[mirror_ubuntu-hirsute-kernel.git] / fs / btrfs / volumes.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 */

#ifndef BTRFS_VOLUMES_H
#define BTRFS_VOLUMES_H

#include <linux/bio.h>
#include <linux/sort.h>
#include <linux/btrfs.h>
#include "async-thread.h"

#define BTRFS_MAX_DATA_CHUNK_SIZE	(10ULL * SZ_1G)

extern struct mutex uuid_mutex;

#define BTRFS_STRIPE_LEN	SZ_64K

struct buffer_head;

struct btrfs_io_geometry {
	/* remaining bytes before crossing a stripe */
	u64 len;
	/* offset of logical address in chunk */
	u64 offset;
	/* length of single IO stripe */
	u64 stripe_len;
	/* number of stripe where address falls */
	u64 stripe_nr;
	/* offset of address in stripe */
	u64 stripe_offset;
	/* offset of raid56 stripe into the chunk */
	u64 raid56_stripe_offset;
};

/*
 * Use sequence counter to get consistent device stat data on
 * 32-bit processors.
 */
#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
#include <linux/seqlock.h>
#define __BTRFS_NEED_DEVICE_DATA_ORDERED
#define btrfs_device_data_ordered_init(device)	\
	seqcount_init(&device->data_seqcount)
#else
#define btrfs_device_data_ordered_init(device) do { } while (0)
#endif

#define BTRFS_DEV_STATE_WRITEABLE	(0)
#define BTRFS_DEV_STATE_IN_FS_METADATA	(1)
#define BTRFS_DEV_STATE_MISSING		(2)
#define BTRFS_DEV_STATE_REPLACE_TGT	(3)
#define BTRFS_DEV_STATE_FLUSH_SENT	(4)

struct btrfs_device {
	struct list_head dev_list; /* device_list_mutex */
	struct list_head dev_alloc_list; /* chunk mutex */
	struct list_head post_commit_list; /* chunk mutex */
	struct btrfs_fs_devices *fs_devices;
	struct btrfs_fs_info *fs_info;

	struct rcu_string *name;

	u64 generation;

	struct block_device *bdev;

	/* the mode sent to blkdev_get */
	fmode_t mode;

	unsigned long dev_state;
	blk_status_t last_flush_error;

#ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
	seqcount_t data_seqcount;
#endif

	/* the internal btrfs device id */
	u64 devid;

	/* size of the device in memory */
	u64 total_bytes;

	/* size of the device on disk */
	u64 disk_total_bytes;

	/* bytes used */
	u64 bytes_used;

	/* optimal io alignment for this device */
	u32 io_align;

	/* optimal io width for this device */
	u32 io_width;
	/* type and info about this device */
	u64 type;

	/* minimal io size for this device */
	u32 sector_size;

	/* physical drive uuid (or lvm uuid) */
	u8 uuid[BTRFS_UUID_SIZE];

	/*
	 * size of the device on the current transaction
	 *
	 * This variant is update when committing the transaction,
	 * and protected by chunk mutex
	 */
	u64 commit_total_bytes;

	/* bytes used on the current transaction */
	u64 commit_bytes_used;

	/* for sending down flush barriers */
	struct bio *flush_bio;
	struct completion flush_wait;

	/* per-device scrub information */
	struct scrub_ctx *scrub_ctx;

	struct btrfs_work work;

	/* readahead state */
	atomic_t reada_in_flight;
	u64 reada_next;
	struct reada_zone *reada_curr_zone;
	struct radix_tree_root reada_zones;
	struct radix_tree_root reada_extents;

	/* disk I/O failure stats. For detailed description refer to
	 * enum btrfs_dev_stat_values in ioctl.h */
	int dev_stats_valid;

	/* Counter to record the change of device stats */
	atomic_t dev_stats_ccnt;
	atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];

	struct extent_io_tree alloc_state;
};

/*
 * If we read those variants at the context of their own lock, we needn't
 * use the following helpers, reading them directly is safe.
 */
#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
#define BTRFS_DEVICE_GETSET_FUNCS(name)					\
static inline u64							\
btrfs_device_get_##name(const struct btrfs_device *dev)			\
{									\
	u64 size;							\
	unsigned int seq;						\
									\
	do {								\
		seq = read_seqcount_begin(&dev->data_seqcount);		\
		size = dev->name;					\
	} while (read_seqcount_retry(&dev->data_seqcount, seq));	\
	return size;							\
}									\
									\
static inline void							\
btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
{									\
	preempt_disable();						\
	write_seqcount_begin(&dev->data_seqcount);			\
	dev->name = size;						\
	write_seqcount_end(&dev->data_seqcount);			\
	preempt_enable();						\
}
#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
#define BTRFS_DEVICE_GETSET_FUNCS(name)					\
static inline u64							\
btrfs_device_get_##name(const struct btrfs_device *dev)			\
{									\
	u64 size;							\
									\
	preempt_disable();						\
	size = dev->name;						\
	preempt_enable();						\
	return size;							\
}									\
									\
static inline void							\
btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
{									\
	preempt_disable();						\
	dev->name = size;						\
	preempt_enable();						\
}
#else
#define BTRFS_DEVICE_GETSET_FUNCS(name)					\
static inline u64							\
btrfs_device_get_##name(const struct btrfs_device *dev)			\
{									\
	return dev->name;						\
}									\
									\
static inline void							\
btrfs_device_set_##name(struct btrfs_device *dev, u64 size)		\
{									\
	dev->name = size;						\
}
#endif

