On 2014-10-22 at 14:01, Max Reitz wrote:
On 2014-10-22 at 13:59, Gonglei wrote:
On 2014/10/22 19:45, Zhang Haoyu wrote:
Use local variable to bdrv_pwrite_sync L1 table,
needless to make conversion of cached L1 table between
big-endian and host style.
Signed-off-by: Zhang Haoyu <zhan...@sangfor.com>
Reviewed-by: Max Reitz <mre...@redhat.com>
---
v3 -> v4:
- convert local L1 table to host-style before copy it
back to s->l1_table
v2 -> v3:
- replace g_try_malloc0 with qemu_try_blockalign
- copy the latest local L1 table back to s->l1_table
after successfully bdrv_pwrite_sync L1 table
v1 -> v2:
- remove the superflous assignment, l1_table = NULL;
- replace 512 with BDRV_SECTOR_SIZE, and align_offset with ROUND_UP
- remove needless check of if (l1_table) before g_free(l1_table)
block/qcow2-refcount.c | 28 ++++++++++++----------------
1 file changed, 12 insertions(+), 16 deletions(-)
diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
index 2bcaaf9..3e4050a 100644
--- a/block/qcow2-refcount.c
+++ b/block/qcow2-refcount.c
@@ -881,14 +881,17 @@ int
qcow2_update_snapshot_refcount(BlockDriverState *bs,
{
BDRVQcowState *s = bs->opaque;
uint64_t *l1_table, *l2_table, l2_offset, offset, l1_size2;
- bool l1_allocated = false;
int64_t old_offset, old_l2_offset;
int i, j, l1_modified = 0, nb_csectors, refcount;
int ret;
l2_table = NULL;
- l1_table = NULL;
l1_size2 = l1_size * sizeof(uint64_t);
+ l1_table = qemu_try_blockalign(bs->file, l1_size2);
+ if (l1_size2 && l1_table == NULL) {
I think this check has a logic problem. If l1_size2 != 0 and
l1_table == NULL,
What will happen?
Then this condition is met and you return with -ENOMEM...?
Oh, but I see something different: qemu_try_blockalign() never returns
NULL, not even when you request 0 bytes. Therefore, just "if (l1_table
== NULL)" is sufficient.
Max