Commit Graph

475616 Commits

Author SHA1 Message Date
Joonsoo Kim
12220dea07 mm/slab: support slab merge
Slab merge is good feature to reduce fragmentation.  If new creating slab
have similar size and property with exsitent slab, this feature reuse it
rather than creating new one.  As a result, objects are packed into fewer
slabs so that fragmentation is reduced.

Below is result of my testing.

* After boot, sleep 20; cat /proc/meminfo | grep Slab

<Before>
Slab: 25136 kB

<After>
Slab: 24364 kB

We can save 3% memory used by slab.

For supporting this feature in SLAB, we need to implement SLAB specific
kmem_cache_flag() and __kmem_cache_alias(), because SLUB implements some
SLUB specific processing related to debug flag and object size change on
these functions.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:51 -04:00
Joonsoo Kim
423c929cbb mm/slab_common: commonize slab merge logic
Slab merge is good feature to reduce fragmentation.  Now, it is only
applied to SLUB, but, it would be good to apply it to SLAB.  This patch is
preparation step to apply slab merge to SLAB by commonizing slab merge
logic.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:51 -04:00
Mikulas Patocka
9163582c3f slab: fix for_each_kmem_cache_node()
Fix a bug (discovered with kmemcheck) in for_each_kmem_cache_node().  The
for loop reads the array "node" before verifying that the index is within
the range.  This results in kmemcheck warning.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:51 -04:00
Nishanth Aravamudan
109228389a kernel/kthread.c: partial revert of 81c98869fa ("kthread: ensure locality of task_struct allocations")
After discussions with Tejun, we don't want to spread the use of
cpu_to_mem() (and thus knowledge of allocators/NUMA topology details) into
callers, but would rather ensure the callees correctly handle memoryless
nodes.  With the previous patches ("topology: add support for
node_to_mem_node() to determine the fallback node" and "slub: fallback to
node_to_mem_node() node if allocating on memoryless node") adding and
using node_to_mem_node(), we can safely undo part of the change to the
kthread logic from 81c98869fa.

Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Han Pingtian <hanpt@linux.vnet.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Anton Blanchard <anton@samba.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:51 -04:00
Joonsoo Kim
a561ce00b0 slub: fall back to node_to_mem_node() node if allocating on memoryless node
Update the SLUB code to search for partial slabs on the nearest node with
memory in the presence of memoryless nodes.  Additionally, do not consider
it to be an ALLOC_NODE_MISMATCH (and deactivate the slab) when a
memoryless-node specified allocation goes off-node.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Han Pingtian <hanpt@linux.vnet.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Anton Blanchard <anton@samba.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:51 -04:00
Joonsoo Kim
ad2c814441 topology: add support for node_to_mem_node() to determine the fallback node
Anton noticed (http://www.spinics.net/lists/linux-mm/msg67489.html) that
on ppc LPARs with memoryless nodes, a large amount of memory was consumed
by slabs and was marked unreclaimable.  He tracked it down to slab
deactivations in the SLUB core when we allocate remotely, leading to poor
efficiency always when memoryless nodes are present.

After much discussion, Joonsoo provided a few patches that help
significantly.  They don't resolve the problem altogether:

 - memory hotplug still needs testing, that is when a memoryless node
   becomes memory-ful, we want to dtrt
 - there are other reasons for going off-node than memoryless nodes,
   e.g., fully exhausted local nodes

Neither case is resolved with this series, but I don't think that should
block their acceptance, as they can be explored/resolved with follow-on
patches.

The series consists of:

[1/3] topology: add support for node_to_mem_node() to determine the
      fallback node

[2/3] slub: fallback to node_to_mem_node() node if allocating on
      memoryless node

      - Joonsoo's patches to cache the nearest node with memory for each
        NUMA node

[3/3] Partial revert of 81c98869fa (""kthread: ensure locality of
      task_struct allocations")

 - At Tejun's request, keep the knowledge of memoryless node fallback
   to the allocator core.

This patch (of 3):

We need to determine the fallback node in slub allocator if the allocation
target node is memoryless node.  Without it, the SLUB wrongly select the
node which has no memory and can't use a partial slab, because of node
mismatch.  Introduced function, node_to_mem_node(X), will return a node Y
with memory that has the nearest distance.  If X is memoryless node, it
will return nearest distance node, but, if X is normal node, it will
return itself.

