mirror of
https://github.com/torvalds/linux.git
synced 2024-12-05 10:32:35 +00:00
caf292ae5b
Pull block driver core update from Jens Axboe: "This is the pull request for the core block IO changes for 3.19. Not a huge round this time, mostly lots of little good fixes: - Fix a bug in sysfs blktrace interface causing a NULL pointer dereference, when enabled/disabled through that API. From Arianna Avanzini. - Various updates/fixes/improvements for blk-mq: - A set of updates from Bart, mostly fixing buts in the tag handling. - Cleanup/code consolidation from Christoph. - Extend queue_rq API to be able to handle batching issues of IO requests. NVMe will utilize this shortly. From me. - A few tag and request handling updates from me. - Cleanup of the preempt handling for running queues from Paolo. - Prevent running of unmapped hardware queues from Ming Lei. - Move the kdump memory limiting check to be in the correct location, from Shaohua. - Initialize all software queues at init time from Takashi. This prevents a kobject warning when CPUs are brought online that weren't online when a queue was registered. - Single writeback fix for I_DIRTY clearing from Tejun. Queued with the core IO changes, since it's just a single fix. - Version X of the __bio_add_page() segment addition retry from Maurizio. Hope the Xth time is the charm. - Documentation fixup for IO scheduler merging from Jan. - Introduce (and use) generic IO stat accounting helpers for non-rq drivers, from Gu Zheng. - Kill off artificial limiting of max sectors in a request from Christoph" * 'for-3.19/core' of git://git.kernel.dk/linux-block: (26 commits) bio: modify __bio_add_page() to accept pages that don't start a new segment blk-mq: Fix uninitialized kobject at CPU hotplugging blktrace: don't let the sysfs interface remove trace from running list blk-mq: Use all available hardware queues blk-mq: Micro-optimize bt_get() blk-mq: Fix a race between bt_clear_tag() and bt_get() blk-mq: Avoid that __bt_get_word() wraps multiple times blk-mq: Fix a use-after-free blk-mq: prevent unmapped hw queue from being scheduled blk-mq: re-check for available tags after running the hardware queue blk-mq: fix hang in bt_get() blk-mq: move the kdump check to blk_mq_alloc_tag_set blk-mq: cleanup tag free handling blk-mq: use 'nr_cpu_ids' as highest CPU ID count for hwq <-> cpu map blk: introduce generic io stat accounting help function blk-mq: handle the single queue case in blk_mq_hctx_next_cpu genhd: check for int overflow in disk_expand_part_tbl() blk-mq: add blk_mq_free_hctx_request() blk-mq: export blk_mq_free_request() blk-mq: use get_cpu/put_cpu instead of preempt_disable/preempt_enable ...
675 lines
14 KiB
C
675 lines
14 KiB
C
#include <linux/module.h>
|
|
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/blk-mq.h>
|
|
#include <linux/hrtimer.h>
|
|
|
|
struct nullb_cmd {
|
|
struct list_head list;
|
|
struct llist_node ll_list;
|
|
struct call_single_data csd;
|
|
struct request *rq;
|
|
struct bio *bio;
|
|
unsigned int tag;
|
|
struct nullb_queue *nq;
|
|
};
|
|
|
|
struct nullb_queue {
|
|
unsigned long *tag_map;
|
|
wait_queue_head_t wait;
|
|
unsigned int queue_depth;
|
|
|
|
struct nullb_cmd *cmds;
|
|
};
|
|
|
|
struct nullb {
|
|
struct list_head list;
|
|
unsigned int index;
|
|
struct request_queue *q;
|
|
struct gendisk *disk;
|
|
struct blk_mq_tag_set tag_set;
|
|
struct hrtimer timer;
|
|
unsigned int queue_depth;
|
|
spinlock_t lock;
|
|
|
|
struct nullb_queue *queues;
|
|
unsigned int nr_queues;
|
|
};
|
|
|
|
static LIST_HEAD(nullb_list);
|
|
static struct mutex lock;
|
|
static int null_major;
|
|
static int nullb_indexes;
|
|
|
|
struct completion_queue {
|
|
struct llist_head list;
|
|
struct hrtimer timer;
|
|
};
|
|
|
|
/*
|
|
* These are per-cpu for now, they will need to be configured by the
|
|
* complete_queues parameter and appropriately mapped.
