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>

28 files changed, 165 insertions, 165 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index 950cf12a10fc..f0ae9a6308cb 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -76,16 +76,16 @@
  *  ->i_mutex
  *    ->i_mmap_rwsem		(truncate->unmap_mapping_range)
  *
- *  ->mmap_sem
+ *  ->mmap_lock
  *    ->i_mmap_rwsem
  *      ->page_table_lock or pte_lock	(various, mainly in memory.c)
  *        ->i_pages lock	(arch-dependent flush_dcache_mmap_lock)
  *
- *  ->mmap_sem
+ *  ->mmap_lock
  *    ->lock_page		(access_process_vm)
  *
  *  ->i_mutex			(generic_perform_write)
- *    ->mmap_sem		(fault_in_pages_readable->do_page_fault)
+ *    ->mmap_lock		(fault_in_pages_readable->do_page_fault)
  *
  *  bdi->wb.list_lock
  *    sb_lock			(fs/fs-writeback.c)
@@ -1371,21 +1371,21 @@ EXPORT_SYMBOL_GPL(__lock_page_killable);
 
 /*
  * Return values:
- * 1 - page is locked; mmap_sem is still held.
+ * 1 - page is locked; mmap_lock is still held.
  * 0 - page is not locked.
  *     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.
+ *     which case mmap_lock is still held.
  *
  * If neither ALLOW_RETRY nor KILLABLE are set, will always return 1
- * with the page locked and the mmap_sem unperturbed.
+ * with the page locked and the mmap_lock unperturbed.
  */
 int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
 			 unsigned int flags)
 {
 	if (fault_flag_allow_retry_first(flags)) {
 		/*
-		 * CAUTION! In this case, mmap_sem is not released
+		 * CAUTION! In this case, mmap_lock is not released
 		 * even though return 0.
 		 */
 		if (flags & FAULT_FLAG_RETRY_NOWAIT)
@@ -2313,14 +2313,14 @@ EXPORT_SYMBOL(generic_file_read_iter);
 #ifdef CONFIG_MMU
 #define MMAP_LOTSAMISS  (100)
 /*
- * lock_page_maybe_drop_mmap - lock the page, possibly dropping the mmap_sem
+ * lock_page_maybe_drop_mmap - lock the page, possibly dropping the mmap_lock
  * @vmf - the vm_fault for this fault.
  * @page - the page to lock.
  * @fpin - the pointer to the file we may pin (or is already pinned).
  *
- * This works similar to lock_page_or_retry in that it can drop the mmap_sem.
+ * This works similar to lock_page_or_retry in that it can drop the mmap_lock.
  * It differs in that it actually returns the page locked if it returns 1 and 0
- * if it couldn't lock the page.  If we did have to drop the mmap_sem then fpin
+ * if it couldn't lock the page.  If we did have to drop the mmap_lock then fpin
  * will point to the pinned file and needs to be fput()'ed at a later point.
  */
 static int lock_page_maybe_drop_mmap(struct vm_fault *vmf, struct page *page,
@@ -2331,7 +2331,7 @@ static int lock_page_maybe_drop_mmap(struct vm_fault *vmf, struct page *page,
 
 	/*
 	 * NOTE! This will make us return with VM_FAULT_RETRY, but with
-	 * the mmap_sem still held. That's how FAULT_FLAG_RETRY_NOWAIT
+	 * the mmap_lock still held. That's how FAULT_FLAG_RETRY_NOWAIT
 	 * is supposed to work. We have way too many special cases..
 	 */
 	if (vmf->flags & FAULT_FLAG_RETRY_NOWAIT)
@@ -2341,10 +2341,10 @@ static int lock_page_maybe_drop_mmap(struct vm_fault *vmf, struct page *page,
 	if (vmf->flags & FAULT_FLAG_KILLABLE) {
 		if (__lock_page_killable(page)) {
 			/*
-			 * We didn't have the right flags to drop the mmap_sem,
+			 * We didn't have the right flags to drop the mmap_lock,
 			 * but all fault_handlers only check for fatal signals
 			 * if we return VM_FAULT_RETRY, so we need to drop the
-			 * mmap_sem here and return 0 if we don't have a fpin.
+			 * mmap_lock here and return 0 if we don't have a fpin.
 			 */
 			if (*fpin == NULL)
 				mmap_read_unlock(vmf->vma->vm_mm);
@@ -2409,7 +2409,7 @@ static struct file *do_sync_mmap_readahead(struct vm_fault *vmf)
 /*
  * Asynchronous readahead happens when we find the page and PG_readahead,
  * so we want to possibly extend the readahead further.  We return the file that
- * was pinned if we have to drop the mmap_sem in order to do IO.
+ * was pinned if we have to drop the mmap_lock in order to do IO.
  */
 static struct file *do_async_mmap_readahead(struct vm_fault *vmf,
 					    struct page *page)
@@ -2444,12 +2444,12 @@ static struct file *do_async_mmap_readahead(struct vm_fault *vmf,
  * it in the page cache, and handles the special cases reasonably without
  * having a lot of duplicated code.
  *
- * vma->vm_mm->mmap_sem must be held on entry.
+ * vma->vm_mm->mmap_lock must be held on entry.
  *
- * If our return value has VM_FAULT_RETRY set, it's because the mmap_sem
+ * If our return value has VM_FAULT_RETRY set, it's because the mmap_lock
  * may be dropped before doing I/O or by lock_page_maybe_drop_mmap().
  *
- * If our return value does not have VM_FAULT_RETRY set, the mmap_sem
+ * If our return value does not have VM_FAULT_RETRY set, the mmap_lock
  * has not been released.
  *
  * We never return with VM_FAULT_RETRY and a bit from VM_FAULT_ERROR set.
@@ -2519,7 +2519,7 @@ retry_find:
 		goto page_not_uptodate;
 
 	/*
-	 * We've made it this far and we had to drop our mmap_sem, now is the
+	 * We've made it this far and we had to drop our mmap_lock, now is the
 	 * time to return to the upper layer and have it re-find the vma and
 	 * redo the fault.
 	 */
@@ -2569,7 +2569,7 @@ page_not_uptodate:
 
 out_retry:
 	/*
-	 * We dropped the mmap_sem, we need to return to the fault handler to
+	 * We dropped the mmap_lock, we need to return to the fault handler to
 	 * re-find the vma and come back and find our hopefully still populated
 	 * page.
 	 */
diff --git a/mm/frame_vector.c b/mm/frame_vector.c
index c2578e1a2bb7..10f82d5643b6 100644
--- a/mm/frame_vector.c
+++ b/mm/frame_vector.c
@@ -29,7 +29,7 @@
  * different type underlying the specified range of virtual addresses.
  * When the function isn't able to map a single page, it returns error.
  *
- * This function takes care of grabbing mmap_sem as necessary.
+ * This function takes care of grabbing mmap_lock as necessary.
  */
 int get_vaddr_frames(unsigned long start, unsigned int nr_frames,
 		     unsigned int gup_flags, struct frame_vector *vec)
diff --git a/mm/gup.c b/mm/gup.c
index bbb8851f4656..de9e36262ccb 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -592,7 +592,7 @@ retry:
 		pmdval = READ_ONCE(*pmd);
 		/*
 		 * MADV_DONTNEED may convert the pmd to null because
-		 * mmap_sem is held in read mode
+		 * mmap_lock is held in read mode
 		 */
 		if (pmd_none(pmdval))
 			return no_page_table(vma, flags);
@@ -855,8 +855,8 @@ unmap:
 }
 
