1. 28 3月, 2014 1 次提交
  2. 21 3月, 2014 2 次提交
    • H
      mm: fix swapops.h:131 bug if remap_file_pages raced migration · 7e09e738
      Hugh Dickins 提交于
      Add remove_linear_migration_ptes_from_nonlinear(), to fix an interesting
      little include/linux/swapops.h:131 BUG_ON(!PageLocked) found by trinity:
      indicating that remove_migration_ptes() failed to find one of the
      migration entries that was temporarily inserted.
      
      The problem comes from remap_file_pages()'s switch from vma_interval_tree
      (good for inserting the migration entry) to i_mmap_nonlinear list (no good
      for locating it again); but can only be a problem if the remap_file_pages()
      range does not cover the whole of the vma (zap_pte() clears the range).
      
      remove_migration_ptes() needs a file_nonlinear method to go down the
      i_mmap_nonlinear list, applying linear location to look for migration
      entries in those vmas too, just in case there was this race.
      
      The file_nonlinear method does need rmap_walk_control.arg to do this;
      but it never needed vma passed in - vma comes from its own iteration.
      Reported-and-tested-by: NDave Jones <davej@redhat.com>
      Reported-and-tested-by: NSasha Levin <sasha.levin@oracle.com>
      Signed-off-by: NHugh Dickins <hughd@google.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7e09e738
    • V
      tracing: Fix array size mismatch in format string · 87291347
      Vaibhav Nagarnaik 提交于
      In event format strings, the array size is reported in two locations.
      One in array subscript and then via the "size:" attribute. The values
      reported there have a mismatch.
      
      For e.g., in sched:sched_switch the prev_comm and next_comm character
      arrays have subscript values as [32] where as the actual field size is
      16.
      
      name: sched_switch
      ID: 301
      format:
              field:unsigned short common_type;       offset:0;       size:2; signed:0;
              field:unsigned char common_flags;       offset:2;       size:1; signed:0;
              field:unsigned char common_preempt_count;       offset:3;       size:1;signed:0;
              field:int common_pid;   offset:4;       size:4; signed:1;
      
              field:char prev_comm[32];       offset:8;       size:16;        signed:1;
              field:pid_t prev_pid;   offset:24;      size:4; signed:1;
              field:int prev_prio;    offset:28;      size:4; signed:1;
              field:long prev_state;  offset:32;      size:8; signed:1;
              field:char next_comm[32];       offset:40;      size:16;        signed:1;
              field:pid_t next_pid;   offset:56;      size:4; signed:1;
              field:int next_prio;    offset:60;      size:4; signed:1;
      
      After bisection, the following commit was blamed:
      92edca07 tracing: Use direct field, type and system names
      
      This commit removes the duplication of strings for field->name and
      field->type assuming that all the strings passed in
      __trace_define_field() are immutable. This is not true for arrays, where
      the type string is created in event_storage variable and field->type for
      all array fields points to event_storage.
      
      Use __stringify() to create a string constant for the type string.
      
      Also, get rid of event_storage and event_storage_mutex that are not
      needed anymore.
      
      also, an added benefit is that this reduces the overhead of events a bit more:
      
         text    data     bss     dec     hex filename
      8424787 2036472 1302528 11763787         b3804b vmlinux
      8420814 2036408 1302528 11759750         b37086 vmlinux.patched
      
      Link: http://lkml.kernel.org/r/1392349908-29685-1-git-send-email-vnagarnaik@google.com
      
      Cc: Laurent Chavey <chavey@google.com>
      Cc: stable@vger.kernel.org # 3.10+
      Signed-off-by: NVaibhav Nagarnaik <vnagarnaik@google.com>
      Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      87291347
  3. 19 3月, 2014 1 次提交
  4. 11 3月, 2014 1 次提交
    • J
      mm: fix GFP_THISNODE callers and clarify · e97ca8e5
      Johannes Weiner 提交于
      GFP_THISNODE is for callers that implement their own clever fallback to
      remote nodes.  It restricts the allocation to the specified node and
      does not invoke reclaim, assuming that the caller will take care of it
      when the fallback fails, e.g.  through a subsequent allocation request
      without GFP_THISNODE set.
      
