diff options
Diffstat (limited to 'block/qed-cluster.c')
| -rw-r--r-- | block/qed-cluster.c | 39 |
1 files changed, 22 insertions, 17 deletions
diff --git a/block/qed-cluster.c b/block/qed-cluster.c index d2799446b3..88dc979d8c 100644 --- a/block/qed-cluster.c +++ b/block/qed-cluster.c @@ -67,22 +67,27 @@ static unsigned int qed_count_contiguous_clusters(BDRVQEDState *s, * @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 + * @len: Number of bytes (may be shortened on return) + * @img_offset: Contains offset in the image file on success * * 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. + * image file. The translated offset or unallocated range in the image file is + * reported back in *img_offset and *len. * * 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. + * + * On success QED_CLUSTER_FOUND is returned and img_offset/len are a contiguous + * range in the image file. + * + * On failure QED_CLUSTER_L2 or QED_CLUSTER_L1 is returned for missing L2 or L1 + * table offset, respectively. len is number of contiguous unallocated bytes. */ -void qed_find_cluster(BDRVQEDState *s, QEDRequest *request, uint64_t pos, - size_t len, QEDFindClusterFunc *cb, void *opaque) +int qed_find_cluster(BDRVQEDState *s, QEDRequest *request, uint64_t pos, + size_t *len, uint64_t *img_offset) { uint64_t l2_offset; uint64_t offset = 0; @@ -93,16 +98,16 @@ void qed_find_cluster(BDRVQEDState *s, QEDRequest *request, uint64_t pos, /* 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); + *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; + *img_offset = 0; + return QED_CLUSTER_L1; } if (!qed_check_table_offset(s, l2_offset)) { - cb(opaque, -EINVAL, 0, 0); - return; + *img_offset = *len = 0; + return -EINVAL; } ret = qed_read_l2_table(s, request, l2_offset); @@ -112,8 +117,7 @@ void qed_find_cluster(BDRVQEDState *s, QEDRequest *request, uint64_t pos, } index = qed_l2_index(s, pos); - n = qed_bytes_to_clusters(s, - qed_offset_into_cluster(s, pos) + len); + n = qed_bytes_to_clusters(s, qed_offset_into_cluster(s, pos) + *len); n = qed_count_contiguous_clusters(s, request->l2_table->table, index, n, &offset); @@ -127,10 +131,11 @@ void qed_find_cluster(BDRVQEDState *s, QEDRequest *request, uint64_t pos, ret = -EINVAL; } - len = MIN(len, - n * s->header.cluster_size - qed_offset_into_cluster(s, pos)); + *len = MIN(*len, + n * s->header.cluster_size - qed_offset_into_cluster(s, pos)); out: - cb(opaque, ret, offset, len); + *img_offset = offset; qed_release(s); + return ret; } |