 /*
- * mmap_sem must be held on entry.  If @locked != NULL and *@flags
- * does not include FOLL_NOWAIT, the mmap_sem may be released.  If it
+ * mmap_lock must be held on entry.  If @locked != NULL and *@flags
+ * does not include FOLL_NOWAIT, the mmap_lock may be released.  If it
  * is, *@locked will be set to 0 and -EBUSY returned.
  */
 static int faultin_page(struct task_struct *tsk, struct vm_area_struct *vma,
@@ -979,7 +979,7 @@ static int check_vma_flags(struct vm_area_struct *vma, unsigned long gup_flags)
  *		only intends to ensure the pages are faulted in.
  * @vmas:	array of pointers to vmas corresponding to each page.
  *		Or NULL if the caller does not require them.
- * @locked:     whether we're still with the mmap_sem held
+ * @locked:     whether we're still with the mmap_lock held
  *
  * Returns either number of pages pinned (which may be less than the
  * number requested), or an error. Details about the return value:
@@ -992,9 +992,9 @@ static int check_vma_flags(struct vm_area_struct *vma, unsigned long gup_flags)
  *
  * The caller is responsible for releasing returned @pages, via put_page().
  *
- * @vmas are valid only as long as mmap_sem is held.
+ * @vmas are valid only as long as mmap_lock is held.
  *
- * Must be called with mmap_sem held.  It may be released.  See below.
+ * Must be called with mmap_lock held.  It may be released.  See below.
  *
  * __get_user_pages walks a process's page tables and takes a reference to
  * each struct page that each user address corresponds to at a given
@@ -1015,12 +1015,12 @@ static int check_vma_flags(struct vm_area_struct *vma, unsigned long gup_flags)
  * appropriate) must be called after the page is finished with, and
  * before put_page is called.
  *
- * If @locked != NULL, *@locked will be set to 0 when mmap_sem is
+ * If @locked != NULL, *@locked will be set to 0 when mmap_lock is
  * released by an up_read().  That can happen if @gup_flags does not
  * have FOLL_NOWAIT.
  *
  * A caller using such a combination of @locked and @gup_flags
- * must therefore hold the mmap_sem for reading only, and recognize
+ * must therefore hold the mmap_lock for reading only, and recognize
  * when it's been released.  Otherwise, it must be held for either
  * reading or writing and will not be released.
  *
@@ -1083,7 +1083,7 @@ static long __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
 				if (locked && *locked == 0) {
 					/*
 					 * We've got a VM_FAULT_RETRY
-					 * and we've lost mmap_sem.
+					 * and we've lost mmap_lock.
 					 * We must stop here.
 					 */
 					BUG_ON(gup_flags & FOLL_NOWAIT);
@@ -1190,7 +1190,7 @@ static bool vma_permits_fault(struct vm_area_struct *vma,
  * @mm:		mm_struct of target mm
  * @address:	user address
  * @fault_flags:flags to pass down to handle_mm_fault()
- * @unlocked:	did we unlock the mmap_sem while retrying, maybe NULL if caller
+ * @unlocked:	did we unlock the mmap_lock while retrying, maybe NULL if caller
  *		does not allow retry. If NULL, the caller must guarantee
  *		that fault_flags does not contain FAULT_FLAG_ALLOW_RETRY.
  *
@@ -1211,8 +1211,8 @@ static bool vma_permits_fault(struct vm_area_struct *vma,
  * such architectures, gup() will not be enough to make a subsequent access
  * succeed.
  *
- * This function will not return with an unlocked mmap_sem. So it has not the
- * same semantics wrt the @mm->mmap_sem as does filemap_fault().
+ * This function will not return with an unlocked mmap_lock. So it has not the
+ * same semantics wrt the @mm->mmap_lock as does filemap_fault().
  */
 int fixup_user_fault(struct task_struct *tsk, struct mm_struct *mm,
 		     unsigned long address, unsigned int fault_flags,
@@ -1400,13 +1400,13 @@ retry:
  * @vma:   target vma
  * @start: start address
  * @end:   end address
- * @locked: whether the mmap_sem is still held
+ * @locked: whether the mmap_lock is still held
  *
  * This takes care of mlocking the pages too if VM_LOCKED is set.
  *
  * return 0 on success, negative error code on error.
  *
- * vma->vm_mm->mmap_sem must be held.
+ * vma->vm_mm->mmap_lock must be held.
  *
  * If @locked is NULL, it may be held for read or write and will
  * be unperturbed.
@@ -1458,7 +1458,7 @@ long populate_vma_page_range(struct vm_area_struct *vma,
  *
  * This is used to implement mlock() and the MAP_POPULATE / MAP_LOCKED mmap
  * flags. VMAs must be already marked with the desired vm_flags, and
- * mmap_sem must not be held.
+ * mmap_lock must not be held.
  */
 int __mm_populate(unsigned long start, unsigned long len, int ignore_errors)
 {
@@ -1525,7 +1525,7 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors)
  * NULL wherever the ZERO_PAGE, or an anonymous pte_none, has been found -
  * allowing a hole to be left in the corefile to save diskspace.
  *
- * Called without mmap_sem, but after all other threads have been killed.
+ * Called without mmap_lock, but after all other threads have been killed.
  */
 #ifdef CONFIG_ELF_CORE
 struct page *get_dump_page(unsigned long addr)
@@ -1886,9 +1886,9 @@ static long __get_user_pages_remote(struct task_struct *tsk,
  *
  * The caller is responsible for releasing returned @pages, via put_page().
  *
- * @vmas are valid only as long as mmap_sem is held.
+ * @vmas are valid only as long as mmap_lock is held.
  *
- * Must be called with mmap_sem held for read or write.
+ * Must be called with mmap_lock held for read or write.
  *
  * get_user_pages_remote walks a process's page tables and takes a reference
  * to each struct page that each user address corresponds to at a given
@@ -2873,7 +2873,7 @@ EXPORT_SYMBOL_GPL(get_user_pages_fast_only);
  * @pages:      array that receives pointers to the pages pinned.
  *              Should be at least nr_pages long.
  *
- * Attempt to pin user pages in memory without taking mm->mmap_sem.
+ * Attempt to pin user pages in memory without taking mm->mmap_lock.
  * If not successful, it will fall back to taking the lock and
  * calling get_user_pages().
  *
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index de201f0b5a4a..78c84bee7e29 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1746,7 +1746,7 @@ bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
 
