On 10/19 09:34, Jeremy Evans wrote:
> Currently, when creating an archive file with pax(1), pax will attempt
> to open a file even if the file will be skipped due to an -s
> replacement with the empty string. With this change, pax will not
> attempt to open files that it knows will be skipped.
>
> When doing direct copies to a directory (-rw), pax already skips
> the file before attempting to open it. So this makes the behavior
> more consistent.
>
> My main reason for this change is to be able to silence the following
> warning when backing up:
>
> pax: Unable to open /etc/spwd.db to read: Operation not permitted
>
> One other possible benefit is if you are skipping a lot of files,
> avoiding the open syscall for each file may make pax faster.
>
> OKs?
Ping. I still think this is worth doing. I've tested and it is also
measurably faster (25%) if you are excluding a lot of files:
$ doas time obj/pax -f /dev/null -w -x cpio -s '/^.*$//' /some-path
2.65 real 1.95 user 0.73 sys
$ doas time pax -f /dev/null -w -x cpio -s '/^.*$//' /some-path
3.34 real 2.04 user 1.30 sys
OKs?
Thanks,
Jeremy
>
> Jeremy
>
> Index: ar_subs.c
> ===================================================================
> RCS file: /cvs/src/bin/pax/ar_subs.c,v
> retrieving revision 1.49
> diff -u -p -r1.49 ar_subs.c
> --- ar_subs.c 28 Jun 2019 13:34:59 -0000 1.49
> +++ ar_subs.c 19 Oct 2021 16:05:31 -0000
> @@ -441,6 +441,23 @@ wr_archive(ARCHD *arcn, int is_app)
> if (hlk && (chk_lnk(arcn) < 0))
> break;
>
> + /*
> + * Modify the name as requested by the user
> + */
> + if ((res = mod_name(arcn)) < 0) {
> + /*
> + * pax finished, purge link table entry and stop
> + */
> + purg_lnk(arcn);
> + break;
> + } else if (res > 0) {
> + /*
> + * skipping file, purge link table entry
> + */
> + purg_lnk(arcn);
> + continue;
> + }
> +
> if (PAX_IS_REG(arcn->type) || (arcn->type == PAX_HRG)) {
> /*
> * we will have to read this file. by opening it now we
> @@ -456,20 +473,7 @@ wr_archive(ARCHD *arcn, int is_app)
> }
> }
>
> - /*
> - * Now modify the name as requested by the user
> - */
> - if ((res = mod_name(arcn)) < 0) {
> - /*
> - * name modification says to skip this file, close the
> - * file and purge link table entry
> - */
> - rdfile_close(arcn, &fd);
> - purg_lnk(arcn);
> - break;
> - }
> -
> - if ((res > 0) || (docrc && (set_crc(arcn, fd) < 0))) {
> + if (docrc && (set_crc(arcn, fd) < 0)) {
> /*
> * unable to obtain the crc we need, close the file,
> * purge link table entry
