* [PATCH v3] block/backup-top: fix flags handling
@ 2020-02-07 16:12 Vladimir Sementsov-Ogievskiy
2020-02-07 16:30 ` Max Reitz
0 siblings, 1 reply; 3+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2020-02-07 16:12 UTC (permalink / raw)
To: qemu-block; +Cc: kwolf, vsementsov, qemu-devel, mreitz
backup-top "supports" write-unchanged, by skipping CBW operation in
backup_top_co_pwritev. But it forgets to do the same in
backup_top_co_pwrite_zeroes, as well as declare support for
BDRV_REQ_WRITE_UNCHANGED.
Fix this, and, while being here, declare also support for flags
supported by source child.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
v3: rebase on master, keep state initialization after check top != NULL.
v2: restrict flags propagation like it is done in other filters [Eric]
move state variable initialization to the top
block/backup-top.c | 31 ++++++++++++++++++++-----------
1 file changed, 20 insertions(+), 11 deletions(-)
diff --git a/block/backup-top.c b/block/backup-top.c
index fa78f3256d..1bfb360bd3 100644
--- a/block/backup-top.c
+++ b/block/backup-top.c
@@ -48,11 +48,17 @@ static coroutine_fn int backup_top_co_preadv(
}
static coroutine_fn int backup_top_cbw(BlockDriverState *bs, uint64_t offset,
- uint64_t bytes)
+ uint64_t bytes, BdrvRequestFlags flags)
{
BDRVBackupTopState *s = bs->opaque;
- uint64_t end = QEMU_ALIGN_UP(offset + bytes, s->bcs->cluster_size);
- uint64_t off = QEMU_ALIGN_DOWN(offset, s->bcs->cluster_size);
+ uint64_t off, end;
+
+ if (flags & BDRV_REQ_WRITE_UNCHANGED) {
+ return 0;
+ }
+
+ off = QEMU_ALIGN_DOWN(offset, s->bcs->cluster_size);
+ end = QEMU_ALIGN_UP(offset + bytes, s->bcs->cluster_size);
return block_copy(s->bcs, off, end - off, NULL);
}
@@ -60,7 +66,7 @@ static coroutine_fn int backup_top_cbw(BlockDriverState *bs, uint64_t offset,
static int coroutine_fn backup_top_co_pdiscard(BlockDriverState *bs,
int64_t offset, int bytes)
{
- int ret = backup_top_cbw(bs, offset, bytes);
+ int ret = backup_top_cbw(bs, offset, bytes, 0);
if (ret < 0) {
return ret;
}
@@ -71,7 +77,7 @@ static int coroutine_fn backup_top_co_pdiscard(BlockDriverState *bs,
static int coroutine_fn backup_top_co_pwrite_zeroes(BlockDriverState *bs,
int64_t offset, int bytes, BdrvRequestFlags flags)
{
- int ret = backup_top_cbw(bs, offset, bytes);
+ int ret = backup_top_cbw(bs, offset, bytes, flags);
if (ret < 0) {
return ret;
}
@@ -84,11 +90,9 @@ static coroutine_fn int backup_top_co_pwritev(BlockDriverState *bs,
uint64_t bytes,
QEMUIOVector *qiov, int flags)
{
- if (!(flags & BDRV_REQ_WRITE_UNCHANGED)) {
- int ret = backup_top_cbw(bs, offset, bytes);
- if (ret < 0) {
- return ret;
- }
+ int ret = backup_top_cbw(bs, offset, bytes, flags);
+ if (ret < 0) {
+ return ret;
}
return bdrv_co_pwritev(bs->backing, offset, bytes, qiov, flags);
@@ -196,8 +200,13 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
return NULL;
}
- top->total_sectors = source->total_sectors;
state = top->opaque;
+ top->total_sectors = source->total_sectors;
+ top->supported_write_flags = BDRV_REQ_WRITE_UNCHANGED |
+ (BDRV_REQ_FUA & source->supported_write_flags);
+ top->supported_zero_flags = BDRV_REQ_WRITE_UNCHANGED |
+ ((BDRV_REQ_FUA | BDRV_REQ_MAY_UNMAP | BDRV_REQ_NO_FALLBACK) &
+ source->supported_zero_flags);
bdrv_ref(target);
state->target = bdrv_attach_child(top, target, "target", &child_file, errp);
--
2.21.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v3] block/backup-top: fix flags handling
2020-02-07 16:12 [PATCH v3] block/backup-top: fix flags handling Vladimir Sementsov-Ogievskiy
@ 2020-02-07 16:30 ` Max Reitz
2020-02-07 16:47 ` Vladimir Sementsov-Ogievskiy
0 siblings, 1 reply; 3+ messages in thread
From: Max Reitz @ 2020-02-07 16:30 UTC (permalink / raw)
To: Vladimir Sementsov-Ogievskiy, qemu-block; +Cc: kwolf, qemu-devel
[-- Attachment #1.1: Type: text/plain, Size: 1381 bytes --]
On 07.02.20 17:12, Vladimir Sementsov-Ogievskiy wrote:
> backup-top "supports" write-unchanged, by skipping CBW operation in
> backup_top_co_pwritev. But it forgets to do the same in
> backup_top_co_pwrite_zeroes, as well as declare support for
> BDRV_REQ_WRITE_UNCHANGED.
