[PATCH 5/8] ubifs: Factor out ubifs_set_feature_flag()

[Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>]

The code setting a feature flag can be reused for upcoming projid
support. Factor out a function to share the code.

Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
---
 fs/ubifs/sb.c | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c
index c160f718c288..87466836fcfc 100644
--- a/fs/ubifs/sb.c
+++ b/fs/ubifs/sb.c
@@ -924,28 +924,34 @@ int ubifs_fixup_free_space(struct ubifs_info *c)
 	return err;
 }
 
-int ubifs_enable_encryption(struct ubifs_info *c)
+static int ubifs_set_feature_flag(struct ubifs_info *c, unsigned int flag)
 {
-	int err;
 	struct ubifs_sb_node *sup = c->sup_node;
 
-	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION))
-		return -EOPNOTSUPP;
-
-	if (c->encrypted)
+	if ((sup->flags & cpu_to_le32(flag)) == cpu_to_le32(flag))
 		return 0;
 
 	if (c->ro_mount || c->ro_media)
 		return -EROFS;
 
 	if (c->fmt_version < 5) {
-		ubifs_err(c, "on-flash format version 5 is needed for encryption");
+		ubifs_err(c, "on-flash format version 5 is needed for feature flags");
 		return -EINVAL;
 	}
 
-	sup->flags |= cpu_to_le32(UBIFS_FLG_ENCRYPTION);
+	sup->flags |= cpu_to_le32(flag);
+
+	return ubifs_write_sb_node(c, sup);
+}
+
+int ubifs_enable_encryption(struct ubifs_info *c)
+{
+	int err;
+
+	if (!IS_ENABLED(CONFIG_FS_ENCRYPTION))
+		return -EOPNOTSUPP;
 
-	err = ubifs_write_sb_node(c, sup);
+	err = ubifs_set_feature_flag(c, UBIFS_FLG_ENCRYPTION);
 	if (!err)
 		c->encrypted = 1;
 
-- 
2.20.1