BTRFS_DEVICE_GETSET_FUNCS(total_bytes);
BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes);
BTRFS_DEVICE_GETSET_FUNCS(bytes_used);

struct btrfs_fs_devices {
	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
	u8 metadata_uuid[BTRFS_FSID_SIZE];
	bool fsid_change;
	struct list_head fs_list;

	u64 num_devices;
	u64 open_devices;
	u64 rw_devices;
	u64 missing_devices;
	u64 total_rw_bytes;
	u64 total_devices;

	/* Highest generation number of seen devices */
	u64 latest_generation;

	struct block_device *latest_bdev;

	/* all of the devices in the FS, protected by a mutex
	 * so we can safely walk it to write out the supers without
	 * worrying about add/remove by the multi-device code.
	 * Scrubbing super can kick off supers writing by holding
	 * this mutex lock.
	 */
	struct mutex device_list_mutex;

	/* List of all devices, protected by device_list_mutex */
	struct list_head devices;

	/*
	 * Devices which can satisfy space allocation. Protected by
	 * chunk_mutex
	 */
	struct list_head alloc_list;

	struct btrfs_fs_devices *seed;
	bool seeding;

	int opened;

	/* set when we find or add a device that doesn't have the
	 * nonrot flag set
	 */
	int rotating;

	struct btrfs_fs_info *fs_info;
	/* sysfs kobjects */
	struct kobject fsid_kobj;
	struct kobject *device_dir_kobj;
	struct completion kobj_unregister;
};

#define BTRFS_BIO_INLINE_CSUM_SIZE	64

#define BTRFS_MAX_DEVS(info) ((BTRFS_MAX_ITEM_SIZE(info)	\
			- sizeof(struct btrfs_chunk))		\
			/ sizeof(struct btrfs_stripe) + 1)

#define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE	\
				- 2 * sizeof(struct btrfs_disk_key)	\
				- 2 * sizeof(struct btrfs_chunk))	\
				/ sizeof(struct btrfs_stripe) + 1)

/*
 * we need the mirror number and stripe index to be passed around
 * the call chain while we are processing end_io (especially errors).
 * Really, what we need is a btrfs_bio structure that has this info
 * and is properly sized with its stripe array, but we're not there
 * quite yet.  We have our own btrfs bioset, and all of the bios
 * we allocate are actually btrfs_io_bios.  We'll cram as much of
 * struct btrfs_bio as we can into this over time.
 */
struct btrfs_io_bio {
	unsigned int mirror_num;
	unsigned int stripe_index;
	u64 logical;
	u8 *csum;
	u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
	struct bvec_iter iter;
	/*
	 * This member must come last, bio_alloc_bioset will allocate enough
	 * bytes for entire btrfs_io_bio but relies on bio being last.
	 */
	struct bio bio;
};

static inline struct btrfs_io_bio *btrfs_io_bio(struct bio *bio)
{
	return container_of(bio, struct btrfs_io_bio, bio);
}

static inline void btrfs_io_bio_free_csum(struct btrfs_io_bio *io_bio)
{
	if (io_bio->csum != io_bio->csum_inline) {
		kfree(io_bio->csum);
		io_bio->csum = NULL;
	}
}

struct btrfs_bio_stripe {
	struct btrfs_device *dev;
	u64 physical;
	u64 length; /* only used for discard mappings */
};

struct btrfs_bio {
	refcount_t refs;
	atomic_t stripes_pending;
	struct btrfs_fs_info *fs_info;
	u64 map_type; /* get from map_lookup->type */
	bio_end_io_t *end_io;
	struct bio *orig_bio;
	void *private;
	atomic_t error;
	int max_errors;
	int num_stripes;
	int mirror_num;
	int num_tgtdevs;
	int *tgtdev_map;
	/*
	 * logical block numbers for the start of each stripe
	 * The last one or two are p/q.  These are sorted,
	 * so raid_map[0] is the start of our full stripe
	 */
	u64 *raid_map;
	struct btrfs_bio_stripe stripes[];
};

struct btrfs_device_info {
	struct btrfs_device *dev;
	u64 dev_offset;
	u64 max_avail;
	u64 total_avail;
};

struct btrfs_raid_attr {
	u8 sub_stripes;		/* sub_stripes info for map */
	u8 dev_stripes;		/* stripes per dev */
	u8 devs_max;		/* max devs to use */
	u8 devs_min;		/* min devs needed */
	u8 tolerated_failures;	/* max tolerated fail devs */
	u8 devs_increment;	/* ndevs has to be a multiple of this */
	u8 ncopies;		/* how many copies to data has */
	u8 nparity;		/* number of stripes worth of bytes to store
				 * parity information */
	u8 mindev_error;	/* error code if min devs requisite is unmet */
	const char raid_name[8]; /* name of the raid */
	u64 bg_flag;		/* block group flag of the raid */
};

extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];

struct map_lookup {
	u64 type;
	int io_align;
	int io_width;
	u64 stripe_len;
	int num_stripes;
	int sub_stripes;
	int verified_stripes; /* For mount time dev extent verification */
	struct btrfs_bio_stripe stripes[];
};

