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|
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2017-2018 Christoph Hellwig.
*/
#include <linux/backing-dev.h>
#include <linux/moduleparam.h>
#include <linux/vmalloc.h>
#include <trace/events/block.h>
#include "nvme.h"
bool multipath = true;
module_param(multipath, bool, 0444);
MODULE_PARM_DESC(multipath,
"turn on native support for multiple controllers per subsystem");
static const char *nvme_iopolicy_names[] = {
[NVME_IOPOLICY_NUMA] = "numa",
[NVME_IOPOLICY_RR] = "round-robin",
[NVME_IOPOLICY_QD] = "queue-depth",
};
static int iopolicy = NVME_IOPOLICY_NUMA;
static int nvme_set_iopolicy(const char *val, const struct kernel_param *kp)
{
if (!val)
return -EINVAL;
if (!strncmp(val, "numa", 4))
iopolicy = NVME_IOPOLICY_NUMA;
else if (!strncmp(val, "round-robin", 11))
iopolicy = NVME_IOPOLICY_RR;
else if (!strncmp(val, "queue-depth", 11))
iopolicy = NVME_IOPOLICY_QD;
else
return -EINVAL;
return 0;
}
static int nvme_get_iopolicy(char *buf, const struct kernel_param *kp)
{
return sprintf(buf, "%s\n", nvme_iopolicy_names[iopolicy]);
}
module_param_call(iopolicy, nvme_set_iopolicy, nvme_get_iopolicy,
&iopolicy, 0644);
MODULE_PARM_DESC(iopolicy,
"Default multipath I/O policy; 'numa' (default), 'round-robin' or 'queue-depth'");
void nvme_mpath_default_iopolicy(struct nvme_subsystem *subsys)
{
subsys->iopolicy = iopolicy;
}
void nvme_mpath_unfreeze(struct nvme_subsystem *subsys)
{
struct nvme_ns_head *h;
lockdep_assert_held(&subsys->lock);
list_for_each_entry(h, &subsys->nsheads, entry)
if (h->disk)
blk_mq_unfreeze_queue(h->disk->queue);
}
void nvme_mpath_wait_freeze(struct nvme_subsystem *subsys)
{
struct nvme_ns_head *h;
lockdep_assert_held(&subsys->lock);
list_for_each_entry(h, &subsys->nsheads, entry)
if (h->disk)
blk_mq_freeze_queue_wait(h->disk->queue);
}
void nvme_mpath_start_freeze(struct nvme_subsystem *subsys)
{
struct nvme_ns_head *h;
lockdep_assert_held(&subsys->lock);
list_for_each_entry(h, &subsys->nsheads, entry)
if (h->disk)
blk_freeze_queue_start(h->disk->queue);
}
void nvme_failover_req(struct request *req)
{
struct nvme_ns *ns = req->q->queuedata;
u16 status = nvme_req(req)->status & NVME_SCT_SC_MASK;
unsigned long flags;
struct bio *bio;
nvme_mpath_clear_current_path(ns);
/*
* If we got back an ANA error, we know the controller is alive but not
* ready to serve this namespace. Kick of a re-read of the ANA
* information page, and just try any other available path for now.
*/
if (nvme_is_ana_error(status) && ns->ctrl->ana_log_buf) {
set_bit(NVME_NS_ANA_PENDING, &ns->flags);
queue_work(nvme_wq, &ns->ctrl->ana_work);
}
spin_lock_irqsave(&ns->head->requeue_lock, flags);
for (bio = req->bio; bio; bio = bio->bi_next) {
bio_set_dev(bio, ns->head->disk->part0);
if (bio->bi_opf & REQ_POLLED) {
bio->bi_opf &= ~REQ_POLLED;
bio->bi_cookie = BLK_QC_T_NONE;
}
/*
* The alternate request queue that we may end up submitting
* the bio to may be frozen temporarily, in this case REQ_NOWAIT
* will fail the I/O immediately with EAGAIN to the issuer.
* We are not in the issuer context which cannot block. Clear
* the flag to avoid spurious EAGAIN I/O failures.
