Kent Overstreet [Fri, 7 Jun 2013 00:07:07 +0000 (10:07 +1000)]
aio: fix io_destroy() regression by using call_rcu()
There was a regression introduced by 36f5588 ("aio: refcounting cleanup"),
reported by Jens Axboe - the refcounting cleanup switched to using RCU in
the shutdown path, but the synchronize_rcu() was done in the context of
the io_destroy() syscall greatly increasing the time it could block.
This patch switches it to call_rcu() and makes shutdown asynchronous (more
asynchronous than it was originally; before the refcount changes
io_destroy() would still wait on pending kiocbs).
Note that there's a global quota on the max outstanding kiocbs, and that
quota must be manipulated synchronously; otherwise io_setup() could return
-EAGAIN when there isn't quota available, and userspace won't have any way
of waiting until shutdown of the old kioctxs has finished (besides busy
looping).
So we release our quota before kioctx shutdown has finished, which should
be fine since the quota never corresponded to anything real anyways.
Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Reported-by: Jens Axboe <axboe@kernel.dk> Tested-by: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Benjamin LaHaise <bcrl@kvack.org> Tested-by: Benjamin LaHaise <bcrl@kvack.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Johan Hovold [Fri, 7 Jun 2013 00:07:07 +0000 (10:07 +1000)]
rtc-at91rm9200: use shadow IMR on at91sam9x5
Add support for the at91sam9x5-family which must use the shadow interrupt
mask due to a hardware issue (causing RTC_IMR to always be zero).
Signed-off-by: Johan Hovold <jhovold@gmail.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Douglas Gilbert <dgilbert@interlog.com> Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Cc: Ludovic Desroches <ludovic.desroches@atmel.com> Cc: Robert Nelson <Robert.Nelson@digikey.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Johan Hovold [Fri, 7 Jun 2013 00:07:06 +0000 (10:07 +1000)]
rtc-at91rm9200: add shadow interrupt mask
Add shadow interrupt-mask register which can be used on SoCs where the
actual hardware register is broken.
Note that some care needs to be taken to make sure the shadow mask
corresponds to the actual hardware state. The added overhead is not an
issue for the non-broken SoCs due to the relatively infrequent
interrupt-mask updates. We do, however, only use the shadow mask value as
a fall-back when it actually needed as there is still a theoretical
possibility that the mask is incorrect (see the code for details).
Signed-off-by: Johan Hovold <jhovold@gmail.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Douglas Gilbert <dgilbert@interlog.com> Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Cc: Ludovic Desroches <ludovic.desroches@atmel.com> Cc: Robert Nelson <Robert.Nelson@digikey.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This will allow us to easily add a shadow interrupt-mask register to
use on SoCs where the interrupt-mask register cannot be used.
Signed-off-by: Johan Hovold <jhovold@gmail.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Douglas Gilbert <dgilbert@interlog.com> Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Cc: Ludovic Desroches <ludovic.desroches@atmel.com> Cc: Robert Nelson <Robert.Nelson@digikey.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Johan Hovold [Fri, 7 Jun 2013 00:07:06 +0000 (10:07 +1000)]
rtc-at91rm9200: add configuration support
Add configuration support which can be used to implement SoC-specific
workarounds for broken hardware.
Signed-off-by: Johan Hovold <jhovold@gmail.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Douglas Gilbert <dgilbert@interlog.com> Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Cc: Ludovic Desroches <ludovic.desroches@atmel.com> Cc: Robert Nelson <Robert.Nelson@digikey.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Johan Hovold [Fri, 7 Jun 2013 00:07:06 +0000 (10:07 +1000)]
rtc-at91rm9200: add match-table compile guard
The members of Atmel's at91sam9x5 family (9x5) have a broken RTC interrupt
mask register (AT91_RTC_IMR). It does not reflect enabled interrupts but
instead always returns zero.
The kernel's rtc-at91rm9200 driver handles the RTC for the 9x5 family.
Currently when the date/time is set, an interrupt is generated and this
driver neglects to handle the interrupt. The kernel complains about the
un-handled interrupt and disables it henceforth. This not only breaks the
RTC function, but since that interrupt is shared (Atmel's SYS interrupt)
then other things break as well (e.g. the debug port no longer accepts
characters).
Tested on the at91sam9g25. Bug confirmed by Atmel.
This patch (of 5):
Add missing match-table compile guard.
