sbin/hammer: Add assert_volume_offset()
[dragonfly.git] / sbin / hammer / ondisk.c
1 /*
2  * Copyright (c) 2007 The DragonFly Project.  All rights reserved.
3  *
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34
35 #include <sys/diskslice.h>
36 #include <sys/diskmbr.h>
37
38 #include "hammer_util.h"
39
40 static void check_volume(struct volume_info *vol);
41 static void get_buffer_readahead(struct buffer_info *base);
42 static void *get_ondisk(hammer_off_t buf_offset, struct buffer_info **bufferp,
43                         int isnew);
44 static __inline int readhammervol(struct volume_info *vol);
45 static __inline int readhammerbuf(struct buffer_info *buf);
46 static __inline int writehammervol(struct volume_info *vol);
47 static __inline int writehammerbuf(struct buffer_info *buf);
48
49 uuid_t Hammer_FSType;
50 uuid_t Hammer_FSId;
51 int UseReadBehind = -4;
52 int UseReadAhead = 4;
53 int DebugOpt;
54
55 TAILQ_HEAD(volume_list, volume_info);
56 static struct volume_list VolList = TAILQ_HEAD_INITIALIZER(VolList);
57 static int valid_hammer_volumes;
58
59 static __inline
60 int
61 buffer_hash(hammer_off_t buf_offset)
62 {
63         int hi;
64
65         hi = (int)(buf_offset / HAMMER_BUFSIZE) & HAMMER_BUFLISTMASK;
66         return(hi);
67 }
68
69 static struct buffer_info*
70 find_buffer(struct volume_info *volume, hammer_off_t buf_offset)
71 {
72         int hi;
73         struct buffer_info *buf;
74
75         hi = buffer_hash(buf_offset);
76         TAILQ_FOREACH(buf, &volume->buffer_lists[hi], entry)
77                 if (buf->buf_offset == buf_offset)
78                         return(buf);
79         return(NULL);
80 }
81
82 static
83 struct volume_info *
84 __alloc_volume(const char *volname, int oflags)
85 {
86         struct volume_info *vol;
87         int i;
88
89         vol = malloc(sizeof(*vol));
90         if (vol == NULL)
91                 err(1, "alloc_volume");
92         bzero(vol, sizeof(*vol));
93
94         vol->vol_no = -1;
95         vol->rdonly = (oflags == O_RDONLY);
96         vol->name = strdup(volname);
97         vol->fd = open(vol->name, oflags);
98         if (vol->fd < 0)
99                 err(1, "alloc_volume: Failed to open %s", vol->name);
100         check_volume(vol);
101
102         vol->ondisk = malloc(HAMMER_BUFSIZE);
103         if (vol->ondisk == NULL)
104                 err(1, "alloc_volume");
105         bzero(vol->ondisk, HAMMER_BUFSIZE);
106
107         for (i = 0; i < HAMMER_BUFLISTS; ++i)
108                 TAILQ_INIT(&vol->buffer_lists[i]);
109
110         return(vol);
111 }
112
113 static void
114 __add_volume(struct volume_info *vol)
115 {
116         struct volume_info *scan;
117         struct stat st1, st2;
118
119         if (fstat(vol->fd, &st1) != 0)
120                 errx(1, "add_volume: %s: Failed to stat", vol->name);
121
122         TAILQ_FOREACH(scan, &VolList, entry) {
123                 if (scan->vol_no == vol->vol_no) {
124                         errx(1, "add_volume: %s: Duplicate volume number %d "
125                                 "against %s",
126                                 vol->name, vol->vol_no, scan->name);
127                 }
128                 if (fstat(scan->fd, &st2) != 0) {
129                         errx(1, "add_volume: %s: Failed to stat %s",
130                                 vol->name, scan->name);
131                 }
132                 if ((st1.st_ino == st2.st_ino) && (st1.st_dev == st2.st_dev)) {
133                         errx(1, "add_volume: %s: Specified more than once",
134                                 vol->name);
135                 }
136         }
137
138         TAILQ_INSERT_TAIL(&VolList, vol, entry);
139 }
140
141 /*
142  * Initialize a volume structure and ondisk vol_no field.
143  */
144 struct volume_info *
145 init_volume(int32_t vol_no, const char *filename, int oflags)
146 {
147         struct volume_info *vol;
148
149         vol = __alloc_volume(filename, oflags);
150         vol->vol_no = vol->ondisk->vol_no = vol_no;
151
152         __add_volume(vol);
153
154         return(vol);
155 }
156
157 /*
158  * Initialize a volume structure and read ondisk volume header.
