this patch makes sure that it terminates if any IO in
progress and also makes sure that all the buffers are unmapped.
It was observed that with several runs of application the application
sometimes failed to allocate memory, This patch makes sure it
all the buffers are released.

Using kmemleak it was found that buffer were not released, this patch
fixes following issue,

 echo scan > /sys/kernel/debug/kmemleak
  Kernel message reads:
      memleak: 3 new suspected memory leaks (see /sys/kernel/debug/kmemleak)

Then,
     cat /sys/kernel/debug/kmemleak

  unreferenced object 0xc564a480 (size 192):
  comm "mttest", pid 764, jiffies 4294945878 (age 487.160s)
  hex dump (first 32 bytes):
    00 00 00 00 28 07 07 20 d0 02 00 00 e0 01 00 00  ....(.. ........
    00 00 00 00 00 64 05 00 01 00 00 00 01 00 00 00  .....d..........
  backtrace:
    [<c00a98dc>] create_object+0x10c/0x28c
    [<c03ba8ec>] kmemleak_alloc+0x3c/0x70
    [<c00a67c0>] __kmalloc+0x11c/0x1d4
    [<c02b6f48>] __videobuf_alloc+0x1c/0x3c
    [<c02b6194>] videobuf_alloc_vb+0x38/0x80
    [<c02b6638>] __videobuf_mmap_setup+0x9c/0x108
    [<c02b6da0>] videobuf_reqbufs.part.10+0x12c/0x1bc
    [<c02b6e9c>] videobuf_reqbufs+0x6c/0x8c
    [<c02be2c4>] vpfe_reqbufs+0xcc/0x130
    [<c02aae90>] v4l_reqbufs+0x50/0x54
    [<c02aab54>] __video_do_ioctl+0x260/0x2c4
    [<c02a9dd4>] video_usercopy+0xf0/0x310
    [<c02aa008>] video_ioctl2+0x14/0x1c
    [<c02a562c>] v4l2_ioctl+0x104/0x14c
    [<c00bd320>] do_vfs_ioctl+0x80/0x2d0
    [<c00bd5b4>] SyS_ioctl+0x44/0x64
unreferenced object 0xc564ac00 (size 192):
  comm "mttest", pid 764, jiffies 4294945878 (age 487.160s)
  hex dump (first 32 bytes):
    01 00 00 00 28 07 07 20 d0 02 00 00 e0 01 00 00  ....(.. ........
    00 00 00 00 00 64 05 00 01 00 00 00 01 00 00 00  .....d..........
  backtrace:
    [<c00a98dc>] create_object+0x10c/0x28c
    [<c03ba8ec>] kmemleak_alloc+0x3c/0x70
    [<c00a67c0>] __kmalloc+0x11c/0x1d4
    [<c02b6f48>] __videobuf_alloc+0x1c/0x3c
    [<c02b6194>] videobuf_alloc_vb+0x38/0x80
    [<c02b6638>] __videobuf_mmap_setup+0x9c/0x108
    [<c02b6da0>] videobuf_reqbufs.part.10+0x12c/0x1bc
    [<c02b6e9c>] videobuf_reqbufs+0x6c/0x8c
    [<c02be2c4>] vpfe_reqbufs+0xcc/0x130
    [<c02aae90>] v4l_reqbufs+0x50/0x54
    [<c02aab54>] __video_do_ioctl+0x260/0x2c4
    [<c02a9dd4>] video_usercopy+0xf0/0x310
    [<c02aa008>] video_ioctl2+0x14/0x1c
    [<c02a562c>] v4l2_ioctl+0x104/0x14c
    [<c00bd320>] do_vfs_ioctl+0x80/0x2d0
    [<c00bd5b4>] SyS_ioctl+0x44/0x64
unreferenced object 0xc564a180 (size 192):
  comm "mttest", pid 764, jiffies 4294945880 (age 487.140s)
  hex dump (first 32 bytes):
    02 00 00 00 28 07 07 20 d0 02 00 00 e0 01 00 00  ....(.. ........
    00 00 00 00 00 64 05 00 01 00 00 00 01 00 00 00  .....d..........
  backtrace:
    [<c00a98dc>] create_object+0x10c/0x28c
    [<c03ba8ec>] kmemleak_alloc+0x3c/0x70
    [<c00a67c0>] __kmalloc+0x11c/0x1d4
    [<c02b6f48>] __videobuf_alloc+0x1c/0x3c
    [<c02b6194>] videobuf_alloc_vb+0x38/0x80
    [<c02b6638>] __videobuf_mmap_setup+0x9c/0x108
    [<c02b6da0>] videobuf_reqbufs.part.10+0x12c/0x1bc
    [<c02b6e9c>] videobuf_reqbufs+0x6c/0x8c
    [<c02be2c4>] vpfe_reqbufs+0xcc/0x130
    [<c02aae90>] v4l_reqbufs+0x50/0x54
    [<c02aab54>] __video_do_ioctl+0x260/0x2c4
    [<c02a9dd4>] video_usercopy+0xf0/0x310
    [<c02aa008>] video_ioctl2+0x14/0x1c
    [<c02a562c>] v4l2_ioctl+0x104/0x14c
    [<c00bd320>] do_vfs_ioctl+0x80/0x2d0
    [<c00bd5b4>] SyS_ioctl+0x44/0x64
Reported-by: Jimmy Ho <jimmygge@gmail.com>
Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>