Reimplement per-dev PM.  The original implementation directly put the
device into suspended mode and didn't synchronize w/ EH operations
including hotplug.  This patch reimplements ata_scsi_device_suspend()
and ata_scsi_device_resume() such that they request EH to perform the
respective operations.  Both functions synchronize with hotplug such
that it doesn't operate on detached devices.

Suspend waits for completion but resume just issues request and
returns.  This allows parallel wake up of devices and thus speeds up
system resume.

Due to sdev detach synchronization, it's not feasible to separate out
EH requesting from sdev handling; thus, ata_device_suspend/resume()
are removed and everything is implemented in the respective
libata-scsi functions.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement two PM per-dev EH actions - ATA_EH_SUSPEND and
ATA_EH_RESUME.  Each action puts the target device into suspended mode
and resumes from it respectively.

Once a device is put to suspended mode, no EH operations other than
RESUME is allowed on the device.  The device will stay suspended till
it gets resumed and thus reset and revalidated.  To implement this, a
new device state helper - ata_dev_ready() - is implemented and used in
EH action implementations to make them operate only on attached &
running devices.

If all possible devices on a port are suspended, reset is skipped too.
This prevents spurious events including hotplug events from disrupting
suspended devices.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement ATA_EHI_NO_AUTOPSY and QUIET.  These used to be implied by
ATA_PFLAG_LOADING, but new power management and PMP support need to
use these separately.  e.g. Suspend/resume operations shouldn't print
full EH messages and resume shouldn't be recorded as an error.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

The names of predefined debounce timing parameters didn't exactly
match their usages.  Rename to more generic names and implement param
selection helper sata_ehc_deb_timing() which uses EHI_HOTPLUGGED to
select params.

Combined with the previous EHI_RESUME_LINK differentiation, this makes
parameter selection accurate.  e.g. user scan resumes link but normal
deb param is used instead of hotplug param.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement ATA_EHI_RESUME_LINK, which indicates that the link needs to
be resumed.  This used to be implied by ATA_EHI_HOTPLUGGED.  However,
hotplug isn't the only event which requires link resume and separating
this out allows other places to request link resume.  This
differentiation also allows better debounce timing selection.

This patch converts user scan to use ATA_EHI_RESUME_LINK.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ap_lock was used because &ap->host_set->lock was too long and used a
lot.  Now that &ap->host_set->lock is replaced with ap->lock, there's
no reason to keep ap_lock.

[ed. note: that's not entirely true.  ap_lock is a local variable,
caching the results of a de-ref.  In theory, if the compiler is smart
enough, this patch is cosmetic.  However, since this is not a fast
path (it is the error path), this patch is nonetheless acceptable,
even though it _may_ introduce a performance regression.]
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ata_eh_autopsy() used to directly assign determined action mask to
ehc->i.action thus overriding actions set by some of nested analyze
functions.  This patch makes ata_eh_autopsy() add action masks just as
it's done in other places.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

ap->flags is way too clamped.  Separate out core dynamic flags to
ap->pflags.  ATA_FLAG_DISABLED is a dynamic flag but left alone as
it's referenced by a lot of LLDs and it's gonna be removed once all
LLDs are converted to new EH.
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

In preparation for SAS attached SATA devices, which will
not have a libata scsi_host, only setup host->max_cmd_len
if ap->host exists.
Signed-off-by: NBrian King <brking@us.ibm.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Hi,

sata_vsc is an MMIO device, and should use the correct data_xfer
function.  This problem was introduced by:

   commit a6b2c5d4
   Author: Alan Cox <alan@lxorguk.ukuu.org.uk>
   Date:   Mon May 22 16:59:59 2006 +0100

        [PATCH] PATCH: libata. Add ->data_xfer method
Signed-off-by: NMartin Hicks <mort@bork.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

lockdep needs to have the waitqueue lock initialized for on-stack waitqueues
implicitly initialized by DECLARE_COMPLETION().  Annotate on-stack completions
accordingly.

