From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([209.51.188.92]:54235) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hBo4d-0002L3-NO for qemu-devel@nongnu.org; Wed, 03 Apr 2019 18:09:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hBo4b-0007qj-KW for qemu-devel@nongnu.org; Wed, 03 Apr 2019 18:09:35 -0400 Received: from ipmail03.adl6.internode.on.net ([150.101.137.143]:38080) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hBo4W-0007VK-R7 for qemu-devel@nongnu.org; Wed, 03 Apr 2019 18:09:31 -0400 Date: Thu, 4 Apr 2019 09:09:12 +1100 From: Dave Chinner Message-ID: <20190403220912.GB26298@dastard> References: <20190403104018.23947-1-pagupta@redhat.com> <20190403104018.23947-6-pagupta@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190403104018.23947-6-pagupta@redhat.com> 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: Pankaj Gupta 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@intel.com, zwisler@kernel.org, vishal.l.verma@intel.com, dave.jiang@intel.com, 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@dilger.ca, darrick.wong@oracle.com, 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@gmail.com On Wed, Apr 03, 2019 at 04:10:18PM +0530, Pankaj Gupta wrote: > 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; } 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.... Cheers, Dave. -- Dave Chinner david@fromorbit.com