[issue1793] tmpfs calling bawrite instead of buwrite

Alex Hornung (via DragonFly issue tracker) sinknull at leaf.dragonflybsd.org
Sat Jul 10 10:16:45 PDT 2010

New submission from Alex Hornung <ahornung at gmail.com>:

While testing lvm root mounts, I've encountered an issue with tmpfs. In the 
initrd environment I'm mounting /tmp and /var from tmpfs, and creating a small 
directory structure on them. So far so good, but when lvm creates a bunch of 
files on one of the mount points, the writes fail.
It seems buwrite() should be called, but bawrite is being called due to the 
(uio->uio_segflg == UIO_NOCOPY) check in tmpfs_write.

These screenshots show the symptom:
This second shot shows the relevant flags, etc that are used in the checks 
whenever the tmpfs_write bwrite error message is called.

And this is the commit that introduced that check:

The initrd basically runs an extremely minimalistic /sbin/init that just 
launches another extremely minimalistic /etc/rc, which just does the stuff 
described above. No swap is activated at this time, of course. Also, there 
should be no memory pressure whatsoever.

messages: 8714
nosy: alexh
status: unread
title: tmpfs calling bawrite instead of buwrite

DragonFly issue tracker <bugs at lists.dragonflybsd.org>

More information about the Bugs mailing list