On Thu, May 10, 2018 at 4:58 AM, Goldwyn Rodrigues <rgoldwyn@xxxxxxx> wrote:
> From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
>
> Preparatory patch to carve out do_copy_file_range() from
> vfs_copy_file_range
>
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
> ---
> fs/read_write.c | 60 ++++++++++++++++++++++++++++++++-------------------------
> 1 file changed, 34 insertions(+), 26 deletions(-)
>
> diff --git a/fs/read_write.c b/fs/read_write.c
> index c4eabbfc90df..525f2a67e15a 100644
> --- a/fs/read_write.c
> +++ b/fs/read_write.c
> @@ -1541,6 +1541,38 @@ COMPAT_SYSCALL_DEFINE4(sendfile64, int, out_fd, int, in_fd,
> }
> #endif
>
> +static ssize_t do_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)
> +{
> + ssize_t ret = 0;
> +
> + if (len == 0)
> + return 0;
> +
> + /*
> + * Try cloning first, this is supported by more file systems, and
> + * more efficient if both clone and copy are supported (e.g. NFS).
> + */
> + if (file_in->f_op->clone_file_range) {
> + ret = file_in->f_op->clone_file_range(file_in, pos_in,
> + file_out, pos_out, len);
> + if (ret == 0)
> + return len;
> + }
> +
> + if (file_out->f_op->copy_file_range) {
> + ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out,
> + pos_out, len, flags);
> + if (ret != -EOPNOTSUPP)
> + return ret;
> + }
> +
> + ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
> + len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
> + return ret;
> +}
> +
> /*
> * copy_file_range() differs from regular file read and write in that it
> * specifically allows return partial success. When it does so is up to
> @@ -1579,35 +1611,11 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in,
> if (inode_in->i_sb != inode_out->i_sb)
> return -EXDEV;
>
> - if (len == 0)
> - return 0;
> -
> file_start_write(file_out);
>
> - /*
> - * Try cloning first, this is supported by more file systems, and
> - * more efficient if both clone and copy are supported (e.g. NFS).
> - */
> - if (file_in->f_op->clone_file_range) {
> - ret = file_in->f_op->clone_file_range(file_in, pos_in,
> - file_out, pos_out, len);
> - if (ret == 0) {
> - ret = len;
> - goto done;
> - }
> - }
> -
> - if (file_out->f_op->copy_file_range) {
> - ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out,
> - pos_out, len, flags);
> - if (ret != -EOPNOTSUPP)
> - goto done;
> - }
> -
> - ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
> - len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
> + ret = do_copy_file_range(file_in, pos_in,
> + file_out, pos_out, len, flags);
>
> -done:
> if (ret > 0) {
> fsnotify_access(file_in);
> add_rchar(current, ret);
> --
> 2.16.3
>
> --
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