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qcow2: Try to aggregate free clusters and freed clusters (Laurent Vivier)

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In alloc_cluster_offset(), try to aggregate free clusters and freed clusters.

Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5008 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
aliguori 2008-08-14 18:11:52 +00:00
parent 768706a52f
commit bc352085d2
1 changed files with 36 additions and 18 deletions
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54
block-qcow2.c
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@ -870,7 +870,7 @@ static uint64_t alloc_cluster_offset(BlockDriverState *bs,
BDRVQcowState *s = bs->opaque;
int l2_index, ret;
uint64_t l2_offset, *l2_table, cluster_offset;
int nb_available, nb_clusters, i;
int nb_available, nb_clusters, i, j;
uint64_t start_sect, current;
ret = get_cluster_table(bs, offset, &l2_table, &l2_offset, &l2_index);
@ -909,32 +909,50 @@ static uint64_t alloc_cluster_offset(BlockDriverState *bs,
if (cluster_offset & QCOW_OFLAG_COMPRESSED)
nb_clusters = 1;
/* how many empty or how many to free ? */
/* how many available clusters ? */
if (!cluster_offset) {
i = 0;
while (i < nb_clusters) {
/* how many free clusters ? */
i++;
i = 1;
while (i < nb_clusters &&
l2_table[l2_index + i] == 0) {
i++;
}
nb_clusters = i;
if (!cluster_offset) {
} else {
/* how many free clusters ? */
/* how many contiguous clusters ? */
while (i < nb_clusters) {
cluster_offset = l2_table[l2_index + i];
if (cluster_offset != 0)
break;
i++;
}
for (i = 1; i < nb_clusters; i++) {
current = be64_to_cpu(l2_table[l2_index + i]);
if (cluster_offset + (i << s->cluster_bits) != current)
if ((cluster_offset & QCOW_OFLAG_COPIED) ||
(cluster_offset & QCOW_OFLAG_COMPRESSED))
break;
}
nb_clusters = i;
free_any_clusters(bs, cluster_offset, i);
} else {
/* how many contiguous clusters ? */
j = 1;
current = 0;
while (i < nb_clusters) {
current = be64_to_cpu(l2_table[l2_index + i]);
if (cluster_offset + (j << s->cluster_bits) != current)
break;
i++;
j++;
}
free_any_clusters(bs, cluster_offset, j);
if (current)
break;
cluster_offset = current;
}
}
nb_clusters = i;
/* allocate a new cluster */