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2013-09-25mmc: core: remove dead function mmc_try_claim_hostGrant Grundler
cscope says there are no callers for mmc_try_claim_host in the kernel. No reason to keep it. Signed-off-by: Grant Grundler <grundler@chromium.org> Acked-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Chris Ball <cjb@laptop.org>
2013-09-25Merge tag 'stable/for-linus-3.12-rc2-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull Xen fixes from Konrad Rzeszutek Wilk: "Bug-fixes and one update to the kernel-paramters.txt documentation. - Fix PV spinlocks triggering jump_label code bug - Remove extraneous code in the tpm front driver - Fix ballooning out of pages when non-preemptible - Fix deadlock when using a 32-bit initial domain with large amount of memory - Add xen_nopvpsin parameter to the documentation" * tag 'stable/for-linus-3.12-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/spinlock: Document the xen_nopvspin parameter. xen/p2m: check MFN is in range before using the m2p table xen/balloon: don't alloc page while non-preemptible xen: Do not enable spinlocks before jump_label_init() has executed tpm: xen-tpmfront: Remove the locality sysfs attribute tpm: xen-tpmfront: Fix default durations
2013-09-25Merge tag 'dm-3.12-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm Pull device-mapper fixes from Mike Snitzer: "A few fixes for dm-snapshot, a 32 bit fix for dm-stats, a couple error handling fixes for dm-multipath. A fix for the thin provisioning target to not expose non-zero discard limits if discards are disabled. Lastly, add two DM module parameters which allow users to tune the emergency memory reserves that DM mainatins per device -- this helps fix a long-standing issue for dm-multipath. The conservative default reserve for request-based dm-multipath devices (256) has proven problematic for users with many multipathed SCSI devices but relatively little memory. To responsibly select a smaller value users should use the new nr_bios tracepoint info (via commit 75afb352 "block: Add nr_bios to block_rq_remap tracepoint") to determine the peak number of bios their workloads create" * tag 'dm-3.12-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: dm: add reserved_bio_based_ios module parameter dm: add reserved_rq_based_ios module parameter dm: lower bio-based mempool reservation dm thin: do not expose non-zero discard limits if discards disabled dm mpath: disable WRITE SAME if it fails dm-snapshot: fix performance degradation due to small hash size dm snapshot: workaround for a false positive lockdep warning dm stats: fix possible counter corruption on 32-bit systems dm mpath: do not fail path on -ENOSPC
2013-09-25Merge git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds
Pull MIPS fixes from Ralf Baechle: - Fix a comment - A small cleanup the main purpose of which is to work around an internal compiler error bug in certain Codesource toolchains. * git://git.linux-mips.org/pub/scm/ralf/upstream-linus: MIPS: mm: Move some checks out of 'for' loop in DMA operations MIPS: cpu-features.h: s/MIPS53/MIPS64/
2013-09-25Merge branch 'merge' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull powerpc fixes from Ben Herrenschmidt: "Here are a few things for -rc2, this time it's all written by me so it can only be perfect .... right ? :) So we have the fix to call irq_enter/exit on the irq stack we've been discussing, plus a cleanup on top to remove an unused (and broken) stack limit tracking feature (well, make it 32-bit only in fact where it is used and works properly). Then we have two things that I wrote over the last couple of days and made the executive decision to include just because I can (and I'm sure you won't object .... right ?). They fix a couple of annoying and long standing "issues": - We had separate zImages for when booting via Open Firmware vs. booting via a flat device-tree, while it's trivial to make one that deals with both - We wasted a ton of cycles spinning secondary CPUs uselessly at boot instead of starting them when needed on pseries, thus contributing significantly to global warming" * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: powerpc/pseries: Do not start secondaries in Open Firmware powerpc/zImage: make the "OF" wrapper support ePAPR boot powerpc: Remove ksp_limit on ppc64 powerpc/irq: Run softirqs off the top of the irq stack
2013-09-25Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "An EFI fix and two reboot-quirk fixes" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/reboot: Fix apparent cut-n-paste mistake in Dell reboot workaround x86/reboot: Add quirk to make Dell C6100 use reboot=pci automatically x86, efi: Don't map Boot Services on i386
2013-09-25Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Three small fixes" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/balancing: Fix cfs_rq->task_h_load calculation sched/balancing: Fix 'local->avg_load > busiest->avg_load' case in fix_small_imbalance() sched/balancing: Fix 'local->avg_load > sds->avg_load' case in calculate_imbalance()
2013-09-25Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Assorted standalone fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Add model number for Avoton Silvermont perf: Fix capabilities bitfield compatibility in 'struct perf_event_mmap_page' perf/x86/intel/uncore: Don't use smp_processor_id() in validate_group() perf: Update ABI comment tools lib lk: Uninclude linux/magic.h in debugfs.c perf tools: Fix old GCC build error in trace-event-parse.c:parse_proc_kallsyms() perf probe: Fix finder to find lines of given function perf session: Check for SIGINT in more loops perf tools: Fix compile with libelf without get_phdrnum perf tools: Fix buildid cache handling of kallsyms with kcore perf annotate: Fix objdump line parsing offset validation perf tools: Fill in new definitions for madvise()/mmap() flags perf tools: Sharpen the libaudit dependencies test
2013-09-25update contact information for Mikael PetterssonMikael Pettersson
My old @it.uu.se email address is going away, so update relevant files to point to my @gmail.com address instead. In sata_promise.c just delete the address, people can get it from MAINTAINERS. Signed-off-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-25MIPS: mm: Move some checks out of 'for' loop in DMA operationsJayachandran C
The check cpu_needs_post_dma_flush() in mips_dma_sync_sg_for_cpu() and the check !plat_device_is_coherent() in mips_dma_sync_sg_for_device() can be moved outside the for loop. As a side effect, this also avoids a GCC bug that caused kernel compile to fail with the error: arch/mips/mm/dma-default.c: In function 'mips_dma_sync_sg_for_cpu': arch/mips/mm/dma-default.c:316:1: internal compiler error: in add_insn_before, at emit-rtl.c:3852 This gcc failure is seen in Code Sourcery toolchains [e.g. gcc version 4.7.2 (Sourcery CodeBench Lite 2012.09-99)] after commit "MIPS: Optimize current_cpu_type() for better code." Signed-off-by: Jayachandran C <jchandra@broadcom.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/5907/ Reviewed-by: Markos Chandras <markos.chandras@imgtec.com> Tested-by: Markos Chandras <markos.chandras@imgtec.com> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2013-09-25xen/spinlock: Document the xen_nopvspin parameter.Konrad Rzeszutek Wilk
Which disables in the ticketlock slowpath the Xen PV optimization's. Useful for diagnosing issues and comparing benchmarks in over-commit CPU scenarios. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-09-25xen/p2m: check MFN is in range before using the m2p tableDavid Vrabel
On hosts with more than 168 GB of memory, a 32-bit guest may attempt to grant map an MFN that is error cannot lookup in its mapping of the m2p table. There is an m2p lookup as part of m2p_add_override() and m2p_remove_override(). The lookup falls off the end of the mapped portion of the m2p and (because the mapping is at the highest virtual address) wraps around and the lookup causes a fault on what appears to be a user space address. do_page_fault() (thinking it's a fault to a userspace address), tries to lock mm->mmap_sem. If the gntdev device is used for the grant map, m2p_add_override() is called from from gnttab_mmap() with mm->mmap_sem already locked. do_page_fault() then deadlocks. The deadlock would most commonly occur when a 64-bit guest is started and xenconsoled attempts to grant map its console ring. Introduce mfn_to_pfn_no_overrides() which checks the MFN is within the mapped portion of the m2p table before accessing the table and use this in m2p_add_override(), m2p_remove_override(), and mfn_to_pfn() (which already had the correct range check). All faults caused by accessing the non-existant parts of the m2p are thus within the kernel address space and exception_fixup() is called without trying to lock mm->mmap_sem. This means that for MFNs that are outside the mapped range of the m2p then mfn_to_pfn() will always look in the m2p overrides. This is correct because it must be a foreign MFN (and the PFN in the m2p in this case is only relevant for the other domain). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Cc: Stefano Stabellini <stefano.stabellini@citrix.com> Cc: Jan Beulich <JBeulich@suse.com> -- v3: check for auto_translated_physmap in mfn_to_pfn_no_overrides() v2: in mfn_to_pfn() look in m2p_overrides if the MFN is out of range as it's probably foreign. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
2013-09-25x86/reboot: Fix apparent cut-n-paste mistake in Dell reboot workaroundDave Jones
This seems to have been copied from the Optiplex 990 entry above, but somoene forgot to change the ident text. Signed-off-by: Dave Jones <davej@fedoraproject.org> Link: http://lkml.kernel.org/r/20130925001344.GA13554@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-09-25powerpc/pseries: Do not start secondaries in Open FirmwareBenjamin Herrenschmidt
Starting secondary CPUs early on from Open Firmware and placing them in a holding spin loop slows down the boot process significantly under some hypervisors such as KVM. This is also unnecessary when RTAS supports querying the CPU state So let's not do it. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-25powerpc/zImage: make the "OF" wrapper support ePAPR bootBenjamin Herrenschmidt
This makes the "OF" zImage wrapper (zImage.pseries, zImage.pmac, zImage.maple) work if booted via a flat device-tree (ePAPR boot mode), and thus potentially usable with kexec. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-25powerpc: Remove ksp_limit on ppc64Benjamin Herrenschmidt
We've been keeping that field in thread_struct for a while, it contains the "limit" of the current stack pointer and is meant to be used for detecting stack overflows. It has a few problems however: - First, it was never actually *used* on 64-bit. Set and updated but not actually exploited - When switching stack to/from irq and softirq stacks, it's update is racy unless we hard disable interrupts, which is costly. This is fine on 32-bit as we don't soft-disable there but not on 64-bit. Thus rather than fixing 2 in order to implement 1 in some hypothetical future, let's remove the code completely from 64-bit. In order to avoid a clutter of ifdef's, we remove the updates from C code completely during interrupt stack switching, and instead maintain it from the asm helper that is used to do the stack switching in the first place. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-25powerpc/irq: Run softirqs off the top of the irq stackBenjamin Herrenschmidt
Nowadays, irq_exit() calls __do_softirq() pretty much directly instead of calling do_softirq() which switches to the decicated softirq stack. This has lead to observed stack overflows on powerpc since we call irq_enter() and irq_exit() outside of the scope that switches to the irq stack. This fixes it by moving the stack switching up a level, making irq_enter() and irq_exit() run off the irq stack. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-24mm: Place preemption point in do_mlockall() loopPaul E. McKenney
There is a loop in do_mlockall() that lacks a preemption point, which means that the following can happen on non-preemptible builds of the kernel. Dave Jones reports: "My fuzz tester keeps hitting this. Every instance shows the non-irq stack came in from mlockall. I'm only seeing this on one box, but that has more ram (8gb) than my other machines, which might explain it. INFO: rcu_preempt self-detected stall on CPU { 3} (t=6500 jiffies g=470344 c=470343 q=0) sending NMI to all CPUs: NMI backtrace for cpu 3 CPU: 3 PID: 29664 Comm: trinity-child2 Not tainted 3.11.0-rc1+ #32 Call Trace: lru_add_drain_all+0x15/0x20 SyS_mlockall+0xa5/0x1a0 tracesys+0xdd/0xe2" This commit addresses this problem by inserting the required preemption point. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: Michel Lespinasse <walken@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24Merge branch 'akpm' (patches from Andrew Morton)Linus Torvalds
Merge fixes from Andrew Morton: "Bunch of fixes. And a reversion of mhocko's "Soft limit rework" patch series. This is actually your fault for opening the merge window when I was off racing ;) I didn't read the email thread before sending everything off. Johannes Weiner raised significant issues: http://www.spinics.net/lists/cgroups/msg08813.html and we agreed to back it all out" I clearly need to be more aware of Andrew's racing schedule. * akpm: MAINTAINERS: update mach-bcm related email address checkpatch: make extern in .h prototypes quieter cciss: fix info leak in cciss_ioctl32_passthru() cpqarray: fix info leak in ida_locked_ioctl() kernel/reboot.c: re-enable the function of variable reboot_default audit: fix endless wait in audit_log_start() revert "memcg, vmscan: integrate soft reclaim tighter with zone shrinking code" revert "memcg: get rid of soft-limit tree infrastructure" revert "vmscan, memcg: do softlimit reclaim also for targeted reclaim" revert "memcg: enhance memcg iterator to support predicates" revert "memcg: track children in soft limit excess to improve soft limit" revert "memcg, vmscan: do not attempt soft limit reclaim if it would not scan anything" revert "memcg: track all children over limit in the root" revert "memcg, vmscan: do not fall into reclaim-all pass too quickly" fs/ocfs2/super.c: use a bigger nodestr in ocfs2_dismount_volume watchdog: update watchdog_thresh properly watchdog: update watchdog attributes atomically
2013-09-24MAINTAINERS: update mach-bcm related email addressChristian Daudt
Update email address on mach-bcm + drivers for Broadcom mobile SoCs. Signed-off-by: Christian Daudt <csd@broadcom.com> Cc: Olof Johansson <olof@lixom.net> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24checkpatch: make extern in .h prototypes quieterJoe Perches
