Intro
BBT是一個lun上所有block狀態(tài)的列表，每個block可能的狀態(tài)如下：
一個BBT的項目數(shù)(entry number)是geo->nplanes * geo-nblocks.
另外断楷，Bad-Block Table是需要由開發(fā)者自己維護的，可以通過mark&&flush來修改在內(nèi)存中的BBT或持久化BBT（將內(nèi)存中的BBT寫入設(shè)備：寫到哪里可能還需要去探索qemu中相關(guān)的處理）.
/**
* Representation of valid values of bad-block-table states
*/
enum nvm_bbt_state {
NVM_BBT_FREE = 0x0, ///< Block is free AKA good
NVM_BBT_BAD = 0x1, ///< Block is bad
NVM_BBT_GBAD = 0x2, ///< Block has grown bad
NVM_BBT_DMRK = 0x4, ///< Block has been marked by device side
NVM_BBT_HMRK = 0x8 ///< Block has been marked by host side
};
struct nvm_dev {
char name[NVM_DEV_NAME_LEN]; ///< Device name e.g. "nvme0n1"
char path[NVM_DEV_PATH_LEN]; ///< Device path e.g. "/dev/nvme0n1"
struct nvm_addr_fmt fmt; ///< Device address format
struct nvm_addr_fmt_mask mask; ///< Device address format mask
struct nvm_geo geo; ///< Device geometry
uint64_t ssw; ///< Bit-width for LBA fmt conversion
int pmode; ///< Default plane-mode I/O
int fd; ///< Device fd / IOCTL handle
int erase_naddrs_max; ///< Maximum # of address for erase
int read_naddrs_max; ///< Maximum # of address for read
int write_naddrs_max; ///< Maximum # of address for write
int bbts_cached; ///< Whether to cache bbts
size_t nbbts; ///< Number of entries in cache
struct nvm_bbt **bbts; ///< Cache of bad-block-tables
enum meta_mode meta_mode; ///< Flag to indicate the how meta is w
};
- 從dev_open可以看出：
- 一個lun一個bbt.
- 初始時每個lun對應(yīng)的bbt（dev->bbts[i]）都是空（NULL）.
struct nvm_dev *nvm_dev_open(const char *dev_path)
{
...
dev->bbts_cached = 0;
dev->nbbts = dev->geo.nchannels * dev->geo.nluns;
dev->bbts = malloc(sizeof(*dev->bbts) * dev->nbbts);
for (size_t i = 0; i < dev->nbbts; ++i)
dev->bbts[i] = NULL;
return dev;
}
使用bbt的時候如果沒有設(shè)置標(biāo)記
nvm_dev_set_bbts_cached(dev, 1)可能會出現(xiàn)一些預(yù)想不到的結(jié)果桌肴，具體原因正在分析中.(可提issue)使用bbt設(shè)置時（
nvm_bbt_mark其最大addrs也是不能超過NVM_NADDR_MAX）test code:
#include <liblightnvm.h>
#include <malloc.h>
#include <nvm.h>
#include <stdio.h>
#include <string.h>
static char nvm_dev_path[NVM_DEV_PATH_LEN] = "/dev/nvme0n1";
static struct nvm_dev *dev;
static const struct nvm_geo *geo;
static struct nvm_addr lun_addr;
static int channel = 0;
static int lun = 0;
static void *Buf_for_1_read = NULL; //Buf for reading 1 sector
static void *Buf_for_1_meta_read = NULL; // Buf for reading 1 metadata
const int FirstBLK = 0;
const int SecondBLK = 1;
const int Plane = 0;
const uint16_t State_HBAD = NVM_BBT_HMRK;
const uint16_t State_FREE = NVM_BBT_FREE;
const char* TestStr = "K:Foo;V:Bar";
#include "common.h"
int setup(void)
{
dev = nvm_dev_open(nvm_dev_path);
if (!dev) {
perror("nvm_dev_open");
return -1;
