On Tue, Apr 04, 2023 at 09:10:47AM -0700, Darrick J. Wong wrote:
> On Tue, Apr 04, 2023 at 04:53:15PM +0200, Andrey Albershteyn wrote:
> > The direct path is not supported on verity files. Attempts to use direct
> > I/O path on such files should fall back to buffered I/O path.
> >
> > Signed-off-by: Andrey Albershteyn <aalbe...@redhat.com>
> > ---
> > fs/xfs/xfs_file.c | 14 +++++++++++---
> > 1 file changed, 11 insertions(+), 3 deletions(-)
> >
> > diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> > index 947b5c436172..9e072e82f6c1 100644
> > --- a/fs/xfs/xfs_file.c
> > +++ b/fs/xfs/xfs_file.c
> > @@ -244,7 +244,8 @@ xfs_file_dax_read(
> > struct kiocb *iocb,
> > struct iov_iter *to)
> > {
> > - struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host);
> > + struct inode *inode = iocb->ki_filp->f_mapping->host;
> > + struct xfs_inode *ip = XFS_I(inode);
> > ssize_t ret = 0;
> >
> > trace_xfs_file_dax_read(iocb, to);
> > @@ -297,10 +298,17 @@ xfs_file_read_iter(
> >
> > if (IS_DAX(inode))
> > ret = xfs_file_dax_read(iocb, to);
> > - else if (iocb->ki_flags & IOCB_DIRECT)
> > + else if (iocb->ki_flags & IOCB_DIRECT && !fsverity_active(inode))
> > ret = xfs_file_dio_read(iocb, to);
> > - else
> > + else {
> > + /*
> > + * In case fs-verity is enabled, we also fallback to the
> > + * buffered read from the direct read path. Therefore,
> > + * IOCB_DIRECT is set and need to be cleared
> > + */
> > + iocb->ki_flags &= ~IOCB_DIRECT;
> > ret = xfs_file_buffered_read(iocb, to);
>
> XFS doesn't usually allow directio fallback to the pagecache. Why
> would fsverity be any different?
Didn't know that, this is what happens on ext4 so I did the same.
Then it probably make sense to just error on DIRECT on verity
sealed file.
>
> --D
>
> > + }
> >
> > if (ret > 0)
> > XFS_STATS_ADD(mp, xs_read_bytes, ret);
> > --
> > 2.38.4
> >
>
--
- Andrey