#define map_lookup_size(n) (sizeof(struct map_lookup) + \
			    (sizeof(struct btrfs_bio_stripe) * (n)))

struct btrfs_balance_args;
struct btrfs_balance_progress;
struct btrfs_balance_control {
	struct btrfs_balance_args data;
	struct btrfs_balance_args meta;
	struct btrfs_balance_args sys;

	u64 flags;

	struct btrfs_balance_progress stat;
};

enum btrfs_map_op {
	BTRFS_MAP_READ,
	BTRFS_MAP_WRITE,
	BTRFS_MAP_DISCARD,
	BTRFS_MAP_GET_READ_MIRRORS,
};

static inline enum btrfs_map_op btrfs_op(struct bio *bio)
{
	switch (bio_op(bio)) {
	case REQ_OP_DISCARD:
		return BTRFS_MAP_DISCARD;
	case REQ_OP_WRITE:
		return BTRFS_MAP_WRITE;
	default:
		WARN_ON_ONCE(1);
		/* fall through */
	case REQ_OP_READ:
		return BTRFS_MAP_READ;
	}
}

void btrfs_get_bbio(struct btrfs_bio *bbio);
void btrfs_put_bbio(struct btrfs_bio *bbio);
int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
		    u64 logical, u64 *length,
		    struct btrfs_bio **bbio_ret, int mirror_num);
int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
		     u64 logical, u64 *length,
		     struct btrfs_bio **bbio_ret);
int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
		u64 logical, u64 len, struct btrfs_io_geometry *io_geom);
int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
		     u64 physical, u64 **logical, int *naddrs, int *stripe_len);
int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, u64 type);
void btrfs_mapping_tree_free(struct extent_map_tree *tree);
blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
			   int mirror_num);
int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
		       fmode_t flags, void *holder);
struct btrfs_device *btrfs_scan_one_device(const char *path,
					   fmode_t flags, void *holder);
int btrfs_forget_devices(const char *path);
int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step);
void btrfs_assign_next_active_device(struct btrfs_device *device,
				     struct btrfs_device *this_dev);
struct btrfs_device *btrfs_find_device_by_devspec(struct btrfs_fs_info *fs_info,
						  u64 devid,
						  const char *devpath);
struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
					const u64 *devid,
					const u8 *uuid);
void btrfs_free_device(struct btrfs_device *device);
int btrfs_rm_device(struct btrfs_fs_info *fs_info,
		    const char *device_path, u64 devid);
void __exit btrfs_cleanup_fs_uuids(void);
int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
int btrfs_grow_device(struct btrfs_trans_handle *trans,
		      struct btrfs_device *device, u64 new_size);
struct btrfs_device *btrfs_find_device(struct btrfs_fs_devices *fs_devices,
				       u64 devid, u8 *uuid, u8 *fsid, bool seed);
int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *path);
int btrfs_balance(struct btrfs_fs_info *fs_info,
		  struct btrfs_balance_control *bctl,
		  struct btrfs_ioctl_balance_args *bargs);
void btrfs_describe_block_groups(u64 flags, char *buf, u32 size_buf);
int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info);
int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset);
int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
			 u64 *start, u64 *max_avail);
void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
			struct btrfs_ioctl_get_dev_stats *stats);
void btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
int btrfs_run_dev_stats(struct btrfs_trans_handle *trans);
void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev);
void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev);
void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev);
void btrfs_scratch_superblocks(struct block_device *bdev, const char *device_path);
int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
			   u64 logical, u64 len);
unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
				    u64 logical);
int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
			     u64 chunk_offset, u64 chunk_size);
int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);
struct extent_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,
				       u64 logical, u64 length);

static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
				      int index)
{
	atomic_inc(dev->dev_stat_values + index);
	/*
	 * This memory barrier orders stores updating statistics before stores
	 * updating dev_stats_ccnt.
	 *
	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
	 */
	smp_mb__before_atomic();
	atomic_inc(&dev->dev_stats_ccnt);
}

static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
				      int index)
{
	return atomic_read(dev->dev_stat_values + index);
}

static inline int btrfs_dev_stat_read_and_reset(struct btrfs_device *dev,
						int index)
{
	int ret;

	ret = atomic_xchg(dev->dev_stat_values + index, 0);
	/*
	 * atomic_xchg implies a full memory barriers as per atomic_t.txt:
	 * - RMW operations that have a return value are fully ordered;
	 *
	 * This implicit memory barriers is paired with the smp_rmb in
	 * btrfs_run_dev_stats
	 */
	atomic_inc(&dev->dev_stats_ccnt);
	return ret;
}

static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
				      int index, unsigned long val)
{
	atomic_set(dev->dev_stat_values + index, val);
	/*
	 * This memory barrier orders stores updating statistics before stores
	 * updating dev_stats_ccnt.
	 *
	 * It pairs with smp_rmb() in btrfs_run_dev_stats().
	 */
	smp_mb__before_atomic();
	atomic_inc(&dev->dev_stats_ccnt);
}

/*
 * Convert block group flags (BTRFS_BLOCK_GROUP_*) to btrfs_raid_types, which
 * can be used as index to access btrfs_raid_array[].
 */
static inline enum btrfs_raid_types btrfs_bg_flags_to_raid_index(u64 flags)
{
	if (flags & BTRFS_BLOCK_GROUP_RAID10)
		return BTRFS_RAID_RAID10;
	else if (flags & BTRFS_BLOCK_GROUP_RAID1)
		return BTRFS_RAID_RAID1;
	else if (flags & BTRFS_BLOCK_GROUP_RAID1C3)
		return BTRFS_RAID_RAID1C3;
	else if (flags & BTRFS_BLOCK_GROUP_RAID1C4)
		return BTRFS_RAID_RAID1C4;
	else if (flags & BTRFS_BLOCK_GROUP_DUP)
		return BTRFS_RAID_DUP;
	else if (flags & BTRFS_BLOCK_GROUP_RAID0)
		return BTRFS_RAID_RAID0;
	else if (flags & BTRFS_BLOCK_GROUP_RAID5)
		return BTRFS_RAID_RAID5;
	else if (flags & BTRFS_BLOCK_GROUP_RAID6)
		return BTRFS_RAID_RAID6;

	return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
}

void btrfs_commit_device_sizes(struct btrfs_transaction *trans);

struct list_head * __attribute_const__ btrfs_get_fs_uuids(void);
void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info);
void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info);
bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
					struct btrfs_device *failing_dev);

int btrfs_bg_type_to_factor(u64 flags);
const char *btrfs_bg_type_to_raid_name(u64 flags);
int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);

