When nvme_delete_queue fails in the first pass of the
nvme_disable_io_queues() loop, we return early, failing to suspend all
of the IO queues.  Later, on the nvme_pci_disable path, this causes us
to disable MSI without actually having freed all the IRQs, which
triggers the BUG_ON in free_msi_irqs(), as show below.

This patch refactors nvme_disable_io_queues to suspend all queues before
start submitting delete queue commands.  This way, we ensure that we
have at least returned every IRQ before continuing with the removal
path.

[  487.529200] kernel BUG at ../drivers/pci/msi.c:368!
cpu 0x46: Vector: 700 (Program Check) at [c0000078c5b83650]
    pc: c000000000627a50: free_msi_irqs+0x90/0x200
    lr: c000000000627a40: free_msi_irqs+0x80/0x200
    sp: c0000078c5b838d0
   msr: 9000000100029033
  current = 0xc0000078c5b40000
  paca    = 0xc000000002bd7600   softe: 0        irq_happened: 0x01
    pid   = 1376, comm = kworker/70:1H
kernel BUG at ../drivers/pci/msi.c:368!
Linux version 4.7.0.mainline+ (root@iod76) (gcc version 5.3.1 20160413
(Ubuntu/IBM 5.3.1-14ubuntu2.1) ) #104 SMP Fri Jul 29 09:20:17 CDT 2016
enter ? for help
[c0000078c5b83920] d0000000363b0cd8 nvme_dev_disable+0x208/0x4f0 [nvme]
[c0000078c5b83a10] d0000000363b12a4 nvme_timeout+0xe4/0x250 [nvme]
[c0000078c5b83ad0] c0000000005690e4 blk_mq_rq_timed_out+0x64/0x110
[c0000078c5b83b40] c00000000056c930 bt_for_each+0x160/0x170
[c0000078c5b83bb0] c00000000056d928 blk_mq_queue_tag_busy_iter+0x78/0x110
[c0000078c5b83c00] c0000000005675d8 blk_mq_timeout_work+0xd8/0x1b0
[c0000078c5b83c50] c0000000000e8cf0 process_one_work+0x1e0/0x590
[c0000078c5b83ce0] c0000000000e9148 worker_thread+0xa8/0x660
[c0000078c5b83d80] c0000000000f2090 kthread+0x110/0x130
[c0000078c5b83e30] c0000000000095f0 ret_from_kernel_thread+0x5c/0x6c
Signed-off-by: NGabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>
Cc: Brian King <brking@linux.vnet.ibm.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: linux-nvme@lists.infradead.org
Signed-off-by: NJens Axboe <axboe@fb.com>

Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>

When we reset or reconnect to a controller, we are cancelling the
async event handler so we can safely re-establish resources, but we
need to remember to start it again when we successfully reconnect.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

The host is allowed to issue identify as many times
as it wants, we need to stay consistent when reporting
the serial number for a given controller.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Under extreme conditions this might cause data corruptions. By doing that
we we repost the buffer and then post this buffer for the device to send.
If we happen to use shared receive queues the device might write to the
buffer before it sends it (there is no ordering between send and recv
queues). Without SRQs we probably won't get that if the host doesn't
mis-behave and send more than we allowed it, but relying on that is not
really a good idea.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

When configuring a device attached listener, we may
see device removal events. In this case we return a
non-zero return code from the cm event handler which
implicitly destroys the cm_id. It is possible that in
the future the user will remove this listener and by
that trigger a second call to rdma_destroy_id on an
already destroyed cm_id -> BUG.

In addition, when a queue bound (active session) cm_id
generates a DEVICE_REMOVAL event we must guarantee all
resources are cleaned up by the time we return from the
event handler.

Introduce nvmet_rdma_device_removal which addresses
(or at least attempts to) both scenarios.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Relying on ctrl state in nvme_rdma_shutdown_ctrl is wrong because
it will never be NVME_CTRL_LIVE (delete_ctrl or reset_ctrl invoked it).

Instead, check that the admin queue is connected. Note that it is safe
because we can never see a copmeting thread trying to destroy the admin
queue (reset or delete controller).
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

nvme_uninit_ctrl already does that for us. Note that we
reordered nvme_loop_shutdown_ctrl with nvme_uninit_ctrl
but its safe because we want controller uninit to happen
before we shutdown the transport resources.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

If we wait until we free the controller (free_ctrl) we might
lose our rdma device without any notification while we still
have open resources (tags mrs and dma mappings).