*/
bio->bi_opf &= ~REQ_NOWAIT;
}
blk_steal_bios(&ns->head->requeue_list, req);
spin_unlock_irqrestore(&ns->head->requeue_lock, flags);
nvme_req(req)->status = 0;
nvme_end_req(req);
kblockd_schedule_work(&ns->head->requeue_work);
}
void nvme_mpath_start_request(struct request *rq)
{
struct nvme_ns *ns = rq->q->queuedata;
struct gendisk *disk = ns->head->disk;
if (READ_ONCE(ns->head->subsys->iopolicy) == NVME_IOPOLICY_QD) {
atomic_inc(&ns->ctrl->nr_active);
nvme_req(rq)->flags |= NVME_MPATH_CNT_ACTIVE;
}
if (!blk_queue_io_stat(disk->queue) || blk_rq_is_passthrough(rq))
return;
nvme_req(rq)->flags |= NVME_MPATH_IO_STATS;
nvme_req(rq)->start_time = bdev_start_io_acct(disk->part0, req_op(rq),
jiffies);
}
EXPORT_SYMBOL_GPL(nvme_mpath_start_request);
void nvme_mpath_end_request(struct request *rq)
{
struct nvme_ns *ns = rq->q->queuedata;
if (nvme_req(rq)->flags & NVME_MPATH_CNT_ACTIVE)
atomic_dec_if_positive(&ns->ctrl->nr_active);
if (!(nvme_req(rq)->flags & NVME_MPATH_IO_STATS))
return;
bdev_end_io_acct(ns->head->disk->part0, req_op(rq),
blk_rq_bytes(rq) >> SECTOR_SHIFT,
nvme_req(rq)->start_time);
}
void nvme_kick_requeue_lists(struct nvme_ctrl *ctrl)
{
struct nvme_ns *ns;
int srcu_idx;
srcu_idx = srcu_read_lock(&ctrl->srcu);
list_for_each_entry_rcu(ns, &ctrl->namespaces, list) {
if (!ns->head->disk)
continue;
kblockd_schedule_work(&ns->head->requeue_work);
if (nvme_ctrl_state(ns->ctrl) == NVME_CTRL_LIVE)
disk_uevent(ns->head->disk, KOBJ_CHANGE);
}
srcu_read_unlock(&ctrl->srcu, srcu_idx);
}
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",
};
bool nvme_mpath_clear_current_path(struct nvme_ns *ns)
{
struct nvme_ns_head *head = ns->head;
bool changed = false;
int node;
if (!head)
goto out;
for_each_node(node) {
if (ns == rcu_access_pointer(head->current_path[node])) {
rcu_assign_pointer(head->current_path[node], NULL);
changed = true;
}
}
out:
return changed;
}
void nvme_mpath_clear_ctrl_paths(struct nvme_ctrl *ctrl)
{
struct nvme_ns *ns;
int srcu_idx;
srcu_idx = srcu_read_lock(&ctrl->srcu);
list_for_each_entry_rcu(ns, &ctrl->namespaces, list) {
nvme_mpath_clear_current_path(ns);
kblockd_schedule_work(&ns->head->requeue_work);
}
srcu_read_unlock(&ctrl->srcu, srcu_idx);
}
void nvme_mpath_revalidate_paths(struct nvme_ns *ns)
{
struct nvme_ns_head *head = ns->head;
sector_t capacity = get_capacity(head->disk);
int node;
int srcu_idx;
srcu_idx = srcu_read_lock(&head->srcu);
list_for_each_entry_rcu(ns, &head->list, siblings) {
if (capacity != get_capacity(ns->disk))
clear_bit(NVME_NS_READY, &ns->flags);
}
srcu_read_unlock(&head->srcu, srcu_idx);
for_each_node(node)
rcu_assign_pointer(head->current_path[node], NULL);
kblockd_schedule_work(&head->requeue_work);
}
static bool nvme_path_is_disabled(struct nvme_ns *ns)
{
enum nvme_ctrl_state state = nvme_ctrl_state(ns->ctrl);
/*
* We don't treat NVME_CTRL_DELETING as a disabled path as I/O should
* still be able to complete assuming that the controller is connected.
* Otherwise it will fail immediately and return to the requeue list.
