• Dan Williams's avatar
    md: 'array_size' sysfs attribute · b522adcd
    Dan Williams authored
    Allow userspace to set the size of the array according to the following
    semantics:
    
    1/ size must be <= to the size returned by mddev->pers->size(mddev, 0, 0)
       a) If size is set before the array is running, do_md_run will fail
          if size is greater than the default size
       b) A reshape attempt that reduces the default size to less than the set
          array size should be blocked
    2/ once userspace sets the size the kernel will not change it
    3/ writing 'default' to this attribute returns control of the size to the
       kernel and reverts to the size reported by the personality
    
    Also, convert locations that need to know the default size from directly
    reading ->array_sectors to <pers>_size.  Resync/reshape operations
    always follow the default size.
    
    Finally, fixup other locations that read a number of 1k-blocks from
    userspace to use strict_blocks_to_sectors() which checks for unsigned
    long long to sector_t overflow and blocks to sectors overflow.
    Reviewed-by: default avatarAndre Noll <maan@systemlinux.org>
    Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
    b522adcd
raid0.c 14.5 KB