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[PATCH v3 3/8] parallels: Use generic infrastructure for BAT writing in parallels_co_check()

Alexander Ivanov posted 8 patches 3 years, 5 months ago
Maintainers: Stefan Hajnoczi <stefanha@redhat.com>, "Denis V. Lunev" <den@openvz.org>, Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>, Kevin Wolf <kwolf@redhat.com>, Hanna Reitz <hreitz@redhat.com>
There is a newer version of this series
[PATCH v3 3/8] parallels: Use generic infrastructure for BAT writing in parallels_co_check()
Posted by Alexander Ivanov 3 years, 5 months ago 
BAT is written in the context of conventional operations over
the image inside bdrv_co_flush() when it calls
parallels_co_flush_to_os() callback. Thus we should not
modify BAT array directly, but call parallels_set_bat_entry()
helper and bdrv_co_flush() further on. After that there is no
need to manually write BAT and track its modification.

This makes code more generic and allows to split
parallels_set_bat_entry() for independent pieces.

Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
---
v2: Patch order was changed so the replacement is done in parallels_co_check.
    Now we use a helper to set BAT entry and mark the block dirty.
v3: Fix commit message.

 block/parallels.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/block/parallels.c b/block/parallels.c
index 7f68f3cbc9..6879ea4597 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -428,7 +428,6 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs,
     int64_t size, prev_off, high_off;
     int ret;
     uint32_t i;
-    bool flush_bat = false;
 
     size = bdrv_getlength(bs->file->bs);
     if (size < 0) {
@@ -467,9 +466,8 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs,
             res->corruptions++;
             if (fix & BDRV_FIX_ERRORS) {
                 prev_off = 0;
-                s->bat_bitmap[i] = 0;
+                parallels_set_bat_entry(s, i, 0);
                 res->corruptions_fixed++;
-                flush_bat = true;
                 continue;
             }
         }
@@ -485,15 +483,6 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs,
         prev_off = off;
     }
 
-    ret = 0;
-    if (flush_bat) {
-        ret = bdrv_co_pwrite_sync(bs->file, 0, s->header_size, s->header, 0);
-        if (ret < 0) {
-            res->check_errors++;
-            goto out;
-        }
-    }
-
     res->image_end_offset = high_off + s->cluster_size;
     if (size > res->image_end_offset) {
         int64_t count;
@@ -522,6 +511,12 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs,
 
 out:
     qemu_co_mutex_unlock(&s->lock);
+
+    ret = bdrv_co_flush(bs);
+    if (ret < 0) {
+        res->check_errors++;
+    }
+
     return ret;
 }
 
-- 
2.34.1
Re: [PATCH v3 3/8] parallels: Use generic infrastructure for BAT writing in parallels_co_check()
Posted by Vladimir Sementsov-Ogievskiy 3 years, 5 months ago 
On 8/15/22 12:02, Alexander Ivanov wrote:
> BAT is written in the context of conventional operations over
> the image inside bdrv_co_flush() when it calls
> parallels_co_flush_to_os() callback. Thus we should not
> modify BAT array directly, but call parallels_set_bat_entry()
> helper and bdrv_co_flush() further on. After that there is no
> need to manually write BAT and track its modification.
> 
> This makes code more generic and allows to split
> parallels_set_bat_entry() for independent pieces.
> 
> Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
> ---
> v2: Patch order was changed so the replacement is done in parallels_co_check.
>      Now we use a helper to set BAT entry and mark the block dirty.
> v3: Fix commit message.
> 
>   block/parallels.c | 19 +++++++------------
>   1 file changed, 7 insertions(+), 12 deletions(-)
> 
> diff --git a/block/parallels.c b/block/parallels.c
> index 7f68f3cbc9..6879ea4597 100644
> --- a/block/parallels.c
> +++ b/block/parallels.c
> @@ -428,7 +428,6 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs,
>       int64_t size, prev_off, high_off;
>       int ret;
>       uint32_t i;
> -    bool flush_bat = false;
>   
>       size = bdrv_getlength(bs->file->bs);
>       if (size < 0) {
> @@ -467,9 +466,8 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs,
>               res->corruptions++;
>               if (fix & BDRV_FIX_ERRORS) {
>                   prev_off = 0;
> -                s->bat_bitmap[i] = 0;
> +                parallels_set_bat_entry(s, i, 0);
>                   res->corruptions_fixed++;
> -                flush_bat = true;
>                   continue;
>               }
>           }
> @@ -485,15 +483,6 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs,
>           prev_off = off;
>       }
>   
> -    ret = 0;
> -    if (flush_bat) {
> -        ret = bdrv_co_pwrite_sync(bs->file, 0, s->header_size, s->header, 0);
> -        if (ret < 0) {
> -            res->check_errors++;
> -            goto out;
> -        }
> -    }
> -
>       res->image_end_offset = high_off + s->cluster_size;
>       if (size > res->image_end_offset) {
>           int64_t count;
> @@ -522,6 +511,12 @@ static int coroutine_fn parallels_co_check(BlockDriverState *bs,
>   
>   out:
>       qemu_co_mutex_unlock(&s->lock);
> +
> +    ret = bdrv_co_flush(bs);

