Fix various whitespace and indent issues (no functional change).
[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/types.h>
36 #include <assert.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <stdarg.h>
40 #include <string.h>
41 #include <unistd.h>
42 #include <stddef.h>
43 #include <err.h>
44 #include <fcntl.h>
45 #include "hammer_util.h"
46
47 static void *alloc_blockmap(int zone, int bytes, hammer_off_t *result_offp,
48                         struct buffer_info **bufferp);
49 static hammer_off_t alloc_bigblock(struct volume_info *volume, int zone);
50 static void get_buffer_readahead(struct buffer_info *base);
51 #if 0
52 static void init_fifo_head(hammer_fifo_head_t head, u_int16_t hdr_type);
53 static hammer_off_t hammer_alloc_fifo(int32_t base_bytes, int32_t ext_bytes,
54                         struct buffer_info **bufp, u_int16_t hdr_type);
55 static void readhammerbuf(struct volume_info *vol, void *data,
56                         int64_t offset);
57 #endif
58 static void writehammerbuf(struct volume_info *vol, const void *data,
59                         int64_t offset);
60
61 int DebugOpt;
62
63 uuid_t Hammer_FSType;
64 uuid_t Hammer_FSId;
65 int64_t BootAreaSize;
66 int64_t MemAreaSize;
67 int64_t UndoBufferSize;
68 int     UsingSuperClusters;
69 int     NumVolumes;
70 int     RootVolNo = -1;
71 int     UseReadBehind = -4;
72 int     UseReadAhead = 4;
73 int     AssertOnFailure = 1;
74 struct volume_list VolList = TAILQ_HEAD_INITIALIZER(VolList);
75
76 static __inline
77 int
78 buffer_hash(hammer_off_t buf_offset)
79 {
80         int hi;
81
82         hi = (int)(buf_offset / HAMMER_BUFSIZE) & HAMMER_BUFLISTMASK;
83         return(hi);
84 }
85
86 /*
87  * Lookup the requested information structure and related on-disk buffer.
88  * Missing structures are created.
89  */
90 struct volume_info *
91 setup_volume(int32_t vol_no, const char *filename, int isnew, int oflags)
92 {
93         struct volume_info *vol;
94         struct volume_info *scan;
95         struct hammer_volume_ondisk *ondisk;
96         int i, n;
97
98         /*
99          * Allocate the volume structure
100          */
101         vol = malloc(sizeof(*vol));
102         bzero(vol, sizeof(*vol));
103         for (i = 0; i < HAMMER_BUFLISTS; ++i)
104                 TAILQ_INIT(&vol->buffer_lists[i]);
105         vol->name = strdup(filename);
106         vol->fd = open(filename, oflags);
107         if (vol->fd < 0) {
108                 free(vol->name);
109                 free(vol);
110                 err(1, "setup_volume: %s: Open failed", filename);
111         }
112
113         /*
114          * Read or initialize the volume header
115          */
116         vol->ondisk = ondisk = malloc(HAMMER_BUFSIZE);
117         if (isnew > 0) {
118                 bzero(ondisk, HAMMER_BUFSIZE);
119         } else {
120                 n = pread(vol->fd, ondisk, HAMMER_BUFSIZE, 0);
121                 if (n != HAMMER_BUFSIZE) {
122                         err(1, "setup_volume: %s: Read failed at offset 0",
123                             filename);
124                 }
125                 vol_no = ondisk->vol_no;
126                 if (RootVolNo < 0) {
127                         RootVolNo = ondisk->vol_rootvol;
128                 } else if (RootVolNo != (int)ondisk->vol_rootvol) {
129                         errx(1, "setup_volume: %s: root volume disagreement: "
130                                 "%d vs %d",
131                                 vol->name, RootVolNo, ondisk->vol_rootvol);
132                 }
133
134                 if (bcmp(&Hammer_FSType, &ondisk->vol_fstype, sizeof(Hammer_FSType)) != 0) {
135                         errx(1, "setup_volume: %s: Header does not indicate "
136                                 "that this is a hammer volume", vol->name);
137                 }
138                 if (TAILQ_EMPTY(&VolList)) {
139                         Hammer_FSId = vol->ondisk->vol_fsid;
140                 } else if (bcmp(&Hammer_FSId, &ondisk->vol_fsid, sizeof(Hammer_FSId)) != 0) {
141                         errx(1, "setup_volume: %s: FSId does match other "
142                                 "volumes!", vol->name);
143                 }
144         }
145         vol->vol_no = vol_no;
146
147         if (isnew > 0) {
148                 /*init_fifo_head(&ondisk->head, HAMMER_HEAD_TYPE_VOL);*/
