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References: <20181203083416.28978-1-david@fromorbit.com> <20181203083416.28978-10-david@fromorbit.com>
In-Reply-To: <20181203083416.28978-10-david@fromorbit.com>
From:   Olga Kornievskaia <olga.kornievskaia@gmail.com>
Date:   Mon, 3 Dec 2018 12:58:09 -0500
Message-ID: <CAN-5tyFs9RuoDOnsB36KUEGymMOxb7=VUYqJOxYgUxMu6w7fFg@mail.gmail.com>
Subject: Re: [PATCH 09/11] vfs: push copy_file_ranges -EXDEV checks down
To:     david@fromorbit.com
Cc:     linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org,
        linux-nfs <linux-nfs@vger.kernel.org>,
        linux-unionfs@vger.kernel.org, ceph-devel@vger.kernel.org,
        linux-cifs@vger.kernel.org
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Sender: linux-nfs-owner@vger.kernel.org
Precedence: bulk

On Mon, Dec 3, 2018 at 3:34 AM Dave Chinner <david@fromorbit.com> wrote:
>
> From: Dave Chinner <dchinner@redhat.com>
>
> We want to enable cross-filesystem copy_file_range functionality
> where possible, so push the "same superblock only" checks down to
> the individual filesystem callouts so they can make their own
> decisions about cross-superblock copy offload.
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>

Overall VFS/NFS bits look good to me. I'm re-basing my client and
server patch series on top of this and will test it out.

Thank you.

