This is needed by things like USB storage that want to set up static
commands for later use at start of day.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Since the way we allocate commands with a separate sense buffer is
getting complicated, we should isolate setup and teardown to a single
routine so that if it gets even more complex, there's only one place
in the code that needs to be altered.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Since 2.6.25-rc7, I've been seeing an occasional livelock on one x86_64
machine, copying kernel trees to tmpfs, paging out to swap.

Signature: 6000 pages under writeback but never getting written; most
tasks of interest trying to reclaim, but each get_swap_bio waiting for a
bio in mempool_alloc's io_schedule_timeout(5*HZ); every five seconds an
atomic page allocation failure report from kblockd failing to allocate a
sense_buffer in __scsi_get_command.

__scsi_get_command has a (one item) free_list to protect against this,
but rc1's [SCSI] use dynamically allocated sense buffer
de25deb1 upset that slightly.  When it
fails to allocate from the separate sense_slab, instead of giving up, it
must fall back to the command free_list, which is sure to have a
sense_buffer attached.

Either my earlier -rc testing missed this, or there's some recent
contributory factor.  One very significant factor is SLUB, which merges
slab caches when it can, and on 64-bit happens to merge both bio cache
and sense_slab cache into kmalloc's 128-byte cache: so that under this
swapping load, bios above are liable to gobble up all the slots needed
for scsi_cmnd sense_buffers below.

That's disturbing behaviour, and I tried a few things to fix it.  Adding
a no-op constructor to the sense_slab inhibits SLUB from merging it, and
stops all the allocation failures I was seeing; but it's rather a hack,
and perhaps in different configurations we have other caches on the
swapout path which are ill-merged.

Another alternative is to revert the separate sense_slab, using
cache-line-aligned sense_buffer allocated beyond scsi_cmnd from the one
kmem_cache; but that might waste more memory, and is only a way of
diverting around the known problem.

While I don't like seeing the allocation failures, and hate the idea of
all those bios piled up above a scsi host working one by one, it does
seem to emerge fairly soon with the livelock fix.  So lacking better
ideas, stick with that one clear fix for now.
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Peter Zijlstra <a.p.ziljstra@chello.nl>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Original patch from Tejun Heo <htejun@gmail.com> but should use ->extra_len
and not ->data_len, as we would then overshoot the original request size.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Add missing function parameter descriptions.
Make function short description fit on one line as required.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

In preparation for bidi we abstract all IO members of scsi_cmnd,
that will need to duplicate, into a substructure.

- Group all IO members of scsi_cmnd into a scsi_data_buffer
  structure.
- Adjust accessors to new members.
- scsi_{alloc,free}_sgtable receive a scsi_data_buffer instead of
  scsi_cmnd. And work on it.
- Adjust scsi_init_io() and  scsi_release_buffers() for above
  change.
- Fix other parts of scsi_lib/scsi.c to members migration. Use
  accessors where appropriate.

- fix Documentation about scsi_cmnd in scsi_host.h

- scsi_error.c
  * Changed needed members of struct scsi_eh_save.
  * Careful considerations in scsi_eh_prep/restore_cmnd.

- sd.c and sr.c
  * sd and sr would adjust IO size to align on device's block
    size so code needs to change once we move to scsi_data_buff
    implementation.
  * Convert code to use scsi_for_each_sg
  * Use data accessors where appropriate.

- tgt: convert libsrp to use scsi_data_buffer

- isd200: This driver still bangs on scsi_cmnd IO members,
  so need changing

[jejb: rebased on top of sg_table patches fixed up conflicts
and used the synergy to eliminate use_sg and sg_count]
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Only hosts which actually have ISA DMA requirements need sense buffers
coming out of ZONE_DMA, so only use the __GFP_DMA flag for that case
to avoid allocating this scarce resource if it's not necessary.

[tomo: fixed slab leak in failure case]
Acked-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This removes static array sense_buffer in scsi_cmnd and uses
dynamically allocated sense_buffer (with GFP_DMA).

The reason for doing this is that some architectures need cacheline
aligned buffer for DMA:

http://lkml.org/lkml/2007/11/19/2

The problems are that scsi_eh_prep_cmnd puts scsi_cmnd::sense_buffer
to sglist and some LLDs directly DMA to scsi_cmnd::sense_buffer. It's
necessary to DMA to scsi_cmnd::sense_buffer safely. This patch solves
these issues.

__scsi_get_command allocates sense_buffer via kmem_cache_alloc and
attaches it to a scsi_cmnd so everything just work as before.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Looks like that host_cmd_pool_mutex are necessary here.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

- Change title to remove "Mid-Layer" since the doc is about all of the
SCSI layers.
- Use "SCSI" instead of "scsi" in docbook text.
- Use "*/" to end kernel-doc notation blocks.
- A few other minor typo fixes.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

Add Documentation/DocBook/scsi_midlayer.tmpl, add to Makefile, and update
lots of kerneldoc comments in drivers/scsi/*.

Updated with comments from Stefan Richter, Stephen M. Cameron,
 James Bottomley and Randy Dunlap.
Signed-off-by: NRob Landley <rob@landley.net>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

This reverts commit ac40532e, which gets
us back the original cleanup of 6f5391c2.

It turns out that the bug that was triggered by that commit was
apparently not actually triggered by that commit at all, and just the
testing conditions had changed enough to make it appear to be due to it.

The real problem seems to have been found by Peter Osterlund:

  "pktcdvd sets it [block device size] when opening the /dev/pktcdvd
   device, but when the drive is later opened as /dev/scd0, there is
   nothing that sets it back.  (Btw, 40944 is possible if the disk is a
   CDRW that was formatted with "cdrwtool -m 10236".)

   The problem is that pktcdvd opens the cd device in non-blocking mode
   when pktsetup is run, and doesn't close it again until pktsetup -d is
   run.  The effect is that if you meanwhile open the cd device,
   blkdev.c:do_open() doesn't call bd_set_size() because
   bdev->bd_openers is non-zero."

In particular, to repeat the bug (regardless of whether commit
6f5391c2 is applied or not):

  " 1. Start with an empty drive.
    2. pktsetup 0 /dev/scd0
    3. Insert a CD containing an isofs filesystem.
    4. mount /dev/pktcdvd/0 /mnt/tmp
    5. umount /mnt/tmp
    6. Press the eject button.
    7. Insert a DVD containing a non-writable filesystem.
    8. mount /dev/scd0 /mnt/tmp
    9. find /mnt/tmp -type f -print0 | xargs -0 sha1sum >/dev/null
    10. If the DVD contains data beyond the physical size of a CD, you
        get I/O errors in the terminal, and dmesg reports lots of
        "attempt to access beyond end of device" errors."

which in turn is because the nested open after the media change won't
cause the size to be set properly (because the original open still holds
the block device, and we only do the bd_set_size() when we don't have
other people holding the device open).

The proper fix for that is probably to just do something like

	bdev->bd_inode->i_size = (loff_t)get_capacity(disk)<<9;

in fs/block_dev.c:do_open() even for the cases where we're not the
original opener (but *not* call bd_set_size(), since that will also
change the block size of the device).

Cc: Peter Osterlund <petero2@telia.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit 6f5391c2 ("[SCSI]
Get rid of scsi_cmnd->done") that was supposed to be a cleanup commit,
but apparently it causes regressions:

  Bug 9370 - v2.6.24-rc2-409-g9418d5dc: attempt to access beyond end of device
  http://bugzilla.kernel.org/show_bug.cgi?id=9370

this patch should be reintroduced in a more split-up form to make
testing of it easier.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NMatthew Wilcox <matthew@wil.cx>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The esp_reset_cleanup() function is called with the host lock held and
invokes starget_for_each_device() which wants to take it too.  Here is a
fix along the lines of shost_for_each_device()/__shost_for_each_device()
adding a __starget_for_each_device() counterpart which assumes the lock
has already been taken.

Eventually, I think the driver should get modified so that more work is
done as a softirq rather than in the interrupt context, but for now it
fixes a bug that causes the spinlock debugger to fire.

While at it, it fixes a small number of cosmetic problems with
starget_for_each_device() too.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The ULD ->done callback moves into the scsi_driver.  By moving the call
to scsi_io_completion() from scsi_blk_pc_done() to scsi_finish_command(),
we can eliminate the latter entirely.  By returning 'good_bytes' from
the ->done callback (rather than invoking scsi_io_completion()), we can
stop exporting scsi_io_completion().

Also move the prototypes from sd.h to sd.c as they're all internal anyway.
Rename sd_rw_intr to sd_done and rw_intr to sr_done.
Inspired-by: NChristoph Hellwig <hch@infradead.org>
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The pid field is a duplicate of the serial_number field and has been
scheduled for removal for a long time.  A few drivers were still using
it, so just change them to use serial_number instead.
Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Slab destructors were no longer supported after Christoph's
c59def9f change. They've been
BUGs for both slab and slub, and slob never supported them
either.

This rips out support for the dtor pointer from kmem_cache_create()
completely and fixes up every single callsite in the kernel (there were
about 224, not including the slab allocator definitions themselves,
or the documentation references).
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

 - a couple of prints, they can use the accessors
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Removes an obsolete method scsi_device_cancel which isn't being used
anywhere in the kernel.
Signed-off-by: NPriyanka Gupta <priyankag@google.com>
Acked-by: NGrant Grundler <grundler@parisc-linux.org>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch enhances SCSI error printing by:

 - Making use of scsi_print_result() in the completion functions.

 - Having scmd_printk() output the disk name (when applicable).
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

After Al Viro (finally) succeeded in removing the sched.h #include in module.h
recently, it makes sense again to remove other superfluous sched.h includes.
There are quite a lot of files which include it but don't actually need
anything defined in there.  Presumably these includes were once needed for
macros that used to live in sched.h, but moved to other header files in the
course of cleaning it up.

To ease the pain, this time I did not fiddle with any header files and only
removed #includes from .c-files, which tend to cause less trouble.

Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha,
arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig,
allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all
configs in arch/arm/configs on arm.  I also checked that no new warnings were
introduced by the patch (actually, some warnings are removed that were emitted
by unnecessarily included header files).
Signed-off-by: NTim Schmielau <tim@physik3.uni-rostock.de>
Acked-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

scsi_retry_command only has a single caller, so there is no point
in having this function.  Additionally the memset of the sense
buffer it does is entirely superflous as scsi_request_fn already
calls scsi_init_cmd_errh to perform this memset before the command
is reissued.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
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>

This patch contains the needed changes to the scsi-ml for the target
mode support.

Note, per the last review we moved almost all the fields we added
to the scsi_cmnd to our internal data structure which we are going
to try and kill off when we can replace it with support from other
parts of the kernel.

The one field we left on was the offset variable. This is needed to handle
the case where the target gets request that is so large that it cannot
execute it in one dma operation. So max_secotors or a segment limit may
limit the size of the transfer. In this case our tgt core code will
break up the command into managable transfers and send them to the
LLD one at a time. The offset is then used to tell the LLD where in
the command we are at. Is there another field on the scsi_cmd for
that?
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>

Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

this overrun was spotted by coverity (cid #1403).

If type == ARRAY_SIZE(scsi_device_types), we are off by one.
Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

It is a leftover from before the softirq completion was migrated
to the block layer.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

After Christophs SCSI change, the only usage left is RQ_ACTIVE
and RQ_INACTIVE. The block layer sets RQ_INACTIVE right before freeing
the request, so any check for RQ_INACTIVE in a driver is a bug and
indicates use-after-free.

So kill/clean the remaining users, straight forward.
Signed-off-by: NJens Axboe <axboe@suse.de>

Some user tools parse /proc/scsi/scsi, so we can't yet change the names.
Change the existing ones back to their old names, and add an admonition
to not make the same mistake that I did.

Andrew Morton reports that this was breaking YDL 4.1 userspace.
Signed-off-by: NMatthew Wilcox <matthew@wil.cx>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

  LD      .tmp_vmlinux1
drivers/built-in.o(.text+0x8e1f9): In function `scsi_device_put':
drivers/scsi/scsi.c:887: undefined reference to `module_refcount'
make: *** [.tmp_vmlinux1] Error 1

There are only two users of module_refcount() outside of kernel/module.c
and the other one uses ifdef's similar to this.
Signed-Off-By: NDaniel Walker <dwalker@mvista.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The recent change to the way scsi_device_get()/put() work broke the
non modular build (we do a module_refcount on a NULL).  Fix this by
checking for non-null before checking module_refcount().
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch formally adds support for the posting of FC events via netlink.
It is a followup to the original RFC at:
  http://marc.theaimsgroup.com/?l=linux-scsi&m=114530667923464&w=2
and the initial posting at:
  http://marc.theaimsgroup.com/?l=linux-scsi&m=115507374832500&w=2

The patch has been updated to optimize the send path, per the discussions
in the initial posting.

Per discussions at the Storage Summit and at OLS, we are to use netlink for
async events from transports. Also per discussions, to avoid a netlink
protocol per transport, I've create a single NETLINK_SCSITRANSPORT protocol,
which can then be used by all transports.

