On Mon, Feb 04, 2008 at 10:23:16AM -0500, Josef Bacik wrote: > On Monday 04 February 2008 5:12:28 am Aneesh Kumar K.V wrote: > > Hi, > > > > This is with the new ext3 -> ext4 migrate code added. The recently added > > lockdep for jbd2 helped to find this out. We want to hold the i_data_sem > > on the ext3 inode during migration to prevent walking the ext3 inode > > when it is being converted to ext4 format. Also we want to avoid > > file truncation and new blocks being added while converting to ext4. > > Also we dont want to reserve large number of credits for journal. > > Any idea how to fix this ? > > > > Hello, > > Seems you should be taking the i_data_sem after starting the journal in > ext4_ext_migrate. I haven't looked at this stuff too much, but everywhere I > see i_data_sem taken its within a journal_start/journal_stop. Here's the > patch. Let me know if I'm way off btw, like I said I'm new to this :). Thank > you, But that doesn't help. Because we call ext4_journal_restart after taking i_data_sem. That implies we can sleep waiting for other running transaction to commit. And if that transaction (in the above example rm) is waiting for i_data_sem we deadlock. -aneesh - To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
