dm crypt: fix ctx pending
authorMilan Broz <mbroz@redhat.com>
Fri, 28 Mar 2008 21:16:07 +0000 (14:16 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 28 Mar 2008 21:45:22 +0000 (14:45 -0700)
commit3f1e9070f63b0eecadfa059959bf7c9dbe835962
tree1d47de4bdae1009b6efc80824ca882de0a97cfef
parentab473a52500528a276920a26cb35b722a868ab6e
dm crypt: fix ctx pending

Fix regression in dm-crypt introduced in commit
3a7f6c990ad04e6f576a159876c602d14d6f7fef ("dm crypt: use async crypto").

If write requests need to be split into pieces, the code must not process them
in parallel because the crypto context cannot be shared.  So there can be
parallel crypto operations on one part of the write, but only one write bio
can be processed at a time.

This is not optimal and the workqueue code needs to be optimized for parallel
processing, but for now it solves the problem without affecting the
performance of synchronous crypto operation (most of current dm-crypt users).

http://bugzilla.kernel.org/show_bug.cgi?id=10242
http://bugzilla.kernel.org/show_bug.cgi?id=10207

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/md/dm-crypt.c