In some cases it is useful to not overwrite connection parametes and
instead just create default ones if they don't exist. This function
does exactly that. hci_conn_params_add will allow to create new
default connection parameters. hci_conn_params_set will set the
values and also create new parameters if they don't exist.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Store the connection latency and supervision timeout default values
with all the other controller defaults. And when needed use them
for new connections.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
When devices are added or removed, then make sure that events are send
out to all other clients so that the list of devices can be easily
tracked. This is especially important when external clients are
adding or removing devices within the auto-connection list.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This allows adding or removing devices from the background scanning
list the kernel maintains. Device flagged for auto-connection will
be automatically connected if they are found.
The passive scanning required for auto-connection will be started
and stopped on demand.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
When the slave updates the connection parameters, store also the
connection latency and supervision timeout information in the
internal list of connection parameters for known devices.
Having these values available allowes the auto-connection
procedure to use the correct values from the beginning without
having to request an update on every connection establishment.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This patch implements support for the Get Clock Information mgmt
command. This is done by performing one or two HCI_Read_Clock commands
and creating the response from the stored values in the hci_dev and
hci_conn structs.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch adds support for storing the local and piconet clock values
from the HCI_Read_Clock command response to the hci_dev and hci_conn
structs. This will be later used in another patch to implement support
for the Get Clock Info mgmt command.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When the connection is in master role and it is going to be
disconnected based on the disconnection timeout, then send
the HCI_Read_Clock_Offset command in an attempt to update the
clock offset value in the inquiry cache.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The smp_conn member of struct hci_conn was simply a pointer to the
l2cap_conn object. Since we already have hcon->l2cap_data that points to
the same thing there's no need to have this second variable. This patch
removes it and changes the single place that was using it to use
hcon->l2cap_data instead.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch replaces the hard-coded value in hci_bdaddr_is_rpa() helper
by the corresponding macro ADDR_LE_DEV_RANDOM.
Signed-off-by: Andre Guedes <andre.guedes@openbossa.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Since the link_mode member of the hci_conn struct is a bit field and we
already have a flags member as well it makes sense to merge these two
together. This patch moves all used link_mode bits into corresponding
flags. To keep backwards compatibility with user space we still need to
provide a get_link_mode() helper function for the ioctl's that expect a
link_mode style value.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
To pave the way for actively using debug keys for pairing this patch
adds a new HCI_USE_DEBUG_KEYS flag for the purpose. When the flag is set
we issue a HCI_Write_SSP_Debug mode whenever HCI_Write_SSP_Mode(0x01)
has been issued as well as before issuing a HCI_Write_SSP_Mode(0x00)
command.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There's no point in having boolean variables in the hci_conn struct
since it already has a flags member. This patch converts the flush_key
member into a proper flag.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We're planning to add a flag to actively use debug keys in addition to
simply just accepting them, which makes the current generically named
DEBUG_KEYS flag a bit confusing. Since the flag in practice affects
whether the kernel keeps debug keys around or not rename it to
HCI_KEEP_DEBUG_KEYS.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There are two callers of hci_add_link_key(). The first one is the HCI
Link Key Notification event and the second one the mgmt code that
receives a list of link keys from user space. Previously we've had the
hci_add_link_key() function being responsible for also emitting a mgmt
signal but for the latter use case this should not happen. Because of
this a rather awkward new_key paramter has been passed to the function.
This patch moves the mgmt event sending out from the hci_add_link_key()
function, thereby making the code a bit more understandable.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
By returning the added (or updated) key we pave the way for further
refactoring (in subsequent patches) that allows moving the mgmt event
sending out from this function (and thereby removal of the awkward
new_key parameter).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When the LE controller changes its connection parameters, it will send
a connection parameter update event. Make sure that the new set of
parameters are stored in hci_conn struct and thus will properly update
the previous values retrieved from the connection complete event.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The LE connection parameters are needed later on to be able to decide
if it is required to trigger connection update procedures. So when the
connection has been established successfully, store the current used
parameters in hci_conn struct.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Create a CoC dynamically instead of one fixed channel for communication
to peer devices.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The highly optimized TX path for L2CAP channels and its fragmentation
within the HCI ACL packets requires to copy data from user provided
IO vectors and also kernel provided memory buffers.
This patch allows channel clients to provide a memcpy_fromiovec callback
to keep this optimized behavior, but adapt it to kernel vs user memory
for the TX path. For all kernel internal L2CAP channels, a default
implementation is provided that can be referenced.
In case of A2MP, this fixes a long-standing issue with wrongly accessing
kernel memory as user memory.
