bus_id -> dev_name() conversions in s390 code.

[cornelia.huck@de.ibm.com: minor adaptions]
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

* Implement disk_devt() and part_devt() and use them to directly
  access devt instead of computing it from ->major and ->first_minor.

  Note that all references to ->major and ->first_minor outside of
  block layer is used to determine devt of the disk (the part0) and as
  ->major and ->first_minor will continue to represent devt for the
  disk, converting these users aren't strictly necessary.  However,
  convert them for consistency.

* Implement disk_max_parts() to avoid directly deferencing
  genhd->minors.

* Update bdget_disk() such that it doesn't assume consecutive minor
  space.

* Move devt computation from register_disk() to add_disk() and make it
  the only one (all other usages use the initially determined value).

These changes clean up the code and will help disk->part dereference
fix and extended block device numbers.
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Fix this compile bug:

  CC      drivers/s390/block/dcssblk.o
drivers/s390/block/dcssblk.c: In function 'dcssblk_add_store':
drivers/s390/block/dcssblk.c:387: error: implicit declaration of function 'dcssblk_get_segment_by_name'
drivers/s390/block/dcssblk.c:389: error: label 'release_gd' used but not defined
make[1]: *** [drivers/s390/block/dcssblk.o] Error 1
make: *** [drivers/s390/block/] Error 2

Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Concurrently adding the same segment may lead to duplicate device_register()
calls, which will trigger an error in kobject code:
"... don't try to register things with the same name in the same directory".
This patch adds a check to avoid this.
Signed-off-by: NGerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Calling a ccw driver's notify function without the ccw device lock
held opens up a race window between discovery and handling of a change
in the device operational state. As a result, the device driver may
encounter unexpected device malfunction, leading to out-of-retry
situations or similar.

Remove race by extending the ccw device lock from state change
discovery to the calling of the notify function.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

The Perform Subsystem Function/Prepare for Read Subsystem Data
command requires 12 bytes of parameter data, but the respective data
structure dasd_psf_prssd_data has a length of 16 bytes.
Current storage servers ignore the obsolete bytes, but older models
fail to execute the command and report an incorrect length error.
This causes the device initilization for these devices to fail.
To fix this problem we need to correct the dasd_psf_prssd_data
structure and shorten it to the correct length.
Reported-by: NIvan Warren <ivan@vmfacility.fr>
Reviewed-by: NIvan Warren <ivan@vmfacility.fr>
Tested-by: NIvan Warren <ivan@vmfacility.fr>
CC: stable <stable@kernel.org>
Signed-off-by: NStefan Weinhuber <wein@de.ibm.com>

In case of error, functions dasd_kmalloc_request and idal_buffer_alloc
return an ERR pointer, but never return the NULL pointer. So after a
call to one of these functions, a NULL test should be replaced by an
IS_ERR test.

A simplified version of the semantic patch that makes this change is
as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@correct_null_test@
expression x,E;
statement S1, S2;
@@
x =
(
  dasd_kmalloc_request(...)
|
  idal_buffer_alloc(...)
)
<... when != x = E
if (
(
- x@p2 != NULL
+ ! IS_ERR ( x )
|
- x@p2 == NULL
+ IS_ERR( x )
)
 )
S1
else S2
...>
? x = E;
// </smpl>
Signed-off-by: NJulien Brunel <brunel@diku.dk>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When z/VM provides two virtual devices (minidisks) that reside on the
same real device, both will receive the configuration data from the
real device and thus get the same uid. To fix this problem, z/VM
provides an additional configuration data record that allows to
distinguish between minidisks.
z/VM APAR VM64273 needs be installed so this fix has an effect.
Signed-off-by: NStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

return value -ENOTSUPP is not valid in userspace context, use
-EOPNOTSUPP instead
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>

