Commit Graph

131 Commits

Author SHA1 Message Date
Bart Van Assche c8d9cf22cf block: Change argument type of scsi_req_init()
Since scsi_req_init() works on a struct scsi_request, change the
argument type into struct scsi_request *.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-20 19:27:14 -06:00
Bart Van Assche ca18d6f769 block: Make most scsi_req_init() calls implicit
Instead of explicitly calling scsi_req_init() after blk_get_request(),
call that function from inside blk_get_request(). Add an
.initialize_rq_fn() callback function to the block drivers that need
it. Merge the IDE .init_rq_fn() function into .initialize_rq_fn()
because it is too small to keep it as a separate function. Keep the
scsi_req_init() call in ide_prep_sense() because it follows a
blk_rq_init() call.

References: commit 82ed4db499 ("block: split scsi_request out of struct request")
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-20 19:27:14 -06:00
Christoph Hellwig 2a842acab1 block: introduce new block status code type
Currently we use nornal Linux errno values in the block layer, and while
we accept any error a few have overloaded magic meanings.  This patch
instead introduces a new  blk_status_t value that holds block layer specific
status codes and explicitly explains their meaning.  Helpers to convert from
and to the previous special meanings are provided for now, but I suspect
we want to get rid of them in the long run - those drivers that have a
errno input (e.g. networking) usually get errnos that don't know about
the special block layer overloads, and similarly returning them to userspace
will usually return somethings that strictly speaking isn't correct
for file system operations, but that's left as an exercise for later.

For now the set of errors is a very limited set that closely corresponds
to the previous overloaded errno values, but there is some low hanging
fruite to improve it.

blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
typechecking, so that we can easily catch places passing the wrong values.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00
Christoph Hellwig 17d5363b83 scsi: introduce a result field in struct scsi_request
This passes on the scsi_cmnd result field to users of passthrough
requests.  Currently we abuse req->errors for this purpose, but that
field will go away in its current form.

Note that the old IDE code abuses the errors field in very creative
ways and stores all kinds of different values in it.  I didn't dare
to touch this magic, so the abuses are brought forward 1:1.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20 12:16:10 -06:00
Christoph Hellwig b7819b9259 block: remove the blk_execute_rq return value
The function only returns -EIO if rq->errors is non-zero, which is not
very useful and lets a large number of callers ignore the return value.

Just let the callers figure out their error themselves.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20 12:16:10 -06:00
Christoph Hellwig aebf526b53 block: fold cmd_type into the REQ_OP_ space
Instead of keeping two levels of indirection for requests types, fold it
all into the operations.  The little caveat here is that previously
cmd_type only applied to struct request, while the request and bio op
fields were set to plain REQ_OP_READ/WRITE even for passthrough
operations.

Instead this patch adds new REQ_OP_* for SCSI passthrough and driver
private requests, althought it has to add two for each so that we
can communicate the data in/out nature of the request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 14:00:44 -07:00
Christoph Hellwig 2f5a8e80f7 ide: don't abuse cmd_type
Currently the legacy ide driver defines several request types of it's own,
which is in the way of removing that field entirely.

Instead add a type field to struct ide_request and use that to distinguish
the different types of IDE-internal requests.

It's a bit of a mess, but so is the surrounding code..

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-31 14:00:39 -07:00
Christoph Hellwig 82ed4db499 block: split scsi_request out of struct request
And require all drivers that want to support BLOCK_PC to allocate it
as the first thing of their private data.  To support this the legacy
IDE and BSG code is switched to set cmd_size on their queues to let
the block layer allocate the additional space.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-01-27 15:08:35 -07:00
Christoph Hellwig e806402130 block: split out request-only flags into a new namespace
A lot of the REQ_* flags are only used on struct requests, and only of
use to the block layer and a few drivers that dig into struct request
internals.

This patch adds a new req_flags_t rq_flags field to struct request for
them, and thus dramatically shrinks the number of common requests.  It
also removes the unfortunate situation where we have to fit the fields
from the same enum into 32 bits for struct bio and 64 bits for
struct request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Shaun Tancheff <shaun.tancheff@seagate.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-28 08:45:17 -06:00
Mel Gorman 71baba4b92 mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIM
__GFP_WAIT was used to signal that the caller was in atomic context and
could not sleep.  Now it is possible to distinguish between true atomic
context and callers that are not willing to sleep.  The latter should
clear __GFP_DIRECT_RECLAIM so kswapd will still wake.  As clearing
__GFP_WAIT behaves differently, there is a risk that people will clear the
wrong flags.  This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly
indicate what it does -- setting it allows all reclaim activity, clearing
them prevents it.

