linuxdebug/fs/btrfs/volumes.h

763 lines
22 KiB
C

/* 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
/* Used by sanity check for btrfs_raid_types. */
#define const_ffs(n) (__builtin_ctzll(n) + 1)
/*
* The conversion from BTRFS_BLOCK_GROUP_* bits to btrfs_raid_type requires
* RAID0 always to be the lowest profile bit.
* Although it's part of on-disk format and should never change, do extra
* compile-time sanity checks.
*/
static_assert(const_ffs(BTRFS_BLOCK_GROUP_RAID0) <
const_ffs(BTRFS_BLOCK_GROUP_PROFILE_MASK & ~BTRFS_BLOCK_GROUP_RAID0));
static_assert(const_ilog2(BTRFS_BLOCK_GROUP_RAID0) >
ilog2(BTRFS_BLOCK_GROUP_TYPE_MASK));
/* ilog2() can handle both constants and variables */
#define BTRFS_BG_FLAG_TO_INDEX(profile) \
ilog2((profile) >> (ilog2(BTRFS_BLOCK_GROUP_RAID0) - 1))
enum btrfs_raid_types {
/* SINGLE is the special one as it doesn't have on-disk bit. */
BTRFS_RAID_SINGLE = 0,
BTRFS_RAID_RAID0 = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID0),
BTRFS_RAID_RAID1 = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID1),
BTRFS_RAID_DUP = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_DUP),
BTRFS_RAID_RAID10 = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID10),
BTRFS_RAID_RAID5 = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID5),
BTRFS_RAID_RAID6 = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID6),
BTRFS_RAID_RAID1C3 = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID1C3),
BTRFS_RAID_RAID1C4 = BTRFS_BG_FLAG_TO_INDEX(BTRFS_BLOCK_GROUP_RAID1C4),
BTRFS_NR_RAID_TYPES
};
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 */
u32 stripe_len;
/* offset of address in stripe */
u32 stripe_offset;
/* number of stripe where address falls */
u64 stripe_nr;
/* 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)
#define BTRFS_DEV_STATE_NO_READA (5)
struct btrfs_zoned_device_info;
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 __rcu *name;
u64 generation;
struct block_device *bdev;
struct btrfs_zoned_device_info *zone_info;
/* the mode sent to blkdev_get */
fmode_t mode;
/*
* Device's major-minor number. Must be set even if the device is not
* opened (bdev == NULL), unless the device is missing.
*/
dev_t devt;
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;
/* Bio used for flushing device barriers */
struct bio flush_bio;
struct completion flush_wait;
/* per-device scrub information */
struct scrub_ctx *scrub_ctx;
/* 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;
struct completion kobj_unregister;
/* For sysfs/FSID/devinfo/devid/ */
struct kobject devid_kobj;
/* Bandwidth limit for scrub, in bytes */
u64 scrub_speed_max;
};
/*
* Block group or device which contains an active swapfile. Used for preventing
* unsafe operations while a swapfile is active.
*
* These are sorted on (ptr, inode) (note that a block group or device can
* contain more than one swapfile). We compare the pointer values because we
* don't actually care what the object is, we just need a quick check whether
* the object exists in the rbtree.
*/
struct btrfs_swapfile_pin {
struct rb_node node;
void *ptr;
struct inode *inode;
/*
* If true, ptr points to a struct btrfs_block_group. Otherwise, ptr
* points to a struct btrfs_device.
*/
bool is_block_group;
/*
* Only used when 'is_block_group' is true and it is the number of
* extents used by a swapfile for this block group ('ptr' field).
*/
int bg_extent_count;
};
/*
* 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_PREEMPTION)
#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);
enum btrfs_chunk_allocation_policy {
BTRFS_CHUNK_ALLOC_REGULAR,
BTRFS_CHUNK_ALLOC_ZONED,
};
/*
* Read policies for mirrored block group profiles, read picks the stripe based
* on these policies.
*/
enum btrfs_read_policy {
/* Use process PID to choose the stripe */
BTRFS_READ_POLICY_PID,
BTRFS_NR_READ_POLICY,
};
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;
/*
* Number of devices under this fsid including missing and
* replace-target device and excludes seed devices.
*/
u64 num_devices;
/*
* The number of devices that successfully opened, including
* replace-target, excludes seed devices.
*/
u64 open_devices;
/* The number of devices that are under the chunk allocation list. */
u64 rw_devices;
/* Count of missing devices under this fsid excluding seed device. */
u64 missing_devices;
u64 total_rw_bytes;
/*
* Count of devices from btrfs_super_block::num_devices for this fsid,
* which includes the seed device, excludes the transient replace-target
* device.
