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[thirdparty/mdadm.git] / bitmap.c
1 /*
2 * mdadm - manage Linux "md" devices aka RAID arrays.
3 *
4 * Copyright (C) 2004 Paul Clements, SteelEye Technology, Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21 #include "mdadm.h"
22
23 static inline void sb_le_to_cpu(bitmap_super_t *sb)
24 {
25 sb->magic = __le32_to_cpu(sb->magic);
26 sb->version = __le32_to_cpu(sb->version);
27 /* uuid gets no translation */
28 sb->events = __le64_to_cpu(sb->events);
29 sb->events_cleared = __le64_to_cpu(sb->events_cleared);
30 sb->state = __le32_to_cpu(sb->state);
31 sb->chunksize = __le32_to_cpu(sb->chunksize);
32 sb->daemon_sleep = __le32_to_cpu(sb->daemon_sleep);
33 sb->sync_size = __le64_to_cpu(sb->sync_size);
34 sb->write_behind = __le32_to_cpu(sb->write_behind);
35 sb->nodes = __le32_to_cpu(sb->nodes);
36 sb->sectors_reserved = __le32_to_cpu(sb->sectors_reserved);
37 }
38
39 static inline void sb_cpu_to_le(bitmap_super_t *sb)
40 {
41 sb_le_to_cpu(sb); /* these are really the same thing */
42 }
43
44 mapping_t bitmap_states[] = {
45 { "OK", 0 },
46 { "Out of date", 2 },
47 { NULL, -1 }
48 };
49
50 static const char *bitmap_state(int state_num)
51 {
52 char *state = map_num(bitmap_states, state_num);
53 return state ? state : "Unknown";
54 }
55
56 static const char *human_chunksize(unsigned long bytes)
57 {
58 static char buf[16];
59 char *suffixes[] = { "B", "KB", "MB", "GB", "TB", NULL };
60 int i = 0;
61
62 while (bytes >> 10) {
63 bytes >>= 10;
64 i++;
65 }
66
67 snprintf(buf, sizeof(buf), "%lu %s", bytes, suffixes[i]);
68
69 return buf;
70 }
71
72 typedef struct bitmap_info_s {
73 bitmap_super_t sb;
74 unsigned long long total_bits;
75 unsigned long long dirty_bits;
76 } bitmap_info_t;
77
78 /* count the dirty bits in the first num_bits of byte */
79 static inline int count_dirty_bits_byte(char byte, int num_bits)
80 {
81 int num = 0;
82
83 switch (num_bits) { /* fall through... */
84 case 8: if (byte & 128) num++;
85 case 7: if (byte & 64) num++;
86 case 6: if (byte & 32) num++;
87 case 5: if (byte & 16) num++;
88 case 4: if (byte & 8) num++;
89 case 3: if (byte & 4) num++;
90 case 2: if (byte & 2) num++;
91 case 1: if (byte & 1) num++;
92 default: break;
93 }
94
95 return num;
96 }
97
98 static int count_dirty_bits(char *buf, int num_bits)
99 {
100 int i, num = 0;
101
102 for (i = 0; i < num_bits / 8; i++)
103 num += count_dirty_bits_byte(buf[i], 8);
104
105 if (num_bits % 8) /* not an even byte boundary */
106 num += count_dirty_bits_byte(buf[i], num_bits % 8);
107
108 return num;
109 }
110
111 static bitmap_info_t *bitmap_fd_read(int fd, int brief)
112 {
113 /* Note: fd might be open O_DIRECT, so we must be
114 * careful to align reads properly
115 */
116 unsigned long long total_bits = 0, read_bits = 0, dirty_bits = 0;
117 bitmap_info_t *info;
118 void *buf;
119 unsigned int n, skip;
120
121 if (posix_memalign(&buf, 4096, 8192) != 0) {
122 pr_err("failed to allocate 8192 bytes\n");
123 return NULL;
124 }
125 n = read(fd, buf, 8192);
126
127 info = xmalloc(sizeof(*info));
128
129 if (n < sizeof(info->sb)) {
