bcache-tools: define separated super block for in-memory and on-disk format
This patch syncrhonizes the super block definition from bcache kernel
code, now the original super block structure is changed into two,
- struct cache_sb_disk
This is for on-disk bcache super block format, which is exactly same
as original struct cache_sb.
- struct cache_sb
This is only for in-memory super block, it is no longer exactly
mapping to the members and offsets to the cache_sb_disk.
Most part of the patch is to make source code to be consistent to the
data structures change.
Signed-off-by: Coly Li <colyli@suse.de>
diff --git a/Makefile b/Makefile
index 2c326cf..b4546a1 100644
--- a/Makefile
+++ b/Makefile
@@ -31,7 +31,7 @@
bcache-super-show: LDLIBS += `pkg-config --libs uuid`
bcache-super-show: CFLAGS += -std=gnu99
-bcache-super-show: crc64.o
+bcache-super-show: crc64.o lib.o
bcache-register: bcache-register.o
diff --git a/bcache-super-show.c b/bcache-super-show.c
index 26cc40e..883410f 100644
--- a/bcache-super-show.c
+++ b/bcache-super-show.c
@@ -25,7 +25,8 @@
#include <uuid/uuid.h>
#include "bcache.h"
-
+#include "lib.h"
+#include "bitwise.h"
static void usage()
{
@@ -61,6 +62,7 @@
bool force_csum = false;
int o;
extern char *optarg;
+ struct cache_sb_disk sb_disk;
struct cache_sb sb;
char uuid[40];
uint64_t expected_csum;
@@ -90,11 +92,13 @@
exit(2);
}
- if (pread(fd, &sb, sizeof(sb), SB_START) != sizeof(sb)) {
+ if (pread(fd, &sb_disk, sizeof(sb_disk), SB_START) != sizeof(sb_disk)) {
fprintf(stderr, "Couldn't read\n");
exit(2);
}
+ to_cache_sb(&sb, &sb_disk);
+
printf("sb.magic\t\t");
if (!memcmp(sb.magic, bcache_magic, 16)) {
printf("ok\n");
@@ -104,7 +108,7 @@
exit(2);
}
- printf("sb.first_sector\t\t%" PRIu64, sb.offset);
+ printf("sb.first_sector\t\t%llu", sb.offset);
if (sb.offset == SB_SECTOR) {
printf(" [match]\n");
} else {
@@ -113,9 +117,9 @@
exit(2);
}
- printf("sb.csum\t\t\t%" PRIX64, sb.csum);
- expected_csum = csum_set(&sb);
- if (sb.csum == expected_csum) {
+ printf("sb.csum\t\t\t%llx", le64_to_cpu(sb_disk.csum));
+ expected_csum = csum_set(&sb_disk);
+ if (le64_to_cpu(sb_disk.csum) == expected_csum) {
printf(" [match]\n");
} else {
printf(" [expected %" PRIX64 "]\n", expected_csum);
@@ -125,7 +129,7 @@
}
}
- printf("sb.version\t\t%" PRIu64, sb.version);
+ printf("sb.version\t\t%llu", sb.version);
switch (sb.version) {
// These are handled the same by the kernel
case BCACHE_SB_VERSION_CDEV:
@@ -168,8 +172,8 @@
if (!SB_IS_BDEV(&sb)) {
// total_sectors includes the superblock;
printf("dev.cache.first_sector\t%u\n"
- "dev.cache.cache_sectors\t%ju\n"
- "dev.cache.total_sectors\t%ju\n"
+ "dev.cache.cache_sectors\t%llu\n"
+ "dev.cache.total_sectors\t%llu\n"
"dev.cache.ordered\t%s\n"
"dev.cache.discard\t%s\n"
"dev.cache.pos\t\t%u\n"
diff --git a/bcache.h b/bcache.h
index 82fe580..250da9d 100644
--- a/bcache.h
+++ b/bcache.h
@@ -94,38 +94,41 @@
__le64 d[SB_JOURNAL_BUCKETS]; /* journal buckets */
};
+/*
+ * This is for in-memory bcache super block.
+ * NOTE: cache_sb is NOT exactly mapping to cache_sb_disk, the member
+ * size, ordering and even whole struct size may be different
+ * from cache_sb_disk.
