xref: /dragonfly/sys/vfs/hammer2/hammer2_disk.h (revision b8c93cad)
1 /*
2  * Copyright (c) 2011-2014 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  * MINALLOCSIZE		- The minimum allocation size.  This can be smaller
94  *		  	  or larger than the minimum physical IO size.
95  *
96  *			  NOTE: Should not be larger than 1K since inodes
97  *				are 1K.
98  *
99  * MINIOSIZE		- The minimum IO size.  This must be less than
100  *			  or equal to HAMMER2_LBUFSIZE.
101  *
102  * HAMMER2_LBUFSIZE	- Nominal buffer size for I/O rollups.
103  *
104  * HAMMER2_PBUFSIZE	- Topological block size used by files for all
105  *			  blocks except the block straddling EOF.
106  *
107  * HAMMER2_SEGSIZE	- Allocation map segment size, typically 2MB
108  *			  (space represented by a level0 bitmap).
109  */
110 
111 #define HAMMER2_SEGSIZE		(1 << HAMMER2_FREEMAP_LEVEL0_RADIX)
112 #define HAMMER2_SEGRADIX	HAMMER2_FREEMAP_LEVEL0_RADIX
113 
114 #define HAMMER2_PBUFRADIX	16	/* physical buf (1<<16) bytes */
115 #define HAMMER2_PBUFSIZE	65536
116 #define HAMMER2_LBUFRADIX	14	/* logical buf (1<<14) bytes */
117 #define HAMMER2_LBUFSIZE	16384
118 
119 /*
120  * Generally speaking we want to use 16K and 64K I/Os
121  */
122 #define HAMMER2_MINIORADIX	HAMMER2_LBUFRADIX
123 #define HAMMER2_MINIOSIZE	HAMMER2_LBUFSIZE
124 
125 #define HAMMER2_IND_BYTES_MIN	4096
126 #define HAMMER2_IND_BYTES_NOM	HAMMER2_LBUFSIZE
127 #define HAMMER2_IND_BYTES_MAX	HAMMER2_PBUFSIZE
128 #define HAMMER2_IND_RADIX_MIN	12
129 #define HAMMER2_IND_RADIX_NOM	HAMMER2_LBUFRADIX
130 #define HAMMER2_IND_RADIX_MAX	HAMMER2_PBUFRADIX
131 #define HAMMER2_IND_COUNT_MIN	(HAMMER2_IND_BYTES_MIN / \
132 				 sizeof(hammer2_blockref_t))
133 #define HAMMER2_IND_COUNT_MAX	(HAMMER2_IND_BYTES_MAX / \
134 				 sizeof(hammer2_blockref_t))
135 
136 /*
137  * In HAMMER2, arrays of blockrefs are fully set-associative, meaning that
138  * any element can occur at any index and holes can be anywhere.  As a
139  * future optimization we will be able to flag that such arrays are sorted
140  * and thus optimize lookups, but for now we don't.
141  *
142  * Inodes embed either 512 bytes of direct data or an array of 8 blockrefs,
143  * resulting in highly efficient storage for files <= 512 bytes and for files
144  * <= 512KB.  Up to 8 directory entries can be referenced from a directory
145  * without requiring an indirect block.
146  *
147  * Indirect blocks are typically either 4KB (64 blockrefs / ~4MB represented),
148  * or 64KB (1024 blockrefs / ~64MB represented).
149  */
150 #define HAMMER2_SET_RADIX		2	/* radix 2 = 4 entries */
151 #define HAMMER2_SET_COUNT		(1 << HAMMER2_SET_RADIX)
152 #define HAMMER2_EMBEDDED_BYTES		512	/* inode blockset/dd size */
153 #define HAMMER2_EMBEDDED_RADIX		9
154 
155 #define HAMMER2_PBUFMASK	(HAMMER2_PBUFSIZE - 1)
156 #define HAMMER2_LBUFMASK	(HAMMER2_LBUFSIZE - 1)
157 #define HAMMER2_SEGMASK		(HAMMER2_SEGSIZE - 1)
158 
159 #define HAMMER2_LBUFMASK64	((hammer2_off_t)HAMMER2_LBUFMASK)
160 #define HAMMER2_PBUFSIZE64	((hammer2_off_t)HAMMER2_PBUFSIZE)
161 #define HAMMER2_PBUFMASK64	((hammer2_off_t)HAMMER2_PBUFMASK)
162 #define HAMMER2_SEGSIZE64	((hammer2_off_t)HAMMER2_SEGSIZE)
163 #define HAMMER2_SEGMASK64	((hammer2_off_t)HAMMER2_SEGMASK)
164 
165 #define HAMMER2_UUID_STRING	"5cbb9ad1-862d-11dc-a94d-01301bb8a9f5"
166 
167 /*
168  * A HAMMER2 filesystem is always sized in multiples of 8MB.
169  *
170  * A 4MB segment is reserved at the beginning of each 2GB zone.  This segment
171  * contains the volume header (or backup volume header), the free block
172  * table, and possibly other information in the future.
173  *
174  * 4MB = 64 x 64K blocks.  Each 4MB segment is broken down as follows:
175  *
176  *	+-----------------------+
177  *      |	Volume Hdr	| block 0	volume header & alternates
178  *	+-----------------------+		(first four zones only)
179  *	|   FreeBlk Section A   | block 1-4
180  *	+-----------------------+
181  *	|   FreeBlk Section B   | block 5-8
182  *	+-----------------------+
183  *	|   FreeBlk Section C   | block 9-12
184  *	+-----------------------+
185  *	|   FreeBlk Section D   | block 13-16
186  *	+-----------------------+
187  *      |			| block 17...63
188  *      |	reserved	|
189  *      |			|
190  *	+-----------------------+
191  *
192  * The first few 2GB zones contain volume headers and volume header backups.
193  * After that the volume header block# is reserved for future use.  Similarly,
194  * there are many blocks related to various Freemap levels which are not
195  * used in every segment and those are also reserved for future use.
196  *
197  *			Freemap (see the FREEMAP document)
198  *
199  * The freemap utilizes blocks #1-16 in 8 sets of 4 blocks.  Each block in
200  * a set represents a level of depth in the freemap topology.  Eight sets
201  * exist to prevent live updates from disturbing the state of the freemap
202  * were a crash/reboot to occur.  That is, a live update is not committed
203  * until the update's flush reaches the volume root.  There are FOUR volume
204  * roots representing the last four synchronization points, so the freemap
205  * must be consistent no matter which volume root is chosen by the mount
206  * code.
207  *
208  * Each freemap set is 4 x 64K blocks and represents the 2GB, 2TB, 2PB,
209  * and 2EB indirect map.  The volume header itself has a set of 8 freemap
210  * blockrefs representing another 3 bits, giving us a total 64 bits of
211  * representable address space.
212  *
213  * The Level 0 64KB block represents 2GB of storage represented by
214  * (64 x struct hammer2_bmap_data).  Each structure represents 2MB of storage
215  * and has a 256 bit bitmap, using 2 bits to represent a 16KB chunk of
216  * storage.  These 2 bits represent the following states:
217  *
218  *	00	Free
219  *	01	(reserved) (Possibly partially allocated)
220  *	10	Possibly free
221  *	11	Allocated
222  *
223  * One important thing to note here is that the freemap resolution is 16KB,
224  * but the minimum storage allocation size is 1KB.  The hammer2 vfs keeps
225  * track of sub-allocations in memory, which means that on a unmount or reboot
226  * the entire 16KB of a partially allocated block will be considered fully
227  * allocated.  It is possible for fragmentation to build up over time, but
228  * defragmentation is fairly easy to accomplish since all modifications
229  * allocate a new block.
230  *
231  * The Second thing to note is that due to the way snapshots and inode
232  * replication works, deleting a file cannot immediately free the related
233  * space.  Furthermore, deletions often do not bother to traverse the
234  * block subhierarchy being deleted.  And to go even further, whole
235  * sub-directory trees can be deleted simply by deleting the directory inode
236  * at the top.  So even though we have a symbol to represent a 'possibly free'
237  * block (binary 10), only the bulk free scanning code can actually use it.
238  * Normal 'rm's or other deletions do not.