}
geo = nvm_dev_get_geo(dev);
lun_addr.ppa = 0;
lun_addr.g.ch = channel;
lun_addr.g.lun = lun;
Buf_for_1_read = nvm_buf_alloc(geo, 2 * geo->sector_nbytes);
if (!Buf_for_1_read) {
FAIL_ALLOC;
return -1;
}
Buf_for_1_meta_read = nvm_buf_alloc(geo, 2 * geo->meta_nbytes);
if (!Buf_for_1_meta_read) {
FAIL_ALLOC;
return -1;
}
return 0;
}
int teardown(void)
{
nvm_dev_close(dev);
if ( Buf_for_1_read ) {
free(Buf_for_1_read);
}
if ( Buf_for_1_meta_read) {
free(Buf_for_1_meta_read);
}
return 0;
}
static inline int _bbt_idx(const struct nvm_dev *dev,
const struct nvm_addr addr)
{
return addr.g.ch * dev->geo.nluns + addr.g.lun;
}
uint64_t alignblk(struct nvm_addr addr)
{
struct nvm_addr alg;
alg.ppa = addr.ppa;
alg.g.pg = 0;
alg.g.sec = 0;
return alg.ppa;
}
int GetPmode(int npl)
{
int x;
switch (npl) {
case 1:
x = NVM_FLAG_PMODE_SNGL; break;
case 2:
x = NVM_FLAG_PMODE_DUAL; break;
case 4:
x = NVM_FLAG_PMODE_QUAD; break;
default:
x = -1;
}
return x;
}
void EraseNpl_1Blk(struct nvm_addr wh)//
{
struct nvm_ret ret;
ssize_t res;
const int npl = geo->nplanes;
int pmode = GetPmode(npl);
struct nvm_addr whichblk[npl];
for(int i = 0; i < npl; ++i){
whichblk[i].ppa = alignblk(wh);
whichblk[i].g.pl = i;
}
res = nvm_addr_erase(dev, whichblk, npl, pmode, &ret);//Erase 1 block of all planes inside a lun.
if(res < 0){
FAIL_ERASE;
nvm_ret_pr(&ret);
}
}
void Write_1Sector(struct nvm_addr wh, const char *IO, int use_meta, const char *Meta)
{
struct nvm_ret ret;
ssize_t res;
int pmode = NVM_FLAG_PMODE_SNGL;
void *bufptr = NULL, *bufptr_meta = NULL;
int addr_valid = nvm_addr_check(wh, geo);
if(addr_valid){
ADDR_INVALID;
nvm_bounds_pr(addr_valid);
goto OUT;
}
//buf setup
bufptr = nvm_buf_alloc(geo, geo->sector_nbytes);//sector size
if(!bufptr){
FAIL_ALLOC;
goto OUT;
}
memcpy(bufptr, IO, strlen(IO));
if(use_meta){
bufptr_meta = nvm_buf_alloc(geo, geo->meta_nbytes);
if(!bufptr_meta){
FAIL_ALLOC;
goto FREE_OUT1;
}
memcpy(bufptr_meta, Meta, geo->meta_nbytes);
}
//2. write
res = nvm_addr_write(dev, &wh, 1, bufptr,
use_meta ? bufptr_meta : NULL, pmode, &ret);//Write 1 sector
if(res < 0){
FAIL_WRITE;
}
free(bufptr_meta);
FREE_OUT1:
free(bufptr);
OUT:
if(res < 0){
nvm_ret_pr(&ret);
}
return;
}
void Read_1Sector(struct nvm_addr wh, int use_meta)
{
struct nvm_ret ret;
ssize_t res;
int pmode = NVM_FLAG_PMODE_SNGL;
res = nvm_addr_read(dev, &wh, 1, Buf_for_1_read,
use_meta ? Buf_for_1_meta_read : NULL, pmode, &ret);//only use the first sector_nbytes
if(res < 0){
FAIL_READ;
nvm_ret_pr(&ret);
}
}
void Erase1LunALLBlk(struct nvm_addr lun_addr)//
{
//#define TEST_EraseAllLunBlk_FUNC
#define WAY1 1
#define WAY2 2
#define WAY WAY2 //WAY1 is not good!!
struct nvm_ret ret;
ssize_t res;
int i, j;
const int npl = geo->nplanes;
const int nblks = geo->nblocks;
int pmode = GetPmode(npl);
// int pmode = NVM_FLAG_PMODE_SNGL;
if (pmode < 0) {
PLANE_EINVAL;
return;
}
const int max_naddrs_1_time = NVM_NADDR_MAX;
const int naddrs_1_time = max_naddrs_1_time / npl;
struct nvm_addr whichblks[NVM_NADDR_MAX];//for all block
for(i = 0; i < NVM_NADDR_MAX; ++i){
whichblks[i].ppa = 0;
whichblks[i].g.ch = lun_addr.g.ch;
whichblks[i].g.lun = lun_addr.g.lun;
}
printf("Nblks: %d, Npl: %d\n", nblks, npl);
int t = 0;
int erased = 0;
while (erased < nblks) {
int issue_nblks = NVM_MIN(nblks - erased, naddrs_1_time);
int naddrs = issue_nblks * npl;
//SUM: issue_nblks * npl
if (WAY == WAY1) { //TEST Result: 2 ways of addr layout are both OK.
//Way 1:
for (i = 0; i < issue_nblks; ++i) {
for (j = 0; j < npl; j++) {
whichblks[j * issue_nblks + i].g.blk = erased + i;
whichblks[j * issue_nblks + i].g.pl = j;
}
}
}else{
//Way 2:
for (i = 0; i < issue_nblks; ++i) {
for (j = 0; j < npl; j++) {
whichblks[i * npl + j].g.blk = erased + i;
whichblks[i * npl + j].g.pl = j;
}
}
}
#ifdef TEST_EraseAllLunBlk_FUNC
char title[10];
sprintf(title, "idx%d", t);
My_pr_addr_cap(title);
for (int idx = 0; idx < naddrs; ++idx) {
My_pr_nvm_addr(whichblks[idx]);
}
#endif
res = nvm_addr_erase(dev, whichblks, naddrs, pmode, &ret);//Erase SUM blocks
if(res < 0){
FAIL_ERASE;
printf("%d naadrs From:\n", naddrs);
My_pr_addr_with_str("Bad Addr", whichblks[0]);
nvm_ret_pr(&ret);
printf("Stop\n");
return ;
}
erased += naddrs_1_time;
t++;
}
}
void Set1LunALLFree(struct nvm_addr lun_addr)
{
struct nvm_ret ret;
int res;
int i, j;
const int npl = geo->nplanes;
const int nblks = geo->nblocks;
const int max_naddrs_1_time = NVM_NADDR_MAX;
const int naddrs_1_time = max_naddrs_1_time / npl;
struct nvm_addr whichblks[NVM_NADDR_MAX];//for all block
for(i = 0; i < NVM_NADDR_MAX; ++i){
whichblks[i].ppa = 0;
whichblks[i].g.ch = lun_addr.g.ch;
whichblks[i].g.lun = lun_addr.g.lun;
}
printf("Nblks: %d, Npl: %d\n", nblks, npl);
int t = 0;
int erased = 0;
while (erased < nblks) {
int issue_nblks = NVM_MIN(nblks - erased, naddrs_1_time);
int naddrs = issue_nblks * npl;
//SUM: issue_nblks * npl
if (WAY == WAY1) { //TEST Result: 2 ways of addr layout are both OK.
