HAMMER 30/many: blockmap work.
[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  * $DragonFly: src/sbin/hammer/ondisk.c,v 1.13 2008/02/23 03:01:06 dillon Exp $
35  */
36
37 #include <sys/types.h>
38 #include <assert.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <stdarg.h>
42 #include <string.h>
43 #include <unistd.h>
44 #include <err.h>
45 #include <fcntl.h>
46 #include "hammer_util.h"
47
48 static void *alloc_blockmap(int zone, int bytes, hammer_off_t *result_offp,
49                         struct buffer_info **bufferp);
50 static hammer_off_t alloc_bigblock(struct volume_info *volume,
51                         hammer_off_t owner);
52 #if 0
53 static void init_fifo_head(hammer_fifo_head_t head, u_int16_t hdr_type);
54 static hammer_off_t hammer_alloc_fifo(int32_t base_bytes, int32_t ext_bytes,
55                         struct buffer_info **bufp, u_int16_t hdr_type);
56 static void readhammerbuf(struct volume_info *vol, void *data,
57                         int64_t offset);
58 #endif
59 static void writehammerbuf(struct volume_info *vol, const void *data,
60                         int64_t offset);
61
62
63 uuid_t Hammer_FSType;
64 uuid_t Hammer_FSId;
65 int64_t BootAreaSize;
66 int64_t MemAreaSize;
67 int     UsingSuperClusters;
68 int     NumVolumes;
69 int     RootVolNo = -1;
70 struct volume_list VolList = TAILQ_HEAD_INITIALIZER(VolList);
71
72 /*
73  * Lookup the requested information structure and related on-disk buffer.
74  * Missing structures are created.
75  */
76 struct volume_info *
77 setup_volume(int32_t vol_no, const char *filename, int isnew, int oflags)
78 {
79         struct volume_info *vol;
80         struct volume_info *scan;
81         struct hammer_volume_ondisk *ondisk;
82         int n;
83
84         /*
85          * Allocate the volume structure
86          */
87         vol = malloc(sizeof(*vol));
88         bzero(vol, sizeof(*vol));
89         TAILQ_INIT(&vol->buffer_list);
90         vol->name = strdup(filename);
91         vol->fd = open(filename, oflags);
92         if (vol->fd < 0) {
93                 free(vol->name);
94                 free(vol);
95                 err(1, "setup_volume: %s: Open failed", filename);
96         }
97
98         /*
99          * Read or initialize the volume header
100          */
101         vol->ondisk = ondisk = malloc(HAMMER_BUFSIZE);
102         if (isnew) {
103                 bzero(ondisk, HAMMER_BUFSIZE);
104         } else {
105                 n = pread(vol->fd, ondisk, HAMMER_BUFSIZE, 0);
106                 if (n != HAMMER_BUFSIZE) {
107                         err(1, "setup_volume: %s: Read failed at offset 0",
108                             filename);
109                 }
110                 vol_no = ondisk->vol_no;
111                 if (RootVolNo < 0) {
112                         RootVolNo = ondisk->vol_rootvol;
113                 } else if (RootVolNo != (int)ondisk->vol_rootvol) {
114                         errx(1, "setup_volume: %s: root volume disagreement: "
115                                 "%d vs %d",
116                                 vol->name, RootVolNo, ondisk->vol_rootvol);
117                 }
118
119                 if (bcmp(&Hammer_FSType, &ondisk->vol_fstype, sizeof(Hammer_FSType)) != 0) {
120                         errx(1, "setup_volume: %s: Header does not indicate "
121                                 "that this is a hammer volume", vol->name);
122                 }
123                 if (TAILQ_EMPTY(&VolList)) {
124                         Hammer_FSId = vol->ondisk->vol_fsid;
125                 } else if (bcmp(&Hammer_FSId, &ondisk->vol_fsid, sizeof(Hammer_FSId)) != 0) {
126                         errx(1, "setup_volume: %s: FSId does match other "
127                                 "volumes!", vol->name);
128                 }
129         }
130         vol->vol_no = vol_no;
131
132         if (isnew) {
133                 /*init_fifo_head(&ondisk->head, HAMMER_HEAD_TYPE_VOL);*/
134                 vol->cache.modified = 1;
135         }
136
137         /*
138          * Link the volume structure in
139          */
140         TAILQ_FOREACH(scan, &VolList, entry) {
141                 if (scan->vol_no == vol_no) {
142                         errx(1, "setup_volume %s: Duplicate volume number %d "
143                                 "against %s", filename, vol_no, scan->name);
144                 }
145         }
146         TAILQ_INSERT_TAIL(&VolList, vol, entry);
147         return(vol);
148 }
149
150 struct volume_info *
151 get_volume(int32_t vol_no)
152 {