We will use this function in following patch to determine the fallback
node.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Han Pingtian <hanpt@linux.vnet.ibm.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Anton Blanchard <anton@samba.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:51 -04:00
Christoph Lameter
c9e16131d6 slub: disable tracing and failslab for merged slabs
Tracing of mergeable slabs as well as uses of failslab are confusing since
the objects of multiple slab caches will be affected.  Moreover this
creates a situation where a mergeable slab will become unmergeable.

If tracing or failslab testing is desired then it may be best to switch
merging off for starters.

Signed-off-by: Christoph Lameter <cl@linux.com>
Tested-by: WANG Chao <chaowang@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:51 -04:00
Joonsoo Kim
25c4f304be mm/slab: factor out unlikely part of cache_free_alien()
cache_free_alien() is rarely used function when node mismatch.  But, it is
defined with inline attribute so it is inlined to __cache_free() which is
core free function of slab allocator.  It uselessly makes
kmem_cache_free()/kfree() functions large.  What we really need to inline
is just checking node match so this patch factor out other parts of
cache_free_alien() to reduce code size of kmem_cache_free()/ kfree().

<Before>
nm -S mm/slab.o | grep -e "T kfree" -e "T kmem_cache_free"
00000000000011e0 0000000000000228 T kfree
0000000000000670 0000000000000216 T kmem_cache_free

<After>
nm -S mm/slab.o | grep -e "T kfree" -e "T kmem_cache_free"
0000000000001110 00000000000001b5 T kfree
0000000000000750 0000000000000181 T kmem_cache_free

You can see slightly reduced size of text: 0x228->0x1b5, 0x216->0x181.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:51 -04:00
Joonsoo Kim
d3aec34466 mm/slab: noinline __ac_put_obj()
Our intention of __ac_put_obj() is that it doesn't affect anything if
sk_memalloc_socks() is disabled.  But, because __ac_put_obj() is too
small, compiler inline it to ac_put_obj() and affect code size of free
path.  This patch add noinline keyword for __ac_put_obj() not to distrupt
normal free path at all.

<Before>
nm -S slab-orig.o |
	grep -e "t cache_alloc_refill" -e "T kfree" -e "T kmem_cache_free"

0000000000001e80 00000000000002f5 t cache_alloc_refill
0000000000001230 0000000000000258 T kfree
0000000000000690 000000000000024c T kmem_cache_free

<After>
nm -S slab-patched.o |
	grep -e "t cache_alloc_refill" -e "T kfree" -e "T kmem_cache_free"

0000000000001e00 00000000000002e5 t cache_alloc_refill
00000000000011e0 0000000000000228 T kfree
0000000000000670 0000000000000216 T kmem_cache_free

cache_alloc_refill: 0x2f5->0x2e5
kfree: 0x256->0x228
kmem_cache_free: 0x24c->0x216

code size of each function is reduced slightly.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:50 -04:00
Joonsoo Kim
3d88019408 mm/slab: move cache_flusharray() out of unlikely.text section
Now, due to likely keyword, compiled code of cache_flusharray() is on
unlikely.text section.  Although it is uncommon case compared to free to
cpu cache case, it is common case than free_block().  But, free_block() is
on normal text section.  This patch fix this odd situation to remove
likely keyword.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:50 -04:00
Joonsoo Kim
61f47105a2 mm/sl[ao]b: always track caller in kmalloc_(node_)track_caller()
Now, we track caller if tracing or slab debugging is enabled.  If they are
disabled, we could save one argument passing overhead by calling
__kmalloc(_node)().  But, I think that it would be marginal.  Furthermore,
default slab allocator, SLUB, doesn't use this technique so I think that
it's okay to change this situation.

After this change, we can turn on/off CONFIG_DEBUG_SLAB without full
kernel build and remove some complicated '#if' defintion.  It looks more
benefitial to me.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:50 -04:00
Joonsoo Kim
07f361b2be mm/slab_common: move kmem_cache definition to internal header
We don't need to keep kmem_cache definition in include/linux/slab.h if we
don't need to inline kmem_cache_size().  According to my code inspection,
this function is only called at lc_create() in lib/lru_cache.c which may
be called at initialization phase of something, so we don't need to inline
it.  Therfore, move it to slab_common.c and move kmem_cache definition to
internal header.

After this change, we can change kmem_cache definition easily without full
kernel build.  For instance, we can turn on/off CONFIG_SLUB_STATS without
full kernel build.