*/
if (state != NVME_CTRL_LIVE && state != NVME_CTRL_DELETING)
return true;
if (test_bit(NVME_NS_ANA_PENDING, &ns->flags) ||
!test_bit(NVME_NS_READY, &ns->flags))
return true;
return false;
}
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;
list_for_each_entry_rcu(ns, &head->list, siblings) {
if (nvme_path_is_disabled(ns))
continue;
if (ns->ctrl->numa_node != NUMA_NO_NODE &&
READ_ONCE(head->subsys->iopolicy) == NVME_IOPOLICY_NUMA)
distance = node_distance(node, ns->ctrl->numa_node);
else
distance = LOCAL_DISTANCE;
switch (ns->ana_state) {
case NVME_ANA_OPTIMIZED:
if (distance < found_distance) {
found_distance = distance;
found = ns;
}
break;
case NVME_ANA_NONOPTIMIZED:
if (distance < fallback_distance) {
fallback_distance = distance;
fallback = ns;
}
break;
default:
break;
}
}
if (!found)
found = fallback;
if (found)
rcu_assign_pointer(head->current_path[node], found);
return found;
}
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)
{
struct nvme_ns *ns, *found = NULL;
int node = numa_node_id();
struct nvme_ns *old = srcu_dereference(head->current_path[node],
&head->srcu);
if (unlikely(!old))
return __nvme_find_path(head, node);
if (list_is_singular(&head->list)) {
if (nvme_path_is_disabled(old))
return NULL;
return old;
}
for (ns = nvme_next_ns(head, old);
ns && ns != old;
ns = nvme_next_ns(head, ns)) {
if (nvme_path_is_disabled(ns))
continue;
if (ns->ana_state == NVME_ANA_OPTIMIZED) {
found = ns;
goto out;
}
if (ns->ana_state == NVME_ANA_NONOPTIMIZED)
found = ns;
}
/*
* The loop above skips the current path for round-robin semantics.
* Fall back to the current path if either:
* - no other optimized path found and current is optimized,
* - no other usable path found and current is usable.
*/
if (!nvme_path_is_disabled(old) &&
(old->ana_state == NVME_ANA_OPTIMIZED ||
(!found && old->ana_state == NVME_ANA_NONOPTIMIZED)))
return old;
if (!found)
return NULL;
out:
rcu_assign_pointer(head->current_path[node], found);
return found;
}
static struct nvme_ns *nvme_queue_depth_path(struct nvme_ns_head *head)
{
struct nvme_ns *best_opt = NULL, *best_nonopt = NULL, *ns;
unsigned int min_depth_opt = UINT_MAX, min_depth_nonopt = UINT_MAX;
unsigned int depth;
list_for_each_entry_rcu(ns, &head->list, siblings) {
if (nvme_path_is_disabled(ns))
continue;
depth = atomic_read(&ns->ctrl->nr_active);
switch (ns->ana_state) {
case NVME_ANA_OPTIMIZED:
if (depth < min_depth_opt) {
min_depth_opt = depth;
best_opt = ns;
}
break;
case NVME_ANA_NONOPTIMIZED:
if (depth < min_depth_nonopt) {
min_depth_nonopt = depth;
best_nonopt = ns;
}
break;
default:
break;
}
if (min_depth_opt == 0)
return best_opt;
}
return best_opt ? best_opt : best_nonopt;
}
static inline bool nvme_path_is_optimized(struct nvme_ns *ns)
{
return nvme_ctrl_state(ns->ctrl) == NVME_CTRL_LIVE &&
ns->ana_state == NVME_ANA_OPTIMIZED;
}
static struct nvme_ns *nvme_numa_path(struct nvme_ns_head *head)
{
int node = numa_node_id();
struct nvme_ns *ns;
ns = srcu_dereference(head->current_path[node], &head->srcu);
if (unlikely(!ns))
return __nvme_find_path(head, node);
if (unlikely(!nvme_path_is_optimized(ns)))
return __nvme_find_path(head, node);
return ns;
}
inline struct nvme_ns *nvme_find_path(struct nvme_ns_head *head)
{
switch (READ_ONCE(head->subsys->iopolicy)) {
case NVME_IOPOLICY_QD:
return nvme_queue_depth_path(head);
case NVME_IOPOLICY_RR:
return nvme_round_robin_path(head);
default:
return nvme_numa_path(head);
}
}
static bool nvme_available_path(struct nvme_ns_head *head)
{
struct nvme_ns *ns;
if (!test_bit(NVME_NSHEAD_DISK_LIVE, &head->flags))
return NULL;
list_for_each_entry_rcu(ns, &head->list, siblings) {
if (test_bit(NVME_CTRL_FAILFAST_EXPIRED, &ns->ctrl->flags))
continue;
switch (nvme_ctrl_state(ns->ctrl)) {
case NVME_CTRL_LIVE:
case NVME_CTRL_RESETTING:
case NVME_CTRL_CONNECTING:
return true;
default:
break;
}
}
return false;
}
static void nvme_ns_head_submit_bio(struct bio *bio)
{
struct nvme_ns_head *head = bio->bi_bdev->bd_disk->private_data;
struct device *dev = disk_to_dev(head->disk);
struct nvme_ns *ns;
int srcu_idx;
/*
* The namespace might be going away and the bio might be moved to a
* different queue via blk_steal_bios(), so we need to use the bio_split
* pool from the original queue to allocate the bvecs from.
