If we have a good resync rate, we will frequently update the on-disk
bitmap, which, if not accounted for as resync io, may let an otherwise
idle device appear to be "busy", and cause us to throttle resync.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
The last commit, drbd: add missing spinlock to bitmap receive,
introduced a cond_resched_lock(), where the lock in question is taken
with irqs disabled.
As we must not schedule with IRQs disabled,
and cond_resched_lock_irq() does not exist, yet,
we re-aquire the spin_lock_irq() for each bitmap page processed in turn.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
During bitmap exchange, when using the RLE bitmap compression scheme,
we have a code path that can set the whole bitmap at once.
To avoid holding spin_lock_irq() for too long, we used to lock out other
bitmap modifications during bitmap exchange by other means, and then,
knowing we have exclusive access to the bitmap, modify it without
the spinlock, and with IRQs enabled.
Since we now allow local IO to continue, potentially setting additional
bits during the bitmap receive phase, this is no longer true, and we get
uncoordinated updates of bitmap members, causing bm_set to no longer
accurately reflect the total number of set bits.
To actually see this, you'd need to have a large bitmap, use RLE bitmap
compression, and have busy IO during sync handshake and bitmap exchange.
Fix this by taking the spin_lock_irq() in this code path as well, but
calling cond_resched_lock() after each page worth of bits processed.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
In file included from drivers/block/drbd/drbd_main.c:54: drivers/block/drbd/drbd_int.h:1190: warning: parameter has incomplete type
Forward declarations of enums do not work.
Fix it unpleasantly by moving the prototype.
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Lars Ellenberg <drbd-dev@lists.linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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>
An administrative detach used to request a state change directly to D_DISKLESS,
first suspending IO to avoid the last put_ldev() occuring from an endio handler,
potentially in irq context.
This is not enough on the receiving side (typically secondary), we may miss
some peer_req on the way to local disk, which then may do the last put_ldev()
from their drbd_peer_request_endio().
This patch makes the detach always go through the intermediate D_FAILED state.
We may consider to rename it D_DETACHING.
Alternative approach would be to create yet an other work item to be scheduled
on the worker, do the destructor work from there, and get the timing right.
manually picked commit 564040f from the drbd 8.4 branch.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
The old (optimistic) implementation could shrink the bio size
on an primary device.
Shrinking the bio size on a primary device is bad. Since there
we might get BIOs with the old (bigger) size shortly after
we published the new size.
The new implementation is more conservative, and eventually
increases the max_bio_size on a primary device (which is valid).
It does so, when it knows the local limit AND the remote limit.
We cache the last seen max_bio_size of the peer in the meta
data, and rely on that, to make the operation of single
nodes more efficient.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
It seems that the real cause of all the issues where that
we did not noticed in drbd_try_connect() when the other
guy closes one socket if the round trip time gets higher
than 100ms. There were that 100ms hard coded!
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
It is no longer sufficient to trigger on local WRITE,
we need to check on (rq_state & RQ_IN_ACT_LOG)
before calling drbd_al_complete_io also in the error path.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
If there is no replication traffic within the idle timeout
(ping-int seconds), DRBD will send a P_PING,
and adjust the timeout to ping-timeout.
If there is no P_PING_ACK received within this ping-timeout,
DRBD finally drops the connection, and tries to re-establish it.
To decide which timeout was active, we compared the current timeout
with the ping-timeout, and dropped the connection, if that was the case.
By default, ping-int is 10 seconds, ping-timeout is 500 ms.
Unfortunately, if you configure ping-timeout to be the same as ping-int,
expiry of the idle-timeout had been mistaken for a missing ping ack,
and caused an immediate reconnection attempt.
Fix:
Allow both timeouts to be equal, use a local variable
to store which timeout is active.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@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>
In case a write failes on the local disk, go into D_INCONSISTENT
disk state. That causes future reads of that block to be shipped
to the peer.
Read retry remote was already in place.
