xref: /dragonfly/sys/vfs/hammer2/hammer2_disk.h (revision a071436b)
1 /*
2  * Copyright (c) 2011-2019 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@dragonflybsd.org>
6  * by Venkatesh Srinivas <vsrinivas@dragonflybsd.org>
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in
16  *    the documentation and/or other materials provided with the
17  *    distribution.
18  * 3. Neither the name of The DragonFly Project nor the names of its
19  *    contributors may be used to endorse or promote products derived
20  *    from this software without specific, prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
26  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #ifndef _VFS_HAMMER2_DISK_H_
37 #define _VFS_HAMMER2_DISK_H_
38 
39 #ifndef _SYS_UUID_H_
40 #include <sys/uuid.h>
41 #endif
42 #ifndef _SYS_DMSG_H_
43 #include <sys/dmsg.h>
44 #endif
45 
46 /*
47  * The structures below represent the on-disk media structures for the HAMMER2
48  * filesystem.  Note that all fields for on-disk structures are naturally
49  * aligned.  The host endian format is typically used - compatibility is
50  * possible if the implementation detects reversed endian and adjusts accesses
51  * accordingly.
52  *
53  * HAMMER2 primarily revolves around the directory topology:  inodes,
54  * directory entries, and block tables.  Block device buffer cache buffers
55  * are always 64KB.  Logical file buffers are typically 16KB.  All data
56  * references utilize 64-bit byte offsets.
57  *
58  * Free block management is handled independently using blocks reserved by
59  * the media topology.
60  */
61 
62 /*
63  * The data at the end of a file or directory may be a fragment in order
64  * to optimize storage efficiency.  The minimum fragment size is 1KB.
65  * Since allocations are in powers of 2 fragments must also be sized in
66  * powers of 2 (1024, 2048, ... 65536).
67  *
68  * For the moment the maximum allocation size is HAMMER2_PBUFSIZE (64K),
69  * which is 2^16.  Larger extents may be supported in the future.  Smaller
70  * fragments might be supported in the future (down to 64 bytes is possible),
71  * but probably will not be.
72  *
73  * A full indirect block use supports 512 x 128-byte blockrefs in a 64KB
74  * buffer.  Indirect blocks down to 1KB are supported to keep small
75  * directories small.
76  *
77  * A maximally sized file (2^64-1 bytes) requires ~6 indirect block levels
78  * using 64KB indirect blocks (128 byte refs, 512 or radix 9 per indblk).
79  *
80  *	16(datablk) + 9 + 9 + 9 + 9 + 9 + 9 = ~70.
81  *	16(datablk) + 7 + 9 + 9 + 9 + 9 + 9 = ~68.  (smaller top level indblk)
82  *
83  * The actual depth depends on copies redundancy and whether the filesystem
84  * has chosen to use a smaller indirect block size at the top level or not.
85  */
86 #define HAMMER2_ALLOC_MIN	1024	/* minimum allocation size */
87 #define HAMMER2_RADIX_MIN	10	/* minimum allocation size 2^N */
88 #define HAMMER2_ALLOC_MAX	65536	/* maximum allocation size */
89 #define HAMMER2_RADIX_MAX	16	/* maximum allocation size 2^N */
90 #define HAMMER2_RADIX_KEY	64	/* number of bits in key */
91 
92 /*
93  * HAMMER2_LBUFSIZE	- Nominal buffer size for I/O rollups.
94  *
95  * HAMMER2_PBUFSIZE	- Topological block size used by files for all
96  *			  blocks except the block straddling EOF.
97  *
98  * HAMMER2_SEGSIZE	- Allocation map segment size, typically 4MB
99  *			  (space represented by a level0 bitmap).
100  */
101 
102 #define HAMMER2_SEGSIZE		(1 << HAMMER2_FREEMAP_LEVEL0_RADIX)
103 #define HAMMER2_SEGRADIX	HAMMER2_FREEMAP_LEVEL0_RADIX
104 
105 #define HAMMER2_PBUFRADIX	16	/* physical buf (1<<16) bytes */
106 #define HAMMER2_PBUFSIZE	65536
107 #define HAMMER2_LBUFRADIX	14	/* logical buf (1<<14) bytes */
108 #define HAMMER2_LBUFSIZE	16384
109 
110 #define HAMMER2_IND_BYTES_MIN	4096
111 #define HAMMER2_IND_BYTES_NOM	HAMMER2_LBUFSIZE
112 #define HAMMER2_IND_BYTES_MAX	HAMMER2_PBUFSIZE
113 #define HAMMER2_IND_RADIX_MIN	12
114 #define HAMMER2_IND_RADIX_NOM	HAMMER2_LBUFRADIX
115 #define HAMMER2_IND_RADIX_MAX	HAMMER2_PBUFRADIX
116 #define HAMMER2_IND_COUNT_MIN	(HAMMER2_IND_BYTES_MIN / \
117 				 sizeof(hammer2_blockref_t))
118 #define HAMMER2_IND_COUNT_NOM	(HAMMER2_IND_BYTES_NOM / \
119 				 sizeof(hammer2_blockref_t))
120 #define HAMMER2_IND_COUNT_MAX	(HAMMER2_IND_BYTES_MAX / \
121 				 sizeof(hammer2_blockref_t))
122 
123 /*
124  * In HAMMER2, arrays of blockrefs are fully set-associative, meaning that
125  * any element can occur at any index and holes can be anywhere.
126  *
127  * Inodes embed either 512 bytes of direct data or an array of 4 blockrefs,
128  * resulting in highly efficient storage for files <= 512 bytes and for files
129  * <= 512KB.  Up to 4 directory entries can be referenced from a directory
130  * without requiring an indirect block.
131  */
132 #define HAMMER2_SET_RADIX		2	/* radix 2 = 4 entries */
133 #define HAMMER2_SET_COUNT		(1 << HAMMER2_SET_RADIX)
134 #define HAMMER2_EMBEDDED_BYTES		512	/* inode blockset/dd size */
135 #define HAMMER2_EMBEDDED_RADIX		9
136 
137 #define HAMMER2_PBUFMASK	(HAMMER2_PBUFSIZE - 1)
138 #define HAMMER2_LBUFMASK	(HAMMER2_LBUFSIZE - 1)
139 #define HAMMER2_SEGMASK		(HAMMER2_SEGSIZE - 1)
140 
141 #define HAMMER2_LBUFMASK64	((hammer2_off_t)HAMMER2_LBUFMASK)
142 #define HAMMER2_PBUFSIZE64	((hammer2_off_t)HAMMER2_PBUFSIZE)
143 #define HAMMER2_PBUFMASK64	((hammer2_off_t)HAMMER2_PBUFMASK)
144 #define HAMMER2_SEGSIZE64	((hammer2_off_t)HAMMER2_SEGSIZE)
145 #define HAMMER2_SEGMASK64	((hammer2_off_t)HAMMER2_SEGMASK)
146 
147 #define HAMMER2_UUID_STRING	"5cbb9ad1-862d-11dc-a94d-01301bb8a9f5"
148 
149 /*
150  * A 4MB segment is reserved at the beginning of each 1GB.  This segment
151  * contains the volume header (or backup volume header), the free block
152  * table, and possibly other information in the future.
153  *
154  * 4MB = 64 x 64K blocks.  Each 4MB segment is broken down as follows:
155  *
156  * ==========
157  *  0 volume header (for the first four 2GB zones)
158  *  1 freemap00 level1 FREEMAP_LEAF (256 x 128B bitmap data per 1GB)
159  *  2           level2 FREEMAP_NODE (256 x 128B indirect block per 256GB)
160  *  3           level3 FREEMAP_NODE (256 x 128B indirect block per 64TB)
161  *  4           level4 FREEMAP_NODE (256 x 128B indirect block per 16PB)
162  *  5           level5 FREEMAP_NODE (256 x 128B indirect block per 4EB)
163  *  6 freemap01 level1 (rotation)
164  *  7           level2
165  *  8           level3
166  *  9           level4
167  * 10           level5
168  * 11 freemap02 level1 (rotation)
169  * 12           level2
170  * 13           level3
171  * 14           level4
172  * 15           level5
173  * 16 freemap03 level1 (rotation)
174  * 17           level2
175  * 18           level3
176  * 19           level4
177  * 20           level5
178  * 21 freemap04 level1 (rotation)
179  * 22           level2
180  * 23           level3
181  * 24           level4
182  * 25           level5
183  * 26 freemap05 level1 (rotation)
184  * 27           level2
185  * 28           level3
186  * 29           level4
187  * 30           level5
188  * 31 freemap06 level1 (rotation)
189  * 32           level2
190  * 33           level3
191  * 34           level4
192  * 35           level5
193  * 36 freemap07 level1 (rotation)
194  * 37           level2
195  * 38           level3
196  * 39           level4
197  * 40           level5
198  * 41 unused
199  * .. unused
200  * 63 unused
201  * ==========
202  *
203  * The first four 2GB zones contain volume headers and volume header backups.
