]>
git.ipfire.org Git - thirdparty/mdadm.git/blob - bitmap.c
2 * mdadm - manage Linux "md" devices aka RAID arrays.
4 * Copyright (C) 2004 Paul Clements, SteelEye Technology, Inc.
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.
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.
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
23 static inline void sb_le_to_cpu(bitmap_super_t
*sb
)
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
);
39 static inline void sb_cpu_to_le(bitmap_super_t
*sb
)
41 sb_le_to_cpu(sb
); /* these are really the same thing */
44 mapping_t bitmap_states
[] = {
50 const char *bitmap_state(int state_num
)
52 char *state
= map_num(bitmap_states
, state_num
);
53 return state
? state
: "Unknown";
56 const char *human_chunksize(unsigned long bytes
)
59 char *suffixes
[] = { "B", "KB", "MB", "GB", "TB", NULL
};
67 snprintf(buf
, sizeof(buf
), "%lu %s", bytes
, suffixes
[i
]);
72 typedef struct bitmap_info_s
{
74 unsigned long long total_bits
;
75 unsigned long long dirty_bits
;
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
)
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
++;
98 int count_dirty_bits(char *buf
, int num_bits
)
102 for (i
= 0; i
< num_bits
/ 8; i
++)
103 num
+= count_dirty_bits_byte(buf
[i
], 8);
105 if (num_bits
% 8) /* not an even byte boundary */
106 num
+= count_dirty_bits_byte(buf
[i
], num_bits
% 8);
111 /* calculate the size of the bitmap given the array size and bitmap chunksize */
112 unsigned long long bitmap_bits(unsigned long long array_size
,
113 unsigned long chunksize
)
115 return (array_size
* 512 + chunksize
- 1) / chunksize
;
118 unsigned long bitmap_sectors(struct bitmap_super_s
*bsb
)
120 unsigned long long bits
= bitmap_bits(__le64_to_cpu(bsb
->sync_size
),
121 __le32_to_cpu(bsb
->chunksize
));
122 int bits_per_sector
= 8*512;
123 return (bits
+ bits_per_sector
- 1) / bits_per_sector
;
126 bitmap_info_t
*bitmap_fd_read(int fd
, int brief
)
128 /* Note: fd might be open O_DIRECT, so we must be
129 * careful to align reads properly
131 unsigned long long total_bits
= 0, read_bits
= 0, dirty_bits
= 0;
134 unsigned int n
, skip
;
136 if (posix_memalign(&buf
, 4096, 8192) != 0) {
137 pr_err("failed to allocate 8192 bytes\n");
140 n
= read(fd
, buf
, 8192);
142 info
= xmalloc(sizeof(*info
));
144 if (n
< sizeof(info
->sb
)) {
145 pr_err("failed to read superblock of bitmap file: %s\n", strerror(errno
));
150 memcpy(&info
->sb
, buf
, sizeof(info
->sb
));
151 skip
= sizeof(info
->sb
);
153 sb_le_to_cpu(&info
->sb
); /* convert superblock to CPU byte ordering */
155 if (brief
|| info
->sb
.sync_size
== 0 || info
->sb
.chunksize
== 0)
158 /* read the rest of the file counting total bits and dirty bits --
159 * we stop when either:
160 * 1) we hit EOF, in which case we assume the rest of the bits (if any)
162 * 2) we've read the full bitmap, in which case we ignore any trailing
165 total_bits
= bitmap_bits(info
->sb
.sync_size
, info
->sb
.chunksize
);
167 while(read_bits
< total_bits
) {
168 unsigned long long remaining
= total_bits
- read_bits
;
171 n
= read(fd
, buf
, 8192);
176 if (remaining
> (n
-skip
) * 8) /* we want the full buffer */
177 remaining
= (n
-skip
) * 8;
179 dirty_bits
