对mtd,disk,filemap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.21cloudbox.com
    国外:https://weharmony.github.io

fs/include/disk.h

@@ -247,7 +247,7 @@ typedef struct _los_disk_ {	//磁盘描述符
     UINT8 type;				//flash的类型 例如:EMMC
     CHAR *disk_name;		//设备名称,通过名称创建一个磁盘,los_alloc_diskid_byname
     LOS_DL_LIST head;       /* link head of all the partitions */ //双向链表上挂所有分区(los_part->list)
-    struct pthread_mutex disk_mutex;
+    struct pthread_mutex disk_mutex;//磁盘互斥锁, @notewhy 为什么不锁分区而锁磁盘 ?
 } los_disk;
 
 
@@ -258,7 +258,7 @@ typedef struct _los_part_ {//分区描述符
     UINT32 part_no_mbr : 5;  /* partition number in the mbr */	  //硬盘主引导记录（即Master Boot Record，一般简称为MBR），主分区数量	
     UINT32 reserved : 3;	////保留，注意 disk_id|part_id|part_no_disk|part_no_mbr|reserved 共用一个UINT32
     UINT8 filesystem_type;   /* filesystem used in the partition */ //文件系统类型
-    UINT8 type;				//flash的类型 例如:EMMC
+    UINT8 type;				//介质类型 例如:EMMC
     struct inode *dev;      /* dev devices used in the partition */ //分区中使用的索引节点
     CHAR *part_name;		//区名称
     UINT64 sector_start;     /* //开始扇区编号

fs/include/fs/vnode.h

@@ -79,8 +79,8 @@ enum VnodeType {//节点类型
     VNODE_TYPE_UNKNOWN,       /* unknown type */	//未知类型
     VNODE_TYPE_REG,           /* regular file */	//正则文件(普通文件)
     VNODE_TYPE_DIR,           /* directory */		//目录
-    VNODE_TYPE_BLK,           /* block device */	//块设备
-    VNODE_TYPE_CHR,           /* char device */		//字符设备
+    VNODE_TYPE_BLK,           /* block device */	//块设备驱动
+    VNODE_TYPE_CHR,           /* char device */		//字符设备驱动
     VNODE_TYPE_BCHR,          /* block char mix device *///块和字符设备混合
     VNODE_TYPE_FIFO,          /* pipe */			//管道文件
     VNODE_TYPE_LNK,           /* link */			//链接,这里的链接指的是上层硬链接概念
@@ -95,6 +95,9 @@ struct IATTR;
 * 这里顺便说一下目录文件的"链接数"。创建目录时，默认会生成两个目录项："."和".."。前者的inode号码就是当前目录的inode号码，
 	等同于当前目录的"硬链接"；后者的inode号码就是当前目录的父目录的inode号码，等同于父目录的"硬链接"。
 	所以，任何一个目录的"硬链接"总数，总是等于2加上它的子目录总数（含隐藏目录）
+	
+由于 vnode 是对所有设备的一个抽象，因此不同类型的设备，他们的操作方法也不一样，
+因此 vop ,fop 都是接口, data 因设备不同而不同.
 */
 struct Vnode {
     enum VnodeType type;                /* vnode type */	//节点类型
@@ -106,9 +109,9 @@ struct Vnode {
     LIST_HEAD parentPathCaches;         /* pathCaches point to parents */	//指向父级路径缓存,上面的都是当了爸爸节点
     LIST_HEAD childPathCaches;          /* pathCaches point to children */	//指向子级路径缓存,上面都是当了别人儿子的节点
     struct Vnode *parent;               /* parent vnode */	//父节点
-    struct VnodeOps *vop;               /* vnode operations */	//以 Vnode 方式访问数据(接口实现|驱动程序)
-    struct file_operations_vfs *fop;    /* file operations */	//以 File 方式访问数据(接口实现|驱动程序)
-    void *data;                         /* private data */		//私有数据 (drv_data),在 ( register_blockdriver | register_driver )中分配内存
+    struct VnodeOps *vop;               /* vnode operations */	//以 Vnode 方式操作数据(接口实现|驱动程序)
+    struct file_operations_vfs *fop;    /* file operations */	//以 file 方式操作数据(接口实现|驱动程序)
+    void *data;                         /* private data */		//指向每种具体设备私有的成员，例如 ( drv_data | nfsnode | ....)
     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/jffs2/src/vfs_jffs2.c

@@ -53,17 +53,41 @@
 
 #include "os-linux.h"
 #include "jffs2/nodelist.h"
+/*************************************************************
+JFFS2 直接在闪存上提供文件系统，而不是模拟块设备。
+JFFS2是Journalling Flash File System Version 2（日志文件系统）的缩写，是MTD设备上实现的日志型文件系统。
+JFFS2主要应用于NOR FLASH，其特点是：可读写、支持数据压缩、提供了崩溃/掉电安全保护、提供“写平衡”支持等。
 
+闪存与磁盘介质有许多差异，因此直接将磁盘文件系统运行在闪存上存在性能和安全性上的不足。
+为解决这一问题，需要实现一个特别针对闪存的文件系统，JFFS2就是这样一种文件系统。
+
+OpenHarmony内核的JFFS2主要应用于对NOR Flash闪存的文件管理，并且支持多分区。
+
+添加JFFS2分区
+
+调用 add_mtd_partition 函数添加JFFS2分区，该函数会自动为设备节点命名，对于JFFS2，其命名规则是“/dev/spinorblk”加上分区号。
+
+add_mtd_partition函数有四个参数，第一个参数表示介质，有“nand”和“spinor”两种，
+JFFS2分区在“spinor”上使用，而“nand”是提供给YAFFS2使用的。
+
+第二个参数表示起始地址，第三个参数表示分区大小，这两个参数都以16进制的形式传入。
+
+最后一个参数表示分区号，有效值为0~19。
+
+
+
+
+*************************************************************/
 #ifdef LOSCFG_FS_JFFS
 
 /* forward define */
-struct VnodeOps g_jffs2Vops;
-struct file_operations_vfs g_jffs2Fops;
+struct VnodeOps g_jffs2Vops;//vnode操作接口实现
+struct file_operations_vfs g_jffs2Fops;//vfs接口实现
 
-static LosMux g_jffs2FsLock;  /* lock for all jffs2 ops */
+static LosMux g_jffs2FsLock;  /* lock for all jffs2 ops *///操作 jffs2文件系统锁
 
 static pthread_mutex_t g_jffs2NodeLock = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
-struct Vnode *g_jffs2PartList[CONFIG_MTD_PATTITION_NUM];
+struct Vnode *g_jffs2PartList[CONFIG_MTD_PATTITION_NUM];//分区列表
 
 static void Jffs2SetVtype(struct jffs2_inode *node, struct Vnode *pVnode)
 {
@@ -775,8 +799,8 @@ void Jffs2MutexDelete(void)
     (void)LOS_MuxDestroy(&g_jffs2FsLock);
 }
 
-const struct MountOps jffs_operations = {
-    .Mount = VfsJffs2Bind,
+const struct MountOps jffs_operations = {//jffs对mount接口实现
+    .Mount = VfsJffs2Bind,	//mount()函数实现设备节点和挂载点的挂载。
     .Unmount = VfsJffs2Unbind,
     .Statfs = VfsJffs2Statfs,
 };
@@ -808,7 +832,7 @@ struct file_operations_vfs g_jffs2Fops = {
     .fsync = VfsJffs2Fsync,
 };
 
-
+//文件系统与内存的映射
 FSMAP_ENTRY(jffs_fsmap, "jffs2", jffs_operations, TRUE, TRUE);
 
