> On Mar 10, 2017, at 6:00 PM, Robert Elz <k...@munnari.oz.au> wrote: > > In messages related to PR kern/52056 (in gnats) and on netbsd-bugs@n.o > (I am adding current-users as this needs opinions from a wider community). > > The PR is mostly about kernel issues, this issue with mount -u is only > relevant because that happened to trigger the kernel, if -u worked > differently, the actual problem from the PR might not have been noticed. > > Date: Fri, 10 Mar 2017 15:00:13 +0100 > From: =?UTF-8?B?SmFyb23DrXIgRG9sZcSNZWs=?= > <jaromir.dole...@gmail.com> > Message-ID: > <camnsw54zjhn1kj_-bg8hj11wsffzcy9xt0ebap52gjcrl3f...@mail.gmail.com> > > | Some volunteer for checking why the -u doesn't work as advertized? > > The issue is that the man page (mount(8)) says that -u takes options from > fstab, then the command line -o options, and then -r or -w - but the code > does not do that, fstab options are ignored with -u, only options from the > command line are used. > > It kind of seems to be deliberate - though I have no idea why. > > Back in the early days (until mid 1994) it seems to have worked as the > man page states - the relevant text in the man page has been essentially > unchanged since version 1.1. When 4.4-lite was incorporated in June 1994 > the code changed, and the following lines appeared ... > > /* If it's an update, ignore the fstab file options. */ > fs->fs_mntops = NULL; > > (in the code processing the -u case). The code was restructured in 1998, > but this was not altered in substance - the comment was deleted though. > > It has remained essentially unchanged ever since. > > So, it appears that 4.4-lite made this change, and apparently intentionally, > but I have no idea why. > > Changing it is trivial, if that is desired. The question now is, which > should be fixed, the man page, or the code? > > One last thing that's interesting, back in Nov 1997, a correction to the > man page has this as its commit log message ... > > Add a clarification how the missing data are looked up if either > mount source or target are omitted. Adresses PR 3240. > XXX This is not the complete truth. Things change with the -u > option. Should be fixed in "mount.c". > > The actual change that commit made is not relevant here, but the XXX > note indicates that way back then this issue was known, and at least one > developer thought it should be fixed in the source. > > So, does anyone believe that we should change the man page, and note that > options from fstab are ignored with -u, or should the code be changed so > that it works as the man page has (always) advertised (but which it hasn't > done for the past (almost) 23 years.) > > kre >
What do the other BSDs do in this case?