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 1.55 2008/11/13 02:18:43 dillon Exp $
35 */
36
37#ifndef VFS_HAMMER_DISK_H_
38#define VFS_HAMMER_DISK_H_
39
40#include <sys/endian.h>
41
42#ifndef _SYS_UUID_H_
43#include <sys/uuid.h>
44#endif
45
46/*
47 * The structures below represent the on-disk format for a HAMMER
48 * filesystem.  Note that all fields for on-disk structures are naturally
49 * aligned.  HAMMER uses little endian for fields in on-disk structures.
50 * HAMMER doesn't support big endian arch, but is planned.
51 *
52 * Most of HAMMER revolves around the concept of an object identifier.  An
53 * obj_id is a 64 bit quantity which uniquely identifies a filesystem object
54 * FOR THE ENTIRE LIFE OF THE FILESYSTEM.  This uniqueness allows backups
55 * and mirrors to retain varying amounts of filesystem history by removing
56 * any possibility of conflict through identifier reuse.
57 *
58 * A HAMMER filesystem may span multiple volumes.
59 *
60 * A HAMMER filesystem uses a 16K filesystem buffer size.  All filesystem
61 * I/O is done in multiples of 16K.
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: 60 bits		1 MTB
67 * Per-filesystem storage limit: 60 bits	1 MTB
68 */
69#define HAMMER_BUFSIZE		16384
70#define HAMMER_XBUFSIZE		65536
71#define HAMMER_HBUFSIZE		(HAMMER_BUFSIZE / 2)
72#define HAMMER_XDEMARC		(1024 * 1024)
73#define HAMMER_BUFMASK		(HAMMER_BUFSIZE - 1)
74#define HAMMER_XBUFMASK		(HAMMER_XBUFSIZE - 1)
75
76#define HAMMER_BUFSIZE64	((uint64_t)HAMMER_BUFSIZE)
77#define HAMMER_BUFMASK64	((uint64_t)HAMMER_BUFMASK)
78
79#define HAMMER_XBUFSIZE64	((uint64_t)HAMMER_XBUFSIZE)
80#define HAMMER_XBUFMASK64	((uint64_t)HAMMER_XBUFMASK)
81
82#define HAMMER_OFF_ZONE_MASK	0xF000000000000000ULL /* zone portion */
83#define HAMMER_OFF_VOL_MASK	0x0FF0000000000000ULL /* volume portion */
84#define HAMMER_OFF_SHORT_MASK	0x000FFFFFFFFFFFFFULL /* offset portion */
85#define HAMMER_OFF_LONG_MASK	0x0FFFFFFFFFFFFFFFULL /* offset portion */
86
87#define HAMMER_OFF_BAD		((hammer_off_t)-1)
88
89#define HAMMER_BUFSIZE_DOALIGN(offset)				\
90	(((offset) + HAMMER_BUFMASK) & ~HAMMER_BUFMASK)
91#define HAMMER_BUFSIZE64_DOALIGN(offset)			\
92	(((offset) + HAMMER_BUFMASK64) & ~HAMMER_BUFMASK64)
93
94#define HAMMER_XBUFSIZE_DOALIGN(offset)				\
95	(((offset) + HAMMER_XBUFMASK) & ~HAMMER_XBUFMASK)
96#define HAMMER_XBUFSIZE64_DOALIGN(offset)			\
97	(((offset) + HAMMER_XBUFMASK64) & ~HAMMER_XBUFMASK64)
98
99/*
100 * The current limit of volumes that can make up a HAMMER FS
101 */
102#define HAMMER_MAX_VOLUMES	256
103
104/*
105 * Reserved space for (future) header junk after the volume header.
106 */
107#define HAMMER_MIN_VOL_JUNK	(HAMMER_BUFSIZE * 16)	/* 256 KB */
108#define HAMMER_MAX_VOL_JUNK	HAMMER_MIN_VOL_JUNK
109#define HAMMER_VOL_JUNK_SIZE	HAMMER_MIN_VOL_JUNK
110
111/*
112 * Hammer transaction ids are 64 bit unsigned integers and are usually
113 * synchronized with the time of day in nanoseconds.
114 *
115 * Hammer offsets are used for FIFO indexing and embed a cycle counter
116 * and volume number in addition to the offset.  Most offsets are required
117 * to be 16 KB aligned.
118 */
119typedef uint64_t hammer_tid_t;
120typedef uint64_t hammer_off_t;
121typedef uint32_t hammer_crc_t;
122typedef uuid_t hammer_uuid_t;
123
124#define HAMMER_MIN_TID		0ULL			/* unsigned */
125#define HAMMER_MAX_TID		0xFFFFFFFFFFFFFFFFULL	/* unsigned */
126#define HAMMER_MIN_KEY		-0x8000000000000000LL	/* signed */
127#define HAMMER_MAX_KEY		0x7FFFFFFFFFFFFFFFLL	/* signed */
128#define HAMMER_MIN_OBJID	HAMMER_MIN_KEY		/* signed */
129#define HAMMER_MAX_OBJID	HAMMER_MAX_KEY		/* signed */
130#define HAMMER_MIN_RECTYPE	0x0U			/* unsigned */
131#define HAMMER_MAX_RECTYPE	0xFFFFU			/* unsigned */
132#define HAMMER_MIN_OFFSET	0ULL			/* unsigned */
133#define HAMMER_MAX_OFFSET	0xFFFFFFFFFFFFFFFFULL	/* unsigned */
134
135/*
136 * hammer_off_t has several different encodings.  Note that not all zones
137 * encode a vol_no.  Zone bits are not a part of filesystem capacity as
138 * the zone bits aren't directly or indirectly mapped to physical volumes.
139 *
140 * In other words, HAMMER's logical filesystem offset consists of 64 bits,
141 * but the filesystem is considered 60 bits filesystem, not 64 bits.
142 * The maximum filesystem capacity is 1EB, not 16EB.
