+ if (le16_to_cpu(fs->sb->version) < bcachefs_metadata_version_member_seq ||
+ le16_to_cpu(sb->sb->version) < bcachefs_metadata_version_member_seq)
+ return 0;
+
+ if (fs->sb->seq == sb->sb->seq &&
+ fs->sb->write_time != sb->sb->write_time) {
+ struct printbuf buf = PRINTBUF;
+
+ prt_str(&buf, "Split brain detected between ");
+ prt_bdevname(&buf, sb->bdev);
+ prt_str(&buf, " and ");
+ prt_bdevname(&buf, fs->bdev);
+ prt_char(&buf, ':');
+ prt_newline(&buf);
+ prt_printf(&buf, "seq=%llu but write_time different, got", le64_to_cpu(sb->sb->seq));
+ prt_newline(&buf);
+
+ prt_bdevname(&buf, fs->bdev);
+ prt_char(&buf, ' ');
+ bch2_prt_datetime(&buf, le64_to_cpu(fs->sb->write_time));;
+ prt_newline(&buf);
+
+ prt_bdevname(&buf, sb->bdev);
+ prt_char(&buf, ' ');
+ bch2_prt_datetime(&buf, le64_to_cpu(sb->sb->write_time));;
+ prt_newline(&buf);
+
+ prt_printf(&buf, "Not using older sb");
+
+ pr_err("%s", buf.buf);
+ printbuf_exit(&buf);
+ return -BCH_ERR_device_splitbrain;
+ }
+
+ struct bch_member m = bch2_sb_member_get(fs->sb, sb->sb->dev_idx);
+ u64 seq_from_fs = le64_to_cpu(m.seq);
+ u64 seq_from_member = le64_to_cpu(sb->sb->seq);
+
+ if (seq_from_fs && seq_from_fs < seq_from_member) {
+ struct printbuf buf = PRINTBUF;
+
+ prt_str(&buf, "Split brain detected between ");
+ prt_bdevname(&buf, sb->bdev);
+ prt_str(&buf, " and ");
+ prt_bdevname(&buf, fs->bdev);
+ prt_char(&buf, ':');
+ prt_newline(&buf);
+
+ prt_bdevname(&buf, fs->bdev);
+ prt_str(&buf, " believes seq of ");
+ prt_bdevname(&buf, sb->bdev);
+ prt_printf(&buf, " to be %llu, but ", seq_from_fs);
+ prt_bdevname(&buf, sb->bdev);
+ prt_printf(&buf, " has %llu\n", seq_from_member);
+ prt_str(&buf, "Not using ");
+ prt_bdevname(&buf, sb->bdev);
+
+ pr_err("%s", buf.buf);
+ printbuf_exit(&buf);
+ return -BCH_ERR_device_splitbrain;
+ }
+
+ return 0;