- 13 Aug, 2012 3 commits
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Mike Galbraith authored
With multiple instances of task_groups, for_each_rt_rq() is a noop, no task groups having been added to the rt.c list instance. This renders __enable/disable_runtime() and print_rt_stats() noop, the user (non) visible effect being that rt task groups are missing in /proc/sched_debug. Signed-off-by:
Mike Galbraith <efault@gmx.de> Cc: stable@kernel.org # v3.3+ Signed-off-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1344308413.6846.7.camel@marge.simpson.netSigned-off-by:
Thomas Gleixner <tglx@linutronix.de>
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Stanislaw Gruszka authored
On architectures where cputime_t is 64 bit type, is possible to trigger divide by zero on do_div(temp, (__force u32) total) line, if total is a non zero number but has lower 32 bit's zeroed. Removing casting is not a good solution since some do_div() implementations do cast to u32 internally. This problem can be triggered in practice on very long lived processes: PID: 2331 TASK: ffff880472814b00 CPU: 2 COMMAND: "oraagent.bin" #0 [ffff880472a51b70] machine_kexec at ffffffff8103214b #1 [ffff880472a51bd0] crash_kexec at ffffffff810b91c2 #2 [ffff880472a51ca0] oops_end at ffffffff814f0b00 #3 [ffff880472a51cd0] die at ffffffff8100f26b #4 [ffff880472a51d00] do_trap at ffffffff814f03f4 #5 [ffff880472a51d60] do_divide_error at ffffffff8100cfff #6 [ffff880472a51e00] divide_error at ffffffff8100be7b [exception RIP: thread_group_times+0x56] RIP: ffffffff81056a16 RSP: ffff880472a51eb8 RFLAGS: 00010046 RAX: bc3572c9fe12d194 RBX: ffff880874150800 RCX: 0000000110266fad RDX: 0000000000000000 RSI: ffff880472a51eb8 RDI: 001038ae7d9633dc RBP: ffff880472a51ef8 R8: 00000000b10a3a64 R9: ffff880874150800 R10: 00007fcba27ab680 R11: 0000000000000202 R12: ffff880472a51f08 R13: ffff880472a51f10 R14: 0000000000000000 R15: 0000000000000007 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffff880472a51f00] do_sys_times at ffffffff8108845d #8 [ffff880472a51f40] sys_times at ffffffff81088524 #9 [ffff880472a51f80] system_call_fastpath at ffffffff8100b0f2 RIP: 0000003808caac3a RSP: 00007fcba27ab6d8 RFLAGS: 00000202 RAX: 0000000000000064 RBX: ffffffff8100b0f2 RCX: 0000000000000000 RDX: 00007fcba27ab6e0 RSI: 000000000076d58e RDI: 00007fcba27ab6e0 RBP: 00007fcba27ab700 R8: 0000000000000020 R9: 000000000000091b R10: 00007fcba27ab680 R11: 0000000000000202 R12: 00007fff9ca41940 R13: 0000000000000000 R14: 00007fcba27ac9c0 R15: 00007fff9ca41940 ORIG_RAX: 0000000000000064 CS: 0033 SS: 002b Cc: stable@vger.kernel.org Signed-off-by:Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by:
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Peter Zijlstra authored
Peter Portante reported that for large cgroup hierarchies (and or on large CPU counts) we get immense lock contention on rq->lock and stuff stops working properly. His workload was a ton of processes, each in their own cgroup, everybody idling except for a sporadic wakeup once every so often. It was found that: schedule() idle_balance() load_balance() local_irq_save() double_rq_lock() update_h_load() walk_tg_tree(tg_load_down) tg_load_down() Results in an entire cgroup hierarchy walk under rq->lock for every new-idle balance and since new-idle balance isn't throttled this results in a lot of work while holding the rq->lock. This patch does two things, it removes the work from under rq->lock based on the good principle of race and pray which is widely employed in the load-balancer as a whole. And secondly it throttles the update_h_load() calculation to max once per jiffy. I considered excluding update_h_load() for new-idle balance all-together, but purely relying on regular balance passes to update this data might not work out under some rare circumstances where the new-idle busiest isn't the regular busiest for a while (unlikely, but a nightmare to debug if someone hits it and suffers). Cc: pjt@google.com Cc: Larry Woodman <lwoodman@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Reported-by:Peter Portante <pportant@redhat.com> Signed-off-by:
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- 31 Jul, 2012 1 commit
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Michael Wang authored
With this patch struct ld_env will have a pointer of the load balancing cpumask and we don't need to pass a cpumask around anymore. Signed-off-by:
Michael Wang <wangyun@linux.vnet.ibm.com> Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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- 26 Jul, 2012 4 commits
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Srivatsa S. Bhat authored
PREEMPT_ACTIVE flag is bit 27, not 28. Fix the comment. Signed-off-by:
Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: paulmck@linux.vnet.ibm.com Cc: josh@joshtriplett.org Cc: rostedt@goodmis.org Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20120720192459.6149.14821.stgit@srivatsabhat.in.ibm.comSigned-off-by:
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Ying Xue authored
Delete redudant spaces between type name and data name or operators. Signed-off-by:
Ying Xue <ying.xue0@gmail.com> Signed-off-by:
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Namhyung Kim authored
It seems there's no specific reason to open-code it. I guess commit 0122ec5b ("sched: Add p->pi_lock to task_rq_lock()") simply missed it. Let's be consistent with others. Signed-off-by:
Namhyung Kim <namhyung@kernel.org> Signed-off-by:
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Alex Shi authored
Commit 8e7fbcbc ("sched: Remove stale power aware scheduling remnants and dysfunctional knobs") removed SD_PERFER_SIBLING from the CPU domain. On NUMA machines this causes that load_balance() doesn't perfer LCPU in same physical CPU package. It causes some actual performance regressions on our NUMA machines from Core2 to NHM and SNB. Adding this domain flag again recovers the performance drop. This change doesn't have any bad impact on any of my benchmarks: specjbb, kbuild, fio, hackbench .. etc, on all my machines. Signed-off-by:
Alex Shi <alex.shi@intel.com> Signed-off-by:
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- 24 Jul, 2012 10 commits
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Peter Zijlstra authored
Stefan reported a crash on a kernel before a3e5d109 ("sched: Don't call task_group() too many times in set_task_rq()"), he found the reason to be that the multiple task_group() invocations in set_task_rq() returned different values. Looking at all that I found a lack of serialization and plain wrong comments. The below tries to fix it using an extra pointer which is updated under the appropriate scheduler locks. Its not pretty, but I can't really see another way given how all the cgroup stuff works. Reported-and-tested-by:
Stefan Bader <stefan.bader@canonical.com> Signed-off-by:
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Srivatsa Vaddagiri authored
Current load balance scheme requires only one cpu in a sched_group (balance_cpu) to look at other peer sched_groups for imbalance and pull tasks towards itself from a busy cpu. Tasks thus pulled by balance_cpu could later get picked up by cpus that are in the same sched_group as that of balance_cpu. This scheme however fails to pull tasks that are not allowed to run on balance_cpu (but are allowed to run on other cpus in its sched_group). That can affect fairness and in some worst case scenarios cause starvation. Consider a two core (2 threads/core) system running tasks as below: Core0 Core1 / \ / \ C0 C1 C2 C3 | | | | v v v v F0 T1 F1 [idle] T2 F0 = SCHED_FIFO task (pinned to C0) F1 = SCHED_FIFO task (pinned to C2) T1 = SCHED_OTHER task (pinned to C1) T2 = SCHED_OTHER task (pinned to C1 and C2) F1 could become a cpu hog, which will starve T2 unless C1 pulls it. Between C0 and C1 however, C0 is required to look for imbalance between cores, which will fail to pull T2 towards Core0. T2 will starve eternally in this case. The same scenario can arise in presence of non-rt tasks as well (say we replace F1 with high irq load). We tackle this problem by having balance_cpu move pinned tasks to one of its sibling cpus (where they can run). We first check if load balance goal can be met by ignoring pinned tasks, failing which we retry move_tasks() with a new env->dst_cpu. This patch modifies load balance semantics on who can move load towards a given cpu in a given sched_domain. Before this patch, a given_cpu or a ilb_cpu acting on behalf of an idle given_cpu is responsible for moving load to given_cpu. With this patch applied, balance_cpu can in addition decide on moving some load to a given_cpu. There is a remote possibility that excess load could get moved as a result of this (balance_cpu and given_cpu/ilb_cpu deciding *independently* and at *same* time to move some load to a given_cpu). However we should see less of such conflicting decisions in practice and moreover subsequent load balance cycles should correct the excess load moved to given_cpu. Signed-off-by:Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com> Signed-off-by:
Prashanth Nageshappa <prashanth@linux.vnet.ibm.com> Signed-off-by:
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Prashanth Nageshappa authored
While load balancing, if all tasks on the source runqueue are pinned, we retry after excluding the corresponding source cpu. However, loop counters env.loop and env.loop_break are not reset before retrying, which can lead to failure in moving the tasks. In this patch we reset env.loop and env.loop_break to their inital values before we retry. Signed-off-by:
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Prashanth Nageshappa authored
Members of 'struct lb_env' are not in appropriate order to reuse compiler added padding on 64bit architectures. In this patch we reorder those struct members and help reduce the size of the structure from 96 bytes to 80 bytes on 64 bit architectures. Suggested-by:
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Mike Galbraith authored
Traversing an entire package is not only expensive, it also leads to tasks bouncing all over a partially idle and possible quite large package. Fix that up by assigning a 'buddy' CPU to try to motivate. Each buddy may try to motivate that one other CPU, if it's busy, tough, it may then try its SMT sibling, but that's all this optimization is allowed to cost. Sibling cache buddies are cross-wired to prevent bouncing. 4 socket 40 core + SMT Westmere box, single 30 sec tbench runs, higher is better: clients 1 2 4 8 16 32 64 128 .......................................................................... pre 30 41 118 645 3769 6214 12233 14312 post 299 603 1211 2418 4697 6847 11606 14557 A nice increase in performance. Signed-off-by:
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Srivatsa S. Bhat authored
cpuset_track_online_cpus() is no longer present. So remove the outdated comment and replace it with reference to cpuset_update_active_cpus() which is its equivalent. Also, we don't lack memory hot-unplug anymore. And David Rientjes pointed out how it is dealt with. So update that comment as well. Signed-off-by:
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Srivatsa S. Bhat authored
Separate out the cpuset related handling for CPU/Memory online/offline. This also helps us exploit the most obvious and basic level of optimization that any notification mechanism (CPU/Mem online/offline) has to offer us: "We *know* why we have been invoked. So stop pretending that we are lost, and do only the necessary amount of processing!". And while at it, rename scan_for_empty_cpusets() to scan_cpusets_upon_hotplug(), which is more appropriate considering how it is restructured. Signed-off-by:
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Srivatsa S. Bhat authored
At present, the functions that deal with cpusets during CPU/Mem hotplug are quite messy, since a lot of the functionality is mixed up without clear separation. And this takes a toll on optimization as well. For example, the function cpuset_update_active_cpus() is called on both CPU offline and CPU online events; and it invokes scan_for_empty_cpusets(), which makes sense only for CPU offline events. And hence, the current code ends up unnecessarily traversing the cpuset tree during CPU online also. As a first step towards cleaning up those functions, encapsulate the cpuset tree traversal in a helper function, so as to facilitate upcoming changes. Signed-off-by:
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Srivatsa S. Bhat authored
In the event of CPU hotplug, the kernel modifies the cpusets' cpus_allowed masks as and when necessary to ensure that the tasks belonging to the cpusets have some place (online CPUs) to run on. And regular CPU hotplug is destructive in the sense that the kernel doesn't remember the original cpuset configurations set by the user, across hotplug operations. However, suspend/resume (which uses CPU hotplug) is a special case in which the kernel has the responsibility to restore the system (during resume), to exactly the same state it was in before suspend. In order to achieve that, do the following: 1. Don't modify cpusets during suspend/resume. At all. In particular, don't move the tasks from one cpuset to another, and don't modify any cpuset's cpus_allowed mask. So, simply ignore cpusets during the CPU hotplug operations that are carried out in the suspend/resume path. 2. However, cpusets and sched domains are related. We just want to avoid altering cpusets alone. So, to keep the sched domains updated, build a single sched domain (containing all active cpus) during each of the CPU hotplug operations carried out in s/r path, effectively ignoring the cpusets' cpus_allowed masks. (Since userspace is frozen while doing all this, it will go unnoticed.) 3. During the last CPU online operation during resume, build the sched domains by looking up the (unaltered) cpusets' cpus_allowed masks. That will bring back the system to the same original state as it was in before suspend. Ultimately, this will not only solve the cpuset problem related to suspend resume (ie., restores the cpusets to exactly what it was before suspend, by not touching it at all) but also speeds up suspend/resume because we avoid running cpuset update code for every CPU being offlined/onlined. Signed-off-by:
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Peter Zijlstra authored