//Way 1:
for (i = 0; i < issue_nblks; ++i) {
for (j = 0; j < npl; j++) {
whichblks[j * issue_nblks + i].g.blk = erased + i;
whichblks[j * issue_nblks + i].g.pl = j;
}
}
}else{
//Way 2:
for (i = 0; i < issue_nblks; ++i) {
for (j = 0; j < npl; j++) {
whichblks[i * npl + j].g.blk = erased + i;
whichblks[i * npl + j].g.pl = j;
}
}
}
res = nvm_bbt_mark(dev, whichblks, naddrs, State_FREE, &ret);
if (res < 0) {
MARK_BBT_FAIL;
printf("%d naadrs From:\n", naddrs);
My_pr_addr_with_str("Bad Addr", whichblks[0]);
nvm_ret_pr(&ret);
printf("Stop\n");
return ;
}
erased += naddrs_1_time;
t++;
}
}
void test_get_bbt_1(void)
{
struct nvm_ret ret = {};
const struct nvm_bbt *bbt;
bbt = nvm_bbt_get(dev, lun_addr, &ret);
if (!bbt) {
GET_BBT_FAIL;
nvm_ret_pr(&ret);
}
My_nvm_bbt_pr(bbt);
}
void test_run_erase_blk_1_lun(void)
{
Erase1LunALLBlk(lun_addr);
}
void test_write_to_blk(int plnum, int blknum)//write all pages inside a blk of block=blknum, plane=plnum
{
const int npl = geo->nplanes;
struct nvm_addr a0;
a0.ppa = lun_addr.ppa;
a0.g.pl = plnum;
a0.g.blk = blknum;
for (int i = 0; i < geo->npages; i++) {
a0.g.pg = i;
Write_1Sector(a0, TestStr, 0, NULL);
((char*)Buf_for_1_read)[0] = '\0';
Read_1Sector(a0, 0);
if (strcmp((char*)Buf_for_1_read, TestStr) != 0) {
NOT_THE_SAME_IO;
My_pr_addr_with_str("not same:", a0);
}
}
}
void Test_Erase1()
{
struct nvm_ret ret;
ssize_t res;
int pl[4] = {0,1,0,1};
int blk[4] = {0,0,1,1};
struct nvm_addr a0[4];
for (int i = 0; i < 4; i++) {
a0[i].ppa = 0;
a0[i].g.pl = pl[i];
a0[i].g.blk = blk[i];
}
res = nvm_addr_erase(dev, a0, 4, NVM_FLAG_PMODE_DUAL, &ret);//Erase 4 blocks
if(res < 0){
FAIL_ERASE;
nvm_ret_pr(&ret);
}
}
void Test_Erase2()
{
struct nvm_ret ret;
ssize_t res;
int pl[4] = {0,0,1,1};
int blk[4] = {0,1,0,1};
struct nvm_addr a0[4];
for (int i = 0; i < 4; i++) {
a0[i].ppa = 0;
a0[i].g.pl = pl[i];
a0[i].g.blk = blk[i];
}
res = nvm_addr_erase(dev, a0, 4, NVM_FLAG_PMODE_DUAL, &ret);//Erase 4 blocks
if(res < 0){
FAIL_ERASE;
nvm_ret_pr(&ret);
}
}
void test_E1_ok()
{
struct nvm_addr a0;
a0.ppa = 0;
a0.g.blk = 1;
Test_Erase1();
Write_1Sector(a0,"This is the test.", 0, NULL);
}
void test_E2_fail()
{
struct nvm_addr a0;
a0.ppa = 0;
a0.g.blk = 1;
Test_Erase2();
Write_1Sector(a0,"This is the test.", 0, NULL);
}
void test_set_cache_bbt(void)
{
nvm_dev_set_bbts_cached(dev, 1);
}
void test_clean_all_mark_all_free(void)
{
struct nvm_ret ret;
ssize_t res;
Erase1LunALLBlk(lun_addr);
Set1LunALLFree(lun_addr);