159  */
160 struct volume_info*
161 load_volume(const char *filename, int oflags)
162 {
163         struct volume_info *vol;
164         hammer_volume_ondisk_t ondisk;
165         int n;
166
167         vol = __alloc_volume(filename, oflags);
168
169         n = readhammervol(vol);
170         if (n == -1) {
171                 err(1, "load_volume: %s: Read failed at offset 0", vol->name);
172         }
173         ondisk = vol->ondisk;
174         vol->vol_no = ondisk->vol_no;
175
176         if (ondisk->vol_rootvol != HAMMER_ROOT_VOLNO) {
177                 errx(1, "load_volume: Invalid root volume# %d",
178                         ondisk->vol_rootvol);
179         }
180
181         if (bcmp(&Hammer_FSType, &ondisk->vol_fstype, sizeof(Hammer_FSType))) {
182                 errx(1, "load_volume: %s: Header does not indicate "
183                         "that this is a hammer volume", vol->name);
184         }
185
186         if (valid_hammer_volumes++ == 0) {
187                 Hammer_FSId = ondisk->vol_fsid;
188         } else if (bcmp(&Hammer_FSId, &ondisk->vol_fsid, sizeof(Hammer_FSId))) {
189                 errx(1, "load_volume: %s: FSId does match other volumes!",
190                         vol->name);
191         }
192
193         __add_volume(vol);
194
195         return(vol);
196 }
197
198 /*
199  * Check basic volume characteristics.
200  */
201 static void
202 check_volume(struct volume_info *vol)
203 {
204         struct partinfo pinfo;
205         struct stat st;
206
207         /*
208          * Get basic information about the volume
209          */
210         if (ioctl(vol->fd, DIOCGPART, &pinfo) < 0) {
211                 /*
212                  * Allow the formatting of regular files as HAMMER volumes
213                  */
214                 if (fstat(vol->fd, &st) < 0)
215                         err(1, "Unable to stat %s", vol->name);
216                 vol->size = st.st_size;
217                 vol->type = "REGFILE";
218         } else {
219                 /*
220                  * When formatting a block device as a HAMMER volume the
221                  * sector size must be compatible.  HAMMER uses 16384 byte
222                  * filesystem buffers.
223                  */
224                 if (pinfo.reserved_blocks) {
225                         errx(1, "HAMMER cannot be placed in a partition "
226                                 "which overlaps the disklabel or MBR");
227                 }
228                 if (pinfo.media_blksize > HAMMER_BUFSIZE ||
229                     HAMMER_BUFSIZE % pinfo.media_blksize) {
230                         errx(1, "A media sector size of %d is not supported",
231                              pinfo.media_blksize);
232                 }
233
234                 vol->size = pinfo.media_size;
235                 vol->device_offset = pinfo.media_offset;
236                 vol->type = "DEVICE";
237         }
238 }
239
240 void
241 assert_volume_offset(struct volume_info *vol)
242 {
243         assert(hammer_is_zone_raw_buffer(vol->vol_free_off));
244         assert(hammer_is_zone_raw_buffer(vol->vol_free_end));
245 }
246
247 struct volume_info *
248 get_volume(int32_t vol_no)
249 {
250         struct volume_info *vol;
251
252         TAILQ_FOREACH(vol, &VolList, entry) {
253                 if (vol->vol_no == vol_no)
254                         break;
255         }
256
257         return(vol);
258 }
259
260 struct volume_info *
261 get_root_volume(void)
262 {
263         struct volume_info *root_vol;
264
265         root_vol = get_volume(HAMMER_ROOT_VOLNO);
266         assert(root_vol != NULL);
267
268         return(root_vol);
269 }
270
271 /*
272  * Acquire the specified buffer.  isnew is -1 only when called
273  * via get_buffer_readahead() to prevent another readahead.
