Signed-off-by: NKent Overstreet <koverstreet@google.com>
Cc: linux-bcache@vger.kernel.org
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Recently introduced al_begin_io_nonblock() was returning -EBUSY,
even when it should return -EWOULDBLOCK.

Impact:
A few spurious wake_up() calls in prepare_al_transaction_nonblock().
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

It was unnoticed for some time that assigning to current->policy is
no longer sufficient to set a real time priority for a kernel thread.
Reported-by: NCharlie Suffin <Charlie.Suffin@stratus.com>
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

With an automatic after split-brain recovery policy of
"after-sb-1pri call-pri-lost-after-sb",
when trying to drbd_set_role() to R_SECONDARY,
we run into a deadlock.

This was first recognized and supposedly fixed by
2009-06-10 "Fixed a deadlock when using automatic split brain recovery when both nodes are"
replacing drbd_set_role() with drbd_change_state() in that code-path,
but the first hunk of that patch forgets to remove the drbd_set_role().

We apparently only ever tested the "two primaries" case.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

If single_open() fails in drbd_proc_open(), module refcount is left incremented.
The patch adds module_put() on the error path.

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: NAlexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The sanity check when receiving P_BARRIER_ACK does expect all write
requests with a given req->epoch to have been either all replicated,
or all not replicated.

Because req->epoch was assigned before calling maybe_pull_ahead(),
this expectation was not met, leading to an off-by-one in the sanity
check, and further to a "Protocol Error".

Fix: move the call to maybe_pull_ahead() a few lines up,
and assign req->epoch only after that.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We validated resync_after dependencies, if changed via disk-options.
But we did not validate them when first created via attach.
We also did not check or cleanup dependencies that used to be correct,
but now point to meanwhile removed minor devices.

If the drbd_resync_after_valid() validation in disk-options tried to
follow a dependency chain in this way, this could lead to NULL pointer
dereference.

Validate resync_after settings in drbd_adm_attach() already, as well as
in drbd_adm_disk_opts(), and and only reject dependency loops.
Depending on non-existing disks is allowed and equivalent to no dependency.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We forgot to free the disk_conf,
so for each attach/detach cycle we leaked 336 bytes.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We completed empty flushes (blkdev_issue_flush()) with IO error
if we lost the local disk, even if we still have an established
replication link to a healthy remote disk.

Fix this to only report errors to upper layers,
if neither local nor remote data is reachable.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The issue was that if the connection broke while we did the
gracefull state change to C_DISCONNECTING (C_TEARDOWN), then
we returned a success code from the state engine. (SS_CW_NO_NEED)

The result of that is that we missed to call the fence-peer
script in such a case.

Fixed that by introducing a new error code (SS_OUTDATE_WO_CONN).
This one should never reach back into user space.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Introduced in drbd: always write bitmap on detach,
the bitmap bulk writeout on detach was indicating
it expected exclusive bitmap access.

Where I meant to say: expect no more modifications,
but testing/counting is still allowed.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Patch best viewed with git diff --ignore-space-change.

Now that we attempt the fallback to local bitmap operation
only when disconnected, we can safely drop the extra "silent"
state request from both invalidate and invalidate-remote.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Since commit
  drbd: Disallow the peer_disk_state to be D_OUTDATED while connected
trying to invalidate a disconnected Primary returned an error code
that did not really match the situation:
"Refusing to be Outdated while Connected"

Insert two more specific conditions into is_valid_state(),
changing that to "Need access to UpToDate data",
respectively "Need a connection to start verify or resync".
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

To avoid other state change requests, after passing through
sanitize_state(), to be mistaken for an invalidate,
move the "set all bits as out-of-sync" into the invalidate path.

Make invalidate and invalidate-remote behave consistently wrt.
current connection state (need either an established replication link,
or really be disconnected). Also mention that in the documentation.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

We've seen a spurious full resync, because a connection breakage
raced with drbd_start_resync(, C_SYNC_TARGET),
and the resulting state change request intended to start the resync
ended up looking like a local invalidate.

