对文件系统 磁盘,分区描述符的注释

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fs/include/disk.h

@@ -191,9 +191,9 @@ typedef struct _los_disk_ {	//磁盘描述符
 
 typedef struct _los_part_ {//分区描述符
     UINT32 disk_id : 8;      /* physics disk number */	//标识磁盘ID
-    UINT32 part_id : 8;      /* partition number in the system */ //标识整个系统的分区ID
-    UINT32 part_no_disk : 8; /* partition number in the disk */	  //标识所属磁盘的分区ID
-    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ID	
+    UINT32 part_id : 8;      /* partition number in the system */ //标识整个系统的分区数量
+    UINT32 part_no_disk : 8; /* partition number in the disk */	  //标识所属磁盘的分区数量
+    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

fs/vfs/disk/disk.c

@@ -242,27 +242,27 @@ static UINT64 GetFirstPartStart(const los_part *part)
     firstPart = (disk == NULL) ? NULL : LOS_DL_LIST_ENTRY(disk->head.pstNext, los_part, list);
     return (firstPart == NULL) ? 0 : firstPart->sector_start;
 }
-
+//磁盘增加一个分区
 static VOID DiskPartAddToDisk(los_disk *disk, los_part *part)
 {
-    part->disk_id = disk->disk_id;
-    part->part_no_disk = disk->part_count;
-    LOS_ListTailInsert(&disk->head, &part->list);
-    disk->part_count++;
+    part->disk_id = disk->disk_id;//分区描述符记录磁盘ID
+    part->part_no_disk = disk->part_count;//分区数量
+    LOS_ListTailInsert(&disk->head, &part->list);//将分区结点挂入磁盘分区双链表
+    disk->part_count++;//磁盘分区数量增加
 }
-
+//删除磁盘分区
 static VOID DiskPartDelFromDisk(los_disk *disk, los_part *part)
 {
-    LOS_ListDelete(&part->list);
-    disk->part_count--;
+    LOS_ListDelete(&part->list);//从链表上摘掉分区结点
+    disk->part_count--;//磁盘分区数量减少
 }
-
+//设置分区信息
 static los_part *DiskPartAllocate(struct inode *dev, UINT64 start, UINT64 count)
 {
     UINT32 i;
     los_part *part = get_part(0); /* traversing from the beginning of the array */
 
-    for (i = 0; i < SYS_MAX_PART; i++) {
+    for (i = 0; i < SYS_MAX_PART; i++) {//从数组开始遍历
         if (part->dev == NULL) {
             part->part_id = i;
             part->part_no_mbr = 0;
@@ -279,7 +279,7 @@ static los_part *DiskPartAllocate(struct inode *dev, UINT64 start, UINT64 count)
 
     return NULL;
 }
-
+//清空分区信息
 static VOID DiskPartRelease(los_part *part)
 {
     part->dev = NULL;
@@ -297,8 +297,8 @@ static VOID DiskPartRelease(los_part *part)
  * 'p' : 1
  * part_count: 1
  */
-#define DEV_NAME_BUFF_SIZE  (DISK_NAME + 3)
-
+#define DEV_NAME_BUFF_SIZE  (DISK_NAME + 3)//为何加3, 就是上面的disk_name+p+part_count
+//磁盘增加一个分区
 static INT32 DiskAddPart(los_disk *disk, UINT64 sectorStart, UINT64 sectorCount)
 {
     CHAR devName[DEV_NAME_BUFF_SIZE];
@@ -312,12 +312,12 @@ static INT32 DiskAddPart(los_disk *disk, UINT64 sectorStart, UINT64 sectorCount)
         (disk->dev == NULL)) {
         return VFS_ERROR;
     }
-
+	//扇区判断,磁盘在创建伊始就扇区数量就固定了
     if ((sectorCount > disk->sector_count) || ((disk->sector_count - sectorCount) < sectorStart)) {
         PRINT_ERR("DiskAddPart failed: sector start is %llu, sector count is %llu\n", sectorStart, sectorCount);
         return VFS_ERROR;
     }
-
+	///devName = /dev/mmcblk0p2 代表的是 0号磁盘的2号分区
     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) {
@@ -325,12 +325,12 @@ static INT32 DiskAddPart(los_disk *disk, UINT64 sectorStart, UINT64 sectorCount)
     }
 
     diskDev = disk->dev;
-    if (register_blockdriver(devName, diskDev->u.i_bops, RWE_RW_RW, diskDev->i_private)) {
+    if (register_blockdriver(devName, diskDev->u.i_bops, RWE_RW_RW, diskDev->i_private)) {//注册块驱动程序
         PRINT_ERR("DiskAddPart : register %s fail!\n", devName);
         return VFS_ERROR;
     }
 
-    SETUP_SEARCH(&desc, devName, false);
+    SETUP_SEARCH(&desc, devName, false);//
     ret = inode_find(&desc);
     if (ret < 0) {
         PRINT_ERR("DiskAddPart : find %s fail!\n", devName);