Commit 557aaa7ffa ("ft232: support the ASYNC_LOW_LATENCY
flag") enables unprivileged users to set the FTDI latency timer,
but there was a logic flaw that skipped sending the corresponding
USB control message to the device.
Specifically, the device latency timer would not be updated until next
open, something which was later also inadvertently broken by commit
c19db4c9e4 ("USB: ftdi_sio: set device latency timeout at port
probe").
A recent commit c6dce26266 ("USB: serial: ftdi_sio: fix extreme
low-latency setting") disabled the low-latency mode by default so we now
need this fix to allow unprivileged users to again enable it.
Signed-off-by: Anthony Mallet <anthony.mallet@laas.fr>
[johan: amend commit message]
Fixes: 557aaa7ffa ("ft232: support the ASYNC_LOW_LATENCY flag")
Fixes: c19db4c9e4 ("USB: ftdi_sio: set device latency timeout at port probe").
Cc: stable <stable@vger.kernel.org> # 2.6.31
Signed-off-by: Johan Hovold <johan@kernel.org>
I finally got around to creating trampolines for dynamically allocated
ftrace_ops with using synchronize_rcu_tasks(). For users of the ftrace
function hook callbacks, like perf, that allocate the ftrace_ops
descriptor via kmalloc() and friends, ftrace was not able to optimize
the functions being traced to use a trampoline because they would also
need to be allocated dynamically. The problem is that they cannot be
freed when CONFIG_PREEMPT is set, as there's no way to tell if a task
was preempted on the trampoline. That was before Paul McKenney
implemented synchronize_rcu_tasks() that would make sure all tasks
(except idle) have scheduled out or have entered user space.
While testing this, I triggered this bug:
BUG: unable to handle kernel paging request at ffffffffa0230077
...
RIP: 0010:0xffffffffa0230077
...
Call Trace:
schedule+0x5/0xe0
schedule_preempt_disabled+0x18/0x30
do_idle+0x172/0x220
What happened was that the idle task was preempted on the trampoline.
As synchronize_rcu_tasks() ignores the idle thread, there's nothing
that lets ftrace know that the idle task was preempted on a trampoline.
The idle task shouldn't need to ever enable preemption. The idle task
is simply a loop that calls schedule or places the cpu into idle mode.
In fact, having preemption enabled is inefficient, because it can
happen when idle is just about to call schedule anyway, which would
cause schedule to be called twice. Once for when the interrupt came in
and was returning back to normal context, and then again in the normal
path that the idle loop is running in, which would be pointless, as it
had already scheduled.
The only reason schedule_preempt_disable() enables preemption is to be
able to call sched_submit_work(), which requires preemption enabled. As
this is a nop when the task is in the RUNNING state, and idle is always
in the running state, there's no reason that idle needs to enable
preemption. But that means it cannot use schedule_preempt_disable() as
other callers of that function require calling sched_submit_work().
Adding a new function local to kernel/sched/ that allows idle to call
the scheduler without enabling preemption, fixes the
synchronize_rcu_tasks() issue, as well as removes the pointless spurious
schedule calls caused by interrupts happening in the brief window where
preemption is enabled just before it calls schedule.
Reviewed: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170414084809.3dacde2a@gandalf.local.home
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch adds support for Telit ME910 PID 0x1100.
Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Moving most of the shared code to virt/kvm/arm had for consequence
that KVM/ARM doesn't build anymore, because the code that used to
define the tracepoints is now somewhere else.
Fix this by defining CREATE_TRACE_POINTS in coproc.c, and clean-up
trace.h as well.
Fixes: 35d2d5d490 ("KVM: arm/arm64: Move shared files to virt/kvm/arm")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
If there are no clean blocks to be demoted the writeback will be
triggered at that point. Preemptively writing back can hurt high IO
load scenarios.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Drop the MODERATE state since it wasn't buying us much.
Also, in check_migrations(), prepare for the next commit ("dm cache
policy smq: don't do any writebacks unless IDLE") by deferring to the
policy to make the final decision on whether writebacks can be
serviced.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
IO tracking used to throttle writebacks when the origin device is busy.
Even if all the IO is going to the fast device, writebacks can
significantly degrade performance. So track all IO to gauge whether the
cache is busy or not.
