Drivers shouldn't really mess with the readahead size, as that is a VM
concept.  Instead set it based on the optimal I/O size by lifting the
algorithm from the md driver when registering the disk.  Also set
bdi->io_pages there as well by applying the same scheme based on
max_sectors.  To ensure the limits work well for stacking drivers a
new helper is added to update the readahead limits from the block
limits, which is also called from disk_stack_limits.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Acked-by: NColy Li <colyli@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Keep control in the NVMe driver instead of going through an indirect
call back into ->revalidate_disk.  Also reorder the function a bit to be
easier to follow with the additional code.

And now that we have removed all callers of revalidate_disk() in the nvme
code, ->revalidate_disk is only called from the open code when first
opening the device.  Which is of course totally pointless as we have
a valid size since the initial scan, and will get an updated view
through the asynchronous notifiation everytime the size changes.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJosef Bacik <josef@toxicpanda.com>
Reviewed-by: NJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

In nvme_set_queue_dying we really just want to ensure the disk and bdev
sizes are set to zero.  Going through revalidate_disk leads to a somewhat
arcance and complex callchain relying on special behavior in a few
places.  Instead just lift the set_capacity directly to
nvme_set_queue_dying, and rename and move the nvme_mpath_update_disk_size
helper so that we can use it in nvme_set_queue_dying to propagate the
size to the bdev without detours.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Replace bd_set_size with a version that takes the number of sectors
instead, as that fits most of the current and future callers much better.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

This patch addresses an irq free warning and null pointer dereference
error problem when nvme devices got timeout error during initialization.
This problem happens when nvme_timeout() function is called while
nvme_reset_work() is still in execution. This patch fixed the problem by
setting flag of the problematic request to NVME_REQ_CANCELLED before
calling nvme_dev_disable() to make sure __nvme_submit_sync_cmd() returns
an error code and let nvme_submit_sync_cmd() fail gracefully.
The following is console output.

