I was considering making a kernel patch that reported it was an exFATfilesystem when the mount failed, which you would see if you were onttyC0, or could call up with dmesg, as with the kernel messages thathappen when you first plug a drive in. Is there a concise "philosophy" of when the kernel should print amessage post-boot? Just when devices are dynamically configured?
-------- Original Message -------- Subject: Re: exFAT support From: Ingo Schwarze <schwa...@usta.de> Date: Thu, August 06, 2020 3:57 pm To: jo...@armadilloaerospace.com Cc: t...@openbsd.org Hi, in addition to what Bryan said... This message is wildly off-topic on tech@. If you reply, please reply to misc@. Quoting from https://www.openbsd.org/mail.html (please read that!): Developer lists: [...] t...@openbsd.org Discussion of technical topics for OpenBSD developers and advanced users. This is _not_ a "tech support" forum - do not use it as such. jo...@armadilloaerospace.com wrote on Thu, Aug 06, 2020 at 02:16:11PM -0700: > I tried to mount a 12TB USB drive, and was getting an "Inappropriate > file type or format" error. Even on misc@, when asking questions, please state what you are actually doing, showing the exact commands you type and the exact output you get, together in the original order, for example like this: isnote# mount -t msdos /dev/sd1a /mnt mount_msdos: /dev/sd1a on /mnt: Inappropriate file type or format > It turned out to be due to exFAT formatting, but it took me some > investigating to figure that out. Would it be reasonable to have the > kernel print You didn't say where you saw the message, but i assume it was the output of mount(8), not kernel output on the system console or in /var/log/messages. The kernel doesn't print such messages. The application program (e.g. mount(8)) prints them. All the kernel does is return an errno(2) to the mount(2) syscall. So you can find an exhaustive list of the messages that could be printed in the errno(2) manual page. Also, which errno(2) is returned from syscalls in which error case is not arbitrary and cannot be changed arbitrarily. > a more informative warning like "exFAT filesystem not > supported" when you try to mount it with mount_msdos, or are additional > kernel prints considered bad form? I bet if the kernel had printed anything, you wouldn't even have noticed. Besides, yes indeed, the kernel is absolutely not supposed to print anything when users type wrong commands. Yours, Ingo