 #endif

fs/vfs/disk/disk.c

@@ -852,8 +852,8 @@ INT32 los_disk_read(INT32 drvID, VOID *buf, UINT64 sector, UINT32 count, BOOL us
             goto ERROR_HANDLE;
         }
         len = disk->bcache->sectorSize * count;
-        /* useRead should be FALSE when reading large contiguous data */
-        result = BlockCacheRead(disk->bcache, (UINT8 *)buf, &len, sector, useRead);
+        /* useRead should be FALSE when reading large contiguous data *///读取大量连续数据时，useRead 应为 FALSE
+        result = BlockCacheRead(disk->bcache, (UINT8 *)buf, &len, sector, useRead);//从缓存区里读
         if (result != ENOERR) {
             PRINT_ERR("los_disk_read read err = %d, sector = %llu, len = %u\n", result, sector, len);
         }
@@ -862,9 +862,9 @@ INT32 los_disk_read(INT32 drvID, VOID *buf, UINT64 sector, UINT32 count, BOOL us
     if (disk->dev == NULL) {
         goto ERROR_HANDLE;
     }
-    struct block_operations *bops = (struct block_operations *)((struct drv_data *)disk->dev->data)->ops;
+    struct block_operations *bops = (struct block_operations *)((struct drv_data *)disk->dev->data)->ops;//获取块操作数据方式
     if ((bops != NULL) && (bops->read != NULL)) {
-        result = bops->read(disk->dev, (UINT8 *)buf, sector, count);
+        result = bops->read(disk->dev, (UINT8 *)buf, sector, count);//读取绝对扇区内容至buf
         if (result == (INT32)count) {
             result = ENOERR;
         }
@@ -884,7 +884,7 @@ ERROR_HANDLE:
     DISK_UNLOCK(&disk->disk_mutex);
     return VFS_ERROR;
 }
-
+//将buf内容写到指定扇区,
 INT32 los_disk_write(INT32 drvID, const VOID *buf, UINT64 sector, UINT32 count)
 {
 #ifdef LOSCFG_FS_FAT_CACHE
@@ -916,15 +916,15 @@ INT32 los_disk_write(INT32 drvID, const VOID *buf, UINT64 sector, UINT32 count)
             goto ERROR_HANDLE;
         }
         len = disk->bcache->sectorSize * count;
-        result = BlockCacheWrite(disk->bcache, (const UINT8 *)buf, &len, sector);
+        result = BlockCacheWrite(disk->bcache, (const UINT8 *)buf, &len, sector);//写入缓存,后续由缓存同步至磁盘
         if (result != ENOERR) {
             PRINT_ERR("los_disk_write write err = %d, sector = %llu, len = %u\n", result, sector, len);
         }
     } else {
-#endif
+#endif//无缓存情况下获取操作块实现函数指针结构体
     struct block_operations *bops = (struct block_operations *)((struct drv_data *)disk->dev->data)->ops;
     if ((disk->dev != NULL) && (bops != NULL) && (bops->write != NULL)) {
-        result = bops->write(disk->dev, (UINT8 *)buf, sector, count);
+        result = bops->write(disk->dev, (UINT8 *)buf, sector, count);//真正的写磁盘
         if (result == (INT32)count) {
             result = ENOERR;
         }
@@ -997,10 +997,10 @@ ERROR_HANDLE:
     DISK_UNLOCK(&disk->disk_mutex);
     return VFS_ERROR;
 }
-
+//读分区上扇区内容
 INT32 los_part_read(INT32 pt, VOID *buf, UINT64 sector, UINT32 count, BOOL useRead)
 {
-    const los_part *part = get_part(pt);
+    const los_part *part = get_part(pt);//先拿到分区信息
     los_disk *disk = NULL;
     INT32 ret;
 
@@ -1008,24 +1008,24 @@ INT32 los_part_read(INT32 pt, VOID *buf, UINT64 sector, UINT32 count, BOOL useRe
         return VFS_ERROR;
     }
 
-    disk = get_disk((INT32)part->disk_id);
+    disk = get_disk((INT32)part->disk_id);//再拿到磁盘信息
     if (disk == NULL) {
         return VFS_ERROR;
     }
 
-    DISK_LOCK(&disk->disk_mutex);
+    DISK_LOCK(&disk->disk_mutex);//锁磁盘
     if ((part->dev == NULL) || (disk->disk_status != STAT_INUSED)) {
         goto ERROR_HANDLE;
     }
 
-    if (count > part->sector_count) {
+    if (count > part->sector_count) {//不能超过分区总扇区数量
         PRINT_ERR("los_part_read failed, invaild count, count = %u\n", count);
         goto ERROR_HANDLE;
     }
 
