static int memfs_seek(struct fnode *fno, int off, int whence)
{
struct memfs_fnode *mfno;
int new_off;
mfno = FNO_MOD_PRIV(fno, &mod_memfs);
if (!mfno)
return -1;
switch(whence) {
case SEEK_CUR:
new_off = fno->off + off;
break;
case SEEK_SET:
new_off = off;
break;
case SEEK_END:
new_off = fno->size + off;
break;
default:
return -1;
}
if (new_off < 0)
new_off = 0;
if (new_off > fno->size) {
mfno->content = krealloc(mfno->content, new_off);
memset(mfno->content + fno->size, 0, new_off - fno->size);
fno->size = new_off;
}
fno->off = new_off;
return 0;
}
static int sysfs_close(struct fnode *fno)
{
struct sysfs_fnode *mfno;
mfno = FNO_MOD_PRIV(fno, &mod_sysfs);
if (!mfno)
return -1;
fno->off = 0;
return 0;
}
static int sysfs_write(struct fnode *fno, const void *buf, unsigned int len)
{
struct sysfs_fnode *mfno;
if (len <= 0)
return len;
mfno = FNO_MOD_PRIV(fno, &mod_sysfs);
if (mfno)
return -1;
if (mfno->do_write) {
return mfno->do_write(mfno, buf, len);
}
return -1;
}
static int sysfs_read(struct fnode *fno, void *buf, unsigned int len)
{
struct sysfs_fnode *mfno;
if (len <= 0)
return len;
mfno = FNO_MOD_PRIV(fno, &mod_sysfs);
if (!mfno)
return -1;
if (mfno->do_read) {
return mfno->do_read(mfno, buf, len);
}
return -1;
}
static int memfs_read(struct fnode *fno, void *buf, unsigned int len)
{
struct memfs_fnode *mfno;
if (len <= 0)
return len;
mfno = FNO_MOD_PRIV(fno, &mod_memfs);
if (!mfno)
return -1;
if (fno->size <= (fno->off))
return -1;
if (len > (fno->size - fno->off))
len = fno->size - fno->off;
memcpy(buf, mfno->content + fno->off, len);
fno->off += len;
return len;
}
static int memfs_write(struct fnode *fno, const void *buf, unsigned int len)
{
struct memfs_fnode *mfno;
if (len <= 0)
return len;
mfno = FNO_MOD_PRIV(fno, &mod_memfs);
if (!mfno)
return -1;
if (fno->size < (fno->off + len)) {
mfno->content = krealloc(mfno->content, fno->off + len);
}
if (!mfno->content)
return -1;
memcpy(mfno->content + fno->off, buf, len);
fno->off += len;
if (fno->size < fno->off)
fno->size = fno->off;
return len;
}
