ext4: correct inconsistent error msg in nojournal mode

When we used the journal_async_commit mounting option in nojournal mode,
the kernel told me that "can't mount with journal_checksum", was very
confusing. I find that when we mount with journal_async_commit, both the
JOURNAL_ASYNC_COMMIT and EXPLICIT_JOURNAL_CHECKSUM flags are set. However,
in the error branch, CHECKSUM is checked before ASYNC_COMMIT. As a result,
the above inconsistency occurs, and the ASYNC_COMMIT branch becomes dead
code that cannot be executed. Therefore, we exchange the positions of the
two judgments to make the error msg more accurate.
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20221109074343.4184862-1-libaokun1@huawei.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

fs/ext4/super.c

@@ -5288,14 +5288,15 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
 		goto failed_mount3a;
 	} else {
 		/* Nojournal mode, all journal mount options are illegal */
-		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
+		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
 			ext4_msg(sb, KERN_ERR, "can't mount with "
-				 "journal_checksum, fs mounted w/o journal");
+				 "journal_async_commit, fs mounted w/o journal");
 			goto failed_mount3a;
 		}
-		if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
+
+		if (test_opt2(sb, EXPLICIT_JOURNAL_CHECKSUM)) {
 			ext4_msg(sb, KERN_ERR, "can't mount with "
-				 "journal_async_commit, fs mounted w/o journal");
+				 "journal_checksum, fs mounted w/o journal");
 			goto failed_mount3a;
 		}
 		if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {