Remove the superfluous variable "bdev" that is only used once in the
nvmet_bdev_alloc_bip() and use req->ns->bdev that is used everywhere in
the code to access the nvmet request's bdev.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Initialize keep-alive work only once, as part of alloc_ctrl
and not each time that nvmet_start_keep_alive_timer is being called
Signed-off-by: Amit Engel <amit.engel@dell.com>
Reviewed-by: Hou Pu <houpu.main@gmail.com>
Now that only one caller is left remove the helpers by restructuring
nvme_pr_command so that it has two helpers for sending a command of to a
given nsid using either the ns_head for multipath, or the namespace
stored in the gendisk.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Split multipath support out of nvme_report_zones into a separate helper
and simplify the non-multipath version as a result.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Move the CSI check into nvme_ns_report_zones to clean up the code
a little bit and prepare for further refactoring.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Add the __releases annotation to tell sparse that nvme_ns_head_ctrl_ioctl
is expected to unlock head->srcu.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
nvme_ns_head_ctrl_ioctl is always used on multipath nodes, so just call
srcu_read_unlock directly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
nvme_ns_head_ioctl is always used on multipath nodes, no need to
deal with the de-multiplexers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
nvme_ns_head_chr_ioctl is always used on multipath nodes, so just call
srcu_read_unlock and consolidate the two unlock paths.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
No need to use the braces around ~ operator.
No functionality change in this patch.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Remove the comment at the end of the switch that is not needed as
function is small enough.
No functionality change in this patch.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Remove the extra lines in the switch block that is not common practice
in the kernel code.
No functionality change in this patch.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Fix the comment style that matches existing code.
No functionality change in this patch.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
In our application, we need a way to force TCP connections to go out a
specific IP interface instead of letting Linux select the interface
based on the routing tables.
Add the 'host-iface' option to allow specifying the interface to use.
When the option host-iface is specified, the driver uses the specified
interface to set the option SO_BINDTODEVICE on the TCP socket before
connecting.
This new option is needed in addtion to the existing host-traddr for
the following reasons:
Specifying an IP interface by its associated IP address is less
intuitive than specifying the actual interface name and, in some cases,
simply doesn't work. That's because the association between interfaces
and IP addresses is not predictable. IP addresses can be changed or can
change by themselves over time (e.g. DHCP). Interface names are
predictable [1] and will persist over time. Consider the following
configuration.
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state ...
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 100.0.0.100/24 scope global lo
valid_lft forever preferred_lft forever
2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc ...
link/ether 08:00:27:21:65:ec brd ff:ff:ff:ff:ff:ff
inet 100.0.0.100/24 scope global enp0s3
valid_lft forever preferred_lft forever
3: enp0s8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc ...
link/ether 08:00:27:4f:95:5c brd ff:ff:ff:ff:ff:ff
inet 100.0.0.100/24 scope global enp0s8
valid_lft forever preferred_lft forever
The above is a VM that I configured with the same IP address
(100.0.0.100) on all interfaces. Doing a reverse lookup to identify the
unique interface associated with 100.0.0.100 does not work here. And
this is why the option host_iface is required. I understand that the
above config does not represent a standard host system, but I'm using
this to prove a point: "We can never know how users will configure
their systems". By te way, The above configuration is perfectly fine
by Linux.
The current TCP implementation for host_traddr performs a
bind()-before-connect(). This is a common construct to set the source
IP address on a TCP socket before connecting. This has no effect on how
Linux selects the interface for the connection. That's because Linux
uses the Weak End System model as described in RFC1122 [2]. On the other
hand, setting the Source IP Address has benefits and should be supported
by linux-nvme. In fact, setting the Source IP Address is a mandatory
FedGov requirement (e.g. connection to a RADIUS/TACACS+ server).
Consider the following configuration.
$ ip addr list dev enp0s8
3: enp0s8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc ...
link/ether 08:00:27:4f:95:5c brd ff:ff:ff:ff:ff:ff
inet 192.168.56.101/24 brd 192.168.56.255 scope global enp0s8
valid_lft 426sec preferred_lft 426sec
inet 192.168.56.102/24 scope global secondary enp0s8
valid_lft forever preferred_lft forever
inet 192.168.56.103/24 scope global secondary enp0s8
valid_lft forever preferred_lft forever
inet 192.168.56.104/24 scope global secondary enp0s8
valid_lft forever preferred_lft forever
Here we can see that several addresses are associated with interface
enp0s8. By default, Linux always selects the default IP address,
192.168.56.101, as the source address when connecting over interface
enp0s8. Some users, however, want the ability to specify a different
source address (e.g., 192.168.56.102, 192.168.56.103, ...). The option
host_traddr can be used as-is to perform this function.
