jbd2: don't load superblock in jbd2_journal_check_used_features()

Since load_superblock() has been moved to journal_init_common(), the
in-memory superblock structure is initialized and contains valid data
once the file system has a journal_t object, so it's safe to access it,
let's drop the call to journal_get_superblock() from
jbd2_journal_check_used_features() and also drop the setting/clearing of
the veirfy bit of the superblock buffer.

Signed-off-by: Zhang Yi <[email protected]>
Reviewed-by: Jan Kara <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Theodore Ts'o <[email protected]>

Author: zhangyi089

fs/jbd2/journal.c

@@ -1361,8 +1361,6 @@ static int journal_get_superblock(journal_t *journal)
 	bh = journal->j_sb_buffer;
 
 	J_ASSERT(bh != NULL);
-	if (buffer_verified(bh))
-		return 0;
 
 	err = bh_read(bh, 0);
 	if (err < 0) {
@@ -1437,7 +1435,6 @@ static int journal_get_superblock(journal_t *journal)
 			goto out;
 		}
 	}
-	set_buffer_verified(bh);
 	return 0;
 
 out:
@@ -2226,8 +2223,6 @@ int jbd2_journal_check_used_features(journal_t *journal, unsigned long compat,
 
 	if (!compat && !ro && !incompat)
 		return 1;
-	if (journal_get_superblock(journal))
-		return 0;
 	if (!jbd2_format_support_feature(journal))
 		return 0;