山大操作系统课程设计报告（全套）(9)

} }

delete [] data; /*revised*/ } bool

FileHeader::AppSectors(BitMap *freeMap, int appFileSize) {

/*revised*/

if(appFileSize <= 0)return false;

int restFileSize = SectorSize * numSectors - numBytes;

if(restFileSize >= appFileSize) {

numBytes += appFileSize; return true; } else {

int moreFileSize = appFileSize - restFileSize;

if(freeMap->NumClear()< divRoundUp(moreFileSize, SectorSize)) return FALSE;

else if(NumDirect + NumDirect2 <= numSectors + divRoundUp(moreFileSize, SectorSize)) return FALSE;

int i = numSectors;

numBytes += appFileSize;

numSectors += divRoundUp(moreFileSize, SectorSize);

/*toNextNode 是保留第二个索引节点的扇区号*/

int toNextNode = NumDirect-1; //test if has the second node if(dataSectors[toNextNode] == -1) {

//test if need the second node if(numSectors < toNextNode) for( ; i < numSectors; i++)

dataSectors[i] = freeMap -> Find();

//need the second node else {

for( ; i< toNextNode ; i++)

dataSectors[i]= freeMap ->Find();

dataSectors[toNextNode] = freeMap ->Find(); int dataSectors2[NumDirect2]; for ( ; i < numSectors ; i++)

dataSectors2[i - toNextNode] = freeMap->Find();

synchDisk->WriteSector(dataSectors[toNextNode], (char *)dataSectors2); } } /*

* If before appending, there is already a secondary index */

//First read the dataSectors2 from the Disk. //Then, append the file size.

//At last, write back the secondary index block into the sector, else {

int dataSectors2[NumDirect2];

synchDisk->ReadSector(dataSectors[toNextNode], (char *)dataSectors2); for( ; i < numSectors; i++)

dataSectors2[i-toNextNode] = freeMap -> Find();//the var toNextNode==the number of int that synchDisk->WriteSector(dataSectors[toNextNode], (char *)dataSectors2);//the fefault synchDisk } }

return TRUE; /*revised*/ }

运行结果：首先运行命令 ./nachos –f 格式化Nachos磁盘

然后运行 ./nachos –ap test/big big 若干次，知道出现提示，文件太大不能再追究为止。 start value: 1168, amountRead 10, result of write: 10 start value: 1178, amountRead 10, result of write: 10 start value: 1188, amountRead 10, result of write: 10 start value: 1198, amountRead 10, result of write: 10 start value: 1208, amountRead 8, result of write: 8 inodes have been written back

No threads ready or runnable, and no pending interrupts. Assuming the program completed.

Machine halting!

Ticks: total 1091100, idle 1086750, system 4350, user 0 Disk I/O: reads 76, writes 68 Console I/O: reads 0, writes 0 Paging: faults 0

Network I/O: packets received 0, sent 0

Cleaning up...

lu@ubuntu:~/csc2404/nachos-3.4/code/filesys2nodehdr$ ./nachos -ap test/big big The appending file is too big! Appending file failed

No threads ready or runnable, and no pending interrupts. Assuming the program completed. Machine halting!

Ticks: total 4200, idle 3970, system 230, user 0 Disk I/O: reads 7, writes 0 Console I/O: reads 0, writes 0 Paging: faults 0

Network I/O: packets received 0, sent 0

Cleaning up...

然后运行 ./nachos -ap test/small big ，直到可以出现The appending file is too big!

lu@ubuntu:~/csc2404/nachos-3.4/code/filesys2nodehdr$ ./nachos -ap test/small big openFile see filesize 7790 value of start 38

start value: 38, amountRead 10, result of write: 10 start value: 48, amountRead 10, result of write: 10 start value: 58, amountRead 10, result of write: 10 start value: 68, amountRead 8, result of write: 8 inodes have been written back

No threads ready or runnable, and no pending interrupts. Assuming the program completed. Machine halting!

Ticks: total 83100, idle 82470, system 630, user 0 Disk I/O: reads 14, writes 6 Console I/O: reads 0, writes 0 Paging: faults 0

Network I/O: packets received 0, sent 0

Cleaning up...

lu@ubuntu:~/csc2404/nachos-3.4/code/filesys2nodehdr$ ./nachos -ap test/small big The appending file is too big! Appending file failed

No threads ready or runnable, and no pending interrupts. Assuming the program completed. Machine halting!

Ticks: total 4200, idle 3970, system 230, user 0 Disk I/O: reads 7, writes 0 Console I/O: reads 0, writes 0 Paging: faults 0

Network I/O: packets received 0, sent 0

Cleaning up...

然后显示结果，运行命令 ./nachos –D

lu@ubuntu:~/csc2404/nachos-3.4/code/filesys2nodehdr$ ./nachos -D Bit map file header:

FileHeader contents. File size: 128. File blocks: 2

File contents:

\\ff\\ff\\ff\\ff\\ff\\ff\\ff\\ff\\f\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\\\0\\0

Directory file header:

FileHeader contents. File size: 200. File blocks: 3 4

File contents:

\\1\\0\\0\\0\\5\\0\\0\\0big\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\0\\Bitmap set:

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, Directory contents: Name: big, Sector: 5 …… 此处隐藏：2614字，全部文档内容请下载后查看。喜欢就下载吧 ……