239  *
240  * WARNING!  ZONE_SEG and VOLUME_ALIGN must be a multiple of 1<<LEVEL0_RADIX
241  *	     (i.e. a multiple of 2MB).  VOLUME_ALIGN must be >= ZONE_SEG.
242  *
243  * In Summary:
244  *
245  * (1) Modifications to freemap blocks 'allocate' a new copy (aka use a block
246  *     from the next set).  The new copy is reused until a flush occurs at
247  *     which point the next modification will then rotate to the next set.
248  *
249  * (2) A total of 10 freemap sets is required.
250  *
251  *     - 8 sets - 2 sets per volume header backup x 4 volume header backups
252  *     - 2 sets used as backing store for the bulk freemap scan.
253  *     - The freemap recovery scan which runs on-mount just uses the inactive
254  *	 set for whichever volume header was selected by the mount code.
255  *
256  */
257 #define HAMMER2_VOLUME_ALIGN		(8 * 1024 * 1024)
258 #define HAMMER2_VOLUME_ALIGN64		((hammer2_off_t)HAMMER2_VOLUME_ALIGN)
259 #define HAMMER2_VOLUME_ALIGNMASK	(HAMMER2_VOLUME_ALIGN - 1)
260 #define HAMMER2_VOLUME_ALIGNMASK64     ((hammer2_off_t)HAMMER2_VOLUME_ALIGNMASK)
261 
262 #define HAMMER2_NEWFS_ALIGN		(HAMMER2_VOLUME_ALIGN)
263 #define HAMMER2_NEWFS_ALIGN64		((hammer2_off_t)HAMMER2_VOLUME_ALIGN)
264 #define HAMMER2_NEWFS_ALIGNMASK		(HAMMER2_VOLUME_ALIGN - 1)
265 #define HAMMER2_NEWFS_ALIGNMASK64	((hammer2_off_t)HAMMER2_NEWFS_ALIGNMASK)
266 
267 #define HAMMER2_ZONE_BYTES64		(2LLU * 1024 * 1024 * 1024)
268 #define HAMMER2_ZONE_MASK64		(HAMMER2_ZONE_BYTES64 - 1)
269 #define HAMMER2_ZONE_SEG		(4 * 1024 * 1024)
270 #define HAMMER2_ZONE_SEG64		((hammer2_off_t)HAMMER2_ZONE_SEG)
271 #define HAMMER2_ZONE_BLOCKS_SEG		(HAMMER2_ZONE_SEG / HAMMER2_PBUFSIZE)
272 
273 #define HAMMER2_ZONE_FREEMAP_INC	5	/* 5 deep */
274 
275 #define HAMMER2_ZONE_VOLHDR		0	/* volume header or backup */
276 #define HAMMER2_ZONE_FREEMAP_00		1	/* normal freemap rotation */
277 #define HAMMER2_ZONE_FREEMAP_01		6	/* normal freemap rotation */
278 #define HAMMER2_ZONE_FREEMAP_02		11	/* normal freemap rotation */
279 #define HAMMER2_ZONE_FREEMAP_03		16	/* normal freemap rotation */
280 #define HAMMER2_ZONE_FREEMAP_04		21	/* normal freemap rotation */
281 #define HAMMER2_ZONE_FREEMAP_05		26	/* normal freemap rotation */
282 #define HAMMER2_ZONE_FREEMAP_06		31	/* normal freemap rotation */
283 #define HAMMER2_ZONE_FREEMAP_07		36	/* normal freemap rotation */
284 #define HAMMER2_ZONE_FREEMAP_END	41	/* (non-inclusive) */
285 
286 #define HAMMER2_ZONE_UNUSED41		41
287 #define HAMMER2_ZONE_UNUSED42		42
288 #define HAMMER2_ZONE_UNUSED43		43
289 #define HAMMER2_ZONE_UNUSED44		44
290 #define HAMMER2_ZONE_UNUSED45		45
291 #define HAMMER2_ZONE_UNUSED46		46
292 #define HAMMER2_ZONE_UNUSED47		47
293 #define HAMMER2_ZONE_UNUSED48		48
294 #define HAMMER2_ZONE_UNUSED49		49
295 #define HAMMER2_ZONE_UNUSED50		50
296 #define HAMMER2_ZONE_UNUSED51		51
297 #define HAMMER2_ZONE_UNUSED52		52
298 #define HAMMER2_ZONE_UNUSED53		53
299 #define HAMMER2_ZONE_UNUSED54		54
300 #define HAMMER2_ZONE_UNUSED55		55
301 #define HAMMER2_ZONE_UNUSED56		56
302 #define HAMMER2_ZONE_UNUSED57		57
303 #define HAMMER2_ZONE_UNUSED58		58
304 #define HAMMER2_ZONE_UNUSED59		59
305 #define HAMMER2_ZONE_UNUSED60		60
306 #define HAMMER2_ZONE_UNUSED61		61
307 #define HAMMER2_ZONE_UNUSED62		62
308 #define HAMMER2_ZONE_UNUSED63		63
309 #define HAMMER2_ZONE_END		64	/* non-inclusive */
310 
311 #define HAMMER2_NFREEMAPS		8	/* FREEMAP_00 - FREEMAP_07 */
312 
313 						/* relative to FREEMAP_x */
314 #define HAMMER2_ZONEFM_LEVEL1		0	/* 1GB leafmap */
315 #define HAMMER2_ZONEFM_LEVEL2		1	/* 256GB indmap */
316 #define HAMMER2_ZONEFM_LEVEL3		2	/* 64TB indmap */
317 #define HAMMER2_ZONEFM_LEVEL4		3	/* 16PB indmap */
318 #define HAMMER2_ZONEFM_LEVEL5		4	/* 4EB indmap */
319 /* LEVEL6 is a set of 4 blockrefs in the volume header 16EB */
320 
321 /*
322  * Freemap radix.  Assumes a set-count of 4, 128-byte blockrefs,
323  * 32KB indirect block for freemap (LEVELN_PSIZE below).
324  *
325  * Leaf entry represents 4MB of storage broken down into a 512-bit
326  * bitmap, 2-bits per entry.  So course bitmap item represents 16KB.
327  */
328 #if HAMMER2_SET_COUNT != 4
329 #error "hammer2_disk.h - freemap assumes SET_COUNT is 4"
330 #endif
331 #define HAMMER2_FREEMAP_LEVEL6_RADIX	64	/* 16EB (end) */
332 #define HAMMER2_FREEMAP_LEVEL5_RADIX	62	/* 4EB */
333 #define HAMMER2_FREEMAP_LEVEL4_RADIX	54	/* 16PB */
334 #define HAMMER2_FREEMAP_LEVEL3_RADIX	46	/* 64TB */
335 #define HAMMER2_FREEMAP_LEVEL2_RADIX	38	/* 256GB */
336 #define HAMMER2_FREEMAP_LEVEL1_RADIX	30	/* 1GB */
337 #define HAMMER2_FREEMAP_LEVEL0_RADIX	22	/* 4MB (128by in l-1 leaf) */
338 
339 #define HAMMER2_FREEMAP_LEVELN_PSIZE	32768	/* physical bytes */
340 
341 #define HAMMER2_FREEMAP_LEVEL5_SIZE	((hammer2_off_t)1 <<		\
342 					 HAMMER2_FREEMAP_LEVEL5_RADIX)
343 #define HAMMER2_FREEMAP_LEVEL4_SIZE	((hammer2_off_t)1 <<		\
344 					 HAMMER2_FREEMAP_LEVEL4_RADIX)
345 #define HAMMER2_FREEMAP_LEVEL3_SIZE	((hammer2_off_t)1 <<		\
346 					 HAMMER2_FREEMAP_LEVEL3_RADIX)
347 #define HAMMER2_FREEMAP_LEVEL2_SIZE	((hammer2_off_t)1 <<		\
348 					 HAMMER2_FREEMAP_LEVEL2_RADIX)
349 #define HAMMER2_FREEMAP_LEVEL1_SIZE	((hammer2_off_t)1 <<		\
350 					 HAMMER2_FREEMAP_LEVEL1_RADIX)
351 #define HAMMER2_FREEMAP_LEVEL0_SIZE	((hammer2_off_t)1 <<		\
352 					 HAMMER2_FREEMAP_LEVEL0_RADIX)
353 
354 #define HAMMER2_FREEMAP_LEVEL5_MASK	(HAMMER2_FREEMAP_LEVEL5_SIZE - 1)
355 #define HAMMER2_FREEMAP_LEVEL4_MASK	(HAMMER2_FREEMAP_LEVEL4_SIZE - 1)
356 #define HAMMER2_FREEMAP_LEVEL3_MASK	(HAMMER2_FREEMAP_LEVEL3_SIZE - 1)
357 #define HAMMER2_FREEMAP_LEVEL2_MASK	(HAMMER2_FREEMAP_LEVEL2_SIZE - 1)
358 #define HAMMER2_FREEMAP_LEVEL1_MASK	(HAMMER2_FREEMAP_LEVEL1_SIZE - 1)
359 #define HAMMER2_FREEMAP_LEVEL0_MASK	(HAMMER2_FREEMAP_LEVEL0_SIZE - 1)
360 
361 #define HAMMER2_FREEMAP_COUNT		(int)(HAMMER2_FREEMAP_LEVELN_PSIZE / \
362 					 sizeof(hammer2_bmap_data_t))
363 
364 /*
365  * 16KB bitmap granularity (x2 bits per entry).