130 pr_err("failed to read superblock of bitmap file: %s\n", strerror(errno));
131 free(info);
132 free(buf);
133 return NULL;
134 }
135 memcpy(&info->sb, buf, sizeof(info->sb));
136 skip = sizeof(info->sb);
137
138 sb_le_to_cpu(&info->sb); /* convert superblock to CPU byte ordering */
139
140 if (brief || info->sb.sync_size == 0 || info->sb.chunksize == 0)
141 goto out;
142
143 /* read the rest of the file counting total bits and dirty bits --
144 * we stop when either:
145 * 1) we hit EOF, in which case we assume the rest of the bits (if any)
146 * are dirty
147 * 2) we've read the full bitmap, in which case we ignore any trailing
148 * data in the file
149 */
150 total_bits = bitmap_bits(info->sb.sync_size, info->sb.chunksize);
151
152 while(read_bits < total_bits) {
153 unsigned long long remaining = total_bits - read_bits;
154
155 if (n == 0) {
156 n = read(fd, buf, 8192);
157 skip = 0;
158 if (n <= 0)
159 break;
160 }
161 if (remaining > (n-skip) * 8) /* we want the full buffer */
162 remaining = (n-skip) * 8;
163
164 dirty_bits += count_dirty_bits(buf+skip, remaining);
165
166 read_bits += remaining;
167 n = 0;
168 }
169
170 if (read_bits < total_bits) { /* file truncated... */
171 pr_err("WARNING: bitmap file is not large enough for array size %llu!\n\n",
172 (unsigned long long)info->sb.sync_size);
173 total_bits = read_bits;
174 }
175 out:
176 free(buf);
177 info->total_bits = total_bits;
178 info->dirty_bits = dirty_bits;
179 return info;
180 }
181
182 static int
183 bitmap_file_open(char *filename, struct supertype **stp, int node_num)
184 {
185 int fd;
186 struct stat stb;
187 struct supertype *st = *stp;
188
189 fd = open(filename, O_RDONLY|O_DIRECT);
190 if (fd < 0) {
191 pr_err("failed to open bitmap file %s: %s\n",
192 filename, strerror(errno));
193 return -1;
194 }
195
196 if (fstat(fd, &stb) < 0) {
197 pr_err("failed to determine bitmap file/device type: %s\n",
198 strerror(errno));
199 close(fd);
200 return -1;
201 }
202
203 if ((stb.st_mode & S_IFMT) == S_IFBLK) {
204 /* block device, so we are probably after an internal bitmap */
205 if (!st)
206 st = guess_super(fd);
207 if (!st) {
208 /* just look at device... */
209 lseek(fd, 0, 0);
210 } else if (!st->ss->locate_bitmap) {
211 pr_err("No bitmap possible with %s metadata\n",
212 st->ss->name);
213 close(fd);
214 return -1;
215 } else {
216 if (st->ss->locate_bitmap(st, fd, node_num)) {
217 pr_err("%s doesn't have bitmap\n", filename);
218 close(fd);
219 fd = -1;
220 }
221 }
222
223 *stp = st;
224 }
225
226 return fd;
227 }
228
229 static __u32 swapl(__u32 l)
230 {
231 char *c = (char*)&l;
232 char t= c[0];
233 c[0] = c[3];
234 c[3] = t;
235
236 t = c[1];
237 c[1] = c[2];
238 c[2] = t;
239 return l;
240 }
241 int ExamineBitmap(char *filename, int brief, struct supertype *st)
242 {
243 /*
244 * Read the bitmap file and display its contents
245 */
246
247 bitmap_super_t *sb;
248 bitmap_info_t *info;
249 int rv = 1;
250 char buf[64];
251 int swap;
252 int fd, i;
253 __u32 uuid32[4];
254
255 fd = bitmap_file_open(filename, &st, 0);
256 if (fd < 0)
257 return rv;
258
259 info = bitmap_fd_read(fd, brief);
260 if (!info)
261 return rv;
262 sb = &info->sb;
