linux.git/mm, branch v4.2-rc5

mm/cma_debug: correct size input to bitmap function

2015-07-17T23:39:54+00:00

In CMA, 1 bit in bitmap means 1 << order_per_bits pages so size of
bitmap is cma->count >> order_per_bits rather than just cma->count.
This patch fixes it.

Signed-off-by: Joonsoo Kim 
Acked-by: Michal Nazarewicz 
Cc: Sasha Levin 
Cc: Stefan Strogin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/cma_debug: fix debugging alloc/free interface

2015-07-17T23:39:54+00:00

CMA has alloc/free interface for debugging.  It is intended that
alloc/free occurs in specific CMA region, but, currently, alloc/free
interface is on root dir due to the bug so we can't select CMA region
where alloc/free happens.

This patch fixes this problem by making alloc/free interface per CMA
region.

Signed-off-by: Joonsoo Kim 
Acked-by: Michal Nazarewicz 
Cc: Sasha Levin 
Cc: Stefan Strogin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/page_owner: set correct gfp_mask on page_owner

2015-07-17T23:39:54+00:00

Currently, we set wrong gfp_mask to page_owner info in case of isolated
freepage by compaction and split page.  It causes incorrect mixed
pageblock report that we can get from '/proc/pagetypeinfo'.  This metric
is really useful to measure fragmentation effect so should be accurate.
This patch fixes it by setting correct information.

Without this patch, after kernel build workload is finished, number of
mixed pageblock is 112 among roughly 210 movable pageblocks.

But, with this fix, output shows that mixed pageblock is just 57.

Signed-off-by: Joonsoo Kim 
Cc: Mel Gorman 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/page_owner: fix possible access violation

2015-07-17T23:39:54+00:00

When I tested my new patches, I found that page pointer which is used
for setting page_owner information is changed.  This is because page
pointer is used to set new migratetype in loop.  After this work, page
pointer could be out of bound.  If this wrong pointer is used for
page_owner, access violation happens.  Below is error message that I
got.

  BUG: unable to handle kernel paging request at 0000000000b00018
  IP: [] save_stack_address+0x30/0x40
  PGD 1af2d067 PUD 166e0067 PMD 0
  Oops: 0002 [#1] SMP
  ...snip...
  Call Trace:
    print_context_stack+0xcf/0x100
    dump_trace+0x15f/0x320
    save_stack_trace+0x2f/0x50
    __set_page_owner+0x46/0x70
    __isolate_free_page+0x1f7/0x210
    split_free_page+0x21/0xb0
    isolate_freepages_block+0x1e2/0x410
    compaction_alloc+0x22d/0x2d0
    migrate_pages+0x289/0x8b0
    compact_zone+0x409/0x880
    compact_zone_order+0x6d/0x90
    try_to_compact_pages+0x110/0x210
    __alloc_pages_direct_compact+0x3d/0xe6
    __alloc_pages_nodemask+0x6cd/0x9a0
    alloc_pages_current+0x91/0x100
    runtest_store+0x296/0xa50
    simple_attr_write+0xbd/0xe0
    __vfs_write+0x28/0xf0
    vfs_write+0xa9/0x1b0
    SyS_write+0x46/0xb0
    system_call_fastpath+0x16/0x75

This patch fixes this error by moving up set_page_owner().

Signed-off-by: Joonsoo Kim 
Cc: Mel Gorman 
Cc: Vlastimil Babka 
Acked-by: Minchan Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, meminit: suppress unused memory variable warning

2015-07-17T23:39:53+00:00

The kbuild test robot reported the following

  tree:   git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
  head:   14a6f1989dae9445d4532941bdd6bbad84f4c8da
  commit: 3b242c66ccbd60cf47ab0e8992119d9617548c23 x86: mm: enable deferred struct page initialisation on x86-64
  date:   3 days ago
  config: x86_64-randconfig-x006-201527 (attached as .config)
  reproduce:
    git checkout 3b242c66ccbd60cf47ab0e8992119d9617548c23
    # save the attached .config to linux build tree
    make ARCH=x86_64

  All warnings (new ones prefixed by >>):

     mm/page_alloc.c: In function 'early_page_uninitialised':
  >> mm/page_alloc.c:247:6: warning: unused variable 'nid' [-Wunused-variable]
       int nid = early_pfn_to_nid(pfn);

It's due to the NODE_DATA macro ignoring the nid parameter on !NUMA
configurations.  This patch avoids the warning by not declaring nid.

Signed-off-by: Mel Gorman 
Reported-by: Wu Fengguang 
Cc: "Kirill A. Shutemov" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: avoid setting up anonymous pages into file mapping

2015-07-09T18:12:48+00:00

Reading page fault handler code I've noticed that under right
circumstances kernel would map anonymous pages into file mappings: if
the VMA doesn't have vm_ops->fault() and the VMA wasn't fully populated
on ->mmap(), kernel would handle page fault to not populated pte with
do_anonymous_page().

Let's change page fault handler to use do_anonymous_page() only on
anonymous VMA (->vm_ops == NULL) and make sure that the VMA is not
shared.

For file mappings without vm_ops->fault() or shred VMA without vm_ops,
page fault on pte_none() entry would lead to SIGBUS.