This patch originally by Marcel Holtmann.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
All the special settings configured via debugfs are either developer
only options or temporary solutions. To not clutter the standard flags,
move them to their own dbg_flags entry.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
These defines were probably put in to track authenticated vs
unauthenticated LTKs, however since the LTK struct has a separate
boolean authenticated member these were never used.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The LTK type has really nothing to do with HCI so it makes more sense to
have these in smp.h than hci.h. This patch moves the defines to smp.h
and removes the HCI_ prefix in the same go.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We never store the "master" type of STKs since we request encryption
directly with them so we only need one STK type (the one that's
looked-up on the slave side). Simply remove the unnecessary define and
rename the _SLAVE one to the shorter form.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Since the whole HCI command, event and data packet processing has been
migrated to use workqueues instead of tasklets, it makes sense to use
struct delayed_work instead of struct timer_list for the timeout
handling. This patch converts the hdev->cmd_timer to use workqueue
as well.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
When allocating the L2CAP SKB for transmission, provide the upper layers
with a clear distinction on what is the header and what is the body
portion of the SKB.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The struct l2cap_ctrl fields are wasting an unsigned int when all the
bits can fit into an __u8 field.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The SKB for L2CAP sockets are all allocated in a central callback
in the socket support. Instead of having to pass around the socket
priority all the time, assign it to skb->priority when actually
allocating the SKB.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The struct l2cap_ops field should not allow any modifications and thus
it is better declared as const.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Driver is now responsible for veryfing if the
switch is possible.
Since this is inherently tricky driver may decide
to disconnect an interface later with
cfg80211_stop_iface().
This doesn't mean driver can accept everything. It
should do it's best to verify requests and reject
them as soon as possible.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Multi-vif in-place reservations happen when
it is impossible to allocate more channel contexts
as indicated by interface combinations.
Such reservations are not finalized until all
assigned interfaces are ready.
This still doesn't handle all possible cases
(i.e. degradation of number of channels) properly.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Split sched scan IEs to band specific and not band specific
blocks. Common IEs blocks may be sent to the FW once per command,
instead of per band.
This allows optimization of size of the command, which may be
required by some drivers (eg. iwlmvm with newer firmware version).
As this changes the mac80211 API, update all drivers to use the
new version correctly, even if they don't (yet) make use of the
split data.
Signed-off-by: David Spinadel <david.spinadel@intel.com>
Reviewed-by: Alexander Bondar <alexander.bondar@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Some drivers (such as iwlmvm) can handle multiple bands in a single
HW scan request. Add a HW flag to indicate that the driver support
this. To hold the required data, create a separate structure for
HW scan request that holds cfg scan request and data about
different parts of the scan IEs.
As this changes the mac80211 API, update all drivers using it to
use the correct new function type/argument.
Signed-off-by: David Spinadel <david.spinadel@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
After sending a TDLS discovery-request, we expect a reply to arrive on
the AP's channel. We must stay on the channel (no PSM, scan, etc.), since
a TDLS setup-response is a direct packet not buffered by the AP.
Add a new mac80211 driver callback to allow discovery session protection.
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Write a mac80211 to the cfg80211 API for requesting a userspace TDLS
operation. Define TDLS specific reason codes that can be used here.
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The TDLS initiator is set once during link setup. If determines the
address ordering in the link identifier IE.
Fix dependent drivers - mwifiex and mac80211.
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Currently, cfg80211 tries to implement ethtool, but that doesn't
really scale well, with all the different operations. Make the
lower-level driver responsible for it, which currently only has
an effect on mac80211. It will similarly not scale well at that
level though, since mac80211 also has many drivers.
To cleanly implement this in mac80211, introduce a new file and
move some code to appropriate places.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Pull networking fixes from David Miller:
1) Fix checksumming regressions, from Tom Herbert.
2) Undo unintentional permissions changes for SCTP rto_alpha and
rto_beta sysfs knobs, from Denial Borkmann.
3) VXLAN, like other IP tunnels, should advertize it's encapsulation
size using dev->needed_headroom instead of dev->hard_header_len.
From Cong Wang.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
net: sctp: fix permissions for rto_alpha and rto_beta knobs
vxlan: Checksum fixes
net: add skb_pop_rcv_encapsulation
udp: call __skb_checksum_complete when doing full checksum
net: Fix save software checksum complete
net: Fix GSO constants to match NETIF flags
udp: ipv4: do not waste time in __udp4_lib_mcast_demux_lookup
vxlan: use dev->needed_headroom instead of dev->hard_header_len
MAINTAINERS: update cxgb4 maintainer
Pull more clock framework updates from Mike Turquette:
"This contains the second half the of the clk changes for 3.16.
They are simply fixes and code refactoring for the OMAP clock drivers.