204  * After that the volume header block# is reserved for future use.  Similarly,
205  * there are many blocks related to various Freemap levels which are not
206  * used in every segment and those are also reserved for future use.
207  * Note that each FREEMAP_LEAF or FREEMAP_NODE uses 32KB out of 64KB slot.
208  *
209  *			Freemap (see the FREEMAP document)
210  *
211  * The freemap utilizes blocks #1-40 in 8 sets of 5 blocks.  Each block in
212  * a set represents a level of depth in the freemap topology.  Eight sets
213  * exist to prevent live updates from disturbing the state of the freemap
214  * were a crash/reboot to occur.  That is, a live update is not committed
215  * until the update's flush reaches the volume root.  There are FOUR volume
216  * roots representing the last four synchronization points, so the freemap
217  * must be consistent no matter which volume root is chosen by the mount
218  * code.
219  *
220  * Each freemap set is 5 x 64K blocks and represents the 1GB, 256GB, 64TB,
221  * 16PB and 4EB indirect map.  The volume header itself has a set of 4 freemap
222  * blockrefs representing another 2 bits, giving us a total 64 bits of
223  * representable address space.
224  *
225  * The Level 0 64KB block represents 1GB of storage represented by 32KB
226  * (256 x struct hammer2_bmap_data).  Each structure represents 4MB of storage
227  * and has a 512 bit bitmap, using 2 bits to represent a 16KB chunk of
228  * storage.  These 2 bits represent the following states:
229  *
230  *	00	Free
231  *	01	(reserved) (Possibly partially allocated)
232  *	10	Possibly free
233  *	11	Allocated
234  *
235  * One important thing to note here is that the freemap resolution is 16KB,
236  * but the minimum storage allocation size is 1KB.  The hammer2 vfs keeps
237  * track of sub-allocations in memory, which means that on a unmount or reboot
238  * the entire 16KB of a partially allocated block will be considered fully
239  * allocated.  It is possible for fragmentation to build up over time, but
240  * defragmentation is fairly easy to accomplish since all modifications
241  * allocate a new block.
242  *
243  * The Second thing to note is that due to the way snapshots and inode
244  * replication works, deleting a file cannot immediately free the related
245  * space.  Furthermore, deletions often do not bother to traverse the
246  * block subhierarchy being deleted.  And to go even further, whole
247  * sub-directory trees can be deleted simply by deleting the directory inode
248  * at the top.  So even though we have a symbol to represent a 'possibly free'
249  * block (binary 10), only the bulk free scanning code can actually use it.
250  * Normal 'rm's or other deletions do not.
251  *
252  * WARNING!  ZONE_SEG and VOLUME_ALIGN must be a multiple of 1<<LEVEL0_RADIX
253  *	     (i.e. a multiple of 4MB).  VOLUME_ALIGN must be >= ZONE_SEG.
254  *
255  * In Summary:
256  *
257  * (1) Modifications to freemap blocks 'allocate' a new copy (aka use a block
258  *     from the next set).  The new copy is reused until a flush occurs at
259  *     which point the next modification will then rotate to the next set.
260  */
261 #define HAMMER2_VOLUME_ALIGN		(8 * 1024 * 1024)
262 #define HAMMER2_VOLUME_ALIGN64		((hammer2_off_t)HAMMER2_VOLUME_ALIGN)
263 #define HAMMER2_VOLUME_ALIGNMASK	(HAMMER2_VOLUME_ALIGN - 1)
264 #define HAMMER2_VOLUME_ALIGNMASK64	((hammer2_off_t)HAMMER2_VOLUME_ALIGNMASK)
265 
266 #define HAMMER2_NEWFS_ALIGN		(HAMMER2_VOLUME_ALIGN)
267 #define HAMMER2_NEWFS_ALIGN64		((hammer2_off_t)HAMMER2_VOLUME_ALIGN)
268 #define HAMMER2_NEWFS_ALIGNMASK		(HAMMER2_VOLUME_ALIGN - 1)
269 #define HAMMER2_NEWFS_ALIGNMASK64	((hammer2_off_t)HAMMER2_NEWFS_ALIGNMASK)
270 
271 #define HAMMER2_ZONE_BYTES64		(2LLU * 1024 * 1024 * 1024)
272 #define HAMMER2_ZONE_MASK64		(HAMMER2_ZONE_BYTES64 - 1)
273 #define HAMMER2_ZONE_SEG		(4 * 1024 * 1024)
274 #define HAMMER2_ZONE_SEG64		((hammer2_off_t)HAMMER2_ZONE_SEG)
275 #define HAMMER2_ZONE_BLOCKS_SEG		(HAMMER2_ZONE_SEG / HAMMER2_PBUFSIZE)
276 
277 #define HAMMER2_ZONE_FREEMAP_INC	5	/* 5 deep */
278 
279 #define HAMMER2_ZONE_VOLHDR		0	/* volume header or backup */
280 #define HAMMER2_ZONE_FREEMAP_00		1	/* normal freemap rotation */
281 #define HAMMER2_ZONE_FREEMAP_01		6	/* normal freemap rotation */
282 #define HAMMER2_ZONE_FREEMAP_02		11	/* normal freemap rotation */
283 #define HAMMER2_ZONE_FREEMAP_03		16	/* normal freemap rotation */
284 #define HAMMER2_ZONE_FREEMAP_04		21	/* normal freemap rotation */
285 #define HAMMER2_ZONE_FREEMAP_05		26	/* normal freemap rotation */
286 #define HAMMER2_ZONE_FREEMAP_06		31	/* normal freemap rotation */
287 #define HAMMER2_ZONE_FREEMAP_07		36	/* normal freemap rotation */
288 #define HAMMER2_ZONE_FREEMAP_END	41	/* (non-inclusive) */
289 
290 #define HAMMER2_ZONE_UNUSED41		41
291 #define HAMMER2_ZONE_UNUSED42		42
292 #define HAMMER2_ZONE_UNUSED43		43
293 #define HAMMER2_ZONE_UNUSED44		44
294 #define HAMMER2_ZONE_UNUSED45		45
295 #define HAMMER2_ZONE_UNUSED46		46
296 #define HAMMER2_ZONE_UNUSED47		47
297 #define HAMMER2_ZONE_UNUSED48		48
298 #define HAMMER2_ZONE_UNUSED49		49
299 #define HAMMER2_ZONE_UNUSED50		50
300 #define HAMMER2_ZONE_UNUSED51		51
301 #define HAMMER2_ZONE_UNUSED52		52
302 #define HAMMER2_ZONE_UNUSED53		53
303 #define HAMMER2_ZONE_UNUSED54		54
304 #define HAMMER2_ZONE_UNUSED55		55
305 #define HAMMER2_ZONE_UNUSED56		56
306 #define HAMMER2_ZONE_UNUSED57		57
307 #define HAMMER2_ZONE_UNUSED58		58
308 #define HAMMER2_ZONE_UNUSED59		59
309 #define HAMMER2_ZONE_UNUSED60		60
310 #define HAMMER2_ZONE_UNUSED61		61
311 #define HAMMER2_ZONE_UNUSED62		62
312 #define HAMMER2_ZONE_UNUSED63		63
313 #define HAMMER2_ZONE_END		64	/* non-inclusive */
314 
315 #define HAMMER2_NFREEMAPS		8	/* FREEMAP_00 - FREEMAP_07 */
316 
317 						/* relative to FREEMAP_x */
318 #define HAMMER2_ZONEFM_LEVEL1		0	/* 1GB leafmap */
319 #define HAMMER2_ZONEFM_LEVEL2		1	/* 256GB indmap */
320 #define HAMMER2_ZONEFM_LEVEL3		2	/* 64TB indmap */
321 #define HAMMER2_ZONEFM_LEVEL4		3	/* 16PB indmap */
322 #define HAMMER2_ZONEFM_LEVEL5		4	/* 4EB indmap */
323 /* LEVEL6 is a set of 4 blockrefs in the volume header 16EB */
324 
325 /*
326  * Freemap radix.  Assumes a set-count of 4, 128-byte blockrefs,
327  * 32KB indirect block for freemap (LEVELN_PSIZE below).
328  *
329  * Leaf entry represents 4MB of storage broken down into a 512-bit
330  * bitmap, 2-bits per entry.  So course bitmap item represents 16KB.
