Commit Graph

68709 Commits

Author SHA1 Message Date
Al Viro
230c6402b1 ovl_lookup_real_one(): don't bother with strlen()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-04-26 13:13:33 -04:00
Jann Horn
b987222654 tracing: Fix buffer_ref pipe ops
This fixes multiple issues in buffer_pipe_buf_ops:

 - The ->steal() handler must not return zero unless the pipe buffer has
   the only reference to the page. But generic_pipe_buf_steal() assumes
   that every reference to the pipe is tracked by the page's refcount,
   which isn't true for these buffers - buffer_pipe_buf_get(), which
   duplicates a buffer, doesn't touch the page's refcount.
   Fix it by using generic_pipe_buf_nosteal(), which refuses every
   attempted theft. It should be easy to actually support ->steal, but the
   only current users of pipe_buf_steal() are the virtio console and FUSE,
   and they also only use it as an optimization. So it's probably not worth
   the effort.
 - The ->get() and ->release() handlers can be invoked concurrently on pipe
   buffers backed by the same struct buffer_ref. Make them safe against
   concurrency by using refcount_t.
 - The pointers stored in ->private were only zeroed out when the last
   reference to the buffer_ref was dropped. As far as I know, this
   shouldn't be necessary anyway, but if we do it, let's always do it.

Link: http://lkml.kernel.org/r/20190404215925.253531-1-jannh@google.com

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
Fixes: 73a757e631 ("ring-buffer: Return reader page back into existing ring buffer")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-04-26 11:44:39 -04:00
Joerg Roedel
d53bff888f Merge branch 'api-features' into arm/smmu 2019-04-26 17:11:46 +02:00
Joerg Roedel
26ac2b6ee6 Merge branch 'for-joerg/arm-smmu/updates' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into arm/smmu 2019-04-26 15:48:52 +02:00
Will Deacon
cbafee55b5 Merge branch 'core/speculation' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into for-next/mitigations
Pull in core support for the "mitigations=" cmdline option from Thomas
Gleixner via -tip, which we can build on top of when we expose our
mitigation state via sysfs.
2019-04-26 13:32:20 +01:00
Andy Shevchenko
ffcfc20f74 dmaengine: idma64: Move driver name to the header
There are two drivers that are relying on the iDMA 64-bit driver name
to match. Instead of duplicating string in both of them, dedicate
a header file and share it between users.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
2019-04-26 16:55:23 +05:30
Liad Kaufman
abaea61c79 ieee80211: update HE IEs to D4.0 spec
Update the out-dated comments as well, and have them point to
the correct sections in the D4.0 spec.

Signed-off-by: Liad Kaufman <liad.kaufman@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-04-26 13:02:11 +02:00
Sara Sharon
f7dacfb114 cfg80211: support non-inheritance element
Subelement profile may specify element IDs it doesn't inherit
from the management frame. Support it.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-04-26 13:02:11 +02:00
Christian Borntraeger
cdd6ad3ac6 KVM: polling: add architecture backend to disable polling
There are cases where halt polling is unwanted. For example when running
KVM on an over committed LPAR we rather want to give back the CPU to
neighbour LPARs instead of polling. Let us provide a callback that
allows architectures to disable polling.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2019-04-26 09:08:17 +02:00
David S. Miller
ad759c9069 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================
pull-request: bpf 2019-04-25

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) the bpf verifier fix to properly mark registers in all stack frames, from Paul.

2) preempt_enable_no_resched->preempt_enable fix, from Peter.

3) other misc fixes.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26 01:54:42 -04:00
David S. Miller
89eb6e0967 Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next
Johan Hedberg says:

====================
pull request: bluetooth-next 2019-04-25

Here's the main bluetooth-next pull request for the 5.2 kernel.

 - Added support for Mediatek SDIO controllers
 - Added support for Broadcom BCM2076B1 UART controller
 - Added support for Marvel SD8987 chipset
 - Fix buffer overflow bug in hidp protocol
 - Various other smaller fixes & improvements

Please let me know if there are any issues pulling. Thanks.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26 01:39:38 -04:00
David S. Miller
8b44836583 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Two easy cases of overlapping changes.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-25 23:52:29 -04:00
Peter Zijlstra
0edd6b64d1 bpf: Fix preempt_enable_no_resched() abuse
Unless the very next line is schedule(), or implies it, one must not use
preempt_enable_no_resched(). It can cause a preemption to go missing and
thereby cause arbitrary delays, breaking the PREEMPT=y invariant.

Cc: Roman Gushchin <guro@fb.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-25 17:20:06 -07:00
Stanislav Fomichev
118c8e9ae6 bpf: support BPF_PROG_QUERY for BPF_FLOW_DISSECTOR attach_type
target_fd is target namespace. If there is a flow dissector BPF program
attached to that namespace, its (single) id is returned.

v5:
* drop net ref right after rcu unlock (Daniel Borkmann)

v4:
* add missing put_net (Jann Horn)

v3:
* add missing inline to skb_flow_dissector_prog_query static def
  (kbuild test robot <lkp@intel.com>)

v2:
* don't sleep in rcu critical section (Jakub Kicinski)
* check input prog_cnt (exit early)

Cc: Jann Horn <jannh@google.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-04-25 23:49:06 +02:00
Jonathan Chocron
4166bfe530 PCI: al: Add Amazon Annapurna Labs PCIe host controller driver
Add driver for Amazon's Annapurna Labs PCIe host controller.  The
controller is based on DesignWare's IP.

The controller doesn't support accessing the Root Port's config space via
ECAM, so we obtain its base address via an AMZN0001 device.

Furthermore, the DesignWare PCIe controller doesn't filter out config
transactions sent to devices 1 and up on its bus, so they are filtered by
the driver.

All subordinate buses do support ECAM access.

Implementing specific PCI config access functions involves:
 - Adding an init function to obtain the Root Port's base address from
   an AMZN0001 device.
 - Adding a new entry in the MCFG quirk array.

[bhelgaas: Note that there is no Kconfig option for this driver because it
is only intended for use with the generic ACPI host bridge driver.  This
driver is only needed because the DesignWare IP doesn't completely support
ECAM access to the root bus.]

Link: https://lore.kernel.org/lkml/1553774276-24675-1-git-send-email-jonnyc@amazon.com
Co-developed-by: Vladimir Aerov <vaerov@amazon.com>
Signed-off-by: Jonathan Chocron <jonnyc@amazon.com>
Signed-off-by: Vladimir Aerov <vaerov@amazon.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
2019-04-25 16:33:07 -05:00
Ulf Hansson
f9ccd7c3a1 PM / Domains: Allow to attach a CPU via genpd_dev_pm_attach_by_id|name()
Attaching a device via genpd_dev_pm_attach_by_id|name() makes
genpd allocate a virtual device that it attaches instead. This
leads to a problem in case when the base device belongs to a CPU.
More precisely, it means genpd_get_cpu() compares against the
virtual device, thus it fails to find a matching CPU device.

Address this limitation by passing the base device to genpd_get_cpu()
rather than the virtual device.

Moreover, to deal with detach correctly from genpd_remove_device(),
store the CPU number in struct generic_pm_domain_data, so as to be
able to clear the corresponding bit in the cpumask for the genpd.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-04-25 23:18:03 +02:00
Rafael J. Wysocki
40aa4db6d5 Merge cpuidle material depended on by the subsequent changes. 2019-04-25 23:17:07 +02:00
Kimberly Brown
aa30f47cf6 kobject: Add support for default attribute groups to kobj_type
kobj_type currently uses a list of individual attributes to store
default attributes. Attribute groups are more flexible than a list of
attributes because groups provide support for attribute visibility. So,
add support for default attribute groups to kobj_type.

In future patches, the existing uses of kobj_type’s attribute list will
be converted to attribute groups. When that is complete, kobj_type’s
attribute list, “default_attrs”, will be removed.

Signed-off-by: Kimberly Brown <kimbrownkd@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25 22:06:10 +02:00
Mathieu Poirier
a0f08a6a9f coresight: Communicate perf event to sink buffer allocation functions
Make struct perf_event available to sink buffer allocation functions in
order to use the pid they carry to allocate and free buffer memory along
with regimenting access to what source a sink can collect data for.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Robert Walker <robert.walker@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25 22:00:17 +02:00
Mathieu Poirier
6c817a95d8 coresight: Adding return code to sink::disable() operation
In preparation to handle device reference counting inside of the sink
drivers, add a return code to the sink::disable() operation so that
proper action can be taken if a sink has not been disabled.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Robert Walker <robert.walker@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25 22:00:16 +02:00
Mathieu Poirier
82500a810e coresight: etm4x: Add kernel configuration for CONTEXTID
Set the proper bit in the configuration register when contextID tracing
has been requested by user space.  That way PE_CONTEXT elements are
generated by the tracers when a process is installed on a CPU.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Robert Walker <robert.walker@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25 22:00:16 +02:00
Christina Quast
0d1a393d61 fs: kernfs: Corrected spelling mistake
flies => files

Signed-off-by: Christina Quast <cquast@hanoverdisplays.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25 21:41:35 +02:00
Yufen Yu
5de719e3d0 dm mpath: fix missing call of path selector type->end_io
After commit 396eaf21ee ("blk-mq: improve DM's blk-mq IO merging via
blk_insert_cloned_request feedback"), map_request() will requeue the tio
when issued clone request return BLK_STS_RESOURCE or BLK_STS_DEV_RESOURCE.

Thus, if device driver status is error, a tio may be requeued multiple
times until the return value is not DM_MAPIO_REQUEUE.  That means
type->start_io may be called multiple times, while type->end_io is only
called when IO complete.

In fact, even without commit 396eaf21ee, setup_clone() failure can
also cause tio requeue and associated missed call to type->end_io.

The service-time path selector selects path based on in_flight_size,
which is increased by st_start_io() and decreased by st_end_io().
Missed calls to st_end_io() can lead to in_flight_size count error and
will cause the selector to make the wrong choice.  In addition,
queue-length path selector will also be affected.

To fix the problem, call type->end_io in ->release_clone_rq before tio
requeue.  map_info is passed to ->release_clone_rq() for map_request()
error path that result in requeue.

Fixes: 396eaf21ee ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback")
Cc: stable@vger.kernl.org
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
2019-04-25 15:38:52 -04:00
Alexandre Belloni
e5be537064 clk: at91: master: Add sam9x60 support
The sam9x60 cpu clock is located at a different offset but is otherwise
similar to the master clock.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-04-25 12:34:05 -07:00
Alexandre Belloni
e4cfb823bd clk: at91: allow configuring generated PCR layout
The PCR register layout for GCLKCSS is changing for the future SoCs, allow
configuring it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-04-25 12:34:03 -07:00
Alexandre Belloni
cb4f4949b1 clk: at91: allow configuring peripheral PCR layout
The PCR register actually changed layout for each SoC. By chance, this
didn't have impact on sama5d[2-4] support but since sama5d3, PID is seven
bits wide and sama5d4 and sama5d2 don't have DIV.

For the DT backward compatibility, keep the layout as is.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-04-25 12:34:03 -07:00
Patrick Havelange
cdff431498 include/fsl: add common FlexTimer #defines in a separate header.
Several files are/will be using the same #defines to use the Flextimer
module. Regroup them in a common file.

Reviewed-by: Esben Haabendal <esben@haabendal.dk>
Signed-off-by: Patrick Havelange <patrick.havelange@essensium.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25 21:33:41 +02:00
William Breathitt Gray
0040a390d2 counter: Introduce the Generic Counter interface
This patch introduces the Generic Counter interface for supporting
counter devices.

In the context of the Generic Counter interface, a counter is defined as
a device that reports one or more "counts" based on the state changes of
one or more "signals" as evaluated by a defined "count function."

Driver callbacks should be provided to communicate with the device: to
read and write various Signals and Counts, and to set and get the
"action mode" and "count function" for various Synapses and Counts
respectively.

To support a counter device, a driver must first allocate the available
Counter Signals via counter_signal structures. These Signals should
be stored as an array and set to the signals array member of an
allocated counter_device structure before the Counter is registered to
the system.

Counter Counts may be allocated via counter_count structures, and
respective Counter Signal associations (Synapses) made via
counter_synapse structures. Associated counter_synapse structures are
stored as an array and set to the the synapses array member of the
respective counter_count structure. These counter_count structures are
set to the counts array member of an allocated counter_device structure
before the Counter is registered to the system.