143 *
144 * zone 0:		available, a big-block that contains the offset is unused
145 * zone 1 (z,v,o):	raw volume relative (offset 0 is the volume header)
146 * zone 2 (z,v,o):	raw buffer relative (offset 0 is the first buffer)
147 * zone 3 (z,o):	undo/redo fifo	- fixed zone-2 offset array in volume header
148 * zone 4 (z,v,o):	freemap		- only real blockmap
149 * zone 8 (z,v,o):	B-Tree		- actually zone-2 address
150 * zone 9 (z,v,o):	meta		- actually zone-2 address
151 * zone 10 (z,v,o):	large-data	- actually zone-2 address
152 * zone 11 (z,v,o):	small-data	- actually zone-2 address
153 * zone 15:		unavailable, usually the offset is beyond volume size
154 *
155 * layer1/layer2 direct map:
156 *	     Maximum HAMMER filesystem capacity from volume aspect
157 *	     2^8(max volumes) * 2^52(max volume size) = 2^60 = 1EB (long offset)
158 *	    <------------------------------------------------------------->
159 *	     8bits   52bits (short offset)
160 *	    <------><----------------------------------------------------->
161 *	zzzzvvvvvvvvoooo oooooooooooooooo oooooooooooooooo oooooooooooooooo
162 *	----111111111111 1111112222222222 222222222ooooooo oooooooooooooooo
163 *	    <-----------------><------------------><---------------------->
164 *	     18bits             19bits              23bits
165 *	    <------------------------------------------------------------->
166 *	     2^18(layer1) * 2^19(layer2) * 2^23(big-block) = 2^60 = 1EB
167 *	     Maximum HAMMER filesystem capacity from blockmap aspect
168 *
169 * volume#0 layout
170 *	+-------------------------> offset 0 of a device/partition
171 *	| volume header (1928 bytes)
172 *	| the rest of header junk space (HAMMER_BUFSIZE aligned)
173 *	+-------------------------> vol_bot_beg
174 *	| boot area (HAMMER_BUFSIZE aligned)
175 *	+-------------------------> vol_mem_beg
176 *	| memory log (HAMMER_BUFSIZE aligned)
177 *	+-------------------------> vol_buf_beg (physical offset of zone-2)
178 *	| zone-4 big-block for layer1
179 *	+-------------------------> vol_buf_beg + HAMMER_BIGBLOCK_SIZE
180 *	| zone-4 big-blocks for layer2
181 *	| ... (1 big-block per 4TB space)
182 *	+-------------------------> vol_buf_beg + HAMMER_BIGBLOCK_SIZE * ...
183 *	| zone-3 big-blocks for UNDO/REDO FIFO
184 *	| ... (max 128 big-blocks)
185 *	+-------------------------> vol_buf_beg + HAMMER_BIGBLOCK_SIZE * ...
186 *	| zone-8 big-block for root B-Tree node/etc
187 *	+-------------------------> vol_buf_beg + HAMMER_BIGBLOCK_SIZE * ...
188 *	| zone-9 big-block for root inode/PFS/etc
189 *	+-------------------------> vol_buf_beg + HAMMER_BIGBLOCK_SIZE * ...
190 *	| zone-X big-blocks
191 *	| ... (big-blocks for new zones after newfs_hammer)
192 *	| ...
193 *	| ...
194 *	| ...
195 *	| ...
196 *	+-------------------------> vol_buf_end (HAMMER_BUFSIZE aligned)
197 *	+-------------------------> end of a device/partition
198 *
199 * volume#N layout (0<N<256)
200 *	+-------------------------> offset 0 of a device/partition
201 *	| volume header (1928 bytes)
202 *	| the rest of header junk space (HAMMER_BUFSIZE aligned)
203 *	+-------------------------> vol_bot_beg
204 *	| boot area (HAMMER_BUFSIZE aligned)
205 *	+-------------------------> vol_mem_beg
206 *	| memory log (HAMMER_BUFSIZE aligned)
207 *	+-------------------------> vol_buf_beg (physical offset of zone-2)
208 *	| zone-4 big-blocks for layer2
209 *	| ... (1 big-block per 4TB space)
210 *	+-------------------------> vol_buf_beg + HAMMER_BIGBLOCK_SIZE * ...
211 *	| zone-X big-blocks
212 *	| ... (unused until volume#(N-1) runs out of space)
213 *	| ...
214 *	| ...
215 *	| ...
216 *	| ...
217 *	+-------------------------> vol_buf_end (HAMMER_BUFSIZE aligned)
218 *	+-------------------------> end of a device/partition
219 */
220
221#define HAMMER_ZONE_RAW_VOLUME		0x1000000000000000ULL
222#define HAMMER_ZONE_RAW_BUFFER		0x2000000000000000ULL
223#define HAMMER_ZONE_UNDO		0x3000000000000000ULL
224#define HAMMER_ZONE_FREEMAP		0x4000000000000000ULL
225#define HAMMER_ZONE_RESERVED05		0x5000000000000000ULL  /* not used */
226#define HAMMER_ZONE_RESERVED06		0x6000000000000000ULL  /* not used */
227#define HAMMER_ZONE_RESERVED07		0x7000000000000000ULL  /* not used */
228#define HAMMER_ZONE_BTREE		0x8000000000000000ULL
229#define HAMMER_ZONE_META		0x9000000000000000ULL
230#define HAMMER_ZONE_LARGE_DATA		0xA000000000000000ULL
231#define HAMMER_ZONE_SMALL_DATA		0xB000000000000000ULL
232#define HAMMER_ZONE_RESERVED0C		0xC000000000000000ULL  /* not used */
233#define HAMMER_ZONE_RESERVED0D		0xD000000000000000ULL  /* not used */
234#define HAMMER_ZONE_RESERVED0E		0xE000000000000000ULL  /* not used */
235#define HAMMER_ZONE_UNAVAIL		0xF000000000000000ULL
236
237#define HAMMER_ZONE_RAW_VOLUME_INDEX	1
238#define HAMMER_ZONE_RAW_BUFFER_INDEX	2
239#define HAMMER_ZONE_UNDO_INDEX		3
240#define HAMMER_ZONE_FREEMAP_INDEX	4
241#define HAMMER_ZONE_BTREE_INDEX		8
242#define HAMMER_ZONE_META_INDEX		9
243#define HAMMER_ZONE_LARGE_DATA_INDEX	10
244#define HAMMER_ZONE_SMALL_DATA_INDEX	11
245#define HAMMER_ZONE_UNAVAIL_INDEX	15
246
247#define HAMMER_MAX_ZONES		16
248
249#define HAMMER_ZONE(offset)		((offset) & HAMMER_OFF_ZONE_MASK)
250
251#define hammer_is_zone_raw_volume(offset)		\
252	(HAMMER_ZONE(offset) == HAMMER_ZONE_RAW_VOLUME)
253#define hammer_is_zone_raw_buffer(offset)		\
254	(HAMMER_ZONE(offset) == HAMMER_ZONE_RAW_BUFFER)
255#define hammer_is_zone_undo(offset)			\
256	(HAMMER_ZONE(offset) == HAMMER_ZONE_UNDO)
257#define hammer_is_zone_freemap(offset)			\
258	(HAMMER_ZONE(offset) == HAMMER_ZONE_FREEMAP)
259#define hammer_is_zone_btree(offset)			\
260	(HAMMER_ZONE(offset) == HAMMER_ZONE_BTREE)
261#define hammer_is_zone_meta(offset)			\
262	(HAMMER_ZONE(offset) == HAMMER_ZONE_META)
263#define hammer_is_zone_large_data(offset)		\
264	(HAMMER_ZONE(offset) == HAMMER_ZONE_LARGE_DATA)
265#define hammer_is_zone_small_data(offset)		\
266	(HAMMER_ZONE(offset) == HAMMER_ZONE_SMALL_DATA)
267#define hammer_is_zone_unavail(offset)			\
268	(HAMMER_ZONE(offset) == HAMMER_ZONE_UNAVAIL)
269#define hammer_is_zone_data(offset)			\
270	(hammer_is_zone_large_data(offset) || hammer_is_zone_small_data(offset))
271
272#define hammer_is_index_record(zone)			\
273	((zone) >= HAMMER_ZONE_BTREE_INDEX &&		\
274	 (zone) < HAMMER_MAX_ZONES)
275
276#define hammer_is_zone_record(offset)			\
277	hammer_is_index_record(HAMMER_ZONE_DECODE(offset))
278
279#define hammer_is_index_direct_xlated(zone)		\
280	(((zone) == HAMMER_ZONE_RAW_BUFFER_INDEX) ||	\
281	 ((zone) == HAMMER_ZONE_FREEMAP_INDEX) ||	\
282	 hammer_is_index_record(zone))
283
284#define hammer_is_zone_direct_xlated(offset)		\
285	hammer_is_index_direct_xlated(HAMMER_ZONE_DECODE(offset))
286
287#define HAMMER_ZONE_ENCODE(zone, ham_off)		\
288	(((hammer_off_t)(zone) << 60) | (ham_off))
289#define HAMMER_ZONE_DECODE(ham_off)			\
290	((int)(((hammer_off_t)(ham_off) >> 60)))
291
292#define HAMMER_VOL_ENCODE(vol_no)			\
293	((hammer_off_t)((vol_no) & 255) << 52)
294#define HAMMER_VOL_DECODE(ham_off)			\
295	((int)(((hammer_off_t)(ham_off) >> 52) & 255))
296
297#define HAMMER_OFF_SHORT_ENCODE(offset)			\
298	((hammer_off_t)(offset) & HAMMER_OFF_SHORT_MASK)
299#define HAMMER_OFF_LONG_ENCODE(offset)			\
300	((hammer_off_t)(offset) & HAMMER_OFF_LONG_MASK)
301
302#define HAMMER_ENCODE(zone, vol_no, offset)		\
303	(((hammer_off_t)(zone) << 60) |			\
304	HAMMER_VOL_ENCODE(vol_no) |			\
305	HAMMER_OFF_SHORT_ENCODE(offset))
306#define HAMMER_ENCODE_RAW_VOLUME(vol_no, offset)	\
307	HAMMER_ENCODE(HAMMER_ZONE_RAW_VOLUME_INDEX, vol_no, offset)
308#define HAMMER_ENCODE_RAW_BUFFER(vol_no, offset)	\
309	HAMMER_ENCODE(HAMMER_ZONE_RAW_BUFFER_INDEX, vol_no, offset)
310#define HAMMER_ENCODE_UNDO(offset)			\
311	HAMMER_ENCODE(HAMMER_ZONE_UNDO_INDEX, HAMMER_ROOT_VOLNO, offset)
312#define HAMMER_ENCODE_FREEMAP(vol_no, offset)		\
313	HAMMER_ENCODE(HAMMER_ZONE_FREEMAP_INDEX, vol_no, offset)
314
315/*
316 * Translate a zone address to zone-X address.
317 */
318#define hammer_xlate_to_zoneX(zone, offset)		\
319	HAMMER_ZONE_ENCODE((zone), (offset) & ~HAMMER_OFF_ZONE_MASK)
320#define hammer_xlate_to_zone2(offset)			\
321	hammer_xlate_to_zoneX(HAMMER_ZONE_RAW_BUFFER_INDEX, (offset))
322
323#define hammer_data_zone(data_len)			\
324	(((data_len) >= HAMMER_BUFSIZE) ?		\
325	 HAMMER_ZONE_LARGE_DATA :			\
326	 HAMMER_ZONE_SMALL_DATA)
327#define hammer_data_zone_index(data_len)		\
328	(((data_len) >= HAMMER_BUFSIZE) ?		\
329	 HAMMER_ZONE_LARGE_DATA_INDEX :			\
330	 HAMMER_ZONE_SMALL_DATA_INDEX)
331
332/*
333 * Big-Block backing store
334 *
335 * A blockmap is a two-level map which translates a blockmap-backed zone
336 * offset into a raw zone 2 offset.  The layer 1 handles 18 bits and the
337 * layer 2 handles 19 bits.  The 8M big-block size is 23 bits so two
338 * layers gives us 18+19+23 = 60 bits of address space.
339 *
340 * When using hinting for a blockmap lookup, the hint is lost when the
341 * scan leaves the HINTBLOCK, which is typically several BIGBLOCK's.
342 * HINTBLOCK is a heuristic.
343 */
344#define HAMMER_HINTBLOCK_SIZE		(HAMMER_BIGBLOCK_SIZE * 4)
345#define HAMMER_HINTBLOCK_MASK64		((uint64_t)HAMMER_HINTBLOCK_SIZE - 1)
346#define HAMMER_BIGBLOCK_SIZE		(8192 * 1024)
347#define HAMMER_BIGBLOCK_SIZE64		((uint64_t)HAMMER_BIGBLOCK_SIZE)
348#define HAMMER_BIGBLOCK_MASK		(HAMMER_BIGBLOCK_SIZE - 1)
349#define HAMMER_BIGBLOCK_MASK64		((uint64_t)HAMMER_BIGBLOCK_SIZE - 1)
350#define HAMMER_BIGBLOCK_BITS		23
351#if 0
352#define HAMMER_BIGBLOCK_OVERFILL	(6144 * 1024)
353#endif
354#if (1 << HAMMER_BIGBLOCK_BITS) != HAMMER_BIGBLOCK_SIZE
355#error "HAMMER_BIGBLOCK_BITS BROKEN"
356#endif
357
358#define HAMMER_BUFFERS_PER_BIGBLOCK			\
359	(HAMMER_BIGBLOCK_SIZE / HAMMER_BUFSIZE)
360#define HAMMER_BUFFERS_PER_BIGBLOCK_MASK		\
361	(HAMMER_BUFFERS_PER_BIGBLOCK - 1)
362#define HAMMER_BUFFERS_PER_BIGBLOCK_MASK64		\
363	((hammer_off_t)HAMMER_BUFFERS_PER_BIGBLOCK_MASK)
364
365#define HAMMER_BIGBLOCK_DOALIGN(offset)				\
366	(((offset) + HAMMER_BIGBLOCK_MASK64) & ~HAMMER_BIGBLOCK_MASK64)
367
368/*
369 * Maximum number of mirrors operating in master mode (multi-master
370 * clustering and mirroring). Note that HAMMER1 does not support
371 * multi-master clustering as of 2015.
372 */
373#define HAMMER_MAX_MASTERS		16
374
375/*
376 * The blockmap is somewhat of a degenerate structure.  HAMMER only actually
377 * uses it in its original incarnation to implement the freemap.
378 *
379 * zone:1	raw volume (no blockmap)
380 * zone:2	raw buffer (no blockmap)
381 * zone:3	undomap    (direct layer2 array in volume header)
382 * zone:4	freemap    (the only real blockmap)
383 * zone:8-15	zone id used to classify big-block only, address is actually
384 *		a zone-2 address.
385 */
386typedef struct hammer_blockmap {
387	hammer_off_t	phys_offset;  /* zone-2 offset only used by zone-4 */
388	hammer_off_t	first_offset; /* zone-X offset only used by zone-3 */
389	hammer_off_t	next_offset;  /* zone-X offset for allocation */
390	hammer_off_t	alloc_offset; /* zone-X offset only used by zone-3 */
391	uint32_t	reserved01;
392	hammer_crc_t	entry_crc;
393} *hammer_blockmap_t;
394
395#define HAMMER_BLOCKMAP_CRCSIZE	\
396	offsetof(struct hammer_blockmap, entry_crc)
397
398/*
399 * The blockmap is a 2-layer entity made up of big-blocks.  The first layer
400 * contains 262144 32-byte entries (18 bits), the second layer contains
401 * 524288 16-byte entries (19 bits), representing 8MB (23 bit) blockmaps.
402 * 18+19+23 = 60 bits.  The top four bits are the zone id.
403 *
404 * Currently only the freemap utilizes both layers in all their glory.
405 * All primary data/meta-data zones actually encode a zone-2 address
406 * requiring no real blockmap translation.
407 *
408 * The freemap uses the upper 8 bits of layer-1 to identify the volume,
409 * thus any space allocated via the freemap can be directly translated
410 * to a zone:2 (or zone:8-15) address.
411 *
412 * zone-X blockmap offset: [zone:4][layer1:18][layer2:19][big-block:23]
413 */
414
415/*
416 * 32 bytes layer1 entry for 8MB big-block.
417 * A big-block can hold 2^23 / 2^5 = 2^18 layer1 entries,
418 * which equals bits assigned for layer1 in zone-2 address.
419 */
420typedef struct hammer_blockmap_layer1 {
421	hammer_off_t	blocks_free;	/* big-blocks free */
422	hammer_off_t	phys_offset;	/* UNAVAIL or zone-2 */
423	hammer_off_t	reserved01;
424	hammer_crc_t	layer2_crc;	/* xor'd crc's of HAMMER_BLOCKSIZE */
425					/* (not yet used) */
426	hammer_crc_t	layer1_crc;	/* MUST BE LAST FIELD OF STRUCTURE*/
427} *hammer_blockmap_layer1_t;
428
429#define HAMMER_LAYER1_CRCSIZE	\
430	offsetof(struct hammer_blockmap_layer1, layer1_crc)
431
432/*
433 * 16 bytes layer2 entry for 8MB big-blocks.
434 * A big-block can hold 2^23 / 2^4 = 2^19 layer2 entries,
435 * which equals bits assigned for layer2 in zone-2 address.
436 *
437 * NOTE: bytes_free is signed and can legally go negative if/when data
438 *	 de-dup occurs.  This field will never go higher than
439 *	 HAMMER_BIGBLOCK_SIZE.  If exactly HAMMER_BIGBLOCK_SIZE
440 *	 the big-block is completely free.
441 */
442typedef struct hammer_blockmap_layer2 {
443	uint8_t		zone;		/* typed allocation zone */
444	uint8_t		reserved01;
445	uint16_t	reserved02;
446	uint32_t	append_off;	/* allocatable space index */
447	int32_t		bytes_free;	/* bytes free within this big-block */
448	hammer_crc_t	entry_crc;
449} *hammer_blockmap_layer2_t;
450
451#define HAMMER_LAYER2_CRCSIZE	\
452	offsetof(struct hammer_blockmap_layer2, entry_crc)
453
454#define HAMMER_BLOCKMAP_UNAVAIL	((hammer_off_t)-1LL)
455
456#define HAMMER_BLOCKMAP_RADIX1	/* 2^18 = 262144 */	\
457	((int)(HAMMER_BIGBLOCK_SIZE / sizeof(struct hammer_blockmap_layer1)))
458#define HAMMER_BLOCKMAP_RADIX2	/* 2^19 = 524288 */	\
459	((int)(HAMMER_BIGBLOCK_SIZE / sizeof(struct hammer_blockmap_layer2)))
460
461#define HAMMER_BLOCKMAP_LAYER1	/* 2^(18+19+23) = 1EB */	\
462	(HAMMER_BLOCKMAP_RADIX1 * HAMMER_BLOCKMAP_LAYER2)
463#define HAMMER_BLOCKMAP_LAYER2	/* 2^(19+23) = 4TB */		\
464	(HAMMER_BLOCKMAP_RADIX2 * HAMMER_BIGBLOCK_SIZE64)
465
466#define HAMMER_BLOCKMAP_LAYER1_MASK	(HAMMER_BLOCKMAP_LAYER1 - 1)
467#define HAMMER_BLOCKMAP_LAYER2_MASK	(HAMMER_BLOCKMAP_LAYER2 - 1)
468
469#define HAMMER_BLOCKMAP_LAYER2_DOALIGN(offset)			\
470	(((offset) + HAMMER_BLOCKMAP_LAYER2_MASK) &		\
471	 ~HAMMER_BLOCKMAP_LAYER2_MASK)
472
473/*
474 * Index within layer1 or layer2 big-block for the entry representing
475 * a zone-2 physical offset.
476 */
477#define HAMMER_BLOCKMAP_LAYER1_INDEX(zone2_offset)		\
478	((int)(((zone2_offset) & HAMMER_BLOCKMAP_LAYER1_MASK) /	\
479	 HAMMER_BLOCKMAP_LAYER2))
480
481#define HAMMER_BLOCKMAP_LAYER2_INDEX(zone2_offset)		\
482	((int)(((zone2_offset) & HAMMER_BLOCKMAP_LAYER2_MASK) /	\
483	HAMMER_BIGBLOCK_SIZE64))
484
485/*
486 * Byte offset within layer1 or layer2 big-block for the entry representing
487 * a zone-2 physical offset.  Multiply the index by sizeof(blockmap_layer).
488 */
489#define HAMMER_BLOCKMAP_LAYER1_OFFSET(zone2_offset)		\
490	(HAMMER_BLOCKMAP_LAYER1_INDEX(zone2_offset) *		\
491	 sizeof(struct hammer_blockmap_layer1))
492
493#define HAMMER_BLOCKMAP_LAYER2_OFFSET(zone2_offset)		\
494	(HAMMER_BLOCKMAP_LAYER2_INDEX(zone2_offset) *		\
495	 sizeof(struct hammer_blockmap_layer2))
496
497/*
498 * Move on to offset 0 of the next layer1 or layer2.
499 */
500#define HAMMER_ZONE_LAYER1_NEXT_OFFSET(offset)			\
501	(((offset) + HAMMER_BLOCKMAP_LAYER2) & ~HAMMER_BLOCKMAP_LAYER2_MASK)
502
503#define HAMMER_ZONE_LAYER2_NEXT_OFFSET(offset)			\
504	(((offset) + HAMMER_BIGBLOCK_SIZE) & ~HAMMER_BIGBLOCK_MASK64)
505
506/*
507 * HAMMER UNDO parameters.  The UNDO fifo is mapped directly in the volume
508 * header with an array of zone-2 offsets.  A maximum of (128x8MB) = 1GB,
509 * and minimum of (64x8MB) = 512MB may be reserved.  The size of the undo
510 * fifo is usually set a newfs time.
