From: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Date: Tue, 26 Jul 2016 22:25:48 +0000 (-0700)
Subject: thp: run vma_adjust_trans_huge() outside i_mmap_rwsem
X-Git-Tag: v4.1.12-117.0_27200813_3~137
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=4d7b345aa33f47579be4149efb0137168c7b9414;p=users%2Fjedix%2Flinux-maple.git

thp: run vma_adjust_trans_huge() outside i_mmap_rwsem

vma_addjust_trans_huge() splits pmd if it's crossing VMA boundary.
During split we munlock the huge page which requires rmap walk.  rmap
wants to take the lock on its own.

Let's move vma_adjust_trans_huge() outside i_mmap_rwsem to fix this.

Link: http://lkml.kernel.org/r/1466021202-61880-19-git-send-email-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Conflicts:
	mm/mmap.c

Orabug: 27026170

(cherry picked from commit 37f9f5595c26d3cb644ca2fab83dc4c4db119f9f)
Signed-off-by: Aruna Ramakrishna <aruna.ramakrishna@oracle.com>
Reviewed-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Dhaval Giani <dhaval.giani@oracle.com>
---

diff --git a/mm/mmap.c b/mm/mmap.c
index 4c07adafa01b..839d816bd5c3 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -805,6 +805,9 @@ int vma_adjust(struct vm_area_struct *vma, unsigned long start,
 		}
 	}
 
+again:
+	vma_adjust_trans_huge(vma, start, end, adjust_next);
+
 	if (file) {
 		mapping = file->f_mapping;
 		root = &mapping->i_mmap;
@@ -824,8 +827,6 @@ int vma_adjust(struct vm_area_struct *vma, unsigned long start,
 			__vma_link_file(insert);
 		}
 	}
-again:
-	vma_adjust_trans_huge(vma, start, end, adjust_next);
 
 	anon_vma = vma->anon_vma;
 	if (!anon_vma && adjust_next)