     /* Read from absolute sector. */
-    if (part->type == EMMC) {
-        if ((disk->sector_count - part->sector_start) > sector) {
+    if (part->type == EMMC) {//如果分区类型是磁盘介质
+        if ((disk->sector_count - part->sector_start) > sector) {//从绝对扇区读取
             sector += part->sector_start;
         } else {
             PRINT_ERR("los_part_read failed, invaild sector, sector = %llu\n", sector);
@@ -1033,13 +1033,13 @@ INT32 los_part_read(INT32 pt, VOID *buf, UINT64 sector, UINT32 count, BOOL useRe
         }
     }
 
-    if ((sector >= GetFirstPartStart(part)) &&
+    if ((sector >= GetFirstPartStart(part)) &&	//扇区范围判断
         (((sector + count) > (part->sector_start + part->sector_count)) || (sector < part->sector_start))) {
         PRINT_ERR("los_part_read error, sector = %llu, count = %u, part->sector_start = %llu, "
                   "part->sector_count = %llu\n", sector, count, part->sector_start, part->sector_count);
         goto ERROR_HANDLE;
     }
-
+	//读取大量连续数据时，useRead 应为 FALSE
     /* useRead should be FALSE when reading large contiguous data */
     ret = los_disk_read((INT32)part->disk_id, buf, sector, count, useRead);
     if (ret < 0) {
@@ -1053,7 +1053,7 @@ ERROR_HANDLE:
     DISK_UNLOCK(&disk->disk_mutex);
     return VFS_ERROR;
 }
-
+//将数据写入指定分区的指定扇区
 INT32 los_part_write(INT32 pt, const VOID *buf, UINT64 sector, UINT32 count)
 {
     const los_part *part = get_part(pt);
@@ -1095,8 +1095,8 @@ INT32 los_part_write(INT32 pt, const VOID *buf, UINT64 sector, UINT32 count)
                   "part->sector_count = %llu\n", sector, count, part->sector_start, part->sector_count);
         goto ERROR_HANDLE;
     }
-
-    ret = los_disk_write((INT32)part->disk_id, buf, sector, count);
+	//sector已变成磁盘绝对扇区
+    ret = los_disk_write((INT32)part->disk_id, buf, sector, count);//直接写入磁盘,
     if (ret < 0) {
         goto ERROR_HANDLE;
     }

fs/vfs/multi_partition/src/mtd_partition.c

@@ -384,6 +384,13 @@ static INT32 CharDriverUnregister(mtd_partition *node)
  * Attention: both startAddr and length should be aligned with block size.
  * If not, the actual start address and length won't be what you expected.
  *///注意：startAddr 和length 都应该与block size 对齐。如果不是，实际的起始地址和长度将不是你所期望的
+ /*
+add_mtd_partition函数有四个参数，
+	第一个参数表示介质，有“nand”和“spinor”两种，JFFS2分区在“spinor”上使用，而“nand”是提供给YAFFS2使用的。
+	第二个参数表示起始地址，
+	第三个参数表示分区大小，这两个参数都以16进制的形式传入。
+	最后一个参数表示分区号，有效值为0~19
+ */
 INT32 add_mtd_partition(const CHAR *type, UINT32 startAddr,
                         UINT32 length, UINT32 partitionNum)
 {
@@ -428,7 +435,7 @@ INT32 add_mtd_partition(const CHAR *type, UINT32 startAddr,
         goto ERROR_OUT2;
     }
 
-    LOS_ListTailInsert(&param->partition_head->node_info, &newNode->node_info);//挂到全局链表上
+    LOS_ListTailInsert(&param->partition_head->node_info, &newNode->node_info);//挂到全局分区链表上
     (VOID)LOS_MuxInit(&newNode->lock, NULL);//初始化锁,每个分区节点都有自己的互斥锁
 
     ret = pthread_mutex_unlock(&g_mtdPartitionLock);

fs/vfs/operation/fs_readv.c

@@ -87,7 +87,7 @@ static char *pread_buf_and_check(int fd, const struct iovec *iov, int iovcnt, ss
 
     return buf;
 }
-
+//供系统调用
 ssize_t vfs_readv(int fd, const struct iovec *iov, int iovcnt, off_t *offset)
 {
     int i;

fs/vfs/operation/fullpath.c

@@ -214,14 +214,14 @@ static char *vfs_normalize_fullpath(const char *directory, const char *filename,
 {
     char *fullpath = NULL;
 
