xref: /dragonfly/sys/vfs/hammer/hammer_disk.h (revision 51f35c5c)
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  *
34  * $DragonFly: src/sys/vfs/hammer/hammer_disk.h,v 1.48 2008/07/09 10:29:20 dillon Exp $
35  */
36 
37 #ifndef VFS_HAMMER_DISK_H_
38 #define VFS_HAMMER_DISK_H_
39 
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 span multiple volumes.
57  *
58  * A HAMMER filesystem uses a 16K filesystem buffer size.  All filesystem
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.
62  *
63  * 64K X-bufs are used for blocks >= a file's 1MB mark.
64  *
65  * Per-volume storage limit: 52 bits		4096 TB
66  * Per-Zone storage limit: 59 bits		512 KTB (due to blockmap)
67  * Per-filesystem storage limit: 60 bits	1 MTB
68  */
69 #define HAMMER_BUFSIZE		16384
70 #define HAMMER_XBUFSIZE		65536
71 #define HAMMER_XDEMARC		(1024 * 1024)
72 #define HAMMER_BUFMASK		(HAMMER_BUFSIZE - 1)
73 #define HAMMER_XBUFMASK		(HAMMER_XBUFSIZE - 1)
74 #define HAMMER_BUFFER_BITS	14
75 
76 #if (1 << HAMMER_BUFFER_BITS) != HAMMER_BUFSIZE
77 #error "HAMMER_BUFFER_BITS BROKEN"
78 #endif
79 
80 #define HAMMER_BUFSIZE64	((u_int64_t)HAMMER_BUFSIZE)
81 #define HAMMER_BUFMASK64	((u_int64_t)HAMMER_BUFMASK)
82 
83 #define HAMMER_XBUFSIZE64	((u_int64_t)HAMMER_XBUFSIZE)
84 #define HAMMER_XBUFMASK64	((u_int64_t)HAMMER_XBUFMASK)
85 
86 #define HAMMER_OFF_ZONE_MASK	0xF000000000000000ULL /* zone portion */
87 #define HAMMER_OFF_VOL_MASK	0x0FF0000000000000ULL /* volume portion */
88 #define HAMMER_OFF_SHORT_MASK	0x000FFFFFFFFFFFFFULL /* offset portion */
89 #define HAMMER_OFF_LONG_MASK	0x0FFFFFFFFFFFFFFFULL /* offset portion */
90 #define HAMMER_OFF_SHORT_REC_MASK 0x000FFFFFFF000000ULL /* recovery boundary */
91 #define HAMMER_OFF_LONG_REC_MASK 0x0FFFFFFFFF000000ULL /* recovery boundary */
92 #define HAMMER_RECOVERY_BND	0x0000000001000000ULL
93 
94 /*
95  * Hammer transction ids are 64 bit unsigned integers and are usually
96  * synchronized with the time of day in nanoseconds.
97  *
98  * Hammer offsets are used for FIFO indexing and embed a cycle counter
99  * and volume number in addition to the offset.  Most offsets are required
100  * to be 64-byte aligned.
101  */
102 typedef u_int64_t hammer_tid_t;
103 typedef u_int64_t hammer_off_t;
104 typedef u_int32_t hammer_seq_t;
105 typedef u_int32_t hammer_crc_t;
106 
107 #define HAMMER_MIN_TID		0ULL			/* unsigned */
108 #define HAMMER_MAX_TID		0xFFFFFFFFFFFFFFFFULL	/* unsigned */
109 #define HAMMER_MIN_KEY		-0x8000000000000000LL	/* signed */
110 #define HAMMER_MAX_KEY		0x7FFFFFFFFFFFFFFFLL	/* signed */
111 #define HAMMER_MIN_OBJID	HAMMER_MIN_KEY		/* signed */
112 #define HAMMER_MAX_OBJID	HAMMER_MAX_KEY		/* signed */
113 #define HAMMER_MIN_RECTYPE	0x0U			/* unsigned */
114 #define HAMMER_MAX_RECTYPE	0xFFFFU			/* unsigned */
115 #define HAMMER_MIN_OFFSET	0ULL			/* unsigned */
116 #define HAMMER_MAX_OFFSET	0xFFFFFFFFFFFFFFFFULL	/* unsigned */
117 
118 /*
119  * hammer_off_t has several different encodings.  Note that not all zones
120  * encode a vol_no.