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-06 17:50:42 -08:00
Christoph Hellwig b0b93b48a3 block: move REQ_TYPE_SENSE to the ide driver
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-05 13:40:07 -06:00
Christoph Hellwig 4f8c9510ba block: rename REQ_TYPE_SPECIAL to REQ_TYPE_DRV_PRIV
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-05-05 13:40:03 -06:00
Paul Gortmaker 38789fda29 ide/ata: Add export.h for EXPORT_SYMBOL/THIS_MODULE where needed
They were getting this implicitly by an include of module.h
from device.h -- but we are going to clean that up and break
that include chain, so include export.h explicitly now.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:31:37 -04:00
Jens Axboe 7eaceaccab block: remove per-queue plugging
Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10 08:52:07 +01:00
Christoph Hellwig 4c4762d10f block: fix some more cmd_type cleanup fallout
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:22:29 +02:00
Christoph Hellwig 33659ebbae block: remove wrappers for request type/flags
Remove all the trivial wrappers for the cmd_type and cmd_flags fields in
struct requests.  This allows much easier grepping for different request
types instead of unwinding through macros.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07 18:17:56 +02:00
Linus Torvalds cf90bfe2eb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6:
  ide: Fix IDE taskfile with cfq scheduler
  ide: Must hold queue lock when requeueing
  ide: Requeue request after DMA timeout
2010-04-08 07:45:36 -07:00
Herbert Xu 1af1850346 ide: Must hold queue lock when requeueing
ide-atapi requeues requests without holding the queue lock.
This patch fixes it by using ide_requeue_and_plug.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-01 01:31:14 -07:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Linus Torvalds e6423407d0 Merge branch 'for-2.6.31' of git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6
* 'for-2.6.31' of git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6: (34 commits)
  ide-cd: prevent null pointer deref via cdrom_newpc_intr
  ide: BUG() on unknown requests
  ide: filter out invalid DMA xfer mode changes in HDIO_DRIVE_CMD ioctl handler
  ide: do not access ide_drive_t 'drive_data' field directly
  sl82c105: implement test_irq() method
  siimage: implement test_irq() method
  pdc202xx_old: implement test_irq() method (take 2)
  cmd64x: implement test_irq() method
  cmd640: implement test_irq() method
  ide: move ack_intr() method into 'struct ide_port_ops' (take 2)
  ide: move IRQ clearing from ack_intr() method to clear_irq() method (take 2)
  siimage: use ide_dma_test_irq() (take 2)
  cmd64x: implement clear_irq() method (take 2)
  ide: call clear_irq() method in ide_timer_expiry()
  sgiioc4: coding style cleanup
  ide: don't enable IORDY at a probe time
  ide: IORDY handling fixes
  ata: add ata_id_pio_need_iordy() helper (v2)
  ide-tape: fix build issue
  ide: unify interrupt reason checking
  ...
2009-06-20 10:11:11 -07:00
Linus Torvalds 489f7ab6c1 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (31 commits)
  trivial: remove the trivial patch monkey's name from SubmittingPatches
  trivial: Fix a typo in comment of addrconf_dad_start()
  trivial: usb: fix missing space typo in doc
  trivial: pci hotplug: adding __init/__exit macros to sgi_hotplug
  trivial: Remove the hyphen from git commands
  trivial: fix ETIMEOUT -> ETIMEDOUT typos
  trivial: Kconfig: .ko is normally not included in module names
  trivial: SubmittingPatches: fix typo
  trivial: Documentation/dell_rbu.txt: fix typos