|
|
*/
|
|
static DEFINE_PER_CPU(struct completion_queue, completion_queues);
|
|
|
|
enum {
|
|
NULL_IRQ_NONE = 0,
|
|
NULL_IRQ_SOFTIRQ = 1,
|
|
NULL_IRQ_TIMER = 2,
|
|
};
|
|
|
|
enum {
|
|
NULL_Q_BIO = 0,
|
|
NULL_Q_RQ = 1,
|
|
NULL_Q_MQ = 2,
|
|
};
|
|
|
|
static int submit_queues;
|
|
module_param(submit_queues, int, S_IRUGO);
|
|
MODULE_PARM_DESC(submit_queues, "Number of submission queues");
|
|
|
|
static int home_node = NUMA_NO_NODE;
|
|
module_param(home_node, int, S_IRUGO);
|
|
MODULE_PARM_DESC(home_node, "Home node for the device");
|
|
|
|
static int queue_mode = NULL_Q_MQ;
|
|
|
|
static int null_param_store_val(const char *str, int *val, int min, int max)
|
|
{
|
|
int ret, new_val;
|
|
|
|
ret = kstrtoint(str, 10, &new_val);
|
|
if (ret)
|
|
return -EINVAL;
|
|
|
|
if (new_val < min || new_val > max)
|
|
return -EINVAL;
|
|
|
|
*val = new_val;
|
|
return 0;
|
|
}
|
|
|
|
static int null_set_queue_mode(const char *str, const struct kernel_param *kp)
|
|
{
|
|
return null_param_store_val(str, &queue_mode, NULL_Q_BIO, NULL_Q_MQ);
|
|
}
|
|
|
|
static struct kernel_param_ops null_queue_mode_param_ops = {
|
|
.set = null_set_queue_mode,
|
|
.get = param_get_int,
|
|
};
|
|
|
|
device_param_cb(queue_mode, &null_queue_mode_param_ops, &queue_mode, S_IRUGO);
|
|
MODULE_PARM_DESC(queue_mode, "Block interface to use (0=bio,1=rq,2=multiqueue)");
|
|
|
|
static int gb = 250;
|
|
module_param(gb, int, S_IRUGO);
|
|
MODULE_PARM_DESC(gb, "Size in GB");
|
|
|
|
static int bs = 512;
|
|
module_param(bs, int, S_IRUGO);
|
|
MODULE_PARM_DESC(bs, "Block size (in bytes)");
|
|
|
|
static int nr_devices = 2;
|
|
module_param(nr_devices, int, S_IRUGO);
|
|
MODULE_PARM_DESC(nr_devices, "Number of devices to register");
|
|
|
|
static int irqmode = NULL_IRQ_SOFTIRQ;
|
|
|
|
static int null_set_irqmode(const char *str, const struct kernel_param *kp)
|
|
{
|
|
return null_param_store_val(str, &irqmode, NULL_IRQ_NONE,
|
|
NULL_IRQ_TIMER);
|
|
}
|
|
|
|
static struct kernel_param_ops null_irqmode_param_ops = {
|
|
.set = null_set_irqmode,
|
|
.get = param_get_int,
|
|
};
|
|
|
|
device_param_cb(irqmode, &null_irqmode_param_ops, &irqmode, S_IRUGO);
|
|
MODULE_PARM_DESC(irqmode, "IRQ completion handler. 0-none, 1-softirq, 2-timer");
|
|
|
|
static int completion_nsec = 10000;
|
|
module_param(completion_nsec, int, S_IRUGO);
|
|
MODULE_PARM_DESC(completion_nsec, "Time in ns to complete a request in hardware. Default: 10,000ns");
|
|
|
|
static int hw_queue_depth = 64;
|
|
module_param(hw_queue_depth, int, S_IRUGO);
|
|
MODULE_PARM_DESC(hw_queue_depth, "Queue depth for each hardware queue. Default: 64");
|
|
|
|
static bool use_per_node_hctx = false;
|
|
module_param(use_per_node_hctx, bool, S_IRUGO);
|
|
MODULE_PARM_DESC(use_per_node_hctx, "Use per-node allocation for hardware context queues. Default: false");
