[people/ms/linux.git] / fs / btrfs / raid56.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 2012 Fusion-io  All rights reserved.
 * Copyright (C) 2012 Intel Corp. All rights reserved.
 */

#ifndef BTRFS_RAID56_H
#define BTRFS_RAID56_H

#include <linux/workqueue.h>
#include "volumes.h"

enum btrfs_rbio_ops {
	BTRFS_RBIO_WRITE,
	BTRFS_RBIO_READ_REBUILD,
	BTRFS_RBIO_PARITY_SCRUB,
	BTRFS_RBIO_REBUILD_MISSING,
};

struct btrfs_raid_bio {
	struct btrfs_io_context *bioc;

	/*
	 * While we're doing RMW on a stripe we put it into a hash table so we
	 * can lock the stripe and merge more rbios into it.
	 */
	struct list_head hash_list;

	/* LRU list for the stripe cache */
	struct list_head stripe_cache;

	/* For scheduling work in the helper threads */
	struct work_struct work;

	/*
	 * bio_list and bio_list_lock are used to add more bios into the stripe
	 * in hopes of avoiding the full RMW
	 */
	struct bio_list bio_list;
	spinlock_t bio_list_lock;

	/*
	 * Also protected by the bio_list_lock, the plug list is used by the
	 * plugging code to collect partial bios while plugged.  The stripe
	 * locking code also uses it to hand off the stripe lock to the next
	 * pending IO.
	 */
	struct list_head plug_list;

	/* Flags that tell us if it is safe to merge with this bio. */
	unsigned long flags;

	/*
	 * Set if we're doing a parity rebuild for a read from higher up, which
	 * is handled differently from a parity rebuild as part of RMW.
	 */
	enum btrfs_rbio_ops operation;

	/* How many pages there are for the full stripe including P/Q */
	u16 nr_pages;

	/* How many sectors there are for the full stripe including P/Q */
	u16 nr_sectors;

	/* Number of data stripes (no p/q) */
	u8 nr_data;

	/* Numer of all stripes (including P/Q) */
	u8 real_stripes;

	/* How many pages there are for each stripe */
	u8 stripe_npages;

	/* How many sectors there are for each stripe */
	u8 stripe_nsectors;

	/* First bad stripe, -1 means no corruption */
	s8 faila;

	/* Second bad stripe (for RAID6 use) */
	s8 failb;

	/* Stripe number that we're scrubbing  */
	u8 scrubp;

	/*
	 * Size of all the bios in the bio_list.  This helps us decide if the
	 * rbio maps to a full stripe or not.
	 */
	int bio_list_bytes;

	int generic_bio_cnt;

	refcount_t refs;

	atomic_t stripes_pending;

	atomic_t error;

	struct work_struct end_io_work;

	/* Bitmap to record which horizontal stripe has data */
	unsigned long dbitmap;

	/* Allocated with stripe_nsectors-many bits for finish_*() calls */
	unsigned long finish_pbitmap;

	/*
	 * These are two arrays of pointers.  We allocate the rbio big enough
	 * to hold them both and setup their locations when the rbio is
	 * allocated.
	 */

	/*
	 * Pointers to pages that we allocated for reading/writing stripes
	 * directly from the disk (including P/Q).
	 */
	struct page **stripe_pages;

	/* Pointers to the sectors in the bio_list, for faster lookup */
	struct sector_ptr *bio_sectors;

	/*
	 * For subpage support, we need to map each sector to above
	 * stripe_pages.
	 */
	struct sector_ptr *stripe_sectors;

	/* Allocated with real_stripes-many pointers for finish_*() calls */
	void **finish_pointers;
};

/*
 * For trace event usage only. Records useful debug info for each bio submitted
 * by RAID56 to each physical device.
 *
 * No matter signed or not, (-1) is always the one indicating we can not grab
 * the proper stripe number.
 */
struct raid56_bio_trace_info {
	u64 devid;

	/* The offset inside the stripe. (<= STRIPE_LEN) */
	u32 offset;

	/*
	 * Stripe number.
	 * 0 is the first data stripe, and nr_data for P stripe,
	 * nr_data + 1 for Q stripe.
	 * >= real_stripes for
	 */
	u8 stripe_nr;
};

static inline int nr_data_stripes(const struct map_lookup *map)
{
	return map->num_stripes - btrfs_nr_parity_stripes(map->type);
}