Oops that's wrong. Here we probably rewrite previous error of bdrv_truncate stored in ret variable.

> +    if (ret < 0) {
> +        res->check_errors++;
> +    }
> +
>       return ret;
>   }
>   


-- 
Best regards,
Vladimir
Re: [PATCH v3 3/8] parallels: Use generic infrastructure for BAT writing in parallels_co_check()
Posted by Alexander Ivanov 3 years, 5 months ago 
On 17.08.2022 21:48, Vladimir Sementsov-Ogievskiy wrote:
> On 8/15/22 12:02, Alexander Ivanov wrote:
>> BAT is written in the context of conventional operations over
>> the image inside bdrv_co_flush() when it calls
>> parallels_co_flush_to_os() callback. Thus we should not
>> modify BAT array directly, but call parallels_set_bat_entry()
>> helper and bdrv_co_flush() further on. After that there is no
>> need to manually write BAT and track its modification.
>>
>> This makes code more generic and allows to split
>> parallels_set_bat_entry() for independent pieces.
>>
>> Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
>> ---
>> v2: Patch order was changed so the replacement is done in 
>> parallels_co_check.
>>      Now we use a helper to set BAT entry and mark the block dirty.
>> v3: Fix commit message.
>>
>>   block/parallels.c | 19 +++++++------------
>>   1 file changed, 7 insertions(+), 12 deletions(-)
>>
>> diff --git a/block/parallels.c b/block/parallels.c
>> index 7f68f3cbc9..6879ea4597 100644
>> --- a/block/parallels.c
>> +++ b/block/parallels.c
>> @@ -428,7 +428,6 @@ static int coroutine_fn 
>> parallels_co_check(BlockDriverState *bs,
>>       int64_t size, prev_off, high_off;
>>       int ret;
>>       uint32_t i;
>> -    bool flush_bat = false;
>>         size = bdrv_getlength(bs->file->bs);
>>       if (size < 0) {
>> @@ -467,9 +466,8 @@ static int coroutine_fn 
>> parallels_co_check(BlockDriverState *bs,
>>               res->corruptions++;
>>               if (fix & BDRV_FIX_ERRORS) {
>>                   prev_off = 0;
>> -                s->bat_bitmap[i] = 0;
>> +                parallels_set_bat_entry(s, i, 0);
>>                   res->corruptions_fixed++;
>> -                flush_bat = true;
>>                   continue;
>>               }
>>           }
>> @@ -485,15 +483,6 @@ static int coroutine_fn 
>> parallels_co_check(BlockDriverState *bs,
>>           prev_off = off;
>>       }
>>   -    ret = 0;
>> -    if (flush_bat) {
>> -        ret = bdrv_co_pwrite_sync(bs->file, 0, s->header_size, 
>> s->header, 0);
>> -        if (ret < 0) {
>> -            res->check_errors++;
>> -            goto out;
>> -        }
>> -    }
>> -
>>       res->image_end_offset = high_off + s->cluster_size;
>>       if (size > res->image_end_offset) {
>>           int64_t count;
>> @@ -522,6 +511,12 @@ static int coroutine_fn 
>> parallels_co_check(BlockDriverState *bs,
>>     out:
>>       qemu_co_mutex_unlock(&s->lock);
>> +
>> +    ret = bdrv_co_flush(bs);
>
> Oops that's wrong. Here we probably rewrite previous error of 
> bdrv_truncate stored in ret variable.

