linux-toradex.git/drivers/nvme, branch v5.10-rc3 Linux kernel for Apalis and Colibri modules Merge tag 'nvme-5.10-2020-11-05' of git://git.infradead.org/nvme into block-5.10 2020-11-05T14:10:50+00:00 Jens Axboe axboe@kernel.dk 2020-11-05T14:10:50+00:00 7ae7a8de054253024624abebd86eb25c5bdaf1c8 Pull NVMe fixes from Christoph: "nvme fixes for 5.10: - revert a nvme_queue size optimization (Keith Bush) - fabrics timeout races fixes (Chao Leng and Sagi Grimberg)" * tag 'nvme-5.10-2020-11-05' of git://git.infradead.org/nvme: nvme-tcp: avoid repeated request completion nvme-rdma: avoid repeated request completion nvme-tcp: avoid race between time out and tear down nvme-rdma: avoid race between time out and tear down nvme: introduce nvme_sync_io_queues Revert "nvme-pci: remove last_sq_tail" 
Pull NVMe fixes from Christoph:

"nvme fixes for 5.10:

 - revert a nvme_queue size optimization (Keith Bush)
 - fabrics timeout races fixes (Chao Leng and Sagi Grimberg)"

* tag 'nvme-5.10-2020-11-05' of git://git.infradead.org/nvme:
  nvme-tcp: avoid repeated request completion
  nvme-rdma: avoid repeated request completion
  nvme-tcp: avoid race between time out and tear down
  nvme-rdma: avoid race between time out and tear down
  nvme: introduce nvme_sync_io_queues
  Revert "nvme-pci: remove last_sq_tail"
nvme-tcp: avoid repeated request completion 2020-11-03T09:26:02+00:00 Sagi Grimberg sagi@grimberg.me 2020-10-22T02:15:31+00:00 0a8a2c85b83589a5c10bc5564b796836bf4b4984 The request may be executed asynchronously, and rq->state may be changed to IDLE. To avoid repeated request completion, only MQ_RQ_COMPLETE of rq->state is checked in nvme_tcp_complete_timed_out. It is not safe, so need adding check IDLE for rq->state. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Chao Leng <lengchao@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de> 
The request may be executed asynchronously, and rq->state may be
changed to IDLE. To avoid repeated request completion, only
MQ_RQ_COMPLETE of rq->state is checked in nvme_tcp_complete_timed_out.
It is not safe, so need adding check IDLE for rq->state.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Chao Leng <lengchao@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
nvme-rdma: avoid repeated request completion 2020-11-03T09:26:02+00:00 Sagi Grimberg sagi@grimberg.me 2020-10-22T02:15:23+00:00 fdf58e02adecbef4c7cbb2073d8ea225e6fd5f26 The request may be executed asynchronously, and rq->state may be changed to IDLE. To avoid repeated request completion, only MQ_RQ_COMPLETE of rq->state is checked in nvme_rdma_complete_timed_out. It is not safe, so need adding check IDLE for rq->state. Signed-off-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Chao Leng <lengchao@huawei.com> Signed-off-by: Christoph Hellwig <hch@lst.de> 
The request may be executed asynchronously, and rq->state may be
changed to IDLE. To avoid repeated request completion, only
MQ_RQ_COMPLETE of rq->state is checked in nvme_rdma_complete_timed_out.
It is not safe, so need adding check IDLE for rq->state.

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Chao Leng <lengchao@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
nvme-tcp: avoid race between time out and tear down 2020-11-03T09:26:02+00:00 Chao Leng lengchao@huawei.com 2020-10-22T02:15:15+00:00 d6f66210f4b1aa2f5944f0e34e0f8db44f499f92 Now use teardown_lock to serialize for time out and tear down. This may cause abnormal: first cancel all request in tear down, then time out may complete the request again, but the request may already be freed or restarted. To avoid race between time out and tear down, in tear down process, first we quiesce the queue, and then delete the timer and cancel the time out work for the queue. At the same time we need to delete teardown_lock. Signed-off-by: Chao Leng <lengchao@huawei.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de> 
Now use teardown_lock to serialize for time out and tear down. This may
cause abnormal: first cancel all request in tear down, then time out may
complete the request again, but the request may already be freed or
restarted.

To avoid race between time out and tear down, in tear down process,
first we quiesce the queue, and then delete the timer and cancel
the time out work for the queue. At the same time we need to delete
teardown_lock.