366  */
367 #define HAMMER2_FREEMAP_BLOCK_RADIX	14
368 #define HAMMER2_FREEMAP_BLOCK_SIZE	(1 << HAMMER2_FREEMAP_BLOCK_RADIX)
369 #define HAMMER2_FREEMAP_BLOCK_MASK	(HAMMER2_FREEMAP_BLOCK_SIZE - 1)
370 
371 /*
372  * bitmap[] structure.  2 bits per HAMMER2_FREEMAP_BLOCK_SIZE.
373  *
374  * 8 x 64-bit elements, 2 bits per block.
375  * 32 blocks (radix 5) per element.
376  * representing INDEX_SIZE bytes worth of storage per element.
377  */
378 
379 typedef uint64_t			hammer2_bitmap_t;
380 
381 #define HAMMER2_BMAP_ALLONES		((hammer2_bitmap_t)-1)
382 #define HAMMER2_BMAP_ELEMENTS		8
383 #define HAMMER2_BMAP_BITS_PER_ELEMENT	64
384 #define HAMMER2_BMAP_INDEX_RADIX	5	/* 32 blocks per element */
385 #define HAMMER2_BMAP_BLOCKS_PER_ELEMENT	(1 << HAMMER2_BMAP_INDEX_RADIX)
386 
387 #define HAMMER2_BMAP_INDEX_SIZE		(HAMMER2_FREEMAP_BLOCK_SIZE * \
388 					 HAMMER2_BMAP_BLOCKS_PER_ELEMENT)
389 #define HAMMER2_BMAP_INDEX_MASK		(HAMMER2_BMAP_INDEX_SIZE - 1)
390 
391 /*
392  * Two linear areas can be reserved after the initial 2MB segment in the base
393  * zone (the one starting at offset 0).  These areas are NOT managed by the
394  * block allocator and do not fall under HAMMER2 crc checking rules based
395  * at the volume header (but can be self-CRCd internally, depending).
396  */
397 #define HAMMER2_BOOT_MIN_BYTES		HAMMER2_VOLUME_ALIGN
398 #define HAMMER2_BOOT_NOM_BYTES		(64*1024*1024)
399 #define HAMMER2_BOOT_MAX_BYTES		(256*1024*1024)
400 
401 #define HAMMER2_REDO_MIN_BYTES		HAMMER2_VOLUME_ALIGN
402 #define HAMMER2_REDO_NOM_BYTES		(256*1024*1024)
403 #define HAMMER2_REDO_MAX_BYTES		(1024*1024*1024)
404 
405 /*
406  * Most HAMMER2 types are implemented as unsigned 64-bit integers.
407  * Transaction ids are monotonic.
408  *
409  * We utilize 32-bit iSCSI CRCs.
410  */
411 typedef uint64_t hammer2_tid_t;
412 typedef uint64_t hammer2_off_t;
413 typedef uint64_t hammer2_key_t;
414 typedef uint32_t hammer2_crc32_t;
415 
416 /*
417  * Miscellanious ranges (all are unsigned).
418  */
419 #define HAMMER2_TID_MIN		1ULL
420 #define HAMMER2_TID_MAX		0xFFFFFFFFFFFFFFFFULL
421 #define HAMMER2_KEY_MIN		0ULL
422 #define HAMMER2_KEY_MAX		0xFFFFFFFFFFFFFFFFULL
423 #define HAMMER2_OFFSET_MIN	0ULL
424 #define HAMMER2_OFFSET_MAX	0xFFFFFFFFFFFFFFFFULL
425 
426 /*
427  * HAMMER2 data offset special cases and masking.
428  *
429  * All HAMMER2 data offsets have to be broken down into a 64K buffer base
430  * offset (HAMMER2_OFF_MASK_HI) and a 64K buffer index (HAMMER2_OFF_MASK_LO).
431  *
432  * Indexes into physical buffers are always 64-byte aligned.  The low 6 bits
433  * of the data offset field specifies how large the data chunk being pointed
434  * to as a power of 2.  The theoretical minimum radix is thus 6 (The space
435  * needed in the low bits of the data offset field).  However, the practical
436  * minimum allocation chunk size is 1KB (a radix of 10), so HAMMER2 sets
437  * HAMMER2_RADIX_MIN to 10.  The maximum radix is currently 16 (64KB), but
438  * we fully intend to support larger extents in the future.
439  */
440 #define HAMMER2_OFF_BAD		((hammer2_off_t)-1)
441 #define HAMMER2_OFF_MASK	0xFFFFFFFFFFFFFFC0ULL
442 #define HAMMER2_OFF_MASK_LO	(HAMMER2_OFF_MASK & HAMMER2_PBUFMASK64)
443 #define HAMMER2_OFF_MASK_HI	(~HAMMER2_PBUFMASK64)
444 #define HAMMER2_OFF_MASK_RADIX	0x000000000000003FULL
445 #define HAMMER2_MAX_COPIES	6
446 
447 /*
448  * HAMMER2 directory support and pre-defined keys
449  */
450 #define HAMMER2_DIRHASH_VISIBLE	0x8000000000000000ULL
451 #define HAMMER2_DIRHASH_USERMSK	0x7FFFFFFFFFFFFFFFULL
452 #define HAMMER2_DIRHASH_LOMASK	0x0000000000007FFFULL
453 #define HAMMER2_DIRHASH_HIMASK	0xFFFFFFFFFFFF0000ULL
454 #define HAMMER2_DIRHASH_FORCED	0x0000000000008000ULL	/* bit forced on */
455 
456 #define HAMMER2_SROOT_KEY	0x0000000000000000ULL	/* volume to sroot */
457 #define HAMMER2_BOOT_KEY	0xd9b36ce135528000ULL	/* sroot to BOOT PFS */
458 
459 /************************************************************************
460  *				DMSG SUPPORT				*
461  ************************************************************************
462  * LNK_VOLCONF
463  *
464  * All HAMMER2 directories directly under the super-root on your local
465  * media can be mounted separately, even if they share the same physical
466  * device.
467  *
468  * When you do a HAMMER2 mount you are effectively tying into a HAMMER2
469  * cluster via local media.  The local media does not have to participate
470  * in the cluster, other than to provide the hammer2_volconf[] array and
471  * root inode for the mount.
472  *
473  * This is important: The mount device path you specify serves to bootstrap
474  * your entry into the cluster, but your mount will make active connections
475  * to ALL copy elements in the hammer2_volconf[] array which match the
476  * PFSID of the directory in the super-root that you specified.  The local
477  * media path does not have to be mentioned in this array but becomes part
478  * of the cluster based on its type and access rights.  ALL ELEMENTS ARE
479  * TREATED ACCORDING TO TYPE NO MATTER WHICH ONE YOU MOUNT FROM.
480  *
481  * The actual cluster may be far larger than the elements you list in the
482  * hammer2_volconf[] array.  You list only the elements you wish to
483  * directly connect to and you are able to access the rest of the cluster
484  * indirectly through those connections.
