linux-stable.git/block, branch v5.10.9

blk-mq-debugfs: Add decode for BLK_MQ_F_TAG_HCTX_SHARED

2021-01-19T17:27:29+00:00

[ Upstream commit 02f938e9fed1681791605ca8b96c2d9da9355f6a ]

Showing the hctx flags for when BLK_MQ_F_TAG_HCTX_SHARED is set gives
something like:

root@debian:/home/john# more /sys/kernel/debug/block/sda/hctx0/flags
alloc_policy=FIFO SHOULD_MERGE|TAG_QUEUE_SHARED|3

Add the decoding for that flag.

Fixes: 32bc15afed04b ("blk-mq: Facilitate a shared sbitmap per tagset")
Signed-off-by: John Garry 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

bfq: Fix computation of shallow depth

2021-01-19T17:27:26+00:00

[ Upstream commit 6d4d273588378c65915acaf7b2ee74e9dd9c130a ]

BFQ computes number of tags it allows to be allocated for each request type
based on tag bitmap. However it uses 1 << bitmap.shift as number of
available tags which is wrong. 'shift' is just an internal bitmap value
containing logarithm of how many bits bitmap uses in each bitmap word.
Thus number of tags allowed for some request types can be far to low.
Use proper bitmap.depth which has the number of tags instead.

Signed-off-by: Jan Kara 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

block: fix use-after-free in disk_part_iter_next

2021-01-17T13:17:05+00:00

commit aebf5db917055b38f4945ed6d621d9f07a44ff30 upstream.

Make sure that bdgrab() is done on the 'block_device' instance before
referring to it for avoiding use-after-free.

Cc: 
Reported-by: syzbot+825f0f9657d4e528046e@syzkaller.appspotmail.com
Signed-off-by: Ming Lei 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

blk-iocost: fix NULL iocg deref from racing against initialization

2021-01-12T19:18:23+00:00

commit d16baa3f1453c14d680c5fee01cd122a22d0e0ce upstream.

When initializing iocost for a queue, its rqos should be registered before
the blkcg policy is activated to allow policy data initiailization to lookup
the associated ioc. This unfortunately means that the rqos methods can be
called on bios before iocgs are attached to all existing blkgs.

While the race is theoretically possible on ioc_rqos_throttle(), it mostly
happened in ioc_rqos_merge() due to the difference in how they lookup ioc.
The former determines it from the passed in @rqos and then bails before
dereferencing iocg if the looked up ioc is disabled, which most likely is
the case if initialization is still in progress. The latter looked up ioc by
dereferencing the possibly NULL iocg making it a lot more prone to actually
triggering the bug.

* Make ioc_rqos_merge() use the same method as ioc_rqos_throttle() to look
  up ioc for consistency.

* Make ioc_rqos_throttle() and ioc_rqos_merge() test for NULL iocg before
  dereferencing it.

* Explain the danger of NULL iocgs in blk_iocost_init().

Signed-off-by: Tejun Heo 
Reported-by: Jonathan Lemon 
Cc: stable@vger.kernel.org # v5.4+
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

scsi: block: Do not accept any requests while suspended

2021-01-12T19:18:17+00:00

[ Upstream commit 52abca64fd9410ea6c9a3a74eab25663b403d7da ]

blk_queue_enter() accepts BLK_MQ_REQ_PM requests independent of the runtime
power management state. Now that SCSI domain validation no longer depends
on this behavior, modify the behavior of blk_queue_enter() as follows:

   - Do not accept any requests while suspended.

   - Only process power management requests while suspending or resuming.

Submitting BLK_MQ_REQ_PM requests to a device that is runtime suspended
causes runtime-suspended devices not to resume as they should. The request
which should cause a runtime resume instead gets issued directly, without
resuming the device first. Of course the device can't handle it properly,
the I/O fails, and the device remains suspended.

The problem is fixed by checking that the queue's runtime-PM status isn't
RPM_SUSPENDED before allowing a request to be issued, and queuing a
runtime-resume request if it is.  In particular, the inline
blk_pm_request_resume() routine is renamed blk_pm_resume_queue() and the
code is unified by merging the surrounding checks into the routine.  If the
queue isn't set up for runtime PM, or there currently is no restriction on
allowed requests, the request is allowed.  Likewise if the BLK_MQ_REQ_PM
flag is set and the status isn't RPM_SUSPENDED.  Otherwise a runtime resume
is queued and the request is blocked until conditions are more suitable.

