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>
From:
michaelc@cs.wisc.edufujita.tomonori@lab.ntt.co.jpda-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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
