xref: /linux/fs/btrfs/volumes.h (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
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 	/* readahead state */
97 	spinlock_t reada_lock;
98 	atomic_t reada_in_flight;
99 	u64 reada_next;
100 	struct reada_zone *reada_curr_zone;
101 	struct radix_tree_root reada_zones;
102 	struct radix_tree_root reada_extents;
103 };
104 
105 struct btrfs_fs_devices {
106 	u8 fsid[BTRFS_FSID_SIZE]; /* FS specific uuid */
107 
108 	/* the device with this id has the most recent copy of the super */
109 	u64 latest_devid;
110 	u64 latest_trans;
111 	u64 num_devices;
112 	u64 open_devices;
113 	u64 rw_devices;
114 	u64 missing_devices;
115 	u64 total_rw_bytes;
116 	u64 num_can_discard;
117 	struct block_device *latest_bdev;
118 
119 	/* all of the devices in the FS, protected by a mutex
120 	 * so we can safely walk it to write out the supers without
121 	 * worrying about add/remove by the multi-device code
122 	 */
123 	struct mutex device_list_mutex;
124 	struct list_head devices;
125 
126 	/* devices not currently being allocated */
127 	struct list_head alloc_list;
128 	struct list_head list;
129 
130 	struct btrfs_fs_devices *seed;
131 	int seeding;
132 
133 	int opened;
134 
135 	/* set when we find or add a device that doesn't have the
136 	 * nonrot flag set
137 	 */
138 	int rotating;
139 };
140 
141 struct btrfs_bio_stripe {
142 	struct btrfs_device *dev;
143 	u64 physical;
144 	u64 length; /* only used for discard mappings */
145 };
146 
147 struct btrfs_bio;
148 typedef void (btrfs_bio_end_io_t) (struct btrfs_bio *bio, int err);
149 
150 struct btrfs_bio {
151 	atomic_t stripes_pending;
152 	bio_end_io_t *end_io;
153 	struct bio *orig_bio;
154 	void *private;
155 	atomic_t error;
156 	int max_errors;
157 	int num_stripes;
158 	int mirror_num;
159 	struct btrfs_bio_stripe stripes[];
160 };
161 
162 struct btrfs_device_info {
163 	struct btrfs_device *dev;
164 	u64 dev_offset;
165 	u64 max_avail;
166 	u64 total_avail;
167 };
168 
169 struct map_lookup {
170 	u64 type;
171 	int io_align;
172 	int io_width;
173 	int stripe_len;
174 	int sector_size;
175 	int num_stripes;
176 	int sub_stripes;
177 	struct btrfs_bio_stripe stripes[];
178 };
179 
180 #define map_lookup_size(n) (sizeof(struct map_lookup) + \
181 			    (sizeof(struct btrfs_bio_stripe) * (n)))
182 
183 int btrfs_account_dev_extents_size(struct btrfs_device *device, u64 start,
184 				   u64 end, u64 *length);
185 
186 #define btrfs_bio_size(n) (sizeof(struct btrfs_bio) + \
187 			    (sizeof(struct btrfs_bio_stripe) * (n)))
188 
189 int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
190 			   struct btrfs_device *device,
191 			   u64 chunk_tree, u64 chunk_objectid,
192 			   u64 chunk_offset, u64 start, u64 num_bytes);
193 int btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
194 		    u64 logical, u64 *length,
195 		    struct btrfs_bio **bbio_ret, int mirror_num);
196 int btrfs_rmap_block(struct btrfs_mapping_tree *map_tree,
197 		     u64 chunk_start, u64 physical, u64 devid,
198 		     u64 **logical, int *naddrs, int *stripe_len);
199 int btrfs_read_sys_array(struct btrfs_root *root);
200 int btrfs_read_chunk_tree(struct btrfs_root *root);
201 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
202 		      struct btrfs_root *extent_root, u64 type);
203 void btrfs_mapping_init(struct btrfs_mapping_tree *tree);
204 void btrfs_mapping_tree_free(struct btrfs_mapping_tree *tree);
205 int btrfs_map_bio(struct btrfs_root *root, int rw, struct bio *bio,
206 		  int mirror_num, int async_submit);
207 int btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
208 		       fmode_t flags, void *holder);
209 int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder,
210 			  struct btrfs_fs_devices **fs_devices_ret);
211 int btrfs_close_devices(struct btrfs_fs_devices *fs_devices);
212 int btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices);
213 int btrfs_add_device(struct btrfs_trans_handle *trans,
214 		     struct btrfs_root *root,
215 		     struct btrfs_device *device);
216 int btrfs_rm_device(struct btrfs_root *root, char *device_path);
217 int btrfs_cleanup_fs_uuids(void);
218 int btrfs_num_copies(struct btrfs_mapping_tree *map_tree, u64 logical, u64 len);
219 int btrfs_grow_device(struct btrfs_trans_handle *trans,
220 		      struct btrfs_device *device, u64 new_size);
221 struct btrfs_device *btrfs_find_device(struct btrfs_root *root, u64 devid,
222 				       u8 *uuid, u8 *fsid);
223 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
224 int btrfs_init_new_device(struct btrfs_root *root, char *path);
225 int btrfs_balance(struct btrfs_root *dev_root);
226 int btrfs_chunk_readonly(struct btrfs_root *root, u64 chunk_offset);
227 int find_free_dev_extent(struct btrfs_trans_handle *trans,
228 			 struct btrfs_device *device, u64 num_bytes,
229 			 u64 *start, u64 *max_avail);
230 #endif
231