The commit 39793c69 "[media] mx2_camera: Convert it to platform driver"
used module_platform_driver() to make code smaller,
but since the driver used platform_driver_probe is more appropriate
to use module_platform_driver_probe().
Signed-off-by: Fabio Porcedda <fabio.porcedda@gmail.com>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

This patch converts the drivers to use the
module_platform_driver_probe() macro which makes the code smaller and
a bit simpler.
Signed-off-by: Fabio Porcedda <fabio.porcedda@gmail.com>
[g.liakhovetski@gmx.de: also remove redundant .probe initialisation]
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

To protect against open() racing with rmmod, hold the list_lock also while
obtaining a reference to the camera host driver and check that the video
device hasn't been unregistered yet.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

As reported by Dan Carpenter:
	FYI, there are new smatch warnings show up in

	tree:   git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next master
	head:   da17d7bda957ae4697b6abc0793f74fb9b50b58f
	commit: 4c3bdb5e [media] siano: better debug send/receive messages

	drivers/media/common/siano/smscoreapi.c:396 smscore_translate_msg() error: buffer overflow 'siano_msgs' 401 <= 401

While it is almost impossible for this error to happen in
practice, as it would require the siano's firmware to return
an special invalid answer to a message request, fixing it
is trivial. So, let's do it.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Linux 3.9-rc5

* tag 'v3.9-rc5': (1080 commits)
  Linux 3.9-rc5
  Revert "lockdep: check that no locks held at freeze time"
  dw_dmac: adjust slave_id accordingly to request line base
  dmaengine: dw_dma: fix endianess for DT xlate function
  PNP: List Rafael Wysocki as a maintainer
  rbd: don't zero-fill non-image object requests
  ia64 idle: delete stale (*idle)() function pointer
  Btrfs: don't drop path when printing out tree errors in scrub
  target: Fix RESERVATION_CONFLICT status regression for iscsi-target special case
  tcm_vhost: Avoid VIRTIO_RING_F_EVENT_IDX feature bit
  Revert "mm: introduce VM_POPULATE flag to better deal with racy userspace programs"
  usb: ftdi_sio: Add support for Mitsubishi FX-USB-AW/-BD
  mg_disk: fix error return code in mg_probe()
  Btrfs: fix wrong return value of btrfs_lookup_csum()
  Btrfs: fix wrong reservation of csums
  Btrfs: fix double free in the btrfs_qgroup_account_ref()
  Btrfs: limit the global reserve to 512mb
  Btrfs: hold the ordered operations mutex when waiting on ordered extents
  Btrfs: fix space accounting for unlink and rename
  Btrfs: fix space leak when we fail to reserve metadata space
  ...

Pull slave-dmaengine fixes from Vinod Koul:
 "Two fixes for slave-dmaengine.

  The first one is for making slave_id value correct for dw_dmac and
  the other one fixes the endieness in DT parsing"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  dw_dmac: adjust slave_id accordingly to request line base
  dmaengine: dw_dma: fix endianess for DT xlate function

Pull media fixes from Mauro Carvalho Chehab:
 "For a some fixes for Kernel 3.9:
   - subsystem build fix when VIDEO_DEV=y, VIDEO_V4L2=m and I2C=m
   - compilation fix for arm multiarch preventing IR_RX51 to be selected
   - regression fix at bttv crop logic
   - s5p-mfc/m5mols/exynos: a few fixes for cameras on exynos hardware"

* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  [media] [REGRESSION] bt8xx: Fix too large height in cropcap
  [media] fix compilation with both V4L2 and I2C as 'm'
  [media] m5mols: Fix bug in stream on handler
  [media] s5p-fimc: Do not attempt to disable not enabled media pipeline
  [media] s5p-mfc: Fix encoder control 15 issue
  [media] s5p-mfc: Fix frame skip bug
  [media] s5p-fimc: send valid m2m ctx to fimc_m2m_job_finish
  [media] exynos-gsc: send valid m2m ctx to gsc_m2m_job_finish
  [media] fimc-lite: Fix the variable type to avoid possible crash
  [media] fimc-lite: Initialize 'step' field in fimc_lite_ctrl structure
  [media] ir: IR_RX51 only works on OMAP2

Pull block fixes from Jens Axboe:
 "Alright, this time from 10K up in the air.