485  *
486  * WARNING!  This structure must be exactly 128 bytes long for its config
487  *	     array to fit in the volume header.
488  */
489 struct hammer2_volconf {
490 	uint8_t	copyid;		/* 00	 copyid 0-255 (must match slot) */
491 	uint8_t inprog;		/* 01	 operation in progress, or 0 */
492 	uint8_t chain_to;	/* 02	 operation chaining to, or 0 */
493 	uint8_t chain_from;	/* 03	 operation chaining from, or 0 */
494 	uint16_t flags;		/* 04-05 flags field */
495 	uint8_t error;		/* 06	 last operational error */
496 	uint8_t priority;	/* 07	 priority and round-robin flag */
497 	uint8_t remote_pfs_type;/* 08	 probed direct remote PFS type */
498 	uint8_t reserved08[23];	/* 09-1F */
499 	uuid_t	pfs_clid;	/* 20-2F copy target must match this uuid */
500 	uint8_t label[16];	/* 30-3F import/export label */
501 	uint8_t path[64];	/* 40-7F target specification string or key */
502 } __packed;
503 
504 typedef struct hammer2_volconf hammer2_volconf_t;
505 
506 #define DMSG_VOLF_ENABLED	0x0001
507 #define DMSG_VOLF_INPROG	0x0002
508 #define DMSG_VOLF_CONN_RR	0x80	/* round-robin at same priority */
509 #define DMSG_VOLF_CONN_EF	0x40	/* media errors flagged */
510 #define DMSG_VOLF_CONN_PRI	0x0F	/* select priority 0-15 (15=best) */
511 
512 struct dmsg_lnk_hammer2_volconf {
513 	dmsg_hdr_t		head;
514 	hammer2_volconf_t	copy;	/* copy spec */
515 	int32_t			index;
516 	int32_t			unused01;
517 	uuid_t			mediaid;
518 	int64_t			reserved02[32];
519 } __packed;
520 
521 typedef struct dmsg_lnk_hammer2_volconf dmsg_lnk_hammer2_volconf_t;
522 
523 #define DMSG_LNK_HAMMER2_VOLCONF DMSG_LNK(DMSG_LNK_CMD_HAMMER2_VOLCONF, \
524 					  dmsg_lnk_hammer2_volconf)
525 
526 #define H2_LNK_VOLCONF(msg)	((dmsg_lnk_hammer2_volconf_t *)(msg)->any.buf)
527 
528 /*
529  * The media block reference structure.  This forms the core of the HAMMER2
530  * media topology recursion.  This 128-byte data structure is embedded in the
531  * volume header, in inodes (which are also directory entries), and in
532  * indirect blocks.
533  *
534  * A blockref references a single media item, which typically can be a
535  * directory entry (aka inode), indirect block, or data block.
536  *
537  * The primary feature a blockref represents is the ability to validate
538  * the entire tree underneath it via its check code.  Any modification to
539  * anything propagates up the blockref tree all the way to the root, replacing
540  * the related blocks and compounding the generated check code.
541  *
542  * The check code can be a simple 32-bit iscsi code, a 64-bit crc, or as
543  * complex as a 512 bit cryptographic hash.  I originally used a 64-byte
544  * blockref but later expanded it to 128 bytes to be able to support the
545  * larger check code as well as to embed statistics for quota operation.
546  *
547  * Simple check codes are not sufficient for unverified dedup.  Even with
548  * a maximally-sized check code unverified dedup should only be used in
549  * in subdirectory trees where you do not need 100% data integrity.
550  *
551  * Unverified dedup is deduping based on meta-data only without verifying
552  * that the data blocks are actually identical.  Verified dedup guarantees
553  * integrity but is a far more I/O-expensive operation.
554  *
555  * --
556  *
557  * mirror_tid - per cluster node modified (propagated upward by flush)
558  * modify_tid - clc record modified (not propagated).
559  * update_tid - clc record updated (propagated upward on verification)
560  *
561  * CLC - Stands for 'Cluster Level Change', identifiers which are identical
562  *	 within the topology across all cluster nodes (when fully
563  *	 synchronized).
564  *
565  * NOTE: The range of keys represented by the blockref is (key) to
566  *	 ((key) + (1LL << keybits) - 1).  HAMMER2 usually populates
567  *	 blocks bottom-up, inserting a new root when radix expansion
568  *	 is required.
569  *
570  *				    RESERVED FIELDS
571  *
572  * A number of blockref fields are reserved and should generally be set to
573  * 0 for future compatibility.
574  *
575  *				FUTURE BLOCKREF EXPANSION
576  *
577  * CONTENT ADDRESSABLE INDEXING (future) - Using a 256 or 512-bit check code.
578  */
579 struct hammer2_blockref {		/* MUST BE EXACTLY 64 BYTES */
580 	uint8_t		type;		/* type of underlying item */
581 	uint8_t		methods;	/* check method & compression method */
582 	uint8_t		copyid;		/* specify which copy this is */
583 	uint8_t		keybits;	/* #of keybits masked off 0=leaf */
584 	uint8_t		vradix;		/* virtual data/meta-data size */
585 	uint8_t		flags;		/* blockref flags */
586 	uint8_t		reserved06;
587 	uint8_t		reserved07;
588 	hammer2_key_t	key;		/* key specification */
589 	hammer2_tid_t	mirror_tid;	/* media flush topology & freemap */
590 	hammer2_tid_t	modify_tid;	/* clc modify (not propagated) */
591 	hammer2_off_t	data_off;	/* low 6 bits is phys size (radix)*/
592 	hammer2_key_t	data_count;	/* statistics aggregation */
593 	hammer2_key_t	inode_count;	/* statistics aggregation */
594 	hammer2_tid_t	update_tid;	/* clc modify (propagated upward) */
595 	union {				/* check info */
596 		char	buf[64];
597 		struct {
598 			uint32_t value;
599 			uint32_t reserved[15];
600 		} iscsi32;
601 		struct {
602 			uint64_t value;
603 			uint64_t reserved[7];
604 		} xxhash64;
605 		struct {
606 			char data[24];
607 			char reserved[40];
608 		} sha192;
609 		struct {
610 			char data[32];
611 			char reserved[32];
612 		} sha256;
613 		struct {
614 			char data[64];
615 		} sha512;
616 
617 		/*
618 		 * Freemap hints are embedded in addition to the icrc32.
619 		 *
620 		 * bigmask - Radixes available for allocation (0-31).
621 		 *	     Heuristical (may be permissive but not
622 		 *	     restrictive).  Typically only radix values
623 		 *	     10-16 are used (i.e. (1<<10) through (1<<16)).
624 		 *
625 		 * avail   - Total available space remaining, in bytes
626 		 */
627 		struct {
628 			uint32_t icrc32;
629 			uint32_t bigmask;	/* available radixes */
630 			uint64_t avail;		/* total available bytes */
631 			char reserved[48];
632 		} freemap;
633 	} check;
634 } __packed;
635 
636 typedef struct hammer2_blockref hammer2_blockref_t;
637 
638 #define HAMMER2_BLOCKREF_BYTES		128	/* blockref struct in bytes */
639 #define HAMMER2_BLOCKREF_RADIX		7
640 
641 /*
642  * On-media and off-media blockref types.
643  *
644  * types >= 128 are pseudo values that should never be present on-media.
645  */
646 #define HAMMER2_BREF_TYPE_EMPTY		0
647 #define HAMMER2_BREF_TYPE_INODE		1
648 #define HAMMER2_BREF_TYPE_INDIRECT	2
649 #define HAMMER2_BREF_TYPE_DATA		3
650 #define HAMMER2_BREF_TYPE_UNUSED04	4
651 #define HAMMER2_BREF_TYPE_FREEMAP_NODE	5
652 #define HAMMER2_BREF_TYPE_FREEMAP_LEAF	6
653 #define HAMMER2_BREF_TYPE_FREEMAP	254	/* pseudo-type */
654 #define HAMMER2_BREF_TYPE_VOLUME	255	/* pseudo-type */
655 
656 #define HAMMER2_BREF_FLAG_PFSROOT	0x01	/* see also related opflag */
657 #define HAMMER2_BREF_FLAG_ZERO		0x02
658 
659 /*
660  * Encode/decode check mode and compression mode for
661  * bref.methods.  The compression level is not encoded in
662  * bref.methods.
