Commit Graph

119 Commits

Author SHA1 Message Date
Nigel Cunningham 082776e4be [PATCH] Make libata not powerdown drivers on PM_EVENT_FREEZE.
At the moment libata doesn't pass pm_message_t down ata_device_suspend.
This causes drives to be powered down when we just want a freeze,
causing unnecessary wear and tear. This patch gets pm_message_t passed
down so that it can be used to determine whether to power down the
drive.

Signed-off-by: Nigel Cunningham <nigel@suspend2.net>

 drivers/scsi/libata-core.c |    5 +++--
 drivers/scsi/libata-scsi.c |    4 ++--
 drivers/scsi/scsi_sysfs.c  |    2 +-
 include/linux/libata.h     |    4 ++--
 include/scsi/scsi_host.h   |    2 +-
 5 files changed, 9 insertions(+), 8 deletions(-)
Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-03-24 09:51:36 -05:00
James Bottomley d04cdb6421 Merge ../linux-2.6 2006-03-21 13:05:45 -06:00
James Bottomley 2f8600dff2 [SCSI] eliminate rphy allocation in favour of expander/end device allocation
This allows the removal of the contained flag and also does a bit of
class renaming (sas_rphy->sas_device).

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-03-19 10:21:16 -06:00
James Bottomley 5baba830e9 [SCSI] add scsi_mode_select to scsi_lib.c
This complements the scsi_mode_sense() function

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-03-19 10:19:14 -06:00
James Bottomley e28482c5b2 [SCSI] add scsi_reprobe_device
Original from Christoph Hellwig and Eric Moore.  This version exports
the scsi_reprobe_device() function as an inline.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-03-14 14:24:55 -06:00
James Bottomley 79cb1819e2 [SCSI] add preliminary expander support to the sas transport class
This patch makes expanders appear as labelled objects with properties in
the SAS tree.

I've also modified the phy code to make expander phys appear labelled by
host number, expander number and phy index.

So, for my current config, you see something like this in sysfs:

/sys/class/scsi_host/host1/device/phy-1:4/expander-1:0/phy-1-0:12/rphy-1:0-12/target1:0:1

And the expander properties are:

jejb@sparkweed> cd /sys/class/sas_expander/expander-1\:0/
jejb@sparkweed> for f in *; do echo -n $f ": "; cat $f; done
component_id : 29024
component_revision_id : 4
component_vendor_id : VITESSE
device : cat: device: Is a directory
level : 0
product_id : VSC7160 Eval Brd
product_rev : 4
uevent : cat: uevent: Permission denied
vendor_id : VITESSE

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-03-14 12:36:19 -06:00
James Smart c829c39416 [SCSI] FC transport : Avoid device offline cases by stalling aborts until device unblocked
This moves the eh_timed_out functionality from the scsi_host_template
to the transport_template. Given that this is now a transport function,
the EH_RESET_TIMER case no longer caps the timer reschedulings. The
transport guarantees that this is not an infinite condition.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-03-13 08:58:58 -06:00
James Bottomley 42ab03609c [PATCH] convert aic94xx over to using the sas transport end device
Begin introducing the concept of sas remote devices that have an rphy
embedded.  The first one (this) is a simple end device.  All that an
end device really does is have port mode page parameters contained.
The next and more complex piece will be expander remote devices.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-03-06 09:43:17 -06:00
James Bottomley 7e6dff62da [SCSI] add 6.0 Gbit phy definitions to the sas transport class
I don't think these exist in silicon yet, but the aic94xx driver has a
register setting for them.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-03-02 22:36:58 -06:00
James Bottomley ffedb45225 [SCSI] fix scsi process problems and clean up the target reap issues
In order to use the new execute_in_process_context() API, you have to
provide it with the work storage, which I do in SCSI in scsi_device and
scsi_target, but which also means that we can no longer queue up the
target reaps, so instead I moved the target to a state model which
allows target_alloc to detect if we've received a dying target and wait
for it to be gone.  Hopefully, this should also solve the target
namespace race.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-02-27 23:37:45 -06:00
Alan Stern 1bfc5d9d5e [SCSI] Recognize missing LUNs for non-standard devices
Some non-standard SCSI targets or protocols, such as USB UFI, report "no
LUN present" by setting the Peripheral Device Type to 0x1f and the
Peripheral Qualifier to 0 (not 3 as the standard requires) in the INQUIRY
response.  This patch (as650b) adds a new target flag and code to
accomodate such targets.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-02-27 23:24:09 -06:00
Christoph Hellwig a012564136 [SCSI] sas: add support for enclosure and bad ID rphy attributes
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-02-27 22:55:13 -06:00
Matthew Wilcox 6ea3c0b2da [SCSI] Add spi_populate_*_msg functions
Introduce new helpers:
 - spi_populate_width_msg()
 - spi_populate_sync_msg()
 - spi_populate_ppr_msg()