 	/*
 	 * We don't have to worry about the ordering of src and dst
-	 * ptlocks because exclusive mmap_sem prevents deadlock.
+	 * ptlocks because exclusive mmap_lock prevents deadlock.
 	 */
 	old_ptl = __pmd_trans_huge_lock(old_pmd, vma);
 	if (old_ptl) {
@@ -2618,7 +2618,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list)
 
 	if (PageAnon(head)) {
 		/*
-		 * The caller does not necessarily hold an mmap_sem that would
+		 * The caller does not necessarily hold an mmap_lock that would
 		 * prevent the anon_vma disappearing so we first we take a
 		 * reference to it and then lock the anon_vma for write. This
 		 * is similar to page_lock_anon_vma_read except the write lock
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index f102eb82f81d..57ece74e3aae 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -4695,7 +4695,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 						(const void __user *) src_addr,
 						pages_per_huge_page(h), false);
 
-		/* fallback to copy_from_user outside mmap_sem */
+		/* fallback to copy_from_user outside mmap_lock */
 		if (unlikely(ret)) {
 			ret = -ENOENT;
 			*pagep = page;
diff --git a/mm/internal.h b/mm/internal.h
index 3d3eb867030a..9886db20d94f 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -344,7 +344,7 @@ static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
 }
 
 /*
- * must be called with vma's mmap_sem held for read or write, and page locked.
+ * must be called with vma's mmap_lock held for read or write, and page locked.
  */
 extern void mlock_vma_page(struct page *page);
 extern unsigned int munlock_vma_page(struct page *page);
@@ -413,7 +413,7 @@ static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf,
 