663  */
664 #define HAMMER2_ENC_CHECK(n)		(((n) & 15) << 4)
665 #define HAMMER2_DEC_CHECK(n)		(((n) >> 4) & 15)
666 #define HAMMER2_ENC_COMP(n)		((n) & 15)
667 #define HAMMER2_DEC_COMP(n)		((n) & 15)
668 
669 #define HAMMER2_CHECK_NONE		0
670 #define HAMMER2_CHECK_DISABLED		1
671 #define HAMMER2_CHECK_ISCSI32		2
672 #define HAMMER2_CHECK_XXHASH64		3
673 #define HAMMER2_CHECK_SHA192		4
674 #define HAMMER2_CHECK_FREEMAP		5
675 
676 #define HAMMER2_CHECK_DEFAULT		HAMMER2_CHECK_XXHASH64
677 
678 /* user-specifiable check modes only */
679 #define HAMMER2_CHECK_STRINGS		{ "none", "disabled", "crc32", \
680 					  "xxhash64", "sha192" }
681 #define HAMMER2_CHECK_STRINGS_COUNT	5
682 
683 /*
684  * Encode/decode check or compression algorithm request in
685  * ipdata->meta.check_algo and ipdata->meta.comp_algo.
686  */
687 #define HAMMER2_ENC_ALGO(n)		(n)
688 #define HAMMER2_DEC_ALGO(n)		((n) & 15)
689 #define HAMMER2_ENC_LEVEL(n)		((n) << 4)
690 #define HAMMER2_DEC_LEVEL(n)		(((n) >> 4) & 15)
691 
692 #define HAMMER2_COMP_NONE		0
693 #define HAMMER2_COMP_AUTOZERO		1
694 #define HAMMER2_COMP_LZ4		2
695 #define HAMMER2_COMP_ZLIB		3
696 
697 #define HAMMER2_COMP_NEWFS_DEFAULT	HAMMER2_COMP_LZ4
698 #define HAMMER2_COMP_STRINGS		{ "none", "autozero", "lz4", "zlib" }
699 #define HAMMER2_COMP_STRINGS_COUNT	4
700 
701 /*
702  * Passed to hammer2_chain_create(), causes methods to be inherited from
703  * parent.
704  */
705 #define HAMMER2_METH_DEFAULT		-1
706 
707 /*
708  * HAMMER2 block references are collected into sets of 4 blockrefs.  These
709  * sets are fully associative, meaning the elements making up a set are
710  * not sorted in any way and may contain duplicate entries, holes, or
711  * entries which shortcut multiple levels of indirection.  Sets are used
712  * in various ways:
713  *
714  * (1) When redundancy is desired a set may contain several duplicate
715  *     entries pointing to different copies of the same data.  Up to 4 copies
716  *     are supported.
717  *
718  * (2) The blockrefs in a set can shortcut multiple levels of indirections
719  *     within the bounds imposed by the parent of set.
720  *
721  * When a set fills up another level of indirection is inserted, moving
722  * some or all of the set's contents into indirect blocks placed under the
723  * set.  This is a top-down approach in that indirect blocks are not created
724  * until the set actually becomes full (that is, the entries in the set can
725  * shortcut the indirect blocks when the set is not full).  Depending on how
726  * things are filled multiple indirect blocks will eventually be created.
727  *
728  * Indirect blocks are typically 4KB (64 entres) or 64KB (1024 entries) and
729  * are also treated as fully set-associative.
730  */
731 struct hammer2_blockset {
732 	hammer2_blockref_t	blockref[HAMMER2_SET_COUNT];
733 };
734 
735 typedef struct hammer2_blockset hammer2_blockset_t;
736 
737 /*
738  * Catch programmer snafus
739  */
740 #if (1 << HAMMER2_SET_RADIX) != HAMMER2_SET_COUNT
741 #error "hammer2 direct radix is incorrect"
742 #endif
743 #if (1 << HAMMER2_PBUFRADIX) != HAMMER2_PBUFSIZE
744 #error "HAMMER2_PBUFRADIX and HAMMER2_PBUFSIZE are inconsistent"
745 #endif
746 #if (1 << HAMMER2_RADIX_MIN) != HAMMER2_ALLOC_MIN
747 #error "HAMMER2_RADIX_MIN and HAMMER2_ALLOC_MIN are inconsistent"
748 #endif
749 
750 /*
751  * hammer2_bmap_data - A freemap entry in the LEVEL1 block.
752  *
753  * Each 128-byte entry contains the bitmap and meta-data required to manage
754  * a LEVEL0 (128KB) block of storage.  The storage is managed in 128 x 1KB
755  * chunks.
756  *
757  * A smaller allocation granularity is supported via a linear iterator and/or
758  * must otherwise be tracked in ram.
759  *
760  * (data structure must be 128 bytes exactly)
761  *
762  * linear  - A BYTE linear allocation offset used for sub-16KB allocations
763  *	     only.  May contain values between 0 and 2MB.  Must be ignored
764  *	     if 16KB-aligned (i.e. force bitmap scan), otherwise may be
765  *	     used to sub-allocate within the 16KB block (which is already
766  *	     marked as allocated in the bitmap).
767  *
768  *	     Sub-allocations need only be 1KB-aligned and do not have to be
769  *	     size-aligned, and 16KB or larger allocations do not update this
770  *	     field, resulting in pretty good packing.
771  *
772  *	     Please note that file data granularity may be limited by
773  *	     other issues such as buffer cache direct-mapping and the
774  *	     desire to support sector sizes up to 16KB (so H2 only issues
775  *	     I/O's in multiples of 16KB anyway).
776  *
777  * class   - Clustering class.  Cleared to 0 only if the entire leaf becomes
778  *	     free.  Used to cluster device buffers so all elements must have
779  *	     the same device block size, but may mix logical sizes.
780  *
781  *	     Typically integrated with the blockref type in the upper 8 bits
782  *	     to localize inodes and indrect blocks, improving bulk free scans
783  *	     and directory scans.
784  *
785  * bitmap  - Two bits per 16KB allocation block arranged in arrays of
786  *	     32-bit elements, 256x2 bits representing ~4MB worth of media
787  *	     storage.  Bit patterns are as follows:
788  *
789  *	     00	Unallocated
790  *	     01 (reserved)
791  *	     10 Possibly free
792  *           11 Allocated
793  */
794 struct hammer2_bmap_data {
795 	int32_t linear;		/* 00 linear sub-granular allocation offset */
796 	uint16_t class;		/* 04-05 clustering class ((type<<8)|radix) */
797 	uint8_t reserved06;	/* 06 */
798 	uint8_t reserved07;	/* 07 */
799 	uint32_t reserved08;	/* 08 */
800 	uint32_t reserved0C;	/* 0C */
801 	uint32_t reserved10;	/* 10 */
802 	uint32_t reserved14;	/* 14 */
803 	uint32_t reserved18;	/* 18 */
804 	uint32_t avail;		/* 1C */
805 	uint32_t reserved20[8];	/* 20-3F 256 bits manages 128K/1KB/2-bits */
806 				/* 40-7F 512 bits manages 4MB of storage */
807 	hammer2_bitmap_t bitmapq[HAMMER2_BMAP_ELEMENTS];
808 } __packed;
809 
810 typedef struct hammer2_bmap_data hammer2_bmap_data_t;
811 
812 /*
813  * In HAMMER2 inodes ARE directory entries, with a special exception for
814  * hardlinks.  The inode number is stored in the inode rather than being
815  * based on the location of the inode (since the location moves every time
816  * the inode or anything underneath the inode is modified).
817  *
818  * The inode is 1024 bytes, made up of 256 bytes of meta-data, 256 bytes
819  * for the filename, and 512 bytes worth of direct file data OR an embedded
820  * blockset.  The in-memory hammer2_inode structure contains only the mostly-
821  * node-independent meta-data portion (some flags are node-specific and will
822  * not be synchronized).  The rest of the inode is node-specific and chain I/O
823  * is required to obtain it.