*/
u64 total_devices;
/* Highest generation number of seen devices */
u64 latest_generation;
/*
* The mount device or a device with highest generation after removal
* or replace.
*/
struct btrfs_device *latest_dev;
/* 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 list_head seed_list;
bool seeding;
int opened;
/* set when we find or add a device that doesn't have the
* nonrot flag set
*/
bool rotating;
struct btrfs_fs_info *fs_info;
/* sysfs kobjects */
struct kobject fsid_kobj;
struct kobject *devices_kobj;
struct kobject *devinfo_kobj;
struct completion kobj_unregister;
enum btrfs_chunk_allocation_policy chunk_alloc_policy;
/* Policy used to read the mirrored stripes */
enum btrfs_read_policy read_policy;
};
#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)
/*
* Maximum number of sectors for a single bio to limit the size of the
* checksum array. This matches the number of bio_vecs per bio and thus the
* I/O size for buffered I/O.
*/
#define BTRFS_MAX_BIO_SECTORS (256)
typedef void (*btrfs_bio_end_io_t)(struct btrfs_bio *bbio);
/*
* Additional info to pass along bio.
*
* Mostly for btrfs specific features like csum and mirror_num.
*/
struct btrfs_bio {
unsigned int mirror_num;
struct bvec_iter iter;
/* for direct I/O */
u64 file_offset;
/* @device is for stripe IO submission. */
struct btrfs_device *device;
u8 *csum;
u8 csum_inline[BTRFS_BIO_INLINE_CSUM_SIZE];
/* End I/O information supplied to btrfs_bio_alloc */
btrfs_bio_end_io_t end_io;
void *private;
/* For read end I/O handling */
struct work_struct end_io_work;
/*
* This member must come last, bio_alloc_bioset will allocate enough
* bytes for entire btrfs_bio but relies on bio being last.
*/
struct bio bio;
};
static inline struct btrfs_bio *btrfs_bio(struct bio *bio)
{
return container_of(bio, struct btrfs_bio, bio);
}
int __init btrfs_bioset_init(void);
void __cold btrfs_bioset_exit(void);
struct bio *btrfs_bio_alloc(unsigned int nr_vecs, blk_opf_t opf,
btrfs_bio_end_io_t end_io, void *private);
struct bio *btrfs_bio_clone_partial(struct bio *orig, u64 offset, u64 size,
btrfs_bio_end_io_t end_io, void *private);
static inline void btrfs_bio_end_io(struct btrfs_bio *bbio, blk_status_t status)
{
bbio->bio.bi_status = status;
bbio->end_io(bbio);
}
static inline void btrfs_bio_free_csum(struct btrfs_bio *bbio)
{
if (bbio->csum != bbio->csum_inline) {
kfree(bbio->csum);
bbio->csum = NULL;
}
}
/*
* Iterate through a btrfs_bio (@bbio) on a per-sector basis.
*
* bvl - struct bio_vec
* bbio - struct btrfs_bio
* iters - struct bvec_iter
* bio_offset - unsigned int
*/
#define btrfs_bio_for_each_sector(fs_info, bvl, bbio, iter, bio_offset) \
for ((iter) = (bbio)->iter, (bio_offset) = 0; \
(iter).bi_size && \
(((bvl) = bio_iter_iovec((&(bbio)->bio), (iter))), 1); \
(bio_offset) += fs_info->sectorsize, \
bio_advance_iter_single(&(bbio)->bio, &(iter), \
(fs_info)->sectorsize))
struct btrfs_io_stripe {
struct btrfs_device *dev;
union {
/* Block mapping */
u64 physical;
/* For the endio handler */
struct btrfs_io_context *bioc;
};
};
struct btrfs_discard_stripe {
struct btrfs_device *dev;
u64 physical;
u64 length;
};
/*
* Context for IO subsmission for device stripe.
*
* - Track the unfinished mirrors for mirror based profiles
* Mirror based profiles are SINGLE/DUP/RAID1/RAID10.
*
* - Contain the logical -> physical mapping info
* Used by submit_stripe_bio() for mapping logical bio
* into physical device address.
*
* - Contain device replace info
* Used by handle_ops_on_dev_replace() to copy logical bios
* into the new device.
