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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 #define min(a,b) (((a) < (b)) ? (a) : (b))
25 inline void sb_le_to_cpu(bitmap_super_t
*sb
)
27 sb
->magic
= __le32_to_cpu(sb
->magic
);
28 sb
->version
= __le32_to_cpu(sb
->version
);
29 /* uuid gets no translation */
30 sb
->events
= __le64_to_cpu(sb
->events
);
31 sb
->events_cleared
= __le64_to_cpu(sb
->events_cleared
);
32 sb
->state
= __le32_to_cpu(sb
->state
);
33 sb
->chunksize
= __le32_to_cpu(sb
->chunksize
);
34 sb
->daemon_sleep
= __le32_to_cpu(sb
->daemon_sleep
);
35 sb
->sync_size
= __le64_to_cpu(sb
->sync_size
);
38 inline void sb_cpu_to_le(bitmap_super_t
*sb
)
40 sb_le_to_cpu(sb
); /* these are really the same thing */
43 mapping_t bitmap_states
[] = {
49 const char *bitmap_state(int state_num
)
51 char *state
= map_num(bitmap_states
, state_num
);
52 return state
? state
: "Unknown";
55 const char *human_chunksize(unsigned long bytes
)
58 char *suffixes
[] = { "B", "KB", "MB", "GB", "TB", NULL
};
66 snprintf(buf
, sizeof(buf
), "%lu %s", bytes
, suffixes
[i
]);
71 typedef struct bitmap_info_s
{
73 unsigned long long total_bits
;
74 unsigned long long dirty_bits
;
77 /* count the dirty bits in the first num_bits of byte */
78 inline int count_dirty_bits_byte(char byte
, int num_bits
)
82 switch (num_bits
) { /* fall through... */
83 case 8: if (byte
& 128) num
++;
84 case 7: if (byte
& 64) num
++;
85 case 6: if (byte
& 32) num
++;
86 case 5: if (byte
& 16) num
++;
87 case 4: if (byte
& 8) num
++;
88 case 3: if (byte
& 4) num
++;
89 case 2: if (byte
& 2) num
++;
90 case 1: if (byte
& 1) num
++;
97 int count_dirty_bits(char *buf
, int num_bits
)
101 for (i
=0; i
< num_bits
/ 8; i
++)
102 num
+= count_dirty_bits_byte(buf
[i
], 8);
104 if (num_bits
% 8) /* not an even byte boundary */
105 num
+= count_dirty_bits_byte(buf
[i
], num_bits
% 8);
110 /* calculate the size of the bitmap given the array size and bitmap chunksize */
111 unsigned long long bitmap_bits(unsigned long long array_size
,
112 unsigned long chunksize
)
114 return (array_size
* 512 + chunksize
- 1) / chunksize
;
117 bitmap_info_t
*bitmap_fd_read(int fd
, int brief
)
119 /* Note: fd might be open O_DIRECT, so we must be
120 * careful to align reads properly
122 unsigned long long total_bits
= 0, read_bits
= 0, dirty_bits
= 0;
124 char *buf
, *unaligned
;
127 unaligned
= malloc(8192*2);
128 buf
= (char*) ((unsigned long)unaligned
| 8191)+1;
129 n
= read(fd
, buf
, 8192);
131 info
= malloc(sizeof(*info
));
134 fprintf(stderr
, Name
": failed to allocate %d bytes\n",
137 fprintf(stderr
, Name
": failed to allocate %zd bytes\n",
143 if (n
< sizeof(info
->sb
)) {
144 fprintf(stderr
, Name
": failed to read superblock of bitmap "
145 "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)
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 fprintf(stderr
, Name
": WARNING: bitmap file is not large "
187 "enough for array size %llu!\n\n",
188 (unsigned long long)info
->sb
.sync_size
);
189 total_bits
= read_bits
;
192 info
->total_bits
= total_bits
;
193 info
->dirty_bits
= dirty_bits
;
197 bitmap_info_t
*bitmap_file_read(char *filename
, int brief
, struct supertype
**stp
)
202 struct supertype
*st
= *stp
;
204 if (stat(filename
, &stb
) < 0) {
205 fprintf(stderr
, Name
": failed to find file %s: %s\n",
206 filename
, strerror(errno
));
209 if ((S_IFMT
& stb
.st_mode
) == S_IFBLK
) {
210 fd
= open(filename
, O_RDONLY
);
212 fprintf(stderr
, Name
": failed to open bitmap file %s: %s\n",
213 filename
, strerror(errno
));
216 /* block device, so we are probably after an internal bitmap */
217 if (!st
) st
= guess_super(fd
);
219 /* just look at device... */
222 st
->ss
->locate_bitmap(st
, fd
, NULL
);
224 ioctl(fd
