summaryrefslogtreecommitdiff
path: root/make-bcache.c
diff options
context:
space:
mode:
Diffstat (limited to 'make-bcache.c')
-rw-r--r--make-bcache.c156
1 files changed, 80 insertions, 76 deletions
diff --git a/make-bcache.c b/make-bcache.c
index 7ab2405..2db48de 100644
--- a/make-bcache.c
+++ b/make-bcache.c
@@ -71,26 +71,94 @@ void usage()
exit(EXIT_FAILURE);
}
+void write_sb(char *dev, struct cache_sb *sb)
+{
+ int fd;
+ char uuid[40], set_uuid[40];
+
+ if (sb->version > 1) {
+ printf("Must specify one of -C or -B\n");
+ usage();
+ }
+
+ if ((sb->bucket_size & (sb->bucket_size - 1)) ||
+ (sb->block_size & (sb->block_size - 1))) {
+ printf("Block and bucket sizes must be powers of two\n");
+ exit(EXIT_FAILURE);
+ }
+
+ if (sb->bucket_size < sb->block_size) {
+ printf("Bad bucket size %i\n", sb->bucket_size);
+ exit(EXIT_FAILURE);
+ }
+
+ if ((fd = open(dev, O_RDWR)) == -1) {
+ printf("Can't open dev %s: %s\n", dev, strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+
+ sb->offset = SB_SECTOR;
+ memcpy(sb->magic, bcache_magic, 16);
+ sb->nbuckets = getblocks(fd) / sb->bucket_size;
+ sb->nr_in_set = 1;
+ sb->first_bucket = (23 / sb->bucket_size) + 1;
+ uuid_unparse(sb->uuid, uuid);
+ uuid_unparse(sb->set_uuid, set_uuid);
+
+ if (sb->nbuckets < 1 << 7) {
+ printf("Not enough buckets: %ju, need %u\n",
+ sb->nbuckets, 1 << 7);
+ exit(EXIT_FAILURE);
+ }
+
+ printf("UUID: %s\n"
+ "Set UUID: %s\n"
+ "nbuckets: %ju\n"
+ "block_size: %u\n"
+ "bucket_size: %u\n"
+ "nr_in_set: %u\n"
+ "nr_this_dev: %u\n"
+ "first_bucket: %u\n",
+ uuid, set_uuid,
+ sb->nbuckets,
+ sb->block_size,
+ sb->bucket_size,
+ sb->nr_in_set,
+ sb->nr_this_dev,
+ sb->first_bucket);
+
+ if (pwrite(fd, sb, sizeof(*sb), SB_SECTOR << 9) != sizeof(*sb)) {
+ perror("write error\n");
+ exit(EXIT_FAILURE);
+ }
+
+ fsync(fd);
+ close(fd);
+
+ uuid_generate(sb->uuid);
+}
+
int main(int argc, char **argv)
{
- bool cache = false, backingdev = false;
- int fd, c;
- int64_t nblocks;
- char uuid[40], set_uuid[40], *dev;
+ bool written = false;
+ int c;
struct cache_sb sb;
memset(&sb, 0, sizeof(struct cache_sb));
+ sb.version = 2;
+ sb.block_size = 8;
+ sb.bucket_size = 1024;
uuid_generate(sb.uuid);
uuid_generate(sb.set_uuid);
- while ((c = getopt(argc, argv, "CBU:w:b:j:")) != -1)
+ while ((c = getopt(argc, argv, "-CBU:w:b:")) != -1)
switch (c) {
case 'C':
- cache = true;
+ sb.version = 0;
break;
case 'B':
- backingdev = true;
+ sb.version = CACHE_BACKING_DEV;
break;
case 'b':
sb.bucket_size = hatoi(optarg) / 512;
@@ -104,80 +172,16 @@ int main(int argc, char **argv)
exit(EXIT_FAILURE);
}
break;
- case 'S':
- if (uuid_parse(optarg, sb.set_uuid)) {
- printf("Bad uuid\n");
- exit(EXIT_FAILURE);
- }
+ case 1:
+ write_sb(optarg, &sb);
+ written = true;
break;
}
- if (!sb.block_size)
- sb.block_size = 4;
-
- if (!sb.bucket_size)
- sb.bucket_size = cache ? 256 : 8192;
-
- if (cache == backingdev) {
- printf("Must specify one of -C or -B\n");
- usage();
- }
-
- if (argc <= optind) {
+ if (!written) {
printf("Please supply a device\n");
exit(EXIT_FAILURE);
}
- dev = argv[optind];
- fd = open(dev, O_RDWR);
- if (fd == -1) {
- printf("Can't open dev %s: %s\n", dev, strerror(errno));
- exit(EXIT_FAILURE);
- }
- nblocks = getblocks(fd);
- printf("device is %ju sectors\n", nblocks);
-
- sb.offset_this_sb = 8;
- memcpy(sb.magic, bcache_magic, 16);
- sb.version = backingdev ? CACHE_BACKING_DEV : 0;
- sb.nbuckets = nblocks / sb.bucket_size;
- sb.nr_in_set = 1;
- uuid_unparse(sb.uuid, uuid);
- uuid_unparse(sb.set_uuid, set_uuid);
-
- sb.first_bucket = (23 / sb.bucket_size) + 1;
-
- if (cache)
- if (sb.bucket_size < sb.block_size ||
- sb.bucket_size > nblocks / 8) {
- printf("Bad bucket size %i\n", sb.bucket_size);
- exit(EXIT_FAILURE);
- }
-
- printf("UUID: %s\n"
- "Set UUID: %s\n"
- "nbuckets: %ju\n"
- "block_size: %u\n"
- "bucket_size: %u\n"
- "nr_in_set: %u\n"
- "nr_this_dev: %u\n"
- "first_bucket: %u\n"
- "sizeof sb: %lu\n",
- uuid, set_uuid,
- sb.nbuckets,
- sb.block_size,
- sb.bucket_size,
- sb.nr_in_set,
- sb.nr_this_dev,
- sb.first_bucket,
- sizeof(sb));
-
- if (pwrite(fd, &sb, sizeof(sb), 4096) != sizeof(sb))
- goto err;
-
- fsync(fd);
- exit(EXIT_SUCCESS);
-err:
- perror("write error\n");
- return 1;
+ return 0;
}