263 if (sb->magic != BITMAP_MAGIC && md_get_version(fd) > 0) {
264 pr_err("This is an md array. To view a bitmap you need to examine\n");
265 pr_err("a member device, not the array.\n");
266 pr_err("Reporting bitmap that would be used if this array were used\n");
267 pr_err("as a member of some other array\n");
268 }
269 close(fd);
270 printf(" Filename : %s\n", filename);
271 printf(" Magic : %08x\n", sb->magic);
272 if (sb->magic != BITMAP_MAGIC) {
273 pr_err("invalid bitmap magic 0x%x, the bitmap file appears\n",
274 sb->magic);
275 pr_err("to be corrupted or missing.\n");
276 }
277 printf(" Version : %d\n", sb->version);
278 if (sb->version < BITMAP_MAJOR_LO ||
279 sb->version > BITMAP_MAJOR_CLUSTERED) {
280 pr_err("unknown bitmap version %d, either the bitmap file\n",
281 sb->version);
282 pr_err("is corrupted or you need to upgrade your tools\n");
283 goto free_info;
284 }
285
286 rv = 0;
287 if (st)
288 swap = st->ss->swapuuid;
289 else
290 #if __BYTE_ORDER == BIG_ENDIAN
291 swap = 0;
292 #else
293 swap = 1;
294 #endif
295 memcpy(uuid32, sb->uuid, 16);
296 if (swap)
297 printf(" UUID : %08x:%08x:%08x:%08x\n",
298 swapl(uuid32[0]),
299 swapl(uuid32[1]),
300 swapl(uuid32[2]),
301 swapl(uuid32[3]));
302 else
303 printf(" UUID : %08x:%08x:%08x:%08x\n",
304 uuid32[0],
305 uuid32[1],
306 uuid32[2],
307 uuid32[3]);
308
309 if (sb->nodes == 0) {
310 printf(" Events : %llu\n", (unsigned long long)sb->events);
311 printf(" Events Cleared : %llu\n", (unsigned long long)sb->events_cleared);
312 printf(" State : %s\n", bitmap_state(sb->state));
313
314 }
315
316 printf(" Chunksize : %s\n", human_chunksize(sb->chunksize));
317 printf(" Daemon : %ds flush period\n", sb->daemon_sleep);
318 if (sb->write_behind)
319 sprintf(buf, "Allow write behind, max %d", sb->write_behind);
320 else
321 sprintf(buf, "Normal");
322 printf(" Write Mode : %s\n", buf);
323 printf(" Sync Size : %llu%s\n", (unsigned long long)sb->sync_size/2,
324 human_size(sb->sync_size * 512));
325
326 if (sb->nodes == 0) {
327 if (brief)
328 goto free_info;
329 printf(" Bitmap : %llu bits (chunks), %llu dirty (%2.1f%%)\n",
330 info->total_bits, info->dirty_bits,
331 100.0 * info->dirty_bits / (info->total_bits?:1));
332 } else {
333 printf(" Cluster nodes : %d\n", sb->nodes);
334 printf(" Cluster name : %-64s\n", sb->cluster_name);
335 for (i = 0; i < (int)sb->nodes; i++) {
336 st = NULL;
337 free(info);
338 fd = bitmap_file_open(filename, &st, i);
339 if (fd < 0) {
340 printf(" Unable to open bitmap file on node: %i\n", i);
341
342 continue;
343 }
344 info = bitmap_fd_read(fd, brief);
345 if (!info) {
346 close(fd);
347 printf(" Unable to read bitmap on node: %i\n", i);
348 continue;
349 }
350 sb = &info->sb;
351 if (sb->magic != BITMAP_MAGIC)
352 pr_err("invalid bitmap magic 0x%x, the bitmap file appears to be corrupted\n", sb->magic);
353
354 printf(" Node Slot : %d\n", i);
355 printf(" Events : %llu\n",
356 (unsigned long long)sb->events);
357 printf(" Events Cleared : %llu\n",
358 (unsigned long long)sb->events_cleared);
359 printf(" State : %s\n", bitmap_state(sb->state));
360 if (brief)
361 continue;
362 printf(" Bitmap : %llu bits (chunks), %llu dirty (%2.1f%%)\n",
