Date: Tue, 20 Jan 1998 09:23:05 +0300 (MSK) From: Fedor Gubarev <Fedor.Gubarev@itep.ru> To: freebsd-questions@FreeBSD.ORG Subject: mount_umap and system crash. Message-ID: <Pine.BSF.3.96.980120092118.1496A-100000@raven.itep.ru>
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Hi,
I have a problem with mount_umap command -- every time it results
in crash of the system (2.2.5 release)... I don't know what's
this - it really looks like a bug.
Symptoms:
1) Trying to include support of NULLFS and UMAPFS in the
kernel configuration file, I get the following:
Options: options NULLFS
options UMAPFS
options SAFETY
work fine, but with "options NULLFS_DIAGNOSTIC" or
"options UMAPFS_DIAGNOSTIC" compilation of the kernel fails (although
config reports no problems).
2) The usage of mount_umap reported in "man 8 mount_umap" is different
from the actual usage of this command. Compare:
# man 8 mount_umap
mount_umap [-o options] target mount-point uid-mapfile gid-mapfile
#mount_umap
usage: mount_umap [-o options] -u usermap -g groupmap target_fs mount_point
3) A simplest way to crash the system using mount_umap is:
with uid-mapfile and gid-mapfile consisting of a single line "0"
do:
# mount_umap -u uid-mapfile -g gid-mapfile /var /mnt
With this command everything is OK untill you try:
# umount /mnt
Immediate system crash follows with some kernel message.
4) Another way to crash: suppose you may mount NFS file system:
#mount -t nfs SomeHost:/somefs /home/somefs
Now with uid-mapfile, gid-mapfile as in 3) do:
# mount_umap -u uid-mapfile -g gid-mapfile /home/somefs /mnt
Immediate crash follows after the command like:
#ls -l /mnt
------------------
Please, help, since I don't understand what is going wrong.
For everybody who are interested in I may give complete kernel output
in the case 3)-4) or any other needed details (but this means one more
crash....)
Thanks for your attention, Gubarev Fedor.
Fedor.Gubarev@itep.ru
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