Has no effect on non-lockdep kernels.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

There was a logic fault in scsi_io_completion() where zero transfer
commands that complete successfully were sent to the block layer as
not up to date.  This patch removes the if (good_bytes > 0) gate
around the successful completion, since zero transfer commands do have
good_bytes == 0.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Fix section mismatch warnings:
WARNING: drivers/scsi/qla1280.o - Section mismatch: reference to
.init.data: from .text between 'qla1280_get_token' (at offset 0x2a16)
and 'qla1280_probe_one'
WARNING: drivers/scsi/qla1280.o - Section mismatch: reference to
.init.data: from .text between 'qla1280_get_token' (at offset 0x2a3c)
and 'qla1280_probe_one'
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Make some needlessly global functions static.
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: NAndrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Add a few spaces to MODULE_PARM_DESC() text for qla2xxx. Without these
spaces text runs together when modinfo prints the text.
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Acked-by: NAndrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

I got a NULL derefrence in cdev_del+1 when called from sg_remove. By looking at
the code of sg_add, sg_alloc and sg_remove (all in drivers/scsi/sg.c) I found
out that sg_add is calling sg_alloc but if it fails afterwards it does not
deallocate the space that was allocated in sg_alloc and the redundant entry has
NULL in cdev. When sg_remove is being called, it tries to perform cdev_del to
this NULL cdev and fails.
Signed-off-by: NIshai Rabinovitz <ishai@mellanox.co.il>
Acked-by: NDouglas Gilbert <dougg@torque.net>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Acked-by: NMauro Carvalho Chehab <mchehab@infradead.org>

A bit of a brown paper bag issue.  The previous patch to remove the soon
to be ripped out fields that were used in autosense actually broke the
driver.  This patch fixes it and has been tested (honestly).
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch adds or modifies the transport class functions
used to notify userspace of session state events.

We modify the session addition up event and add a destruction event
to notify userspace of session creation, relogin and destruction.

And we modify the conn error event to be sent by broadcast
since multiple listeners may want to listen for it.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

So the drivers do not use the channel numbers, but some do
use the target numbers. We were just adding some goofy
variable that just increases for the target nr. This is useless
for software iscsi because it is always zero. And for qla4xxx
the target nr is actually the index of the target/session
in its FW or FLASH tables. We needed to expose this to userspace
so apps could access those numbers so this patch just adds the
target nr to the iscsi session creation functions. This way
when qla4xxx's Hw thinks a session is at target nr 4
in its hw, it is exposed as that number in sysfs.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

qla4xxx is initialized in two steps like other HW drivers.
It allocates the host, sets up the HW, then adds the host.
For iscsi part of HW setup is setting up persistent iscsi
sessions. At that time, the interupts are off and the driver
is not completely set up so we just want to allocate them.
We do not want to add them to sysfs and expose them to userspace
because userspace could try to do lots of fun things with them
like scanning and at that time the driver is not ready.

So this patch breakes up the session creation like other
functions that use the driver model in two the alloc
and add parts. When the driver is ready, it can then add
the sessions and userspace can begin using them.

This also fixes a bug in the addition error patch where
we forgot to do a get on the session.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

I do not remember what I was thinking when we added the channel
as a argument to the session create function. It was probably
due to too much cut and paste work from the FC transport class.

The channel is meaningless for iscsi drivers so this patch drops
its usage everywhere in the iscsi related code.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

iscsi_tcp and iser cannot be rmmod from the kernel when sessions
are running because session removal is driven from userspace. For
those modules we get a module reference when a session is
created then drop it when the session is removed.

For qla4xxx, they can jsut remove the sessions from the pci remove
function like normal HW drivers, so this patch moves the module
reference from the transport class functions shared by all
drivers to the libiscsi functions only used be software iscsi
modules.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Convert iscsi_tcp to new lib functions.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Reduce duplication in the software iscsi_transport modules by
adding a libiscsi function to handle the common grunt work.

This also has the drivers return specifc -EXXX values for different
errors so userspace can finally handle them in a sane way.

Also just pass the sysfs buffers to the drivers so HW iscsi can
get/set its string values, like targetname, and initiatorname.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Patch from david.somayajulu@qlogic.com:

Add target discovery event. We may have a setup where the iscsi traffic
is on a different netowrk than the other network traffic. In this case
we will want to do discovery though the iscsi card. This patch adds
a event to the transport class that can be used by hw iscsi cards that
support this.
Signed-off-by: NMike Christie <michaelc@cs.wisc.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

