ext4: fix special inode number checks in __ext4_iget()

BugLink: https://bugs.launchpad.net/bugs/1878246

commit 191ce178 upstream.

The check for special (reserved) inode number checks in __ext4_iget()
was broken by commit 8a363970: ("ext4: avoid declaring fs
inconsistent due to invalid file handles").  This was caused by a
botched reversal of the sense of the flag now known as
EXT4_IGET_SPECIAL (when it was previously named EXT4_IGET_NORMAL).
Fix the logic appropriately.

Fixes: 8a363970 ("ext4: avoid declaring fs inconsistent...")
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable@kernel.org
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ian May <ian.may@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

fs/ext4/inode.c

@@ -4238,7 +4238,7 @@ struct inode *__ext4_iget(struct super_block *sb, unsigned long ino,
 	uid_t i_uid;
 	gid_t i_gid;
 
-	if (((flags & EXT4_IGET_NORMAL) &&
+	if ((!(flags & EXT4_IGET_SPECIAL) &&
 	     (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)) ||
 	    (ino < EXT4_ROOT_INO) ||
 	    (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))) {