In conclusion, I believe that we need 2 options for TCP connections.
One that can be used to specify an interface (host-iface). And one that
can be used to set the source address (host-traddr). Users should be
allowed to use one or the other, or both, or none. Of course, the
documentation for host_traddr will need some clarification. It should
state that when used for TCP connection, this option only sets the
source address. And the documentation for host_iface should say that
this option is only available for TCP connections.
References:
[1] https://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/
[2] https://tools.ietf.org/html/rfc1122
Tested both IPv4 and IPv6 connections.
Signed-off-by: Martin Belanger <martin.belanger@dell.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The algorithm that was used until now for building the APST configuration
table has been found to produce entries with excessively long ITPT
(idle time prior to transition) for devices declaring relatively long
entry and exit latencies for non-operational power states. This leads
to unnecessary waste of power and, as a result, failure to pass
mandatory power consumption tests on Chromebook platforms.
The new algorithm is based on two predefined ITPT values and two
predefined latency tolerances. Based on these values, as well as on
exit and entry latencies reported by the device, the algorithm looks
for up to 2 suitable non-operational power states to use as primary
and secondary APST transition targets. The predefined values are
supplied to the nvme driver as module parameters:
- apst_primary_timeout_ms (default: 100)
- apst_secondary_timeout_ms (default: 2000)
- apst_primary_latency_tol_us (default: 15000)
- apst_secondary_latency_tol_us (default: 100000)
The algorithm echoes the approach used by Intel's and Microsoft's drivers
on Windows. The specific default parameter values are also based on those
drivers. Yet, this patch doesn't introduce the ability to dynamically
regenerate the APST table in the event of switching the power source from
AC to battery and back. Adding this functionality may be considered in the
future. In the meantime, the timeouts and tolerances reflect a compromise
between values used by Microsoft for AC and battery scenarios.
In most NVMe devices the new algorithm causes them to implement a more
aggressive power saving policy. While beneficial in most cases, this
sometimes comes at the price of a higher IO processing latency in certain
scenarios as well as at the price of a potential impact on the drive's
endurance (due to more frequent context saving when entering deep non-
operational states). So in order to provide a fallback for systems where
these regressions cannot be tolerated, the patch allows to revert to
the legacy behavior by setting either apst_primary_timeout_ms or
apst_primary_latency_tol_us parameter to 0. Eventually (and possibly after
fine tuning the default values of the module parameters) the legacy behavior
can be removed.
TESTING.
The new algorithm has been extensively tested. Initially, simulations were
used to compare APST tables generated by old and new algorithms for a wide
range of devices. After that, power consumption, performance and latencies
were measured under different workloads on devices from multiple vendors
(WD, Intel, Samsung, Hynix, Kioxia). Below is the description of the tests
and the findings.
General observations.
The effect the patch has on the APST table varies depending on the entry and
exit latencies advertised by the devices. For some devices, the effect is
negligible (e.g. Kioxia KBG40ZNS), for some significant, making the
transitions to PS3 and PS4 much quicker (e.g. WD SN530, Intel 760P), or making
the sleep deeper, PS4 rather than PS3 after a similar amount of time (e.g.
SK Hynix BC511). For some devices (e.g. Samsung PM991) the effect is mixed:
the initial transition happens after a longer idle time, but takes the device
to a lower power state.
Workflows.
In order to evaluate the patch's effect on the power consumption and latency,
7 workflows were used for each device. The workflows were designed to test
the scenarios where significant differences between the old and new behaviors
are most likely. Each workflow was tested twice: with the new and with the
old APST table generation implementation. Power consumption, performance and
latency were measured in the process. The following workflows were used:
1) Consecutive write at the maximum rate with IO depth of 2, with no pauses
2) Repeated pattern of 1000 consecutive writes of 4K packets followed by 50ms
idle time
3) Repeated pattern of 1000 consecutive writes of 4K packets followed by 150ms
idle time
4) Repeated pattern of 1000 consecutive writes of 4K packets followed by 500ms
idle time
5) Repeated pattern of 1000 consecutive writes of 4K packets followed by 1.5s
idle time
6) Repeated pattern of 1000 consecutive writes of 4K packets followed by 5s
idle time
7) Repeated pattern of a single random read of a 4K packet followed by 150ms
idle time
Power consumption
Actual power consumption measurements produced predictable results in
accordance with the APST mechanism's theory of operation.
