4.14-stable patches

added patches:
	mm-memcg-fix-reclaim-deadlock-with-writeback.patch

diff --git a/queue-4.14/mm-memcg-fix-reclaim-deadlock-with-writeback.patch b/queue-4.14/mm-memcg-fix-reclaim-deadlock-with-writeback.patch
new file mode 100644 (file)
index 0000000..4377adb
--- /dev/null
+++ b/queue-4.14/mm-memcg-fix-reclaim-deadlock-with-writeback.patch
@@ -0,0 +1,147 @@
+From 63f3655f950186752236bb88a22f8252c11ce394 Mon Sep 17 00:00:00 2001
+From: Michal Hocko <mhocko@suse.com>
+Date: Tue, 8 Jan 2019 15:23:07 -0800
+Subject: mm, memcg: fix reclaim deadlock with writeback
+
+From: Michal Hocko <mhocko@suse.com>
+
+commit 63f3655f950186752236bb88a22f8252c11ce394 upstream.
+
+Liu Bo has experienced a deadlock between memcg (legacy) reclaim and the
+ext4 writeback
+
+  task1:
+    wait_on_page_bit+0x82/0xa0
+    shrink_page_list+0x907/0x960
+    shrink_inactive_list+0x2c7/0x680
+    shrink_node_memcg+0x404/0x830
+    shrink_node+0xd8/0x300
+    do_try_to_free_pages+0x10d/0x330
+    try_to_free_mem_cgroup_pages+0xd5/0x1b0
+    try_charge+0x14d/0x720
+    memcg_kmem_charge_memcg+0x3c/0xa0
+    memcg_kmem_charge+0x7e/0xd0
+    __alloc_pages_nodemask+0x178/0x260
+    alloc_pages_current+0x95/0x140
+    pte_alloc_one+0x17/0x40
+    __pte_alloc+0x1e/0x110
+    alloc_set_pte+0x5fe/0xc20
+    do_fault+0x103/0x970
+    handle_mm_fault+0x61e/0xd10
+    __do_page_fault+0x252/0x4d0
+    do_page_fault+0x30/0x80
+    page_fault+0x28/0x30
+
+  task2:
+    __lock_page+0x86/0xa0
+    mpage_prepare_extent_to_map+0x2e7/0x310 [ext4]
+    ext4_writepages+0x479/0xd60
+    do_writepages+0x1e/0x30
+    __writeback_single_inode+0x45/0x320
+    writeback_sb_inodes+0x272/0x600
+    __writeback_inodes_wb+0x92/0xc0
+    wb_writeback+0x268/0x300
+    wb_workfn+0xb4/0x390
+    process_one_work+0x189/0x420
+    worker_thread+0x4e/0x4b0
+    kthread+0xe6/0x100
+    ret_from_fork+0x41/0x50
+
+He adds
+ "task1 is waiting for the PageWriteback bit of the page that task2 has
+  collected in mpd->io_submit->io_bio, and tasks2 is waiting for the
+  LOCKED bit the page which tasks1 has locked"
+
+More precisely task1 is handling a page fault and it has a page locked
+while it charges a new page table to a memcg.  That in turn hits a
+memory limit reclaim and the memcg reclaim for legacy controller is
+waiting on the writeback but that is never going to finish because the
+writeback itself is waiting for the page locked in the #PF path.  So
+this is essentially ABBA deadlock:
+
+                                        lock_page(A)
+                                        SetPageWriteback(A)
+                                        unlock_page(A)
+  lock_page(B)
+                                        lock_page(B)
+  pte_alloc_pne
+    shrink_page_list
+      wait_on_page_writeback(A)
+                                        SetPageWriteback(B)
+                                        unlock_page(B)
+
+                                        # flush A, B to clear the writeback
+
+This accumulating of more pages to flush is used by several filesystems
+to generate a more optimal IO patterns.
+
+Waiting for the writeback in legacy memcg controller is a workaround for
+pre-mature OOM killer invocations because there is no dirty IO
+throttling available for the controller.  There is no easy way around
+that unfortunately.  Therefore fix this specific issue by pre-allocating
+the page table outside of the page lock.  We have that handy
+infrastructure for that already so simply reuse the fault-around pattern
+which already does this.
+
+There are probably other hidden __GFP_ACCOUNT | GFP_KERNEL allocations
+from under a fs page locked but they should be really rare.  I am not
+aware of a better solution unfortunately.
+
+[akpm@linux-foundation.org: fix mm/memory.c:__do_fault()]
+[akpm@linux-foundation.org: coding-style fixes]
+[mhocko@kernel.org: enhance comment, per Johannes]
+  Link: http://lkml.kernel.org/r/20181214084948.GA5624@dhcp22.suse.cz
+Link: http://lkml.kernel.org/r/20181213092221.27270-1-mhocko@kernel.org
+Fixes: c3b94f44fcb0 ("memcg: further prevent OOM with too many dirty pages")
+Signed-off-by: Michal Hocko <mhocko@suse.com>
+Reported-by: Liu Bo <bo.liu@linux.alibaba.com>
+Debugged-by: Liu Bo <bo.liu@linux.alibaba.com>
+Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
+Acked-by: Johannes Weiner <hannes@cmpxchg.org>
+Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com>
+Cc: Jan Kara <jack@suse.cz>
+Cc: Dave Chinner <david@fromorbit.com>
+Cc: Theodore Ts'o <tytso@mit.edu>
+Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
+Cc: Shakeel Butt <shakeelb@google.com>
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ mm/memory.c |   23 +++++++++++++++++++++++
+ 1 file changed, 23 insertions(+)
+
+--- a/mm/memory.c
++++ b/mm/memory.c
+@@ -3191,6 +3191,29 @@ static int __do_fault(struct vm_fault *v
+       struct vm_area_struct *vma = vmf->vma;
+       int ret;
+ 
++      /*
++       * Preallocate pte before we take page_lock because this might lead to
++       * deadlocks for memcg reclaim which waits for pages under writeback:
++       *                              lock_page(A)
++       *                              SetPageWriteback(A)
++       *                              unlock_page(A)
++       * lock_page(B)
++       *                              lock_page(B)
++       * pte_alloc_pne
++       *   shrink_page_list
++       *     wait_on_page_writeback(A)
++       *                              SetPageWriteback(B)
++       *                              unlock_page(B)
++       *                              # flush A, B to clear the writeback
++       */
++      if (pmd_none(*vmf->pmd) && !vmf->prealloc_pte) {
++              vmf->prealloc_pte = pte_alloc_one(vmf->vma->vm_mm,
++                                                vmf->address);
++              if (!vmf->prealloc_pte)
++                      return VM_FAULT_OOM;
++              smp_wmb(); /* See comment in __pte_alloc() */
++      }
++
+       ret = vma->vm_ops->fault(vmf);
+       if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY |
+                           VM_FAULT_DONE_COW)))

diff --git a/queue-4.14/series b/queue-4.14/series
index 0cd93fd6ca095bf12f085d51055436f1c61c585e..7f0f9325126f774d915311d9a7b6b635b59c5538 100644 (file)
--- a/queue-4.14/series
+++ b/queue-4.14/series
@@ -12,3 +12,4 @@ usb-storage-add-quirk-for-smi-sm3350.patch
 usb-add-usb_quirk_delay_ctrl_msg-quirk-for-corsair-k70-rgb.patch
 slab-alien-caches-must-not-be-initialized-if-the-allocation-of-the-alien-cache-failed.patch
 mm-page_mapped-don-t-assume-compound-page-is-huge-or-thp.patch
+mm-memcg-fix-reclaim-deadlock-with-writeback.patch