linux-toradex.git/include/linux, branch v2.6.29.3

mm: fix Committed_AS underflow on large NR_CPUS environment

2009-05-08T22:45:11+00:00

commit 00a62ce91e554198ef28234c91c36f850f5a3bc9 upstream

The Committed_AS field can underflow in certain situations:

>         # while true; do cat /proc/meminfo  | grep _AS; sleep 1; done | uniq -c
>               1 Committed_AS: 18446744073709323392 kB
>              11 Committed_AS: 18446744073709455488 kB
>               6 Committed_AS:    35136 kB
>               5 Committed_AS: 18446744073709454400 kB
>               7 Committed_AS:    35904 kB
>               3 Committed_AS: 18446744073709453248 kB
>               2 Committed_AS:    34752 kB
>               9 Committed_AS: 18446744073709453248 kB
>               8 Committed_AS:    34752 kB
>               3 Committed_AS: 18446744073709320960 kB
>               7 Committed_AS: 18446744073709454080 kB
>               3 Committed_AS: 18446744073709320960 kB
>               5 Committed_AS: 18446744073709454080 kB
>               6 Committed_AS: 18446744073709320960 kB

Because NR_CPUS can be greater than 1000 and meminfo_proc_show() does
not check for underflow.

But NR_CPUS proportional isn't good calculation.  In general,
possibility of lock contention is proportional to the number of online
cpus, not theorical maximum cpus (NR_CPUS).

The current kernel has generic percpu-counter stuff.  using it is right
way.  it makes code simplify and percpu_counter_read_positive() don't
make underflow issue.

Reported-by: Dave Hansen 
Signed-off-by: KOSAKI Motohiro 
Cc: Eric B Munson 
Cc: Mel Gorman 
Cc: Christoph Lameter 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

New locking/refcounting for fs_struct

2009-05-08T22:45:08+00:00

commit 498052bba55ecaff58db6a1436b0e25bfd75a7ff upstream.

* all changes of current->fs are done under task_lock and write_lock of
  old fs->lock
* refcount is not atomic anymore (same protection)
* its decrements are done when removing reference from current; at the
  same time we decide whether to free it.
* put_fs_struct() is gone
* new field - ->in_exec.  Set by check_unsafe_exec() if we are trying to do
  execve() and only subthreads share fs_struct.  Cleared when finishing exec
  (success and failure alike).  Makes CLONE_FS fail with -EAGAIN if set.
* check_unsafe_exec() may fail with -EAGAIN if another execve() from subthread
  is in progress.

Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

Take fs_struct handling to new file (fs/fs_struct.c)

2009-05-08T22:45:07+00:00

commit 3e93cd671813e204c258f1e6c797959920cf7772 upstream.

Pure code move; two new helper functions for nfsd and daemonize
(unshare_fs_struct() and daemonize_fs_struct() resp.; for now -
the same code as used to be in callers).  unshare_fs_struct()
exported (for nfsd, as copy_fs_struct()/exit_fs() used to be),
copy_fs_struct() and exit_fs() don't need exports anymore.

Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

Annotate struct fs_struct's usage count restriction

2009-05-08T22:45:06+00:00

commit 795e2fe0a3b69dbc040d7efcf517e0cbad6901d0 upstream.

Annotate struct fs_struct's usage count to indicate the restrictions upon it.
It may not be incremented, except by clone(CLONE_FS), as this affects the
check in check_unsafe_exec() in fs/exec.c.

Signed-off-by: David Howells 
Signed-off-by: Hugh Dickins 
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

PCI: fix incorrect mask of PM No_Soft_Reset bit

2009-05-08T22:45:01+00:00

commit 998dd7c719f62dcfa91d7bf7f4eb9c160e03d817 upstream.

Reviewed-by: Matthew Wilcox 
Signed-off-by: Yu Zhao 
Signed-off-by: Jesse Barnes 
Signed-off-by: Greg Kroah-Hartman

block: include empty disks in /proc/diskstats

2009-05-08T22:45:00+00:00

commit 71982a409f12c50d011325a4471aa20666bb908d upstream.

/proc/diskstats used to show stats for all disks whether they're
zero-sized or not and their non-zero partitions.  Commit
074a7aca7afa6f230104e8e65eba3420263714a5 accidentally changed the
behavior such that it doesn't print out zero sized disks.  This patch
implements DISK_PITER_INCL_EMPTY_PART0 flag to partition iterator and
uses it in diskstats_show() such that empty part0 is shown in
/proc/diskstats.

Reported and bisectd by Dianel Collins.

Signed-off-by: Tejun Heo 
Reported-by: Daniel Collins 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

KVM: Fix overlapping check for memory slots

2009-05-08T22:44:59+00:00

upstream commit: 4cd481f68dde99ac416003b825c835f71e364393

When checking for overlapping slots on registration of a new one, kvm
currently also considers zero-length (ie. deleted) slots and rejects
requests incorrectly. This finally denies user space from joining slots.
Fix the check by skipping deleted slots and advertise this via a
KVM_CAP_JOIN_MEMORY_REGIONS_WORKS.

Cc: stable@kernel.org
Signed-off-by: Jan Kiszka 
Signed-off-by: Avi Kivity 
Signed-off-by: Chris Wright

KVM: Interrupt mask notifiers for ioapic

2009-04-27T17:37:03+00:00

upstream commit: 75858a84a6207f5e60196f6bbd18fde4250e5759

Allow clients to request notifications when the guest masks or unmasks a
particular irq line.  This complements irq ack notifications, as the guest
will not ack an irq line that is masked.

Currently implemented for the ioapic only.

Signed-off-by: Avi Kivity 
Signed-off-by: Chris Wright

add some long-missing capabilities to fs_mask

2009-04-27T17:37:00+00:00

upstream commit: 0ad30b8fd5fe798aae80df6344b415d8309342cc

When POSIX capabilities were introduced during the 2.1 Linux
cycle, the fs mask, which represents the capabilities which having
fsuid==0 is supposed to grant, did not include CAP_MKNOD and
CAP_LINUX_IMMUTABLE.  However, before capabilities the privilege
to call these did in fact depend upon fsuid==0.

This patch introduces those capabilities into the fsmask,
restoring the old behavior.

See the thread starting at http://lkml.org/lkml/2009/3/11/157 for
reference.

Note that if this fix is deemed valid, then earlier kernel versions (2.4
and 2.2) ought to be fixed too.

Changelog:
	[Mar 23] Actually delete old CAP_FS_SET definition...
	[Mar 20] Updated against J. Bruce Fields's patch

Reported-by: Igor Zhbanov 
Signed-off-by: Serge E. Hallyn 
Cc: stable@kernel.org
Cc: J. Bruce Fields 
Signed-off-by: Linus Torvalds 
Signed-off-by: Chris Wright

hrtimer: fix rq->lock inversion (again)

2009-04-27T17:37:00+00:00

upstream commit: 7f1e2ca9f04b02794597f60e7b1d43f0a1317939

It appears I inadvertly introduced rq->lock recursion to the
hrtimer_start() path when I delegated running already expired
timers to softirq context.

This patch fixes it by introducing a __hrtimer_start_range_ns()
method that will not use raise_softirq_irqoff() but
__raise_softirq_irqoff() which avoids the wakeup.

It then also changes schedule() to check for pending softirqs and
do the wakeup then, I'm not quite sure I like this last bit, nor
am I convinced its really needed.

Signed-off-by: Peter Zijlstra 
Cc: Peter Zijlstra 
Cc: paulus@samba.org
LKML-Reference: <20090313112301.096138802@chello.nl>
Signed-off-by: Ingo Molnar 
Tested-by: Mikael Pettersson 
Signed-off-by: Chris Wright