[PATCH v6 6/7] ext4: call dax_pfn_mkwrite() for DAX fsync/msync

Ross Zwisler
2015-12-23T19:39:45Z

To properly support the new DAX fsync/msync infrastructure filesystems
need to call dax_pfn_mkwrite() so that DAX can track when user pages are
dirtied.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
---
fs/ext4/file.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 60683ab..fa899c9 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -291,8 +291,8 @@ static int ext4_dax_pfn_mkwrite(struct vm_area_struct *vma,
{
struct inode *inode = file_inode(vma->vm_file);
struct super_block *sb = inode->i_sb;
- int ret = VM_FAULT_NOPAGE;
loff_t size;
+ int ret;

sb_start_pagefault(sb);
file_update_time(vma->vm_file);
@@ -300,6 +300,8 @@ static int ext4_dax_pfn_mkwrite(struct vm_area_struct *vma,
size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
if (vmf->pgoff >= size)
ret = VM_FAULT_SIGBUS;
+ else
+ ret = dax_pfn_mkwrite(vma, vmf);
up_read(&EXT4_I(inode)->i_mmap_sem);
sb_end_pagefault(sb);

--
2.6.3