ext4: disable map_sync for async flush

Dont support 'MAP_SYNC' with non-DAX files and DAX files
with asynchronous dax_device. 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@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Pankaj Gupta 2019-07-05 19:33:27 +05:30 committed by Dan Williams
parent 32de148464
commit e46bfc3f03

View File

@ -367,15 +367,17 @@ 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;
/*
* We don't support synchronous mappings for non-DAX files. At least
* until someone comes with a sensible use case.
* We don't support synchronous mappings for non-DAX files and
* for DAX files if underneath dax_device is not synchronous.
*/
if (!IS_DAX(file_inode(file)) && (vma->vm_flags & VM_SYNC))
if (!daxdev_mapping_supported(vma, dax_dev))
return -EOPNOTSUPP;
file_accessed(file);