[akpm@linux-foundation.org: export kmem_cache_size() to modules]
[rdunlap@infradead.org: add header files to fix kmemcheck.c build errors]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:50 -04:00
Andrew Morton
3aa24f519e mm/slab_common.c: suppress warning
False positive:

mm/slab_common.c: In function 'kmem_cache_create':
mm/slab_common.c:204: warning: 's' may be used uninitialized in this function

Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:50 -04:00
Baoquan He
bf3e269246 fs/proc/kcore.c: don't add modules range to kcore if it's equal to vmcore range
On some ARCHs modules range is eauql to vmalloc range. E.g on i686

	"#define MODULES_VADDR   VMALLOC_START"
	"#define MODULES_END     VMALLOC_END"

This will cause 2 duplicate program segments in /proc/kcore, and no flag
to indicate they are different.  This is confusing.  And usually people
who need check the elf header or read the content of kcore will check
memory ranges.  Two program segments which are the same are unnecessary.

So check if the modules range is equal to vmalloc range.  If so, just skip
adding the modules range.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:50 -04:00
Oleg Nesterov
58cb65487e proc/maps: make vm_is_stack() logic namespace-friendly
- Rename vm_is_stack() to task_of_stack() and change it to return
  "struct task_struct *" rather than the global (and thus wrong in
  general) pid_t.

- Add the new pid_of_stack() helper which calls task_of_stack() and
  uses the right namespace to report the correct pid_t.

  Unfortunately we need to define this helper twice, in task_mmu.c
  and in task_nommu.c. perhaps it makes sense to add fs/proc/util.c
  and move at least pid_of_stack/task_of_stack there to avoid the
  code duplication.

- Change show_map_vma() and show_numa_map() to use the new helper.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:50 -04:00
Oleg Nesterov
2c03376d2d proc/maps: replace proc_maps_private->pid with "struct inode *inode"
m_start() can use get_proc_task() instead, and "struct inode *"
provides more potentially useful info, see the next changes.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:50 -04:00
Oleg Nesterov
47fecca15c fs/proc/task_nommu.c: don't use priv->task->mm
I do not know if CONFIG_PREEMPT/SMP is possible without CONFIG_MMU
but the usage of task->mm in m_stop(). The task can exit/exec before
we take mmap_sem, in this case m_stop() can hit NULL or unlock the
wrong rw_semaphore.

Also, this code uses priv->task != NULL to decide whether we need
up_read/mmput. This is correct, but we will probably kill priv->task.
Change m_start/m_stop to rely on IS_ERR_OR_NULL() like task_mmu.c does.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov
27692cd56e fs/proc/task_nommu.c: shift mm_access() from m_start() to proc_maps_open()
Copy-and-paste the changes from "fs/proc/task_mmu.c: shift mm_access()
from m_start() to proc_maps_open()" into task_nommu.c.

Change maps_open() to initialize priv->mm using proc_mem_open(), m_start()
can rely on atomic_inc_not_zero(mm_users) like task_mmu.c does.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov
ce34fddb5b fs/proc/task_nommu.c: change maps_open() to use __seq_open_private()
Cleanup and preparation. maps_open() can use __seq_open_private()
like proc_maps_open() does.

[akpm@linux-foundation.org: deuglify]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov
557c2d8a73 fs/proc/task_mmu.c: update m->version in the main loop in m_start()
Change the main loop in m_start() to update m->version. Mostly for
consistency, but this can help to avoid the same loop if the very
1st ->show() fails due to seq_overflow().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov
b8c20a9b85 fs/proc/task_mmu.c: reintroduce m->version logic
Add the "last_addr" optimization back. Like before, every ->show()
method checks !seq_overflow() and sets m->version = vma->vm_start.

However, it also checks that m_next_vma(vma) != NULL, otherwise it
sets m->version = -1 for the lockless "EOF" fast-path in m_start().

m_start() can simply do find_vma() + m_next_vma() if last_addr is
not zero, the code looks clear and simple and this case is clearly
separated from "scan vmas" path.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov
ad2a00e4b7 fs/proc/task_mmu.c: introduce m_next_vma() helper
Extract the tail_vma/vm_next calculation from m_next() into the new
trivial helper, m_next_vma().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov
0c255321f8 fs/proc/task_mmu.c: simplify m_start() to make it readable
Now that m->version is gone we can cleanup m_start(). In particular,

  - Remove the "unsigned long" typecast, m->index can't be negative
    or exceed ->map_count. But lets use "unsigned int pos" to make
    it clear that "pos < map_count" is safe.

