draft-ietf-nvo3-geneve-08 says:
It is strongly RECOMMENDED that Path MTU Discovery ([RFC1191],
[RFC1981]) be used by setting the DF bit in the IP header when Geneve
packets are transmitted over IPv4 (this is the default with IPv6).
Now that ICMP error handling is working for GENEVE, we can comply with
this recommendation.
Make this configurable, though, to avoid breaking existing setups. By
default, DF won't be set. It can be set or inherited from inner IPv4
packets. If it's configured to be inherited and we are encapsulating IPv6,
it will be set.
This only applies to non-lwt tunnels: if an external control plane is
used, tunnel key will still control the DF flag.
v2:
- DF behaviour configuration only applies for non-lwt tunnels, apply DF
setting only if (!geneve->collect_md) in geneve_xmit_skb()
(Stephen Hemminger)
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow users to set the IPv4 DF bit in outgoing packets, or to inherit its
value from the IPv4 inner header. If the encapsulated protocol is IPv6 and
DF is configured to be inherited, always set it.
For IPv4, inheriting DF from the inner header was probably intended from
the very beginning judging by the comment to vxlan_xmit(), but it wasn't
actually implemented -- also because it would have done more harm than
good, without handling for ICMP Fragmentation Needed messages.
According to RFC 7348, "Path MTU discovery MAY be used". An expired RFC
draft, draft-saum-nvo3-pmtud-over-vxlan-05, whose purpose was to describe
PMTUD implementation, says that "is a MUST that Vxlan gateways [...]
SHOULD set the DF-bit [...]", whatever that means.
Given this background, the only sane option is probably to let the user
decide, and keep the current behaviour as default.
This only applies to non-lwt tunnels: if an external control plane is
used, tunnel key will still control the DF flag.
v2:
- DF behaviour configuration only applies for non-lwt tunnels, move DF
setting to if (!info) block in vxlan_xmit_one() (Stephen Hemminger)
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
For both IPv4 and IPv6, if we can't match errors to a socket, try
tunnels before ignoring them. Look up a socket with the original source
and destination ports as found in the UDP packet inside the ICMP payload,
this will work for tunnels that force the same destination port for both
endpoints, i.e. VXLAN and GENEVE.
Actually, lwtunnels could break this assumption if they are configured by
an external control plane to have different destination ports on the
endpoints: in this case, we won't be able to trace ICMP messages back to
them.
For IPv6 redirect messages, call ip6_redirect() directly with the output
interface argument set to the interface we received the packet from (as
it's the very interface we should build the exception on), otherwise the
new nexthop will be rejected. There's no such need for IPv4.
Tunnels can now export an encap_err_lookup() operation that indicates a
match. Pass the packet to the lookup function, and if the tunnel driver
reports a matching association, continue with regular ICMP error handling.
v2:
- Added newline between network and transport header sets in
__udp{4,6}_lib_err_encap() (David Miller)
- Removed redundant skb_reset_network_header(skb); in
__udp4_lib_err_encap()
- Removed redundant reassignment of iph in __udp4_lib_err_encap()
(Sabrina Dubroca)
- Edited comment to __udp{4,6}_lib_err_encap() to reflect the fact this
won't work with lwtunnels configured to use asymmetric ports. By the way,
it's VXLAN, not VxLAN (Jiri Benc)
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Qdisc graft operation of offload-capable qdiscs performs a few
extra steps which are identical among all the qdiscs. Add
a helper to share this code.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Qdisc dump operation of offload-capable qdiscs performs a few
extra steps which are identical among all the qdiscs. Add
a helper to share this code.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: John Hurley <john.hurley@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After the recent changes in the state machine state PHY_AN isn't used
any longer and can be removed.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Devices that does not use managed affinity can not export a vector
affinity as the consumer relies on having a static mapping it can map to
upper layer affinity (e.g. sw queues). If the driver allows the user to
set the device irq affinity, then the affinitization of a long term
existing entites is not relevant.
For example, nvme-rdma controllers queue-irq affinitization is determined
at init time so if the irq affinity changes over time, we are no longer
aligned.
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
For debugging purpose, it will be useful to expose the content of the
subparts_cpus as a read-only file to see if the code work correctly.
However, subparts_cpus will not be used at all in most use cases. So
adding a new cpuset file that clutters the cgroup directory may not be
desirable. This is now being done by using the hidden "cgroup_debug"
kernel command line option to expose a new "cpuset.cpus.subpartitions"
file.