153         struct volume_info *vol;
154
155         TAILQ_FOREACH(vol, &VolList, entry) {
156                 if (vol->vol_no == vol_no)
157                         break;
158         }
159         if (vol == NULL)
160                 errx(1, "get_volume: Volume %d does not exist!", vol_no);
161         ++vol->cache.refs;
162         /* not added to or removed from hammer cache */
163         return(vol);
164 }
165
166 void
167 rel_volume(struct volume_info *volume)
168 {
169         /* not added to or removed from hammer cache */
170         --volume->cache.refs;
171 }
172
173 /*
174  * Acquire the specified buffer.
175  */
176 struct buffer_info *
177 get_buffer(hammer_off_t buf_offset, int isnew)
178 {
179         void *ondisk;
180         struct buffer_info *buf;
181         struct volume_info *volume;
182         int vol_no;
183         int zone;
184         int n;
185
186         zone = HAMMER_ZONE_DECODE(buf_offset);
187         if (zone > HAMMER_ZONE_RAW_BUFFER_INDEX) {
188                 buf_offset = blockmap_lookup(buf_offset, NULL, NULL);
189         }
190         assert((buf_offset & HAMMER_OFF_ZONE_MASK) == HAMMER_ZONE_RAW_BUFFER);
191         vol_no = HAMMER_VOL_DECODE(buf_offset);
192         volume = get_volume(vol_no);
193         buf_offset &= ~HAMMER_BUFMASK64;
194
195         TAILQ_FOREACH(buf, &volume->buffer_list, entry) {
196                 if (buf->buf_offset == buf_offset)
197                         break;
198         }
199         if (buf == NULL) {
200                 buf = malloc(sizeof(*buf));
201                 bzero(buf, sizeof(*buf));
202                 buf->buf_offset = buf_offset;
203                 buf->buf_disk_offset = volume->ondisk->vol_buf_beg +
204                                         (buf_offset & HAMMER_OFF_SHORT_MASK);
205                 buf->volume = volume;
206                 TAILQ_INSERT_TAIL(&volume->buffer_list, buf, entry);
207                 ++volume->cache.refs;
208                 buf->cache.u.buffer = buf;
209                 hammer_cache_add(&buf->cache, ISBUFFER);
210         }
211         ++buf->cache.refs;
212         hammer_cache_flush();
213         if ((ondisk = buf->ondisk) == NULL) {
214                 buf->ondisk = ondisk = malloc(HAMMER_BUFSIZE);
215                 if (isnew == 0) {
216                         n = pread(volume->fd, ondisk, HAMMER_BUFSIZE,
217                                   buf->buf_disk_offset);
218                         if (n != HAMMER_BUFSIZE) {
219                                 err(1, "get_buffer: %s:%016llx Read failed at "
220                                        "offset %lld",
221                                     volume->name, buf->buf_offset,
222                                     buf->buf_disk_offset);
223                         }
224                 }
225         }
226         if (isnew) {
227                 bzero(ondisk, HAMMER_BUFSIZE);
228                 buf->cache.modified = 1;
229         }
230         return(buf);
231 }
232
233 void
234 rel_buffer(struct buffer_info *buffer)
235 {
236         struct volume_info *volume;
237
238         assert(buffer->cache.refs > 0);
239         if (--buffer->cache.refs == 0) {
240                 if (buffer->cache.delete) {
241                         volume = buffer->volume;
242                         if (buffer->cache.modified)
243                                 flush_buffer(buffer);
244                         TAILQ_REMOVE(&volume->buffer_list, buffer, entry);
245                         hammer_cache_del(&buffer->cache);
246                         free(buffer->ondisk);
247                         free(buffer);
248                         rel_volume(volume);
249                 }
250         }
251 }
252
253 void *
254 get_buffer_data(hammer_off_t buf_offset, struct buffer_info **bufferp,
255                 int isnew)
256 {
257         struct buffer_info *buffer;
258
259         if ((buffer = *bufferp) != NULL) {
260                 if (isnew || 
261                     ((buffer->buf_offset ^ buf_offset) & ~HAMMER_BUFMASK64)) {
262                         rel_buffer(buffer);
263                         buffer = *bufferp = NULL;
264                 }
265         }
266         if (buffer == NULL)
267                 buffer = *bufferp = get_buffer(buf_offset, isnew);
268         return((char *)buffer->ondisk + ((int32_t)buf_offset & HAMMER_BUFMASK));
269 }
270
271 /*
272  * Retrieve a pointer to a B-Tree node given a cluster offset.  The underlying
273  * bufp is freed if non-NULL and a referenced buffer is loaded into it.