Devices with long entry and exit latencies such as WD SN530 showed huge
improvement on scenarios 4,5 and 6 of up to 62%. Devices such as Kioxia
KBG40ZNS where the resulting APST table looks virtually identical with
both legacy and new algorithms, showed little or no change in the average power
consumption on all workflows. Devices with extra short latencies such as
Samsung PM991 showed moderate increase in power consumption of up to 18% in
worst case scenarios.
In addition, on Intel and Samsung devices a more complex impact was observed
on scenarios 3, 4 and 7. Our understanding is that due to longer stay in deep
non-operational states between the writes the devices start performing background
operations leading to an increase of power consumption. With the old APST tables
part of these operations are delayed until the scenario is over and a longer idle
period begins, but eventually this extra power is consumed anyway.
Performance.
In terms of performance measured on sustained write or read scenarios, the
effect of the patch is minimal as in this case the device doesn't enter low power
states.
Latency
As expected, in devices where the patch causes a more aggressive power saving
policy (e.g. WD SN530, Intel 760P), an increase in latency was observed in
certain scenarios. Workflow number 7, specifically designed to simulate the
worst case scenario as far as latency is concerned, indeed shows a sharp
increase in average latency (~2ms -> ~53ms on Intel 760P and 0.6 -> 10ms on
WD SN530). The latency increase on other workloads and other devices is much
milder or non-existent.
Signed-off-by: Alexey Bogoslavsky <alexey.bogoslavsky@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The variable ret is being initialized with a value that is never read,
it is being updated later on. The assignment is redundant and can be
removed.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
The __nvmf_check_ready() routine used to bounce all filesystem io if the
controller state isn't LIVE. However, a later patch changed the logic so
that it rejection ends up being based on the Q live check. The FC
transport has a slightly different sequence from rdma and tcp for
shutting down queues/marking them non-live. FC marks its queue non-live
after aborting all ios and waiting for their termination, leaving a
rather large window for filesystem io to continue to hit the transport.
Unfortunately this resulted in filesystem I/O or applications seeing I/O
errors.
Change the FC transport to mark the queues non-live at the first sign of
teardown for the association (when I/O is initially terminated).
Fixes: 73a5379937 ("nvme-fabrics: allow to queue requests for live queues")
Signed-off-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
A possible race condition exists where the request to send data is
enqueued from nvme_tcp_handle_r2t()'s will not be observed by
nvme_tcp_send_all() if it happens to be running. The driver relies on
io_work to send the enqueued request when it is runs again, but the
concurrently running nvme_tcp_send_all() may not have released the
send_mutex at that time. If no future commands are enqueued to re-kick
the io_work, the request will timeout in the SEND_H2C state, resulting
in a timeout error like:
nvme nvme0: queue 1: timeout request 0x3 type 6
Ensure the io_work continues to run as long as the req_list is not empty.
Fixes: db5ad6b7f8 ("nvme-tcp: try to send request in queue_rq context")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Commit db5ad6b7f8 ("nvme-tcp: try to send request in queue_rq
context") added a second context that may perform a network send.
This means that now RX and TX are not serialized in nvme_tcp_io_work
and can run concurrently.
While there is correct mutual exclusion in the TX path (where
the send_mutex protect the queue socket send activity) RX activity,
and more specifically request completion may run concurrently.
This means we must guarantee that any mutation of the request state
related to its lifetime, bytes sent must not be accessed when a completion
may have possibly arrived back (and processed).
The race may trigger when a request completion arrives, processed
_and_ reused as a fresh new request, exactly in the (relatively short)
window between the last data payload sent and before the request iov_iter
is advanced.
Consider the following race:
1. 16K write request is queued
2. The nvme command and the data is sent to the controller (in-capsule
or solicited by r2t)
3. After the last payload is sent but before the req.iter is advanced,
the controller sends back a completion.
4. The completion is processed, the request is completed, and reused
to transfer a new request (write or read)
5. The new request is queued, and the driver reset the request parameters
(nvme_tcp_setup_cmd_pdu).
6. Now context in (2) resumes execution and advances the req.iter
==> use-after-completion as this is already a new request.
Fix this by making sure the request is not advanced after the last
data payload send, knowing that a completion may have arrived already.
An alternative solution would have been to delay the request completion
or state change waiting for reference counting on the TX path, but besides
adding atomic operations to the hot-path, it may present challenges in
multi-stage R2T scenarios where a r2t handler needs to be deferred to
an async execution.
Reported-by: Narayan Ayalasomayajula <narayan.ayalasomayajula@wdc.com>
Tested-by: Anil Mishra <anil.mishra@wdc.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
When creating loop ctrl in nvme_loop_create_ctrl(), if nvme_init_ctrl()
fails, the loop ctrl should be freed before jumping to the "out" label.
Fixes: 3a85a5de29 ("nvme-loop: add a NVMe loopback host driver")
Signed-off-by: Wu Bo <wubo40@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
When creating ctrl in nvmet_alloc_ctrl(), if the cntlid_min is larger
than cntlid_max of the subsystem, and jumps to the
"out_free_changed_ns_list" label, but the ctrl->sqs lack of be freed.
Fix this by jumping to the "out_free_sqs" label.
Fixes: 94a39d61f8 ("nvmet: make ctrl-id configurable")
Signed-off-by: Wu Bo <wubo40@huawei.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reset the ns->file value to NULL also in the error case in
nvmet_file_ns_enable().
The ns->file variable points either to file object or contains the
error code after the filp_open() call. This can lead to following
problem:
When the user first setups an invalid file backend and tries to enable
the ns, it will fail. Then the user switches over to a bdev backend
and enables successfully the ns. The first received I/O will crash the
system because the IO backend is chosen based on the ns->file value:
static u16 nvmet_parse_io_cmd(struct nvmet_req *req)
{
[...]
if (req->ns->file)
return nvmet_file_parse_io_cmd(req);
return nvmet_bdev_parse_io_cmd(req);
}
Reported-by: Enzo Matsumiya <ematsumiya@suse.com>
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Host can send invalid commands and flood the target with error messages.
Demote the error message from pr_err() to pr_debug() in
nvmet_parse_fabrics_cmd() and nvmet_parse_connect_cmd().
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Use the helper nvmet_report_invalid_opcode() to report invalid opcode
so we can remove the duplicate code.
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Host can send invalid commands and flood the target with error messages
for the discovery controller. Demote the error message from pr_err() to
pr_debug( in nvmet_parse_discovery_cmd().
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
When handling passthru commands, for inline bio allocation we only
consider the transfer size. This works well when req->sg_cnt fits into
the req->inline_bvec, but it will result in the early return from
bio_add_hw_page() when req->sg_cnt > NVMET_MAX_INLINE_BVEC.
Consider an I/O of size 32768 and first buffer is not aligned to the
page boundary, then I/O is split in following manner :-
[ 2206.256140] nvmet: sg->length 3440 sg->offset 656
[ 2206.256144] nvmet: sg->length 4096 sg->offset 0
[ 2206.256148] nvmet: sg->length 4096 sg->offset 0
[ 2206.256152] nvmet: sg->length 4096 sg->offset 0
[ 2206.256155] nvmet: sg->length 4096 sg->offset 0
[ 2206.256159] nvmet: sg->length 4096 sg->offset 0
[ 2206.256163] nvmet: sg->length 4096 sg->offset 0
[ 2206.256166] nvmet: sg->length 4096 sg->offset 0
[ 2206.256170] nvmet: sg->length 656 sg->offset 0
Now the req->transfer_size == NVMET_MAX_INLINE_DATA_LEN i.e. 32768, but
the req->sg_cnt is (9) > NVMET_MAX_INLINE_BIOVEC which is (8).
This will result in early return in the following code path :-
nvmet_bdev_execute_rw()
bio_add_pc_page()
bio_add_hw_page()
if (bio_full(bio, len))
return 0;
Use previously introduced helper nvmet_use_inline_bvec() to consider
req->sg_cnt when using inline bio. This only affects nvme-loop
transport.
