From eb9054a32e22d04c8ff3c7521084c0632ed80e70 Mon Sep 17 00:00:00 2001
From: Kent Overstreet <koverstreet@google.com>
Date: Thu, 19 May 2011 20:25:14 -0700
Subject: [PATCH] Updates for backing devices
---
bcache.h | 20 ++++++++++++++++----
make-bcache.c | 46 +++++++++++++++++++++++++---------------------
2 files changed, 41 insertions(+), 25 deletions(-)
diff --git a/bcache.h b/bcache.h
index 3f94dcee..deadbe38 100644
--- a/bcache.h
+++ b/bcache.h
@@ -5,24 +5,36 @@ static const char bcache_magic[] = {
0xc6, 0x85, 0x73, 0xf6, 0x4e, 0x1a, 0x45, 0xca,
0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81 };
+struct bkey {
+ uint64_t header;
+ uint64_t key;
+ uint64_t ptr[];
+};
+
struct cache_sb {
uint8_t magic[16];
+ uint8_t uuid[16];
+ uint8_t set_uuid[16];
+ uint64_t sequence;
+
#define CACHE_CLEAN 1
#define CACHE_SYNC 2
-#define CACHE_BACKING_DEVICE 4
+#define CACHE_BACKING_DEV 4
uint32_t version;
uint16_t block_size; /* sectors */
uint16_t bucket_size; /* sectors */
uint32_t journal_start; /* buckets */
uint32_t first_bucket; /* start of data */
uint64_t nbuckets; /* device size */
- uint64_t btree_root;
+
+ union {
+ struct bkey btree_root;
+ uint64_t _pad[8];
+ };
uint16_t btree_level;
uint16_t nr_in_set;
uint16_t nr_this_dev;
uint16_t _pad[1];
- uint8_t uuid[16];
- uint8_t set_uuid[16];
};
struct bucket_disk {
diff --git a/make-bcache.c b/make-bcache.c
index b213f9e4..02fe4053 100644
--- a/make-bcache.c
+++ b/make-bcache.c
@@ -1,6 +1,6 @@
#define _FILE_OFFSET_BITS 64
#define __USE_FILE_OFFSET64
-#define _XOPEN_SOURCE 500
+#define _XOPEN_SOURCE 600
#include <fcntl.h>
#include <linux/fs.h>
@@ -19,9 +19,9 @@
char zero[4096];
-long getblocks(int fd)
+uint64_t getblocks(int fd)
{
- long ret;
+ uint64_t ret;
struct stat statbuf;
if (fstat(fd, &statbuf)) {
perror("stat error\n");
@@ -36,10 +36,10 @@ long getblocks(int fd)
return ret;
}
-long hatoi(const char *s)
+uint64_t hatoi(const char *s)
{
char *e;
- long long i = strtol(s, &e, 10);
+ long long i = strtoll(s, &e, 10);
switch (*e) {
case 't':
case 'T':
@@ -70,15 +70,17 @@ void usage()
int main(int argc, char **argv)
{
bool cache = false, backingdev = false;
- int64_t nblocks;
+ int64_t nblocks, journal = 0;
int fd, i, c;
- char uuid[40];
- struct cache_sb sb = { .block_size = 8, .bucket_size = 0 };
+ char uuid[40], set_uuid[40];
+ struct cache_sb sb;
+
+ memset(&sb, 0, sizeof(struct cache_sb));
uuid_generate(sb.uuid);
uuid_generate(sb.set_uuid);
- while ((c = getopt(argc, argv, "CBU:w:b:")) != -1)
+ while ((c = getopt(argc, argv, "CBU:w:b:j:")) != -1)
switch (c) {
case 'C':
cache = true;
@@ -92,6 +94,9 @@ int main(int argc, char **argv)
case 'w':
sb.block_size = hatoi(optarg) / 512;
break;
+ case 'j':
+ journal = atoi(optarg);
+ break;
case 'U':
if (uuid_parse(optarg, sb.uuid)) {
printf("Bad uuid\n");
@@ -100,6 +105,9 @@ int main(int argc, char **argv)
break;
}
+ if (!sb.block_size)
+ sb.block_size = 4;
+
if (!sb.bucket_size)
sb.bucket_size = cache ? 256 : 8192;
@@ -119,7 +127,7 @@ int main(int argc, char **argv)
exit(EXIT_FAILURE);
}
nblocks = getblocks(fd);
- printf("device is %li sectors\n", nblocks);
+ printf("device is %ju sectors\n", nblocks);
if (sb.bucket_size < sb.block_size ||
sb.bucket_size > nblocks / 8) {
@@ -128,32 +136,28 @@ int main(int argc, char **argv)
}
memcpy(sb.magic, bcache_magic, 16);
- sb.version = backingdev ? CACHE_BACKING_DEVICE : 0;
+ 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);
- do
- sb.first_bucket = ((--sb.nbuckets * sizeof(struct bucket_disk)) + (24 << 9)) / (sb.bucket_size << 9) + 1;
- while ((sb.nbuckets + sb.first_bucket) * sb.bucket_size > nblocks);
-
- sb.journal_start = sb.first_bucket;
-
- sb.btree_root = sb.first_bucket * sb.bucket_size;
- sb.btree_level = 0;
+ sb.journal_start = ((sb.nbuckets * sizeof(struct bucket_disk)) + (24 << 9)) / (sb.bucket_size << 9) + 1;
+ sb.first_bucket = sb.journal_start + journal;
printf("block_size: %u\n"
"bucket_size: %u\n"
"journal_start: %u\n"
"first_bucket: %u\n"
"nbuckets: %ju\n"
- "UUID: %s\n",
+ "UUID: %s\n"
+ "Set UUID: %s\n",
sb.block_size,
sb.bucket_size,
sb.journal_start,
sb.first_bucket,
sb.nbuckets,
- uuid);
+ uuid, set_uuid);
/* Zero out priorities */
lseek(fd, 4096, SEEK_SET);