Re: [PATCH] Ext3 online resizing locking issue

2005-08-31 Thread Stephen C. Tweedie
Hi, On Wed, 2005-08-31 at 12:35, Glauber de Oliveira Costa wrote: > At a first look, i thought about locking gdt-related data. But in a > closer one, it seemed to me that we're in fact modifying a little bit > more than that in the resize code. But all these modifications seem to > be somehow rel

Re: [PATCH] Ext3 online resizing locking issue

2005-08-31 Thread Glauber de Oliveira Costa
> > The two different uses of the superblock lock are really quite > different; I don't see any particular problem with using two different > locks for the two different things. Mount and the namespace code are > not locking the same thing --- the fact that the resize code uses the > superblock l

Re: [PATCH] Ext3 online resizing locking issue

2005-08-30 Thread Stephen C. Tweedie
Hi, On Thu, 2005-08-25 at 21:43, Glauber de Oliveira Costa wrote: > Just a question here. With s_lock held by the remount code, we're > altering the struct super_block, and believing we're safe. We try to > acquire it inside the resize functions, because we're trying to modify > this same data.

Re: [PATCH] Ext3 online resizing locking issue

2005-08-25 Thread Glauber de Oliveira Costa
> NAK, this is wrong: > > > + lock_super(sb); > > err = ext3_group_extend(sb, EXT3_SB(sb)->s_es, n_blocks_count); > > + unlock_super(sb); > > This basically reverses the order of locking between lock_super() and > journal_start() (the latter acts like a lock beca

Re: [PATCH] Ext3 online resizing locking issue

2005-08-25 Thread Stephen C. Tweedie
Hi, On Wed, 2005-08-24 at 22:03, Glauber de Oliveira Costa wrote: > This simple patch provides a fix for a locking issue found in the online > resizing code. The problem actually happened while trying to resize the > filesystem trough the resize=xxx option in a remount. NAK, this is wrong: > +