linux.git/block, branch v5.2-rc4

block, bfq: add weight symlink to the bfq.weight cgroup parameter

2019-06-07T07:29:40+00:00

Many userspace tools and services use the proportional-share policy of
the blkio/io cgroups controller. The CFQ I/O scheduler implemented
this policy for the legacy block layer. To modify the weight of a
group in case CFQ was in charge, the 'weight' parameter of the group
must be modified. On the other hand, the BFQ I/O scheduler implements
the same policy in blk-mq, but, with BFQ, the parameter to modify has
a different name: bfq.weight (forced choice until legacy block was
present, because two different policies cannot share a common parameter
in cgroups).

Due to CFQ legacy, most if not all userspace configurations still use
the parameter 'weight', and for the moment do not seem likely to be
changed. But, when CFQ went away with legacy block, such a parameter
ceased to exist.

So, a simple workaround has been proposed [1] to make all
configurations work: add a symlink, named weight, to bfq.weight. This
commit adds such a symlink.

[1] https://lkml.org/lkml/2019/4/8/555

Suggested-by: Johannes Thumshirn 
Signed-off-by: Angelo Ruocco 
Signed-off-by: Paolo Valente 
Signed-off-by: Jens Axboe

block: free sched's request pool in blk_cleanup_queue

2019-06-07T04:39:39+00:00

In theory, IO scheduler belongs to request queue, and the request pool
of sched tags belongs to the request queue too.

However, the current tags allocation interfaces are re-used for both
driver tags and sched tags, and driver tags is definitely host wide,
and doesn't belong to any request queue, same with its request pool.
So we need tagset instance for freeing request of sched tags.

Meantime, blk_mq_free_tag_set() often follows blk_cleanup_queue() in case
of non-BLK_MQ_F_TAG_SHARED, this way requires that request pool of sched
tags to be freed before calling blk_mq_free_tag_set().

Commit 47cdee29ef9d94e ("block: move blk_exit_queue into __blk_release_queue")
moves blk_exit_queue into __blk_release_queue for simplying the fast
path in generic_make_request(), then causes oops during freeing requests
of sched tags in __blk_release_queue().

Fix the above issue by move freeing request pool of sched tags into
blk_cleanup_queue(), this way is safe becasue queue has been frozen and no any
in-queue requests at that time. Freeing sched tags has to be kept in queue's
release handler becasue there might be un-completed dispatch activity
which might refer to sched tags.

Cc: Bart Van Assche 
Cc: Christoph Hellwig 
Fixes: 47cdee29ef9d94e485eb08f962c74943023a5271 ("block: move blk_exit_queue into __blk_release_queue")
Tested-by: Yi Zhang 
Reported-by: kernel test robot 
Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe

block: Drop unlikely before IS_ERR(_OR_NULL)

2019-06-05T14:22:24+00:00

IS_ERR(_OR_NULL) already contain an 'unlikely' compiler flag,
so no need to do that again from its callers. Drop it.

Cc: Jens Axboe 
Cc: linux-block@vger.kernel.org
Signed-off-by: Kefeng Wang 
Signed-off-by: Jens Axboe

block: print offending values when cloned rq limits are exceeded

2019-05-31T21:12:34+00:00

While troubleshooting issues where cloned request limits have been
exceeded, it is often beneficial to know the actual values that
have been breached.  Print these values, assisting in ease of
identification of root cause of the breach.

Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Ming Lei 
Signed-off-by: John Pittman 
Signed-off-by: Jens Axboe

blk-mq: Document the blk_mq_hw_queue_to_node() arguments

2019-05-31T21:12:34+00:00

Document the meaning of the blk_mq_hw_queue_to_node() arguments.

Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Bart Van Assche 
Signed-off-by: Jens Axboe

blk-mq: Fix spelling in a source code comment

2019-05-31T21:12:34+00:00

Change one occurrence of 'performace' into 'performance'.

Cc: Max Gurtovoy 
Fixes: fe631457ff3e ("blk-mq: map all HWQ also in hyperthreaded system") # v4.13.
Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Bart Van Assche 
Signed-off-by: Jens Axboe

block: Fix bsg_setup_queue() kernel-doc header

2019-05-31T21:12:34+00:00

Document all bsg_setup_queue() arguments as required.

Fixes: aae3b069d5ce ("bsg: pass in desired timeout handler") # v5.0.
Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Bart Van Assche 
Signed-off-by: Jens Axboe

block: Fix rq_qos_wait() kernel-doc header

2019-05-31T21:12:34+00:00

Add documentation for the @rqw argument and change " - " into ": ".

Fixes: 84f603246db9 ("block: add rq_qos_wait to rq_qos") # v5.0-rc1~52^2~140.
Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Bart Van Assche 
Signed-off-by: Jens Axboe

block: Fix blk_mq_*_map_queues() kernel-doc headers

2019-05-31T21:12:34+00:00

This patch avoids that the kernel-doc script complains about these
function headers when building with W=1.

Cc: Hannes Reinecke 
Cc: Keith Busch 
Fixes: ed76e329d74a ("blk-mq: abstract out queue map") # v5.0.
Fixes: e42b3867de4b ("blk-mq-rdma: pass in queue map to blk_mq_rdma_map_queues") # v5.0.
Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Bart Van Assche 
Signed-off-by: Jens Axboe

block: Fix throtl_pending_timer_fn() kernel-doc header

2019-05-31T21:12:34+00:00

Commit e99e88a9d2b0 renamed a function argument without updating the
corresponding kernel-doc header. Update the kernel-doc header.

Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Kees Cook 
Fixes: e99e88a9d2b0 ("treewide: setup_timer() -> timer_setup()") # v4.15.
Signed-off-by: Bart Van Assche 
Signed-off-by: Jens Axboe