-    if (filename[0] != '/') {
+    if (filename[0] != '/') {//不是绝对路径
         /* not a absolute path */
 
         fullpath = vfs_not_absolute_path(directory, filename, pathname, namelen);
         if (fullpath == NULL) {
             return (char *)NULL;
         }
-    } else {
+    } else {//如果是绝对路径
         /* it's a absolute path, use it directly */
 
         fullpath = strdup(filename); /* copy string */
@@ -241,7 +241,7 @@ static char *vfs_normalize_fullpath(const char *directory, const char *filename,
 
     return fullpath;
 }
-//虚拟文件系统 | 标准化路径
+//虚拟文件系统 | 获取文件绝对路径
 int vfs_normalize_path(const char *directory, const char *filename, char **pathname)
 {
     char *fullpath = NULL;

fs/vfs/vfs_cmd/vfs_shellcmd.c

@@ -738,7 +738,7 @@ int osShellCmdTouch(int argc, const char **argv)
   filename = argv[0];
   ret = vfs_normalize_path(shell_working_directory, filename, &fullpath);
   ERROR_OUT_IF(ret < 0, set_err(-ret, "touch error"), return -1);
-
+  //如果没有就创建文件方式 
   fd = open(fullpath, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
   free(fullpath);
   if (fd == -1)

kernel/base/include/los_vm_map.h

@@ -114,7 +114,7 @@ struct VmMapRegion {//线性区描述符,内核通过线性区管理虚拟地址
     UINT8               forkFlags;      /**< vm space fork flags: COPY, ZERO, */	//fork的方式
     UINT8               regionType;     /**< vm region type: ANON, FILE, DEV */	//映射类型是匿名,文件,还是设备,所谓匿名可理解为内存映射
     union {
-        struct VmRegionFile {//
+        struct VmRegionFile {//文件映射
             unsigned int fileMagic;//具有特殊文件格式的文件,魔法数字.例如 stack top 的魔法数字为 0xCCCCCCCC
             struct file *file;		//文件指针
             const LosVmFileOps *vmFOps;//文件处理各操作接口
@@ -122,7 +122,7 @@ struct VmMapRegion {//线性区描述符,内核通过线性区管理虚拟地址
         struct VmRegionAnon {//匿名映射可理解为就是物理内存
             LOS_DL_LIST  node;          /**< region LosVmPage list */ 	//线性区虚拟页链表
         } ra;
-        struct VmRegionDev {
+        struct VmRegionDev {//设备映射
             LOS_DL_LIST  node;          /**< region LosVmPage list */	//线性区虚拟页链表
             const LosVmFileOps *vmFOps; //设备也是一种文件
         } rd;
@@ -238,7 +238,7 @@ STATIC INLINE VOID LOS_SetRegionTypeFile(LosVmMapRegion* region)
 {
     region->regionType = VM_MAP_REGION_TYPE_FILE;
 }
-//是否为设备映射线性区
+//是否为设备映射线性区 /dev/...
 STATIC INLINE BOOL LOS_IsRegionTypeDev(LosVmMapRegion* region)
 {
     return region->regionType == VM_MAP_REGION_TYPE_DEV;

kernel/base/vm/los_vm_filemap.c

@@ -488,14 +488,14 @@ VOID OsFileCacheRemove(struct page_mapping *mapping)
         OsDoFlushDirtyPage(fpage);//遍历脏页链表,一页一页处理
     }
 }
-
+//虚拟内存文件操作实现类
 LosVmFileOps g_commVmOps = {//
     .open = NULL,
     .close = NULL,
     .fault = OsVmmFileFault, //缺页中断处理
     .remove = OsVmmFileRemove,//删除页
 };
-
+//文件映射
 INT32 OsVfsFileMmap(struct file *filep, LosVmMapRegion *region)
 {
     region->unTypeData.rf.vmFOps = &g_commVmOps;//文件操作
@@ -504,7 +504,7 @@ INT32 OsVfsFileMmap(struct file *filep, LosVmMapRegion *region)
     return ENOERR;
 }
 /******************************************************************************
- 有名映射,跟匿名映射相对应
+ 有名映射,可理解为文件映射,跟匿名映射相对应
  参数filep是广义的文件,在鸿蒙内核,目录/普通文件/字符设备/块设备/网络套接字/管道/链接 都是文件
 ******************************************************************************/
 STATUS_T OsNamedMMap(struct file *filep, LosVmMapRegion *region)
@@ -519,10 +519,10 @@ STATUS_T OsNamedMMap(struct file *filep, LosVmMapRegion *region)
     }
 
