[PATCH v6 11/12] mmap locking API: convert mmap_sem API comments

From: Michel Lespinasse
Date: Wed May 20 2020 - 01:29:44 EST


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

Signed-off-by: Michel Lespinasse <walken@xxxxxxxxxx>
---
Documentation/vm/hmm.rst | 6 +++---
arch/alpha/mm/fault.c | 2 +-
arch/ia64/mm/fault.c | 2 +-
arch/m68k/mm/fault.c | 2 +-
arch/microblaze/mm/fault.c | 2 +-
arch/mips/mm/fault.c | 2 +-
arch/nds32/mm/fault.c | 2 +-
arch/nios2/mm/fault.c | 2 +-
arch/openrisc/mm/fault.c | 2 +-
arch/parisc/mm/fault.c | 2 +-
arch/riscv/mm/fault.c | 2 +-
arch/sh/mm/fault.c | 2 +-
arch/sparc/mm/fault_32.c | 2 +-
arch/sparc/mm/fault_64.c | 2 +-
arch/xtensa/mm/fault.c | 2 +-
drivers/android/binder_alloc.c | 4 ++--
fs/hugetlbfs/inode.c | 2 +-
fs/userfaultfd.c | 2 +-
mm/filemap.c | 2 +-
mm/gup.c | 12 ++++++------
mm/huge_memory.c | 4 ++--
mm/khugepaged.c | 2 +-
mm/ksm.c | 2 +-
mm/memory.c | 4 ++--
mm/mempolicy.c | 2 +-
mm/migrate.c | 4 ++--
mm/mmap.c | 2 +-
mm/oom_kill.c | 8 ++++----
net/ipv4/tcp.c | 2 +-
29 files changed, 43 insertions(+), 43 deletions(-)

diff --git a/Documentation/vm/hmm.rst b/Documentation/vm/hmm.rst
index 4e3e9362afeb..046817505033 100644
--- a/Documentation/vm/hmm.rst
+++ b/Documentation/vm/hmm.rst
@@ -194,15 +194,15 @@ The usage pattern is::

again:
range.notifier_seq = mmu_interval_read_begin(&interval_sub);
- down_read(&mm->mmap_sem);
+ mmap_read_lock(mm);
ret = hmm_range_fault(&range);
if (ret) {
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);
if (ret == -EBUSY)
goto again;
return ret;
}
- up_read(&mm->mmap_sem);
+ mmap_read_unlock(mm);

take_lock(driver->update);
if (mmu_interval_read_retry(&ni, range.notifier_seq) {
diff --git a/arch/alpha/mm/fault.c b/arch/alpha/mm/fault.c
index 36efa778ee1a..c2303a8c2b9f 100644
--- a/arch/alpha/mm/fault.c
+++ b/arch/alpha/mm/fault.c
@@ -171,7 +171,7 @@ do_page_fault(unsigned long address, unsigned long mmcsr,
if (fault & VM_FAULT_RETRY) {
flags |= FAULT_FLAG_TRIED;

- /* No need to up_read(&mm->mmap_sem) as we would
+ /* No need to mmap_read_unlock(mm) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
diff --git a/arch/ia64/mm/fault.c b/arch/ia64/mm/fault.c
index 9b95050c2048..0f788992608a 100644
--- a/arch/ia64/mm/fault.c
+++ b/arch/ia64/mm/fault.c
@@ -169,7 +169,7 @@ ia64_do_page_fault (unsigned long address, unsigned long isr, struct pt_regs *re
if (fault & VM_FAULT_RETRY) {
flags |= FAULT_FLAG_TRIED;

- /* No need to up_read(&mm->mmap_sem) as we would
+ /* No need to mmap_read_unlock(mm) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
diff --git a/arch/m68k/mm/fault.c b/arch/m68k/mm/fault.c
index 650acab0d77d..a94a814ad6ad 100644
--- a/arch/m68k/mm/fault.c
+++ b/arch/m68k/mm/fault.c
@@ -165,7 +165,7 @@ int do_page_fault(struct pt_regs *regs, unsigned long address,
flags |= FAULT_FLAG_TRIED;

/*
- * No need to up_read(&mm->mmap_sem) as we would
+ * No need to mmap_read_unlock(mm) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
diff --git a/arch/microblaze/mm/fault.c b/arch/microblaze/mm/fault.c
index 9d7c423dea1d..ebf1ac50b291 100644
--- a/arch/microblaze/mm/fault.c
+++ b/arch/microblaze/mm/fault.c
@@ -239,7 +239,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long address,
flags |= FAULT_FLAG_TRIED;