511 */
512#define HAMMER_MIN_UNDO_BIGBLOCKS		64
513#define HAMMER_MAX_UNDO_BIGBLOCKS		128
514
515/*
516 * All on-disk HAMMER structures which make up elements of the UNDO FIFO
517 * contain a hammer_fifo_head and hammer_fifo_tail structure.  This structure
518 * contains all the information required to validate the fifo element
519 * and to scan the fifo in either direction.  The head is typically embedded
520 * in higher level hammer on-disk structures while the tail is typically
521 * out-of-band.  hdr_size is the size of the whole mess, including the tail.
522 *
523 * All undo structures are guaranteed to not cross a 16K filesystem
524 * buffer boundary.  Most undo structures are fairly small.  Data spaces
525 * are not immediately reused by HAMMER so file data is not usually recorded
526 * as part of an UNDO.
527 *
528 * PAD elements are allowed to take up only 8 bytes of space as a special
529 * case, containing only hdr_signature, hdr_type, and hdr_size fields,
530 * and with the tail overloaded onto the head structure for 8 bytes total.
531 *
532 * Every undo record has a sequence number.  This number is unrelated to
533 * transaction ids and instead collects the undo transactions associated
534 * with a single atomic operation.  A larger transactional operation, such
535 * as a remove(), may consist of several smaller atomic operations
536 * representing raw meta-data operations.
537 *
538 *				HAMMER VERSION 4 CHANGES
539 *
540 * In HAMMER version 4 the undo structure alignment is reduced from 16384
541 * to 512 bytes in order to ensure that each 512 byte sector begins with
542 * a header.  The hdr_seq field in the header is a 32 bit sequence number
543 * which allows the recovery code to detect missing sectors
544 * without relying on the 32-bit crc and to definitively identify the current
545 * undo sequence space without having to rely on information from the volume
546 * header.  In addition, new REDO entries in the undo space are used to
547 * record write, write/extend, and transaction id updates.
548 *
549 * The grand result is:
550 *
551 * (1) The volume header no longer needs to be synchronized for most
552 *     flush and fsync operations.
553 *
554 * (2) Most fsync operations need only lay down REDO records
555 *
556 * (3) Data overwrite for nohistory operations covered by REDO records
557 *     can be supported (instead of rolling a new block allocation),
558 *     by rolling UNDO for the prior contents of the data.
559 *
560 *				HAMMER VERSION 5 CHANGES
561 *
562 * Hammer version 5 contains a minor adjustment making layer2's bytes_free
563 * field signed, allowing dedup to push it into the negative domain.
564 */
565#define HAMMER_HEAD_ALIGN		8
566#define HAMMER_HEAD_ALIGN_MASK		(HAMMER_HEAD_ALIGN - 1)
567#define HAMMER_HEAD_DOALIGN(bytes)	\
568	(((bytes) + HAMMER_HEAD_ALIGN_MASK) & ~HAMMER_HEAD_ALIGN_MASK)
569
570#define HAMMER_UNDO_ALIGN		512
571#define HAMMER_UNDO_ALIGN64		((uint64_t)512)
572#define HAMMER_UNDO_MASK		(HAMMER_UNDO_ALIGN - 1)
573#define HAMMER_UNDO_MASK64		(HAMMER_UNDO_ALIGN64 - 1)
574#define HAMMER_UNDO_DOALIGN(offset)	\
575	(((offset) + HAMMER_UNDO_MASK) & ~HAMMER_UNDO_MASK64)
576
577typedef struct hammer_fifo_head {
578	uint16_t hdr_signature;
579	uint16_t hdr_type;
580	uint32_t hdr_size;	/* Aligned size of the whole mess */
581	uint32_t hdr_seq;	/* Sequence number */
582	hammer_crc_t hdr_crc;	/* XOR crc up to field w/ crc after field */
583} *hammer_fifo_head_t;
584
585#define HAMMER_FIFO_HEAD_CRCOFF	offsetof(struct hammer_fifo_head, hdr_crc)
586
587typedef struct hammer_fifo_tail {
588	uint16_t tail_signature;
589	uint16_t tail_type;
590	uint32_t tail_size;	/* aligned size of the whole mess */
591} *hammer_fifo_tail_t;
592
593/*
594 * Fifo header types.
595 *
596 * NOTE: 0x8000U part of HAMMER_HEAD_TYPE_PAD can be removed if the HAMMER
597 * version ever gets bumped again. It exists only to keep compatibility with
598 * older versions.
599 */
600#define HAMMER_HEAD_TYPE_PAD	(0x0040U | 0x8000U)
601#define HAMMER_HEAD_TYPE_DUMMY	0x0041U		/* dummy entry w/seqno */
602#define HAMMER_HEAD_TYPE_UNDO	0x0043U		/* random UNDO information */
603#define HAMMER_HEAD_TYPE_REDO	0x0044U		/* data REDO / fast fsync */
604
605#define HAMMER_HEAD_SIGNATURE	0xC84EU
606#define HAMMER_TAIL_SIGNATURE	0xC74FU
607
608/*
609 * Misc FIFO structures.
610 *
611 * UNDO - Raw meta-data media updates.
612 */
613typedef struct hammer_fifo_undo {
614	struct hammer_fifo_head	head;
615	hammer_off_t		undo_offset;	/* zone-1,2 offset */
616	int32_t			undo_data_bytes;
617	int32_t			undo_reserved01;
618	/* followed by data */
619} *hammer_fifo_undo_t;
620
621/*
622 * REDO (HAMMER version 4+) - Logical file writes/truncates.
623 *
624 * REDOs contain information which will be duplicated in a later meta-data
625 * update, allowing fast write()+fsync() operations.  REDOs can be ignored
626 * without harming filesystem integrity but must be processed if fsync()
627 * semantics are desired.
628 *
629 * Unlike UNDOs which are processed backwards within the recovery span,
630 * REDOs must be processed forwards starting further back (starting outside
631 * the recovery span).
632 *
633 *	WRITE	- Write logical file (with payload).  Executed both
634 *		  out-of-span and in-span.  Out-of-span WRITEs may be
635 *		  filtered out by TERMs.
636 *
637 *	TRUNC	- Truncate logical file (no payload).  Executed both
638 *		  out-of-span and in-span.  Out-of-span WRITEs may be
639 *		  filtered out by TERMs.
640 *
641 *	TERM_*	- Indicates meta-data was committed (if out-of-span) or
642 *		  will be rolled-back (in-span).  Any out-of-span TERMs
643 *		  matching earlier WRITEs remove those WRITEs from
644 *		  consideration as they might conflict with a later data
645 *		  commit (which is not being rolled-back).
646 *
647 *	SYNC	- The earliest in-span SYNC (the last one when scanning
648 *		  backwards) tells the recovery code how far out-of-span
649 *		  it must go to run REDOs.
650 *
651 * NOTE: WRITEs do not always have matching TERMs even under
652 *	 perfect conditions because truncations might remove the
653 *	 buffers from consideration.  I/O problems can also remove
654 *	 buffers from consideration.
655 *
656 *	 TRUNCSs do not always have matching TERMs because several
657 *	 truncations may be aggregated together into a single TERM.
658 */
659typedef struct hammer_fifo_redo {
660	struct hammer_fifo_head	head;
661	int64_t			redo_objid;	/* file being written */
662	hammer_off_t		redo_offset;	/* logical offset in file */
663	int32_t			redo_data_bytes;
664	uint32_t		redo_flags;
665	uint32_t		redo_localization;
666	uint32_t		redo_reserved01;
667	uint64_t		redo_reserved02;
668	/* followed by data */
669} *hammer_fifo_redo_t;
670
671#define HAMMER_REDO_WRITE	0x00000001
672#define HAMMER_REDO_TRUNC	0x00000002
673#define HAMMER_REDO_TERM_WRITE	0x00000004
674#define HAMMER_REDO_TERM_TRUNC	0x00000008
675#define HAMMER_REDO_SYNC	0x00000010
676
677typedef union hammer_fifo_any {
678	struct hammer_fifo_head	head;
679	struct hammer_fifo_undo	undo;
680	struct hammer_fifo_redo	redo;
681} *hammer_fifo_any_t;
682
683/*
684 * Volume header types
685 */
686#define HAMMER_FSBUF_VOLUME	0xC8414D4DC5523031ULL	/* HAMMER01 */
687#define HAMMER_FSBUF_VOLUME_REV	0x313052C54D4D41C8ULL	/* (reverse endian) */
688
689/*
690 * HAMMER Volume header
691 *
692 * A HAMMER filesystem can be built from 1-256 block devices, each block
693 * device contains a volume header followed by however many buffers fit
694 * into the volume.
695 *
696 * One of the volumes making up a HAMMER filesystem is the root volume.
697 * The root volume is always volume #0 which is the first block device path
698 * specified by newfs_hammer(8).  All HAMMER volumes have a volume header,
699 * however the root volume may be the only volume that has valid values for
700 * some fields in the header.
701 *
702 * Special field notes:
703 *
704 *	vol_bot_beg - offset of boot area (mem_beg - bot_beg bytes)
705 *	vol_mem_beg - offset of memory log (buf_beg - mem_beg bytes)
706 *	vol_buf_beg - offset of the first buffer in volume
707 *	vol_buf_end - offset of volume EOF (on buffer boundary)
708 *
709 *	The memory log area allows a kernel to cache new records and data
710 *	in memory without allocating space in the actual filesystem to hold
711 *	the records and data.  In the event that a filesystem becomes full,
712 *	any records remaining in memory can be flushed to the memory log
713 *	area.  This allows the kernel to immediately return success.
714 *
715 *	The buffer offset is a physical offset of zone-2 offset. The lower
716 *	52 bits of the zone-2 offset is added to the buffer offset of each
717 *	volume to generate an actual I/O offset within the block device.
718 *
719 *	NOTE: boot area and memory log are currently not used.
720 */
721
722/*
723 * Filesystem type string
724 */
725#define HAMMER_FSTYPE_STRING		"DragonFly HAMMER"
726
727/*
728 * These macros are only used by userspace when userspace commands either
729 * initialize or add a new HAMMER volume.
730 */
731#define HAMMER_BOOT_MINBYTES		(32*1024)
732#define HAMMER_BOOT_NOMBYTES		(64LL*1024*1024)
733#define HAMMER_BOOT_MAXBYTES		(256LL*1024*1024)
734
735#define HAMMER_MEM_MINBYTES		(256*1024)
736#define HAMMER_MEM_NOMBYTES		(1LL*1024*1024*1024)
737#define HAMMER_MEM_MAXBYTES		(64LL*1024*1024*1024)
738
739typedef struct hammer_volume_ondisk {
740	uint64_t vol_signature;	/* HAMMER_FSBUF_VOLUME for a valid header */
741
742	/*
743	 * These are relative to block device offset, not zone offsets.
744	 */
745	int64_t vol_bot_beg;	/* offset of boot area */
746	int64_t vol_mem_beg;	/* offset of memory log */
747	int64_t vol_buf_beg;	/* offset of the first buffer in volume */
748	int64_t vol_buf_end;	/* offset of volume EOF (on buffer boundary) */
749	int64_t vol_reserved01;
750
751	hammer_uuid_t vol_fsid;	/* identify filesystem */
752	hammer_uuid_t vol_fstype; /* identify filesystem type */
753	char vol_label[64];	/* filesystem label */
754
755	int32_t vol_no;		/* volume number within filesystem */
756	int32_t vol_count;	/* number of volumes making up filesystem */
757
758	uint32_t vol_version;	/* version control information */
759	hammer_crc_t vol_crc;	/* header crc */
760	uint32_t vol_flags;	/* volume flags */
761	uint32_t vol_rootvol;	/* the root volume number (must be 0) */
762
763	uint32_t vol_reserved[8];
764
765	/*
766	 * These fields are initialized and space is reserved in every
767	 * volume making up a HAMMER filesystem, but only the root volume
768	 * contains valid data.  Note that vol0_stat_bigblocks does not
769	 * include big-blocks for freemap and undomap initially allocated
770	 * by newfs_hammer(8).
771	 */
772	int64_t vol0_stat_bigblocks;	/* total big-blocks when fs is empty */
773	int64_t vol0_stat_freebigblocks;/* number of free big-blocks */
774	int64_t	vol0_reserved01;
775	int64_t vol0_stat_inodes;	/* for statfs only */
776	int64_t vol0_reserved02;
777	hammer_off_t vol0_btree_root;	/* B-Tree root offset in zone-8 */
778	hammer_tid_t vol0_next_tid;	/* highest partially synchronized TID */
779	hammer_off_t vol0_reserved03;
780
781	/*
782	 * Blockmaps for zones.  Not all zones use a blockmap.  Note that
783	 * the entire root blockmap is cached in the hammer_mount structure.
784	 */
785	struct hammer_blockmap	vol0_blockmap[HAMMER_MAX_ZONES];
786
787	/*
788	 * Array of zone-2 addresses for undo FIFO.