Otherwise, synthetic IO tests (e.g. fio) that might send all IO to the
fast device wouldn't cause writebacks to get throttled.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
It causes a lot of churn if the working set's size is close to the fast
device's size.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This stops entries bouncing in and out of the cache quickly.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If there are no clean entries to demote we really want to writeback
immediately.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Heavy IO load may mean there are very few clean blocks in the cache, and
we risk demoting entries that get hit a lot.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Some bios have no payload (eg, a FLUSH), don't reset the idle_time when
these come in.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The new pm domain driver causes a build failure when CONFIG_PM
is not set:
warning: (IMX7_PM_DOMAINS) selects PM_GENERIC_DOMAINS which has unmet direct dependencies (PM)
drivers/base/power/domain_governor.c: In function 'default_suspend_ok':
drivers/base/power/domain_governor.c:75:17: error: 'struct dev_pm_info' has no member named 'ignore_children'
This adds a dependency to ensure that we don't attempt to build the
driver without CONFIG_PM.
Fixes: 03aa12629f ("soc: imx: Add GPCv2 power gating driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
The board file for imx6sx-sdb overrides cpufreq operating points to use
higher voltages. This is done because the board has a shared rail for
VDD_ARM_IN and VDD_SOC_IN and when using LDO bypass the shared voltage
needs to be a value suitable for both ARM and SOC.
This only applies to LDO bypass mode, a feature not present in upstream.
When LDOs are enabled the effect is to use higher voltages than necessary
for no good reason.
Setting these higher voltages can make some boards fail to boot with ugly
semi-random crashes reminiscent of memory corruption. These failures only
happen on board rev. C, rev. B is reported to still work.
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Fixes: 54183bd7f7 ("ARM: imx6sx-sdb: add revb board and make it default")
Cc: stable@vger.kernel.org
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Currently the following errors are seen:
[ 14.015056] mc13xxx 0-0008: Failed to read IRQ status: -6
[ 27.321093] mc13xxx 0-0008: Failed to read IRQ status: -6
[ 27.411681] mc13xxx 0-0008: Failed to read IRQ status: -6
[ 27.456281] mc13xxx 0-0008: Failed to read IRQ status: -6
[ 30.527106] mc13xxx 0-0008: Failed to read IRQ status: -6
[ 36.596900] mc13xxx 0-0008: Failed to read IRQ status: -6
Also when reading the interrupts via 'cat /proc/interrupts' the
PMIC GPIO interrupt counter does not stop increasing.
The reason for the storm of interrupts is that the PUS field of
register IOMUXC_SW_PAD_CTL_PAD_CSI0_DAT5 is currently configured as:
10 : 100k pullup
and the PMIC interrupt is being registered as IRQ_TYPE_LEVEL_HIGH type,
which is the correct type as per the MC34708 datasheet.
Use the default power on value for the IOMUX, which sets PUS field as:
00: 360k pull down
This prevents the spurious PMIC interrupts from happening.
Commit e1ffceb078 ("ARM: imx53: qsrb: fix PMIC interrupt level")
correctly described the irq type as IRQ_TYPE_LEVEL_HIGH, but
missed to update the IOMUX of the PMIC GPIO as pull down.
Fixes: e1ffceb078 ("ARM: imx53: qsrb: fix PMIC interrupt level")
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
The recent conversion to the hotplug state machine missed that the original
hotplug notifiers did not execute in the frozen state, which is used on
suspend on resume.
This does not matter on single socket machines, but on multi socket systems
this breaks when the device for a non-boot socket is removed when the last
CPU of that socket is brought offline. The device removal locks up the
machine hard w/o any debug output.
Prevent executing the hotplug callbacks when cpuhp_tasks_frozen is true.
Thanks to Tommi for providing debug information patiently while I failed to
spot the obvious.
Fixes: e00ca5df37 ("hwmon: (coretemp) Convert to hotplug state machine")
Reported-by: Tommi Rantala <tt.rantala@gmail.com>
Tested-by: Tommi Rantala <tt.rantala@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Root flow table is dynamically changed by the underlying flow steering
layer, and IPoIB/ULPs have no idea what will be the root flow table in
the future, hence we need a dynamic infrastructure to move Underlay QPs
with the root flow table.
Fixes: b3ba51498b ("net/mlx5: Refactor create flow table method to accept underlay QP")
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Signed-off-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
IPoIB doesn't support striding RQ at the moment, for this
we need to explicitly choose non striding RQ in IPoIB init,
even if the HW supports it.
Fixes: 8f493ffd88 ("net/mlx5e: IPoIB, RX steering RSS RQTs and TIRs")
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Fail-safe support patches introduced a trivial bug,
setup tc callback is doing a wrong check of the netdevice state,
the fix is simply to invert the condition.
