[PATCH 6.7 614/713] bcachefs: fix simulateously upgrading & downgrading

[Sasha Levin]

From: Kent Overstreet <kent.overstreet@xxxxxxxxx>

commit e7999235e6c437b99fad03d8301a4341be0d2bb5 upstream.

Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 fs/bcachefs/super-io.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/fs/bcachefs/super-io.c b/fs/bcachefs/super-io.c
index 6405cc1d651fd..c925dc5742fa4 100644
--- a/fs/bcachefs/super-io.c
+++ b/fs/bcachefs/super-io.c
@@ -1085,13 +1085,22 @@ bool bch2_check_version_downgrade(struct bch_fs *c)
 	/*
 	 * Downgrade, if superblock is at a higher version than currently
 	 * supported:
+	 *
+	 * c->sb will be checked before we write the superblock, so update it as
+	 * well:
 	 */
-	if (BCH_SB_VERSION_UPGRADE_COMPLETE(c->disk_sb.sb) > bcachefs_metadata_version_current)
+	if (BCH_SB_VERSION_UPGRADE_COMPLETE(c->disk_sb.sb) > bcachefs_metadata_version_current) {
 		SET_BCH_SB_VERSION_UPGRADE_COMPLETE(c->disk_sb.sb, bcachefs_metadata_version_current);
-	if (c->sb.version > bcachefs_metadata_version_current)
+		c->sb.version_upgrade_complete = bcachefs_metadata_version_current;
+	}
+	if (c->sb.version > bcachefs_metadata_version_current) {
 		c->disk_sb.sb->version = cpu_to_le16(bcachefs_metadata_version_current);
-	if (c->sb.version_min > bcachefs_metadata_version_current)
+		c->sb.version = bcachefs_metadata_version_current;
+	}
+	if (c->sb.version_min > bcachefs_metadata_version_current) {
 		c->disk_sb.sb->version_min = cpu_to_le16(bcachefs_metadata_version_current);
+		c->sb.version_min = bcachefs_metadata_version_current;
+	}
 	c->disk_sb.sb->compat[0] &= cpu_to_le64((1ULL << BCH_COMPAT_NR) - 1);
 	return ret;
 }
-- 
2.43.0