lkml.org 
[lkml]   [2002]   [Jun]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch 12/16] fix race between writeback and unlink


On Tue, 4 Jun 2002, Andrew Morton wrote:
>
> But after the vma has been destroyed (the application did exit()),
> the dirty pagecache data against the sparse mapped file still
> hasn't been written, and still doesn't have a disk mapping.
>
> So in this case, we have an inode which still has pending block
> allocations which has no struct file's pointing at it. Or
> am I wrong?

I think you're right..

> The current preallocation will screw up is when there's a
> large-and-sparse file which has blocks being allocated against it
> at two or more offsets. And those allocations are for a large number
> of blocks, and they are proceeding slowly.

Sure. However, I don't think it should come as any surprise to anybody
that trying to write to two different points in the same file is a bad
idea. _regardless_ of whether you do pre-allocation or not, and whether
the pre-allocation is on the inode or file level.

I'd still love to see a "fast and slightly stupid" allocator for both
blocks and inodes, and have some infrastructure to do run-time defragging
in the background.

Linus

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:26    [from the cache]
©2003-2011 Jasper Spaans