Fixes: 6f9485af40 ("net/mlx5e: Fail safe tc setup")
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Pause bit should set when RX pause is on, not TX pause.
Also, setting Asym_Pause is incorrect, and should be turned off.
Fixes: 665bc53969 ("net/mlx5e: Use new ethtool get/set link ksettings API")
Signed-off-by: Gal Pressman <galp@mellanox.com>
Cc: kernel-team@fb.com
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Query the operational pause from firmware (PFCC register) instead of
always passing zeros.
Fixes: 665bc53969 ("net/mlx5e: Use new ethtool get/set link ksettings API")
Signed-off-by: Gal Pressman <galp@mellanox.com>
Cc: kernel-team@fb.com
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Remove the duplicate brcm,bcm7425-sun-top-ctrl compatible string and
replace it with brcm,bcm7435-sun-top-ctrl which was intended.
Fixes: bd0faf08dc ("soc: bcm: brcmstb: Match additional compatible strings")
Reported-by: Andreas Oberritter <obi@saftware.de>
Acked-by: Gregory Fong <gregory.0xf0@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Tetsuo reports:
fs/built-in.o: In function `xfs_file_iomap_end':
xfs_iomap.c:(.text+0xe0ef9): undefined reference to `put_dax'
fs/built-in.o: In function `xfs_file_iomap_begin':
xfs_iomap.c:(.text+0xe1a7f): undefined reference to `dax_get_by_host'
make: *** [vmlinux] Error 1
$ grep DAX .config
CONFIG_DAX=m
# CONFIG_DEV_DAX is not set
# CONFIG_FS_DAX is not set
When FS_DAX=n we can/must throw away the dax code in filesystems.
Implement 'fs_' versions of dax_get_by_host() and put_dax() that are
nops in the FS_DAX=n case.
Cc: <linux-xfs@vger.kernel.org>
Cc: <linux-ext4@vger.kernel.org>
Cc: Jan Kara <jack@suse.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Fixes: ef51042472 ("block, dax: move 'select DAX' from BLOCK to FS_DAX")
Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
In the BLOCK=n case the dax core does not need to / must not emit the
block-device-dax helpers. Otherwise it leads to compile errors.
Cc: Arnd Bergmann <arnd@arndb.de>
Reported-by: Fabian Frederick <fabf@skynet.be>
Fixes: ef51042472 ("block, dax: move 'select DAX' from BLOCK to FS_DAX")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Imagine we have a pid namespace and a task from its parent's pid_ns,
which made setns() to the pid namespace. The task is doing fork(),
while the pid namespace's child reaper is dying. We have the race
between them:
Task from parent pid_ns Child reaper
copy_process() ..
alloc_pid() ..
.. zap_pid_ns_processes()
.. disable_pid_allocation()
.. read_lock(&tasklist_lock)
.. iterate over pids in pid_ns
.. kill tasks linked to pids
.. read_unlock(&tasklist_lock)
write_lock_irq(&tasklist_lock); ..
attach_pid(p, PIDTYPE_PID); ..
.. ..
So, just created task p won't receive SIGKILL signal,
and the pid namespace will be in contradictory state.
Only manual kill will help there, but does the userspace
care about this? I suppose, the most users just inject
a task into a pid namespace and wait a SIGCHLD from it.
The patch fixes the problem. It simply checks for
(pid_ns->nr_hashed & PIDNS_HASH_ADDING) in copy_process().
We do it under the tasklist_lock, and can't skip
PIDNS_HASH_ADDING as noted by Oleg:
"zap_pid_ns_processes() does disable_pid_allocation()
and then takes tasklist_lock to kill the whole namespace.
Given that copy_process() checks PIDNS_HASH_ADDING
under write_lock(tasklist) they can't race;
if copy_process() takes this lock first, the new child will
be killed, otherwise copy_process() can't miss
the change in ->nr_hashed."
If allocation is disabled, we just return -ENOMEM
like it's made for such cases in alloc_pid().
v2: Do not move disable_pid_allocation(), do not
introduce a new variable in copy_process() and simplify
the patch as suggested by Oleg Nesterov.
Account the problem with double irq enabling
found by Eric W. Biederman.
