linux.git/drivers/md/dm-rq.h, branch v6.17.10

dm: change "unsigned" to "unsigned int"

2023-02-14T19:23:06+00:00

Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer

dm: add missing SPDX-License-Indentifiers

2023-02-14T19:23:06+00:00

'GPL-2.0-only' is used instead of 'GPL-2.0' because SPDX has
deprecated its use.

Suggested-by: John Wiele 
Signed-off-by: Heinz Mauelshagen 
Signed-off-by: Mike Snitzer

dm: remove unused _rq_tio_cache and _rq_cache

2019-03-05T19:48:50+00:00

Also move dm_rq_target_io structure definition from dm-rq.h to dm-rq.c

Fixes: 6a23e05c2fe3c6 ("dm: remove legacy request-based IO path")
Signed-off-by: Mike Snitzer

dm: remove legacy request-based IO path

2018-10-11T15:36:09+00:00

dm supports both, and since we're killing off the legacy path in
general, get rid of it in dm.

Signed-off-by: Jens Axboe 
Signed-off-by: Mike Snitzer

dm rq: do not update rq partially in each ending bio

2017-08-28T14:23:28+00:00

We don't need to update the original dm request partially when ending
each cloned bio: just update original dm request once when the whole
cloned request is finished.  This still allows full support for partial
completion because a new 'completed' counter accounts for incremental
progress as the clone bios complete.

Partial request update can be a bit expensive, so we should try to avoid
it, especially because it is run in softirq context.

Avoiding all the partial request updates fixes both hard lockup and
soft lockups that were easily reproduced while running Laurence's
test[1] on IB/SRP.

BTW, after d4acf3650c7c ("block: Make blk_mq_delay_kick_requeue_list()
rerun the queue at a quiet time"), we need to make the test more
aggressive for reproducing the lockup:

	1) run hammer_write.sh 32 or 64 concurrently.
	2) write 8M each time

[1] https://marc.info/?l=linux-block&m=150220185510245&w=2

Signed-off-by: Ming Lei 
Signed-off-by: Mike Snitzer

block: introduce new block status code type

2017-06-09T15:27:32+00:00

Currently we use nornal Linux errno values in the block layer, and while
we accept any error a few have overloaded magic meanings.  This patch
instead introduces a new  blk_status_t value that holds block layer specific
status codes and explicitly explains their meaning.  Helpers to convert from
and to the previous special meanings are provided for now, but I suspect
we want to get rid of them in the long run - those drivers that have a
errno input (e.g. networking) usually get errnos that don't know about
the special block layer overloads, and similarly returning them to userspace
will usually return somethings that strictly speaking isn't correct
for file system operations, but that's left as an exercise for later.

For now the set of errors is a very limited set that closely corresponds
to the previous overloaded errno values, but there is some low hanging
fruite to improve it.

blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
typechecking, so that we can easily catch places passing the wrong values.

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

dm: always defer request allocation to the owner of the request_queue

2017-01-27T22:08:35+00:00

DM already calls blk_mq_alloc_request on the request_queue of the
underlying device if it is a blk-mq device.  But now that we allow drivers
to allocate additional data and initialize it ahead of time we need to do
the same for all drivers.   Doing so and using the new cmd_size
infrastructure in the block layer greatly simplifies the dm-rq and mpath
code, and should also make arbitrary combinations of SQ and MQ devices
with SQ or MQ device mapper tables easily possible as a further step.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Hannes Reinecke 
Reviewed-by: Mike Snitzer 
Signed-off-by: Jens Axboe

dm rq: introduce dm_mq_kick_requeue_list()

2016-09-15T15:16:05+00:00

Make it possible for a request-based target to kick the DM device's
blk-mq request_queue's requeue_list.

Signed-off-by: Mike Snitzer 
Reviewed-by: Hannes Reinecke

dm mpath: add optional "queue_mode" feature

2016-06-10T19:16:02+00:00

Allow a user to specify an optional feature 'queue_mode ' where
 may be "bio", "rq" or "mq" -- which corresponds to bio-based,
request_fn rq-based, and blk-mq rq-based respectively.

If the queue_mode feature isn't specified the default for the
"multipath" target is still "rq" but if dm_mod.use_blk_mq is set to Y
it'll default to mode "mq".

This new queue_mode feature introduces the ability for each multipath
device to have its own queue_mode (whereas before this feature all
multipath devices effectively had to have the same queue_mode).

This commit also goes a long way to eliminate the awkward (ab)use of
DM_TYPE_*, the associated filter_md_type() and other relatively fragile
and difficult to maintain code.

Signed-off-by: Mike Snitzer

dm: move request-based code out to dm-rq.[hc]

2016-06-10T19:15:44+00:00

Add some seperation between bio-based and request-based DM core code.

'struct mapped_device' and other DM core only structures and functions
have been moved to dm-core.h and all relevant DM core .c files have been
updated to include dm-core.h rather than dm.h

DM targets should _never_ include dm-core.h!

[block core merge conflict resolution from Stephen Rothwell]
Signed-off-by: Mike Snitzer 
Signed-off-by: Stephen Rothwell