274  */
275 static struct buffer_info *
276 get_buffer(hammer_off_t buf_offset, int isnew)
277 {
278         struct buffer_info *buf;
279         struct volume_info *volume;
280         int vol_no;
281         int zone;
282         int hi;
283         int dora = 0;
284         int error = 0;
285
286         zone = HAMMER_ZONE_DECODE(buf_offset);
287         if (zone > HAMMER_ZONE_RAW_BUFFER_INDEX)
288                 buf_offset = blockmap_lookup(buf_offset, NULL, NULL, &error);
289         if (error || buf_offset == HAMMER_OFF_BAD)
290                 return(NULL);
291         assert(hammer_is_zone_raw_buffer(buf_offset));
292
293         vol_no = HAMMER_VOL_DECODE(buf_offset);
294         volume = get_volume(vol_no);
295         assert(volume != NULL);
296
297         buf_offset &= ~HAMMER_BUFMASK64;
298         buf = find_buffer(volume, buf_offset);
299
300         if (buf == NULL) {
301                 buf = malloc(sizeof(*buf));
302                 bzero(buf, sizeof(*buf));
303                 buf->buf_offset = buf_offset;
304                 buf->raw_offset = hammer_xlate_to_phys(volume->ondisk,
305                                                         buf_offset);
306                 buf->volume = volume;
307                 buf->ondisk = malloc(HAMMER_BUFSIZE);
308                 if (isnew <= 0) {
309                         if (readhammerbuf(buf) == -1) {
310                                 err(1, "get_buffer: %s:%016jx "
311                                     "Read failed at offset %016jx",
312                                     volume->name,
313                                     (intmax_t)buf->buf_offset,
314                                     (intmax_t)buf->raw_offset);
315                         }
316                 }
317
318                 hi = buffer_hash(buf_offset);
319                 TAILQ_INSERT_TAIL(&volume->buffer_lists[hi], buf, entry);
320                 hammer_cache_add(&buf->cache);
321                 dora = (isnew == 0);
322         } else {
323                 assert(buf->ondisk != NULL);
324                 assert(isnew != -1);
325                 hammer_cache_used(&buf->cache);
326         }
327
328         ++buf->cache.refs;
329         hammer_cache_flush();
330
331         if (isnew > 0) {
332                 assert(buf->cache.modified == 0);
333                 bzero(buf->ondisk, HAMMER_BUFSIZE);
334                 buf->cache.modified = 1;
335         }
336         if (dora)
337                 get_buffer_readahead(buf);
338         return(buf);
339 }
340
341 static void
342 get_buffer_readahead(struct buffer_info *base)
343 {
344         struct buffer_info *buf;
345         struct volume_info *vol;
346         hammer_off_t buf_offset;
347         int64_t raw_offset;
348         int ri = UseReadBehind;
349         int re = UseReadAhead;
350
351         raw_offset = base->raw_offset + ri * HAMMER_BUFSIZE;
352         vol = base->volume;
353
354         while (ri < re) {
355                 if (raw_offset >= vol->ondisk->vol_buf_end)
356                         break;
357                 if (raw_offset < vol->ondisk->vol_buf_beg || ri == 0) {
358                         ++ri;
359                         raw_offset += HAMMER_BUFSIZE;
360                         continue;
361                 }
362                 buf_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no,
363                         raw_offset - vol->ondisk->vol_buf_beg);
364                 buf = find_buffer(vol, buf_offset);
365                 if (buf == NULL) {
366                         buf = get_buffer(buf_offset, -1);
367                         rel_buffer(buf);
368                 }
369                 ++ri;
370                 raw_offset += HAMMER_BUFSIZE;
371         }
372 }
373
374 void
375 rel_buffer(struct buffer_info *buffer)
376 {
377         struct volume_info *volume;
378         int hi;
379
380         if (buffer == NULL)
381                 return;
382         assert(buffer->cache.refs > 0);
383         if (--buffer->cache.refs == 0) {
384                 if (buffer->cache.delete) {
385                         hi = buffer_hash(buffer->buf_offset);
386                         volume = buffer->volume;
387                         if (buffer->cache.modified)
388                                 flush_buffer(buffer);
389                         TAILQ_REMOVE(&volume->buffer_lists[hi], buffer, entry);
390                         hammer_cache_del(&buffer->cache);
391                         free(buffer->ondisk);
392                         free(buffer);
393                 }
394         }
395 }
396
397 /*
398  * Retrieve a pointer to a buffer data given a buffer offset.  The underlying
399  * bufferp is freed if isnew or the offset is out of range of the cached data.
400  * If bufferp is freed a referenced buffer is loaded into it.
