[PATCHv3 18/29] thp: run vma_adjust_trans_huge() outside i_mmap_rwsem

[Kirill A. Shutemov]

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.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
 mm/mmap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index af6722385edf..2cb88eb252b8 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -677,6 +677,8 @@ again:			remove_next = 1 + (end > next->vm_end);
 		}
 	}
 
+	vma_adjust_trans_huge(vma, start, end, adjust_next);
+
 	if (file) {
 		mapping = file->f_mapping;
 		root = &mapping->i_mmap;
@@ -697,8 +699,6 @@ again:			remove_next = 1 + (end > next->vm_end);
 		}
 	}
 
-	vma_adjust_trans_huge(vma, start, end, adjust_next);
-
 	anon_vma = vma->anon_vma;
 	if (!anon_vma && adjust_next)
 		anon_vma = next->anon_vma;
-- 
2.7.0