The use of extern in .h files is a bit contentious. Make the warning be emitted only when --strict is used on the command line. Signed-off-by: Joe Perches <joe@perches.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24cciss: fix info leak in cciss_ioctl32_passthru()Dan Carpenter
The arg64 struct has a hole after ->buf_size which isn't cleared. Or if any of the calls to copy_from_user() fail then that would cause an information leak as well. This was assigned CVE-2013-2147. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Mike Miller <mike.miller@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24cpqarray: fix info leak in ida_locked_ioctl()Dan Carpenter
The pciinfo struct has a two byte hole after ->dev_fn so stack information could be leaked to the user. This was assigned CVE-2013-2147. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Mike Miller <mike.miller@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24kernel/reboot.c: re-enable the function of variable reboot_defaultChuansheng Liu
Commit 1b3a5d02ee07 ("reboot: move arch/x86 reboot= handling to generic kernel") did some cleanup for reboot= command line, but it made the reboot_default inoperative. The default value of variable reboot_default should be 1, and if command line reboot= is not set, system will use the default reboot mode. [akpm@linux-foundation.org: fix comment layout] Signed-off-by: Li Fei <fei.li@intel.com> Signed-off-by: liu chuansheng <chuansheng.liu@intel.com> Acked-by: Robin Holt <robinmholt@linux.com> Cc: <stable@vger.kernel.org> [3.11.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24audit: fix endless wait in audit_log_start()Konstantin Khlebnikov
After commit 829199197a43 ("kernel/audit.c: avoid negative sleep durations") audit emitters will block forever if userspace daemon cannot handle backlog. After the timeout the waiting loop turns into busy loop and runs until daemon dies or returns back to work. This is a minimal patch for that bug. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Richard Guy Briggs <rgb@redhat.com> Cc: Eric Paris <eparis@redhat.com> Cc: Chuck Anderson <chuck.anderson@oracle.com> Cc: Dan Duval <dan.duval@oracle.com> Cc: Dave Kleikamp <dave.kleikamp@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24revert "memcg, vmscan: integrate soft reclaim tighter with zone shrinking code"Andrew Morton
Revert commit 3b38722efd9f ("memcg, vmscan: integrate soft reclaim tighter with zone shrinking code") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24revert "memcg: get rid of soft-limit tree infrastructure"Andrew Morton
Revert commit e883110aad71 ("memcg: get rid of soft-limit tree infrastructure") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24revert "vmscan, memcg: do softlimit reclaim also for targeted reclaim"Andrew Morton
Revert commit a5b7c87f9207 ("vmscan, memcg: do softlimit reclaim also for targeted reclaim") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24revert "memcg: enhance memcg iterator to support predicates"Andrew Morton
Revert commit de57780dc659 ("memcg: enhance memcg iterator to support predicates") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24revert "memcg: track children in soft limit excess to improve soft limit"Andrew Morton
Revert commit 7d910c054be4 ("memcg: track children in soft limit excess to improve soft limit") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24revert "memcg, vmscan: do not attempt soft limit reclaim if it would not ↵Andrew Morton
scan anything" Revert commit e839b6a1c8d0 ("memcg, vmscan: do not attempt soft limit reclaim if it would not scan anything") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24revert "memcg: track all children over limit in the root"Andrew Morton
Revert commit 1be171d60bdd ("memcg: track all children over limit in the root") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24revert "memcg, vmscan: do not fall into reclaim-all pass too quickly"Andrew Morton
Revert commit e975de998b96 ("memcg, vmscan: do not fall into reclaim-all pass too quickly") I merged this prematurely - Michal and Johannes still disagree about the overall design direction and the future remains unclear. Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24fs/ocfs2/super.c: use a bigger nodestr in ocfs2_dismount_volumeGoldwyn Rodrigues
While printing 32-bit node numbers, an 8-byte string is not enough. Increase the size of the string to 12 chars. This got left out in commit 49fa8140e487 ("fs/ocfs2/super.c: Use bigger nodestr to accomodate 32-bit node numbers"). Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24watchdog: update watchdog_thresh properlyMichal Hocko
