linux-toradex.git/drivers/s390/block/dasd.c, branch v2.6.31.2

[S390] drivers/s390: put NULL test before dereference

2009-08-23T16:10:00+00:00

If the NULL test on block is needed, it should be before the dereference of
the base field.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// 
@r@
expression E1,E2;
identifier fld;
statement S1,S2;
@@

E1 = E2->fld;
(
if (E1 == NULL) S1 else S2
|
*if (E2 == NULL) S1 else S2
)
// 

Signed-off-by: Julia Lawall 
Signed-off-by: Martin Schwidefsky

[S390] dasd: fix refcounting in dasd_change_state

2009-06-22T10:08:23+00:00

To set a dasd online dasd_change_state is called twice. The first
cycle will schedule initial analysis of the device, set the rc to
-EAGAIN and will not touch the device state any more.
The initial analysis will in turn call dasd_change_state to increase
the state to the final DASD_STATE_ONLINE.

If the dasd_change_state on the second thread outruns the other one
both finish with the state set to DASD_STATE_ONLINE and the device
refcount will be decreased by 2.

Fix this by leaving dasd_change_state on rc == -EAGAIN so that the
refcount will always be decreased by 1.

Signed-off-by: Sebastian Ott 
Signed-off-by: Martin Schwidefsky

[S390] dasd_pm: fix stop flag handling

2009-06-22T10:08:22+00:00

The stop flags are handled in the generic restore function so the
stop flag is removed also for FBA and DIAG devices.

Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky

[S390] pm: dasd power management callbacks.

2009-06-16T08:31:10+00:00

Introduce the power management callbacks to the dasd driver. On suspend
the dasd devices are stopped and removed from the focus of alias
management.
On resume they are reinitialized by rereading the device characteristics
and adding the device to the alias management.
In case the device has gone away during suspend it will caught in the
suspend state with stopped flag set to UNRESUMED. After it appears again
the restore function is called again.

Signed-off-by: Stefan Haberland 
Signed-off-by: Martin Schwidefsky

[S390] dasd: forward internal errors to dasd_sleep_on caller

2009-06-12T08:27:36+00:00

If a DASD requests is started with dasd_sleep_on and fails, then the
calling function may need to know the reason for the failure.
In cases of hardware errors it can inspect the sense data in the irb,
but when the reason is internal (e.g. start_IO failed) then it needs
a meaningfull return code.

Signed-off-by: Stefan Weinhuber 
Signed-off-by: Martin Schwidefsky

[S390] dasd: check_characteristics cleanup

2009-06-12T08:27:35+00:00

Fix a broken memset (sizeof pointer vs sizeof the underlying
structure) by cleaning up the involved functions.

Signed-off-by: Sebastian Ott 
Signed-off-by: Martin Schwidefsky

block: Do away with the notion of hardsect_size

2009-05-22T21:22:54+00:00

Until now we have had a 1:1 mapping between storage device physical
block size and the logical block sized used when addressing the device.
With SATA 4KB drives coming out that will no longer be the case.  The
sector size will be 4KB but the logical block size will remain
512-bytes.  Hence we need to distinguish between the physical block size
and the logical ditto.

This patch renames hardsect_size to logical_block_size.

Signed-off-by: Martin K. Petersen 
Signed-off-by: Jens Axboe

block: implement and enforce request peek/start/fetch

2009-05-11T07:52:18+00:00

Till now block layer allowed two separate modes of request execution.
A request is always acquired from the request queue via
elv_next_request().  After that, drivers are free to either dequeue it
or process it without dequeueing.  Dequeue allows elv_next_request()
to return the next request so that multiple requests can be in flight.

Executing requests without dequeueing has its merits mostly in
allowing drivers for simpler devices which can't do sg to deal with
segments only without considering request boundary.  However, the
benefit this brings is dubious and declining while the cost of the API
ambiguity is increasing.  Segment based drivers are usually for very
old or limited devices and as converting to dequeueing model isn't
difficult, it doesn't justify the API overhead it puts on block layer
and its more modern users.

Previous patches converted all block low level drivers to dequeueing
model.  This patch completes the API transition by...