401  */
402 void *
403 get_buffer_data(hammer_off_t buf_offset, struct buffer_info **bufferp,
404                 int isnew)
405 {
406         if (*bufferp != NULL) {
407                 if (isnew > 0 ||
408                     (((*bufferp)->buf_offset ^ buf_offset) & ~HAMMER_BUFMASK64)) {
409                         rel_buffer(*bufferp);
410                         *bufferp = NULL;
411                 }
412         }
413         return(get_ondisk(buf_offset, bufferp, isnew));
414 }
415
416 /*
417  * Retrieve a pointer to a B-Tree node given a zone offset.  The underlying
418  * bufferp is freed if non-NULL and a referenced buffer is loaded into it.
419  */
420 hammer_node_ondisk_t
421 get_node(hammer_off_t node_offset, struct buffer_info **bufferp)
422 {
423         if (*bufferp != NULL) {
424                 rel_buffer(*bufferp);
425                 *bufferp = NULL;
426         }
427         return(get_ondisk(node_offset, bufferp, 0));
428 }
429
430 /*
431  * Return a pointer to a buffer data given a buffer offset.
432  * If *bufferp is NULL acquire the buffer otherwise use that buffer.
433  */
434 static void *
435 get_ondisk(hammer_off_t buf_offset, struct buffer_info **bufferp, int isnew)
436 {
437         if (*bufferp == NULL) {
438                 *bufferp = get_buffer(buf_offset, isnew);
439                 if (*bufferp == NULL)
440                         return(NULL);
441         }
442
443         return(((char *)(*bufferp)->ondisk) +
444                 ((int32_t)buf_offset & HAMMER_BUFMASK));
445 }
446
447 /*
448  * Allocate HAMMER elements - B-Tree nodes
449  */
450 void *
451 alloc_btree_element(hammer_off_t *offp, struct buffer_info **data_bufferp)
452 {
453         hammer_node_ondisk_t node;
454
455         node = alloc_blockmap(HAMMER_ZONE_BTREE_INDEX, sizeof(*node),
456                               offp, data_bufferp);
457         bzero(node, sizeof(*node));
458         return (node);
459 }
460
461 /*
462  * Allocate HAMMER elements - meta data (inode, direntry, PFS, etc)
463  */
464 void *
465 alloc_meta_element(hammer_off_t *offp, int32_t data_len,
466                    struct buffer_info **data_bufferp)
467 {
468         void *data;
469
470         data = alloc_blockmap(HAMMER_ZONE_META_INDEX, data_len,
471                               offp, data_bufferp);
472         bzero(data, data_len);
473         return (data);
474 }
475
476 /*
477  * Allocate HAMMER elements - data storage
478  *
479  * The only data_len supported by HAMMER userspace for large data zone
480  * (zone 10) is HAMMER_BUFSIZE which is 16KB.  >16KB data does not fit
481  * in a buffer allocated by get_buffer().  Also alloc_blockmap() does
482  * not consider >16KB buffer size.
483  */
484 void *
485 alloc_data_element(hammer_off_t *offp, int32_t data_len,
486                    struct buffer_info **data_bufferp)
487 {
488         void *data;
489         int zone;
490
491         if (data_len == 0)
492                 return(NULL);
493
494         zone = hammer_data_zone_index(data_len);
495         assert(data_len <= HAMMER_BUFSIZE); /* just one buffer */
496         assert(zone == HAMMER_ZONE_LARGE_DATA_INDEX ||
497                zone == HAMMER_ZONE_SMALL_DATA_INDEX);
498
499         data = alloc_blockmap(zone, data_len, offp, data_bufferp);
500         bzero(data, data_len);
501         return(data);
502 }
503
504 /*
505  * Format a new blockmap.  This is mostly a degenerate case because
506  * all allocations are now actually done from the freemap.
507  */
508 void
509 format_blockmap(struct volume_info *root_vol, int zone, hammer_off_t offset)
510 {
511         hammer_blockmap_t blockmap;
512         hammer_off_t zone_base;
513
514         /* Only root volume needs formatting */
515         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
516
517         assert(hammer_is_zone2_mapped_index(zone));
518
519         blockmap = &root_vol->ondisk->vol0_blockmap[zone];
520         zone_base = HAMMER_ZONE_ENCODE(zone, offset);
521
522         bzero(blockmap, sizeof(*blockmap));
523         blockmap->phys_offset = 0;
524         blockmap->first_offset = zone_base;
525         blockmap->next_offset = zone_base;
526         blockmap->alloc_offset = HAMMER_ENCODE(zone, 255, -1);
527         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
528 }
529
530 /*
531  * Format a new freemap.  Set all layer1 entries to UNAVAIL.  The initialize
532  * code will load each volume's freemap.
