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         struct btrfs_work work;
  89 };
  90
  91 struct btrfs_fs_devices {
  92         u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
  93
  94         /* the device with this id has the most recent copy of the super */
  95         u64 latest_devid;
  96         u64 latest_trans;
  97         u64 num_devices;
  98         u64 open_devices;
  99         u64 rw_devices;
 100         u64 missing_devices;
 101         u64 total_rw_bytes;
 102         struct block_device *latest_bdev;
 103
 104         /* all of the devices in the FS, protected by a mutex
 105          * so we can safely walk it to write out the supers without
 106          * worrying about add/remove by the multi-device code
 107          */
 108         struct mutex device_list_mutex;
 109         struct list_head devices;
 110
 111         /* devices not currently being allocated */
 112         struct list_head alloc_list;
 113         struct list_head list;
 114
 115         struct btrfs_fs_devices *seed;
 116         int seeding;
 117
 118         int opened;
 119
 120         /* set when we find or add a device that doesn't have the
 121          * nonrot flag set
 122          */
 123         int rotating;
 124 };
 125
 126 struct btrfs_bio_stripe {
 127         struct btrfs_device *dev;
 128         u64 physical;
 129         u64 length; /* only used for discard mappings */
 130 };
 131
 132 struct btrfs_multi_bio {
 133         atomic_t stripes_pending;
 134         bio_end_io_t *end_io;
 135         struct bio *orig_bio;
 136         void *private;
 137         atomic_t error;
 138         int max_errors;
 139         int num_stripes;
 140         struct btrfs_bio_stripe stripes[];
 141 };
 142
 143 struct btrfs_device_info {
 144         struct btrfs_device *dev;
 145         u64 dev_offset;
 146         u64 max_avail;
 147 };
 148
 149 struct map_lookup {
 150         u64 type;
 151         int io_align;
 152         int io_width;
 153         int stripe_len;
 154         int sector_size;
 155         int num_stripes;
 156         int sub_stripes;
 157         struct btrfs_bio_stripe stripes[];
 158 };
 159
 160 /* Used to sort the devices by max_avail(descending sort) */
 161 int btrfs_cmp_device_free_bytes(const void *dev_info1, const void *dev_info2);
 162
 163 /*
 164  * sort the devices by max_avail, in which max free extent size of each device
 165  * is stored.(Descending Sort)
 166  */
 167 static inline void btrfs_descending_sort_devices(
 168                                         struct btrfs_device_info *devices,
 169                                         size_t nr_devices)
 170 {
 171         sort(devices, nr_devices, sizeof(struct btrfs_device_info),
 172              btrfs_cmp_device_free_bytes, NULL);
 173 }
 174
 175 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
 176                                    u64 end, u64 *length);
 177
 178 #define btrfs_multi_bio_size(n) (sizeof(struct btrfs_multi_bio) + \
 179                             (sizeof(struct btrfs_bio_stripe) * (n)))
 180
 181 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
 182                            struct btrfs_device *device,
 183                            u64 chunk_tree, u64 chunk_objectid,
 184                            u64 chunk_offset, u64 start, u64 num_bytes);
 185 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
 186                     u64 logical, u64 *length,
 187                     struct btrfs_multi_bio **multi_ret, int mirror_num);
 188 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
 189                      u64 chunk_start, u64 physical, u64 devid,
 190                      u64 **logical, int *naddrs, int *stripe_len);
 191 int btrfs_read_sys_array(struct btrfs_root *root);
 192 int btrfs_read_chunk_tree(struct btrfs_root *root);
 193 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 194                       struct btrfs_root *extent_root, u64 type);
 195 void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
 196 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
 197 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
 198                   int mirror_num, int async_submit);
 199 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf);
 200 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 201                        fmode_t flags, void *holder);
 202 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 203                           struct btrfs_fs_devices **fs_devices_ret);
 204 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 205 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices);
 206 int btrfs_add_device(struct btrfs_trans_handle *trans,
 207                      struct btrfs_root *root,
 208                      struct btrfs_device *device);
 209 int btrfs_rm_device(struct btrfs_root *root, char *device_path);
 210 int btrfs_cleanup_fs_uuids(void);
 211 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len);
 212 int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
 213                       u64 logical, struct page *page);
 214 int btrfs_grow_device(struct btrfs_trans_handle *trans,
 215                       struct btrfs_device *device, u64 new_size);
 216 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
 217                                        u8 *uuid, u8 *fsid);
 218 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 219 int btrfs_init_new_device(struct btrfs_root *root, char *path);
 220 int btrfs_balance(struct btrfs_root *dev_root);
 221 void btrfs_unlock_volumes(void);
 222 void btrfs_lock_volumes(void);
 223 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
 224 int find_free_dev_extent(struct btrfs_trans_handle *trans,
 225                          struct btrfs_device *device, u64 num_bytes,
 226                          u64 *start, u64 *max_avail);
 227 #endif