From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:57323) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hBvjM-00083S-T4 for qemu-devel@nongnu.org; Thu, 04 Apr 2019 02:20:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hBvc3-0000Zk-0Q for qemu-devel@nongnu.org; Thu, 04 Apr 2019 02:12:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40078) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hBvc2-0000ZE-LT for qemu-devel@nongnu.org; Thu, 04 Apr 2019 02:12:34 -0400 Date: Thu, 4 Apr 2019 02:12:30 -0400 (EDT) From: Pankaj Gupta Message-ID: <1518295599.17367903.1554358350929.JavaMail.zimbra@redhat.com> In-Reply-To: <20190403220912.GB26298@dastard> References: <20190403104018.23947-1-pagupta@redhat.com> <20190403104018.23947-6-pagupta@redhat.com> <20190403220912.GB26298@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v4 5/5] xfs: disable map_sync for async flush List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Dave Chinner , darrick wong Cc: linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-acpi@vger.kernel.org, qemu-devel@nongnu.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, dan j williams , zwisler@kernel.org, vishal l verma , dave jiang , mst@redhat.com, jasowang@redhat.com, willy@infradead.org, rjw@rjwysocki.net, hch@infradead.org, lenb@kernel.org, jack@suse.cz, tytso@mit.edu, adilger kernel , lcapitulino@redhat.com, kwolf@redhat.com, imammedo@redhat.com, jmoyer@redhat.com, nilal@redhat.com, riel@surriel.com, stefanha@redhat.com, aarcange@redhat.com, david@redhat.com, cohuck@redhat.com, xiaoguangrong eric 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 > > --- > > 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 >