, BLKFLSBUF
, 0); /* make sure we read current data */
227 fd
= open(filename
, O_RDONLY
|O_DIRECT
);
229 fprintf(stderr
, Name
": failed to open bitmap file %s: %s\n",
230 filename
, strerror(errno
));
235 info
= bitmap_fd_read(fd
, brief
);
252 int ExamineBitmap(char *filename
, int brief
, struct supertype
*st
)
255 * Read the bitmap file and display its contents
263 info
= bitmap_file_read(filename
, brief
, &st
);
268 printf(" Filename : %s\n", filename
);
269 printf(" Magic : %08x\n", sb
->magic
);
270 if (sb
->magic
!= BITMAP_MAGIC
) {
271 fprintf(stderr
, Name
": invalid bitmap magic 0x%x, the bitmap file appears to be corrupted\n", sb
->magic
);
273 printf(" Version : %d\n", sb
->version
);
274 if (sb
->version
< BITMAP_MAJOR_LO
||
275 sb
->version
> BITMAP_MAJOR_HI
) {
276 fprintf(stderr
, Name
": unknown bitmap version %d, either the bitmap file is corrupted or you need to upgrade your tools\n", sb
->version
);
281 if (st
&& st
->ss
->swapuuid
) {
282 printf(" UUID : %08x.%08x.%08x.%08x\n",
283 swapl(*(__u32
*)(sb
->uuid
+0)),
284 swapl(*(__u32
*)(sb
->uuid
+4)),
285 swapl(*(__u32
*)(sb
->uuid
+8)),
286 swapl(*(__u32
*)(sb
->uuid
+12)));
288 printf(" UUID : %08x.%08x.%08x.%08x\n",
289 *(__u32
*)(sb
->uuid
+0),
290 *(__u32
*)(sb
->uuid
+4),
291 *(__u32
*)(sb
->uuid
+8),
292 *(__u32
*)(sb
->uuid
+12));
294 printf(" Events : %llu\n", (unsigned long long)sb
->events
);
295 printf(" Events Cleared : %llu\n", (unsigned long long)sb
->events_cleared
);
296 printf(" State : %s\n", bitmap_state(sb
->state
));
297 printf(" Chunksize : %s\n", human_chunksize(sb
->chunksize
));
298 printf(" Daemon : %ds flush period\n", sb
->daemon_sleep
);
299 if (sb
->write_behind
)
300 sprintf(buf
, "Allow write behind, max %d", sb
->write_behind
);
302 sprintf(buf
, "Normal");
303 printf(" Write Mode : %s\n", buf
);
304 printf(" Sync Size : %llu%s\n", (unsigned long long)sb
->sync_size
/2,
305 human_size(sb
->sync_size
* 512));
308 printf(" Bitmap : %llu bits (chunks), %llu dirty (%2.1f%%)\n",
309 info
->total_bits
, info
->dirty_bits
,
310 100.0 * info
->dirty_bits
/ (info
->total_bits
+ 1));
316 int CreateBitmap(char *filename
, int force
, char uuid
[16],
317 unsigned long chunksize
, unsigned long daemon_sleep
,
318 unsigned long write_behind
,
319 unsigned long long array_size
/* sectors */,
323 * Create a bitmap file with a superblock and (optionally) a full bitmap
330 long long bytes
, filesize
;
332 if (!force
&& access(filename
, F_OK
) == 0) {
333 fprintf(stderr
, Name
": bitmap file %s already exists, use --force to overwrite\n", filename
);
337 fp
= fopen(filename
, "w");
339 fprintf(stderr
, Name
": failed to open bitmap file %s: %s\n",
340 filename
, strerror(errno
));
344 memset(&sb
, 0, sizeof(sb
));
345 sb
.magic
= BITMAP_MAGIC
;
348 memcpy(sb
.uuid
, uuid
, 16);
349 sb
.chunksize
= chunksize
;
350 sb
.daemon_sleep
= daemon_sleep
;
351 sb
.write_behind
= write_behind
;
352 sb
.sync_size
= array_size
;
354 sb_cpu_to_le(&sb
); /* convert to on-disk byte ordering */
356 if (fwrite(&sb
, sizeof(sb
), 1, fp
) != 1) {
357 fprintf(stderr
, Name
": failed to write superblock to bitmap file %s: %s\n", filename
, strerror(errno
));
361 /* calculate the size of the bitmap and write it to disk */
362 bytes
= (bitmap_bits(array_size
, chunksize
) + 7) / 8;
368 filesize
= bytes
+ sizeof(sb
);
370 memset(block
, 0xff, sizeof(block
));
373 if (fwrite(block
, sizeof(block
), 1, fp
) != 1) {
374 fprintf(stderr
, Name
": failed to write bitmap file %s: %s\n", filename
, strerror(errno
));
377 bytes
-= sizeof(block
);
381 /* make the file be the right size (well, to the nearest byte) */
382 if (ftruncate(fileno(fp
), filesize
))
387 unlink(filename
); /* possibly corrupted, better get rid of it */