Minor code reordering and documentation adjustments.
[dragonfly.git] / sys / vfs / hammer / hammer_disk.h
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1/*
2 * Copyright (c) 2007 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@backplane.com>
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in
15 * the documentation and/or other materials provided with the
16 * distribution.
17 * 3. Neither the name of The DragonFly Project nor the names of its
18 * contributors may be used to endorse or promote products derived
19 * from this software without specific, prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
059819e3 34 * $DragonFly: src/sys/vfs/hammer/hammer_disk.h,v 1.28 2008/04/22 19:00:15 dillon Exp $
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35 */
36
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37#ifndef VFS_HAMMER_DISK_H_
38#define VFS_HAMMER_DISK_H_
39
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40#ifndef _SYS_UUID_H_
41#include <sys/uuid.h>
42#endif
43
44/*
45 * The structures below represent the on-disk format for a HAMMER
46 * filesystem. Note that all fields for on-disk structures are naturally
47 * aligned. The host endian format is used - compatibility is possible
48 * if the implementation detects reversed endian and adjusts data accordingly.
49 *
50 * Most of HAMMER revolves around the concept of an object identifier. An
51 * obj_id is a 64 bit quantity which uniquely identifies a filesystem object
52 * FOR THE ENTIRE LIFE OF THE FILESYSTEM. This uniqueness allows backups
53 * and mirrors to retain varying amounts of filesystem history by removing
54 * any possibility of conflict through identifier reuse.
55 *
56 * A HAMMER filesystem may spam multiple volumes.
57 *
58 * A HAMMER filesystem uses a 16K filesystem buffer size. All filesystem
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59 * I/O is done in multiples of 16K. Most buffer-sized headers such as those
60 * used by volumes, super-clusters, clusters, and basic filesystem buffers
61 * use fixed-sized A-lists which are heavily dependant on HAMMER_BUFSIZE.
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62 *
63 * Per-volume storage limit: 52 bits 4096 TB
64 * Per-Zone storage limit: 59 bits 512 KTB (due to blockmap)
65 * Per-filesystem storage limit: 60 bits 1 MTB
8750964d 66 */
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67#define HAMMER_BUFSIZE 16384
68#define HAMMER_BUFMASK (HAMMER_BUFSIZE - 1)
69#define HAMMER_MAXDATA (256*1024)
70#define HAMMER_BUFFER_BITS 14
71
72#if (1 << HAMMER_BUFFER_BITS) != HAMMER_BUFSIZE
73#error "HAMMER_BUFFER_BITS BROKEN"
74#endif
8750964d 75
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76#define HAMMER_BUFSIZE64 ((u_int64_t)HAMMER_BUFSIZE)
77#define HAMMER_BUFMASK64 ((u_int64_t)HAMMER_BUFMASK)
78
79#define HAMMER_OFF_ZONE_MASK 0xF000000000000000ULL /* zone portion */
80#define HAMMER_OFF_VOL_MASK 0x0FF0000000000000ULL /* volume portion */
81#define HAMMER_OFF_SHORT_MASK 0x000FFFFFFFFFFFFFULL /* offset portion */
82#define HAMMER_OFF_LONG_MASK 0x0FFFFFFFFFFFFFFFULL /* offset portion */
83#define HAMMER_OFF_SHORT_REC_MASK 0x000FFFFFFF000000ULL /* recovery boundary */
84#define HAMMER_OFF_LONG_REC_MASK 0x0FFFFFFFFF000000ULL /* recovery boundary */
85#define HAMMER_RECOVERY_BND 0x0000000001000000ULL
86
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87/*
88 * Hammer transction ids are 64 bit unsigned integers and are usually
89 * synchronized with the time of day in nanoseconds.
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90 *
91 * Hammer offsets are used for FIFO indexing and embed a cycle counter
92 * and volume number in addition to the offset. Most offsets are required
93 * to be 64-byte aligned.
