int yaffs_read(int fd, void *buf, unsigned int nbyte)
{
yaffsfs_Handle *h = NULL;
yaffs_Object *obj = NULL;
int pos = 0;
int nRead = -1;
int maxRead;
yaffsfs_Lock();
h = yaffsfs_GetHandlePointer(fd);
obj = yaffsfs_GetHandleObject(fd);
if(!h || !obj)
{
// bad handle
yaffsfs_SetError(-EBADF);
}
else if( h && obj)
{
pos= h->position;
if(yaffs_GetObjectFileLength(obj) > pos)
{
maxRead = yaffs_GetObjectFileLength(obj) - pos;
}
else
{
maxRead = 0;
}
if(nbyte > maxRead)
{
nbyte = maxRead;
}
if(nbyte > 0)
{
nRead = yaffs_ReadDataFromFile(obj,buf,pos,nbyte);
if(nRead >= 0)
{
h->position = pos + nRead;
}
else
{
//todo error
}
}
else
{
nRead = 0;
}
}
yaffsfs_Unlock();
return (nRead >= 0) ? nRead : -1;
}
static int yaffs_readpage_nolock(struct file *f, struct page *pg)
{
yaffs_Object *obj;
unsigned char *pg_buf;
int ret;
yaffs_Device *dev;
T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_readpage at %08x, size %08x\n",
(unsigned)(pg->index << PAGE_CACHE_SHIFT),
(unsigned)PAGE_CACHE_SIZE));
obj = yaffs_DentryToObject(f->f_dentry);
dev = obj->myDev;
#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,5,0))
BUG_ON(!PageLocked(pg));
#else
if (!PageLocked(pg))
PAGE_BUG(pg);
#endif
pg_buf = kmap(pg);
yaffs_GrossLock(dev);
ret =
yaffs_ReadDataFromFile(obj, pg_buf, pg->index << PAGE_CACHE_SHIFT,
PAGE_CACHE_SIZE);
yaffs_GrossUnlock(dev);
if (ret >= 0)
ret = 0;
if (ret) {
ClearPageUptodate(pg);
SetPageError(pg);
} else {
SetPageUptodate(pg);
ClearPageError(pg);
}
flush_dcache_page(pg);
kunmap(pg);
T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_readpage done\n"));
return ret;
}