[   62.472097] nvme nvme0: I/O 13 QID 0 timeout, disable controller
[   62.488796] nvme nvme0: could not set timestamp (881)
[   62.494888] ------------[ cut here ]------------
[   62.495142] Trying to free already-free IRQ 11
[   62.495366] WARNING: CPU: 0 PID: 7 at kernel/irq/manage.c:1751 free_irq+0x1f7/0x370
[   62.495742] Modules linked in:
[   62.495902] CPU: 0 PID: 7 Comm: kworker/u4:0 Not tainted 5.8.0+ #8
[   62.496206] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-48-gd9c812dda519-p4
[   62.496772] Workqueue: nvme-reset-wq nvme_reset_work
[   62.497019] RIP: 0010:free_irq+0x1f7/0x370
[   62.497223] Code: e8 ce 49 11 00 48 83 c4 08 4c 89 e0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 44 89 f6 48 c70
[   62.498133] RSP: 0000:ffffa96800043d40 EFLAGS: 00010086
[   62.498391] RAX: 0000000000000000 RBX: ffff9b87fc458400 RCX: 0000000000000000
[   62.498741] RDX: 0000000000000001 RSI: 0000000000000096 RDI: ffffffff9693d72c
[   62.499091] RBP: ffff9b87fd4c8f60 R08: ffffa96800043bfd R09: 0000000000000163
[   62.499440] R10: ffffa96800043bf8 R11: ffffa96800043bfd R12: ffff9b87fd4c8e00
[   62.499790] R13: ffff9b87fd4c8ea4 R14: 000000000000000b R15: ffff9b87fd76b000
[   62.500140] FS:  0000000000000000(0000) GS:ffff9b87fdc00000(0000) knlGS:0000000000000000
[   62.500534] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   62.500816] CR2: 0000000000000000 CR3: 000000003aa0a000 CR4: 00000000000006f0
[   62.501165] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   62.501515] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   62.501864] Call Trace:
[   62.501993]  pci_free_irq+0x13/0x20
[   62.502167]  nvme_reset_work+0x5d0/0x12a0
[   62.502369]  ? update_load_avg+0x59/0x580
[   62.502569]  ? ttwu_queue_wakelist+0xa8/0xc0
[   62.502780]  ? try_to_wake_up+0x1a2/0x450
[   62.502979]  process_one_work+0x1d2/0x390
[   62.503179]  worker_thread+0x45/0x3b0
[   62.503361]  ? process_one_work+0x390/0x390
[   62.503568]  kthread+0xf9/0x130
[   62.503726]  ? kthread_park+0x80/0x80
[   62.503911]  ret_from_fork+0x22/0x30
[   62.504090] ---[ end trace de9ed4a70f8d71e2 ]---
[  123.912275] nvme nvme0: I/O 12 QID 0 timeout, disable controller
[  123.914670] nvme nvme0: 1/0/0 default/read/poll queues
[  123.916310] BUG: kernel NULL pointer dereference, address: 0000000000000000
[  123.917469] #PF: supervisor write access in kernel mode
[  123.917725] #PF: error_code(0x0002) - not-present page
[  123.917976] PGD 0 P4D 0
[  123.918109] Oops: 0002 [#1] SMP PTI
[  123.918283] CPU: 0 PID: 7 Comm: kworker/u4:0 Tainted: G        W         5.8.0+ #8
[  123.918650] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-48-gd9c812dda519-p4
[  123.919219] Workqueue: nvme-reset-wq nvme_reset_work
[  123.919469] RIP: 0010:__blk_mq_alloc_map_and_request+0x21/0x80
[  123.919757] Code: 66 0f 1f 84 00 00 00 00 00 41 55 41 54 55 48 63 ee 53 48 8b 47 68 89 ee 48 89 fb 8b4
[  123.920657] RSP: 0000:ffffa96800043d40 EFLAGS: 00010286
[  123.920912] RAX: ffff9b87fc4fee40 RBX: ffff9b87fc8cb008 RCX: 0000000000000000
[  123.921258] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9b87fc618000
[  123.921602] RBP: 0000000000000000 R08: ffff9b87fdc2c4a0 R09: ffff9b87fc616000
[  123.921949] R10: 0000000000000000 R11: ffff9b87fffd1500 R12: 0000000000000000
[  123.922295] R13: 0000000000000000 R14: ffff9b87fc8cb200 R15: ffff9b87fc8cb000
[  123.922641] FS:  0000000000000000(0000) GS:ffff9b87fdc00000(0000) knlGS:0000000000000000
[  123.923032] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  123.923312] CR2: 0000000000000000 CR3: 000000003aa0a000 CR4: 00000000000006f0
[  123.923660] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  123.924007] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  123.924353] Call Trace:
[  123.924479]  blk_mq_alloc_tag_set+0x137/0x2a0
[  123.924694]  nvme_reset_work+0xed6/0x12a0
[  123.924898]  process_one_work+0x1d2/0x390
[  123.925099]  worker_thread+0x45/0x3b0
[  123.925280]  ? process_one_work+0x390/0x390
[  123.925486]  kthread+0xf9/0x130
[  123.925642]  ? kthread_park+0x80/0x80
[  123.925825]  ret_from_fork+0x22/0x30
[  123.926004] Modules linked in:
[  123.926158] CR2: 0000000000000000
[  123.926322] ---[ end trace de9ed4a70f8d71e3 ]---
[  123.926549] RIP: 0010:__blk_mq_alloc_map_and_request+0x21/0x80
[  123.926832] Code: 66 0f 1f 84 00 00 00 00 00 41 55 41 54 55 48 63 ee 53 48 8b 47 68 89 ee 48 89 fb 8b4
[  123.927734] RSP: 0000:ffffa96800043d40 EFLAGS: 00010286
[  123.927989] RAX: ffff9b87fc4fee40 RBX: ffff9b87fc8cb008 RCX: 0000000000000000
[  123.928336] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9b87fc618000
[  123.928679] RBP: 0000000000000000 R08: ffff9b87fdc2c4a0 R09: ffff9b87fc616000
[  123.929025] R10: 0000000000000000 R11: ffff9b87fffd1500 R12: 0000000000000000
[  123.929370] R13: 0000000000000000 R14: ffff9b87fc8cb200 R15: ffff9b87fc8cb000
[  123.929715] FS:  0000000000000000(0000) GS:ffff9b87fdc00000(0000) knlGS:0000000000000000
[  123.930106] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  123.930384] CR2: 0000000000000000 CR3: 000000003aa0a000 CR4: 00000000000006f0
[  123.930731] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  123.931077] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Co-developed-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NTong Zhang <ztong0001@gmail.com>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

The kernel requires a power of two for boundaries because that's the
only way it can efficiently split commands that cross them. A
controller, however, may report a non-power of two boundary.

The driver had been rounding the controller's value to one the kernel
can use, but splitting on the wrong boundary provides no benefit on the
device side, and incurs additional submission overhead from non-optimal
splits.