331  */
332 #if HAMMER2_SET_COUNT != 4
333 #error "hammer2_disk.h - freemap assumes SET_COUNT is 4"
334 #endif
335 #define HAMMER2_FREEMAP_LEVEL6_RADIX	64	/* 16EB (end) */
336 #define HAMMER2_FREEMAP_LEVEL5_RADIX	62	/* 4EB */
337 #define HAMMER2_FREEMAP_LEVEL4_RADIX	54	/* 16PB */
338 #define HAMMER2_FREEMAP_LEVEL3_RADIX	46	/* 64TB */
339 #define HAMMER2_FREEMAP_LEVEL2_RADIX	38	/* 256GB */
340 #define HAMMER2_FREEMAP_LEVEL1_RADIX	30	/* 1GB */
341 #define HAMMER2_FREEMAP_LEVEL0_RADIX	22	/* 4MB (x 256 in l-1 leaf) */
342 
343 #define HAMMER2_FREEMAP_LEVELN_PSIZE	32768	/* physical bytes */
344 
345 #define HAMMER2_FREEMAP_LEVEL5_SIZE	((hammer2_off_t)1 <<		\
346 					 HAMMER2_FREEMAP_LEVEL5_RADIX)
347 #define HAMMER2_FREEMAP_LEVEL4_SIZE	((hammer2_off_t)1 <<		\
348 					 HAMMER2_FREEMAP_LEVEL4_RADIX)
349 #define HAMMER2_FREEMAP_LEVEL3_SIZE	((hammer2_off_t)1 <<		\
350 					 HAMMER2_FREEMAP_LEVEL3_RADIX)
351 #define HAMMER2_FREEMAP_LEVEL2_SIZE	((hammer2_off_t)1 <<		\
352 					 HAMMER2_FREEMAP_LEVEL2_RADIX)
353 #define HAMMER2_FREEMAP_LEVEL1_SIZE	((hammer2_off_t)1 <<		\
354 					 HAMMER2_FREEMAP_LEVEL1_RADIX)
355 #define HAMMER2_FREEMAP_LEVEL0_SIZE	((hammer2_off_t)1 <<		\
356 					 HAMMER2_FREEMAP_LEVEL0_RADIX)
357 
358 #define HAMMER2_FREEMAP_LEVEL5_MASK	(HAMMER2_FREEMAP_LEVEL5_SIZE - 1)
359 #define HAMMER2_FREEMAP_LEVEL4_MASK	(HAMMER2_FREEMAP_LEVEL4_SIZE - 1)
360 #define HAMMER2_FREEMAP_LEVEL3_MASK	(HAMMER2_FREEMAP_LEVEL3_SIZE - 1)
361 #define HAMMER2_FREEMAP_LEVEL2_MASK	(HAMMER2_FREEMAP_LEVEL2_SIZE - 1)
362 #define HAMMER2_FREEMAP_LEVEL1_MASK	(HAMMER2_FREEMAP_LEVEL1_SIZE - 1)
363 #define HAMMER2_FREEMAP_LEVEL0_MASK	(HAMMER2_FREEMAP_LEVEL0_SIZE - 1)
364 
365 #define HAMMER2_FREEMAP_COUNT		(int)(HAMMER2_FREEMAP_LEVELN_PSIZE / \
366 					 sizeof(hammer2_bmap_data_t))
367 
368 /*
369  * XXX I made a mistake and made the reserved area begin at each LEVEL1 zone,
370  *     which is on a 1GB demark.  This will eat a little more space but for
371  *     now we retain compatibility and make FMZONEBASE every 1GB
372  */
373 #define H2FMZONEBASE(key)	((key) & ~HAMMER2_FREEMAP_LEVEL1_MASK)
374 #define H2FMBASE(key, radix)	rounddown2(key, (hammer2_off_t)1 << (radix))
375 
376 /*
377  * 16KB bitmap granularity (x2 bits per entry).
378  */
379 #define HAMMER2_FREEMAP_BLOCK_RADIX	14
380 #define HAMMER2_FREEMAP_BLOCK_SIZE	(1 << HAMMER2_FREEMAP_BLOCK_RADIX)
381 #define HAMMER2_FREEMAP_BLOCK_MASK	(HAMMER2_FREEMAP_BLOCK_SIZE - 1)
382 
383 /*
384  * bitmap[] structure.  2 bits per HAMMER2_FREEMAP_BLOCK_SIZE.
385  *
386  * 8 x 64-bit elements, 2 bits per block.
387  * 32 blocks (radix 5) per element.
388  * representing INDEX_SIZE bytes worth of storage per element.
389  */
390 
391 typedef uint64_t hammer2_bitmap_t;
392 
393 #define HAMMER2_BMAP_ALLONES		((hammer2_bitmap_t)-1)
394 #define HAMMER2_BMAP_ELEMENTS		8
395 #define HAMMER2_BMAP_BITS_PER_ELEMENT	64
396 #define HAMMER2_BMAP_INDEX_RADIX	5	/* 32 blocks per element */
397 #define HAMMER2_BMAP_BLOCKS_PER_ELEMENT	(1 << HAMMER2_BMAP_INDEX_RADIX)
398 
399 #define HAMMER2_BMAP_INDEX_SIZE		(HAMMER2_FREEMAP_BLOCK_SIZE * \
400 					 HAMMER2_BMAP_BLOCKS_PER_ELEMENT)
401 #define HAMMER2_BMAP_INDEX_MASK		(HAMMER2_BMAP_INDEX_SIZE - 1)
402 
403 #define HAMMER2_BMAP_SIZE		(HAMMER2_BMAP_INDEX_SIZE * \
404 					 HAMMER2_BMAP_ELEMENTS)
405 #define HAMMER2_BMAP_MASK		(HAMMER2_BMAP_SIZE - 1)
406 
407 /*
408  * Two linear areas can be reserved after the initial 4MB segment in the base
409  * zone (the one starting at offset 0).  These areas are NOT managed by the
410  * block allocator and do not fall under HAMMER2 crc checking rules based
411  * at the volume header (but can be self-CRCd internally, depending).
412  */
413 #define HAMMER2_BOOT_MIN_BYTES		HAMMER2_VOLUME_ALIGN
414 #define HAMMER2_BOOT_NOM_BYTES		(64*1024*1024)
415 #define HAMMER2_BOOT_MAX_BYTES		(256*1024*1024)
416 
417 #define HAMMER2_AUX_MIN_BYTES		HAMMER2_VOLUME_ALIGN
418 #define HAMMER2_AUX_NOM_BYTES		(256*1024*1024)
419 #define HAMMER2_AUX_MAX_BYTES		(1024*1024*1024)
420 
421 /*
422  * Most HAMMER2 types are implemented as unsigned 64-bit integers.
423  * Transaction ids are monotonic.
424  *
425  * We utilize 32-bit iSCSI CRCs.
426  */
427 typedef uint64_t hammer2_tid_t;
428 typedef uint64_t hammer2_off_t;
429 typedef uint64_t hammer2_key_t;
430 typedef uint32_t hammer2_crc32_t;
431 
432 /*
433  * Miscellaneous ranges (all are unsigned).
434  */
435 #define HAMMER2_TID_MIN		1ULL
436 #define HAMMER2_TID_MAX		0xFFFFFFFFFFFFFFFFULL
437 #define HAMMER2_KEY_MIN		0ULL
438 #define HAMMER2_KEY_MAX		0xFFFFFFFFFFFFFFFFULL
439 
440 /*
441  * HAMMER2 data offset special cases and masking.
442  *
443  * All HAMMER2 data offsets have to be broken down into a 64K buffer base
444  * offset (HAMMER2_OFF_MASK_HI) and a 64K buffer index (HAMMER2_OFF_MASK_LO).
445  *
446  * Indexes into physical buffers are always 64-byte aligned.  The low 6 bits
447  * of the data offset field specifies how large the data chunk being pointed
448  * to as a power of 2.  The theoretical minimum radix is thus 6 (The space
449  * needed in the low bits of the data offset field).  However, the practical
450  * minimum allocation chunk size is 1KB (a radix of 10), so HAMMER2 sets
451  * HAMMER2_RADIX_MIN to 10.  The maximum radix is currently 16 (64KB), but
452  * we fully intend to support larger extents in the future.
453  *
454  * WARNING! A radix of 0 (such as when data_off is all 0's) is a special
455  *	    case which means no data associated with the blockref, and
456  *	    not the '1 byte' it would otherwise calculate to.