*/
bio = bio_split_to_limits(bio);
if (!bio)
return;
srcu_idx = srcu_read_lock(&head->srcu);
ns = nvme_find_path(head);
if (likely(ns)) {
bio_set_dev(bio, ns->disk->part0);
bio->bi_opf |= REQ_NVME_MPATH;
trace_block_bio_remap(bio, disk_devt(ns->head->disk),
bio->bi_iter.bi_sector);
submit_bio_noacct(bio);
} else if (nvme_available_path(head)) {
dev_warn_ratelimited(dev, "no usable path - requeuing I/O\n");
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 available path - failing I/O\n");
bio_io_error(bio);
}
srcu_read_unlock(&head->srcu, srcu_idx);
}
static int nvme_ns_head_open(struct gendisk *disk, blk_mode_t mode)
{
if (!nvme_tryget_ns_head(disk->private_data))
return -ENXIO;
return 0;
}
static void nvme_ns_head_release(struct gendisk *disk)
{
nvme_put_ns_head(disk->private_data);
}
static int nvme_ns_head_get_unique_id(struct gendisk *disk, u8 id[16],
enum blk_unique_id type)
{
struct nvme_ns_head *head = disk->private_data;
struct nvme_ns *ns;
int srcu_idx, ret = -EWOULDBLOCK;
srcu_idx = srcu_read_lock(&head->srcu);
ns = nvme_find_path(head);
if (ns)
ret = nvme_ns_get_unique_id(ns, id, type);
srcu_read_unlock(&head->srcu, srcu_idx);
return ret;
}
#ifdef CONFIG_BLK_DEV_ZONED
static int nvme_ns_head_report_zones(struct gendisk *disk, sector_t sector,
unsigned int nr_zones, report_zones_cb cb, void *data)
{
struct nvme_ns_head *head = disk->private_data;
struct nvme_ns *ns;
int srcu_idx, ret = -EWOULDBLOCK;
srcu_idx = srcu_read_lock(&head->srcu);
ns = nvme_find_path(head);
if (ns)
ret = nvme_ns_report_zones(ns, sector, nr_zones, cb, data);
srcu_read_unlock(&head->srcu, srcu_idx);
return ret;
}
#else
#define nvme_ns_head_report_zones NULL
#endif /* CONFIG_BLK_DEV_ZONED */
const struct block_device_operations nvme_ns_head_ops = {
.owner = THIS_MODULE,
.submit_bio = nvme_ns_head_submit_bio,
.open = nvme_ns_head_open,
.release = nvme_ns_head_release,
.ioctl = nvme_ns_head_ioctl,
.compat_ioctl = blkdev_compat_ptr_ioctl,
.getgeo = nvme_getgeo,
.get_unique_id = nvme_ns_head_get_unique_id,
.report_zones = nvme_ns_head_report_zones,
.pr_ops = &nvme_pr_ops,
};
static inline struct nvme_ns_head *cdev_to_ns_head(struct cdev *cdev)
{
return container_of(cdev, struct nvme_ns_head, cdev);
}
static int nvme_ns_head_chr_open(struct inode *inode, struct file *file)
{
if (!nvme_tryget_ns_head(cdev_to_ns_head(inode->i_cdev)))
return -ENXIO;
return 0;
}
static int nvme_ns_head_chr_release(struct inode *inode, struct file *file)
{
nvme_put_ns_head(cdev_to_ns_head(inode->i_cdev));
return 0;
}
static const struct file_operations nvme_ns_head_chr_fops = {
.owner = THIS_MODULE,
.open = nvme_ns_head_chr_open,
.release = nvme_ns_head_chr_release,
.unlocked_ioctl = nvme_ns_head_chr_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.uring_cmd = nvme_ns_head_chr_uring_cmd,
.uring_cmd_iopoll = nvme_ns_chr_uring_cmd_iopoll,
};
static int nvme_add_ns_head_cdev(struct nvme_ns_head *head)
{
int ret;
head->cdev_device.parent = &head->subsys->dev;
ret = dev_set_name(&head->cdev_device, "ng%dn%d",
head->subsys->instance, head->instance);
if (ret)
return ret;
ret = nvme_cdev_add(&head->cdev, &head->cdev_device,
&nvme_ns_head_chr_fops, THIS_MODULE);
return ret;
}
static void nvme_partition_scan_work(struct work_struct *work)
{
struct nvme_ns_head *head =
container_of(work, struct nvme_ns_head, partition_scan_work);
if (WARN_ON_ONCE(!test_and_clear_bit(GD_SUPPRESS_PART_SCAN,
&head->disk->state)))
return;
mutex_lock(&head->disk->open_mutex);
bdev_disk_changed(head->disk, false);
mutex_unlock(&head->disk->open_mutex);
}
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;
submit_bio_noacct(bio);
}
}
int nvme_mpath_alloc_disk(struct nvme_ctrl *ctrl, struct nvme_ns_head *head)
{
struct queue_limits lim;
mutex_init(&head->lock);
bio_list_init(&head->requeue_list);
spin_lock_init(&head->requeue_lock);
INIT_WORK(&head->requeue_work, nvme_requeue_work);
INIT_WORK(&head->partition_scan_work, nvme_partition_scan_work);
/*
* Add a multipath node if the subsystems supports multiple controllers.
* We also do this for private namespaces as the namespace sharing flag
* could change after a rescan.
*/
if (!(ctrl->subsys->cmic & NVME_CTRL_CMIC_MULTI_CTRL) ||
!nvme_is_unique_nsid(ctrl, head) || !multipath)
return 0;
blk_set_stacking_limits(&lim);
lim.dma_alignment = 3;
lim.features |= BLK_FEAT_IO_STAT | BLK_FEAT_NOWAIT | BLK_FEAT_POLL;
if (head->ids.csi == NVME_CSI_ZNS)
lim.features |= BLK_FEAT_ZONED;
else
lim.max_zone_append_sectors = 0;
head->disk = blk_alloc_disk(&lim, ctrl->numa_node);
if (IS_ERR(head->disk))
return PTR_ERR(head->disk);
head->disk->fops = &nvme_ns_head_ops;
head->disk->private_data = head;
/*
* We need to suppress the partition scan from occuring within the
* controller's scan_work context. If a path error occurs here, the IO
* will wait until a path becomes available or all paths are torn down,
* but that action also occurs within scan_work, so it would deadlock.
* Defer the partion scan to a different context that does not block
* scan_work.
*/
set_bit(GD_SUPPRESS_PART_SCAN, &head->disk->state);
sprintf(head->disk->disk_name, "nvme%dn%d",
ctrl->subsys->instance, head->instance);
return 0;
}
static void nvme_mpath_set_live(struct nvme_ns *ns)
{
struct nvme_ns_head *head = ns->head;
int rc;
if (!head->disk)
return;
/*
* test_and_set_bit() is used because it is protecting against two nvme
* paths simultaneously calling device_add_disk() on the same namespace
* head.
*/
if (!test_and_set_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) {
rc = device_add_disk(&head->subsys->dev, head->disk,
nvme_ns_attr_groups);
if (rc) {
clear_bit(NVME_NSHEAD_DISK_LIVE, &head->flags);
return;
}
nvme_add_ns_head_cdev(head);
kblockd_schedule_work(&head->partition_scan_work);
}
mutex_lock(&head->lock);
if (nvme_path_is_optimized(ns)) {
int node, srcu_idx;
srcu_idx = srcu_read_lock(&head->srcu);
for_each_online_node(node)
__nvme_find_path(head, node);
srcu_read_unlock(&head->srcu, srcu_idx);
}
mutex_unlock(&head->lock);
synchronize_srcu(&head->srcu);
kblockd_schedule_work(&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;
size_t nsid_buf_size;
if (WARN_ON_ONCE(offset > ctrl->ana_log_size - sizeof(*desc)))
return -EINVAL;
nr_nsids = le32_to_cpu(desc->nnsids);
nsid_buf_size = flex_array_size(desc, nsids, nr_nsids);
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;
}
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)
{
ns->ana_grpid = le32_to_cpu(desc->grpid);
ns->ana_state = desc->state;
clear_bit(NVME_NS_ANA_PENDING, &ns->flags);
/*
* nvme_mpath_set_live() will trigger I/O to the multipath path device
* and in turn to this path device. However we cannot accept this I/O
* if the controller is not live. This may deadlock if called from
* nvme_mpath_init_identify() and the ctrl will never complete
* initialization, preventing I/O from completing. For this case we
* will reprocess the ANA log page in nvme_mpath_update() once the
* controller is ready.
