Libguestfs - Apr 2019 - [PATCH nbdkit] log: Decode the extent type in output.

Instead of printing something like ‘type=0’ or ‘type=3’, this changes
the output to show the hole and zero flags separately.  For example:

  $ ./nbdkit -U - --filter=log sh - logfile=/dev/stdout \
      --run 'qemu-img map $nbd' <<'EOF'
  case "$1" in
     get_size) echo 1M ;;
     pread) dd if=/dev/zero count=$3 iflag=count_bytes ;;
     can_extents) exit 0 ;;
     extents)
         echo "0   32K    zero"
         echo "32K 32K    hole,zero"
         echo "64K 983040 "
         ;;
     *) exit 2 ;;
  esac
  EOF
  [...]
  2019-04-01 11:49:40.818357 connection=1 Extents id=2 offset=0x0 count=0x100000
req_one=1 ...
  2019-04-01 11:49:40.819848 connection=1 ...Extents id=2 extents=[{ offset=0x0,
length=0x8000, hole=0, zero=1 }, { offset=0x8000, length=0x8000, hole=1, zero=1
}, { offset=0x10000, length=0xf0000, hole=0, zero=0 }] return=0

Updates commit ed868b00f192cd72e91265e4fcdf3c3fbe8b7613.

Thanks: Martin Kletzander
---
 filters/log/log.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/filters/log/log.c b/filters/log/log.c
index 4878db2..02a2522 100644
--- a/filters/log/log.c
+++ b/filters/log/log.c
@@ -382,8 +382,10 @@ log_extents (struct nbdkit_next_ops *next_ops, void
*nxdata,
         if (i > 0)
           fprintf (fp, ", ");
         fprintf (fp, "{ offset=0x%" PRIx64 ", length=0x%"
PRIx64 ", "
-                 "type=%" PRIu32 " }",
-                 e.offset, e.length, e.type);
+                 "hole=%d, zero=%d }",
+                 e.offset, e.length,
+                 !!(e.type & NBDKIT_EXTENT_HOLE),
+                 !!(e.type & NBDKIT_EXTENT_ZERO));
       }
 
       fclose (fp);
-- 
2.20.1

On 4/1/19 6:53 AM, Richard W.M. Jones wrote:
> Instead of printing something like ‘type=0’ or ‘type=3’, this changes
> the output to show the hole and zero flags separately.  For example:
> 
>   $ ./nbdkit -U - --filter=log sh - logfile=/dev/stdout \
>       --run 'qemu-img map $nbd' <<'EOF'
>   case "$1" in
>      get_size) echo 1M ;;
>      pread) dd if=/dev/zero count=$3 iflag=count_bytes ;;
>      can_extents) exit 0 ;;
>      extents)
>          echo "0   32K    zero"
>          echo "32K 32K    hole,zero"
>          echo "64K 983040 "
>          ;;
>      *) exit 2 ;;
>   esac
>   EOF
>   [...]
>   2019-04-01 11:49:40.818357 connection=1 Extents id=2 offset=0x0
count=0x100000 req_one=1 ...
>   2019-04-01 11:49:40.819848 connection=1 ...Extents id=2 extents=[{
offset=0x0, length=0x8000, hole=0, zero=1 }, { offset=0x8000, length=0x8000,
hole=1, zero=1 }, { offset=0x10000, length=0xf0000, hole=0, zero=0 }] return=0
> 
> Updates commit ed868b00f192cd72e91265e4fcdf3c3fbe8b7613.
Yes, that's nicer.
> 
> Thanks: Martin Kletzander
> ---
>  filters/log/log.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org

On Mon, Apr 01, 2019 at 07:40:14AM -0500, Eric Blake
wrote:
>On 4/1/19 6:53 AM, Richard W.M. Jones wrote:
>> Instead of printing something like ‘type=0’ or ‘type=3’, this changes
>> the output to show the hole and zero flags separately.  For example:
>>
>>   $ ./nbdkit -U - --filter=log sh - logfile=/dev/stdout \
>>       --run 'qemu-img map $nbd' <<'EOF'
>>   case "$1" in
>>      get_size) echo 1M ;;
>>      pread) dd if=/dev/zero count=$3 iflag=count_bytes ;;
>>      can_extents) exit 0 ;;
>>      extents)
>>          echo "0   32K    zero"
>>          echo "32K 32K    hole,zero"
>>          echo "64K 983040 "
>>          ;;
>>      *) exit 2 ;;
>>   esac
>>   EOF
>>   [...]
>>   2019-04-01 11:49:40.818357 connection=1 Extents id=2 offset=0x0
count=0x100000 req_one=1 ...
>>   2019-04-01 11:49:40.819848 connection=1 ...Extents id=2 extents=[{
offset=0x0, length=0x8000, hole=0, zero=1 }, { offset=0x8000, length=0x8000,
hole=1, zero=1 }, { offset=0x10000, length=0xf0000, hole=0, zero=0 }] return=0
>>
>> Updates commit ed868b00f192cd72e91265e4fcdf3c3fbe8b7613.
>
>Yes, that's nicer.
>
Even nicer than what I thought of.
>>
>> Thanks: Martin Kletzander
>> ---
>>  filters/log/log.c | 6 ++++--
>>  1 file changed, 4 insertions(+), 2 deletions(-)
>
>
>-- 
>Eric Blake, Principal Software Engineer
>Red Hat, Inc.           +1-919-301-3226
>Virtualization:  qemu.org | libvirt.org
>


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