The sunxi clock driver changes include splitting out the one
mega-driver into several smaller pieces and adding support for the A31
SoC clocks"
* tag 'clk-for-linus-3.16-part2' of git://git.linaro.org/people/mike.turquette/linux: (25 commits)
clk: sunxi: document PRCM clock compatible strings
clk: sunxi: add PRCM (Power/Reset/Clock Management) clks support
clk: sun6i: Protect SDRAM gating bit
clk: sun6i: Protect CPU clock
clk: sunxi: Rework clock protection code
clk: sunxi: Move the GMAC clock to a file of its own
clk: sunxi: Move the 24M oscillator to a file of its own
clk: sunxi: Remove calls to clk_put
clk: sunxi: document new A31 USB clock compatible
clk: sunxi: Implement A31 USB clock
ARM: dts: OMAP5/DRA7: use omap5-mpu-dpll-clock capable of dealing with higher frequencies
CLK: TI: dpll: support OMAP5 MPU DPLL that need special handling for higher frequencies
ARM: OMAP5+: dpll: support Duty Cycle Correction(DCC)
CLK: TI: clk-54xx: Set the rate for dpll_abe_m2x2_ck
CLK: TI: Driver for DRA7 ATL (Audio Tracking Logic)
dt:/bindings: DRA7 ATL (Audio Tracking Logic) clock bindings
ARM: dts: dra7xx-clocks: Correct name for atl clkin3 clock
CLK: TI: gate: add composite interface clock to OMAP2 only build
ARM: OMAP2: clock: add DT boot support for cpufreq_ck
CLK: TI: OMAP2: add clock init support
...
Pull NVMe update from Matthew Wilcox:
"Mostly bugfixes again for the NVMe driver. I'd like to call out the
exported tracepoint in the block layer; I believe Keith has cleared
this with Jens.
We've had a few reports from people who're really pounding on NVMe
devices at scale, hence the timeout changes (and new module
parameters), hotplug cpu deadlock, tracepoints, and minor performance
tweaks"
[ Jens hadn't seen that tracepoint thing, but is ok with it - it will
end up going away when mq conversion happens ]
* git://git.infradead.org/users/willy/linux-nvme: (22 commits)
NVMe: Fix START_STOP_UNIT Scsi->NVMe translation.
NVMe: Use Log Page constants in SCSI emulation
NVMe: Define Log Page constants
NVMe: Fix hot cpu notification dead lock
NVMe: Rename io_timeout to nvme_io_timeout
NVMe: Use last bytes of f/w rev SCSI Inquiry
NVMe: Adhere to request queue block accounting enable/disable
NVMe: Fix nvme get/put queue semantics
NVMe: Delete NVME_GET_FEAT_TEMP_THRESH
NVMe: Make admin timeout a module parameter
NVMe: Make iod bio timeout a parameter
NVMe: Prevent possible NULL pointer dereference
NVMe: Fix the buffer size passed in GetLogPage(CDW10.NUMD)
NVMe: Update data structures for NVMe 1.2
NVMe: Enable BUILD_BUG_ON checks
NVMe: Update namespace and controller identify structures to the 1.1a spec
NVMe: Flush with data support
NVMe: Configure support for block flush
NVMe: Add tracepoints
NVMe: Protect against badly formatted CQEs
...
This function is used by UDP encapsulation protocols in RX when
crossing encapsulation boundary. If ip_summed is set to
CHECKSUM_UNNECESSARY and encapsulation is not set, change to
CHECKSUM_NONE since the checksum has not been validated within the
encapsulation. Clears csum_valid by the same rationale.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In __udp_lib_checksum_complete check if checksum is being done over all
the data (len is equal to skb->len) and if it is call
__skb_checksum_complete instead of __skb_checksum_complete_head. This
allows checksum to be saved in checksum complete.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Joseph Gasparakis reported that VXLAN GSO offload stopped working with
i40e device after recent UDP changes. The problem is that the
SKB_GSO_* bits are out of sync with the corresponding NETIF flags. This
patch fixes that. Also, we add BUILD_BUG_ONs in net_gso_ok for several
GSO constants that were missing to avoid the problem in the future.
