Commit Graph

1254 Commits

Author SHA1 Message Date
Lai Jiangshan
e9f05b4cfe drbd: use RB_DECLARE_CALLBACKS() to define augment callbacks
The original code are the same as RB_DECLARE_CALLBACKS().

CC: Michel Lespinasse <walken@google.com>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-18 09:00:17 -06:00
Lai Jiangshan
82cfb90bc9 drbd: compute the end before rb_insert_augmented()
Commit 98683650 "Merge branch 'drbd-8.4_ed6' into
for-3.8-drivers-drbd-8.4_ed6" switches to the new augment API, but the
new API requires that the tree is augmented before rb_insert_augmented()
is called, which is missing.

So we add the augment-code to drbd_insert_interval() when it travels the
tree up to down before rb_insert_augmented().  See the example in
include/linux/interval_tree_generic.h or Documentation/rbtree.txt.

drbd_insert_interval() may cancel the insertion when traveling, in this
case, the just added augment-code does nothing before cancel since the
@this node is already in the subtrees in this case.

CC: Michel Lespinasse <walken@google.com>
CC: stable@kernel.org # v3.10+
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-18 09:00:16 -06:00
Philipp Reisner
590001c229 drbd: Add missing newline in resync progress display in /proc/drbd
Was broken in 2010 with commit 4b0715f096

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-11 08:41:29 -06:00
Lars Ellenberg
729e8b87ba drbd: reduce lock contention in drbd_worker
The worker may now dequeue work items in batches.
This should reduce lock contention during busy periods.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-11 08:41:29 -06:00
Lars Ellenberg
abde9cc6a5 drbd: Improve asender performance
Shorten receive path in the asender thread. Reduces CPU utilisation
of asender when receiving packets, and with that increases IOPs.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-11 08:41:29 -06:00
Andreas Gruenbacher
b47a06d105 drbd: Get rid of the WORK_PENDING macro
This macro doesn't add any value; just use test_bit() instead.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-11 08:41:29 -06:00
Andreas Gruenbacher
d1b8085356 drbd: Get rid of the __no_warn and __cond_lock macros
These macros can easily be replaced with its definition.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-11 08:41:29 -06:00
Andreas Gruenbacher
8d4ba3f0fa drbd: Avoid inconsistent locking warning
request_timer_fn() takes resource->req_lock via the device and releases it via
the connection.  Avoid this as it is confusing static code checkers.

Reported-by: "Dan Carpenter" <dan.carpenter@oracle.com>
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-11 08:41:29 -06:00
Philipp Marek
f0c21e6228 drbd: Remove superfluous newline from "resync_extents" debugfs entry.
See "drbd/resources/*/volumes/*/resync_extents".

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-11 08:41:29 -06:00
Andreas Gruenbacher
ed15b79509 drbd: Use consistent names for all the bi_end_io callbacks
Now they follow the _endio naming sheme.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-11 08:41:29 -06:00
Andreas Gruenbacher
11f8b2b69d drbd: Use better variable names
Rename local variable 'ds' to 'disk_state' or 'data_size'.
'dgs' to 'digest_size'

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-09-11 08:41:29 -06:00
Linus Torvalds
d429a3639c Merge branch 'for-3.17/drivers' of git://git.kernel.dk/linux-block
Pull block driver changes from Jens Axboe:
 "Nothing out of the ordinary here, this pull request contains:

   - A big round of fixes for bcache from Kent Overstreet, Slava Pestov,
     and Surbhi Palande.  No new features, just a lot of fixes.

   - The usual round of drbd updates from Andreas Gruenbacher, Lars
     Ellenberg, and Philipp Reisner.

   - virtio_blk was converted to blk-mq back in 3.13, but now Ming Lei
     has taken it one step further and added support for actually using
     more than one queue.

