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>
Shaohua Li [Fri, 9 Nov 2012 07:44:27 +0000 (08:44 +0100)]
block: recursive merge requests
In a workload, thread 1 accesses a, a+2, ..., thread 2 accesses a+1, a+3,....
When the requests are flushed to queue, a and a+1 are merged to (a, a+1), a+2
and a+3 too to (a+2, a+3), but (a, a+1) and (a+2, a+3) aren't merged.
If we do recursive merge for such interleave access, some workloads throughput
get improvement. A recent worload I'm checking on is swap, below change
boostes the throughput around 5% ~ 10%.
Signed-off-by: Shaohua Li <shli@fusionio.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Ed Cashin [Fri, 9 Nov 2012 00:17:15 +0000 (19:17 -0500)]
aoe: avoid running request handler on plugged queue
Calling the request handler directly on a plugged queue defeats
the performance improvements provided by the plugging mechanism.
Use the __blk_run_queue function instead of calling the request
handler directly, so that we don't interfere with the block
layer's ability to plug the queue.
Signed-off-by: Ed Cashin <ecashin@coraid.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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>
Linus Torvalds [Fri, 9 Nov 2012 05:59:04 +0000 (06:59 +0100)]
Merge tag 'pinctrl-for-v3.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl
Pull pinctrl fixes from Linus Walleij:
- A set of SPEAr pinctrl fixes that recently arrived
- A fixup for the Samsung/Exynos Kconfig deps
* tag 'pinctrl-for-v3.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
pinctrl: samsung and exynos need to depend on OF && GPIOLIB
pinctrl: SPEAr1340: Add clcd sleep mode pin configuration
pinctrl: SPEAr1340: Make DDR reset & clock pads as gpio
pinctrl: SPEAr1310: add register entries for enabling pad direction
pinctrl: SPEAr1310: Separate out pci pins from pcie_sata pin group
pinctrl: SPEAr1310: Fix value of PERIP_CFG reigster and MCIF_SEL_SHIFT
pinctrl: SPEAr1310: fix clcd high resolution pin group name
pinctrl: SPEAr320: Correct pad mux entries for rmii/smii
pinctrl: SPEAr3xx: correct register space to configure pwm
pinctrl: SPEAr: Don't update all non muxreg bits on pinctrl_disable
Linus Torvalds [Fri, 9 Nov 2012 05:57:56 +0000 (06:57 +0100)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Martin Schwidefsky:
"A couple of bug fixes. I keep the fingers crossed that we now got
transparent huge pages ready for prime time."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/cio: fix length calculation in idset.c
s390/sclp: fix addressing mode clobber
s390: Move css limits from drivers/s390/cio/ to include/asm/.
s390/thp: respect page protection in pmd_none() and pmd_present()
s390/mm: use pmd_large() instead of pmd_huge()
s390/cio: suppress 2nd path verification during resume
Linus Torvalds [Fri, 9 Nov 2012 05:56:23 +0000 (06:56 +0100)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
Pull HID fix from Jiri Kosina:
"This reverts a patch that causes regression in binding between HID
devices and drivers during device unplug/replug cycle."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
HID: hidraw: put old deallocation mechanism in place
Linus Torvalds [Fri, 9 Nov 2012 05:53:02 +0000 (06:53 +0100)]
Merge branch 'akpm' (Fixes from Andrew)
Merge misc fixes from Andrew Morton:
"Five fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (5 patches)
h8300: add missing L1_CACHE_SHIFT
mm: bugfix: set current->reclaim_state to NULL while returning from kswapd()
fanotify: fix missing break
revert "epoll: support for disabling items, and a self-test app"
checkpatch: improve network block comment style checking
Linus Torvalds [Fri, 9 Nov 2012 05:49:24 +0000 (06:49 +0100)]
Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
Pull drm fixes from Dave Airlie:
"Just radeon and nouveau, mostly regressions fixers, and a couple of
radeon register checker fixes."
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/nouveau: fix acpi edid retrieval
drm/nvc0/disp: fix regression in vblank semaphore release
drm/nv40/mpeg: fix context handling
drm/nv40/graph: fix typo in type names
drm/nv41/vm: fix typo in type name
drm/radeon/si: add some missing regs to the VM reg checker
drm/radeon/cayman: add some missing regs to the VM reg checker
drm/radeon/dce3: switch back to old pll allocation order for discrete
Linus Torvalds [Fri, 9 Nov 2012 05:47:55 +0000 (06:47 +0100)]
Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull virtio and module fixes from Rusty Russell:
"YA module signing build tweak, and two cc'd to stable."
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
virtio: Don't access index after unregister.
modules: don't break modules_install on external modules with no key.
module: fix out-by-one error in kallsyms
Linus Torvalds [Fri, 9 Nov 2012 05:42:51 +0000 (06:42 +0100)]
Merge tag 'for-linus-v3.7-rc5' of git://oss.sgi.com/xfs/xfs
Pull xfs bugfixes from Ben Myers:
- fix for large transactions spanning multiple iclog buffers
- zero the allocation_args structure on the stack before using it to
determine whether to use a worker for allocation
- move allocation stack switch to xfs_bmapi_allocate in order to
prevent deadlock on AGF buffers
- growfs no longer reads in garbage for new secondary superblocks
- silence a build warning
- ensure that invalid buffers never get written to disk while on free
list
- don't vmap inode cluster buffers during free
- fix buffer shutdown reference count mismatch
- fix reading of wrapped log data
* tag 'for-linus-v3.7-rc5' of git://oss.sgi.com/xfs/xfs:
xfs: fix reading of wrapped log data
xfs: fix buffer shudown reference count mismatch
xfs: don't vmap inode cluster buffers during free
xfs: invalidate allocbt blocks moved to the free list
xfs: silence uninitialised f.file warning.
xfs: growfs: don't read garbage for new secondary superblocks
xfs: move allocation stack switch up to xfs_bmapi_allocate
xfs: introduce XFS_BMAPI_STACK_SWITCH
xfs: zero allocation_args on the kernel stack
xfs: only update the last_sync_lsn when a transaction completes
Fengguang Wu [Thu, 8 Nov 2012 23:53:41 +0000 (15:53 -0800)]
h8300: add missing L1_CACHE_SHIFT
Fix the build error
lib/atomic64.c: In function 'lock_addr':
lib/atomic64.c:40:11: error: 'L1_CACHE_SHIFT' undeclared (first use in this function)
lib/atomic64.c:40:11: note: each undeclared identifier is reported only once for each function it appears in
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm: bugfix: set current->reclaim_state to NULL while returning from kswapd()
In kswapd(), set current->reclaim_state to NULL before returning, as
current->reclaim_state holds reference to variable on kswapd()'s stack.
In rare cases, while returning from kswapd() during memory offlining,
__free_slab() and freepages() can access the dangling pointer of
current->reclaim_state.
but never applied it. Repeated attempts over time to actually get him
to apply it have never had a reply from anyone who has raised it
So apply it anyway
Signed-off-by: Alan Cox <alan@linux.intel.com> Reported-by: Anders Blomdell <anders.blomdell@control.lth.se> Cc: Eric Paris <eparis@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrew Morton [Thu, 8 Nov 2012 23:53:35 +0000 (15:53 -0800)]
revert "epoll: support for disabling items, and a self-test app"
Revert commit 03a7beb55b9f ("epoll: support for disabling items, and a
self-test app") pending resolution of the issues identified by Michael
Kerrisk, copied below.
We'll revisit this for 3.8.
: I've taken a look at this patch as it currently stands in 3.7-rc1, and
: done a bit of testing. (By the way, the test program
: tools/testing/selftests/epoll/test_epoll.c does not compile...)
:
: There are one or two places where the behavior seems a little strange,
: so I have a question or two at the end of this mail. But other than
: that, I want to check my understanding so that the interface can be
: correctly documented.
:
: Just to go though my understanding, the problem is the following
: scenario in a multithreaded application:
:
: 1. Multiple threads are performing epoll_wait() operations,
: and maintaining a user-space cache that contains information
: corresponding to each file descriptor being monitored by
: epoll_wait().
:
: 2. At some point, a thread wants to delete (EPOLL_CTL_DEL)
: a file descriptor from the epoll interest list, and
: delete the corresponding record from the user-space cache.
:
: 3. The problem with (2) is that some other thread may have
: previously done an epoll_wait() that retrieved information
: about the fd in question, and may be in the middle of using
: information in the cache that relates to that fd. Thus,
: there is a potential race.
:
: 4. The race can't solved purely in user space, because doing
: so would require applying a mutex across the epoll_wait()
: call, which would of course blow thread concurrency.
:
: Right?
:
: Your solution is the EPOLL_CTL_DISABLE operation. I want to
: confirm my understanding about how to use this flag, since
: the description that has accompanied the patches so far
: has been a bit sparse
:
: 0. In the scenario you're concerned about, deleting a file
: descriptor means (safely) doing the following:
: (a) Deleting the file descriptor from the epoll interest list
: using EPOLL_CTL_DEL
: (b) Deleting the corresponding record in the user-space cache
:
: 1. It's only meaningful to use this EPOLL_CTL_DISABLE in
: conjunction with EPOLLONESHOT.
:
: 2. Using EPOLL_CTL_DISABLE without using EPOLLONESHOT in
: conjunction is a logical error.
:
: 3. The correct way to code multithreaded applications using
: EPOLL_CTL_DISABLE and EPOLLONESHOT is as follows:
:
: a. All EPOLL_CTL_ADD and EPOLL_CTL_MOD operations should
: should EPOLLONESHOT.
:
: b. When a thread wants to delete a file descriptor, it
: should do the following:
:
: [1] Call epoll_ctl(EPOLL_CTL_DISABLE)
: [2] If the return status from epoll_ctl(EPOLL_CTL_DISABLE)
: was zero, then the file descriptor can be safely
: deleted by the thread that made this call.
: [3] If the epoll_ctl(EPOLL_CTL_DISABLE) fails with EBUSY,
: then the descriptor is in use. In this case, the calling
: thread should set a flag in the user-space cache to
: indicate that the thread that is using the descriptor
: should perform the deletion operation.
:
: Is all of the above correct?
:
: The implementation depends on checking on whether
: (events & ~EP_PRIVATE_BITS) == 0
: This replies on the fact that EPOLL_CTL_AD and EPOLL_CTL_MOD always
: set EPOLLHUP and EPOLLERR in the 'events' mask, and EPOLLONESHOT
: causes those flags (as well as all others in ~EP_PRIVATE_BITS) to be
: cleared.
:
: A corollary to the previous paragraph is that using EPOLL_CTL_DISABLE
: is only useful in conjunction with EPOLLONESHOT. However, as things
: stand, one can use EPOLL_CTL_DISABLE on a file descriptor that does
: not have EPOLLONESHOT set in 'events' This results in the following
: (slightly surprising) behavior:
:
: (a) The first call to epoll_ctl(EPOLL_CTL_DISABLE) returns 0
: (the indicator that the file descriptor can be safely deleted).
: (b) The next call to epoll_ctl(EPOLL_CTL_DISABLE) fails with EBUSY.
:
: This doesn't seem particularly useful, and in fact is probably an
: indication that the user made a logic error: they should only be using
: epoll_ctl(EPOLL_CTL_DISABLE) on a file descriptor for which
: EPOLLONESHOT was set in 'events'. If that is correct, then would it
: not make sense to return an error to user space for this case?
Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: "Paton J. Lewis" <palewis@adobe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some comment styles in net and drivers/net are flagged inappropriately.
Avoid proclaiming inline comments like:
int a = b; /* some comment */
and block comments like:
/*********************
* some comment
********************/
are defective.
Tested with
$ cat drivers/net/t.c
/* foo */
/*
* foo
*/
/* foo
*/
/* foo
* bar */
/****************************
* some long block comment
***************************/
struct foo {
int bar; /* another test */
};
$
Signed-off-by: Joe Perches <joe@perches.com> Reported-by: Larry Finger <Larry.Finger@lwfinger.net> Cc: David Miller <davem@davemloft.net> Cc: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dave Airlie [Fri, 9 Nov 2012 04:57:02 +0000 (14:57 +1000)]
Merge branch 'drm-nouveau-fixes' of git://anongit.freedesktop.org/git/nouveau/linux-2.6 into drm-fixes
just some misc regression fixes and typo fixes.
* 'drm-nouveau-fixes' of git://anongit.freedesktop.org/git/nouveau/linux-2.6:
drm/nouveau: fix acpi edid retrieval
drm/nvc0/disp: fix regression in vblank semaphore release
drm/nv40/mpeg: fix context handling
drm/nv40/graph: fix typo in type names
drm/nv41/vm: fix typo in type name
Cornelia Huck [Fri, 9 Nov 2012 04:24:12 +0000 (14:54 +1030)]
virtio: Don't access index after unregister.
Virtio wants to release used indices after the corresponding
virtio device has been unregistered. However, virtio does not
hold an extra reference, giving up its last reference with
device_unregister(), making accessing dev->index afterwards
invalid.
I actually saw problems when testing my (not-yet-merged)
virtio-ccw code:
- device_add virtio-net,id=xxx
-> creates device virtio<n> with n>0
- device_del xxx
-> deletes virtio<n>, but calls ida_simple_remove with an
index of 0
- device_add virtio-net,id=xxx
-> tries to add virtio0, which is still in use...
So let's save the index we want to release before calling
device_unregister().
Commit c0077061e7ea accidentally inverted the logic for nouveau_acpi_edid,
causing it to only show a connector as connected when the edid could not
be retrieved with acpi.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com> Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Dave Airlie [Fri, 9 Nov 2012 03:29:07 +0000 (13:29 +1000)]
Merge branch 'drm-fixes-3.7' of git://people.freedesktop.org/~agd5f/linux into drm-fixes
Just some minor fixes for VM reg check and a regression fix for dce3 plls
* 'drm-fixes-3.7' of git://people.freedesktop.org/~agd5f/linux:
drm/radeon/si: add some missing regs to the VM reg checker
drm/radeon/cayman: add some missing regs to the VM reg checker
drm/radeon/dce3: switch back to old pll allocation order for discrete
Dave Chinner [Fri, 2 Nov 2012 00:38:44 +0000 (11:38 +1100)]
xfs: fix reading of wrapped log data
Commit 4439647 ("xfs: reset buffer pointers before freeing them") in
3.0-rc1 introduced a regression when recovering log buffers that
wrapped around the end of log. The second part of the log buffer at
the start of the physical log was being read into the header buffer
rather than the data buffer, and hence recovery was seeing garbage
in the data buffer when it got to the region of the log buffer that
was incorrectly read.
Cc: <stable@vger.kernel.org> # 3.0.x, 3.2.x, 3.4.x 3.6.x Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Fri, 2 Nov 2012 03:23:12 +0000 (14:23 +1100)]
xfs: fix buffer shudown reference count mismatch
When we shut down the filesystem, we have to unpin and free all the
buffers currently active in the CIL. To do this we unpin and remove
them in one operation as a result of a failed iclogbuf write. For
buffers, we do this removal via a simultated IO completion of after
marking the buffer stale.
At the time we do this, we have two references to the buffer - the
active LRU reference and the buf log item. The LRU reference is
removed by marking the buffer stale, and the active CIL reference is
by the xfs_buf_iodone() callback that is run by
xfs_buf_do_callbacks() during ioend processing (via the bp->b_iodone
callback).
However, ioend processing requires one more reference - that of the
IO that it is completing. We don't have this reference, so we free
the buffer prematurely and use it after it is freed. For buffers
marked with XBF_ASYNC, this leads to assert failures in
xfs_buf_rele() on debug kernels because the b_hold count is zero.
Fix this by making sure we take the necessary IO reference before
starting IO completion processing on the stale buffer, and set the
XBF_ASYNC flag to ensure that IO completion processing removes all
the active references from the buffer to ensure it is fully torn
down.
Cc: <stable@vger.kernel.org> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Fri, 2 Nov 2012 00:38:42 +0000 (11:38 +1100)]
xfs: don't vmap inode cluster buffers during free
Inode buffers do not need to be mapped as inodes are read or written
directly from/to the pages underlying the buffer. This fixes a
regression introduced by commit 611c994 ("xfs: make XBF_MAPPED the
default behaviour").
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Fri, 2 Nov 2012 00:38:41 +0000 (11:38 +1100)]
xfs: invalidate allocbt blocks moved to the free list
When we free a block from the alloc btree tree, we move it to the
freelist held in the AGFL and mark it busy in the busy extent tree.
This typically happens when we merge btree blocks.
Once the transaction is committed and checkpointed, the block can
remain on the free list for an indefinite amount of time. Now, this
isn't the end of the world at this point - if the free list is
shortened, the buffer is invalidated in the transaction that moves
it back to free space. If the buffer is allocated as metadata from
the free list, then all the modifications getted logged, and we have
no issues, either. And if it gets allocated as userdata direct from
the freelist, it gets invalidated and so will never get written.
However, during the time it sits on the free list, pressure on the
log can cause the AIL to be pushed and the buffer that covers the
block gets pushed for write. IOWs, we end up writing a freed
metadata block to disk. Again, this isn't the end of the world
because we know from the above we are only writing to free space.
The problem, however, is for validation callbacks. If the block was
on old btree root block, then the level of the block is going to be
higher than the current tree root, and so will fail validation.
There may be other inconsistencies in the block as well, and
currently we don't care because the block is in free space. Shutting
down the filesystem because a freed block doesn't pass write
validation, OTOH, is rather unfriendly.
So, make sure we always invalidate buffers as they move from the
free space trees to the free list so that we guarantee they never
get written to disk while on the free list.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Phil White <pwhite@sgi.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Thu, 25 Oct 2012 06:22:30 +0000 (17:22 +1100)]
xfs: silence uninitialised f.file warning.
Uninitialised variable build warning introduced by 2903ff0 ("switch
simple cases of fget_light to fdget"), gcc is not smart enough to
work out that the variable is not used uninitialised, and the commit
removed the initialisation at declaration that the old variable had.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Tue, 9 Oct 2012 03:50:52 +0000 (14:50 +1100)]
xfs: growfs: don't read garbage for new secondary superblocks
When updating new secondary superblocks in a growfs operation, the
superblock buffer is read from the newly grown region of the
underlying device. This is not guaranteed to be zero, so violates
the underlying assumption that the unused parts of superblocks are
zero filled. Get a new buffer for these secondary superblocks to
ensure that the unused regions are zero filled correctly.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Fri, 5 Oct 2012 01:06:59 +0000 (11:06 +1000)]
xfs: move allocation stack switch up to xfs_bmapi_allocate
Switching stacks are xfs_alloc_vextent can cause deadlocks when we
run out of worker threads on the allocation workqueue. This can
occur because xfs_bmap_btalloc can make multiple calls to
xfs_alloc_vextent() and even if xfs_alloc_vextent() fails it can
return with the AGF locked in the current allocation transaction.
If we then need to make another allocation, and all the allocation
worker contexts are exhausted because the are blocked waiting for
the AGF lock, holder of the AGF cannot get it's xfs-alloc_vextent
work completed to release the AGF. Hence allocation effectively
deadlocks.
To avoid this, move the stack switch one layer up to
xfs_bmapi_allocate() so that all of the allocation attempts in a
single switched stack transaction occur in a single worker context.
This avoids the problem of an allocation being blocked waiting for
a worker thread whilst holding the AGF.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Fri, 5 Oct 2012 01:06:58 +0000 (11:06 +1000)]
xfs: introduce XFS_BMAPI_STACK_SWITCH
Certain allocation paths through xfs_bmapi_write() are in situations
where we have limited stack available. These are almost always in
the buffered IO writeback path when convertion delayed allocation
extents to real extents.
The current stack switch occurs for userdata allocations, which
means we also do stack switches for preallocation, direct IO and
unwritten extent conversion, even those these call chains have never
been implicated in a stack overrun.
Hence, let's target just the single stack overun offended for stack
switches. To do that, introduce a XFS_BMAPI_STACK_SWITCH flag that
the caller can pass xfs_bmapi_write() to indicate it should switch
stacks if it needs to do allocation.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
Dave Chinner [Mon, 8 Oct 2012 10:56:12 +0000 (21:56 +1100)]
xfs: only update the last_sync_lsn when a transaction completes
The log write code stamps each iclog with the current tail LSN in
the iclog header so that recovery knows where to find the tail of
thelog once it has found the head. Normally this is taken from the
first item on the AIL - the log item that corresponds to the oldest
active item in the log.
The problem is that when the AIL is empty, the tail lsn is dervied
from the the l_last_sync_lsn, which is the LSN of the last iclog to
be written to the log. In most cases this doesn't happen, because
the AIL is rarely empty on an active filesystem. However, when it
does, it opens up an interesting case when the transaction being
committed to the iclog spans multiple iclogs.
That is, the first iclog is stamped with the l_last_sync_lsn, and IO
is issued. Then the next iclog is setup, the changes copied into the
iclog (takes some time), and then the l_last_sync_lsn is stamped
into the header and IO is issued. This is still the same
transaction, so the tail lsn of both iclogs must be the same for log
recovery to find the entire transaction to be able to replay it.
The problem arises in that the iclog buffer IO completion updates
the l_last_sync_lsn with it's own LSN. Therefore, If the first iclog
completes it's IO before the second iclog is filled and has the tail
lsn stamped in it, it will stamp the LSN of the first iclog into
it's tail lsn field. If the system fails at this point, log recovery
will not see a complete transaction, so the transaction will no be
replayed.
The fix is simple - the l_last_sync_lsn is updated when a iclog
buffer IO completes, and this is incorrect. The l_last_sync_lsn
shoul dbe updated when a transaction is completed by a iclog buffer
IO. That is, only iclog buffers that have transaction commit
callbacks attached to them should update the l_last_sync_lsn. This
means that the last_sync_lsn will only move forward when a commit
record it written, not in the middle of a large transaction that is
rolling through multiple iclog buffers.
Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.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>
projects / karo-tx-linux.git / log