     if (filep->ops != NULL && filep->ops->mmap != NULL) {
-        if (vnode->type == VNODE_TYPE_CHR || vnode->type == VNODE_TYPE_BLK) {
-            LOS_SetRegionTypeDev(region);
+        if (vnode->type == VNODE_TYPE_CHR || vnode->type == VNODE_TYPE_BLK) {//块设备或者字符设备 /dev/..
+            LOS_SetRegionTypeDev(region);//设置为设备类型 
         } else {
-            LOS_SetRegionTypeFile(region);
+            LOS_SetRegionTypeFile(region);//设置为文件类型
         }
         int ret = filep->ops->mmap(filep, region);
         if (ret != LOS_OK) {

kernel/base/vm/los_vm_map.c

@@ -715,14 +715,14 @@ STATIC LosVmMapRegion *OsVmRegionSplit(LosVmMapRegion *oldRegion, VADDR_T newReg
 #endif
     return newRegion;
 }
-
+//对线性区进行调整
 STATUS_T OsVmRegionAdjust(LosVmSpace *space, VADDR_T newRegionStart, size_t size)
 {
     LosVmMapRegion *region = NULL;
     VADDR_T nextRegionBase = newRegionStart + size;
     LosVmMapRegion *newRegion = NULL;
 
-    region = LOS_RegionFind(space, newRegionStart);
+    region = LOS_RegionFind(space, newRegionStart);//先找到线性区
     if ((region != NULL) && (newRegionStart > region->range.base)) {
         newRegion = OsVmRegionSplit(region, newRegionStart);
         if (newRegion == NULL) {

kernel/base/vm/los_vm_syscall.c

@@ -306,7 +306,7 @@ int LOS_DoMprotect(VADDR_T vaddr, size_t len, unsigned long prot)
     int ret;
 
     (VOID)LOS_MuxAcquire(&space->regionMux);
-    region = LOS_RegionFind(space, vaddr);
+    region = LOS_RegionFind(space, vaddr);//通过虚拟地址找到线性区
     if (!IS_ALIGNED(vaddr, PAGE_SIZE) || (region == NULL) || (vaddr > vaddr + len)) {
         ret = -EINVAL;
         goto OUT_MPROTECT;
@@ -316,12 +316,12 @@ int LOS_DoMprotect(VADDR_T vaddr, size_t len, unsigned long prot)
         ret = -EINVAL;
         goto OUT_MPROTECT;
     }
-
+	//如果是堆区或VDSO区,说明区内容是不能修改的
     if ((region->regionFlags & VM_MAP_REGION_FLAG_VDSO) || (region->regionFlags & VM_MAP_REGION_FLAG_HEAP)) {
         ret = -EPERM;
         goto OUT_MPROTECT;
     }
-
+	//如果是共享文件,说明内容也不能修改
     if (LOS_IsRegionTypeFile(region) && (region->regionFlags & VM_MAP_REGION_FLAG_SHARED)) {
         if (!OsProtMprotectPermCheck(prot, region)) {
             ret = -EACCES;
@@ -330,14 +330,14 @@ int LOS_DoMprotect(VADDR_T vaddr, size_t len, unsigned long prot)
     }
     len = LOS_Align(len, PAGE_SIZE);
     /* can't operation cross region */
-    if (region->range.base + region->range.size < vaddr + len) {
+    if (region->range.base + region->range.size < vaddr + len) {//判断范围,不能跨区域操作
         ret = -EINVAL;
         goto OUT_MPROTECT;
     }
 
