-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 roland wrote: > Hi Bryn, > > after some first tests which looked very very promising (could dmlosetup > files >2gb, could create more than 256 loop dm-loop devices...), i have > bad news. > maybe it`s not that "bad" because you may be able to fix it quickly, but > it seems that dm-loop is racy (or whatever). maybe smp safeness, since i > was testing on a P4 with HT enabled ? i did my first tests on non-smp > system (VM), but it wasn`t put under that load as i did now. Hi Roland, At first sight, this doesn't look SMP related. The backtrace you posted comes from a BUG() macro in the source that triggers when we can't find an extent we're looking for in the table. There's also a rather odd number in the "not using" message: device-mapper: loop: not using 4294967296 bytes in incomplete block at EOF So I think for some reason we're not building a correct block map for this file. I'll have time to take a proper look at this this evening - while I'm looking into this one, do you have any other info on the file that gave the problem: - - was it a sparse file? - - was an offset used when creating the device? If you have the time, I'd also be interested in seeing the following information: - - output of dmsetup table <device> - - debugfs output for the loop file concerned For the first one, there's no need to perform any I/O to the device after creating it, so you shouldn't need to trigger the BUG() again - it might help to kill udevd though, as it will try to run vol_id etc. on the device otherwise. For the debugfs data, please run the attached script on the device/file that had the problem, for e.g.: do_debugfs.sh /dev/hda3 src/5gig.dat > /tmp/5gig.dat.out The first argument is the device containing the file and the second is the path relative to the device's root directory - change the path/device to suit your system. This will give a complete block map for the file so I can see what we're tripping over. For a 5G file this may take a few minutes and the file will be 50-100k in size - you can send it to me privately rather than spamming the whole list :) > ps: > hey, why not announcing this on lkml, so this gut get some more notice > or being reviewed by others? So that we can work these kind of problems out first! ;) Kind regards, Bryn. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org iD8DBQFF0Iai6YSQoMYUY94RAiNmAKC99G8+slz+tVDnSkCiVsPN6GVoJwCeJcCg wQ3iLG/ZVzGsualWfcmVv34= =y8/d -----END PGP SIGNATURE-----
Attachment:
do_debugfs.sh
Description: application/shellscript
-- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
