mmap locking API: convert mmap_sem API comments

Convert comments that reference old mmap_sem APIs to reference
corresponding new mmap locking APIs instead.

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: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
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/20200520052908.204642-12-walken@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

10 files changed, 21 insertions, 21 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index b1442c4b36b7..950cf12a10fc 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1373,7 +1373,7 @@ EXPORT_SYMBOL_GPL(__lock_page_killable);
  * Return values:
  * 1 - page is locked; mmap_sem is still held.
  * 0 - page is not locked.
- *     mmap_sem has been released (up_read()), unless flags had both
+ *     mmap_lock has been released (mmap_read_unlock(), unless flags had both
  *     FAULT_FLAG_ALLOW_RETRY and FAULT_FLAG_RETRY_NOWAIT set, in
  *     which case mmap_sem is still held.
  *
diff --git a/mm/gup.c b/mm/gup.c
index 762fb9f733b2..bbb8851f4656 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1993,19 +1993,19 @@ EXPORT_SYMBOL(get_user_pages);
 /**
  * get_user_pages_locked() is suitable to replace the form:
  *
- *      down_read(&mm->mmap_sem);
+ *      mmap_read_lock(mm);
  *      do_something()
  *      get_user_pages(tsk, mm, ..., pages, NULL);
- *      up_read(&mm->mmap_sem);
+ *      mmap_read_unlock(mm);
  *
  *  to:
  *
  *      int locked = 1;
- *      down_read(&mm->mmap_sem);
+ *      mmap_read_lock(mm);
  *      do_something()
  *      get_user_pages_locked(tsk, mm, ..., pages, &locked);
  *      if (locked)
- *          up_read(&mm->mmap_sem);
+ *          mmap_read_unlock(mm);
  *
  * @start:      starting user address
  * @nr_pages:   number of pages from start to pin
@@ -2050,9 +2050,9 @@ EXPORT_SYMBOL(get_user_pages_locked);
 /*
  * get_user_pages_unlocked() is suitable to replace the form:
  *
- *      down_read(&mm->mmap_sem);
+ *      mmap_read_lock(mm);
  *      get_user_pages(tsk, mm, ..., pages, NULL);
- *      up_read(&mm->mmap_sem);
+ *      mmap_read_unlock(mm);
  *
  *  with:
  *
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index d9b2e0e0580a..de201f0b5a4a 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1833,9 +1833,9 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd,
 		goto unlock;
 
 	/*
-	 * In case prot_numa, we are under down_read(mmap_sem). It's critical
+	 * In case prot_numa, we are under mmap_read_lock(mm). It's critical
 	 * to not clear pmd intermittently to avoid race with MADV_DONTNEED
-	 * which is also under down_read(mmap_sem):
+	 * which is also under mmap_read_lock(mm):
 	 *
 	 *	CPU0:				CPU1:
 	 *				change_huge_pmd(prot_numa=1)
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 19f3401e568a..2c318ad1db20 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1543,7 +1543,7 @@ static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff)
 		/*
 		 * Check vma->anon_vma to exclude MAP_PRIVATE mappings that
 		 * got written to. These VMAs are likely not worth investing
-		 * down_write(mmap_sem) as PMD-mapping is likely to be split
+		 * mmap_write_lock(mm) as PMD-mapping is likely to be split
 		 * later.
 		 *
 		 * Not that vma->anon_vma check is racy: it can be set up after
diff --git a/mm/ksm.c b/mm/ksm.c
index 098b580e7d76..3efe7f28cc3f 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -2362,7 +2362,7 @@ next_mm:
 	} else {
 		mmap_read_unlock(mm);
 		/*
-		 * up_read(&mm->mmap_sem) first because after
+		 * mmap_read_unlock(mm) first because after
 		 * spin_unlock(&ksm_mmlist_lock) run, the "mm" may
 		 * already have been freed under us by __ksm_exit()
 		 * because the "mm_slot" is still hashed and
diff --git a/mm/memory.c b/mm/memory.c
index 823982a8f0b0..4e2e17bb1281 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3323,10 +3323,10 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 	 * pte_offset_map() on pmds where a huge pmd might be created
 	 * from a different thread.
 	 *
-	 * pte_alloc_map() is safe to use under down_write(mmap_sem) or when
+	 * pte_alloc_map() is safe to use under mmap_write_lock(mm) or when
 	 * parallel threads are excluded by other means.
 	 *
-	 * Here we only have down_read(mmap_sem).
+	 * Here we only have mmap_read_lock(mm).
 	 */
 	if (pte_alloc(vma->vm_mm, vmf->pmd))
 		return VM_FAULT_OOM;
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 4930a9254068..a38cd4cc3206 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2185,7 +2185,7 @@ static struct page *alloc_page_interleave(gfp_t gfp, unsigned order,
  *
  * 	This function allocates a page from the kernel page pool and applies
  *	a NUMA policy associated with the VMA or the current process.
- *	When VMA is not NULL caller must hold down_read on the mmap_sem of the
+ *	When VMA is not NULL caller must read-lock the mmap_lock of the
  *	mm_struct of the VMA to prevent it from going away. Should be used for
  *	all allocations for pages that will be mapped into user space. Returns
  *	NULL when no page can be allocated.
diff --git a/mm/migrate.c b/mm/migrate.c
index 0aa8f83789c5..f69b09e0829c 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -2772,10 +2772,10 @@ static void migrate_vma_insert_page(struct migrate_vma *migrate,
 	 * pte_offset_map() on pmds where a huge pmd might be created
 	 * from a different thread.
 	 *
-	 * pte_alloc_map() is safe to use under down_write(mmap_sem) or when
+	 * pte_alloc_map() is safe to use under mmap_write_lock(mm) or when
 	 * parallel threads are excluded by other means.
 	 *
-	 * Here we only have down_read(mmap_sem).
+	 * Here we only have mmap_read_lock(mm).
 	 */
 	if (pte_alloc(mm, pmdp))
 		goto abort;
diff --git a/mm/mmap.c b/mm/mmap.c
index a28778da76a3..79005049fbfc 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1361,7 +1361,7 @@ static inline bool file_mmap_ok(struct file *file, struct inode *inode,
 }
 
 /*
- * The caller must hold down_write(&current->mm->mmap_sem).
+ * The caller must write-lock current->mm->mmap_lock.
  */
 unsigned long do_mmap(struct file *file, unsigned long addr,
 			unsigned long len, unsigned long prot,
diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index af3de7a92a9f..3b5d78dfebe9 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -577,8 +577,8 @@ static bool oom_reap_task_mm(struct task_struct *tsk, struct mm_struct *mm)
 	/*
 	 * MMF_OOM_SKIP is set by exit_mmap when the OOM reaper can't
 	 * work on the mm anymore. The check for MMF_OOM_SKIP must run
-	 * under mmap_sem for reading because it serializes against the
-	 * down_write();up_write() cycle in exit_mmap().
+	 * under mmap_lock for reading because it serializes against the
+	 * mmap_write_lock();mmap_write_unlock() cycle in exit_mmap().
 	 */
 	if (test_bit(MMF_OOM_SKIP, &mm->flags)) {
 		trace_skip_task_reaping(tsk->pid);
@@ -611,7 +611,7 @@ static void oom_reap_task(struct task_struct *tsk)
 	int attempts = 0;
 	struct mm_struct *mm = tsk->signal->oom_mm;
 
-	/* Retry the down_read_trylock(mmap_sem) a few times */
+	/* Retry the mmap_read_trylock(mm) a few times */
 	while (attempts++ < MAX_OOM_REAP_RETRIES && !oom_reap_task_mm(tsk, mm))
 		schedule_timeout_idle(HZ/10);
 
@@ -629,7 +629,7 @@ done:
 
 	/*
 	 * Hide this mm from OOM killer because it has been either reaped or
-	 * somebody can't call up_write(mmap_sem).
+	 * somebody can't call mmap_write_unlock(mm).
 	 */
 	set_bit(MMF_OOM_SKIP, &mm->flags);