Merge branch 'akpm' (patches from Andrew)

Merge updates from Andrew Morton:

 - a few hot fixes

 - ocfs2 updates

 - almost all of -mm (slab-generic, slab, slub, kmemleak, kasan,
   cleanups, debug, pagecache, memcg, gup, pagemap, memory-hotplug,
   sparsemem, vmalloc, initialization, z3fold, compaction, mempolicy,
   oom-kill, hugetlb, migration, thp, mmap, madvise, shmem, zswap,
   zsmalloc)

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (132 commits)
  mm/zsmalloc.c: fix a -Wunused-function warning
  zswap: do not map same object twice
  zswap: use movable memory if zpool support allocate movable memory
  zpool: add malloc_support_movable to zpool_driver
  shmem: fix obsolete comment in shmem_getpage_gfp()
  mm/madvise: reduce code duplication in error handling paths
  mm: mmap: increase sockets maximum memory size pgoff for 32bits
  mm/mmap.c: refine find_vma_prev() with rb_last()
  riscv: make mmap allocation top-down by default
  mips: use generic mmap top-down layout and brk randomization
  mips: replace arch specific way to determine 32bit task with generic version
  mips: adjust brk randomization offset to fit generic version
  mips: use STACK_TOP when computing mmap base address
  mips: properly account for stack randomization and stack guard gap
  arm: use generic mmap top-down layout and brk randomization
  arm: use STACK_TOP when computing mmap base address
  arm: properly account for stack randomization and stack guard gap
  arm64, mm: make randomization selected by generic topdown mmap layout
  arm64, mm: move generic mmap layout functions to mm
  arm64: consider stack randomization for mmap base only when necessary
  ...

1 files changed, 8 insertions, 0 deletions

diff --git a/fs/open.c b/fs/open.c
index a59abe3c669a..c60cd22cc052 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -818,6 +818,14 @@ static int do_dentry_open(struct file *f,
 		if (!f->f_mapping->a_ops || !f->f_mapping->a_ops->direct_IO)
 			return -EINVAL;
 	}
+
+	/*
+	 * XXX: Huge page cache doesn't support writing yet. Drop all page
+	 * cache for this file before processing writes.
+	 */
+	if ((f->f_mode & FMODE_WRITE) && filemap_nr_thps(inode->i_mapping))
+		truncate_pagecache(inode, 0);
+
 	return 0;
 
 cleanup_all: