Commit Graph

217 Commits

Author SHA1 Message Date
Josef Bacik 32e67a3a06 nbd: handle interrupted sendmsg with a sndtimeo set
If you do not set sk_sndtimeo you will get -ERESTARTSYS if there is a
pending signal when you enter sendmsg, which we handle properly.
However if you set a timeout for your commands we'll set sk_sndtimeo to
that timeout, which means that sendmsg will start returning -EINTR
instead of -ERESTARTSYS.  Fix this by checking either cases and doing
the correct thing.

Cc: stable@vger.kernel.org
Fixes: dc88e34d69 ("nbd: set sk->sk_sndtimeo for our sockets")
Reported-and-tested-by: Daniel Xu <dlxu@fb.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-24 18:50:59 -06:00
Josef Bacik 639812a1ed nbd: don't set the device size until we're connected
A user reported a regression with using the normal ioctl interface on
newer kernels.  This happens because I was setting the device size
before the device was actually connected, which caused us to error out
and close everything down.  This didn't happen on netlink because we
hold the device lock the whole time we're setting things up, but we
don't do that for the ioctl path.  This fixes the problem.

Cc: stable@vger.kernel.org
Fixes: 29eaadc ("nbd: stop using the bdev everywhere")
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-09 12:29:22 -06:00
Josef Bacik 6e60a3bbb4 nbd: fix -ERESTARTSYS handling
Christoph made it so that if we return'ed BLK_STS_RESOURCE whenever we
got ERESTARTSYS from sending our packets we'd return BLK_STS_OK, which
means we'd never requeue and just hang.  We really need to return the
right value from the upper layer.

Fixes: fc17b6534e ("blk-mq: switch ->queue_rq return value to blk_status_t")
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-02 14:29:09 -06:00
Josef Bacik 1dae69bede nbd: ignore non-nbd ioctl's
In testing we noticed that nbd would spew if you ran a fio job against
the raw device itself.  This is because fio calls a block device
specific ioctl, however the block layer will first pass this back to the
driver ioctl handler in case the driver wants to do something special.
Since the device was setup using netlink this caused us to spew every
time fio called this ioctl.  Since we don't have special handling, just
error out for any non-nbd specific ioctl's that come in.  This fixes the
spew.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-09-25 08:56:05 -06:00
Bhumika Goyal dfbde55249 nbd: make device_attribute const
Make this const as is is only passed as an argument to the
function device_create_file and device_remove_file and the corresponding
arguments are of type const.
Done using Coccinelle

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-28 15:21:27 -06:00
Josef Bacik 7a8362a0b5 nbd: change the default nbd partitions
There's no reason to have partitions disabled for nbd by default, it costs us
nothing to have it enabled and is just confusing/obnoxious to users who try to
use partitions with nbd.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-17 11:02:59 -06:00
Josef Bacik e6a76272d0 nbd: allow device creation at a specific index
If users really want to use a particular index for their nbd device and it
doesn't already exist there's no reason we can't just create it for them.  Do
this instead of erroring out.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-17 11:02:57 -06:00
Josef Bacik 7a362ea96d nbd: clear disconnected on reconnect
If our device loses its connection for longer than the dead timeout we
will set NBD_DISCONNECTED in order to quickly fail any pending IO's that
flood in after the IO's that were waiting during the dead timer.
However if we re-connect at some point in the future we'll still see
this DISCONNECTED flag set if we then lose our connection again after
that, which means we won't get notifications for our newly lost
connections.  Fix this by just clearing the DISCONNECTED flag on
reconnect in order to make sure everything works as it's supposed to.

Reported-by: Dan Melnic <dmm@fb.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-25 13:58:34 -06:00
Josef Bacik a7ee8cf190 nbd: only set sndtimeo if we have a timeout set
A user reported that he was getting immediate disconnects with my
sndtimeo patch applied.  This is because by default the OSS nbd client
doesn't set a timeout, so we end up setting the sndtimeo to 0, which of
course means we have send errors a lot.  Instead only set our sndtimeo
if the user specified a timeout, otherwise we'll just wait forever like
we did previously.