if(nvm_bbt_flush(dev, lun_addr, &ret)){//flush the lun's bbt
FLUSH_BBT_FAIL;
nvm_ret_pr(&ret);
}
}
void test_write_into_1st_2ed_blk(void)//write something into all pages inside the 1st/2ed block of all plane inside <lun_addr>
{
for (int i = 0; i < geo->nplanes; i++) {
test_write_to_blk(i, FirstBLK);
test_write_to_blk(i, SecondBLK);
}
}
void set_1st_2ed_blk_flush(uint16_t flag)
{
struct nvm_ret ret;
int res;
const int nblks = 2;//1st 2ed
const int naddrs = nblks * geo->nplanes;//the 1st/2ed block of LUN 0 across all plane
struct nvm_addr addrs[naddrs];
//*****Sequence: Must Be Like WAY2*****
for (int i = 0; i < geo->nplanes; i++) {
for (int j = 0; j < nblks; j++) {
addrs[j * geo->nplanes + i].ppa = lun_addr.ppa;
addrs[j * geo->nplanes + i].g.pl = i;
addrs[j * geo->nplanes + i].g.blk = j;
}
}
//My_pr_naddrs_with_str("Test", addrs, naddrs);
res = nvm_bbt_mark(dev, addrs, naddrs, flag, &ret);
if (res < 0) {
MARK_BBT_FAIL;
nvm_ret_pr(&ret);
}
if(nvm_bbt_flush(dev, lun_addr,&ret)){//flush the lun's bbt
FLUSH_BBT_FAIL;
nvm_ret_pr(&ret);
}
}
void test_set_1st_2ed_blk_bad(void)//set them as HBAD block so that background GC will then GC them.
{
set_1st_2ed_blk_flush(State_HBAD);
}
void test_GC(void)//**find all HBAD blocks and erase them**(erase operation must be issued to all plane inside a LUN)
{
struct nvm_ret ret = {};
const struct nvm_bbt *bbt;
int nbad = 0;
ssize_t res;
bbt = nvm_bbt_get(dev, lun_addr, &ret);
if (!bbt) {
GET_BBT_FAIL;
nvm_ret_pr(&ret);
}
const int max_naddrs_1_time = NVM_NADDR_MAX;
struct nvm_addr whichblks[NVM_NADDR_MAX];//for all block
int idx = 0;
//iterator all block, from nvm_bbt_pr
for (int i = 0; i < bbt->nblks; i += bbt->dev->geo.nplanes) {
int blk = i / bbt->dev->geo.nplanes;
int blk_num = blk;
int pl_num = 0;
for (int blk = i; blk < (i+ bbt->dev->geo.nplanes); ++blk, ++pl_num) {
if(bbt->blks[blk] == State_HBAD){
printf("HBAD: %d %d\n", pl_num, blk_num);
//setup address array
whichblks[idx].ppa = lun_addr.ppa;
whichblks[idx].g.pl = pl_num;
whichblks[idx].g.blk = blk_num;
idx++;
nbad++;
}
}
if (max_naddrs_1_time - idx < bbt->dev->geo.nplanes) {
//do erase.
res = nvm_addr_erase(dev, whichblks, idx, NVM_FLAG_PMODE_DUAL, &ret);
if(res < 0){
FAIL_ERASE;
nvm_ret_pr(&ret);
}
//set them as FREE again
if (nvm_bbt_mark(dev, whichblks, idx, State_FREE, &ret) < 0) {
MARK_BBT_FAIL;
nvm_ret_pr(&ret);
}
if(nvm_bbt_flush(dev, lun_addr,&ret)){//flush the lun's bbt
FLUSH_BBT_FAIL;
nvm_ret_pr(&ret);
}
idx = 0;
}
}
if (idx > 0) {
//do erase.
