As previously reported via Michael Reed, the FC transport took a hit
in 2.6.15 (perhaps a little earlier) when we solved a recursion error.
There are 2 deadlocks occurring:
- With scan and the delete items sharing the same workq, flushing the
workq for the delete code was getting it stalled behind a very long
running scan code path.
- There's a deadlock where scsi_remove_target() has to sit behind
scsi_scan_target() due to contention over the scan_lock().
This patch resolves the 1st deadlock and significantly reduces the
odds of the second. So far, we have only replicated the 2nd deadlock
on a highly-parallel SMP system. More on the 2nd deadlock in a following
email.
This patch reworks the transport to:
- Only use the scsi host workq for scanning
- Use 2 other workq's internally. One for deletions, the other for
scheduled deletions. Originally, we tried this with a single workq,
but the occassional flushes of the scheduled queues was hitting the
second deadlock with a slightly higher frequency. In the future, we'll
look at the LLDD's and the transport to see if we can get rid of this
extra overhead.
- When moving to the other workq's we tightened up some object states
and some lock handling.
- Properly syncs adds/deletes
- minor code cleanups
- directly reference fc_host_attrs, rather than through attribute
macros
- flush the right workq on delayed work cancel failures.
Large kudos to Michael Reed who has been working this issue for the last
month.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.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: James Bottomley <James.Bottomley@SteelEye.com>
We currently have two implementations of this obsolete ioctl, one in
the block layer and one in the scsi code. Both of them have drawbacks.
This patch kills the scsi layer version after updating the block version
with the missing bits:
- argument checking
- use scatterlist I/O
- set number of retries based on the submitted command
This is the last user of non-S/G I/O except for the gdth driver, so
getting this in ASAP and through the scsi tree would be nie to kill
the non-S/G I/O path. Jens, what do you think about adding a check
for non-S/G I/O in the midlayer?
Thanks to Or Gerlitz for testing this patch.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Overriding the whole EH code is a per-transport, not per-host thing.
Move ->eh_strategy_handler to the transport class, same as
->eh_timed_out.
Downside is that scsi_host_alloc can't check for the total lack of EH
anymore, but the transition period from old EH where we needed it is
long gone already.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