      However, many current GFP_THISNODE users only want the node exclusive
      aspect of the flag, without actually implementing their own fallback or
      triggering reclaim if necessary.  This results in things like page
      migration failing prematurely even when there is easily reclaimable
      memory available, unless kswapd happens to be running already or a
      concurrent allocation attempt triggers the necessary reclaim.
      
      Convert all callsites that don't implement their own fallback strategy
      to __GFP_THISNODE.  This restricts the allocation a single node too, but
      at the same time allows the allocator to enter the slowpath, wake
      kswapd, and invoke direct reclaim if necessary, to make the allocation
      happen when memory is full.
      Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
      Acked-by: NRik van Riel <riel@redhat.com>
      Cc: Jan Stancek <jstancek@redhat.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e97ca8e5
  5. 10 3月, 2014 3 次提交
    • A
      get rid of fget_light() · bd2a31d5
      Al Viro 提交于
      instead of returning the flags by reference, we can just have the
      low-level primitive return those in lower bits of unsigned long,
      with struct file * derived from the rest.
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      bd2a31d5
    • L
      vfs: atomic f_pos accesses as per POSIX · 9c225f26
      Linus Torvalds 提交于
      Our write() system call has always been atomic in the sense that you get
      the expected thread-safe contiguous write, but we haven't actually
      guaranteed that concurrent writes are serialized wrt f_pos accesses, so
      threads (or processes) that share a file descriptor and use "write()"
      concurrently would quite likely overwrite each others data.
      
      This violates POSIX.1-2008/SUSv4 Section XSI 2.9.7 that says:
      
       "2.9.7 Thread Interactions with Regular File Operations
      
        All of the following functions shall be atomic with respect to each
        other in the effects specified in POSIX.1-2008 when they operate on
        regular files or symbolic links: [...]"
      
      and one of the effects is the file position update.
      
      This unprotected file position behavior is not new behavior, and nobody
      has ever cared.  Until now.  Yongzhi Pan reported unexpected behavior to
      Michael Kerrisk that was due to this.
      
      This resolves the issue with a f_pos-specific lock that is taken by
      read/write/lseek on file descriptors that may be shared across threads
      or processes.
      Reported-by: NYongzhi Pan <panyongzhi@gmail.com>
      Reported-by: NMichael Kerrisk <mtk.manpages@gmail.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      9c225f26
    • N
      selinux: add gfp argument to security_xfrm_policy_alloc and fix callers · 52a4c640
      Nikolay Aleksandrov 提交于
      security_xfrm_policy_alloc can be called in atomic context so the
      allocation should be done with GFP_ATOMIC. Add an argument to let the
      callers choose the appropriate way. In order to do so a gfp argument
      needs to be added to the method xfrm_policy_alloc_security in struct
      security_operations and to the internal function
      selinux_xfrm_alloc_user. After that switch to GFP_ATOMIC in the atomic
      callers and leave GFP_KERNEL as before for the rest.
      The path that needed the gfp argument addition is:
      security_xfrm_policy_alloc -> security_ops.xfrm_policy_alloc_security ->
      all users of xfrm_policy_alloc_security (e.g. selinux_xfrm_policy_alloc) ->
      selinux_xfrm_alloc_user (here the allocation used to be GFP_KERNEL only)
      
      Now adding a gfp argument to selinux_xfrm_alloc_user requires us to also
      add it to security_context_to_sid which is used inside and prior to this
      patch did only GFP_KERNEL allocation. So add gfp argument to
      security_context_to_sid and adjust all of its callers as well.
      
      CC: Paul Moore <paul@paul-moore.com>
      CC: Dave Jones <davej@redhat.com>
      CC: Steffen Klassert <steffen.klassert@secunet.com>
      CC: Fan Du <fan.du@windriver.com>
      CC: David S. Miller <davem@davemloft.net>
      CC: LSM list <linux-security-module@vger.kernel.org>
      CC: SELinux list <selinux@tycho.nsa.gov>
      Signed-off-by: NNikolay Aleksandrov <nikolay@redhat.com>
      Acked-by: NPaul Moore <paul@paul-moore.com>
      Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
      52a4c640
  6. 07 3月, 2014 1 次提交
    • T
      firewire: don't use PREPARE_DELAYED_WORK · 70044d71
      Tejun Heo 提交于
      PREPARE_[DELAYED_]WORK() are being phased out.  They have few users
      and a nasty surprise in terms of reentrancy guarantee as workqueue
      considers work items to be different if they don't have the same work
      function.
      
