Spotted by: Dan Aloni <da-xx@monatomic.org>

The problem is there's inconsistent locking semantic usage of
scsi_alloc_target().  Two callers assume the target comes back with
reference unincremented and the third assumes its incremented.  Fix by
always making the reference incremented on return.  Also fix path in
target alloc that could consistently increment the parent lock.
Finally document scsi_alloc_target() so its callers know what the
expectations are.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Sanitize the Vendor, Product, and Revision strings contained in an
INQUIRY result by setting all non-graphic or non-ASCII characters to ' '.
Since the standard disallows such characters, this will affect
only non-compliant devices.

To help maintain backward compatibility, NUL characters are treated
specially.  They are taken as string terminators; they and all the
following characters are set to ' '.  If some valid characters get
erased as a result... well, we weren't seeing them before so we haven't
lost anything.

The primary purpose of this change is to allow blacklist entries to
match devices with illegal Vendor or Product strings.

In addition, the patch updates a couple of function prototypes, giving
inq_result its correct type (unsigned char *).
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Some targets may return slight variations of PQ and PDT to indicate
no LUN mapped.  USB UFI setting PDT=0x1f but having reserved bits for
PQ is one example, and NetApp targets returning PQ=1 and PDT=0x1f is
another.  Both instances seem like reasonable responses according to
SPC-3 and UFI specs.

The current scsi_probe_and_add_lun() code adds a scsi_device
for targets that return PQ=1 and PDT=0x1f.  This causes LUNs of type
"UNKNOWN" to show up in /proc/scsi/scsi when no LUNs are mapped.
In addition, subsequent rescans fail to recognize LUNs that may be
added on the target, unless preceded by a write to the delete attribute
of the "UNKNOWN" LUN.

This patch addresses this problem by skipping over the scsi_add_lun()
when PQ=1,PDT=0x1f is encountered, and just returns
SCSI_SCAN_TARGET_PRESENT.
Signed-off-by: NDave Wysochanski <davidw@netapp.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

A recent drivers base commit:

3e95637a

Caused the bus to be added to dev_printk, so now our SCSI inquiry short
messages print like this:

scsiscsi 2:0:0:0: Direct access     IBM-ESXS ST973401SS       B519 PQ: 0 ANSI: 5

Just remove the "scsi" from the sdev_printk to compensate.
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>

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

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>

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>

The scsi_scan_host_selected() should return -EINVAL when the id is equal
to the max_id. Currently it uses ">" when comparing with max_id, and
hence leaves the border case when "id==max_id".
The channel and lun have values valid from 0 up to,
and including, max_channel or max_lun. But, the valid values for id
range from 0 to max_id-1. This patch fixes the problem.
Signed-off-by: NAmit Arora <aarora@in.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/scsi_scan.c: In function `scsi_probe_and_add_lun':
drivers/scsi/scsi_scan.c:926: warning: unused variable `vend'
drivers/scsi/scsi_scan.c:926: warning: unused variable `mod'
drivers/scsi/scsi_scan.c: At top level:
drivers/scsi/scsi_scan.c:829: warning: `scsi_inq_str' defined but not used

Fix those, tighten up the (somewhat poorly-designed) logging macro and fix
some coding-style warts.
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Some devices report a peripheral qualifier of 3 for LUN 0; with the original
code, we would still try a REPORT_LUNS scan (if SCSI level is >= 3 or if we
have the BLIST_REPORTLUNS2 passed in), but NOT any sequential scan.
Also, the device at LUN 0 (which is not connected according to the PQ) is not
registered with the OS.

Unfortunately, SANs exist that are SCSI-2 and do NOT support REPORT_LUNS, but
report a unknown device with PQ 3 on LUN 0. We still need to scan them, and
most probably we even need BLIST_SPARSELUN (and BLIST_LARGELUN). See the bug
reference for an infamous example.

This is patch 3/3:
3. Implement the blacklist flag BLIST_ATTACH_PQ3 that makes the scsi
   scanning code register PQ3 devices and continues scanning; only sg
   will attach thanks to scsi_bus_match().
Signed-off-by: NKurt Garloff <garloff@suse.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Some devices report a peripheral qualifier of 3 for LUN 0; with the original
code, we would still try a REPORT_LUNS scan (if SCSI level is >= 3 or if we
have the BLIST_REPORTLUNS2 passed in), but NOT any sequential scan.
Also, the device at LUN 0 (which is not connected according to the PQ) is not
registered with the OS.

Unfortunately, SANs exist that are SCSI-2 and do NOT support REPORT_LUNS, but
report a unknown device with PQ 3 on LUN 0. We still need to scan them, and
most probably we even need BLIST_SPARSELUN (and BLIST_LARGELUN). See the bug
reference for an infamous example.

This patch 2/3:
If a PQ3 device is found, log a message that describes the device
(INQUIRY DATA and C:B:T:U tuple) and make a suggestion for blacklisting
it.
Signed-off-by: NKurt Garloff <garloff@suse.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Some devices report a peripheral qualifier of 3 for LUN 0; with the original
code, we would still try a REPORT_LUNS scan (if SCSI level is >= 3 or if we
have the BLIST_REPORTLUNS2 passed in), but NOT any sequential scan.
Also, the device at LUN 0 (which is not connected according to the PQ) is not
registered with the OS.

Unfortunately, SANs exist that are SCSI-2 and do NOT support REPORT_LUNS, but
report a unknown device with PQ 3 on LUN 0. We still need to scan them, and
most probably we even need BLIST_SPARSELUN (and BLIST_LARGELUN). See the bug
reference for an infamous example.

This is patch 1/3:
If we end up in sequential scan, at least try LUN 1 for devices
that reported a PQ of 3 for LUN 0.
Also return blacklist flags, even for PQ3 devices.
Signed-off-by: NKurt Garloff <garloff@suse.de>
Signed-off-by: NJames 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: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch moves the calling of target_destroy next to the list_del. This
closed a race being seen while doing a device add on the aic7xxx.
Signed-off-by: NMike Anderson <andmike@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

If the scsi_alloc_queue or the slave_alloc calls in scsi_alloc_device fail,
we forget to release the locally allocated sdev on the failure path.

Coverity #609
Signed-off-by: NDave Jones <davej@redhat.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Fixes scsi to handle device_add failure in scsi_alloc_target.
Without this patch, if this call were to fail, we can oops
when we free the target.
Signed-off-by: NBrian King <brking@us.ibm.com>
Signed-off-by: NJames 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: NJames 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: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

in __scsi_add_device, sdev may be uninitialised if
scsi_host_scan_allowed() returns false.  Fix by initialising at the
top of the routine.  Also rely on the fact that
scsi_probe_and_add_lun() only actually fills in the sdev pointer if
the SCSI_SCAN_LUN_PRESENT case (so no need to check the return value).
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>

Change the core SCSI code to use kzalloc rather than kmalloc+memset
where possible.
Signed-off-by: NJes Sorensen <jes@sgi.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

When >slave_configure fails the scsi midlayer should handle it.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

There's a bug in releasing scsi_device where the release function
actually frees the block queue.  However, the block queue release
calls flush_work(), which requires process context (the scsi_device
structure may release from irq context).  Update the release function
to invoke via the execute_in_process_context() API.

Also clean up the scsi_target structure releasing via this API.
Signed-off-by: NJames 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: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames 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: NArjan van de Ven <arjan@infradead.org>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The oops is characteristic of the underlying device being removed from
visibility before the class device, and sure enough we do device_del()
before transport_unregister() in the scsi_target_reap() routines.  I've
no idea why this is suddenly showing up, since the code has been in
there since that function was first invented.  However, I've confirmed
this fixes Andrew Vasquez's boot oops.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

scsi_reap_target() was desgined to be called from any context.
However it must do a device_del() of the target device, which may only
be called from user context.  Thus we have to reimplement
scsi_reap_target() via a workqueue.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

patch below marks a few scsi core datastructures as const, so that they end up
in the .rodata section and don't cacheline share with things that get dirtied
Signed-off-by: NArjan van de Ven <arjan@infradead.org>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

There is a double free in the scsi scan code if a LLDD's slave_alloc()
call fails.  There is a direct call to scsi_free_queue and then the
following put_device calls the release function, which also frees the
queue.

Remove the redundant scsi_free_queue.
Signed-off-by: NBrian King <brking@us.ibm.com>
Tested-by: NNathan Lynch <ntl@pobox.com>
[ Also removed some strange whitespace artifacts in that area ]
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Current scsi scanning code appears to have a use after free
bug is a LLDD's slave_alloc fails. Remove the redundant
scsi_free_queue.
Signed-off-by: NBrian King <brking@us.ibm.com>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

rejections fixed and
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This should eliminate (at least in the mid layer) to make numeric
assumptions about any of the enumeration variables.  As a side effect,
it will also make all the messages consistent and line us up nicely for
the error logging strategy (if it ever shows itself again).
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

Currently we just ignore the device, which means there are a few
arrays out there that we don't find.

This patch updates the scsi_report_lun_scan() to take a target instead
of a device so it can be called on a return of
SCSI_SCAN_TARGET_PRESENT, which is what a PQ 3 device returns.
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch (as545) fixes the list traversals in __scsi_remove_target and
scsi_forget_host.  In each case the existing code list_for_each_entry_safe
in an _unsafe_ manner, because the list was not protected from outside
modification while the iteration was running.

The new scsi_forget_host routine takes the moderately controversial step
of iterating over devices for removal rather than iterating over targets.
This makes more sense to me because the current scheme treats targets as
second-class citizens, created and removed on demand, rather than as
objects corresponding to actual hardware.  (Also I couldn't figure out any
safe way to iterate over the target list, since it's not so easy to tell
when a target has already been removed.)
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

The original API returned either an ERR_PTR() or a refcounted sdev.
Unfortunately, if it's successful, you need to do a scsi_device_put() on
the sdev otherwise the refcounting is wrong.

Everyone seems to expect that scsi_add_device() should be callable
without doing the ref put, so alter the API so it is (we still have
__scsi_add_device with the original behaviour).

The only actual caller that needs altering is the one in firewire ...
not because it gets this right, but because it acts on the error if one
is returned.
Acked-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

This patch (as546) fixes an oops-causing failure to check the return code
from scsi_device_get.  The call can return an error if the LLD is being
unloaded from memory.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>