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94 */
95typedef u_int64_t hammer_tid_t;
47197d71 96typedef u_int64_t hammer_off_t;
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97typedef u_int32_t hammer_seq_t;
98typedef u_int32_t hammer_crc_t;
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99
100#define HAMMER_MIN_TID 0ULL /* unsigned */
101#define HAMMER_MAX_TID 0xFFFFFFFFFFFFFFFFULL /* unsigned */
102#define HAMMER_MIN_KEY -0x8000000000000000LL /* signed */
103#define HAMMER_MAX_KEY 0x7FFFFFFFFFFFFFFFLL /* signed */
104#define HAMMER_MIN_OBJID HAMMER_MIN_KEY /* signed */
105#define HAMMER_MAX_OBJID HAMMER_MAX_KEY /* signed */
106#define HAMMER_MIN_RECTYPE 0x0U /* unsigned */
107#define HAMMER_MAX_RECTYPE 0xFFFFU /* unsigned */
108#define HAMMER_MIN_OFFSET 0ULL /* unsigned */
109#define HAMMER_MAX_OFFSET 0xFFFFFFFFFFFFFFFFULL /* unsigned */
110
111/*
112 * hammer_off_t has several different encodings. Note that not all zones
113 * encode a vol_no.
114 *
115 * zone 0 (z,v,o): reserved (for sanity)
116 * zone 1 (z,v,o): raw volume relative (offset 0 is the volume header)
117 * zone 2 (z,v,o): raw buffer relative (offset 0 is the first buffer)
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118 * zone 3 (z,o): undo fifo - fixed layer2 array in root vol hdr
119 * zone 4 (z,v,o): freemap - freemap-backed self-mapping special
120 * cased layering.
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121 *
122 * zone 8 (z,o): B-Tree - blkmap-backed
123 * zone 9 (z,o): Record - blkmap-backed
124 * zone 10 (z,o): Large-data - blkmap-backed
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125 */
126
127#define HAMMER_ZONE_RAW_VOLUME 0x1000000000000000ULL
128#define HAMMER_ZONE_RAW_BUFFER 0x2000000000000000ULL
40043e7f 129#define HAMMER_ZONE_UNDO 0x3000000000000000ULL
c3be93f2 130#define HAMMER_ZONE_FREEMAP 0x4000000000000000ULL
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131#define HAMMER_ZONE_RESERVED05 0x5000000000000000ULL
132#define HAMMER_ZONE_RESERVED06 0x6000000000000000ULL
133#define HAMMER_ZONE_RESERVED07 0x7000000000000000ULL
134#define HAMMER_ZONE_BTREE 0x8000000000000000ULL
135#define HAMMER_ZONE_RECORD 0x9000000000000000ULL
136#define HAMMER_ZONE_LARGE_DATA 0xA000000000000000ULL
137#define HAMMER_ZONE_SMALL_DATA 0xB000000000000000ULL
138#define HAMMER_ZONE_RESERVED0C 0xC000000000000000ULL
139#define HAMMER_ZONE_RESERVED0D 0xD000000000000000ULL
140#define HAMMER_ZONE_RESERVED0E 0xE000000000000000ULL
141#define HAMMER_ZONE_RESERVED0F 0xF000000000000000ULL
142
143#define HAMMER_ZONE_RAW_VOLUME_INDEX 1
144#define HAMMER_ZONE_RAW_BUFFER_INDEX 2
145#define HAMMER_ZONE_UNDO_INDEX 3
c3be93f2 146#define HAMMER_ZONE_FREEMAP_INDEX 4
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147#define HAMMER_ZONE_BTREE_INDEX 8
148#define HAMMER_ZONE_RECORD_INDEX 9
149#define HAMMER_ZONE_LARGE_DATA_INDEX 10
150#define HAMMER_ZONE_SMALL_DATA_INDEX 11
151
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152/*
153 * Per-zone size limitation. This just makes the iterator easier
154 * to deal with by preventing an iterator overflow.
