release/src-rt-6.x.4708/linux/linux-2.6.36/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 "async-thread.h"
  24
  25 struct buffer_head;
  26 struct btrfs_pending_bios {
  27         struct bio *head;
  28         struct bio *tail;
  29 };
  30
  31 struct btrfs_device {
  32         struct list_head dev_list;
  33         struct list_head dev_alloc_list;
  34         struct btrfs_fs_devices *fs_devices;
  35         struct btrfs_root *dev_root;
  36
  37         /* regular prio bios */
  38         struct btrfs_pending_bios pending_bios;
  39         /* WRITE_SYNC bios */
  40         struct btrfs_pending_bios pending_sync_bios;
  41
  42         int running_pending;
  43         u64 generation;
  44
  45         int barriers;
  46         int writeable;
  47         int in_fs_metadata;
  48
  49         spinlock_t io_lock;
  50
  51         struct block_device *bdev;
  52
  53         /* the mode sent to open_bdev_exclusive */
  54         fmode_t mode;
  55
  56         char *name;
  57
  58         /* the internal btrfs device id */
  59         u64 devid;
  60
  61         /* size of the device */
  62         u64 total_bytes;
  63
  64         /* size of the disk */
  65         u64 disk_total_bytes;
  66
  67         /* bytes used */
  68         u64 bytes_used;
  69
  70         /* optimal io alignment for this device */
  71         u32 io_align;
  72
  73         /* optimal io width for this device */
  74         u32 io_width;
  75
  76         /* minimal io size for this device */
  77         u32 sector_size;
  78
  79         /* type and info about this device */
  80         u64 type;
  81
  82         /* physical drive uuid (or lvm uuid) */
  83         u8 uuid[BTRFS_UUID_SIZE];
  84
  85         struct btrfs_work work;
  86 };
  87
  88 struct btrfs_fs_devices {
  89         u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
  90
  91         /* the device with this id has the most recent copy of the super */
  92         u64 latest_devid;
  93         u64 latest_trans;
  94         u64 num_devices;
  95         u64 open_devices;
  96         u64 rw_devices;
  97         u64 total_rw_bytes;
  98         struct block_device *latest_bdev;
  99
 100         /* all of the devices in the FS, protected by a mutex
 101          * so we can safely walk it to write out the supers without
 102          * worrying about add/remove by the multi-device code
 103          */
 104         struct mutex device_list_mutex;
 105         struct list_head devices;
 106
 107         /* devices not currently being allocated */
 108         struct list_head alloc_list;
 109         struct list_head list;
 110
 111         struct btrfs_fs_devices *seed;
 112         int seeding;
 113
 114         int opened;
 115
 116         /* set when we find or add a device that doesn't have the
 117          * nonrot flag set
 118          */
 119         int rotating;
 120 };
 121
 122 struct btrfs_bio_stripe {
 123         struct btrfs_device *dev;
 124         u64 physical;
 125 };
 126
 127 struct btrfs_multi_bio {
 128         atomic_t stripes_pending;
 129         bio_end_io_t *end_io;
 130         struct bio *orig_bio;
 131         void *private;
 132         atomic_t error;
 133         int max_errors;
 134         int num_stripes;
 135         struct btrfs_bio_stripe stripes[];
 136 };
 137
 138 #define btrfs_multi_bio_size(n) (sizeof(struct btrfs_multi_bio) + \
 139                             (sizeof(struct btrfs_bio_stripe) * (n)))
 140
 141 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
 142                            struct btrfs_device *device,
 143                            u64 chunk_tree, u64 chunk_objectid,
 144                            u64 chunk_offset, u64 start, u64 num_bytes);
 145 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
 146                     u64 logical, u64 *length,
 147                     struct btrfs_multi_bio **multi_ret, int mirror_num);
 148 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
 149                      u64 chunk_start, u64 physical, u64 devid,
 150                      u64 **logical, int *naddrs, int *stripe_len);
 151 int btrfs_read_sys_array(struct btrfs_root *root);
 152 int btrfs_read_chunk_tree(struct btrfs_root *root);
 153 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 154                       struct btrfs_root *extent_root, u64 type);
 155 void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
 156 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
 157 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
 158                   int mirror_num, int async_submit);
 159 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf);
 160 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 161                        fmode_t flags, void *holder);
 162 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 163                           struct btrfs_fs_devices **fs_devices_ret);
 164 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 165 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices);
 166 int btrfs_add_device(struct btrfs_trans_handle *trans,
 167                      struct btrfs_root *root,
 168                      struct btrfs_device *device);
 169 int btrfs_rm_device(struct btrfs_root *root, char *device_path);
 170 int btrfs_cleanup_fs_uuids(void);
 171 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len);
 172 int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
 173                       u64 logical, struct page *page);
 174 int btrfs_grow_device(struct btrfs_trans_handle *trans,
 175                       struct btrfs_device *device, u64 new_size);
 176 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
 177                                        u8 *uuid, u8 *fsid);
 178 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 179 int btrfs_init_new_device(struct btrfs_root *root, char *path);
 180 int btrfs_balance(struct btrfs_root *dev_root);
 181 void btrfs_unlock_volumes(void);
 182 void btrfs_lock_volumes(void);
 183 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
 184 int find_free_dev_extent(struct btrfs_trans_handle *trans,
 185                          struct btrfs_device *device, u64 num_bytes,
 186                          u64 *start, u64 *max_avail);
 187 #endif