  trivial: Fix Pavel's address in MAINTAINERS
  trivial: ftrace:fix description of trace directory
  trivial: unnecessary (void*) cast removal in sound/oss/msnd.c
  trivial: input/misc: Fix typo in Kconfig
  trivial: fix grammo in bus_for_each_dev() kerneldoc
  trivial: rbtree.txt: fix rb_entry() parameters in sample code
  trivial: spelling fix in ppc code comments
  trivial: fix typo in bio_alloc kernel doc
  trivial: Documentation/rbtree.txt: cleanup kerneldoc of rbtree.txt
  trivial: Miscellaneous documentation typo fixes
  trivial: fix typo milisecond/millisecond for documentation and source comments.
  ...
2009-06-14 13:46:25 -07:00
Bartlomiej Zolnierkiewicz 8dcce40813 Merge branch 'bp-remove-pc-buf' into for-next
Conflicts:
	drivers/ide/ide-tape.c
2009-06-13 12:00:54 +02:00
Linus Torvalds d614aec475 Merge branch 'for-2.6.31' of git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6
* 'for-2.6.31' of git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6: (29 commits)
  ide: re-implement ide_pci_init_one() on top of ide_pci_init_two()
  ide: unexport ide_find_dma_mode()
  ide: fix PowerMac bootup oops
  ide: skip probe if there are no devices on the port (v2)
  sl82c105: add printk() logging facility
  ide-tape: fix proc warning
  ide: add IDE_DFLAG_NIEN_QUIRK device flag
  ide: respect quirk_drives[] list on all controllers
  hpt366: enable all quirks for devices on quirk_drives[] list
  hpt366: sync quirk_drives[] list with pdc202xx_{new,old}.c
  ide: remove superfluous SELECT_MASK() call from do_rw_taskfile()
  ide: remove superfluous SELECT_MASK() call from ide_driveid_update()
  icside: remove superfluous ->maskproc method
  ide-tape: fix IDE_AFLAG_* atomic accesses
  ide-tape: change IDE_AFLAG_IGNORE_DSC non-atomically
  pdc202xx_old: kill resetproc() method
  pdc202xx_old: don't call pdc202xx_reset() on IRQ timeout
  pdc202xx_old: use ide_dma_test_irq()
  ide: preserve Host Protected Area by default (v2)
  ide-gd: implement block device ->set_capacity method (v2)
  ...
2009-06-12 09:29:42 -07:00
Martin Olsson 19af5cdb7c trivial: fix typo milisecond/millisecond for documentation and source comments.
Signed-off-by: Martin Olsson <martin@minimum.se>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-06-12 18:01:46 +02:00
Linus Torvalds c9059598ea Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block: (153 commits)
  block: add request clone interface (v2)
  floppy: fix hibernation
  ramdisk: remove long-deprecated "ramdisk=" boot-time parameter
  fs/bio.c: add missing __user annotation
  block: prevent possible io_context->refcount overflow
  Add serial number support for virtio_blk, V4a
  block: Add missing bounce_pfn stacking and fix comments
  Revert "block: Fix bounce limit setting in DM"
  cciss: decode unit attention in SCSI error handling code
  cciss: Remove no longer needed sendcmd reject processing code
  cciss: change SCSI error handling routines to work with interrupts enabled.
  cciss: separate error processing and command retrying code in sendcmd_withirq_core()
  cciss: factor out fix target status processing code from sendcmd functions
  cciss: simplify interface of sendcmd() and sendcmd_withirq()
  cciss: factor out core of sendcmd_withirq() for use by SCSI error handling code
  cciss: Use schedule_timeout_uninterruptible in SCSI error handling code
  block: needs to set the residual length of a bidi request
  Revert "block: implement blkdev_readpages"
  block: Fix bounce limit setting in DM
  Removed reference to non-existing file Documentation/PCI/PCI-DMA-mapping.txt
  ...