149                 vol->cache.modified = 1;
150         }
151
152         /*
153          * Link the volume structure in
154          */
155         TAILQ_FOREACH(scan, &VolList, entry) {
156                 if (scan->vol_no == vol_no) {
157                         errx(1, "setup_volume %s: Duplicate volume number %d "
158                                 "against %s", filename, vol_no, scan->name);
159                 }
160         }
161         TAILQ_INSERT_TAIL(&VolList, vol, entry);
162         return(vol);
163 }
164
165 struct volume_info *
166 test_volume(int32_t vol_no)
167 {
168         struct volume_info *vol;
169
170         TAILQ_FOREACH(vol, &VolList, entry) {
171                 if (vol->vol_no == vol_no)
172                         break;
173         }
174         if (vol == NULL)
175                 return(NULL);
176         ++vol->cache.refs;
177         /* not added to or removed from hammer cache */
178         return(vol);
179 }
180
181 struct volume_info *
182 get_volume(int32_t vol_no)
183 {
184         struct volume_info *vol;
185
186         TAILQ_FOREACH(vol, &VolList, entry) {
187                 if (vol->vol_no == vol_no)
188                         break;
189         }
190         if (vol == NULL)
191                 errx(1, "get_volume: Volume %d does not exist!", vol_no);
192         ++vol->cache.refs;
193         /* not added to or removed from hammer cache */
194         return(vol);
195 }
196
197 void
198 rel_volume(struct volume_info *volume)
199 {
200         /* not added to or removed from hammer cache */
201         --volume->cache.refs;
202 }
203
204 /*
205  * Acquire the specified buffer.
206  */
207 struct buffer_info *
208 get_buffer(hammer_off_t buf_offset, int isnew)
209 {
210         void *ondisk;
211         struct buffer_info *buf;
212         struct volume_info *volume;
213         hammer_off_t orig_offset = buf_offset;
214         int vol_no;
215         int zone;
216         int hi, n;
217         int dora = 0;
218
219         zone = HAMMER_ZONE_DECODE(buf_offset);
220         if (zone > HAMMER_ZONE_RAW_BUFFER_INDEX) {
221                 buf_offset = blockmap_lookup(buf_offset, NULL, NULL, NULL);
222         }
223         if (buf_offset == HAMMER_OFF_BAD)
224                 return(NULL);
225
226         if (AssertOnFailure) {
227                 assert((buf_offset & HAMMER_OFF_ZONE_MASK) ==
228                        HAMMER_ZONE_RAW_BUFFER);
229         }
230         vol_no = HAMMER_VOL_DECODE(buf_offset);
231         volume = test_volume(vol_no);
232         if (volume == NULL) {
233                 if (AssertOnFailure)
234                         errx(1, "get_buffer: Volume %d not found!", vol_no);
235                 return(NULL);
236         }
237
238         buf_offset &= ~HAMMER_BUFMASK64;
239
240         hi = buffer_hash(buf_offset);
241
242         TAILQ_FOREACH(buf, &volume->buffer_lists[hi], entry) {
243                 if (buf->buf_offset == buf_offset)
244                         break;
245         }
246         if (buf == NULL) {
247                 buf = malloc(sizeof(*buf));
248                 bzero(buf, sizeof(*buf));
249                 if (DebugOpt) {
250                         fprintf(stderr, "get_buffer %016llx %016llx\n",
251                                 (long long)orig_offset, (long long)buf_offset);
252                 }
253                 buf->buf_offset = buf_offset;
254                 buf->raw_offset = volume->ondisk->vol_buf_beg +
255                                   (buf_offset & HAMMER_OFF_SHORT_MASK);
256                 buf->volume = volume;
257                 TAILQ_INSERT_TAIL(&volume->buffer_lists[hi], buf, entry);
258                 ++volume->cache.refs;
259                 buf->cache.u.buffer = buf;
260                 hammer_cache_add(&buf->cache, ISBUFFER);
261                 dora = (isnew == 0);
262                 if (isnew < 0)
263                         buf->flags |= HAMMER_BUFINFO_READAHEAD;
264         } else {
265                 if (isnew >= 0) {
266                         buf->flags &= ~HAMMER_BUFINFO_READAHEAD;
267                         hammer_cache_used(&buf->cache);
268                 }
269                 ++buf->use_count;
270         }
271         ++buf->cache.refs;
272         hammer_cache_flush();