Reported-by: Joseph Gasparakis <joseph.gasparakis@intel.com>
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull more btrfs updates from Chris Mason:
"This has a few fixes since our last pull and a new ioctl for doing
btree searches from userland. It's very similar to the existing
ioctl, but lets us return larger items back down to the app"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: fix error handling in create_pending_snapshot
btrfs: fix use of uninit "ret" in end_extent_writepage()
btrfs: free ulist in qgroup_shared_accounting() error path
Btrfs: fix qgroups sanity test crash or hang
btrfs: prevent RCU warning when dereferencing radix tree slot
Btrfs: fix unfinished readahead thread for raid5/6 degraded mounting
btrfs: new ioctl TREE_SEARCH_V2
btrfs: tree_search, search_ioctl: direct copy to userspace
btrfs: new function read_extent_buffer_to_user
btrfs: tree_search, copy_to_sk: return needed size on EOVERFLOW
btrfs: tree_search, copy_to_sk: return EOVERFLOW for too small buffer
btrfs: tree_search, search_ioctl: accept varying buffer
btrfs: tree_search: eliminate redundant nr_items check
Pull hwmon updates from Guenter Roeck:
- new driver for Sensirion SHTC1 humidity / temperature sensor
- convert ltc4151 and vexpress drivers to use devm functions
- drop generic chip detection from lm85 driver
- avoid forward declarations in atxp1 driver
- fix sign extensions in ina2xx driver
* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
hwmon: vexpress: Use devm helper for hwmon device registration
hwmon: (atxp1) Avoid forward declaration
hwmon: add support for Sensirion SHTC1 sensor
hwmon: (ltc4151) Convert to devm_hwmon_device_register_with_groups
hwmon: (lm85) Drop generic detection
hwmon: (ina2xx) Cast to s16 on shunt and current regs
This new ioctl call allows the user to supply a buffer of varying size in which
a tree search can store its results. This is much more flexible if you want to
receive items which are larger than the current fixed buffer of 3992 bytes or
if you want to fetch more items at once. Items larger than this buffer are for
example some of the type EXTENT_CSUM.
Signed-off-by: Gerhard Heift <Gerhard@Heift.Name>
Signed-off-by: Chris Mason <clm@fb.com>
Acked-by: David Sterba <dsterba@suse.cz>
There is a potential dead lock if a cpu event occurs during nvme probe
since it registered with hot cpu notification. This fixes the race by
having the module register with notification outside of probe rather
than have each device register.
The actual work is done in a scheduled work queue instead of in the
notifier since assigning IO queues has the potential to block if the
driver creates additional queues.
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Pull sound fixes from Takashi Iwai:
"Most of changes are small and easy cleanup or fixes:
- a few HD-audio Realtek codec fixes and quirks
- Intel HDMI audio fixes for Broadwell and Haswell / ValleyView
- FireWire sound stack cleanups
- a couple of sequencer core fixes
- compress ABI fix for 64bit
- conversion to modern ktime*() API"
* tag 'sound-fix-3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (23 commits)
ALSA: hda/realtek - Add more entry for enable HP mute led
ALSA: hda - Add quirk for external mic on Lifebook U904
ALSA: hda - fix a fixup value for codec alc293 in the pin_quirk table
ALSA: intel8x0: Use ktime and ktime_get()
ALSA: core: Use ktime_get_ts()
ALSA: hda - verify pin:converter connection on unsol event for HSW and VLV
ALSA: compress: Cancel the optimization of compiler and fix the size of struct for all platform.
ALSA: hda - Add quirk for ABit AA8XE
Revert "ALSA: hda - mask buggy stream DMA0 for Broadwell display controller"
ALSA: hda - using POS_FIX_LPIB on Broadwell HDMI Audio
ALSA: hda/realtek - Add support of ALC667 codec
ALSA: hda/realtek - Add more codec rename
ALSA: hda/realtek - New vendor ID for ALC233
ALSA: hda - add two new pin tables
ALSA: hda/realtek - Add support of ALC891 codec
ALSA: seq: Continue broadcasting events to ports if one of them fails
ALSA: bebob: Remove unused function prototype
ALSA: fireworks: Remove meaningless mutex_destroy()
ALSA: fireworks: Remove a constant over width to which it's applied
ALSA: fireworks: Improve comments about Fireworks transaction
...
Pull Ceph updates from Sage Weil:
"This has a mix of bug fixes and cleanups.
Alex's patch fixes a rare race in RBD. Ilya's patches fix an ENOENT
check when a second rbd image is mapped and a couple memory leaks.
Zheng fixes several issues with fragmented directories and multiple
MDSs. Josh fixes a spin/sleep issue, and Josh and Guangliang's
patches fix setting and unsetting RBD images read-only.
Naturally there are several other cleanups mixed in for good measure"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (23 commits)
rbd: only set disk to read-only once
rbd: move calls that may sleep out of spin lock range
rbd: add ioctl for rbd
ceph: use truncate_pagecache() instead of truncate_inode_pages()
ceph: include time stamp in every MDS request
rbd: fix ida/idr memory leak
rbd: use reference counts for image requests
rbd: fix osd_request memory leak in __rbd_dev_header_watch_sync()
rbd: make sure we have latest osdmap on 'rbd map'
libceph: add ceph_monc_wait_osdmap()
libceph: mon_get_version request infrastructure
libceph: recognize poolop requests in debugfs
ceph: refactor readpage_nounlock() to make the logic clearer
mds: check cap ID when handling cap export message
ceph: remember subtree root dirfrag's auth MDS
ceph: introduce ceph_fill_fragtree()
ceph: handle cap import atomically
ceph: pre-allocate ceph_cap struct for ceph_add_cap()
ceph: update inode fields according to issued caps
rbd: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
...