      firewire core-device and sbp2 have been been multiplexing work items
      with multiple work functions.  Introduce fw_device_workfn() and
      sbp2_lu_workfn() which invoke fw_device->workfn and
      sbp2_logical_unit->workfn respectively and always use the two
      functions as the work functions and update the users to set the
      ->workfn fields instead of overriding work functions using
      PREPARE_DELAYED_WORK().
      
      This fixes a variety of possible regressions since a2c1c57b
      "workqueue: consider work function when searching for busy work items"
      due to which fw_workqueue lost its required non-reentrancy property.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Acked-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
      Cc: linux1394-devel@lists.sourceforge.net
      Cc: stable@vger.kernel.org # v3.9+
      Cc: stable@vger.kernel.org # v3.8.2+
      Cc: stable@vger.kernel.org # v3.4.60+
      Cc: stable@vger.kernel.org # v3.2.40+
      70044d71
  7. 04 3月, 2014 4 次提交
    • L
      mm: numa: bugfix for LAST_CPUPID_NOT_IN_PAGE_FLAGS · 1ae71d03
      Liu Ping Fan 提交于
      When doing some numa tests on powerpc, I triggered an oops bug.  I find
      it is caused by using page->_last_cpupid.  It should be initialized as
      "-1 & LAST_CPUPID_MASK", but not "-1".  Otherwise, in task_numa_fault(),
      we will miss the checking (last_cpupid == (-1 & LAST_CPUPID_MASK)).  And
      finally cause an oops bug in task_numa_group(), since the online cpu is
      less than possible cpu.  This happen with CONFIG_SPARSE_VMEMMAP disabled
      
      Call trace:
      
        SMP NR_CPUS=64 NUMA PowerNV
        Modules linked in:
        CPU: 24 PID: 804 Comm: systemd-udevd Not tainted3.13.0-rc1+ #32
        task: c000001e2746aa80 ti: c000001e32c50000 task.ti:c000001e32c50000
        REGS: c000001e32c53510 TRAP: 0300   Not tainted(3.13.0-rc1+)
        MSR: 9000000000009032 <SF,HV,EE,ME,IR,DR,RI>  CR:28024424  XER: 20000000
        CFAR: c000000000009324 DAR: 7265717569726857 DSISR:40000000 SOFTE: 1
        NIP  .task_numa_fault+0x1470/0x2370
        LR  .task_numa_fault+0x1468/0x2370
        Call Trace:
         .task_numa_fault+0x1468/0x2370 (unreliable)
         .do_numa_page+0x480/0x4a0
         .handle_mm_fault+0x4ec/0xc90
         .do_page_fault+0x3a8/0x890
         handle_page_fault+0x10/0x30
        Instruction dump:
        3c82fefb 3884b138 48d9cff1 60000000 48000574 3c62fefb3863af78 3c82fefb
        3884b138 48d9cfd5 60000000 e93f0100 <812902e4> 7d2907b45529063e 7d2a07b4
        ---[ end trace 15f2510da5ae07cf ]---
      Signed-off-by: NLiu Ping Fan <pingfank@linux.vnet.ibm.com>
      Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Acked-by: NPeter Zijlstra <peterz@infradead.org>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1ae71d03
    • V
      mm: include VM_MIXEDMAP flag in the VM_SPECIAL list to avoid m(un)locking · 9050d7eb
      Vlastimil Babka 提交于
      Daniel Borkmann reported a VM_BUG_ON assertion failing:
      
