[PATCH v10 07/25] mm: introduce INIT_VMA()

[Laurent Dufour <ldufour@linux.vnet.ibm.com>]

Some VMA struct fields need to be initialized once the VMA structure is
allocated.
Currently this only concerns anon_vma_chain field but some other will be
added to support the speculative page fault.

Instead of spreading the initialization calls all over the code, let's
introduce a dedicated inline function.

Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
---
 fs/exec.c          |  2 +-
 include/linux/mm.h |  5 +++++
 kernel/fork.c      |  2 +-
 mm/mmap.c          | 10 +++++-----
 mm/nommu.c         |  2 +-
 5 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/fs/exec.c b/fs/exec.c
index 32eea4c65909..bd03689aa358 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -311,7 +311,7 @@ static int __bprm_mm_init(struct linux_binprm *bprm)
 	vma->vm_start = vma->vm_end - PAGE_SIZE;
 	vma->vm_flags = VM_SOFTDIRTY | VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP;
 	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
-	INIT_LIST_HEAD(&vma->anon_vma_chain);
+	INIT_VMA(vma);
 
 	err = insert_vm_struct(mm, vma);
 	if (err)
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 714da99d77a3..efc1248b82bd 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1261,6 +1261,11 @@ struct zap_details {
 	pgoff_t last_index;			/* Highest page->index to unmap */
 };
 
+static inline void INIT_VMA(struct vm_area_struct *vma)
+{
+	INIT_LIST_HEAD(&vma->anon_vma_chain);
+}
+
 struct page *_vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
 			     pte_t pte, bool with_public_device);
 #define vm_normal_page(vma, addr, pte) _vm_normal_page(vma, addr, pte, false)
diff --git a/kernel/fork.c b/kernel/fork.c
index b1d877f1a0ac..d937e5945f77 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -451,7 +451,7 @@ static __latent_entropy int dup_mmap(struct mm_struct *mm,
 		if (!tmp)
 			goto fail_nomem;
 		*tmp = *mpnt;
-		INIT_LIST_HEAD(&tmp->anon_vma_chain);
+		INIT_VMA(tmp);
 		retval = vma_dup_policy(mpnt, tmp);
 		if (retval)
 			goto fail_nomem_policy;
diff --git a/mm/mmap.c b/mm/mmap.c
index 188f195883b9..8bd9ae1dfacc 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1700,7 +1700,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
 	vma->vm_flags = vm_flags;
 	vma->vm_page_prot = vm_get_page_prot(vm_flags);
 	vma->vm_pgoff = pgoff;
-	INIT_LIST_HEAD(&vma->anon_vma_chain);
+	INIT_VMA(vma);
 
 	if (file) {
 		if (vm_flags & VM_DENYWRITE) {
@@ -2586,7 +2586,7 @@ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
 	/* most fields are the same, copy all, and then fixup */
 	*new = *vma;
 
-	INIT_LIST_HEAD(&new->anon_vma_chain);
+	INIT_VMA(new);
 
 	if (new_below)
 		new->vm_end = addr;
@@ -2956,7 +2956,7 @@ static int do_brk_flags(unsigned long addr, unsigned long request, unsigned long
 		return -ENOMEM;
 	}
 
-	INIT_LIST_HEAD(&vma->anon_vma_chain);
+	INIT_VMA(vma);
 	vma->vm_mm = mm;
 	vma->vm_start = addr;
 	vma->vm_end = addr + len;
@@ -3167,7 +3167,7 @@ struct vm_area_struct *copy_vma(struct vm_area_struct **vmap,
 		new_vma->vm_pgoff = pgoff;
 		if (vma_dup_policy(vma, new_vma))
 			goto out_free_vma;
-		INIT_LIST_HEAD(&new_vma->anon_vma_chain);
+		INIT_VMA(new_vma);
 		if (anon_vma_clone(new_vma, vma))
 			goto out_free_mempol;
 		if (new_vma->vm_file)
@@ -3310,7 +3310,7 @@ static struct vm_area_struct *__install_special_mapping(
 	if (unlikely(vma == NULL))
 		return ERR_PTR(-ENOMEM);
 
-	INIT_LIST_HEAD(&vma->anon_vma_chain);
+	INIT_VMA(vma);
 	vma->vm_mm = mm;
 	vma->vm_start = addr;
 	vma->vm_end = addr + len;
diff --git a/mm/nommu.c b/mm/nommu.c
index 13723736d38f..6909ea0bf88d 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1212,7 +1212,7 @@ unsigned long do_mmap(struct file *file,
 	region->vm_flags = vm_flags;
 	region->vm_pgoff = pgoff;
 
-	INIT_LIST_HEAD(&vma->anon_vma_chain);
+	INIT_VMA(vma);
 	vma->vm_flags = vm_flags;
 	vma->vm_pgoff = pgoff;
 
-- 
2.7.4