Fixes: dc88e34d69 ("nbd: set sk->sk_sndtimeo for our sockets")
Reported-by: Adam Borowski <kilobyte@angband.pl>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-22 11:12:32 -06:00
Josef Bacik b4b2aeccf0 nbd: take tx_lock before disconnecting
We need to take the tx_lock so we don't interleave our disconnect
request between real data going down the wire.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-22 11:12:31 -06:00
Josef Bacik 2e13456fb3 nbd: allow multiple disconnects to be sent
There's no reason to limit ourselves to one disconnect message per
socket.  Sometimes networks do strange things, might as well let
sysadmins hit the panic button as much as they want.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-22 11:12:29 -06:00
Kefeng Wang 768516894f nbd: kill unused ret in recv_work
No need to return value in queue work, kill ret variable.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-07-13 08:03:30 -06:00
Sagi Grimberg b52c2e9254 nbd: quiesce request queues to make sure no submissions are inflight
Unlike blk_mq_stop_hw_queues, blk_mq_quiesce_queue respects the
submission path rcu grace. quiesce the queue before iterating
on live tags.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
2017-07-06 09:49:05 +03:00
Jens Axboe 8f66439eec Linux 4.12-rc5
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Merge tag 'v4.12-rc5' into for-4.13/block

We've already got a few conflicts and upcoming work depends on some of the
changes that have gone into mainline as regression fixes for this series.

Pull in 4.12-rc5 to resolve these conflicts and make it easier on down stream
trees to continue working on 4.13 changes.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-12 08:30:13 -06:00
Christoph Hellwig fc17b6534e blk-mq: switch ->queue_rq return value to blk_status_t
Use the same values for use for request completion errors as the return
value from ->queue_rq.  BLK_STS_RESOURCE is special cased to cause
a requeue, and all the others are completed as-is.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00
Christoph Hellwig 2a842acab1 block: introduce new block status code type
Currently we use nornal Linux errno values in the block layer, and while
we accept any error a few have overloaded magic meanings.  This patch
instead introduces a new  blk_status_t value that holds block layer specific
status codes and explicitly explains their meaning.  Helpers to convert from
and to the previous special meanings are provided for now, but I suspect
we want to get rid of them in the long run - those drivers that have a
errno input (e.g. networking) usually get errnos that don't know about
the special block layer overloads, and similarly returning them to userspace
will usually return somethings that strictly speaking isn't correct
for file system operations, but that's left as an exercise for later.

For now the set of errors is a very limited set that closely corresponds
to the previous overloaded errno values, but there is some low hanging
fruite to improve it.

blk_status_t (ab)uses the sparse __bitwise annotations to allow for sparse
typechecking, so that we can easily catch places passing the wrong values.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00
Josef Bacik dc88e34d69 nbd: set sk->sk_sndtimeo for our sockets
If the nbd server stops receiving packets altogether we will get stuck
waiting for them to receive indefinitely as the tcp buffer will never
empty, which looks like a deadlock.  Fix this by setting the sk send
timeout to our configured timeout, that way if the server really
misbehaves we'll disconnect cleanly instead of waiting forever.

Reported-by: Dan Melnic <dmm@fb.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 08:33:19 -06:00
Shaun McDowell 685c9b24ad nbd: add FUA op support
NBD userland client and server have FUA (forced unit access) support
and flags defined. Make NBD kernel module recognize NBD_FLAG_SEND_FUA,
enable FUA on the queue, and forward FUA requests to the server.

Signed-off-by: Shaun McDowell <shaunjmcdowell@gmail.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-05-30 08:20:25 -06:00
Ilya Dryomov fa9765323a nbd: don't leak nbd_config
nbd_config is allocated in nbd_alloc_config(), but never freed.

Fixes: 5ea8d10802 ("nbd: separate out the config information")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-05-30 08:15:08 -06:00
Ilya Dryomov af622b8666 nbd: nbd_reset() call in nbd_dev_add() is redundant
There is nothing to clear -- nbd_device has just been allocated.
Fold nbd_reset() into its other caller, nbd_config_put().

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-05-30 08:15:07 -06:00
Vlastimil Babka f108304872 treewide: convert PF_MEMALLOC manipulations to new helpers
We now have memalloc_noreclaim_{save,restore} helpers for robust setting
and clearing of PF_MEMALLOC.  Let's convert the code which was using the
generic tsk_restore_flags().  No functional change.

