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完成对磁盘分区模块的注解 

    百万汉字注解 + 百篇博客分析 => 挖透鸿蒙内核源码
    国内:https://weharmony.gitee.io
    国外:https://weharmony.github.io
上级 b76aa02c
隐藏空白更改
内联 并排
Showing with 108 addition and 88 deletion
fs/include/disk.h
浏览文件 @ e59bc41c
......@@ -128,46 +128,66 @@ https://blog.csdn.net/Hilavergil/article/details/79270379
#define FOURTH_BYTE 4
#define BIT_FOR_BYTE 8
//高低位互换函数(16位), 0x0102 - > 变成 0x0201
#define LD_WORD_DISK(ptr) (UINT16)(((UINT16)*((UINT8 *)(ptr) + FIRST_BYTE) << (BIT_FOR_BYTE * FIRST_BYTE)) | \
(UINT16)*(UINT8 *)(ptr))
//高低位互换函数(32位), 0x01020304 - > 变成 0x04030201
#define LD_DWORD_DISK(ptr) (UINT32)(((UINT32)*((UINT8 *)(ptr) + THIRD_BYTE) << (BIT_FOR_BYTE * THIRD_BYTE)) | \
((UINT32)*((UINT8 *)(ptr) + SECOND_BYTE) << (BIT_FOR_BYTE * SECOND_BYTE)) | \
((UINT16)*((UINT8 *)(ptr) + FIRST_BYTE) << (BIT_FOR_BYTE * FIRST_BYTE)) | \
(*(UINT8 *)(ptr)))
//高低位互换函数(64位), 0x01..08 - > 变成 0x08...01
#define LD_QWORD_DISK(ptr) ((UINT64)(((UINT64)LD_DWORD_DISK(&(ptr)[FOURTH_BYTE]) << (BIT_FOR_BYTE * FOURTH_BYTE)) | \
LD_DWORD_DISK(ptr)))
/* Check VBR string, including FAT, NTFS */
//每个分区的引导记录（VBR）
/* Check VBR string, including FAT, NTFS */ //确认文件系统
#define VERIFY_FS(ptr) (((LD_DWORD_DISK(&(ptr)[BS_FILSYSTEMTYPE32]) & BS_FS_TYPE_MASK) == BS_FS_TYPE_VALUE) || \
!strncmp(&(ptr)[BS_FILSYSTYPE], "FAT", strlen("FAT")) || \
!strncmp(&(ptr)[BS_JMPBOOT], "\xEB\x52\x90" "NTFS ", \
strlen("\xEB\x52\x90" "NTFS ")))
//开头 EB5290 代表是 NTFS文件系统,ptr[36]开始为"FAT"代表 FAT文件系统
//https://www.jianshu.com/p/1be47267b98b
//GPT格式解析
#define PARTION_MODE_BTYE (PAR_OFFSET + PAR_TYPE_OFFSET) /* 0xEE: GPT(GUID), else: MBR */ //两种分区模式
#define PARTION_MODE_GPT 0xEE /* 0xEE: GPT(GUID), else: MBR */ //GPT和MBR
#define SIGNATURE_OFFSET 0 /* The offset of GPT partition header signature */
#define SIGNATURE_LEN 8 /* The length of GPT signature */
#define HEADER_SIZE_OFFSET 12 /* The offset of GPT header size */
#define TABLE_SIZE_OFFSET 84 /* The offset of GPT table size */
#define TABLE_NUM_OFFSET 80 /* The number of GPT table */
#define SIGNATURE_OFFSET 0 /* The offset of GPT partition header signature */ //从这个位置读取分区表头签名
#define SIGNATURE_LEN 8 /* The length of GPT signature *///分区表签名的长度,占8个字节
#define HEADER_SIZE_OFFSET 12 /* The offset of GPT header size *///从这个位置读取分区表头大小
