qcow2: Update handle_alloc() to support L2 slices

handle_alloc() loads an L2 table and limits the number of checked
clusters to the amount that fits inside that table. Since we'll be
loading L2 slices instead of full tables we need to update that limit.

Apart from that, this function doesn't need any additional changes, so
this patch simply updates the variable name from l2_table to l2_slice.

Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: b243299c7136f7014c5af51665431ddbf5e99afd.1517840877.git.berto@igalia.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Alberto Garcia 2018-02-05 16:33:23 +02:00 committed by Max Reitz
parent cde917662a
commit 6d99a34447

View File

@ -1274,7 +1274,7 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
{ {
BDRVQcow2State *s = bs->opaque; BDRVQcow2State *s = bs->opaque;
int l2_index; int l2_index;
uint64_t *l2_table; uint64_t *l2_slice;
uint64_t entry; uint64_t entry;
uint64_t nb_clusters; uint64_t nb_clusters;
int ret; int ret;
@ -1287,29 +1287,29 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
assert(*bytes > 0); assert(*bytes > 0);
/* /*
* Calculate the number of clusters to look for. We stop at L2 table * Calculate the number of clusters to look for. We stop at L2 slice
* boundaries to keep things simple. * boundaries to keep things simple.
*/ */
nb_clusters = nb_clusters =
size_to_clusters(s, offset_into_cluster(s, guest_offset) + *bytes); size_to_clusters(s, offset_into_cluster(s, guest_offset) + *bytes);
l2_index = offset_to_l2_index(s, guest_offset); l2_index = offset_to_l2_slice_index(s, guest_offset);
nb_clusters = MIN(nb_clusters, s->l2_size - l2_index); nb_clusters = MIN(nb_clusters, s->l2_slice_size - l2_index);
assert(nb_clusters <= INT_MAX); assert(nb_clusters <= INT_MAX);
/* Find L2 entry for the first involved cluster */ /* Find L2 entry for the first involved cluster */
ret = get_cluster_table(bs, guest_offset, &l2_table, &l2_index); ret = get_cluster_table(bs, guest_offset, &l2_slice, &l2_index);
if (ret < 0) { if (ret < 0) {
return ret; return ret;
} }
entry = be64_to_cpu(l2_table[l2_index]); entry = be64_to_cpu(l2_slice[l2_index]);
/* For the moment, overwrite compressed clusters one by one */ /* For the moment, overwrite compressed clusters one by one */
if (entry & QCOW_OFLAG_COMPRESSED) { if (entry & QCOW_OFLAG_COMPRESSED) {
nb_clusters = 1; nb_clusters = 1;
} else { } else {
nb_clusters = count_cow_clusters(s, nb_clusters, l2_table, l2_index); nb_clusters = count_cow_clusters(s, nb_clusters, l2_slice, l2_index);
} }
/* This function is only called when there were no non-COW clusters, so if /* This function is only called when there were no non-COW clusters, so if
@ -1338,7 +1338,7 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
* nb_clusters already to a range of COW clusters */ * nb_clusters already to a range of COW clusters */
preallocated_nb_clusters = preallocated_nb_clusters =
count_contiguous_clusters(nb_clusters, s->cluster_size, count_contiguous_clusters(nb_clusters, s->cluster_size,
&l2_table[l2_index], QCOW_OFLAG_COPIED); &l2_slice[l2_index], QCOW_OFLAG_COPIED);
assert(preallocated_nb_clusters > 0); assert(preallocated_nb_clusters > 0);
nb_clusters = preallocated_nb_clusters; nb_clusters = preallocated_nb_clusters;
@ -1349,7 +1349,7 @@ static int handle_alloc(BlockDriverState *bs, uint64_t guest_offset,
keep_old_clusters = true; keep_old_clusters = true;
} }
qcow2_cache_put(s->l2_table_cache, (void **) &l2_table); qcow2_cache_put(s->l2_table_cache, (void **) &l2_slice);
if (!alloc_cluster_offset) { if (!alloc_cluster_offset) {
/* Allocate, if necessary at a given offset in the image file */ /* Allocate, if necessary at a given offset in the image file */