457  */
458 #define HAMMER2_OFF_MASK	0xFFFFFFFFFFFFFFC0ULL
459 #define HAMMER2_OFF_MASK_LO	(HAMMER2_OFF_MASK & HAMMER2_PBUFMASK64)
460 #define HAMMER2_OFF_MASK_HI	(~HAMMER2_PBUFMASK64)
461 #define HAMMER2_OFF_MASK_RADIX	0x000000000000003FULL
462 
463 /*
464  * HAMMER2 directory support and pre-defined keys
465  */
466 #define HAMMER2_DIRHASH_VISIBLE	0x8000000000000000ULL
467 #define HAMMER2_DIRHASH_USERMSK	0x7FFFFFFFFFFFFFFFULL
468 #define HAMMER2_DIRHASH_LOMASK	0x0000000000007FFFULL
469 #if 0
470 #define HAMMER2_DIRHASH_HIMASK	0xFFFFFFFFFFFF0000ULL
471 #define HAMMER2_DIRHASH_FORCED	0x0000000000008000ULL	/* bit forced on */
472 #endif
473 
474 #define HAMMER2_SROOT_KEY	0x0000000000000000ULL	/* volume to sroot */
475 #define HAMMER2_BOOT_KEY	0xd9b36ce135528000ULL	/* sroot to BOOT PFS */
476 
477 /************************************************************************
478  *				DMSG SUPPORT				*
479  ************************************************************************
480  * LNK_VOLCONF
481  *
482  * All HAMMER2 directories directly under the super-root on your local
483  * media can be mounted separately, even if they share the same physical
484  * device.
485  *
486  * When you do a HAMMER2 mount you are effectively tying into a HAMMER2
487  * cluster via local media.  The local media does not have to participate
488  * in the cluster, other than to provide the hammer2_volconf[] array and
489  * root inode for the mount.
490  *
491  * This is important: The mount device path you specify serves to bootstrap
492  * your entry into the cluster, but your mount will make active connections
493  * to ALL copy elements in the hammer2_volconf[] array which match the
494  * PFSID of the directory in the super-root that you specified.  The local
495  * media path does not have to be mentioned in this array but becomes part
496  * of the cluster based on its type and access rights.  ALL ELEMENTS ARE
497  * TREATED ACCORDING TO TYPE NO MATTER WHICH ONE YOU MOUNT FROM.
498  *
499  * The actual cluster may be far larger than the elements you list in the
500  * hammer2_volconf[] array.  You list only the elements you wish to
501  * directly connect to and you are able to access the rest of the cluster
502  * indirectly through those connections.
503  *
504  * WARNING!  This structure must be exactly 128 bytes long for its config
505  *	     array to fit in the volume header.
506  */
507 struct hammer2_volconf {
508 	uint8_t	copyid;		/* 00	 copyid 0-255 (must match slot) */
509 	uint8_t inprog;		/* 01	 operation in progress, or 0 */
510 	uint8_t chain_to;	/* 02	 operation chaining to, or 0 */
511 	uint8_t chain_from;	/* 03	 operation chaining from, or 0 */
512 	uint16_t flags;		/* 04-05 flags field */
513 	uint8_t error;		/* 06	 last operational error */
514 	uint8_t priority;	/* 07	 priority and round-robin flag */
515 	uint8_t remote_pfs_type;/* 08	 probed direct remote PFS type */
516 	uint8_t reserved08[23];	/* 09-1F */
517 	uuid_t	pfs_clid;	/* 20-2F copy target must match this uuid */
518 	uint8_t label[16];	/* 30-3F import/export label */
519 	uint8_t path[64];	/* 40-7F target specification string or key */
520 } __packed;
521 
522 typedef struct hammer2_volconf hammer2_volconf_t;
523 
524 #define DMSG_VOLF_ENABLED	0x0001
525 #define DMSG_VOLF_INPROG	0x0002
526 #define DMSG_VOLF_CONN_RR	0x80	/* round-robin at same priority */
527 #define DMSG_VOLF_CONN_EF	0x40	/* media errors flagged */
528 #define DMSG_VOLF_CONN_PRI	0x0F	/* select priority 0-15 (15=best) */
529 
530 struct dmsg_lnk_hammer2_volconf {
531 	dmsg_hdr_t		head;
532 	hammer2_volconf_t	copy;	/* copy spec */
533 	int32_t			index;
534 	int32_t			unused01;
535 	uuid_t			mediaid;
536 	int64_t			reserved02[32];
537 } __packed;
538 
539 typedef struct dmsg_lnk_hammer2_volconf dmsg_lnk_hammer2_volconf_t;
540 
541 #define DMSG_LNK_HAMMER2_VOLCONF DMSG_LNK(DMSG_LNK_CMD_HAMMER2_VOLCONF, \
542 					  dmsg_lnk_hammer2_volconf)
543 
544 #define H2_LNK_VOLCONF(msg)	((dmsg_lnk_hammer2_volconf_t *)(msg)->any.buf)
545 
546 /*
547  * HAMMER2 directory entry header (embedded in blockref)  exactly 16 bytes
548  */
549 struct hammer2_dirent_head {
550 	hammer2_tid_t		inum;		/* inode number */
551 	uint16_t		namlen;		/* name length */
552 	uint8_t			type;		/* OBJTYPE_*	*/
553 	uint8_t			unused0B;
554 	uint8_t			unused0C[4];
555 } __packed;
556 
557 typedef struct hammer2_dirent_head hammer2_dirent_head_t;
558 
559 /*
560  * The media block reference structure.  This forms the core of the HAMMER2
561  * media topology recursion.  This 128-byte data structure is embedded in the
562  * volume header, in inodes (which are also directory entries), and in
563  * indirect blocks.
564  *
565  * A blockref references a single media item, which typically can be a
566  * directory entry (aka inode), indirect block, or data block.
567  *
568  * The primary feature a blockref represents is the ability to validate
569  * the entire tree underneath it via its check code.  Any modification to
570  * anything propagates up the blockref tree all the way to the root, replacing
571  * the related blocks and compounding the generated check code.
572  *
573  * The check code can be a simple 32-bit iscsi code, a 64-bit crc, or as
574  * complex as a 512 bit cryptographic hash.  I originally used a 64-byte
575  * blockref but later expanded it to 128 bytes to be able to support the
576  * larger check code as well as to embed statistics for quota operation.
577  *
578  * Simple check codes are not sufficient for unverified dedup.  Even with
579  * a maximally-sized check code unverified dedup should only be used in
580  * in subdirectory trees where you do not need 100% data integrity.
581  *
582  * Unverified dedup is deduping based on meta-data only without verifying
583  * that the data blocks are actually identical.  Verified dedup guarantees
584  * integrity but is a far more I/O-expensive operation.
585  *
586  * --
587  *
588  * mirror_tid - per cluster node modified (propagated upward by flush)
589  * modify_tid - clc record modified (not propagated).
590  * update_tid - clc record updated (propagated upward on verification)
591  *
592  * CLC - Stands for 'Cluster Level Change', identifiers which are identical
593  *	 within the topology across all cluster nodes (when fully
594  *	 synchronized).
595  *
596  * NOTE: The range of keys represented by the blockref is (key) to
597  *	 ((key) + (1LL << keybits) - 1).  HAMMER2 usually populates
598  *	 blocks bottom-up, inserting a new root when radix expansion
599  *	 is required.
600  *
601  * leaf_count  - Helps manage leaf collapse calculations when indirect
602  *		 blocks become mostly empty.  This value caps out at
603  *		 HAMMER2_BLOCKREF_LEAF_MAX (65535).
604  *
605  *		 Used by the chain code to determine when to pull leafs up
606  *		 from nearly empty indirect blocks.  For the purposes of this
607  *		 calculation, BREF_TYPE_INODE is considered a leaf, along
608  *		 with DIRENT and DATA.
609  *
610  *				    RESERVED FIELDS
611  *
612  * A number of blockref fields are reserved and should generally be set to
613  * 0 for future compatibility.
614  *
615  *				FUTURE BLOCKREF EXPANSION
616  *
617  * CONTENT ADDRESSABLE INDEXING (future) - Using a 256 or 512-bit check code.
618  */
619 struct hammer2_blockref {		/* MUST BE EXACTLY 64 BYTES */
620 	uint8_t		type;		/* type of underlying item */
621 	uint8_t		methods;	/* check method & compression method */
622 	uint8_t		copyid;		/* specify which copy this is */
623 	uint8_t		keybits;	/* #of keybits masked off 0=leaf */
624 	uint8_t		vradix;		/* virtual data/meta-data size */
625 	uint8_t		flags;		/* blockref flags */
626 	uint16_t	leaf_count;	/* leaf aggregation count */
627 	hammer2_key_t	key;		/* key specification */
628 	hammer2_tid_t	mirror_tid;	/* media flush topology & freemap */
629 	hammer2_tid_t	modify_tid;	/* clc modify (not propagated) */
630 	hammer2_off_t	data_off;	/* low 6 bits is phys size (radix)*/
631 	hammer2_tid_t	update_tid;	/* clc modify (propagated upward) */
632 	union {
633 		char	buf[16];
634 
635 		/*
636 		 * Directory entry header (BREF_TYPE_DIRENT)
637 		 *
638 		 * NOTE: check.buf contains filename if <= 64 bytes.  Longer
639 		 *	 filenames are stored in a data reference of size
640 		 *	 HAMMER2_ALLOC_MIN (at least 256, typically 1024).
