linux-stable/drivers/nvme/host/multipath.c

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// SPDX-License-Identifier: GPL-2.0
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
/*
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
* Copyright (c) 2017-2018 Christoph Hellwig.
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
*/
#include <linux/moduleparam.h>
#include <trace/events/block.h>
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
#include "nvme.h"
static bool multipath = true;
module_param(multipath, bool, 0444);
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
MODULE_PARM_DESC(multipath,
"turn on native support for multiple controllers per subsystem");
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
inline bool nvme_ctrl_use_ana(struct nvme_ctrl *ctrl)
{
return multipath && ctrl->subsys && (ctrl->subsys->cmic & (1 << 3));
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
}
/*
* If multipathing is enabled we need to always use the subsystem instance
* number for numbering our devices to avoid conflicts between subsystems that
* have multiple controllers and thus use the multipath-aware subsystem node
* and those that have a single controller and use the controller node
* directly.
*/
void nvme_set_disk_name(char *disk_name, struct nvme_ns *ns,
struct nvme_ctrl *ctrl, int *flags)
{
if (!multipath) {
sprintf(disk_name, "nvme%dn%d", ctrl->instance, ns->head->instance);
} else if (ns->head->disk) {
sprintf(disk_name, "nvme%dc%dn%d", ctrl->subsys->instance,
ctrl->cntlid, ns->head->instance);
*flags = GENHD_FL_HIDDEN;
} else {
sprintf(disk_name, "nvme%dn%d", ctrl->subsys->instance,
ns->head->instance);
}
}
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
void nvme_failover_req(struct request *req)
{
struct nvme_ns *ns = req->q->queuedata;
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
u16 status = nvme_req(req)->status;
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
unsigned long flags;
spin_lock_irqsave(&ns->head->requeue_lock, flags);
blk_steal_bios(&ns->head->requeue_list, req);
spin_unlock_irqrestore(&ns->head->requeue_lock, flags);
blk_mq_end_request(req, 0);
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
switch (status & 0x7ff) {
case NVME_SC_ANA_TRANSITION:
case NVME_SC_ANA_INACCESSIBLE:
case NVME_SC_ANA_PERSISTENT_LOSS:
/*
* If we got back an ANA error we know the controller is alive,
* but not ready to serve this namespaces. The spec suggests
* we should update our general state here, but due to the fact
* that the admin and I/O queues are not serialized that is
* fundamentally racy. So instead just clear the current path,
* mark the the path as pending and kick of a re-read of the ANA
* log page ASAP.
*/
nvme_mpath_clear_current_path(ns);
if (ns->ctrl->ana_log_buf) {
set_bit(NVME_NS_ANA_PENDING, &ns->flags);
queue_work(nvme_wq, &ns->ctrl->ana_work);
}
break;
nvme: call nvme_complete_rq when nvmf_check_ready fails for mpath I/O When an io is rejected by nvmf_check_ready() due to validation of the controller state, the nvmf_fail_nonready_command() will normally return BLK_STS_RESOURCE to requeue and retry. However, if the controller is dying or the I/O is marked for NVMe multipath, the I/O is failed so that the controller can terminate or so that the io can be issued on a different path. Unfortunately, as this reject point is before the transport has accepted the command, blk-mq ends up completing the I/O and never calls nvme_complete_rq(), which is where multipath may preserve or re-route the I/O. The end result is, the device user ends up seeing an EIO error. Example: single path connectivity, controller is under load, and a reset is induced. An I/O is received: a) while the reset state has been set but the queues have yet to be stopped; or b) after queues are started (at end of reset) but before the reconnect has completed. The I/O finishes with an EIO status. This patch makes the following changes: - Adds the HOST_PATH_ERROR pathing status from TP4028 - Modifies the reject point such that it appears to queue successfully, but actually completes the io with the new pathing status and calls nvme_complete_rq(). - nvme_complete_rq() recognizes the new status, avoids resetting the controller (likely was already done in order to get this new status), and calls the multipather to clear the current path that errored. This allows the next command (retry or new command) to select a new path if there is one. Signed-off-by: James Smart <jsmart2021@gmail.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Christoph Hellwig <hch@lst.de>
2018-09-27 23:58:54 +00:00
case NVME_SC_HOST_PATH_ERROR:
/*
* Temporary transport disruption in talking to the controller.
* Try to send on a new path.
*/
nvme_mpath_clear_current_path(ns);
break;
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
default:
/*
* Reset the controller for any non-ANA error as we don't know
* what caused the error.
*/
nvme_reset_ctrl(ns->ctrl);
break;
}
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
kblockd_schedule_work(&ns->head->requeue_work);
}
void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl)
{
struct nvme_ns *ns;
down_read(&ctrl->namespaces_rwsem);
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
list_for_each_entry(ns, &ctrl->namespaces, list) {
if (ns->head->disk)
kblockd_schedule_work(&ns->head->requeue_work);
}
up_read(&ctrl->namespaces_rwsem);
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
}
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
static const char *nvme_ana_state_names[] = {
[0] = "invalid state",
[NVME_ANA_OPTIMIZED] = "optimized",
[NVME_ANA_NONOPTIMIZED] = "non-optimized",
[NVME_ANA_INACCESSIBLE] = "inaccessible",
[NVME_ANA_PERSISTENT_LOSS] = "persistent-loss",
[NVME_ANA_CHANGE] = "change",
};
void nvme_mpath_clear_current_path(struct nvme_ns *ns)
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
{
struct nvme_ns_head *head = ns->head;
int node;
if (!head)
return;
for_each_node(node) {
if (ns == rcu_access_pointer(head->current_path[node]))
rcu_assign_pointer(head->current_path[node], NULL);
}
}
static struct nvme_ns *__nvme_find_path(struct nvme_ns_head *head, int node)
{
int found_distance = INT_MAX, fallback_distance = INT_MAX, distance;
struct nvme_ns *found = NULL, *fallback = NULL, *ns;
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
list_for_each_entry_rcu(ns, &head->list, siblings) {
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
if (ns->ctrl->state != NVME_CTRL_LIVE ||
test_bit(NVME_NS_ANA_PENDING, &ns->flags))
continue;
if (READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_NUMA)
distance = node_distance(node, ns->ctrl->numa_node);
else
distance = LOCAL_DISTANCE;
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
switch (ns->ana_state) {
case NVME_ANA_OPTIMIZED:
if (distance < found_distance) {
found_distance = distance;
found = ns;
}
break;
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
case NVME_ANA_NONOPTIMIZED:
if (distance < fallback_distance) {
fallback_distance = distance;
fallback = ns;
}
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
break;
default:
break;
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
}
}
if (!found)
found = fallback;
if (found)
rcu_assign_pointer(head->current_path[node], found);
return found;
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
}
static struct nvme_ns *nvme_next_ns(struct nvme_ns_head *head,
struct nvme_ns *ns)
{
ns = list_next_or_null_rcu(&head->list, &ns->siblings, struct nvme_ns,
siblings);
if (ns)
return ns;
return list_first_or_null_rcu(&head->list, struct nvme_ns, siblings);
}
static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head,
int node, struct nvme_ns *old)
{
struct nvme_ns *ns, *found, *fallback = NULL;
if (list_is_singular(&head->list))
return old;
for (ns = nvme_next_ns(head, old);
ns != old;
ns = nvme_next_ns(head, ns)) {
if (ns->ctrl->state != NVME_CTRL_LIVE ||
test_bit(NVME_NS_ANA_PENDING, &ns->flags))
continue;
if (ns->ana_state == NVME_ANA_OPTIMIZED) {
found = ns;
goto out;
}
if (ns->ana_state == NVME_ANA_NONOPTIMIZED)
fallback = ns;
}
if (!fallback)
return NULL;
found = fallback;
out:
rcu_assign_pointer(head->current_path[node], found);
return found;
}
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
static inline bool nvme_path_is_optimized(struct nvme_ns *ns)
{
return ns->ctrl->state == NVME_CTRL_LIVE &&
ns->ana_state == NVME_ANA_OPTIMIZED;
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