#endif
Commit	Line	Data
	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	/*
	3	* Copyright (C) 2007 Oracle. All rights reserved.
	4	*/
	5
	6	#ifndef BTRFS_VOLUMES_H
	7	#define BTRFS_VOLUMES_H
	8
	9	#include <linux/bio.h>
	10	#include <linux/sort.h>
	11	#include <linux/btrfs.h>
	12	#include "async-thread.h"
	13
	14	#define BTRFS_MAX_DATA_CHUNK_SIZE (10ULL * SZ_1G)
	15
	16	extern struct mutex uuid_mutex;
	17
	18	#define BTRFS_STRIPE_LEN SZ_64K
	19
	20	struct buffer_head;
	21
	22	struct btrfs_io_geometry {
	23	/* remaining bytes before crossing a stripe */
	24	u64 len;
	25	/* offset of logical address in chunk */
	26	u64 offset;
	27	/* length of single IO stripe */
	28	u64 stripe_len;
	29	/* number of stripe where address falls */
	30	u64 stripe_nr;
	31	/* offset of address in stripe */
	32	u64 stripe_offset;
	33	/* offset of raid56 stripe into the chunk */
	34	u64 raid56_stripe_offset;
	35	};
	36
	37	/*
	38	* Use sequence counter to get consistent device stat data on
	39	* 32-bit processors.
	40	*/
	41	#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
	42	#include <linux/seqlock.h>
	43	#define __BTRFS_NEED_DEVICE_DATA_ORDERED
	44	#define btrfs_device_data_ordered_init(device) \
	45	seqcount_init(&device->data_seqcount)
	46	#else
	47	#define btrfs_device_data_ordered_init(device) do { } while (0)
	48	#endif
	49
	50	#define BTRFS_DEV_STATE_WRITEABLE (0)
	51	#define BTRFS_DEV_STATE_IN_FS_METADATA (1)
	52	#define BTRFS_DEV_STATE_MISSING (2)
	53	#define BTRFS_DEV_STATE_REPLACE_TGT (3)
	54	#define BTRFS_DEV_STATE_FLUSH_SENT (4)
	55
	56	struct btrfs_device {
	57	struct list_head dev_list; /* device_list_mutex */
	58	struct list_head dev_alloc_list; /* chunk mutex */
	59	struct list_head post_commit_list; /* chunk mutex */
	60	struct btrfs_fs_devices *fs_devices;
	61	struct btrfs_fs_info *fs_info;
	62
	63	struct rcu_string *name;
	64
	65	u64 generation;
	66
	67	struct block_device *bdev;
	68
	69	/* the mode sent to blkdev_get */
	70	fmode_t mode;
	71
	72	unsigned long dev_state;
	73	blk_status_t last_flush_error;
	74
	75	#ifdef __BTRFS_NEED_DEVICE_DATA_ORDERED
	76	seqcount_t data_seqcount;
	77	#endif
	78
	79	/* the internal btrfs device id */
	80	u64 devid;
	81
	82	/* size of the device in memory */
	83	u64 total_bytes;
	84
	85	/* size of the device on disk */
	86	u64 disk_total_bytes;
	87
	88	/* bytes used */
	89	u64 bytes_used;
	90
	91	/* optimal io alignment for this device */
	92	u32 io_align;
	93
	94	/* optimal io width for this device */
	95	u32 io_width;
	96	/* type and info about this device */
	97	u64 type;
	98
	99	/* minimal io size for this device */
	100	u32 sector_size;
	101
	102	/* physical drive uuid (or lvm uuid) */
	103	u8 uuid[BTRFS_UUID_SIZE];
	104
	105	/*
	106	* size of the device on the current transaction
	107	*
	108	* This variant is update when committing the transaction,
	109	* and protected by chunk mutex
	110	*/
	111	u64 commit_total_bytes;
	112
	113	/* bytes used on the current transaction */
	114	u64 commit_bytes_used;
	115
	116	/* for sending down flush barriers */
	117	struct bio *flush_bio;
	118	struct completion flush_wait;
	119
	120	/* per-device scrub information */
	121	struct scrub_ctx *scrub_ctx;
	122
	123	struct btrfs_work work;
	124
	125	/* readahead state */
	126	atomic_t reada_in_flight;
	127	u64 reada_next;
	128	struct reada_zone *reada_curr_zone;
	129	struct radix_tree_root reada_zones;
	130	struct radix_tree_root reada_extents;
	131
	132	/* disk I/O failure stats. For detailed description refer to
	133	* enum btrfs_dev_stat_values in ioctl.h */
	134	int dev_stats_valid;
	135
	136	/* Counter to record the change of device stats */
	137	atomic_t dev_stats_ccnt;
	138	atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
	139
	140	struct extent_io_tree alloc_state;
	141	};
	142
	143	/*
	144	* If we read those variants at the context of their own lock, we needn't
	145	* use the following helpers, reading them directly is safe.
	146	*/
	147	#if BITS_PER_LONG==32 && defined(CONFIG_SMP)
	148	#define BTRFS_DEVICE_GETSET_FUNCS(name) \
	149	static inline u64 \
	150	btrfs_device_get_##name(const struct btrfs_device *dev) \
	151	{ \
	152	u64 size; \
	153	unsigned int seq; \
	154	\
	155	do { \
	156	seq = read_seqcount_begin(&dev->data_seqcount); \
	157	size = dev->name; \
	158	} while (read_seqcount_retry(&dev->data_seqcount, seq)); \
	159	return size; \
	160	} \
	161	\
	162	static inline void \
	163	btrfs_device_set_##name(struct btrfs_device *dev, u64 size) \
	164	{ \
	165	preempt_disable(); \
	166	write_seqcount_begin(&dev->data_seqcount); \
	167	dev->name = size; \
	168	write_seqcount_end(&dev->data_seqcount); \
	169	preempt_enable(); \
	170	}
	171	#elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