* renaming elv_next_request() to blk_peek_request()

* renaming blkdev_dequeue_request() to blk_start_request()

* adding blk_fetch_request() which is combination of peek and start

* disallowing completion of queued (not started) requests

* applying new API to all LLDs

Renamings are for consistency and to break out of tree code so that
it's apparent that out of tree drivers need updating.

[ Impact: block request issue API cleanup, no functional change ]

Signed-off-by: Tejun Heo 
Cc: Rusty Russell 
Cc: James Bottomley 
Cc: Mike Miller 
Cc: unsik Kim 
Cc: Paul Clements 
Cc: Tim Waugh 
Cc: Geert Uytterhoeven 
Cc: David S. Miller 
Cc: Laurent Vivier 
Cc: Jeff Garzik 
Cc: Jeremy Fitzhardinge 
Cc: Grant Likely 
Cc: Adrian McMenamin 
Cc: Stephen Rothwell 
Cc: Bartlomiej Zolnierkiewicz 
Cc: Borislav Petkov 
Cc: Sergei Shtylyov 
Cc: Alex Dubov 
Cc: Pierre Ossman 
Cc: David Woodhouse 
Cc: Markus Lidel 
Cc: Stefan Weinhuber 
Cc: Martin Schwidefsky 
Cc: Pete Zaitcev 
Cc: FUJITA Tomonori 
Signed-off-by: Jens Axboe

block: convert to pos and nr_sectors accessors

2009-05-11T07:50:54+00:00

With recent cleanups, there is no place where low level driver
directly manipulates request fields.  This means that the 'hard'
request fields always equal the !hard fields.  Convert all
rq->sectors, nr_sectors and current_nr_sectors references to
accessors.

While at it, drop superflous blk_rq_pos() < 0 test in swim.c.

[ Impact: use pos and nr_sectors accessors ]

Signed-off-by: Tejun Heo 
Acked-by: Geert Uytterhoeven 
Tested-by: Grant Likely 
Acked-by: Grant Likely 
Tested-by: Adrian McMenamin 
Acked-by: Adrian McMenamin 
Acked-by: Mike Miller 
Cc: James Bottomley 
Cc: Bartlomiej Zolnierkiewicz 
Cc: Borislav Petkov 
Cc: Sergei Shtylyov 
Cc: Eric Moore 
Cc: Alan Stern 
Cc: FUJITA Tomonori 
Cc: Pete Zaitcev 
Cc: Stephen Rothwell 
Cc: Paul Clements 
Cc: Tim Waugh 
Cc: Jeff Garzik 
Cc: Jeremy Fitzhardinge 
Cc: Alex Dubov 
Cc: David Woodhouse 
Cc: Martin Schwidefsky 
Cc: Dario Ballabio 
Cc: David S. Miller 
Cc: Rusty Russell 
Cc: unsik Kim 
Cc: Laurent Vivier 
Signed-off-by: Jens Axboe

block: implement and use [__]blk_end_request_all()

2009-04-28T05:37:35+00:00

There are many [__]blk_end_request() call sites which call it with
full request length and expect full completion.  Many of them ensure
that the request actually completes by doing BUG_ON() the return
value, which is awkward and error-prone.

This patch adds [__]blk_end_request_all() which takes @rq and @error
and fully completes the request.  BUG_ON() is added to to ensure that
this actually happens.

Most conversions are simple but there are a few noteworthy ones.

* cdrom/viocd: viocd_end_request() replaced with direct calls to
  __blk_end_request_all().

* s390/block/dasd: dasd_end_request() replaced with direct calls to
  __blk_end_request_all().

* s390/char/tape_block: tapeblock_end_request() replaced with direct
  calls to blk_end_request_all().

[ Impact: cleanup ]

Signed-off-by: Tejun Heo 
Cc: Russell King 
Cc: Stephen Rothwell 
Cc: Mike Miller 
Cc: Martin Schwidefsky 
Cc: Jeff Garzik 
Cc: Rusty Russell 
Cc: Jeremy Fitzhardinge 
Cc: Alex Dubov 
Cc: James Bottomley