Commit Graph

798667 Commits

Author SHA1 Message Date
Chengguang Xu 93f87a74fd block: sunvdc: remove redundant code
Code cleanup for removing redundant break in switch case.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-22 14:45:33 -07:00
Chengguang Xu c41103691b block: loop: remove redundant code
Code cleanup for removing redundant break in switch case.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-22 14:45:31 -07:00
Christoph Hellwig 2e5b2d7c40 bsg: deprecate BIDI support in bsg
Besides the OSD command set that never got traction, the only SCSI
command using bidirectional buffers is XDWRITEREAD in the 10 and 32 byte
variants, which is extremely esoteric and has been removed from the spec
again as of SBC4r15.  It probably doesn't make sense to keep the support
code around just for that, so start deprecating the support.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-21 08:47:58 -07:00
Dennis Zhou 6b4505352e blkcg: remove unused __blkg_release_rcu()
An earlier commit 7fcf2b033b ("blkcg: change blkg reference counting
to use percpu_ref") moved around the release call from blkg_put() to be
a part of the percpu_ref cleanup. Remove the additional unused code
which should have been removed earlier.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-21 08:47:58 -07:00
Dennis Zhou 6ab2187992 blkcg: clean up blkg_tryget_closest()
The implementation of blkg_tryget_closest() wasn't super obvious and
became a point of suspicion when debugging [1]. So let's clean it up so
it's obviously not the problem.

Also add missing RCU read locking to bio_clone_blkg_association(), which
got exposed by adding the RCU read lock held check in
blkg_tryget_closest().

[1] https://lore.kernel.org/linux-block/a7e97e4b-0dd8-3a54-23b7-a0f27b17fde8@kernel.dk/

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-21 08:47:05 -07:00
Nathan Chancellor 5816a0932b drbd: Change drbd_request_detach_interruptible's return type to int
Clang warns when an implicit conversion is done between enumerated
types:

drivers/block/drbd/drbd_state.c:708:8: warning: implicit conversion from
enumeration type 'enum drbd_ret_code' to different enumeration type
'enum drbd_state_rv' [-Wenum-conversion]
                rv = ERR_INTR;
                   ~ ^~~~~~~~

drbd_request_detach_interruptible's only call site is in the return
statement of adm_detach, which returns an int. Change the return type of
drbd_request_detach_interruptible to match, silencing Clang's warning.

Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:31 -07:00
Nathan Chancellor a52c5a16cf drbd: Avoid Clang warning about pointless switch statment
There are several warnings from Clang about no case statement matching
the constant 0:

In file included from drivers/block/drbd/drbd_receiver.c:48:
In file included from drivers/block/drbd/drbd_int.h:48:
In file included from ./include/linux/drbd_genl_api.h:54:
In file included from ./include/linux/genl_magic_struct.h:236:
./include/linux/drbd_genl.h:321:1: warning: no case matching constant
switch condition '0'
GENL_struct(DRBD_NLA_HELPER, 24, drbd_helper_info,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/genl_magic_struct.h:220:10: note: expanded from macro
'GENL_struct'
        switch (0) {
                ^

Silence this warning by adding a 'case 0:' statement. Additionally,
adjust the alignment of the statements in the ct_assert_unique macro to
avoid a checkpatch warning.

This solution was originally sent by Arnd Bergmann with a default case
statement: https://lore.kernel.org/patchwork/patch/756723/

Link: https://github.com/ClangBuiltLinux/linux/issues/43
Suggested-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:31 -07:00
Lars Ellenberg f31e583aa2 drbd: introduce P_ZEROES (REQ_OP_WRITE_ZEROES on the "wire")
And also re-enable partial-zero-out + discard aligned.

With the introduction of REQ_OP_WRITE_ZEROES,
we started to use that for both WRITE_ZEROES and DISCARDS,
hoping that WRITE_ZEROES would "do what we want",
UNMAP if possible, zero-out the rest.

The example scenario is some LVM "thin" backend.

While an un-allocated block on dm-thin reads as zeroes, on a dm-thin
with "skip_block_zeroing=true", after a partial block write allocated
that block, that same block may well map "undefined old garbage" from
the backends on LBAs that have not yet been written to.