     /* if only move some part of region, we need to split first */
-    if (region->range.size > len) {
-        OsVmRegionAdjust(space, vaddr, len);
+    if (region->range.size > len) {//如果只修改部分区域，我们需要先拆分区
+        OsVmRegionAdjust(space, vaddr, len);//调整下线性区范围
     }
 
     vmFlags = OsCvtProtFlagsToRegionFlags(prot, 0);//转换FLAGS

kernel/common/console.c

@@ -1088,7 +1088,7 @@ STATIC INT32 OsConsoleFileInit(CONSOLE_CB *consoleCB)
         goto ERROUT_WITH_FULLPATH;
     }
     filep->f_path = fullpath;
-    filep->ops = (struct file_operations_vfs *)((struct drv_data *)vnode->data)->ops;//关系驱动程序
+    filep->ops = (struct file_operations_vfs *)((struct drv_data *)vnode->data)->ops;//关联驱动程序
     VnodeDrop();
     return LOS_OK;
 

kernel/common/console.h

@@ -70,7 +70,7 @@ TTY 是 Teletype 或 Teletypewriter 的缩写，字符设备的通称,原来是
 /dev/console是一个虚拟的tty，在鸿蒙它映射到真正的dev/ttyS0(UART0)上
 能直接显示系统消息的那个终端称为控制台，其他的则称为终端
 **********************************************************/
-#define CONSOLE  "/dev/console"
+#define CONSOLE  "/dev/console"	
 #define CONSOLE_NAMELEN 16
 #define CONSOLE_RD_BLOCK               1
 #define CONSOLE_RD_NONBLOCK            0

kernel/extended/trace/los_trace.c

@@ -511,4 +511,4 @@ SHELLCMD_ENTRY(trace_shellcmd, CMD_TYPE_EX, "trace", 1, (CmdCallBackFunc)OsShell
 
 #endif
 
-LOS_MODULE_INIT(OsTraceInit, LOS_INIT_LEVEL_EARLIEST);
+LOS_MODULE_INIT(OsTraceInit, LOS_INIT_LEVEL_EARLIEST);//跟踪初始化

shell/full/src/base/shell_lk.c

@@ -41,6 +41,7 @@
 #include "los_init.h"
 #include "los_printf_pri.h"
 
+//LK 注者的理解是 log kernel(内核日志)
 #ifdef LOSCFG_SHELL_LK
 
 typedef enum {//模块等级
@@ -201,7 +202,7 @@ STATIC INLINE VOID OsLogCycleRecord(INT32 level)//日志循环记录
     }
 }
 #endif
-//默认打印函数,用于回调函数
+//内核打印函数,在LOS_LkPrint中回调
 VOID OsLkDefaultFunc(INT32 level, const CHAR *func, INT32 line, const CHAR *fmt, va_list ap)
 {
     if (level > OsLkTraceLvGet()) {
@@ -238,7 +239,7 @@ UINT32 OsLkLoggerInit(VOID)
 {
     (VOID)memset_s(&g_logger, sizeof(Logger), 0, sizeof(Logger));
     OsLkTraceLvSet(TRACE_DEFAULT);
-    LOS_LkRegHook(OsLkDefaultFunc);
+    LOS_LkRegHook(OsLkDefaultFunc);//注册钩子函数,将在 LOS_LkPrint中回调钩子
 #ifdef LOSCFG_SHELL_DMESG
     (VOID)LOS_DmesgLvSet(TRACE_DEFAULT);
 #endif

syscall/fs_syscall.c

@@ -1320,7 +1320,7 @@ int SysFsync(int fd)
     }
     return ret;
 }
-//从文件读入数据到缓冲数组中
+//通过FD读入数据到缓冲数组中,fd为进程描述符
 ssize_t SysReadv(int fd, const struct iovec *iov, int iovcnt)
 {
     int ret;
@@ -1328,7 +1328,7 @@ ssize_t SysReadv(int fd, const struct iovec *iov, int iovcnt)
     struct iovec *iovRet = NULL;
 
     /* Process fd convert to system global fd */
-    fd = GetAssociatedSystemFd(fd);
+    fd = GetAssociatedSystemFd(fd);//进程FD转成系统FD
     if ((iov == NULL) || (iovcnt <= 0) || (iovcnt > IOV_MAX)) {
         ret = vfs_readv(fd, iov, iovcnt, NULL);
         return -get_errno();

zzz/git/push.sh

 git add -A
-git commit -m  '对 vdso 实现注解 
+git commit -m  '对mtd,disk,filemap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.21cloudbox.com
     国外:https://weharmony.github.io