linux-stable.git/include/linux/blk_types.h, branch v5.3.7

block: remove REQ_NOWAIT_INLINE

2019-08-15T17:09:16+00:00

We had a few issues with this code, and there's still a problem around
how we deal with error handling for chained/split bios. For now, just
revert the code and we'll try again with a thoroug solution. This
reverts commits:

e15c2ffa1091 ("block: fix O_DIRECT error handling for bio fragments")
0eb6ddfb865c ("block: Fix __blkdev_direct_IO() for bio fragments")
6a43074e2f46 ("block: properly handle IOCB_NOWAIT for async O_DIRECT IO")
893a1c97205a ("blk-mq: allow REQ_NOWAIT to return an error inline")

Signed-off-by: Jens Axboe

blk-mq: allow REQ_NOWAIT to return an error inline

2019-07-22T03:46:23+00:00

By default, if a caller sets REQ_NOWAIT and we need to block, we'll
return -EAGAIN through the bio->bi_end_io() callback. For some use
cases, this makes it hard to use.

Allow a caller to ask for inline return of errors related to
blocking by also setting REQ_NOWAIT_INLINE.

Signed-off-by: Jens Axboe

blkcg: implement REQ_CGROUP_PUNT

2019-07-10T15:00:57+00:00

When a shared kthread needs to issue a bio for a cgroup, doing so
synchronously can lead to priority inversions as the kthread can be
trapped waiting for that cgroup.  This patch implements
REQ_CGROUP_PUNT flag which makes submit_bio() punt the actual issuing
to a dedicated per-blkcg work item to avoid such priority inversions.

This will be used to fix priority inversions in btrfs compression and
should be generally useful as we grow filesystem support for
comprehensive IO control.

Cc: Chris Mason 
Reviewed-by: Josef Bacik 
Reviewed-by: Jan Kara 
Signed-off-by: Tejun Heo 
Signed-off-by: Jens Axboe

block: remove the bi_phys_segments field in struct bio

2019-06-20T16:29:22+00:00

We only need the number of segments in the blk-mq submission path.
Remove the field from struct bio, and return it from a variant of
blk_queue_split instead of that it can passed as an argument to
those functions that need the value.

This also means we stop recounting segments except for cloning
and partial segments.

To keep the number of arguments in this how path down remove
pointless struct request_queue arguments from any of the functions
that had it and grew a nr_segs argument.

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

block: remove the bi_seg_{front,back}_size fields in struct bio

2019-05-23T16:25:26+00:00

At this point these fields aren't used for anything, so we can remove
them.

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

block: bio: ensure newly added bio flags don't override BVEC_POOL_IDX

2019-04-04T15:30:37+00:00

With the introduction of BIO_NO_PAGE_REF we've used up all available bits
in bio::bi_flags.

Convert the defines of the flags to an enum and add a BUILD_BUG_ON() call
to make sure no-one adds a new one and thus overrides the BVEC_POOL_IDX
causing crashes.

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

block: add BIO_NO_PAGE_REF flag

2019-03-18T16:44:48+00:00

If bio_iov_iter_get_pages() is called on an iov_iter that is flagged
with NO_REF, then we don't need to add a page reference for the pages
that we add.

Add BIO_NO_PAGE_REF to track this in the bio, so IO completion knows
not to drop a reference to these pages.

Signed-off-by: Jens Axboe

block: Fix comment typo

2019-01-24T18:11:45+00:00

Fix typo in REQ_OP_ZONE_RESET description.

Signed-off-by: Damien Le Moal 
Signed-off-by: Jens Axboe

block: make request_to_qc_t public

2018-12-18T16:50:47+00:00

block consumers will need it for polling requests that
are sent with blk_execute_rq_nowait. Also, get rid of
blk_tag_to_qc_t and open-code it instead.

Reviewed-by: Jens Axboe 
Signed-off-by: Sagi Grimberg 
Signed-off-by: Christoph Hellwig

block: fix blk-iolatency accounting underflow

2018-12-17T18:19:54+00:00

The blk-iolatency controller measures the time from rq_qos_throttle() to
rq_qos_done_bio() and attributes this time to the first bio that needs
to create the request. This means if a bio is plug-mergeable or
bio-mergeable, it gets to bypass the blk-iolatency controller.

The recent series [1], to tag all bios w/ blkgs undermined how iolatency
was determining which bios it was charging and should process in
rq_qos_done_bio(). Because all bios are being tagged, this caused the
atomic_t for the struct rq_wait inflight count to underflow and result
in a stall.

This patch adds a new flag BIO_TRACKED to let controllers know that a
bio is going through the rq_qos path. blk-iolatency now checks if this
flag is set to see if it should process the bio in rq_qos_done_bio().

Overloading BLK_QUEUE_ENTERED works, but makes the flag rules confusing.
BIO_THROTTLED was another candidate, but the flag is set for all bios
that have gone through blk-throttle code. Overloading a flag comes with
the burden of making sure that when either implementation changes, a
change in setting rules for one doesn't cause a bug in the other. So
here, we unfortunately opt for adding a new flag.

[1] https://lore.kernel.org/lkml/20181205171039.73066-1-dennis@kernel.org/

Fixes: 5cdf2e3fea5e ("blkcg: associate blkg when associating a device")
Signed-off-by: Dennis Zhou 
Cc: Josef Bacik 
Signed-off-by: Jens Axboe