Fixes: dab3902b19 ("nvmet: use inline bio for passthru fast path")
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
When handling rw commands, for inline bio case we only consider
transfer size. This works well when req->sg_cnt fits into the
req->inline_bvec, but it will result in the warning in
__bio_add_page() when req->sg_cnt > NVMET_MAX_INLINE_BVEC.
Consider an I/O size 32768 and first page is not aligned to the page
boundary, then I/O is split in following manner :-
[ 2206.256140] nvmet: sg->length 3440 sg->offset 656
[ 2206.256144] nvmet: sg->length 4096 sg->offset 0
[ 2206.256148] nvmet: sg->length 4096 sg->offset 0
[ 2206.256152] nvmet: sg->length 4096 sg->offset 0
[ 2206.256155] nvmet: sg->length 4096 sg->offset 0
[ 2206.256159] nvmet: sg->length 4096 sg->offset 0
[ 2206.256163] nvmet: sg->length 4096 sg->offset 0
[ 2206.256166] nvmet: sg->length 4096 sg->offset 0
[ 2206.256170] nvmet: sg->length 656 sg->offset 0
Now the req->transfer_size == NVMET_MAX_INLINE_DATA_LEN i.e. 32768, but
the req->sg_cnt is (9) > NVMET_MAX_INLINE_BIOVEC which is (8).
This will result in the following warning message :-
nvmet_bdev_execute_rw()
bio_add_page()
__bio_add_page()
WARN_ON_ONCE(bio_full(bio, len));
This scenario is very hard to reproduce on the nvme-loop transport only
with rw commands issued with the passthru IOCTL interface from the host
application and the data buffer is allocated with the malloc() and not
the posix_memalign().
Fixes: 73383adfad ("nvmet: don't split large I/Os unconditionally")
Signed-off-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
nvme_init_identify and thus nvme_mpath_init can be called multiple
times and thus must not overwrite potentially initialized or in-use
fields. Split out a helper for the basic initialization when the
controller is initialized and make sure the init_identify path does
not blindly change in-use data structures.
Fixes: 0d0b660f21 ("nvme: add ANA support")
Reported-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Nothing can stop a host from submitting invalid commands. The target
just needs to respond with an appropriate status, but that's not a
target error. Demote invalid command messages to the debug level so
these events don't spam the kernel logs.
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
When a request finally completes in end_io() after it has failed over,
the bdev pointer can be stale and thus the system can crash. Set the
bdev back to ns head, so the request is map to an active path when
resubmitted.
Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
reset_work() in nvme-pci may hang forever in the following scenario:
1) A reset caused by a command timeout occurs due to a controller being
temporarily irresponsive.
2) nvme_reset_work() restarts admin queue at nvme_alloc_admin_tags(). At
the same time, a user-submitted admin command is queued and waiting
for completion. Then, reset_work() changes its state to CONNECTING,
and submits an identify command.
3) However, the controller does still not respond to any command,
causing a timeout being fired at the user-submitted command.
Unfortunately, nvme_timeout() does not see the completion on cq, and
any timeout that takes place under CONNECTING state causes a
controller shutdown.
4) Normally, the identify command in reset_work() would be canceled with
SC_HOST_ABORTED by nvme_dev_disable(), then reset_work can tear down
the controller accordingly. But the controller happens to return
online and respond the identify command before nvme_dev_disable()
should have been reaped it off.
5) reset_work() continues to setup_io_queues() as it observes no error
in init_identify(). However, the admin queue has already been
quiesced in dev_disable(). Thus, any following commands would be
blocked forever in blk_execute_rq().
This can be fixed by restricting usercmd commands when controller is not
in a LIVE state in nvme_queue_rq(), as what has been done previously in
fabrics.
```
nvme_reset_work(): |
nvme_alloc_admin_tags() |
| nvme_submit_user_cmd():
nvme_init_identify(): | ...
__nvme_submit_sync_cmd(): |
... | ...