        ------------[ cut here ]------------
        kernel BUG at mm/mlock.c:528!
        invalid opcode: 0000 [#1] SMP
        Modules linked in: ccm arc4 iwldvm [...]
         video
        CPU: 3 PID: 2266 Comm: netsniff-ng Not tainted 3.14.0-rc2+ #8
        Hardware name: LENOVO 2429BP3/2429BP3, BIOS G4ET37WW (1.12 ) 05/29/2012
        task: ffff8801f87f9820 ti: ffff88002cb44000 task.ti: ffff88002cb44000
        RIP: 0010:[<ffffffff81171ad0>]  [<ffffffff81171ad0>] munlock_vma_pages_range+0x2e0/0x2f0
        Call Trace:
          do_munmap+0x18f/0x3b0
          vm_munmap+0x41/0x60
          SyS_munmap+0x22/0x30
          system_call_fastpath+0x1a/0x1f
        RIP   munlock_vma_pages_range+0x2e0/0x2f0
        ---[ end trace a0088dcf07ae10f2 ]---
      
      because munlock_vma_pages_range() thinks it's unexpectedly in the middle
      of a THP page.  This can be reproduced with default config since 3.11
      kernels.  A reproducer can be found in the kernel's selftest directory
      for networking by running ./psock_tpacket.
      
      The problem is that an order=2 compound page (allocated by
      alloc_one_pg_vec_page() is part of the munlocked VM_MIXEDMAP vma (mapped
      by packet_mmap()) and mistaken for a THP page and assumed to be order=9.
      
      The checks for THP in munlock came with commit ff6a6da6 ("mm:
      accelerate munlock() treatment of THP pages"), i.e.  since 3.9, but did
      not trigger a bug.  It just makes munlock_vma_pages_range() skip such
      compound pages until the next 512-pages-aligned page, when it encounters
      a head page.  This is however not a problem for vma's where mlocking has
      no effect anyway, but it can distort the accounting.
      
      Since commit 7225522b ("mm: munlock: batch non-THP page isolation
      and munlock+putback using pagevec") this can trigger a VM_BUG_ON in
      PageTransHuge() check.
      
      This patch fixes the issue by adding VM_MIXEDMAP flag to VM_SPECIAL, a
      list of flags that make vma's non-mlockable and non-mergeable.  The
      reasoning is that VM_MIXEDMAP vma's are similar to VM_PFNMAP, which is
      already on the VM_SPECIAL list, and both are intended for non-LRU pages
      where mlocking makes no sense anyway.  Related Lkml discussion can be
      found in [2].
      
       [1] tools/testing/selftests/net/psock_tpacket
       [2] https://lkml.org/lkml/2014/1/10/427Signed-off-by: NVlastimil Babka <vbabka@suse.cz>
      Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
      Reported-by: NDaniel Borkmann <dborkman@redhat.com>
      Tested-by: NDaniel Borkmann <dborkman@redhat.com>
      Cc: Thomas Hellstrom <thellstrom@vmware.com>
      Cc: John David Anglin <dave.anglin@bell.net>
      Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
      Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
      Cc: Carsten Otte <cotte@de.ibm.com>
      Cc: Jared Hulbert <jaredeh@gmail.com>
      Tested-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
      Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Acked-by: NRik van Riel <riel@redhat.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: <stable@vger.kernel.org> [3.11.x+]
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9050d7eb
    • D
      mm: close PageTail race · 668f9abb
      David Rientjes 提交于
      Commit bf6bddf1 ("mm: introduce compaction and migration for
      ballooned pages") introduces page_count(page) into memory compaction
      which dereferences page->first_page if PageTail(page).
      
      This results in a very rare NULL pointer dereference on the
      aforementioned page_count(page).  Indeed, anything that does
      compound_head(), including page_count() is susceptible to racing with
      prep_compound_page() and seeing a NULL or dangling page->first_page
      pointer.
      
      This patch uses Andrea's implementation of compound_trans_head() that
      deals with such a race and makes it the default compound_head()
      implementation.  This includes a read memory barrier that ensures that
      if PageTail(head) is true that we return a head page that is neither
      NULL nor dangling.  The patch then adds a store memory barrier to
      prep_compound_page() to ensure page->first_page is set.
      
      This is the safest way to ensure we see the head page that we are
      expecting, PageTail(page) is already in the unlikely() path and the
      memory barriers are unfortunately required.
      