If we cannot distinguish between zero-out and discard on the receiving
side, to avoid "undefined old garbage" to pop up randomly at later times
on supposedly zero-initialized blocks, we'd need to map all discards to
zero-out on the receiving side.  But that would potentially do a full
alloc on thinly provisioned backends, even when the expectation was to
unmap/trim/discard/de-allocate.

We need to distinguish on the protocol level, whether we need to guarantee
zeroes (and thus use zero-out, potentially doing the mentioned full-alloc),
or if we want to put the emphasis on discard, and only do a "best effort
zeroing" (by "discarding" blocks aligned to discard-granularity, and zeroing
only potential unaligned head and tail clippings to at least *try* to
avoid "false positives" in an online-verify later), hoping that someone
set skip_block_zeroing=false.

For some discussion regarding this on dm-devel, see also
https://www.mail-archive.com/dm-devel%40redhat.com/msg07965.html
https://www.redhat.com/archives/dm-devel/2018-January/msg00271.html

For backward compatibility, P_TRIM means zero-out, unless the
DRBD_FF_WZEROES feature flag is agreed upon during handshake.

To have upper layers even try to submit WRITE ZEROES requests,
we need to announce "efficient zeroout" independently.

We need to fixup max_write_zeroes_sectors after blk_queue_stack_limits():
if we can handle "zeroes" efficiently on the protocol,
we want to do that, even if our backend does not announce
max_write_zeroes_sectors itself.

Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:31 -07:00
Lars Ellenberg 9848b6ddd8 drbd: skip spurious timeout (ping-timeo) when failing promote
If you try to promote a Secondary while connected to a Primary
and allow-two-primaries is NOT set, we will wait for "ping-timeout"
to give this node a chance to detect a dead primary,
in case the cluster manager noticed faster than we did.

But if we then are *still* connected to a Primary,
we fail (after an additional timeout of ping-timout).

This change skips the spurious second timeout.

Most people won't notice really,
since "ping-timeout" by default is half a second.

But in some installations, ping-timeout may be 10 or 20 seconds or more,
and spuriously delaying the error return becomes annoying.

Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:31 -07:00
Lars Ellenberg 9049ccd46f drbd: don't retry connection if peers do not agree on "authentication" settings
emma: "Unexpected data packet AuthChallenge (0x0010)"
 ava: "expected AuthChallenge packet, received: ReportProtocol (0x000b)"
      "Authentication of peer failed, trying again."

Pattern repeats.

There is no point in retrying the handshake,
if we expect to receive an AuthChallenge,
but the peer is not even configured to expect or use a shared secret.

Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:31 -07:00
Luc Van Oostenryck 2c38f03511 drbd: fix print_st_err()'s prototype to match the definition
print_st_err() is defined with its 4th argument taking an
'enum drbd_state_rv' but its prototype use an int for it.

Fix this by using 'enum drbd_state_rv' in the prototype too.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Roland Kammerer <roland.kammerer@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:30 -07:00
Lars Ellenberg be80ff8835 drbd: avoid spurious self-outdating with concurrent disconnect / down
If peers are "simultaneously" told to disconnect from each other,
either explicitly, or implicitly by taking down the resource,
with bad timing, one side may see its disconnect "fail" with
a result of "state change failed by peer", and interpret this as
"please oudate yourself".

Try to catch this by checking for current connection status,
and possibly retry as local-only state change instead.

Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:30 -07:00
Lars Ellenberg f708bd08ec drbd: do not block when adjusting "disk-options" while IO is frozen
"suspending" IO is overloaded.
It can mean "do not allow new requests" (obviously),
but it also may mean "must not complete pending IO",
for example while the fencing handlers do their arbitration.

When adjusting disk options, we suspend io (disallow new requests), then
wait for the activity-log to become unused (drain all IO completions),
and possibly replace it with a new activity log of different size.

If the other "suspend IO" aspect is active, pending IO completions won't
happen, and we would block forever (unkillable drbdsetup process).

Fix this by skipping the activity log adjustment if the "al-extents"
setting did not change. Also, in case it did change, fail early without
blocking if it looks like we would block forever.

Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:30 -07:00
Lars Ellenberg a2823ea920 drbd: fix comment typos
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:30 -07:00
Lars Ellenberg fe43ed97bb drbd: reject attach of unsuitable uuids even if connected
Multiple failure scenario:
a) all good
   Connected Primary/Secondary UpToDate/UpToDate
b) lose disk on Primary,
   Connected Primary/Secondary Diskless/UpToDate
c) continue to write to the device,
   changes only make it to the Secondary storage.
d) lose disk on Secondary,
   Connected Primary/Secondary Diskless/Diskless
e) now try to re-attach on Primary

This would have succeeded before, even though that is clearly the
wrong data set to attach to (missing the modifications from c).
Because we only compared our "effective" and the "to-be-attached"
data generation uuid tags if (device->state.conn < C_CONNECTED).

Fix: change that constraint to (device->state.pdsk != D_UP_TO_DATE)
compare the uuids, and reject the attach.

This patch also tries to improve the reverse scenario:
first lose Secondary, then Primary disk,
then try to attach the disk on Secondary.

Before this patch, the attach on the Secondary succeeds, but since commit
drbd: disconnect, if the wrong UUIDs are attached on a connected peer
the Primary will notice unsuitable data, and drop the connection hard.

Though unfortunately at a point in time during the handshake where
we cannot easily abort the attach on the peer without more
refactoring of the handshake.

We now reject any attach to "unsuitable" uuids,
as long as we can see a Primary role,
unless we already have access to "good" data.

Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:30 -07:00
Lars Ellenberg ad6e897902 drbd: attach on connected diskless peer must not shrink a consistent device
If we would reject a new handshake, if the peer had attached first,
and then connected, we should force disconnect if the peer first connects,
and only then attaches.

Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:30 -07:00
Lars Ellenberg 4ef2a4f43f drbd: fix confusing error message during attach
If we attach a (consistent) backing device,
which knows about a last-agreed effective size,
and that effective size is *larger* than the currently requested size,
we refused to attach with ERR_DISK_TOO_SMALL
  Failure: (111) Low.dev. smaller than requested DRBD-dev. size.
which is confusing to say the least.

This patch changes the error code in that case to ERR_IMPLICIT_SHRINK
  Failure: (170) Implicit device shrinking not allowed. See kernel log.
  additional info from kernel:
  To-be-attached device has last effective > current size, and is consistent
  (9999 > 7777 sectors). Refusing to attach.

It also allows to attach with an explicit size.

Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:30 -07:00
Lars Ellenberg b17b59602b drbd: disconnect, if the wrong UUIDs are attached on a connected peer
With "on-no-data-accessible suspend-io", DRBD requires the next attach
or connect to be to the very same data generation uuid tag it lost last.

If we first lost connection to the peer,
then later lost connection to our own disk,
we would usually refuse to re-connect to the peer,
because it presents the wrong data set.

However, if the peer first connects without a disk,
and then attached its disk, we accepted that same wrong data set,
which would be "unexpected" by any user of that DRBD
and cause "undefined results" (read: very likely data corruption).

The fix is to forcefully disconnect as soon as we notice that the peer
attached to the "wrong" dataset.

Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:30 -07:00
Lars Ellenberg 94c43a13b8 drbd: ignore "all zero" peer volume sizes in handshake
During handshake, if we are diskless ourselves, we used to accept any size
presented by the peer.

Which could be zero if that peer was just brought up and connected
to us without having a disk attached first, in which case both
peers would just "flip" their volume sizes.

Now, even a diskless node will ignore "zero" sizes
presented by a diskless peer.

Also a currently Diskless Primary will refuse to shrink during handshake:
it may be frozen, and waiting for a "suitable" local disk or peer to
re-appear (on-no-data-accessible suspend-io). If the peer is smaller
than what we used to be, it is not suitable.

The logic for a diskless node during handshake is now supposed to be:
believe the peer, if
 - I don't have a current size myself
 - we agree on the size anyways
 - I do have a current size, am Secondary, and he has the only disk
 - I do have a current size, am Primary, and he has the only disk,
   which is larger than my current size

Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:29 -07:00
Lars Ellenberg d5412e8d8e drbd: centralize printk reporting of new size into drbd_set_my_capacity()
Previously, some implicit resizes that happend during handshake
have not been reported as prominently as explicit resize.

Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:29 -07:00
Lars Ellenberg 792c3fdd94 drbd: must not use connection after kref_put(&connection->kref)
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:29 -07:00
Roland Kammerer d29e89e349 drbd: narrow rcu_read_lock in drbd_sync_handshake
So far there was the possibility that we called
genlmsg_new(GFP_NOIO)/mutex_lock() while holding an rcu_read_lock().

This included cases like:

drbd_sync_handshake (acquire the RCU lock)
  drbd_asb_recover_1p
    drbd_khelper
      drbd_bcast_event
        genlmsg_new(GFP_NOIO) --> may sleep

drbd_sync_handshake (acquire the RCU lock)
  drbd_asb_recover_1p
    drbd_khelper
      notify_helper
        genlmsg_new(GFP_NOIO) --> may sleep

drbd_sync_handshake (acquire the RCU lock)
  drbd_asb_recover_1p
    drbd_khelper
      notify_helper
        mutex_lock --> may sleep

While using GFP_ATOMIC whould have been possible in the first two cases,
the real fix is to narrow the rcu_read_lock.

Reported-by: Jia-Ju Bai <baijiaju1990@163.com>
Reviewed-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Roland Kammerer <roland.kammerer@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-20 09:51:29 -07:00
Ming Lei 3a762de55b block: save irq state in blkg_lookup_create()
blkg_lookup_create() may be called from pool_map() in which
irq state is saved, so we have to do that in blkg_lookup_create().

Otherwise, the following lockdep warning can be triggered:

[  104.258537] ================================
[  104.259129] WARNING: inconsistent lock state
[  104.259725] 4.20.0-rc6+ #545 Not tainted
[  104.260268] --------------------------------
[  104.260865] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
[  104.261727] swapper/49/0 [HC0[0]:SC1[1]:HE0:SE0] takes:
[  104.262444] 00000000db365b5d (&(&pool->lock)->rlock#3){+.?.}, at: thin_endio+0xcf/0x2a3 [dm_thin_pool]
[  104.263747] {SOFTIRQ-ON-W} state was registered at:
[  104.264417]   _raw_spin_unlock_irq+0x29/0x4c
[  104.265014]   blkg_lookup_create+0xdc/0xe6
[  104.265609]   bio_associate_blkg_from_css+0xd3/0x13f
[  104.266312]   bio_associate_blkg+0x15a/0x1bb
[  104.266913]   pool_map+0xe8/0x103 [dm_thin_pool]
[  104.267572]   __map_bio+0x98/0x29c [dm_mod]
[  104.268162]   __split_and_process_non_flush+0x29e/0x306 [dm_mod]
[  104.269003]   __split_and_process_bio+0x16a/0x25b [dm_mod]
[  104.269971]   __dm_make_request.isra.14+0xdc/0x124 [dm_mod]
[  104.270973]   generic_make_request+0x3f5/0x68b
[  104.271676]   process_prepared_mapping+0x166/0x1ef [dm_thin_pool]
[  104.272531]   schedule_zero+0x239/0x273 [dm_thin_pool]
[  104.273245]   process_cell+0x60c/0x6f1 [dm_thin_pool]
[  104.273967]   do_worker+0x60c/0xca8 [dm_thin_pool]
[  104.274635]   process_one_work+0x4eb/0x834
[  104.275203]   worker_thread+0x318/0x484
[  104.275740]   kthread+0x1d1/0x1e1
[  104.276203]   ret_from_fork+0x3a/0x50
[  104.276714] irq event stamp: 170003
[  104.277201] hardirqs last  enabled at (170002): [<ffffffff81bcc33e>] _raw_spin_unlock_irqrestore+0x44/0x6b
[  104.278535] hardirqs last disabled at (170003): [<ffffffff81bcc1ad>] _raw_spin_lock_irqsave+0x20/0x55
[  104.280273] softirqs last  enabled at (169978): [<ffffffff810d13d4>] irq_enter+0x4c/0x73
[  104.281617] softirqs last disabled at (169979): [<ffffffff810d1479>] irq_exit+0x7e/0x11d
[  104.282744]
[  104.282744] other info that might help us debug this:
[  104.283640]  Possible unsafe locking scenario:
[  104.283640]
[  104.284452]        CPU0
[  104.284803]        ----
[  104.285150]   lock(&(&pool->lock)->rlock#3);
[  104.285762]   <Interrupt>
[  104.286130]     lock(&(&pool->lock)->rlock#3);
[  104.286750]
[  104.286750]  *** DEADLOCK ***
[  104.286750]
[  104.287564] no locks held by swapper/49/0.
[  104.288129]
[  104.288129] stack backtrace:
[  104.288738] CPU: 49 PID: 0 Comm: swapper/49 Not tainted 4.20.0-rc6+ #545
[  104.289700] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-2.fc27 04/01/2014
[  104.290858] Call Trace:
[  104.291204]  <IRQ>
[  104.291502]  dump_stack+0x9a/0xe6
[  104.291968]  mark_lock+0x56c/0x7a6
[  104.292442]  ? check_usage_backwards+0x209/0x209
[  104.293086]  __lock_acquire+0x400/0x15bf
[  104.293662]  ? check_chain_key+0x150/0x1aa
[  104.294236]  lock_acquire+0x1a6/0x1e3
[  104.294768]  ? thin_endio+0xcf/0x2a3 [dm_thin_pool]
[  104.295444]  ? _raw_spin_unlock_irqrestore+0x44/0x6b
[  104.296143]  ? process_prepared_discard_fail+0x36/0x36 [dm_thin_pool]
[  104.297031]  _raw_spin_lock_irqsave+0x46/0x55
[  104.297659]  ? thin_endio+0xcf/0x2a3 [dm_thin_pool]
[  104.298335]  thin_endio+0xcf/0x2a3 [dm_thin_pool]
[  104.298997]  ? process_prepared_discard_fail+0x36/0x36 [dm_thin_pool]
[  104.299886]  ? check_flags+0x20a/0x20a
[  104.300408]  ? lock_acquire+0x1a6/0x1e3
[  104.300954]  ? process_prepared_discard_fail+0x36/0x36 [dm_thin_pool]
[  104.301865]  clone_endio+0x1bb/0x22d [dm_mod]
[  104.302491]  ? disable_write_zeroes+0x20/0x20 [dm_mod]
[  104.303200]  ? bio_disassociate_blkg+0xc6/0x15f
[  104.303836]  ? bio_endio+0x2b2/0x2da
[  104.304349]  clone_endio+0x1f3/0x22d [dm_mod]
[  104.304978]  ? disable_write_zeroes+0x20/0x20 [dm_mod]
[  104.305709]  ? bio_disassociate_blkg+0xc6/0x15f
[  104.306333]  ? bio_endio+0x2b2/0x2da
[  104.306853]  clone_endio+0x1f3/0x22d [dm_mod]
[  104.307476]  ? disable_write_zeroes+0x20/0x20 [dm_mod]
[  104.308185]  ? bio_disassociate_blkg+0xc6/0x15f
[  104.308817]  ? bio_endio+0x2b2/0x2da
[  104.309319]  blk_update_request+0x2de/0x4cc
[  104.309927]  blk_mq_end_request+0x2a/0x183
[  104.310498]  blk_done_softirq+0x16a/0x1a6
[  104.311051]  ? blk_softirq_cpu_dead+0xe2/0xe2
[  104.311653]  ? __lock_is_held+0x2a/0x87
[  104.312186]  __do_softirq+0x250/0x4e8
[  104.312705]  irq_exit+0x7e/0x11d
[  104.313157]  call_function_single_interrupt+0xf/0x20
[  104.313860]  </IRQ>
[  104.314163] RIP: 0010:native_safe_halt+0x2/0x3
[  104.314792] Code: 63 02 df f0 83 44 24 fc 00 48 89 df e8 cc 3f 7a ff 48 8b 03 a8 08 74 0b 65 81 25 9d 31 45 7e ff ff ff 7f 5b 5d 41 5c c3 fb f4 <c3> f4 c3 0f 1f 44 00 00 41 56 41 55 41 54 55 53 e8 a2 0d 5c ff e8
[  104.317339] RSP: 0018:ffff888106c9fdc0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff04
[  104.318390] RAX: 1ffff11020d92100 RBX: 0000000000000000 RCX: ffffffff81159ac7
[  104.319366] RDX: 1ffffffff05d5e69 RSI: 0000000000000007 RDI: ffff888106c90d1c
[  104.320339] RBP: 0000000000000000 R08: dffffc0000000000 R09: 0000000000000001
[  104.321313] R10: ffffed1025d57ba0 R11: ffffed1025d57b9f R12: 1ffff11020d93fbf
[  104.322328] R13: 0000000000000031 R14: ffff888106c90040 R15: 0000000000000000
[  104.323307]  ? lockdep_hardirqs_on+0x26b/0x278
[  104.323927]  default_idle+0xd9/0x1a8
[  104.324427]  do_idle+0x162/0x2b2
[  104.324891]  ? arch_cpu_idle_exit+0x28/0x28
[  104.325467]  ? mark_held_locks+0x28/0x7f
[  104.326031]  ? _raw_spin_unlock_irqrestore+0x44/0x6b
[  104.326719]  cpu_startup_entry+0x1d/0x1f
[  104.327261]  start_secondary+0x2cb/0x308
[  104.327806]  ? set_cpu_sibling_map+0x8a3/0x8a3
[  104.328421]  secondary_startup_64+0xa4/0xb0