#define TABLE_SIZE_OFFSET 84 /* The offset of GPT table size *///从这个位置读取分区表大小
#define TABLE_NUM_OFFSET 80 /* The number of GPT table */ //从这个位置读取分区表数量
#define TABLE_START_SECTOR 2
#define TABLE_MAX_NUM 128
#define TABLE_SIZE 128
#define GPT_PAR_START_OFFSET 32
#define GPT_PAR_START_OFFSET 32 //开始扇区偏移位置
#define GPT_PAR_END_OFFSET 40
#define PAR_ENTRY_NUM_PER_SECTOR 4
#define PAR_ENTRY_NUM_PER_SECTOR 4 //每个扇区分区项目数量
#define HEADER_SIZE_MASK 0xFFFFFFFF
#define HEADER_SIZE 0x5C
#define HARD_DISK_GUID_OFFSET 56
#define HARD_DISK_GUID_FOR_ESP 0x0020004900460045
#define HARD_DISK_GUID_FOR_MSP 0x007200630069004D
#define HARD_DISK_GUID_FOR_ESP 0x0020004900460045
#define HARD_DISK_GUID_FOR_MSP 0x007200630069004D //@note_thinking 是否写错了,应该是 MSR
#define PAR_VALID_OFFSET0 0
#define PAR_VALID_OFFSET1 4
#define PAR_VALID_OFFSET2 8
#define PAR_VALID_OFFSET3 12
/*
一、esp即EFI系统分区
1、全称EFI system partition，简写为ESP。ESP虽然是一个FAT16或FAT32格式的物理分区，但是其分区标识是EF(十六进制)
而非常规的0E或0C；因此，该分区在 Windows 操作系统下一般是不可见的。支持EFI模式的电脑需要从ESP启动系统，EFI固件
可从ESP加载EFI启动程序和应用程序。
2、ESP是一个独立于操作系统之外的分区，操作系统被引导之后，就不再依赖它。这使得ESP非常适合用来存储那些系统级的
维护性的工具和数据，比如：引导管理程序、驱动程序、系统维护工具、系统备份等，甚至可以在ESP里安装一个特殊的操作系统；
3、ESP也可以看做是一个安全的隐藏的分区，可以把引导管理程序、系统维护工具、系统恢复工具及镜像等放到ESP，可以自己
打造“一键恢复系统”。而且，不仅可以自己进行DIY，还要更方便、更通用；
二、msr分区是保留分区
1、windows不会向msr分区建立文件系统或者写数据，而是为了调整分区结构而保留的分区。在Win8以上系统更新时，会检测msr分区。
msr分区本质上就是写在分区表上面的【未分配空间】，目的是微软不想让别人乱动；
2、msr分区的用途是防止将一块GPT磁盘接到老系统中，被当作未格式化的空硬盘而继续操作（例如重新格式化）导致数据丢失。
GPT磁盘上有了这个分区，当把它接入XP等老系统中，会提示无法识别的磁盘，也无法进一步操作；
*/
#define VERIFY_GPT(ptr) ((!strncmp(&(ptr)[SIGNATURE_OFFSET], "EFI PART", SIGNATURE_LEN)) && \
((LD_DWORD_DISK(&(ptr)[HEADER_SIZE_OFFSET]) & HEADER_SIZE_MASK) == HEADER_SIZE))
......@@ -255,14 +275,14 @@ typedef struct _los_part_ {//分区描述符
struct partition_info {//分区信息
UINT8 type; //分区类型,是主分区还是扩展分区
UINT64 sector_start;//开始扇区位置
UINT64 sector_count;//扇区大小
UINT64 sector_count;//扇区总数量
};
struct disk_divide_info {//每个磁盘分区总信息
UINT64 sector_count; //磁盘扇区总大小
UINT32 sector_size; //扇区大小,一般是512字节
UINT32 part_count; //当前分区数量 需 < MAX_DIVIDE_PART_PER_DISK + MAX_PRIMARY_PART_PER_DISK
UINT32 part_count; //磁盘真实的分区数量 需 < MAX_DIVIDE_PART_PER_DISK + MAX_PRIMARY_PART_PER_DISK
/*
* The primary partition place should be reversed and set to 0 in case all the partitions are
* logical partition (maximum 16 currently). So the maximum part number should be 4 + 16.