Good point!

As you said in 8/8, now it doesn't matter, but I'll fix it for the patch 
correctness.

>
>> +    if (ret < 0) {
>> +        res->check_errors++;
>> +    }
>> +
>>       return ret;
>>   }
>
>
Re: [PATCH v3 3/8] parallels: Use generic infrastructure for BAT writing in parallels_co_check()
Posted by Denis V. Lunev 3 years, 5 months ago 
On 17.08.2022 21:48, Vladimir Sementsov-Ogievskiy wrote:
> On 8/15/22 12:02, Alexander Ivanov wrote:
>> BAT is written in the context of conventional operations over
>> the image inside bdrv_co_flush() when it calls
>> parallels_co_flush_to_os() callback. Thus we should not
>> modify BAT array directly, but call parallels_set_bat_entry()
>> helper and bdrv_co_flush() further on. After that there is no
>> need to manually write BAT and track its modification.
>>
>> This makes code more generic and allows to split
>> parallels_set_bat_entry() for independent pieces.
>>
>> Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
>> ---
>> v2: Patch order was changed so the replacement is done in 
>> parallels_co_check.
>>      Now we use a helper to set BAT entry and mark the block dirty.
>> v3: Fix commit message.
>>
>>   block/parallels.c | 19 +++++++------------
>>   1 file changed, 7 insertions(+), 12 deletions(-)
>>
>> diff --git a/block/parallels.c b/block/parallels.c
>> index 7f68f3cbc9..6879ea4597 100644
>> --- a/block/parallels.c
>> +++ b/block/parallels.c
>> @@ -428,7 +428,6 @@ static int coroutine_fn 
>> parallels_co_check(BlockDriverState *bs,
>>       int64_t size, prev_off, high_off;
>>       int ret;
>>       uint32_t i;
>> -    bool flush_bat = false;
>>         size = bdrv_getlength(bs->file->bs);
>>       if (size < 0) {
>> @@ -467,9 +466,8 @@ static int coroutine_fn 
>> parallels_co_check(BlockDriverState *bs,
>>               res->corruptions++;
>>               if (fix & BDRV_FIX_ERRORS) {
>>                   prev_off = 0;
>> -                s->bat_bitmap[i] = 0;
>> +                parallels_set_bat_entry(s, i, 0);
>>                   res->corruptions_fixed++;
>> -                flush_bat = true;
>>                   continue;
>>               }
>>           }
>> @@ -485,15 +483,6 @@ static int coroutine_fn 
>> parallels_co_check(BlockDriverState *bs,
>>           prev_off = off;
>>       }
>>   -    ret = 0;
>> -    if (flush_bat) {
>> -        ret = bdrv_co_pwrite_sync(bs->file, 0, s->header_size, 
>> s->header, 0);
>> -        if (ret < 0) {
>> -            res->check_errors++;
>> -            goto out;
>> -        }
>> -    }
>> -
>>       res->image_end_offset = high_off + s->cluster_size;
>>       if (size > res->image_end_offset) {
>>           int64_t count;
>> @@ -522,6 +511,12 @@ static int coroutine_fn 
>> parallels_co_check(BlockDriverState *bs,
>>     out:
>>       qemu_co_mutex_unlock(&s->lock);
>> +
>> +    ret = bdrv_co_flush(bs);
>
> Oops that's wrong. Here we probably rewrite previous error of 
> bdrv_truncate stored in ret variable.
>

You absolutely right, we have missed this point.

Good catch!

>> +    if (ret < 0) {
>> +        res->check_errors++;
>> +    }
>> +
>>       return ret;
>>   }
>
>

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