      Hugetlbfs is the exception, we don't enforce a store memory barrier
      during init since no race is possible.
      Signed-off-by: NDavid Rientjes <rientjes@google.com>
      Cc: Holger Kiehl <Holger.Kiehl@dwd.de>
      Cc: Christoph Lameter <cl@linux.com>
      Cc: Rafael Aquini <aquini@redhat.com>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      668f9abb
    • S
      tracing: Do not add event files for modules that fail tracepoints · 45ab2813
      Steven Rostedt (Red Hat) 提交于
      If a module fails to add its tracepoints due to module tainting, do not
      create the module event infrastructure in the debugfs directory. As the events
      will not work and worse yet, they will silently fail, making the user wonder
      why the events they enable do not display anything.
      
      Having a warning on module load and the events not visible to the users
      will make the cause of the problem much clearer.
      
      Link: http://lkml.kernel.org/r/20140227154923.265882695@goodmis.org
      
      Fixes: 6d723736 "tracing/events: add support for modules to TRACE_EVENT"
      Acked-by: NMathieu Desnoyers <mathieu.desnoyers@efficios.com>
      Cc: stable@vger.kernel.org # 2.6.31+
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      45ab2813
  8. 02 3月, 2014 1 次提交
  9. 01 3月, 2014 1 次提交
  10. 26 2月, 2014 1 次提交
    • D
      ipc,mqueue: remove limits for the amount of system-wide queues · f3713fd9
      Davidlohr Bueso 提交于
      Commit 93e6f119 ("ipc/mqueue: cleanup definition names and
      locations") added global hardcoded limits to the amount of message
      queues that can be created.  While these limits are per-namespace,
      reality is that it ends up breaking userspace applications.
      Historically users have, at least in theory, been able to create up to
      INT_MAX queues, and limiting it to just 1024 is way too low and dramatic
      for some workloads and use cases.  For instance, Madars reports:
      
       "This update imposes bad limits on our multi-process application.  As
        our app uses approaches that each process opens its own set of queues
        (usually something about 3-5 queues per process).  In some scenarios
        we might run up to 3000 processes or more (which of-course for linux
        is not a problem).  Thus we might need up to 9000 queues or more.  All
        processes run under one user."
      
      Other affected users can be found in launchpad bug #1155695:
        https://bugs.launchpad.net/ubuntu/+source/manpages/+bug/1155695
      
      Instead of increasing this limit, revert it entirely and fallback to the
      original way of dealing queue limits -- where once a user's resource
      limit is reached, and all memory is used, new queues cannot be created.
      Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
      Reported-by: NMadars Vitolins <m@silodev.com>
      Acked-by: NDoug Ledford <dledford@redhat.com>
      Cc: Manfred Spraul <manfred@colorfullife.com>
      Cc: <stable@vger.kernel.org>	[3.5+]
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f3713fd9
  11. 25 2月, 2014 2 次提交
    • L
      sysfs: fix namespace refcnt leak · fed95bab
      Li Zefan 提交于
      As mount() and kill_sb() is not a one-to-one match, we shoudn't get
      ns refcnt unconditionally in sysfs_mount(), and instead we should
      get the refcnt only when kernfs_mount() allocated a new superblock.
      
      v2:
      - Changed the name of the new argument, suggested by Tejun.
      - Made the argument optional, suggested by Tejun.
      
      v3:
      - Make the new argument as second-to-last arg, suggested by Tejun.
      Signed-off-by: NLi Zefan <lizefan@huawei.com>
      Acked-by: NTejun Heo <tj@kernel.org>
       ---
       fs/kernfs/mount.c      | 8 +++++++-
       fs/sysfs/mount.c       | 5 +++--
       include/linux/kernfs.h | 9 +++++----
       3 files changed, 15 insertions(+), 7 deletions(-)
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      fed95bab
    • J
      fsnotify: Allocate overflow events with proper type · ff57cd58
      Jan Kara 提交于
      Commit 7053aee2 "fsnotify: do not share events between notification
      groups" used overflow event statically allocated in a group with the
      size of the generic notification event. This causes problems because
      some code looks at type specific parts of event structure and gets
      confused by a random data it sees there and causes crashes.
      