Don't provide any boundary hint if the controller's value can't be used
and log a warning when first scanning a disk's unreported IO boundary.
Since the chunk sector logic has grown, move it to a separate function.

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

If the driver has to unbind from the controller for an early failure
before the subsystem has been set up, there won't be a subsystem holding
the controller's instance, so the controller needs to free its own
instance in this case.

Fixes: 733e4b69 ("nvme: Assign subsys instance from first ctrl")
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

PCIe controllers do not have fabric opts, verify they exist before
showing ctrl_loss_tmo or reconnect_delay attributes.

Fixes: 764075fd ("nvme: expose reconnect_delay and ctrl_loss_tmo via sysfs")
Reported-by: NTobias Markus <tobias@markus-regensburg.de>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

If the controller becomes unresponsive in the middle of a reset, we
will hang because we are waiting for the freeze to complete, but that
cannot happen since we have commands that are inflight holding the
q_usage_counter, and we can't blindly fail requests that times out.

So give a timeout and if we cannot wait for queue freeze before
unfreezing, fail and have the error handling take care how to
proceed (either schedule a reconnect of remove the controller).
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

When a request times out in a LIVE state, we simply trigger error
recovery and let the error recovery handle the request cancellation,
however when a request times out in a non LIVE state, we make sure to
complete it immediately as it might block controller setup or teardown
and prevent forward progress.

However tearing down the entire set of I/O and admin queues causes
freeze/unfreeze imbalance (q->mq_freeze_depth) because and is really
an overkill to what we actually need, which is to just fence controller
teardown that may be running, stop the queue, and cancel the request if
it is not already completed.

Now that we have the controller teardown_lock, we can safely serialize
request cancellation. This addresses a hang caused by calling extra
queue freeze on controller namespaces, causing unfreeze to not complete
correctly.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJames Smart <james.smart@broadcom.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

In the timeout handler we may need to complete a request because the
request that timed out may be an I/O that is a part of a serial sequence
of controller teardown or initialization. In order to complete the
request, we need to fence any other context that may compete with us
and complete the request that is timing out.

In this case, we could have a potential double completion in case
a hard-irq or a different competing context triggered error recovery
and is running inflight request cancellation concurrently with the
timeout handler.

Protect using a ctrl teardown_lock to serialize contexts that may
complete a cancelled request due to error recovery or a reset.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJames Smart <james.smart@broadcom.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

If the controller becomes unresponsive in the middle of a reset, we will
hang because we are waiting for the freeze to complete, but that cannot
happen since we have commands that are inflight holding the
q_usage_counter, and we can't blindly fail requests that times out.

So give a timeout and if we cannot wait for queue freeze before
unfreezing, fail and have the error handling take care how to proceed
(either schedule a reconnect of remove the controller).
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

When a request times out in a LIVE state, we simply trigger error
recovery and let the error recovery handle the request cancellation,
however when a request times out in a non LIVE state, we make sure to
complete it immediately as it might block controller setup or teardown
and prevent forward progress.

However tearing down the entire set of I/O and admin queues causes
freeze/unfreeze imbalance (q->mq_freeze_depth) because and is really
an overkill to what we actually need, which is to just fence controller
teardown that may be running, stop the queue, and cancel the request if
it is not already completed.

Now that we have the controller teardown_lock, we can safely serialize
request cancellation. This addresses a hang caused by calling extra
queue freeze on controller namespaces, causing unfreeze to not complete
correctly.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

In the timeout handler we may need to complete a request because the
request that timed out may be an I/O that is a part of a serial sequence
of controller teardown or initialization. In order to complete the
request, we need to fence any other context that may compete with us
and complete the request that is timing out.

In this case, we could have a potential double completion in case
a hard-irq or a different competing context triggered error recovery
and is running inflight request cancellation concurrently with the
timeout handler.