Actually the documentation needs to get fixed now. Since the
application is still shielded from the error. (as long as we have
only a single disk failing) The difference to detach is that
we keep the disk. And therefore might keep all the other, still
working sectors up to date.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
In commit 95a0f10cdd ("drbd: store in-core bitmap little endian,
regardless of architecture") drbd had made the sane choice to use
little-endian bitmap functions everywhere. However, it used the
horrible old functions names from <asm-generic/bitops/le.h>, that were
never really meant to be exported.
In the meantime, things got cleaned up, and in commit c4945b9ed4
("asm-generic: rename generic little-endian bitops functions") we
renamed the LE bitops to something sane, exactly so that they could be
used in random code without people gouging their eyes out when seeing
the crazy jumble of letters that were the old internal names.
As a result the drbd thing merged cleanly (commit 8d49a77568: "Merge
branch 'for-2.6.39/drivers' of git://git.kernel.dk/linux-2.6-block"),
since there was no data conflict - but the end result obviously doesn't
actually compile.
Reported-and-tested-by: Ingo Molnar <mingo@elte.hu>
Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-2.6.39/drivers' of git://git.kernel.dk/linux-2.6-block: (122 commits)
cciss: fix lost command issue
drbd: need include for bitops functions declarations
Revert "cciss: Add missing allocation in scsi_cmd_stack_setup and corresponding deallocation"
cciss: fix missed command status value CMD_UNABORTABLE
cciss: remove unnecessary casts
cciss: Mask off error bits of c->busaddr in cmd_special_free when calling pci_free_consistent
cciss: Inform controller we are using 32-bit tags.
cciss: hoist tag masking out of loop
cciss: Add missing allocation in scsi_cmd_stack_setup and corresponding deallocation
cciss: export resettable host attribute
drbd: drop code present under #ifdef which is relevant to 2.6.28 and below
drbd: Fixed handling of read errors on a 'VerifyS' node
drbd: Fixed handling of read errors on a 'VerifyT' node
drbd: Implemented real timeout checking for request processing time
drbd: Remove unused function atodb_endio()
drbd: improve log message if received sector offset exceeds local capacity
drbd: kill dead code
drbd: don't BUG_ON, if bio_add_page of a single page to an empty bio fails
drbd: Removed left over, now wrong comments
drbd: serialize admin requests for new verify run with pending bitmap io
...
* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits)
Documentation/iostats.txt: bit-size reference etc.
cfq-iosched: removing unnecessary think time checking
cfq-iosched: Don't clear queue stats when preempt.
blk-throttle: Reset group slice when limits are changed
blk-cgroup: Only give unaccounted_time under debug
cfq-iosched: Don't set active queue in preempt
block: fix non-atomic access to genhd inflight structures
block: attempt to merge with existing requests on plug flush
block: NULL dereference on error path in __blkdev_get()
cfq-iosched: Don't update group weights when on service tree
fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away
block: Require subsystems to explicitly allocate bio_set integrity mempool
jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
fs: make fsync_buffers_list() plug
mm: make generic_writepages() use plugging
blk-cgroup: Add unaccounted time to timeslice_used.
block: fixup plugging stubs for !CONFIG_BLOCK
block: remove obsolete comments for blkdev_issue_zeroout.
blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
...
Fix up conflicts in fs/{aio.c,super.c}
Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This code became obsolete and unused last December with
drbd: bitmap keep track of changes vs on-disk bitmap
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>
This is an addendum to
drbd: serialize admin requests for new resync with pending bitmap io
It avoids a race that could trigger "FIXME" assert log messages.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
When we receive a barrier ack, we walk the ring list of drbd requests
in the transfer log of the respective epoch, do some housekeeping,
and free those objects.
We tried to keep epochs of mirrored and unmirrored drbd requests
separate, and assert that no local-only requests are present in a
barrier_acked epoch.
It turns out that this has quite a number of corner cases and would
add bloated code without functional benefit.