   - Addition of an explicit SG_FLAG_Q_AT_HEAD for block/bsg, to
     compliment the the default behavior of adding to the tail of the
     queue.  From Douglas Gilbert"

* 'for-3.17/drivers' of git://git.kernel.dk/linux-block: (86 commits)
  bcache: Drop unneeded blk_sync_queue() calls
  bcache: add mutex lock for bch_is_open
  bcache: Correct printing of btree_gc_max_duration_ms
  bcache: try to set b->parent properly
  bcache: fix memory corruption in init error path
  bcache: fix crash with incomplete cache set
  bcache: Fix more early shutdown bugs
  bcache: fix use-after-free in btree_gc_coalesce()
  bcache: Fix an infinite loop in journal replay
  bcache: fix crash in bcache_btree_node_alloc_fail tracepoint
  bcache: bcache_write tracepoint was crashing
  bcache: fix typo in bch_bkey_equal_header
  bcache: Allocate bounce buffers with GFP_NOWAIT
  bcache: Make sure to pass GFP_WAIT to mempool_alloc()
  bcache: fix uninterruptible sleep in writeback thread
  bcache: wait for buckets when allocating new btree root
  bcache: fix crash on shutdown in passthrough mode
  bcache: fix lockdep warnings on shutdown
  bcache allocator: send discards with correct size
  bcache: Fix to remove the rcu_sched stalls.
  ...
2014-08-14 09:10:21 -06:00
Dan Carpenter
bf0d6e4a11 drbd: silence underflow warning in read_in_block()
My static checker warns that "data_size" could be negative and underflow
the limit check.  The code looks suspicious but I don't know if it is a
real bug.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:23 +02:00
Lars Ellenberg
1e39152fea drbd: implicitly truncate cpu-mask
Don't error out with misleading "out of memory"
if the cpu-mask has more bits set than there are CPUs.
Just truncate to nr_cpu_ids implicitly.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:22 +02:00
Lars Ellenberg
193cb00ce3 drbd: drop spurious parameters from _drbd_md_sync_page_io
size is always 4096,
page is always device->md_io.page.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:22 +02:00
Lars Ellenberg
f5b90b6bf0 drbd: resync should only lock out specific ranges
During resync, if we need to block some specific incoming write because
of active resync requests to that same range, we potentially caused
*all* new application writes (to "cold" activity log extents) to block
until this one request has been processed.

Improve the do_submit() logic to
 * grab all incoming requests to some "incoming" list
 * process this list
   - move aside requests that are blocked by resync
   - prepare activity log transactions,
   - commit transactions and submit corresponding requests
   - if there are remaining requests that only wait for
     activity log extents to become free, stop the fast path
     (mark activity log as "starving")
   - iterate until no more requests are waiting for the activity log,
     but all potentially remaining requests are only blocked by resync
 * only then grab new incoming requests

That way, very busy IO on currently "hot" activity log extents cannot
starve scattered IO to "cold" extents. And blocked-by-resync requests
are processed once resync traffic on the affected region has ceased,
without blocking anything else.

The only blocking mode left is when we cannot start requests to "cold"
extents because all currently "hot" extents are actually used.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:21 +02:00
Lars Ellenberg
cc356f85bb drbd: debugfs: add per device data_gen_id
The data generation identifiers used to be exposed via sysfs
at /sys/block/drbdX/drbd/meta_data/data_gen_id (out-of-tree),
for advanced policy scripting.
Bring that information over to debugfs.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:21 +02:00
Lars Ellenberg
3d299f48a9 drbd: debugfs: add per connection oldest requests
Information of former /sys/block/drbdX/drbd/oldest_requests
is already with higher detail in these files:
 debugfs/drbd/resource/$name/in_flight_summary,
 debugfs/drbd/resource/$name/volumes/$vnr/oldest_requests

This patch adds
 debugfs/drbd/resource/$name/connections/peer/oldest_requests

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:20 +02:00
Lars Ellenberg
b44e1184fc drbd: debugfs: add version tag to debugfs files
Make the first line of debugfs files a version number,
starting now with "v: 0".

If we change content of presentation, we will bump that.
Monitoring or diagnostic scritps that may parse these files
can then easily know when they need to be reviewed.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:19 +02:00
Lars Ellenberg
54e6fc38e8 drbd: debugfs: add per volume oldest_requests
Show oldest requests
 * pending master bio completion and,
 * if different, local disk bio completion.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:19 +02:00
Lars Ellenberg
944410e97c drbd: debugfs: add callback_history
Add a per-connection worker thread callback_history
with timing details, call site and callback function.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:18 +02:00
Lars Ellenberg
f418815f7a drbd: debugfs: Add in_flight_summary
* Add details about pending meta data operations to in_flight_summary.