#define RAID5_P_STRIPE ((u64)-2)
#define RAID6_Q_STRIPE ((u64)-1)

#define is_parity_stripe(x) (((x) == RAID5_P_STRIPE) ||		\
			     ((x) == RAID6_Q_STRIPE))

struct btrfs_device;

void raid56_parity_recover(struct bio *bio, struct btrfs_io_context *bioc,
			   int mirror_num, bool generic_io);
void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc);

void raid56_add_scrub_pages(struct btrfs_raid_bio *rbio, struct page *page,
			    unsigned int pgoff, u64 logical);

struct btrfs_raid_bio *raid56_parity_alloc_scrub_rbio(struct bio *bio,
				struct btrfs_io_context *bioc,
				struct btrfs_device *scrub_dev,
				unsigned long *dbitmap, int stripe_nsectors);
void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio);

struct btrfs_raid_bio *
raid56_alloc_missing_rbio(struct bio *bio, struct btrfs_io_context *bioc);
void raid56_submit_missing_rbio(struct btrfs_raid_bio *rbio);

int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info);
void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info);

#endif
Commit	Line	Data
9888c340	1	/* SPDX-License-Identifier: GPL-2.0 */
53b381b3 DW	2	/*
	3	* Copyright (C) 2012 Fusion-io All rights reserved.
	4	* Copyright (C) 2012 Intel Corp. All rights reserved.
53b381b3 DW	5	*/
53b381b3 DW	6
9888c340 DS	7	#ifndef BTRFS_RAID56_H
	8	#define BTRFS_RAID56_H
	9
b8bea09a QW	10	#include <linux/workqueue.h>
	11	#include "volumes.h"
	12
	13	enum btrfs_rbio_ops {
	14	BTRFS_RBIO_WRITE,
	15	BTRFS_RBIO_READ_REBUILD,
	16	BTRFS_RBIO_PARITY_SCRUB,
	17	BTRFS_RBIO_REBUILD_MISSING,
	18	};
	19
	20	struct btrfs_raid_bio {
	21	struct btrfs_io_context *bioc;
	22
	23	/*
	24	* While we're doing RMW on a stripe we put it into a hash table so we
	25	* can lock the stripe and merge more rbios into it.
	26	*/
	27	struct list_head hash_list;
	28
	29	/* LRU list for the stripe cache */
	30	struct list_head stripe_cache;
	31
	32	/* For scheduling work in the helper threads */
	33	struct work_struct work;
	34
	35	/*
	36	* bio_list and bio_list_lock are used to add more bios into the stripe
	37	* in hopes of avoiding the full RMW
	38	*/
	39	struct bio_list bio_list;
	40	spinlock_t bio_list_lock;
	41
	42	/*
	43	* Also protected by the bio_list_lock, the plug list is used by the
	44	* plugging code to collect partial bios while plugged. The stripe
	45	* locking code also uses it to hand off the stripe lock to the next
	46	* pending IO.
	47	*/
	48	struct list_head plug_list;
	49
	50	/* Flags that tell us if it is safe to merge with this bio. */
	51	unsigned long flags;
	52
	53	/*
	54	* Set if we're doing a parity rebuild for a read from higher up, which
	55	* is handled differently from a parity rebuild as part of RMW.
	56	*/
	57	enum btrfs_rbio_ops operation;
	58
b8bea09a QW	59	/* How many pages there are for the full stripe including P/Q */
	60	u16 nr_pages;
	61
	62	/* How many sectors there are for the full stripe including P/Q */
	63	u16 nr_sectors;
	64
	65	/* Number of data stripes (no p/q) */
	66	u8 nr_data;
	67
	68	/* Numer of all stripes (including P/Q) */
	69	u8 real_stripes;
	70
	71	/* How many pages there are for each stripe */
	72	u8 stripe_npages;
	73
	74	/* How many sectors there are for each stripe */
	75	u8 stripe_nsectors;
	76
	77	/* First bad stripe, -1 means no corruption */
	78	s8 faila;
	79
	80	/* Second bad stripe (for RAID6 use) */
	81	s8 failb;
	82
	83	/* Stripe number that we're scrubbing */
	84	u8 scrubp;
	85
	86	/*