Signed-off-by: Johan Hovold <jhovold@gmail.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Douglas Gilbert <dgilbert@interlog.com> Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Cc: Ludovic Desroches <ludovic.desroches@atmel.com> Cc: Robert Nelson <Robert.Nelson@digikey.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
fs/ocfs2/namei.c: remove unecessary ERROR when removing non-empty directory
While removing a non-empty directory, the kernel dumps a message:
(rmdir,21743,1):ocfs2_unlink:953 ERROR: status = -39
Suppress the error message from being printed in the dmesg so users
don't panic.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Acked-by: Sunil Mushran <sunil.mushran@gmail.com> Reviewed-by: Jie Liu <jeff.liu@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Rafael Aquini [Fri, 7 Jun 2013 00:07:05 +0000 (10:07 +1000)]
swap: avoid read_swap_cache_async() race to deadlock while waiting on discard I/O completion
read_swap_cache_async() can race against get_swap_page(), and stumble
across a SWAP_HAS_CACHE entry in the swap map whose page wasn't brought
into the swapcache yet. This transient swap_map state is expected to be
transitory, but the actual placement of discard at scan_swap_map() inserts
a wait for I/O completion thus making the thread at
read_swap_cache_async() to loop around its -EEXIST case, while the other
end at get_swap_page() is scheduled away at scan_swap_map(). This can
leave the system deadlocked if the I/O completion happens to be waiting on
the CPU waitqueue where read_swap_cache_async() is busy looping and
!CONFIG_PREEMPT.
This patch introduces a cond_resched() call to make the aforementioned
read_swap_cache_async() busy loop condition to bail out when necessary,
thus avoiding the subtle race window.
Signed-off-by: Rafael Aquini <aquini@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tony Lindgren [Fri, 7 Jun 2013 00:07:05 +0000 (10:07 +1000)]
drivers/rtc/rtc-twl.c: fix missing device_init_wakeup() when booted with device tree
When booted in legacy mode device_init_wakeup() gets called by
drivers/mfd/twl-core.c when the children are initialized. However, when
booted using device tree, the children are created with
of_platform_populate() instead add_children().
This means that the RTC driver will not have device_init_wakeup() set, and
we need to call it from the driver probe like RTC drivers typically do.
Without this we cannot test PM wake-up events on omaps for cases where
there may not be any physical wake-up event.
Signed-off-by: Tony Lindgren <tony@atomide.com> Reported-by: Kevin Hilman <khilman@linaro.org> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Jingoo Han <jg1.han@samsung.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If a new logical drive is added and the CCISS_REGNEWD ioctl is invoked (as
is normal with the Array Configuration Utility) the process will hang as
below. It attempts to acquire the same mutex twice, once in do_ioctl()
and once in cciss_unlocked_open(). The BKL was recursive, the mutex
isn't.
This mutex usage was added into the ioctl path when the big kernel lock
was removed. As it turns out, these paths are all thread safe anyway (or
can easily be made so) and we don't want ioctl() to be single threaded in
any case.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Mike Miller <mike.miller@hp.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Oleg Nesterov [Fri, 7 Jun 2013 00:07:04 +0000 (10:07 +1000)]
audit: wait_for_auditd() should use TASK_UNINTERRUPTIBLE
audit_log_start() does wait_for_auditd() in a loop until
audit_backlog_wait_time passes or audit_skb_queue has a room.
If signal_pending() is true this becomes a busy-wait loop, schedule() in
TASK_INTERRUPTIBLE won't block.
Thanks to Guy for fully investigating and explaining the problem.
(akpm: that'll cause the system to lock up on a non-preemptible
uniprocessor kernel)
(Guy: "Our customer was in fact running a uniprocessor machine, and they
reported a system hang.")
Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Guy Streeter <streeter@redhat.com> Cc: Eric Paris <eparis@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
During resume, we call hpet_rtc_timer_init after masking an irq bit in
hpet. This will cause the call to hpet_disable_rtc_channel to be undone
if RTC_AIE is the only bit not masked.
Allowing the cmos interrupt handler to run before resuming caused some
issues where the timer for the alarm was not removed. This would cause
other, later timers to not be cleared, so utilities such as hwclock would
time out when waiting for the update interrupt.
Signed-off-by: Derek Basehore <dbasehore@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use device_init_wakeup() instead of device_set_wakeup_capable() and move
it before rtc dev registering. This fixes alarmtimer not registered when
tps6586x rtc is the only wakeup compatible rtc in the system.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Andrey Vagin [Fri, 7 Jun 2013 00:07:03 +0000 (10:07 +1000)]
memcg: don't initialize kmem-cache destroying work for root caches
struct memcg_cache_params has a union. Different parts of this union are
used for root and non-root caches. A part with destroying work is used
only for non-root caches.