I noticed that in_use in st_buffer is not used. The patch below
against 2.6.17-rc3 removes it, assuming there is no future use for it.
It was tested in a sparc SS20 with a DLT4000.
Signed-off-by: NMartin Habets <errandir_news@mph.eclipse.co.uk>
Acked-by: NKai Mäkisara <kai.makisara@kolumbus.fi>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The atp870u driver is the largest stack eater reported by checkstack
(on x86_864, allmodconfig).  This converts the offending function
to kmalloc+kfree struct atp_unit instead of allocating it on the stack.
Was:
0x0000164c atp870u_probe [atp870u]:			3176
Now:
0x0000164c atp870u_probe [atp870u]:			408
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

this patch introduces a port object, separates out ports and phys,
with ports becoming the primary objects of the tree.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

If a device gets offlined as a result of the Inquiry sent
during scanning, the following oops can occur. After the
disk gets put into the SDEV_OFFLINE state, the error handler
sends back the failed inquiry, which wakes the thread doing
the scan. This starts a race between the scanning thread
freeing the scsi device and the error handler calling
scsi_run_host_queues to restart the host. Since the disk
is in the SDEV_OFFLINE state, scsi_device_get will still
work, which results in __scsi_iterate_devices getting
a reference to the scsi disk when it shouldn't.

The following execution thread causes the oops:

CPU 0 (scan)				CPU 1 (eh)

---------------------------------------------------------
scsi_probe_and_add_lun
                        ....
                                        scsi_eh_offline_sdevs
                                        scsi_eh_flush_done_q
scsi_destroy_sdev
scsi_device_dev_release
                                        scsi_restart_operations
                                         scsi_run_host_queues
                                          __scsi_iterate_devices
                                           get_device
scsi_device_dev_release_usercontext
                                          scsi_run_queue
                                            <---OOPS--->

The patch fixes this by changing the state of the sdev to SDEV_DEL
before doing the final put_device, which should prevent the race
from occurring.

Original oops follows:

Badness in kref_get at lib/kref.c:32
Call Trace:
[C00000002F4476D0] [C00000000000EE20] .show_stack+0x68/0x1b0 (unreliable)
[C00000002F447770] [C00000000037515C] .program_check_exception+0x1cc/0x5a8
[C00000002F447840] [C00000000000446C] program_check_common+0xec/0x100
 Exception: 700 at .kref_get+0x10/0x28
    LR = .kobject_get+0x20/0x3c
[C00000002F447B30] [C00000002F447BC0] 0xc00000002f447bc0 (unreliable)
[C00000002F447BB0] [C000000000254BDC] .get_device+0x20/0x3c
[C00000002F447C30] [D000000000063188] .scsi_device_get+0x34/0xdc [scsi_mod]
[C00000002F447CC0] [D0000000000633EC] .__scsi_iterate_devices+0x50/0xbc [scsi_mod]
[C00000002F447D60] [D00000000006A910] .scsi_run_host_queues+0x34/0x5c [scsi_mod]
[C00000002F447DF0] [D000000000069054] .scsi_error_handler+0xdb4/0xe44 [scsi_mod]
[C00000002F447EE0] [C00000000007B4E0] .kthread+0x128/0x178
[C00000002F447F90] [C000000000025E84] .kernel_thread+0x4c/0x68
Unable to handle kernel paging request for <7>PCI: Enabling device: (0002:41:01.1), cmd 143
data at address 0x000001b8
Faulting instruction address: 0xd0000000000698e4
sym1: <1010-66> rev 0x1 at pci 0002:41:01.1 irq 216
sym1: No NVRAM, ID 7, Fast-80, LVD, parity checking
sym1: SCSI BUS has been reset.
scsi2 : sym-2.2.2
cpu 0x0: Vector: 300 (Data Access) at [c00000002f447a30]
    pc: d0000000000698e4: .scsi_run_queue+0x2c/0x218 [scsi_mod]
    lr: d00000000006a904: .scsi_run_host_queues+0x28/0x5c [scsi_mod]
    sp: c00000002f447cb0
   msr: 9000000000009032
   dar: 1b8
 dsisr: 40000000
  current = 0xc0000000045fecd0
  paca    = 0xc00000000048ee80
    pid   = 1123, comm = scsi_eh_1
enter ? for help
[c00000002f447d60] d00000000006a904 .scsi_run_host_queues+0x28/0x5c [scsi_mod]
[c00000002f447df0] d000000000069054 .scsi_error_handler+0xdb4/0xe44 [scsi_mod]
[c00000002f447ee0] c00000000007b4e0 .kthread+0x128/0x178
[c00000002f447f90] c000000000025e84 .kernel_thread+0x4c/0x68
Signed-off-by: NBrian King <brking@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This is a resend of a patch I generated in response to an email sent
by Ruben Faelens <parasietje@gmail.com>. His original email to
linux-scsi requested a method in which he could spin down a scsi disk
when not in use and have the kernel automatically spin it back up when
an I/O was generated to the disk. The infrastructure to automatically
spin a disk up has been in the scsi error handler for some time now,
but it is not enabled by default. This patch adds an sd sysfs attribute
which allows userspace to enable this behavior.
Signed-off-by: NBrian King <brking@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Remove redundant NULL chck before kfree + tiny CodingStyle cleanup for
drivers/
Signed-off-by: NJesper Juhl <jesper.juhl@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

locking init cleanups:

 - convert " = SPIN_LOCK_UNLOCKED" to spin_lock_init() or DEFINE_SPINLOCK()
 - convert rwlocks in a similar manner

this patch was generated automatically.

Motivation:

 - cleanliness
 - lockdep needs control of lock initialization, which the open-coded
   variants do not give
 - it's also useful for -rt and for lock debugging in general
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This is needed if we wish to change the size of the resource structures.

Based on an original patch from Vivek Goyal <vgoyal@in.ibm.com>

Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Original post was incorrect as it didn't realize that we already had
a self-referenc due to device_initialize(), and we were really only
missing the put on our own reference. This was hidden by the other bug
which had the midlayer reusing stargets after they were already free,
which was doing too many puts on our rport.

Updating FC transport for:
- Add put in fc_rport_final_delete(), to release the rport.
  Prior, we were leaving the rport with a reference, thus the shost
  with references, etc. If the driver was unloaded, shosts and rports
  remained, along with work threads, etc
- Fix fc_rport_create failure path - too many put's on parent
- Add commenting to easily track ref taking.
Signed-off-by: NJames Smart <james.smart@emulex.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Updated patch to address comments from Pat Mansfield and Michael Reed:
Bumped max to 600 (10mins). Set default dev_loss_tmo to a value other
than the max (30s).
Signed-off-by: NJames Smart <James.Smart@emulex.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

In a prior posting to linux-scsi on the fc transport and workq
deadlocks, we noted a second error that did not have a patch:
  http://marc.theaimsgroup.com/?l=linux-scsi&m=114467847711383&w=2
  - There's a deadlock where scsi_remove_target() has to sit behind
    scsi_scan_target() due to contention over the scan_lock().

Subsequently we posted a request for comments about the deadlock:
  http://marc.theaimsgroup.com/?l=linux-scsi&m=114469358829500&w=2

This posting resolves the second error. Here's what we now understand,
and are implementing:

  If the lldd deletes the rport while a scan is active, the sdev's queue
  is blocked which stops the issuing of commands associated with the scan.
  At this point, the scan stalls, and does so with the shost->scan_mutex held.
  If, at this point, if any scan or delete request is made on the host, it
  will stall waiting for the scan_mutex.

  For the FC transport, we queue all delete work to a single workq.
  So, things worked fine when competing with the scan, as long as the
  target blocking the scan was the same target at the top of our delete
  workq, as the delete workq routine always unblocked just prior to
  requesting the delete.  Unfortunately, if the top of our delete workq
  was for a different target, we deadlock.  Additionally, if the target
  blocking scan returned, we were unblocking it in the scan workq routine,
  which really won't execute until the existing stalled scan workq
  completes (e.g. we're re-scheduling it while it is in the midst of its
  execution).

  This patch moves the unblock out of the workq routines and moves it to
  the context that is scheduling the work. This ensures that at some point,
  we will unblock the target that is blocking scan.  Please note, however,
  that the deadlock condition may still occur while it waits for the
  transport to timeout an unblock on a target.  Worst case, this is bounded
  by the transport dev_loss_tmo (default: 30 seconds).

Finally, Michael Reed deserves the credit for the bulk of this patch,
analysis, and it's testing. Thank you for your help.

Note: The request for comments statements about the gross-ness of the
  scan_mutex still stand.
Signed-off-by: NMichael Reed <mdr@sgi.com>
Signed-off-by: NJames Smart <james.smart@emulex.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>