and use them in drivers which already enable the SPI transport.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-02-27 22:55:09 -06:00
Greg KH 5e3c34c1e9 [SCSI] Remove devfs support from the SCSI subsystem
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: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-02-27 22:55:04 -06:00
Matthew Wilcox c67a848c35 [SCSI] Neaten comments in scsi_cmnd.h
Wrap these two comments at 80 columns

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-02-27 22:55:02 -06:00
Jeff Garzik 5b2ffed906 Merge branch 'master' 2006-02-20 02:16:23 -05:00
James Bottomley faead26d7a [PATCH] add scsi_execute_in_process_context() API
We have several points in the SCSI stack (primarily for our device
functions) where we need to guarantee process context, but (given the
place where the last reference was released) we cannot guarantee this.

This API gets around the issue by executing the function directly if
the caller has process context, but scheduling a workqueue to execute
in process context if the caller doesn't have it.  Unfortunately, it
requires memory allocation in interrupt context, but it's better than
what we have previously.  The true solution will require a bit of
re-engineering, so isn't appropriate for 2.6.16.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-02-14 11:14:26 -06:00
Mike Christie 7b7232f3fb [SCSI] iscsi update: cleanup iscsi class interface
From:
michaelc@cs.wisc.edu
fujita.tomonori@lab.ntt.co.jp
da-x@monatomic.org

and err path fixup from:
ogerlitz@voltaire.com

This patch cleans up that interface by having the lld and class
pass a iscsi_cls_session or iscsi_cls_conn between each other when
the function is used by HW and SW iscsi llds. This way the lld
does not have to remember if it has to send a handle or pointer
and a handle or pointer to connection, session or host.

This also has the class verify the session handle that gets passed from
userspace instead of using the pointer passed into the kernel directly.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Alex Aizman <itn780@yahoo.com>
Signed-off-by: Dmitry Yusupov <dmitry_yus@yahoo.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-02-04 16:17:03 -06:00
Jeff Garzik 18ee361004 Merge branch 'master' 2006-02-02 01:12:54 -05:00
Linus Torvalds e0ae23550f Merge master.kernel.org:/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6 2006-01-31 13:12:41 -08:00
Tejun Heo 041c5fc33c [PATCH] SCSI: export scsi_eh_finish_cmd() and scsi_eh_flush_done_q()
Export two SCSI EH command handling functions.  To be used by libata EH.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
2006-01-26 22:36:28 -05:00
brking@us.ibm.com bb1d1073a1 [SCSI] Prevent scsi_execute_async from guessing cdb length
When the scsi_execute_async interface was added it ended up reducing
the flexibility of userspace to send arbitrary scsi commands through
sg using SG_IO. The SG_IO interface allows userspace to specify the
CDB length. This is now ignored in scsi_execute_async and it is
guessed using the COMMAND_SIZE macro, which is not always correct,
particularly for vendor specific commands. This patch adds a cmd_len
parameter to the scsi_execute_async interface to allow the caller
to specify the length of the CDB.

Signed-off-by: Brian King <brking@us.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-01-26 15:13:50 -05:00
Tetsuo Takata dfcd77d16b [SCSI] Remove host template ordered_flush variable
After the recent overhaul of the block layer the variable
"ordered_flush" is no longer used.

