Re: [Qemu-block] [PATCH v3 27/39] qcow2: Update qcow2_update_snapshot_refcount() to support L2 slices

2018-02-02 Thread Alberto Garcia
On Thu 01 Feb 2018 08:26:26 PM CET, Max Reitz  wrote:
>> @@ -1273,12 +1276,13 @@ int qcow2_update_snapshot_refcount(BlockDriverState 
>> *bs,
>>  case QCOW2_CLUSTER_NORMAL:
>>  case QCOW2_CLUSTER_ZERO_ALLOC:
>>  if (offset_into_cluster(s, offset)) {
>> +int l2_index = slice * s->l2_slice_size + j;
>>  qcow2_signal_corruption(
>>  bs, true, -1, -1, "Cluster "
>>  "allocation offset %#" PRIx64
>>  " unaligned (L2 offset: %#"
>>  PRIx64 ", L2 index: %#x)",
>> -offset, l2_offset, j);
>> +offset, l2_offset, l2_index);
>
> This makes it a bit weird that in other patches l2_index is now
> generally the L2 slice index...

You're right, I can call it l2_table_index, I think this is the only
case where it does not refer to the slice index.

Berto



Re: [Qemu-block] [PATCH v3 27/39] qcow2: Update qcow2_update_snapshot_refcount() to support L2 slices

2018-02-01 Thread Max Reitz
On 2018-01-26 15:59, Alberto Garcia wrote:
> qcow2_update_snapshot_refcount() increases the refcount of all
> clusters of a given snapshot. In order to do that it needs to load all
> its L2 tables and iterate over their entries. Since we'll be loading
> L2 slices instead of full tables we need to add an extra loop that
> iterates over all slices of each L2 table.
> 
> This function doesn't need any additional changes so apart from that
> this patch simply updates the variable name from l2_table to l2_slice.
> 
> Signed-off-by: Alberto Garcia 
> ---
>  block/qcow2-refcount.c | 31 +--
>  1 file changed, 17 insertions(+), 14 deletions(-)
> 
> diff --git a/block/qcow2-refcount.c b/block/qcow2-refcount.c
> index dfa28301c4..60b521cb89 100644
> --- a/block/qcow2-refcount.c
> +++ b/block/qcow2-refcount.c
> @@ -1183,17 +1183,20 @@ int qcow2_update_snapshot_refcount(BlockDriverState 
> *bs,
>  int64_t l1_table_offset, int l1_size, int addend)
>  {
>  BDRVQcow2State *s = bs->opaque;
> -uint64_t *l1_table, *l2_table, l2_offset, entry, l1_size2, refcount;
> +uint64_t *l1_table, *l2_slice, l2_offset, entry, l1_size2, refcount;
>  bool l1_allocated = false;
>  int64_t old_entry, old_l2_offset;
> +unsigned slice, slice_size2, n_slices;

Hm, well. Hm.

>  int i, j, l1_modified = 0, nb_csectors;
>  int ret;
>  
>  assert(addend >= -1 && addend <= 1);
>  
> -l2_table = NULL;
> +l2_slice = NULL;
>  l1_table = NULL;
>  l1_size2 = l1_size * sizeof(uint64_t);
> +slice_size2 = s->l2_slice_size * sizeof(uint64_t);
> +n_slices = s->cluster_size / slice_size2;
>  
>  s->cache_discards = true;
>  

[...]

> @@ -1273,12 +1276,13 @@ int qcow2_update_snapshot_refcount(BlockDriverState 
> *bs,
>  case QCOW2_CLUSTER_NORMAL:
>  case QCOW2_CLUSTER_ZERO_ALLOC:
>  if (offset_into_cluster(s, offset)) {
> +int l2_index = slice * s->l2_slice_size + j;
>  qcow2_signal_corruption(
>  bs, true, -1, -1, "Cluster "
>  "allocation offset %#" PRIx64
>  " unaligned (L2 offset: %#"
>  PRIx64 ", L2 index: %#x)",
> -offset, l2_offset, j);
> +offset, l2_offset, l2_index);

This makes it a bit weird that in other patches l2_index is now
generally the L2 slice index...

Oh well.

Reviewed-by: Max Reitz 

>  ret = -EIO;
>  goto fail;
>  }



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Re: [Qemu-block] [PATCH v3 27/39] qcow2: Update qcow2_update_snapshot_refcount() to support L2 slices

2018-01-26 Thread Eric Blake
On 01/26/2018 08:59 AM, Alberto Garcia wrote:
> qcow2_update_snapshot_refcount() increases the refcount of all
> clusters of a given snapshot. In order to do that it needs to load all
> its L2 tables and iterate over their entries. Since we'll be loading
> L2 slices instead of full tables we need to add an extra loop that
> iterates over all slices of each L2 table.
> 
> This function doesn't need any additional changes so apart from that
> this patch simply updates the variable name from l2_table to l2_slice.
> 
> Signed-off-by: Alberto Garcia 
> ---
>  block/qcow2-refcount.c | 31 +--
>  1 file changed, 17 insertions(+), 14 deletions(-)
> 

Reviewed-by: Eric Blake 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.   +1-919-301-3266
Virtualization:  qemu.org | libvirt.org



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