On Wed 03-04-19 16:10:17, Pankaj Gupta wrote:
> Virtio pmem provides asynchronous host page cache flush
> mechanism. We don't support 'MAP_SYNC' with virtio pmem
> and ext4.
>
> Signed-off-by: Pankaj Gupta <pagupta@xxxxxxxxxx>
The patch looks good to me. You can add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/ext4/file.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> index 69d65d49837b..86e4bf464320 100644
> --- a/fs/ext4/file.c
> +++ b/fs/ext4/file.c
> @@ -360,8 +360,10 @@ static const struct vm_operations_struct ext4_file_vm_ops = {
> static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
> {
> struct inode *inode = file->f_mapping->host;
> + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
> + struct dax_device *dax_dev = sbi->s_daxdev;
>
> - if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
> + if (unlikely(ext4_forced_shutdown(sbi)))
> return -EIO;
>
> /*
> @@ -371,6 +373,13 @@ static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
> if (!IS_DAX(file_inode(file)) && (vma->vm_flags & VM_SYNC))
> return -EOPNOTSUPP;
>
> + /* We don't support synchronous mappings with DAX files if
> + * dax_device is not synchronous.
> + */
> + if (IS_DAX(file_inode(file)) && !dax_synchronous(dax_dev)
> + && (vma->vm_flags & VM_SYNC))
> + return -EOPNOTSUPP;
> +
> file_accessed(file);
> if (IS_DAX(file_inode(file))) {
> vma->vm_ops = &ext4_dax_vm_ops;
> --
> 2.20.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
