[Qemu-devel] [Bug 1462949] [NEW] vmdk files cause qemu-img to consume lots of time and memory

[Richard Jones]

Public bug reported:

The two attached files cause 'qemu-img info' to consume lots of time and
memory.  Around 10-12 seconds of CPU time, and around 3-4 GB of heap.

$ /usr/bin/time ~/d/qemu/qemu-img info afl10.img 
qemu-img: Can't get size of device 'image': File too large
0.40user 11.57system 0:12.03elapsed 99%CPU (0avgtext+0avgdata 
4197804maxresident)k
56inputs+0outputs (0major+1045672minor)pagefaults 0swaps

$ /usr/bin/time ~/d/qemu/qemu-img info afl11.img 
image: afl11.img
file format: vmdk
virtual size: 12802T (14075741666803712 bytes)
disk size: 4.0K
cluster_size: 65536
Format specific information:
    cid: 4294967295
    parent cid: 4294967295
    create type: monolithicSparse
    extents:
        [0]:
            virtual size: 14075741666803712
            filename: afl11.img
            cluster size: 65536
            format: 
0.29user 9.10system 0:09.43elapsed 99%CPU (0avgtext+0avgdata 
3297360maxresident)k
8inputs+0outputs (0major+820507minor)pagefaults 0swaps

** Affects: qemu
     Importance: Undecided
         Status: New

** Attachment added: "afl10.img"
   https://bugs.launchpad.net/bugs/1462949/+attachment/4411475/+files/afl10.img

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https://bugs.launchpad.net/bugs/1462949

Title:
  vmdk files cause qemu-img to consume lots of time and memory

Status in QEMU:
  New

Bug description:
  The two attached files cause 'qemu-img info' to consume lots of time
  and memory.  Around 10-12 seconds of CPU time, and around 3-4 GB of
  heap.

  $ /usr/bin/time ~/d/qemu/qemu-img info afl10.img 
  qemu-img: Can't get size of device 'image': File too large
  0.40user 11.57system 0:12.03elapsed 99%CPU (0avgtext+0avgdata 
4197804maxresident)k
  56inputs+0outputs (0major+1045672minor)pagefaults 0swaps

  $ /usr/bin/time ~/d/qemu/qemu-img info afl11.img 
  image: afl11.img
  file format: vmdk
  virtual size: 12802T (14075741666803712 bytes)
  disk size: 4.0K
  cluster_size: 65536
  Format specific information:
      cid: 4294967295
      parent cid: 4294967295
      create type: monolithicSparse
      extents:
          [0]:
              virtual size: 14075741666803712
              filename: afl11.img
              cluster size: 65536
              format: 
  0.29user 9.10system 0:09.43elapsed 99%CPU (0avgtext+0avgdata 
3297360maxresident)k
  8inputs+0outputs (0major+820507minor)pagefaults 0swaps

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