273         if ((ondisk = buf->ondisk) == NULL) {
274                 buf->ondisk = ondisk = malloc(HAMMER_BUFSIZE);
275                 if (isnew <= 0) {
276                         n = pread(volume->fd, ondisk, HAMMER_BUFSIZE,
277                                   buf->raw_offset);
278                         if (n != HAMMER_BUFSIZE) {
279                                 if (AssertOnFailure)
280                                         err(1, "get_buffer: %s:%016llx "
281                                             "Read failed at offset %016llx",
282                                             volume->name,
283                                             (long long)buf->buf_offset,
284                                             (long long)buf->raw_offset);
285                                 bzero(ondisk, HAMMER_BUFSIZE);
286                         }
287                 }
288         }
289         if (isnew > 0) {
290                 bzero(ondisk, HAMMER_BUFSIZE);
291                 buf->cache.modified = 1;
292         }
293         if (dora)
294                 get_buffer_readahead(buf);
295         return(buf);
296 }
297
298 static void
299 get_buffer_readahead(struct buffer_info *base)
300 {
301         struct buffer_info *buf;
302         struct volume_info *vol;
303         hammer_off_t buf_offset;
304         int64_t raw_offset;
305         int ri = UseReadBehind;
306         int re = UseReadAhead;
307         int hi;
308
309         raw_offset = base->raw_offset + ri * HAMMER_BUFSIZE;
310         vol = base->volume;
311
312         while (ri < re) {
313                 if (raw_offset >= vol->ondisk->vol_buf_end)
314                         break;
315                 if (raw_offset < vol->ondisk->vol_buf_beg) {
316                         ++ri;
317                         raw_offset += HAMMER_BUFSIZE;
318                         continue;
319                 }
320                 buf_offset = HAMMER_VOL_ENCODE(vol->vol_no) |
321                              HAMMER_ZONE_RAW_BUFFER |
322                              (raw_offset - vol->ondisk->vol_buf_beg);
323                 hi = buffer_hash(raw_offset);
324                 TAILQ_FOREACH(buf, &vol->buffer_lists[hi], entry) {
325                         if (buf->raw_offset == raw_offset)
326                                 break;
327                 }
328                 if (buf == NULL) {
329                         buf = get_buffer(buf_offset, -1);
330                         rel_buffer(buf);
331                 }
332                 ++ri;
333                 raw_offset += HAMMER_BUFSIZE;
334         }
335 }
336
337 void
338 rel_buffer(struct buffer_info *buffer)
339 {
340         struct volume_info *volume;
341         int hi;
342
343         assert(buffer->cache.refs > 0);
344         if (--buffer->cache.refs == 0) {
345                 if (buffer->cache.delete) {
346                         hi = buffer_hash(buffer->buf_offset);
347                         volume = buffer->volume;
348                         if (buffer->cache.modified)
349                                 flush_buffer(buffer);
350                         TAILQ_REMOVE(&volume->buffer_lists[hi], buffer, entry);
351                         hammer_cache_del(&buffer->cache);
352                         free(buffer->ondisk);
353                         free(buffer);
354                         rel_volume(volume);
355                 }
356         }
357 }
358
359 void *
360 get_buffer_data(hammer_off_t buf_offset, struct buffer_info **bufferp,
361                 int isnew)
362 {
363         struct buffer_info *buffer;
364
365         if ((buffer = *bufferp) != NULL) {
366                 if (isnew > 0 ||
367                     ((buffer->buf_offset ^ buf_offset) & ~HAMMER_BUFMASK64)) {
368                         rel_buffer(buffer);
369                         buffer = *bufferp = NULL;
370                 }
371         }
372         if (buffer == NULL)
373                 buffer = *bufferp = get_buffer(buf_offset, isnew);
374         if (buffer == NULL)
375                 return (NULL);
376         return((char *)buffer->ondisk + ((int32_t)buf_offset & HAMMER_BUFMASK));
377 }
378
379 /*
380  * Retrieve a pointer to a B-Tree node given a cluster offset.  The underlying
381  * bufp is freed if non-NULL and a referenced buffer is loaded into it.