533  */
534 void
535 format_freemap(struct volume_info *root_vol)
536 {
537         struct buffer_info *buffer = NULL;
538         hammer_off_t layer1_offset;
539         hammer_blockmap_t blockmap;
540         hammer_blockmap_layer1_t layer1;
541         int i, isnew;
542
543         /* Only root volume needs formatting */
544         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
545
546         layer1_offset = alloc_bigblock(root_vol, HAMMER_ZONE_FREEMAP_INDEX);
547         for (i = 0; i < HAMMER_BIGBLOCK_SIZE; i += sizeof(*layer1)) {
548                 isnew = ((i % HAMMER_BUFSIZE) == 0);
549                 layer1 = get_buffer_data(layer1_offset + i, &buffer, isnew);
550                 bzero(layer1, sizeof(*layer1));
551                 layer1->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
552                 layer1->blocks_free = 0;
553                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
554         }
555         assert(i == HAMMER_BIGBLOCK_SIZE);
556         rel_buffer(buffer);
557
558         blockmap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
559         bzero(blockmap, sizeof(*blockmap));
560         blockmap->phys_offset = layer1_offset;
561         blockmap->first_offset = 0;
562         blockmap->next_offset = HAMMER_ENCODE_RAW_BUFFER(0, 0);
563         blockmap->alloc_offset = HAMMER_ENCODE_RAW_BUFFER(255, -1);
564         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
565 }
566
567 /*
568  * Load the volume's remaining free space into the freemap.
569  *
570  * Returns the number of big-blocks available.
571  */
572 int64_t
573 initialize_freemap(struct volume_info *vol)
574 {
575         struct volume_info *root_vol;
576         struct buffer_info *buffer1 = NULL;
577         struct buffer_info *buffer2 = NULL;
578         hammer_blockmap_layer1_t layer1;
579         hammer_blockmap_layer2_t layer2;
580         hammer_off_t layer1_offset;
581         hammer_off_t layer2_offset;
582         hammer_off_t phys_offset;
583         hammer_off_t block_offset;
584         hammer_off_t aligned_vol_free_end;
585         hammer_blockmap_t freemap;
586         int64_t count = 0;
587         int64_t layer1_count = 0;
588
589         root_vol = get_root_volume();
590
591         assert_volume_offset(vol);
592         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
593                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
594
595         printf("initialize freemap volume %d\n", vol->vol_no);
596
597         /*
598          * Initialize the freemap.  First preallocate the big-blocks required
599          * to implement layer2.   This preallocation is a bootstrap allocation
600          * using blocks from the target volume.
601          */
602         freemap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
603
604         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
605              phys_offset < aligned_vol_free_end;
606              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
607                 layer1_offset = freemap->phys_offset +
608                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
609                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
610                 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
611                         layer1->phys_offset = alloc_bigblock(vol,
612                                                 HAMMER_ZONE_FREEMAP_INDEX);
613                         layer1->blocks_free = 0;
614                         buffer1->cache.modified = 1;
615                         layer1->layer1_crc = crc32(layer1,
616                                                    HAMMER_LAYER1_CRCSIZE);
617                 }
618         }
619
620         /*
621          * Now fill everything in.
622          */
623         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
624              phys_offset < aligned_vol_free_end;
625              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
626                 layer1_count = 0;
627                 layer1_offset = freemap->phys_offset +
628                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
629                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
630                 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
631
632                 for (block_offset = 0;
633                      block_offset < HAMMER_BLOCKMAP_LAYER2;
634                      block_offset += HAMMER_BIGBLOCK_SIZE) {
635                         layer2_offset = layer1->phys_offset +
636                                         HAMMER_BLOCKMAP_LAYER2_OFFSET(block_offset);
637                         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
638                         bzero(layer2, sizeof(*layer2));
639
640                         if (phys_offset + block_offset < vol->vol_free_off) {
641                                 /*
642                                  * Fixups XXX - big-blocks already allocated as part
643                                  * of the freemap bootstrap.
644                                  */
645                                 layer2->zone = HAMMER_ZONE_FREEMAP_INDEX;
646                                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
647                                 layer2->bytes_free = 0;
648                         } else if (phys_offset + block_offset < vol->vol_free_end) {
649                                 layer2->zone = 0;
650                                 layer2->append_off = 0;
651                                 layer2->bytes_free = HAMMER_BIGBLOCK_SIZE;
652                                 ++count;
653                                 ++layer1_count;
654                         } else {
655                                 layer2->zone = HAMMER_ZONE_UNAVAIL_INDEX;
656                                 layer2->append_off = HAMMER_BIGBLOCK_SIZE;
657                                 layer2->bytes_free = 0;
658                         }
659                         layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
660                         buffer2->cache.modified = 1;
661                 }
662
663                 layer1->blocks_free += layer1_count;
664                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
665                 buffer1->cache.modified = 1;
666         }
667
668         rel_buffer(buffer1);
669         rel_buffer(buffer2);
670         return(count);
671 }
672
673 /*
674  * Returns the number of big-blocks available for filesystem data and undos
675  * without formatting.
676  */
677 int64_t
678 count_freemap(struct volume_info *vol)
679 {
680         hammer_off_t phys_offset;
681         hammer_off_t vol_free_off;
682         hammer_off_t aligned_vol_free_end;
683         int64_t count = 0;
684
685         vol_free_off = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
686
687         assert_volume_offset(vol);
688         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
689                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
690
691         if (vol->vol_no == HAMMER_ROOT_VOLNO)
692                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
693
694         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
695              phys_offset < aligned_vol_free_end;
696              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
697                 vol_free_off += HAMMER_BIGBLOCK_SIZE;
698         }
699
700         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
701              phys_offset < aligned_vol_free_end;
702              phys_offset += HAMMER_BIGBLOCK_SIZE) {
703                 if (phys_offset < vol_free_off) {
704                         ;
705                 } else if (phys_offset < vol->vol_free_end) {
706                         ++count;
707                 }
708         }
709
710         return(count);
711 }
712
713 /*
714  * Format the undomap for the root volume.
715  */
716 void
717 format_undomap(struct volume_info *root_vol, int64_t *undo_buffer_size)
718 {
719         const int undo_zone = HAMMER_ZONE_UNDO_INDEX;
720         hammer_off_t undo_limit;
721         hammer_blockmap_t blockmap;
722         hammer_volume_ondisk_t ondisk;
723         struct buffer_info *buffer = NULL;
724         hammer_off_t scan;
725         int n;
726         int limit_index;
727         uint32_t seqno;
728
729         /* Only root volume needs formatting */
730         assert(root_vol->vol_no == HAMMER_ROOT_VOLNO);
731         ondisk = root_vol->ondisk;
732
733         /*
734          * Size the undo buffer in multiples of HAMMER_BIGBLOCK_SIZE,
735          * up to HAMMER_UNDO_LAYER2 big-blocks.  Size to approximately
736          * 0.1% of the disk.
737          *
738          * The minimum UNDO fifo size is 500MB, or approximately 1% of
739          * the recommended 50G disk.
740          *
741          * Changing this minimum is rather dangerous as complex filesystem
742          * operations can cause the UNDO FIFO to fill up otherwise.