The x86 sched power implementation has been broken forever and gets in the way of other stuff, remove it. [ For archaeological interest, fixing this code would require dealing with the cross-cpu calling of these functions and more importantly, we need to filter idle time out of the a/m-perf stuff because the ratio will go down to 0 when idle, giving a 0 capacity which is not what we'd want. ] Signed-off-by:
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- 21 Jul, 2012 7 commits
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Linus Torvalds authored
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Rafael J. Wysocki authored
The SYSTEM_SUSPEND_DISK system state is never used, so drop it. Signed-off-by:
Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Linus Torvalds authored
Merge emailed kgdb dmesg fixups patches from Anton Vorontsov: "The dmesg command appears to be broken after the printk rework. The old logic in the kdb code makes no sense in terms of current printk/logging storage format, and KDB simply hangs forever upon entering 'dmesg' command. The first patch revives the command by switching to kmsg_dumper iterator. As a side-effect, the code is now much more simpler. A few changes were needed in the printk.c: we needed unlocked variant of the kmsg_dumper iterator, but these can surely wait for 3.6. It's probably too late even for the first patch to go to 3.5, but I'll try to convince otherwise. :-) Here we go: - The current code is broken for sure, and has no hope to work at all. It is a regression - The new code works for me, and probably works for everyone else; - If it compiles (and I urge everyone to compile-test it on your setup), it hardly can make things worse." * Merge emailed patches from Anton Vorontsov: (4 commits) kdb: Switch to nolock variants of kmsg_dump functions printk: Implement some unlocked kmsg_dump functions printk: Remove kdb_syslog_data kdb: Revive dmesg command -
Anton Vorontsov authored
The locked variants are prone to deadlocks (suppose we got to the debugger w/ the logbuf lock held), so let's switch to nolock variants. Signed-off-by:
Anton Vorontsov <anton.vorontsov@linaro.org> Signed-off-by:
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Anton Vorontsov authored
If used from KDB, the locked variants are prone to deadlocks (suppose we got to the debugger w/ the logbuf lock held). So, we have to implement a few routines that grab no logbuf lock. Yet we don't need these functions in modules, so we don't export them. Signed-off-by:
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Anton Vorontsov authored
The function is no longer needed, so remove it. Signed-off-by:
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Anton Vorontsov authored
The kgdb dmesg command is broken after the printk rework. The old logic in kdb code makes no sense in terms of current printk/logging storage format, and KDB simply hangs forever. This patch revives the command by switching to kmsg_dumper iterator. The code is now much more simpler and shorter. Signed-off-by:
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- 20 Jul, 2012 13 commits
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git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds authored
Pull late MIPS fixes from Ralf Baechle: "This fixes a number of lose ends in the MIPS code and various bug fixes. Aside of dropping some patch that should not be in this pull request everything has sat in -next for quite a while and there are no known issues. The biggest patch in this patch set moves the allocation of an array that is aliased to a function (for runtime generated code) to assembler code. This avoids an issue with certain toolchains when building for microMIPS." * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (35 commits) MIPS: PCI: Move fixups from __init to __devinit. MIPS: Fix bug.h MIPS build regression MIPS: sync-r4k: remove redundant irq operation MIPS: smp: Warn on too early irq enable MIPS: call set_cpu_online() on cpu being brought up with irq disabled MIPS: call ->smp_finish() a little late MIPS: Yosemite: delay irq enable to ->smp_finish() MIPS: SMTC: delay irq enable to ->smp_finish() MIPS: BMIPS: delay irq enable to ->smp_finish() MIPS: Octeon: delay enable irq to ->smp_finish() MIPS: Oprofile: Fix build as a module. MIPS: BCM63XX: Fix BCM6368 IPSec clock bit MIPS: perf: Fix build error caused by unused counters_per_cpu_to_total() MIPS: Fix Magic SysRq L kernel crash. MIPS: BMIPS: Fix duplicate header inclusion. mips: mark const init data with __initconst instead of __initdata MIPS: cmpxchg.h: Add missing include MIPS: Malta may also be equipped with MIPS64 R2 processors. MIPS: Fix typo multipy -> multiply MIPS: Cavium: Fix duplicate ARCH_SPARSEMEM_ENABLE in kconfig. ...