/*
- * No need to up_read(&mm->mmap_sem) as we would
+ * No need to mmap_read_unlock(mm) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
diff --git a/arch/mips/mm/fault.c b/arch/mips/mm/fault.c
index 9ef2dd39111e..01b168a90434 100644
--- a/arch/mips/mm/fault.c
+++ b/arch/mips/mm/fault.c
@@ -181,7 +181,7 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,
flags |= FAULT_FLAG_TRIED;

/*
- * No need to up_read(&mm->mmap_sem) as we would
+ * No need to mmap_read_unlock(mm) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
diff --git a/arch/nds32/mm/fault.c b/arch/nds32/mm/fault.c
index 21bab96fd6c3..ea370f84ac54 100644
--- a/arch/nds32/mm/fault.c
+++ b/arch/nds32/mm/fault.c
@@ -248,7 +248,7 @@ void do_page_fault(unsigned long entry, unsigned long addr,
if (fault & VM_FAULT_RETRY) {
flags |= FAULT_FLAG_TRIED;

- /* No need to up_read(&mm->mmap_sem) as we would
+ /* No need to mmap_read_unlock(mm) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
diff --git a/arch/nios2/mm/fault.c b/arch/nios2/mm/fault.c
index 2c873f9eea1b..775e9fe1eddc 100644
--- a/arch/nios2/mm/fault.c
+++ b/arch/nios2/mm/fault.c
@@ -160,7 +160,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long cause,
flags |= FAULT_FLAG_TRIED;

/*
- * No need to up_read(&mm->mmap_sem) as we would
+ * No need to mmap_read_unlock(mm) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
diff --git a/arch/openrisc/mm/fault.c b/arch/openrisc/mm/fault.c
index 1dbce831f960..d6f203667361 100644
--- a/arch/openrisc/mm/fault.c
+++ b/arch/openrisc/mm/fault.c
@@ -183,7 +183,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address,
if (fault & VM_FAULT_RETRY) {
flags |= FAULT_FLAG_TRIED;

- /* No need to up_read(&mm->mmap_sem) as we would
+ /* No need to mmap_read_unlock(mm) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
diff --git a/arch/parisc/mm/fault.c b/arch/parisc/mm/fault.c
index bc840fdb398f..66ac0719bd49 100644
--- a/arch/parisc/mm/fault.c
+++ b/arch/parisc/mm/fault.c
@@ -329,7 +329,7 @@ void do_page_fault(struct pt_regs *regs, unsigned long code,
current->min_flt++;
if (fault & VM_FAULT_RETRY) {
/*
- * No need to up_read(&mm->mmap_sem) as we would
+ * No need to mmap_read_unlock(mm) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c
index cd7f4af95e56..996db5ebbf39 100644
--- a/arch/riscv/mm/fault.c
+++ b/arch/riscv/mm/fault.c
@@ -147,7 +147,7 @@ asmlinkage void do_page_fault(struct pt_regs *regs)
flags |= FAULT_FLAG_TRIED;

/*
- * No need to up_read(&mm->mmap_sem) as we would
+ * No need to mmap_read_unlock(mm) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c
index beb83e8ec0b3..ce9f492f9049 100644
--- a/arch/sh/mm/fault.c
+++ b/arch/sh/mm/fault.c
@@ -484,7 +484,7 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,
flags |= FAULT_FLAG_TRIED;

/*
- * No need to up_read(&mm->mmap_sem) as we would
+ * No need to mmap_read_unlock(mm) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
diff --git a/arch/sparc/mm/fault_32.c b/arch/sparc/mm/fault_32.c
index e69bcd957c78..18e97b2a8413 100644
--- a/arch/sparc/mm/fault_32.c
+++ b/arch/sparc/mm/fault_32.c
@@ -263,7 +263,7 @@ asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
if (fault & VM_FAULT_RETRY) {
flags |= FAULT_FLAG_TRIED;