382  */
383 hammer_node_ondisk_t
384 get_node(hammer_off_t node_offset, struct buffer_info **bufp)
385 {
386         struct buffer_info *buf;
387
388         if (*bufp)
389                 rel_buffer(*bufp);
390         *bufp = buf = get_buffer(node_offset, 0);
391         if (buf) {
392                 return((void *)((char *)buf->ondisk +
393                                 (int32_t)(node_offset & HAMMER_BUFMASK)));
394         } else {
395                 return(NULL);
396         }
397 }
398
399 /*
400  * Allocate HAMMER elements - btree nodes, data storage, and record elements
401  *
402  * NOTE: hammer_alloc_fifo() initializes the fifo header for the returned
403  * item and zero's out the remainder, so don't bzero() it.
404  */
405 void *
406 alloc_btree_element(hammer_off_t *offp)
407 {
408         struct buffer_info *buffer = NULL;
409         hammer_node_ondisk_t node;
410
411         node = alloc_blockmap(HAMMER_ZONE_BTREE_INDEX, sizeof(*node),
412                               offp, &buffer);
413         bzero(node, sizeof(*node));
414         /* XXX buffer not released, pointer remains valid */
415         return(node);
416 }
417
418 void *
419 alloc_data_element(hammer_off_t *offp, int32_t data_len,
420                    struct buffer_info **data_bufferp)
421 {
422         void *data;
423
424         if (data_len >= HAMMER_BUFSIZE) {
425                 assert(data_len <= HAMMER_BUFSIZE); /* just one buffer */
426                 data = alloc_blockmap(HAMMER_ZONE_LARGE_DATA_INDEX, data_len,
427                                       offp, data_bufferp);
428                 bzero(data, data_len);
429         } else if (data_len) {
430                 data = alloc_blockmap(HAMMER_ZONE_SMALL_DATA_INDEX, data_len,
431                                       offp, data_bufferp);
432                 bzero(data, data_len);
433         } else {
434                 data = NULL;
435         }
436         return (data);
437 }
438
439 /*
440  * Format a new freemap.  Set all layer1 entries to UNAVAIL.  The initialize
441  * code will load each volume's freemap.
442  */
443 void
444 format_freemap(struct volume_info *root_vol, hammer_blockmap_t blockmap)
445 {
446         struct buffer_info *buffer = NULL;
447         hammer_off_t layer1_offset;
448         struct hammer_blockmap_layer1 *layer1;
449         int i, isnew;
450
451         layer1_offset = alloc_bigblock(root_vol, HAMMER_ZONE_FREEMAP_INDEX);
452         for (i = 0; i < (int)HAMMER_BLOCKMAP_RADIX1; ++i) {
453                 isnew = ((i % HAMMER_BLOCKMAP_RADIX1_PERBUFFER) == 0);
454                 layer1 = get_buffer_data(layer1_offset + i * sizeof(*layer1),
455                                          &buffer, isnew);
456                 bzero(layer1, sizeof(*layer1));
457                 layer1->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
458                 layer1->blocks_free = 0;
459                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
460         }
461         rel_buffer(buffer);
462
463         blockmap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
464         blockmap->phys_offset = layer1_offset;
465         blockmap->alloc_offset = HAMMER_ENCODE_RAW_BUFFER(255, -1);
466         blockmap->next_offset = HAMMER_ENCODE_RAW_BUFFER(0, 0);
467         blockmap->reserved01 = 0;
468         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
469         root_vol->cache.modified = 1;
470 }
471
472 /*
473  * Load the volume's remaining free space into the freemap.
474  *
475  * Returns the number of bigblocks available.
476  */
477 int64_t
478 initialize_freemap(struct volume_info *vol)
479 {
480         struct volume_info *root_vol;
481         struct buffer_info *buffer1 = NULL;
482         struct buffer_info *buffer2 = NULL;
483         struct hammer_blockmap_layer1 *layer1;
484         struct hammer_blockmap_layer2 *layer2;
485         hammer_off_t layer1_base;
486         hammer_off_t layer1_offset;
487         hammer_off_t layer2_offset;
488         hammer_off_t phys_offset;
489         hammer_off_t aligned_vol_free_end;
490         int64_t count = 0;
491         int modified1 = 0;
492
493         root_vol = get_volume(RootVolNo);
494         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
495                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
496
497         printf("initialize freemap volume %d\n", vol->vol_no);
498
499         /*
500          * Initialize the freemap.  First preallocate the bigblocks required
501          * to implement layer2.   This preallocation is a bootstrap allocation
502          * using blocks from the target volume.
503          */
504         layer1_base = root_vol->ondisk->vol0_blockmap[
505                                         HAMMER_ZONE_FREEMAP_INDEX].phys_offset;
506         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
507              phys_offset < aligned_vol_free_end;
508              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
509                 layer1_offset = layer1_base +
510                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
511                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
512                 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
513                         layer1->phys_offset = alloc_bigblock(vol,
514                                                 HAMMER_ZONE_FREEMAP_INDEX);
515                         layer1->blocks_free = 0;
516                         buffer1->cache.modified = 1;
517                         layer1->layer1_crc = crc32(layer1,
518                                                    HAMMER_LAYER1_CRCSIZE);
519                 }
520         }
521
522         /*
523          * Now fill everything in.
524          */
525         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
526              phys_offset < aligned_vol_free_end;
527              phys_offset += HAMMER_LARGEBLOCK_SIZE) {
528                 modified1 = 0;
529                 layer1_offset = layer1_base +
530                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
531                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
532
533                 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
534                 layer2_offset = layer1->phys_offset +
535                                 HAMMER_BLOCKMAP_LAYER2_OFFSET(phys_offset);
536
537                 layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
538                 bzero(layer2, sizeof(*layer2));
539                 if (phys_offset < vol->vol_free_off) {
540                         /*
541                          * Fixups XXX - bigblocks already allocated as part
542                          * of the freemap bootstrap.
543                          */
544                         if (layer2->zone == 0) {
545                                 layer2->zone = HAMMER_ZONE_FREEMAP_INDEX;
546                                 layer2->append_off = HAMMER_LARGEBLOCK_SIZE;
547                                 layer2->bytes_free = 0;
548                         }
549                 } else if (phys_offset < vol->vol_free_end) {
550                         ++layer1->blocks_free;
551                         buffer1->cache.modified = 1;
552                         layer2->zone = 0;
553                         layer2->append_off = 0;
554                         layer2->bytes_free = HAMMER_LARGEBLOCK_SIZE;
555                         ++count;
556                         modified1 = 1;
557                 } else {
558                         layer2->zone = HAMMER_ZONE_UNAVAIL_INDEX;
559                         layer2->append_off = HAMMER_LARGEBLOCK_SIZE;
560                         layer2->bytes_free = 0;
561                 }
562                 layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
563                 buffer2->cache.modified = 1;
564
565                 /*
566                  * Finish-up layer 1
567                  */
568                 if (modified1) {
569                         layer1->layer1_crc = crc32(layer1,
570                                                    HAMMER_LAYER1_CRCSIZE);
571                         buffer1->cache.modified = 1;
572                 }
573         }
574         rel_buffer(buffer1);
575         rel_buffer(buffer2);
576         rel_volume(root_vol);
577         return(count);
578 }
579
580 /*
581  * Allocate big-blocks using our poor-man's volume->vol_free_off.
582  *
583  * If the zone is HAMMER_ZONE_FREEMAP_INDEX we are bootstrapping the freemap
584  * itself and cannot update it yet.
585  */
586 hammer_off_t
587 alloc_bigblock(struct volume_info *volume, int zone)
588 {
589         struct buffer_info *buffer = NULL;
590         struct volume_info *root_vol;
591         hammer_off_t result_offset;
592         hammer_off_t layer_offset;
593         struct hammer_blockmap_layer1 *layer1;
594         struct hammer_blockmap_layer2 *layer2;
595         int didget;
596
597         if (volume == NULL) {
598                 volume = get_volume(RootVolNo);
599                 didget = 1;
600         } else {
601                 didget = 0;
602         }
603         result_offset = volume->vol_free_off;
604         if (result_offset >= volume->vol_free_end)
605                 panic("alloc_bigblock: Ran out of room, filesystem too small");
606         volume->vol_free_off += HAMMER_LARGEBLOCK_SIZE;
607
608         /*
609          * Update the freemap.