274  */
275 hammer_node_ondisk_t
276 get_node(hammer_off_t node_offset, struct buffer_info **bufp)
277 {
278         struct buffer_info *buf;
279
280         if (*bufp)
281                 rel_buffer(*bufp);
282         *bufp = buf = get_buffer(node_offset, 0);
283         return((void *)((char *)buf->ondisk +
284                         (int32_t)(node_offset & HAMMER_BUFMASK)));
285 }
286
287 /*
288  * Allocate HAMMER elements - btree nodes, data storage, and record elements
289  *
290  * NOTE: hammer_alloc_fifo() initializes the fifo header for the returned
291  * item and zero's out the remainder, so don't bzero() it.
292  */
293 void *
294 alloc_btree_element(hammer_off_t *offp)
295 {
296         struct buffer_info *buffer = NULL;
297         hammer_node_ondisk_t node;
298
299         node = alloc_blockmap(HAMMER_ZONE_BTREE_INDEX, sizeof(*node),
300                               offp, &buffer);
301         bzero(node, sizeof(*node));
302         /* XXX buffer not released, pointer remains valid */
303         return(node);
304 }
305
306 hammer_record_ondisk_t
307 alloc_record_element(hammer_off_t *offp, int32_t data_len, void **datap)
308 {
309         struct buffer_info *record_buffer = NULL;
310         struct buffer_info *data_buffer = NULL;
311         hammer_record_ondisk_t rec;
312
313         rec = alloc_blockmap(HAMMER_ZONE_RECORD_INDEX, sizeof(*rec),
314                              offp, &record_buffer);
315         bzero(rec, sizeof(*rec));
316
317         if (data_len >= HAMMER_BUFSIZE) {
318                 assert(data_len <= HAMMER_BUFSIZE); /* just one buffer */
319                 *datap = alloc_blockmap(HAMMER_ZONE_LARGE_DATA_INDEX, data_len,
320                                         &rec->base.data_off, &data_buffer);
321                 rec->base.data_len = data_len;
322                 bzero(*datap, data_len);
323         } else if (data_len) {
324                 *datap = alloc_blockmap(HAMMER_ZONE_SMALL_DATA_INDEX, data_len,
325                                         &rec->base.data_off, &data_buffer);
326                 rec->base.data_len = data_len;
327                 bzero(*datap, data_len);
328         } else {
329                 *datap = NULL;
330         }
331         /* XXX buf not released, ptr remains valid */
332         return(rec);
333 }
334
335 /*
336  * Format a new freemap.  Set all layer1 entries to UNAVAIL.  The initialize
337  * code will load each volume's freemap.
