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Release mdadm-3.3.4
[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 }
36
37 static inline void sb_cpu_to_le(bitmap_super_t *sb)
38 {
39 sb_le_to_cpu(sb); /* these are really the same thing */
40 }
41
42 mapping_t bitmap_states[] = {
43 { "OK", 0 },
44 { "Out of date", 2 },
45 { NULL, -1 }
46 };
47
48 const char *bitmap_state(int state_num)
49 {
50 char *state = map_num(bitmap_states, state_num);
51 return state ? state : "Unknown";
52 }
53
54 const char *human_chunksize(unsigned long bytes)
55 {
56 static char buf[16];
57 char *suffixes[] = { "B", "KB", "MB", "GB", "TB", NULL };
58 int i = 0;
59
60 while (bytes >> 10) {
61 bytes >>= 10;
62 i++;
63 }
64
65 snprintf(buf, sizeof(buf), "%lu %s", bytes, suffixes[i]);
66
67 return buf;
68 }
69
70 typedef struct bitmap_info_s {
71 bitmap_super_t sb;
72 unsigned long long total_bits;
73 unsigned long long dirty_bits;
74 } bitmap_info_t;
75
76 /* count the dirty bits in the first num_bits of byte */
77 static inline int count_dirty_bits_byte(char byte, int num_bits)
78 {
79 int num = 0;
80
81 switch (num_bits) { /* fall through... */
82 case 8: if (byte & 128) num++;
83 case 7: if (byte & 64) num++;
84 case 6: if (byte & 32) num++;
85 case 5: if (byte & 16) num++;
86 case 4: if (byte & 8) num++;
87 case 3: if (byte & 4) num++;
88 case 2: if (byte & 2) num++;
89 case 1: if (byte & 1) num++;
90 default: break;
91 }
92
93 return num;
94 }
95
96 int count_dirty_bits(char *buf, int num_bits)
97 {
98 int i, num = 0;
99
100 for (i = 0; i < num_bits / 8; i++)
101 num += count_dirty_bits_byte(buf[i], 8);
102
103 if (num_bits % 8) /* not an even byte boundary */
104 num += count_dirty_bits_byte(buf[i], num_bits % 8);
105
106 return num;
107 }
108
109 /* calculate the size of the bitmap given the array size and bitmap chunksize */
110 unsigned long long bitmap_bits(unsigned long long array_size,
111 unsigned long chunksize)
112 {
113 return (array_size * 512 + chunksize - 1) / chunksize;
114 }
115
116 unsigned long bitmap_sectors(struct bitmap_super_s *bsb)
117 {
118 unsigned long long bits = bitmap_bits(__le64_to_cpu(bsb->sync_size),
119 __le32_to_cpu(bsb->chunksize));
120 int bits_per_sector = 8*512;
121 return (bits + bits_per_sector - 1) / bits_per_sector;
122 }
123
124 bitmap_info_t *bitmap_fd_read(int fd, int brief)
125 {
126 /* Note: fd might be open O_DIRECT, so we must be
127 * careful to align reads properly
128 */
129 unsigned long long total_bits = 0, read_bits = 0, dirty_bits = 0;
130 bitmap_info_t *info;
131 void *buf;
132 unsigned int n, skip;
133
134 if (posix_memalign(&buf, 4096, 8192) != 0) {
135 pr_err("failed to allocate 8192 bytes\n");
136 return NULL;
137 }
138 n = read(fd, buf, 8192);
139
140 info = xmalloc(sizeof(*info));
141
142 if (n < sizeof(info->sb)) {
143 pr_err("failed to read superblock of bitmap file: %s\n", strerror(errno));
144 free(info);
145 free(buf);
146 return NULL;
147 }
148 memcpy(&info->sb, buf, sizeof(info->sb));
149 skip = sizeof(info->sb);
150
151 sb_le_to_cpu(&info->sb); /* convert superblock to CPU byte ordering */
152
153 if (brief || info->sb.sync_size == 0 || info->sb.chunksize == 0)
154 goto out;
155
156 /* read the rest of the file counting total bits and dirty bits --
157 * we stop when either:
158 * 1) we hit EOF, in which case we assume the rest of the bits (if any)
159 * are dirty
160 * 2) we've read the full bitmap, in which case we ignore any trailing
161 * data in the file
162 */
163 total_bits = bitmap_bits(info->sb.sync_size, info->sb.chunksize);
164
165 while(read_bits < total_bits) {
166 unsigned long long remaining = total_bits - read_bits;
167
168 if (n == 0) {
169 n = read(fd, buf, 8192);