155 */
156#define HAMMER_ZONE_LIMIT \
157 (0x1000000000000000ULL - HAMMER_BLOCKMAP_LAYER2)
158
40043e7f 159#define HAMMER_MAX_ZONES 16
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160
161#define HAMMER_VOL_ENCODE(vol_no) \
162 ((hammer_off_t)((vol_no) & 255) << 52)
163#define HAMMER_VOL_DECODE(ham_off) \
164 (int32_t)(((hammer_off_t)(ham_off) >> 52) & 255)
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165#define HAMMER_ZONE_DECODE(ham_off) \
166 (int32_t)(((hammer_off_t)(ham_off) >> 60))
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167#define HAMMER_ZONE_ENCODE(zone, ham_off) \
168 (((hammer_off_t)(zone) << 60) | (ham_off))
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169#define HAMMER_SHORT_OFF_ENCODE(offset) \
170 ((hammer_off_t)(offset) & HAMMER_OFF_SHORT_MASK)
171#define HAMMER_LONG_OFF_ENCODE(offset) \
172 ((hammer_off_t)(offset) & HAMMER_OFF_LONG_MASK)
173
174#define HAMMER_ENCODE_RAW_VOLUME(vol_no, offset) \
175 (HAMMER_ZONE_RAW_VOLUME | \
176 HAMMER_VOL_ENCODE(vol_no) | \
177 HAMMER_SHORT_OFF_ENCODE(offset))
178
179#define HAMMER_ENCODE_RAW_BUFFER(vol_no, offset) \
180 (HAMMER_ZONE_RAW_BUFFER | \
181 HAMMER_VOL_ENCODE(vol_no) | \
182 HAMMER_SHORT_OFF_ENCODE(offset))
8750964d 183
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184#define HAMMER_ENCODE_FREEMAP(vol_no, offset) \
185 (HAMMER_ZONE_FREEMAP | \
186 HAMMER_VOL_ENCODE(vol_no) | \
187 HAMMER_SHORT_OFF_ENCODE(offset))
188
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189/*
190 * Large-Block backing store
191 *
192 * A blockmap is a two-level map which translates a blockmap-backed zone
193 * offset into a raw zone 2 offset. Each layer handles 18 bits. The 8M
194 * large-block size is 23 bits so two layers gives us 23+18+18 = 59 bits
195 * of address space.
196 */
197#define HAMMER_LARGEBLOCK_SIZE (8192 * 1024)
c3be93f2 198#define HAMMER_LARGEBLOCK_SIZE64 ((u_int64_t)HAMMER_LARGEBLOCK_SIZE)
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199#define HAMMER_LARGEBLOCK_MASK (HAMMER_LARGEBLOCK_SIZE - 1)
200#define HAMMER_LARGEBLOCK_MASK64 ((u_int64_t)HAMMER_LARGEBLOCK_SIZE - 1)
201#define HAMMER_LARGEBLOCK_BITS 23
202#if (1 << HAMMER_LARGEBLOCK_BITS) != HAMMER_LARGEBLOCK_SIZE
203#error "HAMMER_LARGEBLOCK_BITS BROKEN"
204#endif
205
206#define HAMMER_BUFFERS_PER_LARGEBLOCK \
207 (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE)
208#define HAMMER_BUFFERS_PER_LARGEBLOCK_MASK \
209 (HAMMER_BUFFERS_PER_LARGEBLOCK - 1)
210#define HAMMER_BUFFERS_PER_LARGEBLOCK_MASK64 \
211 ((hammer_off_t)HAMMER_BUFFERS_PER_LARGEBLOCK_MASK)
212
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213/*
214 * Every blockmap has this root structure in the root volume header.
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215 *
216 * NOTE: zone 3 (the undo FIFO) does not use phys_offset. first and next
217 * offsets represent the FIFO.
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218 */
219struct hammer_blockmap {
220 hammer_off_t phys_offset; /* zone-2 physical offset */
bf686dbe 221 hammer_off_t first_offset; /* zone-X logical offset (zone 3) */
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222 hammer_off_t next_offset; /* zone-X logical offset */
223 hammer_off_t alloc_offset; /* zone-X logical offset */
059819e3 224 hammer_crc_t entry_crc;
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225 u_int32_t reserved01;
226};
40043e7f 227
c3be93f2 228typedef struct hammer_blockmap *hammer_blockmap_t;
40043e7f 229
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230/*
231 * The blockmap is a 2-layer entity made up of big-blocks. The first layer
232 * contains 262144 32-byte entries (18 bits), the second layer contains
233 * 524288 16-byte entries (19 bits), representing 8MB (23 bit) blockmaps.
234 * 18+19+23 = 60 bits. The top four bits are the zone id.
235 *
236 * Layer 2 encodes the physical bigblock mapping for a blockmap. The freemap
237 * uses this field to encode the virtual blockmap offset that allocated the
238 * physical block.
239 *
240 * NOTE: The freemap maps the vol_no in the upper 8 bits of layer1.