  - Remove the unnecessary "vma != NULL" check in the main loop. It
    can't be NULL unless we have a vm bug.

  - This also means that "pos < map_count" case can simply return the
    valid vma and avoid "goto" and subsequent checks.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov
ebb6cdde1a fs/proc/task_mmu.c: kill the suboptimal and confusing m->version logic
m_start() carefully documents, checks, and sets "m->version = -1" if
we are going to return NULL. The only problem is that we will be never
called again if m_start() returns NULL, so this is simply pointless
and misleading.

Otoh, ->show() methods m->version = 0 if vma == tail_vma and this is
just wrong, we want -1 in this case. And in fact we also want -1 if
->vm_next == NULL and ->tail_vma == NULL.

And it is not used consistently, the "scan vmas" loop in m_start()
should update last_addr too.

Finally, imo the whole "last_addr" logic in m_start() looks horrible.
find_vma(last_addr) is called unconditionally even if we are not going
to use the result. But the main problem is that this code participates
in tail_vma-or-NULL mess, and this looks simply unfixable.

Remove this optimization. We will add it back after some cleanups.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov
0d5f5f45f9 fs/proc/task_mmu.c: shift "priv->task = NULL" from m_start() to m_stop()
1. There is no reason to reset ->tail_vma in m_start(), if we return
   IS_ERR_OR_NULL() it won't be used.

2. m_start() also clears priv->task to ensure that m_stop() won't use
   the stale pointer if we fail before get_task_struct(). But this is
   ugly and confusing, move this initialization in m_stop().

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:49 -04:00
Oleg Nesterov
23d54837e4 fs/proc/task_mmu.c: cleanup the "tail_vma" horror in m_next()
1. Kill the first "vma != NULL" check. Firstly this is not possible,
   m_next() won't be called if ->start() or the previous ->next()
   returns NULL.

   And if it was possible the 2nd "vma != tail_vma" check is buggy,
   we should not wrongly return ->tail_vma.

2. Make this function readable. The logic is very simple, we should
   return check "vma != tail" once and return "vm_next || tail_vma".

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:48 -04:00
Oleg Nesterov
59b4bf12d4 fs/proc/task_mmu.c: simplify the vma_stop() logic
m_start() drops ->mmap_sem and does mmput() if it retuns vsyscall
vma. This is because in this case m_stop()->vma_stop() obviously
can't use gate_vma->vm_mm.

Now that we have proc_maps_private->mm we can simplify this logic:

  - Change m_start() to return with ->mmap_sem held unless it returns
    IS_ERR_OR_NULL().

  - Change vma_stop() to use priv->mm and avoid the ugly vma checks,
    this makes "vm_area_struct *vma" unnecessary.

  - This also allows m_start() to use vm_stop().

  - Cleanup m_next() to follow the new locking rule.

    Note: m_stop() looks very ugly, and this temporary uglifies it
    even more. Fixed by the next change.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:48 -04:00
Oleg Nesterov
29a40ace84 fs/proc/task_mmu.c: shift mm_access() from m_start() to proc_maps_open()
A simple test-case from Kirill Shutemov

	cat /proc/self/maps >/dev/null
	chmod +x /proc/self/net/packet
	exec /proc/self/net/packet

makes lockdep unhappy, cat/exec take seq_file->lock + cred_guard_mutex in
the opposite order.

It's a false positive and probably we should not allow "chmod +x" on proc
files. Still I think that we should avoid mm_access() and cred_guard_mutex
in sys_read() paths, security checking should happen at open time. Besides,
this doesn't even look right if the task changes its ->mm between m_stop()
and m_start().

Add the new "mm_struct *mm" member into struct proc_maps_private and change
proc_maps_open() to initialize it using proc_mem_open(). Change m_start() to
use priv->mm if atomic_inc_not_zero(mm_users) succeeds or return NULL (eof)
otherwise.

The only complication is that proc_maps_open() users should additionally do
mmdrop() in fop->release(), add the new proc_map_release() helper for that.