610          */
611         if (zone != HAMMER_ZONE_FREEMAP_INDEX) {
612                 root_vol = get_volume(RootVolNo);
613                 layer_offset = root_vol->ondisk->vol0_blockmap[
614                                         HAMMER_ZONE_FREEMAP_INDEX].phys_offset;
615                 layer_offset += HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset);
616                 layer1 = get_buffer_data(layer_offset, &buffer, 0);
617                 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
618                 --layer1->blocks_free;
619                 layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
620                 buffer->cache.modified = 1;
621                 layer_offset = layer1->phys_offset +
622                                HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset);
623                 layer2 = get_buffer_data(layer_offset, &buffer, 0);
624                 assert(layer2->zone == 0);
625                 layer2->zone = zone;
626                 layer2->append_off = HAMMER_LARGEBLOCK_SIZE;
627                 layer2->bytes_free = 0;
628                 layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
629                 buffer->cache.modified = 1;
630
631                 --root_vol->ondisk->vol0_stat_freebigblocks;
632                 root_vol->cache.modified = 1;
633
634                 rel_buffer(buffer);
635                 rel_volume(root_vol);
636         }
637
638         if (didget)
639                 rel_volume(volume);
640         return(result_offset);
641 }
642
643 /*
644  * Format the undo-map for the root volume.
645  */
646 void
647 format_undomap(hammer_volume_ondisk_t ondisk)
648 {
649         const int undo_zone = HAMMER_ZONE_UNDO_INDEX;
650         hammer_off_t undo_limit;
651         hammer_blockmap_t blockmap;
652         struct buffer_info *buffer = NULL;
653         hammer_off_t scan;
654         int n;
655         int limit_index;
656         u_int32_t seqno;
657
658         /*
659          * Size the undo buffer in multiples of HAMMER_LARGEBLOCK_SIZE,
660          * up to HAMMER_UNDO_LAYER2 large blocks.  Size to approximately
661          * 0.1% of the disk.
662          *
663          * The minimum UNDO fifo size is 500MB, or approximately 1% of
664          * the recommended 50G disk.
665          *
666          * Changing this minimum is rather dangerous as complex filesystem
667          * operations can cause the UNDO FIFO to fill up otherwise.
668          */
669         undo_limit = UndoBufferSize;
670         if (undo_limit == 0) {
671                 undo_limit = (ondisk->vol_buf_end - ondisk->vol_buf_beg) / 1000;
672                 if (undo_limit < 500*1024*1024)
673                         undo_limit = 500*1024*1024;
674         }
675         undo_limit = (undo_limit + HAMMER_LARGEBLOCK_MASK64) &
676                      ~HAMMER_LARGEBLOCK_MASK64;
677         if (undo_limit < HAMMER_LARGEBLOCK_SIZE)
678                 undo_limit = HAMMER_LARGEBLOCK_SIZE;
679         if (undo_limit > HAMMER_LARGEBLOCK_SIZE * HAMMER_UNDO_LAYER2)
680                 undo_limit = HAMMER_LARGEBLOCK_SIZE * HAMMER_UNDO_LAYER2;
681         UndoBufferSize = undo_limit;
682
683         blockmap = &ondisk->vol0_blockmap[undo_zone];
684         bzero(blockmap, sizeof(*blockmap));
685         blockmap->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
686         blockmap->first_offset = HAMMER_ZONE_ENCODE(undo_zone, 0);
687         blockmap->next_offset = blockmap->first_offset;
688         blockmap->alloc_offset = HAMMER_ZONE_ENCODE(undo_zone, undo_limit);
689         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
690
691         n = 0;
692         scan = blockmap->next_offset;
693         limit_index = undo_limit / HAMMER_LARGEBLOCK_SIZE;
694
695         assert(limit_index <= HAMMER_UNDO_LAYER2);
696
697         for (n = 0; n < limit_index; ++n) {
698                 ondisk->vol0_undo_array[n] = alloc_bigblock(NULL,
699                                                         HAMMER_ZONE_UNDO_INDEX);
700                 scan += HAMMER_LARGEBLOCK_SIZE;
701         }
702         while (n < HAMMER_UNDO_LAYER2) {
703                 ondisk->vol0_undo_array[n] = HAMMER_BLOCKMAP_UNAVAIL;
704                 ++n;
705         }
706
707         /*
708          * Pre-initialize the UNDO blocks (HAMMER version 4+)
709          */
710         printf("initializing the undo map (%jd MB)\n",
711                 (intmax_t)(blockmap->alloc_offset & HAMMER_OFF_LONG_MASK) /
712                 (1024 * 1024));
713
714         scan = blockmap->first_offset;
715         seqno = 0;
716
717         while (scan < blockmap->alloc_offset) {
718                 hammer_fifo_head_t head;
719                 hammer_fifo_tail_t tail;
720                 int isnew;
721                 int bytes = HAMMER_UNDO_ALIGN;
722
723                 isnew = ((scan & HAMMER_BUFMASK64) == 0);
724                 head = get_buffer_data(scan, &buffer, isnew);
725                 buffer->cache.modified = 1;
726                 tail = (void *)((char *)head + bytes - sizeof(*tail));
727
728                 bzero(head, bytes);
729                 head->hdr_signature = HAMMER_HEAD_SIGNATURE;
730                 head->hdr_type = HAMMER_HEAD_TYPE_DUMMY;
731                 head->hdr_size = bytes;
732                 head->hdr_seq = seqno++;
733
734                 tail->tail_signature = HAMMER_TAIL_SIGNATURE;
735                 tail->tail_type = HAMMER_HEAD_TYPE_DUMMY;
736                 tail->tail_size = bytes;
737
738                 head->hdr_crc = crc32(head, HAMMER_FIFO_HEAD_CRCOFF) ^
739                                 crc32(head + 1, bytes - sizeof(*head));
740
741                 scan += bytes;
742         }
743         if (buffer)
744                 rel_buffer(buffer);
745 }
746
747 /*
748  * Format a new blockmap.  This is mostly a degenerate case because
749  * all allocations are now actually done from the freemap.
750  */
751 void
752 format_blockmap(hammer_blockmap_t blockmap, hammer_off_t zone_base)
753 {
754         blockmap->phys_offset = 0;
755         blockmap->alloc_offset = zone_base | HAMMER_VOL_ENCODE(255) |
756                                  HAMMER_SHORT_OFF_ENCODE(-1);
757         blockmap->first_offset = zone_base;
758         blockmap->next_offset = zone_base;
759         blockmap->entry_crc = crc32(blockmap, HAMMER_BLOCKMAP_CRCSIZE);
760 }
761
762 /*
763  * Allocate a chunk of data out of a blockmap.  This is a simplified
764  * version which uses next_offset as a simple allocation iterator.
765  */
766 static
767 void *
768 alloc_blockmap(int zone, int bytes, hammer_off_t *result_offp,
769                struct buffer_info **bufferp)
770 {
771         struct buffer_info *buffer1 = NULL;
772         struct buffer_info *buffer2 = NULL;
773         struct volume_info *volume;
774         hammer_blockmap_t blockmap;
775         hammer_blockmap_t freemap;
776         struct hammer_blockmap_layer1 *layer1;
777         struct hammer_blockmap_layer2 *layer2;
778         hammer_off_t layer1_offset;
779         hammer_off_t layer2_offset;
780         hammer_off_t zone2_offset;
781         void *ptr;
782
783         volume = get_volume(RootVolNo);
784
785         blockmap = &volume->ondisk->vol0_blockmap[zone];
786         freemap = &volume->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
787
788         /*
789          * Alignment and buffer-boundary issues.  If the allocation would
790          * cross a buffer boundary we have to skip to the next buffer.
791          */
792         bytes = (bytes + 15) & ~15;
793
794 again:
795         if ((blockmap->next_offset ^ (blockmap->next_offset + bytes - 1)) &
796             ~HAMMER_BUFMASK64) {
797                 volume->cache.modified = 1;
798                 blockmap->next_offset = (blockmap->next_offset + bytes) &
799                                         ~HAMMER_BUFMASK64;
800         }
801
802         /*
803          * Dive layer 1.  For now we can't allocate data outside of volume 0.
804          */
805         layer1_offset = freemap->phys_offset +
806                         HAMMER_BLOCKMAP_LAYER1_OFFSET(blockmap->next_offset);
807
808         layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
809
810         if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
811                 fprintf(stderr, "alloc_blockmap: ran out of space!\n");
812                 exit(1);
813         }
814
815         /*
816          * Dive layer 2
817          */
818         layer2_offset = layer1->phys_offset +
819                         HAMMER_BLOCKMAP_LAYER2_OFFSET(blockmap->next_offset);
820
821         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
822
823         if (layer2->zone == HAMMER_ZONE_UNAVAIL_INDEX) {
824                 fprintf(stderr, "alloc_blockmap: ran out of space!\n");
825                 exit(1);
826         }
827
828         /*
829          * If we are entering a new bigblock assign ownership to our
830          * zone.  If the bigblock is owned by another zone skip it.
831          */
832         if (layer2->zone == 0) {
833                 --layer1->blocks_free;
834                 layer2->zone = zone;
835                 assert(layer2->bytes_free == HAMMER_LARGEBLOCK_SIZE);
836                 assert(layer2->append_off == 0);
837         }
838         if (layer2->zone != zone) {
839                 blockmap->next_offset = (blockmap->next_offset + HAMMER_LARGEBLOCK_SIZE) &
840                                         ~HAMMER_LARGEBLOCK_MASK64;
841                 goto again;
842         }
843
844         buffer1->cache.modified = 1;
845         buffer2->cache.modified = 1;
846         volume->cache.modified = 1;
847         assert(layer2->append_off ==
848                (blockmap->next_offset & HAMMER_LARGEBLOCK_MASK));
849         layer2->bytes_free -= bytes;
850         *result_offp = blockmap->next_offset;
851         blockmap->next_offset += bytes;
852         layer2->append_off = (int)blockmap->next_offset &
853                               HAMMER_LARGEBLOCK_MASK;
854
855         layer1->layer1_crc = crc32(layer1, HAMMER_LAYER1_CRCSIZE);
856         layer2->entry_crc = crc32(layer2, HAMMER_LAYER2_CRCSIZE);
857
858         zone2_offset = (*result_offp & ~HAMMER_OFF_ZONE_MASK) |
859                         HAMMER_ZONE_ENCODE(zone, 0);
860
861         ptr = get_buffer_data(zone2_offset, bufferp, 0);
862         (*bufferp)->cache.modified = 1;
863
864         if (buffer1)
865                 rel_buffer(buffer1);
866         if (buffer2)
867                 rel_buffer(buffer2);
868
869         rel_volume(volume);
870         return(ptr);
871 }
872
873 /*
874  * Flush various tracking structures to disk
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         writehammerbuf(volume, volume->ondisk, 0);
900         volume->cache.modified = 0;
901 }
902
903 void
904 flush_buffer(struct buffer_info *buffer)
905 {
906         writehammerbuf(buffer->volume, buffer->ondisk, buffer->raw_offset);
907         buffer->cache.modified = 0;
908 }
909
910 #if 0
911 /*
912  * Generic buffer initialization
913  */
914 static void
915 init_fifo_head(hammer_fifo_head_t head, u_int16_t hdr_type)
916 {
917         head->hdr_signature = HAMMER_HEAD_SIGNATURE;
918         head->hdr_type = hdr_type;
919         head->hdr_size = 0;
920         head->hdr_crc = 0;
921         head->hdr_seq = 0;
922 }
923
924 #endif
925
926 #if 0
927 /*
928  * Core I/O operations
929  */
930 static void
931 readhammerbuf(struct volume_info *vol, void *data, int64_t offset)
932 {
933         ssize_t n;
934
935         n = pread(vol->fd, data, HAMMER_BUFSIZE, offset);
936         if (n != HAMMER_BUFSIZE)
937                 err(1, "Read volume %d (%s)", vol->vol_no, vol->name);
938 }
939
940 #endif
941
942 static void
943 writehammerbuf(struct volume_info *vol, const void *data, int64_t offset)
944 {
945         ssize_t n;
946
947         n = pwrite(vol->fd, data, HAMMER_BUFSIZE, offset);
948         if (n != HAMMER_BUFSIZE)
949                 err(1, "Write volume %d (%s)", vol->vol_no, vol->name);
950 }
951
952 void
953 panic(const char *ctl, ...)
954 {
955         va_list va;
956
957         va_start(va, ctl);
958         vfprintf(stderr, ctl, va);
959         va_end(va);
960         fprintf(stderr, "\n");
961         exit(1);
962 }
963