linux-stable.git/block/blk.h, branch v5.7

block: move bio_map_* to blk-map.c

2020-03-27T18:04:34+00:00

The bio_map_* helpers are just the low-level helpers for the
blk_rq_map_* APIs.  Move them together for better logical grouping,
as no there isn't much overlap with other code in bio.c.

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

block: simplify queue allocation

2020-03-27T16:23:43+00:00

Current make_request based drivers use either blk_alloc_queue_node or
blk_alloc_queue to allocate a queue, and then set up the make_request_fn
function pointer and a few parameters using the blk_queue_make_request
helper.  Simplify this by passing the make_request pointer to
blk_alloc_queue, and while at it merge the _node variant into the main
helper by always passing a node_id, and remove the superfluous gfp_mask
parameter.  A lower-level __blk_alloc_queue is kept for the blk-mq case.

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

block: move the part_stat* helpers from genhd.h to a new header

2020-03-25T15:50:09+00:00

These macros are just used by a few files.  Move them out of genhd.h,
which is included everywhere into a new standalone header.

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

block: move block layer internals out of include/linux/genhd.h

2020-03-25T15:50:08+00:00

None of this needs to be exposed to drivers.

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

block: move sysfs methods shared by disks and partitions to genhd.c

2020-03-24T13:57:07+00:00

Move the sysfs _show methods that are used both on the full disk and
partition nodes to genhd.c instead of hiding them in the partitioning
code.  Also move the declaration for these methods to block/blk.h so
that we don't expose them to drivers.

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

block: remove unneeded argument from blk_alloc_flush_queue

2020-03-12T13:42:54+00:00

Remove 'q' from arguments since it is not used anymore after
commit 7e992f847a08e ("block: remove non mq parts from the
flush code").

Signed-off-by: Guoqing Jiang 
Reviewed-by: Nikolay Borisov 
Reviewed-by: Bart Van Assche 
Reviewed-by: Chaitanya Kulkarni 
Signed-off-by: Jens Axboe

block: Fix a lockdep complaint triggered by request queue flushing

2019-12-20T18:52:01+00:00

Avoid that running test nvme/012 from the blktests suite triggers the
following false positive lockdep complaint:

============================================
WARNING: possible recursive locking detected
5.0.0-rc3-xfstests-00015-g1236f7d60242 #841 Not tainted
--------------------------------------------
ksoftirqd/1/16 is trying to acquire lock:
000000000282032e (&(&fq->mq_flush_lock)->rlock){..-.}, at: flush_end_io+0x4e/0x1d0

but task is already holding lock:
00000000cbadcbc2 (&(&fq->mq_flush_lock)->rlock){..-.}, at: flush_end_io+0x4e/0x1d0

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&(&fq->mq_flush_lock)->rlock);
  lock(&(&fq->mq_flush_lock)->rlock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

1 lock held by ksoftirqd/1/16:
 #0: 00000000cbadcbc2 (&(&fq->mq_flush_lock)->rlock){..-.}, at: flush_end_io+0x4e/0x1d0

stack backtrace:
CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.0.0-rc3-xfstests-00015-g1236f7d60242 #841
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 dump_stack+0x67/0x90
 __lock_acquire.cold.45+0x2b4/0x313
 lock_acquire+0x98/0x160
 _raw_spin_lock_irqsave+0x3b/0x80
 flush_end_io+0x4e/0x1d0
 blk_mq_complete_request+0x76/0x110
 nvmet_req_complete+0x15/0x110 [nvmet]
 nvmet_bio_done+0x27/0x50 [nvmet]
 blk_update_request+0xd7/0x2d0
 blk_mq_end_request+0x1a/0x100
 blk_flush_complete_seq+0xe5/0x350
 flush_end_io+0x12f/0x1d0
 blk_done_softirq+0x9f/0xd0
 __do_softirq+0xca/0x440
 run_ksoftirqd+0x24/0x50
 smpboot_thread_fn+0x113/0x1e0
 kthread+0x121/0x140
 ret_from_fork+0x3a/0x50

Cc: Christoph Hellwig 
Cc: Ming Lei 
Cc: Hannes Reinecke 
Signed-off-by: Bart Van Assche 
Signed-off-by: Jens Axboe

block: fix memleak of bio integrity data

2019-12-05T18:38:36+00:00

7c20f11680a4 ("bio-integrity: stop abusing bi_end_io") moves
bio_integrity_free from bio_uninit() to bio_integrity_verify_fn()
and bio_endio(). This way looks wrong because bio may be freed
without calling bio_endio(), for example, blk_rq_unprep_clone() is
called from dm_mq_queue_rq() when the underlying queue of dm-mpath
is busy.