Note: this is the user-visible change, if the task execs after open("maps")
the new ->mm won't be visible via this file. I hope this is fine, and this
matches /proc/pid/mem bahaviour.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: "Kirill A. Shutemov" <kirill@shutemov.name>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:48 -04:00
Oleg Nesterov
5381e169e7 proc: introduce proc_mem_open()
Extract the mm_access() code from __mem_open() into the new helper,
proc_mem_open(), the next patch will add another caller.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:48 -04:00
Oleg Nesterov
4db7d0ee19 fs/proc/task_mmu.c: unify/simplify do_maps_open() and numa_maps_open()
do_maps_open() and numa_maps_open() are overcomplicated, they could use
__seq_open_private().  Plus they do the same, just sizeof(*priv)

Change them to use a new simple helper, proc_maps_open(ops, psize).  This
simplifies the code and allows us to do the next changes.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:48 -04:00
Oleg Nesterov
46c298cf69 fs/proc/task_mmu.c: don't use task->mm in m_start() and show_*map()
get_gate_vma(priv->task->mm) looks ugly and wrong, task->mm can be NULL or
it can changed by exec right after mm_access().

And in theory this race is not harmless, the task can exec and then later
exit and free the new mm_struct.  In this case get_task_mm(oldmm) can't
help, get_gate_vma(task->mm) can read the freed/unmapped memory.

I think that priv->task should simply die and hold_task_mempolicy() logic
can be simplified.  tail_vma logic asks for cleanups too.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:48 -04:00
chai wen
b1a8de1f53 softlockup: make detector be aware of task switch of processes hogging cpu
For now, soft lockup detector warns once for each case of process
softlockup.  But the thread 'watchdog/n' may not always get the cpu at the
time slot between the task switch of two processes hogging that cpu to
reset soft_watchdog_warn.

An example would be two processes hogging the cpu.  Process A causes the
softlockup warning and is killed manually by a user.  Process B
immediately becomes the new process hogging the cpu preventing the
softlockup code from resetting the soft_watchdog_warn variable.

This case is a false negative of "warn only once for a process", as there
may be a different process that is going to hog the cpu.  Resolve this by
saving/checking the task pointer of the hogging process and use that to
reset soft_watchdog_warn too.

[dzickus@redhat.com: update comment]
Signed-off-by: chai wen <chaiw.fnst@cn.fujitsu.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:48 -04:00
Junxiao Bi
f775da2fc2 ocfs2: fix deadlock due to wrong locking order
For commit ocfs2 journal, ocfs2 journal thread will acquire the mutex
osb->journal->j_trans_barrier and wake up jbd2 commit thread, then it
will wait until jbd2 commit thread done. In order journal mode, jbd2
needs flushing dirty data pages first, and this needs get page lock.
So osb->journal->j_trans_barrier should be got before page lock.

But ocfs2_write_zero_page() and ocfs2_write_begin_inline() obey this
locking order, and this will cause deadlock and hung the whole cluster.

One deadlock catched is the following:

PID: 13449  TASK: ffff8802e2f08180  CPU: 31  COMMAND: "oracle"
 #0 [ffff8802ee3f79b0] __schedule at ffffffff8150a524
 #1 [ffff8802ee3f7a58] schedule at ffffffff8150acbf
 #2 [ffff8802ee3f7a68] rwsem_down_failed_common at ffffffff8150cb85
 #3 [ffff8802ee3f7ad8] rwsem_down_read_failed at ffffffff8150cc55
 #4 [ffff8802ee3f7ae8] call_rwsem_down_read_failed at ffffffff812617a4
 #5 [ffff8802ee3f7b50] ocfs2_start_trans at ffffffffa0498919 [ocfs2]
 #6 [ffff8802ee3f7ba0] ocfs2_zero_start_ordered_transaction at ffffffffa048b2b8 [ocfs2]
 #7 [ffff8802ee3f7bf0] ocfs2_write_zero_page at ffffffffa048e9bd [ocfs2]
 #8 [ffff8802ee3f7c80] ocfs2_zero_extend_range at ffffffffa048ec83 [ocfs2]
 #9 [ffff8802ee3f7ce0] ocfs2_zero_extend at ffffffffa048edfd [ocfs2]
 #10 [ffff8802ee3f7d50] ocfs2_extend_file at ffffffffa049079e [ocfs2]
 #11 [ffff8802ee3f7da0] ocfs2_setattr at ffffffffa04910ed [ocfs2]
 #12 [ffff8802ee3f7e70] notify_change at ffffffff81187d29
 #13 [ffff8802ee3f7ee0] do_truncate at ffffffff8116bbc1
 #14 [ffff8802ee3f7f50] sys_ftruncate at ffffffff8116bcbd
 #15 [ffff8802ee3f7f80] system_call_fastpath at ffffffff81515142
    RIP: 00007f8de750c6f7  RSP: 00007fffe786e478  RFLAGS: 00000206
    RAX: 000000000000004d  RBX: ffffffff81515142  RCX: 0000000000000000
    RDX: 0000000000000200  RSI: 0000000000028400  RDI: 000000000000000d
    RBP: 00007fffe786e040   R8: 0000000000000000   R9: 000000000000000d
    R10: 0000000000000000  R11: 0000000000000206  R12: 000000000000000d
    R13: 00007fffe786e710  R14: 00007f8de70f8340  R15: 0000000000028400
    ORIG_RAX: 000000000000004d  CS: 0033  SS: 002b

