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git.ipfire.org Git - thirdparty/mdadm.git/blob - bitmap.c
5252069b09c4ac10f269e9700aed0a07852f3e95
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
21 #include <sys/types.h>
24 #include <asm/byteorder.h>
26 #define min(a,b) (((a) < (b)) ? (a) : (b))
28 inline void sb_le_to_cpu(bitmap_super_t
*sb
)
30 sb
->magic
= __le32_to_cpu(sb
->magic
);
31 sb
->version
= __le32_to_cpu(sb
->version
);
32 /* uuid gets no translation */
33 sb
->events
= __le64_to_cpu(sb
->events
);
34 sb
->events_cleared
= __le64_to_cpu(sb
->events_cleared
);
35 sb
->state
= __le32_to_cpu(sb
->state
);
36 sb
->chunksize
= __le32_to_cpu(sb
->chunksize
);
37 sb
->daemon_sleep
= __le32_to_cpu(sb
->daemon_sleep
);
38 sb
->sync_size
= __le64_to_cpu(sb
->sync_size
);
41 inline void sb_cpu_to_le(bitmap_super_t
*sb
)
43 sb_le_to_cpu(sb
); /* these are really the same thing */
46 mapping_t bitmap_states
[] = {
52 const char *bitmap_state(int state_num
)
54 char *state
= map_num(bitmap_states
, state_num
);
55 return state
? state
: "Unknown";
58 const char *human_chunksize(unsigned long bytes
)
61 char *suffixes
[] = { "B", "KB", "MB", "GB", "TB", NULL
};
69 snprintf(buf
, sizeof(buf
), "%lu %s", bytes
, suffixes
[i
]);
74 typedef struct bitmap_info_s
{
76 unsigned long long total_bits
;
77 unsigned long long dirty_bits
;
80 /* count the dirty bits in the first num_bits of byte */
81 inline int count_dirty_bits_byte(char byte
, int num_bits
)
85 switch (num_bits
) { /* fall through... */
86 case 8: if (byte
& 128) num
++;
87 case 7: if (byte
& 64) num
++;
88 case 6: if (byte
& 32) num
++;
89 case 5: if (byte
& 16) num
++;
90 case 4: if (byte
& 8) num
++;
91 case 3: if (byte
& 4) num
++;
92 case 2: if (byte
& 2) num
++;
93 case 1: if (byte
& 1) num
++;
100 int count_dirty_bits(char *buf
, int num_bits
)
104 for (i
=0; i
< num_bits
/ 8; i
++)
105 num
+= count_dirty_bits_byte(buf
[i
], 8);
107 if (num_bits
% 8) /* not an even byte boundary */
108 num
+= count_dirty_bits_byte(buf
[i
], num_bits
% 8);
113 /* calculate the size of the bitmap given the array size and bitmap chunksize */
114 unsigned long long bitmap_bits(unsigned long long array_size
,
115 unsigned long chunksize
)
117 return (array_size
* 512 + chunksize
- 1) / chunksize
;
120 bitmap_info_t
*bitmap_fd_read(int fd
, int brief
)
122 unsigned long long total_bits
= 0, read_bits
= 0, dirty_bits
= 0;
127 info
= malloc(sizeof(*info
));
129 fprintf(stderr
, Name
": failed to allocate %d bytes\n",
134 if (read(fd
, &info
->sb
, sizeof(info
->sb
)) != sizeof(info
->sb
)) {
135 fprintf(stderr
, Name
": failed to read superblock of bitmap "
136 "file: %s\n", strerror(errno
));
141 sb_le_to_cpu(&info
->sb
); /* convert superblock to CPU byte ordering */
143 if (brief
|| info
->sb
.sync_size
== 0)
146 /* read the rest of the file counting total bits and dirty bits --
147 * we stop when either:
148 * 1) we hit EOF, in which case we assume the rest of the bits (if any)
150 * 2) we've read the full bitmap, in which case we ignore any trailing
153 total_bits
= bitmap_bits(info
->sb
.sync_size
, info
->sb
.chunksize
);
155 while ((n
= read(fd
, buf
, sizeof(buf
))) > 0) {
156 unsigned long long remaining
= total_bits
- read_bits
;
158 if (remaining
> sizeof(buf
) * 8) /* we want the full buffer */
159 remaining
= sizeof(buf
) * 8;
160 if (remaining
> n
* 8) /* the file is truncated */
162 dirty_bits
+= count_dirty_bits(buf
, remaining
);
164 read_bits
+= remaining
;
165 if (read_bits
>= total_bits
) /* we've got what we want */
169 if (read_bits
< total_bits
) { /* file truncated... */
170 fprintf(stderr
, Name
": WARNING: bitmap file is not large "
171 "enough for array size %llu!\n\n", info
->sb
.sync_size
);
172 total_bits
= read_bits
;
175 info
->total_bits
= total_bits
;
176 info
->dirty_bits
= dirty_bits
;
180 bitmap_info_t
*bitmap_file_read(char *filename
, int brief
, struct supertype
**stp
)
