mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.

The change is generated using coccinelle with the following rule:

// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .

@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Reviewed-by: Laurent Dufour <ldufour@linux.ibm.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ying Han <yinghan@google.com>
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 1965e26..4930a92 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -405,10 +405,10 @@ void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
 {
 	struct vm_area_struct *vma;
 
-	down_write(&mm->mmap_sem);
+	mmap_write_lock(mm);
 	for (vma = mm->mmap; vma; vma = vma->vm_next)
 		mpol_rebind_policy(vma->vm_policy, new);
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 }
 
 static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
@@ -932,7 +932,7 @@ static int lookup_node(struct mm_struct *mm, unsigned long addr)
 		put_page(p);
 	}
 	if (locked)
-		up_read(&mm->mmap_sem);
+		mmap_read_unlock(mm);
 	return err;
 }
 
@@ -965,10 +965,10 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask,
 		 * vma/shared policy at addr is NULL.  We
 		 * want to return MPOL_DEFAULT in this case.
 		 */
-		down_read(&mm->mmap_sem);
+		mmap_read_lock(mm);
 		vma = find_vma_intersection(mm, addr, addr+1);
 		if (!vma) {
-			up_read(&mm->mmap_sem);
+			mmap_read_unlock(mm);
 			return -EFAULT;
 		}
 		if (vma->vm_ops && vma->vm_ops->get_policy)
@@ -1027,7 +1027,7 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask,
  out:
 	mpol_cond_put(pol);
 	if (vma)
-		up_read(&mm->mmap_sem);
+		mmap_read_unlock(mm);
 	if (pol_refcount)
 		mpol_put(pol_refcount);
 	return err;
@@ -1136,7 +1136,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
 	if (err)
 		return err;
 
-	down_read(&mm->mmap_sem);
+	mmap_read_lock(mm);
 
 	/*
 	 * Find a 'source' bit set in 'tmp' whose corresponding 'dest'
@@ -1217,7 +1217,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
 		if (err < 0)
 			break;
 	}
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 	if (err < 0)
 		return err;
 	return busy;
@@ -1340,12 +1340,12 @@ static long do_mbind(unsigned long start, unsigned long len,
 	{
 		NODEMASK_SCRATCH(scratch);
 		if (scratch) {
-			down_write(&mm->mmap_sem);
+			mmap_write_lock(mm);
 			task_lock(current);
 			err = mpol_set_nodemask(new, nmask, scratch);
 			task_unlock(current);
 			if (err)
-				up_write(&mm->mmap_sem);
+				mmap_write_unlock(mm);
 		} else
 			err = -ENOMEM;
 		NODEMASK_SCRATCH_FREE(scratch);
@@ -1382,7 +1382,7 @@ static long do_mbind(unsigned long start, unsigned long len,
 			putback_movable_pages(&pagelist);
 	}
 
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 mpol_out:
 	mpol_put(new);
 	return err;