338  */
339 void
340 format_freemap(struct volume_info *root_vol, hammer_blockmap_t blockmap)
341 {
342         struct buffer_info *buffer = NULL;
343         hammer_off_t layer1_offset;
344         struct hammer_blockmap_layer1 *layer1;
345         int i, isnew;
346
347         layer1_offset = alloc_bigblock(root_vol, 0);
348         for (i = 0; i < (int)HAMMER_BLOCKMAP_RADIX1; ++i) {
349                 isnew = ((i % HAMMER_BLOCKMAP_RADIX1_PERBUFFER) == 0);
350                 layer1 = get_buffer_data(layer1_offset + i * sizeof(*layer1),
351                                          &buffer, isnew);
352                 bzero(layer1, sizeof(*layer1));
353                 layer1->phys_offset = HAMMER_BLOCKMAP_UNAVAIL;
354                 layer1->layer1_crc = crc32(layer1, sizeof(*layer1));
355         }
356         rel_buffer(buffer);
357
358         blockmap = &root_vol->ondisk->vol0_blockmap[HAMMER_ZONE_FREEMAP_INDEX];
359         blockmap->phys_offset = layer1_offset;
360         blockmap->alloc_offset = HAMMER_ENCODE_RAW_BUFFER(255, -1);
361         blockmap->next_offset = HAMMER_ENCODE_RAW_BUFFER(0, 0);
362         blockmap->reserved01 = 0;
363         blockmap->entry_crc = crc32(blockmap, sizeof(*blockmap));
364         root_vol->cache.modified = 1;
365 }
366
367 /*
368  * Load the volume's remaining free space into the freemap.  If this is
369  * the root volume, initialize the freemap owner for the layer1 bigblock.
370  *
371  * Returns the number of bigblocks available.
372  */
373 int64_t
374 initialize_freemap(struct volume_info *vol)
375 {
376         struct volume_info *root_vol;
377         struct buffer_info *buffer1 = NULL;
378         struct buffer_info *buffer2 = NULL;
379         struct hammer_blockmap_layer1 *layer1;
380         struct hammer_blockmap_layer2 *layer2;
381         hammer_off_t layer1_base;
382         hammer_off_t layer1_offset;
383         hammer_off_t layer2_offset;
384         hammer_off_t phys_offset;
385         hammer_off_t aligned_vol_free_end;
386         int64_t count = 0;
387
388         root_vol = get_volume(RootVolNo);
389         aligned_vol_free_end = (vol->vol_free_end + HAMMER_BLOCKMAP_LAYER2_MASK)
390                                 & ~HAMMER_BLOCKMAP_LAYER2_MASK;
391
392         printf("initialize freemap volume %d\n", vol->vol_no);
393
394         /*
395          * Initialize the freemap.  First preallocate the bigblocks required
396          * to implement layer2.   This preallocation is a bootstrap allocation
397          * using blocks from the target volume.
398          */
399         layer1_base = root_vol->ondisk->vol0_blockmap[
400                                         HAMMER_ZONE_FREEMAP_INDEX].phys_offset;
401         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
402              phys_offset < aligned_vol_free_end;
403              phys_offset += HAMMER_BLOCKMAP_LAYER2) {
404                 layer1_offset = layer1_base +
405                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
406                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
407                 if (layer1->phys_offset == HAMMER_BLOCKMAP_UNAVAIL) {
408                         layer1->phys_offset = alloc_bigblock(vol, 0);
409                         layer1->blocks_free = 0;
410                         buffer1->cache.modified = 1;
411                 }
412         }
413
414         /*
415          * Now fill everything in.
416          */
417         for (phys_offset = HAMMER_ENCODE_RAW_BUFFER(vol->vol_no, 0);
418              phys_offset < aligned_vol_free_end;
419              phys_offset += HAMMER_LARGEBLOCK_SIZE) {
420                 layer1_offset = layer1_base +
421                                 HAMMER_BLOCKMAP_LAYER1_OFFSET(phys_offset);
422                 layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
423
424                 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
425                 layer2_offset = layer1->phys_offset +
426                                 HAMMER_BLOCKMAP_LAYER2_OFFSET(phys_offset);
427
428                 layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
429                 if (phys_offset < vol->vol_free_off) {
430                         /*
431                          * Fixups XXX - bigblocks already allocated as part
432                          * of the freemap bootstrap.