	172	#define BTRFS_DEVICE_GETSET_FUNCS(name) \
	173	static inline u64 \
	174	btrfs_device_get_##name(const struct btrfs_device *dev) \
	175	{ \
	176	u64 size; \
	177	\
	178	preempt_disable(); \
	179	size = dev->name; \
	180	preempt_enable(); \
	181	return size; \
	182	} \
	183	\
	184	static inline void \
	185	btrfs_device_set_##name(struct btrfs_device *dev, u64 size) \
	186	{ \
	187	preempt_disable(); \
	188	dev->name = size; \
	189	preempt_enable(); \
	190	}
	191	#else
	192	#define BTRFS_DEVICE_GETSET_FUNCS(name) \
	193	static inline u64 \
	194	btrfs_device_get_##name(const struct btrfs_device *dev) \
	195	{ \
	196	return dev->name; \
	197	} \
	198	\
	199	static inline void \
	200	btrfs_device_set_##name(struct btrfs_device *dev, u64 size) \
	201	{ \
	202	dev->name = size; \
	203	}
	204	#endif
	205
	206	BTRFS_DEVICE_GETSET_FUNCS(total_bytes);
	207	BTRFS_DEVICE_GETSET_FUNCS(disk_total_bytes);
	208	BTRFS_DEVICE_GETSET_FUNCS(bytes_used);
	209
	210	struct btrfs_fs_devices {
	211	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
	212	u8 metadata_uuid[BTRFS_FSID_SIZE];
	213	bool fsid_change;
	214	struct list_head fs_list;
	215
	216	u64 num_devices;
	217	u64 open_devices;
	218	u64 rw_devices;
	219	u64 missing_devices;
	220	u64 total_rw_bytes;
	221	u64 total_devices;
	222
	223	/* Highest generation number of seen devices */
	224	u64 latest_generation;
	225
	226	struct block_device *latest_bdev;
	227
	228	/* all of the devices in the FS, protected by a mutex
	229	* so we can safely walk it to write out the supers without
	230	* worrying about add/remove by the multi-device code.
	231	* Scrubbing super can kick off supers writing by holding
	232	* this mutex lock.
	233	*/
	234	struct mutex device_list_mutex;
	235
	236	/* List of all devices, protected by device_list_mutex */
	237	struct list_head devices;
	238
	239	/*
	240	* Devices which can satisfy space allocation. Protected by
	241	* chunk_mutex
	242	*/
	243	struct list_head alloc_list;
	244
	245	struct btrfs_fs_devices *seed;
	246	bool seeding;
	247
	248	int opened;
	249
	250	/* set when we find or add a device that doesn't have the
	251	* nonrot flag set
	252	*/
	253	int rotating;
	254
	255	struct btrfs_fs_info *fs_info;
	256	/* sysfs kobjects */
	257	struct kobject fsid_kobj;
	258	struct kobject *device_dir_kobj;
	259	struct completion kobj_unregister;
	260	};
	261
	262	#define BTRFS_BIO_INLINE_CSUM_SIZE 64
	263
	264	#define BTRFS_MAX_DEVS(info) ((BTRFS_MAX_ITEM_SIZE(info) \
	265	- sizeof(struct btrfs_chunk)) \
	266	/ sizeof(struct btrfs_stripe) + 1)
	267
	268	#define BTRFS_MAX_DEVS_SYS_CHUNK ((BTRFS_SYSTEM_CHUNK_ARRAY_SIZE \
	269	- 2 * sizeof(struct btrfs_disk_key) \
	270	- 2 * sizeof(struct btrfs_chunk)) \
	271	/ sizeof(struct btrfs_stripe) + 1)
	272
	273	/*
	274	* we need the mirror number and stripe index to be passed around
	275	* the call chain while we are processing end_io (especially errors).
	276	* Really, what we need is a btrfs_bio structure that has this info
	277	* and is properly sized with its stripe array, but we're not there
	278	* quite yet. We have our own btrfs bioset, and all of the bios
	279	* we allocate are actually btrfs_io_bios. We'll cram as much of
	280	* struct btrfs_bio as we can into this over time.
	281	*/
	282	struct btrfs_io_bio {
	283	unsigned int mirror_num;
	284	unsigned int stripe_index;
	285	u64 logical;
	286	u8 *csum;
	287	u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
	288	struct bvec_iter iter;
	289	/*
	290	* This member must come last, bio_alloc_bioset will allocate enough
	291	* bytes for entire btrfs_io_bio but relies on bio being last.
	292	*/
	293	struct bio bio;
	294	};
	295
	296	static inline struct btrfs_io_bio btrfs_io_bio(struct bio bio)
	297	{
	298	return container_of(bio, struct btrfs_io_bio, bio);
	299	}
	300
	301	static inline void btrfs_io_bio_free_csum(struct btrfs_io_bio *io_bio)
	302	{
	303	if (io_bio->csum != io_bio->csum_inline) {
	304	kfree(io_bio->csum);
	305	io_bio->csum = NULL;
	306	}
	307	}
	308
	309	struct btrfs_bio_stripe {
	310	struct btrfs_device *dev;
	311	u64 physical;
	312	u64 length; /* only used for discard mappings */
	313	};
	314
	315	struct btrfs_bio {
	316	refcount_t refs;
	317	atomic_t stripes_pending;
	318	struct btrfs_fs_info *fs_info;
	319	u64 map_type; /* get from map_lookup->type */
	320	bio_end_io_t *end_io;
	321	struct bio *orig_bio;
	322	void *private;
	323	atomic_t error;
	324	int max_errors;
	325	int num_stripes;
	326	int mirror_num;
	327	int num_tgtdevs;
	328	int *tgtdev_map;
	329	/*
	330	* logical block numbers for the start of each stripe
	331	* The last one or two are p/q. These are sorted,
	332	* so raid_map[0] is the start of our full stripe