+= count_dirty_bits(buf
+skip
, remaining
);
181 read_bits
+= remaining
;
185 if (read_bits
< total_bits
) { /* file truncated... */
186 pr_err("WARNING: bitmap file is not large enough for array size %llu!\n\n",
187 (unsigned long long)info
->sb
.sync_size
);
188 total_bits
= read_bits
;
192 info
->total_bits
= total_bits
;
193 info
->dirty_bits
= dirty_bits
;
197 int bitmap_file_open(char *filename
, struct supertype
**stp
, int node_num
)
201 struct supertype
*st
= *stp
;
203 if (stat(filename
, &stb
) < 0) {
204 pr_err("failed to find file %s: %s\n",
205 filename
, strerror(errno
));
208 if ((S_IFMT
& stb
.st_mode
) == S_IFBLK
) {
209 fd
= open(filename
, O_RDONLY
|O_DIRECT
);
211 pr_err("failed to open bitmap file %s: %s\n",
212 filename
, strerror(errno
));
215 /* block device, so we are probably after an internal bitmap */
216 if (!st
) st
= guess_super(fd
);
218 /* just look at device... */
220 } else if (!st
->ss
->locate_bitmap
) {
221 pr_err("No bitmap possible with %s metadata\n",
226 if (st
->ss
->locate_bitmap(st
, fd
, node_num
)) {
227 pr_err("%s doesn't have bitmap\n", filename
);
235 fd
= open(filename
, O_RDONLY
|O_DIRECT
);
237 pr_err("failed to open bitmap file %s: %s\n",
238 filename
, strerror(errno
));
258 int ExamineBitmap(char *filename
, int brief
, struct supertype
*st
)
261 * Read the bitmap file and display its contents
272 fd
= bitmap_file_open(filename
, &st
, 0);
276 info
= bitmap_fd_read(fd
, brief
);
280 if (sb
->magic
!= BITMAP_MAGIC
&& md_get_version(fd
) > 0) {
281 pr_err("This is an md array. To view a bitmap you need to examine\n");
282 pr_err("a member device, not the array.\n");
283 pr_err("Reporting bitmap that would be used if this array were used\n");
284 pr_err("as a member of some other array\n");
287 printf(" Filename : %s\n", filename
);
288 printf(" Magic : %08x\n", sb
->magic
);
289 if (sb
->magic
!= BITMAP_MAGIC
) {
290 pr_err("invalid bitmap magic 0x%x, the bitmap file appears\n",
292 pr_err("to be corrupted or missing.\n");
294 printf(" Version : %d\n", sb
->version
);
295 if (sb
->version
< BITMAP_MAJOR_LO
||
296 sb
->version
> BITMAP_MAJOR_CLUSTERED
) {
297 pr_err("unknown bitmap version %d, either the bitmap file\n",
299 pr_err("is corrupted or you need to upgrade your tools\n");
305 swap
= st
->ss
->swapuuid
;
307 #if __BYTE_ORDER == BIG_ENDIAN
312 memcpy(uuid32
, sb
->uuid
, 16);
314 printf(" UUID : %08x:%08x:%08x:%08x\n",
320 printf(" UUID : %08x:%08x:%08x:%08x\n",
326 if (sb
->nodes
== 0) {
327 printf(" Events : %llu\n", (unsigned long long)sb
->events
);
328 printf(" Events Cleared : %llu\n", (unsigned long long)sb
->events_cleared
);
329 printf(" State : %s\n", bitmap_state(sb
->state
));
333 printf(" Chunksize : %s\n", human_chunksize(sb
->chunksize
));
334 printf(" Daemon : %ds flush period\n", sb
->daemon_sleep
);
335 if (sb
->write_behind
)
336 sprintf(buf
, "Allow write behind, max %d", sb
->write_behind
);
338 sprintf(buf
, "Normal");
339 printf(" Write Mode : %s\n", buf
);
340 printf(" Sync Size : %llu%s\n", (unsigned long long)sb
->sync_size
/2,
341 human_size(sb
->sync_size
* 512));
343 if (sb
->nodes
== 0) {
346 printf(" Bitmap : %llu bits (chunks), %llu dirty (%2.1f%%)\n",
347 info
->total_bits
