Reproducible crash in kAFS with just "cp -a"

[Gaja Sophie Peters]

Am 03.03.21 um 23:33 schrieb David Howells:

> Would it be possible for you to test the attached patch?

Thanks for the quick solution - the good news: it works!
"cp -a" runs through without any error.

The - hm - moderate news, an explicit "cp --preserve=xattr" gives
warnings (but at least does copy the file)

The not very good news, "rsync -X" fails without copying the file.

In detail:

> $ LC_ALL=C cp --preserve=xattr /afs/some.openafs.cell/some.file /tmp
> cp: getting attribute 'afs.yfs.acl' of 'afs.yfs.acl': No data available
> cp: getting attribute 'afs.yfs.acl_inherited' of 'afs.yfs.acl_inherited': No data available
> cp: getting attribute 'afs.yfs.acl_num_cleaned' of 'afs.yfs.acl_num_cleaned': No data available
> cp: getting attribute 'afs.yfs.vol_acl' of 'afs.yfs.vol_acl': No data available
> cp: setting attributes for '/tmp/krb5.conf': Operation not supported

The file /tmp/krb5.conf DOES exist in the end though.

> $ LC_ALL=C rsync -X /afs/some.openafs.cell/some.file /tmp
> rsync: get_xattr_data: lgetxattr("/afs/math.uni-hamburg.de/common/Windows/krb5.conf","afs.yfs.acl",0) failed: No data available (61)
> rsync error: some files/attrs were not transferred (see previous errors) (code 23) at main.c(1207) [sender=3.1.3]

rsync quit after encountering the first "unreadable" xattr and did NOT
copy the file krb5.conf.

I am not sure if this is in any way relevant, because when copying from
OpenAFS, nobody is going to include explicitly the instruction to copy
xattrs, it would only be relevant, if somebody uses backup-scripts or
something like that which include these parameters.

All these tests were with the line "afs.* skip" in the file /etc/xattr.conf


In the end the MOST important fact: there was no kernel crash (or any
other afs-related output in dmesg) in my attempts with the patched kernel.

Greetings,
Gaja Peters


-- 
+----------
| IT-Gruppe, Systemadministration
| Universität Hamburg, Fachbereich Mathematik
| Bundesstr. 55 (Geomatikum)
| Raum 212; Tel. 42838-5175
+----------