Fixes: c876ad7682 ("pidns: Stop pid allocation when init dies")
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Ingo Molnar <mingo@kernel.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Mike Rapoport <rppt@linux.vnet.ibm.com>
CC: Michal Hocko <mhocko@suse.com>
CC: Andy Lutomirski <luto@kernel.org>
CC: "Eric W. Biederman" <ebiederm@xmission.com>
CC: Andrei Vagin <avagin@openvz.org>
CC: Cyrill Gorcunov <gorcunov@openvz.org>
CC: Serge Hallyn <serge@hallyn.com>
Cc: stable@vger.kernel.org
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
The code can potentially sleep for an indefinite amount of time in
zap_pid_ns_processes triggering the hung task timeout, and increasing
the system average. This is undesirable. Sleep with a task state of
TASK_INTERRUPTIBLE instead of TASK_UNINTERRUPTIBLE to remove these
undesirable side effects.
Apparently under heavy load this has been allowing Chrome to trigger
the hung time task timeout error and cause ChromeOS to reboot.
Reported-by: Vovo Yang <vovoy@google.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Fixes: 6347e90091 ("pidns: guarantee that the pidns init will be the last pidns process reaped")
Cc: stable@vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Pull some more input subsystem updates from Dmitry Torokhov:
"An updated xpad driver with a few more recognized device IDs, and a
new psxpad-spi driver, allowing connecting Playstation 1 and 2 joypads
via SPI bus"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: cros_ec_keyb - remove extraneous 'const'
Input: add support for PlayStation 1/2 joypads connected via SPI
Input: xpad - add USB IDs for Mad Catz Brawlstick and Razer Sabertooth
Input: xpad - sync supported devices with xboxdrv
Input: xpad - sort supported devices by USB ID
Pull UML fixes from Richard Weinberger:
"No new stuff, just fixes"
* 'for-linus-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: Add missing NR_CPUS include
um: Fix to call read_initrd after init_bootmem
um: Include kbuild.h instead of duplicating its macros
um: Fix PTRACE_POKEUSER on x86_64
um: Set number of CPUs
um: Fix _print_addr()
Merge misc fixes from Andrew Morton:
"15 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm, docs: update memory.stat description with workingset* entries
mm: vmscan: scan until it finds eligible pages
mm, thp: copying user pages must schedule on collapse
dax: fix PMD data corruption when fault races with write
dax: fix data corruption when fault races with write
ext4: return to starting transaction in ext4_dax_huge_fault()
mm: fix data corruption due to stale mmap reads
dax: prevent invalidation of mapped DAX entries
Tigran has moved
mm, vmalloc: fix vmalloc users tracking properly
mm/khugepaged: add missed tracepoint for collapse_huge_page_swapin
gcov: support GCC 7.1
mm, vmstat: Remove spurious WARN() during zoneinfo print
time: delete current_fs_time()
hwpoison, memcg: forcibly uncharge LRU pages
Some minor cleanup of cifs query xattr functions (will also make
SMB3 xattr implementation cleaner as well).
Signed-off-by: Steve French <steve.french@primarydata.com>
Use time_after kernel macro for time comparison
that has safety check.
Signed-off-by: Karim Eshapa <karim.eshapa@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
In fs/cifs/smb2pdu.h, we have:
#define SMB2_SHARE_TYPE_DISK 0x01
#define SMB2_SHARE_TYPE_PIPE 0x02
#define SMB2_SHARE_TYPE_PRINT 0x03
Knowing that, with the current code, the SMB2_SHARE_TYPE_PRINT case can
never trigger and printer share would be interpreted as disk share.
So, test the ShareType value for equality instead.
Fixes: faaf946a7d ("CIFS: Add tree connect/disconnect capability for SMB2")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Create an ops variable to store tcon->ses->server->ops and cache
indirections and reduce code size a trivial bit.
$ size fs/cifs/cifsacl.o*
text data bss dec hex filename
5338 136 8 5482 156a fs/cifs/cifsacl.o.new
5371 136 8 5515 158b fs/cifs/cifsacl.o.old
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Commit 4b4cea91691d ("mm: vmscan: fix IO/refault regression in cache
workingset transition") introduced three new entries in memory stat
file:
- workingset_refault
- workingset_activate
- workingset_nodereclaim
This commit adds a corresponding description to the cgroup v2 docs.
Link: http://lkml.kernel.org/r/1494530293-31236-1-git-send-email-guro@fb.com
Signed-off-by: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have encountered need_resched warnings in __collapse_huge_page_copy()
while doing {clear,copy}_user_highpage() over HPAGE_PMD_NR source pages.
mm->mmap_sem is held for write, but the iteration is well bounded.
Reschedule as needed.
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1705101426380.109808@chino.kir.corp.google.com
Signed-off-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is based on a patch from Jan Kara that fixed the equivalent race in
the DAX PTE fault path.
Currently DAX PMD read fault can race with write(2) in the following
way:
CPU1 - write(2) CPU2 - read fault
dax_iomap_pmd_fault()
->iomap_begin() - sees hole
dax_iomap_rw()
iomap_apply()
->iomap_begin - allocates blocks
dax_iomap_actor()
invalidate_inode_pages2_range()
- there's nothing to invalidate
grab_mapping_entry()
- we add huge zero page to the radix tree
and map it to page tables
The result is that hole page is mapped into page tables (and thus zeros
are seen in mmap) while file has data written in that place.
Fix the problem by locking exception entry before mapping blocks for the
fault. That way we are sure invalidate_inode_pages2_range() call for
racing write will either block on entry lock waiting for the fault to
finish (and unmap stale page tables after that) or read fault will see
already allocated blocks by write(2).
Fixes: 9f141d6ef6 ("dax: Call ->iomap_begin without entry lock during dax fault")
Link: http://lkml.kernel.org/r/20170510172700.18991-1-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently DAX read fault can race with write(2) in the following way:
CPU1 - write(2) CPU2 - read fault
dax_iomap_pte_fault()
->iomap_begin() - sees hole
dax_iomap_rw()
iomap_apply()
->iomap_begin - allocates blocks
dax_iomap_actor()
invalidate_inode_pages2_range()
- there's nothing to invalidate
grab_mapping_entry()
- we add zero page in the radix tree
and map it to page tables
The result is that hole page is mapped into page tables (and thus zeros
are seen in mmap) while file has data written in that place.
Fix the problem by locking exception entry before mapping blocks for the
fault. That way we are sure invalidate_inode_pages2_range() call for
racing write will either block on entry lock waiting for the fault to
finish (and unmap stale page tables after that) or read fault will see
already allocated blocks by write(2).
Fixes: 9f141d6ef6
Link: http://lkml.kernel.org/r/20170510085419.27601-5-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
DAX will return to locking exceptional entry before mapping blocks for a
page fault to fix possible races with concurrent writes. To avoid lock
inversion between exceptional entry lock and transaction start, start
the transaction already in ext4_dax_huge_fault().
Fixes: 9f141d6ef6
Link: http://lkml.kernel.org/r/20170510085419.27601-4-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, we didn't invalidate page tables during invalidate_inode_pages2()
for DAX. That could result in e.g. 2MiB zero page being mapped into
page tables while there were already underlying blocks allocated and
thus data seen through mmap were different from data seen by read(2).
The following sequence reproduces the problem:
- open an mmap over a 2MiB hole
- read from a 2MiB hole, faulting in a 2MiB zero page
- write to the hole with write(3p). The write succeeds but we
incorrectly leave the 2MiB zero page mapping intact.
- via the mmap, read the data that was just written. Since the zero
page mapping is still intact we read back zeroes instead of the new
data.
Fix the problem by unconditionally calling invalidate_inode_pages2_range()
in dax_iomap_actor() for new block allocations and by properly
invalidating page tables in invalidate_inode_pages2_range() for DAX
mappings.
Fixes: c6dcf52c23
Link: http://lkml.kernel.org/r/20170510085419.27601-3-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Patch series "mm,dax: Fix data corruption due to mmap inconsistency",
v4.
This series fixes data corruption that can happen for DAX mounts when
page faults race with write(2) and as a result page tables get out of
sync with block mappings in the filesystem and thus data seen through
mmap is different from data seen through read(2).
The series passes testing with t_mmap_stale test program from Ross and
also other mmap related tests on DAX filesystem.
This patch (of 4):
dax_invalidate_mapping_entry() currently removes DAX exceptional entries
only if they are clean and unlocked. This is done via:
invalidate_mapping_pages()
invalidate_exceptional_entry()
dax_invalidate_mapping_entry()
However, for page cache pages removed in invalidate_mapping_pages()
there is an additional criteria which is that the page must not be
mapped. This is noted in the comments above invalidate_mapping_pages()
and is checked in invalidate_inode_page().
For DAX entries this means that we can can end up in a situation where a
DAX exceptional entry, either a huge zero page or a regular DAX entry,
could end up mapped but without an associated radix tree entry. This is
inconsistent with the rest of the DAX code and with what happens in the
page cache case.