185 struct supertype
*st
= *stp
;
187 fd
= open(filename
, O_RDONLY
);
189 fprintf(stderr
, Name
": failed to open bitmap file %s: %s\n",
190 filename
, strerror(errno
));
194 if ((S_IFMT
& stb
.st_mode
) == S_IFBLK
) {
195 /* block device, so we are probably after an internal bitmap */
196 if (!st
) st
= guess_super(fd
);
198 /* just look at device... */
201 st
->ss
->locate_bitmap(st
, fd
);
203 ioctl(fd
, BLKFLSBUF
, 0); /* make sure we read current data */
207 info
= bitmap_fd_read(fd
, brief
);
224 int ExamineBitmap(char *filename
, int brief
, struct supertype
*st
)
227 * Read the bitmap file and display its contents
235 info
= bitmap_file_read(filename
, brief
, &st
);
240 printf(" Filename : %s\n", filename
);
241 printf(" Magic : %08x\n", sb
->magic
);
242 if (sb
->magic
!= BITMAP_MAGIC
) {
243 fprintf(stderr
, Name
": invalid bitmap magic 0x%x, the bitmap file appears to be corrupted\n", sb
->magic
);
245 printf(" Version : %d\n", sb
->version
);
246 if (sb
->version
!= BITMAP_MAJOR
) {
247 fprintf(stderr
, Name
": unknown bitmap version %d, either the bitmap file is corrupted or you need to upgrade your tools\n", sb
->version
);
252 if (st
&& st
->ss
->swapuuid
) {
253 printf(" UUID : %08x.%08x.%08x.%08x\n",
254 swapl(*(__u32
*)(sb
->uuid
+0)),
255 swapl(*(__u32
*)(sb
->uuid
+4)),
256 swapl(*(__u32
*)(sb
->uuid
+8)),
257 swapl(*(__u32
*)(sb
->uuid
+12)));
259 printf(" UUID : %08x.%08x.%08x.%08x\n",
260 *(__u32
*)(sb
->uuid
+0),
261 *(__u32
*)(sb
->uuid
+4),
262 *(__u32
*)(sb
->uuid
+8),
263 *(__u32
*)(sb
->uuid
+12));
265 printf(" Events : %llu\n", sb
->events
);
266 printf(" Events Cleared : %llu\n", sb
->events_cleared
);
267 printf(" State : %s\n", bitmap_state(sb
->state
));
268 printf(" Chunksize : %s\n", human_chunksize(sb
->chunksize
));
269 printf(" Daemon : %ds flush period\n", sb
->daemon_sleep
);
270 if (sb
->write_behind
)
271 sprintf(buf
, "Allow write behind, max %d", sb
->write_behind
);
273 sprintf(buf
, "Normal");
274 printf(" Write Mode : %s\n", buf
);
275 printf(" Sync Size : %llu%s\n", sb
->sync_size
/2,
276 human_size(sb
->sync_size
* 512));
279 printf(" Bitmap : %llu bits (chunks), %llu dirty (%2.1f%%)\n",
280 info
->total_bits
, info
->dirty_bits
,
281 100.0 * info
->dirty_bits
/ (info
->total_bits
+ 1));
287 int CreateBitmap(char *filename
, int force
, char uuid
[16],
288 unsigned long chunksize
, unsigned long daemon_sleep
,
289 unsigned long write_behind
,
290 unsigned long long array_size
/* sectors */)
293 * Create a bitmap file with a superblock and (optionally) a full bitmap
300 long long bytes
, filesize
;
302 if (!force
&& access(filename
, F_OK
) == 0) {
303 fprintf(stderr
, Name
": bitmap file %s already exists, use --force to overwrite\n", filename
);
307 fp
= fopen(filename
, "w");
309 fprintf(stderr
, Name
": failed to open bitmap file %s: %s\n",
310 filename
, strerror(errno
));
314 memset(&sb
, 0, sizeof(sb
));
315 sb
.magic
= BITMAP_MAGIC
;
316 sb
.version
= BITMAP_MAJOR
;
318 memcpy(sb
.uuid
, uuid
, 16);
319 sb
.chunksize
= chunksize
;
320 sb
.daemon_sleep
= daemon_sleep
;
321 sb
.write_behind
= write_behind
;
322 sb
.sync_size
= array_size
;
324 sb_cpu_to_le(&sb
); /* convert to on-disk byte ordering */
326 if (fwrite(&sb
, sizeof(sb
), 1, fp
) != 1) {
327 fprintf(stderr
, Name
": failed to write superblock to bitmap file %s: %s\n", filename
, strerror(errno
));
331 /* calculate the size of the bitmap and write it to disk */
332 bytes
= (bitmap_bits(array_size
, chunksize
) + 7) / 8;
338 filesize
= bytes
+ sizeof(sb
);
340 memset(block
, 0xff, sizeof(block
));
343 if (fwrite(block
, sizeof(block
), 1, fp
) != 1) {
344 fprintf(stderr
, Name
": failed to write bitmap file %s: %s\n", filename
, strerror(errno
));
347 bytes
-= sizeof(block
);
351 /* make the file be the right size (well, to the nearest byte) */
352 ftruncate(fileno(fp
), filesize
);
356 unlink(filename
); /* possibly corrupted, better get rid of it */