res = nvm_addr_erase(dev, whichblks, idx, NVM_FLAG_PMODE_DUAL, &ret);
if(res < 0){
FAIL_ERASE;
nvm_ret_pr(&ret);
}
//set them as FREE again
if (nvm_bbt_mark(dev, whichblks, idx, State_FREE, &ret) < 0) {
MARK_BBT_FAIL;
nvm_ret_pr(&ret);
}
if(nvm_bbt_flush(dev, lun_addr,&ret)){//flush the lun's bbt
FLUSH_BBT_FAIL;
nvm_ret_pr(&ret);
}
idx = 0;
}
printf("HBAD block number: %d\n", nbad);
}
typedef void (* FuncType) (void);
void RunTests()
{
FuncType tests[] = {
// test_run_erase_blk_1_lun,
// test_write_to_1st_blk,
// test_write_to_2ed_blk,
// test_get_bbt_1,
// test_E1_ok,
// test_E2_fail
test_set_cache_bbt,
test_clean_all_mark_all_free,
test_get_bbt_1,
test_write_into_1st_2ed_blk,
test_set_1st_2ed_blk_bad,
test_get_bbt_1,
test_GC,
test_get_bbt_1
};
const char *teststr[] = {
// "test_run_erase_blk_1_lun",
// "test_write_to_1st_blk",
// "test_write_to_2ed_blk",
// "test_get_bbt_1",
// "test_E1_ok",
// "test_E2_fail"
"test_set_cache_bbt",
"test_clean_all_mark_all_free",
"test_get_bbt_1",
"test_write_into_1st_2ed_blk",
"test_set_1st_2ed_blk_bad",
"test_get_bbt_1",
"test_GC",
"test_get_bbt_1"
};
for(int i = 0; i < (sizeof(tests) / sizeof(FuncType)); i++){
printf("====Test %d : %s====\n", i, teststr[i]);
tests[i]();
}
}
int main()
{
if( setup() < 0){
goto OUT;
}
RunTests();
OUT:
teardown();
return 0;
}
common.h:
#ifndef COMMON_H
#define COMMON_H
#include <liblightnvm.h>
#include <nvm.h>
#define DEBUG_MSG(MSG) do{ printf("[DEBUG] - "#MSG"\n"); }while(0)
//for io_issue:
#define FAIL_ERASE DEBUG_MSG(FAIL_ERASE)
#define FAIL_ALLOC DEBUG_MSG(FAIL_ALLOC)
#define FAIL_WRITE DEBUG_MSG(FAIL_WRITE)
#define FAIL_READ DEBUG_MSG(FAIL_READ)
#define ADDR_INVALID DEBUG_MSG(ADDR_INVALID)
#define THE_SAME_IO DEBUG_MSG(THE_SAME_IO)
#define NOT_THE_SAME_IO DEBUG_MSG(NOT_THE_SAME_IO)
#define THE_SAME_META DEBUG_MSG(THE_SAME_META)
#define NOT_THE_SAME_META DEBUG_MSG(NOT_THE_SAME_META)
//for bbt_issue:
#define PLANE_EINVAL DEBUG_MSG(PLANE_EINVAL)
#define GET_BBT_FAIL DEBUG_MSG(GET_BBT_FAIL)
#define FLUSH_BBT_FAIL DEBUG_MSG(FLUSH_BBT_FAIL)
#define MARK_BBT_FAIL DEBUG_MSG(MARK_BBT_FAIL)
//for common use:
#define NVM_MIN(x, y) ({ \
__typeof__(x) _min1 = (x); \
__typeof__(y) _min2 = (y); \
(void) (&_min1 == &_min2); \
_min1 < _min2 ? _min1 : _min2; })
inline static void My_pr_addr_cap(const char* str)
{
#define digestlen 8
char digest[digestlen];
strncpy(digest, str, digestlen);
digest[digestlen - 1] = '\0';
printf("%8s | %s | %s | %s | %-4s | %3s | %s \n",
digest,"ch", "lun", "pl", "blk", "pg", "sec");
}
inline static void My_pr_nvm_addr(struct nvm_addr addr)
{
printf(" | %2d | %3d | %2d | %4d | %3d | %d\n",
addr.g.ch, addr.g.lun, addr.g.pl,
