fs/btrfs/volumes.h - linux - Git at Google

 /*
  * 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>
 #include <linux/sort.h>
 #include "async-thread.h"

 #define BTRFS_STRIPE_LEN	(64 * 1024)

 struct buffer_head;
 struct btrfs_pending_bios {
 	struct bio *head;
 	struct bio *tail;
 };

 struct btrfs_device {
 	struct list_head dev_list;
 	struct list_head dev_alloc_list;
 	struct btrfs_fs_devices *fs_devices;
 	struct btrfs_root *dev_root;

 	/* regular prio bios */
 	struct btrfs_pending_bios pending_bios;
 	/* WRITE_SYNC bios */
 	struct btrfs_pending_bios pending_sync_bios;

 	int running_pending;
 	u64 generation;

 	int writeable;
 	int in_fs_metadata;
 	int missing;

 	spinlock_t io_lock;

 	struct block_device *bdev;

 	/* the mode sent to blkdev_get */
 	fmode_t mode;

 	char *name;

 	/* the internal btrfs device id */
 	u64 devid;

 	/* size of the device */
 	u64 total_bytes;

 	/* size of the disk */
 	u64 disk_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];

 	/* per-device scrub information */
 	struct scrub_dev *scrub_device;

 	struct btrfs_work work;
 };

 struct btrfs_fs_devices {
 	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */

 	/* the device with this id has the most recent copy of the super */
 	u64 latest_devid;
 	u64 latest_trans;
 	u64 num_devices;
 	u64 open_devices;
 	u64 rw_devices;
 	u64 missing_devices;
 	u64 total_rw_bytes;
 	struct block_device *latest_bdev;

 	/* all of the devices in the FS, protected by a mutex
 	 * so we can safely walk it to write out the supers without
 	 * worrying about add/remove by the multi-device code
 	 */
 	struct mutex device_list_mutex;
 	struct list_head devices;

 	/* devices not currently being allocated */
 	struct list_head alloc_list;
 	struct list_head list;

 	struct btrfs_fs_devices *seed;
 	int seeding;

 	int opened;

 	/* set when we find or add a device that doesn't have the
 	 * nonrot flag set
 	 */
 	int rotating;
 };

 struct btrfs_bio_stripe {
 	struct btrfs_device *dev;
 	u64 physical;
 	u64 length; /* only used for discard mappings */
 };

 struct btrfs_multi_bio {
 	atomic_t stripes_pending;
 	bio_end_io_t *end_io;
 	struct bio *orig_bio;
 	void *private;
 	atomic_t error;
 	int max_errors;
 	int num_stripes;
 	struct btrfs_bio_stripe stripes[];
 };

 struct btrfs_device_info {
 	struct btrfs_device *dev;
 	u64 dev_offset;
 	u64 max_avail;
 };

 struct map_lookup {
 	u64 type;
 	int io_align;
 	int io_width;
 	int stripe_len;
 	int sector_size;
 	int num_stripes;
 	int sub_stripes;
 	struct btrfs_bio_stripe stripes[];
 };

 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
 			    (sizeof(struct btrfs_bio_stripe) * (n)))

 /* Used to sort the devices by max_avail(descending sort) */
 int btrfs_cmp_device_free_bytes(const void *dev_info1, const void *dev_info2);

 /*
  * sort the devices by max_avail, in which max free extent size of each device
  * is stored.(Descending Sort)
  */
 static inline void btrfs_descending_sort_devices(
 					struct btrfs_device_info *devices,
 					size_t nr_devices)
 {
 	sort(devices, nr_devices, sizeof(struct btrfs_device_info),
 	     btrfs_cmp_device_free_bytes, NULL);
 }

 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
 				   u64 end, u64 *length);

 #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 start, u64 num_bytes);
 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_rmap_block(struct btrfs_mapping_tree *map_tree,
 		     u64 chunk_start, u64 physical, u64 devid,
 		     u64 **logical, int *naddrs, int *stripe_len);
 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 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 async_submit);
 int btrfs_read_super_device(struct btrfs_root *root, struct extent_buffer *buf);
 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
 		       fmode_t flags, void *holder);
 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
 			  struct btrfs_fs_devices **fs_devices_ret);
 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
 int btrfs_close_extra_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_rm_device(struct btrfs_root *root, char *device_path);
 int btrfs_cleanup_fs_uuids(void);
 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len);
 int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
 		      u64 logical, struct page *page);
 int btrfs_grow_device(struct btrfs_trans_handle *trans,
 		      struct btrfs_device *device, u64 new_size);
 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
 				       u8 *uuid, u8 *fsid);
 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 int btrfs_init_new_device(struct btrfs_root *root, char *path);
 int btrfs_balance(struct btrfs_root *dev_root);
 void btrfs_unlock_volumes(void);
 void btrfs_lock_volumes(void);
 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
 int find_free_dev_extent(struct btrfs_trans_handle *trans,
 			 struct btrfs_device *device, u64 num_bytes,
 			 u64 *start, u64 *max_avail);
 #endif
	/*
	* 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>
	#include <linux/sort.h>
	#include "async-thread.h"