241 *
242 * zone-4 blockmap offset: [z:4][layer1:18][layer2:19][bigblock:23]
243 */
244struct hammer_blockmap_layer1 {
245 hammer_off_t blocks_free; /* big-blocks free */
246 hammer_off_t phys_offset; /* UNAVAIL or zone-2 */
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247 hammer_crc_t layer1_crc; /* crc of this entry */
248 hammer_crc_t layer2_crc; /* xor'd crc's of HAMMER_BLOCKSIZE */
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249 hammer_off_t reserved01;
250};
40043e7f 251
c3be93f2 252struct hammer_blockmap_layer2 {
059819e3 253 hammer_crc_t entry_crc;
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254 u_int32_t bytes_free; /* bytes free within this bigblock */
255 union {
256 hammer_off_t owner; /* used by freemap */
257 hammer_off_t phys_offset; /* used by blockmap */
258 } u;
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259};
260
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261#define HAMMER_BLOCKMAP_FREE 0ULL
262#define HAMMER_BLOCKMAP_UNAVAIL ((hammer_off_t)-1LL)
263
264#define HAMMER_BLOCKMAP_RADIX1 /* 262144 (18) */ \
265 (HAMMER_LARGEBLOCK_SIZE / sizeof(struct hammer_blockmap_layer1))
266#define HAMMER_BLOCKMAP_RADIX2 /* 524288 (19) */ \
267 (HAMMER_LARGEBLOCK_SIZE / sizeof(struct hammer_blockmap_layer2))
268
269#define HAMMER_BLOCKMAP_RADIX1_PERBUFFER \
270 (HAMMER_BLOCKMAP_RADIX1 / (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE))
271#define HAMMER_BLOCKMAP_RADIX2_PERBUFFER \
272 (HAMMER_BLOCKMAP_RADIX2 / (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE))
273
274#define HAMMER_BLOCKMAP_LAYER1 /* 18+19+23 */ \
275 (HAMMER_BLOCKMAP_RADIX1 * HAMMER_BLOCKMAP_LAYER2)
276#define HAMMER_BLOCKMAP_LAYER2 /* 19+23 */ \
277 (HAMMER_BLOCKMAP_RADIX2 * HAMMER_LARGEBLOCK_SIZE64)
278
279#define HAMMER_BLOCKMAP_LAYER1_MASK (HAMMER_BLOCKMAP_LAYER1 - 1)
280#define HAMMER_BLOCKMAP_LAYER2_MASK (HAMMER_BLOCKMAP_LAYER2 - 1)
281
282/*
283 * byte offset within layer1 or layer2 big-block for the entry representing
284 * a zone-2 physical offset.
285 */
286#define HAMMER_BLOCKMAP_LAYER1_OFFSET(zone2_offset) \
287 (((zone2_offset) & HAMMER_BLOCKMAP_LAYER1_MASK) / \
288 HAMMER_BLOCKMAP_LAYER2 * sizeof(struct hammer_blockmap_layer1))
289
290#define HAMMER_BLOCKMAP_LAYER2_OFFSET(zone2_offset) \
291 (((zone2_offset) & HAMMER_BLOCKMAP_LAYER2_MASK) / \
292 HAMMER_LARGEBLOCK_SIZE64 * sizeof(struct hammer_blockmap_layer2))
66325755 293
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294/*
295 * HAMMER UNDO parameters. The UNDO fifo is mapped directly in the volume
296 * header with an array of layer2 structures. A maximum of (64x8MB) = 512MB
297 * may be reserved. The size of the undo fifo is usually set a newfs time
298 * but can be adjusted if the filesystem is taken offline.
299 */
300
301#define HAMMER_UNDO_LAYER2 64 /* max layer2 undo mapping entries */
302
9380c752 303/*
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304 * All on-disk HAMMER structures which make up elements of the UNDO FIFO
305 * contain a hammer_fifo_head and hammer_fifo_tail structure. This structure
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306 * contains all the information required to validate the fifo element
307 * and to scan the fifo in either direction. The head is typically embedded
308 * in higher level hammer on-disk structures while the tail is typically
309 * out-of-band. hdr_size is the size of the whole mess, including the tail.
47197d71 310 *
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311 * All undo structures are guaranteed to not cross a 16K filesystem
312 * buffer boundary. Most undo structures are fairly small. Data spaces
313 * are not immediately reused by HAMMER so file data is not usually recorded
314 * as part of an UNDO.
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315 *
316 * PAD elements are allowed to take up only 8 bytes of space as a special
317 * case, containing only hdr_signature, hdr_type, and hdr_size fields,
318 * and with the tail overloaded onto the head structure for 8 bytes total.