Instead, destroy the tags with their rdma resources once we
delete the device and not when freeing it.

Note that we don't do that in nvme_rdma_shutdown_ctrl because
controller reset uses it as well and we want to give active I/O
a chance to complete successfully.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

nvme_uninit_ctrl already does that for us. Note that we reordered
nvme_rdma_shutdown_ctrl and nvme_uninit_ctrl, this is perfectly
fine because we actually want ctrl uninit (aen, scan cancellation
and namespaces removal) to happen before we shutdown the rdma
resources.

Also, centralize the deletion work and the dead controller removal
work code duplication into __nvme_rdma_shutdown_ctrl that accepts
a shutdown boolean.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Device removal sequence may have crashed because the
controller (and admin queue space) was freed before
we destroyed the admin queue resources. Thus we
want to destroy the admin queue and only then queue
controller deletion and wait for it to complete.

More specifically we:
1. own the controller deletion (make sure we are not
   competing with another deletion).
2. get rid of inflight reconnects if exists (which
   also destroy and create queues).
3. destroy the queue.
4. safely queue controller deletion (and wait for it
   to complete).
Reported-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

On an ordered target shutdown, the target can send a AEN on a namespace
removal, this will trigger the host to queue ns-list query. The shutdown
will trigger error recovery which will attepmt periodic reconnect.

We can hit a race where the ns rescanning fails (error recovery kicked
in and we're not connected) causing removing all the namespaces and when
we reconnect we won't see any namespaces for this controller.

So, queue a namespace rescan after we successfully reconnected to the target.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Zero out the full nvme_rdma_cm_req structure before sending it.
Otherwise we end up leaking kernel memory in the reserved field, which
might break forward compatibility in the future.
Signed-off-by: NRoland Dreier <roland@purestorage.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

This registers an sr-iov callback for nvme.
Signed-off-by: NKeith Busch <keith.busch@intel.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

It is typically not good coding or secure coding practice
to logical OR a variable without an initialization value first.
Here on this line:

integrity.flags |= BLK_INTEGRITY_DEVICE_CAPABLE;

BLK_INTEGRITY_DEVICE_CAPABLE is being OR'ed to a member variable
never set to an initial value. This patch fixes that.
Signed-off-by: NJay Freyensee <james.p.freyensee@intel.com>
Reviewed-by: NMing Lin <ming.l@samsung.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

blk_get_request is used for BLOCK_PC and similar passthrough requests.
Currently we always need to call blk_rq_set_block_pc or an open coded
version of it to allow appending bios using the request mapping helpers
later on, which is a somewhat awkward API.  Instead move the
initialization part of blk_rq_set_block_pc into blk_get_request, so that
we always have a safe to use request.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

These two are confusing leftover of the old world order, combining
values of the REQ_OP_ and REQ_ namespaces.  For callers that don't
special case we mostly just replace bi_rw with bio_data_dir or
op_is_write, except for the few cases where a switch over the REQ_OP_
values makes more sense.  Any check for READA is replaced with an
explicit check for REQ_RAHEAD.  Also remove the READA alias for
REQ_RAHEAD.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NMike Christie <mchristi@redhat.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

When alloc_disk(0) is used, the ->major number is ignored.  All device
numbers are allocated with a major of BLOCK_EXT_MAJOR.

So remove all references to nvme_major.

[akpm@linux-foundation.org: one unregister_blkdev() was missed]
Link: http://lkml.kernel.org/r/20160602064318.4403.93301.stgit@nobleSigned-off-by: NNeilBrown <neilb@suse.com>
Reviewed-by: NKeith Busch <keith.busch@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJens Axboe <axboe@fb.com>

We can't sleep with RCU read lock held, but we need to do potentially
blocking stuff to namespace queues when iterating the list. This patch
removes the RCU locking and holds a mutex instead.

To prevent deadlocks, this patch removes holding the mutex during
namespace scanning and removal. The unlocked namespace scanning is made
safe by holding a reference to the namespace being scanned.

List iteration that does IO has to be unlocked to allow error recovery.
The caller must ensure the list can not be manipulated during such an
event, so this patch adds a comment explaining this requirement to the
only function that iterates an unlocked list. All callers currently
meet this requirement, so no further changes required.

List iterations that do not do IO can safely use the lock since it couldn't
block recovery from missing forced IO completions.

Reported-by: Ming Lin <mlin at kernel.org>
[fixes 0bf77e9d nvme: switch to RCU freeing the namespace]
Signed-off-by: NKeith Busch <keith.busch@intel.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

When CONFIG_NUMA is enabled and node 0 is memoryless, the system
crashes because nvme_probe() sets the device->numa_node to 0 by
set_dev_node(&pdev->dev, 0), so it tries to allocate memory from node 0.
To avoid the crash, we should change the 0 to first_memory_node.
Signed-off-by: NMasayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: NKeith Busch <keith.busch@intel.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Many controller implementations will return errors to commands that will
not succeed, but without the DNR bit set. The driver previously retried
these commands an unlimited number of times until the command timeout
has exceeded, which takes an unnecessarilly long period of time.

This patch limits the number of retries a command can have, defaulting
to 5, but is user tunable at load or runtime.

The struct request's 'retries' field is used to track the number of
retries attempted. This is in contrast with scsi's use of this field,
which indicates how many retries are allowed.
Signed-off-by: NKeith Busch <keith.busch@intel.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

I ran into the same problem on NVME_TARGET_RDMA now,
which otherwise needs dependencies on both CONFIG_BLOCK and
CONFIGFS_FS:

    warning: (NVME_TARGET_LOOP && NVME_TARGET_RDMA) selects NVME_TARGET which has unmet direct dependencies (BLOCK && CONFIGFS_FS)
    0xA002B368 Mon Jul 11 18:00:45 CEST 2016 failed
    In file included from ../drivers/nvme/target/core.c:16:0:
    drivers/nvme/target/nvmet.h:222:14: error: field 'inline_bio' has incomplete type
      struct bio  inline_bio;
                  ^~~~~~~~~~
    drivers/nvme/target/core.c: In function 'nvmet_async_event_work':
    drivers/nvme/target/core.c:98:3: error: implicit declaration of function 'kfree' [-Werror=implicit-function-declaration]
       kfree(aen);
       ^~~~~
    ../drivers/nvme/target/core.c: In function 'nvmet_ns_enable':
    ../drivers/nvme/target/core.c:269:13: error: implicit declaration of function 'blkdev_get_by_path' [-Werror=implicit-function-declaration]
      ns->bdev = blkdev_get_by_path(ns->device_path, FMODE_READ | FMODE_WRITE,

Folding in my patch below should address that too.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reported-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

In case of error, the function kstrndup() returns NULL pointer
not ERR_PTR(). The IS_ERR() test in the return value check
should be replaced with NULL test.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Reviewed-by: NJay Freyensee <james_p_freyensee@linux.intel.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Repeatedly adding then removing the same NVMe-over-Fabrics controller
over and over again (shown below) can cause a kernel crash (also shown
below).  This patch fixes that.

[nvmf]# ./setup_nvme_connections.sh
traddr=192.168.1.100,transport=rdma,trsvcid=4420,nqn=darkside
-nqn,hostnqn=evil-wins-nqn,nr_io_queues=16 > /dev/nvme-fabrics
traddr=192.168.1.100,transport=rdma,trsvcid=4420,nqn=lightside
-nqn,hostnqn=good-wins-nqn > /dev/nvme-fabrics
[nvmf]# ./remove_nvme_connections.sh 2
echo 1 > /sys/class/nvme/nvme0/delete_controller
echo 1 > /sys/class/nvme/nvme1/delete_controller
[nvmf]# ./setup_nvme_connections.sh
traddr=192.168.1.100,transport=rdma,trsvcid=4420,nqn=darkside
-nqn,hostnqn=evil-wins-nqn,nr_io_queues=16 > /dev/nvme-fabrics
Killed