*/
if (nvme_state_is_live(ns->ana_state) &&
nvme_ctrl_state(ns->ctrl) == NVME_CTRL_LIVE)
nvme_mpath_set_live(ns);
}
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;
int srcu_idx;
dev_dbg(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;
srcu_idx = srcu_read_lock(&ctrl->srcu);
list_for_each_entry_rcu(ns, &ctrl->namespaces, list) {
unsigned nsid;
again:
nsid = le32_to_cpu(desc->nsids[n]);
if (ns->head->ns_id < nsid)
continue;
if (ns->head->ns_id == nsid)
nvme_update_ns_ana_state(desc, ns);
if (++n == nr_nsids)
break;
if (ns->head->ns_id > nsid)
goto again;
}
srcu_read_unlock(&ctrl->srcu, srcu_idx);
return 0;
}
static int nvme_read_ana_log(struct nvme_ctrl *ctrl)
{
u32 nr_change_groups = 0;
int error;
mutex_lock(&ctrl->ana_lock);
error = nvme_get_log(ctrl, NVME_NSID_ALL, NVME_LOG_ANA, 0, NVME_CSI_NVM,
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);
if (nvme_ctrl_state(ctrl) != NVME_CTRL_LIVE)
return;
nvme_read_ana_log(ctrl);
}
void nvme_mpath_update(struct nvme_ctrl *ctrl)
{
u32 nr_change_groups = 0;
if (!ctrl->ana_log_buf)
return;
mutex_lock(&ctrl->ana_lock);
nvme_parse_ana_log(ctrl, &nr_change_groups, nvme_update_ana_state);
mutex_unlock(&ctrl->ana_lock);
}
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 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 sysfs_emit(buf, "%s\n",
nvme_iopolicy_names[READ_ONCE(subsys->iopolicy)]);
}
static void nvme_subsys_iopolicy_update(struct nvme_subsystem *subsys,
int iopolicy)
{
struct nvme_ctrl *ctrl;
int old_iopolicy = READ_ONCE(subsys->iopolicy);
if (old_iopolicy == iopolicy)
return;
WRITE_ONCE(subsys->iopolicy, iopolicy);
/* iopolicy changes clear the mpath by design */
mutex_lock(&nvme_subsystems_lock);
list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry)
nvme_mpath_clear_ctrl_paths(ctrl);
mutex_unlock(&nvme_subsystems_lock);
pr_notice("subsysnqn %s iopolicy changed from %s to %s\n",
subsys->subnqn,
nvme_iopolicy_names[old_iopolicy],
nvme_iopolicy_names[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])) {
nvme_subsys_iopolicy_update(subsys, i);
return count;
}
}
return -EINVAL;
}
SUBSYS_ATTR_RW(iopolicy, S_IRUGO | S_IWUSR,
nvme_subsys_iopolicy_show, nvme_subsys_iopolicy_store);
static ssize_t ana_grpid_show(struct device *dev, struct device_attribute *attr,
char *buf)
{
return sysfs_emit(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 sysfs_emit(buf, "%s\n", nvme_ana_state_names[ns->ana_state]);
}
DEVICE_ATTR_RO(ana_state);
static int nvme_lookup_ana_group_desc(struct nvme_ctrl *ctrl,
struct nvme_ana_group_desc *desc, void *data)
{
struct nvme_ana_group_desc *dst = data;
if (desc->grpid != dst->grpid)
return 0;
*dst = *desc;
return -ENXIO; /* just break out of the loop */
}
void nvme_mpath_add_disk(struct nvme_ns *ns, __le32 anagrpid)
{
if (nvme_ctrl_use_ana(ns->ctrl)) {
struct nvme_ana_group_desc desc = {
.grpid = anagrpid,
.state = 0,
};
mutex_lock(&ns->ctrl->ana_lock);
ns->ana_grpid = le32_to_cpu(anagrpid);
nvme_parse_ana_log(ns->ctrl, &desc, nvme_lookup_ana_group_desc);