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319 *
320 * Every undo record has a sequence number. This number is unrelated to
321 * transaction ids and instead collects the undo transactions associated
322 * with a single atomic operation. A larger transactional operation, such
323 * as a remove(), may consist of several smaller atomic operations
324 * representing raw meta-data operations.
9380c752 325 */
36f82b23 326#define HAMMER_HEAD_ONDISK_SIZE 32
40043e7f 327#define HAMMER_HEAD_ALIGN 8
47197d71 328#define HAMMER_HEAD_ALIGN_MASK (HAMMER_HEAD_ALIGN - 1)
40043e7f 329#define HAMMER_TAIL_ONDISK_SIZE 8
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330
331struct hammer_fifo_head {
332 u_int16_t hdr_signature;
333 u_int16_t hdr_type;
40043e7f 334 u_int32_t hdr_size; /* aligned size of the whole mess */
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335 u_int32_t reserved01; /* (0) reserved for future use */
336 hammer_crc_t hdr_crc;
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337};
338
339struct hammer_fifo_tail {
340 u_int16_t tail_signature;
341 u_int16_t tail_type;
342 u_int32_t tail_size; /* aligned size of the whole mess */
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343};
344
345typedef struct hammer_fifo_head *hammer_fifo_head_t;
40043e7f 346typedef struct hammer_fifo_tail *hammer_fifo_tail_t;
9380c752 347
8750964d 348/*
47197d71 349 * Fifo header types.
8750964d 350 */
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351#define HAMMER_HEAD_TYPE_PAD (0x0040U|HAMMER_HEAD_FLAG_FREE)
352#define HAMMER_HEAD_TYPE_VOL 0x0041U /* Volume (dummy header) */
353#define HAMMER_HEAD_TYPE_BTREE 0x0042U /* B-Tree node */
354#define HAMMER_HEAD_TYPE_UNDO 0x0043U /* random UNDO information */
355#define HAMMER_HEAD_TYPE_DELETE 0x0044U /* record deletion */
356#define HAMMER_HEAD_TYPE_RECORD 0x0045U /* Filesystem record */
47197d71 357
40043e7f 358#define HAMMER_HEAD_FLAG_FREE 0x8000U /* Indicates object freed */
8750964d 359
47197d71 360#define HAMMER_HEAD_SIGNATURE 0xC84EU
40043e7f 361#define HAMMER_TAIL_SIGNATURE 0xC74FU
47197d71 362
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363#define HAMMER_HEAD_SEQ_BEG 0x80000000U
364#define HAMMER_HEAD_SEQ_END 0x40000000U
365#define HAMMER_HEAD_SEQ_MASK 0x3FFFFFFFU
366
47197d71 367/*
bf686dbe 368 * Misc FIFO structures.
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369 */
370struct hammer_fifo_undo {
371 struct hammer_fifo_head head;
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372 hammer_off_t undo_offset; /* zone-1 offset */
373 int32_t undo_data_bytes;
374 int32_t undo_reserved01;
47197d71 375 /* followed by data */
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376};
377
47197d71 378typedef struct hammer_fifo_undo *hammer_fifo_undo_t;
8750964d 379
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380struct hammer_fifo_buf_commit {
381 hammer_off_t undo_offset;
382};
383
c60bb2c5 384/*
47197d71 385 * Volume header types
c60bb2c5 386 */
8750964d 387#define HAMMER_FSBUF_VOLUME 0xC8414D4DC5523031ULL /* HAMMER01 */
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388#define HAMMER_FSBUF_VOLUME_REV 0x313052C54D4D41C8ULL /* (reverse endian) */
389
390/*
391 * The B-Tree structures need hammer_fsbuf_head.
392 */
393#include "hammer_btree.h"
394
395/*
396 * HAMMER Volume header
397 *
398 * A HAMMER filesystem is built from any number of block devices, Each block
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399 * device contains a volume header followed by however many buffers fit
400 * into the volume.
8750964d 401 *
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402 * One of the volumes making up a HAMMER filesystem is the master, the
403 * rest are slaves. It does not have to be volume #0.
c60bb2c5 404 *
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405 * The volume header takes up an entire 16K filesystem buffer and may
406 * represent up to 64KTB (65536 TB) of space.
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407 *
408 * Special field notes:
409 *
410 * vol_bot_beg - offset of boot area (mem_beg - bot_beg bytes)
411 * vol_mem_beg - offset of memory log (clu_beg - mem_beg bytes)
47197d71 412 * vol_buf_beg - offset of the first buffer.
