bcachefs: bch2_version_compatible()

This adds a new helper for checking if an on-disk version is compatible
with the running version of bcachefs - prep work for introducing
major:minor version numbers.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/bcachefs_format.h

@@ -1574,8 +1574,6 @@ struct bch_sb_field_journal_seq_blacklist {
  * One common version number for all on disk data structures - superblock, btree
  * nodes, journal entries
  */
-#define BCH_JSET_VERSION_OLD			2
-#define BCH_BSET_VERSION_OLD			3
 
 #define BCH_METADATA_VERSIONS()				\
 	x(bkey_renumber,		10)		\

fs/bcachefs/btree_io.c

@@ -699,11 +699,9 @@ static int validate_bset(struct bch_fs *c, struct bch_dev *ca,
 	struct printbuf buf2 = PRINTBUF;
 	int ret = 0;
 
-	btree_err_on((version != BCH_BSET_VERSION_OLD &&
-		      version < bcachefs_metadata_version_min) ||
-		     version >= bcachefs_metadata_version_max,
+	btree_err_on(!bch2_version_compatible(version),
 		     BTREE_ERR_INCOMPATIBLE, c, ca, b, i,
-		     "unsupported bset version");
+		     "unsupported bset version %u", version);
 
 	if (btree_err_on(version < c->sb.version_min,
 			 BTREE_ERR_FIXABLE, c, NULL, b, i,
@@ -2019,9 +2017,7 @@ void __bch2_btree_node_write(struct bch_fs *c, struct btree *b, unsigned flags)
 	BUG_ON(BSET_BIG_ENDIAN(i) != CPU_BIG_ENDIAN);
 	BUG_ON(i->seq != b->data->keys.seq);
 
-	i->version = c->sb.version < bcachefs_metadata_version_bkey_renumber
-		? cpu_to_le16(BCH_BSET_VERSION_OLD)
-		: cpu_to_le16(c->sb.version);
+	i->version = cpu_to_le16(c->sb.version);
 	SET_BSET_OFFSET(i, b->written);
 	SET_BSET_CSUM_TYPE(i, bch2_meta_checksum_type(c));
 

fs/bcachefs/journal_io.c

@@ -745,14 +745,10 @@ static int jset_validate(struct bch_fs *c,
 		return JOURNAL_ENTRY_NONE;
 
 	version = le32_to_cpu(jset->version);
-	if (journal_entry_err_on((version != BCH_JSET_VERSION_OLD &&
-				  version < bcachefs_metadata_version_min) ||
-				 version >= bcachefs_metadata_version_max,
-				 c, jset, NULL,
-			"%s sector %llu seq %llu: unknown journal entry version %u",
+	if (journal_entry_err_on(!bch2_version_compatible(version), c, jset, NULL,
+			"%s sector %llu seq %llu: incompatible journal entry version %u",
 			ca ? ca->name : c->name,
-			sector, le64_to_cpu(jset->seq),
-			version)) {
+			sector, le64_to_cpu(jset->seq), version)) {
 		/* don't try to continue: */
 		return -EINVAL;
 	}
@@ -796,14 +792,10 @@ static int jset_validate_early(struct bch_fs *c,
 		return JOURNAL_ENTRY_NONE;
 
 	version = le32_to_cpu(jset->version);
-	if (journal_entry_err_on((version != BCH_JSET_VERSION_OLD &&
-				  version < bcachefs_metadata_version_min) ||
-				 version >= bcachefs_metadata_version_max,
-				 c, jset, NULL,
+	if (journal_entry_err_on(!bch2_version_compatible(version), c, jset, NULL,
 			"%s sector %llu seq %llu: unknown journal entry version %u",
 			ca ? ca->name : c->name,
-			sector, le64_to_cpu(jset->seq),
-			version)) {
+			sector, le64_to_cpu(jset->seq), version)) {
 		/* don't try to continue: */
 		return -EINVAL;
 	}
@@ -1755,9 +1747,7 @@ void bch2_journal_write(struct closure *cl)
 	}
 
 	jset->magic		= cpu_to_le64(jset_magic(c));
-	jset->version		= c->sb.version < bcachefs_metadata_version_bkey_renumber
-		? cpu_to_le32(BCH_JSET_VERSION_OLD)
-		: cpu_to_le32(c->sb.version);
+	jset->version		= cpu_to_le32(c->sb.version);
 
 	SET_JSET_BIG_ENDIAN(jset, CPU_BIG_ENDIAN);
 	SET_JSET_CSUM_TYPE(jset, bch2_meta_checksum_type(c));

fs/bcachefs/super-io.c

@@ -269,40 +269,58 @@ static int validate_sb_layout(struct bch_sb_layout *layout, struct printbuf *out
 	return 0;
 }
 