mutex_unlock(&ns->ctrl->ana_lock);
if (desc.state) {
/* found the group desc: update */
nvme_update_ns_ana_state(&desc, ns);
} else {
/* group desc not found: trigger a re-read */
set_bit(NVME_NS_ANA_PENDING, &ns->flags);
queue_work(nvme_wq, &ns->ctrl->ana_work);
}
} else {
ns->ana_state = NVME_ANA_OPTIMIZED;
nvme_mpath_set_live(ns);
}
#ifdef CONFIG_BLK_DEV_ZONED
if (blk_queue_is_zoned(ns->queue) && ns->head->disk)
ns->head->disk->nr_zones = ns->disk->nr_zones;
#endif
}
void nvme_mpath_shutdown_disk(struct nvme_ns_head *head)
{
if (!head->disk)
return;
if (test_and_clear_bit(NVME_NSHEAD_DISK_LIVE, &head->flags)) {
nvme_cdev_del(&head->cdev, &head->cdev_device);
/*
* requeue I/O after NVME_NSHEAD_DISK_LIVE has been cleared
* to allow multipath to fail all I/O.
*/
synchronize_srcu(&head->srcu);
kblockd_schedule_work(&head->requeue_work);
del_gendisk(head->disk);
}
}
void nvme_mpath_remove_disk(struct nvme_ns_head *head)
{
if (!head->disk)
return;
/* make sure all pending bios are cleaned up */
kblockd_schedule_work(&head->requeue_work);
flush_work(&head->requeue_work);
flush_work(&head->partition_scan_work);
put_disk(head->disk);
}
void nvme_mpath_init_ctrl(struct nvme_ctrl *ctrl)
{
mutex_init(&ctrl->ana_lock);
timer_setup(&ctrl->anatt_timer, nvme_anatt_timeout, 0);
INIT_WORK(&ctrl->ana_work, nvme_ana_work);
}
int nvme_mpath_init_identify(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
{
size_t max_transfer_size = ctrl->max_hw_sectors << SECTOR_SHIFT;
size_t ana_log_size;
int error = 0;
/* check if multipath is enabled and we have the capability */
if (!multipath || !ctrl->subsys ||
!(ctrl->subsys->cmic & NVME_CTRL_CMIC_ANA))
return 0;
/* initialize this in the identify path to cover controller resets */
atomic_set(&ctrl->nr_active, 0);
if (!ctrl->max_namespaces ||
ctrl->max_namespaces > le32_to_cpu(id->nn)) {
dev_err(ctrl->device,
"Invalid MNAN value %u\n", ctrl->max_namespaces);
return -EINVAL;
}
ctrl->anacap = id->anacap;
ctrl->anatt = id->anatt;
ctrl->nanagrpid = le32_to_cpu(id->nanagrpid);
ctrl->anagrpmax = le32_to_cpu(id->anagrpmax);
ana_log_size = sizeof(struct nvme_ana_rsp_hdr) +
ctrl->nanagrpid * sizeof(struct nvme_ana_group_desc) +
ctrl->max_namespaces * sizeof(__le32);
if (ana_log_size > max_transfer_size) {
dev_err(ctrl->device,
"ANA log page size (%zd) larger than MDTS (%zd).\n",
ana_log_size, max_transfer_size);
dev_err(ctrl->device, "disabling ANA support.\n");
goto out_uninit;
}
if (ana_log_size > ctrl->ana_log_size) {
nvme_mpath_stop(ctrl);
nvme_mpath_uninit(ctrl);
ctrl->ana_log_buf = kvmalloc(ana_log_size, GFP_KERNEL);
if (!ctrl->ana_log_buf)
return -ENOMEM;
}
ctrl->ana_log_size = ana_log_size;
error = nvme_read_ana_log(ctrl);
if (error)
goto out_uninit;
return 0;
out_uninit:
nvme_mpath_uninit(ctrl);
return error;
}
void nvme_mpath_uninit(struct nvme_ctrl *ctrl)
{
kvfree(ctrl->ana_log_buf);
ctrl->ana_log_buf = NULL;
ctrl->ana_log_size = 0;
}
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