......
fs/include/fs/vnode.h
浏览文件 @ e59bc41c
......@@ -108,7 +108,7 @@ struct Vnode {
struct Vnode *parent; /* parent vnode */ //父节点
struct VnodeOps *vop; /* vnode operations */ //节点虚拟操作
struct file_operations_vfs *fop; /* file operations */ //虚拟 <--> 真实的文件系统操作
void *data; /* private data */ //私有数据 (drv_data)
void *data; /* private data */ //私有数据 (drv_data),在 ( register_blockdriver | register_driver )中分配内存
uint32_t flag; /* vnode flag */ //节点标签
LIST_ENTRY hashEntry; /* list entry for bucket in hash table */ //通过它挂入哈希表 g_vnodeHashEntrys[i], i:[0,g_vnodeHashMask]
LIST_ENTRY actFreeEntry; /* vnode active/free list entry */ //通过本节点挂到空闲链表和使用链表上
......
fs/vfs/disk/disk.c
浏览文件 @ e59bc41c
......@@ -296,7 +296,7 @@ static los_part *DiskPartAllocate(struct Vnode *dev, UINT64 start, UINT64 count)
part->sector_start = start;//开始扇区
part->sector_count = count;//扇区总大小
part->part_name = NULL; //分区名称,暂无
LOS_ListInit(&part->list); //初始化链表节点,将通过它挂入全局分区链表.
LOS_ListInit(&part->list); //初始化链表节点,将通过它挂入磁盘分区链表上(los_disk->head).
return part; //就这个分区了.
}
......@@ -308,11 +308,11 @@ static los_part *DiskPartAllocate(struct Vnode *dev, UINT64 start, UINT64 count)
//清空分区信息
static VOID DiskPartRelease(los_part *part)
{
part->dev = NULL;//
part->part_no_disk = 0;
part->part_no_mbr = 0;
part->dev = NULL;//全局释放这步最关键,因为 DiskPartAllocate 中是通过它来判断是否全局分区项已被占用
part->part_no_disk = 0; //复位归0
part->part_no_mbr = 0; //复位归0
if (part->part_name != NULL) {
free(part->part_name);
free(part->part_name);//分区名称是内核内存分配的,所以要单独释放.
part->part_name = NULL;
}
}
......@@ -345,13 +345,13 @@ static INT32 DiskAddPart(los_disk *disk, UINT64 sectorStart, UINT64 sectorCount,
//devName = /dev/mmcblk0p2 代表的是 0号磁盘的2号分区
diskDev = disk->dev;
if (IsValidPart == TRUE) {
if (IsValidPart == TRUE) {//有效分区处理
ret = snprintf_s(devName, sizeof(devName), sizeof(devName) - 1, "%s%c%u",
((disk->disk_name == NULL) ? "null" : disk->disk_name), 'p', disk->part_count);
if (ret < 0) {
return VFS_ERROR;
}
//注册块设备驱动
//为节点注册块设备驱动,目的是从此可以通过块操作访问私有数据
if (register_blockdriver(devName, ((struct drv_data *)diskDev->data)->ops,
RWE_RW_RW, ((struct drv_data *)diskDev->data)->priv)) {
PRINT_ERR("DiskAddPart : register %s fail!\n", devName);
......@@ -365,13 +365,13 @@ static INT32 DiskAddPart(los_disk *disk, UINT64 sectorStart, UINT64 sectorCount,
PRINT_ERR("DiskAddPart : find %s fail!\n", devName);
return VFS_ERROR;
}
part = DiskPartAllocate(partDev, sectorStart, sectorCount);//分配一个扇区
part = DiskPartAllocate(partDev, sectorStart, sectorCount);//从全局分区池中分配分区项
VnodeDrop();
if (part == NULL) {
(VOID)unregister_blockdriver(devName);
return VFS_ERROR;
}
} else {
} else { //无效的分区也分配一个? @note_why
part = DiskPartAllocate(diskDev, sectorStart, sectorCount);
if (part == NULL) {
return VFS_ERROR;
......@@ -421,12 +421,12 @@ static CHAR GPTPartitionTypeRecognition(const CHAR *parBuf)
{
const CHAR *buf = parBuf;
const CHAR *fsType = "FAT";
const CHAR *str = "\xEB\x52\x90" "NTFS "; /* NTFS Boot entry point */ //NTFS 引导入口点
const CHAR *str = "\xEB\x52\x90" "NTFS "; /* NTFS Boot entry point */ //NTFS 引导入口点
if (((LD_DWORD_DISK(&buf[BS_FILSYSTEMTYPE32]) & BS_FS_TYPE_MASK) == BS_FS_TYPE_VALUE) ||
(strncmp(&buf[BS_FILSYSTYPE], fsType, strlen(fsType)) == 0)) {
(strncmp(&buf[BS_FILSYSTYPE], fsType, strlen(fsType)) == 0)) {//识别FAT的方法
return BS_FS_TYPE_FAT;
} else if (strncmp(&buf[BS_JMPBOOT], str, strlen(str)) == 0) {
} else if (strncmp(&buf[BS_JMPBOOT], str, strlen(str)) == 0) {//识别NTFS的方法
return BS_FS_TYPE_NTFS;
}
......@@ -463,7 +463,7 @@ static INT32 GPTInfoGet(struct Vnode *blkDrv, CHAR *gptBuf)
INT32 ret;
//获取驱动程序
struct block_operations *bops = (struct block_operations *)((struct drv_data *)blkDrv->data)->ops;
//从第一个扇区,从这可以看出 GPT是兼容 MBR的,因为 MBR的内容是放在 0 扇区的.
//从第一个扇区,从这可以看出 GPT是兼容 MBR的,因为 MBR的内容是放在 0 扇区.
ret = bops->read(blkDrv, (UINT8 *)gptBuf, 1, 1); /* Read the device first sector */
if (ret != 1) { /* Read failed */
PRINT_ERR("%s %d\n", __FUNCTION__, __LINE__);
......@@ -477,22 +477,22 @@ static INT32 GPTInfoGet(struct Vnode *blkDrv, CHAR *gptBuf)
return ENOERR;
}
//解析GPT分区内容
static INT32 OsGPTPartitionRecognitionSub(struct disk_divide_info *info, const CHAR *partitionBuf,
UINT32 *partitionCount, UINT64 partitionStart, UINT64 partitionEnd)
{
CHAR partitionType;
if (VERIFY_FS(partitionBuf)) {
partitionType = GPTPartitionTypeRecognition(partitionBuf);
partitionType = GPTPartitionTypeRecognition(partitionBuf);//文件系统类型,支持FAT和NTFS
if (partitionType) {
if (*partitionCount >= MAX_DIVIDE_PART_PER_DISK) {
return VFS_ERROR;
}
info->part[*partitionCount].type = partitionType;
info->part[*partitionCount].sector_start = partitionStart;
info->part[*partitionCount].sector_count = (partitionEnd - partitionStart) + 1;
(*partitionCount)++;
info->part[*partitionCount].type = partitionType;//文件系统
info->part[*partitionCount].sector_start = partitionStart;//开始扇区
info->part[*partitionCount].sector_count = (partitionEnd - partitionStart) + 1;//扇区总数
(*partitionCount)++;//磁盘扇区数量增加
} else {
PRINT_ERR("The partition type is not allowed to use!\n");
