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authorKevin Wolf <kwolf@redhat.com>2010-07-14 10:33:49 +0200
committerKevin Wolf <kwolf@redhat.com>2010-07-14 10:33:49 +0200
commit82e9cbeb0d369a896e898fee6ab6527e416ee631 (patch)
tree6d1ebce4333711e60996db64169c75041175ff34
parentvmdk: fix double free (diff)
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qcow2: Fix creation of large images
qcow_create2 assumes that the new image will only need one cluster for its refcount table initially. Obviously that's not true any more when the image is big enough (exact value depends on the cluster size). This patch calculates the refcount table size dynamically. Signed-off-by: Kevin Wolf <kwolf@redhat.com> (cherry picked from commit 4768fa902c3860f2fe34403e6e1c83bfca6da034) Conflicts: block/qcow2.c Signed-off-by: Kevin Wolf <kwolf@redhat.com>
-rw-r--r--block/qcow2.c41
1 files changed, 32 insertions, 9 deletions
diff --git a/block/qcow2.c b/block/qcow2.c
index 5d33d6c79..35c05e0b2 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -747,10 +747,11 @@ static int qcow_create2(const char *filename, int64_t total_size,
{
int fd, header_size, backing_filename_len, l1_size, i, shift, l2_bits;
- int ref_clusters, backing_format_len = 0;
+ int ref_clusters, reftable_clusters, backing_format_len = 0;
int rounded_ext_bf_len = 0;
QCowHeader header;
uint64_t tmp, offset;
+ uint64_t old_ref_clusters;
QCowCreateState s1, *s = &s1;
QCowExtension ext_bf = {0, 0};
@@ -809,17 +810,37 @@ static int qcow_create2(const char *filename, int64_t total_size,
header.l1_size = cpu_to_be32(l1_size);
offset += align_offset(l1_size * sizeof(uint64_t), s->cluster_size);
- s->refcount_table = qemu_mallocz(s->cluster_size);
+ /* count how many refcount blocks needed */
+
+#define NUM_CLUSTERS(bytes) \
+ (((bytes) + (s->cluster_size) - 1) / (s->cluster_size))
+
+ ref_clusters = NUM_CLUSTERS(NUM_CLUSTERS(offset) * sizeof(uint16_t));
+
+ do {
+ uint64_t image_clusters;
+ old_ref_clusters = ref_clusters;
+
+ /* Number of clusters used for the refcount table */
+ reftable_clusters = NUM_CLUSTERS(ref_clusters * sizeof(uint64_t));
+
+ /* Number of clusters that the whole image will have */
+ image_clusters = NUM_CLUSTERS(offset) + ref_clusters
+ + reftable_clusters;
+
+ /* Number of refcount blocks needed for the image */
+ ref_clusters = NUM_CLUSTERS(image_clusters * sizeof(uint16_t));
+
+ } while (ref_clusters != old_ref_clusters);
+
+ s->refcount_table = qemu_mallocz(reftable_clusters * s->cluster_size);
s->refcount_table_offset = offset;
header.refcount_table_offset = cpu_to_be64(offset);
- header.refcount_table_clusters = cpu_to_be32(1);
- offset += s->cluster_size;
+ header.refcount_table_clusters = cpu_to_be32(reftable_clusters);
+ offset += (reftable_clusters * s->cluster_size);
s->refcount_block_offset = offset;
- /* count how many refcount blocks needed */
- tmp = offset >> s->cluster_bits;
- ref_clusters = (tmp >> (s->cluster_bits - REFCOUNT_SHIFT)) + 1;
for (i=0; i < ref_clusters; i++) {
s->refcount_table[i] = cpu_to_be64(offset);
offset += s->cluster_size;
@@ -831,7 +852,8 @@ static int qcow_create2(const char *filename, int64_t total_size,
qcow2_create_refcount_update(s, 0, header_size);
qcow2_create_refcount_update(s, s->l1_table_offset,
l1_size * sizeof(uint64_t));
- qcow2_create_refcount_update(s, s->refcount_table_offset, s->cluster_size);
+ qcow2_create_refcount_update(s, s->refcount_table_offset,
+ reftable_clusters * s->cluster_size);
qcow2_create_refcount_update(s, s->refcount_block_offset,
ref_clusters * s->cluster_size);
@@ -859,7 +881,8 @@ static int qcow_create2(const char *filename, int64_t total_size,
write(fd, &tmp, sizeof(tmp));
}
lseek(fd, s->refcount_table_offset, SEEK_SET);
- write(fd, s->refcount_table, s->cluster_size);
+ write(fd, s->refcount_table,
+ reftable_clusters * s->cluster_size);
lseek(fd, s->refcount_block_offset, SEEK_SET);
write(fd, s->refcount_block, ref_clusters * s->cluster_size);