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git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dmLinus Torvalds authored
Pull device-mapper discard fixes from Alasdair G Kergon: - avoid a crash in dm-raid1 when discards coincide with mirror recovery; - avoid discarding shared data that's still needed in dm-thin; - don't guarantee that discarded blocks will be wiped in dm-raid1. * tag 'dm-3.5-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm: dm raid1: set discard_zeroes_data_unsupported dm thin: do not send discards to shared blocks dm raid1: fix crash with mirror recovery and discard -
git://git.open-osd.org/linux-open-osdLinus Torvalds authored
Pull pnfs/ore fixes from Boaz Harrosh: "These are catastrophic fixes to the pnfs objects-layout that were just discovered. They are also destined for @stable. I have found these and worked on them at around RC1 time but unfortunately went to the hospital for kidney stones and had a very slow recovery. I refrained from sending them as is, before proper testing, and surly I have found a bug just yesterday. So now they are all well tested, and have my sign-off. Other then fixing the problem at hand, and assuming there are no bugs at the new code, there is low risk to any surrounding code. And in anyway they affect only these paths that are now broken. That is RAID5 in pnfs objects-layout code. It does also affect exofs (which was not broken) but I have tested exofs and it is lower priority then objects-layout because no one is using exofs, but objects-layout has lots of users." * 'for-linus' of git://git.open-osd.org/linux-open-osd: pnfs-obj: Fix __r4w_get_page when offset is beyond i_size pnfs-obj: don't leak objio_state if ore_write/read fails ore: Unlock r4w pages in exact reverse order of locking ore: Remove support of partial IO request (NFS crash) ore: Fix NFS crash by supporting any unaligned RAID IO
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git://git.infradead.org/linux-ubifsLinus Torvalds authored
Pull UBIFS free space fix-up bugfix from Artem Bityutskiy: "It's been reported already twice recently: http://lists.infradead.org/pipermail/linux-mtd/2012-May/041408.html http://lists.infradead.org/pipermail/linux-mtd/2012-June/042422.html and we finally have the fix. I am quite confident the fix is correct because I could reproduce the problem with nandsim and verify the fix. It was also verified by Iwo (the reporter). I am also confident that this is OK to merge the fix so late because this patch affects only the fixup functionality, which is not used by most users." * tag 'upstream-3.5-rc8' of git://git.infradead.org/linux-ubifs: UBIFS: fix a bug in empty space fix-up -
Mikulas Patocka authored
We can't guarantee that REQ_DISCARD on dm-mirror zeroes the data even if the underlying disks support zero on discard. So this patch sets ti->discard_zeroes_data_unsupported. For example, if the mirror is in the process of resynchronizing, it may happen that kcopyd reads a piece of data, then discard is sent on the same area and then kcopyd writes the piece of data to another leg. Consequently, the data is not zeroed. The flag was made available by commit 983c7db3 (dm crypt: always disable discard_zeroes_data). Signed-off-by:
Mikulas Patocka <mpatocka@redhat.com> Cc: stable@kernel.org Signed-off-by:
Alasdair G Kergon <agk@redhat.com>
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Mikulas Patocka authored
When process_discard receives a partial discard that doesn't cover a full block, it sends this discard down to that block. Unfortunately, the block can be shared and the discard would corrupt the other snapshots sharing this block. This patch detects block sharing and ends the discard with success when sending it to the shared block. The above change means that if the device supports discard it can't be guaranteed that a discard request zeroes data. Therefore, we set ti->discard_zeroes_data_unsupported. Thin target discard support with this bug arrived in commit 104655fd (dm thin: support discards). Signed-off-by:
Mike Snitzer <snitzer@redhat.com> Signed-off-by:
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Mikulas Patocka authored
This patch fixes a crash when a discard request is sent during mirror recovery. Firstly, some background. Generally, the following sequence happens during mirror synchronization: - function do_recovery is called - do_recovery calls dm_rh_recovery_prepare - dm_rh_recovery_prepare uses a semaphore to limit the number simultaneously recovered regions (by default the semaphore value is 1, so only one region at a time is recovered) - dm_rh_recovery_prepare calls __rh_recovery_prepare, __rh_recovery_prepare asks the log driver for the next region to recover. Then, it sets the region state to DM_RH_RECOVERING. If there are no pending I/Os on this region, the region is added to quiesced_regions list. If there are pending I/Os, the region is not added to any list. It is added to the quiesced_regions list later (by dm_rh_dec function) when all I/Os finish. - when the region is on quiesced_regions list, there are no I/Os in flight on this region. The region is popped from the list in dm_rh_recovery_start function. Then, a kcopyd job is started in the recover function. - when the kcopyd job finishes, recovery_complete is called. It calls dm_rh_recovery_end. dm_rh_recovery_end adds the region to recovered_regions or failed_recovered_regions list (depending on whether the copy operation was successful or not). The above mechanism assumes that if the region is in DM_RH_RECOVERING state, no new I/Os are started on this region. When I/O is started, dm_rh_inc_pending is called, which increases reg->pending count. When I/O is finished, dm_rh_dec is called. It decreases reg->pending count. If the count is zero and the region was in DM_RH_RECOVERING state, dm_rh_dec adds it to the quiesced_regions list. Consequently, if we call dm_rh_inc_pending/dm_rh_dec while the region is in DM_RH_RECOVERING state, it could be added to quiesced_regions list multiple times or it could be added to this list when kcopyd is copying data (it is assumed that the region is not on any list while kcopyd does its jobs). This results in memory corruption and crash. There already exist bypasses for REQ_FLUSH requests: REQ_FLUSH requests do not belong to any region, so they are always added to the sync list in do_writes. dm_rh_inc_pending does not increase count for REQ_FLUSH requests. In mirror_end_io, dm_rh_dec is never called for REQ_FLUSH requests. These bypasses avoid the crash possibility described above. These bypasses were improperly implemented for REQ_DISCARD when the mirror target gained discard support in commit 5fc2ffea (dm raid1: support discard). In do_writes, REQ_DISCARD requests is always added to the sync queue and immediately dispatched (even if the region is in DM_RH_RECOVERING). However, dm_rh_inc and dm_rh_dec is called for REQ_DISCARD resusts. So it violates the rule that no I/Os are started on DM_RH_RECOVERING regions, and causes the list corruption described above. This patch changes it so that REQ_DISCARD requests follow the same path as REQ_FLUSH. This avoids the crash. Reference: https://bugzilla.redhat.com/837607Signed-off-by:
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Boaz Harrosh authored
It is very common for the end of the file to be unaligned on stripe size. But since we know it's beyond file's end then the XOR should be preformed with all zeros. Old code used to just read zeros out of the OSD devices, which is a great waist. But what scares me more about this situation is that, we now have pages attached to the file's mapping that are beyond i_size. I don't like the kind of bugs this calls for. Fix both birds, by returning a global zero_page, if offset is beyond i_size. TODO: Change the API to ->__r4w_get_page() so a NULL can be returned without being considered as error, since XOR API treats NULL entries as zero_pages. [Bug since 3.2. Should apply the same way to all Kernels since] CC: Stable Tree <stable@kernel.org> Signed-off-by:Boaz Harrosh <bharrosh@panasas.com>
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Boaz Harrosh authored
[Bug since 3.2 Kernel] CC: Stable Tree <stable@kernel.org> Signed-off-by: -
Boaz Harrosh authored
The read-4-write pages are locked in address ascending order. But where unlocked in a way easiest for coding. Fix that, locks should be released in opposite order of locking, .i.e descending address order. I have not hit this dead-lock. It was found by inspecting the dbug print-outs. I suspect there is an higher lock at caller that protects us, but fix it regardless. Signed-off-by: -
Boaz Harrosh authored
Do to OOM situations the ore might fail to allocate all resources needed for IO of the full request. If some progress was possible it would proceed with a partial/short request, for the sake of forward progress. Since this crashes NFS-core and exofs is just fine without it just remove this contraption, and fail. TODO: Support real forward progress with some reserved allocations of resources, such as mem pools and/or bio_sets [Bug since 3.2 Kernel] CC: Stable Tree <stable@kernel.org> CC: Benny Halevy <bhalevy@tonian.com> Signed-off-by: -
Boaz Harrosh authored