743          */
744         undo_limit = *undo_buffer_size;
745         if (undo_limit == 0) {
746                 undo_limit = HAMMER_VOL_BUF_SIZE(ondisk) / 1000;
747                 if (undo_limit < 500*1024*1024)
748                         undo_limit = 500*1024*1024;
749         }
750         undo_limit = (undo_limit + HAMMER_BIGBLOCK_MASK64) &
751                      ~HAMMER_BIGBLOCK_MASK64;
752         if (undo_limit < HAMMER_BIGBLOCK_SIZE)
753                 undo_limit = HAMMER_BIGBLOCK_SIZE;
754         if (undo_limit > HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2)
755                 undo_limit = HAMMER_BIGBLOCK_SIZE * HAMMER_UNDO_LAYER2;
756         *undo_buffer_size = undo_limit;
757
758         blockmap = &ondisk->vol0_blockmap[undo_zone];
759         bzero(blockmap, sizeof(*blockmap));
760         blockmap->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
761         blockmap->first_offset = HAMMER_ZONE_ENCODE(undo_zone, 0);
762         blockmap->next_offset = blockmap->first_offset;
763         blockmap->alloc_offset = HAMMER_ZONE_ENCODE(undo_zone, undo_limit);
764         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
765
766         limit_index = undo_limit / HAMMER_BIGBLOCK_SIZE;
767         assert(limit_index <= HAMMER_UNDO_LAYER2);
768
769         for (n = 0; n < limit_index; ++n) {
770                 ondisk->vol0_undo_array[n] = alloc_bigblock(root_vol,
771                                                         HAMMER_ZONE_UNDO_INDEX);
772         }
773         while (n < HAMMER_UNDO_LAYER2) {
774                 ondisk->vol0_undo_array[n++] = HAMMER_BLOCKMAP_UNAVAIL;
775         }
776
777         /*
778          * Pre-initialize the UNDO blocks (HAMMER version 4+)
779          */
780         printf("initializing the undo map (%jd MB)\n",
781                 (intmax_t)(blockmap->alloc_offset & HAMMER_OFF_LONG_MASK) /
782                 (1024 * 1024));
783
784         scan = blockmap->first_offset;
785         seqno = 0;
786
787         while (scan < blockmap->alloc_offset) {
788                 hammer_fifo_head_t head;
789                 hammer_fifo_tail_t tail;
790                 int isnew;
791                 int bytes = HAMMER_UNDO_ALIGN;
792
793                 isnew = ((scan & HAMMER_BUFMASK64) == 0);
794                 head = get_buffer_data(scan, &buffer, isnew);
795                 buffer->cache.modified = 1;
796                 tail = (void *)((char *)head + bytes - sizeof(*tail));
797
798                 bzero(head, bytes);
799                 head->hdr_signature = HAMMER_HEAD_SIGNATURE;
800                 head->hdr_type = HAMMER_HEAD_TYPE_DUMMY;
801                 head->hdr_size = bytes;
802                 head->hdr_seq = seqno++;
803
804                 tail->tail_signature = HAMMER_TAIL_SIGNATURE;
805                 tail->tail_type = HAMMER_HEAD_TYPE_DUMMY;
806                 tail->tail_size = bytes;
807
808                 head->hdr_crc = crc32(head, HAMMER_FIFO_HEAD_CRCOFF) ^
809                                 crc32(head + 1, bytes - sizeof(*head));
810
811                 scan += bytes;
812         }
813         rel_buffer(buffer);
814 }
815
816 const char *zone_labels[] = {
817         "",             /* 0 */
818         "raw_volume",   /* 1 */
819         "raw_buffer",   /* 2 */
820         "undo",         /* 3 */
821         "freemap",      /* 4 */
822         "",             /* 5 */
823         "",             /* 6 */
824         "",             /* 7 */
825         "btree",        /* 8 */
826         "meta",         /* 9 */
827         "large_data",   /* 10 */
828         "small_data",   /* 11 */
829         "",             /* 12 */
830         "",             /* 13 */
831         "",             /* 14 */
832         "unavail",      /* 15 */
833 };
834
835 void
836 print_blockmap(const struct volume_info *root_vol)
837 {
838         hammer_blockmap_t blockmap;
839         hammer_volume_ondisk_t ondisk;
840         int64_t size, used;
841         int i;
842 #define INDENT ""
843
844         ondisk = root_vol->ondisk;
845         printf(INDENT"vol_label\t%s\n", ondisk->vol_label);
846         printf(INDENT"vol_count\t%d\n", ondisk->vol_count);
847         printf(INDENT"vol_bot_beg\t%s\n", sizetostr(ondisk->vol_bot_beg));
848         printf(INDENT"vol_mem_beg\t%s\n", sizetostr(ondisk->vol_mem_beg));
849         printf(INDENT"vol_buf_beg\t%s\n", sizetostr(ondisk->vol_buf_beg));
850         printf(INDENT"vol_buf_end\t%s\n", sizetostr(ondisk->vol_buf_end));
851         printf(INDENT"vol0_next_tid\t%016jx\n",