}
......@@ -501,7 +501,7 @@ static INT32 OsGPTPartitionRecognitionSub(struct disk_divide_info *info, const C
}
return ENOERR;
}
//识别GPT分区内容
static INT32 OsGPTPartitionRecognition(struct Vnode *blkDrv, struct disk_divide_info *info,
const CHAR *gptBuf, CHAR *partitionBuf, UINT32 *partitionCount)
{
......@@ -511,7 +511,7 @@ static INT32 OsGPTPartitionRecognition(struct Vnode *blkDrv, struct disk_divide_
struct block_operations *bops = NULL;
for (j = 0; j < PAR_ENTRY_NUM_PER_SECTOR; j++) {
if (!VERITY_AVAILABLE_PAR(&gptBuf[j * TABLE_SIZE])) {
if (!VERITY_AVAILABLE_PAR(&gptBuf[j * TABLE_SIZE])) {//ESP 和 MSR 分区
PRINTK("The partition type is ESP or MSR!\n");
continue;
}
......@@ -520,8 +520,8 @@ static INT32 OsGPTPartitionRecognition(struct Vnode *blkDrv, struct disk_divide_
return VFS_ERROR;
}
partitionStart = LD_QWORD_DISK(&gptBuf[(j * TABLE_SIZE) + GPT_PAR_START_OFFSET]);
partitionEnd = LD_QWORD_DISK(&gptBuf[(j * TABLE_SIZE) + GPT_PAR_END_OFFSET]);
partitionStart = LD_QWORD_DISK(&gptBuf[(j * TABLE_SIZE) + GPT_PAR_START_OFFSET]);//读取开始扇区
partitionEnd = LD_QWORD_DISK(&gptBuf[(j * TABLE_SIZE) + GPT_PAR_END_OFFSET]);//读取结束扇区
if ((partitionStart >= partitionEnd) || (partitionEnd > info->sector_count)) {
PRINT_ERR("GPT partition %u recognition failed : partitionStart = %llu, partitionEnd = %llu\n",
j, partitionStart, partitionEnd);
......@@ -532,7 +532,7 @@ static INT32 OsGPTPartitionRecognition(struct Vnode *blkDrv, struct disk_divide_
bops = (struct block_operations *)((struct drv_data *)blkDrv->data)->ops;
ret = bops->read(blkDrv, (UINT8 *)partitionBuf, partitionStart, 1);
ret = bops->read(blkDrv, (UINT8 *)partitionBuf, partitionStart, 1);//读取扇区内容
if (ret != 1) { /* read failed */
PRINT_ERR("%s %d\n", __FUNCTION__, __LINE__);
return -EIO;
......@@ -560,7 +560,7 @@ static INT32 DiskGPTPartitionRecognition(struct Vnode *blkDrv, struct disk_divid
return ret;
}
ret = GPTInfoGet(blkDrv, gptBuf);
ret = GPTInfoGet(blkDrv, gptBuf);//获取GDT类型的引导扇区信息
if (ret < 0) {
goto OUT_WITH_MEM;
}
......@@ -614,7 +614,7 @@ static INT32 OsMBRInfoGet(struct Vnode *blkDrv, CHAR *mbrBuf)
}
/* Check boot record signature. *///检查引导记录签名
if (LD_WORD_DISK(&mbrBuf[BS_SIG55AA]) != BS_SIG55AA_VALUE) {
if (LD_WORD_DISK(&mbrBuf[BS_SIG55AA]) != BS_SIG55AA_VALUE) {//高低换位
return VFS_ERROR;
}
......@@ -626,14 +626,14 @@ static INT32 OsEBRInfoGet(struct Vnode *blkDrv, const struct disk_divide_info *i
{
INT32 ret;
if (VERIFY_FS(mbrBuf)) {
if (VERIFY_FS(mbrBuf)) {//确认是个文件系统的引导扇区,因为紧接着要去读这个扇区内容,所以先判断有没有这个扇区.