Protect using a ctrl teardown_lock to serialize contexts that may
complete a cancelled request due to error recovery or a reset.
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

Users can detect if the wait has completed or not and take appropriate
actions based on this information (e.g. weather to continue
initialization or rather fail and schedule another initialization
attempt).
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

NVME_CTRL_NEW should never see any I/O, because in order to start
initialization it has to transition to NVME_CTRL_CONNECTING and from
there it will never return to this state.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-throughSigned-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>

If a command send through nvme-multipath failed on a dying queue, resend it
on another path.
Signed-off-by: NChao Leng <lengchao@huawei.com>
[hch: rebased on top of the completion refactoring]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Check the SCT sub-field for a path related status instead of enumerating
invididual status code.  As of NVMe 1.4 this adds "Internal Path Error"
and "Controller Pathing Error" to the list, but it also future proofs for
additional status codes added to the category.
Suggested-by: NChao Leng <lengchao@huawei.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Lift all the code to decide the dispostition of a completed command
from nvme_complete_rq and nvme_failover_req into a new helper, which
returns an emum of the potential actions.  nvme_complete_rq then
just switches on those and calls the proper helper for the action.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

nvme_end_request is a bit misnamed, as it wraps around the
blk_mq_complete_* API.  It's semantics also are non-trivial, so give it
a more descriptive name and add a comment explaining the semantics.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NMike Snitzer <snitzer@redhat.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Zoned block devices reuse the chunk_sectors queue limit to define zone
boundaries. If a such a device happens to also report an optimal
boundary, do not use that to define the chunk_sectors as that may
intermittently interfere with io splitting and zone size queries.
Signed-off-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

All operations are based on the controller, not the host page size.
Switch the dma pool to use the controller page size as well to avoid
massive overallocations on large page size systems.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Recently nvme_dev.q_depth was changed from an int to u16 type.

This falls over for the queue depth calculation in nvme_pci_enable(),
where NVME_CAP_MQES(dev->ctrl.cap) + 1 may overflow as a u16, as
NVME_CAP_MQES() is a 16b number also. That happens for me, and this is the
result:

root@ubuntu:/home/john# [148.272996] Unable to handle kernel NULL pointer
dereference at virtual address 0000000000000010
Mem abort info:
ESR = 0x96000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000004
CM = 0, WnR = 0
user pgtable: 4k pages, 48-bit VAs, pgdp=00000a27bf3c9000
[0000000000000010] pgd=0000000000000000, p4d=0000000000000000
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in: nvme nvme_core
CPU: 56 PID: 256 Comm: kworker/u195:0 Not tainted
5.8.0-next-20200812 #27
Hardware name: Huawei D06 /D06, BIOS Hisilicon D06 UEFI RC0 -
V1.16.01 03/15/2019
Workqueue: nvme-reset-wq nvme_reset_work [nvme]
pstate: 80c00009 (Nzcv daif +PAN +UAO BTYPE=--)
pc : __sg_alloc_table_from_pages+0xec/0x238
lr : __sg_alloc_table_from_pages+0xc8/0x238
sp : ffff800013ccbad0
x29: ffff800013ccbad0 x28: ffff0a27b3d380a8
x27: 0000000000000000 x26: 0000000000002dc2
x25: 0000000000000dc0 x24: 0000000000000000
x23: 0000000000000000 x22: ffff800013ccbbe8
x21: 0000000000000010 x20: 0000000000000000
x19: 00000000fffff000 x18: ffffffffffffffff
x17: 00000000000000c0 x16: fffffe289eaf6380
x15: ffff800011b59948 x14: ffff002bc8fe98f8
x13: ff00000000000000 x12: ffff8000114ca000
x11: 0000000000000000 x10: ffffffffffffffff
x9 : ffffffffffffffc0 x8 : ffff0a27b5f9b6a0
x7 : 0000000000000000 x6 : 0000000000000001
x5 : ffff0a27b5f9b680 x4 : 0000000000000000
x3 : ffff0a27b5f9b680 x2 : 0000000000000000
 x1 : 0000000000000001 x0 : 0000000000000000
 Call trace:
__sg_alloc_table_from_pages+0xec/0x238
sg_alloc_table_from_pages+0x18/0x28
iommu_dma_alloc+0x474/0x678
dma_alloc_attrs+0xd8/0xf0
nvme_alloc_queue+0x114/0x160 [nvme]
nvme_reset_work+0xb34/0x14b4 [nvme]
process_one_work+0x1e8/0x360
worker_thread+0x44/0x478
kthread+0x150/0x158
ret_from_fork+0x10/0x34
 Code: f94002c3 6b01017f 540007c2 11000486 (f8645aa5)
---[ end trace 89bb2b72d59bf925 ]---

Fix by making onto a u32.

Also use u32 for nvme_dev.q_depth, as we assign this value from
nvme_dev.q_depth, and nvme_dev.q_depth will possibly hold 65536 - this
avoids the same crash as above.