852                (uintmax_t)ondisk->vol0_next_tid);
853
854         blockmap = &ondisk->vol0_blockmap[HAMMER_ZONE_UNDO_INDEX];
855         size = blockmap->alloc_offset & HAMMER_OFF_LONG_MASK;
856         if (blockmap->first_offset <= blockmap->next_offset)
857                 used = blockmap->next_offset - blockmap->first_offset;
858         else
859                 used = blockmap->alloc_offset - blockmap->first_offset +
860                         (blockmap->next_offset & HAMMER_OFF_LONG_MASK);
861         printf(INDENT"undo_size\t%s\n", sizetostr(size));
862         printf(INDENT"undo_used\t%s\n", sizetostr(used));
863
864         printf(INDENT"zone #             "
865                "phys             first            next             alloc\n");
866         for (i = 0; i < HAMMER_MAX_ZONES; i++) {
867                 blockmap = &ondisk->vol0_blockmap[i];
868                 printf(INDENT"zone %-2d %-10s %016jx %016jx %016jx %016jx\n",
869                         i, zone_labels[i],
870                         (uintmax_t)blockmap->phys_offset,
871                         (uintmax_t)blockmap->first_offset,
872                         (uintmax_t)blockmap->next_offset,
873                         (uintmax_t)blockmap->alloc_offset);
874         }
875 }
876
877 /*
878  * Flush various tracking structures to disk
879  */
880 void
881 flush_all_volumes(void)
882 {
883         struct volume_info *vol;
884
885         TAILQ_FOREACH(vol, &VolList, entry)
886                 flush_volume(vol);
887 }
888
889 void
890 flush_volume(struct volume_info *volume)
891 {
892         struct buffer_info *buffer;
893         int i;
894
895         for (i = 0; i < HAMMER_BUFLISTS; ++i) {
896                 TAILQ_FOREACH(buffer, &volume->buffer_lists[i], entry)
897                         flush_buffer(buffer);
898         }
899         if (writehammervol(volume) == -1)
900                 err(1, "Write volume %d (%s)", volume->vol_no, volume->name);
901 }
902
903 void
904 flush_buffer(struct buffer_info *buffer)
905 {
906         struct volume_info *vol;
907
908         vol = buffer->volume;
909         if (writehammerbuf(buffer) == -1)
910                 err(1, "Write volume %d (%s)", vol->vol_no, vol->name);
911         buffer->cache.modified = 0;
912 }
913
914 /*
915  * Core I/O operations
916  */
917 static int
918 __read(struct volume_info *vol, void *data, int64_t offset, int size)
919 {
920         ssize_t n;
921
922         n = pread(vol->fd, data, size, offset);
923         if (n != size)
924                 return(-1);
925         return(0);
926 }
927
928 static __inline int
929 readhammervol(struct volume_info *vol)
930 {
931         return(__read(vol, vol->ondisk, 0, HAMMER_BUFSIZE));
932 }
933
934 static __inline int
935 readhammerbuf(struct buffer_info *buf)
936 {
937         return(__read(buf->volume, buf->ondisk, buf->raw_offset, HAMMER_BUFSIZE));
938 }
939
940 static int
941 __write(struct volume_info *vol, const void *data, int64_t offset, int size)
942 {
943         ssize_t n;
944
945         if (vol->rdonly)
946                 return(0);
947
948         n = pwrite(vol->fd, data, size, offset);
949         if (n != size)
950                 return(-1);
951         return(0);
952 }
953
954 static __inline int
955 writehammervol(struct volume_info *vol)
956 {
957         return(__write(vol, vol->ondisk, 0, HAMMER_BUFSIZE));
958 }
959
960 static __inline int
961 writehammerbuf(struct buffer_info *buf)
962 {
963         return(__write(buf->volume, buf->ondisk, buf->raw_offset, HAMMER_BUFSIZE));
964 }
965
966 int64_t init_boot_area_size(int64_t value, off_t avg_vol_size)
967 {
968         if (value == 0) {
969                 value = HAMMER_BOOT_NOMBYTES;
970                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
971                         value >>= 1;
972                 if (value < HAMMER_BOOT_MINBYTES)
973                         value = 0;
974         } else if (value < HAMMER_BOOT_MINBYTES) {
975                 value = HAMMER_BOOT_MINBYTES;
976         }
977
978         return(value);
979 }
980
981 int64_t init_mem_area_size(int64_t value, off_t avg_vol_size)
982 {
983         if (value == 0) {
984                 value = HAMMER_MEM_NOMBYTES;
985                 while (value > avg_vol_size / HAMMER_MAX_VOLUMES)
986                         value >>= 1;
987                 if (value < HAMMER_MEM_MINBYTES)
988                         value = 0;
989         } else if (value < HAMMER_MEM_MINBYTES) {
990                 value = HAMMER_MEM_MINBYTES;
991         }
992
993         return(value);
994 }