/**
* Find the offset of a data cluster
*
* @s: QED state
* @request: L2 cache entry
* @pos: Byte position in device
* @len: Number of bytes
* @cb: Completion function
* @opaque: User data for completion function
*
* This function translates a position in the block device to an offset in the
* image file. It invokes the cb completion callback to report back the
* translated offset or unallocated range in the image file.
*
* If the L2 table exists, request->l2_table points to the L2 table cache entry
* and the caller must free the reference when they are finished. The cache
* entry is exposed in this way to avoid callers having to read the L2 table
* again later during request processing. If request->l2_table is non-NULL it
* will be unreferenced before taking on the new cache entry.
*/
void qed_find_cluster(BDRVQEDState *s, QEDRequest *request, uint64_t pos,
size_t len, QEDFindClusterFunc *cb, void *opaque)
{
QEDFindClusterCB *find_cluster_cb;
uint64_t l2_offset;
/* Limit length to L2 boundary. Requests are broken up at the L2 boundary
* so that a request acts on one L2 table at a time.
*/
len = MIN(len, (((pos >> s->l1_shift) + 1) << s->l1_shift) - pos);
l2_offset = s->l1_table->offsets[qed_l1_index(s, pos)];
if (qed_offset_is_unalloc_cluster(l2_offset)) {
cb(opaque, QED_CLUSTER_L1, 0, len);
return;
}
if (!qed_check_table_offset(s, l2_offset)) {
cb(opaque, -EINVAL, 0, 0);
return;
}
find_cluster_cb = g_malloc(sizeof(*find_cluster_cb));
find_cluster_cb->s = s;
find_cluster_cb->pos = pos;
find_cluster_cb->len = len;
find_cluster_cb->cb = cb;
find_cluster_cb->opaque = opaque;
find_cluster_cb->request = request;
qed_read_l2_table(s, request, l2_offset,
qed_find_cluster_cb, find_cluster_cb);
}
int qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request, uint64_t offset)
{
int ret = -EINPROGRESS;
qed_read_l2_table(s, request, offset, qed_sync_cb, &ret);
while (ret == -EINPROGRESS) {
qemu_aio_wait();
}
return ret;
}
int qed_read_l2_table_sync(BDRVQEDState *s, QEDRequest *request, uint64_t offset)
{
int ret = -EINPROGRESS;
qed_read_l2_table(s, request, offset, qed_sync_cb, &ret);
while (ret == -EINPROGRESS) {
aio_poll(bdrv_get_aio_context(s->bs), true);
}
return ret;
}