641 		 *
642 		 * NOTE: inode structure may contain a copy of a recently
643 		 *	 associated filename, for recovery purposes.
644 		 *
645 		 * NOTE: Superroot entries are INODEs, not DIRENTs.  Code
646 		 *	 allows both cases.
647 		 */
648 		hammer2_dirent_head_t dirent;
649 
650 		/*
651 		 * Statistics aggregation (BREF_TYPE_INODE, BREF_TYPE_INDIRECT)
652 		 */
653 		struct {
654 			hammer2_key_t	data_count;
655 			hammer2_key_t	inode_count;
656 		} stats;
657 	} embed;
658 	union {				/* check info */
659 		char	buf[64];
660 		struct {
661 			uint32_t value;
662 			uint32_t reserved[15];
663 		} iscsi32;
664 		struct {
665 			uint64_t value;
666 			uint64_t reserved[7];
667 		} xxhash64;
668 		struct {
669 			char data[24];
670 			char reserved[40];
671 		} sha192;
672 		struct {
673 			char data[32];
674 			char reserved[32];
675 		} sha256;
676 		struct {
677 			char data[64];
678 		} sha512;
679 
680 		/*
681 		 * Freemap hints are embedded in addition to the icrc32.
682 		 *
683 		 * bigmask - Radixes available for allocation (0-31).
684 		 *	     Heuristical (may be permissive but not
685 		 *	     restrictive).  Typically only radix values
686 		 *	     10-16 are used (i.e. (1<<10) through (1<<16)).
687 		 *
688 		 * avail   - Total available space remaining, in bytes
689 		 */
690 		struct {
691 			uint32_t icrc32;
692 			uint32_t bigmask;	/* available radixes */
693 			uint64_t avail;		/* total available bytes */
694 			char reserved[48];
695 		} freemap;
696 	} check;
697 } __packed;
698 
699 typedef struct hammer2_blockref hammer2_blockref_t;
700 
701 #define HAMMER2_BLOCKREF_BYTES		128	/* blockref struct in bytes */
702 #define HAMMER2_BLOCKREF_RADIX		7
703 
704 #define HAMMER2_BLOCKREF_LEAF_MAX	65535
705 
706 /*
707  * On-media and off-media blockref types.
708  *
709  * types >= 128 are pseudo values that should never be present on-media.
710  */
711 #define HAMMER2_BREF_TYPE_EMPTY		0
712 #define HAMMER2_BREF_TYPE_INODE		1
713 #define HAMMER2_BREF_TYPE_INDIRECT	2
714 #define HAMMER2_BREF_TYPE_DATA		3
715 #define HAMMER2_BREF_TYPE_DIRENT	4
716 #define HAMMER2_BREF_TYPE_FREEMAP_NODE	5
717 #define HAMMER2_BREF_TYPE_FREEMAP_LEAF	6
718 #define HAMMER2_BREF_TYPE_INVALID	7
719 #define HAMMER2_BREF_TYPE_FREEMAP	254	/* pseudo-type */
720 #define HAMMER2_BREF_TYPE_VOLUME	255	/* pseudo-type */
721 
722 #define HAMMER2_BREF_FLAG_PFSROOT	0x01	/* see also related opflag */
723 #define HAMMER2_BREF_FLAG_UNUSED	0x02
724 #define HAMMER2_BREF_FLAG_EMERG_MIP	0x04	/* emerg modified-in-place */
725 
726 /*
727  * Encode/decode check mode and compression mode for bref.methods.
728  * The compression level is not encoded in bref.methods.
729  */
730 #define HAMMER2_ENC_CHECK(n)		(((n) & 15) << 4)
731 #define HAMMER2_DEC_CHECK(n)		(((n) >> 4) & 15)
732 #define HAMMER2_ENC_COMP(n)		((n) & 15)
733 #define HAMMER2_DEC_COMP(n)		((n) & 15)
734 
735 #define HAMMER2_CHECK_NONE		0
736 #define HAMMER2_CHECK_DISABLED		1
737 #define HAMMER2_CHECK_ISCSI32		2
738 #define HAMMER2_CHECK_XXHASH64		3
739 #define HAMMER2_CHECK_SHA192		4
740 #define HAMMER2_CHECK_FREEMAP		5
741 
742 #define HAMMER2_CHECK_DEFAULT		HAMMER2_CHECK_XXHASH64
743 
744 /*
745  * Encode/decode check or compression algorithm request in
746  * ipdata->meta.check_algo and ipdata->meta.comp_algo.
747  */
748 #define HAMMER2_ENC_ALGO(n)		(n)
749 #define HAMMER2_DEC_ALGO(n)		((n) & 15)
750 #define HAMMER2_ENC_LEVEL(n)		((n) << 4)
751 #define HAMMER2_DEC_LEVEL(n)		(((n) >> 4) & 15)
752 
753 #define HAMMER2_COMP_NONE		0
754 #define HAMMER2_COMP_AUTOZERO		1
755 #define HAMMER2_COMP_LZ4		2
756 #define HAMMER2_COMP_ZLIB		3
757 
758 #define HAMMER2_COMP_DEFAULT		HAMMER2_COMP_LZ4
759 
760 /*
761  * HAMMER2 block references are collected into sets of 4 blockrefs.  These
762  * sets are fully associative, meaning the elements making up a set may
763  * contain duplicate entries, holes, but valid elements are always sorted.
764  *
765  * When redundancy is desired a set may contain several duplicate
766  * entries pointing to different copies of the same data.  Up to 4 copies
767  * are supported. Not implemented.
768  *
769  * When a set fills up another level of indirection is inserted, moving
770  * some or all of the set's contents into indirect blocks placed under the
771  * set.  This is a top-down approach in that indirect blocks are not created
772  * until the set actually becomes full (that is, the entries in the set can
773  * shortcut the indirect blocks when the set is not full).  Depending on how
774  * things are filled multiple indirect blocks will eventually be created.
775  */
776 struct hammer2_blockset {
777 	hammer2_blockref_t	blockref[HAMMER2_SET_COUNT];
778 };
779 
780 typedef struct hammer2_blockset hammer2_blockset_t;
781 
782 /*
783  * Catch programmer snafus
784  */
785 #if (1 << HAMMER2_SET_RADIX) != HAMMER2_SET_COUNT
786 #error "hammer2 direct radix is incorrect"
787 #endif
788 #if (1 << HAMMER2_PBUFRADIX) != HAMMER2_PBUFSIZE
789 #error "HAMMER2_PBUFRADIX and HAMMER2_PBUFSIZE are inconsistent"
790 #endif
791 #if (1 << HAMMER2_RADIX_MIN) != HAMMER2_ALLOC_MIN
792 #error "HAMMER2_RADIX_MIN and HAMMER2_ALLOC_MIN are inconsistent"
793 #endif
794 
795 /*
796  * hammer2_bmap_data - A freemap entry in the LEVEL1 block.
797  *
798  * Each 128-byte entry contains the bitmap and meta-data required to manage
799  * a LEVEL0 (4MB) block of storage.  The storage is managed in 256 x 16KB
800  * chunks.
801  *
802  * A smaller allocation granularity is supported via a linear iterator and/or
803  * must otherwise be tracked in ram.
804  *
805  * (data structure must be 128 bytes exactly)
806  *
807  * linear  - A BYTE linear allocation offset used for sub-16KB allocations
808  *	     only.  May contain values between 0 and 4MB.  Must be ignored
809  *	     if 16KB-aligned (i.e. force bitmap scan), otherwise may be
810  *	     used to sub-allocate within the 16KB block (which is already
811  *	     marked as allocated in the bitmap).
812  *
813  *	     Sub-allocations need only be 1KB-aligned and do not have to be
814  *	     size-aligned, and 16KB or larger allocations do not update this
815  *	     field, resulting in pretty good packing.
816  *
817  *	     Please note that file data granularity may be limited by
818  *	     other issues such as buffer cache direct-mapping and the
819  *	     desire to support sector sizes up to 16KB (so H2 only issues
820  *	     I/O's in multiples of 16KB anyway).
821  *
822  * class   - Clustering class.  Cleared to 0 only if the entire leaf becomes
823  *	     free.  Used to cluster device buffers so all elements must have
824  *	     the same device block size, but may mix logical sizes.