Manually fix conflicts with tracing updates in:
	block/blk-sysfs.c
	drivers/ide/ide-atapi.c
	drivers/ide/ide-cd.c
	drivers/ide/ide-floppy.c
	drivers/ide/ide-tape.c
	include/trace/events/block.h
	kernel/trace/blktrace.c
2009-06-11 11:10:35 -07:00
Borislav Petkov 626542ca22 ide-tape: change IDE_AFLAG_IGNORE_DSC non-atomically
There are two sites where the flag is being changed: ide_retry_pc
and idetape_do_request. Both codepaths are protected by hwif->busy
(ide_lock_port) and therefore we shouldn't need the atomic accesses.

Spotted-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2009-06-07 15:37:05 +02:00
Borislav Petkov 103f7033bd ide: unify interrupt reason checking
Add ide_check_ireason() function that handles all ATAPI devices.
Reorganize all unlikely cases in ireason checking further down in the
code path.

In addition, add PFX for printks originating from ide-atapi. Finally,
remove ide_cd_check_ireason.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
2009-05-15 06:44:45 +02:00
Borislav Petkov 19f52a784f ide-atapi: remove pc->buf
Now after all users of pc->buf have been converted, remove the 64B buffer
embedded in each packet command.

There should be no functional change resulting from this patch.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
2009-05-15 06:44:38 +02:00
Borislav Petkov ae3a8387be ide-atapi: use local sense buffer
Access the sense buffer through the bio in ->pc_callback method thus
alleviating the need for the pc->buf pointer.

There should be no functional change resulting from this patch.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
2009-05-15 06:44:23 +02:00
Borislav Petkov b13345f39d ide-atapi: add a buffer-arg to ide_queue_pc_tail
This is in preparation of removing ide_atapi_pc. Expose the buffer as an
argument to ide_queue_pc_tail with later replacing it with local buffer
or even kmalloc'ed one if needed due to stack usage constraints.

Also, add the possibility of passing a NULL-ptr buffer for cmds which
don't transfer data besides the cdb. While at it, switch to local buffer
in idetape_get_mode_sense_results().

There should be no functional change resulting from this patch.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
2009-05-15 06:44:09 +02:00
Borislav Petkov 5a0e43b5e2 ide-atapi: add a len-parameter to ide_queue_pc_tail
This is in preparation for removing ide_atapi_pc.

There should be no functional change resulting from this patch.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
2009-05-15 06:44:06 +02:00
Borislav Petkov 077e6dba20 ide-atapi: switch to rq->resid_len
Now that we have rq->resid_len, use it to account partial completion
amount during the lifetime of an rq, decrementing it on each successful
transfer. As a result, get rid of now unused pc->xferred.

While at it, remove noisy debug call in ide_prep_sense.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
2009-05-15 06:44:02 +02:00
Borislav Petkov dfb7e621fa ide-atapi: switch to blk_rq_bytes() on do_request() path
After the recent struct request cleanups, blk_rq_bytes() is guaranteed
to be valid and is the current total length of the rq's bio. Use that
instead of pc->req_xfer in the do_request() path after the command has
been queued

The remaining usage of pc->req_xfer now is only until we map the rq to a
bio.

While at it:

- remove local caching of rq completion length in ide_tape_issue_pc()

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
2009-05-15 06:43:59 +02:00
Tejun Heo 9934c8c045 block: implement and enforce request peek/start/fetch
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 <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Mike Miller <mike.miller@hp.com>
Cc: unsik Kim <donari75@gmail.com>
Cc: Paul Clements <paul.clements@steeleye.com>
Cc: Tim Waugh <tim@cyberelk.net>
Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Laurent Vivier <Laurent@lvivier.info>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: Stefan Weinhuber <wein@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11 09:52:18 +02:00
Tejun Heo 8f6205cd57 ide: dequeue in-flight request
ide generally has single request in flight and tracks it using
hwif->rq and all state handlers follow the following convention.

* ide_started is returned if the request is in flight.

* ide_stopped is returned if the queue needs to be restarted.  The
  request might or might not have been processed fully or partially.

* hwif->rq is set to NULL, when an issued request completes.

So, dequeueing model can be implemented by dequeueing after fetch,
requeueing if hwif->rq isn't NULL on ide_stopped return and doing
about the same thing on completion / port unlock paths.  These changes
can be made in ide-io proper.

In addition to the above main changes, the following updates are
necessary.

* ide-cd shouldn't dequeue a request when issuing REQUEST SENSE for it
  as the request is already dequeued.

* ide-atapi uses request queue as stack when issuing REQUEST SENSE to
  put the REQUEST SENSE in front of the failed request.  This now
  needs to be done using requeueing.

[ Impact: dequeue in-flight request ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11 09:52:14 +02:00
Tejun Heo 34b7d2c957 ide: cleanup rq->data_len usages
With recent unification of fields, it's now guaranteed that
rq->data_len always equals blk_rq_bytes().  Convert all direct users
to accessors.

[ Impact: convert direct rq->data_len usages to blk_rq_bytes() ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11 09:50:55 +02:00
Tejun Heo c3a4d78c58 block: add rq->resid_len
rq->data_len served two purposes - the length of data buffer on issue
and the residual count on completion.  This duality creates some
headaches.

