/mdadm-3.2.5/bitmap.c
C | 449 lines | 344 code | 57 blank | 48 comment | 74 complexity | f3a7e5a160a3d18e1c54184d2113f045 MD5 | raw file
Possible License(s): GPL-2.0
- /*
- * mdadm - manage Linux "md" devices aka RAID arrays.
- *
- * Copyright (C) 2004 Paul Clements, SteelEye Technology, Inc.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
- #include "mdadm.h"
- inline void sb_le_to_cpu(bitmap_super_t *sb)
- {
- sb->magic = __le32_to_cpu(sb->magic);
- sb->version = __le32_to_cpu(sb->version);
- /* uuid gets no translation */
- sb->events = __le64_to_cpu(sb->events);
- sb->events_cleared = __le64_to_cpu(sb->events_cleared);
- sb->state = __le32_to_cpu(sb->state);
- sb->chunksize = __le32_to_cpu(sb->chunksize);
- sb->daemon_sleep = __le32_to_cpu(sb->daemon_sleep);
- sb->sync_size = __le64_to_cpu(sb->sync_size);
- sb->write_behind = __le32_to_cpu(sb->write_behind);
- }
- inline void sb_cpu_to_le(bitmap_super_t *sb)
- {
- sb_le_to_cpu(sb); /* these are really the same thing */
- }
- mapping_t bitmap_states[] = {
- { "OK", 0 },
- { "Out of date", 2 },
- { NULL, -1 }
- };
- const char *bitmap_state(int state_num)
- {
- char *state = map_num(bitmap_states, state_num);
- return state ? state : "Unknown";
- }
- const char *human_chunksize(unsigned long bytes)
- {
- static char buf[16];
- char *suffixes[] = { "B", "KB", "MB", "GB", "TB", NULL };
- int i = 0;
- while (bytes >> 10) {
- bytes >>= 10;
- i++;
- }
- snprintf(buf, sizeof(buf), "%lu %s", bytes, suffixes[i]);
- return buf;
- }
- typedef struct bitmap_info_s {
- bitmap_super_t sb;
- unsigned long long total_bits;
- unsigned long long dirty_bits;
- } bitmap_info_t;
- /* count the dirty bits in the first num_bits of byte */
- inline int count_dirty_bits_byte(char byte, int num_bits)
- {
- int num = 0;
- switch (num_bits) { /* fall through... */
- case 8: if (byte & 128) num++;
- case 7: if (byte & 64) num++;
- case 6: if (byte & 32) num++;
- case 5: if (byte & 16) num++;
- case 4: if (byte & 8) num++;
- case 3: if (byte & 4) num++;
- case 2: if (byte & 2) num++;
- case 1: if (byte & 1) num++;
- default: break;
- }
- return num;
- }
- int count_dirty_bits(char *buf, int num_bits)
- {
- int i, num = 0;
- for (i=0; i < num_bits / 8; i++)
- num += count_dirty_bits_byte(buf[i], 8);
- if (num_bits % 8) /* not an even byte boundary */
- num += count_dirty_bits_byte(buf[i], num_bits % 8);
- return num;
- }
- /* calculate the size of the bitmap given the array size and bitmap chunksize */
- unsigned long long bitmap_bits(unsigned long long array_size,
- unsigned long chunksize)
- {
- return (array_size * 512 + chunksize - 1) / chunksize;
- }
- unsigned long bitmap_sectors(struct bitmap_super_s *bsb)
- {
- unsigned long long bits = bitmap_bits(__le64_to_cpu(bsb->sync_size),
- __le32_to_cpu(bsb->chunksize));
- int bits_per_sector = 8*512;
- return (bits + bits_per_sector - 1) / bits_per_sector;
- }
- bitmap_info_t *bitmap_fd_read(int fd, int brief)
- {
- /* Note: fd might be open O_DIRECT, so we must be
- * careful to align reads properly
- */
- unsigned long long total_bits = 0, read_bits = 0, dirty_bits = 0;
- bitmap_info_t *info;
- void *buf;
- unsigned int n, skip;
- if (posix_memalign(&buf, 4096, 8192) != 0) {
- fprintf(stderr, Name ": failed to allocate 8192 bytes\n");
- return NULL;
- }
- n = read(fd, buf, 8192);
- info = malloc(sizeof(*info));
- if (info == NULL) {
- #if __GNUC__ < 3
- fprintf(stderr, Name ": failed to allocate %d bytes\n",
- (int)sizeof(*info));
- #else
- fprintf(stderr, Name ": failed to allocate %zd bytes\n",
- sizeof(*info));
- #endif
- free(buf);
- return NULL;
- }
- if (n < sizeof(info->sb)) {
- fprintf(stderr, Name ": failed to read superblock of bitmap "
- "file: %s\n", strerror(errno));
