bcachefs: BCH_COMPAT_bformat_overflow_done no longer required

Awhile back, we changed bkey_format generation to ensure that the packed
representation could never represent fields larger than the unpacked
representation.

This was to ensure that bkey_packed_successor() always gave a sensible
result, but in the current code bkey_packed_successor() is only used in
a debug assertion - not for anything important.

This kills the requirement that we've gotten rid of those weird bkey
formats, and instead changes the assertion to check if we're dealing
with an old weird bkey format.

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

1 files changed, 39 insertions, 15 deletions

diff --git a/fs/bcachefs/bkey.c b/fs/bcachefs/bkey.c
index 67f205992629..d6960e259c80 100644
--- a/fs/bcachefs/bkey.c
+++ b/fs/bcachefs/bkey.c
@@ -424,6 +424,24 @@ static bool bkey_packed_successor(struct bkey_packed *out,
 
 	return false;
 }
+
+static bool bkey_format_has_too_big_fields(const struct bkey_format *f)
+{
+	for (unsigned i = 0; i < f->nr_fields; i++) {
+		unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i];
+		u64 unpacked_max = ~((~0ULL << 1) << (unpacked_bits - 1));
+		u64 packed_max = f->bits_per_field[i]
+			? ~((~0ULL << 1) << (f->bits_per_field[i] - 1))
+			: 0;
+		u64 field_offset = le64_to_cpu(f->field_offset[i]);
+
+		if (packed_max + field_offset < packed_max ||
+		    packed_max + field_offset > unpacked_max)
+			return true;
+	}
+
+	return false;
+}
 #endif
 
 /*
@@ -504,7 +522,8 @@ enum bkey_pack_pos_ret bch2_bkey_pack_pos_lossy(struct bkey_packed *out,
 
 		BUG_ON(bkey_cmp_left_packed(b, out, &orig) >= 0);
 		BUG_ON(bkey_packed_successor(&successor, b, *out) &&
-		       bkey_cmp_left_packed(b, &successor, &orig) < 0);
+		       bkey_cmp_left_packed(b, &successor, &orig) < 0 &&
+		       !bkey_format_has_too_big_fields(f));
 	}
 #endif
 
@@ -597,14 +616,17 @@ struct bkey_format bch2_bkey_format_done(struct bkey_format_state *s)
 	{
 		struct printbuf buf = PRINTBUF;
 
-		BUG_ON(bch2_bkey_format_validate(&ret, &buf));
+		BUG_ON(bch2_bkey_format_invalid(NULL, &ret, 0, &buf));
 		printbuf_exit(&buf);
 	}
 #endif
 	return ret;
 }
 
-int bch2_bkey_format_validate(struct bkey_format *f, struct printbuf *err)
+int bch2_bkey_format_invalid(struct bch_fs *c,
+			     struct bkey_format *f,
+			     enum bkey_invalid_flags flags,
+			     struct printbuf *err)
 {
 	unsigned i, bits = KEY_PACKED_BITS_START;
 
@@ -619,18 +641,20 @@ int bch2_bkey_format_validate(struct bkey_format *f, struct printbuf *err)
 	 * unpacked format:
 	 */
 	for (i = 0; i < f->nr_fields; i++) {
-		unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i];
-		u64 unpacked_max = ~((~0ULL << 1) << (unpacked_bits - 1));
-		u64 packed_max = f->bits_per_field[i]
-			? ~((~0ULL << 1) << (f->bits_per_field[i] - 1))
-			: 0;
-		u64 field_offset = le64_to_cpu(f->field_offset[i]);
-
-		if (packed_max + field_offset < packed_max ||
-		    packed_max + field_offset > unpacked_max) {
-			prt_printf(err, "field %u too large: %llu + %llu > %llu",
-				   i, packed_max, field_offset, unpacked_max);
-			return -BCH_ERR_invalid;
+		if (!c || c->sb.version_min >= bcachefs_metadata_version_snapshot) {
+			unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i];
+			u64 unpacked_max = ~((~0ULL << 1) << (unpacked_bits - 1));
+			u64 packed_max = f->bits_per_field[i]
+				? ~((~0ULL << 1) << (f->bits_per_field[i] - 1))
+				: 0;
+			u64 field_offset = le64_to_cpu(f->field_offset[i]);
+
+			if (packed_max + field_offset < packed_max ||
+			    packed_max + field_offset > unpacked_max) {
+				prt_printf(err, "field %u too large: %llu + %llu > %llu",
+					   i, packed_max, field_offset, unpacked_max);
+				return -BCH_ERR_invalid;
+			}
 		}
 
 		bits += f->bits_per_field[i];