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  1. 10 Feb, 2017 3 commits
  3. 09 Feb, 2017 1 commit
  5. 03 Feb, 2017 1 commit
  7. 01 Feb, 2017 2 commits
  9. 28 Jan, 2017 1 commit
  11. 24 Jan, 2017 1 commit
  13. 21 Jan, 2017 1 commit
    • Eric Farman's avatar
      scsi: virtio_scsi: Reject commands when virtqueue is broken · 773c7220
      Eric Farman authored 
      In the case of a graceful set of detaches, where the virtio-scsi-ccw
disk is removed from the guest prior to the controller, the guest
behaves quite normally.  Specifically, the detach gets us into
sd_sync_cache to issue a Synchronize Cache(10) command, which
immediately fails (and is retried a couple of times) because the device
has been removed.  Later, the removal of the controller sees two CRWs
presented, but there's no further indication of the removal from the
guest viewpoint.

 [   17.217458] sd 0:0:0:0: [sda] Synchronizing SCSI cache
 [   17.219257] sd 0:0:0:0: [sda] Synchronize Cache(10) failed: Result: hostbyte=DID_BAD_TARGET driverbyte=DRIVER_OK
 [   21.449400] crw_info : CRW reports slct=0, oflw=0, chn=1, rsc=3, anc=0, erc=4, rsid=2
 [   21.449406] crw_info : CRW reports slct=0, oflw=0, chn=0, rsc=3, anc=0, erc=4, rsid=0

However, on s390, the SCSI disks can be removed "by surprise" when an
entire controller (host) is removed and all associated disks are removed
via the loop in scsi_forget_host.  The same call to sd_sync_cache is
made, but because the controller has already been removed, the
Synchronize Cache(10) command is neither issued (and then failed) nor
rejected.

That the I/O isn't returned means the guest cannot have other devices
added nor removed, and other tasks (such as shutdown or reboot) issued
by the guest will not complete either.  The virtio ring has already been
marked as broken (via virtio_break_device in virtio_ccw_remove), but we
still attempt to queue the command only to have it remain there.  The
calling sequence provides a bit of distinction for us:

  virtscsi_queuecommand()
   -> virtscsi_kick_cmd()
    -> virtscsi_add_cmd()
     -> virtqueue_add_sgs()
      -> virtqueue_add()
         if success
           return 0
         elseif vq->broken or vring_mapping_error()
           return -EIO
         else
           return -ENOSPC

A return of ENOSPC is generally a temporary condition, so returning
"host busy" from virtscsi_queuecommand makes sense here, to have it
redriven in a moment or two.  But the EIO return code is more of a
permanent error and so it would be wise to return the I/O itself and
allow the calling thread to finish gracefully.  The result is these four
kernel messages in the guest (the fourth one does not occur prior to
this patch):

 [   22.921562] crw_info : CRW reports slct=0, oflw=0, chn=1, rsc=3, anc=0, erc=4, rsid=2
 [   22.921580] crw_info : CRW reports slct=0, oflw=0, chn=0, rsc=3, anc=0, erc=4, rsid=0
 [   22.921978] sd 0:0:0:0: [sda] Synchronizing SCSI cache
 [   22.921993] sd 0:0:0:0: [sda] Synchronize Cache(10) failed: Result: hostbyte=DID_BAD_TARGET driverbyte=DRIVER_OK