*
* - Contain RAID56 full stripe logical bytenrs
*/
struct btrfs_io_context {
refcount_t refs;
struct btrfs_fs_info *fs_info;
u64 map_type; /* get from map_lookup->type */
struct bio *orig_bio;
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_io_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;
u32 stripe_len;
int num_stripes;
int sub_stripes;
int verified_stripes; /* For mount time dev extent verification */
struct btrfs_io_stripe stripes[];
};
#define map_lookup_size(n) (sizeof(struct map_lookup) + \
(sizeof(struct btrfs_io_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;
};
/*
* Search for a given device by the set parameters
*/
struct btrfs_dev_lookup_args {
u64 devid;
u8 *uuid;
u8 *fsid;
bool missing;
};
/* We have to initialize to -1 because BTRFS_DEV_REPLACE_DEVID is 0 */
#define BTRFS_DEV_LOOKUP_ARGS_INIT { .devid = (u64)-1 }
#define BTRFS_DEV_LOOKUP_ARGS(name) \
struct btrfs_dev_lookup_args name = BTRFS_DEV_LOOKUP_ARGS_INIT
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:
case REQ_OP_ZONE_APPEND:
return BTRFS_MAP_WRITE;
default:
WARN_ON_ONCE(1);
fallthrough;
case REQ_OP_READ:
return BTRFS_MAP_READ;
}
}
void btrfs_get_bioc(struct btrfs_io_context *bioc);
void btrfs_put_bioc(struct btrfs_io_context *bioc);
int btrfs_map_block(struct btrfs_fs_info *fs_info, enum btrfs_map_op op,
u64 logical, u64 *length,
struct btrfs_io_context **bioc_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_io_context **bioc_ret);
struct btrfs_discard_stripe *btrfs_map_discard(struct btrfs_fs_info *fs_info,
u64 logical, u64 *length_ret,
u32 *num_stripes);
int btrfs_get_io_geometry(struct btrfs_fs_info *fs_info, struct extent_map *map,
enum btrfs_map_op op, u64 logical,
struct btrfs_io_geometry *io_geom);
int btrfs_read_sys_array(struct btrfs_fs_info *fs_info);
int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info);
struct btrfs_block_group *btrfs_create_chunk(struct btrfs_trans_handle *trans,
u64 type);
void btrfs_mapping_tree_free(struct extent_map_tree *tree);
void btrfs_submit_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(dev_t devt);
void btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices);
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);
int btrfs_get_dev_args_from_path(struct btrfs_fs_info *fs_info,
struct btrfs_dev_lookup_args *args,
const char *path);
struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
const u64 *devid,
const u8 *uuid);
void btrfs_put_dev_args_from_path(struct btrfs_dev_lookup_args *args);
void btrfs_free_device(struct btrfs_device *device);
int btrfs_rm_device(struct btrfs_fs_info *fs_info,
struct btrfs_dev_lookup_args *args,
struct block_device **bdev, fmode_t *mode);
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(const struct btrfs_fs_devices *fs_devices,
const struct btrfs_dev_lookup_args *args);
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_relocate_chunk(struct btrfs_fs_info *fs_info, u64 chunk_offset);
int btrfs_cancel_balance(struct btrfs_fs_info *fs_info);
int btrfs_create_uuid_tree(struct btrfs_fs_info *fs_info);
int btrfs_uuid_scan_kthread(void *data);
bool btrfs_chunk_writeable(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);
int 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);
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);
u64 btrfs_calc_stripe_length(const struct extent_map *em);
int btrfs_nr_parity_stripes(u64 type);
int btrfs_chunk_alloc_add_chunk_item(struct btrfs_trans_handle *trans,
struct btrfs_block_group *bg);
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);
void btrfs_release_disk_super(struct btrfs_super_block *super);
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);
}
void btrfs_commit_device_sizes(struct btrfs_transaction *trans);
struct list_head * __attribute_const__ btrfs_get_fs_uuids(void);
bool btrfs_check_rw_degradable(struct btrfs_fs_info *fs_info,
struct btrfs_device *failing_dev);
void btrfs_scratch_superblocks(struct btrfs_fs_info *fs_info,
struct block_device *bdev,
const char *device_path);
enum btrfs_raid_types __attribute_const__ btrfs_bg_flags_to_raid_index(u64 flags);
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);
bool btrfs_repair_one_zone(struct btrfs_fs_info *fs_info, u64 logical);
bool btrfs_pinned_by_swapfile(struct btrfs_fs_info *fs_info, void *ptr);
u8 *btrfs_sb_fsid_ptr(struct btrfs_super_block *sb);
#endif