First of all, block layer and low level drivers can't really determine
what rq->data_len contains while a request is executing.  It could be
the total request length or it coulde be anything else one of the
lower layers is using to keep track of residual count.  This
complicates things because blk_rq_bytes() and thus
[__]blk_end_request_all() relies on rq->data_len for PC commands.
Drivers which want to report residual count should first cache the
total request length, update rq->data_len and then complete the
request with the cached data length.

Secondly, it makes requests default to reporting full residual count,
ie. reporting that no data transfer occurred.  The residual count is
an exception not the norm; however, the driver should clear
rq->data_len to zero to signify the normal cases while leaving it
alone means no data transfer occurred at all.  This reverse default
behavior complicates code unnecessarily and renders block PC on some
drivers (ide-tape/floppy) unuseable.

This patch adds rq->resid_len which is used only for residual count.

While at it, remove now unnecessasry blk_rq_bytes() caching in
ide_pc_intr() as rq->data_len is not changed anymore.

Boaz	: spotted missing conversion in osd
Sergei	: spotted too early conversion to blk_rq_bytes() in ide-tape

[ Impact: cleanup residual count handling, report 0 resid by default ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Mike Miller <mike.miller@hp.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: Mike Miller <mike.miller@hp.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Cc: Darrick J. Wong <djwong@us.ibm.com>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11 09:50:53 +02:00
Tejun Heo 29d1a43710 ide-atapi: kill unused fields and callbacks
Impact: remove fields and code paths which are no longer necessary

Now that ide-tape uses standard mechanisms to transfer data, special
case handling for bh handling can be dropped from ide-atapi.  Drop the
followings.

* pc->cur_pos, b_count, bh and b_data
* drive->pc_update_buffers() and pc_io_buffers().

Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-28 07:37:32 +02:00
Tejun Heo e998f30b45 ide-tape: use standard data transfer mechanism
Impact: use standard way to transfer data

ide-tape uses rq in an interesting way.  For r/w requests, rq->special
is used to carry a private buffer management structure idetape_bh and
rq->nr_sectors and current_nr_sectors are initialized to the number of
idetape blocks which isn't necessary 512 bytes.  Also,
rq->current_nr_sectors is used to report back the residual count in
units of idetape blocks.

This peculiarity taxes both block layer and ide.  ide-atapi has
different paths and hooks to accomodate it and what a rq means becomes
quite confusing and making changes at the block layer becomes quite
difficult and error-prone.

This patch makes ide-tape use bio instead.  With the previous patch,
ide-tape currently is using single contiguos buffer so replacing it
isn't difficult.  Data buffer is mapped into bio using
blk_rq_map_kern() in idetape_queue_rw_tail().  idetape_io_buffers()
and idetape_update_buffers() are dropped and pc->bh is set to null to
tell ide-atapi to use standard data transfer mechanism and idetape_bh
byte counts are updated by the issuer on completion using the residual
count.

This change also nicely removes the FIXME in ide_pc_intr() where
ide-tape rqs need to be completed using ide_rq_bytes() instead of
blk_rq_bytes() (although this didn't really matter as the request
didn't have bio).

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <jens.axboe@oracle.com>
2009-04-28 07:37:31 +02:00
Tejun Heo eb6a61bb95 ide-atapi,tape,floppy: allow ->pc_callback() to change rq->data_len
Impact: allow residual count implementation in ->pc_callback()

rq->data_len has two duties - carrying the number of input bytes on
issue and carrying residual count back to the issuer on completion.
ide-atapi completion callback ->pc_callback() is the right place to do
this but currently ide-atapi depends on rq->data_len carrying the
original request size after calling ->pc_callback() to complete the pc
request.

This patch makes ide_pc_intr(), ide_tape_issue_pc() and
ide_floppy_issue_pc() cache length to complete before calling
->pc_callback() so that it can modify rq->data_len as necessary.

Note: As using rq->data_len for two purposes can make cases like this
      incorrect in subtle ways, future changes will introduce separate
      field for residual count.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <jens.axboe@oracle.com>
2009-04-28 07:37:31 +02:00
Tejun Heo 02e7cf8f84 ide-cd,atapi: use bio for internal commands
Impact: unify request data buffer handling

rq->data is used mostly to pass kernel buffer through request queue
without using bio.  There are only a couple of places which still do
this in kernel and converting to bio isn't difficult.

