dm vdo logger: change from uds_ to vdo_ namespace

Rename all uds_log_* to vdo_log_*.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Chung Chung <cchung@redhat.com>
Signed-off-by: Matthew Sakai <msakai@redhat.com>

dm vdo permassert: audit all of ASSERT to test for VDO_SUCCESS

Also rename ASSERT to VDO_ASSERT and ASSERT_LOG_ONLY to
VDO_ASSERT_LOG_ONLY.

But re-introduce ASSERT and ASSERT_LOG_ONLY as a placeholder
for the benefit of dm-vdo/indexer.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Matthew Sakai <msakai@redhat.com>

dm vdo memory-alloc: change from uds_ to vdo_ namespace

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Matthew Sakai <msakai@redhat.com>

dm vdo: fix various function names referenced in comment blocks

No functional modification involved.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Matthew Sakai <msakai@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

dm vdo flush: initialize return to NULL in allocate_flush

Otherwise, error path could result in allocate_flush's subsequent
check for flush being non-NULL leading to false positive.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Susan LeGendre-McGhee <slegendr@redhat.com>
Signed-off-by: Matthew Sakai <msakai@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

dm vdo: cleanup style for comments in structs

Use /* ... */ rather than /** ... */ if for no other reason than
syntax highlighting is improved (at least for me, in emacs: comments
are now red, code is yellow. Previously comments were also yellow).

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Susan LeGendre-McGhee <slegendr@redhat.com>
Signed-off-by: Matthew Sakai <msakai@redhat.com>

dm vdo wait-queue: rename to vdo_waitq_dequeue_waiter

Rename vdo_waitq_dequeue_next_waiter to vdo_waitq_dequeue_waiter. The
"next" aspect of returned waiter is implied. "next" also isn't
informative ("oldest" would be). Removing "next_" adds symmetry to
vdo_waitq_enqueue_waiter().

Also fix whitespace and comments from previous waitq commit.

Reviewed-by: Ken Raeburn <raeburn@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Matthew Sakai <msakai@redhat.com>

dm vdo wait-queue: add proper namespace to interface

Rename various interfaces and structs associated with vdo's wait-queue,
e.g.: s/wait_queue/vdo_wait_queue/, s/waiter/vdo_waiter/, etc.

Now all function names start with "vdo_waitq_" or "vdo_waiter_".

Reviewed-by: Ken Raeburn <raeburn@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Matthew Sakai <msakai@redhat.com>

dm vdo: add flush support

This patch adds support for handling incoming flush and/or FUA bios. Each
such bio is assigned to a struct vdo_flush. These are allocated as needed,
but there is always one kept in reserve in case allocations fail. In the
event of an allocation failure, bios may need to wait for an outstanding
flush to complete.

The logical address space is partitioned into logical zones, each handled
by its own thread. Each zone keeps a list of all data_vios handling write
requests for logical addresses in that zone. When a flush bio is processed,
each logical zone is informed of the flush. When all of the writes which
are in progress at the time of the notification have completed in all
zones, the flush bio is then allowed to complete.

Co-developed-by: J. corwin Coburn <corwin@hurlbutnet.net>
Signed-off-by: J. corwin Coburn <corwin@hurlbutnet.net>
Co-developed-by: Michael Sclafani <dm-devel@lists.linux.dev>
Signed-off-by: Michael Sclafani <dm-devel@lists.linux.dev>
Co-developed-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me>
Signed-off-by: Matthew Sakai <msakai@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>