/* 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 md_rdev	*rdev, *replacement;	sector_t	head_position;}; struct r10conf {	struct mddev		*mddev;	struct raid10_info	*mirrors;	struct raid10_info	*mirrors_new, *mirrors_old;	spinlock_t		device_lock; 	/* geometry */	struct geom {		int		raid_disks;		int		near_copies;  /* number of copies laid out					       * raid0 style */		int		far_copies;   /* number of copies laid out					       * at large strides across drives					       */		int		far_offset;   /* far_copies are offset by 1					       * stripe instead of many					       */		sector_t	stride;	      /* distance between far copies.					       * This is size / far_copies unless					       * far_offset, in which case it is					       * 1 stripe.					       */		int             far_set_size; /* The number of devices in a set,					       * where a 'set' are devices that					       * contain far/offset copies of					       * each other.					       */		int		chunk_shift; /* shift from chunks to sectors */		sector_t	chunk_mask;	} prev, geo;	int			copies;	      /* near_copies * far_copies.					       * must be <= raid_disks					       */ 	sector_t		dev_sectors;  /* temp copy of					       * mddev->dev_sectors */	sector_t		reshape_progress;	sector_t		reshape_safe;	unsigned long		reshape_checkpoint;	sector_t		offset_diff; 	struct list_head	retry_list;	/* A separate list of r1bio which just need raid_end_bio_io called.	 * This mustn't happen for writes which had any errors if the superblock	 * needs to be written.	 */	struct list_head	bio_end_io_list; 	/* queue pending writes and submit them on unplug */	struct bio_list		pending_bio_list; 	seqlock_t		resync_lock;	atomic_t		nr_pending;	int			nr_waiting;	int			nr_queued;	int			barrier;	int			array_freeze_pending;	sector_t		next_resync;	int			fullsync;  /* set to 1 if a full sync is needed,					    * (fresh device added).					    * Cleared when a sync completes.					    */	int			have_replacement; /* There is at least one						   * replacement device.						   */	wait_queue_head_t	wait_barrier; 	mempool_t		*r10bio_pool;	mempool_t		r10buf_pool;	struct page		*tmppage;	struct bio_set		bio_split; 	/* When taking over an array from a different personality, we store	 * the new thread here until we fully activate the array.	 */	struct md_thread __rcu	*thread; 	/*	 * Keep track of cluster resync window to send to other nodes.	 */	sector_t		cluster_sync_low;	sector_t		cluster_sync_high;}; /* * 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 {	atomic_t		remaining; /* 'have we finished' count,					    * used from IRQ handlers					    */	sector_t		sector;	/* virtual sector number */	int			sectors;	unsigned long		state;	struct mddev		*mddev;	/*	 * original bio going to /dev/mdx	 */	struct bio		*master_bio;	/*	 * if the IO is in READ direction, then this is where we read	 */	int			read_slot; 	struct list_head	retry_list;	/*	 * if the IO is in WRITE direction, then multiple bios are used,	 * one for each copy.	 * When resyncing we also use one for each copy.	 * When reconstructing, we use 2 bios, one for read, one for write.	 * We choose the number when they are allocated.	 * We sometimes need an extra bio to write to the replacement.	 */	struct r10dev {		struct bio	*bio;		union {			struct bio	*repl_bio; /* used for resync and						    * writes */			struct md_rdev	*rdev;	   /* used for reads						    * (read_slot >= 0) */		};		sector_t	addr;		int		devnum;	} devs[];}; /* bits for r10bio.state */enum r10bio_state {	R10BIO_Uptodate,	R10BIO_IsSync,	R10BIO_IsRecover,	R10BIO_IsReshape,/* Set ReadError on bios that experience a read error * so that raid10d knows what to do with them. */	R10BIO_ReadError,/* For bio_split errors, record that bi_end_io was called. */	R10BIO_Returned,/* If a write for this request means we can clear some * known-bad-block records, we set this flag. */	R10BIO_MadeGood,	R10BIO_WriteError,/* During a reshape we might be performing IO on the * 'previous' part of the array, in which case this * flag is set */	R10BIO_Previous,/* failfast devices did receive failfast requests. */	R10BIO_FailFast,	R10BIO_Discard,};#endif