mm: use helper function put_write_access()

In commit 1da177e4c3f4 ("Linux-2.6.12-rc2"), the helper put_write_access()
came with the atomic_dec operation of the i_writecount field.  But it
forgot to use this helper in __vma_link_file() and dup_mmap().

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200924115235.5111-1-linmiaohe@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/fork.c b/kernel/fork.c
index 3ca8f1f..e0f74be 100644 (file)
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -556,7 +556,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
 
                        get_file(file);
                        if (tmp->vm_flags & VM_DENYWRITE)
-                               atomic_dec(&inode->i_writecount);
+                               put_write_access(inode);
                        i_mmap_lock_write(mapping);
                        if (tmp->vm_flags & VM_SHARED)
                                mapping_allow_writable(mapping);

diff --git a/mm/mmap.c b/mm/mmap.c
index 67d11ad..9fb9f8a 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -619,7 +619,7 @@ static void __vma_link_file(struct vm_area_struct *vma)
                struct address_space *mapping = file->f_mapping;
 
                if (vma->vm_flags & VM_DENYWRITE)
-                       atomic_dec(&file_inode(file)->i_writecount);
+                       put_write_access(file_inode(file));
                if (vma->vm_flags & VM_SHARED)
                        mapping_allow_writable(mapping);