* Report number of requests waiting for activity log transactions.

* timing details of peer_requests to in_flight_summary.

* FLUSH details
  DRBD devides the incoming request stream into "epochs",
  in which peers are allowed to re-order writes independendly.

  These epochs are separated by P_BARRIER on the replication link.
  Such barrier packets, depending on configuration, may cause
  the receiving side to drain the lower level device request queues
  and call blkdev_issue_flush().

  This is known to be an other major source of latency in DRBD.

  Track timing details of calls to blkdev_issue_flush(),
  and add them to in_flight_summary.

* data socket stats
  To be able to diagnose bottlenecks and root causes of "slow" IO on DRBD,
  it is useful to see network buffer stats along with the timing details of
  requests, peer requests, and meta data IO.

* pending bitmap IO timing details to in_flight_summary.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:17 +02:00
Lars Ellenberg
4a521cca9b drbd: debugfs: deal with destructor racing with open of debugfs file
Try to close the race between open() and debugfs_remove_recursive()
from inside an object destructor.
Once open succeeds, the object should stay around.
Open should not succeed if the object has already reached its destructor.

This may be overkill, but to make that happen, we check for existence of
a parent directory, "stale-ness" of "this" dentry, and serialize
kref_get_unless_zero() on the outermost object relevant for this file
with d_delete() on this dentry (using the parent's i_mutex).

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:17 +02:00
Lars Ellenberg
db1866ffee drbd: debugfs: add in_flight_summary data
To help diagnosing "high latency" or "hung" IO situations on DRBD,
present per drbd resource group a summary of operations currently in progress.

First item is a list of oldest drbd_request objects
waiting for various things:
 * still being prepared
 * waiting for activity log transaction
 * waiting for local disk
 * waiting to be sent
 * waiting for peer acknowledgement ("receive ack", "write ack")
 * waiting for peer epoch acknowledgement ("barrier ack")

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:16 +02:00
Lars Ellenberg
4d3d5aa83a drbd: debugfs: add basic hierarchy
Add new debugfs hierarchy /sys/kernel/debug/
  drbd/
    resources/
      $resource_name/connections/peer/$volume_number/
      $resource_name/volumes/$volume_number/
    minors/$minor_number -> ../resources/$resource_name/volumes/$volume_number/

Followup commits will populate this hierarchy with files containing
statistics, diagnostic information and some attribute data.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:16 +02:00
Lars Ellenberg
4ce4926683 drbd: track details of bitmap IO
Track start and submit time of bitmap operations, and
add pending bitmap IO contexts to a new pending_bitmap_io list.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:15 +02:00
Lars Ellenberg
c5a2c1509e drbd: register peer requests on read_ee early
Initialize peer_request with timestamp and proper empty list head.
Add peer_request to list early, so debugfs can find this request and
report it as "preparing", even if we sleep before we actually submit it.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:14 +02:00
Lars Ellenberg
21ae5d7f95 drbd: track timing details of peer_requests
To be able to present timing details in debugfs,
we need to track preparation/submit times of peer requests.

Track peer request flags early,
before they are put on the epoch_entry lists.

Waiting for activity log transactions may be a major latency factor.
We want to be able to present the peer_request state accurately in
debugfs, and what it is waiting for.

Consistently mark/unmark peer requests with EE_CALL_AL_COMPLETE_IO.
Set it only *after* calling drbd_al_begin_io(),
clear it as soon as we call drbd_al_complete_io().

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:14 +02:00
Lars Ellenberg
ad3fee7900 drbd: improve throttling decisions of background resynchronisation
Background resynchronisation does some "side-stepping", or throttles
itself, if it detects application IO activity, and the current resync
rate estimate is above the configured "cmin-rate".

What was not detected: if there is no application IO,
because it blocks on activity log transactions.

Introduce a new atomic_t ap_actlog_cnt, tracking such blocked requests,
and count non-zero as application IO activity.
This counter is exposed at proc_details level 2 and above.

