Disconnect should wait for pending bitmap IO.
But if that bitmap IO is not happening, because it is waiting for
pending application IO, and there is no progress, because the fencing
policy suspended application IO because of the disconnect,
then we deadlock.
The bitmap writeout in this case does not care for concurrent
application IO, so there is no point waiting for it.
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>
lsblk should be able to pick up stacking device driver relations
involving DRBD conveniently.
Even though upstream kernel since 2011 says
"DON'T USE THIS UNLESS YOU'RE ALREADY USING IT."
a new user has been added since (bcache),
which sets the precedences for us to use it as well.
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>
When accessing out meta data area on disk, we double check the
plausibility of the requested sector offsets, and are very noisy about
it if they look suspicious.
During initial read of our "superblock", for "external" meta data,
this triggered because the range estimate returned by
drbd_md_last_sector() was still wrong.
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>
Since kernel 3.3, we can use snprintf-style arguments
to create a workqueue.
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>
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 <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This prepares the next patch where the sending on the meta (or
control) socket is moved to a dedicated workqueue.
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>
Instead of using a rwlock for synchronizing state changes across
resources, take the request locks of all resources for global state
changes. Use resources_mutex to serialize global state changes.
This means that taking the request lock of a resource is now enough to
prevent changes of that resource. (Previously, a read lock on the
global state lock was needed as well.)
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>
Also change the enum values to all-capital letters.
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>
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 <axboe@kernel.dk>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: drbd-user@lists.linbit.com
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Yehuda Sadeh <yehuda@inktank.com>
Cc: Sage Weil <sage@inktank.com>
Cc: Alex Elder <elder@kernel.org>
Cc: ceph-devel@vger.kernel.org
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
Cc: Neil Brown <neilb@suse.de>
Cc: linux-raid@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Acked-by: NeilBrown <neilb@suse.de> (for the 'md' bits)
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
[dpark: also remove ->merge_bvec_fn() in dm-thin as well as
dm-era-target, and resolve merge conflicts]
Signed-off-by: Dongsu Park <dpark@posteo.net>
Signed-off-by: Ming Lin <ming.l@ssi.samsung.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Currently, a bdi (backing_dev_info) embeds single wb (bdi_writeback)
and the role of the separation is unclear. For cgroup support for
writeback IOs, a bdi will be updated to host multiple wb's where each
wb serves writeback IOs of a different cgroup on the bdi. To achieve
that, a wb should carry all states necessary for servicing writeback
IOs for a cgroup independently.
This patch moves bdi->state into wb.
* enum bdi_state is renamed to wb_state and the prefix of all enums is
changed from BDI_ to WB_.
* Explicit zeroing of bdi->state is removed without adding zeoring of
wb->state as the whole data structure is zeroed on init anyway.
* As there's still only one bdi_writeback per backing_dev_info, all
uses of bdi->state are mechanically replaced with bdi->wb.state
introducing no behavior changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: drbd-dev@lists.linbit.com
Cc: Neil Brown <neilb@suse.de>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Mempools created for slab caches should use
mempool_create_slab_pool().
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Avoid generic netlink calls in other parts of the code base.
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>
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>
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>
* 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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Get rid of dump_stack() debug statements.
There is no point whatsoever in registering and unregistering a reboot
notifier that doesn't do anything.
The intention was to switch to an "emergency read-only" mode,
so we won't have to resync the full activity log just because
we had been Primary before the reboot.
Once we have that implemented, we may re-introduce the reboot notifier.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This replaces the md_sync_work member of struct drbd_device
by a new MD_SYNC "work bit" in device->flags.
This replaces the resync_start_work member of struct drbd_device
by a new RS_START "work bit" in device->flags.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
The recent fix to put_ldev() (correct ordering of access to local_cnt
and state.disk; memory barrier in __drbd_set_state) guarantees
that the cleanup happens exactly once.
However it does not yet guarantee that the cleanup happens from worker
context, the last put_ldev() may still happen from atomic context,
which must not happen: blkdev_put() may sleep.
Fix this by scheduling the cleanup to the worker instead,
using a couple more bits in device->flags and a new helper,
drbd_device_post_work().
Generalized the "resync progress" work to cover these new work bits.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This should reduce latency for such in-DRBD-protocol "pings",
and may help reduce spurious disconnect/reconnect cycles due to
"PingAck did not arrive in time."
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Since the member of drbd_device is called ldev
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Some parts of the code assumed that get_ldev_if_state(device, D_ATTACHING)
is sufficient to access the ldev member of the device object. That was
wrong. ldev may not be there or might be freed at any time if the device
has a disk state of D_ATTACHING.
bm_rw()
Documented that drbd_bm_read() is only called from drbd_adm_attach.
drbd_bm_write() is only called when a reference is held, and it is
documented that a caller has to hold a reference before calling
drbd_bm_write()
drbd_bm_write_page()
Use get_ldev() instead of get_ldev_if_state(device, D_ATTACHING)
drbd_bmio_set_n_write()
No longer use get_ldev_if_state(device, D_ATTACHING). All callers
hold a reference to ldev now.
drbd_bmio_clear_n_write()
All callers where holding a reference of ldev anyways. Remove the
misleading get_ldev_if_state(device, D_ATTACHING)
drbd_reconsider_max_bio_size()
Removed the get_ldev_if_state(device, D_ATTACHING). All callers
now pass a struct drbd_backing_dev* when they have a proper
reference, or a NULL pointer.
Before this fix, the receiver could trigger a NULL pointer
deref when in drbd_reconsider_max_bio_size()
drbd_bump_write_ordering()
Used get_ldev_if_state(device, D_ATTACHING) with the wrong assumption.
Remove it, and allow the caller to pass in a struct drbd_backing_dev*
when the caller knows that accessing this bdev is safe.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Note that I do NOT call __drbd_chk_io_error for failed REQ_DISCARD.
That may be wrong, though, or needs to differ between EOPNOTSUPP and
other errors...
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>
We plan to use genl_family->parallel_ops = true in the future,
but need to review all possible interactions first.
For now, only selectively drop genl_lock() in drbd_set_role(),
instead serializing on our own internal resource->conf_update mutex.
We now can be promoted/demoted on many resources in parallel,
which may significantly improve cluster failover times
when fencing is required.
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>
Because all administrative requests via genetlink have been globally
serialized via genl_lock(), we used to have one static struct
drbd_config_context "admin context".
Move this on-stack to the respective callback functions.
This will allow us to selectively drop the genl_lock()
(or use genl_family->parallel_ops) in the future.
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>
In the drbd_thread "infrastructure" functions, only use the resource instead of
the connection. Make the connection field of drbd_thread optional. This will
allow to introduce threads which are not associated with a connection.
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
The new function can flush any work queue, not just the work queue of the data
socket of a connection.
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
drbd_device_work is a work item that has a reference to a device,
while drbd_work is a more generic work item that does not carry
a reference to a device.
All callbacks get a pointer to a drbd_work instance, those callbacks
that expect a drbd_device_work use the container_of macro to get it.
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Also fix drbd_calc_cpu_mask() to spread resources equally over all online cpus
independent of device minor numbers.
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
in drbd_adm_down(), drbd_create_device() and drbd_set_role()
Signed-off-by: Andreas Gruenbacher <agruen@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
