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>

fs/xfs/xfs_file.c

@@ -1173,7 +1173,7 @@ xfs_file_llseek(
  * Locking for serialisation of IO during page faults. This results in a lock
  * ordering of:
  *
- * mmap_sem (MM)
+ * mmap_lock (MM)
  *   sb_start_pagefault(vfs, freeze)
  *     i_mmaplock (XFS - truncate serialisation)
  *       page_lock (MM)

fs/xfs/xfs_inode.c

@@ -145,17 +145,17 @@ xfs_ilock_attr_map_shared(
  *
  * i_rwsem -> i_mmap_lock -> page_lock -> i_ilock
  *
- * mmap_sem locking order:
+ * mmap_lock locking order:
  *
- * i_rwsem -> page lock -> mmap_sem
- * mmap_sem -> i_mmap_lock -> page_lock
+ * i_rwsem -> page lock -> mmap_lock
+ * mmap_lock -> i_mmap_lock -> page_lock
  *
- * The difference in mmap_sem locking order mean that we cannot hold the
+ * The difference in mmap_lock locking order mean that we cannot hold the
  * i_mmap_lock over syscall based read(2)/write(2) based IO. These IO paths can
- * fault in pages during copy in/out (for buffered IO) or require the mmap_sem
+ * fault in pages during copy in/out (for buffered IO) or require the mmap_lock
  * in get_user_pages() to map the user pages into the kernel address space for
  * direct IO. Similarly the i_rwsem cannot be taken inside a page fault because
- * page faults already hold the mmap_sem.
+ * page faults already hold the mmap_lock.
  *
  * Hence to serialise fully against both syscall and mmap based IO, we need to
  * take both the i_rwsem and the i_mmap_lock. These locks should *only* be both
@@ -1630,7 +1630,7 @@ xfs_release(
 			return 0;
 		/*
 		 * If we can't get the iolock just skip truncating the blocks
-		 * past EOF because we could deadlock with the mmap_sem
+		 * past EOF because we could deadlock with the mmap_lock
 		 * otherwise. We'll get another chance to drop them once the
 		 * last reference to the inode is dropped, so we'll never leak
 		 * blocks permanently.

fs/xfs/xfs_iops.c

@@ -28,11 +28,11 @@
 #include <linux/fiemap.h>
 
 /*
- * Directories have different lock order w.r.t. mmap_sem compared to regular
+ * Directories have different lock order w.r.t. mmap_lock compared to regular
  * files. This is due to readdir potentially triggering page faults on a user
  * buffer inside filldir(), and this happens with the ilock on the directory
  * held. For regular files, the lock order is the other way around - the
- * mmap_sem is taken during the page fault, and then we lock the ilock to do
+ * mmap_lock is taken during the page fault, and then we lock the ilock to do
  * block mapping. Hence we need a different class for the directory ilock so
  * that lockdep can tell them apart.
  */