bcachefs: Fix dup/misordered check in btree node read

We were checking for out of order keys, but not duplicate keys.

Reported-by: syzbot+dedbd67513939979f84f@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/btree_io.c b/fs/bcachefs/btree_io.c
index 89a42ee81e5c97b2fbbef766dae6cabbc3759b1f..2b5da566fbac5409a2cc46118564f2c2eb3b0dd0 100644 (file)
--- a/fs/bcachefs/btree_io.c
+++ b/fs/bcachefs/btree_io.c
@@ -857,6 +857,14 @@ static bool bkey_packed_valid(struct bch_fs *c, struct btree *b,
        return !__bch2_bkey_validate(c, u.s_c, btree_node_type(b), BCH_VALIDATE_silent);
 }
 
+static inline int btree_node_read_bkey_cmp(const struct btree *b,
+                               const struct bkey_packed *l,
+                               const struct bkey_packed *r)
+{
+       return bch2_bkey_cmp_packed(b, l, r)
+               ?: (int) bkey_deleted(r) - (int) bkey_deleted(l);
+}
+
 static int validate_bset_keys(struct bch_fs *c, struct btree *b,
                         struct bset *i, int write,
                         bool have_retry, bool *saw_error)
@@ -917,7 +925,7 @@ static int validate_bset_keys(struct bch_fs *c, struct btree *b,
                                    BSET_BIG_ENDIAN(i), write,
                                    &b->format, k);
 
-               if (prev && bkey_iter_cmp(b, prev, k) > 0) {
+               if (prev && btree_node_read_bkey_cmp(b, prev, k) >= 0) {
                        struct bkey up = bkey_unpack_key(b, prev);
 
                        printbuf_reset(&buf);