-static int bch2_sb_validate(struct bch_sb_handle *disk_sb, struct printbuf *out,
-			    int rw)
+static int bch2_sb_compatible(struct bch_sb *sb, struct printbuf *out)
 {
-	struct bch_sb *sb = disk_sb->sb;
-	struct bch_sb_field *f;
-	struct bch_sb_field_members *mi;
-	enum bch_opt_id opt_id;
-	u32 version, version_min;
-	u16 block_size;
-	int ret;
-
-	version		= le16_to_cpu(sb->version);
-	version_min	= version >= bcachefs_metadata_version_bkey_renumber
-		? le16_to_cpu(sb->version_min)
-		: version;
-
-	if (version    >= bcachefs_metadata_version_max) {
-		prt_printf(out, "Unsupported superblock version %u (min %u, max %u)",
-		       version, bcachefs_metadata_version_min, bcachefs_metadata_version_max);
+	u16 version		= le16_to_cpu(sb->version);
+	u16 version_min		= le16_to_cpu(sb->version_min);
+
+	if (!bch2_version_compatible(version)) {
+		prt_str(out, "Unsupported superblock version ");
+		bch2_version_to_text(out, version);
+		prt_str(out, " (min ");
+		bch2_version_to_text(out, bcachefs_metadata_version_min);
+		prt_str(out, ", max ");
+		bch2_version_to_text(out, bcachefs_metadata_version_current);
+		prt_str(out, ")");
 		return -BCH_ERR_invalid_sb_version;
 	}
 
-	if (version_min < bcachefs_metadata_version_min) {
-		prt_printf(out, "Unsupported superblock version %u (min %u, max %u)",
-		       version_min, bcachefs_metadata_version_min, bcachefs_metadata_version_max);
+	if (!bch2_version_compatible(version_min)) {
+		prt_str(out, "Unsupported superblock version_min ");
+		bch2_version_to_text(out, version_min);
+		prt_str(out, " (min ");
+		bch2_version_to_text(out, bcachefs_metadata_version_min);
+		prt_str(out, ", max ");
+		bch2_version_to_text(out, bcachefs_metadata_version_current);
+		prt_str(out, ")");
 		return -BCH_ERR_invalid_sb_version;
 	}
 
 	if (version_min > version) {
-		prt_printf(out, "Bad minimum version %u, greater than version field %u",
-		       version_min, version);
+		prt_str(out, "Bad minimum version ");
+		bch2_version_to_text(out, version_min);
+		prt_str(out, ", greater than version field ");
+		bch2_version_to_text(out, version);
 		return -BCH_ERR_invalid_sb_version;
 	}
 
+	return 0;
+}
+
+static int bch2_sb_validate(struct bch_sb_handle *disk_sb, struct printbuf *out,
+			    int rw)
+{
+	struct bch_sb *sb = disk_sb->sb;
+	struct bch_sb_field *f;
+	struct bch_sb_field_members *mi;
+	enum bch_opt_id opt_id;
+	u16 block_size;
+	int ret;
+
+	ret = bch2_sb_compatible(sb, out);
+	if (ret)
+		return ret;
+
 	if (sb->features[1] ||
 	    (le64_to_cpu(sb->features[0]) & (~0ULL << BCH_FEATURE_NR))) {
 		prt_printf(out, "Filesystem has incompatible features");
@@ -350,7 +368,7 @@ static int bch2_sb_validate(struct bch_sb_handle *disk_sb, struct printbuf *out,
 	if (rw == READ) {
 		/*
 		 * Been seeing a bug where these are getting inexplicably
-		 * zeroed, so we'r now validating them, but we have to be
+		 * zeroed, so we're now validating them, but we have to be
 		 * careful not to preven people's filesystems from mounting:
 		 */
 		if (!BCH_SB_JOURNAL_FLUSH_DELAY(sb))
@@ -531,7 +549,6 @@ int bch2_sb_from_fs(struct bch_fs *c, struct bch_dev *ca)
 static int read_one_super(struct bch_sb_handle *sb, u64 offset, struct printbuf *err)
 {
 	struct bch_csum csum;
-	u32 version, version_min;
 	size_t bytes;
 	int ret;
 reread:
@@ -551,22 +568,9 @@ static int read_one_super(struct bch_sb_handle *sb, u64 offset, struct printbuf
 		return -BCH_ERR_invalid_sb_magic;
 	}
 
-	version		= le16_to_cpu(sb->sb->version);
-	version_min	= version >= bcachefs_metadata_version_bkey_renumber
-		? le16_to_cpu(sb->sb->version_min)
-		: version;
-
-	if (version    >= bcachefs_metadata_version_max) {
-		prt_printf(err, "Unsupported superblock version %u (min %u, max %u)",
-		       version, bcachefs_metadata_version_min, bcachefs_metadata_version_max);
-		return -BCH_ERR_invalid_sb_version;
-	}
-
-	if (version_min < bcachefs_metadata_version_min) {
-		prt_printf(err, "Unsupported superblock version %u (min %u, max %u)",
-		       version_min, bcachefs_metadata_version_min, bcachefs_metadata_version_max);
-		return -BCH_ERR_invalid_sb_version;
-	}
+	ret = bch2_sb_compatible(sb->sb, err);
+	if (ret)
+		return ret;
 
 	bytes = vstruct_bytes(sb->sb);
 

fs/bcachefs/super-io.h

@@ -9,6 +9,12 @@
 
 #include <asm/byteorder.h>
 
+static inline bool bch2_version_compatible(u16 version)
+{
+	return version <= bcachefs_metadata_version_current &&
+		version >= bcachefs_metadata_version_min;
+}
+
 void bch2_version_to_text(struct printbuf *, unsigned);
 
 struct bch_sb_field *bch2_sb_field_get(struct bch_sb *, enum bch_sb_field_type);