If you do back to back wait-sync/invalidate on a Primary in a tight loop,
during application IO load, you could trigger a race:
kernel: block drbd6: FIXME going to queue 'set_n_write from StartingSync'
but 'write from resync_finished' still pending?
Fix this by changing the order of the drbd_queue_work() and
the wake_up() in dec_ap_pending(), and adding the additional
drbd_flush_workqueue() before requesting the full sync.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
If the drbd worker thread is synchronously waiting for some userland
callback, we don't want some casual pageout to block on us.
Have drbd_congested() report congestion in that case.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Aborting local requests (not waiting for completion from the lower level
disk) is dangerous: if the master bio has been completed to upper
layers, data pages may be re-used for other things already.
If local IO is still pending and later completes,
this may cause crashes or corrupt unrelated data.
Only abort local IO if explicitly requested.
Intended use case is a lower level device that turned into a tarpit,
not completing io requests, not even doing error completion.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Don't rely on availability of bios from the global fs_bio_set,
we should use our own bio_set for meta data IO.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Symptom: messages similar to
"FIXME asender in bm_change_bits_to,
bitmap locked for 'write from resync_finished' by worker"
If a resync or verify is finished (or aborted), a full bitmap writeout
is triggered. If we have ongoing local IO, the bitmap may still change
during that writeout, pending and not yet processed acks may cause bits
to be cleared, while new writes may cause bits to be to be set.
To fix this, introduce the drbd_bm_write_copy_pages() variant.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
DRBD can freeze IO, due to fencing policy (fencing resource-and-stonith),
or because we lost access to data (on-no-data-accessible suspend-io).
Resuming from there (re-connect, or re-attach, or explicit admin
intervention) should "just work".
Unfortunately, if the re-attach/re-connect did not happen within
the timeout, since the commit
drbd: Implemented real timeout checking for request processing time
if so configured, the request_timer_fn() would timeout and
detach/disconnect virtually immediately.
This change tracks the most recent attach and connect, and does not
timeout within <configured timeout interval> after attach/connect.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Changes to the role and disk state should be delayed or rejected
while we establish a connection.
This is necessary, since the peer will base its resync decision
on the UUIDs and the state we sent in the drbd_connect() function.
The most prominent example for this race is becoming primary after
sending state and UUIDs and before the state changes to C_WF_CONNECTION.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
If the backing device is already frozen during attach, we failed
to recognize that. The current disk-timeout code works on top
of the drbd_request objects. During attach we do not allow IO
and therefore never generate a drbd_request object but block
before that in drbd_make_request().
This patch adds the timeout to all drbd_md_sync_page_io().
Before this patch we used to go from D_ATTACHING directly
to D_DISKLESS if IO failed during attach. We can no longer
do this since we have to stay in D_FAILED until all IO
ops issued to the backing device returned.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
DRBD state changes schedule after_state_ch() actions to a worker thread,
which decides on the old and new states of that change, whether to send
an informational state update packet (P_STATE) to the peer.
If it decides to drbd_send_state(), it would however always send the
_curent_ state, which, if a second state change happens before the
after_state_ch() of the first ran, may "fast-forward" the peer's view
about this node. In most cases that is harmless, but sometimes this can
confuse DRBD, for example into not actually starting a necessary resync
if you do a very tight detach/attach loop on a Connected Secondary.
Fix this by always sending the "new" state of the respective state
transition which scheduled this after_state_ch() work.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
The last bunch of commits prepared the 'detach from tar pit' feature.
With that we can be for long time in disk state FAILED. We need
to accept new IO requests during that time.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
The new function drbd_md_get_buffer() aborts waiting for the buffer
in case the disk failes in the meantime.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Fix warnings of the following nature in the drbd header:
In file included from drivers/block/drbd/drbd_bitmap.c:32:
drivers/block/drbd/drbd_int.h: In function 'drbd_get_syncer_progress':
drivers/block/drbd/drbd_int.h:2234: warning: comparison is always false due to limited range of data
where mdev->rs_total (an unsigned long) is being compared to 1ULL << 32, which
is always false on a 32-bit machine.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
module_param(bool) used to counter-intuitively take an int. In
fddd5201 (mid-2009) we allowed bool or int/unsigned int using a messy
trick.
It's time to remove the int/unsigned int option. For this version
it'll simply give a warning, but it'll break next kernel version.