      Fix the problem by allocating overflow event with type corresponding to
      the group type so code cannot get confused.
      Signed-off-by: NJan Kara <jack@suse.cz>
      ff57cd58
  12. 22 2月, 2014 4 次提交
  13. 20 2月, 2014 1 次提交
  14. 19 2月, 2014 3 次提交
  15. 18 2月, 2014 2 次提交
  16. 17 2月, 2014 3 次提交
  17. 14 2月, 2014 5 次提交
    • L
      workqueue: add args to workqueue lockdep name · fada94ee
      Li Zhong 提交于
      Tommi noticed a 'funny' lock class name: "%s#5" from a lock acquired in
      process_one_work().
      
      Maybe #fmt plus #args could be used as the lock_name to give some more
      information for some fmt string like the above.
      
      __builtin_constant_p() check is removed (as there seems no good way to
      check all the variables in args list). However, by removing the check,
      it only adds two additional "s for those constants.
      
      Some lockdep name examples printed out after the change:
      
      lockdep name                    wq->name
      
      "events_long"                   events_long
      "%s"("khelper")                 khelper
      "xfs-data/%s"mp->m_fsname       xfs-data/dm-3
      Signed-off-by: NLi Zhong <zhong@linux.vnet.ibm.com>
      Signed-off-by: NTejun Heo <tj@kernel.org>
      fada94ee
    • R
      mlx5: Add include of <linux/slab.h> because of kzalloc()/kfree() use · 6ecde51d
      Roland Dreier 提交于
      On some architectures (for example, arm), we don't end up indirectly
      pulling in the declaration of kzalloc() and kfree(), and so building
      anything that includes <linux/mlx5/driver.h> breaks.  Fix this by adding
      an explicit include to get the declaration.
      Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
      Signed-off-by: NRoland Dreier <roland@purestorage.com>
      6ecde51d
    • F
      net: ip, ipv6: handle gso skbs in forwarding path · fe6cc55f
      Florian Westphal 提交于
      Marcelo Ricardo Leitner reported problems when the forwarding link path
      has a lower mtu than the incoming one if the inbound interface supports GRO.
      
      Given:
      Host <mtu1500> R1 <mtu1200> R2
      
      Host sends tcp stream which is routed via R1 and R2.  R1 performs GRO.
      
      In this case, the kernel will fail to send ICMP fragmentation needed
      messages (or pkt too big for ipv6), as GSO packets currently bypass dstmtu
      checks in forward path. Instead, Linux tries to send out packets exceeding
      the mtu.
      
      When locking route MTU on Host (i.e., no ipv4 DF bit set), R1 does
      not fragment the packets when forwarding, and again tries to send out
      packets exceeding R1-R2 link mtu.
      
      This alters the forwarding dstmtu checks to take the individual gso
      segment lengths into account.
      
      For ipv6, we send out pkt too big error for gso if the individual
      segments are too big.
      
      For ipv4, we either send icmp fragmentation needed, or, if the DF bit
      is not set, perform software segmentation and let the output path
      create fragments when the packet is leaving the machine.
      It is not 100% correct as the error message will contain the headers of
      the GRO skb instead of the original/segmented one, but it seems to
      work fine in my (limited) tests.
      
      Eric Dumazet suggested to simply shrink mss via ->gso_size to avoid
      sofware segmentation.
      
      However it turns out that skb_segment() assumes skb nr_frags is related
      to mss size so we would BUG there.  I don't want to mess with it considering
      Herbert and Eric disagree on what the correct behavior should be.
      
      Hannes Frederic Sowa notes that when we would shrink gso_size
      skb_segment would then also need to deal with the case where
      SKB_MAX_FRAGS would be exceeded.
      
      This uses sofware segmentation in the forward path when we hit ipv4
      non-DF packets and the outgoing link mtu is too small.  Its not perfect,
      but given the lack of bug reports wrt. GRO fwd being broken this is a
      rare case anyway.  Also its not like this could not be improved later
      once the dust settles.
      Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
      Reported-by: NMarcelo Ricardo Leitner <mleitner@redhat.com>
      Signed-off-by: NFlorian Westphal <fw@strlen.de>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fe6cc55f
    • F
      net: core: introduce netif_skb_dev_features · d2069403
      Florian Westphal 提交于
      Will be used by upcoming ipv4 forward path change that needs to
      determine feature mask using skb->dst->dev instead of skb->dev.
      Signed-off-by: NFlorian Westphal <fw@strlen.de>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      d2069403
    • A
      PCI/MSI: Add pci_enable_msi_exact() and pci_enable_msix_exact() · 3ce4e860
      Alexander Gordeev 提交于
      The new functions are special cases for pci_enable_msi_range() and
      pci_enable_msix_range() when a particular number of MSI or MSI-X
      is needed.
      
