From e59bc41c7111a26abf12e1a74da99dc31c6992a8 Mon Sep 17 00:00:00 2001 From: kuangyufei Date: Sat, 12 Jun 2021 10:33:27 +0800 Subject: [PATCH] =?UTF-8?q?=E5=AE=8C=E6=88=90=E5=AF=B9=E7=A3=81=E7=9B=98?= =?UTF-8?q?=E5=88=86=E5=8C=BA=E6=A8=A1=E5=9D=97=E7=9A=84=E6=B3=A8=E8=A7=A3?= =?UTF-8?q?=20=20=20=20=20=E7=99=BE=E4=B8=87=E6=B1=89=E5=AD=97=E6=B3=A8?= =?UTF-8?q?=E8=A7=A3=20+=20=E7=99=BE=E7=AF=87=E5=8D=9A=E5=AE=A2=E5=88=86?= =?UTF-8?q?=E6=9E=90=20=3D>=20=E6=8C=96=E9=80=8F=E9=B8=BF=E8=92=99?= =?UTF-8?q?=E5=86=85=E6=A0=B8=E6=BA=90=E7=A0=81=20=20=20=20=20=E5=9B=BD?= =?UTF-8?q?=E5=86=85:https://weharmony.gitee.io=20=20=20=20=20=E5=9B=BD?= =?UTF-8?q?=E5=A4=96:https://weharmony.github.io?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- fs/include/disk.h | 52 +++++++++++----- fs/include/fs/vnode.h | 2 +- fs/vfs/disk/disk.c | 140 +++++++++++++++++++++--------------------- zzz/git/push.sh | 2 +- 4 files changed, 108 insertions(+), 88 deletions(-) diff --git a/fs/include/disk.h b/fs/include/disk.h index 6b6de289..f34812b5 100644 --- a/fs/include/disk.h +++ b/fs/include/disk.h @@ -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. diff --git a/fs/include/fs/vnode.h b/fs/include/fs/vnode.h index 8e3392ef..d17b881d 100644 --- a/fs/include/fs/vnode.h +++ b/fs/include/fs/vnode.h @@ -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 diff --git a/fs/vfs/disk/disk.c b/fs/vfs/disk/disk.c index 52479d73..1f6a6016 100644 --- a/fs/vfs/disk/disk.c +++ b/fs/vfs/disk/disk.c @@ -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) diff --git a/zzz/git/push.sh b/zzz/git/push.sh index 7006e736..b57d509f 100644 --- a/zzz/git/push.sh +++ b/zzz/git/push.sh @@ -1,5 +1,5 @@ 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 -- GitLab