  Collection of fixes that have been queued up since the merge window
  opened, hence postponed until later in the cycle.  The pull request
  contains:

   - A bunch of fixes for the xen blk front/back driver.

   - A round of fixes for the new IBM RamSan driver, fixing various
     nasty issues.

   - Fixes for multiple drives from Wei Yongjun, bad handling of return
     values and wrong pointer math.

   - A fix for loop properly killing partitions when being detached."

* tag 'for-linus-20130331' of git://git.kernel.dk/linux-block: (25 commits)
  mg_disk: fix error return code in mg_probe()
  rsxx: remove unused variable
  rsxx: enable error return of rsxx_eeh_save_issued_dmas()
  block: removes dynamic allocation on stack
  Block: blk-flush: Fixed indent code style
  cciss: fix invalid use of sizeof in cciss_find_cfgtables()
  loop: cleanup partitions when detaching loop device
  loop: fix error return code in loop_add()
  mtip32xx: fix error return code in mtip_pci_probe()
  xen-blkfront: remove frame list from blk_shadow
  xen-blkfront: pre-allocate pages for requests
  xen-blkback: don't store dev_bus_addr
  xen-blkfront: switch from llist to list
  xen-blkback: fix foreach_grant_safe to handle empty lists
  xen-blkfront: replace kmalloc and then memcpy with kmemdup
  xen-blkback: fix dispatch_rw_block_io() error path
  rsxx: fix missing unlock on error return in rsxx_eeh_remap_dmas()
  Adding in EEH support to the IBM FlashSystem 70/80 device driver
  block: IBM RamSan 70/80 error message bug fix.
  block: IBM RamSan 70/80 branding changes.
  ...

This reverts commit 6aa97070.

Commit 6aa97070 ("lockdep: check that no locks held at freeze time")
causes problems with NFS root filesystems.  The failures were noticed on
OMAP2 and 3 boards during kernel init:

  [ BUG: swapper/0/1 still has locks held! ]
  3.9.0-rc3-00344-ga937536b #1 Not tainted
  -------------------------------------
  1 lock held by swapper/0/1:
   #0:  (&type->s_umount_key#13/1){+.+.+.}, at: [<c011e84c>] sget+0x248/0x574

  stack backtrace:
    rpc_wait_bit_killable
    __wait_on_bit
    out_of_line_wait_on_bit
    __rpc_execute
    rpc_run_task
    rpc_call_sync
    nfs_proc_get_root
    nfs_get_root
    nfs_fs_mount_common
    nfs_try_mount
    nfs_fs_mount
    mount_fs
    vfs_kern_mount
    do_mount
    sys_mount
    do_mount_root
    mount_root
    prepare_namespace
    kernel_init_freeable
    kernel_init

Although the rootfs mounts, the system is unstable.  Here's a transcript
from a PM test:

  http://www.pwsan.com/omap/testlogs/test_v3.9-rc3/20130317194234/pm/37xxevm/37xxevm_log.txt

Here's what the test log should look like:

  http://www.pwsan.com/omap/testlogs/test_v3.8/20130218214403/pm/37xxevm/37xxevm_log.txt

Mailing list discussion is here:

  http://lkml.org/lkml/2013/3/4/221

Deal with this for v3.9 by reverting the problem commit, until folks can
figure out the right long-term course of action.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Mandeep Singh Baines <msb@chromium.org>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: <maciej.rutecki@gmail.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ben Chan <benchan@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

radio-si476x depends on SND and SND_SOC, the mfd driver should select
REGMAP_I2C.
Also fix a small compile warning in a debug message:
drivers/mfd/si476x-i2c.c: In function ‘si476x_core_drain_rds_fifo’:
drivers/mfd/si476x-i2c.c:391:4: warning: field width specifier ‘*’ expects argument of type ‘int’, but argument 4 has type ‘long unsigned int’ [-Wformat]
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/usb/dvb-usb/m920x.c:91:6: warning: "ret" may be used uninitialized in this function [-Wuninitialized]
drivers/media/usb/dvb-usb/m920x.c:70:6: note: "ret" was declared here
This is real, if a remote control has an empty initialization sequence
we would get success or failure randomly.
OTOH the initialization of ret in m920x_init is needless, the function
returns with an error as soon as an error happens, so the last return
can only be a success and we can hard-code 0 there.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

em28xx: fix typo in scale_to_size().
The second hscale should be vscale. This bug caused xawtv to fail because it
cannot find a workable image size.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

The s5p-fimc directory now contains drivers for multiple IP blocks
found in multiple Samsung application processors. This includes FIMC
(CAMIF), MIPI CSIS and FIMC LITE. FIMC-IS (Imaging Subsystem) driver
is going to be put into same directory. Hence we rename it to
exynos4-is as s5p-fimc was only relevant for early version of this
driver, when it only supported FIMC IP block.

