Re: git: 35b7759c05cb - main - cp: Fix build without VM_AND_BUFFER_CACHE_SYNCHRONIZED.

From: Rick Macklem <rmacklem_at_uoguelph.ca>
Date: Tue, 30 Aug 2022 15:02:08 UTC
Mateusz Guzik <mjguzik@gmail.com> wrote:
> On 8/30/22, Alexander Motin <mav@freebsd.org> wrote:
> > The branch main has been updated by mav:
> >
> > URL:
> > https://cgit.FreeBSD.org/src/commit/?id=35b7759c05cbc65c06d87141da79f0f80af0f458
> >
> > commit 35b7759c05cbc65c06d87141da79f0f80af0f458
> > Author:     Alexander Motin <mav@FreeBSD.org>
> > AuthorDate: 2022-08-30 14:51:21 +0000
> > Commit:     Alexander Motin <mav@FreeBSD.org>
> > CommitDate: 2022-08-30 14:51:21 +0000
> >
> >     cp: Fix build without VM_AND_BUFFER_CACHE_SYNCHRONIZED.
> >
> >     It allows to not use mmap() for small files, which is not helpful
> >     in case of ZFS.  Should be no functional change.
> >
> 
> This should be of no use thanks to copy_file_range
cp does not use copy_file_range(2) for small files, if I recall correctly.

rick

>     MFC after:      1 week
> ---
>  bin/cp/utils.c | 19 +++++++++----------
>  1 file changed, 9 insertions(+), 10 deletions(-)
>
> diff --git a/bin/cp/utils.c b/bin/cp/utils.c
> index e7ae0c9dd733..07de0495ba9e 100644
> --- a/bin/cp/utils.c
> +++ b/bin/cp/utils.c
> @@ -99,13 +99,12 @@ copy_file(const FTSENT *entp, int dne)
>       static char *buf = NULL;
>       static size_t bufsize;
>       struct stat *fs;
> -     ssize_t rcount, wcount;
> -     size_t wresid;
> +     ssize_t wcount;
>       off_t wtotal;
>       int ch, checkch, from_fd, rval, to_fd;
> -     char *bufp;
>  #ifdef VM_AND_BUFFER_CACHE_SYNCHRONIZED
> -     char *p;
> +     size_t wresid;
> +     char *bufp, *p;
>  #endif
>       int use_copy_file_range = 1;
>
> @@ -234,18 +233,18 @@ copy_file(const FTSENT *entp, int dne)
>                       wtotal = 0;
>                       do {
>                               if (use_copy_file_range) {
> -                                     rcount = copy_file_range(from_fd, NULL,
> +                                     wcount = copy_file_range(from_fd, NULL,
>                                           to_fd, NULL, SSIZE_MAX, 0);
> -                                     if (rcount < 0 && errno == EINVAL) {
> +                                     if (wcount < 0 && errno == EINVAL) {
>                                               /* Prob a non-seekable FD */
>                                               use_copy_file_range = 0;
>                                       }
>                               }
>                               if (!use_copy_file_range) {
> -                                     rcount = copy_fallback(from_fd, to_fd,
> +                                     wcount = copy_fallback(from_fd, to_fd,
>                                           buf, bufsize);
>                               }
> -                             wtotal += rcount;
> +                             wtotal += wcount;
>                               if (info) {
>                                       info = 0;
>                                       (void)fprintf(stderr,
> @@ -253,8 +252,8 @@ copy_file(const FTSENT *entp, int dne)
>                                           entp->fts_path, to.p_path,
>                                           cp_pct(wtotal, fs->st_size));
>                               }
> -                     } while (rcount > 0);
> -                     if (rcount < 0) {
> +                     } while (wcount > 0);
> +                     if (wcount < 0) {
>                               warn("%s", entp->fts_path);
>                               rval = 1;
>                       }
>
>


--
Mateusz Guzik <mjguzik gmail.com>