drivers/md/raid10.c

34  *    far_copies (stored in second byte of layout)
40  * is divided into far_copies sections.   In each section, chunks are laid out
44  * are (near_copies * far_copies) of each chunk, and each is on a different
45  * drive.  near_copies and far_copies must be at least one, and their product
48  * If far_offset is true, then the far_copies are handled a bit differently.
54  * sets that are (near_copies * far_copies) in size.  The far copied stripes
559  * parameters: near_copies and far_copies.
560  * near_copies * far_copies must be <= raid_disks.
568  * If far_copies > 1, then after 1/far_copies of the array has been assigned
605 		stripe *= geo->far_copies;
618 		for (f = 1; f < geo->far_copies; f++) {
685 		fc = sector_div(chunk, geo->far_copies);
721  * depending on near_copies / far_copies geometry.
829 		else if (geo->far_copies > 1)
1583 	int far_copies = geo->far_copies;
1676 		first_stripe_index *= geo->far_copies;
1685 		last_stripe_index *= geo->far_copies;
1809 	if (!geo->far_offset && --far_copies) {
1876 	if (conf->geo.far_copies > 1) {
1878 			seq_printf(seq, " %d offset-copies", conf->geo.far_copies);
1880 			seq_printf(seq, " %d far-copies", conf->geo.far_copies);
3775 	sector_div(size, conf->geo.far_copies);
3790 	sector_div(size, conf->geo.far_copies);
3807 		sector_div(size, conf->geo.far_copies);
3846 	geo->far_copies = fc;
3944 			/* far_copies must be 1 */
4075 		if (conf->geo.far_copies != 1 &&
4078 		if (conf->prev.far_copies != 1 &&
4138 				 conf->prev.far_copies);
4140 				conf->geo.far_copies);
4186 	 * For 'offset', this is far_copies*chunksize.
4189 	 * So if far_copies > 1 && !far_offset, fail.
4190 	 * Else find LCM(raid_disks, near_copy)*far_copies and
4200 	if (conf->geo.far_copies > 1 && !conf->geo.far_offset)
4239 	/* new layout: far_copies = 1, near_copies = 2 */
4301 	if (conf->geo.far_copies != 1 && !conf->geo.far_offset)
4307 	if (geo.far_copies > 1 && !geo.far_offset)
4415 			 conf->prev.far_copies);
4417 			conf->geo.far_copies);
4578 	s *= geo->far_copies;
4592 	s *= geo->far_copies;