if (info->sector_count <= LD_DWORD_DISK(&mbrBuf[PAR_OFFSET + PAR_START_OFFSET])) {
return VFS_ERROR;
}
//获取块设备驱动程序
struct block_operations *bops = (struct block_operations *)((struct drv_data *)blkDrv->data)->ops;
ret = bops->read(blkDrv, (UINT8 *)ebrBuf, LD_DWORD_DISK(&mbrBuf[PAR_OFFSET + PAR_START_OFFSET]), 1);
if ((ret != 1) || (!VERIFY_FS(ebrBuf))) { /* read failed */
ret = bops->read(blkDrv, (UINT8 *)ebrBuf, LD_DWORD_DISK(&mbrBuf[PAR_OFFSET + PAR_START_OFFSET]), 1);//读取某个扇区信息
if ((ret != 1) || (!VERIFY_FS(ebrBuf))) { /* read failed */ //这里同样要确认下读出来的扇区是文件系统的引导扇区
PRINT_ERR("OsEBRInfoGet, verify_fs error, ret = %d\n", ret);
return -EIO;
}
......@@ -668,7 +668,7 @@ static INT32 OsPrimaryPartitionRecognition(const CHAR *mbrBuf, struct disk_divid
return extendedFlag;//返回是否为扩展分区标签
}
//识别逻辑分区,也叫扩展分区
//识别扩展分区
static INT32 OsLogicalPartitionRecognition(struct Vnode *blkDrv, struct disk_divide_info *info,
UINT32 extendedAddress, CHAR *ebrBuf, INT32 mbrCount)
{
......@@ -677,7 +677,7 @@ static INT32 OsLogicalPartitionRecognition(struct Vnode *blkDrv, struct disk_div
CHAR ebrPartitionType;
INT32 ebrCount = 0;
do {
do {//循环读取一个个扩展分区信息
(VOID)memset_s(ebrBuf, info->sector_size, 0, info->sector_size);
if (((UINT64)(extendedAddress) + extendedOffset) >= info->sector_count) {
PRINT_ERR("extended partition is out of disk range: extendedAddress = %u, extendedOffset = %u\n",
......@@ -685,14 +685,14 @@ static INT32 OsLogicalPartitionRecognition(struct Vnode *blkDrv, struct disk_div
break;
}
struct block_operations *bops = (struct block_operations *)((struct drv_data *)blkDrv->data)->ops;
ret = bops->read(blkDrv, (UINT8 *)ebrBuf, extendedAddress + extendedOffset, 1);
ret = bops->read(blkDrv, (UINT8 *)ebrBuf, extendedAddress + extendedOffset, 1);//读取扇区
if (ret != 1) { /* read failed */
PRINT_ERR("driver read return error: %d, extendedAddress = %u, extendedOffset = %u\n", ret,
extendedAddress, extendedOffset);
return -EIO;
}
ebrPartitionType = ebrBuf[PAR_OFFSET + PAR_TYPE_OFFSET];
if (ebrPartitionType && ((mbrCount + ebrCount) < MAX_DIVIDE_PART_PER_DISK)) {
ebrPartitionType = ebrBuf[PAR_OFFSET + PAR_TYPE_OFFSET];//读取分区类型
if (ebrPartitionType && ((mbrCount + ebrCount) < MAX_DIVIDE_PART_PER_DISK)) {//填充分区信息
info->part[MAX_PRIMARY_PART_PER_DISK + ebrCount].type = ebrPartitionType;
info->part[MAX_PRIMARY_PART_PER_DISK + ebrCount].sector_start = extendedAddress + extendedOffset +
LD_DWORD_DISK(&ebrBuf[PAR_OFFSET +
......@@ -701,9 +701,9 @@ static INT32 OsLogicalPartitionRecognition(struct Vnode *blkDrv, struct disk_div
PAR_COUNT_OFFSET]);
ebrCount++;//扩展分区的数量
}
extendedOffset = LD_DWORD_DISK(&ebrBuf[PAR_OFFSET + PAR_START_OFFSET + PAR_TABLE_SIZE]);
extendedOffset = LD_DWORD_DISK(&ebrBuf[PAR_OFFSET + PAR_START_OFFSET + PAR_TABLE_SIZE]);//继续下一个分区
} while ((ebrBuf[PAR_OFFSET + PAR_TYPE_OFFSET + PAR_TABLE_SIZE] != 0) &&
((mbrCount + ebrCount) < MAX_DIVIDE_PART_PER_DISK));
((mbrCount + ebrCount) < MAX_DIVIDE_PART_PER_DISK));//结束条件1.读完分区表 2.总分区数超了
return ebrCount;