The imaging subsystem drivers for Exynos4 SoC series and S5PV210 will
be included in drivers/media/platform/exynos4-is directory, with some
modules shared with exynos5 series, while the rest of exynos5 specific
modules will find their home in drivers/media/platform/exynos5-is.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Drop fimc-lite.h header inclusion to make the exynos-fimc-lite
module independent on other modules. Move struct fimc_fmt
declaration to the driver's private headers as it is used in
multiple modules.
Reported-by: Shaik Ameer Basha <shaik.ameer@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Since the FIMC-IS firmware communicates with an image sensor directly
through the ISP I2C bus controllers the sub-devices power supplies
cannot be simply enabled from left to right or disabled from right
to left along the processing pipeline. Thus a subdev index to call
s_power() on is looked up from a table, rather than doing the op call
based on increasing/decreasing indexes.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Since the FIMC-IS firmware communicates with an image sensor directly
through the ISP I2C bus controllers data streaming cannot be simply
enabled from left to right or disabled from right to left along the
processing pipeline. Thus a subdev index to call s_stream() on is
looked up from a table, rather than doing the op call based on
increasing/decreasing indexes.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

In configurations where FIMC-LITE is used to capture image signal
from an external sensor only we need to ensure one of FIMC devices
is in active power state and the "fimc" gate clock is enabled.
Otherwise the CAMCLK clock output signal will be masked off
preventing an external sensor's operation.
This affect processing pipelines like:
 - sensor -> FIMC-LITE -> memory
 - sensor -> MIPI-CSIS -> FIMC-LITE -> memory
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

A second sink pad is added to each FIMC.N subdev that will be used
to link it to the FIMC-IS-ISP subdev. Only V4L2_MBUS_FMT_YUV10_1X30
format is supported at this pad (FIMC_SD_PAD_SINK_FIFO).
The routine checking for mismatch in the image formats at sides of
the links is updated to account for the fact FIMC.X subdevs now have
sink pads at the pad indexes 0, 1 and source pad at pad index 2.
If link to FIMC.X pad 1 is activated we switch FIMC input data bus
type to the ISP Writeback. Only a single active link to FIMC.X pad 0
or 1 will be allowed at any time.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

This patch ads handling of clocks for the CAMBLK subsystem which
is a glue logic for FIMC-IS or LCD controller and FIMC IP.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

We cannot assume that the passed entity the fimc_pipeline_prepare()
function is supposed to start the media graph traversal from will
always have its sink pad at pad index 0. Find the starting media
entity's sink pad by iterating over its all pads and checking the
pad flags. This ensures proper handling of FIMC, FIMC-LITE and
FIMC-IS-ISP subdevs that have more than one sink and one source pad.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

set_stream error for pipelines is logged or reported to user
space if possible.
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

This patch adds a menu option to the V4L2_CID_EXPOSURE_METERING
control for multi-zone metering.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Before the camera ports can be used the pinmux needs to be configured
properly. This patch adds a function to set the camera ports pinctrl
to a default state within the media driver's probe().
The camera port(s) are then configured for the video bus operation.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

The sensor (I2C and/or SPI client) devices are instantiated by their
corresponding control bus drivers. Since the I2C client's master clock
is often provided by a video bus receiver (host interface) or other
than I2C/SPI controller device, the drivers of those client devices
are not accessing hardware in their driver's probe() callback. Instead,
after enabling clock, the host driver calls back into a sub-device
when it wants to activate them. This pattern is used by some in-tree
drivers and this patch also uses it for DT case. This patch is intended
as a first step for adding device tree support to the S5P/Exynos SoC
camera drivers. The second one is adding support for asynchronous
sub-devices registration and clock control from sub-device driver
level. The bindings shall not change when asynchronous probing support
is added.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

This patch adds changes required for the main camera media device
driver corresponding to the top level 'camera' device node.
The drivers of devices corresponding to child nodes of the 'camera'
node are looked up and and registered as sub-devices to the top
level driver. The main driver's probing is deferred if any of the
sub-device drivers is not yet initialized and ready.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