Signed-off-by: Kirill A. Shutemov 
Acked-by: Oleg Nesterov 
Cc: Andrew Morton 
Cc: Willy Tarreau 
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2015-07-05T02:36:06+00:00

Pull more vfs updates from Al Viro:
 "Assorted VFS fixes and related cleanups (IMO the most interesting in
  that part are f_path-related things and Eric's descriptor-related
  stuff).  UFS regression fixes (it got broken last cycle).  9P fixes.
  fs-cache series, DAX patches, Jan's file_remove_suid() work"

[ I'd say this is much more than "fixes and related cleanups".  The
  file_table locking rule change by Eric Dumazet is a rather big and
  fundamental update even if the patch isn't huge.   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
  9p: cope with bogus responses from server in p9_client_{read,write}
  p9_client_write(): avoid double p9_free_req()
  9p: forgetting to cancel request on interrupted zero-copy RPC
  dax: bdev_direct_access() may sleep
  block: Add support for DAX reads/writes to block devices
  dax: Use copy_from_iter_nocache
  dax: Add block size note to documentation
  fs/file.c: __fget() and dup2() atomicity rules
  fs/file.c: don't acquire files->file_lock in fd_install()
  fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
  vfs: avoid creation of inode number 0 in get_next_ino
  namei: make set_root_rcu() return void
  make simple_positive() public
  ufs: use dir_pages instead of ufs_dir_pages()
  pagemap.h: move dir_pages() over there
  remove the pointless include of lglock.h
  fs: cleanup slight list_entry abuse
  xfs: Correctly lock inode when removing suid and file capabilities
  fs: Call security_ops->inode_killpriv on truncate
  fs: Provide function telling whether file_remove_privs() will do anything
  ...

Merge branch 'for-linus' of git://git.kernel.dk/linux-block

2015-07-03T19:12:16+00:00

Pull block fixes from Jens Axboe:
 "Mainly sending this off now for the writeback fixes, since they fix a
  real regression introduced with the cgroup writeback changes.  The
  NVMe fix could wait for next pull for this series, but it's simple
  enough that we might as well include it.

  This contains:

   - two cgroup writeback fixes from Tejun, fixing a user reported issue
     with luks crypt devices hanging when being closed.

   - NVMe error cleanup fix from Jon Derrick, fixing a case where we'd
     attempt to free an unregistered IRQ"

* 'for-linus' of git://git.kernel.dk/linux-block:
  NVMe: Fix irq freeing when queue_request_irq fails
  writeback: don't drain bdi_writeback_congested on bdi destruction
  writeback: don't embed root bdi_writeback_congested in bdi_writeback

Merge tag 'module_init-alternate_initcall-v4.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux

2015-07-02T17:36:29+00:00

Pull module_init replacement part two from Paul Gortmaker:
 "Replace module_init with appropriate alternate initcall in non
  modules.

  This series converts non-modular code that is using the module_init()
  call to hook itself into the system to instead use one of our
  alternate priority initcalls.

  Unlike the previous series that used device_initcall and hence was a
  runtime no-op, these commits change to one of the alternate initcalls,
  because (a) we have them and (b) it seems like the right thing to do.

  For example, it would seem logical to use arch_initcall for arch
  specific setup code and fs_initcall for filesystem setup code.

  This does mean however, that changes in the init ordering will be
  taking place, and so there is a small risk that some kind of implicit
  init ordering issue may lie uncovered.  But I think it is still better
  to give these ones sensible priorities than to just assign them all to
  device_initcall in order to exactly preserve the old ordering.

  Thad said, we have already made similar changes in core kernel code in
  commit c96d6660dc65 ("kernel: audit/fix non-modular users of
  module_init in core code") without any regressions reported, so this
  type of change isn't without precedent.  It has also got the same
  local testing and linux-next coverage as all the other pull requests
  that I'm sending for this merge window have got.

  Once again, there is an unused module_exit function removal that shows
  up as an outlier upon casual inspection of the diffstat"

* tag 'module_init-alternate_initcall-v4.1-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux:
  x86: perf_event_intel_pt.c: use arch_initcall to hook in enabling
  x86: perf_event_intel_bts.c: use arch_initcall to hook in enabling
  mm/page_owner.c: use late_initcall to hook in enabling
  lib/list_sort: use late_initcall to hook in self tests
  arm: use subsys_initcall in non-modular pl320 IPC code
  powerpc: don't use module_init for non-modular core hugetlb code
  powerpc: use subsys_initcall for Freescale Local Bus
  x86: don't use module_init for non-modular core bootflag code
  netfilter: don't use module_init/exit in core IPV4 code
  fs/notify: don't use module_init for non-modular inotify_user code
  mm: replace module_init usages with subsys_initcall in nommu.c

writeback: don't drain bdi_writeback_congested on bdi destruction

2015-07-02T14:46:00+00:00

52ebea749aae ("writeback: make backing_dev_info host cgroup-specific
bdi_writebacks") made bdi (backing_dev_info) host per-cgroup wb's
(bdi_writeback's).  As the congested state needs to be per-wb and
referenced from blkcg side and multiple wbs, the patch made all
non-root cong's (bdi_writeback_congested's) reference counted and
indexed on bdi.

When a bdi is destroyed, cgwb_bdi_destroy() tries to drain all
non-root cong's; however, this can hang indefinitely because wb's can
also be referenced from blkcg_gq's which are destroyed after bdi
destruction is complete.

This patch fixes the bug by updating bdi destruction to not wait for
cong's to drain.  A cong is unlinked from bdi->cgwb_congested_tree on
bdi destuction regardless of its reference count as the bdi may go
away any point after destruction.  wb_congested_put() checks whether
the cong is already unlinked on release.

Signed-off-by: Tejun Heo 
Reported-by: Jon Christopherson 
Link: https://bugzilla.kernel.org/show_bug.cgi?id=100681
Fixes: 52ebea749aae ("writeback: make backing_dev_info host cgroup-specific bdi_writebacks")
Tested-by: Jon Christopherson 
Signed-off-by: Jens Axboe