Fixes: b978962ad4 ("blkcg: update blkg_lookup_create() to do locking")
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-19 09:35:45 -07:00
Jens Axboe dbe3ece128 dm: don't reuse bio for flushes
DM currently has a statically allocated bio that it uses to issue empty
flushes. It doesn't submit this bio, it just uses it for maintaining
state while setting up clones. Multiple users can access this bio at the
same time. This wasn't previously an issue, even if it was a bit iffy,
but with the blkg associations it can become one.

We setup the blkg association, then clone bio's and submit, then remove
the blkg assocation again. But since we can have multiple tasks doing
this at the same time, against multiple blkg's, then we can either lose
references to a blkg, or put it twice. The latter causes complaints on
the percpu ref being <= 0 when released, and can cause use-after-free as
well. Ming reports that xfstest generic/475 triggers this:

------------[ cut here ]------------
percpu ref (blkg_release) <= 0 (0) after switching to atomic
WARNING: CPU: 13 PID: 0 at lib/percpu-refcount.c:155 percpu_ref_switch_to_atomic_rcu+0x2c9/0x4a0

Switch to just using an on-stack bio for this, and get rid of the
embedded bio.

Fixes: 5cdf2e3fea ("blkcg: associate blkg when associating a device")
Reported-by: Ming Lei <ming.lei@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-19 09:13:34 -07:00
Jens Axboe 499aeb45b2 Merge branch 'nvme-4.21' of git://git.infradead.org/nvme into for-4.21/block
Pull last batch of NVMe updates for 4.21 from Christoph:

"This contains a series from Sagi to restore poll support for nvme-rdma,
 a new tracepoint from yupeng and various fixes."

* 'nvme-4.21' of git://git.infradead.org/nvme:
  nvme-pci: trace SQ status on completions
  nvme-rdma: implement polling queue map
  nvme-fabrics: allow user to pass in nr_poll_queues
  nvme-fabrics: allow nvmf_connect_io_queue to poll
  nvme-core: optionally poll sync commands
  block: make request_to_qc_t public
  nvme-tcp: fix spelling mistake "attepmpt" -> "attempt"
  nvme-tcp: fix endianess annotations
  nvmet-tcp: fix endianess annotations
  nvme-pci: refactor nvme_poll_irqdisable to make sparse happy
  nvme-pci: only set nr_maps to 2 if poll queues are supported
  nvmet: use a macro for default error location
  nvmet: fix comparison of a u16 with -1
2018-12-19 08:08:41 -07:00