121  *
122  * zone 0:		reserved for sanity
123  * zone 1 (z,v,o):	raw volume relative (offset 0 is the volume header)
124  * zone 2 (z,v,o):	raw buffer relative (offset 0 is the first buffer)
125  * zone 3 (z,o):	undo fifo	- actually fixed phys array in vol hdr
126  * zone 4 (z,v,o):	freemap		- only real blockmap
127  * zone 8 (z,v,o):	B-Tree		- actually zone-2 address
128  * zone 9 (z,v,o):	Record		- actually zone-2 address
129  * zone 10 (z,v,o):	Large-data	- actually zone-2 address
130  * zone 15:		reserved for sanity
131  */
132 
133 #define HAMMER_ZONE_RAW_VOLUME		0x1000000000000000ULL
134 #define HAMMER_ZONE_RAW_BUFFER		0x2000000000000000ULL
135 #define HAMMER_ZONE_UNDO		0x3000000000000000ULL
136 #define HAMMER_ZONE_FREEMAP		0x4000000000000000ULL
137 #define HAMMER_ZONE_RESERVED05		0x5000000000000000ULL
138 #define HAMMER_ZONE_RESERVED06		0x6000000000000000ULL
139 #define HAMMER_ZONE_RESERVED07		0x7000000000000000ULL
140 #define HAMMER_ZONE_BTREE		0x8000000000000000ULL
141 #define HAMMER_ZONE_META		0x9000000000000000ULL
142 #define HAMMER_ZONE_LARGE_DATA		0xA000000000000000ULL
143 #define HAMMER_ZONE_SMALL_DATA		0xB000000000000000ULL
144 #define HAMMER_ZONE_RESERVED0C		0xC000000000000000ULL
145 #define HAMMER_ZONE_RESERVED0D		0xD000000000000000ULL
146 #define HAMMER_ZONE_RESERVED0E		0xE000000000000000ULL
147 #define HAMMER_ZONE_UNAVAIL		0xF000000000000000ULL
148 
149 #define HAMMER_ZONE_RAW_VOLUME_INDEX	1
150 #define HAMMER_ZONE_RAW_BUFFER_INDEX	2
151 #define HAMMER_ZONE_UNDO_INDEX		3
152 #define HAMMER_ZONE_FREEMAP_INDEX	4
153 #define HAMMER_ZONE_BTREE_INDEX		8
154 #define HAMMER_ZONE_META_INDEX		9
155 #define HAMMER_ZONE_LARGE_DATA_INDEX	10
156 #define HAMMER_ZONE_SMALL_DATA_INDEX	11
157 #define HAMMER_ZONE_UNAVAIL_INDEX	15	/* unavailable */
158 
159 #define HAMMER_MAX_ZONES		16
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)
165 #define HAMMER_ZONE_DECODE(ham_off)			\
166 	(int32_t)(((hammer_off_t)(ham_off) >> 60))
167 #define HAMMER_ZONE_ENCODE(zone, ham_off)		\
168 	(((hammer_off_t)(zone) << 60) | (ham_off))
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))
183 
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 
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)
198 #define HAMMER_LARGEBLOCK_SIZE64	((u_int64_t)HAMMER_LARGEBLOCK_SIZE)
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 
213 /*
214  * Maximum number of mirrors operating in master mode (multi-master
215  * clustering and mirroring).
216  */
217 #define HAMMER_MAX_MASTERS		16
218 
219 /*
220  * The blockmap is somewhat of a degenerate structure.  HAMMER only actually
221  * uses it in its original incarnation to implement the free-map.
222  *
223  * zone:1	raw volume (no blockmap)
224  * zone:2	raw buffer (no blockmap)
225  * zone:3	undo-map   (direct layer2 array in volume header)
226  * zone:4	free-map   (the only real blockmap)
227  * zone:8-15	zone id used to classify big-block only, address is actually
228  *		a zone-2 address.
