Philipp Reisner [Thu, 22 Nov 2012 16:06:00 +0000 (17:06 +0100)]
drbd: close race between drbd_set_role and drbd_connect
drbd_set_role(, R_PRIMARY, ) does the state change to Primary,
some more housekeeping, and possibly generates a new UUID set.
All of this holding the "state_mutex".
The connection handshake involves sending of various state information,
including the current data generation UUID set, and two connection
state changes from C_WF_CONNECTION to C_WF_REPORT_PARAMS further to
a number of different outcomes, resync being one of them.
If the connection handshake happens between the state change to Primary
and the generation of the new UUIDs, the resync decision based on the
old UUID set may be confused, depending on circumstances.
Make sure that, before we do the handshake, any promotion to Primary
role will either be complete (including the housekeeping stuff), or can
see, and serialize with, the ongoing handshake, based on the
"STATE_SENT" bit, which is set when we start the handshake, and cleared
only when we leave C_WF_REPORT_PARAMS again.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Fri, 16 Nov 2012 11:27:41 +0000 (12:27 +0100)]
drbd: Remove obsolete check
Smatch complained about it this redundanct check.
The check was introduced in 2006-09-13. On 2007-07-24 the body of the
function was enclosed by get_ldev()/put_ldev() reference counting.
Since then the check is useless and miss leading.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Jens Axboe [Fri, 30 Nov 2012 20:20:15 +0000 (21:20 +0100)]
drbd: fixup after wait_even_lock_irq() addition to generic code
Compiling drbd yields:
drivers/block/drbd/drbd_state.c: In function ‘_conn_request_state’:
drivers/block/drbd/drbd_state.c:1804:5: error: macro "wait_event_lock_irq" passed 4 arguments, but takes just 3
drivers/block/drbd/drbd_state.c:1801:3: error: ‘wait_event_lock_irq’ undeclared (first use in this function)
drivers/block/drbd/drbd_state.c:1801:3: note: each undeclared identifier is reported only once for each function it appears in
drivers/block/drbd/drbd_state.c: At top level:
drivers/block/drbd/drbd_state.c:1734:1: warning: ‘_conn_rq_cond’ defined but not used [-Wunused-function]
Due to drbd having copied the MD definition for wait_event_lock_irq()
as well. Kill them.
Lukas Czerner [Fri, 30 Nov 2012 10:42:41 +0000 (11:42 +0100)]
loop: Limit the number of requests in the bio list
Currently there is not limitation of number of requests in the loop bio
list. This can lead into some nasty situations when the caller spawns
tons of bio requests taking huge amount of memory. This is even more
obvious with discard where blkdev_issue_discard() will submit all bios
for the range and wait for them to finish afterwards. On really big loop
devices and slow backing file system this can lead to OOM situation as
reported by Dave Chinner.
With this patch we will wait in loop_make_request() if the number of
bios in the loop bio list would exceed 'nr_congestion_on'.
We'll wake up the process as we process the bios form the list. Some
threshold hysteresis is in place to avoid high frequency oscillation.
Lukas Czerner [Fri, 30 Nov 2012 10:42:40 +0000 (11:42 +0100)]
wait: add wait_event_lock_irq() interface
New wait_event{_interruptible}_lock_irq{_cmd} macros added. This commit
moves the private wait_event_lock_irq() macro from MD to regular wait
includes, introduces new macro wait_event_lock_irq_cmd() instead of using
the old method with omitting cmd parameter which is ugly and makes a use
of new macros in the MD. It also introduces the _interruptible_ variant.
The use of new interface is when one have a special lock to protect data
structures used in the condition, or one also needs to invoke "cmd"
before putting it to sleep.
All new macros are expected to be called with the lock taken. The lock
is released before sleep and is reacquired afterwards. We will leave the
macro with the lock held.
Note to DM: IMO this should also fix theoretical race on waitqueue while
using simultaneously wait_event_lock_irq() and wait_event() because of
lack of locking around current state setting and wait queue removal.
Signed-off-by: Lukas Czerner <lczerner@redhat.com> Cc: Neil Brown <neilb@suse.de> Cc: David Howells <dhowells@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Roger Pau Monne [Fri, 16 Nov 2012 18:26:48 +0000 (19:26 +0100)]
xen-blkback: move free persistent grants code
Move the code that frees persistent grants from the red-black tree
to a function. This will make it easier for other consumers to move
this to a common place.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Stephen Warren [Fri, 9 Nov 2012 00:12:28 +0000 (16:12 -0800)]
block: partition: msdos: provide UUIDs for partitions
The MSDOS/MBR partition table includes a 32-bit unique ID, often referred
to as the NT disk signature. When combined with a partition number within
the table, this can form a unique ID similar in concept to EFI/GPT's
partition UUID. Constructing and recording this value in struct
partition_meta_info allows MSDOS partitions to be referred to on the
kernel command-line using the following syntax:
Stephen Warren [Fri, 9 Nov 2012 00:12:27 +0000 (16:12 -0800)]
init: reduce PARTUUID min length to 1 from 36
Reduce the minimum length for a root=PARTUUID= parameter to be considered
valid from 36 to 1. EFI/GPT partition UUIDs are always exactly 36
characters long, hence the previous limit. However, the next patch will
support DOS/MBR UUIDs too, which have a different, shorter, format.
Instead of validating any particular length, just ensure that at least
some non-empty value was given by the user.
Also, consider a missing UUID value to be a parsing error, in the same
vein as if /PARTNROFF exists and can't be parsed. As such, make both
error cases print a message and disable rootwait. Convert to pr_err while
we're at it.
Signed-off-by: Stephen Warren <swarren@nvidia.com> Cc: Tejun Heo <tj@kernel.org> Cc: Will Drewry <wad@chromium.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stephen Warren [Fri, 9 Nov 2012 00:12:25 +0000 (16:12 -0800)]
block: store partition_meta_info.uuid as a string
This will allow other types of UUID to be stored here, aside from true
UUIDs. This also simplifies code that uses this field, since it's usually
constructed from a, used as a, or compared to other, strings.
Note: A simplistic approach here would be to set uuid_str[36]=0 whenever a
/PARTNROFF option was found to be present. However, this modifies the
input string, and causes subsequent calls to devt_from_partuuid() not to
see the /PARTNROFF option, which causes different results. In order to
avoid misleading future maintainers, this parameter is marked const.
Signed-off-by: Stephen Warren <swarren@nvidia.com> Cc: Tejun Heo <tj@kernel.org> Cc: Will Drewry <wad@chromium.org> Cc: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Akinobu Mita [Fri, 9 Nov 2012 00:12:23 +0000 (16:12 -0800)]
cciss: use check_signature()
Use check_signature() to find a signature in the mmio address.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Mike Miller <mike.miller@hp.com> Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Akinobu Mita [Fri, 9 Nov 2012 00:12:22 +0000 (16:12 -0800)]
cciss: cleanup bitops usage
- Remove unnecessary correction of bit and address
- Use BITS_TO_LONGS macro to calculate bitmap size
- Use bitmap_zero()
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Mike Miller <mike.miller@hp.com> Cc: Stephen M. Cameron <scameron@beardog.cce.hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Akinobu Mita [Fri, 9 Nov 2012 00:12:31 +0000 (16:12 -0800)]
drbd: use copy_highpage
Use copy_highpage() to copy from one page to another.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Mon, 5 Nov 2012 10:54:30 +0000 (11:54 +0100)]
drbd: if the replication link breaks during handshake, keep retrying
The 8.3.12 commit drbd: Bugfix for the connection behavior fixes a
"wasted established connection", if a former connection attempt failed
during its early stages.
However it opened a window for a regression, if a connection attempt
fails during its last stages. The result was a terminated receiver
thread, that left behind the supposedly transient "C_UNCONNECTED" state.
Any later requests to change the connection state fail, as they wait for
the connection state to "stabilize".
Fix: short circuit and keep retrying to restablish a new connection,
if we don't reach C_WF_REPORT_PARAMS.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Jing Wang [Thu, 25 Oct 2012 07:00:56 +0000 (15:00 +0800)]
drbd: check return of kmalloc in receive_uuids
Signed-off-by: Jing Wang <windsdaemon@gmail.com> Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Fri, 19 Oct 2012 12:21:22 +0000 (14:21 +0200)]
drbd: don't try to clear bits once the disk has failed
If the disk has failed already, there is no point trying to change the
bitmap. drbd_set_out_of_sync() already had this safeguard,
time to add it to drbd_set_in_sync() as well.
This also prevents some warning messages, like
FIXME asender in bm_change_bits_to, bitmap locked for 'detach' by worker
if our disk fails during resync, while there are some resync acks queued up.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
recent commit
drbd: always write bitmap on detach
introduced a bitmap writeout during detach,
which obviously needs some meta data device to write to.
Unfortunately, that same error path may be taken if we fail to attach,
e.g. due to UUID mismatch, after we changed state to D_ATTACHING,
but before the lower level device pointer is even assigned.
We need to test for presence of mdev->ldev.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Thu, 27 Sep 2012 13:18:21 +0000 (15:18 +0200)]
drbd: always write bitmap on detach
If we detach due to local read-error (which sets a bit in the bitmap),
stay Primary, and then re-attach (which re-reads the bitmap from disk),
we potentially lost the "out-of-sync" (or, "bad block") information in
the bitmap.
Always (try to) write out the changed bitmap pages before going diskless.
That way, we don't lose the bit for the bad block,
the next resync will fetch it from the peer, and rewrite
it locally, which may result in block reallocation in some
lower layer (or the hardware), and thereby "heal" the bad blocks.
If the bitmap writeout errors out as well, we will (again: try to)
mark the "we need a full sync" bit in our super block,
if it was a READ error; writes are covered by the activity log already.
If that superblock does not make it to disk either, we are sorry.
Maybe we just lost an entire disk or controller (or iSCSI connection),
and there actually are no bad blocks at all, so we don't need to
re-fetch from the peer, there is no "auto-healing" necessary.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Thu, 27 Sep 2012 13:07:11 +0000 (15:07 +0200)]
drbd: wait for meta data IO completion even with failed disk, unless force-detached
The intention of force-detach is to be able to deal with a completely
unresponsive lower level IO stack, which does not even deliver error
completions anymore, but no completion at all.
In all other cases, we must still wait for the meta data IO completion.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Wed, 26 Sep 2012 12:22:40 +0000 (14:22 +0200)]
drbd: a few more GFP_KERNEL -> GFP_NOIO
This has not yet been observed, but conceivably, when using GFP_KERNEL
allocations from drbd_md_sync(), drbd_flush_after_epoch() or
receive_SyncParam(), we could trigger additional IO to our own device,
or an other device in a criss-cross setup, and end up in a local
deadlock, or potentially a distributed deadlock in a criss-cross setup
involving the peer blocked in a similar way waiting for us to make
progress.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Wed, 26 Sep 2012 12:18:51 +0000 (14:18 +0200)]
drbd: fix potential deadlock during bitmap (re-)allocation
The former comment arguing that GFP_KERNEL was good enough was wrong: it
did not take resize into account at all, and assumed the only path
leading here was the normal attach on a still secondary device, so no
deadlock would be possible.
Both resize on a Primary, or attach on a diskless Primary,
could potentially deadlock.
drbd_bm_resize() is called while IO to the respective device is
suspended, so we must use GFP_NOIO to avoid potential deadlock.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Tue, 4 Sep 2012 13:16:20 +0000 (15:16 +0200)]
drbd: panic on delayed completion of aborted requests
"aborting" requests, or force-detaching the disk, is intended for
completely blocked/hung local backing devices which do no longer
complete requests at all, not even do error completions. In this
situation, usually a hard-reset and failover is the only way out.
By "aborting", basically faking a local error-completion,
we allow for a more graceful swichover by cleanly migrating services.
Still the affected node has to be rebooted "soon".
By completing these requests, we allow the upper layers to re-use
the associated data pages.
If later the local backing device "recovers", and now DMAs some data
from disk into the original request pages, in the best case it will
just put random data into unused pages; but typically it will corrupt
meanwhile completely unrelated data, causing all sorts of damage.
Which means delayed successful completion,
especially for READ requests,
is a reason to panic().
We assume that a delayed *error* completion is OK,
though we still will complain noisily about it.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
The condition function _req_st_cond() returned SS_NOTHING_TO_DO, which
caused the wait_event to abort too early. Therefore drbd_req_state()
did not consume the next CL_ST_CHG_SUCCESS or SS_CW_FAILED_BY_PEER
causing serve disruption of the state machine logic...
Detaching from a single volue was one way to trigger this bug.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Mon, 3 Sep 2012 12:08:35 +0000 (14:08 +0200)]
drbd: differentiate early and later "postponing" of requests
We use the RQ_POSTPONED flag to mark a request for several reasons.
It may be a conflicting request in a dual-primary setup,
where conflict detection and resolution on the peer decided that
this request needs to be re-submitted, it needs to re-enter
drbd_make_request() to fix the data divergence caused by these
conflicting, partially overlapping, quasi-simultaneous requests.
In this case we need to mark the corresponding area as out-of-sync,
before we call drbd_al_complete_io().
We also use the RQ_POSTPONED flag to just "push back" a request,
before even processing it, if IO is suspended for some reason.
In this case, as this request was neither submitted nor sent yet,
we must not touch the bitmap.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Wed, 29 Aug 2012 13:23:14 +0000 (15:23 +0200)]
drbd: Fix postponed requests
A postponed request might has RQ_IN_ACT_LOG already set, but
is POSTPONED before it gets something in the RQ_LOCAL_MASK
set. Up to now this caused a left-over active extent.
Fix that by only testing for the RQ_IN_ACT_LOG bit in drbd_req_destroy()
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Tue, 28 Aug 2012 14:48:03 +0000 (16:48 +0200)]
drbd: Call drbd_md_sync() explicitly after a state change on the connection
Without this, the meta-data gets updates after 5 seconds by the
md_sync_timer. Better to do it immeditaly after a state change.
If the asender detects a network failure, it may take a bit until
the worker processes the according after-conn-state-change work item.
The worker might be blocked in sending something, i.e. it
takes until it gets into its timeout. That is 6 seconds by
default which is longer than the 5 seconds of the md_sync_timer.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Tue, 28 Aug 2012 12:39:44 +0000 (14:39 +0200)]
drbd: Fix postponed requests
* Postponed requests should not set or clear out-of-sync marks
* When a request gets postponed we need to drop its reference
mdev->local_cnt (put_ldev()).
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Tue, 28 Aug 2012 09:33:35 +0000 (11:33 +0200)]
drbd: Fix the way the STATE_SENT bit is cleared
With merging the commit
'drbd: Delay/reject other state changes while establishing a connection'
the condition check for clearing the flag was wrong.
Move the bit clearing to the __drbd_set_state() function
in order to have it already cleared for the other parts of
the function. I.e. clearing the susp_fen in the after_state_ch() function.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Wed, 22 Aug 2012 12:59:06 +0000 (14:59 +0200)]
drbd: fix potential list_add corruption
If the md_sync_timer triggers a second time,
while the work queued during the first time is still pending,
this could result in list_add() of an already added item,
and corrupt the work item list.
This likely only triggered because of the erroneous
batch-dequeueing of work items fixed with
drbd: dequeue single work items in wait_for_work()
Still, skip queueing if md_sync_work is already queued.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Wed, 22 Aug 2012 09:47:14 +0000 (11:47 +0200)]
drbd: dequeue single work items in wait_for_work()
As long as we still use drbd_queue_work_front(),
we must only dequeue the single first item during normal operation.
The comment in drbd_worker() even says so,
but bc8a5a1 drbd: remove struct drbd_tl_epoch objects (barrier works)
introduced the batch dequeueing again via list_splice_init() in
wait_for_work().
Change back to list_move() of the first item, if any.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Wed, 22 Aug 2012 14:15:26 +0000 (16:15 +0200)]
drbd: mutex_unlock "... must no be used in interrupt context"
Documentation of mutex_unlock says
we must not use it in interrupt context.
So do not call it while holding the spin_lock_irq,
but give up the spinlock temporarily.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Mon, 20 Aug 2012 12:54:48 +0000 (14:54 +0200)]
drbd: temporarily suspend io in drbd_adm_disk_opts
drbd_adm_disk_opts() does
wait_event(mdev->al_wait, lc_try_lock(mdev->act_log));
drbd_al_shrink(mdev);
If the device is very busy, this can take a very long time to succeed.
Fix this by temporarily suspending IO,
then quickly change the settings, and resume.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Mon, 20 Aug 2012 09:05:23 +0000 (11:05 +0200)]
drbd: don't send out P_BARRIER with stale information
We must only send P_BARRIER for epochs we actually sent P_DATA in.
If we (re-)establish a connection, we reinitialized the
send.current_epoch_nr, but forgot to reset send.current_epoch_writes.
This could result in a spurious P_BARRIER with stale epoch information,
and a disconnect/reconnect cycle once the then "unexpected"
P_BARRIER_ACK is received:
BAD! BarrierAck #28823 received, expected #28829!
Introduce re_init_if_first_write() and maybe_send_barrier() helpers,
and call them appropriately for read/write/set-out-of-sync requests.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Fri, 17 Aug 2012 13:09:13 +0000 (15:09 +0200)]
drbd: properly call drbd_rs_cancel_all() in drbd_disconnected()
drbd_disconnected() is supposed to clear the resync lru cache,
by calling drbd_rs_cancel_all().
We must do so before we call drbd_flush_workqueue(), as at least the
callback w_restart_disk_io() may wait for resync progres, and would
otherwise deadlock.
drbd_finish_peer_reqs() may again populate that cache, which will
then potentially be stale after the next resync handshake and bitmap
exchange, we have to do it again after that.
A stale resync lru cache causes no harm but ugly messages like this:
BAD! sector=196608s enr=6 rs_left=-256 rs_failed=0 count=256 cstate=SyncTarget
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Wed, 8 Aug 2012 19:19:09 +0000 (21:19 +0200)]
drbd: Avoid NetworkFailure state during disconnect
Disconnecting is a cluster wide state change. In case the peer node agrees
to the state transition, it sends back the fact on the meta-data connection
and closes both sockets.
In case the node node that initiated the state transfer sees the closing
action on the data-socket, before the P_STATE_CHG_REPLY packet, it was
going into one of the network failure states.
At least with the fencing option set to something else thatn "dont-care",
the unclean shutdown of the connection causes a short IO freeze or
a fence operation.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Tue, 14 Aug 2012 09:46:59 +0000 (11:46 +0200)]
drbd: Write all pages of the bitmap after an online resize
We need to write the whole bitmap after we moved the meta data
due to an online resize operation.
With the support for one peta byte devices bitmap IO was optimized
to only write out touched pages. This optimization must be turned
off when writing the bitmap after an online resize.
This issue was introduced with drbd-8.3.10.
The impact of this bug is that after an online resize, the next
resync could become larger than expected.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Tue, 14 Aug 2012 09:28:52 +0000 (11:28 +0200)]
drbd: Fix completion of requests while the device is suspended
In various places (E.g. CONNECTION_LOST_WHILE_PENDING) the
RQ_COMPLETION_SUSP mask is passed in the clear set to mod_rq_state().
The issue was that it tried to clear the RQ_COMPLETION_SUSP bit
out of the state mask first, and eventuelly set it afterwards,
in the drbd_req_put_completion_ref() function.
Fixed that by moving the reference getting out of
drbd_req_put_completion_ref() into the mod_rq_state(), before the place
where the extra reference might be put.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
If for some reason (typically "split-brained" cluster manager)
drbd replica data has diverged, we can chose a victim,
and reconnect using "--discard-my-data", causing the victim
to become sync-target, fetching all changed blocks from the peer.
If we are Primary, we are potentially in use, and we refuse to
"roll back" changes to the data below the page cache and other users.
Rename the error symbol for this to ERR_DISCARD_IMPOSSIBLE.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
To avoid confusion with REQ_DISCARD aka TRIM, rename our
"discard concurrent write acks" from P_DISCARD_WRITE to P_SUPERSEDED.
At the same time, rename the drbd request event DISCARD_WRITE
to CONFLICT_RESOLVED. It already triggers both successful completion
or restart of the request, depending on our RQ_POSTPONED flag.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Tue, 7 Aug 2012 04:47:14 +0000 (06:47 +0200)]
drbd: NEG_ACK does not imply a barrier-ack
Don't drop a request from the transfer log just because it was NEG_ACKED.
We need it around to be able to verify P_BARRIER_ACKs against the
transver log.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Tue, 7 Aug 2012 11:28:00 +0000 (13:28 +0200)]
drbd: Finish requests that completed while IO was frozen
Requests of an acked epoch are stored on the barrier_acked_requests list. In
case the private bio of such a request completes while IO on the drbd device
is suspended [req_mod(completed_ok)] then the request stays there.
When thawing IO because the fence_peer handler returned, then we use
tl_clear() to apply the connection_lost_while_pending event to all requests
on the transfer-log and the barrier_acked_requests list.
Up to now the connection_lost_while_pending event was not applied
on requests on the barrier_acked_requests list. Fixed that.
I.e. now the connection_lost_while_pending and resend events are
applied to requests on the barrier_acked_requests list. For that
it is necessary that the resend event finishes (local only)
READS correctly.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Fri, 3 Aug 2012 23:07:55 +0000 (01:07 +0200)]
drbd: Fix a potential issue with the DISCARD_CONCURRENT flag
The DISCARD_CONCURRENT flag should be set on one node and cleared on the
other node.
As the code was before it was theoretical possible that a node accepts the
meta socket, but has to close it later on, and keeps the DISCARD_CONCURRENT
flag.
Correct this by moving the clear_bit(DISCARD_CONCURRENT) where the packet
gets sent.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Fri, 3 Aug 2012 00:19:09 +0000 (02:19 +0200)]
drbd: fix drbd wire compatibility for empty flushes
DRBD has a concept of request epochs or reorder-domains,
which are separated on the wire by P_BARRIER packets.
Older DRBD is not able to handle zero-sized requests at all,
so we need to map empty flushes to these drbd barriers.
These are the equivalent of empty flushes, and
by default trigger flushes on the receiving side anyways
(unless not supported or explicitly disabled),
so there is no need to handle this differently in newer drbd either.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Wed, 1 Aug 2012 12:53:39 +0000 (14:53 +0200)]
drbd: More random to the connect logic
Since the listening socket is open all the time, it was possible to
get into stable "initial packet S crossed" loops.
* when both sides realize in the drbd_socket_okay() call at the end
of the loop that the other side closed the main socket you had
the chance to get into a stable loop with repeated "packet S crossed"
messages.
* when both sides do not realize with the drbd_socket_okay() call at the end
of the loop that the other side closed the main socket you had
the chance to get into a stable loop with alternating "packet S crossed"
"packet M crossed" messages.
In order to break out these stable loops randomize the behaviour if
such a crossing of P_INITIAL_DATA or P_INITIAL_META packets is detected.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Wed, 1 Aug 2012 09:41:01 +0000 (11:41 +0200)]
drbd: Try to connec to peer only once per cycle
Since now our listening socket is open all the time we will get
connection tries of the peer always in. No need to try it three
times.
This is valid when connecting to older peers as well, it simply
increases the probability that the new version DRBD will accept
a connection instead that it will establish one.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Thu, 26 Jul 2012 12:12:59 +0000 (14:12 +0200)]
drbd: Remove redundant and wrong test for NULL simplification in conn_connect()
Since the drbd_socket_okay() function itself tests if the the
socket is NULL, the explicit test "if (sock.socket && &msock.socket)"
was redundent.
Apart from that the address opperator ('&') before msock.socket rendered
the test pointless.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Thu, 26 Jul 2012 12:09:49 +0000 (14:09 +0200)]
drbd: introduce stop-sector to online verify
We now can schedule only a specific range of sectors for online verify,
or interrupt a running verify without interrupting the connection.
Had to bump the protocol version differently, we are now 101.
Added verify_can_do_stop_sector() { protocol >= 97 && protocol != 100; }
Also, the return value convention for worker callbacks has changed,
we returned "true/false" for "keep the connection up" in 8.3,
we return 0 for success and <= for failure in 8.4.
Affected: receive_state()
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Mon, 30 Jul 2012 07:11:38 +0000 (09:11 +0200)]
drbd: flush drbd work queue before invalidate/invalidate remote
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>
Lars Ellenberg [Mon, 30 Jul 2012 07:11:01 +0000 (09:11 +0200)]
drbd: call local-io-error handler early
In case we want to hard-reset from the local-io-error handler,
we need to call it before notifying the peer or aborting local IO.
Otherwise the peer will advance its data generation UUIDs even
if secondary.
This way, local io error looks like a "regular" node crash,
which reduces the number of different failure cases.
This may be useful in a bigger picture where crashed or otherwise
"misbehaving" nodes are automatically re-deployed.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Mon, 30 Jul 2012 07:10:41 +0000 (09:10 +0200)]
drbd: do not reset rs_pending_cnt too early
Fix asserts like
block drbd0: in got_BlockAck:4634: rs_pending_cnt = -35 < 0 !
We reset the resync lru cache and related information (rs_pending_cnt),
once we successfully finished a resync or online verify, or if the
replication connection is lost.
We also need to reset it if a resync or online verify is aborted
because a lower level disk failed.
In that case the replication link is still established,
and we may still have packets queued in the network buffers
which want to touch rs_pending_cnt.
We do not have any synchronization mechanism to know for sure when all
such pending resync related packets have been drained.
To avoid this counter to go negative (and violate the ASSERT that it
will always be >= 0), just do not reset it when we lose a disk.
It is good enough to make sure it is re-initialized before the next
resync can start: reset it when we re-attach a disk.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Mon, 30 Jul 2012 07:09:36 +0000 (09:09 +0200)]
drbd: reset congestion information before reporting it in /proc/drbd
We cache the congestion status in mdev->congestion_reason whenever
drbd_congested() was called.
Reset this cached info before reporting it when reading /proc/drbd.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Mon, 30 Jul 2012 07:08:25 +0000 (09:08 +0200)]
drbd: report congestion if we are waiting for some userland callback
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>
Lars Ellenberg [Mon, 30 Jul 2012 07:07:28 +0000 (09:07 +0200)]
drbd: differentiate between normal and forced detach
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>
Lars Ellenberg [Mon, 30 Jul 2012 07:06:26 +0000 (09:06 +0200)]
drbd: fix null pointer dereference with on-congestion policy when diskless
We must not look at mdev->actlog, unless we have a get_ldev() reference.
It also does not make much sense to try to disconnect or pull-ahead of
the peer, if we don't have good local data.
Only even consider congestion policies, if our local disk is D_UP_TO_DATE.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Tue, 24 Jul 2012 08:13:55 +0000 (10:13 +0200)]
drbd: take error path in drbd_adm_down if interrupted by signal
drbd_adm_down() does adm_detach(), which can fail with various error
codes, or be interrupted by a signal.
The interrupted by signal case was not properly handled,
leading to
block drbd0: ASSERT( mdev->state.disk == D_DISKLESS &&
mdev->state.conn == C_STANDALONE ) in drbd/drbd_worker.c
and further to destroying objects while still in use, and resulting crashes.
Detect the interruption, and take the error path out.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Tue, 24 Jul 2012 08:12:36 +0000 (10:12 +0200)]
drbd: allow read requests to be retried after force-detach
Sometimes, a lower level block device turns into a tar-pit,
not completing requests at all, not even doing error completion.
We can force-detach from such a tar-pit block device,
either by disk-timeout, or by drbdadm detach --force.
Queueing for retry only from the request destruction path (kref hit 0)
makes it impossible to retry affected read requests from the peer,
until the local IO completion happened, as the locally submitted
bio holds a reference on the drbd request object.
If we can only complete READs when the local completion finally
happens, we would not need to force-detach in the first place.
Instead, queue for retry where we otherwise had done the error completion.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Tue, 24 Jan 2012 16:19:42 +0000 (17:19 +0100)]
drbd: base completion and destruction of requests on ref counts
cherry-picked and adapted from drbd 9 devel branch
The logic for when to get or put a reference is in mod_rq_state().
To not get confused in the freeze/thaw respectively resend/restart
paths, or when cleaning up requests waiting for P_BARRIER_ACK, this
also introduces additional state flags:
RQ_COMPLETION_SUSP, and RQ_EXP_BARR_ACK.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
cherry-picked and adapted from drbd 9 devel branch
DRBD requests (struct drbd_request) are already on the per resource
transfer log list, and carry their epoch number. We do not need to
additionally link them on other ring lists in other structs.
The drbd sender thread can recognize itself when to send a P_BARRIER,
by tracking the currently processed epoch, and how many writes
have been processed for that epoch.
If the epoch of the request to be processed does not match the currently
processed epoch, any writes have been processed in it, a P_BARRIER for
this last processed epoch is send out first.
The new epoch then becomes the currently processed epoch.
To not get stuck in drbd_al_begin_io() waiting for P_BARRIER_ACK,
the sender thread also needs to handle the case when the current
epoch was closed already, but no new requests are queued yet,
and send out P_BARRIER as soon as possible.
This is done by comparing the per resource "current transfer log epoch"
(tconn->current_tle_nr) with the per connection "currently processed
epoch number" (tconn->send.current_epoch_nr), while waiting for
new requests to be processed in wait_for_work().
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Mon, 14 Nov 2011 14:42:37 +0000 (15:42 +0100)]
drbd: move the drbd_work_queue from drbd_socket to drbd_connection
cherry-picked and adapted from drbd 9 devel branch
In 8.4, we don't distinguish between "resource work" and "connection
work" yet, we have one worker for both, as we still have only one connection.
We only ever used the "data.work",
no need to keep the "meta.work" around.
Move tconn->data.work to tconn->sender_work.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Thu, 17 Nov 2011 10:49:46 +0000 (11:49 +0100)]
drbd: transfer log epoch numbers are now per resource
cherry-picked from drbd 9 devel branch.
In preparation of multiple connections, the "barrier number" or
"epoch number" needs to be tracked per-resource, not per connection.
The sequence number space will not be reset anymore.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Lars Ellenberg [Fri, 8 Jun 2012 13:06:39 +0000 (15:06 +0200)]
drbd: fix access of unallocated pages and kernel panic
BUG: unable to handle kernel NULL pointer dereference at (null)
...
[<d1e17561>] ? _drbd_bm_set_bits+0x151/0x240 [drbd]
[<d1e236f8>] ? receive_bitmap+0x4f8/0xbc0 [drbd]
This fixes an off-by-one error in the receive_bitmap() path,
if run-length encoded bitmap transfer is enabled.
If the bitmap is an exact multiple of PAGE_SIZE, which means the visible
capacity of the drbd device is an exact multiple of 128 MiB (for 4k page
size), and bitmap compression (use-rle) is enabled (which became default
with 8.4), and the very last bit is dirty and reported in an rle
comressed bitmap packet, we ended up trying to kmap_atomic a page pointer
that does not exist (bitmap->bm_pages[last index + 1]).
bug introduced by:
Date: Fri Jul 24 15:33:24 2009 +0200
set bits: optimize for complete last word, fix off-by-one-word corner case
made effective by:
Date: Thu Dec 16 00:32:38 2010 +0100
drbd: get rid of unused debug code
Long time ago, we had paranoia code in the bitmap that allocated one
extra word, assigned a magic value, and checked on every occasion that
the magic value was still unchanged.
That debug code is unused, the extra long word complicates code a bit.
Get rid of it.
No-one triggered this bug in the last few years, because a large subset
of our userbase is unaffected:
* typically the last few blocks of a device are not modified
frequently, and remain unset
* use-rle was disabled by default in drbd < 8.4
* those with slightly "odd" device sizes, or
* drbd internal meta data (which will skew the device size slightly,
thus makes it harder to have a bug relevant device size)
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Mon, 20 Feb 2012 20:53:28 +0000 (21:53 +0100)]
drbd: New disk option al-updates
By disabling al-updates one might increase performace. The price for
that is that in case a crashed primary (that had al-updates disabled)
is reintegraded, it will receive a full-resync instead of a bitmap
based resync.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Philipp Reisner [Mon, 30 Apr 2012 10:53:52 +0000 (12:53 +0200)]
drbd: use bitmap_parse instead of __bitmap_parse
The buffer 'sc.cpu_mask' is a kernel buffer. If bitmap_parse is used
instead of __bitmap_parse the extra parameter that indicates a kernel
buffer is not needed.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: Philipp Reisner <philipp.reisner@linbit.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com> Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
projects / linux-beck.git / log