/*
* sync everything. Start out by waking pdflush, because that writes back
* all queues in parallel.
*/
static void do_sync(unsigned long wait)
{
wakeup_pdflush(0);
sync_inodes(0); /* All mappings, inodes and their blockdevs */
DQUOT_SYNC(NULL);
sync_supers(); /* Write the superblocks */
sync_filesystems(0); /* Start syncing the filesystems */
sync_filesystems(wait); /* Waitingly sync the filesystems */
sync_inodes(wait); /* Mappings, inodes and blockdevs, again. */
if (!wait)
printk("Emergency Sync complete\n");
if (unlikely(laptop_mode))
laptop_sync_completion();
}
//// 对指定设备进行高速缓冲数据与设备上数据的同步操作。
int
sync_dev( int dev )
{
int i;
struct buffer_head *bh;
bh = start_buffer;
for( i = 0; i < NR_BUFFERS; i++, bh++ )
{
if( bh->b_dev != dev )
{
continue;
}
wait_on_buffer( bh );
if( bh->b_dev == dev && bh->b_dirt )
{
ll_rw_block( WRITE, bh );
}
}
sync_inodes( ); // 将i 节点数据写入高速缓冲。
bh = start_buffer;
for( i = 0; i < NR_BUFFERS; i++, bh++ )
{
if( bh->b_dev != dev )
{
continue;
}
wait_on_buffer( bh );
if( bh->b_dev == dev && bh->b_dirt )
{
ll_rw_block( WRITE, bh );
}
}
return 0;
}
int sync_dev(int dev)
{
sync_buffers(dev);
sync_inodes();
sync_buffers(dev);
return 0;
}
void sync_dev(kdev_t dev)
{
sync_buffers(dev, 0);
sync_supers(dev);
sync_inodes(dev);
sync_buffers(dev, 0);
}
int fsync_dev(dev_t dev)
{
sync_buffers(dev, 0);
sync_supers(dev);
sync_inodes(dev);
return sync_buffers(dev, 1);
}
/*
* struct fs32_flushbuf_parms {
* unsigned short flag;
* unsigned short hVPB;
* };
*/
int FS32ENTRY fs32_flushbuf(struct fs32_flushbuf_parms *parms)
{
int rc;
struct super_block *sb;
if (trace_FS_FLUSHBUF)
{
kernel_printf("FS_FLUSHBUF - flag = %d, hVPB = 0x%0X", (int)(parms->flag), (int)(parms->hVPB));
}
if (Read_Write)
{
sb = getvolume(parms->hVPB);
if ((sb) && (sb->s_magic_internal == SUPER_MAGIC))
{
if (sb->s_status == VOL_STATUS_MOUNTED)
{
kernel_printf("\tmedia is present");
switch (parms->flag)
{
case FLUSH_RETAIN:
case FLUSH_DISCARD:
sync_buffers(sb->s_dev, 1);
if ((sb->s_op) && (sb->s_op->write_super))
sb->s_op->write_super(sb);
sync_inodes(sb->s_dev);
sync_buffers(sb->s_dev, 1);
rc = NO_ERROR;
break;
default:
rc = ERROR_INVALID_PARAMETER;
break;
}
}
else
{
rc = NO_ERROR;
}
}
else
{
rc = ERROR_INVALID_PARAMETER;
}
}
else
{
rc = NO_ERROR;
}
if (trace_FS_FLUSHBUF)
{
kernel_printf("FS_FLUSHBUF - flag = %d, hVPB = 0x%0X, rc = %d", (int)(parms->flag), (int)(parms->hVPB), rc);
}
return rc;
}
int sync_dev(int dev)
{
struct super_block * sb;
if (sb = get_super (dev))
if (sb->s_op && sb->s_op->write_super && sb->s_dirt)
sb->s_op->write_super (sb);
sync_buffers(dev);
sync_inodes();
sync_buffers(dev);
return 0;
}
int sys_sync(void)
{
int i;
struct buffer_head * bh;
sync_inodes(); /* write out inodes into buffers */
bh = start_buffer;
for (i=0 ; i<NR_BUFFERS ; i++,bh++) {
wait_on_buffer(bh);
if (bh->b_dirt)
ll_rw_block(WRITE,bh);
}
return 0;
}
int sys_sync(void)
{
int i;
for (i=0 ; i<NR_SUPER ; i++)
if (super_block[i].s_dev
&& super_block[i].s_op
&& super_block[i].s_op->write_super
&& super_block[i].s_dirt)
super_block[i].s_op->write_super(&super_block[i]);
sync_inodes(); /* write out inodes into buffers */
sync_buffers(0);
return 0;
}
//// 系统调用。同步设备和内存高速缓冲中数据。
int sys_sync(void)//passed
{
int i;
struct buffer_head * bh;
sync_inodes(); /* 将i 节点写入高速缓冲 */
// 扫描所有高速缓冲区，对于已被修改的缓冲块产生写盘请求，将缓冲中数据与设备中同步。
bh = start_buffer;
for (i=0 ; i<NR_BUFFERS ; i++,bh++) {
wait_on_buffer(bh); // 等待缓冲区解锁（如果已上锁的话）。
if (bh->b_dirt)
ll_rw_block(WRITE,bh); // 产生写设备块请求。
}
return 0;
}
//同步设备和内存高速缓冲中的数据， sync_inodes()定义在inode.c中
int sys_sync(void)
{
int i;
struct buffer_head * bh;
//首先调用i节点同步函数，把内存i节点表中所有修改过的i节点写入高速缓冲中。然后扫描所有高速
//缓冲区，对已被修改的缓冲块产生写盘请求，将缓冲中数据写入盘中，做到高速缓冲中的数据与设备
//中的同步。
sync_inodes(); /* write out inodes into buffers */
bh = start_buffer;
for (i=0 ; i<NR_BUFFERS ; i++,bh++) {
wait_on_buffer(bh);
if (bh->b_dirt)
ll_rw_block(WRITE,bh);
}
return 0;
}
int sys_sync(void)
{
sync_inodes(); /* write out inodes into buffers */
sync_buffers(0);
return 0;
}