That option was originally used by the debug controller to expose
itself when configured into the kernel. This is now extended to set an
internal flag used by cgroup_addrm_files(). A new CFTYPE_DEBUG flag
can now be used to specify that a cgroup file should only be created
when the "cgroup_debug" option is specified.
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Returns true if the queue currently has requests pending,
false if not.
DM can use this to replace the atomic_inc/dec they do per device
to see if a device is busy.
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We have this functionality in sbitmap, but we don't export it in
blk-mq for users of the tags busy iteration. This can be useful
for stopping the iteration, if the caller doesn't need to find
more requests.
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
No one is running pre-argonaut. In addition one of the argonaut
features (NOSRCADDR) has been required since day one (and a half,
2.6.34 vs 2.6.35) of the kernel client.
Allow for the possibility of reusing these feature bits later.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Sage Weil <sage@redhat.com>
On NVIDIA Tegra30 there is a requirement for regulator "A" to have voltage
higher than voltage of regulator "B" by N microvolts, the N value changes
depending on the voltage of regulator "B". This is similar to min-spread
between voltages of regulators, the difference is that the spread value
isn't fixed. This means that extra carefulness is required for regulator
"A" to drop its voltage without violating the requirement, hence its
voltage should be changed in steps so that its couple "B" could follow
(there is also max-spread requirement).
Add new "max_uV_step" constraint that breaks voltage change into several
steps, each step is limited by the max_uV_step value.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Device tree binding was changed in a way that now max-spread values must
be defied per regulator pair. Limit number of pairs in order to adapt to
the new binding without changing regulators code.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Pull compiler attribute fixlets from Miguel Ojeda:
"Small improvements to Compiler Attributes:
- Define asm_volatile_goto for non-gcc compilers (Nick Desaulniers)
- Improve the explanation of compiler_attributes.h"
* tag 'compiler-attributes-for-linus-v4.20-rc2' of https://github.com/ojeda/linux:
Compiler Attributes: improve explanation of header
include/linux/compiler*.h: define asm_volatile_goto
Pull MTD fixes from Boris Brezillon:
"MTD changes:
- Kill a VLA in sa1100
SPI NOR changes:
- Make sure ->addr_width is restored when SFDP parsing fails
- Propate errors happening in cqspi_direct_read_execute()
NAND changes:
- Fix kernel-doc mismatch
- Fix nanddev_neraseblocks() to return the correct value
- Avoid selection of BCH_CONST_PARAMS when some users require dynamic
BCH settings"
* tag 'mtd/fixes-for-4.20-rc2' of git://git.infradead.org/linux-mtd:
mtd: nand: Fix nanddev_pos_next_page() kernel-doc header
mtd: sa1100: avoid VLA in sa1100_setup_mtd
mtd: spi-nor: Reset nor->addr_width when SFDP parsing failed
mtd: spi-nor: cadence-quadspi: Return error code in cqspi_direct_read_execute()
mtd: nand: Fix nanddev_neraseblocks()
mtd: nand: drop kernel-doc notation for a deleted function parameter
mtd: docg3: don't set conflicting BCH_CONST_PARAMS option
Update the firmware header file to a more recent version. The major
changes in the new version are:
* add a new MRQ for firmware version query ABI and deprecates the old
* add ABI to query Tegra194 CPU frequency limits
* add ABI to control subset of PCIE UPHY state
The new header contains also some editorial changes to the
documentation.
Signed-off-by: Timo Alho <talho@nvidia.com>
Acked-by: Sivaram Nair <sivaramn@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Explain better what "optional" attributes are, and avoid calling
them so to avoid confusion. Simply retain "Optional" as a word
to look for in the comments.
Moreover, add a couple sentences to explain a bit more the intention
and the documentation links.
Signed-off-by: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Add a helper function to determine if the type of a netdev is geneve based
on its rtnl_link_ops. This allows drivers that may wish to offload tunnels
to check the underlying type of the device.
A recent patch added a similar helper to vxlan.h
Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
phy_trigger_machine() is used in phy.c only, so we can make it static.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In some scenarios, the GRO engine can assemble an UDP GRO packet
that ultimately lands on a non GRO-enabled socket.
This patch tries to address the issue explicitly checking for the UDP
socket features before enqueuing the packet, and eventually segmenting
the unexpected GRO packet, as needed.
We must also cope with re-insertion requests: after segmentation the
UDP code calls the helper introduced by the previous patches, as needed.