824  *
825  * Directories represent one inode per blockref.  Inodes are not laid out
826  * as a file but instead are represented by the related blockrefs.  The
827  * blockrefs, in turn, are indexed by the 64-bit directory hash key.  Remember
828  * that blocksets are fully associative, so a certain degree efficiency is
829  * achieved just from that.
830  *
831  * Up to 512 bytes of direct data can be embedded in an inode, and since
832  * inodes are essentially directory entries this also means that small data
833  * files end up simply being laid out linearly in the directory, resulting
834  * in fewer seeks and highly optimal access.
835  *
836  * The compression mode can be changed at any time in the inode and is
837  * recorded on a blockref-by-blockref basis.
838  *
839  * Hardlinks are supported via the inode map.  Essentially the way a hardlink
840  * works is that all individual directory entries representing the same file
841  * are special cased and specify the same inode number.  The actual file
842  * is placed in the nearest parent directory that is parent to all instances
843  * of the hardlink.  If all hardlinks to a file are in the same directory
844  * the actual file will also be placed in that directory.  This file uses
845  * the inode number as the directory entry key and is invisible to normal
846  * directory scans.  Real directory entry keys are differentiated from the
847  * inode number key via bit 63.  Access to the hardlink silently looks up
848  * the real file and forwards all operations to that file.  Removal of the
849  * last hardlink also removes the real file.
850  *
851  * (attr_tid) is only updated when the inode's specific attributes or regular
852  * file size has changed, and affects path lookups and stat.  (attr_tid)
853  * represents a special cache coherency lock under the inode.  The inode
854  * blockref's modify_tid will always cover it.
855  *
856  * (dirent_tid) is only updated when an entry under a directory inode has
857  * been created, deleted, renamed, or had its attributes change, and affects
858  * directory lookups and scans.  (dirent_tid) represents another special cache
859  * coherency lock under the inode.  The inode blockref's modify_tid will
860  * always cover it.
861  */
862 #define HAMMER2_INODE_BYTES		1024	/* (asserted by code) */
863 #define HAMMER2_INODE_MAXNAME		256	/* maximum name in bytes */
864 #define HAMMER2_INODE_VERSION_ONE	1
865 
866 #define HAMMER2_INODE_START		1024	/* dynamically allocated */
867 
868 struct hammer2_inode_meta {
869 	uint16_t	version;	/* 0000 inode data version */
870 	uint8_t		reserved02;	/* 0002 */
871 	uint8_t		pfs_subtype;	/* 0003 pfs sub-type */
872 
873 	/*
874 	 * core inode attributes, inode type, misc flags
875 	 */
876 	uint32_t	uflags;		/* 0004 chflags */
877 	uint32_t	rmajor;		/* 0008 available for device nodes */
878 	uint32_t	rminor;		/* 000C available for device nodes */
879 	uint64_t	ctime;		/* 0010 inode change time */
880 	uint64_t	mtime;		/* 0018 modified time */
881 	uint64_t	atime;		/* 0020 access time (unsupported) */
882 	uint64_t	btime;		/* 0028 birth time */
883 	uuid_t		uid;		/* 0030 uid / degenerate unix uid */
884 	uuid_t		gid;		/* 0040 gid / degenerate unix gid */
885 
886 	uint8_t		type;		/* 0050 object type */
887 	uint8_t		op_flags;	/* 0051 operational flags */
888 	uint16_t	cap_flags;	/* 0052 capability flags */
889 	uint32_t	mode;		/* 0054 unix modes (typ low 16 bits) */
890 
891 	/*
892 	 * inode size, identification, localized recursive configuration
893 	 * for compression and backup copies.
894 	 */
895 	hammer2_tid_t	inum;		/* 0058 inode number */
896 	hammer2_off_t	size;		/* 0060 size of file */
897 	uint64_t	nlinks;		/* 0068 hard links (typ only dirs) */
898 	hammer2_tid_t	iparent;	/* 0070 parent inum */
899 	hammer2_key_t	name_key;	/* 0078 full filename key */
900 	uint16_t	name_len;	/* 0080 filename length */
901 	uint8_t		ncopies;	/* 0082 ncopies to local media */
902 	uint8_t		comp_algo;	/* 0083 compression request & algo */
903 
904 	/*
905 	 * These fields are currently only applicable to PFSROOTs.
906 	 *
907 	 * NOTE: We can't use {volume_data->fsid, pfs_clid} to uniquely
908 	 *	 identify an instance of a PFS in the cluster because
909 	 *	 a mount may contain more than one copy of the PFS as
910 	 *	 a separate node.  {pfs_clid, pfs_fsid} must be used for
911 	 *	 registration in the cluster.
912 	 */
913 	uint8_t		target_type;	/* 0084 hardlink target type */
914 	uint8_t		check_algo;	/* 0085 check code request & algo */
915 	uint8_t		pfs_nmasters;	/* 0086 (if PFSROOT) if multi-master */
916 	uint8_t		pfs_type;	/* 0087 (if PFSROOT) node type */
917 	uint64_t	pfs_inum;	/* 0088 (if PFSROOT) inum allocator */
918 	uuid_t		pfs_clid;	/* 0090 (if PFSROOT) cluster uuid */
919 	uuid_t		pfs_fsid;	/* 00A0 (if PFSROOT) unique uuid */
920 
921 	/*
922 	 * Quotas and aggregate sub-tree inode and data counters.  Note that
923 	 * quotas are not replicated downward, they are explicitly set by
924 	 * the sysop and in-memory structures keep track of inheritence.
925 	 */
926 	hammer2_key_t	data_quota;	/* 00B0 subtree quota in bytes */
927 	hammer2_key_t	unusedB8;	/* 00B8 subtree byte count */
928 	hammer2_key_t	inode_quota;	/* 00C0 subtree quota inode count */
929 	hammer2_key_t	unusedC8;	/* 00C8 subtree inode count */
930 
931 	/*
932 	 * The last snapshot tid is tested against modify_tid to determine
933 	 * when a copy must be made of a data block whos check mode has been
934 	 * disabled (a disabled check mode allows data blocks to be updated
935 	 * in place instead of copy-on-write).
936 	 */
937 	hammer2_tid_t	pfs_lsnap_tid;	/* 00D0 last snapshot tid */
938 	hammer2_tid_t	reservedD8;	/* 00D8 (avail) */
939 
940 	/*
941 	 * Tracks (possibly degenerate) free areas covering all sub-tree
942 	 * allocations under inode, not counting the inode itself.
943 	 * 0/0 indicates empty entry.  fully set-associative.
944 	 *
945 	 * (not yet implemented)
946 	 */
947 	uint64_t	decrypt_check;	/* 00E0 decryption validator */
948 	hammer2_off_t	reservedE0[3];	/* 00E8/F0/F8 */
949 } __packed;
950 
951 typedef struct hammer2_inode_meta hammer2_inode_meta_t;
952 
953 struct hammer2_inode_data {
954 	hammer2_inode_meta_t	meta;	/* 0000-00FF */
955 	unsigned char	filename[HAMMER2_INODE_MAXNAME];
956 					/* 0100-01FF (256 char, unterminated) */
957 	union {				/* 0200-03FF (64x8 = 512 bytes) */
958 		struct hammer2_blockset blockset;
959 		char data[HAMMER2_EMBEDDED_BYTES];
960 	} u;
961 } __packed;
962 
963 typedef struct hammer2_inode_data hammer2_inode_data_t;
964 
965 #define HAMMER2_OPFLAG_DIRECTDATA	0x01
966 #define HAMMER2_OPFLAG_PFSROOT		0x02	/* (see also bref flag) */
967 #define HAMMER2_OPFLAG_COPYIDS		0x04	/* copyids override parent */
968 
969 #define HAMMER2_OBJTYPE_UNKNOWN		0
970 #define HAMMER2_OBJTYPE_DIRECTORY	1
971 #define HAMMER2_OBJTYPE_REGFILE		2
972 #define HAMMER2_OBJTYPE_FIFO		4
973 #define HAMMER2_OBJTYPE_CDEV		5
974 #define HAMMER2_OBJTYPE_BDEV		6
975 #define HAMMER2_OBJTYPE_SOFTLINK	7
976 #define HAMMER2_OBJTYPE_HARDLINK	8	/* dummy entry for hardlink */
977 #define HAMMER2_OBJTYPE_SOCKET		9
978 #define HAMMER2_OBJTYPE_WHITEOUT	10
979 
980 #define HAMMER2_COPYID_NONE		0
981 #define HAMMER2_COPYID_LOCAL		((uint8_t)-1)
982 
983 #define HAMMER2_COPYID_COUNT		256
984 
985 /*
986  * PFS types identify the role of a PFS within a cluster.  The PFS types
987  * is stored on media and in LNK_SPAN messages and used in other places.
