Found these with the help of ispell -l.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
We limit ourselves to a configurable maximum number of pages used as
temporary bio pages.
If the configured "max_buffers" is not big enough to match the bandwidth
of the respective deployment, a distributed deadlock could be triggered
by e.g. fast online verify and heavy application IO.
TCP connections would block on congestion, because both receivers
would wait on pages to become available.
Fortunately the respective senders in this case would be able to give
back some pages already. So do that.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Just deal with it more gracefully, if we fail to add even a single page
to an empty bio. We used to BUG_ON() there, but it has been observed in
some Xen deployment, so we need to handle that case more robustly now.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
All decisions about sync, sync direction, and wether or not to
allow a connect or attach are based on our set of UUIDs to tag a
data generation.
Log changes to the UUIDs whenever they occur,
logging "new current UUID P:Q:R:S" is more useful
than "Creating new current UUID".
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
The test if rs_pending_cnt == 0 was too weak. Using Test for
unacked_cnt == 0 instead. Moved that into the worker.
Since unacked_cnt gets already increased when an P_RS_DATA_REQ
comes in.
Also using a timer to make Ahead -> SyncSource -> Ahead cycles
slower...
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Besides removed a few lines of code, this moves the inspection
of the state from before the queuing process to after the queuing.
I.e. more closely to the actual invocation of the work.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
When the sync source node replies to a P_RS_DATA_REQUEST packet
when it is already in ahead mode. I.e. those two packets
crossed each other on the wire, that may lead to diverging
bitmaps.
This never happens in a well-tuned-system. In a well-tuned-
system the resync controller has reduced the resync speed
to zero long before we got into ahead-mode.
But we have to be prepared for the not-well-tuned-system
of course as well.
Because -> diverging bitmaps = non terminating resync.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
To improve the latency of IO requests during bitmap exchange,
we recently allowed writes while waiting for the bitmap, sending "set
out-of-sync" information packets for any newly dirtied bits.
We have to make sure that the new resync-uuid does not overtake
these "set oos" packets. Once the resync-uuid is received, the
sync target starts the resync process, and expects the bitmap to
only be cleared, not re-set.
If we use this protocol extension, we queue the generation and sending
of the resync-uuid on the worker, which naturally serializes with all
previously queued packets.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
We must not call it directly from resync_finished,
as we may be in either receiver or worker context there.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
When we set or clear bits in a bitmap page,
also set a flag in the page->private pointer.
This allows us to skip writes of unchanged pages.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
We only issue resync requests if there is no significant application IO
going on. = Application IO has higher priority than resnyc IO.
If application IO can not be started because the resync process locked
an resync_lru entry, start the IO operations necessary to release the
lock ASAP.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This one should be replaced with moving this cleanup to the
'right' position.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
To ease tracking of bios in some hash tables, we want it to
not cross certain boundaries (128k, used to be 32k).
We limit the maximum bio size using queue parameters.
Historically some defines and variables we use there have been named
max_segment_size, which was misguided. Rename them to max_bio_size,
and use [blk_]queue_max_hw_sectors where appropriate.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Preparation patch to be able to use the auto-throttling resync controller
for online-verify requests as well.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Preparation patch to be able to use the auto-throttling resync controller
for online-verify requests as well.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
For network hickups during online-verify, on the next verify
triggered, we by default want to resume where it left off.
After any replication link interruption, there will be a (possibly
empty) resync. Do not reset online-verify start sector if some resync
completed, that would defeats the purpose.
Only reset the start sector once a verify run is completed.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
In commit 9b7f76dc37919ea36caa9680a3f765e5b19b25fb,
Author: Lars Ellenberg <lars.ellenberg@linbit.com>
Date: Wed Aug 11 23:40:24 2010 +0200
drbd: new configuration parameter c-min-rate
a bad chunk slipped through, which is now reverted as well,
restoring the correct irqsave for the endio callback.
This patch also add comments at both req_mod()
and in the endio callback so it should not happen again.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.
Remove this too as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This codepath used to be called only for failed kmalloc GFP_ATOMIC,
but is now also triggered by other things.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
As we usually update the generation UUIDs here, we should explicitly
sync them to disk. So far this has been done only implicitly by related
code paths.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Various cleanup paths have been incomplete, for the very unlikely case
that we cannot allocate enough bios from process context when submitting
on behalf of the peer or resync process.
Never observed.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
If it was an "empty" resync, the SyncSource may have already "finished"
the resync and rotated the UUIDs, before noticing the connection loss
(and generating a new uuid, if Primary, rotating again), while the
SyncTarget did not change its uuids at all, or only got to the previous
sync-uuid.
This would then again lead to a full sync on next handshake
(see also Bug #251).
Fix:
Use explicit resync finished notification even for empty resyncs,
do not finish an empty resync implicitly on the SyncSource.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This caused rs_planed to be not in sync with the content of the fifo.