363 info->total_bits, info->dirty_bits,
364 100.0 * info->dirty_bits / (info->total_bits?:1));
365 close(fd);
366 }
367 }
368
369 free_info:
370 free(info);
371 return rv;
372 }
373
374 int CreateBitmap(char *filename, int force, char uuid[16],
375 unsigned long chunksize, unsigned long daemon_sleep,
376 unsigned long write_behind,
377 unsigned long long array_size /* sectors */,
378 int major)
379 {
380 /*
381 * Create a bitmap file with a superblock and (optionally) a full bitmap
382 */
383
384 FILE *fp;
385 int rv = 1;
386 char block[512];
387 bitmap_super_t sb;
388 long long bytes, filesize;
389
390 if (!force && access(filename, F_OK) == 0) {
391 pr_err("bitmap file %s already exists, use --force to overwrite\n", filename);
392 return rv;
393 }
394
395 fp = fopen(filename, "w");
396 if (fp == NULL) {
397 pr_err("failed to open bitmap file %s: %s\n",
398 filename, strerror(errno));
399 return rv;
400 }
401
402 if (chunksize == UnSet) {
403 /* We don't want more than 2^21 chunks, as 2^11 fill up one
404 * 4K page (2 bytes per chunk), and 2^10 address of those
405 * fill up a 4K indexing page. 2^20 might be safer, especially
406 * on 64bit hosts, so use that.
407 */
408 chunksize = DEFAULT_BITMAP_CHUNK;
409 /* <<20 for 2^20 chunks, >>9 to convert bytes to sectors */
410 while (array_size > ((unsigned long long)chunksize << (20-9)))
411 chunksize <<= 1;
412 }
413
414 memset(&sb, 0, sizeof(sb));
415 sb.magic = BITMAP_MAGIC;
416 sb.version = major;
417 if (uuid != NULL)
418 memcpy(sb.uuid, uuid, 16);
419 sb.chunksize = chunksize;
420 sb.daemon_sleep = daemon_sleep;
421 sb.write_behind = write_behind;
422 sb.sync_size = array_size;
423
424 sb_cpu_to_le(&sb); /* convert to on-disk byte ordering */
425
426 if (fwrite(&sb, sizeof(sb), 1, fp) != 1) {
427 pr_err("failed to write superblock to bitmap file %s: %s\n", filename, strerror(errno));
428 goto out;
429 }
430
431 /* calculate the size of the bitmap and write it to disk */
432 bytes = (bitmap_bits(array_size, chunksize) + 7) / 8;
433 if (!bytes) {
434 rv = 0;
435 goto out;
436 }
437
438 filesize = bytes + sizeof(sb);
439
440 memset(block, 0xff, sizeof(block));
441
442 while (bytes > 0) {
443 if (fwrite(block, sizeof(block), 1, fp) != 1) {
444 pr_err("failed to write bitmap file %s: %s\n", filename, strerror(errno));
445 goto out;
446 }
447 bytes -= sizeof(block);
448 }
449
450 rv = 0;
451 fflush(fp);
452 /* make the file be the right size (well, to the nearest byte) */
453 if (ftruncate(fileno(fp), filesize))
454 perror("ftrunace");
455 out:
456 fclose(fp);
457 if (rv)
458 unlink(filename); /* possibly corrupted, better get rid of it */
459 return rv;
460 }
461
462 int bitmap_update_uuid(int fd, int *uuid, int swap)
463 {
464 struct bitmap_super_s bm;
465 if (lseek(fd, 0, 0) != 0)
466 return 1;
467 if (read(fd, &bm, sizeof(bm)) != sizeof(bm))
468 return 1;
469 if (bm.magic != __cpu_to_le32(BITMAP_MAGIC))
470 return 1;
471 copy_uuid(bm.uuid, uuid, swap);
472 if (lseek(fd, 0, 0) != 0)
473 return 2;
474 if (write(fd, &bm, sizeof(bm)) != sizeof(bm)) {
475 lseek(fd, 0, 0);
476 return 2;
477 }
478 lseek(fd, 0, 0);
479 return 0;
480 }