linux-toradex.git/drivers/block/drbd/drbd_protocol.h, branch v4.11

drbd: introduce WRITE_SAME support

2016-06-14T03:43:07+00:00

We will support WRITE_SAME, if
 * all peers support WRITE_SAME (both in kernel and DRBD version),
 * all peer devices support WRITE_SAME
 * logical_block_size is identical on all peers.

We may at some point introduce a fallback on the receiving side
for devices/kernels that do not support WRITE_SAME,
by open-coding a submit loop. But not yet.

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe

drbd: Create the protocol feature THIN_RESYNC

2016-06-14T03:43:04+00:00

If thinly provisioned volumes are used, during a resync the sync source
tries to find out if a block is deallocated. If it is deallocated, then
the resync target uses block_dev_issue_zeroout() on the range in
question.

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe

drbd: Implement handling of thinly provisioned storage on resync target nodes

2016-06-14T03:43:04+00:00

If during resync we read only zeroes for a range of sectors assume
that these secotors can be discarded on the sync target node.

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe

block, drivers, fs: rename REQ_FLUSH to REQ_PREFLUSH

2016-06-07T19:41:38+00:00

To avoid confusion between REQ_OP_FLUSH, which is handled by
request_fn drivers, and upper layers requesting the block layer
perform a flush sequence along with possibly a WRITE, this patch
renames REQ_FLUSH to REQ_PREFLUSH.

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

drbd: Create a dedicated workqueue for sending acks on the control connection

2015-11-25T16:22:01+00:00

The intention is to reduce CPU utilization. Recent measurements
unveiled that the current performance bottleneck is CPU utilization
on the receiving node. The asender thread became CPU limited.

One of the main points is to eliminate the idr_for_each_entry() loop
from the sending acks code path.

One exception in that is sending back ping_acks. These stay
in the ack-receiver thread. Otherwise the logic becomes too
complicated for no added value.

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe

drbd: Enable QUEUE_FLAG_DISCARD only if the peer can recieve P_TRIM

2014-04-30T19:46:55+00:00

Allow the user of REQ_DISCARD.

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe

drbd: prepare receiving side for REQ_DISCARD

2014-04-30T19:46:55+00:00

If the receiver needs to serve a discard request on a queue that does
not announce to be discard cabable, it falls back to do synchronous
blkdev_issue_zeroout().

We expect only "reasonably" large (up to one activity log extent?)
discard requests.

We do this to not to not block the receiver for too long in this
fallback code path, and to not set/clear too many bits inside one
spinlock_irq_save() in drbd_set_in_sync/drbd_set_out_of_sync,

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe

drbd: Split off on-the-wire protocol definitions

2014-02-17T15:27:49+00:00

Keep the protocol definitions separate from the kernel code; they are useful in
their own right.

Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Philipp Reisner