crash64> bt
PID: 7610   TASK: ffff88100fd56140  CPU: 1   COMMAND: "ocfs2cmt"
 #0 [ffff88100f4d1c50] __schedule at ffffffff8150a524
 #1 [ffff88100f4d1cf8] schedule at ffffffff8150acbf
 #2 [ffff88100f4d1d08] jbd2_log_wait_commit at ffffffffa01274fd [jbd2]
 #3 [ffff88100f4d1d98] jbd2_journal_flush at ffffffffa01280b4 [jbd2]
 #4 [ffff88100f4d1dd8] ocfs2_commit_cache at ffffffffa0499b14 [ocfs2]
 #5 [ffff88100f4d1e38] ocfs2_commit_thread at ffffffffa0499d38 [ocfs2]
 #6 [ffff88100f4d1ee8] kthread at ffffffff81090db6
 #7 [ffff88100f4d1f48] kernel_thread_helper at ffffffff81516284

crash64> bt
PID: 7609   TASK: ffff88100f2d4480  CPU: 0   COMMAND: "jbd2/dm-20-86"
 #0 [ffff88100def3920] __schedule at ffffffff8150a524
 #1 [ffff88100def39c8] schedule at ffffffff8150acbf
 #2 [ffff88100def39d8] io_schedule at ffffffff8150ad6c
 #3 [ffff88100def39f8] sleep_on_page at ffffffff8111069e
 #4 [ffff88100def3a08] __wait_on_bit_lock at ffffffff8150b30a
 #5 [ffff88100def3a58] __lock_page at ffffffff81110687
 #6 [ffff88100def3ab8] write_cache_pages at ffffffff8111b752
 #7 [ffff88100def3be8] generic_writepages at ffffffff8111b901
 #8 [ffff88100def3c48] journal_submit_data_buffers at ffffffffa0120f67 [jbd2]
 #9 [ffff88100def3cf8] jbd2_journal_commit_transaction at ffffffffa0121372[jbd2]
 #10 [ffff88100def3e68] kjournald2 at ffffffffa0127a86 [jbd2]
 #11 [ffff88100def3ee8] kthread at ffffffff81090db6
 #12 [ffff88100def3f48] kernel_thread_helper at ffffffff81516284

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Alex Chen <alex.chen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:48 -04:00
Joseph Qi
70e82a12db ocfs2: fix deadlock between o2hb thread and o2net_wq
The following case may lead to o2net_wq and o2hb thread deadlock on
o2hb_callback_sem.
Currently there are 2 nodes say N1, N2 in the cluster. And N2 down, at
the same time, N3 tries to join the cluster. So N1 will handle node
down (N2) and join (N3) simultaneously.
    o2hb                               o2net_wq
    ->o2hb_do_disk_heartbeat
    ->o2hb_check_slot
    ->o2hb_run_event_list
    ->o2hb_fire_callbacks
    ->down_write(&o2hb_callback_sem)
    ->o2net_hb_node_down_cb
    ->flush_workqueue(o2net_wq)
                                       ->o2net_process_message
                                       ->dlm_query_join_handler
                                       ->o2hb_check_node_heartbeating
                                       ->o2hb_fill_node_map
                                       ->down_read(&o2hb_callback_sem)

No need to take o2hb_callback_sem in dlm_query_join_handler,
o2hb_live_lock is enough to protect live node map.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Cc: xMark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: jiangyiwen <jiangyiwen@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:47 -04:00
Junxiao Bi
5046f18d5b ocfs2: don't fire quorum before connection established
Firing quorum before connection established can cause unexpected node to
reboot.

Assume there are 3 nodes in the cluster, Node 1, 2, 3.  Node 2 and 3 have
wrong ip address of Node 1 in cluster.conf and global heartbeat is enabled
in the cluster.  After the heatbeats are started on these three nodes,
Node 1 will reboot due to quorum fencing.  It is similar case if Node 1's
networking is not ready when starting the global heartbeat.

The reboot is not friendly as customer is not fully ready for ocfs2 to
work.  Fix it by not allowing firing quorum before the connection is
established.  In this case, ocfs2 will wait until the wrong configuration
is fixed or networking is up to continue.  Also update the log to guide
the user where to check when connection is not built for a long time.

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.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>
2014-10-09 22:25:47 -04:00
Rob Jones
1848cb5530 fs/ocfs2/dlmglue.c: use __seq_open_private() not seq_open()
Reduce boilerplate code by using seq_open_private() instead of seq_open()

Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
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>
2014-10-09 22:25:47 -04:00
Rob Jones
f328833848 fs/ocfs2/cluster/netdebug.c: use seq_open_private() not seq_open()
Reduce boilerplate code by using seq_open_private() instead of seq_open()

Note that the code in and using sc_common_open() has been quite
extensively changed.  Not least because there was a latent memory leak in
the code as was: if sc_common_open() failed, the previously allocated
buffer was not freed.

Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
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>
2014-10-09 22:25:47 -04:00
Rob Jones
8f9ac03232 fs/ocfs2/dlm/dlmdebug.c: use seq_open_private() not seq_open()
Reduce boilerplate code by using seq_open_private() instead of seq_open()

Signed-off-by: Rob Jones <rob.jones@codethink.co.uk>
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>
2014-10-09 22:25:47 -04:00
Xue jiufei
6ae075485e ocfs2: remove unused code in dlm_new_lockres()
Remove the branch that free res->lockname.name because the condition
is never satisfied when jump to label error.

Signed-off-by: joyce.xue <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:47 -04:00
alex chen
9a7e6b5a0a ocfs2/dlm: call dlm_lockres_put without resource spinlock
dlm_lockres_put() should be called without &res->spinlock, otherwise a
deadlock case may happen.

spin_lock(&res->spinlock)
...
dlm_lockres_put
  ->dlm_lockres_release
    ->dlm_print_one_lock_resource
      ->spin_lock(&res->spinlock)

Signed-off-by: Alex Chen <alex.chen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:47 -04:00
Joseph Qi
4a4e07c1bd ocfs2: call o2quo_exit() if malloc failed in o2net_init()
In o2net_init, if malloc failed, it directly returns -ENOMEM.  Then
o2quo_exit won't be called in init_o2nm.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: joyce.xue <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:47 -04:00
Joseph Qi
7fa05c6e46 ocfs2: fix shift left operations overflow
ocfs2_inode_info->ip_clusters and ocfs2_dinode->id1.bitmap1.i_total are
defined as type u32, so the shift left operations may overflow if volume
size is large, for example, 2TB and cluster size is 1MB.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Alex Chen <alex.chen@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:47 -04:00
Joseph Qi
190a7721ac ocfs2/dlm: refactor error handling in dlm_alloc_ctxt
Refactoring error handling in dlm_alloc_ctxt to simplify code.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Alex Chen <alex.chen@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:46 -04:00
Andrew Morton
98acbf63d6 fs/ocfs2/stack_user.c: fix typo in ocfs2_control_release()
It is supposed to zero pv_minor.

Reported-by: Himangi Saraogi <himangi774@gmail.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:46 -04:00
Geert Uytterhoeven
e2cabe1d42 score: use Kbuild logic to include <asm-generic/sections.h>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Lennox Wu <lennox.wu@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:46 -04:00
Andrea Gelmini
7143e49441 ntfs: remove bogus space
fs/ntfs/debug.c:124: WARNING: space prohibited between function name and
open parenthesis '('

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Anton Altaparmakov <anton@tuxera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:46 -04:00
Anton Altaparmakov
5272d036b2 ntfs: use find_get_page_flags() to mark page accessed as it is no longer marked later on
Mel Gorman's commit 2457aec637 ("mm: non-atomically mark page accessed
during page cache allocation where possible") removed mark_page_accessed()
calls from NTFS without updating the matching find_lock_page() to
find_get_page_flags(GFP_LOCK | FGP_ACCESSED) thus causing the page to
never be marked accessed.

This patch fixes that.

