linux/drivers/md/raid10.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _RAID10_H
#define _RAID10_H

/* Note: raid10_info.rdev can be set to NULL asynchronously by
 * raid10_remove_disk.
 * There are three safe ways to access raid10_info.rdev.
 * 1/ when holding mddev->reconfig_mutex
 * 2/ when resync/recovery/reshape is known to be happening - i.e. in code
 *    that is called as part of performing resync/recovery/reshape.
 * 3/ while holding rcu_read_lock(), use rcu_dereference to get the pointer
 *    and if it is non-NULL, increment rdev->nr_pending before dropping the
 *    RCU lock.
 * When .rdev is set to NULL, the nr_pending count checked again and if it has
 * been incremented, the pointer is put back in .rdev.
 */

struct raid10_info { … };

struct r10conf { … };

/*
 * this is our 'private' RAID10 bio.
 *
 * it contains information about what kind of IO operations were started
 * for this RAID10 operation, and about their status:
 */

struct r10bio { … };

/* bits for r10bio.state */
enum r10bio_state { … };
#endif