433                          */
434                         layer2->u.owner = HAMMER_ENCODE_FREEMAP(0, 0); /* XXX */
435                 } else if (phys_offset < vol->vol_free_end) {
436                         ++layer1->blocks_free;
437                         buffer1->cache.modified = 1;
438                         layer2->u.owner = HAMMER_BLOCKMAP_FREE;
439                         ++count;
440                 } else {
441                         layer2->u.owner = HAMMER_BLOCKMAP_UNAVAIL;
442                 }
443                 layer2->entry_crc = crc32(layer2, sizeof(*layer2));
444                 buffer2->cache.modified = 1;
445
446                 /*
447                  * Finish-up layer 1
448                  */
449                 if (((phys_offset + HAMMER_LARGEBLOCK_SIZE) & HAMMER_BLOCKMAP_LAYER2_MASK) == 0) {
450                         layer1->layer1_crc = crc32(layer1, sizeof(*layer1));
451                         buffer1->cache.modified = 1;
452                 }
453         }
454         rel_buffer(buffer1);
455         rel_buffer(buffer2);
456         rel_volume(root_vol);
457         return(count);
458 }
459
460 /*
461  * Allocate big-blocks using our poor-man's volume->vol_free_off and
462  * update the freemap if owner != 0.
463  */
464 hammer_off_t
465 alloc_bigblock(struct volume_info *volume, hammer_off_t owner)
466 {
467         struct buffer_info *buffer = NULL;
468         struct volume_info *root_vol;
469         hammer_off_t result_offset;
470         hammer_off_t layer_offset;
471         struct hammer_blockmap_layer1 *layer1;
472         struct hammer_blockmap_layer2 *layer2;
473         int didget;
474
475         if (volume == NULL) {
476                 volume = get_volume(RootVolNo);
477                 didget = 1;
478         } else {
479                 didget = 0;
480         }
481         result_offset = volume->vol_free_off;
482         if (result_offset >= volume->vol_free_end)
483                 panic("alloc_bigblock: Ran out of room, filesystem too small");
484         volume->vol_free_off += HAMMER_LARGEBLOCK_SIZE;
485
486         /*
487          * Update the freemap
488          */
489         if (owner) {
490                 root_vol = get_volume(RootVolNo);
491                 layer_offset = root_vol->ondisk->vol0_blockmap[
492                                         HAMMER_ZONE_FREEMAP_INDEX].phys_offset;
493                 layer_offset += HAMMER_BLOCKMAP_LAYER1_OFFSET(result_offset);
494                 layer1 = get_buffer_data(layer_offset, &buffer, 0);
495                 assert(layer1->phys_offset != HAMMER_BLOCKMAP_UNAVAIL);
496                 --layer1->blocks_free;
497                 layer1->layer1_crc = crc32(layer1, sizeof(*layer1));
498                 buffer->cache.modified = 1;
499                 layer_offset = layer1->phys_offset +
500                                HAMMER_BLOCKMAP_LAYER2_OFFSET(result_offset);
501                 layer2 = get_buffer_data(layer_offset, &buffer, 0);
502                 assert(layer2->u.owner == HAMMER_BLOCKMAP_FREE);
503                 layer2->u.owner = owner;
504                 layer2->entry_crc = crc32(layer2, sizeof(*layer2));
505                 buffer->cache.modified = 1;
506
507                 rel_buffer(buffer);
508                 rel_volume(root_vol);
509         }
510
511         if (didget)
512                 rel_volume(volume);
513         return(result_offset);
514 }
515
516
517 /*
518  * Format a new blockmap.  Set the owner to the base of the blockmap
519  * (meaning either the blockmap layer1 bigblock, layer2 bigblock, or
520  * target bigblock).