229  */
230 struct hammer_blockmap {
231 	hammer_off_t	phys_offset;    /* zone-2 physical offset */
232 	hammer_off_t	first_offset;	/* zone-X logical offset (zone 3) */
233 	hammer_off_t	next_offset;	/* zone-X logical offset */
234 	hammer_off_t	alloc_offset;	/* zone-X logical offset */
235 	u_int32_t	reserved01;
236 	hammer_crc_t	entry_crc;
237 };
238 
239 typedef struct hammer_blockmap *hammer_blockmap_t;
240 
241 #define HAMMER_BLOCKMAP_CRCSIZE	\
242 	offsetof(struct hammer_blockmap, entry_crc)
243 
244 /*
245  * The blockmap is a 2-layer entity made up of big-blocks.  The first layer
246  * contains 262144 32-byte entries (18 bits), the second layer contains
247  * 524288 16-byte entries (19 bits), representing 8MB (23 bit) blockmaps.
248  * 18+19+23 = 60 bits.  The top four bits are the zone id.
249  *
250  * Currently only the freemap utilizes both layers in all their glory.
251  * All primary data/meta-data zones actually encode a zone-2 address
252  * requiring no real blockmap translation.
253  *
254  * The freemap uses the upper 8 bits of layer-1 to identify the volume,
255  * thus any space allocated via the freemap can be directly translated
256  * to a zone:2 (or zone:8-15) address.
257  *
258  * zone-X blockmap offset: [z:4][layer1:18][layer2:19][bigblock:23]
259  */
260 struct hammer_blockmap_layer1 {
261 	hammer_off_t	blocks_free;	/* big-blocks free */
262 	hammer_off_t	phys_offset;	/* UNAVAIL or zone-2 */
263 	hammer_off_t	reserved01;
264 	hammer_crc_t	layer2_crc;	/* xor'd crc's of HAMMER_BLOCKSIZE */
265 					/* (not yet used) */
266 	hammer_crc_t	layer1_crc;	/* MUST BE LAST FIELD OF STRUCTURE*/
267 };
268 
269 typedef struct hammer_blockmap_layer1 *hammer_blockmap_layer1_t;
270 
271 #define HAMMER_LAYER1_CRCSIZE	\
272 	offsetof(struct hammer_blockmap_layer1, layer1_crc)
273 
274 struct hammer_blockmap_layer2 {
275 	u_int8_t	zone;		/* typed allocation zone */
276 	u_int8_t	unused01;
277 	u_int16_t	unused02;
278 	u_int32_t	append_off;	/* allocatable space index */
279 	u_int32_t	bytes_free;	/* bytes free within this bigblock */
280 	hammer_crc_t	entry_crc;
281 };
282 
283 typedef struct hammer_blockmap_layer2 *hammer_blockmap_layer2_t;
284 
285 #define HAMMER_LAYER2_CRCSIZE	\
286 	offsetof(struct hammer_blockmap_layer2, entry_crc)
287 
288 #define HAMMER_BLOCKMAP_FREE	0ULL
289 #define HAMMER_BLOCKMAP_UNAVAIL	((hammer_off_t)-1LL)
290 
291 #define HAMMER_BLOCKMAP_RADIX1	/* 262144 (18) */	\
292 	(HAMMER_LARGEBLOCK_SIZE / sizeof(struct hammer_blockmap_layer1))
293 #define HAMMER_BLOCKMAP_RADIX2	/* 524288 (19) */	\
294 	(HAMMER_LARGEBLOCK_SIZE / sizeof(struct hammer_blockmap_layer2))
295 
296 #define HAMMER_BLOCKMAP_RADIX1_PERBUFFER	\
297 	(HAMMER_BLOCKMAP_RADIX1 / (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE))
298 #define HAMMER_BLOCKMAP_RADIX2_PERBUFFER	\
299 	(HAMMER_BLOCKMAP_RADIX2 / (HAMMER_LARGEBLOCK_SIZE / HAMMER_BUFSIZE))
300 
301 #define HAMMER_BLOCKMAP_LAYER1	/* 18+19+23 */		\
302 	(HAMMER_BLOCKMAP_RADIX1 * HAMMER_BLOCKMAP_LAYER2)
303 #define HAMMER_BLOCKMAP_LAYER2	/* 19+23 - 4TB */		\
304 	(HAMMER_BLOCKMAP_RADIX2 * HAMMER_LARGEBLOCK_SIZE64)
305 
306 #define HAMMER_BLOCKMAP_LAYER1_MASK	(HAMMER_BLOCKMAP_LAYER1 - 1)
307 #define HAMMER_BLOCKMAP_LAYER2_MASK	(HAMMER_BLOCKMAP_LAYER2 - 1)
308 
309 /*
310  * byte offset within layer1 or layer2 big-block for the entry representing
311  * a zone-2 physical offset.