Fixes: 61f3b896 ("nvme-pci: use unsigned for io queue depth")
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

When locking the ctrl->lock spinlock IRQs need to be disabled to avoid a
dead lock. The new spin_lock() calls recently added produce the
following lockdep warning when running the blktest nvme/003:

    ================================
    WARNING: inconsistent lock state
    --------------------------------
    inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
    ksoftirqd/2/22 [HC0[0]:SC1[1]:HE0:SE0] takes:
    ffff888276a8c4c0 (&ctrl->lock){+.?.}-{2:2}, at: nvme_keep_alive_end_io+0x50/0xc0
    {SOFTIRQ-ON-W} state was registered at:
      lock_acquire+0x164/0x500
      _raw_spin_lock+0x28/0x40
      nvme_get_effects_log+0x37/0x1c0
      nvme_init_identify+0x9e4/0x14f0
      nvme_reset_work+0xadd/0x2360
      process_one_work+0x66b/0xb70
      worker_thread+0x6e/0x6c0
      kthread+0x1e7/0x210
      ret_from_fork+0x22/0x30
    irq event stamp: 1449221
    hardirqs last  enabled at (1449220): [<ffffffff81c58e69>] ktime_get+0xf9/0x140
    hardirqs last disabled at (1449221): [<ffffffff83129665>] _raw_spin_lock_irqsave+0x25/0x60
    softirqs last  enabled at (1449210): [<ffffffff83400447>] __do_softirq+0x447/0x595
    softirqs last disabled at (1449215): [<ffffffff81b489b5>] run_ksoftirqd+0x35/0x50

    other info that might help us debug this:
     Possible unsafe locking scenario:

           CPU0
           ----
      lock(&ctrl->lock);
      <Interrupt>
        lock(&ctrl->lock);

     *** DEADLOCK ***

    no locks held by ksoftirqd/2/22.

    stack backtrace:
    CPU: 2 PID: 22 Comm: ksoftirqd/2 Not tainted 5.8.0-rc4-eid-vmlocalyes-dbg-00157-g7236657c #1450
    Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.12.0-1 04/01/2014
    Call Trace:
     dump_stack+0xc8/0x11a
     print_usage_bug.cold.63+0x235/0x23e
     mark_lock+0xa9c/0xcf0
     __lock_acquire+0xd9a/0x2b50
     lock_acquire+0x164/0x500
     _raw_spin_lock_irqsave+0x40/0x60
     nvme_keep_alive_end_io+0x50/0xc0
     blk_mq_end_request+0x158/0x210
     nvme_complete_rq+0x146/0x500
     nvme_loop_complete_rq+0x26/0x30 [nvme_loop]
     blk_done_softirq+0x187/0x1e0
     __do_softirq+0x118/0x595
     run_ksoftirqd+0x35/0x50
     smpboot_thread_fn+0x1d3/0x310
     kthread+0x1e7/0x210
     ret_from_fork+0x22/0x30

Fixes: be93e87e ("nvme: support for multiple Command Sets Supported and Effects log pages")
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Tested-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

If we find an optimized path, we quit the loop immediately. Thus we can use
just one variable for the next path, slighly simplifying the code.
Signed-off-by: NMartin Wilck <mwilck@suse.com>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

If there's only one usable, non-optimized path, nvme_round_robin_path()
returns NULL, which is wrong. Fix it by falling back to "old", like in
the single optimized path case. Also, if the active path isn't changed,
there's no need to re-assign the pointer.

Fixes: 3f6e3246 ("nvme-multipath: fix logic for non-optimized paths")
Signed-off-by: NMartin Wilck <mwilck@suse.com>
Signed-off-by: NMartin George <marting@netapp.com>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

On an error exit path, a negative error code should be returned
instead of a positive return value.

Fixes: e399441d ("nvme-fabrics: Add host support for FC transport")
Cc: James Smart <jsmart2021@gmail.com>
Signed-off-by: NTianjia Zhang <tianjia.zhang@linux.alibaba.com>
Reviewed-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Add a quirk for a device that does not support the Identify Namespace
Identification Descriptor list despite claiming 1.3 compliance.

Fixes: ea43d970 ("nvme: fix identify error status silent ignore")
Reported-by: NIngo Brunberg <ingo_brunberg@web.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NIngo Brunberg <ingo_brunberg@web.de>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>

When nvme_round_robin_path() finds a valid namespace we should be using it;
falling back to __nvme_find_path() for non-optimized paths will cause the
result from nvme_round_robin_path() to be ignored for non-optimized paths.