Segmentation is performed by a common helper, which takes care of
updating socket and protocol stats is case of failure.
rfc v3 -> v1
- fix compile issues with rxrpc
- when gso_segment returns NULL, treat is as an error
- added 'ipv4' argument to udp_rcv_segment()
rfc v2 -> rfc v3
- moved udp_rcv_segment() into net/udp.h, account errors to socket
and ns, always return NULL or segs list
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
So that we can re-use it at the UDP level in the next patch
rfc v3 -> v1:
- add the helper declaration into the ipv6 header
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
So that we can re-use it at the UDP level in a later patch
rfc v3 -> v1
- add the helper declaration into the ip header
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When UDP GRO is enabled, the UDP_GRO cmsg will carry the ingress
datagram size. User-space can use such info to compute the original
packets layout.
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is the RX counterpart of commit bec1f6f697 ("udp: generate gso
with UDP_SEGMENT"). When UDP_GRO is enabled, such socket is also
eligible for GRO in the rx path: UDP segments directed to such socket
are assembled into a larger GSO_UDP_L4 packet.
The core UDP GRO support is enabled with setsockopt(UDP_GRO).
Initial benchmark numbers:
Before:
udp rx: 1079 MB/s 769065 calls/s
After:
udp rx: 1466 MB/s 24877 calls/s
This change introduces a side effect in respect to UDP tunnels:
after a UDP tunnel creation, now the kernel performs a lookup per ingress
UDP packet, while before such lookup happened only if the ingress packet
carried a valid internal header csum.
rfc v2 -> rfc v3:
- fixed typos in macro name and comments
- really enforce UDP_GRO_CNT_MAX, instead of UDP_GRO_CNT_MAX + 1
- acquire socket lock in UDP_GRO setsockopt
rfc v1 -> rfc v2:
- use a new option to enable UDP GRO
- use static keys to protect the UDP GRO socket lookup
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The *encap_needed static keys are enabled by UDP tunnels
and several UDP encapsulations type, but they are never
turned off. This can cause unneeded overall performance
degradation for systems where such features are used
transiently.
This patch introduces complete book-keeping for such keys,
decreasing the usage at socket destruction time, if needed,
and avoiding that the same socket could increase the key
usage multiple times.
rfc v3 -> v1:
- add socket lock around udp_tunnel_encap_enable()
rfc v2 -> rfc v3:
- use udp_tunnel_encap_enable() in setsockopt()
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When there exist a pair of raw sockets one unbound and one bound
to a VRF but equal in all other respects, when a packet is received
in the VRF context, __raw_v4_lookup() matches on both sockets.
This results in the packet being delivered over both sockets,
instead of only the raw socket bound to the VRF. The bound device
checks in __raw_v4_lookup() are replaced with a call to
raw_sk_bound_dev_eq() which correctly handles whether the packet
should be delivered over the unbound socket in such cases.
In __raw_v6_lookup() the match on the device binding of the socket is
similarly updated to use raw_sk_bound_dev_eq() which matches the
handling in __raw_v4_lookup().
Importantly raw_sk_bound_dev_eq() takes the raw_l3mdev_accept sysctl
into account.
Signed-off-by: Duncan Eastoe <deastoe@vyatta.att-mail.com>
Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a sysctl raw_l3mdev_accept to control raw socket lookup in a manner
similar to use of tcp_l3mdev_accept for stream and of udp_l3mdev_accept
for datagram sockets. Have this default to enabled for reasons of
backwards compatibility. This is so as to specify the output device
with cmsg and IP_PKTINFO, but using a socket not bound to the
corresponding VRF. This allows e.g. older ping implementations to be
run with specifying the device but without executing it in the VRF.
If the option is disabled, packets received in a VRF context are only
handled by a raw socket bound to the VRF, and correspondingly packets
in the default VRF are only handled by a socket not bound to any VRF.
Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ensure an unbound datagram skt is chosen when not in a VRF. The check
for a device match in compute_score() for UDP must be performed when
there is no device match. For this, a failure is returned when there is
no device match. This ensures that bound sockets are never selected,
even if there is no unbound socket.
Allow IPv6 packets to be sent over a datagram skt bound to a VRF. These
packets are currently blocked, as flowi6_oif was set to that of the
master vrf device, and the ipi6_ifindex is that of the slave device.
Allow these packets to be sent by checking the device with ipi6_ifindex
has the same L3 scope as that of the bound device of the skt, which is
the master vrf device. Note that this check always succeeds if the skt
is unbound.