312  */
313 #define HAMMER_BLOCKMAP_LAYER1_OFFSET(zone2_offset)	\
314 	(((zone2_offset) & HAMMER_BLOCKMAP_LAYER1_MASK) / 	\
315 	 HAMMER_BLOCKMAP_LAYER2 * sizeof(struct hammer_blockmap_layer1))
316 
317 #define HAMMER_BLOCKMAP_LAYER2_OFFSET(zone2_offset)	\
318 	(((zone2_offset) & HAMMER_BLOCKMAP_LAYER2_MASK) /	\
319 	HAMMER_LARGEBLOCK_SIZE64 * sizeof(struct hammer_blockmap_layer2))
320 
321 /*
322  * HAMMER UNDO parameters.  The UNDO fifo is mapped directly in the volume
323  * header with an array of layer2 structures.  A maximum of (128x8MB) = 1GB
324  * may be reserved.  The size of the undo fifo is usually set a newfs time
325  * but can be adjusted if the filesystem is taken offline.
326  */
327 
328 #define HAMMER_UNDO_LAYER2	128	/* max layer2 undo mapping entries */
329 
330 /*
331  * All on-disk HAMMER structures which make up elements of the UNDO FIFO
332  * contain a hammer_fifo_head and hammer_fifo_tail structure.  This structure
333  * contains all the information required to validate the fifo element
334  * and to scan the fifo in either direction.  The head is typically embedded
335  * in higher level hammer on-disk structures while the tail is typically
336  * out-of-band.  hdr_size is the size of the whole mess, including the tail.
337  *
338  * All undo structures are guaranteed to not cross a 16K filesystem
339  * buffer boundary.  Most undo structures are fairly small.  Data spaces
340  * are not immediately reused by HAMMER so file data is not usually recorded
341  * as part of an UNDO.
342  *
343  * PAD elements are allowed to take up only 8 bytes of space as a special
344  * case, containing only hdr_signature, hdr_type, and hdr_size fields,
345  * and with the tail overloaded onto the head structure for 8 bytes total.
346  *
347  * Every undo record has a sequence number.  This number is unrelated to
348  * transaction ids and instead collects the undo transactions associated
349  * with a single atomic operation.  A larger transactional operation, such
350  * as a remove(), may consist of several smaller atomic operations
351  * representing raw meta-data operations.
352  */
353 #define HAMMER_HEAD_ONDISK_SIZE		32
354 #define HAMMER_HEAD_ALIGN		8
355 #define HAMMER_HEAD_ALIGN_MASK		(HAMMER_HEAD_ALIGN - 1)
356 #define HAMMER_TAIL_ONDISK_SIZE		8
357 
358 struct hammer_fifo_head {
359 	u_int16_t hdr_signature;
360 	u_int16_t hdr_type;
361 	u_int32_t hdr_size;	/* aligned size of the whole mess */
362 	u_int32_t reserved01;	/* (0) reserved for future use */
363 	hammer_crc_t hdr_crc;	/* XOR crc up to field w/ crc after field */
364 };
365 
366 #define HAMMER_FIFO_HEAD_CRCOFF	offsetof(struct hammer_fifo_head, hdr_crc)
367 
368 struct hammer_fifo_tail {
369 	u_int16_t tail_signature;
370 	u_int16_t tail_type;
371 	u_int32_t tail_size;	/* aligned size of the whole mess */
372 };
373 
374 typedef struct hammer_fifo_head *hammer_fifo_head_t;
375 typedef struct hammer_fifo_tail *hammer_fifo_tail_t;
376 
377 /*
378  * Fifo header types.