We now revert the (insufficient) commits
drbd: Fixed an issue with AHEAD -> SYNC_SOURCE transitions
drbd: Ensure that an epoch contains only requests of one kind
and instead fix the processing of barrier acks to cope with
a mix of local-only and mirrored requests.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
If we fail to send the information that we lost our disk,
we have no connection, and no disk: no access to data anymore.
That is either expected (deconfiguration), or there will be so much
noise in the logs that "Sending state failed" is not useful at all.
Drop it.
If the reason for a shorter than expected receive was a signal,
which we sent because we already decided to disconnect,
these additional log messages are confusing and useless.
This patch follows this pattern:
- dev_warn(DEV, "short read expecting header on sock: r=%d\n", r);
+ if (!signal_pending(current))
+ dev_warn(DEV, "short read expecting header on sock: r=%d\n", r);
Also make them all dev_warn for consistency.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Now that we do no longer in-place endian-swap the bitmap, we allow
selected bitmap operations (testing bits, sometimes even settting bits)
during some bulk operations.
This caused us to hit a lot of FIXME asserts similar to
FIXME asender in drbd_bm_count_bits,
bitmap locked for 'write from resync_finished' by worker
Which now is nonsense: looking at the bitmap is perfectly legal
as long as it is not being resized.
This cosmetic patch defines some flags to describe expectations in finer
detail, so the asserts in e.g. bm_change_bits_to() can be skipped if
appropriate.
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>
When the user clears the sync-pause flag, and sync stays in pause
state, give hints to the user, why it still is in pause state.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
The "lazy writeout" of cleared bitmap pages happens during resync, and
should happen again once the resync finishes cleanly, or is aborted.
If resync finished cleanly, or was aborted because of peer disk
failure, we trigger the writeout from worker context in the after
state change work.
If resync was aborted because of connection failure, we should not
immediately trigger bitmap writeout, but rather postpone the
writeout to after the connection cleanup happened. We now do it
in the receiver context from drbd_disconnect().
If resync was aborted because of local disk failure, well, there
is nothing to write to anymore.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
This is a minor optimization and cleanup,
and also considerably reduces some harmless (but noisy) race with
the connection cleanup code.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
The assert in drbd_req.c:755 forces us to have only requests of
one kind in an epoch. The two kinds we distinguish here are:
local-only or mirrored.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Protocol A has no P_WRITE_ACKs, but has P_NEG_ACKs.
The master bio might already be completed, therefore the
request is no longer in the collision hash.
=> Do not try to validate block_id as request
In Protocol B we might already have got a P_RECV_ACK
but then get a P_NEG_ACK after wards.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
The point is that drbd_disconnect() can be called with a cstate of
WFConnection.
That happens if the user issues "drbdsetup disconnect" while the
drbd_connect() function executes. Then drbdd_init() will call
drbdd(), which in turn will return without receiving any
packets. Then drbdd_init() will end up calling drbd_disconnect()
with a cstate of WFConnection.
Bottom line: This assertion is wrong as it is, and we do not
see value in fixing it. => Removing it.
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>
See also commit from 2009-08-15
"drbd_uuid_compare(): Do not full sync in case a P_SYNC_UUID packet gets lost."
We saw cases where the History UUIDs where not as expected. So the
detection of the special case did not trigger. With the sync UUID
no longer being a random number, but deducible from the previous
bitmap UUID, the detection of this special case becomes more
reliable.
The SyncUUID now is the previous bitmap UUID + 0x1000000000000.
Rule 5a:
Cs = H1p & H1p + Offset = Bp
Connection was lost before SyncUUID Packet came through.
Corrent (peer) UUIDs:
Bp = H1p
H1p = H2p
H2p = 0
Become Sync target.
Rule 7a:
Cp = H1s & H1s + Offset = Bs
Connection was lost before SyncUUID Packet came through.
Correct (own) UUIDs:
Bs = H1s
H1s = H2s
H2s = 0
Become Sync source.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