988  *
989  * The low 4 bits specify the current active type while the high 4 bits
990  * specify the transition target if the PFS is being upgraded or downgraded,
991  * If the upper 4 bits are not zero it may effect how a PFS is used during
992  * the transition.
993  *
994  * Generally speaking, downgrading a MASTER to a SLAVE cannot complete until
995  * at least all MASTERs have updated their pfs_nmasters field.  And upgrading
996  * a SLAVE to a MASTER cannot complete until the new prospective master has
997  * been fully synchronized (though theoretically full synchronization is
998  * not required if a (new) quorum of other masters are fully synchronized).
999  *
1000  * It generally does not matter which PFS element you actually mount, you
1001  * are mounting 'the cluster'.  So, for example, a network mount will mount
1002  * a DUMMY PFS type on a memory filesystem.  However, there are two exceptions.
1003  * In order to gain the benefits of a SOFT_MASTER or SOFT_SLAVE, those PFSs
1004  * must be directly mounted.
1005  */
1006 #define HAMMER2_PFSTYPE_NONE		0x00
1007 #define HAMMER2_PFSTYPE_CACHE		0x01
1008 #define HAMMER2_PFSTYPE_UNUSED02	0x02
1009 #define HAMMER2_PFSTYPE_SLAVE		0x03
1010 #define HAMMER2_PFSTYPE_SOFT_SLAVE	0x04
1011 #define HAMMER2_PFSTYPE_SOFT_MASTER	0x05
1012 #define HAMMER2_PFSTYPE_MASTER		0x06
1013 #define HAMMER2_PFSTYPE_UNUSED07	0x07
1014 #define HAMMER2_PFSTYPE_SUPROOT		0x08
1015 #define HAMMER2_PFSTYPE_DUMMY		0x09
1016 #define HAMMER2_PFSTYPE_MAX		16
1017 
1018 #define HAMMER2_PFSTRAN_NONE		0x00	/* no transition in progress */
1019 #define HAMMER2_PFSTRAN_CACHE		0x10
1020 #define HAMMER2_PFSTRAN_UNMUSED20	0x20
1021 #define HAMMER2_PFSTRAN_SLAVE		0x30
1022 #define HAMMER2_PFSTRAN_SOFT_SLAVE	0x40
1023 #define HAMMER2_PFSTRAN_SOFT_MASTER	0x50
1024 #define HAMMER2_PFSTRAN_MASTER		0x60
1025 #define HAMMER2_PFSTRAN_UNUSED70	0x70
1026 #define HAMMER2_PFSTRAN_SUPROOT		0x80
1027 #define HAMMER2_PFSTRAN_DUMMY		0x90
1028 
1029 #define HAMMER2_PFS_DEC(n)		((n) & 0x0F)
1030 #define HAMMER2_PFS_DEC_TRANSITION(n)	(((n) >> 4) & 0x0F)
1031 #define HAMMER2_PFS_ENC_TRANSITION(n)	(((n) & 0x0F) << 4)
1032 
1033 #define HAMMER2_PFSSUBTYPE_NONE		0
1034 #define HAMMER2_PFSSUBTYPE_SNAPSHOT	1	/* manual/managed snapshot */
1035 #define HAMMER2_PFSSUBTYPE_AUTOSNAP	2	/* automatic snapshot */
1036 
1037 /*
1038  * PFS mode of operation is a bitmask.  This is typically not stored
1039  * on-media, but defined here because the field may be used in dmsgs.
1040  */
1041 #define HAMMER2_PFSMODE_QUORUM		0x01
1042 #define HAMMER2_PFSMODE_RW		0x02
1043 
1044 /*
1045  *				Allocation Table
1046  *
1047  */
1048 
1049 
1050 /*
1051  * Flags (8 bits) - blockref, for freemap only
1052  *
1053  * Note that the minimum chunk size is 1KB so we could theoretically have
1054  * 10 bits here, but we might have some future extension that allows a
1055  * chunk size down to 256 bytes and if so we will need bits 8 and 9.
1056  */
1057 #define HAMMER2_AVF_SELMASK		0x03	/* select group */
1058 #define HAMMER2_AVF_ALL_ALLOC		0x04	/* indicate all allocated */
1059 #define HAMMER2_AVF_ALL_FREE		0x08	/* indicate all free */
1060 #define HAMMER2_AVF_RESERVED10		0x10
1061 #define HAMMER2_AVF_RESERVED20		0x20
1062 #define HAMMER2_AVF_RESERVED40		0x40
1063 #define HAMMER2_AVF_RESERVED80		0x80
1064 #define HAMMER2_AVF_AVMASK32		((uint32_t)0xFFFFFF00LU)
1065 #define HAMMER2_AVF_AVMASK64		((uint64_t)0xFFFFFFFFFFFFFF00LLU)
1066 
1067 #define HAMMER2_AV_SELECT_A		0x00
1068 #define HAMMER2_AV_SELECT_B		0x01
1069 #define HAMMER2_AV_SELECT_C		0x02
1070 #define HAMMER2_AV_SELECT_D		0x03
1071 
1072 /*
1073  * The volume header eats a 64K block.  There is currently an issue where
1074  * we want to try to fit all nominal filesystem updates in a 512-byte section
1075  * but it may be a lost cause due to the need for a blockset.
1076  *
1077  * All information is stored in host byte order.  The volume header's magic
1078  * number may be checked to determine the byte order.  If you wish to mount
1079  * between machines w/ different endian modes you'll need filesystem code
1080  * which acts on the media data consistently (either all one way or all the
1081  * other).  Our code currently does not do that.
1082  *
1083  * A read-write mount may have to recover missing allocations by doing an
1084  * incremental mirror scan looking for modifications made after alloc_tid.
1085  * If alloc_tid == last_tid then no recovery operation is needed.  Recovery
1086  * operations are usually very, very fast.
1087  *
1088  * Read-only mounts do not need to do any recovery, access to the filesystem
1089  * topology is always consistent after a crash (is always consistent, period).
1090  * However, there may be shortcutted blockref updates present from deep in
1091  * the tree which are stored in the volumeh eader and must be tracked on
1092  * the fly.
1093  *
1094  * NOTE: The copyinfo[] array contains the configuration for both the
1095  *	 cluster connections and any local media copies.  The volume
1096  *	 header will be replicated for each local media copy.
1097  *
1098  *	 The mount command may specify multiple medias or just one and
1099  *	 allow HAMMER2 to pick up the others when it checks the copyinfo[]
1100  *	 array on mount.
1101  *
1102  * NOTE: root_blockref points to the super-root directory, not the root
1103  *	 directory.  The root directory will be a subdirectory under the
1104  *	 super-root.
1105  *
1106  *	 The super-root directory contains all root directories and all
1107  *	 snapshots (readonly or writable).  It is possible to do a
1108  *	 null-mount of the super-root using special path constructions
1109  *	 relative to your mounted root.
1110  *
1111  * NOTE: HAMMER2 allows any subdirectory tree to be managed as if it were
1112  *	 a PFS, including mirroring and storage quota operations, and this is
1113  *	 prefered over creating discrete PFSs in the super-root.  Instead
1114  *	 the super-root is most typically used to create writable snapshots,
1115  *	 alternative roots, and so forth.  The super-root is also used by
1116  *	 the automatic snapshotting mechanism.
1117  */
1118 #define HAMMER2_VOLUME_ID_HBO	0x48414d3205172011LLU
1119 #define HAMMER2_VOLUME_ID_ABO	0x11201705324d4148LLU
1120 
1121 struct hammer2_volume_data {
1122 	/*
1123 	 * sector #0 - 512 bytes
1124 	 */
1125 	uint64_t	magic;			/* 0000 Signature */
1126 	hammer2_off_t	boot_beg;		/* 0008 Boot area (future) */
1127 	hammer2_off_t	boot_end;		/* 0010 (size = end - beg) */
1128 	hammer2_off_t	aux_beg;		/* 0018 Aux area (future) */
1129 	hammer2_off_t	aux_end;		/* 0020 (size = end - beg) */
1130 	hammer2_off_t	volu_size;		/* 0028 Volume size, bytes */
1131 
1132 	uint32_t	version;		/* 0030 */
1133 	uint32_t	flags;			/* 0034 */
1134 	uint8_t		copyid;			/* 0038 copyid of phys vol */
1135 	uint8_t		freemap_version;	/* 0039 freemap algorithm */
1136 	uint8_t		peer_type;		/* 003A HAMMER2_PEER_xxx */
1137 	uint8_t		reserved003B;		/* 003B */
1138 	uint32_t	reserved003C;		/* 003C */
1139 
1140 	uuid_t		fsid;			/* 0040 */
1141 	uuid_t		fstype;			/* 0050 */
1142 
1143 	/*
1144 	 * allocator_size is precalculated at newfs time and does not include
1145 	 * reserved blocks, boot, or redo areas.
1146 	 *
1147 	 * Initial non-reserved-area allocations do not use the freemap
1148 	 * but instead adjust alloc_iterator.  Dynamic allocations take
1149 	 * over starting at (allocator_beg).  This makes newfs_hammer2's
1150 	 * job a lot easier and can also serve as a testing jig.
1151 	 */
1152 	hammer2_off_t	allocator_size;		/* 0060 Total data space */
1153 	hammer2_off_t   allocator_free;		/* 0068	Free space */
1154 	hammer2_off_t	allocator_beg;		/* 0070 Initial allocations */
1155 
1156 	/*
1157 	 * mirror_tid reflects the highest committed change for this
1158 	 * block device regardless of whether it is to the super-root
1159 	 * or to a PFS or whatever.
1160 	 *
1161 	 * freemap_tid reflects the highest committed freemap change for
1162 	 * this block device.
1163 	 */
1164 	hammer2_tid_t	mirror_tid;		/* 0078 committed tid (vol) */
1165 	hammer2_tid_t	reserved0080;		/* 0080 */
1166 	hammer2_tid_t	reserved0088;		/* 0088 */
1167 	hammer2_tid_t	freemap_tid;		/* 0090 committed tid (fmap) */
1168 	hammer2_tid_t	bulkfree_tid;		/* 0098 bulkfree incremental */
1169 	hammer2_tid_t	reserved00A0[5];	/* 00A0-00C7 */
1170 
1171 	/*
1172 	 * Copyids are allocated dynamically from the copyexists bitmap.
1173 	 * An id from the active copies set (up to 8, see copyinfo later on)
1174 	 * may still exist after the copy set has been removed from the
1175 	 * volume header and its bit will remain active in the bitmap and
1176 	 * cannot be reused until it is 100% removed from the hierarchy.
1177 	 */
1178 	uint32_t	copyexists[8];		/* 00C8-00E7 copy exists bmap */
1179 	char		reserved0140[248];	/* 00E8-01DF */
1180 
1181 	/*
1182 	 * 32 bit CRC array at the end of the first 512 byte sector.
1183 	 *
1184 	 * icrc_sects[7] - First 512-4 bytes of volume header (including all
1185 	 *		   the other icrc's except this one).
1186 	 *
1187 	 * icrc_sects[6] - Sector 1 (512 bytes) of volume header, which is
1188 	 *		   the blockset for the root.
1189 	 *
1190 	 * icrc_sects[5] - Sector 2
1191 	 * icrc_sects[4] - Sector 3
1192 	 * icrc_sects[3] - Sector 4 (the freemap blockset)
1193 	 */
1194 	hammer2_crc32_t	icrc_sects[8];		/* 01E0-01FF */
1195 
1196 	/*
1197 	 * sector #1 - 512 bytes
1198 	 *
1199 	 * The entire sector is used by a blockset.
1200 	 */
1201 	hammer2_blockset_t sroot_blockset;	/* 0200-03FF Superroot dir */
1202 
1203 	/*
1204 	 * sector #2-7
1205 	 */
1206 	char	sector2[512];			/* 0400-05FF reserved */
1207 	char	sector3[512];			/* 0600-07FF reserved */
1208 	hammer2_blockset_t freemap_blockset;	/* 0800-09FF freemap  */
1209 	char	sector5[512];			/* 0A00-0BFF reserved */
1210 	char	sector6[512];			/* 0C00-0DFF reserved */
1211 	char	sector7[512];			/* 0E00-0FFF reserved */
1212 
1213 	/*
1214 	 * sector #8-71	- 32768 bytes
1215 	 *
1216 	 * Contains the configuration for up to 256 copyinfo targets.  These
1217 	 * specify local and remote copies operating as masters or slaves.
1218 	 * copyid's 0 and 255 are reserved (0 indicates an empty slot and 255
1219 	 * indicates the local media).
1220 	 *
1221 	 * Each inode contains a set of up to 8 copyids, either inherited
1222 	 * from its parent or explicitly specified in the inode, which
1223 	 * indexes into this array.
1224 	 */
1225 						/* 1000-8FFF copyinfo config */
1226 	hammer2_volconf_t copyinfo[HAMMER2_COPYID_COUNT];
1227 
1228 	/*
1229 	 * Remaining sections are reserved for future use.
1230 	 */
1231 	char		reserved0400[0x6FFC];	/* 9000-FFFB reserved */
1232 
1233 	/*
1234 	 * icrc on entire volume header
1235 	 */
1236 	hammer2_crc32_t	icrc_volheader;		/* FFFC-FFFF full volume icrc*/
1237 } __packed;
1238 
1239 typedef struct hammer2_volume_data hammer2_volume_data_t;
1240 
1241 /*
1242  * Various parts of the volume header have their own iCRCs.
1243  *
1244  * The first 512 bytes has its own iCRC stored at the end of the 512 bytes
1245  * and not included the icrc calculation.
1246  *
1247  * The second 512 bytes also has its own iCRC but it is stored in the first
1248  * 512 bytes so it covers the entire second 512 bytes.
1249  *
1250  * The whole volume block (64KB) has an iCRC covering all but the last 4 bytes,
1251  * which is where the iCRC for the whole volume is stored.  This is currently
1252  * a catch-all for anything not individually iCRCd.
1253  */
1254 #define HAMMER2_VOL_ICRC_SECT0		7
1255 #define HAMMER2_VOL_ICRC_SECT1		6
1256 
1257 #define HAMMER2_VOLUME_BYTES		65536
1258 
1259 #define HAMMER2_VOLUME_ICRC0_OFF	0
1260 #define HAMMER2_VOLUME_ICRC1_OFF	512
1261 #define HAMMER2_VOLUME_ICRCVH_OFF	0
1262 
1263 #define HAMMER2_VOLUME_ICRC0_SIZE	(512 - 4)
1264 #define HAMMER2_VOLUME_ICRC1_SIZE	(512)
1265 #define HAMMER2_VOLUME_ICRCVH_SIZE	(65536 - 4)
1266 
1267 #define HAMMER2_VOL_VERSION_MIN		1
1268 #define HAMMER2_VOL_VERSION_DEFAULT	1
1269 #define HAMMER2_VOL_VERSION_WIP 	2
1270 
1271 #define HAMMER2_NUM_VOLHDRS		4
1272 
1273 union hammer2_media_data {
1274 	hammer2_volume_data_t	voldata;
1275         hammer2_inode_data_t    ipdata;
1276 	hammer2_blockset_t	blkset;
1277 	hammer2_blockref_t	npdata[HAMMER2_IND_COUNT_MAX];
1278 	hammer2_bmap_data_t	bmdata[HAMMER2_FREEMAP_COUNT];
1279 	char			buf[HAMMER2_PBUFSIZE];
1280 } __packed;
1281 
1282 typedef union hammer2_media_data hammer2_media_data_t;
1283 
1284 #endif /* !_VFS_HAMMER2_DISK_H_ */
1285