379  */
380 #define HAMMER_HEAD_TYPE_PAD	(0x0040U|HAMMER_HEAD_FLAG_FREE)
381 #define HAMMER_HEAD_TYPE_VOL	0x0041U		/* Volume (dummy header) */
382 #define HAMMER_HEAD_TYPE_BTREE	0x0042U		/* B-Tree node */
383 #define HAMMER_HEAD_TYPE_UNDO	0x0043U		/* random UNDO information */
384 #define HAMMER_HEAD_TYPE_DELETE	0x0044U		/* record deletion */
385 #define HAMMER_HEAD_TYPE_RECORD	0x0045U		/* Filesystem record */
386 
387 #define HAMMER_HEAD_FLAG_FREE	0x8000U		/* Indicates object freed */
388 
389 #define HAMMER_HEAD_SIGNATURE	0xC84EU
390 #define HAMMER_TAIL_SIGNATURE	0xC74FU
391 
392 #define HAMMER_HEAD_SEQ_BEG	0x80000000U
393 #define HAMMER_HEAD_SEQ_END	0x40000000U
394 #define HAMMER_HEAD_SEQ_MASK	0x3FFFFFFFU
395 
396 /*
397  * Misc FIFO structures.
398  */
399 struct hammer_fifo_undo {
400 	struct hammer_fifo_head	head;
401 	hammer_off_t		undo_offset;	/* zone-1 offset */
402 	int32_t			undo_data_bytes;
403 	int32_t			undo_reserved01;
404 	/* followed by data */
405 };
406 
407 typedef struct hammer_fifo_undo *hammer_fifo_undo_t;
408 
409 struct hammer_fifo_buf_commit {
410 	hammer_off_t		undo_offset;
411 };
412 
413 /*
414  * Volume header types
415  */
416 #define HAMMER_FSBUF_VOLUME	0xC8414D4DC5523031ULL	/* HAMMER01 */
417 #define HAMMER_FSBUF_VOLUME_REV	0x313052C54D4D41C8ULL	/* (reverse endian) */
418 
419 /*
420  * The B-Tree structures need hammer_fsbuf_head.
421  */
422 #include "hammer_btree.h"
423 
424 /*
425  * HAMMER Volume header
426  *
427  * A HAMMER filesystem is built from any number of block devices,  Each block
428  * device contains a volume header followed by however many buffers fit
429  * into the volume.
430  *
431  * One of the volumes making up a HAMMER filesystem is the master, the
432  * rest are slaves.  It does not have to be volume #0.
433  *
434  * The volume header takes up an entire 16K filesystem buffer and may
435  * represent up to 64KTB (65536 TB) of space.
436  *
437  * Special field notes:
438  *
439  *	vol_bot_beg - offset of boot area (mem_beg - bot_beg bytes)
440  *	vol_mem_beg - offset of memory log (clu_beg - mem_beg bytes)
441  *	vol_buf_beg - offset of the first buffer.
442  *
443  *	The memory log area allows a kernel to cache new records and data
444  *	in memory without allocating space in the actual filesystem to hold
445  *	the records and data.  In the event that a filesystem becomes full,
446  *	any records remaining in memory can be flushed to the memory log
447  *	area.  This allows the kernel to immediately return success.