This patch adds the device tree support for FIMC-LITE device
driver. The bindings include compatible property for the Exynos5
SoC series, however the actual implementation for these SoCs will
be added in a separate patch.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

This patch adds device tree support for FIMC driver on S5PV210
and Exynos4 SoCs.
The FIMC IP block's features and quirks encoded statically in
the driver are now parsed from the device tree. Once all relevant
platforms are converted to device tree based booting the FIMC
variant data structures will all be removed from the driver.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

This patch support for binding the driver to the MIPI-CSIS
devices instantiated from device tree and parsing the SoC
and board specific properties. The MIPI CSI-2 channel is
determined by the value of reg property placed in csis'
port subnode.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Replace some ioctl, file and video buffer queue operation handlers
with the videobuf2 helpers. This allows to get rid of significant
amount of boilerplate.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

mmap/poll file operation and several ioctl handlers are replaced
with the vb2 helper functions. Some helpers are used indirectly
to maintain the buffer queue ownership.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

It doesn't matter whether we start from the sensor of from
the video node entity. Remove use of pipeline->subdevs array
where possible, so we can partly drop dependency on struct
fimc_pipeline in the fimc-lite module, which is also used
by the exynos5-is driver.
Also make sure we revert any media entity pipeline operations
when vb2_streamon() function fails.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Add a V4L2 OF parser, implementing bindings documented in
Documentation/devicetree/bindings/media/video-interfaces.txt.
[s.nawrocki@samsung.com: various corrections and improvements
since the initial version]
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

This patch adds a document describing common OF bindings for video
capture, output and video processing devices. It is curently mainly
focused on video capture devices, with data busses defined by
standards such as ITU-R BT.656 or MIPI-CSI2.
It also documents a method of describing data links between devices.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

Pull SCSI target fixes from Nicholas Bellinger:
 "This includes the bug-fix for a >= v3.8-rc1 regression specific to
  iscsi-target persistent reservation conflict handling (CC'ed to
  stable), and a tcm_vhost patch to drop VIRTIO_RING_F_EVENT_IDX usage
  so that in-flight qemu vhost-scsi-pci device code can detect the
  proper vhost feature bits.

  Also, there are two more tcm_vhost patches still being discussed by
  MST and Asias for v3.9 that will be required for the in-flight qemu
  vhost-scsi-pci device patch to function properly, and that should
  (hopefully) be the last target fixes for this round."

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  target: Fix RESERVATION_CONFLICT status regression for iscsi-target special case
  tcm_vhost: Avoid VIRTIO_RING_F_EVENT_IDX feature bit

On some hardware configurations we have got the request line with the offset.
The patch introduces convert_slave_id() helper for that cases. The request line
base is came from the driver data provided by the platform_device_id table.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

As reported by Wu Fengguang's build robot tracking sparse warnings, the
dma_spec arguments in the dw_dma_xlate are already byte swapped on
little-endian platforms and must not get swapped again. This code is
currently not used anywhere, but will be used in Linux 3.10 when the
ARM SPEAr platform starts using the generic DMA DT binding.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

The Adam Belay's e-mail address in MAINTAINERS under PNP SUPPORT
is not valid any more and I started to maintain that code in the
meantime as a matter of fact, so list myself as a maintainer of it
along with Bjorn and remove the Adam's entry from it.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull ceph fix from Sage Weil:
 "This fixes a regression introduced during the last merge window when
  mapping non-existent images."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: don't zero-fill non-image object requests

A result of ENOENT from a read request for an object that's part of
an rbd image indicates that there is a hole in that portion of the
image.  Similarly, a short read for such an object indicates that
the remainder of the read should be interpreted a full read with
zeros filling out the end of the request.

This behavior is not correct for objects that are not backing rbd
image data.  Currently rbd_img_obj_request_callback() assumes it
should be done for all objects.

Change rbd_img_obj_request_callback() so it only does this zeroing
for image objects.  Encapsulate that special handling in its own
function.  Add an assertion that the image object request is a bio
request, since we assume that (and we currently don't support any
other types).

This resolves a problem identified here:
    http://tracker.ceph.com/issues/4559

The regression was introduced by bf0d5f50.
Reported-by: Dan van der Ster <dan@vanderster.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-off-by: Sage Weil <sage@inktank.com>