[nvmf]# dmesg
[  313.416908] nvme nvme0: creating 16 I/O queues.
[  313.523908] nvme nvme0: new ctrl: NQN "darkside-nqn", addr
192.168.1.100:4420
[  313.524857] BUG: unable to handle kernel NULL pointer dereference at
0000000000000010
[  313.525262] IP: [<ffffffff8136c60e>] strcmp+0xe/0x30
[  313.525490] PGD 0
[  313.525726] Oops: 0000 [#1] SMP
[  313.525900] Modules linked in: nvme_rdma nvme_fabrics nvme_core
ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad rdma_cm ib_cm iw_cm mlx4_en
mlx4_ib ib_core mlx4_core
[  313.527085] CPU: 15 PID: 5856 Comm: setup_nvme_conn Not tainted
4.7.0-rc2+ #2
[  313.527259] Hardware name: Supermicro X9DRT-F/IBQF/IBFF/X9DRT
-F/IBQF/IBFF, BIOS 1.0a 10/09/2012
[  313.527551] task: ffff88027646cd40 ti: ffff88025b980000 task.ti:
ffff88025b980000
[  313.527879] RIP: 0010:[<ffffffff8136c60e>]  [<ffffffff8136c60e>]
strcmp+0xe/0x30
[  313.528232] RSP: 0018:ffff88025b983db0  EFLAGS: 00010206
[  313.528403] RAX: 0000000000000000 RBX: ffff880471879880 RCX:
fffffffffffffff1
[  313.528594] RDX: 0000000000000000 RSI: ffff880474afa860 RDI:
0000000000000011
[  313.528778] RBP: ffff88025b983db0 R08: ffff880474afa860 R09:
ffff880471879058
[  313.528956] R10: 000000000000002c R11: ffff88047f415000 R12:
ffff880471879800
[  313.529129] R13: ffff880471879000 R14: ffff880474afa860 R15:
fffffffffffffff8
[  313.529303] FS:  00007f778f510700(0000) GS:ffff88047fbc0000(0000)
knlGS:0000000000000000
[  313.529629] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  313.529817] CR2: 0000000000000010 CR3: 0000000274174000 CR4:
00000000000406e0
[  313.529989] Stack:
[  313.530154]  ffff88025b983e48 ffffffffa0171c74 0000000000000001
0000000000000059
[  313.530621]  ffff880476f32400 ffff88047e8add80 0000010074b33aa0
ffff880471879059
[  313.531162]  ffff88047187904b ffff880471879058 0000000000000000
ffff88047736e000
[  313.531629] Call Trace:
[  313.531797]  [<ffffffffa0171c74>] nvmf_dev_write+0x674/0x840
[nvme_fabrics]
[  313.531974]  [<ffffffff81180b53>] __vfs_write+0x23/0x120
[  313.532146]  [<ffffffff8119daff>] ? __fd_install+0x1f/0xc0
[  313.532316]  [<ffffffff8119d97a>] ? __alloc_fd+0x3a/0x170
[  313.532487]  [<ffffffff811811f3>] vfs_write+0xb3/0x1b0
[  313.532658]  [<ffffffff8117e321>] ? filp_close+0x51/0x70
[  313.532845]  [<ffffffff811824e1>] SyS_write+0x41/0xa0
[  313.533016]  [<ffffffff8183055b>]
entry_SYSCALL_64_fastpath+0x13/0x8f
[  313.533188] Code: 80 3a 00 75 f7 48 83 c6 01 0f b6 4e ff 48 83 c2 01
84 c9 88 4a ff 75 ed 5d c3 0f 1f 00 55 48 89 e5 eb 04 84 c0 74 18 48 83
c7 01 <0f> b6 47 ff 48 83 c6 01 3a 46 ff 74 eb 19 c0 83 c8 01 5d c3 31
[  313.536563] RIP  [<ffffffff8136c60e>] strcmp+0xe/0x30
[  313.536815]  RSP <ffff88025b983db0>
[  313.536981] CR2: 0000000000000010
[  313.537151] ---[ end trace 3d952e590e7bc2d5 ]---
Reported-and-tested-by: NJay Freyensee <james.p.freyensee@intel.com>
Signed-off-by: NMing Lin <mlin@kernel.org>
Signed-off-by: NJay Freyensee <james.p.freyensee@intel.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

The timeout before error recovery logic kicks in is
dictated by the nvme keep-alive, so we don't really need
a transport layer retry count. transports can retry for
as much as they like.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@fb.com>

Always use the maximum qp retry count as the
error recovery timeout is dictated from the nvme
keep-alive.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@fb.com>

PTR_ERR should be applied before its argument is reassigned, otherwise the
return value will be set to 0, not error code.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Reviewed-by: NJay Freyensee <james_p_freyensee@linux.intel.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

When disabling the controller, the specification says the register
NVME_REG_CC should be written and then driver needs to wait the
adapter to be ready, which is checked by reading another register
bit (NVME_CSTS_RDY). There's a timeout validation in this checking,
so in case this timeout is reached the driver gives up and removes
the adapter from the system.

