linux-toradex.git/include/linux/device-mapper.h, branch v4.4-rc6

dm: refactor ioctl handling

2015-10-31T23:05:59+00:00

This moves the call to blkdev_ioctl and the argument checking to DM core
code, and only leaves a callout to find the block device to operate on
in the targets.  This simplifies the code and allows us to pass through
ioctl-like command using other methods in the next patch.

Also split out a helper around calling the prepare_ioctl method that
will be reused for persistent reservation handling.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Mike Snitzer

block: kill merge_bvec_fn() completely

2015-08-13T18:31:57+00:00

As generic_make_request() is now able to handle arbitrarily sized bios,
it's no longer necessary for each individual block driver to define its
own ->merge_bvec_fn() callback. Remove every invocation completely.

Cc: Jens Axboe 
Cc: Lars Ellenberg 
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina 
Cc: Yehuda Sadeh 
Cc: Sage Weil 
Cc: Alex Elder 
Cc: ceph-devel@vger.kernel.org
Cc: Alasdair Kergon 
Cc: Mike Snitzer 
Cc: dm-devel@redhat.com
Cc: Neil Brown 
Cc: linux-raid@vger.kernel.org
Cc: Christoph Hellwig 
Cc: "Martin K. Petersen" 
Acked-by: NeilBrown  (for the 'md' bits)
Acked-by: Mike Snitzer 
Signed-off-by: Kent Overstreet 
[dpark: also remove ->merge_bvec_fn() in dm-thin as well as
 dm-era-target, and resolve merge conflicts]
Signed-off-by: Dongsu Park 
Signed-off-by: Ming Lin 
Signed-off-by: Jens Axboe

dm: remove unnecessary wrapper around blk_lld_busy

2015-03-31T16:03:49+00:00

There is no need for DM to export a wrapper around the already exported
blk_lld_busy().

Signed-off-by: Mike Snitzer

dm snapshot: suspend merging snapshot when doing exception handover

2015-02-27T19:53:16+00:00

The "dm snapshot: suspend origin when doing exception handover" commit
fixed a exception store handover bug associated with pending exceptions
to the "snapshot-origin" target.

However, a similar problem exists in snapshot merging.  When snapshot
merging is in progress, we use the target "snapshot-merge" instead of
"snapshot-origin".  Consequently, during exception store handover, we
must find the snapshot-merge target and suspend its associated
mapped_device.

To avoid lockdep warnings, the target must be suspended and resumed
without holding _origins_lock.

Introduce a dm_hold() function that grabs a reference on a
mapped_device, but unlike dm_get(), it doesn't crash if the device has
the DMF_FREEING flag set, it returns an error in this case.

In snapshot_resume() we grab the reference to the origin device using
dm_hold() while holding _origins_lock (_origins_lock guarantees that the
device won't disappear).  Then we release _origins_lock, suspend the
device and grab _origins_lock again.

NOTE to stable@ people:
When backporting to kernels 3.18 and older, use dm_internal_suspend and
dm_internal_resume instead of dm_internal_suspend_fast and
dm_internal_resume_fast.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer 
Cc: stable@vger.kernel.org

dm: allocate requests in target when stacking on blk-mq devices

2015-02-09T18:06:47+00:00

For blk-mq request-based DM the responsibility of allocating a cloned
request is transfered from DM core to the target type.  Doing so
enables the cloned request to be allocated from the appropriate
blk-mq request_queue's pool (only the DM target, e.g. multipath, can
know which block device to send a given cloned request to).

Care was taken to preserve compatibility with old-style block request
completion that requires request-based DM _not_ acquire the clone
request's queue lock in the completion path.  As such, there are now 2
different request-based DM target_type interfaces:
1) the original .map_rq() interface will continue to be used for
   non-blk-mq devices -- the preallocated clone request is passed in
   from DM core.
2) a new .clone_and_map_rq() and .release_clone_rq() will be used for
   blk-mq devices -- blk_get_request() and blk_put_request() are used
   respectively from these hooks.

dm_table_set_type() was updated to detect if the request-based target is
being stacked on blk-mq devices, if so DM_TYPE_MQ_REQUEST_BASED is set.
DM core disallows switching the DM table's type after it is set.  This
means that there is no mixing of non-blk-mq and blk-mq devices within
the same request-based DM table.

[This patch was started by Keith and later heavily modified by Mike]

Tested-by: Bart Van Assche 
Signed-off-by: Keith Busch 
Signed-off-by: Mike Snitzer

dm: remove exports for request-based interfaces without external callers

2015-02-09T17:59:48+00:00

Remove exports for dm_dispatch_request, dm_requeue_unmapped_request,
and dm_kill_unmapped_request.

Signed-off-by: Mike Snitzer

dm: add presuspend_undo hook to target_type

2014-11-19T16:24:59+00:00

The DM thin-pool target now must undo the changes performed during
pool_presuspend() so introduce presuspend_undo hook in target_type.

Signed-off-by: Mike Snitzer 
Acked-by: Joe Thornber

dm: remove symbol export for dm_set_device_limits

2014-06-04T13:46:34+00:00

There is no need for code other than DM core to use dm_set_device_limits
so remove its EXPORT_SYMBOL_GPL.  Also, cleanup a couple whitespace nits.

Signed-off-by: Mike Snitzer

dm: introduce dm_accept_partial_bio

2014-06-03T17:44:06+00:00

The function dm_accept_partial_bio allows the target to specify how many
sectors of the current bio it will process.  If the target only wants to
accept part of the bio, it calls dm_accept_partial_bio and the DM core
sends the rest of the data in next bio.

Signed-off-by: Mikulas Patocka 
Signed-off-by: Mike Snitzer

dm table: add dm_table_run_md_queue_async

2014-03-27T20:56:24+00:00

Introduce dm_table_run_md_queue_async() to run the request_queue of the
mapped_device associated with a request-based DM table.

Also add dm_md_get_queue() wrapper to extract the request_queue from a
mapped_device.

Signed-off-by: Mike Snitzer 
Signed-off-by: Hannes Reinecke 
Reviewed-by: Jun'ichi Nomura