	333	*/
	334	u64 *raid_map;
	335	struct btrfs_bio_stripe stripes[];
	336	};
	337
	338	struct btrfs_device_info {
	339	struct btrfs_device *dev;
	340	u64 dev_offset;
	341	u64 max_avail;
	342	u64 total_avail;
	343	};
	344
	345	struct btrfs_raid_attr {
	346	u8 sub_stripes; /* sub_stripes info for map */
	347	u8 dev_stripes; /* stripes per dev */
	348	u8 devs_max; /* max devs to use */
	349	u8 devs_min; /* min devs needed */
	350	u8 tolerated_failures; /* max tolerated fail devs */
	351	u8 devs_increment; /* ndevs has to be a multiple of this */
	352	u8 ncopies; /* how many copies to data has */
	353	u8 nparity; /* number of stripes worth of bytes to store
	354	* parity information */
	355	u8 mindev_error; /* error code if min devs requisite is unmet */
	356	const char raid_name[8]; /* name of the raid */
	357	u64 bg_flag; /* block group flag of the raid */
	358	};
	359
	360	extern const struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES];
	361
	362	struct map_lookup {
	363	u64 type;
	364	int io_align;
	365	int io_width;
	366	u64 stripe_len;
	367	int num_stripes;
	368	int sub_stripes;
	369	int verified_stripes; /* For mount time dev extent verification */
	370	struct btrfs_bio_stripe stripes[];
	371	};
	372
	373	#define map_lookup_size(n) (sizeof(struct map_lookup) + \
	374	(sizeof(struct btrfs_bio_stripe) * (n)))
	375
	376	struct btrfs_balance_args;
	377	struct btrfs_balance_progress;
	378	struct btrfs_balance_control {
	379	struct btrfs_balance_args data;
	380	struct btrfs_balance_args meta;
	381	struct btrfs_balance_args sys;
	382
	383	u64 flags;
	384
	385	struct btrfs_balance_progress stat;
	386	};
	387
	388	enum btrfs_map_op {
	389	BTRFS_MAP_READ,
	390	BTRFS_MAP_WRITE,
	391	BTRFS_MAP_DISCARD,
	392	BTRFS_MAP_GET_READ_MIRRORS,
	393	};
	394
	395	static inline enum btrfs_map_op btrfs_op(struct bio *bio)
	396	{
	397	switch (bio_op(bio)) {
	398	case REQ_OP_DISCARD:
	399	return BTRFS_MAP_DISCARD;
	400	case REQ_OP_WRITE:
	401	return BTRFS_MAP_WRITE;
	402	default:
	403	WARN_ON_ONCE(1);
	404	/* fall through */
	405	case REQ_OP_READ:
	406	return BTRFS_MAP_READ;
	407	}
	408	}
	409
	410	void btrfs_get_bbio(struct btrfs_bio *bbio);
	411	void btrfs_put_bbio(struct btrfs_bio *bbio);
	412	int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
	413	u64 logical, u64 *length,
	414	struct btrfs_bio **bbio_ret, int mirror_num);
	415	int btrfs_map_sblock(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
	416	u64 logical, u64 *length,
	417	struct btrfs_bio **bbio_ret);
	418	int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
	419	u64 logical, u64 len, struct btrfs_io_geometry *io_geom);
	420	int btrfs_rmap_block(struct btrfs_fs_info *fs_info, u64 chunk_start,
	421	u64 physical, u64 *logical, int naddrs, int *stripe_len);
	422	int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
	423	int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
	424	int btrfs_alloc_chunk(struct btrfs_trans_handle *trans, u64 type);
	425	void btrfs_mapping_tree_free(struct extent_map_tree *tree);
	426	blk_status_t btrfs_map_bio(struct btrfs_fs_info fs_info, struct bio bio,
	427	int mirror_num);
	428	int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
	429	fmode_t flags, void *holder);
	430	struct btrfs_device btrfs_scan_one_device(const char path,
	431	fmode_t flags, void *holder);
	432	int btrfs_forget_devices(const char *path);
	433	int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
	434	void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step);
	435	void btrfs_assign_next_active_device(struct btrfs_device *device,
	436	struct btrfs_device *this_dev);
	437	struct btrfs_device btrfs_find_device_by_devspec(struct btrfs_fs_info fs_info,
	438	u64 devid,
	439	const char *devpath);
	440	struct btrfs_device btrfs_alloc_device(struct btrfs_fs_info fs_info,
	441	const u64 *devid,
	442	const u8 *uuid);
	443	void btrfs_free_device(struct btrfs_device *device);
	444	int btrfs_rm_device(struct btrfs_fs_info *fs_info,
	445	const char *device_path, u64 devid);
	446	void __exit btrfs_cleanup_fs_uuids(void);
	447	int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
	448	int btrfs_grow_device(struct btrfs_trans_handle *trans,
	449	struct btrfs_device *device, u64 new_size);
	450	struct btrfs_device btrfs_find_device(struct btrfs_fs_devices fs_devices,
	451	u64 devid, u8 uuid, u8 fsid, bool seed);
	452	int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
	453	int btrfs_init_new_device(struct btrfs_fs_info fs_info, const char path);
	454	int btrfs_balance(struct btrfs_fs_info *fs_info,
	455	struct btrfs_balance_control *bctl,
	456	struct btrfs_ioctl_balance_args *bargs);
	457	void btrfs_describe_block_groups(u64 flags, char *buf, u32 size_buf);