After a firmware activation procedure, the PCI_DEVICE(0x1c58, 0x0003)
(HGST adapter) end up being removed if we issue a reset_controller,
because driver keeps verifying the NVME_REG_CSTS until the timeout is
reached. This patch adds a necessary quirk for this adapter, by
introducing a delay before nvme_wait_ready(), so the reset procedure
is able to be completed. This quirk is needed because just increasing
the timeout is not enough in case of this adapter - the driver must
wait before start reading NVME_REG_CSTS register on this specific
device.
Signed-off-by: NGuilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

This patch implements the RDMA host (initiator in SCSI speak) driver.  It
can be used to connect to remote NVMe over Fabrics controllers over
Infiniband, RoCE or iWarp, and uses the existing NVMe core driver as well
a the new fabrics library.

To connect to all NVMe over Fabrics controller reachable on a given taget
port using RDMA/CM use the following command:

	nvme connect-all -t rdma -a $IPADDR

This requires the latest version of nvme-cli with Fabrics support.
Signed-off-by: NJay Freyensee <james.p.freyensee@intel.com>
Signed-off-by: NMing Lin <ming.l@ssi.samsung.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

This patch implements the RDMA transport for the NVMe over Fabrics target,
which allows exporting NVMe over Fabrics functionality over RDMA fabrics
(Infiniband, RoCE, iWARP).

All NVMe logic is in the generic target and this module just provides a
small glue between it and the generic code in the RDMA subsystem.

Signed-off-by: Armen Baloyan <armenx.baloyan@intel.com>,
Signed-off-by: NJay Freyensee <james.p.freyensee@intel.com>
Signed-off-by: NMing Lin <ming.l@ssi.samsung.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

The nvme fabric (RDMA, FC, etc...) can introduce port, link or node
failures that may require a reconnect to re-establish the connection.

Add a new reconnecting state that will initially be used by the RDMA
driver.
Reviewed-by: NJay Freyensee <james.p.freyensee@intel.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Tested-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

According to the OpenChannel SSD interface specification the NAND flash
MLC page pairing information's number of page page pairings field is the
first two bytes in the MLC Page Pairing data structure. The hardware's
data structure itself is little endian so annotate it as such, like the
rest of lighnvm's data structures.
Signed-off-by: NJohannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: NMatias Bjørling <m@bjorling.me>
Signed-off-by: NJens Axboe <axboe@fb.com>

We accidentally return zero here when ERR_PTR(-ENOMEM) is intended.

Fixes: a07b4970 ('nvmet: add a generic NVMe target')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

CONFIG_NVME_TARGET has a correct CONFIG_CONFIGFS_FS dependency, but the
newly added NVME_TARGET_LOOP is missing this, resulting in a link
failure:

drivers/nvme/built-in.o: In function `nvmet_init_configfs':
loop.c:(.init.text+0x2a0): undefined reference to `config_group_init'
loop.c:(.init.text+0x2c0): undefined reference to `config_group_init_type_name'
loop.c:(.init.text+0x318): undefined reference to `configfs_register_subsystem'
drivers/nvme/built-in.o: In function `nvmet_exit_configfs':
loop.c:(.exit.text+0x9c): undefined reference to `configfs_unregister_subsystem'

This adds the same dependency here.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: 3a85a5de ("nvme-loop: add a NVMe loopback host driver")
Signed-off-by: NJens Axboe <axboe@fb.com>

This patch implements adds nvme-loop which allows to access local devices
exported as NVMe over Fabrics namespaces. This module can be useful for
easy evaluation, testing and also feature experimentation.

To createa nvme-loop device you need to configure the NVMe target to
export a loop port (see the nvmetcli documentaton for that) and then
connect to it using

	nvme connect-all -t loop

which requires the very latest nvme-cli version with Fabrics support.
Signed-off-by: NJay Freyensee <james.p.freyensee@intel.com>
Signed-off-by: NMing Lin <ming.l@ssi.samsung.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

This patch introduces a implementation of NVMe subsystems,
controllers and discovery service which allows to export
NVMe namespaces across fabrics such as Ethernet, FC etc.