- free(info);
- free(buf);
- return NULL;
- }
- memcpy(&info->sb, buf, sizeof(info->sb));
- skip = sizeof(info->sb);
- sb_le_to_cpu(&info->sb); /* convert superblock to CPU byte ordering */
- if (brief || info->sb.sync_size == 0 || info->sb.chunksize == 0)
- goto out;
- /* read the rest of the file counting total bits and dirty bits --
- * we stop when either:
- * 1) we hit EOF, in which case we assume the rest of the bits (if any)
- * are dirty
- * 2) we've read the full bitmap, in which case we ignore any trailing
- * data in the file
- */
- total_bits = bitmap_bits(info->sb.sync_size, info->sb.chunksize);
- while(read_bits < total_bits) {
- unsigned long long remaining = total_bits - read_bits;
- if (n == 0) {
- n = read(fd, buf, 8192);
- skip = 0;
- if (n <= 0)
- break;
- }
- if (remaining > (n-skip) * 8) /* we want the full buffer */
- remaining = (n-skip) * 8;
- dirty_bits += count_dirty_bits(buf+skip, remaining);
- read_bits += remaining;
- n = 0;
- }
- if (read_bits < total_bits) { /* file truncated... */
- fprintf(stderr, Name ": WARNING: bitmap file is not large "
- "enough for array size %llu!\n\n",
- (unsigned long long)info->sb.sync_size);
- total_bits = read_bits;
- }
- out:
- free(buf);
- info->total_bits = total_bits;
- info->dirty_bits = dirty_bits;
- return info;
- }
- bitmap_info_t *bitmap_file_read(char *filename, int brief, struct supertype **stp)
- {
- int fd;
- bitmap_info_t *info;
- struct stat stb;
- struct supertype *st = *stp;
- if (stat(filename, &stb) < 0) {
- fprintf(stderr, Name ": failed to find file %s: %s\n",
- filename, strerror(errno));
- return NULL;
- }
- if ((S_IFMT & stb.st_mode) == S_IFBLK) {
- fd = open(filename, O_RDONLY);
- if (fd < 0) {
- fprintf(stderr, Name ": failed to open bitmap file %s: %s\n",
- filename, strerror(errno));
- return NULL;
- }
- /* block device, so we are probably after an internal bitmap */
- if (!st) st = guess_super(fd);
- if (!st) {
- /* just look at device... */
- lseek(fd, 0, 0);
- } else if (!st->ss->locate_bitmap) {
- fprintf(stderr, Name ": No bitmap possible with %s metadata\n",
- st->ss->name);
- return NULL;
- } else
- st->ss->locate_bitmap(st, fd);
- ioctl(fd, BLKFLSBUF, 0); /* make sure we read current data */
- *stp = st;
- } else {
- fd = open(filename, O_RDONLY|O_DIRECT);
- if (fd < 0) {
- fprintf(stderr, Name ": failed to open bitmap file %s: %s\n",
- filename, strerror(errno));
- return NULL;
- }
- }
- info = bitmap_fd_read(fd, brief);
- close(fd);
- return info;
- }
- __u32 swapl(__u32 l)
- {
- char *c = (char*)&l;
- char t= c[0];
- c[0] = c[3];
- c[3] = t;
- t = c[1];
- c[1] = c[2];
- c[2] = t;
- return l;
- }
- int ExamineBitmap(char *filename, int brief, struct supertype *st)
- {
- /*
- * Read the bitmap file and display its contents
- */
- bitmap_super_t *sb;
- bitmap_info_t *info;
- int rv = 1;
- char buf[64];
- int swap;
- __u32 uuid32[4];
- info = bitmap_file_read(filename, brief, &st);
- if (!info)
- return rv;
- sb = &info->sb;
- printf(" Filename : %s\n", filename);
- printf(" Magic : %08x\n", sb->magic);
- if (sb->magic != BITMAP_MAGIC) {
- fprintf(stderr, Name ": invalid bitmap magic 0x%x, the bitmap file appears to be corrupted\n", sb->magic);
- }
- printf(" Version : %d\n", sb->version);
- if (sb->version < BITMAP_MAJOR_LO ||
- sb->version > BITMAP_MAJOR_HI) {
- fprintf(stderr, Name ": unknown bitmap version %d, either the bitmap file is corrupted or you need to upgrade your tools\n", sb->version);
- goto free_info;
- }
- rv = 0;
- if (st)
- swap = st->ss->swapuuid;
- else
- #if __BYTE_ORDER == BIG_ENDIAN
- swap = 0;
- #else
- swap = 1;
- #endif
- memcpy(uuid32, sb->uuid, 16);
- if (swap)
- printf(" UUID : %08x:%08x:%08x:%08x\n",
- swapl(uuid32[0]),
- swapl(uuid32[1]),