Add missing schedule_bh and check that there is 32 bit sense data.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NHongjie Yang <hongjie@us.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Extend the scsw data structure to the format required by fcx. Also
provide helper functions for easier access to fields which are present
in both the traditional as well as the modified format.
Signed-off-by: NPeter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: NArnd Bergmann <arnd@arndb.de>

Use a generic wait_queue to prevent the wait_queue in dasd_sleep_on_
functions from being referenced by callback_data while it does not
exist any more.
Signed-off-by: NStefan Haberland  <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When the dasd_int_handler is called with an error code instead of
an irb, the associated request should be restarted. This handling
was missing from the -ETIMEDOUT case. In fact it should be done in
any case.
Signed-off-by: NStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

We should use 'const char *' in the busid functions since the
strings are not modified anyway.
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Use proc_create() to make sure that ->proc_fops be setup before gluing PDE to
main tree.
Signed-off-by: NDenis V. Lunev <den@openvz.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove proc_root export.  Creation and removal works well if parent PDE is
supplied as NULL -- it worked always that way.

So, one useless export removed and consistency added, some drivers created
PDEs with &proc_root as parent but removed them as NULL and so on.
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Alter the block device ->direct_access() API to work with the new
get_xip_mem() API (that requires both kaddr and pfn are returned).

Some architectures will not do the right thing in their virt_to_page() for use
by XIP (to translate from the kernel virtual address returned by
direct_access(), to a user mappable pfn in XIP's page fault handler.

However, we can't switch it to just return the pfn and not the kaddr, because
we have no good way to get a kva from a pfn, and XIP requires the kva for its
read(2) and write(2) handlers.  So we have to return both.
Signed-off-by: NJared Hulbert <jaredeh@gmail.com>
Signed-off-by: NNick Piggin <npiggin@suse.de>
Cc: Carsten Otte <cotte@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-mm@kvack.org
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move the function that prints the segment warning messages found in the
monreader driver and the dcssblk driver to the extmem base code.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Most noteable part of this commit is the new local header file entry.h
which contains all the function declarations of functions that get only
called from asm code or are arch internal. That way we can avoid extern
declarations in C files.
This is more or less the same that was done for sparc64.
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Now the system reports system information messages (SIM) to the user.
The System Reference Code (SRC) which is reported to the user gives
the abbility to lookup the reason of the SIM online in the
documentation of the storage server.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

allocating dasd_fba_private without GFP_DMA results in IO error
during read device characteristics of a FBA disk
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

I compiled the kernel without deadline, and the dasd code exits the old
scheduler (CFQ), fails to load the new one (deadline), and then things just
hang - with one of these (sorry about the weird chars - I copy & pasted it
from a 3270 console):

dasd(eckd): 0.0.0151: 3390/0A(CU:3990/01) Cyl:3338 Head:15 Sec:224
------------ cut here ------------
Badness at kernel/mutex.c:134
Modules linked in: dasd_eckd_mod dasd_mod
CPU: 0 Not tainted 2.6.25-rc3 #9
Process exe (pid: 538, task: 000000000d172000, ksp: 000000000d21ef88)
Krnl PSW : 0404000180000000 000000000022fb5c (mutex_lock_nested+0x2a4/0x2cc)
           R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:0 CC:0 PM:0 EA:3
Krnl GPRS: 0000000000024218 000000000076fc78 0000000000000000 000000000000000f
           000000000022f92e 0000000000449898 000000000f921c00 000003e000162590
           00000000001539c4 000000000d172000 070000007fffffff 000000000d21f400
           000000000f8f2560 00000000002413f8 000000000022fb44 000000000d21f400
Krnl Code: 000000000022fb50: bf2f1000           icm     %r2,15,0(%r1)
           000000000022fb54: a774fef6           brc     7,22f940
           000000000022fb58: a7f40001           brc     15,22fb5a
          >000000000022fb5c: a7f4fef2           brc     15,22f940
           000000000022fb60: c0e5fffa112a       brasl   %r14,171db4
           000000000022fb66: 1222               ltr     %r2,%r2
           000000000022fb68: a784fedb           brc     8,22f91e
           000000000022fb6c: c010002a0086       larl    %r1,76fc78
Call Trace:
(<000000000022f92e> mutex_lock_nested+0x76/0x2cc)
 <00000000001539c4> elevator_exit+0x38/0x80
 <0000000000156ffe> blk_cleanup_queue+0x62/0x7c
 <000003e0001d5414> dasd_change_state+0xe0/0x8ec
 <000003e0001d5cae> dasd_set_target_state+0x8e/0x9c
 <000003e0001d5f74> dasd_generic_set_online+0x160/0x284
 <000003e00011e83a> dasd_eckd_set_online+0x2e/0x40
 <0000000000199bf4> ccw_device_set_online+0x170/0x2c0
 <0000000000199d9e> online_store_recog_and_online+0x5a/0x14c
 <000000000019a08a> online_store+0xbe/0x2ec
 <000000000018456c> dev_attr_store+0x38/0x58
 <000000000010efbc> sysfs_write_file+0x130/0x190
 <00000000000af582> vfs_write+0xb2/0x160
 <00000000000afc7c> sys_write+0x54/0x9c
 <0000000000025e16> sys32_write+0x2e/0x50
 <0000000000024218> sysc_noemu+0x10/0x16
 <0000000077e82bd2> 0x77e82bd2