This patch converts ide-cd and atapi to use bio instead of rq->data
for request sense and internal pc commands.  With previous change to
unify sense request handling, this is relatively easily achieved by
adding blk_rq_map_kern() during sense_rq prep and PC issue.

If blk_rq_map_kern() fails for sense, the error is deferred till sense
issue and aborts the failed command which triggered the sense.  Note
that this is a slim possibility as sense prep is done on each command
issue, so for the above condition to actually trigger, all preps since
the last sense issue till the issue of the request which would require
a sense should fail.

* do_request functions might sleep now.  This should be okay as ide
  request_fn - do_ide_request() - is invoked only from make_request
  and plug work.  Make sure this is the case by adding might_sleep()
  to do_ide_request().

* Functions which access the read sense data before the sense request
  is complete now should access bio_data(sense_rq->bio) as the sense
  buffer might have been copied during blk_rq_map_kern().

* ide-tape updated to map sg.

* cdrom_do_block_pc() now doesn't have to deal with REQ_TYPE_ATA_PC
  special case.  Simplified.

* tp_ops->output/input_data path dropped from ide_pc_intr().

Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-28 07:37:30 +02:00
Borislav Petkov 068753203e ide-atapi: convert ide-{floppy,tape} to using preallocated sense buffer
Since we're issuing REQ_TYPE_SENSE now we need to allow those types of
rqs in the ->do_request callbacks. As a future improvement, sense_len
assignment might be unified across all ATAPI devices. Borislav to
check with specs and test.

As a result, get rid of ide_queue_pc_head() and
drive->request_sense_rq.

tj: * Init request sense ide_atapi_pc from sense request.  In the
      longer timer, it would probably better to fold
      ide_create_request_sense_cmd() into its only current user -
      ide_floppy_get_format_progress().

    * ide_retry_pc() no longer takes @disk.

CC: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
CC: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-28 07:37:30 +02:00
Borislav Petkov e69d800f7e ide: add helpers for preparing sense requests
This is in preparation of removing the queueing of a sense request out
of the IRQ handler path.

Use struct request_sense as a general sense buffer for all ATAPI
devices ide-{floppy,tape,cd}.

tj: * blk_get_request(__GFP_WAIT) can't be called from do_request() as
      it can cause deadlock.  Converted to use inline struct request
      and blk_rq_init().

    * Added xfer / cdb len selection depending on device type.

    * All sense prep logics folded into ide_prep_sense() which never
      fails.

    * hwif->rq clearing and sense_rq used handling moved into
      ide_queue_sense_rq().

    * blk_rq_map_kern() conversion is moved to later patch.

CC: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
CC: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-28 07:37:30 +02:00
Tejun Heo ac0b0113dd ide-atapi: don't abuse rq->buffer
Impact: rq->buffer usage cleanup

ide-atapi uses rq->buffer as private opaque value for internal special
requests.  rq->special isn't used for these cases (the only case where
rq->special is used is for ide-tape rw requests).  Use rq->special
instead.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
2009-04-28 07:37:29 +02:00
Tejun Heo 6d7003877c ide-atapi: kill unused fields and callbacks
Impact: remove fields and code paths which are no longer necessary

Now that ide-tape uses standard mechanisms to transfer data, special
case handling for bh handling can be dropped from ide-atapi.  Drop the
followings.

* pc->cur_pos, b_count, bh and b_data
* drive->pc_update_buffers() and pc_io_buffers().

Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-19 08:46:03 +09:00
Tejun Heo 21d9c5d227 ide-tape: use standard data transfer mechanism
Impact: use standard way to transfer data

ide-tape uses rq in an interesting way.  For r/w requests, rq->special
is used to carry a private buffer management structure idetape_bh and
rq->nr_sectors and current_nr_sectors are initialized to the number of
idetape blocks which isn't necessary 512 bytes.  Also,
rq->current_nr_sectors is used to report back the residual count in
units of idetape blocks.

This peculiarity taxes both block layer and ide.  ide-atapi has
different paths and hooks to accomodate it and what a rq means becomes
quite confusing and making changes at the block layer becomes quite
difficult and error-prone.

This patch makes ide-tape use bio instead.  With the previous patch,
ide-tape currently is using single contiguos buffer so replacing it
isn't difficult.  Data buffer is mapped into bio using
blk_rq_map_kern() in idetape_queue_rw_tail().  idetape_io_buffers()
and idetape_update_buffers() are dropped and pc->bh is set to null to
tell ide-atapi to use standard data transfer mechanism and idetape_bh
byte counts are updated by the issuer on completion using the residual
count.