789	 */
790	hammer_off_t		vol0_undo_array[HAMMER_MAX_UNDO_BIGBLOCKS];
791} *hammer_volume_ondisk_t;
792
793#define HAMMER_ROOT_VOLNO		0
794
795#define HAMMER_VOLF_NEEDFLUSH		0x0004	/* volume needs flush */
796
797#define HAMMER_VOL_CRCSIZE1	\
798	offsetof(struct hammer_volume_ondisk, vol_crc)
799#define HAMMER_VOL_CRCSIZE2	\
800	(sizeof(struct hammer_volume_ondisk) - HAMMER_VOL_CRCSIZE1 -	\
801	 sizeof(hammer_crc_t))
802
803#define HAMMER_VOL_VERSION_MIN		1	/* minimum supported version */
804#define HAMMER_VOL_VERSION_DEFAULT	7	/* newfs default version */
805#define HAMMER_VOL_VERSION_WIP		8	/* version >= this is WIP */
806#define HAMMER_VOL_VERSION_MAX		7	/* maximum supported version */
807
808#define HAMMER_VOL_VERSION_ONE		1
809#define HAMMER_VOL_VERSION_TWO		2	/* new dirent layout (2.3+) */
810#define HAMMER_VOL_VERSION_THREE	3	/* new snapshot layout (2.5+) */
811#define HAMMER_VOL_VERSION_FOUR		4	/* new undo/flush (2.5+) */
812#define HAMMER_VOL_VERSION_FIVE		5	/* dedup (2.9+) */
813#define HAMMER_VOL_VERSION_SIX		6	/* DIRHASH_ALG1 */
814#define HAMMER_VOL_VERSION_SEVEN	7	/* use the faster iscsi_crc */
815
816/*
817 * Translate a zone-2 address to physical address
818 */
819#define hammer_xlate_to_phys(volume, zone2_offset)	\
820	((volume)->vol_buf_beg + HAMMER_OFF_SHORT_ENCODE(zone2_offset))
821
822/*
823 * Translate a zone-3 address to zone-2 address
824 */
825#define HAMMER_UNDO_INDEX(zone3_offset)			\
826	(HAMMER_OFF_SHORT_ENCODE(zone3_offset) / HAMMER_BIGBLOCK_SIZE)
827
828#define hammer_xlate_to_undo(volume, zone3_offset)			\
829	((volume)->vol0_undo_array[HAMMER_UNDO_INDEX(zone3_offset)] +	\
830	 (zone3_offset & HAMMER_BIGBLOCK_MASK64))
831
832/*
833 * Effective per-volume filesystem capacity including big-blocks for layer1/2
834 */
835#define HAMMER_VOL_BUF_SIZE(volume)			\
836	((volume)->vol_buf_end - (volume)->vol_buf_beg)
837
838/*
839 * Record types are fairly straightforward.  The B-Tree includes the record
840 * type in its index sort.
841 */
842#define HAMMER_RECTYPE_UNKNOWN		0x0000
843#define HAMMER_RECTYPE_INODE		0x0001	/* inode in obj_id space */
844#define HAMMER_RECTYPE_DATA		0x0010
845#define HAMMER_RECTYPE_DIRENTRY		0x0011
846#define HAMMER_RECTYPE_DB		0x0012
847#define HAMMER_RECTYPE_EXT		0x0013	/* ext attributes */
848#define HAMMER_RECTYPE_FIX		0x0014	/* fixed attribute */
849#define HAMMER_RECTYPE_PFS		0x0015	/* PFS management */
850#define HAMMER_RECTYPE_SNAPSHOT		0x0016	/* Snapshot management */
851#define HAMMER_RECTYPE_CONFIG		0x0017	/* hammer cleanup config */
852#define HAMMER_RECTYPE_MAX		0xFFFF
853
854#define HAMMER_RECTYPE_ENTRY_START	(HAMMER_RECTYPE_INODE + 1)
855#define HAMMER_RECTYPE_CLEAN_START	HAMMER_RECTYPE_EXT
856
857#define HAMMER_FIXKEY_SYMLINK		1
858
859#define HAMMER_OBJTYPE_UNKNOWN		0	/* never exists on-disk as unknown */
860#define HAMMER_OBJTYPE_DIRECTORY	1
861#define HAMMER_OBJTYPE_REGFILE		2
862#define HAMMER_OBJTYPE_DBFILE		3
863#define HAMMER_OBJTYPE_FIFO		4
864#define HAMMER_OBJTYPE_CDEV		5
865#define HAMMER_OBJTYPE_BDEV		6
866#define HAMMER_OBJTYPE_SOFTLINK		7
867#define HAMMER_OBJTYPE_PSEUDOFS		8	/* pseudo filesystem obj */
868#define HAMMER_OBJTYPE_SOCKET		9
869
870/*
871 * HAMMER inode attribute data
872 *
873 * The data reference for a HAMMER inode points to this structure.  Any
874 * modifications to the contents of this structure will result in a
875 * replacement operation.
876 *
877 * parent_obj_id is only valid for directories (which cannot be hard-linked),
878 * and specifies the parent directory obj_id.  This field will also be set
879 * for non-directory inodes as a recovery aid, but can wind up holding
880 * stale information.  However, since object id's are not reused, the worse
881 * that happens is that the recovery code is unable to use it.
882 * A parent_obj_id of 0 means it's a root inode of root or non-root PFS.
883 *
884 * NOTE: Future note on directory hardlinks.  We can implement a record type
885 * which allows us to point to multiple parent directories.
886 */
887typedef struct hammer_inode_data {
888	uint16_t version;	/* inode data version */
889	uint16_t mode;		/* basic unix permissions */
890	uint32_t uflags;	/* chflags */
891	uint32_t rmajor;	/* used by device nodes */
892	uint32_t rminor;	/* used by device nodes */
893	uint64_t ctime;
894	int64_t parent_obj_id;	/* parent directory obj_id */
895	hammer_uuid_t uid;
896	hammer_uuid_t gid;
897
898	uint8_t obj_type;
899	uint8_t cap_flags;	/* capability support flags (extension) */
900	uint16_t reserved01;
901	uint32_t reserved02;
902	uint64_t nlinks;	/* hard links */
903	uint64_t size;		/* filesystem object size */
904	union {
905		char	symlink[24];	/* HAMMER_INODE_BASESYMLEN */
906	} ext;
907	uint64_t mtime;	/* mtime must be second-to-last */
908	uint64_t atime;	/* atime must be last */
909} *hammer_inode_data_t;
910
911/*
912 * Neither mtime nor atime updates are CRCd by the B-Tree element.
913 * mtime updates have UNDO, atime updates do not.
914 */
915#define HAMMER_INODE_CRCSIZE	\
916	offsetof(struct hammer_inode_data, mtime)
917
918#define HAMMER_INODE_DATA_VERSION	1
919#define HAMMER_OBJID_ROOT		1	/* root inodes # */
920#define HAMMER_INODE_BASESYMLEN		24	/* see ext.symlink */
921
922/*
923 * Capability & implementation flags.
924 *
925 * HAMMER_INODE_CAP_DIR_LOCAL_INO - Use inode B-Tree localization
926 * for directory entries.  Also see HAMMER_DIR_INODE_LOCALIZATION().
927 */
928#define HAMMER_INODE_CAP_DIRHASH_MASK	0x03	/* directory: hash algorithm */
929#define HAMMER_INODE_CAP_DIRHASH_ALG0	0x00
930#define HAMMER_INODE_CAP_DIRHASH_ALG1	0x01
931#define HAMMER_INODE_CAP_DIRHASH_ALG2	0x02
932#define HAMMER_INODE_CAP_DIRHASH_ALG3	0x03
933#define HAMMER_INODE_CAP_DIR_LOCAL_INO	0x04	/* use inode localization */
934
935#define HAMMER_DATA_DOALIGN(offset)				\
936	(((offset) + 15) & ~15)
937#define HAMMER_DATA_DOALIGN_WITH(type, offset)			\
938	(((type)(offset) + 15) & (~(type)15))
939
940/*
941 * A HAMMER directory entry associates a HAMMER filesystem object with a
942 * namespace.  It is hooked into a pseudo-filesystem (with its own inode
943 * numbering space) in the filesystem by setting the high 16 bits of the
944 * localization field.  The low 16 bits must be 0 and are reserved for
945 * future use.
946 *
947 * Directory entries are indexed with a 128 bit namekey rather then an
948 * offset.  A portion of the namekey is an iterator/randomizer to deal
949 * with collisions.
950 *
951 * NOTE: leaf.base.obj_type from the related B-Tree leaf entry holds
952 * the filesystem object type of obj_id, e.g. a den_type equivalent.
953 * It is not stored in hammer_direntry_data.
954 *
955 * NOTE: name field / the filename data reference is NOT terminated with \0.
956 */
957typedef struct hammer_direntry_data {
958	int64_t obj_id;			/* object being referenced */
959	uint32_t localization;		/* identify pseudo-filesystem */
960	uint32_t reserved01;
961	char	name[16];		/* name (extended) */
962} *hammer_direntry_data_t;
963
964#define HAMMER_ENTRY_NAME_OFF	offsetof(struct hammer_direntry_data, name[0])
965#define HAMMER_ENTRY_SIZE(nlen)	offsetof(struct hammer_direntry_data, name[nlen])
966
967/*
968 * Symlink data which does not fit in the inode is stored in a separate
969 * FIX type record.
970 */
971typedef struct hammer_symlink_data {
972	char	name[16];		/* name (extended) */
973} *hammer_symlink_data_t;
974
975#define HAMMER_SYMLINK_NAME_OFF	offsetof(struct hammer_symlink_data, name[0])
976
977/*
978 * The root inode for the primary filesystem and root inode for any
979 * pseudo-fs may be tagged with an optional data structure using
980 * HAMMER_RECTYPE_PFS and localization id.  This structure allows
981 * the node to be used as a mirroring master or slave.
982 *
983 * When operating as a slave CD's into the node automatically become read-only
984 * and as-of sync_end_tid.
985 *
986 * When operating as a master the read PFSD info sets sync_end_tid to
987 * the most recently flushed TID.
988 *
989 * sync_low_tid is not yet used but will represent the highest pruning
990 * end-point, after which full history is available.
991 *
992 * We need to pack this structure making it equally sized on both 32-bit and
993 * 64-bit machines as it is part of struct hammer_ioc_mrecord_pfs which is
994 * send over the wire in hammer mirror operations. Only on 64-bit machines
995 * the size of this struct differ when packed or not. This leads us to the
996 * situation where old 64-bit systems (using the non-packed structure),
997 * which were never able to mirror to/from 32-bit systems, are now no longer
998 * able to mirror to/from newer 64-bit systems (using the packed structure).
999 */
1000struct hammer_pseudofs_data {
1001	hammer_tid_t	sync_low_tid;	/* full history beyond this point */
1002	hammer_tid_t	sync_beg_tid;	/* earliest tid w/ full history avail */
1003	hammer_tid_t	sync_end_tid;	/* current synchronizatoin point */
1004	uint64_t	sync_beg_ts;	/* real-time of last completed sync */
1005	uint64_t	sync_end_ts;	/* initiation of current sync cycle */
1006	hammer_uuid_t	shared_uuid;	/* shared uuid (match required) */
1007	hammer_uuid_t	unique_uuid;	/* unique uuid of this master/slave */
1008	int32_t		reserved01;	/* reserved for future master_id */
1009	int32_t		mirror_flags;	/* misc flags */
1010	char		label[64];	/* filesystem space label */
1011	char		snapshots[64];	/* softlink dir for pruning */
1012	int32_t		reserved02;	/* was prune_{time,freq} */
1013	int32_t		reserved03;	/* was reblock_{time,freq} */
1014	int32_t		reserved04;	/* was snapshot_freq */
1015	int32_t		prune_min;	/* do not prune recent history */
1016	int32_t		prune_max;	/* do not retain history beyond here */
1017	int32_t		reserved[16];
1018} __packed;
1019
1020typedef struct hammer_pseudofs_data *hammer_pseudofs_data_t;
1021
1022#define HAMMER_PFSD_SLAVE	0x00000001
1023#define HAMMER_PFSD_DELETED	0x80000000
1024
1025#define hammer_is_pfs_slave(pfsd)			\
1026	(((pfsd)->mirror_flags & HAMMER_PFSD_SLAVE) != 0)
1027#define hammer_is_pfs_master(pfsd)			\
1028	(!hammer_is_pfs_slave(pfsd))
1029#define hammer_is_pfs_deleted(pfsd)			\
1030	(((pfsd)->mirror_flags & HAMMER_PFSD_DELETED) != 0)
1031
1032#define HAMMER_MAX_PFS		65536
1033#define HAMMER_MAX_PFSID	(HAMMER_MAX_PFS - 1)
1034#define HAMMER_ROOT_PFSID	0
1035
1036/*
1037 * Snapshot meta-data { Objid = HAMMER_OBJID_ROOT, Key = tid, rectype = SNAPSHOT }.
1038 *
1039 * Snapshot records replace the old <fs>/snapshots/<softlink> methodology.  Snapshot
1040 * records are mirrored but may be independently managed once they are laid down on
1041 * a slave.
1042 *
1043 * NOTE: The b-tree key is signed, the tid is not, so callers must still sort the
1044 *	 results.
1045 *
1046 * NOTE: Reserved fields must be zero (as usual)
1047 */
1048typedef struct hammer_snapshot_data {
1049	hammer_tid_t	tid;		/* the snapshot TID itself (== key) */
1050	uint64_t	ts;		/* real-time when snapshot was made */
1051	uint64_t	reserved01;
1052	uint64_t	reserved02;
1053	char		label[64];	/* user-supplied description */
1054	uint64_t	reserved03[4];
1055} *hammer_snapshot_data_t;
1056
1057/*
1058 * Config meta-data { ObjId = HAMMER_OBJID_ROOT, Key = 0, rectype = CONFIG }.
1059 *
1060 * Used to store the hammer cleanup config.  This data is not mirrored.
1061 */
1062typedef struct hammer_config_data {
1063	char		text[1024];
1064} *hammer_config_data_t;
1065
1066/*
1067 * Rollup various structures embedded as record data
1068 */
1069typedef union hammer_data_ondisk {
1070	struct hammer_direntry_data entry;
1071	struct hammer_inode_data inode;
1072	struct hammer_symlink_data symlink;
1073	struct hammer_pseudofs_data pfsd;
1074	struct hammer_snapshot_data snap;
1075	struct hammer_config_data config;
1076} *hammer_data_ondisk_t;
1077
1078/*
1079 * Ondisk layout of B-Tree related structures
1080 */
1081#if 0	 /* Not needed for fstype(8) */
1082#include "hammer_btree.h"
1083#endif
1084
1085#define HAMMER_DIR_INODE_LOCALIZATION(ino_data)				\
1086	(((ino_data)->cap_flags & HAMMER_INODE_CAP_DIR_LOCAL_INO) ?	\
1087	 HAMMER_LOCALIZE_INODE :					\
1088	 HAMMER_LOCALIZE_MISC)
1089
1090#endif /* !VFS_HAMMER_DISK_H_ */
1091