Xiaowei.Hu [Fri, 7 Jun 2013 00:07:02 +0000 (10:07 +1000)]
ocfs2: ocfs2_prep_new_orphaned_file() should return ret
If an error occurs, for example an EIO in __ocfs2_prepare_orphan_dir,
ocfs2_prep_new_orphaned_file will release the inode_ac, then when the
caller of ocfs2_prep_new_orphaned_file gets a 0 return, it will refer to a
NULL ocfs2_alloc_context struct in the following functions. A kernel
panic happens.
Signed-off-by: "Xiaowei.Hu" <xiaowei.hu@oracle.com> Reviewed-by: shencanquan <shencanquan@huawei.com> Acked-by: Sunil Mushran <sunil.mushran@gmail.com> Cc: Joe Jin <joe.jin@oracle.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Chen Gang [Fri, 7 Jun 2013 00:07:02 +0000 (10:07 +1000)]
lib/mpi/mpicoder.c: looping issue, need stop when equal to zero, found by 'EXTRA_FLAGS=-W'.
For 'while' looping, need stop when 'nbytes == 0', or will cause issue.
('nbytes' is size_t which is always bigger or equal than zero).
The related warning: (with EXTRA_CFLAGS=-W)
lib/mpi/mpicoder.c:40:2: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
Signed-off-by: Chen Gang <gang.chen@asianux.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: David Howells <dhowells@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Kees Cook [Fri, 7 Jun 2013 00:07:02 +0000 (10:07 +1000)]
kmsg: honor dmesg_restrict sysctl on /dev/kmsg
The dmesg_restrict sysctl currently covers the syslog method for access
dmesg, however /dev/kmsg isn't covered by the same protections. Most
people haven't noticed because util-linux dmesg(1) defaults to using the
syslog method for access in older versions. With util-linux dmesg(1)
defaults to reading directly from /dev/kmsg.
To fix /dev/kmsg, let's compare the existing interfaces and what they allow:
- /proc/kmsg allows:
- open (SYSLOG_ACTION_OPEN) if CAP_SYSLOG since it uses a destructive
single-reader interface (SYSLOG_ACTION_READ).
- everything, after an open.
- syslog syscall allows:
- anything, if CAP_SYSLOG.
- SYSLOG_ACTION_READ_ALL and SYSLOG_ACTION_SIZE_BUFFER, if dmesg_restrict==0.
- nothing else (EPERM).
The use-cases were:
- dmesg(1) needs to do non-destructive SYSLOG_ACTION_READ_ALLs.
- sysklog(1) needs to open /proc/kmsg, drop privs, and still issue the
destructive SYSLOG_ACTION_READs.
AIUI, dmesg(1) is moving to /dev/kmsg, and systemd-journald doesn't clear
the ring buffer.
Based on the comments in devkmsg_llseek, it sounds like actions besides
reading aren't going to be supported by /dev/kmsg (i.e.
SYSLOG_ACTION_CLEAR), so we have a strict subset of the non-destructive
syslog syscall actions.
To this end, move the check as Josh had done, but also rename the
constants to reflect their new uses (SYSLOG_FROM_CALL becomes
SYSLOG_FROM_READER, and SYSLOG_FROM_FILE becomes SYSLOG_FROM_PROC).
SYSLOG_FROM_READER allows non-destructive actions, and SYSLOG_FROM_PROC
allows destructive actions after a capabilities-constrained
SYSLOG_ACTION_OPEN check.
- /dev/kmsg allows:
- open if CAP_SYSLOG or dmesg_restrict==0
- reading/polling, after open
Robin Holt [Fri, 7 Jun 2013 00:07:01 +0000 (10:07 +1000)]
reboot: rigrate shutdown/reboot to boot cpu
We recently noticed that reboot of a 1024 cpu machine takes approx 16
minutes of just stopping the cpus. The slowdown was tracked to commit f96972f.
The current implementation does all the work of hot removing the cpus
before halting the system. We are switching to just migrating to the
boot cpu and then continuing with shutdown/reboot.
This also has the effect of not breaking x86's command line parameter for
specifying the reboot cpu. Note, this code was shamelessly copied from
arch/x86/kernel/reboot.c with bits removed pertaining to the reboot_cpu
command line parameter.
Signed-off-by: Robin Holt <holt@sgi.com> Tested-by: Shawn Guo <shawn.guo@linaro.org> Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Robin Holt <holt@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
CPU hotplug: provide a generic helper to disable/enable CPU hotplug
There are instances in the kernel where we would like to disable CPU
hotplug (from sysfs) during some important operation. Today the freezer
code depends on this and the code to do it was kinda tailor-made for that.
Restructure the code and make it generic enough to be useful for
other usecases too.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
projects / karo-tx-linux.git / log