+ */
struct cache_sb {
- uint64_t csum;
- uint64_t offset; /* sector where this sb was written */
- uint64_t version;
+ __u64 offset; /* sector where this sb was written */
+ __u64 version;
- uint8_t magic[16];
+ __u8 magic[16];
- uint8_t uuid[16];
+ __u8 uuid[16];
union {
- uint8_t set_uuid[16];
- uint64_t set_magic;
+ __u8 set_uuid[16];
+ __u64 set_magic;
};
- uint8_t label[SB_LABEL_SIZE];
+ __u8 label[SB_LABEL_SIZE];
- uint64_t flags;
- uint64_t seq;
- uint64_t pad[8];
+ __u64 flags;
+ __u64 seq;
union {
struct {
/* Cache devices */
- uint64_t nbuckets; /* device size */
+ __u64 nbuckets; /* device size */
- uint16_t block_size; /* sectors */
- uint16_t bucket_size; /* sectors */
-
- uint16_t nr_in_set;
- uint16_t nr_this_dev;
+ __u16 block_size; /* sectors */
+ __u16 nr_in_set;
+ __u16 nr_this_dev;
+ __u32 bucket_size; /* sectors */
};
struct {
/* Backing devices */
- uint64_t data_offset;
+ __u64 data_offset;
/*
* block_size from the cache device section is still used by
@@ -135,14 +138,14 @@
};
};
- uint32_t last_mount; /* time_t */
+ __u32 last_mount; /* time overflow in y2106 */
- uint16_t first_bucket;
+ __u16 first_bucket;
union {
- uint16_t njournal_buckets;
- uint16_t keys;
+ __u16 njournal_buckets;
+ __u16 keys;
};
- uint64_t d[SB_JOURNAL_BUCKETS]; /* journal buckets */
+ __u64 d[SB_JOURNAL_BUCKETS]; /* journal buckets */
};
static inline bool SB_IS_BDEV(const struct cache_sb *sb)
diff --git a/lib.c b/lib.c
index 542f115..9a2fa26 100644
--- a/lib.c
+++ b/lib.c
@@ -293,7 +293,6 @@
strcpy(base->name, devname);
base->magic = "ok";
base->first_sector = SB_SECTOR;
- base->csum = sb.csum;
base->version = sb.version;
strncpy(base->label, (char *) sb.label, SB_LABEL_SIZE);
@@ -325,6 +324,7 @@
int may_add_item(char *devname, struct list_head *head)
{
+ struct cache_sb_disk sb_disk;
struct cache_sb sb;
if (strcmp(devname, ".") == 0 || strcmp(devname, "..") == 0)
@@ -336,10 +336,13 @@
if (fd == -1)
return 0;
- if (pread(fd, &sb, sizeof(sb), SB_START) != sizeof(sb)) {
+ if (pread(fd, &sb_disk, sizeof(sb_disk), SB_START) != sizeof(sb_disk)) {
close(fd);
return 0;
}
+
+ to_cache_sb(&sb, &sb_disk);
+
if (memcmp(sb.magic, bcache_magic, 16)) {
close(fd);
return 0;
@@ -348,6 +351,8 @@
int ret;
tmp = (struct dev *) malloc(DEVLEN);
+
+ tmp->csum = le64_to_cpu(sb_disk.csum);
ret = detail_base(dev, sb, tmp);
if (ret != 0) {
fprintf(stderr, "Failed to get information for %s\n", dev);
@@ -399,6 +404,7 @@
int detail_dev(char *devname, struct bdev *bd, struct cdev *cd, int *type)
{
+ struct cache_sb_disk sb_disk;
struct cache_sb sb;
uint64_t expected_csum;
int fd = open(devname, O_RDONLY);
@@ -408,11 +414,13 @@
return 1;
}
- if (pread(fd, &sb, sizeof(sb), SB_START) != sizeof(sb)) {
+ if (pread(fd, &sb_disk, sizeof(sb_disk), SB_START) != sizeof(sb_disk)) {
fprintf(stderr, "Couldn't read\n");
goto Fail;
}
+ to_cache_sb(&sb, &sb_disk);
+
if (memcmp(sb.magic, bcache_magic, 16)) {
fprintf(stderr,
"Bad magic,make sure this is an bcache device\n");
@@ -424,8 +432,8 @@
goto Fail;
}
- expected_csum = csum_set(&sb);
- if (!(sb.csum == expected_csum)) {
+ expected_csum = csum_set(&sb_disk);
+ if (le64_to_cpu(sb_disk.csum) != expected_csum) {
fprintf(stderr, "Csum is not match with expected one\n");
goto Fail;
}
diff --git a/make.c b/make.c
index cc76863..a239023 100644
--- a/make.c
+++ b/make.c
@@ -223,35 +223,6 @@
return -1;
}
-static void swap_sb(struct cache_sb *sb, int write_cdev_super)
-{
- int i;
-
- /* swap to little endian byte order to write */
- sb->offset = cpu_to_le64(sb->offset);
- sb->version = cpu_to_le64(sb->version);
- sb->flags = cpu_to_le64(sb->flags);
- sb->seq = cpu_to_le64(sb->seq);
- sb->last_mount = cpu_to_le32(sb->last_mount);
- sb->first_bucket = cpu_to_le16(sb->first_bucket);
- sb->keys = cpu_to_le16(sb->keys);
- sb->block_size = cpu_to_le16(sb->block_size);
-
- for (i = 0; i < SB_JOURNAL_BUCKETS; i++)
- sb->d[i] = cpu_to_le64(sb->d[i]);
-
- if (write_cdev_super) {
- /* Cache devices */
- sb->nbuckets = cpu_to_le64(sb->nbuckets);
- sb->bucket_size = cpu_to_le16(sb->bucket_size);
- sb->nr_in_set = cpu_to_le16(sb->nr_in_set);
- sb->nr_this_dev = cpu_to_le16(sb->nr_this_dev);
- } else {
- /* Backing devices */
- sb->data_offset = cpu_to_le64(sb->data_offset);
- }
-}
-
static void write_sb(char *dev, unsigned int block_size,
unsigned int bucket_size,
bool writeback, bool discard, bool wipe_bcache,
@@ -261,9 +232,9 @@
{
int fd;
char uuid_str[40], set_uuid_str[40], zeroes[SB_START] = {0};
+ struct cache_sb_disk sb_disk;
struct cache_sb sb;
blkid_probe pr;
- int write_cdev_super = 1;
fd = open(dev, O_RDWR|O_EXCL);
@@ -320,13 +291,13 @@
if (force)
wipe_bcache = true;
- if (pread(fd, &sb, sizeof(sb), SB_START) != sizeof(sb))
+ if (pread(fd, &sb_disk, sizeof(sb_disk), SB_START) != sizeof(sb_disk))
exit(EXIT_FAILURE);
- if (!memcmp(sb.magic, bcache_magic, 16)) {
+ if (!memcmp(sb_disk.magic, bcache_magic, 16)) {
if (wipe_bcache) {
- if (pwrite(fd, zeroes, sizeof(sb),
- SB_START) != sizeof(sb)) {
+ if (pwrite(fd, zeroes, sizeof(sb_disk),
+ SB_START) != sizeof(sb_disk)) {
fprintf(stderr,
"Failed to erase super block for %s\n",
dev);
@@ -355,6 +326,7 @@
exit(EXIT_FAILURE);
}
+ memset(&sb_disk, 0, sizeof(struct cache_sb_disk));
memset(&sb, 0, sizeof(struct cache_sb));
sb.offset = SB_SECTOR;
@@ -373,8 +345,6 @@
uuid_unparse(sb.set_uuid, set_uuid_str);
if (SB_IS_BDEV(&sb)) {
- write_cdev_super = 0;
-
SET_BDEV_CACHE_MODE(&sb, writeback ?
CACHE_MODE_WRITEBACK : CACHE_MODE_WRITETHROUGH);
@@ -415,7 +385,7 @@
sb.first_bucket = (23 / sb.bucket_size) + 1;
if (sb.nbuckets < 1 << 7) {
- fprintf(stderr, "Not enough buckets: %ju, need %u\n",
+ fprintf(stderr, "Not enough buckets: %llu, need %u\n",
sb.nbuckets, 1 << 7);
exit(EXIT_FAILURE);
}
@@ -429,7 +399,7 @@
printf("UUID: %s\n"
"Set UUID: %s\n"
"version: %u\n"
- "nbuckets: %ju\n"
+ "nbuckets: %llu\n"
"block_size_in_sectors: %u\n"
"bucket_size_in_sectors: %u\n"
"nr_in_set: %u\n"
@@ -462,17 +432,17 @@
* Swap native bytes order to little endian for writing
* the super block out.
*/
- swap_sb(&sb, write_cdev_super);
+ to_cache_sb_disk(&sb_disk, &sb);
/* write csum */
- sb.csum = csum_set(&sb);
+ sb_disk.csum = cpu_to_le64(csum_set(&sb_disk));
/* Zero start of disk */
if (pwrite(fd, zeroes, SB_START, 0) != SB_START) {
perror("write error\n");
exit(EXIT_FAILURE);
}
/* Write superblock */
- if (pwrite(fd, &sb, sizeof(sb), SB_START) != sizeof(sb)) {
+ if (pwrite(fd, &sb_disk, sizeof(sb_disk), SB_START) != sizeof(sb_disk)) {
perror("write error\n");
exit(EXIT_FAILURE);
}
diff --git a/probe-bcache.c b/probe-bcache.c
index c94c972..a640046 100644
--- a/probe-bcache.c
+++ b/probe-bcache.c
@@ -29,7 +29,7 @@
bool udev = false;
int i, o;
extern char *optarg;
- struct cache_sb sb;
+ struct cache_sb_disk sb_disk;
char uuid[40];
blkid_probe pr;
@@ -66,13 +66,13 @@
continue;
}
- if (pread(fd, &sb, sizeof(sb), SB_START) != sizeof(sb))
+ if (pread(fd, &sb_disk, sizeof(sb_disk), SB_START) != sizeof(sb_disk))
continue;
- if (memcmp(sb.magic, bcache_magic, 16))
+ if (memcmp(sb_disk.magic, bcache_magic, 16))
continue;
- uuid_unparse(sb.uuid, uuid);
+ uuid_unparse(sb_disk.uuid, uuid);
if (udev)
printf("ID_FS_UUID=%s\n"
