linux.git/include/linux/blk_types.h, branch v6.1

block: remove PSI accounting from the bio layer

2022-09-20T14:24:38+00:00

PSI accounting is now done by the VM code, where it should have been
since the beginning.

Signed-off-by: Christoph Hellwig 
Acked-by: Johannes Weiner 
Link: https://lore.kernel.org/r/20220915094200.139713-6-hch@lst.de
Signed-off-by: Jens Axboe

blk-throttle: fix that io throttle can only work for single bio

2022-09-12T06:19:48+00:00

Test scripts:
cd /sys/fs/cgroup/blkio/
echo "8:0 1024" > blkio.throttle.write_bps_device
echo $$ > cgroup.procs
dd if=/dev/zero of=/dev/sda bs=10k count=1 oflag=direct &
dd if=/dev/zero of=/dev/sda bs=10k count=1 oflag=direct &

Test result:
10240 bytes (10 kB, 10 KiB) copied, 10.0134 s, 1.0 kB/s
10240 bytes (10 kB, 10 KiB) copied, 10.0135 s, 1.0 kB/s

The problem is that the second bio is finished after 10s instead of 20s.

Root cause:
1) second bio will be flagged:

__blk_throtl_bio
 while (true) {
  ...
  if (sq->nr_queued[rw]) -> some bio is throttled already
   break
 };
 bio_set_flag(bio, BIO_THROTTLED); -> flag the bio

2) flagged bio will be dispatched without waiting:

throtl_dispatch_tg
 tg_may_dispatch
  tg_with_in_bps_limit
   if (bps_limit == U64_MAX || bio_flagged(bio, BIO_THROTTLED))
    *wait = 0; -> wait time is zero
    return true;

commit 9f5ede3c01f9 ("block: throttle split bio in case of iops limit")
support to count split bios for iops limit, thus it adds flagged bio
checking in tg_with_in_bps_limit() so that split bios will only count
once for bps limit, however, it introduce a new problem that io throttle
won't work if multiple bios are throttled.

In order to fix the problem, handle iops/bps limit in different ways:

1) for iops limit, there is no flag to record if the bio is throttled,
   and iops is always applied.
2) for bps limit, original bio will be flagged with BIO_BPS_THROTTLED,
   and io throttle will ignore bio with the flag.

Noted this patch also remove the code to set flag in __bio_clone(), it's
introduced in commit 111be8839817 ("block-throttle: avoid double
charge"), and author thinks split bio can be resubmited and throttled
again, which is wrong because split bio will continue to dispatch from
caller.

Fixes: 9f5ede3c01f9 ("block: throttle split bio in case of iops limit")
Cc: 
Signed-off-by: Yu Kuai 
Acked-by: Tejun Heo 
Link: https://lore.kernel.org/r/20220829022240.3348319-2-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe

block: Introduce the type blk_opf_t

2022-07-14T18:14:30+00:00

Introduce the type blk_opf_t for the request operation and flags (REQ_OP_*
and REQ_*). This type will be used to improve documentation of the block
layer code and also to allow sparse to verify whether request flags are used
correctly.

Cc: Christoph Hellwig 
Cc: Ming Lei 
Cc: Hannes Reinecke 
Cc: Damien Le Moal 
Cc: Johannes Thumshirn 
Signed-off-by: Bart Van Assche 
Link: https://lore.kernel.org/r/20220714180729.1065367-6-bvanassche@acm.org
Signed-off-by: Jens Axboe

block: Change the type of req_op() and bio_op() into enum req_op

2022-07-14T18:14:30+00:00

Improve static type checking by changing the type of the value returned by
req_op() and bio_op() from unsigned int into enum req_op. Insert
'default: break;' in switch statements on the enum req_op type to prevent
that the compiler warns about these switch statements.

Cc: Christoph Hellwig 
Cc: Ming Lei 
Cc: Hannes Reinecke 
Cc: Damien Le Moal 
Cc: Johannes Thumshirn 
Cc: Tim Waugh 
Cc: Alasdair Kergon 
Cc: Mike Snitzer 
Cc: Mikulas Patocka 
Signed-off-by: Bart Van Assche 
Link: https://lore.kernel.org/r/20220714180729.1065367-5-bvanassche@acm.org
Signed-off-by: Jens Axboe

block: Use enum req_op where appropriate

2022-07-14T18:14:30+00:00

Change the type of the arguments that are used to pass a REQ_OP_* value
from int or unsigned int into enum req_op to improve static type
checking.

Cc: Christoph Hellwig 
Cc: Ming Lei 
Cc: Hannes Reinecke 
Cc: Damien Le Moal 
Cc: Johannes Thumshirn 
Signed-off-by: Bart Van Assche 
Link: https://lore.kernel.org/r/20220714180729.1065367-3-bvanassche@acm.org
Signed-off-by: Jens Axboe

treewide: Rename enum req_opf into enum req_op

2022-07-14T18:14:30+00:00

The type name enum req_opf is misleading since it suggests that values of
this type include both an operation type and flags. Since values of this
type represent an operation only, change the type name into enum req_op.

Convert the enum req_op documentation into kernel-doc format. Move a few
definitions such that the enum req_op documentation occurs just above
the enum req_op definition.

The name "req_opf" was introduced by commit ef295ecf090d ("block: better op
and flags encoding").