This patch:
- Creates new files scsi_netlink.c and scsi_netlink.h, which contains the
  single and shared definitions for the SCSI Transport. It is tied into the
  base SCSI subsystem intialization.
  Contains a single interface routine, scsi_send_transport_event(), for a
  transport to send an event (via multicast to a protocol specific group).
- Creates a new scsi_netlink_fc.h file, which contains the FC netlink event
  messages
- Adds 3 new routines to the fc transport:
   fc_get_event_number() -  to get a FC event #
   fc_host_post_event()  -  to send a simple FC event (32 bits of data)
   fc_host_post_vendor_event() - to send a Vendor unique event, with
                                 arbitrary amounts of data.

   Note: the separation of event number allows for a LLD to send a standard
     event, followed by vendor-specific data for the event.

Note: This patch assumes 2 prior fc transport patches have been installed:
   http://marc.theaimsgroup.com/?l=linux-scsi&m=115555807316329&w=2
   http://marc.theaimsgroup.com/?l=linux-scsi&m=115581614930261&w=2

   Sorry - next time I'll do something like making these individual
   patches of the same posting when I know they'll be posted closely
   together.
Signed-off-by: NJames Smart <James.Smart@emulex.com>

Tidy up configuration not to make SCSI always select NET
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The fix isn't actually in sd: it's in scsi_device_get().  I modified it
to allow devices to be returned in SDEV_CANCEL, but not SDEV_DEL.  This
means that the device_remove_driver, which occurs in device_del() in
scsi_remove_device() after the device has gone into SDEV_CANCEL is now
effective at flushing the cache.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

 - Replace scsi_device_types array API with scsi_device_type function API.
   Gets rid of a lot of common code, as well as being easier to use.
 - Add the new device types in SPC4 r05a, and rename some of the older ones.
 - Reformat the printing of inquiry data; now fits on one line and
   includes PQ.

I think I've addressed all the feedback from the previous versions.  My
current test box prints:

scsi 2:0:1:0: Direct access     HP 18.2G ATLAS10K3_18_SCA HP05 PQ: 0 ANSI: 2
Signed-off-by: NMatthew Wilcox <matthew@wil.cx>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Currently struct scsi_cmnd has various fields that are used to backup
original data after the corresponding fields have been overridden for
EH commands.  This means drivers can easily get at it and misuse it.
Due to the old_ naming this doesn't happen for most of them, but two
that have different names have been used wrong a lot (see previous
patch).  Another downside is that they unessecarily bloat the scsi_cmnd
size.

This patch moves them onstack in scsi_send_eh_cmnd to fix those two
issues aswell as allowing future EH fixes like moving the EH command
submissions to use SG lists like everything else.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

With Achim patch the last user (gdth) is switched away from scsi_request
so we an kill it now.  Also disables some code in i2o_scsi that was
broken since the sg driver stopped using scsi_requests.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Introduce scsi_req_abort_cmd(struct scsi_cmnd *).
This function requests that SCSI Core start recovery for the
command by deleting the timer and adding the command to the eh
queue.  It can be called by either LLDDs or SCSI Core.  LLDDs who
implement their own error recovery MAY ignore the timeout event if
they generated scsi_req_abort_cmd.

First post:
http://marc.theaimsgroup.com/?l=linux-scsi&m=113833937421677&w=2Signed-off-by: NLuben Tuikov <ltuikov@yahoo.com>
Signed-off-by: NTejun Heo <htejun@gmail.com>

Original From: Ingo Flaschberger <if@xip.at>

To support the RA4100 array from Compaq.

This patch now correctly handles SCSI_UNKNOWN types with regard to
BLIST_REPORTLUNS2 (allow it) and cdb[1] LUN inclusion (don't).

It also allows a BLIST_MAX_512 flag to restrict the maximum transfer
length to 512 blocks (apparently this is an RA4100 problem).
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

for_each_cpu() actually iterates across all possible CPUs.  We've had mistakes
in the past where people were using for_each_cpu() where they should have been
iterating across only online or present CPUs.  This is inefficient and
possibly buggy.

We're renaming for_each_cpu() to for_each_possible_cpu() to avoid this in the
future.

This patch replaces for_each_cpu with for_each_possible_cpu.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

As devfs has been disabled from the kernel tree for a number of months
now (5 to be exact), here's a patch against 2.6.16-rc1-git1 that removes
support for it from the SCSI subsystem.

The patch also removes the scsi_disk devfs_name field as it's no longer
needed.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>