Distribution: Debian testing/unstable Software Environment: Kernel is actually from http://wiki.debian.org/DebianKernel. Version is 2.6.27-1~experimental.1~snapshot.12516, which appears to be based on 2.6.27.10. Problem Description: I was downloading a file in firefox when my machine starting beeping and I repeatedly had a stacktrace printed to a terminal (see photo). Steps to reproduce: This may or may not be related, but ever since I backed up and restored to a new ext4 filesystem, I've had a lot of trouble downloading stuff with firefox. Symptoms are I'll get to 100% completed download and then it hangs. The directory contains the normal .part but firefox never moves it to the proper name (i.e. whatever.part -> whatever). Most stuff still downloads ok, but I'd estimate since I've gone ext3->ext4 this has happened ~5 times. Also, I'm pretty sure when this happens the download isn't 100% correct. The one time I checked the md5sum did not match.
Created attachment 19740 [details] backtrace from console
This is journal_start failing: /* start a new transaction*/ handle = ext4_journal_start(inode, needed_blocks); if (IS_ERR(handle)) { ret = PTR_ERR(handle); printk(KERN_EMERG "%s: jbd2_start: " "%ld pages, ino %lu; err %d\n", __func__, wbc->nr_to_write, inode->i_ino, ret); dump_stack(); goto out_writepages; } with error -30, which is EROFS. Were there other messages before this, maybe an errors=remount-readonly sort of filesystem problem? Did the filesystem go readonly?
Yes, the filesystem went read only. Unfortunately, I wasn't in the room when it happened and by the time I came in, dmesg was just filled with this backtrace. If it helps, I snapped pictures of the fsck on reboot too. I'll attach those.
Created attachment 19741 [details] fsck part 1
Created attachment 19742 [details] fsck part 2
There was at least one ext4 bug that could have caused this that was fixed in 2.6.28 as well as in the 2.6.29 merge window. Unfortunately, we need to see the original bug to know which bug might as caused the problem. There was also a more recent bug fix that makes ext4_da_writepages much less verbose, since that tends to hide the original root cause of the problem....
Any luck reproducing this problem, especially on a more recent kernel version?
This has not happened again both on 2.6.27 and on 2.6.29 (what I'm running now).
Assigning to myself so I can close.
It sounds like this is fixed, though unfortunately we don't have a nice commit to point to. If this shows up again, please do re-open. Thanks, -Eric