[PATCH v6 3/7] tmpfs: bump the mtime/ctime/iversion when page becomes writeable

[Jeff Layton]

Most filesystems that use the pagecache will update the mtime, ctime,
and change attribute when a page becomes writeable. Add a page_mkwrite
operation for tmpfs and just use it to bump the mtime, ctime and change
attribute.

This fixes xfstest generic/080 on tmpfs.

Signed-off-by: Jeff Layton <jlayton at kernel.org>
---
 mm/shmem.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/mm/shmem.c b/mm/shmem.c
index b154af49d2df..654d9a585820 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2169,6 +2169,16 @@ static vm_fault_t shmem_fault(struct vm_fault *vmf)
 	return ret;
 }
 
+static vm_fault_t shmem_page_mkwrite(struct vm_fault *vmf)
+{
+	struct vm_area_struct *vma = vmf->vma;
+	struct inode *inode = file_inode(vma->vm_file);
+
+	file_update_time(vma->vm_file);
+	inode_inc_iversion(inode);
+	return 0;
+}
+
 unsigned long shmem_get_unmapped_area(struct file *file,
 				      unsigned long uaddr, unsigned long len,
 				      unsigned long pgoff, unsigned long flags)
@@ -4210,6 +4220,7 @@ static const struct super_operations shmem_ops = {
 
 static const struct vm_operations_struct shmem_vm_ops = {
 	.fault		= shmem_fault,
+	.page_mkwrite	= shmem_page_mkwrite,
 	.map_pages	= filemap_map_pages,
 #ifdef CONFIG_NUMA
 	.set_policy     = shmem_set_policy,
@@ -4219,6 +4230,7 @@ static const struct vm_operations_struct shmem_vm_ops = {
 
 static const struct vm_operations_struct shmem_anon_vm_ops = {
 	.fault		= shmem_fault,
+	.page_mkwrite	= shmem_page_mkwrite,
 	.map_pages	= filemap_map_pages,
 #ifdef CONFIG_NUMA
 	.set_policy     = shmem_set_policy,

-- 
2.41.0