truncate: new helpers

Introduce new truncate helpers truncate_pagecache and inode_newsize_ok.
vmtruncate is also consolidated from mm/memory.c and mm/nommu.c and
into mm/truncate.c.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 2 deletions

diff --git a/mm/mremap.c b/mm/mremap.c
index 20a07dba6be0..97bff2547719 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -86,8 +86,8 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
         if (vma->vm_file) {
                 /*
                  * Subtle point from Rajesh Venkatasubramanian: before
-                 * moving file-based ptes, we must lock vmtruncate out,
-                 * since it might clean the dst vma before the src vma,
+                 * moving file-based ptes, we must lock truncate_pagecache
+                 * out, since it might clean the dst vma before the src vma,
                  * and we propagate stale pages into the dst afterward.
                  */
                 mapping = vma->vm_file->f_mapping;