[vbabka@suse.cz: in net/core/sock.c the hunk is missing]
Link: http://lkml.kernel.org/r/20170405074700.29871-4-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Lee Duncan <lduncan@suse.com>
Cc: Chris Leech <cleech@redhat.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Wouter Verhelst <w@uter.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-08 17:15:15 -07:00
Linus Torvalds 044f1daaaa Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull block fixes and updates from Jens Axboe:
 "Some fixes and followup features/changes that should go in, in this
  merge window. This contains:

   - Two fixes for lightnvm from Javier, fixing problems in the new code
     merge previously in this merge window.

   - A fix from Jan for the backing device changes, fixing an issue in
     NFS that causes a failure to mount on certain setups.

   - A change from Christoph, cleaning up the blk-mq init and exit
     request paths.

   - Remove elevator_change(), which is now unused. From Bart.

   - A fix for queue operation invocation on a dead queue, from Bart.

   - A series fixing up mtip32xx for blk-mq scheduling, removing a
     bandaid we previously had in place for this. From me.

   - A regression fix for this series, fixing a case where we wait on
     workqueue flushing from an invalid (non-blocking) context. From me.

   - A fix/optimization from Ming, ensuring that we don't both quiesce
     and freeze a queue at the same time.

   - A fix from Peter on lock ordering for CPU hotplug. Not a real
     problem right now, but will be once the CPU hotplug rework goes in.

   - A series from Omar, cleaning up out blk-mq debugfs support, and
     adding support for exporting info from schedulers in debugfs as
     well. This is really useful in debugging stalls or livelocks. From
     Omar"

* 'for-linus' of git://git.kernel.dk/linux-block: (28 commits)
  mq-deadline: add debugfs attributes
  kyber: add debugfs attributes
  blk-mq-debugfs: allow schedulers to register debugfs attributes
  blk-mq: untangle debugfs and sysfs
  blk-mq: move debugfs declarations to a separate header file
  blk-mq: Do not invoke queue operations on a dead queue
  blk-mq-debugfs: get rid of a bunch of boilerplate
  blk-mq-debugfs: rename hw queue directories from <n> to hctx<n>
  blk-mq-debugfs: don't open code strstrip()
  blk-mq-debugfs: error on long write to queue "state" file
  blk-mq-debugfs: clean up flag definitions
  blk-mq-debugfs: separate flags with |
  nfs: Fix bdi handling for cloned superblocks
  block/mq: Cure cpu hotplug lock inversion
  lightnvm: fix bad back free on error path
  lightnvm: create cmd before allocating request
  blk-mq: don't use sync workqueue flushing from drivers
  mtip32xx: convert internal commands to regular block infrastructure
  mtip32xx: cleanup internal tag assumptions
  block: don't call blk_mq_quiesce_queue() after queue is frozen
  ...
2017-05-06 11:25:08 -07:00
Linus Torvalds 8d65b08deb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Millar:
 "Here are some highlights from the 2065 networking commits that
  happened this development cycle:

   1) XDP support for IXGBE (John Fastabend) and thunderx (Sunil Kowuri)

   2) Add a generic XDP driver, so that anyone can test XDP even if they
      lack a networking device whose driver has explicit XDP support
      (me).

   3) Sparc64 now has an eBPF JIT too (me)

   4) Add a BPF program testing framework via BPF_PROG_TEST_RUN (Alexei
      Starovoitov)

   5) Make netfitler network namespace teardown less expensive (Florian
      Westphal)

   6) Add symmetric hashing support to nft_hash (Laura Garcia Liebana)

   7) Implement NAPI and GRO in netvsc driver (Stephen Hemminger)

   8) Support TC flower offload statistics in mlxsw (Arkadi Sharshevsky)

   9) Multiqueue support in stmmac driver (Joao Pinto)

  10) Remove TCP timewait recycling, it never really could possibly work
      well in the real world and timestamp randomization really zaps any
      hint of usability this feature had (Soheil Hassas Yeganeh)

  11) Support level3 vs level4 ECMP route hashing in ipv4 (Nikolay
      Aleksandrov)

  12) Add socket busy poll support to epoll (Sridhar Samudrala)

  13) Netlink extended ACK support (Johannes Berg, Pablo Neira Ayuso,
      and several others)

  14) IPSEC hw offload infrastructure (Steffen Klassert)"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2065 commits)
  tipc: refactor function tipc_sk_recv_stream()
  tipc: refactor function tipc_sk_recvmsg()
  net: thunderx: Optimize page recycling for XDP
  net: thunderx: Support for XDP header adjustment
  net: thunderx: Add support for XDP_TX
  net: thunderx: Add support for XDP_DROP
  net: thunderx: Add basic XDP support
  net: thunderx: Cleanup receive buffer allocation
  net: thunderx: Optimize CQE_TX handling
  net: thunderx: Optimize RBDR descriptor handling
  net: thunderx: Support for page recycling
  ipx: call ipxitf_put() in ioctl error path
  net: sched: add helpers to handle extended actions
  qed*: Fix issues in the ptp filter config implementation.
  qede: Fix concurrency issue in PTP Tx path processing.
  stmmac: Add support for SIMATIC IOT2000 platform
  net: hns: fix ethtool_get_strings overflow in hns driver
  tcp: fix wraparound issue in tcp_lp
  bpf, arm64: fix jit branch offset related to ldimm64
  bpf, arm64: implement jiting of BPF_XADD
  ...
2017-05-02 16:40:27 -07:00
Christoph Hellwig d6296d39e9 blk-mq: update ->init_request and ->exit_request prototypes
Remove the request_idx parameter, which can't be used safely now that we
support I/O schedulers with blk-mq.  Except for a superflous check in
mtip32xx it was unused anyway.

Also pass the tag_set instead of just the driver data - this allows drivers
to avoid some code duplication in a follow on cleanup.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-05-02 07:52:08 -06:00
Linus Torvalds 3527d3e951 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
 "The main changes in this cycle were:

   - another round of rq-clock handling debugging, robustization and
     fixes

   - PELT accounting improvements

   - CPU hotplug related ->cpus_allowed affinity handling fixes all
     around the tree

   - ... plus misc fixes, cleanups and updates"

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits)
  sched/x86: Update reschedule warning text
  crypto: N2 - Replace racy task affinity logic
  cpufreq/sparc-us2e: Replace racy task affinity logic
  cpufreq/sparc-us3: Replace racy task affinity logic
  cpufreq/sh: Replace racy task affinity logic
  cpufreq/ia64: Replace racy task affinity logic
  ACPI/processor: Replace racy task affinity logic
  ACPI/processor: Fix error handling in __acpi_processor_start()
  sparc/sysfs: Replace racy task affinity logic
  powerpc/smp: Replace open coded task affinity logic
  ia64/sn/hwperf: Replace racy task affinity logic
  ia64/salinfo: Replace racy task affinity logic
  workqueue: Provide work_on_cpu_safe()
  ia64/topology: Remove cpus_allowed manipulation
  sched/fair: Move the PELT constants into a generated header
  sched/fair: Increase PELT accuracy for small tasks
  sched/fair: Fix comments
  sched/Documentation: Add 'sched-pelt' tool
  sched/fair: Fix corner case in __accumulate_sum()
  sched/core: Remove 'task' parameter and rename tsk_restore_flags() to current_restore_flags()
  ...
2017-05-01 19:12:53 -07:00
Josef Bacik 60ae36ad03 nbd: fix use after free on module unload
list_for_each_entry() isn't super safe if we're freeing the objects
while we traverse the list.  Also don't bother taking the extra
reference, the module refcounting stuff will save us from having anybody
messing with the device while we're trying to unload.

Reported-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-28 08:04:01 -06:00
Josef Bacik 1cc1f17aab nbd: set the max segments to USHRT_MAX
I lack the basic understanding of what segments mean, so we were being
limited to 512kib requests even with higher max_sectors sizes set.
Setting the maximum number of segments to unlimited allows us to
actually have arbitrarily large IO's go through NBD.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20 19:53:24 -06:00
Christoph Hellwig 08e0029aa2 blk-mq: remove the error argument to blk_mq_complete_request
Now that all drivers that call blk_mq_complete_requests have a
->complete callback we can remove the direct call to blk_mq_end_request,
as well as the error argument to blk_mq_complete_request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20 12:16:10 -06:00
Christoph Hellwig 1e388ae0b9 nbd: don't use req->errors
Add a nbd-specific field instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20 12:16:10 -06:00
Josef Bacik ebb16d0d1b nbd: set the max segment size to UINT_MAX
NBD doesn't care about limiting the segment size, let the user push the
largest bio's they want.  This allows us to control the request size
solely through max_sectors_kb.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-19 08:16:06 -06:00
Josef Bacik a2c97909f9 nbd: add a flag to destroy an nbd device on disconnect
For ease of management it would be nice for users to specify that the
device node for a nbd device is destroyed once it is disconnected and
there are no more users.  Add a client flag and enable this operation to
happen.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-17 09:58:42 -06:00
Josef Bacik c6a4759ea0 nbd: add device refcounting
In order to support deleting the device on disconnect we need to
refcount the actual nbd_device struct.  So add the refcounting framework
and change how we free the normal devices at rmmod time so we can catch
reference leaks.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-17 09:58:42 -06:00
Josef Bacik 47d902b90a nbd: add a status netlink command
Allow users to query the status of existing nbd devices.  Right now this
only returns whether or not the device is connected, but could be
extended in the future to include more information.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-17 09:58:42 -06:00
Josef Bacik 560bc4b399 nbd: handle dead connections
Sometimes we like to upgrade our server without making all of our
clients freak out and reconnect.  This patch provides a way to specify a
dead connection timeout to allow us to pause all requests and wait for
new connections to be opened.  With this in place I can take down the
nbd server for less than the dead connection timeout time and bring it
back up and everything resumes gracefully.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-17 09:58:42 -06:00
Josef Bacik 2516ab1543 nbd: only clear the queue on device teardown
When running a disconnect torture test I noticed that sometimes we would
crash with a negative ref count on our queue.  This was because we were
ending the same request twice.  Turns out we were racing with
NBD_CLEAR_SOCK clearing the requests as well as the teardown of the
device clearing the requests.  So instead make the ioctl only shutdown
the sockets and make it so that we only ever run nbd_clear_que from the
device teardown.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-17 09:58:42 -06:00
Josef Bacik 799f9a38bc nbd: multicast dead link notifications
Provide a mechanism to notify userspace that there's been a link problem
on a NBD device.  This will allow userspace to re-establish a connection
and provide the new socket to the device without disrupting the device.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-17 09:58:42 -06:00
Josef Bacik b7aa3d3938 nbd: add a reconfigure netlink command
We want to be able to reconnect dead connections to existing block
devices, so add a reconfigure netlink command.  We will also allow users
to change their timeout on the fly, but everything else will require a
disconnect and reconnect.  You won't be able to add more connections
either, simply replace dead connections with new more lively
connections.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-17 09:58:42 -06:00
Josef Bacik e46c7287b1 nbd: add a basic netlink interface
The existing ioctl interface for configuring NBD devices is a bit
cumbersome and hard to extend.  The other problem is we leave a
userspace app sitting in it's syscall until the device disconnects,
which is less than ideal.

This patch introduces a netlink interface for adding and disconnecting
nbd devices.  This has the benefits of being easily extendable without
breaking older userspace applications, and allows us to configure a nbd
device without leaving a userspace app sitting waiting for the device to
disconnect.

With this interface we also gain the ability to configure more devices
than are preallocated at insmod time.  We also have gained the ability
to not specify a particular device and be provided one for us so that
userspace doesn't need to find a free device to configure.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-17 09:58:42 -06:00
Josef Bacik 29eaadc036 nbd: stop using the bdev everywhere
In preparation for the upcoming netlink interface we need to not rely on
already having the bdev for the NBD device we are doing operations on.
Instead of passing the bdev around, just use it in places where we know
we already have the bdev.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-17 09:58:42 -06:00
Josef Bacik 5ea8d10802 nbd: separate out the config information
In order to properly refcount the various aspects of a NBD device we
need to separate out the configuration elements of the nbd device.  The
configuration of a NBD device has a different lifetime from the actual
device, so it doesn't make sense to bundle these two concepts.  Add a
config_refs to keep track of the configuration structure, that way we
can be sure that we never access it when we've torn down the device.
Add a new nbd_config structure to hold all of the transient
configuration information.  Finally create this when we open the device
so that it is in place when we start to configure the device.  This has
a nice side-effect of fixing a long standing problem where you could end
up with a half-configured nbd device that needed to be "disconnected" in
order to be usable again.  Now once we close our device the
configuration will be discarded.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-17 09:58:42 -06:00
Josef Bacik f3733247ae nbd: handle single path failures gracefully
Currently if we have multiple connections and one of them goes down we will tear
down the whole device.  However there's no reason we need to do this as we
could have other connections that are working fine.  Deal with this by keeping
track of the state of the different connections, and if we lose one we mark it
as dead and send all IO destined for that socket to one of the other healthy
sockets.  Any outstanding requests that were on the dead socket will timeout and
be re-submitted properly.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-17 09:58:42 -06:00
Josef Bacik 9b1355d5e3 nbd: put socket in error cases
When adding a new socket we look it up and then try to add it to our
configuration.  If any of those steps fail we need to make sure we put
the socket so we don't leak them.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-17 09:58:42 -06:00
NeilBrown 717a94b5fc sched/core: Remove 'task' parameter and rename tsk_restore_flags() to current_restore_flags()
It is not safe for one thread to modify the ->flags
of another thread as there is no locking that can protect
the update.

So tsk_restore_flags(), which takes a task pointer and modifies
the flags, is an invitation to do the wrong thing.

All current users pass "current" as the task, so no developers have
accepted that invitation.  It would be best to ensure it remains
that way.

So rename tsk_restore_flags() to current_restore_flags() and don't
pass in a task_struct pointer.  Always operate on current->flags.

Signed-off-by: NeilBrown <neilb@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-04-11 09:06:32 +02:00
Christoph Hellwig 48920ff2a5 block: remove the discard_zeroes_data flag
Now that we use the proper REQ_OP_WRITE_ZEROES operation everywhere we can
kill this hack.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-08 11:25:38 -06:00
Jens Axboe 65f619d253 Merge branch 'for-linus' into for-4.12/block
We've added a considerable amount of fixes for stalls and issues
with the blk-mq scheduling in the 4.11 series since forking
off the for-4.12/block branch. We need to do improvements on
top of that for 4.12, so pull in the previous fixes to make
our lives easier going forward.

Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-07 12:45:20 -06:00
Eric Biggers f363b089be blk-mq: constify struct blk_mq_ops
Constify all instances of blk_mq_ops, as they are never modified.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-31 08:28:58 -06:00
Ratna Manoj Bolla abbbdf1249 nbd: replace kill_bdev() with __invalidate_device()
When a filesystem is mounted on a nbd device and on a disconnect, because
of kill_bdev(), and resetting bdev size to zero, buffer_head mappings are
getting destroyed under mounted filesystem.

After a bdev size reset(i.e bdev->bd_inode->i_size = 0) on a disconnect,
followed by a sys_umount(),
        generic_shutdown_super()->...
        ->__sync_blockdev()->...
        -blkdev_writepages()->...
        ->do_invalidatepage()->...
        -discard_buffer()   is discarding superblock buffer_head assumed
to be in mapped state by ext4_commit_super().

[mlin: ported to 4.11-rc2]
Signed-off-by: Ratna Manoj Bolla <manoj.br@gmail.com
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-24 15:42:47 -06:00
Josef Bacik f858685503 nbd: set queue timeout properly
We can't just set the timeout on the tagset, we have to set it on the
queue as it would have been setup already at this point.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-24 15:42:47 -06:00
Josef Bacik c103b4dac8 nbd: set rq->errors to actual error code
We've been relying on the block layer to assume rq->errors being set
translates into -EIO.  I noticed in testing that sometimes this isn't
true, and really there's not much of a reason to have a counter instead
of just using -EIO.  So set it properly so we don't leak random numbers
to unsuspecting victims.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-24 15:42:47 -06:00
Josef Bacik 9dd5d3ab49 nbd: handle ERESTARTSYS properly
We can submit IO in a processes context, which means there can be
pending signals.  This isn't a fatal error for NBD, but it does require
some finesse.  If the signal happens before we transmit anything then we
are ok, just requeue the request and carry on.  However if we've done a
partial transmit we can't allow anything else to be transmitted on this
socket until we transmit the remaining part of the request.  Deal with
this by keeping track of how much we've sent for the current request,
and if we get an ERESTARTSYS during any part of our transmission save
the state of that request and requeue the IO.  If anybody tries to
submit a request that isn't our pending request then requeue that
request until we are able to service the one that is pending.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-03-24 15:42:47 -06:00