Re: [PATCH 2/2] ext4: fix ext4_da_block_invalidatepages() to handle page range properly

[Ted Ts'o <tytso@mit.edu>]

On Fri, Feb 18, 2011 at 01:31:39PM -0800, Curt Wohlgemuth wrote:
> If ext4_da_block_invalidatepages() is called because of a
> failure from ext4_map_blocks() in mpage_da_map_and_submit(),
> it's supposed to clean up -- including unlock -- all the
> pages in the mpd structure.  But these values may not match
> up, even on a system in which block size == page size:
> 
>    mpd->b_blocknr != mpd->first_page
>    mpd->b_size != (mpd->next_page - mpd->first_page)
> 
> ext4_da_block_invalidatepages() has been using b_blocknr and
> b_size; this patch changes it to use first_page and
> next_page.
> 
> Tested:  I injected a small number (5%) of failures in
> ext4_map_blocks() in the case that the flags contain
> EXT4_GET_BLOCKS_DELALLOC_RESERVE, and ran fsstress on this
> kernel.  Without this patch, I got hung tasks every time.
> With this patch, I see no hangs in many runs of fsstress.
> 
> Signed-off-by: Curt Wohlgemuth <curtw@google.com>

Thanks, added to the ext4 patch queue.

						- Ted