I opted to fill in the same response data that is returned from the more
graceful device detach, where the disk device is removed prior to the
controller device.
Signed-off-by: default avatarEric Farman <farman@linux.vnet.ibm.com>
Reviewed-by: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      773c7220
  15. 17 Jan, 2017 7 commits
  17. 16 Jan, 2017 1 commit
  19. 13 Jan, 2017 1 commit
  21. 12 Jan, 2017 3 commits
  23. 10 Jan, 2017 2 commits
    • Dave Jones's avatar
      scsi: qla2xxx: Fix apparent cut-n-paste error. · c3c42394
      Dave Jones authored 
      Commit 093df737 ("scsi: qla2xxx: Fix Target mode handling with
Multiqueue changes.") introduces two bodies of code that look similar
but with s/req/rsp/ in the second instance.  But in one case, it looks
like this conversion was missed.
Signed-off-by: default avatarDave Jones <davej@codemonkey.org.uk>
Reviewed-by: default avatarLaurence Oberman <loberman@redhat.com>
Acked-by: default avatarQuinn Tran <Quinn.Tran@cavium.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      c3c42394
    • Milan P. Gandhi's avatar
      scsi: qla2xxx: Get mutex lock before checking optrom_state · c7702b8c
      Milan P. Gandhi authored 
      There is a race condition with qla2xxx optrom functions where one thread
might modify optrom buffer, optrom_state while other thread is still
reading from it.

In couple of crashes, it was found that we had successfully passed the
following 'if' check where we confirm optrom_state to be
QLA_SREADING. But by the time we acquired mutex lock to proceed with
memory_read_from_buffer function, some other thread/process had already
modified that option rom buffer and optrom_state from QLA_SREADING to
QLA_SWAITING. Then we got ha->optrom_buffer 0x0 and crashed the system:

        if (ha->optrom_state != QLA_SREADING)
                return 0;

        mutex_lock(&ha->optrom_mutex);
        rval = memory_read_from_buffer(buf, count, &off, ha->optrom_buffer,
            ha->optrom_region_size);
        mutex_unlock(&ha->optrom_mutex);

With current optrom function we get following crash due to a race
condition:

[ 1479.466679] BUG: unable to handle kernel NULL pointer dereference at           (null)
[ 1479.466707] IP: [<ffffffff81326756>] memcpy+0x6/0x110
[...]
[ 1479.473673] Call Trace:
[ 1479.474296]  [<ffffffff81225cbc>] ? memory_read_from_buffer+0x3c/0x60
[ 1479.474941]  [<ffffffffa01574dc>] qla2x00_sysfs_read_optrom+0x9c/0xc0 [qla2xxx]
[ 1479.475571]  [<ffffffff8127e76b>] read+0xdb/0x1f0
[ 1479.476206]  [<ffffffff811fdf9e>] vfs_read+0x9e/0x170
[ 1479.476839]  [<ffffffff811feb6f>] SyS_read+0x7f/0xe0
[ 1479.477466]  [<ffffffff816964c9>] system_call_fastpath+0x16/0x1b

Below patch modifies qla2x00_sysfs_read_optrom,
qla2x00_sysfs_write_optrom functions to get the mutex_lock before
checking ha->optrom_state to avoid similar crashes.

The patch was applied and tested and same crashes were no longer
observed again.
Tested-by: default avatarMilan P. Gandhi <mgandhi@redhat.com>
Signed-off-by: default avatarMilan P. Gandhi <mgandhi@redhat.com>
Reviewed-by: default avatarLaurence Oberman <loberman@redhat.com>
Acked-by: default avatarHimanshu Madhani <himanshu.madhani@cavium.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
      c7702b8c
  25. 09 Jan, 2017 1 commit
  27. 06 Jan, 2017 3 commits
  29. 27 Dec, 2016 1 commit
  31. 26 Dec, 2016 2 commits
    • Linus Torvalds's avatar
      Linux 4.10-rc1 · 7ce7d89f
      Linus Torvalds authored
      7ce7d89f
    • Larry Finger's avatar
      powerpc: Fix build warning on 32-bit PPC · 8ae679c4
      Larry Finger authored 
      I am getting the following warning when I build kernel 4.9-git on my
PowerBook G4 with a 32-bit PPC processor:

    AS      arch/powerpc/kernel/misc_32.o
  arch/powerpc/kernel/misc_32.S:299:7: warning: "CONFIG_FSL_BOOKE" is not defined [-Wundef]

This problem is evident after commit 989cea5c ("kbuild: prevent
lib-ksyms.o rebuilds"); however, this change in kbuild only exposes an
error that has been in the code since 2005 when this source file was
created.  That was with commit 9994a338 ("powerpc: Introduce
entry_{32,64}.S, misc_{32,64}.S, systbl.S").