We aren't able to unmap the DAX exceptional entry because according to
its comments invalidate_mapping_pages() isn't allowed to block, and
unmap_mapping_range() takes a write lock on the mapping->i_mmap_rwsem.
Since we essentially never have unmapped DAX entries to evict from the
radix tree, just remove dax_invalidate_mapping_entry().
Fixes: c6dcf52c23 ("mm: Invalidate DAX radix tree entries only if appropriate")
Link: http://lkml.kernel.org/r/20170510085419.27601-2-jack@suse.cz
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Jan Kara <jack@suse.cz>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org> [4.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 1f5307b1e0 ("mm, vmalloc: properly track vmalloc users") has
pulled asm/pgtable.h include dependency to linux/vmalloc.h and that
turned out to be a bad idea for some architectures. E.g. m68k fails
with
In file included from arch/m68k/include/asm/pgtable_mm.h:145:0,
from arch/m68k/include/asm/pgtable.h:4,
from include/linux/vmalloc.h:9,
from arch/m68k/kernel/module.c:9:
arch/m68k/include/asm/mcf_pgtable.h: In function 'nocache_page':
>> arch/m68k/include/asm/mcf_pgtable.h:339:43: error: 'init_mm' undeclared (first use in this function)
#define pgd_offset_k(address) pgd_offset(&init_mm, address)
as spotted by kernel build bot. nios2 fails for other reason
In file included from include/asm-generic/io.h:767:0,
from arch/nios2/include/asm/io.h:61,
from include/linux/io.h:25,
from arch/nios2/include/asm/pgtable.h:18,
from include/linux/mm.h:70,
from include/linux/pid_namespace.h:6,
from include/linux/ptrace.h:9,
from arch/nios2/include/uapi/asm/elf.h:23,
from arch/nios2/include/asm/elf.h:22,
from include/linux/elf.h:4,
from include/linux/module.h:15,
from init/main.c:16:
include/linux/vmalloc.h: In function '__vmalloc_node_flags':
include/linux/vmalloc.h:99:40: error: 'PAGE_KERNEL' undeclared (first use in this function); did you mean 'GFP_KERNEL'?
which is due to the newly added #include <asm/pgtable.h>, which on nios2
includes <linux/io.h> and thus <asm/io.h> and <asm-generic/io.h> which
again includes <linux/vmalloc.h>.
Tweaking that around just turns out a bigger headache than necessary.
This patch reverts 1f5307b1e0 and reimplements the original fix in a
different way. __vmalloc_node_flags can stay static inline which will
cover vmalloc* functions. We only have one external user
(kvmalloc_node) and we can export __vmalloc_node_flags_caller and
provide the caller directly. This is much simpler and it doesn't really
need any games with header files.
[akpm@linux-foundation.org: coding-style fixes]
[mhocko@kernel.org: revert old comment]
Link: http://lkml.kernel.org/r/20170509211054.GB16325@dhcp22.suse.cz
Fixes: 1f5307b1e0 ("mm, vmalloc: properly track vmalloc users")
Link: http://lkml.kernel.org/r/20170509153702.GR6481@dhcp22.suse.cz
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Tobias Klauser <tklauser@distanz.ch>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
One return case of `__collapse_huge_page_swapin()` does not invoke
tracepoint while every other return case does. This commit adds a
tracepoint invocation for the case.
Link: http://lkml.kernel.org/r/20170507101813.30187-1-sj38.park@gmail.com
Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After commit e2ecc8a79e ("mm, vmstat: print non-populated zones in
zoneinfo"), /proc/zoneinfo will show unpopulated zones.
A memoryless node, having no populated zones at all, was previously
ignored, but will now trigger the WARN() in is_zone_first_populated().
Remove this warning, as its only purpose was to warn of a situation that
has since been enabled.
Aside: The "per-node stats" are still printed under the first populated
zone, but that's not necessarily the first stanza any more. I'm not
sure which criteria is more important with regard to not breaking
parsers, but it looks a little weird to the eye.
Fixes: e2ecc8a79e ("mm, vmstat: print node-based stats in zoneinfo file")
Link: http://lkml.kernel.org/r/1493854905-10918-1-git-send-email-arbab@linux.vnet.ibm.com
Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
All uses of the current_fs_time() function have been replaced by other
time interfaces.
And, its use cases can be fulfilled by current_time() or ktime_get_*
variants.
Link: http://lkml.kernel.org/r/1491613030-11599-13-git-send-email-deepa.kernel@gmail.com
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