521  */
522 void
523 format_blockmap(hammer_blockmap_t blockmap, hammer_off_t zone_off)
524 {
525         blockmap->phys_offset = alloc_bigblock(NULL, zone_off);
526         blockmap->alloc_offset = zone_off;
527         blockmap->next_offset = zone_off;
528         blockmap->entry_crc = crc32(blockmap, sizeof(*blockmap));
529 }
530
531 static
532 void *
533 alloc_blockmap(int zone, int bytes, hammer_off_t *result_offp,
534                struct buffer_info **bufferp)
535 {
536         struct buffer_info *buffer1 = NULL;
537         struct buffer_info *buffer2 = NULL;
538         struct volume_info *volume;
539         hammer_blockmap_t rootmap;
540         struct hammer_blockmap_layer1 *layer1;
541         struct hammer_blockmap_layer2 *layer2;
542         hammer_off_t layer1_offset;
543         hammer_off_t layer2_offset;
544         hammer_off_t bigblock_offset;
545         void *ptr;
546
547         volume = get_volume(RootVolNo);
548
549         rootmap = &volume->ondisk->vol0_blockmap[zone];
550
551         /*
552          * Alignment and buffer-boundary issues
553          */
554         bytes = (bytes + 7) & ~7;
555         if ((rootmap->phys_offset ^ (rootmap->phys_offset + bytes - 1)) &
556             ~HAMMER_BUFMASK64) {
557                 volume->cache.modified = 1;
558                 rootmap->phys_offset = (rootmap->phys_offset + bytes) &
559                                        ~HAMMER_BUFMASK64;
560         }
561
562         /*
563          * Dive layer 1
564          */
565         layer1_offset = rootmap->phys_offset +
566                         HAMMER_BLOCKMAP_LAYER1_OFFSET(rootmap->alloc_offset);
567
568         layer1 = get_buffer_data(layer1_offset, &buffer1, 0);
569         if ((rootmap->alloc_offset & HAMMER_BLOCKMAP_LAYER2_MASK) == 0) {
570                 buffer1->cache.modified = 1;
571                 bzero(layer1, sizeof(*layer1));
572                 layer1->blocks_free = HAMMER_BLOCKMAP_RADIX2;
573                 layer1->phys_offset = alloc_bigblock(NULL,
574                                                      rootmap->alloc_offset);
575         }
576
577         /*
578          * Dive layer 2
579          */
580         layer2_offset = layer1->phys_offset +
581                         HAMMER_BLOCKMAP_LAYER2_OFFSET(rootmap->alloc_offset);
582
583         layer2 = get_buffer_data(layer2_offset, &buffer2, 0);
584
585         if ((rootmap->alloc_offset & HAMMER_LARGEBLOCK_MASK64) == 0) {
586                 buffer2->cache.modified = 1;
587                 bzero(layer2, sizeof(*layer2));
588                 layer2->u.phys_offset = alloc_bigblock(NULL,
589                                                        rootmap->alloc_offset);
590                 layer2->bytes_free = HAMMER_LARGEBLOCK_SIZE;
591                 --layer1->blocks_free;
592         }
593
594         buffer1->cache.modified = 1;
595         buffer2->cache.modified = 1;
596         volume->cache.modified = 1;
597         layer2->bytes_free -= bytes;
598         *result_offp = rootmap->alloc_offset;
599         rootmap->alloc_offset += bytes;
600         rootmap->next_offset = rootmap->alloc_offset;
601
602         bigblock_offset = layer2->u.phys_offset + 
603                           (*result_offp & HAMMER_LARGEBLOCK_MASK);
604         ptr = get_buffer_data(bigblock_offset, bufferp, 0);
605         (*bufferp)->cache.modified = 1;
606
607         if (buffer1)
608                 rel_buffer(buffer1);
609         if (buffer2)
610                 rel_buffer(buffer2);
611
612         rel_volume(volume);
613         return(ptr);
614 }
615
616 #if 0
617 /*
618  * Reserve space from the FIFO.  Make sure that bytes does not cross a 
619  * record boundary.
620  *
621  * Zero out base_bytes and initialize the fifo head and tail.  The
622  * data area is not zerod.
623  */
624 static
625 hammer_off_t
626 hammer_alloc_fifo(int32_t base_bytes, int32_t ext_bytes,
627                   struct buffer_info **bufp, u_int16_t hdr_type)
628 {
629         struct buffer_info *buf;
630         struct volume_info *volume;
631         hammer_fifo_head_t head;
632         hammer_fifo_tail_t tail;
633         hammer_off_t off;
634         int32_t aligned_bytes;
635
636         aligned_bytes = (base_bytes + ext_bytes + HAMMER_TAIL_ONDISK_SIZE +
637                          HAMMER_HEAD_ALIGN_MASK) & ~HAMMER_HEAD_ALIGN_MASK;
638
639         volume = get_volume(RootVolNo);
640         off = volume->ondisk->vol0_fifo_end;
641
642         /*
643          * For now don't deal with transitions across buffer boundaries,
644          * only newfs_hammer uses this function.
