ext4: update ext4_data_block_valid related comments

Since ext4_data_block_valid() has been renamed to ext4_inode_block_valid(),
the related comments need to be updated.
Signed-off-by: Chunguang Xu <brookxu@tencent.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/1604764698-4269-5-git-send-email-brookxu@tencent.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/block_validity.c

@@ -206,7 +206,7 @@ static void ext4_destroy_system_zone(struct rcu_head *rcu)
  *
  * The update of system_blks pointer in this function is protected by
  * sb->s_umount semaphore. However we have to be careful as we can be
- * racing with ext4_data_block_valid() calls reading system_blks rbtree
+ * racing with ext4_inode_block_valid() calls reading system_blks rbtree
  * protected only by RCU. That's why we first build the rbtree and then
  * swap it in place.
  */
@@ -258,7 +258,7 @@ int ext4_setup_system_zone(struct super_block *sb)
 
 	/*
 	 * System blks rbtree complete, announce it once to prevent racing
-	 * with ext4_data_block_valid() accessing the rbtree at the same
+	 * with ext4_inode_block_valid() accessing the rbtree at the same
 	 * time.
 	 */
 	rcu_assign_pointer(sbi->s_system_blks, system_blks);
@@ -278,7 +278,7 @@ int ext4_setup_system_zone(struct super_block *sb)
  *
  * The update of system_blks pointer in this function is protected by
  * sb->s_umount semaphore. However we have to be careful as we can be
- * racing with ext4_data_block_valid() calls reading system_blks rbtree
+ * racing with ext4_inode_block_valid() calls reading system_blks rbtree
  * protected only by RCU. So we first clear the system_blks pointer and
  * then free the rbtree only after RCU grace period expires.
  */