| Message ID | 20210209224754.GG3171@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | virtiofs: Fail dax mount if device does not support it | expand |
On Tue, Feb 09, 2021 at 05:47:54PM -0500, Vivek Goyal wrote: > Right now "mount -t virtiofs -o dax myfs /mnt/virtiofs" succeeds even > if filesystem deivce does not have a cache window and hence DAX can't > be supported. > > This gives a false sense to user that they are using DAX with virtiofs > but fact of the matter is that they are not. > > Fix this by returning error if dax can't be supported and user has asked > for it. > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > --- > fs/fuse/virtio_fs.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > Index: redhat-linux/fs/fuse/virtio_fs.c > =================================================================== > --- redhat-linux.orig/fs/fuse/virtio_fs.c 2021-02-04 10:40:21.704370721 -0500 > +++ redhat-linux/fs/fuse/virtio_fs.c 2021-02-09 15:56:45.693653979 -0500 > @@ -1324,8 +1324,15 @@ static int virtio_fs_fill_super(struct s > > /* virtiofs allocates and installs its own fuse devices */ > ctx->fudptr = NULL; > - if (ctx->dax) > + if (ctx->dax) { > + if (!fs->dax_dev) { > + err = -EINVAL; > + pr_err("virtio-fs: dax can't be enabled as filesystem" > + " device does not support it.\n"); > + goto err_free_fuse_devs; > + } > ctx->dax_dev = fs->dax_dev; > + } > err = fuse_fill_super_common(sb, ctx); > if (err < 0) > goto err_free_fuse_devs; Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
On Tue, Feb 09, 2021 at 05:47:54PM -0500, Vivek Goyal wrote: > Right now "mount -t virtiofs -o dax myfs /mnt/virtiofs" succeeds even > if filesystem deivce does not have a cache window and hence DAX can't > be supported. > > This gives a false sense to user that they are using DAX with virtiofs > but fact of the matter is that they are not. > > Fix this by returning error if dax can't be supported and user has asked > for it. Hi Miklos, Did you get a chance to look at this patch. Vivek > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > --- > fs/fuse/virtio_fs.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > Index: redhat-linux/fs/fuse/virtio_fs.c > =================================================================== > --- redhat-linux.orig/fs/fuse/virtio_fs.c 2021-02-04 10:40:21.704370721 -0500 > +++ redhat-linux/fs/fuse/virtio_fs.c 2021-02-09 15:56:45.693653979 -0500 > @@ -1324,8 +1324,15 @@ static int virtio_fs_fill_super(struct s > > /* virtiofs allocates and installs its own fuse devices */ > ctx->fudptr = NULL; > - if (ctx->dax) > + if (ctx->dax) { > + if (!fs->dax_dev) { > + err = -EINVAL; > + pr_err("virtio-fs: dax can't be enabled as filesystem" > + " device does not support it.\n"); > + goto err_free_fuse_devs; > + } > ctx->dax_dev = fs->dax_dev; > + } > err = fuse_fill_super_common(sb, ctx); > if (err < 0) > goto err_free_fuse_devs;
On Fri, Mar 5, 2021 at 2:34 PM Vivek Goyal <vgoyal@redhat.com> wrote: > > On Tue, Feb 09, 2021 at 05:47:54PM -0500, Vivek Goyal wrote: > > Right now "mount -t virtiofs -o dax myfs /mnt/virtiofs" succeeds even > > if filesystem deivce does not have a cache window and hence DAX can't > > be supported. > > > > This gives a false sense to user that they are using DAX with virtiofs > > but fact of the matter is that they are not. > > > > Fix this by returning error if dax can't be supported and user has asked > > for it. > > Hi Miklos, > > Did you get a chance to look at this patch. Thanks for the reminder. Pushed out now. Miklos
Index: redhat-linux/fs/fuse/virtio_fs.c =================================================================== --- redhat-linux.orig/fs/fuse/virtio_fs.c 2021-02-04 10:40:21.704370721 -0500 +++ redhat-linux/fs/fuse/virtio_fs.c 2021-02-09 15:56:45.693653979 -0500 @@ -1324,8 +1324,15 @@ static int virtio_fs_fill_super(struct s /* virtiofs allocates and installs its own fuse devices */ ctx->fudptr = NULL; - if (ctx->dax) + if (ctx->dax) { + if (!fs->dax_dev) { + err = -EINVAL; + pr_err("virtio-fs: dax can't be enabled as filesystem" + " device does not support it.\n"); + goto err_free_fuse_devs; + } ctx->dax_dev = fs->dax_dev; + } err = fuse_fill_super_common(sb, ctx); if (err < 0) goto err_free_fuse_devs;
Right now "mount -t virtiofs -o dax myfs /mnt/virtiofs" succeeds even if filesystem deivce does not have a cache window and hence DAX can't be supported. This gives a false sense to user that they are using DAX with virtiofs but fact of the matter is that they are not. Fix this by returning error if dax can't be supported and user has asked for it. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> --- fs/fuse/virtio_fs.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)