[PATCH 2/3] ext4: add helper to check if flag is changed by ctx

[Baokun Li]

Add helper to check if flag will be changed, return 1 means it will be
set, -1 means it will be cleared, 0 means it will not be changed.

Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
---
 fs/ext4/super.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 5b4a323c218b..fefcd42f34ea 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2042,13 +2042,26 @@ ctx_test_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
 	return (ctx->vals_s_##name & flag);				\
 }
 
+#define EXT4_CHANGED_CTX(name)						\
+static inline int							\
+ctx_changed_##name(struct ext4_fs_context *ctx, unsigned long flag)	\
+{									\
+	if (ctx->vals_s_##name & flag)                                  \
+		return 1;						\
+	if (ctx->mask_s_##name & flag)					\
+		return -1;						\
+	return 0;							\
+}
+
 EXT4_SET_CTX(flags); /* set only */
 EXT4_SET_CTX(mount_opt);
 EXT4_CLEAR_CTX(mount_opt);
 EXT4_TEST_CTX(mount_opt);
+EXT4_CHANGED_CTX(mount_opt);
 EXT4_SET_CTX(mount_opt2);
 EXT4_CLEAR_CTX(mount_opt2);
 EXT4_TEST_CTX(mount_opt2);
+EXT4_CHANGED_CTX(mount_opt2);
 
 static inline void ctx_set_mount_flag(struct ext4_fs_context *ctx, int bit)
 {
@@ -2537,9 +2550,7 @@ static int ext4_check_quota_consistency(struct fs_context *fc,
 
 	quota_flags = EXT4_MOUNT_QUOTA | EXT4_MOUNT_USRQUOTA |
 		      EXT4_MOUNT_GRPQUOTA | EXT4_MOUNT_PRJQUOTA;
-	if (quota_loaded &&
-	    ctx->mask_s_mount_opt & quota_flags &&
-	    !ctx_test_mount_opt(ctx, quota_flags))
+	if (quota_loaded && (ctx_changed_mount_opt(ctx, quota_flags) < 0))
 		goto err_quota_change;
 
 	if (ctx->spec & EXT4_SPEC_JQUOTA) {
-- 
2.31.1