A counter device is registered to the system by passing the respective
initialized counter_device structure to the counter_register function;
similarly, the counter_unregister function unregisters the respective
Counter. The devm_counter_register and devm_counter_unregister functions
serve as device memory-managed versions of the counter_register and
counter_unregister functions respectively.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25 21:33:37 +02:00
Trond Myklebust
c79d183ebb NFS: Remove redundant open context from nfs_page
The lock context already references and tracks the open context, so
take the opportunity to save some space in struct nfs_page.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:15 -04:00
Trond Myklebust
9fcd5960e8 NFS: Add a helper to return a pointer to the open context of a struct nfs_page
Add a helper for when we remove the explicit pointer to the open
context.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:15 -04:00
Trond Myklebust
33344e0f7e pNFS: Add tracking to limit the number of pNFS retries
When the client is reading or writing using pNFS, and hits an error
on the DS, then it typically sends a LAYOUTERROR and/or LAYOUTRETURN
to the MDS, before redirtying the failed pages, and going for a new
round of reads/writebacks. The problem is that if the server has no
way to fix the DS, then we may need a way to interrupt this loop
after a set number of attempts have been made.
This patch adds an optional module parameter that allows the admin
to specify how many times to retry the read/writeback process before
failing with a fatal error.
The default behaviour is to retry forever.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:14 -04:00
Trond Myklebust
28b1d3f5a7 NFS: Remove unused argument from nfs_create_request()
All the callers of nfs_create_request() are now creating page group
heads, so we can remove the redundant 'last' page argument.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:14 -04:00
Trond Myklebust
6fbda89b25 NFS: Replace custom error reporting mechanism with generic one
Replace the NFS custom error reporting mechanism with the generic
mapping_set_error().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:14 -04:00
Trond Myklebust
91a575e1a9 NFS: Add a mount option "softerr" to allow clients to see ETIMEDOUT errors
Add a mount option that exposes the ETIMEDOUT errors that occur during
soft timeouts to the application. This allows aware applications to
distinguish between server disk IO errors and client timeout errors.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:14 -04:00
Trond Myklebust
7b1355b615 NFS: Move internal constants out of uapi/linux/nfs_mount.h
When the label says "for internal use only", then it doesn't belong
in the 'uapi' subtree.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:14 -04:00
Trond Myklebust
ae6ec91847 SUNRPC: Add the 'softerr' rpc_client flag
Add the 'softerr' rpc client flag that sets the RPC_TASK_TIMEOUT
flag on all new rpc tasks that are attached to that rpc client.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:14 -04:00
Trond Myklebust
5ad64b36dd SUNRPC: Add tracking of RPC level errors
Add variables to track RPC level errors so that we can distinguish
between issue that arose in the RPC transport layer as opposed to
those arising from the reply message.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:13 -04:00
Trond Myklebust
24a9d9a21e SUNRPC: Simplify queue timeouts using timer_reduce()
Simplify the setting of queue timeouts by using the timer_reduce()
function.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:13 -04:00
Trond Myklebust
5efd1876e6 SUNRPC: Fix up tracking of timeouts
Add a helper to ensure that debugfs and friends print out the
correct current task timeout value.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:13 -04:00
Trond Myklebust
6b2e685627 SUNRPC: Add function rpc_sleep_on_timeout()
Clean up the RPC task sleep interfaces by replacing the task->tk_timeout
'hidden parameter' to rpc_sleep_on() with a new function that takes an
absolute timeout.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:13 -04:00
Trond Myklebust
8357a9b60f SUNRPC: Remove unused argument 'action' from rpc_sleep_on_priority()
None of the callers set the 'action' argument, so let's just remove it.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:12 -04:00
Trond Myklebust
8ba6a92d01 SUNRPC: Refactor xprt_request_wait_receive()
Convert the transport callback to actually put the request to sleep
instead of just setting a timeout. This is in preparation for
rpc_sleep_on_timeout().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:12 -04:00
Trond Myklebust
ae67bd3821 SUNRPC: Fix up task signalling
The RPC_TASK_KILLED flag should really not be set from another context
because it can clobber data in the struct task when task->tk_flags is
changed non-atomically.
Let's therefore swap out RPC_TASK_KILLED with an atomic flag, and add
a function to set that flag and safely wake up the task.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-04-25 14:18:12 -04:00
Gabriel Krisman Bertazi
b886ee3e77 ext4: Support case-insensitive file name lookups
This patch implements the actual support for case-insensitive file name
lookups in ext4, based on the feature bit and the encoding stored in the
superblock.

A filesystem that has the casefold feature set is able to configure
directories with the +F (EXT4_CASEFOLD_FL) attribute, enabling lookups
to succeed in that directory in a case-insensitive fashion, i.e: match
a directory entry even if the name used by userspace is not a byte per
byte match with the disk name, but is an equivalent case-insensitive
version of the Unicode string.  This operation is called a
case-insensitive file name lookup.

The feature is configured as an inode attribute applied to directories
and inherited by its children.  This attribute can only be enabled on
empty directories for filesystems that support the encoding feature,
thus preventing collision of file names that only differ by case.

