On Wed, Sep 18, 2013 at 2:18 AM, Vyacheslav Dubeyko <slava@xxxxxxxxxxx> wrote: > Hi Michael, > > On Tue, 2013-09-17 at 18:42 -0400, Michael L. Semon wrote: >> Hi! I have an old multi-boot x86 PC that I use for testing. >> One of its root partitions is NILFS2, and it is booted via LILO and >> a JFS-formatted /boot partition. All seems fine, but the umount of / >> can hang, especially when NILFS2 had to recover / on boot in read-only >> mode due to a crash. Using KDB to get stack traces, I wonder if >> segctord is waiting for an event that will not happen. >> > > As far as I can see, your NILFS2 file system was remounted in RO mode > because of internal error. Could you confirm my understanding? Yes, but only on reboot. Other programs crash the PC, and NILFS2 has to recover from that crash. The PC spends a lot of time running xfstests and LTP with a kernel that is set to panic. NILFS2 itself seems OK, and its latest xfstests run looked good, using default mkfs.nilfs2 options and mounting with "-o pp=0". >> [Actually, the umount of NILFS2 partitons can hang in other cases, too. >> This is a narrow case that I can repeat fairly often.] >> >> Is there a guaranteed good way to shutdown nilfs_cleanerd and NILFS2 >> properly on system shutdown? I tried to ensure that the killall5 >> program doesn't touch nilfs_cleanerd on shutdown, but that solution >> has started to not work again. >> > > So, if you have remount in RO mode after some file system operations > then NILFS2 will have troubles with flushing and as a result with > shutdown. Such situation takes place because of continuous trying to > flush dirty pages without success in nilfs_write_page() and > nilfs_mdt_write_page(). This issue was fixed in patch [1]. It is strictly like this so far: 1) NILFS2 / boots OK 2) no problems 3) shutdown is OK 4) NILFS2 / boots OK 5) computer crashes for some other reason 6) NILFS2 / boots OK, but displays a message that recovery was used 7) no problems 8) here, shutdown may hang on sync or umount (50% chance) In other words, NILFS2 has not had an error to make it remount read-only while the PC is running. The problem may solve itself over time, or I may have to boot to another partition, then mount and umount the NILFS2 partition to get it to recover and umount cleanly again. > But I believe that now we understand the reason of the issue with > remounting in RO mode. I posted the patch [2] two weeks ago. This patch > is under discussion yet. > > Please, feel free to report about the issue again if these patches will > not solve your problem. I'll try your patches tonight and report back in 1-2 days. Thanks! Michael > Thanks, > Vyacheslav Dubeyko. > > [1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=8c26c4e2694a163d525976e804d81cd955bbb40c > [2] http://www.spinics.net/lists/linux-fsdevel/msg68054.html > > -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
