Messages in this thread | | | Date | Thu, 4 Apr 2019 02:12:30 -0400 (EDT) | From | Pankaj Gupta <> | Subject | Re: [PATCH v4 5/5] xfs: disable map_sync for async flush |
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Hi Dave,
> > Virtio pmem provides asynchronous host page cache flush > > mechanism. we don't support 'MAP_SYNC' with virtio pmem > > and xfs. > > > > Signed-off-by: Pankaj Gupta <pagupta@redhat.com> > > --- > > fs/xfs/xfs_file.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c > > index 1f2e2845eb76..dced2eb8c91a 100644 > > --- a/fs/xfs/xfs_file.c > > +++ b/fs/xfs/xfs_file.c > > @@ -1203,6 +1203,14 @@ xfs_file_mmap( > > if (!IS_DAX(file_inode(filp)) && (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(filp)) && !dax_synchronous( > > + xfs_find_daxdev_for_inode(file_inode(filp))) && > > + (vma->vm_flags & VM_SYNC)) > > + return -EOPNOTSUPP; > > + > > file_accessed(filp); > > vma->vm_ops = &xfs_file_vm_ops; > > if (IS_DAX(file_inode(filp))) > > All this ad hoc IS_DAX conditional logic is getting pretty nasty. > > xfs_file_mmap( > .... > { > struct inode *inode = file_inode(filp); > > if (vma->vm_flags & VM_SYNC) { > if (!IS_DAX(inode)) > return -EOPNOTSUPP; > if (!dax_synchronous(xfs_find_daxdev_for_inode(inode)) > return -EOPNOTSUPP; > } > > file_accessed(filp); > vma->vm_ops = &xfs_file_vm_ops; > if (IS_DAX(inode)) > vma->vm_flags |= VM_HUGEPAGE; > return 0; > }
Sure, this is better.
> > > Even better, factor out all the "MAP_SYNC supported" checks into a > helper so that the filesystem code just doesn't have to care about > the details of checking for DAX+MAP_SYNC support....
o.k. Will add one common helper function for both ext4 & xfs filesystems.
Thanks for the suggestion.
Best regards, Pankaj
> > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com >
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