This is what's happening: 1 - boot UML using root_fs 2 - shutdown UML - doesn't shutdown properly, leaving root_fs open and locked 3 - boot UML again 4 - new UML cannot use root_fs due to lock held by old UML
I am seeing this problem on my setup. "shutdown" on a UML does not terminate. It gets to the "power down" point but the /usr/bin/linux process does not exit, rather it hangs forever. If I hit ^C then I get a shell prompt back, but there is still a [linux] process which cannot be killed. This is 2.4.26-3um running on host 2.6.10 with the skas3-v8 patch. Observe: baron:~# ps axuww | grep linux usermode 954 0.0 0.0 304 300 ? T Apr29 1:15 [linux] usermode 24870 0.0 0.4 262232 8620 ? T 18:32 0:00 linux con0=fd:0,fd:1 mem=256m eth0=tuntap,,,10.1.0.1ubd0=linux-mantis.image usermode 24991 0.9 3.2 262248 67180 pts/4 S+ 18:38 0:11 linux [depmod] con0=fd:0,fd:1 mem=256m eth0=tuntap,,,10.1.0.1ubd0=linux-mantis.image usermode 24994 0.2 0.1 16392 2124 pts/4 T+ 18:38 0:03 [linux] usermode 25003 0.0 3.2 262248 67180 pts/4 S+ 18:38 0:00 linux [depmod] con0=fd:0,fd:1 mem=256m eth0=tuntap,,,10.1.0.1ubd0=linux-mantis.image usermode 25004 0.0 3.2 262248 67180 pts/4 S+ 18:38 0:00 linux [depmod] con0=fd:0,fd:1 mem=256m eth0=tuntap,,,10.1.0.1ubd0=linux-mantis.image usermode 25005 0.0 3.2 262248 67180 pts/4 S+ 18:38 0:00 linux [depmod] con0=fd:0,fd:1 mem=256m eth0=tuntap,,,10.1.0.1ubd0=linux-mantis.image The last 4 processes are a working UML instance. The first two are old UMLs which did not shutdown or startup correctly. Status 'T' means "traced or stopped". Not a zombie, so it should be killable. baron:~# ls -l /proc/954/fd total 20 lrwx------ 1 root root 64 May 5 18:59 0 -> /dev/pts/0 (deleted) lrwx------ 1 root root 64 May 5 18:59 1 -> /dev/pts/0 (deleted) lrwx------ 1 root root 64 May 5 18:59 10 -> socket:[2912] lrwx------ 1 root root 64 May 5 18:59 11 -> socket:[2913] lrwx------ 1 root root 64 May 5 18:59 12 -> socket:[2914] lrwx------ 1 root root 64 May 5 18:59 13 -> /baron/FileSystems/linux-mantis.image (deleted) l-wx------ 1 root root 64 May 5 18:59 14 -> /proc/mm l-wx------ 1 root root 64 May 5 18:59 15 -> /proc/mm l-wx------ 1 root root 64 May 5 18:59 16 -> /proc/mm l-wx------ 1 root root 64 May 5 18:59 17 -> /proc/mm lr-x------ 1 root root 64 May 5 18:59 18 -> /baron/.uml/wnTBF0 (deleted) lrwx------ 1 root root 64 May 5 18:59 19 -> socket:[2924] lrwx------ 1 root root 64 May 5 18:59 2 -> /dev/pts/0 (deleted) lrwx------ 1 root root 64 May 5 18:59 3 -> /tmp/vm_file-iUsEEz (deleted) lrwx------ 1 root root 64 May 5 18:59 4 -> socket:[2905] lrwx------ 1 root root 64 May 5 18:59 5 -> socket:[2906] lrwx------ 1 root root 64 May 5 18:59 6 -> socket:[2907] lrwx------ 1 root root 64 May 5 18:59 7 -> socket:[2909] lrwx------ 1 root root 64 May 5 18:59 8 -> socket:[2910] lrwx------ 1 root root 64 May 5 18:59 9 -> socket:[2911] I had to copy the filesystem image to another file and rename it over the top of the original before I could run UML again. baron:~# kill -9 954 baron:~# kill -9 954 baron:~# kill -9 954 baron:~# kill -9 954 baron:~# kill -9 24870 baron:~# kill -9 24870 baron:~# kill -9 24870 baron:~# kill -9 24870 baron:~# ps uww 954 USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND usermode 954 0.0 0.0 304 300 ? T Apr29 1:15 [linux] These processes cannot be killed. But I just found that I can do this: baron:~# kill -CONT 954 baron:~# kill -9 954 -bash: kill: (954) - No such process baron:~# kill -CONT 24870 baron:~# ps uww 24860 USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND So sending them a SIGCONT gets the process going again. That leaves the questions: why did the shutdown hang in the first place, is the process SIGSTOPing itself, and if I had done a "kill -CONT" before doing a "kill -9" would the process have exited cleanly? Nick. -- PGP Key ID = 0x418487E7 http://www.nick-andrew.net/ PGP Key fingerprint = B3ED 6894 8E49 1770 C24A 67E3 6266 6EB9 4184 87E7 "I'm not out to destroy Microsoft. That will just be a completely unintentional side effect." -- Linus Torvalds, Sep 2003
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