The implementation conforms to the NVMe 1.2.1 specification
and interoperates with NVMe over fabrics host implementations.

Configuration works using configfs, and is best performed using
the nvmetcli tool from http://git.infradead.org/users/hch/nvmetcli.git,
which also has a detailed explanation of the required steps in the
README file.
Signed-off-by: NArmen Baloyan <armenx.baloyan@intel.com>
Signed-off-by: NAnthony Knapp <anthony.j.knapp@intel.com>
Signed-off-by: NJay Freyensee <james.p.freyensee@intel.com>
Signed-off-by: NMing Lin <ming.l@ssi.samsung.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NSteve Wise <swise@opengridcomputing.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Periodic keep-alive is a mandatory feature in NVMe over Fabrics, and
optional in NVMe 1.2.1 for PCIe.  This patch adds periodic keep-alive
sent from the host to verify that the controller is still responsive
and vice-versa.  The keep-alive timeout is user-defined (with
keep_alive_tmo connection parameter) and defaults to 5 seconds.

In order to avoid a race condition where the host sends a keep-alive
competing with the target side keep-alive timeout expiration, the host
adds a grace period of 10 seconds when publishing the keep-alive timeout
to the target.

In case a keep-alive failed (or timed out), a transport specific error
recovery kicks in.

For now only NVMe over Fabrics is wired up to support keep alive, but
we can add PCIe support easily once controllers actually supporting it
become available.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NSteve Wise <swise@chelsio.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <keith.busch@intel.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

The NVMe over Fabrics library provides an interface for both transports
and the nvme core to handle fabrics specific commands and attributes
independent of the underlying transport.

In addition, the fabrics library adds a misc device interface that allow
actually creating a fabrics controller, as we can't just autodiscover
it like in the PCI case.  The nvme-cli utility has been enhanced to use
this interface to support fabric connect and discovery.

Signed-off-by: Armen Baloyan <armenx.baloyan@intel.com>,
Signed-off-by: Jay Freyensee <james.p.freyensee@intel.com>,
Signed-off-by: NMing Lin <ming.l@ssi.samsung.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <keith.busch@intel.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

The NVMe over Fabrics specification defines a protocol interface and
related extensions to NVMe that enable operation over network protocols.
The NVMe over Fabrics specification has an NVMe Transport binding for
each NVMe Transport.

This patch adds the fabrics related definitions:
- fabric specific command set and error codes
- transport addressing and binding definitions
- fabrics sgl extensions
- controller identification fabrics enhancements
- discovery log page definition
Signed-off-by: NArmen Baloyan <armenx.baloyan@intel.com>
Signed-off-by: NJames Smart <james.smart@broadcom.com>
Signed-off-by: NJay Freyensee <james.p.freyensee@intel.com>
Signed-off-by: NMing Lin <ming.l@ssi.samsung.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <keith.busch@intel.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

- delete_controller: This attribute allows to delete a controller.
  A driver is not obligated to support it (pci doesn't) so it is
  created only if the driver supports it. The new fabrics drivers
  will support it (essentialy a disconnect operation).

  Usage:
  echo > /sys/class/nvme/nvme0/delete_controller

- subsysnqn: This attribute shows the subsystem nqn of the configured
  device. If a driver does not implement the get_subsysnqn method, the
  file will not appear in sysfs.

- transport: This attribute shows the transport name. Added a "name"
  field to struct nvme_ctrl_ops.

  For loop,
  cat /sys/class/nvme/nvme0/transport
  loop

  For RDMA,
  cat /sys/class/nvme/nvme0/transport
  rdma

  For PCIe,
  cat /sys/class/nvme/nvme0/transport
  pcie

- address: This attributes shows the controller address. The fabrics
  drivers that will implement get_address can show the address of the
  connected controller.

  example:
  cat /sys/class/nvme/nvme0/address
  traddr=192.168.2.2,trsvcid=1023
Signed-off-by: NMing Lin <ming.l@ssi.samsung.com>
Reviewed-by: NJay Freyensee <james.p.freyensee@intel.com>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <keith.busch@intel.com>
Signed-off-by: NJens Axboe <axboe@fb.com>