// Write 'n' bytes from 'buf' to 'fd' at the current seek position.
static ssize_t
file_write(struct Fd *fd, const void *buf, size_t n, off_t offset)
{
int r;
size_t tot;
// don't write past the maximum file size
tot = offset + n;
if (tot > MAXFILESIZE)
return -E_NO_DISK;
// increase the file's size if necessary
if (tot > fd->fd_file.file.f_size) {
if ((r = file_trunc(fd, tot)) < 0)
return r;
}
// write the data
memcpy(fd2data(fd) + offset, buf, n);
return n;
}
static void* file_open(void* obj, char* path, s64 flag, s64 mode)
{
assert(IS_PTR(obj));
fatfile_t* file = (fatfile_t*)obj;
down(&file->sem);
if(*path == NULL) // last name in path
{
file->ref ++;
if((!file->attr.directory) && (flag & O_TRUNC))
file_trunc(file);
up_one(&file->sem);
return file;
}
if(!file->attr.directory) // 路径中的名称必须是目录
{
up_one(&file->sem);
return (void*)-1;
}
char filename[32];
char* end = strchr(path, '/');
strncpy(filename, path, end -path);
UpperStr(filename);
if(*end == '/') // skip '/'
end ++;
// find in child list
fatfile_t* child = findChild(file, filename);
if(child == NULL)
{
child = (fatfile_t*)kmalloc(sizeof(fatfile_t));
memset(child, 0, sizeof(fatfile_t));
child->ops = &file_ops;
sem_init(&child->sem, 1, "file sem");
child->fatfs = file->fatfs;
child->name = strdup(filename);
struct FAT_ENTRY entry;
int index = findEntryByName(file, filename, &entry);
if(index >= 0)
{
child->index = index;
child->cluster = (entry.start_clusterHI << 16) | entry.start_clusterLO;
child->size = entry.file_size;
child->attr = entry.attribute;
getEntryCreateDate(child, &entry);
getEntryWriteDate(child, &entry);
}
else
{
if((flag &O_CREAT) && (*end == NULL))
{
rtcdate rtc;
cmostime(&rtc);
child->cdatetime = rtc;
child->wdatetime = rtc;
child->dirty = TRUE; // update entry
}
else
{
kmfree(child->name);
kmfree(child);
up_one(&file->sem);
return (void*)-2;
}
}
insertChild(file, child);
}
up_one(&file->sem);
return file_open(child, end, flag, mode);
}