 	/*
 	 * FAULT_FLAG_RETRY_NOWAIT means we don't want to wait on page locks or
-	 * anything, so we only pin the file and drop the mmap_sem if only
+	 * anything, so we only pin the file and drop the mmap_lock if only
 	 * FAULT_FLAG_ALLOW_RETRY is set, while this is the first attempt.
 	 */
 	if (fault_flag_allow_retry_first(flags) &&
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);
diff --git a/mm/ksm.c b/mm/ksm.c
index 3efe7f28cc3f..4102034cd55a 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -442,7 +442,7 @@ static void insert_to_mm_slots_hash(struct mm_struct *mm,
 /*
  * ksmd, and unmerge_and_remove_all_rmap_items(), must not touch an mm's
  * page tables after it has passed through ksm_exit() - which, if necessary,
- * takes mmap_sem briefly to serialize against them.  ksm_exit() does not set
+ * takes mmap_lock briefly to serialize against them.  ksm_exit() does not set
  * a special flag: they can just back out as soon as mm_users goes to zero.
  * ksm_test_exit() is used throughout to make this test for exit: in some
  * places for correctness, in some places just to avoid unnecessary work.
@@ -831,7 +831,7 @@ static void remove_trailing_rmap_items(struct mm_slot *mm_slot,
  * Though it's very tempting to unmerge rmap_items from stable tree rather
  * than check every pte of a given vma, the locking doesn't quite work for
  * that - an rmap_item is assigned to the stable tree after inserting ksm
- * page and upping mmap_sem.  Nor does it fit with the way we skip dup'ing
+ * page and upping mmap_lock.  Nor does it fit with the way we skip dup'ing
  * rmap_items from parent to child at fork time (so as not to waste time
  * if exit comes before the next scan reaches it).
  *
@@ -1292,7 +1292,7 @@ static int try_to_merge_with_ksm_page(struct rmap_item *rmap_item,
 	/* Unstable nid is in union with stable anon_vma: remove first */
 	remove_rmap_item_from_tree(rmap_item);
 