825  *
826  *	     Typically integrated with the blockref type in the upper 8 bits
827  *	     to localize inodes and indrect blocks, improving bulk free scans
828  *	     and directory scans.
829  *
830  * bitmap  - Two bits per 16KB allocation block arranged in arrays of
831  *	     64-bit elements, 256x2 bits representing ~4MB worth of media
832  *	     storage.  Bit patterns are as follows:
833  *
834  *	     00	Unallocated
835  *	     01 (reserved)
836  *	     10 Possibly free
837  *           11 Allocated
838  *
839  * ==========
840  * level6 freemap
841  * blockref[0]       : 4EB
842  * blockref[1]       : 4EB
843  * blockref[2]       : 4EB
844  * blockref[3]       : 4EB
845  * -----------------------------------------------------------------------
846  * 4 x 128B = 512B   : 4 x 4EB = 16EB
847  *
848  * level2-5 FREEMAP_NODE
849  * blockref[0]       : 1GB,256GB,64TB,16PB
850  * blockref[1]       : 1GB,256GB,64TB,16PB
851  * ...
852  * blockref[255]     : 1GB,256GB,64TB,16PB
853  * -----------------------------------------------------------------------
854  * 256 x 128B = 32KB : 256 x 1GB,256GB,64TB,16PB = 256GB,64TB,16PB,4EB
855  *
856  * level1 FREEMAP_LEAF
857  * bmap_data[0]      : 8 x 8B = 512bits = 256 x 2bits -> 256 x 16KB = 4MB
858  * bmap_data[1]      : 8 x 8B = 512bits = 256 x 2bits -> 256 x 16KB = 4MB
859  * ...
860  * bmap_data[255]    : 8 x 8B = 512bits = 256 x 2bits -> 256 x 16KB = 4MB
861  * -----------------------------------------------------------------------
862  * 256 x 128B = 32KB : 256 x 4MB = 1GB
863  * ==========
864  */
865 struct hammer2_bmap_data {
866 	int32_t linear;		/* 00 linear sub-granular allocation offset */
867 	uint16_t class;		/* 04-05 clustering class ((type<<8)|radix) */
868 	uint8_t reserved06;	/* 06 */
869 	uint8_t reserved07;	/* 07 */
870 	uint32_t reserved08;	/* 08 */
871 	uint32_t reserved0C;	/* 0C */
872 	uint32_t reserved10;	/* 10 */
873 	uint32_t reserved14;	/* 14 */
874 	uint32_t reserved18;	/* 18 */
875 	uint32_t avail;		/* 1C */
876 	uint32_t reserved20[8];	/* 20-3F 256 bits manages 128K/1KB/2-bits */
877 				/* 40-7F 512 bits manages 4MB of storage */
878 	hammer2_bitmap_t bitmapq[HAMMER2_BMAP_ELEMENTS];
879 } __packed;
880 
881 typedef struct hammer2_bmap_data hammer2_bmap_data_t;
882 
883 /*
884  * The inode number is stored in the inode rather than being
885  * based on the location of the inode (since the location moves every time
886  * the inode or anything underneath the inode is modified).
887  *
888  * The inode is 1024 bytes, made up of 256 bytes of meta-data, 256 bytes
889  * for the filename, and 512 bytes worth of direct file data OR an embedded
890  * blockset.  The in-memory hammer2_inode structure contains only the mostly-
891  * node-independent meta-data portion (some flags are node-specific and will
892  * not be synchronized).  The rest of the inode is node-specific and chain I/O
893  * is required to obtain it.
894  *
895  * Directories represent one inode per blockref.  Inodes are not laid out
896  * as a file but instead are represented by the related blockrefs.  The
897  * blockrefs, in turn, are indexed by the 64-bit directory hash key.  Remember
898  * that blocksets are fully associative, so a certain degree efficiency is
899  * achieved just from that.
900  *
901  * Up to 512 bytes of direct data can be embedded in an inode, and since
902  * inodes are essentially directory entries this also means that small data
903  * files end up simply being laid out linearly in the directory, resulting
904  * in fewer seeks and highly optimal access.
905  *
906  * The compression mode can be changed at any time in the inode and is
907  * recorded on a blockref-by-blockref basis.
908  */
909 #define HAMMER2_INODE_BYTES		1024	/* (asserted by code) */
910 #define HAMMER2_INODE_MAXNAME		256	/* maximum name in bytes */
911 #define HAMMER2_INODE_VERSION_ONE	1
912 
913 #define HAMMER2_INODE_START		1024	/* dynamically allocated */
914 
915 struct hammer2_inode_meta {
916 	uint16_t	version;	/* 0000 inode data version */
917 	uint8_t		reserved02;	/* 0002 */
918 	uint8_t		pfs_subtype;	/* 0003 pfs sub-type */
919 
920 	/*
921 	 * core inode attributes, inode type, misc flags
922 	 */
923 	uint32_t	uflags;		/* 0004 chflags */
924 	uint32_t	rmajor;		/* 0008 available for device nodes */
925 	uint32_t	rminor;		/* 000C available for device nodes */
926 	uint64_t	ctime;		/* 0010 inode change time */
927 	uint64_t	mtime;		/* 0018 modified time */
928 	uint64_t	atime;		/* 0020 access time (unsupported) */
929 	uint64_t	btime;		/* 0028 birth time */
930 	uuid_t		uid;		/* 0030 uid / degenerate unix uid */
931 	uuid_t		gid;		/* 0040 gid / degenerate unix gid */
932 
933 	uint8_t		type;		/* 0050 object type */
934 	uint8_t		op_flags;	/* 0051 operational flags */
935 	uint16_t	cap_flags;	/* 0052 capability flags */
936 	uint32_t	mode;		/* 0054 unix modes (typ low 16 bits) */
937 
938 	/*
939 	 * inode size, identification, localized recursive configuration
940 	 * for compression and backup copies.
941 	 *
942 	 * NOTE: Nominal parent inode number (iparent) is only applicable
943 	 *	 for directories but can also help for files during
944 	 *	 catastrophic recovery.
945 	 */
946 	hammer2_tid_t	inum;		/* 0058 inode number */
947 	hammer2_off_t	size;		/* 0060 size of file */
948 	uint64_t	nlinks;		/* 0068 hard links (typ only dirs) */
949 	hammer2_tid_t	iparent;	/* 0070 nominal parent inum */
950 	hammer2_key_t	name_key;	/* 0078 full filename key */
951 	uint16_t	name_len;	/* 0080 filename length */
952 	uint8_t		ncopies;	/* 0082 ncopies to local media */
953 	uint8_t		comp_algo;	/* 0083 compression request & algo */
954 
955 	/*
956 	 * These fields are currently only applicable to PFSROOTs.
957 	 *
958 	 * NOTE: We can't use {volume_data->fsid, pfs_clid} to uniquely
959 	 *	 identify an instance of a PFS in the cluster because
960 	 *	 a mount may contain more than one copy of the PFS as
961 	 *	 a separate node.  {pfs_clid, pfs_fsid} must be used for
962 	 *	 registration in the cluster.
963 	 */
964 	uint8_t		target_type;	/* 0084 hardlink target type */
965 	uint8_t		check_algo;	/* 0085 check code request & algo */
966 	uint8_t		pfs_nmasters;	/* 0086 (if PFSROOT) if multi-master */
967 	uint8_t		pfs_type;	/* 0087 (if PFSROOT) node type */
968 	hammer2_tid_t	pfs_inum;	/* 0088 (if PFSROOT) inum allocator */
969 	uuid_t		pfs_clid;	/* 0090 (if PFSROOT) cluster uuid */
970 	uuid_t		pfs_fsid;	/* 00A0 (if PFSROOT) unique uuid */
971 
972 	/*
973 	 * Quotas and aggregate sub-tree inode and data counters.  Note that
974 	 * quotas are not replicated downward, they are explicitly set by
975 	 * the sysop and in-memory structures keep track of inheritance.
976 	 */
977 	hammer2_key_t	data_quota;	/* 00B0 subtree quota in bytes */
978 	hammer2_key_t	unusedB8;	/* 00B8 subtree byte count */
979 	hammer2_key_t	inode_quota;	/* 00C0 subtree quota inode count */
980 	hammer2_key_t	unusedC8;	/* 00C8 subtree inode count */
981 
982 	/*
983 	 * The last snapshot tid is tested against modify_tid to determine
984 	 * when a copy must be made of a data block whos check mode has been
985 	 * disabled (a disabled check mode allows data blocks to be updated
986 	 * in place instead of copy-on-write).
987 	 */
988 	hammer2_tid_t	pfs_lsnap_tid;	/* 00D0 last snapshot tid */
989 	hammer2_tid_t	reservedD8;	/* 00D8 (avail) */
990 
991 	/*
992 	 * Tracks (possibly degenerate) free areas covering all sub-tree
993 	 * allocations under inode, not counting the inode itself.
994 	 * 0/0 indicates empty entry.  fully set-associative.
995 	 *
996 	 * (not yet implemented)
997 	 */
998 	uint64_t	decrypt_check;	/* 00E0 decryption validator */
999 	hammer2_off_t	reservedE8[3];	/* 00E8/F0/F8 */
1000 } __packed;
1001 
1002 typedef struct hammer2_inode_meta hammer2_inode_meta_t;
1003 
1004 struct hammer2_inode_data {
1005 	hammer2_inode_meta_t	meta;	/* 0000-00FF */
1006 	unsigned char	filename[HAMMER2_INODE_MAXNAME];
1007 					/* 0100-01FF (256 char, unterminated) */
1008 	union {				/* 0200-03FF (64x8 = 512 bytes) */
1009 		hammer2_blockset_t blockset;
1010 		char data[HAMMER2_EMBEDDED_BYTES];
1011 	} u;
1012 } __packed;
1013 
1014 typedef struct hammer2_inode_data hammer2_inode_data_t;
1015 
1016 #define HAMMER2_OPFLAG_DIRECTDATA	0x01
1017 #define HAMMER2_OPFLAG_PFSROOT		0x02	/* (see also bref flag) */
1018 #define HAMMER2_OPFLAG_COPYIDS		0x04	/* copyids override parent */
1019 
1020 #define HAMMER2_OBJTYPE_UNKNOWN		0
1021 #define HAMMER2_OBJTYPE_DIRECTORY	1
1022 #define HAMMER2_OBJTYPE_REGFILE		2
1023 #define HAMMER2_OBJTYPE_FIFO		4
1024 #define HAMMER2_OBJTYPE_CDEV		5
1025 #define HAMMER2_OBJTYPE_BDEV		6
1026 #define HAMMER2_OBJTYPE_SOFTLINK	7
1027 #define HAMMER2_OBJTYPE_UNUSED08	8
1028 #define HAMMER2_OBJTYPE_SOCKET		9
1029 #define HAMMER2_OBJTYPE_WHITEOUT	10
1030 
1031 #define HAMMER2_COPYID_NONE		0
1032 #define HAMMER2_COPYID_LOCAL		((uint8_t)-1)
1033 
1034 #define HAMMER2_COPYID_COUNT		256
1035 
1036 /*
1037  * PFS types identify the role of a PFS within a cluster.  The PFS types
1038  * is stored on media and in LNK_SPAN messages and used in other places.
1039  *
1040  * The low 4 bits specify the current active type while the high 4 bits
1041  * specify the transition target if the PFS is being upgraded or downgraded,
1042  * If the upper 4 bits are not zero it may effect how a PFS is used during
1043  * the transition.
1044  *
1045  * Generally speaking, downgrading a MASTER to a SLAVE cannot complete until
1046  * at least all MASTERs have updated their pfs_nmasters field.  And upgrading
1047  * a SLAVE to a MASTER cannot complete until the new prospective master has
1048  * been fully synchronized (though theoretically full synchronization is
1049  * not required if a (new) quorum of other masters are fully synchronized).
1050  *
1051  * It generally does not matter which PFS element you actually mount, you
1052  * are mounting 'the cluster'.  So, for example, a network mount will mount
1053  * a DUMMY PFS type on a memory filesystem.  However, there are two exceptions.
1054  * In order to gain the benefits of a SOFT_MASTER or SOFT_SLAVE, those PFSs
1055  * must be directly mounted.
1056  */
1057 #define HAMMER2_PFSTYPE_NONE		0x00
1058 #define HAMMER2_PFSTYPE_CACHE		0x01
1059 #define HAMMER2_PFSTYPE_UNUSED02	0x02
1060 #define HAMMER2_PFSTYPE_SLAVE		0x03
1061 #define HAMMER2_PFSTYPE_SOFT_SLAVE	0x04
1062 #define HAMMER2_PFSTYPE_SOFT_MASTER	0x05
1063 #define HAMMER2_PFSTYPE_MASTER		0x06
1064 #define HAMMER2_PFSTYPE_UNUSED07	0x07
1065 #define HAMMER2_PFSTYPE_SUPROOT		0x08
1066 #define HAMMER2_PFSTYPE_DUMMY		0x09
1067 #define HAMMER2_PFSTYPE_MAX		16
1068 
1069 #define HAMMER2_PFSTRAN_NONE		0x00	/* no transition in progress */
1070 #define HAMMER2_PFSTRAN_CACHE		0x10
1071 #define HAMMER2_PFSTRAN_UNUSED20	0x20
1072 #define HAMMER2_PFSTRAN_SLAVE		0x30
1073 #define HAMMER2_PFSTRAN_SOFT_SLAVE	0x40
1074 #define HAMMER2_PFSTRAN_SOFT_MASTER	0x50
1075 #define HAMMER2_PFSTRAN_MASTER		0x60
1076 #define HAMMER2_PFSTRAN_UNUSED70	0x70
1077 #define HAMMER2_PFSTRAN_SUPROOT		0x80
1078 #define HAMMER2_PFSTRAN_DUMMY		0x90
1079 
1080 #define HAMMER2_PFS_DEC(n)		((n) & 0x0F)
1081 #define HAMMER2_PFS_DEC_TRANSITION(n)	(((n) >> 4) & 0x0F)
1082 #define HAMMER2_PFS_ENC_TRANSITION(n)	(((n) & 0x0F) << 4)
1083 
1084 #define HAMMER2_PFSSUBTYPE_NONE		0
1085 #define HAMMER2_PFSSUBTYPE_SNAPSHOT	1	/* manual/managed snapshot */
1086 #define HAMMER2_PFSSUBTYPE_AUTOSNAP	2	/* automatic snapshot */
1087 
1088 /*
1089  * PFS mode of operation is a bitmask.  This is typically not stored
1090  * on-media, but defined here because the field may be used in dmsgs.
1091  */
1092 #define HAMMER2_PFSMODE_QUORUM		0x01
1093 #define HAMMER2_PFSMODE_RW		0x02
1094 
1095 /*
1096  * The volume header eats a 64K block at the beginning of each 2GB zone
1097  * up to four copies.
1098  *
1099  * All information is stored in host byte order.  The volume header's magic
1100  * number may be checked to determine the byte order.  If you wish to mount
1101  * between machines w/ different endian modes you'll need filesystem code
1102  * which acts on the media data consistently (either all one way or all the
1103  * other).  Our code currently does not do that.
1104  *
1105  * A read-write mount may have to recover missing allocations by doing an
1106  * incremental mirror scan looking for modifications made after alloc_tid.
1107  * If alloc_tid == last_tid then no recovery operation is needed.  Recovery
1108  * operations are usually very, very fast.
1109  *
1110  * Read-only mounts do not need to do any recovery, access to the filesystem
1111  * topology is always consistent after a crash (is always consistent, period).
1112  * However, there may be shortcutted blockref updates present from deep in
1113  * the tree which are stored in the volumeh eader and must be tracked on
1114  * the fly.
1115  *
1116  * NOTE: The copyinfo[] array contains the configuration for both the
1117  *	 cluster connections and any local media copies.  The volume
1118  *	 header will be replicated for each local media copy.
1119  *
1120  *	 The mount command may specify multiple medias or just one and
1121  *	 allow HAMMER2 to pick up the others when it checks the copyinfo[]
1122  *	 array on mount.
1123  *
1124  * NOTE: sroot_blockset points to the super-root directory, not the root
1125  *	 directory.  The root directory will be a subdirectory under the
1126  *	 super-root.
1127  *
1128  *	 The super-root directory contains all root directories and all
1129  *	 snapshots (readonly or writable).  It is possible to do a
1130  *	 null-mount of the super-root using special path constructions
1131  *	 relative to your mounted root.
1132  */
1133 #define HAMMER2_VOLUME_ID_HBO	0x48414d3205172011LLU
1134 #define HAMMER2_VOLUME_ID_ABO	0x11201705324d4148LLU
1135 
1136 /*
1137  * If volume version is HAMMER2_VOL_VERSION_MULTI_VOLUMES or above, max
1138  * HAMMER2_MAX_VOLUMES volumes are supported. There must be 1 (and only 1)
1139  * volume with volume id HAMMER2_ROOT_VOLUME.
1140  * Otherwise filesystem only supports 1 volume, and that volume must have
1141  * volume id HAMMER2_ROOT_VOLUME(0) which was a reserved field then.
