linux-toradex.git/drivers/md/dm-mpath.c, branch v4.6-rc1

dm mpath: cleanup reinstate_path() et al based on code review

2016-03-10T22:12:04+00:00

fail_path() will print a "Failing path ..." message but reinstate_path()
doesn't print a "Reinstating path ...".  Add that message to
reinstate_path() to add symmetry and aid system debugging.

Remove reinstate_path()'s check for the path_selector providing
.reinstate_path hook.  All path selectors provide this and any future
ones must too.

activate_path() calls pg_init_done() with SCSI_DH_DEV_OFFLINED but
pg_init_done() doesn't expicitly handle it in its swicth statement.  Add
SCSI_DH_DEV_OFFLINED to the default case.

Signed-off-by: Mike Snitzer

dm mpath: remove __pgpath_busy forward declaration, rename to pgpath_busy

2016-02-23T03:34:44+00:00

Signed-off-by: Mike Snitzer

dm mpath: switch from 'unsigned' to 'bool' for flags where appropriate

2016-02-23T03:34:43+00:00

Signed-off-by: Mike Snitzer

dm path selector: remove 'repeat_count' return from .select_path hook

2016-02-23T03:34:42+00:00

If a path selector has any use for a repeat_count it should be handled
locally and not depend on the dm-mpath core to be concerned with it.

Signed-off-by: Mike Snitzer

dm mpath: remove repeat_count support from multipath core

2016-02-23T03:34:40+00:00

Preparation for making __multipath_map() avoid taking the m->lock
spinlock -- in favor of using RCU locking.

repeat_count was primarily for bio-based DM multipath's benefit.  There
is really no need for it anymore now that DM multipath is request-based.
As such, repeat_count > 1 is no longer honored and a warning is
displayed if the user attempts to use a value > 1.  This is a temporary
change for the round-robin path-selector (as a later commit will restore
its support for repeat_count > 1).

Signed-off-by: Mike Snitzer

dm mpath: remove unnecessary casts in front of ti->private

2016-02-23T03:34:40+00:00

Signed-off-by: Mike Snitzer

dm mpath: use blk_mq_alloc_request() and blk_mq_free_request() directly

2016-02-23T03:34:39+00:00

There isn't any need to support both old .request_fn and blk-mq paths
in the blk-mq specific portion of __multipath_map().  Call
blk_mq_alloc_request() directly rather than use blk_get_request().

Similarly, call blk_mq_free_request(), rather than blk_put_request(), in
multipath_release_clone().

Signed-off-by: Mike Snitzer

dm mpath: cleanup 'struct dm_mpath_io' management code

2016-02-23T03:34:39+00:00

Refactor and rename existing interfaces to be more specific and
self-documenting.

Signed-off-by: Mike Snitzer

dm mpath: use blk-mq pdu for per-request 'struct dm_mpath_io'

2016-02-23T03:34:38+00:00

Allow the multipath target to avoid making small allocations for each
'struct dm_mpath_io' that is needed for each request.

Signed-off-by: Mike Snitzer

dm: distinquish old .request_fn (dm-old) vs dm-mq request-based DM

2016-02-23T03:34:33+00:00

Rename various methods to have either a "dm_old" or "dm_mq" prefix.
Improve code comments to assist with understanding the duality of code
that handles both "dm_old" and "dm_mq" cases.

It is no much easier to quickly look at the code and _know_ that a given
method is either 1) "dm_old" only 2) "dm_mq" only 3) common to both.

Signed-off-by: Mike Snitzer