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413 *
414 * The memory log area allows a kernel to cache new records and data
415 * in memory without allocating space in the actual filesystem to hold
416 * the records and data. In the event that a filesystem becomes full,
417 * any records remaining in memory can be flushed to the memory log
418 * area. This allows the kernel to immediately return success.
8750964d 419 */
8750964d 420
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421#define HAMMER_BOOT_MINBYTES (32*1024)
422#define HAMMER_BOOT_NOMBYTES (64LL*1024*1024)
423#define HAMMER_BOOT_MAXBYTES (256LL*1024*1024)
424
425#define HAMMER_MEM_MINBYTES (256*1024)
426#define HAMMER_MEM_NOMBYTES (1LL*1024*1024*1024)
427#define HAMMER_MEM_MAXBYTES (64LL*1024*1024*1024)
428
8750964d 429struct hammer_volume_ondisk {
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430 u_int64_t vol_signature;/* Signature */
431
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432 int64_t vol_bot_beg; /* byte offset of boot area or 0 */
433 int64_t vol_mem_beg; /* byte offset of memory log or 0 */
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434 int64_t vol_buf_beg; /* byte offset of first buffer in volume */
435 int64_t vol_buf_end; /* byte offset of volume EOF (on buf bndry) */
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436 int64_t vol_locked; /* reserved clusters are >= this offset */
437
438 uuid_t vol_fsid; /* identify filesystem */
439 uuid_t vol_fstype; /* identify filesystem type */
440 char vol_name[64]; /* Name of volume */
441
442 int32_t vol_no; /* volume number within filesystem */
443 int32_t vol_count; /* number of volumes making up FS */
444
445 u_int32_t vol_version; /* version control information */
9775c955 446 u_int32_t vol_reserved01;
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447 u_int32_t vol_flags; /* volume flags */
448 u_int32_t vol_rootvol; /* which volume is the root volume? */
449
40043e7f 450 int32_t vol_reserved04;
47197d71 451 int32_t vol_reserved05;
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452 u_int32_t vol_reserved06;
453 u_int32_t vol_reserved07;
454
fbc6e32a 455 int32_t vol_blocksize; /* for statfs only */
47197d71 456 int32_t vol_reserved08;
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457 int64_t vol_nblocks; /* total allocatable hammer bufs */
458
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459 /*
460 * These fields are initialized and space is reserved in every
461 * volume making up a HAMMER filesytem, but only the master volume
462 * contains valid data.
463 */
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464 int64_t vol0_stat_bigblocks; /* total bigblocks when fs is empty */
465 int64_t vol0_stat_freebigblocks;/* number of free bigblocks */
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466 int64_t vol0_stat_bytes; /* for statfs only */
467 int64_t vol0_stat_inodes; /* for statfs only */
b33e2cc0 468 int64_t vol0_stat_records; /* total records in filesystem */
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469 hammer_off_t vol0_btree_root; /* B-Tree root */
470 hammer_tid_t vol0_next_tid; /* highest synchronized TID */
36f82b23 471 u_int32_t vol0_reserved00;
bf686dbe 472 u_int32_t vol0_reserved01;
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473
474 /*
475 * Blockmaps for zones. Not all zones use a blockmap.
476 */
c3be93f2 477 struct hammer_blockmap vol0_blockmap[HAMMER_MAX_ZONES];
40043e7f 478
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479 /*
480 * Layer-2 array for undo fifo
481 */
482 struct hammer_blockmap_layer2 vol0_undo_array[HAMMER_UNDO_LAYER2];
483
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484};
485
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486typedef struct hammer_volume_ondisk *hammer_volume_ondisk_t;
487
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488#define HAMMER_VOLF_VALID 0x0001 /* valid entry */
489#define HAMMER_VOLF_OPEN 0x0002 /* volume is open */
8cd0a023 490
8750964d 491/*
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492 * All HAMMER records have a common 64-byte base and a 32 byte extension,
493 * plus a possible data reference. The data reference can be in-band or
494 * out-of-band.
8750964d 495 */
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496
497#define HAMMER_RECORD_SIZE (64+32)
498
8750964d 499struct hammer_base_record {
40043e7f 500 u_int32_t signature; /* record signature */
059819e3 501 hammer_crc_t data_crc; /* data crc */
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502 struct hammer_base_elm base; /* 40 byte base element */
503 hammer_off_t data_off; /* in-band or out-of-band */
504 int32_t data_len; /* size of data in bytes */
40043e7f 505 u_int32_t reserved02;
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506};
507
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508/*
509 * Record types are fairly straightforward. The B-Tree includes the record
510 * type in its index sort.