1142  */
1143 #define HAMMER2_MAX_VOLUMES	64
1144 #define HAMMER2_ROOT_VOLUME	0
1145 
1146 struct hammer2_volume_data {
1147 	/*
1148 	 * sector #0 - 512 bytes
1149 	 */
1150 	uint64_t	magic;			/* 0000 Signature */
1151 	hammer2_off_t	boot_beg;		/* 0008 Boot area (future) */
1152 	hammer2_off_t	boot_end;		/* 0010 (size = end - beg) */
1153 	hammer2_off_t	aux_beg;		/* 0018 Aux area (future) */
1154 	hammer2_off_t	aux_end;		/* 0020 (size = end - beg) */
1155 	hammer2_off_t	volu_size;		/* 0028 Volume size, bytes */
1156 
1157 	uint32_t	version;		/* 0030 */
1158 	uint32_t	flags;			/* 0034 */
1159 	uint8_t		copyid;			/* 0038 copyid of phys vol */
1160 	uint8_t		freemap_version;	/* 0039 freemap algorithm */
1161 	uint8_t		peer_type;		/* 003A HAMMER2_PEER_xxx */
1162 	uint8_t		volu_id;		/* 003B */
1163 	uint8_t		nvolumes;		/* 003C */
1164 	uint8_t		reserved003D;		/* 003D */
1165 	uint16_t	reserved003E;		/* 003E */
1166 
1167 	uuid_t		fsid;			/* 0040 */
1168 	uuid_t		fstype;			/* 0050 */
1169 
1170 	/*
1171 	 * allocator_size is precalculated at newfs time and does not include
1172 	 * reserved blocks, boot, or aux areas.
1173 	 *
1174 	 * Initial non-reserved-area allocations do not use the freemap
1175 	 * but instead adjust alloc_iterator.  Dynamic allocations take
1176 	 * over starting at (allocator_beg).  This makes newfs_hammer2's
1177 	 * job a lot easier and can also serve as a testing jig.
1178 	 */
1179 	hammer2_off_t	allocator_size;		/* 0060 Total data space */
1180 	hammer2_off_t   allocator_free;		/* 0068	Free space */
1181 	hammer2_off_t	allocator_beg;		/* 0070 Initial allocations */
1182 
1183 	/*
1184 	 * mirror_tid reflects the highest committed change for this
1185 	 * block device regardless of whether it is to the super-root
1186 	 * or to a PFS or whatever.
1187 	 *
1188 	 * freemap_tid reflects the highest committed freemap change for
1189 	 * this block device.
1190 	 */
1191 	hammer2_tid_t	mirror_tid;		/* 0078 committed tid (vol) */
1192 	hammer2_tid_t	reserved0080;		/* 0080 */
1193 	hammer2_tid_t	reserved0088;		/* 0088 */
1194 	hammer2_tid_t	freemap_tid;		/* 0090 committed tid (fmap) */
1195 	hammer2_tid_t	bulkfree_tid;		/* 0098 bulkfree incremental */
1196 	hammer2_tid_t	reserved00A0[4];	/* 00A0-00BF */
1197 
1198 	hammer2_off_t	total_size;		/* 00C0 Total volume size, bytes */
1199 
1200 	/*
1201 	 * Copyids are allocated dynamically from the copyexists bitmap.
1202 	 * An id from the active copies set (up to 8, see copyinfo later on)
1203 	 * may still exist after the copy set has been removed from the
1204 	 * volume header and its bit will remain active in the bitmap and
1205 	 * cannot be reused until it is 100% removed from the hierarchy.
1206 	 */
1207 	uint32_t	copyexists[8];		/* 00C8-00E7 copy exists bmap */
1208 	char		reserved00E8[248];	/* 00E8-01DF */
1209 
1210 	/*
1211 	 * 32 bit CRC array at the end of the first 512 byte sector.
1212 	 *
1213 	 * icrc_sects[7] - First 512-4 bytes of volume header (including all
1214 	 *		   the other icrc's except this one).
1215 	 *
1216 	 * icrc_sects[6] - Sector 1 (512 bytes) of volume header, which is
1217 	 *		   the blockset for the root.
1218 	 *
1219 	 * icrc_sects[5] - Sector 2
1220 	 * icrc_sects[4] - Sector 3
1221 	 * icrc_sects[3] - Sector 4 (the freemap blockset)
1222 	 */
1223 	hammer2_crc32_t	icrc_sects[8];		/* 01E0-01FF */
1224 
1225 	/*
1226 	 * sector #1 - 512 bytes
1227 	 *
1228 	 * The entire sector is used by a blockset, but currently only first
1229 	 * blockref is used.
1230 	 */
1231 	hammer2_blockset_t sroot_blockset;	/* 0200-03FF Superroot dir */
1232 
1233 	/*
1234 	 * sector #2-6
1235 	 */
1236 	char	sector2[512];			/* 0400-05FF reserved */
1237 	char	sector3[512];			/* 0600-07FF reserved */
1238 	hammer2_blockset_t freemap_blockset;	/* 0800-09FF freemap  */
1239 	char	sector5[512];			/* 0A00-0BFF reserved */
1240 	char	sector6[512];			/* 0C00-0DFF reserved */
1241 
1242 	/*
1243 	 * sector #7 - 512 bytes
1244 	 * Maximum 64 volume offsets within logical offset.
1245 	 */
1246 	hammer2_off_t volu_loff[HAMMER2_MAX_VOLUMES];
1247 
1248 	/*
1249 	 * sector #8-71	- 32768 bytes
1250 	 *
1251 	 * Contains the configuration for up to 256 copyinfo targets.  These
1252 	 * specify local and remote copies operating as masters or slaves.
1253 	 * copyid's 0 and 255 are reserved (0 indicates an empty slot and 255
1254 	 * indicates the local media).
1255 	 */
1256 						/* 1000-8FFF copyinfo config */
1257 	hammer2_volconf_t copyinfo[HAMMER2_COPYID_COUNT];
1258 
1259 	/*
1260 	 * Remaining sections are reserved for future use.
1261 	 */
1262 	char		reserved9000[0x6FFC];	/* 9000-FFFB reserved */
1263 
1264 	/*
1265 	 * icrc on entire volume header
1266 	 */
1267 	hammer2_crc32_t	icrc_volheader;		/* FFFC-FFFF full volume icrc*/
1268 } __packed;
1269 
1270 typedef struct hammer2_volume_data hammer2_volume_data_t;
1271 
1272 /*
1273  * Various parts of the volume header have their own iCRCs.
1274  *
1275  * The first 512 bytes has its own iCRC stored at the end of the 512 bytes
1276  * and not included the icrc calculation.
1277  *
1278  * The second 512 bytes also has its own iCRC but it is stored in the first
1279  * 512 bytes so it covers the entire second 512 bytes.
1280  *
1281  * The whole volume block (64KB) has an iCRC covering all but the last 4 bytes,
1282  * which is where the iCRC for the whole volume is stored.  This is currently
1283  * a catch-all for anything not individually iCRCd.
1284  */
1285 #define HAMMER2_VOL_ICRC_SECT0		7
1286 #define HAMMER2_VOL_ICRC_SECT1		6
1287 
1288 #define HAMMER2_VOLUME_BYTES		65536
1289 
1290 #define HAMMER2_VOLUME_ICRC0_OFF	0
1291 #define HAMMER2_VOLUME_ICRC1_OFF	512
1292 #define HAMMER2_VOLUME_ICRCVH_OFF	0
1293 
1294 #define HAMMER2_VOLUME_ICRC0_SIZE	(512 - 4)
1295 #define HAMMER2_VOLUME_ICRC1_SIZE	(512)
1296 #define HAMMER2_VOLUME_ICRCVH_SIZE	(65536 - 4)
1297 
1298 #define HAMMER2_VOL_VERSION_MULTI_VOLUMES	2
1299 
1300 #define HAMMER2_VOL_VERSION_MIN		1
1301 #define HAMMER2_VOL_VERSION_DEFAULT	HAMMER2_VOL_VERSION_MULTI_VOLUMES
1302 #define HAMMER2_VOL_VERSION_WIP		(HAMMER2_VOL_VERSION_MULTI_VOLUMES + 1)
1303 
1304 #define HAMMER2_NUM_VOLHDRS		4
1305 
1306 union hammer2_media_data {
1307 	hammer2_volume_data_t	voldata;
1308         hammer2_inode_data_t    ipdata;
1309 	hammer2_blockset_t	blkset;
1310 	hammer2_blockref_t	npdata[HAMMER2_IND_COUNT_MAX];
1311 	hammer2_bmap_data_t	bmdata[HAMMER2_FREEMAP_COUNT];
1312 	char			buf[HAMMER2_PBUFSIZE];
1313 } __packed;
1314 
1315 typedef union hammer2_media_data hammer2_media_data_t;
1316 
1317 #endif /* !_VFS_HAMMER2_DISK_H_ */
1318