ext4: warn if delalloc counters are not zero on inactive

The per-inode i_reserved_data_blocks count the reserved delalloc blocks
in a regular file, it should be zero when destroying the file. The
per-fs s_dirtyclusters_counter count all reserved delalloc blocks in a
filesystem, it also should be zero when umounting the filesystem. Now we
have only an error message if the i_reserved_data_blocks is not zero,
which is unable to be simply captured, so add WARN_ON_ONCE to make it
more visable.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20240517124005.347221-4-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Author: zhangyi089

fs/ext4/super.c

@@ -1327,6 +1327,9 @@ static void ext4_put_super(struct super_block *sb)
 
 	ext4_group_desc_free(sbi);
 	ext4_flex_groups_free(sbi);
+
+	WARN_ON_ONCE(!(sbi->s_mount_state & EXT4_ERROR_FS) &&
+		     percpu_counter_sum(&sbi->s_dirtyclusters_counter));
 	ext4_percpu_param_destroy(sbi);
 #ifdef CONFIG_QUOTA
 	for (int i = 0; i < EXT4_MAXQUOTAS; i++)
@@ -1457,7 +1460,8 @@ static void ext4_destroy_inode(struct inode *inode)
 		dump_stack();
 	}
 
-	if (EXT4_I(inode)->i_reserved_data_blocks)
+	if (!(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ERROR_FS) &&
+	    WARN_ON_ONCE(EXT4_I(inode)->i_reserved_data_blocks))
 		ext4_msg(inode->i_sb, KERN_ERR,
 			 "Inode %lu (%p): i_reserved_data_blocks (%u) not cleared!",
 			 inode->i_ino, EXT4_I(inode),