Re: generic_osync_inode() broken?

From: Marcelo Tosatti (marcelo@conectiva.com.br)
Date: Thu Apr 12 2001 - 17:42:18 EST


On Thu, 12 Apr 2001, Linus Torvalds wrote:

>
>
> On Thu, 12 Apr 2001, Marcelo Tosatti wrote:
> >
> > Comments?
> >
> > --- fs/inode.c~ Thu Mar 22 16:04:13 2001
> > +++ fs/inode.c Thu Apr 12 15:18:22 2001
> > @@ -347,6 +347,11 @@
> > #endif
> >
> > spin_lock(&inode_lock);
> > + while (inode->i_state & I_LOCK) {
> > + spin_unlock(&inode_lock);
> > + __wait_on_inode(inode);
> > + spin_lock(&inode_lock);
> > + }
> > if (!(inode->i_state & I_DIRTY))
> > goto out;
> > if (datasync && !(inode->i_state & I_DIRTY_DATASYNC))
>
> Ehh.
>
> Why not just lock the inode around the thing?
>
> The above looks rather ugly.

Ok, me again.
 
The inode->i_state locking is rather nasty: there is no need to lock the
inode. We just have to wait for it to become unlocked, since its
guaranteed that who locked it wrote it to disk. (sync_one())

Aviro suggested the following, which is much cleaner than the previous
patch:

--- fs/inode.c~ Thu Apr 12 21:15:23 2001
+++ fs/inode.c Thu Apr 12 21:16:35 2001
@@ -301,6 +301,8 @@
                 while (inode->i_state & I_DIRTY)
                         sync_one(inode, sync);
                 spin_unlock(&inode_lock);
+ if (sync)
+ wait_on_inode(inode);
         }
         else
                 printk("write_inode_now: no super block\n");
@@ -357,6 +359,7 @@
 
  out:
         spin_unlock(&inode_lock);
+ wait_on_inode(inode);
         return err;
 }
 

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This archive was generated by hypermail 2b29 : Sun Apr 15 2001 - 21:00:20 EST