>
> Fix this, and, while being here, declare also support for flags
> supported by source child.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>
> v3: rebase on master, keep state initialization after check top != NULL.
>
> v2: restrict flags propagation like it is done in other filters [Eric]
> move state variable initialization to the top
> block/backup-top.c | 31 ++++++++++++++++++++-----------
> 1 file changed, 20 insertions(+), 11 deletions(-)
>
> diff --git a/block/backup-top.c b/block/backup-top.c
> index fa78f3256d..1bfb360bd3 100644
> --- a/block/backup-top.c
> +++ b/block/backup-top.c
[...]
> @@ -196,8 +200,13 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
> return NULL;
> }
>
> - top->total_sectors = source->total_sectors;
> state = top->opaque;
> + top->total_sectors = source->total_sectors;
This looks a bit accidental, but, well, whatever.
Thanks, applied to my block branch:
https://git.xanclic.moe/XanClic/qemu/commits/branch/block
Max
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v3] block/backup-top: fix flags handling
2020-02-07 16:30 ` Max Reitz
@ 2020-02-07 16:47 ` Vladimir Sementsov-Ogievskiy
0 siblings, 0 replies; 3+ messages in thread
From: Vladimir Sementsov-Ogievskiy @ 2020-02-07 16:47 UTC (permalink / raw)
To: Max Reitz, qemu-block; +Cc: kwolf, qemu-devel
07.02.2020 19:30, Max Reitz wrote:
> On 07.02.20 17:12, Vladimir Sementsov-Ogievskiy wrote:
>> backup-top "supports" write-unchanged, by skipping CBW operation in
>> backup_top_co_pwritev. But it forgets to do the same in
>> backup_top_co_pwrite_zeroes, as well as declare support for
>> BDRV_REQ_WRITE_UNCHANGED.
>>
>> Fix this, and, while being here, declare also support for flags
>> supported by source child.
>>
>> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>> ---
>>
>> v3: rebase on master, keep state initialization after check top != NULL.
>>
>> v2: restrict flags propagation like it is done in other filters [Eric]
>> move state variable initialization to the top
>> block/backup-top.c | 31 ++++++++++++++++++++-----------
>> 1 file changed, 20 insertions(+), 11 deletions(-)
>>
>> diff --git a/block/backup-top.c b/block/backup-top.c
>> index fa78f3256d..1bfb360bd3 100644
>> --- a/block/backup-top.c
>> +++ b/block/backup-top.c
>
> [...]
>
>> @@ -196,8 +200,13 @@ BlockDriverState *bdrv_backup_top_append(BlockDriverState *source,
>> return NULL;
>> }
>>
>> - top->total_sectors = source->total_sectors;
>> state = top->opaque;
>> + top->total_sectors = source->total_sectors;
>
> This looks a bit accidental, but, well, whatever.
I failed to restrict myself in a wish to keep all "top->.. =" initializers went together :)
Hmm, I could "state =" intializer to go after them. But it's good to keep it at top too.
>
> Thanks, applied to my block branch:
>
> https://git.xanclic.moe/XanClic/qemu/commits/branch/block
>
Thanks!
--
Best regards,
Vladimir
^ permalink raw reply [flat|nested] 3+ messages in thread
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2020-02-07 16:12 [PATCH v3] block/backup-top: fix flags handling Vladimir Sementsov-Ogievskiy
2020-02-07 16:30 ` Max Reitz
2020-02-07 16:47 ` Vladimir Sementsov-Ogievskiy
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