summaryrefslogtreecommitdiff
path: root/bitmap.c
diff options
context:
space:
mode:
Diffstat (limited to 'bitmap.c')
-rw-r--r--bitmap.c485
1 files changed, 485 insertions, 0 deletions
diff --git a/bitmap.c b/bitmap.c
new file mode 100644
index 00000000..dab674b4
--- /dev/null
+++ b/bitmap.c
@@ -0,0 +1,485 @@
+/*
+ * 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"
+
+static 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);
+ sb->nodes = __le32_to_cpu(sb->nodes);
+ sb->sectors_reserved = __le32_to_cpu(sb->sectors_reserved);
+}
+
+static 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+ { "Out of date", 2 },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 */
+static 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) {
+ pr_err("failed to allocate 8192 bytes\n");
+ return NULL;
+ }
+ n = read(fd, buf, 8192);
+
+ info = xmalloc(sizeof(*info));
+
+ if (n < sizeof(info->sb)) {
+ pr_err("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... */
+ pr_err("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;
+}
+
+int bitmap_file_open(char *filename, struct supertype **stp)
+{
+ int fd;
+ struct stat stb;
+ struct supertype *st = *stp;
+
+ if (stat(filename, &stb) < 0) {
+ pr_err("failed to find file %s: %s\n",
+ filename, strerror(errno));
+ return -1;
+ }
+ if ((S_IFMT & stb.st_mode) == S_IFBLK) {
+ fd = open(filename, O_RDONLY|O_DIRECT);
+ if (fd < 0) {
+ pr_err("failed to open bitmap file %s: %s\n",
+ filename, strerror(errno));
+ return -1;
+ }
+ /* 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) {
+ pr_err("No bitmap possible with %s metadata\n",
+ st->ss->name);
+ return -1;
+ } else {
+ if (st->ss->locate_bitmap(st, fd)) {
+ pr_err("%s doesn't have bitmap\n", filename);
+ fd = -1;
+ }
+ }
+
+ *stp = st;
+ } else {
+ fd = open(filename, O_RDONLY|O_DIRECT);
+ if (fd < 0) {
+ pr_err("failed to open bitmap file %s: %s\n",
+ filename, strerror(errno));
+ return -1;
+ }
+ }
+
+ return fd;
+}
+
+__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;
+ int fd, i;
+ __u32 uuid32[4];
+
+ fd = bitmap_file_open(filename, &st);
+ if (fd < 0)
+ return rv;
+
+ info = bitmap_fd_read(fd, brief);
+ if (!info)
+ return rv;
+ sb = &info->sb;
+ if (sb->magic != BITMAP_MAGIC && md_get_version(fd) > 0) {
+ pr_err("This is an md array. To view a bitmap you need to examine\n");
+ pr_err("a member device, not the array.\n");
+ pr_err("Reporting bitmap that would be used if this array were used\n");
+ pr_err("as a member of some other array\n");
+ }
+ close(fd);
+ printf(" Filename : %s\n", filename);
+ printf(" Magic : %08x\n", sb->magic);
+ if (sb->magic != BITMAP_MAGIC) {
+ pr_err("invalid bitmap magic 0x%x, the bitmap file appears\n",
+ sb->magic);
+ pr_err("to be corrupted or missing.\n");
+ }
+ printf(" Version : %d\n", sb->version);
+ if (sb->version < BITMAP_MAJOR_LO ||
+ sb->version > BITMAP_MAJOR_CLUSTERED) {
+ pr_err("unknown bitmap version %d, either the bitmap file\n",
+ sb->version);
+ pr_err("is corrupted or you need to upgrade your tools\n");
+ 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]);
+
+ if (sb->nodes == 0) {
+ 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 (sb->nodes == 0) {
+ 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));
+ } else {
+ printf(" Cluster nodes : %d\n", sb->nodes);
+ printf(" Cluster name : %-64s\n", sb->cluster_name);
+ for (i = 0; i < (int)sb->nodes; i++) {
+ if (i) {
+ free(info);
+ info = bitmap_fd_read(fd, brief);
+ sb = &info->sb;
+ }
+ if (sb->magic != BITMAP_MAGIC)
+ pr_err("invalid bitmap magic 0x%x, the bitmap file appears to be corrupted\n", sb->magic);
+
+ printf(" Node Slot : %d\n", i);
+ 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));
+ if (brief)
+ continue;
+ 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) {
+ pr_err("bitmap file %s already exists, use --force to overwrite\n", filename);
+ return rv;
+ }
+
+ fp = fopen(filename, "w");
+ if (fp == NULL) {
+ pr_err("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) {
+ pr_err("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) {
+ pr_err("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;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-16 05:02:41 +0000