}
inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head)
{
int node = numa_node_id();
struct nvme_ns *ns;
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
ns = srcu_dereference(head->current_path[node], &head->srcu);
if (READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_RR && ns)
ns = nvme_round_robin_path(head, node, ns);
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
if (unlikely(!ns || !nvme_path_is_optimized(ns)))
ns = __nvme_find_path(head, node);
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
return ns;
}
static blk_qc_t nvme_ns_head_make_request(struct request_queue *q,
struct bio *bio)
{
struct nvme_ns_head *head = q->queuedata;
struct device *dev = disk_to_dev(head->disk);
struct nvme_ns *ns;
blk_qc_t ret = BLK_QC_T_NONE;
int srcu_idx;
srcu_idx = srcu_read_lock(&head->srcu);
ns = nvme_find_path(head);
if (likely(ns)) {
bio->bi_disk = ns->disk;
bio->bi_opf |= REQ_NVME_MPATH;
trace_block_bio_remap(bio->bi_disk->queue, bio,
disk_devt(ns->head->disk),
bio->bi_iter.bi_sector);
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
ret = direct_make_request(bio);
} else if (!list_empty_careful(&head->list)) {
dev_warn_ratelimited(dev, "no path available - requeuing I/O\n");
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
spin_lock_irq(&head->requeue_lock);
bio_list_add(&head->requeue_list, bio);
spin_unlock_irq(&head->requeue_lock);
} else {
dev_warn_ratelimited(dev, "no path - failing I/O\n");
bio->bi_status = BLK_STS_IOERR;
bio_endio(bio);
}
srcu_read_unlock(&head->srcu, srcu_idx);
return ret;
}
static void nvme_requeue_work(struct work_struct *work)
{
struct nvme_ns_head *head =
container_of(work, struct nvme_ns_head, requeue_work);
struct bio *bio, *next;
spin_lock_irq(&head->requeue_lock);
next = bio_list_get(&head->requeue_list);
spin_unlock_irq(&head->requeue_lock);
while ((bio = next) != NULL) {
next = bio->bi_next;
bio->bi_next = NULL;
/*
* Reset disk to the mpath node and resubmit to select a new
* path.
*/
bio->bi_disk = head->disk;
generic_make_request(bio);
}
}
int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head)
{
struct request_queue *q;
bool vwc = false;
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
mutex_init(&head->lock);
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
bio_list_init(&head->requeue_list);
spin_lock_init(&head->requeue_lock);
INIT_WORK(&head->requeue_work, nvme_requeue_work);
/*
* Add a multipath node if the subsystems supports multiple controllers.
* We also do this for private namespaces as the namespace sharing data could
* change after a rescan.
*/
if (!(ctrl->subsys->cmic & (1 << 1)) || !multipath)
return 0;
q = blk_alloc_queue_node(GFP_KERNEL, ctrl->numa_node);
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
if (!q)
goto out;
q->queuedata = head;
blk_queue_make_request(q, nvme_ns_head_make_request);
blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
/* set to a default value for 512 until disk is validated */
blk_queue_logical_block_size(q, 512);
blk_set_stacking_limits(&q->limits);
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
/* we need to propagate up the VMC settings */
if (ctrl->vwc & NVME_CTRL_VWC_PRESENT)
vwc = true;
blk_queue_write_cache(q, vwc, vwc);
head->disk = alloc_disk(0);
if (!head->disk)
goto out_cleanup_queue;
head->disk->fops = &nvme_ns_head_ops;
head->disk->private_data = head;
head->disk->queue = q;
head->disk->flags = GENHD_FL_EXT_DEVT;
sprintf(head->disk->disk_name, "nvme%dn%d",
ctrl->subsys->instance, head->instance);
return 0;
out_cleanup_queue:
blk_cleanup_queue(q);
out:
return -ENOMEM;
}
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
static void nvme_mpath_set_live(struct nvme_ns *ns)