addr.g.blk, addr.g.pg, addr.g.sec);
}
inline static void My_pr_addr_with_str(const char *str, struct nvm_addr x)
{
My_pr_addr_cap(str);
My_pr_nvm_addr(x);
}
inline static void My_pr_naddrs_with_str(const char *str, struct nvm_addr x[], int naddrs)
{
My_pr_addr_cap(str);
for (int i = 0; i < naddrs; i++) {
My_pr_nvm_addr(x[i]);
}
}
inline static void My_nvm_bbt_pr(const struct nvm_bbt *bbt)
{
int nnotfree = 0;
const int Pr_num = 4;
int pred = 0, pr_sr = 0;
if (!bbt) {
printf("bbt { NULL }\n");
return;
}
printf("bbt {\n");
printf(" addr"); nvm_addr_pr(bbt->addr);
printf(" nblks(%lu) {", bbt->nblks);
for (int i = 0; i < bbt->nblks; i += bbt->dev->geo.nplanes) {
int blk = i / bbt->dev->geo.nplanes;
if (pred < Pr_num/*first Pr_num ones*/
|| i == bbt->nblks - bbt->dev->geo.nplanes/*last one*/) {
printf("\n blk(%04d): [ ", blk);
for (int blk = i; blk < (i + bbt->dev->geo.nplanes); ++blk) {
nvm_bbt_state_pr(bbt->blks[blk]);
printf(" ");
if (bbt->blks[blk]) {
++nnotfree;
}
}
printf("]");
pred++;
}else if(!pr_sr){
printf("\n....");
pr_sr = 1;
}
}
printf("\n }\n");
printf(" #notfree(%d)\n", nnotfree);
printf("}\n");
}
#endif
1.設(shè)置cache，
2.擦除整個lun
3.拿bbt
4.寫入lun_0的每個plane的前2個block（一共4個block在我的環(huán)境geo下）
5.設(shè)置這4個block為HBAD
5.1拿bbt看是否有變化
6.模擬一個GC過程，把設(shè)為HBAD的block擦除掉
7.拿bbt
Output:
====Test 0 : test_set_cache_bbt====
====Test 1 : test_clean_all_mark_all_free====
Nblks: 2044, Npl: 2
Nblks: 2044, Npl: 2
====Test 2 : test_get_bbt_1====
bbt {
addr(0x0000000000000000){ ch(00), lun(00), pl(0), blk(0000), pg(000), sec(0) }
nblks(4088) {
blk(0000): [ FREE(0) FREE(0) ]
blk(0001): [ FREE(0) FREE(0) ]
blk(0002): [ FREE(0) FREE(0) ]
blk(0003): [ FREE(0) FREE(0) ]
....
blk(2043): [ FREE(0) FREE(0) ]
}
#notfree(0)
}
====Test 3 : test_write_into_1st_2ed_blk====
====Test 4 : test_set_1st_2ed_blk_bad====
====Test 5 : test_get_bbt_1====
bbt {
addr(0x0000000000000000){ ch(00), lun(00), pl(0), blk(0000), pg(000), sec(0) }
nblks(4088) {
blk(0000): [ HBAD(8) HBAD(8) ]
blk(0001): [ HBAD(8) HBAD(8) ]
blk(0002): [ FREE(0) FREE(0) ]
blk(0003): [ FREE(0) FREE(0) ]
....
blk(2043): [ FREE(0) FREE(0) ]
}
#notfree(4)
}
====Test 6 : test_GC====
HBAD: 0 0
HBAD: 1 0
HBAD: 0 1
HBAD: 1 1
HBAD block number: 4
====Test 7 : test_get_bbt_1====
bbt {
addr(0x0000000000000000){ ch(00), lun(00), pl(0), blk(0000), pg(000), sec(0) }
nblks(4088) {
blk(0000): [ FREE(0) FREE(0) ]
blk(0001): [ FREE(0) FREE(0) ]
blk(0002): [ FREE(0) FREE(0) ]
blk(0003): [ FREE(0) FREE(0) ]
....
blk(2043): [ FREE(0) FREE(0) ]
}
#notfree(0)
}
總結(jié)
- 一個bbt對應(yīng)一個lun
- bbt是由用戶自己維護的，并且可以持久化到設(shè)備中.(設(shè)備中對應(yīng)邏輯需要到qemu中查看)
- 使用bbt時需要設(shè)置
dev->bbts_cached標(biāo)記
