/*
* offset and count are in bytes and possibly not aligned. For files opened
* with O_DIRECT, necessary alignments are ensured before calling
* raw_pwrite_aligned to do the actual write.
*/
static int raw_pwrite(BlockDriverState *bs, int64_t offset,
const uint8_t *buf, int count)
{
BDRVRawState *s = bs->opaque;
int size, ret, shift, sum;
sum = 0;
if (s->aligned_buf != NULL) {
if (offset & 0x1ff) {
/* align offset on a 512 bytes boundary */
shift = offset & 0x1ff;
ret = raw_pread_aligned(bs, offset - shift, s->aligned_buf, 512);
if (ret < 0)
return ret;
size = 512 - shift;
if (size > count)
size = count;
memcpy(s->aligned_buf + shift, buf, size);
ret = raw_pwrite_aligned(bs, offset - shift, s->aligned_buf, 512);
if (ret < 0)
return ret;
buf += size;
offset += size;
count -= size;
sum += size;
if (count == 0)
return sum;
}
if (count & 0x1ff || (uintptr_t) buf & 0x1ff) {
while ((size = (count & ~0x1ff)) != 0) {
if (size > ALIGNED_BUFFER_SIZE)
size = ALIGNED_BUFFER_SIZE;
memcpy(s->aligned_buf, buf, size);
ret = raw_pwrite_aligned(bs, offset, s->aligned_buf, size);
if (ret < 0)
return ret;
buf += ret;
offset += ret;
count -= ret;
sum += ret;
}
/* here, count < 512 because (count & ~0x1ff) == 0 */
if (count) {
ret = raw_pread_aligned(bs, offset, s->aligned_buf, 512);
if (ret < 0)
return ret;
memcpy(s->aligned_buf, buf, count);
ret = raw_pwrite_aligned(bs, offset, s->aligned_buf, 512);
if (ret < 0)
return ret;
if (count < ret)
ret = count;
sum += ret;
}
return sum;
}
}
return raw_pwrite_aligned(bs, offset, buf, count) + sum;
}
/*
* offset and count are in bytes and possibly not aligned. For files opened
* with O_DIRECT, necessary alignments are ensured before calling
* raw_pwrite_aligned to do the actual write.
*/
static int raw_pwrite(BlockDriverState *bs, int64_t offset,
const uint8_t *buf, int count)
{
BDRVRawState *s = bs->opaque;
unsigned sector_mask = bs->buffer_alignment - 1;
int size, ret, shift, sum;
sum = 0;
if (s->aligned_buf != NULL) {
if (offset & sector_mask) {
/* align offset on a sector size bytes boundary */
shift = offset & sector_mask;
ret = raw_pread_aligned(bs, offset - shift, s->aligned_buf,
bs->buffer_alignment);
if (ret < 0)
return ret;
size = bs->buffer_alignment - shift;
if (size > count)
size = count;
memcpy(s->aligned_buf + shift, buf, size);
ret = raw_pwrite_aligned(bs, offset - shift, s->aligned_buf,
bs->buffer_alignment);
if (ret < 0)
return ret;
buf += size;
offset += size;
count -= size;
sum += size;
if (count == 0)
return sum;
}
if (count & sector_mask || (uintptr_t) buf & sector_mask) {
while ((size = (count & ~sector_mask)) != 0) {
if (size > s->aligned_buf_size)
size = s->aligned_buf_size;
memcpy(s->aligned_buf, buf, size);
ret = raw_pwrite_aligned(bs, offset, s->aligned_buf, size);
if (ret < 0)
return ret;
buf += ret;
offset += ret;
count -= ret;
sum += ret;
}
/* here, count < sector_size because (count & ~sector_mask) == 0 */
if (count) {
ret = raw_pread_aligned(bs, offset, s->aligned_buf,
bs->buffer_alignment);
if (ret < 0)
return ret;
memcpy(s->aligned_buf, buf, count);
ret = raw_pwrite_aligned(bs, offset, s->aligned_buf,
bs->buffer_alignment);
if (ret < 0)
return ret;
if (count < ret)
ret = count;
sum += ret;
}
return sum;
}
}
return raw_pwrite_aligned(bs, offset, buf, count) + sum;
}
