linux-toradex.git/block, branch v2.6.35-rc2

block: make blk_init_free_list and elevator_init idempotent

2010-06-04T11:47:06+00:00

blk_init_allocated_queue_node may fail and the caller _could_ retry.
Accommodate the unlikely event that blk_init_allocated_queue_node is
called on an already initialized (possibly partially) request_queue.

Signed-off-by: Mike Snitzer 
Signed-off-by: Jens Axboe

block: avoid unconditionally freeing previously allocated request_queue

2010-06-04T11:47:06+00:00

On blk_init_allocated_queue_node failure, only free the request_queue if
it is wasn't previously allocated outside the block layer
(e.g. blk_init_queue_node was blk_init_allocated_queue_node caller).

This addresses an interface bug introduced by the following commit:
01effb0 block: allow initialization of previously allocated
request_queue

Otherwise the request_queue may be free'd out from underneath a caller
that is managing the request_queue directly (e.g. caller uses
blk_alloc_queue + blk_init_allocated_queue_node).

Signed-off-by: Mike Snitzer 
Signed-off-by: Jens Axboe

cfq-iosched: fix an oops caused by slab leak

2010-05-25T08:17:26+00:00

I got below oops when unloading cfq-iosched. Considering scenario:
queue A merge to B, C merge to D and B will be merged to D. Before B is merged
to D, we do split B. We should put B's reference for D.

[  807.768536] =============================================================================
[  807.768539] BUG cfq_queue: Objects remaining on kmem_cache_close()
[  807.768541] -----------------------------------------------------------------------------
[  807.768543]
[  807.768546] INFO: Slab 0xffffea0003e6b4e0 objects=26 used=1 fp=0xffff88011d584fd8 flags=0x200000000004082
[  807.768550] Pid: 5946, comm: rmmod Tainted: G        W   2.6.34-07097-gf4b87de-dirty #724
[  807.768552] Call Trace:
[  807.768560]  [] slab_err+0x8f/0x9d
[  807.768564]  [] ? flush_cpu_slab+0x0/0x93
[  807.768569]  [] ? add_preempt_count+0xe/0xca
[  807.768572]  [] ? sub_preempt_count+0xe/0xb6
[  807.768577]  [] ? _raw_spin_unlock+0x15/0x30
[  807.768580]  [] ? sub_preempt_count+0xe/0xb6
[  807.768584]  [] list_slab_objects+0x9b/0x19f
[  807.768588]  [] ? add_preempt_count+0xc6/0xca
[  807.768591]  [] kmem_cache_destroy+0x13f/0x21d
[  807.768597]  [] cfq_slab_kill+0x1a/0x43 [cfq_iosched]
[  807.768601]  [] cfq_exit+0x93/0x9e [cfq_iosched]
[  807.768606]  [] sys_delete_module+0x1b1/0x219
[  807.768612]  [] system_call_fastpath+0x16/0x1b
[  807.768618] INFO: Object 0xffff88011d584618 @offset=1560
[  807.768622] INFO: Allocated in cfq_get_queue+0x11e/0x274 [cfq_iosched] age=7173 cpu=1 pid=5496
[  807.768626] =============================================================================

Cc: stable@kernel.org
Signed-off-by: Shaohua Li 
Signed-off-by: Jens Axboe

block: Adjust elv_iosched_show to return "none" for bio-based DM

2010-05-24T07:07:32+00:00

Bio-based DM doesn't use an elevator (queue is !blk_queue_stackable()).

Longer-term DM will not allocate an elevator for bio-based DM.  But even
then there will be small potential for an elevator to be allocated for
a request-based DM table only to have a bio-based table be loaded in the
end.

Displaying "none" for bio-based DM will help avoid user confusion.

Signed-off-by: Mike Snitzer 
Signed-off-by: Jens Axboe

cfq-iosched: compact io_context radix_tree

2010-05-24T07:06:59+00:00

Use small consequent indexes as radix tree keys instead of sparse cfqd address.

This change will reduce radix tree depth from 11 (6 for 32-bit hosts)
to 1 if host have <=64 disks under cfq control, or to 0 if there only one disk.
So, this patch save 10*560 bytes for each process (5*296 for 32-bit hosts)

For each cfqd allocate cic index from ida.
To unlink dead cic from tree without cfqd access store index into ->key.
(bit 0 -- dead mark, bits 1..30 -- index: ida produce id in range 0..2^31-1)

Signed-off-by: Konstantin Khlebnikov 
Signed-off-by: Jens Axboe

cfq-iosched: remove dead_key from cfq_io_context

2010-05-24T07:06:59+00:00

Remove ->dead_key field from cfq_io_context to shrink its size to 128 bytes.
(64 bytes for 32-bit hosts)

Use lower bit in ->key as dead-mark, instead of moving key to separate field.
After this for dead cfq_io_context we got cic->key != cfqd automatically.
Thus, io_context's last-hit cache should work without changing.

Now to check ->key for non-dead state compare it with cfqd,
instead of checking ->key for non-null value as it was before.

Plus remove obsolete race protection in cfq_cic_lookup.
This race gone after v2.6.24-1728-g4ac845a

Signed-off-by: Konstantin Khlebnikov 
Signed-off-by: Jens Axboe

Merge branch 'master' into for-2.6.35

2010-05-21T19:27:26+00:00

Conflicts:
	fs/ext3/fsync.c

Signed-off-by: Jens Axboe

block: remove all rcu head initializations

2010-05-21T18:01:02+00:00

Remove all rcu head inits. We don't care about the RCU head state before passing
it to call_rcu() anyway. Only leave the "on_stack" variants so debugobjects can
keep track of objects on stack.

Signed-off-by: Mathieu Desnoyers 
Signed-off-by: Paul E. McKenney 
Signed-off-by: Jens Axboe

block: allow initialization of previously allocated request_queue

2010-05-11T06:57:42+00:00

blk_init_queue() allocates the request_queue structure and then
initializes it as needed (request_fn, elevator, etc).

Split initialization out to blk_init_allocated_queue_node.
Introduce blk_init_allocated_queue wrapper function to model existing
blk_init_queue and blk_init_queue_node interfaces.

Export elv_register_queue to allow a newly added elevator to be
registered with sysfs.  Export elv_unregister_queue for symmetry.

These changes allow DM to initialize a device's request_queue with more
precision.  In particular, DM no longer unconditionally initializes a
full request_queue (elevator et al).  It only does so for a
request-based DM device.

Signed-off-by: Mike Snitzer 
Signed-off-by: Jens Axboe

blk-cgroup: Fix an RCU warning in blkiocg_create()

2010-05-07T06:57:00+00:00

with CONFIG_PROVE_RCU=y, a warning can be triggered:

  # mount -t cgroup -o blkio xxx /mnt
  # mkdir /mnt/subgroup

...
kernel/cgroup.c:4442 invoked rcu_dereference_check() without protection!
...

To fix this, we avoid caling css_depth() here, which is a bit simpler
than the original code.

Signed-off-by: Li Zefan 
Acked-by: Vivek Goyal 
Signed-off-by: Jens Axboe