      By contrast with pci_enable_msi_range() and pci_enable_msix_range()
      functions, pci_enable_msi_exact() and pci_enable_msix_exact()
      return zero in case of success, which indicates MSI or MSI-X
      interrupts have been successfully allocated.
      Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
      Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
      3ce4e860
  18. 13 2月, 2014 2 次提交
  19. 11 2月, 2014 2 次提交
    • K
      block: Fix cloning of discard/write same bios · 8423ae3d
      Kent Overstreet 提交于
      Immutable biovecs changed the way bio segments are treated in such a way that
      bio_for_each_segment() cannot now do what we want for discard/write same bios,
      since bi_size means something completely different for them.
      
      Fortunately discard and write same bios never have more than a single biovec, so
      bio_for_each_segment() is unnecessary and not terribly meaningful for them, but
      we still have to special case them in a few places.
      Signed-off-by: NKent Overstreet <kmo@daterainc.com>
      Tested-by: NRichard W.M. Jones <rjones@redhat.com>
      Signed-off-by: NJens Axboe <axboe@fb.com>
      8423ae3d
    • L
      cgroup: protect modifications to cgroup_idr with cgroup_mutex · 0ab02ca8
      Li Zefan 提交于
      Setup cgroupfs like this:
        # mount -t cgroup -o cpuacct xxx /cgroup
        # mkdir /cgroup/sub1
        # mkdir /cgroup/sub2
      
      Then run these two commands:
        # for ((; ;)) { mkdir /cgroup/sub1/tmp && rmdir /mnt/sub1/tmp; } &
        # for ((; ;)) { mkdir /cgroup/sub2/tmp && rmdir /mnt/sub2/tmp; } &
      
      After seconds you may see this warning:
      
      ------------[ cut here ]------------
      WARNING: CPU: 1 PID: 25243 at lib/idr.c:527 sub_remove+0x87/0x1b0()
      idr_remove called for id=6 which is not allocated.
      ...
      Call Trace:
       [<ffffffff8156063c>] dump_stack+0x7a/0x96
       [<ffffffff810591ac>] warn_slowpath_common+0x8c/0xc0
       [<ffffffff81059296>] warn_slowpath_fmt+0x46/0x50
       [<ffffffff81300aa7>] sub_remove+0x87/0x1b0
       [<ffffffff810f3f02>] ? css_killed_work_fn+0x32/0x1b0
       [<ffffffff81300bf5>] idr_remove+0x25/0xd0
       [<ffffffff810f2bab>] cgroup_destroy_css_killed+0x5b/0xc0
       [<ffffffff810f4000>] css_killed_work_fn+0x130/0x1b0
       [<ffffffff8107cdbc>] process_one_work+0x26c/0x550
       [<ffffffff8107eefe>] worker_thread+0x12e/0x3b0
       [<ffffffff81085f96>] kthread+0xe6/0xf0
       [<ffffffff81570bac>] ret_from_fork+0x7c/0xb0
      ---[ end trace 2d1577ec10cf80d0 ]---
      
      It's because allocating/removing cgroup ID is not properly synchronized.
      
      The bug was introduced when we converted cgroup_ida to cgroup_idr.
      While synchronization is already done inside ida_simple_{get,remove}(),
      users are responsible for concurrent calls to idr_{alloc,remove}().
      
      tj: Refreshed on top of b58c8998 ("cgroup: fix error return from
      cgroup_create()").
      
      Fixes: 4e96ee8e ("cgroup: convert cgroup_ida to cgroup_idr")
      Cc: <stable@vger.kernel.org> #3.12+
      Reported-by: NMichal Hocko <mhocko@suse.cz>
      Signed-off-by: NLi Zefan <lizefan@huawei.com>
      Signed-off-by: NTejun Heo <tj@kernel.org>
      0ab02ca8