Signed-off-by: Tetsuo Takata <takatatt@intellilink.co.jp>
Signed-off-by: Jens Axboe <axboe@suse.de>
2006-01-25 11:12:40 +01:00
Andrew Morton c8d338c8db [PATCH] scsi_transport_spi build fix
On alpha:

In file included from drivers/scsi/sym53c8xx_2/sym_glue.h:59,
                 from drivers/scsi/sym53c8xx_2/sym_fw.c:40:
include/scsi/scsi_transport_spi.h:57: error: field `dv_mutex' has incomplete type

Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-18 19:20:16 -08:00
Mike Christie 7b8631b53b [SCSI] iscsi: seperate iscsi interface from setup functions
This is the second version of the patch to address Christoph's comments.
Instead of doing the lib, I just kept everything in scsi_trnapsort_iscsi.c
like the FC and SPI class. This was becuase the driver model and sysfs
class is tied to the session and connection setup so separating did not
buy very much at this time.

The reason for this patch was becuase HW iscsi LLDs like qla4xxx cannot
use the iscsi class becuase the scsi_host was tied to the interface and
class code. This patch just seperates the session from scsi host so
that LLDs that allocate the host per some resource like pci device
can still use the class.

This is also fixes a couple refcount bugs that can be triggered
when users have a sysfs file open, close the session, then
read or write to the file.

Signed-off-by: Alex Aizman <itn780@yahoo.com>
Signed-off-by: Dmitry Yusupov <dmitry_yus@yahoo.com>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-01-14 10:55:20 -06:00
Christoph Hellwig e02f3f5922 [SCSI] remove target parent limitiation
When James Smart fixed the issue of the userspace scan atributes
crashing the system with the FC transport class he added a patch to
let the transport class check if the parent is valid for a given
transport class.

When adding support for the integrated raid of fusion sas devices
we ran into a problem with that, as it didn't allow adding virtual
raid volumes without the transport class knowing about it.

So this patch adds a user_scan attribute instead, that takes over from
scsi_scan_host_selected if the transport class sets it and thus lets
the transport class control the user-initiated scanning.  As this
plugs the hole about user-initiated scanning the target_parent hook
goes away and we rely on callers of the scanning routines to do
something sensible.

For SAS this meant I had to switch from a spinlock to a mutex to
synchronize the topology linked lists, in FC they were completely
unsynchronized which seems wrong.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-01-14 10:55:05 -06:00
Jes Sorensen d158d26167 [SCSI] sem2mutex: scsi_transport_spi.c
Convert the SCSI transport class code to use a mutex rather than a
semaphore.

Signed-off-by: Jes Sorensen <jes@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-01-14 10:55:01 -06:00
Andreas Herrmann 6b7281d0a0 [SCSI] fc transport: add permanent_port_name fc_host attribute
Add fc_host attribute permanent_port_name which is
used to show the port name of the primary port -
the port that initially logged into the fabric.

For a virtual port (registered via the primary port with
FDISC command) it is useful to know not only its (virtual)
port name but also the permanent port name.

Signed-off-by: Andreas Herrmann <aherrman@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-01-14 10:54:48 -06:00
Christoph Hellwig 776b23a036 [SCSI] always handle REQ_BLOCK_PC requests in common code
LLDDs should never see REQ_BLOCK_PC requests, we can handle them just
fine in the core code.  There is a small behaviour change in that some
check in sr's rw_intr are bypassed, but I consider the old behaviour
a bug.

Mike found this cleanup opportunity and provdided early patches, so all
the credit goes to him, even if I redid the patches from scratch beause
that was easier than forward-porting the old patches.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-01-14 10:54:45 -06:00
Arjan van de Ven 0b95067238 [SCSI] turn most scsi semaphores into mutexes
the scsi layer is using semaphores in a mutex way, this patch converts
these into using mutexes instead

Signed-off-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2006-01-12 11:53:11 -06:00
Linus Torvalds d99cf9d679 Merge branch 'post-2.6.15' of git://brick.kernel.dk/data/git/linux-2.6-block
Manual fixup for merge with Jens' "Suspend support for libata", commit
ID 9b84754866.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 09:01:25 -08:00
Jens Axboe 9b84754866 [PATCH] Suspend support for libata
This patch adds suspend patch to libata, and ata_piix in particular. For
most low level drivers, they should just need to add the 4 hooks to
work. As I can only test ata_piix, I didn't enable it for more
though.