Also make sure to release the currently locked resync extent
if we side-step due to such voluntary throttling.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:13 +02:00
Lars Ellenberg
7753a4c17f drbd: add caching oldest request pointers for replication stages
A request that is to be shipped to the peer goes through a few stages:
- queued
- sent, waiting for ack
- ack received, waiting for "barrier ack", which is re-order epoch being
  closed on the peer by acknowledging a "cache flush" equivalent
  on the lower level device.

In the later two stages, depending on protocol, we may have already
completed this request to the upper layers, so it won't be found anymore
on device->pending_master_completion[] lists.

Track the oldest request yet to be sent (req_next), the oldest not yet
acknowledged (req_ack_pending) and the oldest "still waiting for
something from the peer" (req_not_net_done), doing short list walks on
the transfer log to find the next pending one whenever such a request
makes progress.

Now we have a fast way to look up the oldest requests,
don't do a transfer log walk every time.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:12 +02:00
Lars Ellenberg
844a6ae735 drbd: add lists to find oldest pending requests
Adding requests to per-device fifo lists as soon as possible after
allocating them leaves a simple list_first_entry_or_null() to find the
oldest request, regardless what it is still waiting for.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:12 +02:00
Lars Ellenberg
e5f891b223 drbd: gather detailed timing statistics for drbd_requests
Record (in jiffies) how much time a request spends in which stages.
Followup commits will use and present this additional timing information
so we can better locate and tackle the root causes of latency spikes,
or present the backlog for asynchronous replication.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:11 +02:00
Lars Ellenberg
e37d2438d8 drbd: track meta data IO intent, start and submit time
For diagnostic purposes, track intent, start time
and latest submit time of meta data IO.

Move separate members from struct drbd_device
into the embeded struct drbd_md_io.
s/md_io_(page|in_use)/md_io.\1/

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:10 +02:00
Lars Ellenberg
a8ba0d6069 drbd: fix drbd_destroy_device reference count updates
drbd_destroy_device means to give up reference counts
on the connection(s) reachable via the peer_device(s).

It must not do that by iterating via device->resource->connections,
resource and connections may have already been disassociated
by drbd_free_resource, and we'd leak connection refs.

Instead, iterate via device->peer_devices->connection.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:10 +02:00
Lars Ellenberg
c2258ffc56 drbd: poison free'd device, resource and connection structs
Now that we have additional asynchronous kref_get/kref_put
via debugfs, make sure we catch access after free.

Poison struct drbd_device, drbd_connection and drbd_resource
before kfree() with 0xfd, 0xfc, and 0xf2, respectively.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:09 +02:00
Lars Ellenberg
45d2933c92 drbd: also keep track of trim -> zero-out fallback peer_requests
To be able to find and present such zero-out fallback peer_requests
in debugfs, we add those to "active_ee", once that list drained.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:09 +02:00
Lars Ellenberg
b9ed7080d7 drbd: consistently use list_add_tail for peer_request tracking
Keep the epoch entry lists (active_ee, read_ee, sync_ee, ...)
consistently "oldest first".  That way finding the oldest not yet
successfully processed request is simply list_first_entry_or_null.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:08 +02:00
Lars Ellenberg
41d9f7cd5b drbd: drop drbd_md_flush
The only user of drbd_md_flush was bm_rw(),
and it is always followed by either a drbd_md_sync(),
or an al_write_transaction(), which, if so configured,
both end up submiting a FLUSH|FUA request anyways.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:07 +02:00
Lars Ellenberg
15e26f6a3c drbd: add drbd_queue_work_if_unqueued helper
We sometimes do
    if (list_empty(&w.list))
	drbd_queue_work(&q, &w.list);

Removal (list_del_init) may happen outside all locks, after all
pending work entries have been moved to an on-stack local work list.

For not dynamically allocated, but embeded, work structs,
we must avoid to re-add until it really was removed.

Move that list_empty check inside the spin_lock(&q->q_lock)
within the helper function, and change to list_empty_careful().

This may have been the reason for a list_add corruption
inside drbd_queue_work().

