mmap locking API: convert mmap_sem comments

Convert comments that reference mmap_sem to reference mmap_lock instead.

[akpm@linux-foundation.org: fix up linux-next leftovers]
[akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil]
[akpm@linux-foundation.org: more linux-next fixups, per Michel]

Signed-off-by: Michel Lespinasse <walken@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
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: Laurent Dufour <ldufour@linux.ibm.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/20200520052908.204642-13-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/madvise.c b/mm/madvise.c
index d9b0f66..dd1d43c 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -40,7 +40,7 @@ struct madvise_walk_private {
 
 /*
  * Any behaviour which results in changes to the vma->vm_flags needs to
- * take mmap_sem for writing. Others, which simply traverse vmas, need
+ * take mmap_lock for writing. Others, which simply traverse vmas, need
  * to only take it for reading.
  */
 static int madvise_need_mmap_write(int behavior)
@@ -165,7 +165,7 @@ static long madvise_behavior(struct vm_area_struct *vma,
 
 success:
 	/*
-	 * vm_flags is protected by the mmap_sem held in write mode.
+	 * vm_flags is protected by the mmap_lock held in write mode.
 	 */
 	vma->vm_flags = new_flags;
 
@@ -285,9 +285,9 @@ static long madvise_willneed(struct vm_area_struct *vma,
 	 * Filesystem's fadvise may need to take various locks.  We need to
 	 * explicitly grab a reference because the vma (and hence the
 	 * vma's reference to the file) can go away as soon as we drop
-	 * mmap_sem.
+	 * mmap_lock.
 	 */
-	*prev = NULL;	/* tell sys_madvise we drop mmap_sem */
+	*prev = NULL;	/* tell sys_madvise we drop mmap_lock */
 	get_file(file);
 	mmap_read_unlock(current->mm);
 	offset = (loff_t)(start - vma->vm_start)
@@ -768,7 +768,7 @@ static long madvise_dontneed_free(struct vm_area_struct *vma,
 		return -EINVAL;
 
 	if (!userfaultfd_remove(vma, start, end)) {
-		*prev = NULL; /* mmap_sem has been dropped, prev is stale */
+		*prev = NULL; /* mmap_lock has been dropped, prev is stale */
 
 		mmap_read_lock(current->mm);
 		vma = find_vma(current->mm, start);
@@ -791,7 +791,7 @@ static long madvise_dontneed_free(struct vm_area_struct *vma,
 		if (end > vma->vm_end) {
 			/*
 			 * Don't fail if end > vma->vm_end. If the old
-			 * vma was splitted while the mmap_sem was
+			 * vma was splitted while the mmap_lock was
 			 * released the effect of the concurrent
 			 * operation may not cause madvise() to
 			 * have an undefined result. There may be an
@@ -826,7 +826,7 @@ static long madvise_remove(struct vm_area_struct *vma,
 	int error;
 	struct file *f;
 
-	*prev = NULL;	/* tell sys_madvise we drop mmap_sem */
+	*prev = NULL;	/* tell sys_madvise we drop mmap_lock */
 
 	if (vma->vm_flags & VM_LOCKED)
 		return -EINVAL;
@@ -847,11 +847,11 @@ static long madvise_remove(struct vm_area_struct *vma,
 	 * Filesystem's fallocate may need to take i_mutex.  We need to
 	 * explicitly grab a reference because the vma (and hence the
 	 * vma's reference to the file) can go away as soon as we drop
-	 * mmap_sem.
+	 * mmap_lock.
 	 */
 	get_file(f);
 	if (userfaultfd_remove(vma, start, end)) {
-		/* mmap_sem was not released by userfaultfd_remove() */
+		/* mmap_lock was not released by userfaultfd_remove() */
 		mmap_read_unlock(current->mm);
 	}
 	error = vfs_fallocate(f,
@@ -1153,7 +1153,7 @@ int do_madvise(unsigned long start, size_t len_in, int behavior)
 			goto out;
 		if (prev)
 			vma = prev->vm_next;
-		else	/* madvise_remove dropped mmap_sem */
+		else	/* madvise_remove dropped mmap_lock */
 			vma = find_vma(current->mm, start);
 	}
 out: