RE: [PATCH] Revert "[JFFS2] Reduce time for which erase_free_sem isheld during erase."

["Joakim Tjernlund" <joakim.tjernlund@transmode.se>]

 > -----Original Message-----
> From: Artem Bityutskiy [mailto:dedekind@infradead.org] 
> Sent: den 5 oktober 2007 17:26
> To: David Woodhouse
> Cc: Joakim Tjernlund; linux-mtd@lists.infradead.org
> Subject: [PATCH] Revert "[JFFS2] Reduce time for which 
> erase_free_sem isheld during erase."
> 
> >From e1d782add3a72421eb637a119c594a6d9b774727 Mon Sep 17 
> 00:00:00 2001
> From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
> Date: Fri, 5 Oct 2007 20:09:45 +0300
> Subject: [PATCH] Revert "[JFFS2] Reduce time for which 
> erase_free_sem is held during erase."
> 
> This reverts commit d364fb18cd991734eb54aa8840e70030b0c9f699.
> 
> This patch locks up the system because it takes the 
> 'erase_free_sem' in
> the erase callback function, which is in turn called from NAND/OneNAND
> driver with NAND/OneNAND chip locked. Obviously, another process which
> holds 'erase_free_sem' and calls an I/O function will deadlock at the
> NAND/OneNAND chip lock. Below is the backtrace of this deadlock which
> we observed in practice:

uhh, I guess this problem is NAND specific? I don't think reverting
this patch is the answer. There got to be a better fix, as my patch
solves a real problem too.

 Jocke