The offending line does not make a lot of sense.  This error does not
seem to cause any errors in the executable, thus I am not recommending
that it be applied to any stable versions.

Thanks to Nicholas Piggin for suggesting this solution.

Fixes: 9994a338 ("powerpc: Introduce entry_{32,64}.S, misc_{32,64}.S, systbl.S")
Signed-off-by: default avatarLarry Finger <Larry.Finger@lwfinger.net>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8ae679c4
  33. 25 Dec, 2016 9 commits
    • Linus Torvalds's avatar
      avoid spurious "may be used uninitialized" warning · d33d5a6c
      Linus Torvalds authored 
      The timer type simplifications caused a new gcc warning:

  drivers/base/power/domain.c: In function ‘genpd_runtime_suspend’:
  drivers/base/power/domain.c:562:14: warning: ‘time_start’ may be used uninitialized in this function [-Wmaybe-uninitialized]
     elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));

despite the actual use of "time_start" not having changed in any way.
It appears that simply changing the type of ktime_t from a union to a
plain scalar type made gcc check the use.

The variable wasn't actually used uninitialized, but gcc apparently
failed to notice that the conditional around the use was exactly the
same as the conditional around the initialization of that variable.

Add an unnecessary initialization just to shut up the compiler.
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      d33d5a6c
    • Linus Torvalds's avatar
      Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · 3ddc76df
      Linus Torvalds authored 
      Pull timer type cleanups from Thomas Gleixner:
 "This series does a tree wide cleanup of types related to
  timers/timekeeping.

   - Get rid of cycles_t and use a plain u64. The type is not really
     helpful and caused more confusion than clarity

   - Get rid of the ktime union. The union has become useless as we use
     the scalar nanoseconds storage unconditionally now. The 32bit
     timespec alike storage got removed due to the Y2038 limitations
     some time ago.

     That leaves the odd union access around for no reason. Clean it up.

  Both changes have been done with coccinelle and a small amount of
  manual mopping up"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ktime: Get rid of ktime_equal()
  ktime: Cleanup ktime_set() usage
  ktime: Get rid of the union
  clocksource: Use a plain u64 instead of cycle_t
      3ddc76df
    • Linus Torvalds's avatar
      Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · b272f732
      Linus Torvalds authored 
      Pull SMP hotplug notifier removal from Thomas Gleixner:
 "This is the final cleanup of the hotplug notifier infrastructure. The
  series has been reintgrated in the last two days because there came a
  new driver using the old infrastructure via the SCSI tree.

  Summary:

   - convert the last leftover drivers utilizing notifiers

   - fixup for a completely broken hotplug user

   - prevent setup of already used states

   - removal of the notifiers

   - treewide cleanup of hotplug state names

   - consolidation of state space

  There is a sphinx based documentation pending, but that needs review
  from the documentation folks"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/armada-xp: Consolidate hotplug state space
  irqchip/gic: Consolidate hotplug state space
  coresight/etm3/4x: Consolidate hotplug state space
  cpu/hotplug: Cleanup state names
  cpu/hotplug: Remove obsolete cpu hotplug register/unregister functions
  staging/lustre/libcfs: Convert to hotplug state machine
  scsi/bnx2i: Convert to hotplug state machine
  scsi/bnx2fc: Convert to hotplug state machine
  cpu/hotplug: Prevent overwriting of callbacks
  x86/msr: Remove bogus cleanup from the error path
  bus: arm-ccn: Prevent hotplug callback leak
  perf/x86/intel/cstate: Prevent hotplug callback leak
  ARM/imx/mmcd: Fix broken cpu hotplug handling
  scsi: qedi: Convert to hotplug state machine
      b272f732
    • Linus Torvalds's avatar
      Merge branch 'turbostat' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux · 10bbe759
      Linus Torvalds authored 
      Pull turbostat updates from Len Brown.

