linux-toradex.git/block/blk-timeout.c, branch v5.1-rc4

block: don't hold the queue_lock over blk_abort_request

2018-11-15T19:13:18+00:00

There is nothing it could synchronize against, so don't go through
the pains of acquiring the lock.

Reviewed-by: Hannes Reinecke 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: remove deadline __deadline manipulation helpers

2018-11-15T19:13:16+00:00

No users left since the removal of the legacy request interface, we can
remove all the magic bit stealing now and make it a normal field.

But use WRITE_ONCE/READ_ONCE on the new deadline field, given that we
don't seem to have any mechanism to guarantee a new value actually
gets seen by other threads.

Reviewed-by: Hannes Reinecke 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: remove req->timeout_list

2018-11-09T18:44:10+00:00

Unused now that the legacy request path is gone.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: kill legacy parts of timeout handling

2018-11-07T20:42:33+00:00

The only user of legacy timing now is BSG, which is invoked
from the mq timeout handler. Kill the legacy code, and rename
the q->rq_timed_out_fn to q->bsg_job_timeout_fn.

Reviewed-by: Hannes Reinecke 
Tested-by: Ming Lei 
Reviewed-by: Omar Sandoval 
Signed-off-by: Jens Axboe

blk-mq: Fix timeout handling in case the timeout handler returns BLK_EH_DONE

2018-06-23T16:25:45+00:00

Make sure that RQF_TIMED_OUT is cleared when a request is reused
after a block driver timeout handler has returned BLK_EH_DONE.

Fixes: da6612673988 ("blk-mq: don't time out requests again that are in the timeout handler")
Signed-off-by: Bart Van Assche 
Cc: Christoph Hellwig 
Cc: Jianchao Wang 
Cc: Andrew Randrianasulu 
Signed-off-by: Jens Axboe

block: remove BLK_EH_HANDLED

2018-05-29T14:59:21+00:00

Signed-off-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Jens Axboe

block: rename BLK_EH_NOT_HANDLED to BLK_EH_DONE

2018-05-29T14:59:21+00:00

The BLK_EH_NOT_HANDLED implies nothing happen, but very often that
is not what is happening - instead the driver already completed the
command.  Fix the symbolic name to reflect that a little better.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Jens Axboe

blk-mq: Remove generation seqeunce

2018-05-29T14:59:21+00:00

This patch simplifies the timeout handling by relying on the request
reference counting to ensure the iterator is operating on an inflight
and truly timed out request. Since the reference counting prevents the
tag from being reallocated, the block layer no longer needs to prevent
drivers from completing their requests while the timeout handler is
operating on it: a driver completing a request is allowed to proceed to
the next state without additional syncronization with the block layer.

This also removes any need for generation sequence numbers since the
request lifetime is prevented from being reallocated as a new sequence
while timeout handling is operating on it.

To enables this a refcount is added to struct request so that request
users can be sure they're operating on the same request without it
changing while they're processing it.  The request's tag won't be
released for reuse until both the timeout handler and the completion
are done with it.

Signed-off-by: Keith Busch 
[hch: slight cleanups, added back submission side hctx lock, use cmpxchg
 for completions]
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

blk-mq: Directly schedule q->timeout_work when aborting a request

2018-04-02T22:36:13+00:00

Request abortion is performed by overriding deadline to now and
scheduling timeout handling immediately.  For the latter part, the
code was using mod_timer(timeout, 0) which can't guarantee that the
timer runs afterwards.  Let's schedule the underlying work item
directly instead.

This fixes the hangs during probing reported by Sitsofe but it isn't
yet clear to me how the failure can happen reliably if it's just the
above described race condition.

Signed-off-by: Tejun Heo 
Reported-by: Sitsofe Wheeler 
Reported-by: Meelis Roos 
Fixes: 358f70da49d7 ("blk-mq: make blk_abort_request() trigger timeout path")
Cc: stable@vger.kernel.org # v4.16
Link: http://lkml.kernel.org/r/CALjAwxh-PVYFnYFCJpGOja+m5SzZ8Sa4J7ohxdK=r8NyOF-EMA@mail.gmail.com
Link: http://lkml.kernel.org/r/alpine.LRH.2.21.1802261049140.4893@math.ut.ee
Signed-off-by: Jens Axboe

block: Introduce blk_queue_flag_{set,clear,test_and_{set,clear}}()

2018-03-08T21:13:48+00:00

Introduce functions that modify the queue flags and that protect
these modifications with the request queue lock. Except for moving
one wake_up_all() call from inside to outside a critical section,
this patch does not change any functionality.

Cc: Christoph Hellwig 
Cc: Hannes Reinecke 
Cc: Ming Lei 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: Martin K. Petersen 
Signed-off-by: Bart Van Assche 
Signed-off-by: Jens Axboe