, info
->dirty_bits
,
348 100.0 * info
->dirty_bits
/ (info
->total_bits
?:1));
350 printf(" Cluster nodes : %d\n", sb
->nodes
);
351 printf(" Cluster name : %-64s\n", sb
->cluster_name
);
352 for (i
= 0; i
< (int)sb
->nodes
; i
++) {
355 fd
= bitmap_file_open(filename
, &st
, i
);
356 info
= bitmap_fd_read(fd
, brief
);
358 if (sb
->magic
!= BITMAP_MAGIC
)
359 pr_err("invalid bitmap magic 0x%x, the bitmap file appears to be corrupted\n", sb
->magic
);
361 printf(" Node Slot : %d\n", i
);
362 printf(" Events : %llu\n",
363 (unsigned long long)sb
->events
);
364 printf(" Events Cleared : %llu\n",
365 (unsigned long long)sb
->events_cleared
);
366 printf(" State : %s\n", bitmap_state(sb
->state
));
369 printf(" Bitmap : %llu bits (chunks), %llu dirty (%2.1f%%)\n",
370 info
->total_bits
, info
->dirty_bits
,
371 100.0 * info
->dirty_bits
/ (info
->total_bits
?:1));
381 int CreateBitmap(char *filename
, int force
, char uuid
[16],
382 unsigned long chunksize
, unsigned long daemon_sleep
,
383 unsigned long write_behind
,
384 unsigned long long array_size
/* sectors */,
388 * Create a bitmap file with a superblock and (optionally) a full bitmap
395 long long bytes
, filesize
;
397 if (!force
&& access(filename
, F_OK
) == 0) {
398 pr_err("bitmap file %s already exists, use --force to overwrite\n", filename
);
402 fp
= fopen(filename
, "w");
404 pr_err("failed to open bitmap file %s: %s\n",
405 filename
, strerror(errno
));
409 if (chunksize
== UnSet
) {
410 /* We don't want more than 2^21 chunks, as 2^11 fill up one
411 * 4K page (2 bytes per chunk), and 2^10 address of those
412 * fill up a 4K indexing page. 2^20 might be safer, especially
413 * on 64bit hosts, so use that.
415 chunksize
= DEFAULT_BITMAP_CHUNK
;
416 /* <<20 for 2^20 chunks, >>9 to convert bytes to sectors */
417 while (array_size
> ((unsigned long long)chunksize
<< (20-9)))
421 memset(&sb
, 0, sizeof(sb
));
422 sb
.magic
= BITMAP_MAGIC
;
425 memcpy(sb
.uuid
, uuid
, 16);
426 sb
.chunksize
= chunksize
;
427 sb
.daemon_sleep
= daemon_sleep
;
428 sb
.write_behind
= write_behind
;
429 sb
.sync_size
= array_size
;
431 sb_cpu_to_le(&sb
); /* convert to on-disk byte ordering */
433 if (fwrite(&sb
, sizeof(sb
), 1, fp
) != 1) {
434 pr_err("failed to write superblock to bitmap file %s: %s\n", filename
, strerror(errno
));
438 /* calculate the size of the bitmap and write it to disk */
439 bytes
= (bitmap_bits(array_size
, chunksize
) + 7) / 8;
445 filesize
= bytes
+ sizeof(sb
);
447 memset(block
, 0xff, sizeof(block
));
450 if (fwrite(block
, sizeof(block
), 1, fp
) != 1) {
451 pr_err("failed to write bitmap file %s: %s\n", filename
, strerror(errno
));
454 bytes
-= sizeof(block
);
459 /* make the file be the right size (well, to the nearest byte) */
460 if (ftruncate(fileno(fp
), filesize
))
465 unlink(filename
); /* possibly corrupted, better get rid of it */
469 int bitmap_update_uuid(int fd
, int *uuid
, int swap
)
471 struct bitmap_super_s bm
;
472 if (lseek(fd
, 0, 0) != 0)
474 if (read(fd
, &bm
, sizeof(bm
)) != sizeof(bm
))
476 if (bm
.magic
!= __cpu_to_le32(BITMAP_MAGIC
))
478 copy_uuid(bm
.uuid
, uuid
, swap
);
479 if (lseek(fd
, 0, 0) != 0)
481 if (write(fd
, &bm
, sizeof(bm
)) != sizeof(bm
)) {