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
{
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
struct nvme_ns_head *head = ns->head;
lockdep_assert_held(&ns->head->lock);
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
if (!head->disk)
return;
if (!(head->disk->flags & GENHD_FL_UP))
device_add_disk(&head->subsys->dev, head->disk,
nvme_ns_id_attr_groups);
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
if (nvme_path_is_optimized(ns)) {
int node, srcu_idx;
srcu_idx = srcu_read_lock(&head->srcu);
for_each_node(node)
__nvme_find_path(head, node);
srcu_read_unlock(&head->srcu, srcu_idx);
}
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
kblockd_schedule_work(&ns->head->requeue_work);
}
static int nvme_parse_ana_log(struct nvme_ctrl *ctrl, void *data,
int (*cb)(struct nvme_ctrl *ctrl, struct nvme_ana_group_desc *,
void *))
{
void *base = ctrl->ana_log_buf;
size_t offset = sizeof(struct nvme_ana_rsp_hdr);
int error, i;
lockdep_assert_held(&ctrl->ana_lock);
for (i = 0; i < le16_to_cpu(ctrl->ana_log_buf->ngrps); i++) {
struct nvme_ana_group_desc *desc = base + offset;
u32 nr_nsids = le32_to_cpu(desc->nnsids);
size_t nsid_buf_size = nr_nsids * sizeof(__le32);
if (WARN_ON_ONCE(desc->grpid == 0))
return -EINVAL;
if (WARN_ON_ONCE(le32_to_cpu(desc->grpid) > ctrl->anagrpmax))
return -EINVAL;
if (WARN_ON_ONCE(desc->state == 0))
return -EINVAL;
if (WARN_ON_ONCE(desc->state > NVME_ANA_CHANGE))
return -EINVAL;
offset += sizeof(*desc);
if (WARN_ON_ONCE(offset > ctrl->ana_log_size - nsid_buf_size))
return -EINVAL;
error = cb(ctrl, desc, data);
if (error)
return error;
offset += nsid_buf_size;
if (WARN_ON_ONCE(offset > ctrl->ana_log_size - sizeof(*desc)))
return -EINVAL;
}
return 0;
}
static inline bool nvme_state_is_live(enum nvme_ana_state state)
{
return state == NVME_ANA_OPTIMIZED || state == NVME_ANA_NONOPTIMIZED;
}
static void nvme_update_ns_ana_state(struct nvme_ana_group_desc *desc,
struct nvme_ns *ns)
{
mutex_lock(&ns->head->lock);
ns->ana_grpid = le32_to_cpu(desc->grpid);
ns->ana_state = desc->state;
clear_bit(NVME_NS_ANA_PENDING, &ns->flags);
if (nvme_state_is_live(ns->ana_state))
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
nvme_mpath_set_live(ns);
mutex_unlock(&ns->head->lock);
}
static int nvme_update_ana_state(struct nvme_ctrl *ctrl,
struct nvme_ana_group_desc *desc, void *data)
{
u32 nr_nsids = le32_to_cpu(desc->nnsids), n = 0;
unsigned *nr_change_groups = data;
struct nvme_ns *ns;
dev_info(ctrl->device, "ANA group %d: %s.\n",
le32_to_cpu(desc->grpid),
nvme_ana_state_names[desc->state]);
if (desc->state == NVME_ANA_CHANGE)
(*nr_change_groups)++;
if (!nr_nsids)
return 0;
down_write(&ctrl->namespaces_rwsem);
list_for_each_entry(ns, &ctrl->namespaces, list) {
if (ns->head->ns_id != le32_to_cpu(desc->nsids[n]))
continue;
nvme_update_ns_ana_state(desc, ns);
if (++n == nr_nsids)
break;
}
up_write(&ctrl->namespaces_rwsem);
WARN_ON_ONCE(n < nr_nsids);
return 0;
}
static int nvme_read_ana_log(struct nvme_ctrl *ctrl, bool groups_only)
{
u32 nr_change_groups = 0;
int error;
mutex_lock(&ctrl->ana_lock);
error = nvme_get_log(ctrl, NVME_NSID_ALL, NVME_LOG_ANA,
groups_only ? NVME_ANA_LOG_RGO : 0,
ctrl->ana_log_buf, ctrl->ana_log_size, 0);
if (error) {
dev_warn(ctrl->device, "Failed to get ANA log: %d\n", error);
goto out_unlock;
}
error = nvme_parse_ana_log(ctrl, &nr_change_groups,
nvme_update_ana_state);
if (error)
goto out_unlock;
/*
* In theory we should have an ANATT timer per group as they might enter
* the change state at different times. But that is a lot of overhead
* just to protect against a target that keeps entering new changes
* states while never finishing previous ones. But we'll still
* eventually time out once all groups are in change state, so this
* isn't a big deal.
