]>
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 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
);
37 inline void sb_cpu_to_le(bitmap_super_t
*sb
)
39 sb_le_to_cpu(sb
); /* these are really the same thing */
42 mapping_t bitmap_states
[] = {
48 const char *bitmap_state(int state_num
)
50 char *state
= map_num(bitmap_states
, state_num
);
51 return state
? state
: "Unknown";
54 const char *human_chunksize(unsigned long bytes
)
57 char *suffixes
[] = { "B", "KB", "MB", "GB", "TB", NULL
};
65 snprintf(buf
, sizeof(buf
), "%lu %s", bytes
, suffixes
[i
]);
70 typedef struct bitmap_info_s
{
72 unsigned long long total_bits
;
73 unsigned long long dirty_bits
;
76 /* count the dirty bits in the first num_bits of byte */
77 inline int count_dirty_bits_byte(char byte
, int num_bits
)
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
++;
96 int count_dirty_bits(char *buf
, int num_bits
)
100 for (i
= 0; i
< num_bits
/ 8; i
++)
101 num
+= count_dirty_bits_byte(buf
[i
], 8);
103 if (num_bits
% 8) /* not an even byte boundary */
104 num
+= count_dirty_bits_byte(buf
[i
], num_bits
% 8);
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
)
113 return (array_size
* 512 + chunksize
- 1) / chunksize
;
116 unsigned long bitmap_sectors(struct bitmap_super_s
*bsb
)
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
;
124 bitmap_info_t
*bitmap_fd_read(int fd
, int brief
)
126 /* Note: fd might be open O_DIRECT, so we must be
127 * careful to align reads properly
129 unsigned long long total_bits
= 0, read_bits
= 0, dirty_bits
= 0;
132 unsigned int n
, skip
;
134 if (posix_memalign(&buf
, 4096, 8192) != 0) {
135 pr_err("failed to allocate 8192 bytes\n");
138 n
= read(fd
, buf
, 8192);
140 info
= xmalloc(sizeof(*info
));
142 if (n
< sizeof(info
->sb
)) {
143 pr_err("failed to read superblock of bitmap "
144 "file: %s\n", strerror(errno
));
149 memcpy(&info
->sb
, buf
, sizeof(info
->sb
));
150 skip
= sizeof(info
->sb
);
152 sb_le_to_cpu(&info
->sb
); /* convert superblock to CPU byte ordering */
154 if (brief
|| info
->sb
.sync_size
== 0 || info
->sb
.chunksize
== 0)
157 /* read the rest of the file counting total bits and dirty bits --
158 * we stop when either:
159 * 1) we hit EOF, in which case we assume the rest of the bits (if any)
161 * 2) we've read the full bitmap, in which case we ignore any trailing
164 total_bits
= bitmap_bits(info
->sb
.sync_size
, info
->sb
.chunksize
);
166 while(read_bits
< total_bits
) {
167 unsigned long long remaining
= total_bits
- read_bits
;
170 n
= read(fd
, buf
, 8192);
175 if (remaining
> (n
-skip
) * 8) /* we want the full buffer */
176 remaining
= (n
-skip
) * 8;
178 dirty_bits
+= count_dirty_bits(buf
+skip
, remaining
);
180 read_bits
+= remaining
;
184 if (read_bits
< total_bits
) { /* file truncated... */
185 pr_err("WARNING: bitmap file is not large "
186 "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
)
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",
225 st
->ss
->locate_bitmap(st
, fd
);
229 fd
= open(filename
, O_RDONLY
|O_DIRECT
);
231 pr_err("failed to open bitmap file %s: %s\n",
232 filename
, strerror(errno
));
252 int ExamineBitmap(char *filename
, int brief
, struct supertype
*st
)
255 * Read the bitmap file and display its contents
266 fd
= bitmap_file_open(filename
, &st
);
270 info
= bitmap_fd_read(fd
, brief
);
274 if (sb
->magic
!= BITMAP_MAGIC
&& md_get_version(fd
) > 0) {
275 pr_err("This is an md array. To view a bitmap you need to examine\n");
276 pr_err("a member device, not the array.\n");
277 pr_err("Reporting bitmap that would be used if this array were used\n");
278 pr_err("as a member of some other array\n");
281 printf(" Filename : %s\n", filename
);
282 printf(" Magic : %08x\n", sb