170 skip = 0;
171 if (n <= 0)
172 break;
173 }
174 if (remaining > (n-skip) * 8) /* we want the full buffer */
175 remaining = (n-skip) * 8;
176
177 dirty_bits += count_dirty_bits(buf+skip, remaining);
178
179 read_bits += remaining;
180 n = 0;
181 }
182
183 if (read_bits < total_bits) { /* file truncated... */
184 pr_err("WARNING: bitmap file is not large enough for array size %llu!\n\n",
185 (unsigned long long)info->sb.sync_size);
186 total_bits = read_bits;
187 }
188 out:
189 free(buf);
190 info->total_bits = total_bits;
191 info->dirty_bits = dirty_bits;
192 return info;
193 }
194
195 int bitmap_file_open(char *filename, struct supertype **stp)
196 {
197 int fd;
198 struct stat stb;
199 struct supertype *st = *stp;
200
201 if (stat(filename, &stb) < 0) {
202 pr_err("failed to find file %s: %s\n",
203 filename, strerror(errno));
204 return -1;
205 }
206 if ((S_IFMT & stb.st_mode) == S_IFBLK) {
207 fd = open(filename, O_RDONLY|O_DIRECT);
208 if (fd < 0) {
209 pr_err("failed to open bitmap file %s: %s\n",
210 filename, strerror(errno));
211 return -1;
212 }
213 /* block device, so we are probably after an internal bitmap */
214 if (!st) st = guess_super(fd);
215 if (!st) {
216 /* just look at device... */
217 lseek(fd, 0, 0);
218 } else if (!st->ss->locate_bitmap) {
219 pr_err("No bitmap possible with %s metadata\n",
220 st->ss->name);
221 return -1;
222 } else
223 st->ss->locate_bitmap(st, fd);
224
225 *stp = st;
226 } else {
227 fd = open(filename, O_RDONLY|O_DIRECT);
228 if (fd < 0) {
229 pr_err("failed to open bitmap file %s: %s\n",
230 filename, strerror(errno));
231 return -1;
232 }
233 }
234
235 return fd;
236 }
237
238 __u32 swapl(__u32 l)
239 {
240 char *c = (char*)&l;
241 char t= c[0];
242 c[0] = c[3];
243 c[3] = t;
244
245 t = c[1];
246 c[1] = c[2];
247 c[2] = t;
248 return l;
249 }
250 int ExamineBitmap(char *filename, int brief, struct supertype *st)
251 {
252 /*
253 * Read the bitmap file and display its contents
254 */
255
256 bitmap_super_t *sb;
257 bitmap_info_t *info;
258 int rv = 1;
259 char buf[64];
260 int swap;
261 int fd;
262 __u32 uuid32[4];
263
264 fd = bitmap_file_open(filename, &st);
265 if (fd < 0)
266 return rv;
267
268 info = bitmap_fd_read(fd, brief);
269 if (!info)
270 return rv;
271 sb = &info->sb;
272 if (sb->magic != BITMAP_MAGIC && md_get_version(fd) > 0) {
273 pr_err("This is an md array. To view a bitmap you need to examine\n");
274 pr_err("a member device, not the array.\n");
275 pr_err("Reporting bitmap that would be used if this array were used\n");
276 pr_err("as a member of some other array\n");
277 }
278 close(fd);
279 printf(" Filename : %s\n", filename);
280 printf(" Magic : %08x\n", sb->magic);
281 if (sb->magic != BITMAP_MAGIC) {
282 pr_err("invalid bitmap magic 0x%x, the bitmap file appears\n",
283 sb->magic);
284 pr_err("to be corrupted or missing.\n");
285 }
286 printf(" Version : %d\n", sb->version);
287 if (sb->version < BITMAP_MAJOR_LO ||
288 sb->version > BITMAP_MAJOR_HI) {
289 pr_err("unknown bitmap version %d, either the bitmap file\n",
290 sb->version);
291 pr_err("is corrupted or you need to upgrade your tools\n");
292 goto free_info;
293 }
294
295 rv = 0;
296 if (st)
297 swap = st->ss->swapuuid;
298 else
299 #if __BYTE_ORDER == BIG_ENDIAN
300 swap = 0;
301 #else
302 swap = 1;
303 #endif
304 memcpy(uuid32, sb->uuid, 16);
305 if (swap)
306 printf(" UUID : %08x:%08x:%08x:%08x\n",
307 swapl(uuid32[0]),
308 swapl(uuid32[1]),
309 swapl(uuid32[2]),
310 swapl(uuid32[3]));
311 else
312 printf(" UUID : %08x:%08x:%08x:%08x\n",
313 uuid32[0],
314 uuid32[1],
315 uuid32[2],
316 uuid32[3]);
317
318 printf(" Events : %llu\n", (unsigned long long)sb->events);
