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>

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];

fs/bcachefs/bkey.h

@@ -9,6 +9,12 @@
 #include "util.h"
 #include "vstructs.h"
 
+enum bkey_invalid_flags {
+	BKEY_INVALID_WRITE		= (1U << 0),
+	BKEY_INVALID_COMMIT		= (1U << 1),
+	BKEY_INVALID_JOURNAL		= (1U << 2),
+};
+
 #if 0
 
 /*
@@ -769,7 +775,8 @@ static inline void bch2_bkey_format_add_key(struct bkey_format_state *s, const s
 
 void bch2_bkey_format_add_pos(struct bkey_format_state *, struct bpos);
 struct bkey_format bch2_bkey_format_done(struct bkey_format_state *);
-int bch2_bkey_format_validate(struct bkey_format *, struct printbuf *);
+int bch2_bkey_format_invalid(struct bch_fs *, struct bkey_format *,
+			     enum bkey_invalid_flags, struct printbuf *);
 void bch2_bkey_format_to_text(struct printbuf *, const struct bkey_format *);
 
 #endif /* _BCACHEFS_BKEY_H */

fs/bcachefs/bkey_methods.h

@@ -13,12 +13,6 @@ enum btree_node_type;
 extern const char * const bch2_bkey_types[];
 extern const struct bkey_ops bch2_bkey_null_ops;
 
-enum bkey_invalid_flags {
-	BKEY_INVALID_WRITE		= (1U << 0),
-	BKEY_INVALID_COMMIT		= (1U << 1),
-	BKEY_INVALID_JOURNAL		= (1U << 2),
-};
-
 /*
  * key_invalid: checks validity of @k, returns 0 if good or -EINVAL if bad. If
  * invalid, entire key will be deleted.

fs/bcachefs/btree_io.c

@@ -779,7 +779,7 @@ static int validate_bset(struct bch_fs *c, struct bch_dev *ca,
 			compat_btree_node(b->c.level, b->c.btree_id, version,
 					  BSET_BIG_ENDIAN(i), write, bn);
 
-		btree_err_on(bch2_bkey_format_validate(&bn->format, &buf1),
+		btree_err_on(bch2_bkey_format_invalid(c, &bn->format, write, &buf1),
 			     -BCH_ERR_btree_node_read_err_bad_node, c, ca, b, i,
 			     "invalid bkey format: %s\n  %s", buf1.buf,
 			     (printbuf_reset(&buf2),

fs/bcachefs/recovery.c

@@ -1322,12 +1322,6 @@ int bch2_fs_recovery(struct bch_fs *c)
 		goto err;
 	}
 
-	if (!(c->sb.compat & (1ULL << BCH_COMPAT_bformat_overflow_done))) {
-		bch_err(c, "filesystem may have incompatible bkey formats; run fsck from the compat branch to fix");
-		ret = -EINVAL;
-		goto err;
-	}
-
 	if (c->opts.fsck || !(c->opts.nochanges && c->opts.norecovery))
 		check_version_upgrade(c);
 
@@ -1527,7 +1521,6 @@ int bch2_fs_recovery(struct bch_fs *c)
 	mutex_unlock(&c->sb_lock);
 
 	if (!(c->sb.compat & (1ULL << BCH_COMPAT_extents_above_btree_updates_done)) ||
-	    !(c->sb.compat & (1ULL << BCH_COMPAT_bformat_overflow_done)) ||
 	    c->sb.version_min < bcachefs_metadata_version_btree_ptr_sectors_written) {
 		struct bch_move_stats stats;
 

fs/bcachefs/super.c

@@ -1996,6 +1996,7 @@ static int __init bcachefs_init(void)
 BCH_DEBUG_PARAMS()
 #undef BCH_DEBUG_PARAM
 
+__maybe_unused
 static unsigned bch2_metadata_version = bcachefs_metadata_version_current;
 module_param_named(version, bch2_metadata_version, uint, 0400);