	458	int btrfs_resume_balance_async(struct btrfs_fs_info *fs_info);
	459	int btrfs_recover_balance(struct btrfs_fs_info *fs_info);
	460	int btrfs_pause_balance(struct btrfs_fs_info *fs_info);
	461	int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
	462	int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
	463	int btrfs_check_uuid_tree(struct btrfs_fs_info *fs_info);
	464	int btrfs_chunk_readonly(struct btrfs_fs_info *fs_info, u64 chunk_offset);
	465	int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
	466	u64 start, u64 max_avail);
	467	void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
	468	int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
	469	struct btrfs_ioctl_get_dev_stats *stats);
	470	void btrfs_init_devices_late(struct btrfs_fs_info *fs_info);
	471	int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
	472	int btrfs_run_dev_stats(struct btrfs_trans_handle *trans);
	473	void btrfs_rm_dev_replace_remove_srcdev(struct btrfs_device *srcdev);
	474	void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev);
	475	void btrfs_destroy_dev_replace_tgtdev(struct btrfs_device *tgtdev);
	476	void btrfs_scratch_superblocks(struct block_device bdev, const char device_path);
	477	int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
	478	u64 logical, u64 len);
	479	unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
	480	u64 logical);
	481	int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
	482	u64 chunk_offset, u64 chunk_size);
	483	int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);
	484	struct extent_map btrfs_get_chunk_map(struct btrfs_fs_info fs_info,
	485	u64 logical, u64 length);
	486
	487	static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
	488	int index)
	489	{
	490	atomic_inc(dev->dev_stat_values + index);
	491	/*
	492	* This memory barrier orders stores updating statistics before stores
	493	* updating dev_stats_ccnt.
	494	*
	495	* It pairs with smp_rmb() in btrfs_run_dev_stats().
	496	*/
	497	smp_mb__before_atomic();
	498	atomic_inc(&dev->dev_stats_ccnt);
	499	}
	500
	501	static inline int btrfs_dev_stat_read(struct btrfs_device *dev,
	502	int index)
	503	{
	504	return atomic_read(dev->dev_stat_values + index);
	505	}
	506
	507	static inline int btrfs_dev_stat_read_and_reset(struct btrfs_device *dev,
	508	int index)
	509	{
	510	int ret;
	511
	512	ret = atomic_xchg(dev->dev_stat_values + index, 0);
	513	/*
	514	* atomic_xchg implies a full memory barriers as per atomic_t.txt:
	515	* - RMW operations that have a return value are fully ordered;
	516	*
	517	* This implicit memory barriers is paired with the smp_rmb in
	518	* btrfs_run_dev_stats
	519	*/
	520	atomic_inc(&dev->dev_stats_ccnt);
	521	return ret;
	522	}
	523
	524	static inline void btrfs_dev_stat_set(struct btrfs_device *dev,
	525	int index, unsigned long val)
	526	{
	527	atomic_set(dev->dev_stat_values + index, val);
	528	/*
	529	* This memory barrier orders stores updating statistics before stores
	530	* updating dev_stats_ccnt.
	531	*
	532	* It pairs with smp_rmb() in btrfs_run_dev_stats().
	533	*/
	534	smp_mb__before_atomic();
	535	atomic_inc(&dev->dev_stats_ccnt);
	536	}
	537
	538	/*
	539	* Convert block group flags (BTRFS_BLOCK_GROUP_*) to btrfs_raid_types, which
	540	* can be used as index to access btrfs_raid_array[].
	541	*/
	542	static inline enum btrfs_raid_types btrfs_bg_flags_to_raid_index(u64 flags)
	543	{
	544	if (flags & BTRFS_BLOCK_GROUP_RAID10)
	545	return BTRFS_RAID_RAID10;
	546	else if (flags & BTRFS_BLOCK_GROUP_RAID1)
	547	return BTRFS_RAID_RAID1;
	548	else if (flags & BTRFS_BLOCK_GROUP_RAID1C3)
	549	return BTRFS_RAID_RAID1C3;
	550	else if (flags & BTRFS_BLOCK_GROUP_RAID1C4)
	551	return BTRFS_RAID_RAID1C4;
	552	else if (flags & BTRFS_BLOCK_GROUP_DUP)
	553	return BTRFS_RAID_DUP;
	554	else if (flags & BTRFS_BLOCK_GROUP_RAID0)
	555	return BTRFS_RAID_RAID0;
	556	else if (flags & BTRFS_BLOCK_GROUP_RAID5)
	557	return BTRFS_RAID_RAID5;
	558	else if (flags & BTRFS_BLOCK_GROUP_RAID6)
	559	return BTRFS_RAID_RAID6;
	560
	561	return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */
	562	}
	563
	564	void btrfs_commit_device_sizes(struct btrfs_transaction *trans);
	565
	566	struct list_head * __attribute_const__ btrfs_get_fs_uuids(void);
	567	void btrfs_set_fs_info_ptr(struct btrfs_fs_info *fs_info);
	568	void btrfs_reset_fs_info_ptr(struct btrfs_fs_info *fs_info);
	569	bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
	570	struct btrfs_device *failing_dev);
	571
	572	int btrfs_bg_type_to_factor(u64 flags);
	573	const char *btrfs_bg_type_to_raid_name(u64 flags);
	574	int btrfs_verify_dev_extents(struct btrfs_fs_info *fs_info);
	575
	576	#endif