Fix:
Double check the state inside the lock,
and don't even request that state change,
if we had connection or IO problems.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

And some manual common subexpression elimination which may help the
compiler produce smaller code.
Signed-off-by: NGeorge Spelvin <linux@horizon.com>
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Commit 82a84eaf7e51ba3da0c36cbc401034a4e943492d left a return 0 in
closure_debug_init(). Whoops.
Signed-off-by: NKent Overstreet <koverstreet@google.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Less error prone if we just kill it, it's only used once
anyway.
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Took out some nested functions, and fixed some more checkpatch
complaints.
Signed-off-by: NKent Overstreet <koverstreet@google.com>
Cc: linux-bcache@vger.kernel.org
Signed-off-by: NJens Axboe <axboe@kernel.dk>

config: make ARCH=i386 allmodconfig

All error/warnings:

   drivers/md/bcache/bset.c: In function 'bch_ptr_bad':
>> drivers/md/bcache/bset.c:164:2: warning: format '%li' expects argument of type 'long int', but argument 4 has type 'size_t' [-Wformat]
--
   drivers/md/bcache/debug.c: In function 'bch_pbtree':
>> drivers/md/bcache/debug.c:86:4: warning: format '%li' expects argument of type 'long int', but argument 4 has type 'size_t' [-Wformat]
--
   drivers/md/bcache/btree.c: In function 'bch_btree_read_done':
>> drivers/md/bcache/btree.c:245:8: warning: format '%lu' expects argument of type 'long unsigned int', but argument 4 has type 'size_t' [-Wformat]
--
   drivers/md/bcache/closure.o: In function `closure_debug_init':
>> (.init.text+0x0): multiple definition of `init_module'
>> drivers/md/bcache/super.o:super.c:(.init.text+0x0): first defined here
Signed-off-by: NKent Overstreet <koverstreet@google.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: linux-bcache@vger.kernel.org
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Merge branch 'bcache-for-upstream' of http://evilpiepirate.org/git/linux-bcache into for-3.10/drivers

Does writethrough and writeback caching, handles unclean shutdown, and
has a bunch of other nifty features motivated by real world usage.

See the wiki at http://bcache.evilpiepirate.org for more.
Signed-off-by: NKent Overstreet <koverstreet@google.com>

Hack, but bcache needs a way around lockdep for locking during garbage
collection - we need to keep multiple btree nodes locked for coalescing
and rw_lock_nested() isn't really sufficient or appropriate here.
Signed-off-by: NKent Overstreet <koverstreet@google.com>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Ingo Molnar <mingo@redhat.com>

Exported so it can be used by bcache's tracepoints
Signed-off-by: NKent Overstreet <koverstreet@google.com>
CC: Steven Rostedt <rostedt@goodmis.org>
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@redhat.com>

Needed for bcache - need a cheap source of random numbers for perturbing
IO sizes, for rate limiting IO to the SSD.
Signed-off-by: NKent Overstreet <koverstreet@google.com>
CC: "Theodore Ts'o" <tytso@mit.edu>

This reverts commit 11b80f45.

Bcache needs rw semaphores for cache coherency in writeback mode -
writes have to take a read lock on a per cache device rw sem, and
release it when the bio completes.

But since this is for bios it's naturally not in the context of the
process that originally took the lock.
Signed-off-by: NKent Overstreet <koverstreet@google.com>
CC: Christoph Hellwig <hch@infradead.org>
CC: David Howells <dhowells@redhat.com>

Now that the on-disk activity-log ring buffer size is adjustable,
the maximum active set can become larger, and is now limited by
the use of 16bit "labels".

This increases the maximum working set from 6433 to 65534 extents,
each of which covers an area of 4MiB.
Which means that if you use the maximum, you'd have to resync
more than 250 GiB after an unclean Primary shutdown.
With capable backend storage and replication links,
this is entirely feasible.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

There may have been more incoming requests while we where preparing
the current transaction. Try to consolidate more updates into this
transaction until we make no more progres.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

The IO accounting of the drbd "queue depth" was misleading.
We only started IO accounting once we already wrote the activity log.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Depending on current IO depth, try to consolidate as many updates
as possible into one activity log transaction.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

New helper to be able to consolidate more updates
into a single transaction.
Without this, we can only grab a single refcount
on an updated element while preparing a transaction.

lc_get_cumulative - like lc_get; also finds to-be-changed elements
  @lc: the lru cache to operate on
  @enr: the label to look up

  Unlike lc_get this also returns the element for @enr, if it is belonging to
  a pending transaction, so the return values are like for lc_get(),
  plus:

  pointer to an element already on the "to_be_changed" list.
	  In this case, the cache was already marked %LC_DIRTY.

  Caller needs to make sure that the pending transaction is completed,
  before proceeding to actually use this element.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>

Fixed up by Jens to export lc_get_cumulative().
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

To make the code easier to follow,
use an explicit find_active_resync_extent(),
and add a "nonblock" parameter to _al_get().
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This is in preparation to be able to defer requests that need to wait
for an activity log transaction to a submitter workqueue.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

A request hitting an already "hot" extent should proceed right away,
even if some other requests need to wait for pending transactions.

Without that short-circuit, several simultaneous make_request contexts
race for committing the transaction, possibly penalizing the innocent.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>