* dcache handling:

For a +F directory, Ext4 only stores the first equivalent name dentry
used in the dcache. This is done to prevent unintentional duplication of
dentries in the dcache, while also allowing the VFS code to quickly find
the right entry in the cache despite which equivalent string was used in
a previous lookup, without having to resort to ->lookup().

d_hash() of casefolded directories is implemented as the hash of the
casefolded string, such that we always have a well-known bucket for all
the equivalencies of the same string. d_compare() uses the
utf8_strncasecmp() infrastructure, which handles the comparison of
equivalent, same case, names as well.

For now, negative lookups are not inserted in the dcache, since they
would need to be invalidated anyway, because we can't trust missing file
dentries.  This is bad for performance but requires some leveraging of
the vfs layer to fix.  We can live without that for now, and so does
everyone else.

* on-disk data:

Despite using a specific version of the name as the internal
representation within the dcache, the name stored and fetched from the
disk is a byte-per-byte match with what the user requested, making this
implementation 'name-preserving'. i.e. no actual information is lost
when writing to storage.

DX is supported by modifying the hashes used in +F directories to make
them case/encoding-aware.  The new disk hashes are calculated as the
hash of the full casefolded string, instead of the string directly.
This allows us to efficiently search for file names in the htree without
requiring the user to provide an exact name.

* Dealing with invalid sequences:

By default, when a invalid UTF-8 sequence is identified, ext4 will treat
it as an opaque byte sequence, ignoring the encoding and reverting to
the old behavior for that unique file.  This means that case-insensitive
file name lookup will not work only for that file.  An optional bit can
be set in the superblock telling the filesystem code and userspace tools
to enforce the encoding.  When that optional bit is set, any attempt to
create a file name using an invalid UTF-8 sequence will fail and return
an error to userspace.

* Normalization algorithm:

The UTF-8 algorithms used to compare strings in ext4 is implemented
lives in fs/unicode, and is based on a previous version developed by
SGI.  It implements the Canonical decomposition (NFD) algorithm
described by the Unicode specification 12.1, or higher, combined with
the elimination of ignorable code points (NFDi) and full
case-folding (CF) as documented in fs/unicode/utf8_norm.c.

NFD seems to be the best normalization method for EXT4 because:

  - It has a lower cost than NFC/NFKC (which requires
    decomposing to NFD as an intermediary step)
  - It doesn't eliminate important semantic meaning like
    compatibility decompositions.

Although:

  - This implementation is not completely linguistic accurate, because
  different languages have conflicting rules, which would require the
  specialization of the filesystem to a given locale, which brings all
  sorts of problems for removable media and for users who use more than
  one language.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-25 14:12:08 -04:00
Tero Kristo
869decd1ff clk: ti: dra7: disable the RNG and TIMER12 clkctrl clocks on HS devices
RNG and TIMER12 are reserved for secure side usage only on HS devices,
so disable their clkctrl clocks on HS SoCs also.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Tested-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-04-25 10:51:36 -07:00
Gabriel Krisman Bertazi
9d53690f0d unicode: implement higher level API for string handling
This patch integrates the utf8n patches with some higher level API to
perform UTF-8 string comparison, normalization and casefolding
operations.  Implemented is a variation of NFD, and casefold is
performed by doing full casefold on top of NFD.  These algorithms are
based on the core implemented by Olaf Weber from SGI.

Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2019-04-25 13:51:22 -04:00
Tero Kristo
b88b5b7182 clk: ti: export the omap2_clk_is_hw_omap call
There is one instance outside the TI clock driver that needs the info
whether a clock is an OMAP HW clock or not. Thus, move the function
declaration into the public header.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-04-25 10:51:12 -07:00
Fabrice Gasnier
0a9b2d1ce4 nvmem: core: add nvmem_cell_read_u16
Add nvmem_cell_read_u16() helper to ease read of an u16 value on consumer
side. This is inspired by nvmem_cell_read_u32() function.
This helper is useful on stm32 that has 16 bits data cells stored in non
volatile memory.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-25 19:43:12 +02:00
Dmitry Osipenko
b88c9f4129 clk: Add missing stubs for a few functions
Compilation fails if any of undeclared clk_set_*() functions are in use
and CONFIG_HAVE_CLK=n.

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-04-25 08:19:15 -07:00
Minwoo Im
82bebbde02 nvme-rdma: fix typo in struct comment
struct nvme_rdma_cm_rej has two different attributes: recfmt and sts.
And sts will have value what this comment wanted to show.

Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2019-04-25 16:51:42 +02:00