watchdog_tresh controls how often nmi perf event counter checks per-cpu hrtimer_interrupts counter and blows up if the counter hasn't changed since the last check. The counter is updated by per-cpu watchdog_hrtimer hrtimer which is scheduled with 2/5 watchdog_thresh period which guarantees that hrtimer is scheduled 2 times per the main period. Both hrtimer and perf event are started together when the watchdog is enabled. So far so good. But... But what happens when watchdog_thresh is updated from sysctl handler? proc_dowatchdog will set a new sampling period and hrtimer callback (watchdog_timer_fn) will use the new value in the next round. The problem, however, is that nobody tells the perf event that the sampling period has changed so it is ticking with the period configured when it has been set up. This might result in an ear ripping dissonance between perf and hrtimer parts if the watchdog_thresh is increased. And even worse it might lead to KABOOM if the watchdog is configured to panic on such a spurious lockup. This patch fixes the issue by updating both nmi perf even counter and hrtimers if the threshold value has changed. The nmi one is disabled and then reinitialized from scratch. This has an unpleasant side effect that the allocation of the new event might fail theoretically so the hard lockup detector would be disabled for such cpus. On the other hand such a memory allocation failure is very unlikely because the original event is deallocated right before. It would be much nicer if we just changed perf event period but there doesn't seem to be any API to do that right now. It is also unfortunate that perf_event_alloc uses GFP_KERNEL allocation unconditionally so we cannot use on_each_cpu() and do the same thing from the per-cpu context. The update from the current CPU should be safe because perf_event_disable removes the event atomically before it clears the per-cpu watchdog_ev so it cannot change anything under running handler feet. The hrtimer is simply restarted (thanks to Don Zickus who has pointed this out) if it is queued because we cannot rely it will fire&adopt to the new sampling period before a new nmi event triggers (when the treshold is decreased). [akpm@linux-foundation.org: the UP version of __smp_call_function_single ended up in the wrong place] Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: Don Zickus <dzickus@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Fabio Estevam <festevam@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24watchdog: update watchdog attributes atomicallyMichal Hocko
proc_dowatchdog doesn't synchronize multiple callers which might lead to confusion when two parallel callers might confuse watchdog_enable_all_cpus resp watchdog_disable_all_cpus (eg watchdog gets enabled even if watchdog_thresh was set to 0 already). This patch adds a local mutex which synchronizes callers to the sysctl handler. Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Don Zickus <dzickus@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24Merge branch 'bcache' (bcache fixes from Kent Overstreet)Linus Torvalds
Merge bcache fixes from Kent Overstreet: "There's fixes for _three_ different data corruption bugs, all of which were found by users hitting them in the wild. The first one isn't bcache specific - in 3.11 bcache was switched to the bio_copy_data in fs/bio.c, and that's when the bug in that code was discovered, but it's also used by raid1 and pktcdvd. (That was my code too, so the bug's doubly embarassing given that it was or should've been just a cut and paste from bcache code. Dunno what happened there). Most of these (all the non data corruption bugs, actually) were ready before the merge window and have been sitting in Jens' tree, but I don't know what's been up with him lately..." * emailed patches from Kent Overstreet <kmo@daterainc.com>: bcache: Fix flushes in writeback mode bcache: Fix for handling overlapping extents when reading in a btree node bcache: Fix a shrinker deadlock bcache: Fix a dumb CPU spinning bug in writeback bcache: Fix a flush/fua performance bug bcache: Fix a writeback performance regression bcache: Correct printf()-style format length modifier bcache: Fix for when no journal entries are found bcache: Strip endline when writing the label through sysfs bcache: Fix a dumb journal discard bug block: Fix bio_copy_data()
2013-09-24bcache: Fix flushes in writeback modeKent Overstreet
In writeback mode, when we get a cache flush we need to make sure we issue a flush to the backing device. The code for sending down an extra flush was wrong - by cloning the bio we were probably getting flags that didn't make sense for a bare flush, and also the old code was firing for FUA bios, for which we don't need to send a flush to the backing device. This was causing data corruption somehow - the mechanism was never determined, but this patch fixes it for the users that were seeing it. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24bcache: Fix for handling overlapping extents when reading in a btree nodeKent Overstreet