645          */
646         assert((off & ~HAMMER_BUFMASK64) ==
647                 ((off + aligned_bytes) & ~HAMMER_BUFMASK));
648
649         *bufp = buf = get_buffer(off, 0);
650
651         buf->cache.modified = 1;
652         volume->cache.modified = 1;
653
654         head = (void *)((char *)buf->ondisk + ((int32_t)off & HAMMER_BUFMASK));
655         bzero(head, base_bytes);
656
657         head->hdr_signature = HAMMER_HEAD_SIGNATURE;
658         head->hdr_type = hdr_type;
659         head->hdr_size = aligned_bytes;
660         head->hdr_seq = volume->ondisk->vol0_next_seq++;
661
662         tail = (void*)((char *)head + aligned_bytes - HAMMER_TAIL_ONDISK_SIZE);
663         tail->tail_signature = HAMMER_TAIL_SIGNATURE;
664         tail->tail_type = hdr_type;
665         tail->tail_size = aligned_bytes;
666
667         volume->ondisk->vol0_fifo_end += aligned_bytes;
668         volume->cache.modified = 1;
669
670         rel_volume(volume);
671
672         return(off);
673 }
674
675 #endif
676
677 /*
678  * Flush various tracking structures to disk
679  */
680
681 /*
682  * Flush various tracking structures to disk
683  */
684 void
685 flush_all_volumes(void)
686 {
687         struct volume_info *vol;
688
689         TAILQ_FOREACH(vol, &VolList, entry)
690                 flush_volume(vol);
691 }
692
693 void
694 flush_volume(struct volume_info *volume)
695 {
696         struct buffer_info *buffer;
697
698         TAILQ_FOREACH(buffer, &volume->buffer_list, entry)
699                 flush_buffer(buffer);
700         writehammerbuf(volume, volume->ondisk, 0);
701         volume->cache.modified = 0;
702 }
703
704 void
705 flush_buffer(struct buffer_info *buffer)
706 {
707         writehammerbuf(buffer->volume, buffer->ondisk, buffer->buf_disk_offset);
708         buffer->cache.modified = 0;
709 }
710
711 #if 0
712 /*
713  * Generic buffer initialization
714  */
715 static void
716 init_fifo_head(hammer_fifo_head_t head, u_int16_t hdr_type)
717 {
718         head->hdr_signature = HAMMER_HEAD_SIGNATURE;
719         head->hdr_type = hdr_type;
720         head->hdr_size = 0;
721         head->hdr_crc = 0;
722         head->hdr_seq = 0;
723 }
724
725 #endif
726
727 #if 0
728 /*
729  * Core I/O operations
730  */
731 static void
732 readhammerbuf(struct volume_info *vol, void *data, int64_t offset)
733 {
734         ssize_t n;
735
736         n = pread(vol->fd, data, HAMMER_BUFSIZE, offset);
737         if (n != HAMMER_BUFSIZE)
738                 err(1, "Read volume %d (%s)", vol->vol_no, vol->name);
739 }
740
741 #endif
742
743 static void
744 writehammerbuf(struct volume_info *vol, const void *data, int64_t offset)
745 {
746         ssize_t n;
747
748         n = pwrite(vol->fd, data, HAMMER_BUFSIZE, offset);
749         if (n != HAMMER_BUFSIZE)
750                 err(1, "Write volume %d (%s)", vol->vol_no, vol->name);
751 }
752
753 void
754 panic(const char *ctl, ...)
755 {
756         va_list va;
757
758         va_start(va, ctl);
759         vfprintf(stderr, ctl, va);
760         va_end(va);
761         fprintf(stderr, "\n");
762         exit(1);
763 }
764