319 printf(" Events Cleared : %llu\n", (unsigned long long)sb->events_cleared);
320 printf(" State : %s\n", bitmap_state(sb->state));
321 printf(" Chunksize : %s\n", human_chunksize(sb->chunksize));
322 printf(" Daemon : %ds flush period\n", sb->daemon_sleep);
323 if (sb->write_behind)
324 sprintf(buf, "Allow write behind, max %d", sb->write_behind);
325 else
326 sprintf(buf, "Normal");
327 printf(" Write Mode : %s\n", buf);
328 printf(" Sync Size : %llu%s\n", (unsigned long long)sb->sync_size/2,
329 human_size(sb->sync_size * 512));
330 if (brief)
331 goto free_info;
332 printf(" Bitmap : %llu bits (chunks), %llu dirty (%2.1f%%)\n",
333 info->total_bits, info->dirty_bits,
334 100.0 * info->dirty_bits / (info->total_bits?:1));
335 free_info:
336 free(info);
337 return rv;
338 }
339
340 int CreateBitmap(char *filename, int force, char uuid[16],
341 unsigned long chunksize, unsigned long daemon_sleep,
342 unsigned long write_behind,
343 unsigned long long array_size /* sectors */,
344 int major)
345 {
346 /*
347 * Create a bitmap file with a superblock and (optionally) a full bitmap
348 */
349
350 FILE *fp;
351 int rv = 1;
352 char block[512];
353 bitmap_super_t sb;
354 long long bytes, filesize;
355
356 if (!force && access(filename, F_OK) == 0) {
357 pr_err("bitmap file %s already exists, use --force to overwrite\n", filename);
358 return rv;
359 }
360
361 fp = fopen(filename, "w");
362 if (fp == NULL) {
363 pr_err("failed to open bitmap file %s: %s\n",
364 filename, strerror(errno));
365 return rv;
366 }
367
368 if (chunksize == UnSet) {
369 /* We don't want more than 2^21 chunks, as 2^11 fill up one
370 * 4K page (2 bytes per chunk), and 2^10 address of those
371 * fill up a 4K indexing page. 2^20 might be safer, especially
372 * on 64bit hosts, so use that.
373 */
374 chunksize = DEFAULT_BITMAP_CHUNK;
375 /* <<20 for 2^20 chunks, >>9 to convert bytes to sectors */
376 while (array_size > ((unsigned long long)chunksize << (20-9)))
377 chunksize <<= 1;
378 }
379
380 memset(&sb, 0, sizeof(sb));
381 sb.magic = BITMAP_MAGIC;
382 sb.version = major;
383 if (uuid != NULL)
384 memcpy(sb.uuid, uuid, 16);
385 sb.chunksize = chunksize;
386 sb.daemon_sleep = daemon_sleep;
387 sb.write_behind = write_behind;
388 sb.sync_size = array_size;
389
390 sb_cpu_to_le(&sb); /* convert to on-disk byte ordering */
391
392 if (fwrite(&sb, sizeof(sb), 1, fp) != 1) {
393 pr_err("failed to write superblock to bitmap file %s: %s\n", filename, strerror(errno));
394 goto out;
395 }
396
397 /* calculate the size of the bitmap and write it to disk */
398 bytes = (bitmap_bits(array_size, chunksize) + 7) / 8;
399 if (!bytes) {
400 rv = 0;
401 goto out;
402 }
403
404 filesize = bytes + sizeof(sb);
405
406 memset(block, 0xff, sizeof(block));
407
408 while (bytes > 0) {
409 if (fwrite(block, sizeof(block), 1, fp) != 1) {
410 pr_err("failed to write bitmap file %s: %s\n", filename, strerror(errno));
411 goto out;
412 }
413 bytes -= sizeof(block);
414 }
415
416 rv = 0;
417 fflush(fp);
418 /* make the file be the right size (well, to the nearest byte) */
419 if (ftruncate(fileno(fp), filesize))
420 perror("ftrunace");
421 out:
422 fclose(fp);
423 if (rv)
424 unlink(filename); /* possibly corrupted, better get rid of it */
425 return rv;
426 }
427
428 int bitmap_update_uuid(int fd, int *uuid, int swap)
429 {
430 struct bitmap_super_s bm;
431 if (lseek(fd, 0, 0) != 0)
432 return 1;
433 if (read(fd, &bm, sizeof(bm)) != sizeof(bm))
434 return 1;
435 if (bm.magic != __cpu_to_le32(BITMAP_MAGIC))
436 return 1;
437 copy_uuid(bm.uuid, uuid, swap);
438 if (lseek(fd, 0, 0) != 0)
439 return 2;
440 if (write(fd, &bm, sizeof(bm)) != sizeof(bm)) {
441 lseek(fd, 0, 0);
442 return 2;
443 }
444 lseek(fd, 0, 0);
445 return 0;
446 }