511 *
512 * In particular please note that it is possible to create a pseudo-
513 * filesystem within a HAMMER filesystem by creating a special object
514 * type within a directory. Pseudo-filesystems are used as replication
515 * targets and even though they are built within a HAMMER filesystem they
516 * get their own obj_id space (and thus can serve as a replication target)
517 * and look like a mount point to the system.
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518 *
519 * Inter-cluster records are special-cased in the B-Tree. These records
520 * are referenced from a B-Tree INTERNAL node, NOT A LEAF. This means
521 * that the element in the B-Tree node is actually a boundary element whos
522 * base element fields, including rec_type, reflect the boundary, NOT
523 * the inter-cluster record type.
524 *
525 * HAMMER_RECTYPE_CLUSTER - only set in the actual inter-cluster record,
526 * not set in the left or right boundary elements around the inter-cluster
527 * reference of an internal node in the B-Tree (because doing so would
528 * interfere with the boundary tests).
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529 *
530 * NOTE: hammer_ip_delete_range_all() deletes all record types greater
531 * then HAMMER_RECTYPE_INODE.
c60bb2c5 532 */
8750964d 533#define HAMMER_RECTYPE_UNKNOWN 0
66325755 534#define HAMMER_RECTYPE_LOWEST 1 /* lowest record type avail */
8750964d 535#define HAMMER_RECTYPE_INODE 1 /* inode in obj_id space */
c60bb2c5 536#define HAMMER_RECTYPE_PSEUDO_INODE 2 /* pseudo filesysem */
8cd0a023 537#define HAMMER_RECTYPE_CLUSTER 3 /* inter-cluster reference */
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538#define HAMMER_RECTYPE_DATA 0x0010
539#define HAMMER_RECTYPE_DIRENTRY 0x0011
540#define HAMMER_RECTYPE_DB 0x0012
541#define HAMMER_RECTYPE_EXT 0x0013 /* ext attributes */
542#define HAMMER_RECTYPE_FIX 0x0014 /* fixed attribute */
543#define HAMMER_RECTYPE_MOVED 0x8000 /* special recovery flag */
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544
545#define HAMMER_FIXKEY_SYMLINK 1
8750964d 546
66325755 547#define HAMMER_OBJTYPE_UNKNOWN 0 /* (never exists on-disk) */
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548#define HAMMER_OBJTYPE_DIRECTORY 1
549#define HAMMER_OBJTYPE_REGFILE 2
550#define HAMMER_OBJTYPE_DBFILE 3
551#define HAMMER_OBJTYPE_FIFO 4
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552#define HAMMER_OBJTYPE_CDEV 5
553#define HAMMER_OBJTYPE_BDEV 6
554#define HAMMER_OBJTYPE_SOFTLINK 7
555#define HAMMER_OBJTYPE_PSEUDOFS 8 /* pseudo filesystem obj */
556
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557/*
558 * A HAMMER inode record.
559 *
560 * This forms the basis for a filesystem object. obj_id is the inode number,
561 * key1 represents the pseudo filesystem id for security partitioning
562 * (preventing cross-links and/or restricting a NFS export and specifying the
563 * security policy), and key2 represents the data retention policy id.
564 *
565 * Inode numbers are 64 bit quantities which uniquely identify a filesystem
566 * object for the ENTIRE life of the filesystem, even after the object has
567 * been deleted. For all intents and purposes inode numbers are simply
568 * allocated by incrementing a sequence space.
569 *
570 * There is an important distinction between the data stored in the inode
571 * record and the record's data reference. The record references a
572 * hammer_inode_data structure but the filesystem object size and hard link
573 * count is stored in the inode record itself. This allows multiple inodes
574 * to share the same hammer_inode_data structure. This is possible because
575 * any modifications will lay out new data. The HAMMER implementation need
576 * not use the data-sharing ability when laying down new records.
577 *
578 * A HAMMER inode is subject to the same historical storage requirements
579 * as any other record. In particular any change in filesystem or hard link
580 * count will lay down a new inode record when the filesystem is synced to
581 * disk. This can lead to a lot of junk records which get cleaned up by
582 * the data retention policy.