btree_sort_fixup() was overly clever, because it was trying to avoid pulling a key off the btree iterator in more than one place. This led to a really obscure bug where we'd break early from the loop in btree_sort_fixup() if the current key overlapped with keys in more than one older set, and the next key it overlapped with was zero size. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24bcache: Fix a shrinker deadlockKent Overstreet
GFP_NOIO means we could be getting called recursively - mca_alloc() -> mca_data_alloc() - definitely can't use mutex_lock(bucket_lock) then. Whoops. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24bcache: Fix a dumb CPU spinning bug in writebackKent Overstreet
schedule_timeout() != schedule_timeout_uninterruptible() Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24bcache: Fix a flush/fua performance bugKent Overstreet
bch_journal_meta() was missing the flush to make the journal write actually go down (instead of waiting up to journal_delay_ms)... Whoops Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24bcache: Fix a writeback performance regressionKent Overstreet
Background writeback works by scanning the btree for dirty data and adding those keys into a fixed size buffer, then for each dirty key in the keybuf writing it to the backing device. When read_dirty() finishes and it's time to scan for more dirty data, we need to wait for the outstanding writeback IO to finish - they still take up slots in the keybuf (so that foreground writes can check for them to avoid races) - without that wait, we'll continually rescan when we'll be able to add at most a key or two to the keybuf, and that takes locks that starves foreground IO. Doh. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24bcache: Correct printf()-style format length modifierGeert Uytterhoeven
Fix drivers/md/bcache/btree.c: In function ‘bch_btree_node_read’: drivers/md/bcache/btree.c:259: warning: format ‘%lu’ expects type ‘long unsigned int’, but argument 3 has type ‘size_t’ Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Kent Overstreet <kmo@daterainc.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24bcache: Fix for when no journal entries are foundKent Overstreet
The journal replay code didn't handle this case, causing it to go into an infinite loop... Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24bcache: Strip endline when writing the label through sysfsGabriel de Perthuis
sysfs attributes with unusual characters have crappy failure modes in Squeeze (udev 164); later versions of udev are unaffected. This should make these characters more unusual. Signed-off-by: Gabriel de Perthuis <g2p.code@gmail.com> Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24bcache: Fix a dumb journal discard bugKent Overstreet
That switch statement was obviously wrong, leading to some sort of weird spinning on rare occasion with discards enabled... Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: linux-stable <stable@vger.kernel.org> # >= v3.10 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24block: Fix bio_copy_data()Kent Overstreet
The memcpy() in bio_copy_data() was using the wrong offset vars, leading to data corruption in weird unusual setups. Signed-off-by: Kent Overstreet <kmo@daterainc.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: linux-stable <stable@vger.kernel.org> # >= v3.9 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-24xen/balloon: don't alloc page while non-preemptibleDavid Vrabel
get_balloon_scratch_page() disables preemption so we cannot call alloc_page() in between get/put_balloon_scratch_page(). Shuffle bits around in decrease_reservation() to avoid this. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2013-09-24xen: Do not enable spinlocks before jump_label_init() has executedKonrad Rzeszutek Wilk
xen_init_spinlocks() currently calls static_key_slow_inc() before jump_label_init() is invoked. When CONFIG_JUMP_LABEL is set (which usually is the case) the effect of this static_key_slow_inc() is deferred until after jump_label_init(). This is different from when CONFIG_JUMP_LABEL is not set, in which case the key is set immediately. Thus, depending on the value of config option, we may observe different behavior. In addition, when we come to __jump_label_transform() from jump_label_init(), the key (paravirt_ticketlocks_enabled) is already enabled. On processors where ideal_nop is not the same as default_nop this will cause a BUG() since it is expected that before a key is enabled the latter is replaced by the former during initialization. To address this problem we need to move static_key_slow_inc(&paravirt_ticketlocks_enabled) so that it is called after jump_label_init(). We also need to make sure that this is done before other cpus start to boot. early_initcall appears to be a good place to do so. (Note that we cannot move whole xen_init_spinlocks() there since pv_lock_ops need to be set before alternative_instructions() runs.) Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> [v2: Added extra comments in the code] Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org>