448  */
449 
450 #define HAMMER_BOOT_MINBYTES		(32*1024)
451 #define HAMMER_BOOT_NOMBYTES		(64LL*1024*1024)
452 #define HAMMER_BOOT_MAXBYTES		(256LL*1024*1024)
453 
454 #define HAMMER_MEM_MINBYTES		(256*1024)
455 #define HAMMER_MEM_NOMBYTES		(1LL*1024*1024*1024)
456 #define HAMMER_MEM_MAXBYTES		(64LL*1024*1024*1024)
457 
458 struct hammer_volume_ondisk {
459 	u_int64_t vol_signature;/* Signature */
460 
461 	int64_t vol_bot_beg;	/* byte offset of boot area or 0 */
462 	int64_t vol_mem_beg;	/* byte offset of memory log or 0 */
463 	int64_t vol_buf_beg;	/* byte offset of first buffer in volume */
464 	int64_t vol_buf_end;	/* byte offset of volume EOF (on buf bndry) */
465 	int64_t vol_locked;	/* reserved clusters are >= this offset */
466 
467 	uuid_t    vol_fsid;	/* identify filesystem */
468 	uuid_t    vol_fstype;	/* identify filesystem type */
469 	char	  vol_name[64];	/* Name of volume */
470 
471 	int32_t vol_no;		/* volume number within filesystem */
472 	int32_t vol_count;	/* number of volumes making up FS */
473 
474 	u_int32_t vol_version;	/* version control information */
475 	hammer_crc_t vol_crc;	/* header crc */
476 	u_int32_t vol_flags;	/* volume flags */
477 	u_int32_t vol_rootvol;	/* which volume is the root volume? */
478 
479 	int32_t vol_reserved04;
480 	int32_t vol_reserved05;
481 	u_int32_t vol_reserved06;
482 	u_int32_t vol_reserved07;
483 
484 	int32_t vol_blocksize;		/* for statfs only */
485 	int32_t vol_reserved08;
486 	int64_t vol_nblocks;		/* total allocatable hammer bufs */
487 
488 	/*
489 	 * These fields are initialized and space is reserved in every
490 	 * volume making up a HAMMER filesytem, but only the master volume
491 	 * contains valid data.
492 	 */
493 	int64_t vol0_stat_bigblocks;	/* total bigblocks when fs is empty */
494 	int64_t vol0_stat_freebigblocks;/* number of free bigblocks */
495 	int64_t	vol0_stat_bytes;	/* for statfs only */
496 	int64_t vol0_stat_inodes;	/* for statfs only */
497 	int64_t vol0_stat_records;	/* total records in filesystem */
498 	hammer_off_t vol0_btree_root;	/* B-Tree root */
499 	hammer_tid_t vol0_next_tid;	/* highest synchronized TID */
500 	hammer_off_t vol0_unused03;
501 
502 	/*
503 	 * Blockmaps for zones.  Not all zones use a blockmap.  Note that
504 	 * the entire root blockmap is cached in the hammer_mount structure.
505 	 */
506 	struct hammer_blockmap	vol0_blockmap[HAMMER_MAX_ZONES];
507 
508 	/*
509 	 * Array of zone-2 addresses for undo FIFO.
510 	 */
511 	hammer_off_t		vol0_undo_array[HAMMER_UNDO_LAYER2];
512 
513 };
514 
515 typedef struct hammer_volume_ondisk *hammer_volume_ondisk_t;
516 
517 #define HAMMER_VOLF_VALID		0x0001	/* valid entry */
518 #define HAMMER_VOLF_OPEN		0x0002	/* volume is open */
519 
520 #define HAMMER_VOL_CRCSIZE1	\
521 	offsetof(struct hammer_volume_ondisk, vol_crc)
522 #define HAMMER_VOL_CRCSIZE2	\
523 	(sizeof(struct hammer_volume_ondisk) - HAMMER_VOL_CRCSIZE1 -	\
524 	 sizeof(hammer_crc_t))
525 
526 /*
527  * Record types are fairly straightforward.  The B-Tree includes the record
528  * type in its index sort.