->magic
);
283 if (sb
->magic
!= BITMAP_MAGIC
) {
284 pr_err("invalid bitmap magic 0x%x, the bitmap file appears\n",
286 pr_err("to be corrupted or missing.\n");
288 printf(" Version : %d\n", sb
->version
);
289 if (sb
->version
< BITMAP_MAJOR_LO
||
290 sb
->version
> BITMAP_MAJOR_HI
) {
291 pr_err("unknown bitmap version %d, either the bitmap file\n",
293 pr_err("is corrupted or you need to upgrade your tools\n");
299 swap
= st
->ss
->swapuuid
;
301 #if __BYTE_ORDER == BIG_ENDIAN
306 memcpy(uuid32
, sb
->uuid
, 16);
308 printf(" UUID : %08x:%08x:%08x:%08x\n",
314 printf(" UUID : %08x:%08x:%08x:%08x\n",
320 printf(" Events : %llu\n", (unsigned long long)sb
->events
);
321 printf(" Events Cleared : %llu\n", (unsigned long long)sb
->events_cleared
);
322 printf(" State : %s\n", bitmap_state(sb
->state
));
323 printf(" Chunksize : %s\n", human_chunksize(sb
->chunksize
));
324 printf(" Daemon : %ds flush period\n", sb
->daemon_sleep
);
325 if (sb
->write_behind
)
326 sprintf(buf
, "Allow write behind, max %d", sb
->write_behind
);
328 sprintf(buf
, "Normal");
329 printf(" Write Mode : %s\n", buf
);
330 printf(" Sync Size : %llu%s\n", (unsigned long long)sb
->sync_size
/2,
331 human_size(sb
->sync_size
* 512));
334 printf(" Bitmap : %llu bits (chunks), %llu dirty (%2.1f%%)\n",
335 info
->total_bits
, info
->dirty_bits
,
336 100.0 * info
->dirty_bits
/ (info
->total_bits
?:1));
342 int CreateBitmap(char *filename
, int force
, char uuid
[16],
343 unsigned long chunksize
, unsigned long daemon_sleep
,
344 unsigned long write_behind
,
345 unsigned long long array_size
/* sectors */,
349 * Create a bitmap file with a superblock and (optionally) a full bitmap
356 long long bytes
, filesize
;
358 if (!force
&& access(filename
, F_OK
) == 0) {
359 pr_err("bitmap file %s already exists, use --force to overwrite\n", filename
);
363 fp
= fopen(filename
, "w");
365 pr_err("failed to open bitmap file %s: %s\n",
366 filename
, strerror(errno
));
370 if (chunksize
== UnSet
) {
371 /* We don't want more than 2^21 chunks, as 2^11 fill up one
372 * 4K page (2 bytes per chunk), and 2^10 address of those
373 * fill up a 4K indexing page. 2^20 might be safer, especially
374 * on 64bit hosts, so use that.
376 chunksize
= DEFAULT_BITMAP_CHUNK
;
377 /* <<20 for 2^20 chunks, >>9 to convert bytes to sectors */
378 while (array_size
> ((unsigned long long)chunksize
<< (20-9)))
382 memset(&sb
, 0, sizeof(sb
));
383 sb
.magic
= BITMAP_MAGIC
;
386 memcpy(sb
.uuid
, uuid
, 16);
387 sb
.chunksize
= chunksize
;
388 sb
.daemon_sleep
= daemon_sleep
;
389 sb
.write_behind
= write_behind
;
390 sb
.sync_size
= array_size
;
392 sb_cpu_to_le(&sb
); /* convert to on-disk byte ordering */
394 if (fwrite(&sb
, sizeof(sb
), 1, fp
) != 1) {
395 pr_err("failed to write superblock to bitmap file %s: %s\n", filename
, strerror(errno
));
399 /* calculate the size of the bitmap and write it to disk */
400 bytes
= (bitmap_bits(array_size
, chunksize
) + 7) / 8;
406 filesize
= bytes
+ sizeof(sb
);
408 memset(block
, 0xff, sizeof(block
));
411 if (fwrite(block
, sizeof(block
), 1, fp
) != 1) {
412 pr_err("failed to write bitmap file %s: %s\n", filename
, strerror(errno
));
415 bytes
-= sizeof(block
);
420 /* make the file be the right size (well, to the nearest byte) */
421 if (ftruncate(fileno(fp
), filesize
))
426 unlink(filename
); /* possibly corrupted, better get rid of it */
430 int bitmap_update_uuid(int fd
, int *uuid
, int swap
)
432 struct bitmap_super_s bm
;
433 if (lseek(fd
, 0, 0) != 0)
435 if (read(fd
, &bm
, sizeof(bm
)) != sizeof(bm
))
437 if (bm
.magic
!= __cpu_to_le32(BITMAP_MAGIC
))
439 copy_uuid(bm
.uuid
, uuid
, swap
);
440 if (lseek(fd
, 0, 0) != 0)
442 if (write(fd
, &bm
, sizeof(bm
)) != sizeof(bm
)) {