	87	* Size of all the bios in the bio_list. This helps us decide if the
	88	* rbio maps to a full stripe or not.
	89	*/
	90	int bio_list_bytes;
	91
	92	int generic_bio_cnt;
	93
	94	refcount_t refs;
	95
	96	atomic_t stripes_pending;
	97
	98	atomic_t error;
	99
d34e123d CH	100	struct work_struct end_io_work;
d34e123d CH	101
b8bea09a QW	102	/* Bitmap to record which horizontal stripe has data */
	103	unsigned long dbitmap;
	104
	105	/* Allocated with stripe_nsectors-many bits for finish_() calls /
	106	unsigned long finish_pbitmap;
	107
	108	/*
	109	* These are two arrays of pointers. We allocate the rbio big enough
	110	* to hold them both and setup their locations when the rbio is
	111	* allocated.
	112	*/
	113
	114	/*
	115	* Pointers to pages that we allocated for reading/writing stripes
	116	* directly from the disk (including P/Q).
	117	*/
	118	struct page **stripe_pages;
	119
	120	/* Pointers to the sectors in the bio_list, for faster lookup */
	121	struct sector_ptr *bio_sectors;
	122
	123	/*
	124	* For subpage support, we need to map each sector to above
	125	* stripe_pages.
	126	*/
	127	struct sector_ptr *stripe_sectors;
	128
	129	/* Allocated with real_stripes-many pointers for finish_() calls /
	130	void **finish_pointers;
	131	};
	132
	133	/*
	134	* For trace event usage only. Records useful debug info for each bio submitted
	135	* by RAID56 to each physical device.
	136	*
	137	* No matter signed or not, (-1) is always the one indicating we can not grab
	138	* the proper stripe number.
	139	*/
	140	struct raid56_bio_trace_info {
	141	u64 devid;
	142
	143	/* The offset inside the stripe. (<= STRIPE_LEN) */
	144	u32 offset;
	145
	146	/*
	147	* Stripe number.
	148	* 0 is the first data stripe, and nr_data for P stripe,
	149	* nr_data + 1 for Q stripe.
	150	* >= real_stripes for
	151	*/
	152	u8 stripe_nr;
	153	};
	154
72ad8131	155	static inline int nr_data_stripes(const struct map_lookup *map)
53b381b3	156	{
0b30f719	157	return map->num_stripes - btrfs_nr_parity_stripes(map->type);
53b381b3	158	}
b8bea09a	159
53b381b3 DW	160	#define RAID5_P_STRIPE ((u64)-2)
	161	#define RAID6_Q_STRIPE ((u64)-1)
	162
	163	#define is_parity_stripe(x) (((x) == RAID5_P_STRIPE) \|\| \
	164	((x) == RAID6_Q_STRIPE))
	165
5a6ac9ea MX	166	struct btrfs_device;
5a6ac9ea MX	167
6065fd95 CH	168	void raid56_parity_recover(struct bio bio, struct btrfs_io_context bioc,
6065fd95 CH	169	int mirror_num, bool generic_io);
31683f4a	170	void raid56_parity_write(struct bio bio, struct btrfs_io_context bioc);
53b381b3	171
b4ee1782	172	void raid56_add_scrub_pages(struct btrfs_raid_bio rbio, struct page page,
6346f6bf	173	unsigned int pgoff, u64 logical);
b4ee1782	174
6a258d72	175	struct btrfs_raid_bio raid56_parity_alloc_scrub_rbio(struct bio bio,
ff18a4af	176	struct btrfs_io_context *bioc,
6a258d72 QW	177	struct btrfs_device *scrub_dev,
6a258d72 QW	178	unsigned long *dbitmap, int stripe_nsectors);
5a6ac9ea MX	179	void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio);
5a6ac9ea MX	180
b4ee1782	181	struct btrfs_raid_bio *
ff18a4af	182	raid56_alloc_missing_rbio(struct bio bio, struct btrfs_io_context bioc);
b4ee1782 OS	183	void raid56_submit_missing_rbio(struct btrfs_raid_bio *rbio);
b4ee1782 OS	184
53b381b3 DW	185	int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info);
53b381b3 DW	186	void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info);
9888c340	187
53b381b3	188	#endif