[Qemu-devel] [RFC v2 5/8] qcow2: add bdrv_measure() support

Stefan Hajnoczi posted 8 patches 8 years, 11 months ago
There is a newer version of this series
[Qemu-devel] [RFC v2 5/8] qcow2: add bdrv_measure() support
Posted by Stefan Hajnoczi 8 years, 11 months ago
Use qcow2_calc_prealloc_size() to get the required file size.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
TODO:
 * Query block status and only count allocated clusters if in_bs != NULL
 * Exclude backing file clusters if in_bs != NULL and -o backing_file=
   is given
---
 block/qcow2.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/block/qcow2.c b/block/qcow2.c
index 19be468..a4caf97 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -2940,6 +2940,58 @@ static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs)
     return 0;
 }
 
+static void qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
+                          BlockMeasureInfo *info, Error **errp)
+{
+    Error *local_err = NULL;
+    uint64_t allocated_bytes = 0;
+    uint64_t prealloc_size;
+    uint64_t size;
+    uint64_t refcount_bits;
+    size_t cluster_size;
+    int version;
+
+    size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
+                    BDRV_SECTOR_SIZE);
+
+    cluster_size = qcow2_opt_get_cluster_size_del(opts, &local_err);
+    if (local_err) {
+        goto err;
+    }
+
+    version = qcow2_opt_get_version_del(opts, &local_err);
+    if (local_err) {
+        goto err;
+    }
+
+    refcount_bits = qcow2_opt_get_refcount_bits_del(opts, version, &local_err);
+    if (local_err) {
+        goto err;
+    }
+
+    if (in_bs) {
+        int64_t ssize = bdrv_getlength(in_bs);
+        if (ssize < 0) {
+            error_setg_errno(errp, -ssize, "Unable to get image size");
+            return;
+        }
+
+        size = ssize;
+
+        /* TODO How many clusters are allocated modulo backing file in opts? */
+    }
+
+    prealloc_size = qcow2_calc_prealloc_size(size, cluster_size,
+                                             ctz32(refcount_bits));
+    info->required_bytes = prealloc_size - (align_offset(size, cluster_size) -
+                                            allocated_bytes);
+    info->fully_allocated_bytes = prealloc_size;
+    return;
+
+err:
+    error_propagate(errp, local_err);
+}
+
 static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
 {
     BDRVQcow2State *s = bs->opaque;
@@ -3487,6 +3539,7 @@ BlockDriver bdrv_qcow2 = {
     .bdrv_snapshot_delete   = qcow2_snapshot_delete,
     .bdrv_snapshot_list     = qcow2_snapshot_list,
     .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp,
+    .bdrv_measure           = qcow2_measure,
     .bdrv_get_info          = qcow2_get_info,
     .bdrv_get_specific_info = qcow2_get_specific_info,
 
-- 
2.9.3


Re: [Qemu-devel] [RFC v2 5/8] qcow2: add bdrv_measure() support
Posted by Max Reitz 8 years, 11 months ago
On 15.03.2017 10:29, Stefan Hajnoczi wrote:
> Use qcow2_calc_prealloc_size() to get the required file size.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
> TODO:
>  * Query block status and only count allocated clusters if in_bs != NULL
>  * Exclude backing file clusters if in_bs != NULL and -o backing_file=
>    is given
> ---
>  block/qcow2.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
> 
> diff --git a/block/qcow2.c b/block/qcow2.c
> index 19be468..a4caf97 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c
> @@ -2940,6 +2940,58 @@ static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs)
>      return 0;
>  }
>  
> +static void qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
> +                          BlockMeasureInfo *info, Error **errp)
> +{
> +    Error *local_err = NULL;
> +    uint64_t allocated_bytes = 0;
> +    uint64_t prealloc_size;
> +    uint64_t size;
> +    uint64_t refcount_bits;
> +    size_t cluster_size;
> +    int version;
> +
> +    size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
> +                    BDRV_SECTOR_SIZE);
> +
> +    cluster_size = qcow2_opt_get_cluster_size_del(opts, &local_err);
> +    if (local_err) {
> +        goto err;
> +    }
> +
> +    version = qcow2_opt_get_version_del(opts, &local_err);
> +    if (local_err) {
> +        goto err;
> +    }
> +
> +    refcount_bits = qcow2_opt_get_refcount_bits_del(opts, version, &local_err);
> +    if (local_err) {
> +        goto err;
> +    }
> +
> +    if (in_bs) {
> +        int64_t ssize = bdrv_getlength(in_bs);
> +        if (ssize < 0) {
> +            error_setg_errno(errp, -ssize, "Unable to get image size");
> +            return;
> +        }
> +
> +        size = ssize;
> +
> +        /* TODO How many clusters are allocated modulo backing file in opts? */
> +    }
> +
> +    prealloc_size = qcow2_calc_prealloc_size(size, cluster_size,
> +                                             ctz32(refcount_bits));
> +    info->required_bytes = prealloc_size - (align_offset(size, cluster_size) -
> +                                            allocated_bytes);