583 *
584 * The ino_atime and ino_mtime fields are a special case. Modifications to
585 * these fields do NOT lay down a new record by default, though the values
586 * are effectively frozen for snapshots which access historical versions
587 * of the inode record due to other operations. This means that atime will
588 * not necessarily be accurate in snapshots, backups, or mirrors. mtime
589 * will be accurate in backups and mirrors since it can be regenerated from
590 * the mirroring stream.
591 *
592 * Because nlinks is historically retained the hardlink count will be
593 * accurate when accessing a HAMMER filesystem snapshot.
594 */
595struct hammer_inode_record {
596 struct hammer_base_record base;
597 u_int64_t ino_atime; /* last access time (not historical) */
598 u_int64_t ino_mtime; /* last modified time (not historical) */
599 u_int64_t ino_size; /* filesystem object size */
600 u_int64_t ino_nlinks; /* hard links */
601};
602
603/*
604 * Data records specify the entire contents of a regular file object,
605 * including attributes. Small amounts of data can theoretically be
606 * embedded in the record itself but the use of this ability verses using
607 * an out-of-band data reference depends on the implementation.
608 */
609struct hammer_data_record {
610 struct hammer_base_record base;
40043e7f 611 char data[32];
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612};
613
614/*
615 * A directory entry specifies the HAMMER filesystem object id, a copy of
616 * the file type, and file name (either embedded or as out-of-band data).
617 * If the file name is short enough to fit into den_name[] (including a
618 * terminating nul) then it will be embedded in the record, otherwise it
619 * is stored out-of-band. The base record's data reference always points
620 * to the nul-terminated filename regardless.
621 *
622 * Directory entries are indexed with a 128 bit namekey rather then an
623 * offset. A portion of the namekey is an iterator or randomizer to deal
624 * with collisions.
66325755 625 *
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626 * NOTE: base.base.obj_type holds the filesystem object type of obj_id,
627 * e.g. a den_type equivalent.
628 *
629 * NOTE: den_name / the filename data reference is NOT terminated with \0.
66325755 630 *
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631 */
632struct hammer_entry_record {
633 struct hammer_base_record base;
634 u_int64_t obj_id; /* object being referenced */
635 u_int64_t reserved01;
40043e7f 636 char name[16];
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637};
638
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639/*
640 * Hammer rollup record
641 */
c60bb2c5 642union hammer_record_ondisk {
8750964d 643 struct hammer_base_record base;
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644 struct hammer_inode_record inode;
645 struct hammer_data_record data;
646 struct hammer_entry_record entry;
647};
648
c60bb2c5 649typedef union hammer_record_ondisk *hammer_record_ondisk_t;
8750964d 650
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651/*
652 * HAMMER UNIX Attribute data
653 *
654 * The data reference in a HAMMER inode record points to this structure. Any
655 * modifications to the contents of this structure will result in a record
656 * replacement operation.
657 *
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658 * short_data_off allows a small amount of data to be embedded in the
659 * hammer_inode_data structure. HAMMER typically uses this to represent
660 * up to 64 bytes of data, or to hold symlinks. Remember that allocations
661 * are in powers of 2 so 64, 192, 448, or 960 bytes of embedded data is
662 * support (64+64, 64+192, 64+448 64+960).
663 *
664 * parent_obj_id is only valid for directories (which cannot be hard-linked),
665 * and specifies the parent directory obj_id. This field will also be set
666 * for non-directory inodes as a recovery aid, but can wind up specifying
667 * stale information. However, since object id's are not reused, the worse
668 * that happens is that the recovery code is unable to use it.
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669 */
670struct hammer_inode_data {
671 u_int16_t version; /* inode data version */
672 u_int16_t mode; /* basic unix permissions */
673 u_int32_t uflags; /* chflags */
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674 u_int32_t rmajor; /* used by device nodes */
675 u_int32_t rminor; /* used by device nodes */
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676 u_int64_t ctime;
677 u_int64_t parent_obj_id;/* parent directory obj_id */
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678 uuid_t uid;
679 uuid_t gid;
8cd0a023 680 /* XXX device, softlink extension */
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681};
682
683#define HAMMER_INODE_DATA_VERSION 1
684
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685#define HAMMER_OBJID_ROOT 1
686
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687/*
688 * Rollup various structures embedded as record data
689 */
427e5fc6 690union hammer_data_ondisk {
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691 struct hammer_inode_data inode;
692};
693
7dc57964 694#endif