[PATCH 0/1] LP#444915: readahead not merging in the elevator

[Tim Gardner]

Andy Whitcroft wrote:
> We have reports of slow mounting of FAT filesystems on external drives.
> This turns out to be a bug in the new fastfail code in the elevator which
> completely prevents merging of any readahead requests.  As all of the
> FAT reads are pre-readahead to fix this very performance problem they
> all were submitted to the device as single 512 transactions.  Fail.
> 
> This patch implements the painfully obvious fix for the issue.
> 
> Thanks to Stefan Bader for keeping me sane during the extended debug.
> 
> For Karmic.
> 
> -apw
> 
> Andy Whitcroft (1):
>   UBUNTU: [Upstream] elevator: fix fastfail checks to allow merge of
>     readahead requests
> 
>  block/elevator.c |   14 ++++++++++----
>  1 files changed, 10 insertions(+), 4 deletions(-)
> 
> 

applied. Please do remember to Cc stable at kernel.org when submitting
upstream.

-- 
Tim Gardner tim.gardner at canonical.com