-	/* Must get reference to anon_vma while still holding mmap_sem */
+	/* Must get reference to anon_vma while still holding mmap_lock */
 	rmap_item->anon_vma = vma->anon_vma;
 	get_anon_vma(vma->anon_vma);
 out:
@@ -2343,13 +2343,13 @@ next_mm:
 						struct mm_slot, mm_list);
 	if (ksm_scan.address == 0) {
 		/*
-		 * We've completed a full scan of all vmas, holding mmap_sem
+		 * We've completed a full scan of all vmas, holding mmap_lock
 		 * throughout, and found no VM_MERGEABLE: so do the same as
 		 * __ksm_exit does to remove this mm from all our lists now.
 		 * This applies either when cleaning up after __ksm_exit
 		 * (but beware: we can reach here even before __ksm_exit),
 		 * or when all VM_MERGEABLE areas have been unmapped (and
-		 * mmap_sem then protects against race with MADV_MERGEABLE).
+		 * mmap_lock then protects against race with MADV_MERGEABLE).
 		 */
 		hash_del(&slot->link);
 		list_del(&slot->mm_list);
@@ -2536,7 +2536,7 @@ void __ksm_exit(struct mm_struct *mm)
 	 * This process is exiting: if it's straightforward (as is the
 	 * case when ksmd was never running), free mm_slot immediately.
 	 * But if it's at the cursor or has rmap_items linked to it, use
-	 * mmap_sem to synchronize with any break_cows before pagetables
+	 * mmap_lock to synchronize with any break_cows before pagetables
 	 * are freed, and leave the mm_slot on the list for ksmd to free.
 	 * Beware: ksm may already have noticed it exiting and freed the slot.
 	 */
diff --git a/mm/maccess.c b/mm/maccess.c
index 3ca8d97e5010..81df3b788284 100644
--- a/mm/maccess.c
+++ b/mm/maccess.c
@@ -40,9 +40,9 @@ probe_write_common(void __user *dst, const void *src, size_t size)
  * happens, handle that and return -EFAULT.
  *
  * We ensure that the copy_from_user is executed in atomic context so that
- * do_page_fault() doesn't attempt to take mmap_sem.  This makes
+ * do_page_fault() doesn't attempt to take mmap_lock.  This makes
  * probe_kernel_read() suitable for use within regions where the caller
- * already holds mmap_sem, or other locks which nest inside mmap_sem.
+ * already holds mmap_lock, or other locks which nest inside mmap_lock.
  *
  * probe_kernel_read_strict() is the same as probe_kernel_read() except for
  * the case where architectures have non-overlapping user and kernel address
diff --git a/mm/madvise.c b/mm/madvise.c
index d9b0f66b4396..dd1d43cf026d 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:
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ffae92d4e472..0b38b6ad547d 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5901,7 +5901,7 @@ static void mem_cgroup_move_charge(void)
 retry:
 	if (unlikely(!mmap_read_trylock(mc.mm))) {
 		/*
-		 * Someone who are holding the mmap_sem might be waiting in
+		 * Someone who are holding the mmap_lock might be waiting in
 		 * waitq. So we cancel all extra charges, wake up all waiters,
 		 * and retry. Because we cancel precharges, we might not be able
 		 * to move enough charges, but moving charge is a best-effort
diff --git a/mm/memory.c b/mm/memory.c
index 4e2e17bb1281..dc7f3543b1fd 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1185,7 +1185,7 @@ static inline unsigned long zap_pmd_range(struct mmu_gather *tlb,
 		 * Here there can be other concurrent MADV_DONTNEED or
 		 * trans huge page faults running, and if the pmd is
 		 * none or trans huge it can change under us. This is
-		 * because MADV_DONTNEED holds the mmap_sem in read
+		 * because MADV_DONTNEED holds the mmap_lock in read
 		 * mode.
 		 */
 		if (pmd_none_or_trans_huge_or_clear_bad(pmd))
@@ -1636,7 +1636,7 @@ EXPORT_SYMBOL(vm_insert_pages);
  * The page does not need to be reserved.
  *
  * Usually this function is called from f_op->mmap() handler
- * under mm->mmap_sem write-lock, so it can change vma->vm_flags.
+ * under mm->mmap_lock write-lock, so it can change vma->vm_flags.
  * Caller must set VM_MIXEDMAP on vma if it wants to call this
  * function from other places, for example from page-fault handler.
  *
@@ -2573,7 +2573,7 @@ static vm_fault_t fault_dirty_shared_page(struct vm_fault *vmf)
 	 * mapping may be NULL here because some device drivers do not
 	 * set page.mapping but still dirty their pages
 	 *
-	 * Drop the mmap_sem before waiting on IO, if we can. The file
+	 * Drop the mmap_lock before waiting on IO, if we can. The file
 	 * is pinning the mapping, as per above.
 	 */
 	if ((dirtied || page_mkwrite) && mapping) {
@@ -2623,7 +2623,7 @@ static inline void wp_page_reuse(struct vm_fault *vmf)
 /*
  * Handle the case of a page which we actually need to copy to a new page.
  *
- * Called with mmap_sem locked and the old page referenced, but
+ * Called with mmap_lock locked and the old page referenced, but
  * without the ptl held.
  *
  * High level logic flow:
@@ -2887,9 +2887,9 @@ static vm_fault_t wp_page_shared(struct vm_fault *vmf)
  * change only once the write actually happens. This avoids a few races,
  * and potentially makes it more efficient.
  *
- * We enter with non-exclusive mmap_sem (to exclude vma changes,
+ * We enter with non-exclusive mmap_lock (to exclude vma changes,
  * but allow concurrent faults), with pte both mapped and locked.
- * We return with mmap_sem still held, but pte unmapped and unlocked.
+ * We return with mmap_lock still held, but pte unmapped and unlocked.
  */
 static vm_fa