fs/btrfs/volumes.h

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #ifndef __BTRFS_VOLUMES_
  20 #define __BTRFS_VOLUMES_
  21
  22 #include <linux/bio.h>
  23 #include <linux/sort.h>
  24 #include "async-thread.h"
  25
  26 #define BTRFS_STRIPE_LEN        (64 * 1024)
  27
  28 struct buffer_head;
  29 struct btrfs_pending_bios {
  30         struct bio *head;
  31         struct bio *tail;
  32 };
  33
  34 struct btrfs_device {
  35         struct list_head dev_list;
  36         struct list_head dev_alloc_list;
  37         struct btrfs_fs_devices *fs_devices;
  38         struct btrfs_root *dev_root;
  39
  40         /* regular prio bios */
  41         struct btrfs_pending_bios pending_bios;
  42         /* WRITE_SYNC bios */
  43         struct btrfs_pending_bios pending_sync_bios;
  44
  45         int running_pending;
  46         u64 generation;
  47
  48         int writeable;
  49         int in_fs_metadata;
  50         int missing;
  51
  52         spinlock_t io_lock;
  53
  54         struct block_device *bdev;
  55
  56         /* the mode sent to blkdev_get */
  57         fmode_t mode;
  58
  59         char *name;
  60
  61         /* the internal btrfs device id */
  62         u64 devid;
  63
  64         /* size of the device */
  65         u64 total_bytes;
  66
  67         /* size of the disk */
  68         u64 disk_total_bytes;
  69
  70         /* bytes used */
  71         u64 bytes_used;
  72
  73         /* optimal io alignment for this device */
  74         u32 io_align;
  75
  76         /* optimal io width for this device */
  77         u32 io_width;
  78
  79         /* minimal io size for this device */
  80         u32 sector_size;
  81
  82         /* type and info about this device */
  83         u64 type;
  84
  85         /* physical drive uuid (or lvm uuid) */
  86         u8 uuid[BTRFS_UUID_SIZE];
  87
  88         /* per-device scrub information */
  89         struct scrub_dev *scrub_device;
  90
  91         struct btrfs_work work;
  92         struct rcu_head rcu;
  93         struct work_struct rcu_work;
  94 };
  95
  96 struct btrfs_fs_devices {
  97         u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
  98
  99         /* the device with this id has the most recent copy of the super */
 100         u64 latest_devid;
 101         u64 latest_trans;
 102         u64 num_devices;
 103         u64 open_devices;
 104         u64 rw_devices;
 105         u64 missing_devices;
 106         u64 total_rw_bytes;
 107         struct block_device *latest_bdev;
 108
 109         /* all of the devices in the FS, protected by a mutex
 110          * so we can safely walk it to write out the supers without
 111          * worrying about add/remove by the multi-device code
 112          */
 113         struct mutex device_list_mutex;
 114         struct list_head devices;
 115
 116         /* devices not currently being allocated */
 117         struct list_head alloc_list;
 118         struct list_head list;
 119
 120         struct btrfs_fs_devices *seed;
 121         int seeding;
 122
 123         int opened;
 124
 125         /* set when we find or add a device that doesn't have the
 126          * nonrot flag set
 127          */
 128         int rotating;
 129 };
 130
 131 struct btrfs_bio_stripe {
 132         struct btrfs_device *dev;
 133         u64 physical;
 134         u64 length; /* only used for discard mappings */
 135 };
 136
 137 struct btrfs_multi_bio {
 138         atomic_t stripes_pending;
 139         bio_end_io_t *end_io;
 140         struct bio *orig_bio;
 141         void *private;
 142         atomic_t error;
 143         int max_errors;
 144         int num_stripes;
 145         struct btrfs_bio_stripe stripes[];
 146 };
 147
 148 struct btrfs_device_info {
 149         struct btrfs_device *dev;
 150         u64 dev_offset;
 151         u64 max_avail;
 152         u64 total_avail;
 153 };
 154
 155 struct map_lookup {
 156         u64 type;
 157         int io_align;
 158         int io_width;
 159         int stripe_len;
 160         int sector_size;
 161         int num_stripes;
 162         int sub_stripes;
 163         struct btrfs_bio_stripe stripes[];
 164 };
 165
 166 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
 167                             (sizeof(struct btrfs_bio_stripe) * (n)))
 168
 169 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
 170                                    u64 end, u64 *length);
 171
 172 #define btrfs_multi_bio_size(n) (sizeof(struct btrfs_multi_bio) + \
 173                             (sizeof(struct btrfs_bio_stripe) * (n)))
 174
 175 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
 176                            struct btrfs_device *device,
 177                            u64 chunk_tree, u64 chunk_objectid,
 178                            u64 chunk_offset, u64 start, u64 num_bytes);
 179 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
 180                     u64 logical, u64 *length,
 181                     struct btrfs_multi_bio **multi_ret, int mirror_num);
 182 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
 183                      u64 chunk_start, u64 physical, u64 devid,
 184                      u64 **logical, int *naddrs, int *stripe_len);
 185 int btrfs_read_sys_array(struct btrfs_root *root);
 186 int btrfs_read_chunk_tree(struct btrfs_root *root);
 187 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 188                       struct btrfs_root *extent_root, u64 type);
 189 void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
 190 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
 191 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
 192                   int mirror_num, int async_submit);
 193 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 194                        fmode_t flags, void *holder);
 195 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 196                           struct btrfs_fs_devices **fs_devices_ret);
 197 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 198 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices);
 199 int btrfs_add_device(struct btrfs_trans_handle *trans,
 200                      struct btrfs_root *root,
 201                      struct btrfs_device *device);
 202 int btrfs_rm_device(struct btrfs_root *root, char *device_path);
 203 int btrfs_cleanup_fs_uuids(void);
 204 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len);
 205 int btrfs_grow_device(struct btrfs_trans_handle *trans,
 206                       struct btrfs_device *device, u64 new_size);
 207 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
 208                                        u8 *uuid, u8 *fsid);
 209 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 210 int btrfs_init_new_device(struct btrfs_root *root, char *path);
 211 int btrfs_balance(struct btrfs_root *dev_root);
 212 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
 213 int find_free_dev_extent(struct btrfs_trans_handle *trans,
 214                          struct btrfs_device *device, u64 num_bytes,
 215                          u64 *start, u64 *max_avail);
 216 #endif