Suspend support is the single most important feature on a notebook, and
most new notebooks have sata drives. It's quite embarrassing that we
_still_ do not support this. Right now, it's perfectly possible to
suspend the drive in mid-transfer.

Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-06 08:36:09 -08:00
Tejun Heo 461d4e90c8 [BLOCK] update SCSI to use new blk_ordered for barriers
All ordered request related stuff delegated to HLD.  Midlayer
now doens't deal with ordered setting or prepare_flush
callback.  sd.c updated to deal with blk_queue_ordered
setting.  Currently, ordered tag isn't used as SCSI midlayer
cannot guarantee request ordering.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jens Axboe <axboe@suse.de>
2006-01-06 09:52:55 +01:00
Linus Torvalds f61ea1b0c8 Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6 2006-01-04 16:30:12 -08:00
James.Smart@Emulex.Com 42e33148df [SCSI] fix for fc transport recursion problem.
In the scenario that a link was broken, the devloss timer for each
rport was expire at roughly the same time, causing lots of "delete"
workqueue items being queued. Depth is dependent upon the number of
rports that were on the link.

The rport target remove calls were calling flush_scheduled_work(),
which would interrupt the stream, and start the next workqueue item,
which did the same thing, and so on until recursion depth was large.

This fix stops the recursion in the initial delete path, and pushes it
off to a host-level work item that reaps the dead rports.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-12-15 19:22:14 -08:00
Matthew Wilcox 1abfd37013 [SCSI] Rename scsi_print_msg to spi_print_msg
Rename scsi_print_msg to spi_print_msg and move its prototype from
scsi_dbg.h to scsi_transport_spi.h

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-12-15 18:41:27 -08:00
James Bottomley 7b16318dea Fix up SCSI mismerge
I forgot to do a git-update-cache on the merged files ...
2005-12-15 20:17:02 -06:00
James Bottomley 2a1e1379ba Merge by hand (conflicts in scsi_lib.c)
This merge is pretty extensive.  The conflict is over the new
req->retries parameter, so I had to change the prototype to
scsi_setup_blk_pc_cmnd() and the usage in sd, sr and st.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-12-15 17:35:24 -06:00
Mike Christie 6e68af666f [SCSI] Convert SCSI mid-layer to scsi_execute_async
Add scsi helpers to create really-large-requests and convert
scsi-ml to scsi_execute_async().

Per Jens's previous comments, I placed this function in scsi_lib.c.
I made it follow all the queue's limits - I think I did at least :), so
I removed the warning on the function header.

I think the scsi_execute_* functions should eventually take a request_queue
and be placed some place where the dm-multipath hw_handler can use them
if that failover code is going to stay in the kernel. That conversion
patch will be sent in another mail though.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-12-14 19:03:35 -08:00
James Bottomley c9526497cf [SCSI] Consolidate REQ_BLOCK_PC handling path (fix ipod panic)
This follows on from Jens' patch and consolidates all of the ULD
separate handlers for REQ_BLOCK_PC into a single call which has his
fix for our direction bug.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-12-13 21:29:27 -08:00
Matthew Wilcox 829b84675e [SCSI] Make scsi_transport_spi.h includable by itself
Add forward declarations to allow scsi_transport_spi.h to be compiled by
itself.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-12-13 18:54:40 -07:00
James Bottomley 7f23e146a1 [SCSI] correct some dropped const compiler warnings
Make the vendor, model and rev fields in scsi_device pointers to const
and update a few prototypes of functions using them.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-12-13 18:12:05 -07:00
Christoph Hellwig 7dfdc9a52b [SCSI] use a completion in scsi_send_eh_cmnd
scsi_send_eh_cmnd currently uses a semaphore and an overload of eh_timer
to either get a completion for a command for a timeout.
Switch to using a completion and wait_for_completion_timeout to simply
the code and not having to deal with the races ourselves.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-11-06 12:49:36 -06:00
Christoph Hellwig 262eef663b [SCSI] remove scsi_wait_req
This function has been superceeded by the block request based interfaces
and is unused (except for the uncompilable cpqfc driver).