- swapl(uuid32[2]),
- swapl(uuid32[3]));
- else
- printf(" UUID : %08x:%08x:%08x:%08x\n",
- uuid32[0],
- uuid32[1],
- uuid32[2],
- uuid32[3]);
- printf(" Events : %llu\n", (unsigned long long)sb->events);
- printf(" Events Cleared : %llu\n", (unsigned long long)sb->events_cleared);
- printf(" State : %s\n", bitmap_state(sb->state));
- printf(" Chunksize : %s\n", human_chunksize(sb->chunksize));
- printf(" Daemon : %ds flush period\n", sb->daemon_sleep);
- if (sb->write_behind)
- sprintf(buf, "Allow write behind, max %d", sb->write_behind);
- else
- sprintf(buf, "Normal");
- printf(" Write Mode : %s\n", buf);
- printf(" Sync Size : %llu%s\n", (unsigned long long)sb->sync_size/2,
- human_size(sb->sync_size * 512));
- if (brief)
- goto free_info;
- printf(" Bitmap : %llu bits (chunks), %llu dirty (%2.1f%%)\n",
- info->total_bits, info->dirty_bits,
- 100.0 * info->dirty_bits / (info->total_bits?:1));
- free_info:
- free(info);
- return rv;
- }
- int CreateBitmap(char *filename, int force, char uuid[16],
- unsigned long chunksize, unsigned long daemon_sleep,
- unsigned long write_behind,
- unsigned long long array_size /* sectors */,
- int major)
- {
- /*
- * Create a bitmap file with a superblock and (optionally) a full bitmap
- */
- FILE *fp;
- int rv = 1;
- char block[512];
- bitmap_super_t sb;
- long long bytes, filesize;
- if (!force && access(filename, F_OK) == 0) {
- fprintf(stderr, Name ": bitmap file %s already exists, use --force to overwrite\n", filename);
- return rv;
- }
- fp = fopen(filename, "w");
- if (fp == NULL) {
- fprintf(stderr, Name ": failed to open bitmap file %s: %s\n",
- filename, strerror(errno));
- return rv;
- }
- if (chunksize == UnSet) {
- /* We don't want more than 2^21 chunks, as 2^11 fill up one
- * 4K page (2 bytes per chunk), and 2^10 address of those
- * fill up a 4K indexing page. 2^20 might be safer, especially
- * on 64bit hosts, so use that.
- */
- chunksize = DEFAULT_BITMAP_CHUNK;
- /* <<20 for 2^20 chunks, >>9 to convert bytes to sectors */
- while (array_size > ((unsigned long long)chunksize << (20-9)))
- chunksize <<= 1;
- }
- memset(&sb, 0, sizeof(sb));
- sb.magic = BITMAP_MAGIC;
- sb.version = major;
- if (uuid != NULL)
- memcpy(sb.uuid, uuid, 16);
- sb.chunksize = chunksize;
- sb.daemon_sleep = daemon_sleep;
- sb.write_behind = write_behind;
- sb.sync_size = array_size;
- sb_cpu_to_le(&sb); /* convert to on-disk byte ordering */
- if (fwrite(&sb, sizeof(sb), 1, fp) != 1) {
- fprintf(stderr, Name ": failed to write superblock to bitmap file %s: %s\n", filename, strerror(errno));
- goto out;
- }
- /* calculate the size of the bitmap and write it to disk */
- bytes = (bitmap_bits(array_size, chunksize) + 7) / 8;
- if (!bytes) {
- rv = 0;
- goto out;
- }
- filesize = bytes + sizeof(sb);
- memset(block, 0xff, sizeof(block));
- while (bytes > 0) {
- if (fwrite(block, sizeof(block), 1, fp) != 1) {
- fprintf(stderr, Name ": failed to write bitmap file %s: %s\n", filename, strerror(errno));
- goto out;
- }
- bytes -= sizeof(block);
- }
- rv = 0;
- fflush(fp);
- /* make the file be the right size (well, to the nearest byte) */
- if (ftruncate(fileno(fp), filesize))
- perror("ftrunace");
- out:
- fclose(fp);
- if (rv)
- unlink(filename); /* possibly corrupted, better get rid of it */
- return rv;
- }
- int bitmap_update_uuid(int fd, int *uuid, int swap)
- {
- struct bitmap_super_s bm;
- if (lseek(fd, 0, 0) != 0)
- return 1;
- if (read(fd, &bm, sizeof(bm)) != sizeof(bm))
- return 1;
- if (bm.magic != __cpu_to_le32(BITMAP_MAGIC))
- return 1;
- copy_uuid(bm.uuid, uuid, swap);
- if (lseek(fd, 0, 0) != 0)
- return 2;
- if (write(fd, &bm, sizeof(bm)) != sizeof(bm)) {
- lseek(fd, 0, 0);
- return 2;
- }
- lseek(fd, 0, 0);
- return 0;
- }