So memory leak of bio integrity data is caused by commit 7c20f11680a4.

Fixes this issue by re-adding bio_integrity_free() to bio_uninit().

Fixes: 7c20f11680a4 ("bio-integrity: stop abusing bi_end_io")
Reviewed-by: Christoph Hellwig 
Signed-off-by Justin Tee 

Add commit log, and simplify/fix the original patch wroten by Justin.

Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe

block: account statistics for passthrough requests

2019-10-10T23:52:31+00:00

Presently, passthrough requests are not accounted for because
blk_do_io_stat() expressly rejects them. Based on some digging
in the history, this doesn't seem like a concious decision but
one that evolved from the change from blk_fs_request() to
blk_rq_is_passthrough().

To support this, call blk_account_io_start() in blk_execute_rq_nowait()
and remove the passthrough check in blk_do_io_stat().

Link: https://lore.kernel.org/linux-block/20191010100526.GA27209@lst.de/
Signed-off-by: Logan Gunthorpe 
Cc: Jens Axboe 
Cc: Christoph Hellwig 
Signed-off-by: Jens Axboe

block: fix null pointer dereference in blk_mq_rq_timed_out()

2019-09-27T13:01:25+00:00

We got a null pointer deference BUG_ON in blk_mq_rq_timed_out()
as following:

[  108.825472] BUG: kernel NULL pointer dereference, address: 0000000000000040
[  108.827059] PGD 0 P4D 0
[  108.827313] Oops: 0000 [#1] SMP PTI
[  108.827657] CPU: 6 PID: 198 Comm: kworker/6:1H Not tainted 5.3.0-rc8+ #431
[  108.829503] Workqueue: kblockd blk_mq_timeout_work
[  108.829913] RIP: 0010:blk_mq_check_expired+0x258/0x330
[  108.838191] Call Trace:
[  108.838406]  bt_iter+0x74/0x80
[  108.838665]  blk_mq_queue_tag_busy_iter+0x204/0x450
[  108.839074]  ? __switch_to_asm+0x34/0x70
[  108.839405]  ? blk_mq_stop_hw_queue+0x40/0x40
[  108.839823]  ? blk_mq_stop_hw_queue+0x40/0x40
[  108.840273]  ? syscall_return_via_sysret+0xf/0x7f
[  108.840732]  blk_mq_timeout_work+0x74/0x200
[  108.841151]  process_one_work+0x297/0x680
[  108.841550]  worker_thread+0x29c/0x6f0
[  108.841926]  ? rescuer_thread+0x580/0x580
[  108.842344]  kthread+0x16a/0x1a0
[  108.842666]  ? kthread_flush_work+0x170/0x170
[  108.843100]  ret_from_fork+0x35/0x40

The bug is caused by the race between timeout handle and completion for
flush request.

When timeout handle function blk_mq_rq_timed_out() try to read
'req->q->mq_ops', the 'req' have completed and reinitiated by next
flush request, which would call blk_rq_init() to clear 'req' as 0.

After commit 12f5b93145 ("blk-mq: Remove generation seqeunce"),
normal requests lifetime are protected by refcount. Until 'rq->ref'
drop to zero, the request can really be free. Thus, these requests
cannot been reused before timeout handle finish.

However, flush request has defined .end_io and rq->end_io() is still
called even if 'rq->ref' doesn't drop to zero. After that, the 'flush_rq'
can be reused by the next flush request handle, resulting in null
pointer deference BUG ON.

We fix this problem by covering flush request with 'rq->ref'.
If the refcount is not zero, flush_end_io() return and wait the
last holder recall it. To record the request status, we add a new
entry 'rq_status', which will be used in flush_end_io().

Cc: Christoph Hellwig 
Cc: Keith Busch 
Cc: Bart Van Assche 
Cc: stable@vger.kernel.org # v4.18+
Reviewed-by: Ming Lei 
Reviewed-by: Bob Liu 
Signed-off-by: Yufen Yu 

-------
v2:
 - move rq_status from struct request to struct blk_flush_queue
v3:
 - remove unnecessary '{}' pair.
v4:
 - let spinlock to protect 'fq->rq_status'
v5:
 - move rq_status after flush_running_idx member of struct blk_flush_queue
Signed-off-by: Jens Axboe