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         int can_discard;
  52
  53         spinlock_t io_lock;
  54
  55         struct block_device *bdev;
  56
  57         /* the mode sent to blkdev_get */
  58         fmode_t mode;
  59
  60         char *name;
  61
  62         /* the internal btrfs device id */
  63         u64 devid;
  64
  65         /* size of the device */
  66         u64 total_bytes;
  67
  68         /* size of the disk */
  69         u64 disk_total_bytes;
  70
  71         /* bytes used */
  72         u64 bytes_used;
  73
  74         /* optimal io alignment for this device */
  75         u32 io_align;
  76
  77         /* optimal io width for this device */
  78         u32 io_width;
  79
  80         /* minimal io size for this device */
  81         u32 sector_size;
  82
  83         /* type and info about this device */
  84         u64 type;
  85
  86         /* physical drive uuid (or lvm uuid) */
  87         u8 uuid[BTRFS_UUID_SIZE];
  88
  89         /* per-device scrub information */
  90         struct scrub_dev *scrub_device;
  91
  92         struct btrfs_work work;
  93         struct rcu_head rcu;
  94         struct work_struct rcu_work;
  95 };
  96
  97 struct btrfs_fs_devices {
  98         u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
  99
 100         /* the device with this id has the most recent copy of the super */
 101         u64 latest_devid;
 102         u64 latest_trans;
 103         u64 num_devices;
 104         u64 open_devices;
 105         u64 rw_devices;
 106         u64 missing_devices;
 107         u64 total_rw_bytes;
 108         u64 num_can_discard;
 109         struct block_device *latest_bdev;
 110
 111         /* all of the devices in the FS, protected by a mutex
 112          * so we can safely walk it to write out the supers without
 113          * worrying about add/remove by the multi-device code
 114          */
 115         struct mutex device_list_mutex;
 116         struct list_head devices;
 117
 118         /* devices not currently being allocated */
 119         struct list_head alloc_list;
 120         struct list_head list;
 121
 122         struct btrfs_fs_devices *seed;
 123         int seeding;
 124
 125         int opened;
 126
 127         /* set when we find or add a device that doesn't have the
 128          * nonrot flag set
 129          */
 130         int rotating;
 131 };
 132
 133 struct btrfs_bio_stripe {
 134         struct btrfs_device *dev;
 135         u64 physical;
 136         u64 length; /* only used for discard mappings */
 137 };
 138
 139 struct btrfs_multi_bio {
 140         atomic_t stripes_pending;
 141         bio_end_io_t *end_io;
 142         struct bio *orig_bio;
 143         void *private;
 144         atomic_t error;
 145         int max_errors;
 146         int num_stripes;
 147         struct btrfs_bio_stripe stripes[];
 148 };
 149
 150 struct btrfs_device_info {
 151         struct btrfs_device *dev;
 152         u64 dev_offset;
 153         u64 max_avail;
 154         u64 total_avail;
 155 };
 156
 157 struct map_lookup {
 158         u64 type;
 159         int io_align;
 160         int io_width;
 161         int stripe_len;
 162         int sector_size;
 163         int num_stripes;
 164         int sub_stripes;
 165         struct btrfs_bio_stripe stripes[];
 166 };
 167
 168 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
 169                             (sizeof(struct btrfs_bio_stripe) * (n)))
 170
 171 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
 172                                    u64 end, u64 *length);
 173
 174 #define btrfs_multi_bio_size(n) (sizeof(struct btrfs_multi_bio) + \
 175                             (sizeof(struct btrfs_bio_stripe) * (n)))
 176
 177 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
 178                            struct btrfs_device *device,
 179                            u64 chunk_tree, u64 chunk_objectid,
 180                            u64 chunk_offset, u64 start, u64 num_bytes);
 181 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
 182                     u64 logical, u64 *length,
 183                     struct btrfs_multi_bio **multi_ret, int mirror_num);
 184 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
 185                      u64 chunk_start, u64 physical, u64 devid,
 186                      u64 **logical, int *naddrs, int *stripe_len);
 187 int btrfs_read_sys_array(struct btrfs_root *root);
 188 int btrfs_read_chunk_tree(struct btrfs_root *root);
 189 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 190                       struct btrfs_root *extent_root, u64 type);
 191 void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
 192 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
 193 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
 194                   int mirror_num, int async_submit);
 195 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 196                        fmode_t flags, void *holder);
 197 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 198                           struct btrfs_fs_devices **fs_devices_ret);
 199 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 200 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices);
 201 int btrfs_add_device(struct btrfs_trans_handle *trans,
 202                      struct btrfs_root *root,
 203                      struct btrfs_device *device);
 204 int btrfs_rm_device(struct btrfs_root *root, char *device_path);
 205 int btrfs_cleanup_fs_uuids(void);
 206 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len);
 207 int btrfs_grow_device(struct btrfs_trans_handle *trans,
 208                       struct btrfs_device *device, u64 new_size);
 209 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
 210                                        u8 *uuid, u8 *fsid);
 211 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 212 int btrfs_init_new_device(struct btrfs_root *root, char *path);
 213 int btrfs_balance(struct btrfs_root *dev_root);
 214 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
 215 int find_free_dev_extent(struct btrfs_trans_handle *trans,
 216                          struct btrfs_device *device, u64 num_bytes,
 217                          u64 *start, u64 *max_avail);
 218 #endif