From: Milan Broz <mbroz@redhat.com>
Date: Sat, 21 Jul 2007 11:37:27 +0000 (-0700)
Subject: [PATCH] dm io: fix panic on large request
X-Git-Tag: v2.6.20.17~30
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=04745f208c5b7de16fb35628b0003744b760b2cd;p=thirdparty%2Fkernel%2Fstable.git

[PATCH] dm io: fix panic on large request

Flush workqueue before releasing bioset and mopools in dm-crypt.  There can
be finished but not yet released request.

Call chain causing oops:
  run workqueue
    dec_pending
      bio_endio(...);
      	<remove device request - remove mempool>
      mempool_free(io, cc->io_pool);

This usually happens when cryptsetup create temporary
luks mapping in the beggining of crypt device activation.

When dm-core calls destructor crypt_dtr, no new request
are possible.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Cc: Chuck Ebbert <cebbert@redhat.com>
Cc: Patrick McHardy <kaber@trash.net>
Acked-by: Alasdair G Kergon <agk@redhat.com>
Cc: Christophe Saout <christophe@saout.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index b9ff4e368aad5..6b50991623efb 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -917,6 +917,8 @@ static void crypt_dtr(struct dm_target *ti)
 {
 	struct crypt_config *cc = (struct crypt_config *) ti->private;
 
+	flush_workqueue(_kcryptd_workqueue);
+
 	bioset_free(cc->bs);
 	mempool_destroy(cc->page_pool);
 	mempool_destroy(cc->io_pool);