Adjust limited access message to mention CAP_SYS_PTRACE capability for
processes of unprivileged users. Add link to perf security document in
the end of the section about capabilities.
The change has been inspired by this discussion:
https://lore.kernel.org/lkml/20200722113007.GI77866@kernel.org/
Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/6f8a7425-6e7d-19aa-1605-e59836b9e2a6@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
A single q option decodes ip from only FUP/TIP packets. Make it so that
repeating the q option (i.e. qq) decodes only PSB+, getting ip if there
is a FUP packet within PSB+ (i.e. between PSB and PSBEND).
Example:
$ perf record -e intel_pt//u grep -rI pudding drivers
[ perf record: Woken up 52 times to write data ]
[ perf record: Captured and wrote 57.870 MB perf.data ]
$ time perf script --itrace=bi | wc -l
58948289
real 1m23.863s
user 1m23.251s
sys 0m7.452s
$ time perf script --itrace=biq | wc -l
3385694
real 0m4.453s
user 0m4.455s
sys 0m0.328s
$ time perf script --itrace=biqq | wc -l
1883
real 0m0.047s
user 0m0.043s
sys 0m0.009s
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200710151104.15137-13-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Use the new itrace 'q' option to add support for a mode of decoding that
ignores TNT, does not walk object code, but gets the ip from FUP and TIP
packets.
Example:
$ perf record -e intel_pt//u grep -rI pudding drivers
[ perf record: Woken up 52 times to write data ]
[ perf record: Captured and wrote 57.870 MB perf.data ]
$ time perf script --itrace=bi | wc -l
58948289
real 1m23.863s
user 1m23.251s
sys 0m7.452s
$ time perf script --itrace=biq | wc -l
3385694
real 0m4.453s
user 0m4.455s
sys 0m0.328s
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200710151104.15137-12-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
camss_probe() does not free camss on error handling paths. The patch
introduces an additional error label for this purpose. Besides, it
removes call of v4l2_async_notifier_cleanup() from
camss_of_parse_ports() since its caller, camss_probe(), cleans up all
its resources itself.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Evgeny Novikov <novikov@ispras.ru>
Co-developed-by: Anton Vasilyev <vasilyev@ispras.ru>
Signed-off-by: Anton Vasilyev <vasilyev@ispras.ru>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The 'q' option is for modes of decoding that are quicker because they
skip or omit decoding some aspects of trace data.
If supported, the 'q' option may be repeated to increase the effect.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200710151104.15137-11-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Change the debug logging (when used with the --time option) to time
filter logged perf events, but allow that to be overridden by using
"d+a" instead of plain "d".
That can reduce the size of the log file.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200710151104.15137-10-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The "d" option may be followed by flags which affect what debug messages
will or will not be logged. Each flag must be preceded by either '+' or
'-'. The flags support by Intel PT are:
-a Suppress logging of perf events
Suppressing perf events is useful for decreasing the size of the log.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200710151104.15137-9-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Allow the 'd' option to be followed by flags which will affect what debug
messages will or will not be reported. Each flag must be preceded by either
'+' or '-'. The flags are:
a all perf events
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200710151104.15137-8-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The itrace "e" option may be followed by flags which affect what errors
will or will not be reported. Each flag must be preceded by either '+' or '-'.
The flags supported by Intel PT are:
-o Suppress overflow errors
-l Suppress trace data lost errors
For example, for errors but not overflow or data lost errors:
--itrace=e-o-l
Suppressing those errors can be useful for testing and debugging because
they are not due to decoding.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200710151104.15137-7-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Allow the 'e' option to be followed by flags which will affect what errors
will or will not be reported. Each flag must be preceded by either '+' or
'-'. The flags are:
o overflow
l trace data lost
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200710151104.15137-6-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add missing itrace options o, G and L.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/20200710151104.15137-5-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
While walking code towards a FUP ip, the packet state is
INTEL_PT_STATE_FUP or INTEL_PT_STATE_FUP_NO_TIP. That was mishandled
resulting in the state becoming INTEL_PT_STATE_IN_SYNC prematurely. The
result was an occasional lost EXSTOP event.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: stable@vger.kernel.org
Link: http://lore.kernel.org/lkml/20200710151104.15137-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To sync headers, for instance, in this case tools/perf was ahead of
upstream till Linus merged tip/perf/core to get the
PERF_RECORD_TEXT_POKE changes:
Warning: Kernel ABI header at 'tools/include/uapi/linux/perf_event.h' differs from latest version at 'include/uapi/linux/perf_event.h'
diff -u tools/include/uapi/linux/perf_event.h include/uapi/linux/perf_event.h
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
In case of errors vpif_probe_complete() releases memory for vpif_obj.sd
and unregisters the V4L2 device. But then this is done again by
vpif_probe() itself. The patch removes the cleaning from
vpif_probe_complete().
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Evgeny Novikov <novikov@ispras.ru>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The variable retval is being initialized with a value that is
never read and it is being updated later with a new value. The
initialization is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The pointer header is an alias to msg and msg is being null checked.
However, if msg is null then header is also null and this can lead to
a null pointer dereference on the assignment type = header->type. Fix
this just using header->type after the null check and removing the need
for type as it is only used once.
Addresses-Coverity: ("Dereference before null check")
Fixes: 3de1683966 ("media: allegro: add explicit mail encoding and decoding")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Michael Tretter <m.tretter@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
We need to call of_node_put(comp->dev_node); on the error paths in this
function.
Fixes: c8eb2d7e82 ("[media] media: Add Mediatek MDP Driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The allegro_mbox_init() function returns error pointers, it never
returns NULL.
Fixes: 94dc765602 ("media: allegro: rework mbox handling")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Michael Tretter <m.tretter@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
After commit 9c4a8489ab ("media: meye: use generic power management")
the pm_mchip_mode field should now always be present, even if CONFIG_PM
is not set.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reported-by: kernel test robot <lkp@intel.com>
Fixes: 9c4a8489ab ("media: meye: use generic power management")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Drivers using legacy PM have to manage PCI states and device's PM states
themselves. They also need to take care of configuration registers.
With improved and powerful support of generic PM, PCI Core takes care of
above mentioned, device-independent, jobs.
This driver makes use of PCI helper functions like
pci_save/restore_state() and pci_enable/disable_device() to do required
operations. In generic mode, they are no longer needed.
Change function parameter in both .suspend() and .resume() to
"struct device*" type.
Compile-tested only.
Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The .suspend() and .resume() callbacks are not defined for this driver.
Still, their power management structure follows the legacy framework. To
bring it under the generic framework, simply remove the binding of
callbacks from struct "pci_driver".
Compile-tested only.
Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
V4L2_CAP_VIDEO_M2M is documented as 0x00004000
V4L2_CAP_VIDEO_M2M_MPLANE is documented as 0x00008000
This is different from the definition in include/uapi/linux/videodev2.h
Signed-off-by: Jian-Jia Su <jjsu@chromium.org>
Reviewed-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Silence documentation build warnings by correcting kernel-doc comment
v4l2_subdev_get_fwnode_pad_1_to_1 function
./include/media/v4l2-subdev.h:1045: warning: Function parameter or member 'entity' not described in 'v4l2_subdev_get_fwnode_pad_1_to_1'
./include/media/v4l2-subdev.h:1045: warning: Function parameter or member 'endpoint' not described in 'v4l2_subdev_get_fwnode_pad_1_to_1'
Signed-off-by: Colton Lewis <colton.w.lewis@protonmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Silence documentation build warnings by correcting kernel-doc comment
v4l2_create_fwnode_links_to_pad and v4l2_create_fwnode_links functions.
./include/media/v4l2-mc.h:110: warning: Function parameter or member 'src_sd' not described in 'v4l2_create_fwnode_links_to_pad'
./include/media/v4l2-mc.h:110: warning: Function parameter or member 'sink' not described in 'v4l2_create_fwnode_links_to_pad'
./include/media/v4l2-mc.h:134: warning: Function parameter or member 'src_sd' not described in 'v4l2_create_fwnode_links'
./include/media/v4l2-mc.h:134: warning: Function parameter or member 'sink_sd' not described in 'v4l2_create_fwnode_links'
Signed-off-by: Colton Lewis <colton.w.lewis@protonmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The initial assumption that all VDSO related data can be completely generic
does not hold. S390 needs architecture specific storage to access the clock
steering information.
Add struct arch_vdso_data to the vdso data struct. For architectures which
do not need extra data this defaults to an empty struct. Architectures
which require it, enable CONFIG_ARCH_HAS_VDSO_DATA and provide their
specific struct in asm/vdso/data.h.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200804150124.41692-2-svens@linux.ibm.com
Architectures can have the requirement to add additional architecture
specific data to the VDSO data page which needs to be updated independent
of the timekeeper updates.
To protect these updates vs. concurrent readers and a conflicting update
through timekeeping, provide helper functions to make such updates safe.
vdso_update_begin() takes the timekeeper_lock to protect against a
potential update from timekeeper code and increments the VDSO sequence
count to signal data inconsistency to concurrent readers. vdso_update_end()
makes the sequence count even again to signal data consistency and drops
the timekeeper lock.
[ Sven: Add interrupt disable handling to the functions ]
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200804150124.41692-3-svens@linux.ibm.com
MIPS already uses and S390 will need the vdso data pointer in
__arch_get_hw_counter().
This works nicely as long as the architecture does not support time
namespaces in the VDSO. With time namespaces enabled the regular
accessor to the vdso data pointer __arch_get_vdso_data() will return the
namespace specific VDSO data page for tasks which are part of a
non-root time namespace. This would cause the architectures which need
the vdso data pointer in __arch_get_hw_counter() to access the wrong
vdso data page.
Add a vdso_data pointer argument to __arch_get_hw_counter() and hand it in
from the call sites in the core code. For architectures which do not need
the data pointer in their counter accessor function the compiler will just
optimize it out.
Fix up all existing architecture implementations and make MIPS utilize the
pointer instead of invoking the accessor function.
No functional change and no change in the resulting object code (except
MIPS).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/draft-87wo2ekuzn.fsf@nanos.tec.linutronix.de
The count field is meant to tell if an update to nr_running
is an add or a subtract. Make it do so by adding the missing
minus sign.
Fixes: 9d246053a6 ("sched: Add a tracepoint to track rq->nr_running")
Signed-off-by: Phil Auld <pauld@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200805203138.1411-1-pauld@redhat.com
cr=0 is supposed to be an optimization to save CPU cycles, but if
buddy data (in memory) is not initialized then all this makes no sense
as we have to do sync IO taking a lot of cycles. Also, at cr=0
mballoc doesn't choose any available chunk. cr=1 also skips groups
using heuristic based on avg. fragment size. It's more useful to skip
such groups and switch to cr=2 where groups will be scanned for
available chunks. However, we always read the first block group in a
flex_bg so metadata blocks will get read into the first flex_bg if
possible.
Using sparse image and dm-slow virtual device of 120TB was
simulated, then the image was formatted and filled using debugfs to
mark ~85% of available space as busy. mount process w/o the patch
couldn't complete in half an hour (according to vmstat it would take
~10-11 hours). With the patch applied mount took ~20 seconds.
Lustre-bug-id: https://jira.whamcloud.com/browse/LU-12988
Signed-off-by: Alex Zhuravlev <azhuravlev@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Artem Blagodarenko <artem.blagodarenko@gmail.com>
This should significantly improve bitmap loading, especially for flex
groups as it tries to load all bitmaps within a flex.group instead of
one by one synchronously.
Prefetching is done in 8 * flex_bg groups, so it should be 8
read-ahead reads for a single allocating thread. At the end of
allocation the thread waits for read-ahead completion and initializes
buddy information so that read-aheads are not lost in case of memory
pressure.
At cr=0 the number of prefetching IOs is limited per allocation
context to prevent a situation when mballoc loads thousands of bitmaps
looking for a perfect group and ignoring groups with good chunks.
Together with the patch "ext4: limit scanning of uninitialized groups"
the mount time (which includes few tiny allocations) of a 1PB
filesystem is reduced significantly:
0% full 50%-full unpatched patched
mount time 33s 9279s 563s
[ Restructured by tytso; removed the state flags in the allocation
context, so it can be used to lazily prefetch the allocation bitmaps
immediately after the file system is mounted. Skip prefetching
block groups which are uninitialized. Finally pass in the
REQ_RAHEAD flag to the block layer while prefetching. ]
Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Don't define EXT4_IOC_* aliases to ioctls that already have a generic
FS_IOC_* name. These aliases are unnecessary, and they make it unclear
which ioctls are ext4-specific and which are generic.
Exception: leave EXT4_IOC_GETVERSION_OLD and EXT4_IOC_SETVERSION_OLD
as-is for now, since renaming them to FS_IOC_GETVERSION and
FS_IOC_SETVERSION would probably make them more likely to be confused
with EXT4_IOC_GETVERSION and EXT4_IOC_SETVERSION which also exist.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200714230909.56349-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Define the EXT4_FL_USER_* constants by OR-ing together the appropriate
flags, rather than hard-coding a numeric value. This makes it much
easier to see which flags are listed.
No change in the actual values.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200713031012.192440-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
A customer has reported a BUG_ON in ext4_clear_journal_err() hitting
during an LTP testing. Either this has been caused by a test setup
issue where the filesystem was being overwritten while LTP was mounting
it or the journal replay has overwritten the superblock with invalid
data. In either case it is preferable we don't take the machine down
with a BUG_ON. So handle the situation of unexpectedly missing
has_journal feature more gracefully. We issue warning and fail the mount
in the cases where the race window is narrow and the failed check is
most likely a programming error. In cases where fs corruption is more
likely, we do full ext4_error() handling before failing mount / remount.
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200710140759.18031-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Since commit 378f32bab3 ("ext4: introduce direct I/O write using iomap
infrastructure") we don't properly bail out of RWF_NOWAIT direct IO
write if underlying blocks are not allocated. Also
ext4_dio_write_checks() does not honor RWF_NOWAIT when re-acquiring
i_rwsem. Fix both issues.
Fixes: 378f32bab3 ("ext4: introduce direct I/O write using iomap infrastructure")
Cc: stable@kernel.org
Reported-by: Filipe Manana <fdmanana@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/20200708153516.9507-1-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.
Deterministic algorithm:
For each file:
If not .svg:
For each line:
If doesn't contain `\bxmlns\b`:
For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
If both the HTTP and HTTPS versions
return 200 OK and serve the same content:
Replace HTTP with HTTPS.
Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Link: https://lore.kernel.org/r/20200706190339.20709-1-grandmaster@al2klimov.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If dquot_initialize() return non-zero and trace of ext4_unlink_enter/exit
enabled then the matching-pair of trace_exit will lost in log.
Signed-off-by: Yi Zhuang <zhuangyi1@huawei.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/20200629122621.129953-1-zhuangyi1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
It should call trace exit in all return path for ext4_truncate.
Signed-off-by: zhengliang <zhengliang6@huawei.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/20200701083027.45996-1-zhengliang6@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