In RAID_5/6 We used to not permit an IO that it's end byte is not stripe_size aligned and spans more than one stripe. .i.e the caller must check if after submission the actual transferred bytes is shorter, and would need to resubmit a new IO with the remainder. Exofs supports this, and NFS was supposed to support this as well with it's short write mechanism. But late testing has exposed a CRASH when this is used with none-RPC layout-drivers. The change at NFS is deep and risky, in it's place the fix at ORE to lift the limitation is actually clean and simple. So here it is below. The principal here is that in the case of unaligned IO on both ends, beginning and end, we will send two read requests one like old code, before the calculation of the first stripe, and also a new site, before the calculation of the last stripe. If any "boundary" is aligned or the complete IO is within a single stripe. we do a single read like before. The code is clean and simple by splitting the old _read_4_write into 3 even parts: 1._read_4_write_first_stripe 2. _read_4_write_last_stripe 3. _read_4_write_execute And calling 1+3 at the same place as before. 2+3 before last stripe, and in the case of all in a single stripe then 1+2+3 is preformed additively. Why did I not think of it before. Well I had a strike of genius because I have stared at this code for 2 years, and did not find this simple solution, til today. Not that I did not try. This solution is much better for NFS than the previous supposedly solution because the short write was dealt with out-of-band after IO_done, which would cause for a seeky IO pattern where as in here we execute in order. At both solutions we do 2 separate reads, only here we do it within a single IO request. (And actually combine two writes into a single submission) NFS/exofs code need not change since the ORE API communicates the new shorter length on return, what will happen is that this case would not occur anymore. hurray!! [Stable this is an NFS bug since 3.2 Kernel should apply cleanly] CC: Stable Tree <stable@kernel.org> Signed-off-by: -
Artem Bityutskiy authored
UBIFS has a feature called "empty space fix-up" which is a quirk to work-around limitations of dumb flasher programs. Namely, of those flashers that are unable to skip NAND pages full of 0xFFs while flashing, resulting in empty space at the end of half-filled eraseblocks to be unusable for UBIFS. This feature is relatively new (introduced in v3.0). The fix-up routine (fixup_free_space()) is executed only once at the very first mount if the superblock has the 'space_fixup' flag set (can be done with -F option of mkfs.ubifs). It basically reads all the UBIFS data and metadata and writes it back to the same LEB. The routine assumes the image is pristine and does not have anything in the journal. There was a bug in 'fixup_free_space()' where it fixed up the log incorrectly. All but one LEB of the log of a pristine file-system are empty. And one contains just a commit start node. And 'fixup_free_space()' just unmapped this LEB, which resulted in wiping the commit start node. As a result, some users were unable to mount the file-system next time with the following symptom: UBIFS error (pid 1): replay_log_leb: first log node at LEB 3:0 is not CS node UBIFS error (pid 1): replay_log_leb: log error detected while replaying the log at LEB 3:0 The root-cause of this bug was that 'fixup_free_space()' wrongly assumed that the beginning of empty space in the log head (c->lhead_offs) was known on mount. However, it is not the case - it was always 0. UBIFS does not store in it the master node and finds out by scanning the log on every mount. The fix is simple - just pass commit start node size instead of 0 to 'fixup_leb()'. Signed-off-by:
Artem Bityutskiy <Artem.Bityutskiy@linux.intel.com> Cc: stable@vger.kernel.org [v3.0+] Reported-by:
Iwo Mergler <Iwo.Mergler@netcommwireless.com> Tested-by:
James Nute <newten82@gmail.com>
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- 19 Jul, 2012 2 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-clientLinus Torvalds authored
Pull last minute Ceph fixes from Sage Weil: "The important one fixes a bug in the socket failure handling behavior that was turned up in some recent failure injection testing. The other two are minor bug fixes." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: rbd: endian bug in rbd_req_cb() rbd: Fix ceph_snap_context size calculation libceph: fix messenger retry
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git://neil.brown.name/mdLinus Torvalds authored
Pull three md bugfixes from NeilBrown: "One of the bugs was introduced in 3.5-rc1. Others have been there for longer." * tag 'md-3.5-fixes' of git://neil.brown.name/md: md/raid1: close some possible races on write errors during resync md: avoid crash when stopping md array races with closing other open fds. md: fix bug in handling of new_data_offset
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