- /* No need to up_read(&mm->mmap_sem) as we would
+ /* No need to mmap_read_unlock(mm) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
diff --git a/arch/sparc/mm/fault_64.c b/arch/sparc/mm/fault_64.c
index 43ecd88a9d6f..2e79d7d050ed 100644
--- a/arch/sparc/mm/fault_64.c
+++ b/arch/sparc/mm/fault_64.c
@@ -451,7 +451,7 @@ asmlinkage void __kprobes do_sparc64_fault(struct pt_regs *regs)
if (fault & VM_FAULT_RETRY) {
flags |= FAULT_FLAG_TRIED;

- /* No need to up_read(&mm->mmap_sem) as we would
+ /* No need to mmap_read_unlock(mm) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
diff --git a/arch/xtensa/mm/fault.c b/arch/xtensa/mm/fault.c
index 1c8d22a0cf46..c4decc73fd86 100644
--- a/arch/xtensa/mm/fault.c
+++ b/arch/xtensa/mm/fault.c
@@ -130,7 +130,7 @@ void do_page_fault(struct pt_regs *regs)
if (fault & VM_FAULT_RETRY) {
flags |= FAULT_FLAG_TRIED;

- /* No need to up_read(&mm->mmap_sem) as we would
+ /* No need to mmap_read_unlock(mm) as we would
* have already released it in __lock_page_or_retry
* in mm/filemap.c.
*/
diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c
index cbdc43ed0f9f..42c672f1584e 100644
--- a/drivers/android/binder_alloc.c
+++ b/drivers/android/binder_alloc.c
@@ -933,7 +933,7 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
if (!mmget_not_zero(mm))
goto err_mmget;
if (!mmap_read_trylock(mm))
- goto err_down_read_mmap_sem_failed;
+ goto err_mmap_read_lock_failed;
vma = binder_alloc_get_vma(alloc);

list_lru_isolate(lru, item);
@@ -960,7 +960,7 @@ enum lru_status binder_alloc_free_page(struct list_head *item,
mutex_unlock(&alloc->mutex);
return LRU_REMOVED_RETRY;

-err_down_read_mmap_sem_failed:
+err_mmap_read_lock_failed:
mmput_async(mm);
err_mmget:
err_page_already_freed:
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 991c60c7ffe0..a890f78aa80c 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -186,7 +186,7 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
}

/*
- * Called under down_write(mmap_sem).
+ * Called under mmap_write_lock(mm).
*/

#ifndef HAVE_ARCH_HUGETLB_UNMAPPED_AREA
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 12b492409040..3a63d75ed2fd 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -1248,7 +1248,7 @@ static __always_inline void wake_userfault(struct userfaultfd_ctx *ctx,
/*
* To be sure waitqueue_active() is not reordered by the CPU
* before the pagetable update, use an explicit SMP memory
- * barrier here. PT lock release or up_read(mmap_sem) still
+ * barrier here. PT lock release or mmap_read_unlock(mm) still
* have release semantics that can allow the
* waitqueue_active() to be reordered before the pte update.
*/
diff --git a/mm/filemap.c b/mm/filemap.c
index a4cc12653a39..10d21d0b0536 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1376,7 +1376,7 @@ 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 c1c0b37d0e8f..a8606213bdec 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1967,19 +1967,19 @@ 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);
*/
long get_user_pages_locked(unsigned long start, unsigned long nr_pages,
unsigned int gup_flags, struct page **pages,
@@ -2003,9 +2003,9 @@ 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 6ecd1045113b..aa940124396d 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2038,9 +2038,9 @@ 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 100e61be4379..a173ed7eb2bf 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1444,7 +1444,7 @@ 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 17302642bcbf..0283d4969ef3 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -2362,7 +2362,7 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page)
} 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 c2963e7affa9..3c9a5f6ac9f0 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3322,10 +3322,10 @@ 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 202505195642..a1247d3553da 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -2188,7 +2188,7 @@ 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 fc05d721b032..c3dc86ccb808 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 80a47031d5db..dcdda8473012 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 be9f0a78c408..df99b255d510 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 @@ static void oom_reap_task(struct task_struct *tsk)

/*
* 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);

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index c4aee8379f97..a083d92ef3b9 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1734,7 +1734,7 @@ int tcp_mmap(struct file *file, struct socket *sock,
return -EPERM;
vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC);

- /* Instruct vm_insert_page() to not down_read(mmap_sem) */
+ /* Instruct vm_insert_page() to not mmap_read_lock(mm) */
vma->vm_flags |= VM_MIXEDMAP;

vma->vm_ops = &tcp_vm_ops;
--
2.26.2.761.g0e0b3e54be-goog