}
......@@ -739,21 +739,21 @@ static INT32 DiskPartitionRecognition(struct Vnode *blkDrv, struct disk_divide_i
}
/* The partition type is GPT */
if (mbrBuf[PARTION_MODE_BTYE] == (CHAR)PARTION_MODE_GPT) {
ret = DiskGPTPartitionRecognition(blkDrv, info);
if (mbrBuf[PARTION_MODE_BTYE] == (CHAR)PARTION_MODE_GPT) {//如果采用了GPT的分区方式 0xEE
ret = DiskGPTPartitionRecognition(blkDrv, info);//用GPT方式解析分区信息
goto OUT_WITH_MEM;
}
ret = OsEBRInfoGet(blkDrv, info, ebrBuf, mbrBuf);
if (ret < 0) {
ret = OsEBRInfoGet(blkDrv, info, ebrBuf, mbrBuf);//获取扩展分区信息
if (ret < 0) {//4个分区表中不一定会有扩展分区
ret = 0; /* no mbr */
goto OUT_WITH_MEM;
}
extendedFlag = OsPrimaryPartitionRecognition(mbrBuf, info, &extendedPos, &mbrCount);
if (extendedFlag) {
extendedAddress = LD_DWORD_DISK(&mbrBuf[PAR_OFFSET + PAR_START_OFFSET + (extendedPos * PAR_TABLE_SIZE)]);
ret = OsLogicalPartitionRecognition(blkDrv, info, extendedAddress, ebrBuf, mbrCount);
extendedFlag = OsPrimaryPartitionRecognition(mbrBuf, info, &extendedPos, &mbrCount);//解析主分区信息
if (extendedFlag) {//如果有扩展分区
extendedAddress = LD_DWORD_DISK(&mbrBuf[PAR_OFFSET + PAR_START_OFFSET + (extendedPos * PAR_TABLE_SIZE)]);//逻辑分区开始解析位置
ret = OsLogicalPartitionRecognition(blkDrv, info, extendedAddress, ebrBuf, mbrCount);//解析逻辑分区
if (ret <= 0) {
goto OUT_WITH_MEM;
}
......@@ -775,25 +775,25 @@ INT32 DiskPartitionRegister(los_disk *disk)
//填充disk_divide_info结构体设置分区信息
/* Fill disk_divide_info structure to set partition's infomation. */
(VOID)memset_s(parInfo.part, sizeof(parInfo.part), 0, sizeof(parInfo.part));
partSize = sizeof(parInfo.part) / sizeof(parInfo.part[0]);//获取分区数量
parInfo.sector_size = disk->sector_size;//磁盘扇区大小给分区信息
parInfo.sector_count = disk->sector_count;//扇区大小
count = DiskPartitionRecognition(disk->dev, &parInfo);
if (count == VFS_ERROR) {
part = get_part(DiskAddPart(disk, 0, disk->sector_count, FALSE));
partSize = sizeof(parInfo.part) / sizeof(parInfo.part[0]);//获取能分区的最大数量
parInfo.sector_size = disk->sector_size;//磁盘扇区大小,这是固定的,不管什么分区,扇区大小是不变的(512字节)
parInfo.sector_count = disk->sector_count;//扇区数量,注意:这里只是默认的值,最终的值来源于读取的MBR或EBR内容
//即每个分区的扇区大小和总数量是可以不一样的.
count = DiskPartitionRecognition(disk->dev, &parInfo);//有了分区信息就阔以开始解析了
if (count == VFS_ERROR) {//分区表错误, @note_thinking 直接返回就行了,做 get_part 没意义了吧
part = get_part(DiskAddPart(disk, 0, disk->sector_count, FALSE));//
if (part == NULL) {
return VFS_ERROR;
}
part->part_no_mbr = 0;
part->part_no_mbr = 0;//打印磁盘没有一个可用的分区表
PRINTK("Disk %s doesn't contain a valid partition table.\n", disk->disk_name);
return ENOERR;
} else if (count < 0) {
return VFS_ERROR;
}
parInfo.part_count = count;
if (count == 0) {
parInfo.part_count = count;//保存分区数量
if (count == 0) { //整个函数写的很怪,建议重写 @note_thinking
part = get_part(DiskAddPart(disk, 0, disk->sector_count, TRUE));
if (part == NULL) {
return VFS_ERROR;
......@@ -804,7 +804,7 @@ INT32 DiskPartitionRegister(los_disk *disk)
return ENOERR;
}
for (i = 0; i < partSize; i++) {
for (i = 0; i < partSize; i++) {//磁盘的分区是解析出来了,接着要纳入全局统一管理了.