That in turn could cause that the resync comes to a complete halt.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Forgot to consider the max size for the resync requests.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
BUG trace would look like:
lc_find
drbd_rs_complete_io
got_OVResult
drbd_asender
Could be triggered by explicit, or IO-error policy based,
detach during online-verify.
We may only dereference mdev->resync, if we first get_ldev(), as the
disk may break any time, causing mdev->resync to disappear once all
ldev references have been returned.
Already in flight online-verify requests or replies may still come in,
which we then need to ignore.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
The actual race happened int the drbd_start_resync() function. Where
drbd_resync_finished() -> __drbd_set_state() set STOP_SYNC_TIMER and
armed the timer.
If the timer fired before execution reaches the mod_timer statement
at the end of drbd_start_resync() the latter would cause an
unexpected call to w_make_resync_request().
Removed the STOP_SYNC_TIMER bit, and base it on the connection state.
The STOP_SYNC_TIMER bit probably originates probably the time before
the state engine.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
When the complete device is marked as out of sync, we can disable
updates of the on disk AL. Currently AL updates are only disabled
if one uses the "invalidate-remote" command on an unconnected,
primary device, or when at attach time all bits in the bitmap are
set.
As of now, AL updated do not get disabled when a all bits becomes
set due to application writes to an unconnected DRBD device.
While this is a missing feature, it is not considered important,
and might get added later.
BTW, after initializing a "one legged" DRBD device
drbdadm create-md resX
drbdadm -- --force primary resX
AL updates also get disabled, until the first connect.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
If we intent to use the block_id member of an epoch entry,
we may not use the digest member.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
We now track the data rate of locally submitted resync related requests,
and can thus detect non-resync activity on the lower level device.
If the current sync rate is above c-min-rate, and the lower level device
appears to be busy, we throttle the resyncer.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
also canonicalize the return values of read_for_csum
and drbd_rs_begin_io to return -ESOMETHING, or 0 for success.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
The current resync speed as displayed in /proc/drbd fluctuates a lot.
Using an array of rolling marks makes this calculation much more stable.
We used to have this (a long time ago with 0.7), but it got lost somehow.
If "stalled", do not discard the rest of the information, just add a
" (stalled)" tag to the progress line.
This patch also shortens a spinlock critical section somewhat, and
reduces the number of atomic operations in put_ldev.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
When no data is accessible (no connection to the peer, nor a local disk)
allow the user to select to freeze all IO operations instead of getting
IO errors.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
It was a now abandoned attempt to throttle resync bandwidth
based on the delay it causes on the bulk data socket.
It has no userbase yet, and has been disabled by
9173465ccb51c09cc3102a10af93e9f469a0af6f already.
This removes the now unused code.
The basic feature, namely using up "idle" bandwith
of network and disk IO subsystem, with minimal impact
to application IO, is being reimplemented differently.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
The "Local READ/WRITE failed" messages are too verbose.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
"canceled" w_read_retry_remote never completed, if they have been
canceled after drbd_disconnect connection teardown cleanup has already
run (or we are currently not connected anyways).
Fixed by not queueing a remote retry if we already know it won't work
(pdsk not uptodate), and cleanup ourselves on "cancel", in case we hit a
race with drbd_disconnect.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Introduced a few days ago:
commit 45bb912bd5
Author: Lars Ellenberg <lars.ellenberg@linbit.com>
Date: Fri May 14 17:10:48 2010 +0200
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
this should allow for better background resync performance.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This should allow for better performance if the lower level IO stack
of the peers differs in limits exposed either via the queue,
or via some merge_bvec_fn.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
In a setup with a high bandwidth and high latency network, eventually
involving deep queues in routers, it is beneficial to only fill those
queues up to an limited extend with resync data.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
fix regression introduced in 8.3.3:
commit a9b17323f2875f5d9b132c2b476a750bf44b10c7
Author: Lars Ellenberg <lars.ellenberg@linbit.com>
Date: Wed Aug 12 15:18:33 2009 +0200
out-of-spinlock completion of master bio
: (bio_rw(bio) == READA)
? read_completed_with_error
: read_ahead_completed_with_error;
is obviously not what was intended.
No one noticed because of
* page-cache at work,
* local RAIDs
Impact:
Failed local READs are not retried remotely,
but errored to upper layers, causing filesystems
to remount read-only, or worse.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This is a race condition that existed for ages.
The previous commit reduces the window, this one closes it.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Depending on resync request size,
we need to account for more than one bit.
Impact: cosmetic
If SyncTarget reported correctly 100% equal checksums,
the SyncSource usually reported 12% equal checksums instead,
because it only counted requests, we typically do 32k resync requests,
and the bitmap granularity is still 4k.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
It is force-included on the gcc command line since at least 2.6.15.
Explicit include lines seem to break compilation now in certain configurations.
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
