[PATCH] JFFS2 appears to "freeze" during erase, version 2

[Joakim Tjernlund]

On Tue, 2007-06-05 at 09:51 +0200, Joakim Tjernlund wrote:
> Here is an updated version that contains all everything in one patch. I hope
> this one can be applied as is.
> 
>  Jocke
> 
> >From 87cd93db5895e1506a6abb0dbc891587e96d8547 Mon Sep 17 00:00:00 2001
> From: Joakim Tjernlund <Joakim.Tjernlund at transmode.se>
> Date: Tue, 5 Jun 2007 09:38:53 +0200
> Subject: [PATCH] JFFS2 appears to "freeze" during erase
> Radoslaw Bisewski <radbis at googlemail.com> writes:
> With current desing erase_free_sem is locked every time the flash
> block is being erased. For NOR flashes - ~1 second is needed to erase
> single flash block. In the worst case scenario erase_free_sem may be
> locked for a couple of seconds when the number of blocks is being
> erased (e.g. after large file was removed). When erase_free_sem is
> locked all read/write operations for given JFFS2 partition are locked
> too - in effect from time to time access to the JFFS2 partition is
> locked for a number of seconds. This fix makes critical section in
> flash erasing procedure shorter - now erase_free_sem is locked around
> erase_completion_lock spinlock only.
> 
> Additional bug fixes by me.
> 
> Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund at transmode.se>
> ---
[SNIP patch]

After running our boards a few days with the above patch we have seen
a new hang during SW upgrade of the board.

A simple script that is run to do some validation of the new SW
sometimes takes about 2 minutes to complete instead of 1 second.

FS I/O  part of that script is:
  BOARD=`fw_printenv genBoardType | sed 's/^.*=//' | sed 's/^cu.*/cu/'`
  TMP_FILE=/tmp/.swu_operations.log
  echo "Some text 1" >> $TMP_FILE
  echo "Some text 2" >> $TMP_FILE
  echo `date` >> $TMP_FILE
  echo "Some text 3" >> $TMP_FILE

fw_printenv is an utility that accesses(reads) the u-boots environment
via /dev/mtd.
/tmp is mounted as a tmpfs:
none            /tmp            tmpfs   defaults                        0 0

This is on 2.6.20 with cfi_cmdset_0001 driver

Any ideas what is going on is most welcome.

 Jocke