCACHEFS_ERROR_H */
diff --git a/fs/bcachefs/reflink.c b/fs/bcachefs/reflink.c
index 441e648f28b5..50118661e64b 100644
--- a/fs/bcachefs/reflink.c
+++ b/fs/bcachefs/reflink.c
@@ -185,12 +185,21 @@ static int bch2_indirect_extent_missing_error(struct btree_trans *trans,
 	BUG_ON(missing_start	< refd_start);
 	BUG_ON(missing_end	> refd_end);
 
-	if (fsck_err(trans, reflink_p_to_missing_reflink_v,
-		     "pointer to missing indirect extent\n"
-		     "  %s\n"
-		     "  missing range %llu-%llu",
-		     (bch2_bkey_val_to_text(&buf, c, p.s_c), buf.buf),
-		     missing_start, missing_end)) {
+	struct bpos missing_pos = bkey_start_pos(p.k);
+	missing_pos.offset += missing_start - live_start;
+
+	prt_printf(&buf, "pointer to missing indirect extent in ");
+	ret = bch2_inum_snap_offset_err_msg_trans(trans, &buf, missing_pos);
+	if (ret)
+		goto err;
+
+	prt_printf(&buf, "-%llu\n  ", (missing_pos.offset + (missing_end - missing_start)) << 9);
+	bch2_bkey_val_to_text(&buf, c, p.s_c);
+
+	prt_printf(&buf, "\n  missing reflink btree range %llu-%llu",
+		   missing_start, missing_end);
+
+	if (fsck_err(trans, reflink_p_to_missing_reflink_v, "%s", buf.buf)) {
 		struct bkey_i_reflink_p *new = bch2_bkey_make_mut_noupdate_typed(trans, p.s_c, reflink_p);
 		ret = PTR_ERR_OR_ZERO(new);
 		if (ret)
diff --git a/fs/bcachefs/snapshot.c b/fs/bcachefs/snapshot.c
index ede0b480e7d4..e7f197896db1 100644
--- a/fs/bcachefs/snapshot.c
+++ b/fs/bcachefs/snapshot.c
@@ -390,7 +390,7 @@ static u32 bch2_snapshot_tree_next(struct bch_fs *c, u32 id)
 	return 0;
 }
 
-static u32 bch2_snapshot_tree_oldest_subvol(struct bch_fs *c, u32 snapshot_root)
+u32 bch2_snapshot_tree_oldest_subvol(struct bch_fs *c, u32 snapshot_root)
 {
 	u32 id = snapshot_root;
 	u32 subvol = 0, s;
diff --git a/fs/bcachefs/snapshot.h b/fs/bcachefs/snapshot.h
index 00373cf32e7b..81180181d7c9 100644
--- a/fs/bcachefs/snapshot.h
+++ b/fs/bcachefs/snapshot.h
@@ -105,6 +105,7 @@ static inline u32 bch2_snapshot_nth_parent(struct bch_fs *c, u32 id, u32 n)
 	return id;
 }
 
+u32 bch2_snapshot_tree_oldest_subvol(struct bch_fs *, u32);
 u32 bch2_snapshot_skiplist_get(struct bch_fs *, u32);
 
 static inline u32 bch2_snapshot_root(struct bch_fs *c, u32 id)