linux/fs/btrfs/volumes.h
Chris Mason e17cade25f Btrfs: Add chunk uuids and update multi-device back references
Block headers now store the chunk tree uuid

Chunk items records the device uuid for each stripes

Device extent items record better back refs to the chunk tree

Block groups record better back refs to the chunk tree

The chunk tree format has also changed.  The objectid of BTRFS_CHUNK_ITEM_KEY
used to be the logical offset of the chunk.  Now it is a chunk tree id,
with the logical offset being stored in the offset field of the key.

This allows a single chunk tree to record multiple logical address spaces,
upping the number of bytes indexed by a chunk tree from 2^64 to
2^128.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25 11:04:01 -04:00

123 lines
3.5 KiB
C

/*
* 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>
struct buffer_head;
struct btrfs_device {
struct list_head dev_list;
struct btrfs_root *dev_root;
struct buffer_head *pending_io;
int barriers;
spinlock_t io_lock;
struct block_device *bdev;
u64 total_ios;
char *name;
/* the internal btrfs device id */
u64 devid;
/* size of the device */
u64 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];
};
struct btrfs_fs_devices {
u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
/* the device with this id has the most recent coyp of the super */
u64 latest_devid;
u64 latest_trans;
u64 lowest_devid;
u64 num_devices;
struct block_device *latest_bdev;
struct block_device *lowest_bdev;
struct list_head devices;
struct list_head list;
};
struct btrfs_bio_stripe {
struct btrfs_device *dev;
u64 physical;
};
struct btrfs_multi_bio {
atomic_t stripes_pending;
bio_end_io_t *end_io;
void *private;
int error;
int num_stripes;
struct btrfs_bio_stripe stripes[];
};
#define btrfs_multi_bio_size(n) (sizeof(struct btrfs_multi_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 num_bytes, u64 *start);
int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
u64 logical, u64 *length,
struct btrfs_multi_bio **multi_ret, int mirror_num);
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 *start,
u64 *num_bytes, 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 btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf);
int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
int flags, void *holder);
int btrfs_scan_one_device(const char *path, int flags, void *holder,
struct btrfs_fs_devices **fs_devices_ret);
int btrfs_close_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_cleanup_fs_uuids(void);
int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len);
#endif