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 1hBvjL-00083S-Ro for qemu-devel@nongnu.org; Thu, 04 Apr 2019 02:20:08 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hBvd6-000226-Bc for qemu-devel@nongnu.org; Thu, 04 Apr 2019 02:13:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:4653) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hBvd6-00021O-0b for qemu-devel@nongnu.org; Thu, 04 Apr 2019 02:13:40 -0400 Date: Thu, 4 Apr 2019 02:13:38 -0400 (EDT) From: Pankaj Gupta Message-ID: <1508883801.17367965.1554358418550.JavaMail.zimbra@redhat.com> In-Reply-To: <20190403223921.GM5147@magnolia> References: <20190403104018.23947-1-pagupta@redhat.com> <20190403104018.23947-6-pagupta@redhat.com> <20190403220912.GB26298@dastard> <20190403223921.GM5147@magnolia> 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: "Darrick J. Wong" Cc: Dave Chinner , 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 > > On Thu, Apr 04, 2019 at 09:09:12AM +1100, Dave Chinner wrote: > > 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.... > > Seconded, since ext4 has nearly the same flag validation logic. Agree. Thanks, Pankaj > > --D > > > > > Cheers, > > > > Dave. > > -- > > Dave Chinner > > david@fromorbit.com >