* 'turbostat' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
  tools/power turbostat: remove obsolete -M, -m, -C, -c options
  tools/power turbostat: Make extensible via the --add parameter
  tools/power turbostat: Denverton uses a 25 MHz crystal, not 19.2 MHz
  tools/power turbostat: line up headers when -M is used
  tools/power turbostat: fix SKX PKG_CSTATE_LIMIT decoding
  tools/power turbostat: Support Knights Mill (KNM)
  tools/power turbostat: Display HWP OOB status
  tools/power turbostat: fix Denverton BCLK
  tools/power turbostat: use intel-family.h model strings
  tools/power/turbostat: Add Denverton RAPL support
  tools/power/turbostat: Add Denverton support
  tools/power/turbostat: split core MSR support into status + limit
  tools/power turbostat: fix error case overflow read of slm_freq_table[]
  tools/power turbostat: Allocate correct amount of fd and irq entries
  tools/power turbostat: switch to tab delimited output
  tools/power turbostat: Gracefully handle ACPI S3
  tools/power turbostat: tidy up output on Joule counter overflow
      10bbe759
    • Nicholas Piggin's avatar
      mm: add PageWaiters indicating tasks are waiting for a page bit · 62906027
      Nicholas Piggin authored 
      Add a new page flag, PageWaiters, to indicate the page waitqueue has
tasks waiting. This can be tested rather than testing waitqueue_active
which requires another cacheline load.

This bit is always set when the page has tasks on page_waitqueue(page),
and is set and cleared under the waitqueue lock. It may be set when
there are no tasks on the waitqueue, which will cause a harmless extra
wakeup check that will clears the bit.

The generic bit-waitqueue infrastructure is no longer used for pages.
Instead, waitqueues are used directly with a custom key type. The
generic code was not flexible enough to have PageWaiters manipulation
under the waitqueue lock (which simplifies concurrency).

This improves the performance of page lock intensive microbenchmarks by
2-3%.

Putting two bits in the same word opens the opportunity to remove the
memory barrier between clearing the lock bit and testing the waiters
bit, after some work on the arch primitives (e.g., ensuring memory
operand widths match and cover both bits).
Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      62906027
    • Nicholas Piggin's avatar
      mm: Use owner_priv bit for PageSwapCache, valid when PageSwapBacked · 6326fec1
      Nicholas Piggin authored 
      A page is not added to the swap cache without being swap backed,
so PageSwapBacked mappings can use PG_owner_priv_1 for PageSwapCache.
Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Acked-by: default avatarHugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Lutomirski <luto@kernel.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      6326fec1
    • Thomas Gleixner's avatar
      ktime: Get rid of ktime_equal() · 1f3a8e49
      Thomas Gleixner authored 
      No point in going through loops and hoops instead of just comparing the
values.
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
      1f3a8e49
    • Thomas Gleixner's avatar
      ktime: Cleanup ktime_set() usage · 8b0e1953
      Thomas Gleixner authored 
      ktime_set(S,N) was required for the timespec storage type and is still
useful for situations where a Seconds and Nanoseconds part of a time value
needs to be converted. For anything where the Seconds argument is 0, this
is pointless and can be replaced with a simple assignment.
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
      8b0e1953
    • Thomas Gleixner's avatar
      ktime: Get rid of the union · 2456e855
      Thomas Gleixner authored 
      ktime is a union because the initial implementation stored the time in
scalar nanoseconds on 64 bit machine and in a endianess optimized timespec
variant for 32bit machines. The Y2038 cleanup removed the timespec variant
and switched everything to scalar nanoseconds. The union remained, but
become completely pointless.

Get rid of the union and just keep ktime_t as simple typedef of type s64.

The conversion was done with coccinelle and some manual mopping up.
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
      2456e855
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