volumes.h

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/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#ifndef __BTRFS_VOLUMES_
#define __BTRFS_VOLUMES_

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

#define BTRFS_STRIPE_LEN    (64 * 1024)

struct buffer_head;
struct btrfs_pending_bios {
    struct bio *head;
    struct bio *tail;
};

struct btrfs_device {
    struct list_head dev_list;
    struct list_head dev_alloc_list;
    struct btrfs_fs_devices *fs_devices;
    struct btrfs_root *dev_root;

    /* regular prio bios */
    struct btrfs_pending_bios pending_bios;
    /* WRITE_SYNC bios */
    struct btrfs_pending_bios pending_sync_bios;

    int running_pending;
    u64 generation;

    int writeable;
    int in_fs_metadata;
    int missing;
    int can_discard;

    spinlock_t io_lock;

    struct block_device *bdev;

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

    struct rcu_string *name;

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

    /* size of the device */
    u64 total_bytes;

    /* size of the 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;

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

    /* type and info about this device */
    u64 type;

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

    /* per-device scrub information */
    struct scrub_dev *scrub_device;

    struct btrfs_work work;
    struct rcu_head rcu;
    struct work_struct rcu_work;

    /* readahead state */
    spinlock_t reada_lock;
    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;

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

    /* disk I/O failure stats. For detailed description refer to
     * enum btrfs_dev_stat_values in ioctl.h */
    int dev_stats_valid;
    int dev_stats_dirty; /* counters need to be written to disk */
    atomic_t dev_stat_values[BTRFS_DEV_STAT_VALUES_MAX];
};

struct btrfs_fs_devices {
    u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */

    /* the device with this id has the most recent copy of the super */
    u64 latest_devid;
    u64 latest_trans;
    u64 num_devices;
    u64 open_devices;
    u64 rw_devices;
    u64 missing_devices;
    u64 total_rw_bytes;
    u64 num_can_discard;
    u64 total_devices;
    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
     */
    struct mutex device_list_mutex;
    struct list_head devices;

    /* devices not currently being allocated */
    struct list_head alloc_list;
    struct list_head list;

    struct btrfs_fs_devices *seed;
    int seeding;

    int opened;

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

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

struct btrfs_bio;
typedef void (btrfs_bio_end_io_t) (struct btrfs_bio *bio, int err);

struct btrfs_bio {
    atomic_t stripes_pending;
    bio_end_io_t *end_io;
    struct bio *orig_bio;
    void *private;
    atomic_t error;
    int max_errors;
    int num_stripes;
    int mirror_num;
    struct btrfs_bio_stripe stripes[];
};

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

struct map_lookup {
    u64 type;
    int io_align;
    int io_width;
    int stripe_len;
    int sector_size;
    int num_stripes;
    int sub_stripes;
    struct btrfs_bio_stripe stripes[];
};

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

/*
 * Restriper's general type filter
 */
#define BTRFS_BALANCE_DATA      (1ULL << 0)
#define BTRFS_BALANCE_SYSTEM        (1ULL << 1)
#define BTRFS_BALANCE_METADATA      (1ULL << 2)

#define BTRFS_BALANCE_TYPE_MASK     (BTRFS_BALANCE_DATA |       \
                     BTRFS_BALANCE_SYSTEM |     \
                     BTRFS_BALANCE_METADATA)

#define BTRFS_BALANCE_FORCE     (1ULL << 3)
#define BTRFS_BALANCE_RESUME        (1ULL << 4)

/*
 * Balance filters
 */
#define BTRFS_BALANCE_ARGS_PROFILES (1ULL << 0)
#define BTRFS_BALANCE_ARGS_USAGE    (1ULL << 1)
#define BTRFS_BALANCE_ARGS_DEVID    (1ULL << 2)
#define BTRFS_BALANCE_ARGS_DRANGE   (1ULL << 3)
#define BTRFS_BALANCE_ARGS_VRANGE   (1ULL << 4)

/*
 * Profile changing flags.  When SOFT is set we won't relocate chunk if
 * it already has the target profile (even though it may be
 * half-filled).
 */
#define BTRFS_BALANCE_ARGS_CONVERT  (1ULL << 8)
#define BTRFS_BALANCE_ARGS_SOFT     (1ULL << 9)

struct btrfs_balance_args;
struct btrfs_balance_progress;
struct btrfs_balance_control {
    struct btrfs_fs_info *fs_info;

    struct btrfs_balance_args data;
    struct btrfs_balance_args meta;
    struct btrfs_balance_args sys;

    u64 flags;

    struct btrfs_balance_progress stat;
};

int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
                   u64 end, u64 *length);

#define btrfs_bio_size(n) (sizeof(struct btrfs_bio) + \
                (sizeof(struct btrfs_bio_stripe) * (n)))

int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
               struct btrfs_device *device,
               u64 chunk_tree, u64 chunk_objectid,
               u64 chunk_offset, u64 start, u64 num_bytes);
int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
            u64 logical, u64 *length,
            struct btrfs_bio **bbio_ret, int mirror_num);
int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
             u64 chunk_start, u64 physical, u64 devid,
             u64 **logical, int *naddrs, int *stripe_len);
int btrfs_read_sys_array(struct btrfs_root *root);
int btrfs_read_chunk_tree(struct btrfs_root *root);
int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
              struct btrfs_root *extent_root, u64 type);
void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
          int mirror_num, int async_submit);
int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
               fmode_t flags, void *holder);
int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
              struct btrfs_fs_devices **fs_devices_ret);
int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices);
int btrfs_add_device(struct btrfs_trans_handle *trans,
             struct btrfs_root *root,
             struct btrfs_device *device);
int btrfs_rm_device(struct btrfs_root *root, char *device_path);
void btrfs_cleanup_fs_uuids(void);
int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, 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_root *root, u64 devid,
                       u8 *uuid, u8 *fsid);
int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
int btrfs_init_new_device(struct btrfs_root *root, char *path);
int btrfs_balance(struct btrfs_balance_control *bctl,
          struct btrfs_ioctl_balance_args *bargs);
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_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
int find_free_dev_extent(struct btrfs_device *device, u64 num_bytes,
             u64 *start, u64 *max_avail);
void btrfs_dev_stat_print_on_error(struct btrfs_device *device);
void btrfs_dev_stat_inc_and_print(struct btrfs_device *dev, int index);
int btrfs_get_dev_stats(struct btrfs_root *root,
            struct btrfs_ioctl_get_dev_stats *stats);
int btrfs_init_dev_stats(struct btrfs_fs_info *fs_info);
int btrfs_run_dev_stats(struct btrfs_trans_handle *trans,
            struct btrfs_fs_info *fs_info);

static inline void btrfs_dev_stat_inc(struct btrfs_device *dev,
                      int index)
{
    atomic_inc(dev->dev_stat_values + index);
    dev->dev_stats_dirty = 1;
}

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);
    dev->dev_stats_dirty = 1;
    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);
    dev->dev_stats_dirty = 1;
}

static inline void btrfs_dev_stat_reset(struct btrfs_device *dev,
                    int index)
{
    btrfs_dev_stat_set(dev, index, 0);
}
#endif