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>

1 files changed, 17 insertions, 17 deletions

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 2c318ad1db20..b043c40a21d4 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -534,7 +534,7 @@ void __khugepaged_exit(struct mm_struct *mm)
 		 * under mmap sem read mode). Stop here (after we
 		 * return all pagetables will be destroyed) until
 		 * khugepaged has finished working on the pagetables
-		 * under the mmap_sem.
+		 * under the mmap_lock.
 		 */
 		mmap_write_lock(mm);
 		mmap_write_unlock(mm);
@@ -933,8 +933,8 @@ khugepaged_alloc_page(struct page **hpage, gfp_t gfp, int node)
 #endif
 
 /*
- * If mmap_sem temporarily dropped, revalidate vma
- * before taking mmap_sem.
+ * If mmap_lock temporarily dropped, revalidate vma
+ * before taking mmap_lock.
  * Return 0 if succeeds, otherwise return none-zero
  * value (scan code).
  */
@@ -966,7 +966,7 @@ static int hugepage_vma_revalidate(struct mm_struct *mm, unsigned long address,
  * Only done if khugepaged_scan_pmd believes it is worthwhile.
  *
  * Called and returns without pte mapped or spinlocks held,
- * but with mmap_sem held to protect against vma changes.
+ * but with mmap_lock held to protect against vma changes.
  */
 
 static bool __collapse_huge_page_swapin(struct mm_struct *mm,
@@ -993,7 +993,7 @@ static bool __collapse_huge_page_swapin(struct mm_struct *mm,
 		swapped_in++;
 		ret = do_swap_page(&vmf);
 
-		/* do_swap_page returns VM_FAULT_RETRY with released mmap_sem */
+		/* do_swap_page returns VM_FAULT_RETRY with released mmap_lock */
 		if (ret & VM_FAULT_RETRY) {
 			mmap_read_lock(mm);
 			if (hugepage_vma_revalidate(mm, address, &vmf.vma)) {
@@ -1047,9 +1047,9 @@ static void collapse_huge_page(struct mm_struct *mm,
 	gfp = alloc_hugepage_khugepaged_gfpmask() | __GFP_THISNODE;
 
 	/*
-	 * Before allocating the hugepage, release the mmap_sem read lock.
+	 * Before allocating the hugepage, release the mmap_lock read lock.
 	 * The allocation can take potentially a long time if it involves
-	 * sync compaction, and we do not need to hold the mmap_sem during
+	 * sync compaction, and we do not need to hold the mmap_lock during
 	 * that. We will recheck the vma after taking it again in write mode.
 	 */
 	mmap_read_unlock(mm);
@@ -1080,8 +1080,8 @@ static void collapse_huge_page(struct mm_struct *mm,
 	}
 
 	/*
-	 * __collapse_huge_page_swapin always returns with mmap_sem locked.
-	 * If it fails, we release mmap_sem and jump out_nolock.
+	 * __collapse_huge_page_swapin always returns with mmap_lock locked.
+	 * If it fails, we release mmap_lock and jump out_nolock.
 	 * Continuing to collapse causes inconsistency.
 	 */
 	if (unmapped && !__collapse_huge_page_swapin(mm, vma, address,
@@ -1345,7 +1345,7 @@ out_unmap:
 	pte_unmap_unlock(pte, ptl);
 	if (ret) {
 		node = khugepaged_find_target_node();
-		/* collapse_huge_page will return with the mmap_sem released */
+		/* collapse_huge_page will return with the mmap_lock released */
 		collapse_huge_page(mm, address, hpage, node,
 				referenced, unmapped);
 	}
@@ -1547,7 +1547,7 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff)
 		 * later.
 		 *
 		 * Not that vma->anon_vma check is racy: it can be set up after
-		 * the check but before we took mmap_sem by the fault path.
+		 * the check but before we took mmap_lock by the fault path.
 		 * But page lock would prevent establishing any new ptes of the
 		 * page, so we are safe.
 		 *
@@ -1567,10 +1567,10 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff)
 		if (!pmd)
 			continue;
 		/*
-		 * We need exclusive mmap_sem to retract page table.
+		 * We need exclusive mmap_lock to retract page table.
 		 *
 		 * We use trylock due to lock inversion: we need to acquire
-		 * mmap_sem while holding page lock. Fault path does it in
+		 * mmap_lock while holding page lock. Fault path does it in
 		 * reverse order. Trylock is a way to avoid deadlock.
 		 */
 		if (mmap_write_trylock(vma->vm_mm)) {
@@ -2058,7 +2058,7 @@ static unsigned int khugepaged_scan_mm_slot(unsigned int pages,
 	 */
 	vma = NULL;
 	if (unlikely(!mmap_read_trylock(mm)))
-		goto breakouterloop_mmap_sem;
+		goto breakouterloop_mmap_lock;
 	if (likely(!khugepaged_test_exit(mm)))
 		vma = find_vma(mm, khugepaged_scan.address);
 
@@ -2115,15 +2115,15 @@ skip:
 			khugepaged_scan.address += HPAGE_PMD_SIZE;
 			progress += HPAGE_PMD_NR;
 			if (ret)
-				/* we released mmap_sem so break loop */
-				goto breakouterloop_mmap_sem;
+				/* we released mmap_lock so break loop */
+				goto breakouterloop_mmap_lock;
 			if (progress >= pages)
 				goto breakouterloop;
 		}
 	}
 breakouterloop:
 	mmap_read_unlock(mm); /* exit_mmap will destroy ptes after this */
-breakouterloop_mmap_sem:
+breakouterloop_mmap_lock:
 
 	spin_lock(&khugepaged_mm_lock);
 	VM_BUG_ON(khugepaged_scan.mm_slot != mm_slot);