Cc: Christoph Hellwig 
Cc: Ming Lei 
Cc: Hannes Reinecke 
Cc: Damien Le Moal 
Cc: Johannes Thumshirn 
Signed-off-by: Bart Van Assche 
Link: https://lore.kernel.org/r/20220714180729.1065367-2-bvanassche@acm.org
Signed-off-by: Jens Axboe

Merge tag 'for-5.19/block-2022-06-02' of git://git.kernel.dk/linux-block

2022-06-03T17:14:48+00:00

Pull block fixes from Jens Axboe:
 "Just a collection of fixes that have been queued up since the initial
  merge window pull request, the majority of which are targeted for
  stable as well.

  One bio_set fix that fixes an issue with the dm adoption of cached bio
  structs that got introduced in this merge window"

* tag 'for-5.19/block-2022-06-02' of git://git.kernel.dk/linux-block:
  block: Fix potential deadlock in blk_ia_range_sysfs_show()
  block: fix bio_clone_blkg_association() to associate with proper blkcg_gq
  block: remove useless BUG_ON() in blk_mq_put_tag()
  blk-mq: do not update io_ticks with passthrough requests
  block: make bioset_exit() fully resilient against being called twice
  block: use bio_queue_enter instead of blk_queue_enter in bio_poll
  block: document BLK_STS_AGAIN usage
  block: take destination bvec offsets into account in bio_copy_data_iter
  blk-iolatency: Fix inflight count imbalances and IO hangs on offline
  blk-mq: don't touch ->tagset in blk_mq_get_sq_hctx

block: document BLK_STS_AGAIN usage

2022-05-28T02:38:17+00:00

BLK_STS_AGAIN should only be used if RQF_NOWAIT is set and the bio
would block. So we'd better document that to avoid accidental misuse.

Signed-off-by: Hannes Reinecke 
Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20220524055631.85480-2-hare@suse.de
Signed-off-by: Jens Axboe

Merge tag 'for-5.19/drivers-2022-05-22' of git://git.kernel.dk/linux-block

2022-05-23T21:04:14+00:00

Pull block driver updates from Jens Axboe:
 "Here are the driver updates queued up for 5.19. This contains:

   - NVMe pull requests via Christoph:
       - tighten the PCI presence check (Stefan Roese)
       - fix a potential NULL pointer dereference in an error path (Kyle
         Miller Smith)
       - fix interpretation of the DMRSL field (Tom Yan)
       - relax the data transfer alignment (Keith Busch)
       - verbose error logging improvements (Max Gurtovoy, Chaitanya
         Kulkarni)
       - misc cleanups (Chaitanya Kulkarni, Christoph)
       - set non-mdts limits in nvme_scan_work (Chaitanya Kulkarni)
       - add support for TP4084 - Time-to-Ready Enhancements (Christoph)

   - MD pull request via Song:
       - Improve annotation in raid5 code, by Logan Gunthorpe
       - Support MD_BROKEN flag in raid-1/5/10, by Mariusz Tkaczyk
       - Other small fixes/cleanups

   - null_blk series making the configfs side much saner (Damien)

   - Various minor drbd cleanups and fixes (Haowen, Uladzislau, Jiapeng,
     Arnd, Cai)

   - Avoid using the system workqueue (and hence flushing it) in rnbd
     (Jack)

   - Avoid using the system workqueue (and hence flushing it) in aoe
     (Tetsuo)

   - Series fixing discard_alignment issues in drivers (Christoph)

   - Small series fixing drivers poking at disk->part0 for openers
     information (Christoph)

   - Series fixing deadlocks in loop (Christoph, Tetsuo)

   - Remove loop.h and add SPDX headers (Christoph)

   - Various fixes and cleanups (Julia, Xie, Yu)"

* tag 'for-5.19/drivers-2022-05-22' of git://git.kernel.dk/linux-block: (72 commits)
  mtip32xx: fix typo in comment
  nvme: set non-mdts limits in nvme_scan_work
  nvme: add support for TP4084 - Time-to-Ready Enhancements
  nvme: split the enum used for various register constants
  nbd: Fix hung on disconnect request if socket is closed before
  nvme-fabrics: add a request timeout helper
  nvme-pci: harden drive presence detect in nvme_dev_disable()
  nvme-pci: fix a NULL pointer dereference in nvme_alloc_admin_tags
  nvme: mark internal passthru request RQF_QUIET
  nvme: remove unneeded include from constants file
  nvme: add missing status values to verbose logging
  nvme: set dma alignment to dword
  nvme: fix interpretation of DMRSL
  loop: remove most the top-of-file boilerplate comment from the UAPI header
  loop: remove most the top-of-file boilerplate comment
  loop: add a SPDX header
  loop: remove loop.h
  block: null_blk: Improve device creation with configfs
  block: null_blk: Cleanup messages
  block: null_blk: Cleanup device creation and deletion
  ...

block: Fix the bio.bi_opf comment

2022-05-12T12:33:26+00:00

Commit ef295ecf090d modified the Linux kernel such that the bottom bits
of the bi_opf member contain the operation instead of the topmost bits.
That commit did not update the comment next to bi_opf. Hence this patch.

From commit ef295ecf090d:
-#define bio_op(bio)    ((bio)->bi_opf >> BIO_OP_SHIFT)
+#define bio_op(bio)    ((bio)->bi_opf & REQ_OP_MASK)

Cc: Christoph Hellwig 
Cc: Ming Lei 
Fixes: ef295ecf090d ("block: better op and flags encoding")
Signed-off-by: Bart Van Assche 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/20220511235152.1082246-1-bvanassche@acm.org
Signed-off-by: Jens Axboe