empty files being written instead of data

[bunder2015]

System information

Type	Version/Name
Distribution Name	gentoo
Distribution Version	-
Linux Kernel	4.9.16
Architecture	amd64
ZFS Version	0.7.0-rc4_12_g3d6da72
SPL Version	0.7.0-rc4_1_g8f87971

Describe the problem you're observing

May be related to #6050

My laptop is one sick puppy. First I was getting these:

/var/tmp/portage/gnome-extra/libgda-5.2.4-r2/temp/environment: line 283: Binary: command not found

This morning I got an email from cron:

bzip2: /usr/share/man/man7/gnupg.7.bz2 is not a bzip2 file.
bzip2: /usr/share/man/man7/gnupg.7.bz2 is not a bzip2 file.
bzip2: /usr/share/man/man8/nfsidmap.8.bz2 is not a bzip2 file.
bzip2: /usr/share/man/man8/nfsidmap.8.bz2 is not a bzip2 file.
bzip2: /usr/share/man/man8/umount.nfs.8.bz2 is not a bzip2 file.
bzip2: /usr/share/man/man8/umount.nfs.8.bz2 is not a bzip2 file.
... list truncated for sanity

Recompiling the affected packages fixed that, but then I got this after recompiling qtgui:

/sbin/ldconfig: /usr/lib64/qt4/libQtScriptTools.so.4 is not an ELF file - it has the wrong magic bytes at the start.

/sbin/ldconfig: /usr/lib64/qt4/libQtGui.so.4 is not an ELF file - it has the wrong magic bytes at the start.
... list truncated for sanity

arrandale ~ # file /usr/lib64/qt4/libQtGui.so
/usr/lib64/qt4/libQtGui.so: symbolic link to libQtGui.so.4.8.7
arrandale ~ # file /usr/lib64/qt4/libQtGui.so.4.8.7
/usr/lib64/qt4/libQtGui.so.4.8.7: data
arrandale ~ # less /usr/lib64/qt4/libQtGui.so.4.8.7
00000000  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
*
00ab75f0

Empty files? Something is seriously wrong here... (I looked at the wrong file, but you get the point, the man pages above were also empty files)

Describe how to reproduce the problem

Run a gentoo system on head? I'm honestly not sure at this point. Scrub and smart are good.

Include any warning/errors/backtraces from the system logs

See above

PS: I'm willing to test anything you can throw at me to see if this is indeed 6050.

[bunder2015]

In retrospect, this might have been caused by setting zfs_dmu_offset_next_sync=1 for a couple hours in haste when I saw that "Binary" message a couple days ago. I'm going to keep this open for now though.

[bunder2015]

I'm going to close this, recent package upgrades aren't doing this anymore. Lesson learned, don't play with the tuneables. 😄

[bunder2015]

In retrospect, this may actually be a duplicate of #3125. Not sure why I didn't see that one before.

I still see this on my laptop every now and again from installing/upgrading packages, and reinstalling the affected packages usually fixes it.

I'm going to keep this closed still since 3125 is still open.