tgt notifies a LLD of the failure with sense when it hits the
user-space daemon bugs. However, tgt doesn't know anything about SCSI
devices that initiators talks to. So it's impossible to send proper
sense buffer (format and contents).

This patch changes tgt not to notify a LLD of the failure with bogus
sense. Instead, tgt just re-queues the failure command to the internal
list so that it will be freed cleanly later on when the scsi_host is
removed.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The failure to map user-space pages leads to scsi command leak. It can
happens mostly because of user-space daemon bugs (or OOM). This patch
makes tgt just notify a LLD of the failure with sense when
blk_rq_map_user() fails.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch simplify the way to notify LLDs of the command completion
and addresses the following sense buffer problems:

- can't handle both data and sense.
- forces user-space to use aligned sense buffer

tgt copies sense_data from userspace to cmnd->sense_buffer (if
necessary), maps user-space pages (if necessary) and then calls
host->transfer_response (host->transfer_data is removed).
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

scsi tgt breaks up a command into multple scatterlists
if we cannot fit all the data in one. This was because
the block rq helpers did not support large requests and
because we can get a command of any old size so it is
hard to preallocate pages for scatterlist large enough
(we cannot really preallocate pages with the bio map
user path). In 2.6.20, we added large request support to
the block layer helper, blk_rq_map_user. And at LSF,
we talked about increasing SCSI_MAX_PHYS_SEGMENTS for
scsi tgt if we want to support really really :) large
(greater than 256 * PAGE_SIZE in the worst mapping case)
requests.

The only target currently implemented does not even support
the multiple scatterlists stuff and only supports smaller
requests, so this patch just coverts scsi tgt to use
blk_rq_map_user.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Replace all uses of kmem_cache_t with struct kmem_cache.

The patch was generated using the following script:

	#!/bin/sh
	#
	# Replace one string by another in all the kernel sources.
	#

	set -e

	for file in `find * -name "*.c" -o -name "*.h"|xargs grep -l $1`; do
		quilt add $file
		sed -e "1,\$s/$1/$2/g" $file >/tmp/$$
		mv /tmp/$$ $file
		quilt refresh
	done

The script was run like this

	sh replace kmem_cache_t "struct kmem_cache"
Signed-off-by: NChristoph Lameter <clameter@sgi.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-Off-By: NDavid Howells <dhowells@redhat.com>

The core scsi target lib functions.

TODO:
- mv md/dm-bio-list.h to linux/bio-list.h so md and us do not have to
do that weird include.
- convert scsi_tgt_cmd's work struct to James's execute code. And try
to kill our scsi_tgt_cmd.
- add host state checking. We do refcouting so hotplug is partially
supported, but we need to add state checking to make it easier on
the LLD.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>