	#define BTRFS_STRIPE_LEN (64 * 1024)

	struct buffer_head;
	struct btrfs_pending_bios {
	struct bio *head;
	struct bio *tail;
	};

	struct btrfs_device {
	struct list_head dev_list;
	struct list_head dev_alloc_list;
	struct btrfs_fs_devices *fs_devices;
	struct btrfs_root *dev_root;

	/* regular prio bios */
	struct btrfs_pending_bios pending_bios;
	/* WRITE_SYNC bios */
	struct btrfs_pending_bios pending_sync_bios;

	int running_pending;
	u64 generation;

	int writeable;
	int in_fs_metadata;
	int missing;

	spinlock_t io_lock;

	struct block_device *bdev;

	/* the mode sent to blkdev_get */
	fmode_t mode;

	char *name;

	/* the internal btrfs device id */
	u64 devid;

	/* size of the device */
	u64 total_bytes;

	/* size of the disk */
	u64 disk_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];

	/* per-device scrub information */
	struct scrub_dev *scrub_device;

	struct btrfs_work work;
	};

	struct btrfs_fs_devices {
	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */

	/* the device with this id has the most recent copy of the super */
	u64 latest_devid;
	u64 latest_trans;
	u64 num_devices;
	u64 open_devices;
	u64 rw_devices;
	u64 missing_devices;
	u64 total_rw_bytes;
	struct block_device *latest_bdev;

	/* all of the devices in the FS, protected by a mutex
	* so we can safely walk it to write out the supers without
	* worrying about add/remove by the multi-device code
	*/
	struct mutex device_list_mutex;
	struct list_head devices;

	/* devices not currently being allocated */
	struct list_head alloc_list;
	struct list_head list;

	struct btrfs_fs_devices *seed;
	int seeding;

	int opened;

	/* set when we find or add a device that doesn't have the
	* nonrot flag set
	*/
	int rotating;
	};

	struct btrfs_bio_stripe {
	struct btrfs_device *dev;
	u64 physical;
	u64 length; /* only used for discard mappings */
	};

	struct btrfs_multi_bio {
	atomic_t stripes_pending;
	bio_end_io_t *end_io;
	struct bio *orig_bio;
	void *private;
	atomic_t error;
	int max_errors;
	int num_stripes;
	struct btrfs_bio_stripe stripes[];
	};

	struct btrfs_device_info {
	struct btrfs_device *dev;
	u64 dev_offset;
	u64 max_avail;
	};

	struct map_lookup {
	u64 type;
	int io_align;
	int io_width;
	int stripe_len;
	int sector_size;
	int num_stripes;
	int sub_stripes;
	struct btrfs_bio_stripe stripes[];
	};

	#define map_lookup_size(n) (sizeof(struct map_lookup) + \
	(sizeof(struct btrfs_bio_stripe) * (n)))

	/* Used to sort the devices by max_avail(descending sort) */
	int btrfs_cmp_device_free_bytes(const void dev_info1, const void dev_info2);

	/*
	* sort the devices by max_avail, in which max free extent size of each device
	* is stored.(Descending Sort)
	*/
	static inline void btrfs_descending_sort_devices(
	struct btrfs_device_info *devices,
	size_t nr_devices)
	{
	sort(devices, nr_devices, sizeof(struct btrfs_device_info),
	btrfs_cmp_device_free_bytes, NULL);
	}

	int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
	u64 end, u64 *length);

	#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 start, u64 num_bytes);
	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_rmap_block(struct btrfs_mapping_tree *map_tree,
	u64 chunk_start, u64 physical, u64 devid,
	u64 *logical, int naddrs, int *stripe_len);
	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 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 async_submit);
	int btrfs_read_super_device(struct btrfs_root root, struct extent_buffer buf);
	int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
	fmode_t flags, void *holder);
	int btrfs_scan_one_device(const char path, fmode_t flags, void holder,
	struct btrfs_fs_devices **fs_devices_ret);
	int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
	int btrfs_close_extra_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_rm_device(struct btrfs_root root, char device_path);
	int btrfs_cleanup_fs_uuids(void);
	int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len);
	int btrfs_unplug_page(struct btrfs_mapping_tree *map_tree,
	u64 logical, struct page *page);
	int btrfs_grow_device(struct btrfs_trans_handle *trans,
	struct btrfs_device *device, u64 new_size);
	struct btrfs_device btrfs_find_device(struct btrfs_root root, u64 devid,
	u8 uuid, u8 fsid);
	int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
	int btrfs_init_new_device(struct btrfs_root root, char path);
	int btrfs_balance(struct btrfs_root *dev_root);
	void btrfs_unlock_volumes(void);
	void btrfs_lock_volumes(void);
	int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
	int find_free_dev_extent(struct btrfs_trans_handle *trans,
	struct btrfs_device *device, u64 num_bytes,
	u64 start, u64 max_avail);
	#endif