Even though the right datagram skt is now selected by compute_score(),
a different skt is being returned that is bound to the wrong vrf. The
difference between these and stream sockets is the handling of the skt
option for SO_REUSEPORT. While the handling when adding a skt for reuse
correctly checks that the bound device of the skt is a match, the skts
in the hashslot are already incorrect. So for the same hash, a skt for
the wrong vrf may be selected for the required port. The root cause is
that the skt is immediately placed into a slot when it is created,
but when the skt is then bound using SO_BINDTODEVICE, it remains in the
same slot. The solution is to move the skt to the correct slot by
forcing a rehash.
Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The commit a04a480d43 ("net: Require exact match for TCP socket
lookups if dif is l3mdev") only ensures that the correct socket is
selected for packets in a VRF. However, there is no guarantee that
the unbound socket will be selected for packets when not in a VRF.
By checking for a device match in compute_score() also for the case
when there is no bound device and attaching a score to this, the
unbound socket is selected. And if a failure is returned when there
is no device match, this ensures that bound sockets are never selected,
even if there is no unbound socket.
Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change the inet socket lookup to avoid packets arriving on a device
enslaved to an l3mdev from matching unbound sockets by removing the
wildcard for non sk_bound_dev_if and instead relying on check against
the secondary device index, which will be 0 when the input device is
not enslaved to an l3mdev and so match against an unbound socket and
not match when the input device is enslaved.
Change the socket binding to take the l3mdev into account to allow an
unbound socket to not conflict sockets bound to an l3mdev given the
datapath isolation now guaranteed.
Signed-off-by: Robert Shearman <rshearma@vyatta.att-mail.com>
Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It was previously noted that Kconfig complained about unmet dependencies
when trying to configure skx_edac together with CONFIG_ACPI=n. First fix
for this checked for ACPI when doing
select ACPI_ADXL
but this required stub functions for the case where ACPI wasn't
selected. It also allowed building a driver that didn't actually work
for a system that has non-volatile DIMMs.
Arnd Bergmann pointed out that the right fix is to make EDAC_SKX
"depend on ACPI".
Fixes: a324e9396c ("EDAC, skx: Fix randconfig builds")
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
CC: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Mauro Carvalho Chehab <mchehab@kernel.org>
CC: linux-edac <linux-edac@vger.kernel.org>
CC: qiuxu.zhuo@intel.com
Link: http://lkml.kernel.org/r/20181106183914.GA26731@agluck-desk
Adds support for defining a variable number of poll queues, currently
configurable with the 'poll_queues' module parameter. Defaults to
a single poll queue.
And now we finally have poll support without triggering interrupts!
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We use IOCB_HIPRI to poll for IO in the caller instead of scheduling.
This information is not available for (or after) IO submission. The
driver may make different queue choices based on the type of IO, so
make the fact that we will poll for this IO known to the lower layers
as well.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a queue offset to the tag map. This enables users to map
iteratively, for each queue map type they support.
Bump maximum number of supported maps to 2, we're now fully
able to support more than 1 map.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
We call blk_mq_map_queue() a lot, at least two times for each
request per IO, sometimes more. Since we now have an indirect
call as well in that function. cache the mapping so we don't
have to re-call blk_mq_map_queue() for the same request
multiple times.
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add support for the tag set carrying multiple queue maps, and
for the driver to inform blk-mq how many it wishes to support
through setting set->nr_maps.
This adds an mq_ops helper for drivers that support more than 1
map, mq_ops->rq_flags_to_type(). The function takes request/bio
flags and CPU, and returns a queue map index for that. We then
use the type information in blk_mq_map_queue() to index the map
set.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The mapping used to be dependent on just the CPU location, but
now it's a tuple of (type, cpu) instead. This is a prep patch
for allowing a single software queue to map to multiple hardware
queues. No functional changes in this patch.
This changes the software queue count to an unsigned short
to save a bit of space. We can still support 64K-1 CPUs,
which should be enough. Add a check to catch a wrap.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This is in preparation for allowing multiple sets of maps per
queue, if so desired.
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
It's just a pointer to set->mq_map, use that instead. Move the
assignment a bit earlier, so we always know it's valid.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull in the irq affinity commits, that are staged through Thomas's
tree.
* 'irq/for-block' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq/affinity: Add support for allocating interrupt sets
genirq/affinity: Pass first vector to __irq_build_affinity_masks()
genirq/affinity: Move two stage affinity spreading into a helper function
genirq/affinity: Spread IRQs to all available NUMA nodes
This was used for completion placement for the legacy path,
but for mq we have rq->mq_ctx->cpu for that. Add a helper
to get the request CPU assignment, as the mq_ctx type is
private to blk-mq.
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
