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qcow2: Fix L1 table memory allocation

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Contrary to what one could expect, the size of L1 tables is not cluster
aligned. So as we're writing whole sectors now instead of single entries,
we need to ensure that the L1 table in memory is large enough; otherwise
write would access memory after the end of the L1 table.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This commit is contained in:
Kevin Wolf 2009-07-07 18:09:42 +02:00 committed by Anthony Liguori
parent c53ffce91b
commit 3f6a3ee51e
3 changed files with 4 additions and 3 deletions
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2
block/qcow2-cluster.c
View File

@ -47,7 +47,7 @@ int qcow2_grow_l1_table(BlockDriverState *bs, int min_size)
#endif
new_l1_size2 = sizeof(uint64_t) * new_l1_size;
new_l1_table = qemu_mallocz(new_l1_size2);
new_l1_table = qemu_mallocz(align_offset(new_l1_size2, 512));
memcpy(new_l1_table, s->l1_table, s->l1_size * sizeof(uint64_t));
/* write new table (align to cluster) */

2
block/qcow2-refcount.c
View File

@ -513,7 +513,7 @@ int qcow2_update_snapshot_refcount(BlockDriverState *bs,
l1_size2 = l1_size * sizeof(uint64_t);
l1_allocated = 0;
if (l1_table_offset != s->l1_table_offset) {
l1_table = qemu_malloc(l1_size2);
l1_table = qemu_mallocz(align_offset(l1_size2, 512));
l1_allocated = 1;
if (bdrv_pread(s->hd, l1_table_offset,
l1_table, l1_size2) != l1_size2)

3
block/qcow2.c
View File

@ -200,7 +200,8 @@ static int qcow_open(BlockDriverState *bs, const char *filename, int flags)
if (s->l1_size < s->l1_vm_state_index)
goto fail;
s->l1_table_offset = header.l1_table_offset;
s->l1_table = qemu_malloc(s->l1_size * sizeof(uint64_t));
s->l1_table = qemu_mallocz(
align_offset(s->l1_size * sizeof(uint64_t), 512));
if (bdrv_pread(s->hd, s->l1_table_offset, s->l1_table, s->l1_size * sizeof(uint64_t)) !=
s->l1_size * sizeof(uint64_t))
goto fail;