Signed-off-by: Anton Altaparmakov <anton@tuxera.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:46 -04:00
Michael Opdenacker
2f82df0f3e m32r: remove deprecated IRQF_DISABLED
This patch removes the use of the IRQF_DISABLED flag
from arch/m32r/kernel/time.c

It's a NOOP since 2.6.35 and it will be removed one day.

Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:46 -04:00
Geert Uytterhoeven
3a28663696 m32r: use Kbuild logic to include <asm-generic/sections.h>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:46 -04:00
Yann Droneaud
0b37e097a6 fanotify: enable close-on-exec on events' fd when requested in fanotify_init()
According to commit 80af258867 ("fanotify: groups can specify their
f_flags for new fd"), file descriptors created as part of file access
notification events inherit flags from the event_f_flags argument passed
to syscall fanotify_init(2)[1].

Unfortunately O_CLOEXEC is currently silently ignored.

Indeed, event_f_flags are only given to dentry_open(), which only seems to
care about O_ACCMODE and O_PATH in do_dentry_open(), O_DIRECT in
open_check_o_direct() and O_LARGEFILE in generic_file_open().

It's a pity, since, according to some lookup on various search engines and
http://codesearch.debian.net/, there's already some userspace code which
use O_CLOEXEC:

- in systemd's readahead[2]:

    fanotify_fd = fanotify_init(FAN_CLOEXEC|FAN_NONBLOCK, O_RDONLY|O_LARGEFILE|O_CLOEXEC|O_NOATIME);

- in clsync[3]:

    #define FANOTIFY_EVFLAGS (O_LARGEFILE|O_RDONLY|O_CLOEXEC)

    int fanotify_d = fanotify_init(FANOTIFY_FLAGS, FANOTIFY_EVFLAGS);

- in examples [4] from "Filesystem monitoring in the Linux
  kernel" article[5] by Aleksander Morgado:

    if ((fanotify_fd = fanotify_init (FAN_CLOEXEC,
                                      O_RDONLY | O_CLOEXEC | O_LARGEFILE)) < 0)

Additionally, since commit 48149e9d3a ("fanotify: check file flags
passed in fanotify_init").  having O_CLOEXEC as part of fanotify_init()
second argument is expressly allowed.

So it seems expected to set close-on-exec flag on the file descriptors if
userspace is allowed to request it with O_CLOEXEC.

But Andrew Morton raised[6] the concern that enabling now close-on-exec
might break existing applications which ask for O_CLOEXEC but expect the
file descriptor to be inherited across exec().

In the other hand, as reported by Mihai Dontu[7] close-on-exec on the file
descriptor returned as part of file access notify can break applications
due to deadlock.  So close-on-exec is needed for most applications.

More, applications asking for close-on-exec are likely expecting it to be
enabled, relying on O_CLOEXEC being effective.  If not, it might weaken
their security, as noted by Jan Kara[8].

So this patch replaces call to macro get_unused_fd() by a call to function
get_unused_fd_flags() with event_f_flags value as argument.  This way
O_CLOEXEC flag in the second argument of fanotify_init(2) syscall is
interpreted and close-on-exec get enabled when requested.

[1] http://man7.org/linux/man-pages/man2/fanotify_init.2.html
[2] http://cgit.freedesktop.org/systemd/systemd/tree/src/readahead/readahead-collect.c?id=v208#n294
[3] https://github.com/xaionaro/clsync/blob/v0.2.1/sync.c#L1631
    https://github.com/xaionaro/clsync/blob/v0.2.1/configuration.h#L38
[4] http://www.lanedo.com/~aleksander/fanotify/fanotify-example.c
[5] http://www.lanedo.com/2013/filesystem-monitoring-linux-kernel/
[6] http://lkml.kernel.org/r/20141001153621.65e9258e65a6167bf2e4cb50@linux-foundation.org
[7] http://lkml.kernel.org/r/20141002095046.3715eb69@mdontu-l
[8] http://lkml.kernel.org/r/20141002104410.GB19748@quack.suse.cz

Link: http://lkml.kernel.org/r/cover.1411562410.git.ydroneaud@opteya.com
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Mihai Don\u021bu <mihai.dontu@gmail.com>
Cc: Pádraig Brady <P@draigBrady.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Michael Kerrisk-manpages <mtk.manpages@gmail.com>
Cc: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Cc: Richard Guy Briggs <rgb@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-09 22:25:46 -04:00