[ bvanassche: modified commit message and removed Cc: stable because
  without the previous patches from this series this patch would break
  parallel SCSI domain validation + introduced queue_rpm_status() ]

Link: https://lore.kernel.org/r/20201209052951.16136-9-bvanassche@acm.org
Cc: Jens Axboe 
Cc: Christoph Hellwig 
Cc: Hannes Reinecke 
Cc: Can Guo 
Cc: Stanley Chu 
Cc: Ming Lei 
Cc: Rafael J. Wysocki 
Reported-and-tested-by: Martin Kepplinger 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Can Guo 
Signed-off-by: Alan Stern 
Signed-off-by: Bart Van Assche 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: block: Remove RQF_PREEMPT and BLK_MQ_REQ_PREEMPT

2021-01-12T19:18:17+00:00

[ Upstream commit a4d34da715e3cb7e0741fe603dcd511bed067e00 ]

Remove flag RQF_PREEMPT and BLK_MQ_REQ_PREEMPT since these are no longer
used by any kernel code.

Link: https://lore.kernel.org/r/20201209052951.16136-8-bvanassche@acm.org
Cc: Can Guo 
Cc: Stanley Chu 
Cc: Alan Stern 
Cc: Ming Lei 
Cc: Rafael J. Wysocki 
Cc: Martin Kepplinger 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Jens Axboe 
Reviewed-by: Can Guo 
Signed-off-by: Bart Van Assche 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

scsi: block: Introduce BLK_MQ_REQ_PM

2021-01-12T19:18:15+00:00

[ Upstream commit 0854bcdcdec26aecdc92c303816f349ee1fba2bc ]

Introduce the BLK_MQ_REQ_PM flag. This flag makes the request allocation
functions set RQF_PM. This is the first step towards removing
BLK_MQ_REQ_PREEMPT.

Link: https://lore.kernel.org/r/20201209052951.16136-3-bvanassche@acm.org
Cc: Alan Stern 
Cc: Stanley Chu 
Cc: Ming Lei 
Cc: Rafael J. Wysocki 
Cc: Can Guo 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Jens Axboe 
Reviewed-by: Can Guo 
Signed-off-by: Bart Van Assche 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Sasha Levin

block: add debugfs stanza for QUEUE_FLAG_NOWAIT

2021-01-12T19:18:14+00:00

[ Upstream commit dc30432605bbbd486dfede3852ea4d42c40a84b4 ]

This was missed in 021a24460dc2. Leads to the numeric value of
QUEUE_FLAG_NOWAIT (i.e. 29) showing up in
/sys/kernel/debug/block/*/state.

Fixes: 021a24460dc28e7412aecfae89f60e1847e685c0
Cc: Konstantin Khlebnikov 
Cc: Mike Snitzer 
Cc: Christoph Hellwig 
Cc: Jens Axboe 
Signed-off-by: Andres Freund 
Signed-off-by: Jens Axboe 
Signed-off-by: Sasha Levin

scsi: block: Fix a race in the runtime power management code

2021-01-06T13:56:50+00:00

commit fa4d0f1992a96f6d7c988ef423e3127e613f6ac9 upstream.

With the current implementation the following race can happen:

 * blk_pre_runtime_suspend() calls blk_freeze_queue_start() and
   blk_mq_unfreeze_queue().

 * blk_queue_enter() calls blk_queue_pm_only() and that function returns
   true.

 * blk_queue_enter() calls blk_pm_request_resume() and that function does
   not call pm_request_resume() because the queue runtime status is
   RPM_ACTIVE.

 * blk_pre_runtime_suspend() changes the queue status into RPM_SUSPENDING.

Fix this race by changing the queue runtime status into RPM_SUSPENDING
before switching q_usage_counter to atomic mode.

Link: https://lore.kernel.org/r/20201209052951.16136-2-bvanassche@acm.org
Fixes: 986d413b7c15 ("blk-mq: Enable support for runtime power management")
Cc: Ming Lei 
Cc: Rafael J. Wysocki 
Cc: stable 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Jens Axboe 
Acked-by: Alan Stern 
Acked-by: Stanley Chu 
Co-developed-by: Can Guo 
Signed-off-by: Can Guo 
Signed-off-by: Bart Van Assche 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'block-5.10-2020-12-05' of git://git.kernel.dk/linux-block

2020-12-05T22:45:30+00:00

Pull block fix from Jens Axboe:
 "Single fix for an issue with chunk_sectors and stacked devices"

* tag 'block-5.10-2020-12-05' of git://git.kernel.dk/linux-block:
  block: use gcd() to fix chunk_sectors limit stacking