[v4,13/13] mm: pgtable: remove pte_offset_map_nolock()

Commit Message

Qi Zheng Sept. 24, 2024, 6:10 a.m. UTC

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

Signed-off-by: Qi Zheng <[e-mail]>
Reviewed-by: Muchun Song <[e-mail]>
---
 Documentation/mm/split_page_table_lock.rst |  3 ---
 include/linux/mm.h                         |  2 --
 mm/pgtable-generic.c                       | 21 ---------------------
 3 files changed, 26 deletions(-)

Comments

David Hildenbrand Sept. 24, 2024, 1:02 p.m. UTC | #1

On 24.09.24 08:10, Qi Zheng wrote:
> Now no users are using the pte_offset_map_nolock(), remove it.
> 
> Signed-off-by: Qi Zheng <[e-mail]>
> Reviewed-by: Muchun Song <[e-mail]>
> ---

Acked-by: David Hildenbrand <[e-mail]>

Patch

diff --git a/Documentation/mm/split_page_table_lock.rst b/Documentation/mm/split_page_table_lock.rst
index 08d0e706a32db..581446d4a4eba 100644
--- a/Documentation/mm/split_page_table_lock.rst
+++ b/Documentation/mm/split_page_table_lock.rst
@@ -16,9 +16,6 @@  There are helpers to lock/unlock a table and other accessor functions:
  - 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;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9a4550cd830c9..e2a4502ab019b 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3015,8 +3015,6 @@  static inline pte_t *pte_offset_map_lock(struct mm_struct *mm, pmd_t *pmd,
 	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,
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index 262b7065a5a2e..c68aa655b7872 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -305,18 +305,6 @@  pte_t *__pte_offset_map(pmd_t *pmd, unsigned long addr, pmd_t *pmdvalp)
 	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)
 {
@@ -374,15 +362,6 @@  pte_t *pte_offset_map_rw_nolock(struct mm_struct *mm, pmd_t *pmd,
  * 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