> ---
>  fs/ceph/file.c      |  4 +++-
>  fs/cifs/cifsfs.c    |  8 +++++++-
>  fs/fuse/file.c      |  5 ++++-
>  fs/nfs/nfs4file.c   | 16 ++++++++++------
>  fs/overlayfs/file.c | 10 +++++++++-
>  fs/read_write.c     | 10 ++++------
>  6 files changed, 37 insertions(+), 16 deletions(-)
>
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index cf29f0410dcb..eb876e19c1dc 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -1905,6 +1905,8 @@ static ssize_t __ceph_copy_file_range(struct file *src_file, loff_t src_off,
>
>         if (src_inode == dst_inode)
>                 return -EINVAL;
> +       if (src_inode->i_sb != dst_inode->i_sb)
> +               return -EXDEV;
>         if (ceph_snap(dst_inode) != CEPH_NOSNAP)
>                 return -EROFS;
>
> @@ -2105,7 +2107,7 @@ static ssize_t ceph_copy_file_range(struct file *src_file, loff_t src_off,
>         ret = __ceph_copy_file_range(src_file, src_off, dst_file, dst_off,
>                                         len, flags);
>
> -       if (ret == -EOPNOTSUPP)
> +       if (ret == -EOPNOTSUPP || ret == -EXDEV)
>                 ret = generic_copy_file_range(src_file, src_off, dst_file,
>                                         dst_off, len, flags);
>         return ret;
> diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
> index 5ef4baec6234..03e4b9eacbd1 100644
> --- a/fs/cifs/cifsfs.c
> +++ b/fs/cifs/cifsfs.c
> @@ -1072,6 +1072,12 @@ ssize_t cifs_file_copychunk_range(unsigned int xid,
>                 goto out;
>         }
>
> +       if (src_inode->i_sb != target_inode->i_sb) {
> +               rc = -EXDEV;
> +               goto out;
> +       }
> +
> +
>         if (!src_file->private_data || !dst_file->private_data) {
>                 rc = -EBADF;
>                 cifs_dbg(VFS, "missing cifsFileInfo on copy range src file\n");
> @@ -1142,7 +1148,7 @@ static ssize_t cifs_copy_file_range(struct file *src_file, loff_t off,
>                                         len, flags);
>         free_xid(xid);
>
> -       if (rc == -EOPNOTSUPP)
> +       if (rc == -EOPNOTSUPP || rc == -EXDEV)
>                 rc = generic_copy_file_range(src_file, off, dst_file,
>                                         destoff, len, flags);
>         return rc;
> diff --git a/fs/fuse/file.c b/fs/fuse/file.c
> index b86fb0298739..0758f831a4eb 100644
> --- a/fs/fuse/file.c
> +++ b/fs/fuse/file.c
> @@ -3053,6 +3053,9 @@ static ssize_t __fuse_copy_file_range(struct file *file_in, loff_t pos_in,
>         if (fc->no_copy_file_range)
>                 return -EOPNOTSUPP;
>
> +       if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
> +               return -EXDEV;
> +
>         inode_lock(inode_out);
>
>         if (fc->writeback_cache) {
> @@ -3109,7 +3112,7 @@ static ssize_t fuse_copy_file_range(struct file *src_file, loff_t src_off,
>         ret = __fuse_copy_file_range(src_file, src_off, dst_file, dst_off,
>                                         len, flags);
>
> -       if (ret == -EOPNOTSUPP)
> +       if (ret == -EOPNOTSUPP || ret == -EXDEV)
>                 ret = generic_copy_file_range(src_file, src_off, dst_file,
>                                         dst_off, len, flags);
>         return ret;
> diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
> index d7766a6eb0f4..4783c0c1c49e 100644
> --- a/fs/nfs/nfs4file.c
> +++ b/fs/nfs/nfs4file.c
> @@ -133,16 +133,20 @@ static ssize_t nfs4_copy_file_range(struct file *file_in, loff_t pos_in,
>                                     struct file *file_out, loff_t pos_out,
>                                     size_t count, unsigned int flags)
>  {
> -       ssize_t ret;
> +       ssize_t ret = -EXDEV;
>
>         if (file_inode(file_in) == file_inode(file_out))
>                 return -EINVAL;
> -retry:
> -       ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count);
> -       if (ret == -EAGAIN)
> -               goto retry;
>
> -       if (ret == -EOPNOTSUPP)
> +       /* only offload copy if superblock is the same */
> +       if (file_inode(file_in)->i_sb == file_inode(file_out)->i_sb) {
> +               do {
> +                       ret = nfs42_proc_copy(file_in, pos_in, file_out,
> +                                       pos_out, count);
> +               } while (ret == -EAGAIN);
> +       }
> +
> +       if (ret == -EOPNOTSUPP || ret == -EXDEV)
>                 ret = generic_copy_file_range(file_in, pos_in, file_out,
>                                         pos_out, count, flags);
>         return ret;
> diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
> index 68736e5d6a56..34fb0398d016 100644
> --- a/fs/overlayfs/file.c
> +++ b/fs/overlayfs/file.c
> @@ -443,6 +443,14 @@ static loff_t ovl_copyfile(struct file *file_in, loff_t pos_in,
>         const struct cred *old_cred;
>         loff_t ret;
>
> +       /*
> +        * Temporary. Cross device copy checks should be left to the copy file
> +        * call on the real inodes, but existing behaviour checks the upper
> +        * files only.
> +        */
> +       if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
> +               return -EXDEV;
> +
>         ret = ovl_real_fdget(file_out, &real_out);
>         if (ret)
>                 return ret;
> @@ -491,7 +499,7 @@ static ssize_t ovl_copy_file_range(struct file *file_in, loff_t pos_in,
>         ret =  ovl_copyfile(file_in, pos_in, file_out, pos_out, len, flags,
>                             OVL_COPY);
>
> -       if (ret == -EOPNOTSUPP)
> +       if (ret == -EOPNOTSUPP || ret == -EXDEV)
>                 ret = generic_copy_file_range(file_in, pos_in, file_out,
>                                         pos_out, len, flags);
>         return ret;
> diff --git a/fs/read_write.c b/fs/read_write.c
> index 174cf92eea1d..4e0666de0d69 100644
> --- a/fs/read_write.c
> +++ b/fs/read_write.c
> @@ -1565,6 +1565,10 @@ ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
>                             struct file *file_out, loff_t pos_out,
>                             size_t len, unsigned int flags)
>  {
> +       /* Temporary, do_splice_direct supports cross-sb copies */
> +       if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb)
> +               return -EXDEV;
> +
>         return do_splice_direct(file_in, &pos_in, file_out, &pos_out,
>                         len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
>  }
> @@ -1611,17 +1615,11 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
>                             struct file *file_out, loff_t pos_out,
>                             size_t len, unsigned int flags)
>  {
> -       struct inode *inode_in = file_inode(file_in);
> -       struct inode *inode_out = file_inode(file_out);
>         ssize_t ret;
>
>         if (flags != 0)
>                 return -EINVAL;
>
> -       /* this could be relaxed once a method supports cross-fs copies */
> -       if (inode_in->i_sb != inode_out->i_sb)
> -               return -EXDEV;
> -
>         ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len,
>                                         flags);
>         if (ret < 0)
> --
> 2.19.1
>