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:07 +02:00
Lars Ellenberg
7f34f61490 drbd: drbd_rs_number_requests: fix unit mismatch in comparison
We try to limit the number of "in-flight" resync requests.
One condition for that is the amount of requested data should not exceed
half of what can be covered by our "max-buffers" setting.

However we compared number of 4k pages with number of in-flight 512 Byte
sectors, and this extra throttle triggered much earlier than intended.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:06 +02:00
Lars Ellenberg
f88c5d90cc drbd: cosmetic: change all printk(level, ...) to pr_<level>(...)
Cosmetic change only.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:05 +02:00
Lars Ellenberg
2f2abeae3c drbd: clear CRASHED_PRIMARY only after successful resync
If we lost a disk during the first resync after primary crash,
we could have prematurely cleared the CRASHED_PRIMARY flag.
Testing on C_CONNECTED is not what we meant there,
but testing for both peers to become D_UP_TO_DATE.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:05 +02:00
Lars Ellenberg
506afb6248 drbd: improve resync request throttling due to sendbuf size
If we throttle resync because the socket sendbuffer is filling up,
tell TCP about it, so it may expand the sendbuffer for us.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:04 +02:00
Joe Perches
659b2e3bb8 block: Convert last uses of __FUNCTION__ to __func__
Just about all of these have been converted to __func__,
so convert the last uses.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:04 +02:00
Monam Agarwal
ccdd6a93ee drivers/block: Use RCU_INIT_POINTER(x, NULL) in drbd/drbd_state.c
This patch replaces rcu_assign_pointer(x, NULL) with RCU_INIT_POINTER(x, NULL)

The rcu_assign_pointer() ensures that the initialization of a structure
is carried out before storing a pointer to that structure.
And in the case of the NULL pointer, there is no structure to initialize.
So, rcu_assign_pointer(p, NULL) can be safely converted to RCU_INIT_POINTER(p, NULL)

Signed-off-by: Monam Agarwal <monamagarwal123@gmail.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:03 +02:00
Lars Ellenberg
0c066bc39e drbd: short-circuit in maybe_pull_ahead
If we already "pulled ahead", we can short-circuit,
and avoid logging the same messages over and over again.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:02 +02:00
Lars Ellenberg
08d0dabf48 drbd: application writes may set-in-sync in protocol != C
If "dirty" blocks are written to during resync,
that brings them in-sync.

By explicitly requesting write-acks during resync even in protocol != C,
we now can actually respect this.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:02 +02:00
Philipp Reisner
5d0b17f1a2 drbd: New net configuration option socket-check-timeout
In setups involving a DRBD-proxy and connections that experience a lot of
buffer-bloat it might be necessary to set ping-timeout to an
unusual high value. By default DRBD uses the same value to wait if a newly
established TCP-connection is stable. Since the DRBD-proxy is usually located
in the same data center such a long wait time may hinder DRBD's connect process.

In such setups socket-check-timeout should be set to
at least to the round trip time between DRBD and DRBD-proxy. I.e. in most
cases to 1.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:01 +02:00
Philipp Reisner
4920e37a9e drbd: Limit the time we are waiting for the first packet on an accepted socket
Before the patch
'drbd: Keep the listening socket open while trying to connect to the peer'

the newly created socket inherited the receive timeout from the listen
socket. The listen socket had a receive timeout of connect-intervall
+- 30% random jitter.

The real issue is that after the mentioned patch we had no timeout at all.
Now use 4 times the ping-timeout.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:00 +02:00
Lars Ellenberg
aaaba34576 drbd: implement csums-after-crash-only
Checksum based resync trades CPU cycles for network bandwidth,
in situations where we expect much of the to-be-resynced blocks
to be actually identical on both sides already.

In a "network hickup" scenario, it won't help:
all to-be-resynced blocks will typically be different.

The use case is for the resync of *potentially* different blocks
after crash recovery -- the crash recovery had marked larger areas
(those covered by the activity log) as need-to-be-resynced,
just in case. Most of those blocks will be identical.

This option makes it possible to configure checksum based resync,
but only actually use it for the first resync after primary crash.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2014-07-10 18:35:00 +02:00