529  */
530 #define HAMMER_RECTYPE_UNKNOWN		0
531 #define HAMMER_RECTYPE_LOWEST		1	/* lowest record type avail */
532 #define HAMMER_RECTYPE_INODE		1	/* inode in obj_id space */
533 #define HAMMER_RECTYPE_UNUSED02		2
534 #define HAMMER_RECTYPE_UNUSED03		3
535 #define HAMMER_RECTYPE_DATA		0x0010
536 #define HAMMER_RECTYPE_DIRENTRY		0x0011
537 #define HAMMER_RECTYPE_DB		0x0012
538 #define HAMMER_RECTYPE_EXT		0x0013	/* ext attributes */
539 #define HAMMER_RECTYPE_FIX		0x0014	/* fixed attribute */
540 #define HAMMER_RECTYPE_PFS		0x0015	/* PFS management */
541 #define HAMMER_RECTYPE_MOVED		0x8000	/* special recovery flag */
542 #define HAMMER_RECTYPE_MAX		0xFFFF
543 
544 #define HAMMER_RECTYPE_CLEAN_START	HAMMER_RECTYPE_EXT
545 
546 #define HAMMER_FIXKEY_SYMLINK		1
547 
548 #define HAMMER_OBJTYPE_UNKNOWN		0	/* (never exists on-disk) */
549 #define HAMMER_OBJTYPE_DIRECTORY	1
550 #define HAMMER_OBJTYPE_REGFILE		2
551 #define HAMMER_OBJTYPE_DBFILE		3
552 #define HAMMER_OBJTYPE_FIFO		4
553 #define HAMMER_OBJTYPE_CDEV		5
554 #define HAMMER_OBJTYPE_BDEV		6
555 #define HAMMER_OBJTYPE_SOFTLINK		7
556 #define HAMMER_OBJTYPE_PSEUDOFS		8	/* pseudo filesystem obj */
557 #define HAMMER_OBJTYPE_SOCKET		9
558 
559 /*
560  * HAMMER inode attribute data
561  *
562  * The data reference for a HAMMER inode points to this structure.  Any
563  * modifications to the contents of this structure will result in a
564  * replacement operation.
565  *
566  * parent_obj_id is only valid for directories (which cannot be hard-linked),
567  * and specifies the parent directory obj_id.  This field will also be set
568  * for non-directory inodes as a recovery aid, but can wind up holding
569  * stale information.  However, since object id's are not reused, the worse
570  * that happens is that the recovery code is unable to use it.
571  *
572  * NOTE: Future note on directory hardlinks.  We can implement a record type
573  * which allows us to point to multiple parent directories.
574  *
575  * NOTE: atime is stored in the inode's B-Tree element and not in the inode
576  * data.  This allows the atime to be updated without having to lay down a
577  * new record.
578  */
579 struct hammer_inode_data {
580 	u_int16_t version;	/* inode data version */
581 	u_int16_t mode;		/* basic unix permissions */
582 	u_int32_t uflags;	/* chflags */
583 	u_int32_t rmajor;	/* used by device nodes */
584 	u_int32_t rminor;	/* used by device nodes */
585 	u_int64_t ctime;
586 	int64_t parent_obj_id;	/* parent directory obj_id */
587 	uuid_t	  uid;
588 	uuid_t	  gid;
589 
590 	u_int8_t  obj_type;
591 	u_int8_t  cap_flags;	/* capability support flags (extension) */
592 	u_int16_t reserved02;
593 	u_int32_t reserved03;	/* RESERVED FOR POSSIBLE FUTURE BIRTHTIME */
594 	u_int64_t nlinks;	/* hard links */
595 	u_int64_t size;		/* filesystem object size */
596 	union {
597 		struct {
598 			char	reserved06[16];
599 			u_int32_t parent_obj_localization;
600 			u_int32_t integrity_crc;
601 		} obj;
602 		char	symlink[24];	/* HAMMER_INODE_BASESYMLEN */
603 	} ext;
604 	u_int64_t mtime;	/* mtime must be second-to-last */
605 	u_int64_t atime;	/* atime must be last */
606 };
607 
608 /*
609  * Neither mtime nor atime upates are CRCd by the B-Tree element.
610  * mtime updates have UNDO, atime updates do not.