*
* We also double the ANATT value to provide some slack for transports
* or AEN processing overhead.
*/
if (nr_change_groups)
mod_timer(&ctrl->anatt_timer, ctrl->anatt * HZ * 2 + jiffies);
else
del_timer_sync(&ctrl->anatt_timer);
out_unlock:
mutex_unlock(&ctrl->ana_lock);
return error;
}
static void nvme_ana_work(struct work_struct *work)
{
struct nvme_ctrl *ctrl = container_of(work, struct nvme_ctrl, ana_work);
nvme_read_ana_log(ctrl, false);
}
static void nvme_anatt_timeout(struct timer_list *t)
{
struct nvme_ctrl *ctrl = from_timer(ctrl, t, anatt_timer);
dev_info(ctrl->device, "ANATT timeout, resetting controller.\n");
nvme_reset_ctrl(ctrl);
}
void nvme_mpath_stop(struct nvme_ctrl *ctrl)
{
if (!nvme_ctrl_use_ana(ctrl))
return;
del_timer_sync(&ctrl->anatt_timer);
cancel_work_sync(&ctrl->ana_work);
}
#define SUBSYS_ATTR_RW(_name, _mode, _show, _store) \
struct device_attribute subsys_attr_##_name = \
__ATTR(_name, _mode, _show, _store)
static const char *nvme_iopolicy_names[] = {
[NVME_IOPOLICY_NUMA] = "numa",
[NVME_IOPOLICY_RR] = "round-robin",
};
static ssize_t nvme_subsys_iopolicy_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct nvme_subsystem *subsys =
container_of(dev, struct nvme_subsystem, dev);
return sprintf(buf, "%s\n",
nvme_iopolicy_names[READ_ONCE(subsys->iopolicy)]);
}
static ssize_t nvme_subsys_iopolicy_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct nvme_subsystem *subsys =
container_of(dev, struct nvme_subsystem, dev);
int i;
for (i = 0; i < ARRAY_SIZE(nvme_iopolicy_names); i++) {
if (sysfs_streq(buf, nvme_iopolicy_names[i])) {
WRITE_ONCE(subsys->iopolicy, i);
return count;
}
}
return -EINVAL;
}
SUBSYS_ATTR_RW(iopolicy, S_IRUGO | S_IWUSR,
nvme_subsys_iopolicy_show, nvme_subsys_iopolicy_store);
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
static ssize_t ana_grpid_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return sprintf(buf, "%d\n", nvme_get_ns_from_dev(dev)->ana_grpid);
}
DEVICE_ATTR_RO(ana_grpid);
static ssize_t ana_state_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct nvme_ns *ns = nvme_get_ns_from_dev(dev);
return sprintf(buf, "%s\n", nvme_ana_state_names[ns->ana_state]);
}
DEVICE_ATTR_RO(ana_state);
static int nvme_set_ns_ana_state(struct nvme_ctrl *ctrl,
struct nvme_ana_group_desc *desc, void *data)
{
struct nvme_ns *ns = data;
if (ns->ana_grpid == le32_to_cpu(desc->grpid)) {
nvme_update_ns_ana_state(desc, ns);
return -ENXIO; /* just break out of the loop */
}
return 0;
}
void nvme_mpath_add_disk(struct nvme_ns *ns, struct nvme_id_ns *id)
{
if (nvme_ctrl_use_ana(ns->ctrl)) {
mutex_lock(&ns->ctrl->ana_lock);
ns->ana_grpid = le32_to_cpu(id->anagrpid);
nvme_parse_ana_log(ns->ctrl, ns, nvme_set_ns_ana_state);
mutex_unlock(&ns->ctrl->ana_lock);
} else {
mutex_lock(&ns->head->lock);
ns->ana_state = NVME_ANA_OPTIMIZED;
nvme_mpath_set_live(ns);
mutex_unlock(&ns->head->lock);
}
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
}
void nvme_mpath_remove_disk(struct nvme_ns_head *head)
{
if (!head->disk)
return;
if (head->disk->flags & GENHD_FL_UP)
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
del_gendisk(head->disk);
nvme: implement multipath access to nvme subsystems This patch adds native multipath support to the nvme driver. For each namespace we create only single block device node, which can be used to access that namespace through any of the controllers that refer to it. The gendisk for each controllers path to the name space still exists inside the kernel, but is hidden from userspace. The character device nodes are still available on a per-controller basis. A new link from the sysfs directory for the subsystem allows to find all controllers for a given subsystem. Currently we will always send I/O to the first available path, this will be changed once the NVMe Asynchronous Namespace Access (ANA) TP is