---------------------------------------> nvme_timeout():
(Controller starts reponding commands) | nvme_dev_disable(, true):
nvme_setup_io_queues(): |
__nvme_submit_sync_cmd(): |
(hung in blk_execute_rq |
since run_hw_queue sees |
queue quiesced) |
```
Signed-off-by: Tao Chiu <taochiu@synology.com>
Signed-off-by: Cody Wong <codywong@synology.com>
Reviewed-by: Leon Chien <leonchien@synology.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
queue_rq() in pci only checks if the dispatched queue (nvmeq) is ready,
e.g. not being suspended. Since nvme_alloc_admin_tags() in reset flow
restarts the admin queue, users are able to submit admin commands to a
controller before reset_work() completes. Commands submitted under this
condition may interfere with commands that performs identify, IO queue
setup in reset_work(), and may result in a hang described in the
following patch.
As seen in the fabrics, user commands are prevented from being executed
under inproper controller states. We may reuse this logic to maintain a
clear admin queue during reset_work().
Signed-off-by: Tao Chiu <taochiu@synology.com>
Signed-off-by: Cody Wong <codywong@synology.com>
Reviewed-by: Leon Chien <leonchien@synology.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
nvme_clear_nvme_request() clears the nvme_command, which is unncessary
for passthrough requests as nvme_command is overwritten immediately.
Move clearing part from this helper to the caller, so that double memset
for passthrough requests is avoided.
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
In multipath case, we should consider namespace attachment with
controllers in a subsystem when we find out the live controller for the
namespace. This patch manually reverted the commit 3557a44097
("nvme: don't bother to look up a namespace for controller ioctls") with
few more updates to nvme_ns_head_chr_ioctl which has been newly updated.
Fixes: 3557a44097 ("nvme: don't bother to look up a namespace for
controller ioctls")
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Userspace has not been allowed to I/O to device that's failed to
be initialized. This patch introduces generic per-namespace character
device to allow userspace to I/O regardless the block device is there or
not.
The chardev naming convention will similar to the existing blkdev naming,
using a ng prefix instead of nvme, i.e.
- /dev/ngXnY
It also supports multipath which means it will not expose chardev for the
hidden namespace blkdevs (e.g., nvmeXcYnZ). If /dev/ngXnY is created for
a ns_head, then I/O request will be routed to a specific controller
selected by the iopolicy of the subsystem.
Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Javier González <javier.gonz@samsung.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Tested-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Remove a level of indentation from the main code implementating the table
search by using a goto for the APST not supported case. Also move the
main comment above the function.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Do not call nvme_configure_apst when the controller is not live, given
that nvme_configure_apst will fail due the lack of an admin queue when
the controller is being torn down and nvme_set_latency_tolerance is
called from dev_pm_qos_hide_latency_tolerance.
Fixes: 510a405d945b("nvme: fix memory leak for power latency tolerance")
Reported-by: Peng Liu <liupeng17@lenovo.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Add a 'kato' controller sysfs attribute to display the current
keep-alive timeout value (if any). This allows userspace to identify
persistent discovery controllers, as these will have a non-zero
KATO value.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
According to the NVMe base spec the KATO commands should be sent
at half of the KATO interval, to properly account for round-trip
times.
As we now will only ever send one KATO command per connection we
can easily use the recommended values.
This also fixes a potential issue where the request timeout for
the KATO command does not match the value in the connect command,
which might be causing spurious connection drops from the target.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Issue following command:
nvme set-feature -f 0xf -v 0 /dev/nvme1n1 # disable keep-alive timer
nvme admin-passthru -o 0x18 /dev/nvme1n1 # send keep-alive command
will make keep-alive timer fired and thus delete the controller like
below:
[247459.907635] nvmet: ctrl 1 keep-alive timer (0 seconds) expired!
[247459.930294] nvmet: ctrl 1 fatal error occurred!
Avoid this by not queuing delayed keep-alive if it is disabled when
keep-alive command is received from the admin queue.
Signed-off-by: Hou Pu <houpu.main@gmail.com>
Tested-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Adding entry for dev_attr_fast_io_fail_tmo to avoid the kernel crash
while reading and writing the fast_io_fail_tmo.
Fixes: 09fbed6363 (nvme: export fast_io_fail_tmo to sysfs)
Signed-off-by: Gopal Tiwari <gtiwari@redhat.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Instead of failing to scan the namespace entirely when unsupported
features are detected, just mark the gendisk hidden but allow other
access like the upcoming per-namespace character device.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Javier González <javier.gonz@samsung.com>
These will be reused for the per-namespace character devices.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Javier González <javier.gonz@samsung.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Move the multipath block_device_operations to multipath.c, where they
belong.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Javier González <javier.gonz@samsung.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