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* 'for-3.2/core' of git://git.kernel.dk/linux-block: (29 commits)
block: don't call blk_drain_queue() if elevator is not up
blk-throttle: use queue_is_locked() instead of lockdep_is_held()
blk-throttle: Take blkcg->lock while traversing blkcg->policy_list
blk-throttle: Free up policy node associated with deleted rule
block: warn if tag is greater than real_max_depth.
block: make gendisk hold a reference to its queue
blk-flush: move the queue kick into
blk-flush: fix invalid BUG_ON in blk_insert_flush
block: Remove the control of complete cpu from bio.
block: fix a typo in the blk-cgroup.h file
block: initialize the bounce pool if high memory may be added later
block: fix request_queue lifetime handling by making blk_queue_cleanup() properly shutdown
block: drop @tsk from attempt_plug_merge() and explain sync rules
block: make get_request[_wait]() fail if queue is dead
block: reorganize throtl_get_tg() and blk_throtl_bio()
block: reorganize queue draining
block: drop unnecessary blk_get/put_queue() in scsi_cmd_ioctl() and blk_get_tg()
block: pass around REQ_* flags instead of broken down booleans during request alloc/free
block: move blk_throtl prototypes to block/blk.h
block: fix genhd refcounting in blkio_policy_parse_and_set()
...
Fix up trivial conflicts due to "mddev_t" -> "struct mddev" conversion
and making the request functions be of type "void" instead of "int" in
- drivers/md/{faulty.c,linear.c,md.c,md.h,multipath.c,raid0.c,raid1.c,raid10.c,raid5.c}
- drivers/staging/zram/zram_drv.c
It was pointed out by 'make versioncheck' that some includes of
linux/version.h are not needed in drivers/block/.
This patch removes them.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
There is very little benefit in allowing to let a ->make_request
instance update the bios device and sector and loop around it in
__generic_make_request when we can archive the same through calling
generic_make_request from the driver and letting the loop in
generic_make_request handle it.
Note that various drivers got the return value from ->make_request and
returned non-zero values for errors.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* 'for-2.6.40/drivers' of git://git.kernel.dk/linux-2.6-block: (110 commits)
loop: handle on-demand devices correctly
loop: limit 'max_part' module param to DISK_MAX_PARTS
drbd: fix warning
drbd: fix warning
drbd: Fix spelling
drbd: fix schedule in atomic
drbd: Take a more conservative approach when deciding max_bio_size
drbd: Fixed state transitions after async outdate-peer-handler returned
drbd: Disallow the peer_disk_state to be D_OUTDATED while connected
drbd: Fix for the connection problems on high latency links
drbd: fix potential activity log refcount imbalance in error path
drbd: Only downgrade the disk state in case of disk failures
drbd: fix disconnect/reconnect loop, if ping-timeout == ping-int
drbd: fix potential distributed deadlock
lru_cache.h: fix comments referring to ts_ instead of lc_
drbd: Fix for application IO with the on-io-error=pass-on policy
xen/p2m: Add EXPORT_SYMBOL_GPL to the M2P override functions.
xen/p2m/m2p/gnttab: Support GNTMAP_host_map in the M2P override.
xen/blkback: don't fail empty barrier requests
xen/blkback: fix xenbus_transaction_start() hang caused by double xenbus_transaction_end()
...
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>
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>
After discovering that wide use of prefetch on modern CPUs
could be a net loss instead of a win, net drivers which were
relying on the implicit inclusion of prefetch.h via the list
headers showed up in the resulting cleanup fallout. Give
them an explicit include via the following $0.02 script.
=========================================
#!/bin/bash
MANUAL=""
for i in `git grep -l 'prefetch(.*)' .` ; do
grep -q '<linux/prefetch.h>' $i
if [ $? = 0 ] ; then
continue
fi
( echo '?^#include <linux/?a'
echo '#include <linux/prefetch.h>'
echo .
echo w
echo q
) | ed -s $i > /dev/null 2>&1
if [ $? != 0 ]; then
echo $i needs manual fixup
MANUAL="$i $MANUAL"
fi
done
echo ------------------- 8\<----------------------
echo vi $MANUAL
=========================================
Signed-off-by: Paul <paul.gortmaker@windriver.com>
[ Fixed up some incorrect #include placements, and added some
non-network drivers and the fib_trie.c case - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
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>
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>
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>
The old name is confusing: the function does not increment anything.
Also rename _inc_ap_bio_cond to inc_ap_bio_cond: there is no need for
an underscore.
Finally, make it clear that these functions return boolean values.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
The FAULT_ACTIVE macro just wraps the drbd_insert_fault macro for no
apparent reason.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
