ext4: avoid overflow when setting values via sysfs

ext4: avoid overflow when setting values via sysfs

When setting values of type unsigned int through sysfs, we use kstrtoul()
to parse it and then truncate part of it as the final set value, when the
set value is greater than UINT_MAX, the set value will not match what we
see because of the truncation. As follows:

  $ echo 4294967296 > /sys/fs/ext4/sda/mb_max_linear_groups
  $ cat /sys/fs/ext4/sda/mb_max_linear_groups
    0

So we use kstrtouint() to parse the attr_pointer_ui type to avoid the
inconsistency described above. In addition, a judgment is added to avoid
setting s_resv_clusters less than 0.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240319113325.3110393-2-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>