On Mon, 10 Oct 2011 16:35:24 -0700 Allison Henderson <achender@xxxxxxxxxxxxxxxxxx> wrote: > On 10/10/2011 12:47 PM, Jonathan Corbet wrote: > > One quick question: > > > > On Fri, 7 Oct 2011 00:11:05 -0700 > > Allison Henderson<achender@xxxxxxxxxxxxxxxxxx> wrote: > > > >> + /* Secure delete any blocks still in our range */ > >> + if (jbd2_pblk_count> 0) > >> + err = ext4_secure_delete_pblks(journal->j_inode, > >> + jbd2_pblk_start, jbd2_pblk_count); > >> + > >> +out: > >> + spin_unlock(&journal->j_pair_lock); > > > > ext4_secure_delete_pblks() appears to do its job synchronously - it has > > calls to things like sync_dirty_buffer() and such. How can you do that > > while holding ->j_pair_lock? > > > > Thanks, > > > > jon > > > > Hi Jon, > > Well j_pair_lock is a lock I added to protect the new list of vfs > -> jbd2 block pairs. It is locked by the journal commit thread to > update the list when ever a journal block is modified. The above > code here is called by the same thread that performs a punch hole or > truncate operation, not the journal commit thread. So I'm not > immediately seeing why there would be any lock problems. Is there > another case I'm missing? The problem is that ext4_secure_delete_pblks() can sleep, unless I've misunderstood things very badly. That's not something you want to do while holding a spinlock... jon -- 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