But what if @opts contains a preallocation option?

Max

> +    info->fully_allocated_bytes = prealloc_size;
> +    return;
> +
> +err:
> +    error_propagate(errp, local_err);
> +}
> +
>  static int qcow2_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
>  {
>      BDRVQcow2State *s = bs->opaque;
> @@ -3487,6 +3539,7 @@ BlockDriver bdrv_qcow2 = {
>      .bdrv_snapshot_delete   = qcow2_snapshot_delete,
>      .bdrv_snapshot_list     = qcow2_snapshot_list,
>      .bdrv_snapshot_load_tmp = qcow2_snapshot_load_tmp,
> +    .bdrv_measure           = qcow2_measure,
>      .bdrv_get_info          = qcow2_get_info,
>      .bdrv_get_specific_info = qcow2_get_specific_info,
>  
> 


Re: [Qemu-devel] [RFC v2 5/8] qcow2: add bdrv_measure() support
Posted by Stefan Hajnoczi 8 years, 11 months ago
On Thu, Mar 16, 2017 at 02:57:13AM +0100, Max Reitz wrote:
> On 15.03.2017 10:29, Stefan Hajnoczi wrote:
> > Use qcow2_calc_prealloc_size() to get the required file size.
> > 
> > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> > ---
> > TODO:
> >  * Query block status and only count allocated clusters if in_bs != NULL
> >  * Exclude backing file clusters if in_bs != NULL and -o backing_file=
> >    is given
> > ---
> >  block/qcow2.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 53 insertions(+)
> > 
> > diff --git a/block/qcow2.c b/block/qcow2.c
> > index 19be468..a4caf97 100644
> > --- a/block/qcow2.c
> > +++ b/block/qcow2.c
> > @@ -2940,6 +2940,58 @@ static coroutine_fn int qcow2_co_flush_to_os(BlockDriverState *bs)
> >      return 0;
> >  }
> >  
> > +static void qcow2_measure(QemuOpts *opts, BlockDriverState *in_bs,
> > +                          BlockMeasureInfo *info, Error **errp)
> > +{
> > +    Error *local_err = NULL;
> > +    uint64_t allocated_bytes = 0;
> > +    uint64_t prealloc_size;
> > +    uint64_t size;
> > +    uint64_t refcount_bits;
> > +    size_t cluster_size;
> > +    int version;
> > +
> > +    size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
> > +                    BDRV_SECTOR_SIZE);
> > +
> > +    cluster_size = qcow2_opt_get_cluster_size_del(opts, &local_err);
> > +    if (local_err) {
> > +        goto err;
> > +    }
> > +
> > +    version = qcow2_opt_get_version_del(opts, &local_err);
> > +    if (local_err) {
> > +        goto err;
> > +    }
> > +
> > +    refcount_bits = qcow2_opt_get_refcount_bits_del(opts, version, &local_err);
> > +    if (local_err) {
> > +        goto err;
> > +    }
> > +
> > +    if (in_bs) {
> > +        int64_t ssize = bdrv_getlength(in_bs);
> > +        if (ssize < 0) {
> > +            error_setg_errno(errp, -ssize, "Unable to get image size");
> > +            return;
> > +        }
> > +
> > +        size = ssize;
> > +
> > +        /* TODO How many clusters are allocated modulo backing file in opts? */
> > +    }
> > +
> > +    prealloc_size = qcow2_calc_prealloc_size(size, cluster_size,
> > +                                             ctz32(refcount_bits));
> > +    info->required_bytes = prealloc_size - (align_offset(size, cluster_size) -
> > +                                            allocated_bytes);
> 
> But what if @opts contains a preallocation option?

Will implement in the next revision.

Thanks,
Stefan