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-11-06 12:45:20 -06:00
Christoph Hellwig 474838d5e5 [SCSI] remove Scsi_Host.eh_active
now that the abuse in qla2xxx is gone this field can be remove.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-11-06 12:44:44 -06:00
James Bottomley 849a8924a6 Merge by Hand
Conflicts in dec_esp.c (Thanks Bacchus), scsi_transport_iscsi.c and
scsi_transport_fc.h

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-11-04 22:29:52 -06:00
Linus Torvalds 127f2fa31a Merge branch 'srp' of master.kernel.org:/pub/scm/linux/kernel/git/roland/infiniband 2005-11-04 16:32:36 -08:00
Roland Dreier aef9ec39c4 IB: Add SCSI RDMA Protocol (SRP) initiator
Add an InfiniBand SCSI RDMA Protocol (SRP) initiator.  This driver is
used to talk talk to InfiniBand SRP targets (storage devices).

Signed-off-by: Roland Dreier <rolandd@cisco.com>
2005-11-02 14:07:13 -08:00
Tim Schmielau 4e57b68178 [PATCH] fix missing includes
I recently picked up my older work to remove unnecessary #includes of
sched.h, starting from a patch by Dave Jones to not include sched.h
from module.h. This reduces the number of indirect includes of sched.h
by ~300. Another ~400 pointless direct includes can be removed after
this disentangling (patch to follow later).
However, quite a few indirect includes need to be fixed up for this.

In order to feed the patches through -mm with as little disturbance as
possible, I've split out the fixes I accumulated up to now (complete for
i386 and x86_64, more archs to follow later) and post them before the real
patch.  This way this large part of the patch is kept simple with only
adding #includes, and all hunks are independent of each other.  So if any
hunk rejects or gets in the way of other patches, just drop it.  My scripts
will pick it up again in the next round.

Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-30 17:37:32 -08:00
James.Smart@Emulex.Com 19a7b4aebf [SCSI] update fc_transport for removal of block/unblock functions
We recently went back to implement a board reset. When we perform the
reset, we wanted to tear down the internal data structures and rebuild
them. Unfortunately, when it came to the rport structure, things were
odd. If we deleted them, the scsi targets and sdevs would be
torn down. Not a good thing for a temporary reset. We could block the
rports, but we either maintain the internal structures to keep the
rport reference (perhaps even replicating what's in the transport),
or we have to fatten the fc transport with new search routines to find
the rport (and deal with a case of a dangling rport that the driver
forgets).

It dawned on me that we had actually reached this state incorrectly.
When the fc transport first started, we did the block/unblock first, then
added the rport interface. The purpose of block/unblock is to hide the
temporary disappearance of the rport (e.g. being deleted, then readded).
Why are we making the driver do the block/unblock ? We should be making
the transport have only an rport add/delete, and the let the transport
handle the block/unblock.

So... This patch removes the existing fc_remote_port_block/unblock
functions. It moves the block/unblock functionality into the
fc_remote_port_add/delete functions.  Updates for the lpfc driver are
included. Qlogic driver updates are also enclosed, thanks to the
contributions of Andrew Vasquez. [Note: the qla2xxx changes are
relative to the scsi-misc-2.6 tree as of this morning - which does
not include the recent patches sent by Andrew]. The zfcp driver does
not use the block/unblock functions.

One last comment: The resulting behavior feels very clean. The LLDD is
concerned only with add/delete, which corresponds to the physical
disappearance.  However, the fact that the scsi target and sdevs are
not immediately torn down after the LLDD calls delete causes an
interesting scenario... the midlayer can call the xxx_slave_alloc and
xxx_queuecommand functions with a sdev that is at the location the
rport used to be. The driver must validate the device exists when it
first enters these functions. In thinking about it, this has always
been the case for the LLDD and these routines. The existing drivers
already check for existence. However, this highlights that simple
validation via data structure dereferencing needs to be watched.
To deal with this, a new transport function, fc_remote_port_chkready()
was created that LLDDs should call when they first enter these two
routines. It validates the rport state, and returns a scsi result
which could be returned. In addition to solving the above, it also
creates consistent behavior from the LLDD's when the block and deletes
are occuring.

Rejections fixed up and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
2005-10-28 21:20:07 -05:00