[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Ext2 superblock fault

From: Samuel Thibault
Subject: Re: Ext2 superblock fault
Date: Mon, 10 Mar 2008 01:19:28 +0000
User-agent: Mutt/1.5.12-2006-07-14

While having a beer with Gianluca, I thought about a possible case:

> Thread 7 (thread 588.7):
> #5  0x08052472 in write_all_disknodes ()
>     at /build/mbanck/hurd-20071119/build-tree/hurd/ext2fs/inode.c:592
> #6  0x08054a90 in diskfs_sync_everything (wait=0)

This thread is syncing everything, i.e. asking a lot of writes, which
triggers the creation of a lot of threads.  Unfortunately the superblock
was paged out, so they all block on reading it.  Unfortunately, since in
Debian there is a patch which limits the number of created threads,
the read of the superblock doesn't actually create a new thread, that is
delayed.  But since none of the existing threads can progress (since
they are all waiting for the super block), things are just dead

I'm currently using a quite ugly patch (on top of the >2GB patch) to
avoid this by just always keeping a copy of the superblock, attached.
I'll commit it in the Debian package.


Attachment: patch
Description: Text document

reply via email to

[Prev in Thread] Current Thread [Next in Thread]