linux.git/block, branch v3.0-rc1

Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

2011-05-27T17:24:40+00:00

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  loop: export module parameters
  block: export blk_{get,put}_queue()
  block: remove unused variable in bio_attempt_front_merge()
  block: always allocate genhd->ev if check_events is implemented
  brd: export module parameters
  brd: fix comment on initial device creation
  brd: handle on-demand devices correctly
  brd: limit 'max_part' module param to DISK_MAX_PARTS
  brd: get rid of unused members from struct brd_device
  block: fix oops on !disk->queue and sysfs discard alignment display

block: export blk_{get,put}_queue()

2011-05-27T05:45:45+00:00

We need them in SCSI to fix a bug, but currently they are not
exported to modules. Export them.

Signed-off-by: Jens Axboe

cgroups: add per-thread subsystem callbacks

2011-05-27T00:12:34+00:00

Add cgroup subsystem callbacks for per-thread attachment in atomic contexts

Add can_attach_task(), pre_attach(), and attach_task() as new callbacks
for cgroups's subsystem interface.  Unlike can_attach and attach, these
are for per-thread operations, to be called potentially many times when
attaching an entire threadgroup.

Also, the old "bool threadgroup" interface is removed, as replaced by
this.  All subsystems are modified for the new interface - of note is
cpuset, which requires from/to nodemasks for attach to be globally scoped
(though per-cpuset would work too) to persist from its pre_attach to
attach_task and attach.

This is a pre-patch for cgroup-procs-writable.patch.

Signed-off-by: Ben Blum 
Cc: "Eric W. Biederman" 
Cc: Li Zefan 
Cc: Matt Helsley 
Reviewed-by: Paul Menage 
Cc: Oleg Nesterov 
Cc: David Rientjes 
Cc: Miao Xie 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

block: remove unused variable in bio_attempt_front_merge()

2011-05-26T19:07:26+00:00

sector is never read inside the function.

Signed-off-by: Luca Tettamanti 
Signed-off-by: Jens Axboe

block: always allocate genhd->ev if check_events is implemented

2011-05-26T19:06:50+00:00

9fd097b149 (block: unexport DISK_EVENT_MEDIA_CHANGE for legacy/fringe
drivers) removed DISK_EVENT_MEDIA_CHANGE from legacy/fringe block
drivers which have inadequate ->check_events().  Combined with earlier
change 7c88a168da (block: don't propagate unlisted DISK_EVENTs to
userland), this enables using ->check_events() for internal processing
while avoiding enabling in-kernel block event polling which can lead
to infinite event loop.

Unfortunately, this made many drivers including floppy without any bit
set in disk->events and ->async_events in which case disk_add_events()
simply skipped allocation of disk->ev, which disables whole event
handling.  As ->check_events() is still used during open processing
for revalidation, this can lead to open failure.

This patch always allocates disk->ev if ->check_events is implemented.
In the long term, it would make sense to simply include the event
structure inline into genhd as it's now used by virtually all block
devices.

Signed-off-by: Tejun Heo 
Reported-by: Ondrej Zary 
Reported-by: Alex Villacis Lasso 
Cc: stable@kernel.org
Signed-off-by: Jens Axboe

cfq-iosched: free cic_index if cfqd allocation fails

2011-05-24T08:23:22+00:00

When struct cfq_data allocation fails, cic_index need to be freed.

Signed-off-by: Namhyung Kim 
Signed-off-by: Jens Axboe

cfq-iosched: remove unused 'group_changed' in cfq_service_tree_add()

2011-05-24T08:23:22+00:00

The 'group_changed' variable is initialized to 0 and never changed, so
checking the variable is meaningless.

It is a leftover from 0bbfeb832042 ("cfq-iosched: Always provide group
iosolation."). Let's get rid of it.

Signed-off-by: Namhyung Kim 
Cc: Justin TerAvest 
Signed-off-by: Jens Axboe

cfq-iosched: reduce bit operations in cfq_choose_req()

2011-05-24T08:23:21+00:00

Reduce the number of bit operations in cfq_choose_req() on average
(and worst) cases.

Signed-off-by: Namhyung Kim 
Signed-off-by: Jens Axboe

cfq-iosched: algebraic simplification in cfq_prio_to_maxrq()

2011-05-24T08:23:21+00:00

Simplify the calculation in cfq_prio_to_maxrq(), plus replace CFQ_PRIO_LISTS to
IOPRIO_BE_NR since they are the same and IOPRIO_BE_NR looks more reasonable in
this context IMHO.

Signed-off-by: Namhyung Kim 
Signed-off-by: Jens Axboe

blk-cgroup: Initialize ioc->cgroup_changed at ioc creation time

2011-05-23T17:35:04+00:00

If we don't explicitly initialize it to zero, CFQ might think that
cgroup of ioc has changed and it generates lots of unnecessary calls
to call_for_each_cic(changed_cgroup). Fix it.

cfq_get_io_context()
  cfq_ioc_set_cgroup()
     call_for_each_cic(ioc, changed_cgroup)

Signed-off-by: Vivek Goyal 
Signed-off-by: Jens Axboe