DragonFlyBSD

jail(8) says that you must create an empty /etc/fstab to suppress the warnings:

"Create an empty /etc/fstab to quell startup warnings about missing fstab"

1. mount -p
   fstab: /etc/fstab:0: No such file or directory
   fstab: /etc/fstab:0: No such file or directory
   /dev/ad0s3f / ufs rw 1 1
2. touch /etc/fstab
3. mount -p
   /dev/ad0s3f / ufs rw 1 1 #

sjg at #drafonflybsd suggested that a "fix" (if agree there is a need for one)
woule be to only check for fstab once; if it doesn't exist, print an error, and
fall back to the non- "p" case.

What do you think ?

I don't think it should print a warning at all. This is not the time and
place to print a totally unrelated warning.

cheers
simon

One could ask why mount -p needs /etc/fstab to list the already mounted
filesystems. This happens because device block name, mount point and mount flags
are stored inside the statfs structure (which is returned by getfsstat syscall),
but dump frequency and pass number of fsck are not. This means that mount -p
must open /etc/fstab, parse the lines and get the desired values for every
mounted filesystem.

Thats why simon you get 2 warnings for every mounted filesystem. One while
looking for freq and another one for passno.

The code path that interests us is I think the following:

for every mounted filesystem
---> putfsent
--------> getfsspec
--------------> setfsent [ opens etc/fstab, prints warning ]
--------> getfsfile
--------------> setfsent [ opens etc/fstab, prints warning ]

The reason that freq and passno values are printed, is that there are some
fallback values in the code.

Honestly I don't know how to fix this. The code is messy enough as it is and
adding more cornerstones would make it worse.

Regards,
Stathis

Alright, I am working on a patch. I'll let you know.

Patch in
http://stathisk.ath.cx/0001-Issue-1253-mount-p-reports-bogus-errors-in-chroot.patch

Cheers,
Stathis

Updated patch, based on discussion with Simon in #dragonflybsd

http://stathisk.ath.cx/0001-Silent-mount-p-when-there-is-no-fstab-file.patch

:Stathis Kamperis <ekamperi@gmail.com> added the comment:
:
:Updated patch, based on discussion with Simon in #dragonfly
:
:http://stathisk.ath.cx/0001-Silent-mount-p-when-there-is-no-fstab-file.patch

Looks reasonable, but please put in matching braces.  If either
    part of an if statement sequence uses a braced block then both
    parts should use a braced block.  Just semantics but it makes the
    code more readable.

-Matt
                    Matthew Dillon 
                    <dillon@backplane.com>

Thanks for the feedback.

Matching braces added. Updated patch in the same link as before.

:Stathis Kamperis <ekamperi@gmail.com> added the comment:
:
:Updated patch, based on discussion with Simon in #dragonflybsd
:
:http://stathisk.ath.cx/0001-Silent-mount-p-when-there-is-no-fstab-file.patch

Looks good, I will commit it on Tuesday.

-Matt
                    Matthew Dillon 
                    <dillon@backplane.com>

committed as 3e5c58ea9fae3002473278841dec7b456daffe95