Set elevator pointer to NULL in order to avoid double elevator_exit
calls when elevator_init call for deadline iosched fails.
Also make sure the dasd device driver depends on IOSCHED_DEADLINE so
the default IO scheduler of the dasd driver is present.
Signed-off-by: NJosef 'Jeff' Sipek <jeffpc@josefsipek.net>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>

Using the /proc/dasd/devices interface leaves the reference counter
of alias devices in an inconsistent state. A process that tries to set
such a device offline afterwards will hang.
The dasd_devices_show function returns immediately for alias devices
and this code path was missing a dasd_put_device call.
Signed-off-by: NStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When a request fails that was started on an alias device then the
first recovery step is to retry it on the base device. If the
recovery request fails again with the same symptoms, the next step
should not be a simple retry, but should be a proper recovery based
on sense data, etc. To do so, the dasd recovery functions need to
recognize the alias recovery step in the erp chain by comparing
the start devices.
Signed-off-by: NStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Fix Unlikely(x) != y

Cc: Gerald Schaefer <geraldsc@de.ibm.com>
Cc: Stefan Weinhuber <wein@de.ibm.com>
Cc: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: NRoel Kluin <12o3l@tiscali.nl>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

After setting the status of the cqr and releasing the lock for the
block cqr queue, we call the cqr callback function, which will usually
just trigger the dasd_block_tasklet. But when the tasklet is already
running the cqr might be processed before we invoke the callback
function. In rare cases the callback pointer may already be invalid
by the time we want to call it, which will result in a panic.
Solution: Call the callback function first and then release the lock.
Signed-off-by: NStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

In case a dcss segment cannot be loaded blk_cleanup_queue
will be called before blk_queue_make_request, leaving the
struct work unplug_work of the request queue uninitialized
before it is used.
That leads also to the lockdep message below.
To avoid that call blk_queue_make_request right after the
request_queue has been allocated.
This makes sure that the struct work is always initialized
before it is used.

INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 2 Not tainted 2.6.24 #6
Process swapper (pid: 1, task: 000000000f854038, ksp: 000000000f85f980)
040000000f85f860 000000000f85f880 0000000000000002 0000000000000000
       000000000f85f920 000000000f85f898 000000000f85f898 000000000001622e
       0000000000000000 000000000f85f980 0000000000000000 0000000000000000
       000000000f85f880 000000000000000c 000000000f85f880 000000000f85f8f0
       0000000000342908 000000000001622e 000000000f85f880 000000000f85f8d0
Call Trace:
([<000000000001619e>] show_trace+0xda/0x104)
 [<0000000000016288>] show_stack+0xc0/0xf8
 [<00000000000163d0>] dump_stack+0xb0/0xc0
 [<000000000006e4ea>] __lock_acquire+0x47e/0x1160
 [<000000000006f27c>] lock_acquire+0xb0/0xd8
 [<000000000005a522>] __cancel_work_timer+0x9e/0x240
 [<000000000005a72e>] cancel_work_sync+0x2a/0x3c
 [<0000000000165c46>] kblockd_flush_work+0x26/0x34
 [<0000000000169034>] blk_sync_queue+0x38/0x48
 [<0000000000169080>] blk_release_queue+0x3c/0xa8
 [<000000000017bce8>] kobject_cleanup+0x58/0xac
 [<000000000017bd66>] kobject_release+0x2a/0x38
 [<000000000017d28e>] kref_put+0x6e/0x94
 [<000000000017bc80>] kobject_put+0x38/0x48
 [<00000000001653be>] blk_put_queue+0x2a/0x38
 [<0000000000168fee>] blk_cleanup_queue+0x82/0x90
 [<0000000000213e7e>] dcssblk_add_store+0x34e/0x700
 [<00000000005243b8>] dcssblk_init+0x1a0/0x308
 [<000000000050a3c2>] kernel_init+0x1b2/0x3a4
 [<000000000001ac82>] kernel_thread_starter+0x6/0xc
 [<000000000001ac7c>] kernel_thread_starter+0x0/0xc

INFO: lockdep is turned off.

Cc: Gerald Schaefer <geraldsc@de.ibm.com>
Cc: Carsten Otte <cotte@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

When an alias device is set offline while it is in use this may
result in a panic in the cleanup part of the dasd_block_tasklet.
The problem here is that there may exist some ccw requests that were
originally created for the alias device and transferred to the base
device when the alias was set offline. When these request are
cleaned up later, the discipline pointer in the alias device may not
be valid anymore. To fix this use the base device discipline to find
the cleanup function.
Signed-off-by: NStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Adding interface control check (ifcc) handling in error recovery.
First retry up to 255 times and if all retries fail try an alternate
path if possible.
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

This patch converts s390 to use blk_end_request interfaces.
Related 'uptodate' arguments are converted to 'error'.

As a result, the interfaces of internal functions below are changed:
  o dasd_end_request
  o tapeblock_end_request

Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux390@de.ibm.com
Signed-off-by: NKiyoshi Ueda <k-ueda@ct.jp.nec.com>
Signed-off-by: NJun'ichi Nomura <j-nomura@ce.jp.nec.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Signed-off-by: NPeter Tiedemann <ptiedem@de.ibm.com>

Signed-off-by: NJan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Add time to the 'expires' value to avoid a loop caused by the cqr
termination function
Signed-off-by: NStefan Haberland <stefan.haberland@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Parallel access volumes (PAV) is a storage server feature, that allows
to start multiple channel programs on the same DASD in parallel. It
defines alias devices which can be used as alternative paths to the
same disk. With the old base PAV support we only needed rudimentary
functionality in the DASD device driver. As the mapping between base
and alias devices was static, we just had to export an identifier
(uid) and could leave the combining of devices to external layers
like a device mapper multipath.
Now hyper PAV removes the requirement to dedicate alias devices to
specific base devices. Instead each alias devices can be combined with
multiple base device on a per request basis. This requires full
support by the DASD device driver as now each channel program itself
has to identify the target base device.
The changes to the dasd device driver and the ECKD discipline are:
- Separate subchannel device representation (dasd_device) from block
  device representation (dasd_block). Only base devices are block
  devices.
- Gather information about base and alias devices and possible
  combinations.
- For each request decide which dasd_device should be used (base or
  alias) and build specific channel program.
- Support summary unit checks, which allow the storage server to
  upgrade / downgrade between base and hyper PAV at runtime (support
  is mandatory).
Signed-off-by: NStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>