611  */
612 #define HAMMER_ITIMES_BASE(ino_data)	(&(ino_data)->mtime)
613 #define HAMMER_ITIMES_BYTES		(sizeof(u_int64_t) * 2)
614 
615 #define HAMMER_INODE_CRCSIZE	\
616 	offsetof(struct hammer_inode_data, mtime)
617 
618 #define HAMMER_INODE_DATA_VERSION	1
619 #define HAMMER_OBJID_ROOT		1
620 #define HAMMER_INODE_BASESYMLEN		24	/* see ext.symlink */
621 
622 /*
623  * A HAMMER directory entry associates a HAMMER filesystem object with a
624  * namespace.  It is possible to hook into a pseudo-filesystem (with its
625  * own inode numbering space) in the filesystem by setting the high
626  * 16 bits of the localization field.  The low 16 bits must be 0 and
627  * are reserved for future use.
628  *
629  * Directory entries are indexed with a 128 bit namekey rather then an
630  * offset.  A portion of the namekey is an iterator/randomizer to deal
631  * with collisions.
632  *
633  * NOTE: base.base.obj_type from the related B-Tree leaf entry holds
634  * the filesystem object type of obj_id, e.g. a den_type equivalent.
635  * It is not stored in hammer_entry_data.
636  *
637  * NOTE: den_name / the filename data reference is NOT terminated with \0.
638  */
639 struct hammer_entry_data {
640 	int64_t obj_id;			/* object being referenced */
641 	u_int32_t localization;		/* identify pseudo-filesystem */
642 	u_int32_t reserved02;
643 	char	name[16];		/* name (extended) */
644 };
645 
646 #define HAMMER_ENTRY_NAME_OFF	offsetof(struct hammer_entry_data, name[0])
647 #define HAMMER_ENTRY_SIZE(nlen)	offsetof(struct hammer_entry_data, name[nlen])
648 
649 /*
650  * Symlink data which does not fit in the inode is stored in a separte
651  * FIX type record.
652  */
653 struct hammer_symlink_data {
654 	char	name[16];
655 };
656 
657 #define HAMMER_SYMLINK_NAME_OFF	offsetof(struct hammer_symlink_data, name[0])
658 
659 /*
660  * The root inode for the primary filesystem and root inode for any
661  * pseudo-fs may be tagged with an optional data structure using
662  * HAMMER_RECTYPE_FIX/HAMMER_FIXKEY_PSEUDOFS.  This structure allows
663  * the node to be used as a mirroring master or slave.
664  *
665  * When operating as a slave CD's into the node automatically become read-only
666  * and as-of sync_end_tid.
667  *
668  * When operating as a master the read PFSD info sets sync_end_tid to
669  * the most recently flushed TID.
670  *
671  * sync_low_tid is not yet used but will represent the highest pruning
672  * end-point, after which full history is available.
673  */
674 struct hammer_pseudofs_data {
675 	hammer_tid_t	sync_low_tid;	/* full history beyond this point */
676 	hammer_tid_t	sync_beg_tid;	/* earliest tid w/ full history avail */
677 	hammer_tid_t	sync_end_tid;	/* current synchronizatoin point */
678 	u_int64_t	sync_beg_ts;	/* real-time of last completed sync */
679 	u_int64_t	sync_end_ts;	/* initiation of current sync cycle */
680 	uuid_t		shared_uuid;	/* shared uuid (match required) */
681 	uuid_t		unique_uuid;	/* unique uuid of this master/slave */
682 	int32_t		master_id;	/* 0-15 (-1 if slave) */
683 	int32_t		mirror_flags;	/* (reserved) */
684 	char		label[64];	/* filesystem space label */
685 };
686 
687 typedef struct hammer_pseudofs_data *hammer_pseudofs_data_t;
688 
689 #define HAMMER_PFSD_SLAVE	0x00000001
690 
691 /*
692  * Rollup various structures embedded as record data
693  */
694 union hammer_data_ondisk {
695 	struct hammer_entry_data entry;
696 	struct hammer_inode_data inode;
697 	struct hammer_symlink_data symlink;
698 };
699 
700 typedef union hammer_data_ondisk *hammer_data_ondisk_t;
701 
702 #endif
703