linux.git/block, branch v5.0-rc5

blk-mq: fix a hung issue when fsync

2019-01-30T15:53:54+00:00

Florian reported a io hung issue when fsync(). It should be
triggered by following race condition.

data + post flush         a flush

blk_flush_complete_seq
  case REQ_FSEQ_DATA
    blk_flush_queue_rq
    issued to driver      blk_mq_dispatch_rq_list
                            try to issue a flush req
                            failed due to NON-NCQ command
                            .queue_rq return BLK_STS_DEV_RESOURCE

request completion
  req->end_io // doesn't check RESTART
  mq_flush_data_end_io
    case REQ_FSEQ_POSTFLUSH
      blk_kick_flush
        do nothing because previous flush
        has not been completed
     blk_mq_run_hw_queue
                              insert rq to hctx->dispatch
                              due to RESTART is still set, do nothing

To fix this, replace the blk_mq_run_hw_queue in mq_flush_data_end_io
with blk_mq_sched_restart to check and clear the RESTART flag.

Fixes: bd166ef1 (blk-mq-sched: add framework for MQ capable IO schedulers)
Reported-by: Florian Stecker 
Tested-by: Florian Stecker 
Signed-off-by: Jianchao Wang 
Signed-off-by: Jens Axboe

block: pass no-op callback to INIT_WORK().

2019-01-30T15:53:20+00:00

syzbot is hitting flush_work() warning caused by commit 4d43d395fed12463
("workqueue: Try to catch flush_work() without INIT_WORK().") [1].
Although that commit did not expect INIT_WORK(NULL) case, calling
flush_work() without setting a valid callback should be avoided anyway.
Fix this problem by setting a no-op callback instead of NULL.

[1] https://syzkaller.appspot.com/bug?id=e390366bc48bc82a7c668326e0663be3b91cbd29

Signed-off-by: Tetsuo Handa 
Reported-and-tested-by: syzbot 
Cc: Tejun Heo 
Signed-off-by: Jens Axboe

Revert "block: cover another queue enter recursion via BIO_QUEUE_ENTERED"

2019-01-27T13:35:28+00:00

We can't touch a bio after ->make_request_fn(), for all we know it could
already have been completed by the time this function returns.

This reverts commit 698cef173983b086977e633e46476e0f925ca01e.

Reported-by: syzbot+4df6ca820108fd248943@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe

blk-wbt: Declare local functions static

2019-01-24T18:09:21+00:00

This patch avoids that sparse reports the following warnings:

  CHECK   block/blk-wbt.c
block/blk-wbt.c:600:6: warning: symbol 'wbt_issue' was not declared. Should it be static?
block/blk-wbt.c:620:6: warning: symbol 'wbt_requeue' was not declared. Should it be static?
  CC      block/blk-wbt.o
block/blk-wbt.c:600:6: warning: no previous prototype for wbt_issue [-Wmissing-prototypes]
 void wbt_issue(struct rq_qos *rqos, struct request *rq)
      ^~~~~~~~~
block/blk-wbt.c:620:6: warning: no previous prototype for wbt_requeue [-Wmissing-prototypes]
 void wbt_requeue(struct rq_qos *rqos, struct request *rq)
      ^~~~~~~~~~~

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

blk-mq: fix the cmd_flag_name array

2019-01-24T15:41:42+00:00

Swap REQ_NOWAIT and REQ_NOUNMAP and add REQ_HIPRI.

Acked-by: Jeff Moyer 
Signed-off-by: Jianchao Wang 
Signed-off-by: Jens Axboe

block: cover another queue enter recursion via BIO_QUEUE_ENTERED

2019-01-22T17:24:08+00:00

Except for blk_queue_split(), bio_split() is used for splitting bio too,
then the remained bio is often resubmit to queue via generic_make_request().
So the same queue enter recursion exits in this case too. Unfortunatley
commit cd4a4ae4683dc2 doesn't help this case.

This patch covers the above case by setting BIO_QUEUE_ENTERED before calling
q->make_request_fn.

In theory the per-bio flag is used to simulate one stack variable, it is
just fine to clear it after q->make_request_fn is returned. Especially
the same bio can't be submitted from another context.

Fixes: cd4a4ae4683dc2 ("block: don't use blocking queue entered for recursive bio submits")
Cc: Tetsuo Handa 
Cc: NeilBrown 
Reviewed-by:  Mike Snitzer 
Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe

block: Cleanup license notice

2019-01-18T04:21:40+00:00

Remove the imprecise and sloppy:

  "This files is licensed under the GPL."

license notice in the top level comment.

1) The file already contains a SPDX license identifier which clearly
   states that the license of the file is GPL V2 only

2) The notice resolves to GPL v1 or later for scanners which is just
   contrary to the intent of SPDX identifiers to provide clear and non
   ambiguous license information. Aside of that the value add of this
   notice is below zero,

Cc: Damien Le Moal 
Cc: Matias Bjorling 
Cc: Christoph Hellwig 
Cc: Jens Axboe 
Cc: linux-block@vger.kernel.org
Fixes: 6a5ac9846508 ("block: Make struct request_queue smaller for CONFIG_BLK_DEV_ZONED=n")
Reviewed-by: Bart Van Assche 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Jens Axboe

block: don't lose track of REQ_INTEGRITY flag

2019-01-16T14:28:10+00:00

We need to pass bio->bi_opf after bio intergrity preparing, otherwise
the flag of REQ_INTEGRITY may not be set on the allocated request, then
breaks block integrity.

Fixes: f9afca4d367b ("blk-mq: pass in request/bio flags to queue mapping")
Cc: Hannes Reinecke 
Cc: Keith Busch 
Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe

block, bfq: fix comments on __bfq_deactivate_entity

2019-01-14T13:25:44+00:00

Comments on function __bfq_deactivate_entity contains two imprecise or
wrong statements:
1) The function performs the deactivation of the entity.
2) The function must be invoked only if the entity is on a service tree.

This commits replaces both statements with the correct ones:
1) The functions updates sched_data and service trees for the entity,
so as to represent entity as inactive (which is only part of the steps
needed for the deactivation of the entity).
2) The function must be invoked on every entity being deactivated.

Signed-off-by: Paolo Valente 
Signed-off-by: Jens Axboe

block: fix kerneldoc comment for blk_attempt_plug_merge()

2019-01-09T22:29:08+00:00

Commit 5f0ed774ed29 ("block: sum requests in the plug structure") removed
the request_count parameter from block_attempt_plug_merge(), but did not
remove the associated kerneldoc comment, introducing this warning to the
docs build:

  ./block/blk-core.c:685: warning: Excess function parameter 'request_count' description in 'blk_attempt_plug_merge'

Remove the obsolete description and make things a little quieter.

Signed-off-by: Jonathan Corbet 
Signed-off-by: Jens Axboe