+ mm-pgtable-remove-pte_offset_map_nolock.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: pgtable: remove pte_offset_map_nolock()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-pgtable-remove-pte_offset_map_nolock.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-pgtable-remove-pte_offset_map_nolock.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Qi Zheng <zhengqi.arch@bytedance.com>
Subject: mm: pgtable: remove pte_offset_map_nolock()
Date: Thu, 26 Sep 2024 14:46:26 +0800

Now no users are using the pte_offset_map_nolock(), remove it.

Link: https://lkml.kernel.org/r/d04f9bbbcde048fb6ffa6f2bdbc6f9b22d5286f9.1727332572.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Reviewed-by: Muchun Song <muchun.song@linux.dev>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 Documentation/mm/split_page_table_lock.rst |    3 --
 include/linux/mm.h                         |    2 -
 mm/pgtable-generic.c                       |   21 -------------------
 3 files changed, 26 deletions(-)

--- a/Documentation/mm/split_page_table_lock.rst~mm-pgtable-remove-pte_offset_map_nolock
+++ a/Documentation/mm/split_page_table_lock.rst
@@ -16,9 +16,6 @@ There are helpers to lock/unlock a table
  - pte_offset_map_lock()
 	maps PTE and takes PTE table lock, returns pointer to PTE with
 	pointer to its PTE table lock, or returns NULL if no PTE table;
- - pte_offset_map_nolock()
-	maps PTE, returns pointer to PTE with pointer to its PTE table
-	lock (not taken), or returns NULL if no PTE table;
  - pte_offset_map_ro_nolock()
 	maps PTE, returns pointer to PTE with pointer to its PTE table
 	lock (not taken), or returns NULL if no PTE table;
--- a/include/linux/mm.h~mm-pgtable-remove-pte_offset_map_nolock
+++ a/include/linux/mm.h
@@ -3015,8 +3015,6 @@ static inline pte_t *pte_offset_map_lock
 	return pte;
 }
 
-pte_t *pte_offset_map_nolock(struct mm_struct *mm, pmd_t *pmd,
-			unsigned long addr, spinlock_t **ptlp);
 pte_t *pte_offset_map_ro_nolock(struct mm_struct *mm, pmd_t *pmd,
 				unsigned long addr, spinlock_t **ptlp);
 pte_t *pte_offset_map_rw_nolock(struct mm_struct *mm, pmd_t *pmd,
--- a/mm/pgtable-generic.c~mm-pgtable-remove-pte_offset_map_nolock
+++ a/mm/pgtable-generic.c
@@ -305,18 +305,6 @@ nomap:
 	return NULL;
 }
 
-pte_t *pte_offset_map_nolock(struct mm_struct *mm, pmd_t *pmd,
-			     unsigned long addr, spinlock_t **ptlp)
-{
-	pmd_t pmdval;
-	pte_t *pte;
-
-	pte = __pte_offset_map(pmd, addr, &pmdval);
-	if (likely(pte))
-		*ptlp = pte_lockptr(mm, &pmdval);
-	return pte;
-}
-
 pte_t *pte_offset_map_ro_nolock(struct mm_struct *mm, pmd_t *pmd,
 				unsigned long addr, spinlock_t **ptlp)
 {
@@ -372,15 +360,6 @@ pte_t *pte_offset_map_rw_nolock(struct m
  * and disconnected table.  Until pte_unmap(pte) unmaps and rcu_read_unlock()s
  * afterwards.
  *
- * pte_offset_map_nolock(mm, pmd, addr, ptlp), above, is like pte_offset_map();
- * but when successful, it also outputs a pointer to the spinlock in ptlp - as
- * pte_offset_map_lock() does, but in this case without locking it.  This helps
- * the caller to avoid a later pte_lockptr(mm, *pmd), which might by that time
- * act on a changed *pmd: pte_offset_map_nolock() provides the correct spinlock
- * pointer for the page table that it returns.  In principle, the caller should
- * recheck *pmd once the lock is taken; in practice, no callsite needs that -
- * either the mmap_lock for write, or pte_same() check on contents, is enough.
- *
  * pte_offset_map_ro_nolock(mm, pmd, addr, ptlp), above, is like pte_offset_map();
  * but when successful, it also outputs a pointer to the spinlock in ptlp - as
  * pte_offset_map_lock() does, but in this case without locking it.  This helps
_

Patches currently in -mm which might be from zhengqi.arch@bytedance.com are

mm-pgtable-introduce-pte_offset_map_rorw_nolock.patch
powerpc-assert_pte_locked-use-pte_offset_map_ro_nolock.patch
mm-filemap-filemap_fault_recheck_pte_none-use-pte_offset_map_ro_nolock.patch
mm-khugepaged-__collapse_huge_page_swapin-use-pte_offset_map_ro_nolock.patch
arm-adjust_pte-use-pte_offset_map_rw_nolock.patch
mm-handle_pte_fault-use-pte_offset_map_rw_nolock.patch
mm-khugepaged-collapse_pte_mapped_thp-use-pte_offset_map_rw_nolock.patch
mm-copy_pte_range-use-pte_offset_map_rw_nolock.patch
mm-mremap-move_ptes-use-pte_offset_map_rw_nolock.patch
mm-page_vma_mapped_walk-map_pte-use-pte_offset_map_rw_nolock.patch
mm-userfaultfd-move_pages_pte-use-pte_offset_map_rw_nolock.patch
mm-multi-gen-lru-walk_pte_range-use-pte_offset_map_rw_nolock.patch
mm-pgtable-remove-pte_offset_map_nolock.patch