Fixes: 75c10e73 ("nvme-multipath: round-robin I/O policy")
Signed-off-by: NMartin Wilck <mwilck@suse.com>
Signed-off-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Handle the special case where we have exactly one optimized path,
which we should keep using in this case.

Fixes: 75c10e73 ("nvme-multipath: round-robin I/O policy")
Signed off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: NHannes Reinecke <hare@suse.de>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

commit fe35ec58 ("block: update hctx map when use multiple maps")
exposed an issue where we may hang trying to wait for queue freeze
during I/O. We call blk_mq_update_nr_hw_queues which in case of multiple
queue maps (which we have now for default/read/poll) is attempting to
freeze the queue. However we never started queue freeze when starting the
reset, which means that we have inflight pending requests that entered the
queue that we will not complete once the queue is quiesced.

So start a freeze before we quiesce the queue, and unfreeze the queue
after we successfully connected the I/O queues (and make sure to call
blk_mq_update_nr_hw_queues only after we are sure that the queue was
already frozen).

This follows to how the pci driver handles resets.

Fixes: fe35ec58 ("block: update hctx map when use multiple maps")
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

commit fe35ec58 ("block: update hctx map when use multiple maps")
exposed an issue where we may hang trying to wait for queue freeze
during I/O. We call blk_mq_update_nr_hw_queues which in case of multiple
queue maps (which we have now for default/read/poll) is attempting to
freeze the queue. However we never started queue freeze when starting the
reset, which means that we have inflight pending requests that entered the
queue that we will not complete once the queue is quiesced.

So start a freeze before we quiesce the queue, and unfreeze the queue
after we successfully connected the I/O queues (and make sure to call
blk_mq_update_nr_hw_queues only after we are sure that the queue was
already frozen).

This follows to how the pci driver handles resets.

Fixes: fe35ec58 ("block: update hctx map when use multiple maps")
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

nvme_find_get_ns() and nvme_put_ns() are required by the target passthru
code and are exported under the NVME_TARGET_PASSTHRU namespace.
Based-on-a-patch-by: NChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

nvme_ctrl_get_by_path() is analogous to blkdev_get_by_path() except it
gets a struct nvme_ctrl from the path to its char dev (/dev/nvme0).
It makes use of filp_open() to open the file and uses the private
data to obtain a pointer to the struct nvme_ctrl. If the fops of the
file do not match, -EINVAL is returned.

The purpose of this function is to support NVMe-OF target passthru
and is exported under the NVME_TARGET_PASSTHRU namespace.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Reviewed-by: NMax Gurtovoy <maxg@mellanox.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Introduce a new nvme_execute_passthru_rq() helper which calls
nvme_passthru_[start|end]() around blk_execute_rq(). This ensures
all passthru calls (including nvme_submit_io()) will be wrapped
appropriately.

nvme_execute_passthru_rq() will also be useful for the nvmet passthru
code and is exported in the NVME_TARGET_PASSTHRU namespace.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Separate the code to obtain command effects from the code
to start a passthru request and move the nvme_passthru_start() and
nvme_passthru_end() functions up above nvme_submit_user_cmd() in order
that they may be used in a new helper a subsequent patch.

The new helper function will be necessary for nvmet passthru
code to determine if we need to change out of interrupt context
to handle the effects. It is exported in the NVME_TARGET_PASSTHRU
namespace.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The host driver should decide whether to use SGLs or PRPs and they
currently assume the flags are cleared after the call to
nvme_setup_cmd(). However, passed-through commands may erroneously
set these bits; so clear them for all cases.
Signed-off-by: NLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: NKeith Busch <kbusch@kernel.org>
Reviewed-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Currently the FC transport is set max_hw_sectors based on the lldds
max sgl segment count. However, the block queue max segments is
set based on the controller's max_segments count, which the transport
does not set.  As such, the lldd is receiving sgl lists that are
exceeding its max segment count.

Set the controller max segment count and derive max_hw_sectors from
the max segment count.
Signed-off-by: NJames Smart <jsmart2021@gmail.com>
Reviewed-by: NMax Gurtovoy <maxg@mellanox.com>
Reviewed-by: NHimanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: NEwan D. Milne <emilne@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Stay consistent with the rest of the driver
Signed-off-by: NSagi Grimberg <sagi@grimberg.me>
Signed-off-by: NChristoph Hellwig <hch@lst.de>