ratified and implemented, at which point we will look at the ANA state for each namespace. Another possibility that was prototyped is to use the path that is closes to the submitting NUMA code, which will be mostly interesting for PCI, but might also be useful for RDMA or FC transports in the future. There is not plan to implement round robin or I/O service time path selectors, as those are not scalable with the performance rates provided by NVMe. The multipath device will go away once all paths to it disappear, any delay to keep it alive needs to be implemented at the controller level. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-11-02 11:59:30 +00:00
blk_set_queue_dying(head->disk->queue);
/* make sure all pending bios are cleaned up */
kblockd_schedule_work(&head->requeue_work);
flush_work(&head->requeue_work);
blk_cleanup_queue(head->disk->queue);
put_disk(head->disk);
}
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
int nvme_mpath_init(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
{
int error;
if (!nvme_ctrl_use_ana(ctrl))
return 0;
ctrl->anacap = id->anacap;
ctrl->anatt = id->anatt;
ctrl->nanagrpid = le32_to_cpu(id->nanagrpid);
ctrl->anagrpmax = le32_to_cpu(id->anagrpmax);
mutex_init(&ctrl->ana_lock);
timer_setup(&ctrl->anatt_timer, nvme_anatt_timeout, 0);
ctrl->ana_log_size = sizeof(struct nvme_ana_rsp_hdr) +
ctrl->nanagrpid * sizeof(struct nvme_ana_group_desc);
ctrl->ana_log_size += ctrl->max_namespaces * sizeof(__le32);
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
if (ctrl->ana_log_size > ctrl->max_hw_sectors << SECTOR_SHIFT) {
dev_err(ctrl->device,
"ANA log page size (%zd) larger than MDTS (%d).\n",
ctrl->ana_log_size,
ctrl->max_hw_sectors << SECTOR_SHIFT);
dev_err(ctrl->device, "disabling ANA support.\n");
return 0;
}
INIT_WORK(&ctrl->ana_work, nvme_ana_work);
ctrl->ana_log_buf = kmalloc(ctrl->ana_log_size, GFP_KERNEL);
if (!ctrl->ana_log_buf) {
error = -ENOMEM;
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
goto out;
}
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
error = nvme_read_ana_log(ctrl, true);
if (error)
goto out_free_ana_log_buf;
return 0;
out_free_ana_log_buf:
kfree(ctrl->ana_log_buf);
ctrl->ana_log_buf = NULL;
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
out:
return error;
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
}
void nvme_mpath_uninit(struct nvme_ctrl *ctrl)
{
kfree(ctrl->ana_log_buf);
ctrl->ana_log_buf = NULL;
nvme: add ANA support Add support for Asynchronous Namespace Access as specified in NVMe 1.3 TP 4004. With ANA each namespace attached to a controller belongs to an ANA group that describes the characteristics of accessing the namespaces through this controller. In the optimized and non-optimized states namespaces can be accessed regularly, although in a multi-pathing environment we should always prefer to access a namespace through a controller where an optimized relationship exists. Namespaces in Inaccessible, Permanent-Loss or Change state for a given controller should not be accessed. The states are updated through reading the ANA log page, which is read once during controller initialization, whenever the ANA change notice AEN is received, or when one of the ANA specific status codes that signal a state change is received on a command. The ANA state is kept in the nvme_ns structure, which makes the checks in the fast path very simple. Updating the ANA state when reading the log page is also very simple, the only downside is that finding the initial ANA state when scanning for namespaces is a bit cumbersome. The gendisk for a ns_head is only registered once a live path for it exists. Without that the kernel would hang during partition scanning. Includes fixes and improvements from Hannes Reinecke. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
2018-05-14 06:48:54 +00:00
}