/* Read the disk_divide_info structure to get partition's infomation. */
if ((parInfo.part[i].type != 0) && (parInfo.part[i].type != EXTENDED_PAR) &&
(parInfo.part[i].type != EXTENDED_8G)) {
......@@ -812,8 +812,8 @@ INT32 DiskPartitionRegister(los_disk *disk)
if (part == NULL) {
return VFS_ERROR;
}
part->part_no_mbr = i + 1;
part->filesystem_type = parInfo.part[i].type;
part->part_no_mbr = i + 1;//全局记录 第几个主引导分区
part->filesystem_type = parInfo.part[i].type;//全局记录 文件系统类型
}
}
......@@ -1313,7 +1313,7 @@ static INT32 DiskDivideAndPartitionRegister(struct disk_divide_info *info, los_d
}
return ENOERR;
}
//磁盘反初始化
static INT32 DiskDeinit(los_disk *disk)
{
los_part *part = NULL;
......@@ -1330,11 +1330,11 @@ static INT32 DiskDeinit(los_disk *disk)
if (ret < 0) {
return -ENAMETOOLONG;
}
DiskPartDelFromDisk(disk, part);
(VOID)unregister_blockdriver(devName);
DiskPartRelease(part);
DiskPartDelFromDisk(disk, part);//从磁盘删除分区
(VOID)unregister_blockdriver(devName);//注销块驱动程序
DiskPartRelease(part);//释放分区信息
part = LOS_DL_LIST_ENTRY(disk->head.pstNext, los_part, list);
part = LOS_DL_LIST_ENTRY(disk->head.pstNext, los_part, list);//下一个分区内容
}
}
......@@ -1704,13 +1704,13 @@ VOID show_part(los_part *part)
}
PRINTK("\npart info :\n");
PRINTK("disk id : %u\n", part->disk_id);
PRINTK("part_id in system: %u\n", part->part_id);
PRINTK("part no in disk : %u\n", part->part_no_disk);
PRINTK("part no in mbr : %u\n", part->part_no_mbr);//主分区
PRINTK("part filesystem : %02X\n", part->filesystem_type);
PRINTK("part sec start : %llu\n", part->sector_start);
PRINTK("part sec count : %llu\n", part->sector_count);
PRINTK("disk id : %u\n", part->disk_id); //磁盘ID
PRINTK("part_id in system: %u\n", part->part_id); //在整个系统的分区ID
PRINTK("part no in disk : %u\n", part->part_no_disk);//在磁盘分区的ID
PRINTK("part no in mbr : %u\n", part->part_no_mbr);//主分区ID
PRINTK("part filesystem : %02X\n", part->filesystem_type);//文件系统(FAT | NTFS)
PRINTK("part sec start : %llu\n", part->sector_start);//开始扇区
PRINTK("part sec count : %llu\n", part->sector_count);//扇区大小
}
//通过磁盘ID 擦除磁盘信息
INT32 EraseDiskByID(UINT32 diskID, size_t startSector, UINT32 sectors)
......
zzz/git/push.sh
浏览文件 @ e59bc41c
git add -A
git commit -m '对两种磁盘的组织方式 GPT/MBR 的注解
git commit -m '完成对磁盘分区模块的注解
百万汉字注解 + 百篇博客分析 => 挖透鸿蒙内核源码
国内:https://weharmony.gitee.io
国外:https://weharmony.github.io
......
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