Signed-off-by: Chao Leng <lengchao@huawei.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
nvme-rdma: avoid race between time out and tear down 2020-11-03T09:26:01+00:00 Chao Leng lengchao@huawei.com 2020-10-22T02:15:08+00:00 3017013dcc82a4862bd1e140f8b762cfc594008d Now use teardown_lock to serialize for time out and tear down. This may cause abnormal: first cancel all request in tear down, then time out may complete the request again, but the request may already be freed or restarted. To avoid race between time out and tear down, in tear down process, first we quiesce the queue, and then delete the timer and cancel the time out work for the queue. At the same time we need to delete teardown_lock. Signed-off-by: Chao Leng <lengchao@huawei.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de> 
Now use teardown_lock to serialize for time out and tear down. This may
cause abnormal: first cancel all request in tear down, then time out may
complete the request again, but the request may already be freed or
restarted.

To avoid race between time out and tear down, in tear down process,
first we quiesce the queue, and then delete the timer and cancel
the time out work for the queue. At the same time we need to delete
teardown_lock.

Signed-off-by: Chao Leng <lengchao@huawei.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
nvme: introduce nvme_sync_io_queues 2020-11-03T09:25:55+00:00 Chao Leng lengchao@huawei.com 2020-10-22T02:15:00+00:00 04800fbff4764ab7b32c49d19628605a5d4cb85c Introduce sync io queues for some scenarios which just only need sync io queues not sync all queues. Signed-off-by: Chao Leng <lengchao@huawei.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de> 
Introduce sync io queues for some scenarios which just only need sync
io queues not sync all queues.

Signed-off-by: Chao Leng <lengchao@huawei.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Revert "nvme-pci: remove last_sq_tail" 2020-11-02T18:03:14+00:00 Keith Busch kbusch@kernel.org 2020-10-30T17:28:54+00:00 38210800bf66d7302da1bb5b624ad68638da1562 Multiple CPUs may be mapped to the same hctx, allowing mulitple submission contexts to attempt commit_rqs(). We need to verify we're not writing the same doorbell value multiple times since that's a spec violation. Revert commit 54b2fcee1db041a83b52b51752dade6090cf952f. Link: https://bugzilla.redhat.com/show_bug.cgi?id=1878596 Reported-by: "B.L. Jones" <brandon.gustav@googlemail.com> Signed-off-by: Keith Busch <kbusch@kernel.org> 
Multiple CPUs may be mapped to the same hctx, allowing mulitple
submission contexts to attempt commit_rqs(). We need to verify we're
not writing the same doorbell value multiple times since that's a spec
violation.

Revert commit 54b2fcee1db041a83b52b51752dade6090cf952f.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1878596
Reported-by: "B.L. Jones" <brandon.gustav@googlemail.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Merge tag 'block-5.10-2020-10-30' of git://git.kernel.dk/linux-block 2020-10-30T22:02:49+00:00 Linus Torvalds torvalds@linux-foundation.org 2020-10-30T22:02:49+00:00 5fc6b075e165f641fbc366b58b578055762d5f8c Pull block fixes from Jens Axboe: - null_blk zone fixes (Damien, Kanchan) - NVMe pull request from Christoph: - improve zone revalidation (Keith Busch) - gracefully handle zero length messages in nvme-rdma (zhenwei pi) - nvme-fc error handling fixes (James Smart) - nvmet tracing NULL pointer dereference fix (Chaitanya Kulkarni)" - xsysace platform fixes (Andy) - scatterlist type cleanup (David) - blk-cgroup memory fixes (Gabriel) - nbd block size update fix (Ming) - Flush completion state fix (Ming) - bio_add_hw_page() iteration fix (Naohiro) * tag 'block-5.10-2020-10-30' of git://git.kernel.dk/linux-block: blk-mq: mark flush request as IDLE in flush_end_io() lib/scatterlist: use consistent sg_copy_buffer() return type xsysace: use platform_get_resource() and platform_get_irq_optional() null_blk: Fix locking in zoned mode null_blk: Fix zone reset all tracing nbd: don't update block size after device is started block: advance iov_iter on bio_add_hw_page failure null_blk: synchronization fix for zoned device nvmet: fix a NULL pointer dereference when tracing the flush command nvme-fc: remove nvme_fc_terminate_io() nvme-fc: eliminate terminate_io use by nvme_fc_error_recovery nvme-fc: remove err_work work item nvme-fc: track error_recovery while connecting nvme-rdma: handle unexpected nvme completion data length nvme: ignore zone validate errors on subsequent scans blk-cgroup: Pre-allocate tree node on blkg_conf_prep blk-cgroup: Fix memleak on error path 
Pull block fixes from Jens Axboe:

 - null_blk zone fixes (Damien, Kanchan)

 - NVMe pull request from Christoph:
       - improve zone revalidation (Keith Busch)
       - gracefully handle zero length messages in nvme-rdma (zhenwei pi)
       - nvme-fc error handling fixes (James Smart)
       - nvmet tracing NULL pointer dereference fix (Chaitanya Kulkarni)"

 - xsysace platform fixes (Andy)

 - scatterlist type cleanup (David)

 - blk-cgroup memory fixes (Gabriel)

 - nbd block size update fix (Ming)

 - Flush completion state fix (Ming)

 - bio_add_hw_page() iteration fix (Naohiro)

* tag 'block-5.10-2020-10-30' of git://git.kernel.dk/linux-block:
  blk-mq: mark flush request as IDLE in flush_end_io()
  lib/scatterlist: use consistent sg_copy_buffer() return type
  xsysace: use platform_get_resource() and platform_get_irq_optional()
  null_blk: Fix locking in zoned mode
  null_blk: Fix zone reset all tracing
  nbd: don't update block size after device is started
  block: advance iov_iter on bio_add_hw_page failure
  null_blk: synchronization fix for zoned device
  nvmet: fix a NULL pointer dereference when tracing the flush command
  nvme-fc: remove nvme_fc_terminate_io()
  nvme-fc: eliminate terminate_io use by nvme_fc_error_recovery
  nvme-fc: remove err_work work item
  nvme-fc: track error_recovery while connecting
  nvme-rdma: handle unexpected nvme completion data length
  nvme: ignore zone validate errors on subsequent scans
  blk-cgroup: Pre-allocate tree node on blkg_conf_prep
  blk-cgroup: Fix memleak on error path
RDMA: Add rdma_connect_locked() 2020-10-28T12:14:49+00:00 Jason Gunthorpe jgg@nvidia.com 2020-10-26T14:25:49+00:00 071ba4cc559de47160761b9500b72e8fa09d923d There are two flows for handling RDMA_CM_EVENT_ROUTE_RESOLVED, either the handler triggers a completion and another thread does rdma_connect() or the handler directly calls rdma_connect(). In all cases rdma_connect() needs to hold the handler_mutex, but when handler's are invoked this is already held by the core code. This causes ULPs using the 2nd method to deadlock. Provide a rdma_connect_locked() and have all ULPs call it from their handlers. Link: https://lore.kernel.org/r/0-v2-53c22d5c1405+33-rdma_connect_locking_jgg@nvidia.com Reported-and-tested-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com> Fixes: 2a7cec538169 ("RDMA/cma: Fix locking for the RDMA_CM_CONNECT state") Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com> Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> 
There are two flows for handling RDMA_CM_EVENT_ROUTE_RESOLVED, either the
handler triggers a completion and another thread does rdma_connect() or
the handler directly calls rdma_connect().

In all cases rdma_connect() needs to hold the handler_mutex, but when
handler's are invoked this is already held by the core code. This causes
ULPs using the 2nd method to deadlock.

Provide a rdma_connect_locked() and have all ULPs call it from their
handlers.

Link: https://lore.kernel.org/r/0-v2-53c22d5c1405+33-rdma_connect_locking_jgg@nvidia.com
Reported-and-tested-by: Guoqing Jiang <guoqing.jiang@cloud.ionos.com>
Fixes: 2a7cec538169 ("RDMA/cma: Fix locking for the RDMA_CM_CONNECT state")
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Acked-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
nvmet: fix a NULL pointer dereference when tracing the flush command 2020-10-27T09:02:50+00:00 Chaitanya Kulkarni chaitanya.kulkarni@wdc.com 2020-10-22T23:58:21+00:00 3c3751f2daf6675f6b5bee83b792354c272f5bd2 When target side trace in turned on and flush command is issued from the host it results in the following Oops. [ 856.789724] BUG: kernel NULL pointer dereference, address: 0000000000000068 [ 856.790686] #PF: supervisor read access in kernel mode [ 856.791262] #PF: error_code(0x0000) - not-present page [ 856.791863] PGD 6d7110067 P4D 6d7110067 PUD 66f0ad067 PMD 0 [ 856.792527] Oops: 0000 [#1] SMP NOPTI [ 856.792950] CPU: 15 PID: 7034 Comm: nvme Tainted: G OE 5.9.0nvme-5.9+ #71 [ 856.793790] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e3214 [ 856.794956] RIP: 0010:trace_event_raw_event_nvmet_req_init+0x13e/0x170 [nvmet] [ 856.795734] Code: 41 5c 41 5d c3 31 d2 31 f6 e8 4e 9b b8 e0 e9 0e ff ff ff 49 8b 55 00 48 8b 38 8b 0 [ 856.797740] RSP: 0018:ffffc90001be3a60 EFLAGS: 00010246 [ 856.798375] RAX: 0000000000000000 RBX: ffff8887e7d2c01c RCX: 0000000000000000 [ 856.799234] RDX: 0000000000000020 RSI: 0000000057e70ea2 RDI: ffff8887e7d2c034 [ 856.800088] RBP: ffff88869f710578 R08: ffff888807500d40 R09: 00000000fffffffe [ 856.800951] R10: 0000000064c66670 R11: 00000000ef955201 R12: ffff8887e7d2c034 [ 856.801807] R13: ffff88869f7105c8 R14: 0000000000000040 R15: ffff88869f710440 [ 856.802667] FS: 00007f6a22bd8780(0000) GS:ffff888813a00000(0000) knlGS:0000000000000000 [ 856.803635] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 856.804367] CR2: 0000000000000068 CR3: 00000006d73e0000 CR4: 00000000003506e0 [ 856.805283] Call Trace: [ 856.805613] nvmet_req_init+0x27c/0x480 [nvmet] [ 856.806200] nvme_loop_queue_rq+0xcb/0x1d0 [nvme_loop] [ 856.806862] blk_mq_dispatch_rq_list+0x123/0x7b0 [ 856.807459] ? kvm_sched_clock_read+0x14/0x30 [ 856.808025] __blk_mq_sched_dispatch_requests+0xc7/0x170 [ 856.808708] blk_mq_sched_dispatch_requests+0x30/0x60 [ 856.809372] __blk_mq_run_hw_queue+0x70/0x100 [ 856.809935] __blk_mq_delay_run_hw_queue+0x156/0x170 [ 856.810574] blk_mq_run_hw_queue+0x86/0xe0 [ 856.811104] blk_mq_sched_insert_request+0xef/0x160 [ 856.811733] blk_execute_rq+0x69/0xc0 [ 856.812212] ? blk_mq_rq_ctx_init+0xd0/0x230 [ 856.812784] nvme_execute_passthru_rq+0x57/0x130 [nvme_core] [ 856.813461] nvme_submit_user_cmd+0xeb/0x300 [nvme_core] [ 856.814099] nvme_user_cmd.isra.82+0x11e/0x1a0 [nvme_core] [ 856.814752] blkdev_ioctl+0x1dc/0x2c0 [ 856.815197] block_ioctl+0x3f/0x50 [ 856.815606] __x64_sys_ioctl+0x84/0xc0 [ 856.816074] do_syscall_64+0x33/0x40 [ 856.816533] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 856.817168] RIP: 0033:0x7f6a222ed107 [ 856.817617] Code: 44 00 00 48 8b 05 81 cd 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 8 [ 856.819901] RSP: 002b:00007ffca848f058 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 856.820846] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f6a222ed107 [ 856.821726] RDX: 00007ffca848f060 RSI: 00000000c0484e43 RDI: 0000000000000003 [ 856.822603] RBP: 0000000000000003 R08: 000000000000003f R09: 0000000000000005 [ 856.823478] R10: 00007ffca848ece0 R11: 0000000000000202 R12: 00007ffca84912d3 [ 856.824359] R13: 00007ffca848f4d0 R14: 0000000000000002 R15: 000000000067e900 [ 856.825236] Modules linked in: nvme_loop(OE) nvmet(OE) nvme_fabrics(OE) null_blk nvme(OE) nvme_corel Move the nvmet_req_init() tracepoint after we parse the command in nvmet_req_init() so that we can get rid of the duplicate nvmet_find_namespace() call. Rename __assign_disk_name() -> __assign_req_name(). Now that we call tracepoint after parsing the command simplify the newly added __assign_req_name() which fixes this bug. Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> 
When target side trace in turned on and flush command is issued from the
host it results in the following Oops.

