ext4: add EXT4_JOURNAL_DATA_FL and EXT4_EXTENTS_FL to modifiable mask

Add EXT4_JOURNAL_DATA_FL and EXT4_EXTENTS_FL to EXT4_FL_USER_MODIFIABLE
to recognize that they are modifiable by userspace. So far we got away
without having them there because ext4_ioctl_setflags() treats them in a
special way. But it was really confusing like that.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/ext4.h

@@ -397,7 +397,7 @@ struct flex_groups {
 #define EXT4_RESERVED_FL		0x80000000 /* reserved for ext4 lib */
 
 #define EXT4_FL_USER_VISIBLE		0x304BDFFF /* User visible flags */
-#define EXT4_FL_USER_MODIFIABLE		0x204380FF /* User modifiable flags */
+#define EXT4_FL_USER_MODIFIABLE		0x204BC0FF /* User modifiable flags */
 
 #define EXT4_FL_XFLAG_VISIBLE		(EXT4_SYNC_FL | \
 					 EXT4_IMMUTABLE_FL | \

fs/ext4/ioctl.c

@@ -268,6 +268,9 @@ static int ext4_ioctl_setflags(struct inode *inode,
 	for (i = 0, mask = 1; i < 32; i++, mask <<= 1) {
 		if (!(mask & EXT4_FL_USER_MODIFIABLE))
 			continue;
+		/* These flags get special treatment later */
+		if (mask == EXT4_JOURNAL_DATA_FL || mask == EXT4_EXTENTS_FL)
+			continue;
 		if (mask & flags)
 			ext4_set_inode_flag(inode, i);
 		else