This change also nicely removes the FIXME in ide_pc_intr() where
ide-tape rqs need to be completed using ide_rq_bytes() instead of
blk_rq_bytes() (although this didn't really matter as the request
didn't have bio).

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <jens.axboe@oracle.com>
2009-04-19 08:46:02 +09:00
Tejun Heo b3071d190d ide-atapi,tape,floppy: allow ->pc_callback() to change rq->data_len
Impact: allow residual count implementation in ->pc_callback()

rq->data_len has two duties - carrying the number of input bytes on
issue and carrying residual count back to the issuer on completion.
ide-atapi completion callback ->pc_callback() is the right place to do
this but currently ide-atapi depends on rq->data_len carrying the
original request size after calling ->pc_callback() to complete the pc
request.

This patch makes ide_pc_intr(), ide_tape_issue_pc() and
ide_floppy_issue_pc() cache length to complete before calling
->pc_callback() so that it can modify rq->data_len as necessary.

Note: As using rq->data_len for two purposes can make cases like this
      incorrect in subtle ways, future changes will introduce separate
      field for residual count.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <jens.axboe@oracle.com>
2009-04-19 08:46:02 +09:00
Tejun Heo 5c4be57249 ide-cd,atapi: use bio for internal commands
Impact: unify request data buffer handling

rq->data is used mostly to pass kernel buffer through request queue
without using bio.  There are only a couple of places which still do
this in kernel and converting to bio isn't difficult.

This patch converts ide-cd and atapi to use bio instead of rq->data
for request sense and internal pc commands.  With previous change to
unify sense request handling, this is relatively easily achieved by
adding blk_rq_map_kern() during sense_rq prep and PC issue.

If blk_rq_map_kern() fails for sense, the error is deferred till sense
issue and aborts the failed command which triggered the sense.  Note
that this is a slim possibility as sense prep is done on each command
issue, so for the above condition to actually trigger, all preps since
the last sense issue till the issue of the request which would require
a sense should fail.

* do_request functions might sleep now.  This should be okay as ide
  request_fn - do_ide_request() - is invoked only from make_request
  and plug work.  Make sure this is the case by adding might_sleep()
  to do_ide_request().

* Functions which access the read sense data before the sense request
  is complete now should access bio_data(sense_rq->bio) as the sense
  buffer might have been copied during blk_rq_map_kern().

* ide-tape updated to map sg.

* cdrom_do_block_pc() now doesn't have to deal with REQ_TYPE_ATA_PC
  special case.  Simplified.

* tp_ops->output/input_data path dropped from ide_pc_intr().

Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-19 07:00:42 +09:00
Borislav Petkov 6b544fcc8c ide-atapi: convert ide-{floppy,tape} to using preallocated sense buffer
Since we're issuing REQ_TYPE_SENSE now we need to allow those types of
rqs in the ->do_request callbacks. As a future improvement, sense_len
assignment might be unified across all ATAPI devices. Borislav to
check with specs and test.

As a result, get rid of ide_queue_pc_head() and
drive->request_sense_rq.

tj: * Init request sense ide_atapi_pc from sense request.  In the
      longer timer, it would probably better to fold
      ide_create_request_sense_cmd() into its only current user -
      ide_floppy_get_format_progress().

    * ide_retry_pc() no longer takes @disk.

CC: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
CC: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-19 07:00:42 +09:00
Borislav Petkov a1df5169f9 ide: add helpers for preparing sense requests
This is in preparation of removing the queueing of a sense request out
of the IRQ handler path.

Use struct request_sense as a general sense buffer for all ATAPI
devices ide-{floppy,tape,cd}.

tj: * blk_get_request(__GFP_WAIT) can't be called from do_request() as
      it can cause deadlock.  Converted to use inline struct request
      and blk_rq_init().

    * Added xfer / cdb len selection depending on device type.

    * All sense prep logics folded into ide_prep_sense() which never
      fails.

    * hwif->rq clearing and sense_rq used handling moved into
      ide_queue_sense_rq().

    * blk_rq_map_kern() conversion is moved to later patch.

CC: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
CC: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2009-04-19 07:00:42 +09:00