[  856.789724] BUG: kernel NULL pointer dereference, address: 0000000000000068
[  856.790686] #PF: supervisor read access in kernel mode
[  856.791262] #PF: error_code(0x0000) - not-present page
[  856.791863] PGD 6d7110067 P4D 6d7110067 PUD 66f0ad067 PMD 0
[  856.792527] Oops: 0000 [#1] SMP NOPTI
[  856.792950] CPU: 15 PID: 7034 Comm: nvme Tainted: G           OE     5.9.0nvme-5.9+ #71
[  856.793790] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e3214
[  856.794956] RIP: 0010:trace_event_raw_event_nvmet_req_init+0x13e/0x170 [nvmet]
[  856.795734] Code: 41 5c 41 5d c3 31 d2 31 f6 e8 4e 9b b8 e0 e9 0e ff ff ff 49 8b 55 00 48 8b 38 8b 0
[  856.797740] RSP: 0018:ffffc90001be3a60 EFLAGS: 00010246
[  856.798375] RAX: 0000000000000000 RBX: ffff8887e7d2c01c RCX: 0000000000000000
[  856.799234] RDX: 0000000000000020 RSI: 0000000057e70ea2 RDI: ffff8887e7d2c034
[  856.800088] RBP: ffff88869f710578 R08: ffff888807500d40 R09: 00000000fffffffe
[  856.800951] R10: 0000000064c66670 R11: 00000000ef955201 R12: ffff8887e7d2c034
[  856.801807] R13: ffff88869f7105c8 R14: 0000000000000040 R15: ffff88869f710440
[  856.802667] FS:  00007f6a22bd8780(0000) GS:ffff888813a00000(0000) knlGS:0000000000000000
[  856.803635] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  856.804367] CR2: 0000000000000068 CR3: 00000006d73e0000 CR4: 00000000003506e0
[  856.805283] Call Trace:
[  856.805613]  nvmet_req_init+0x27c/0x480 [nvmet]
[  856.806200]  nvme_loop_queue_rq+0xcb/0x1d0 [nvme_loop]
[  856.806862]  blk_mq_dispatch_rq_list+0x123/0x7b0
[  856.807459]  ? kvm_sched_clock_read+0x14/0x30
[  856.808025]  __blk_mq_sched_dispatch_requests+0xc7/0x170
[  856.808708]  blk_mq_sched_dispatch_requests+0x30/0x60
[  856.809372]  __blk_mq_run_hw_queue+0x70/0x100
[  856.809935]  __blk_mq_delay_run_hw_queue+0x156/0x170
[  856.810574]  blk_mq_run_hw_queue+0x86/0xe0
[  856.811104]  blk_mq_sched_insert_request+0xef/0x160
[  856.811733]  blk_execute_rq+0x69/0xc0
[  856.812212]  ? blk_mq_rq_ctx_init+0xd0/0x230
[  856.812784]  nvme_execute_passthru_rq+0x57/0x130 [nvme_core]
[  856.813461]  nvme_submit_user_cmd+0xeb/0x300 [nvme_core]
[  856.814099]  nvme_user_cmd.isra.82+0x11e/0x1a0 [nvme_core]
[  856.814752]  blkdev_ioctl+0x1dc/0x2c0
[  856.815197]  block_ioctl+0x3f/0x50
[  856.815606]  __x64_sys_ioctl+0x84/0xc0
[  856.816074]  do_syscall_64+0x33/0x40
[  856.816533]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  856.817168] RIP: 0033:0x7f6a222ed107
[  856.817617] Code: 44 00 00 48 8b 05 81 cd 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 8
[  856.819901] RSP: 002b:00007ffca848f058 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[  856.820846] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f6a222ed107
[  856.821726] RDX: 00007ffca848f060 RSI: 00000000c0484e43 RDI: 0000000000000003
[  856.822603] RBP: 0000000000000003 R08: 000000000000003f R09: 0000000000000005
[  856.823478] R10: 00007ffca848ece0 R11: 0000000000000202 R12: 00007ffca84912d3
[  856.824359] R13: 00007ffca848f4d0 R14: 0000000000000002 R15: 000000000067e900
[  856.825236] Modules linked in: nvme_loop(OE) nvmet(OE) nvme_fabrics(OE) null_blk nvme(OE) nvme_corel

Move the nvmet_req_init() tracepoint after we parse the command in
nvmet_req_init() so that we can get rid of the duplicate
nvmet_find_namespace() call.
Rename __assign_disk_name() ->  __assign_req_name(). Now that we call
tracepoint after parsing the command simplify the newly added
__assign_req_name() which fixes this bug.

Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>