|
|
|
|
static void put_tag(struct nullb_queue *nq, unsigned int tag)
|
|
{
|
|
clear_bit_unlock(tag, nq->tag_map);
|
|
|
|
if (waitqueue_active(&nq->wait))
|
|
wake_up(&nq->wait);
|
|
}
|
|
|
|
static unsigned int get_tag(struct nullb_queue *nq)
|
|
{
|
|
unsigned int tag;
|
|
|
|
do {
|
|
tag = find_first_zero_bit(nq->tag_map, nq->queue_depth);
|
|
if (tag >= nq->queue_depth)
|
|
return -1U;
|
|
} while (test_and_set_bit_lock(tag, nq->tag_map));
|
|
|
|
return tag;
|
|
}
|
|
|
|
static void free_cmd(struct nullb_cmd *cmd)
|
|
{
|
|
put_tag(cmd->nq, cmd->tag);
|
|
}
|
|
|
|
static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq)
|
|
{
|
|
struct nullb_cmd *cmd;
|
|
unsigned int tag;
|
|
|
|
tag = get_tag(nq);
|
|
if (tag != -1U) {
|
|
cmd = &nq->cmds[tag];
|
|
cmd->tag = tag;
|
|
cmd->nq = nq;
|
|
return cmd;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, int can_wait)
|
|
{
|
|
struct nullb_cmd *cmd;
|
|
DEFINE_WAIT(wait);
|
|
|
|
cmd = __alloc_cmd(nq);
|
|
if (cmd || !can_wait)
|
|
return cmd;
|
|
|
|
do {
|
|
prepare_to_wait(&nq->wait, &wait, TASK_UNINTERRUPTIBLE);
|
|
cmd = __alloc_cmd(nq);
|
|
if (cmd)
|
|
break;
|
|
|
|
io_schedule();
|
|
} while (1);
|
|
|
|
finish_wait(&nq->wait, &wait);
|
|
return cmd;
|
|
}
|
|
|
|
static void end_cmd(struct nullb_cmd *cmd)
|
|
{
|
|
switch (queue_mode) {
|
|
case NULL_Q_MQ:
|
|
blk_mq_end_request(cmd->rq, 0);
|
|
return;
|
|
case NULL_Q_RQ:
|
|
INIT_LIST_HEAD(&cmd->rq->queuelist);
|
|
blk_end_request_all(cmd->rq, 0);
|
|
break;
|
|
case NULL_Q_BIO:
|
|
bio_endio(cmd->bio, 0);
|
|
break;
|
|
}
|
|
|
|
free_cmd(cmd);
|
|
}
|
|
|
|
static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer)
|
|
{
|
|
struct completion_queue *cq;
|
|
struct llist_node *entry;
|
|
struct nullb_cmd *cmd;
|
|
|
|
cq = &per_cpu(completion_queues, smp_processor_id());
|
|
|
|
while ((entry = llist_del_all(&cq->list)) != NULL) {
|
|
entry = llist_reverse_order(entry);
|
|
do {
|
|
cmd = container_of(entry, struct nullb_cmd, ll_list);
|
|
entry = entry->next;
|
|
end_cmd(cmd);
|
|
} while (entry);
|
|
}
|
|
|
|
return HRTIMER_NORESTART;
|
|
}
|
|
|
|
static void null_cmd_end_timer(struct nullb_cmd *cmd)
|
|
{
|
|
struct completion_queue *cq = &per_cpu(completion_queues, get_cpu());
|
|
|
|
cmd->ll_list.next = NULL;
|
|
if (llist_add(&cmd->ll_list, &cq->list)) {
|
|
ktime_t kt = ktime_set(0, completion_nsec);
|
|
|
|
hrtimer_start(&cq->timer, kt, HRTIMER_MODE_REL);
|
|
}
|
|
|
|
put_cpu();
|
|
}
|
|
|
|
static void null_softirq_done_fn(struct request *rq)
|
|
{
|
|
if (queue_mode == NULL_Q_MQ)
|
|
end_cmd(blk_mq_rq_to_pdu(rq));
|
|
else
|
|
end_cmd(rq->special);
|
|
}
|
|
|
|
static inline void null_handle_cmd(struct nullb_cmd *cmd)
|
|
{
|
|
/* Complete IO by inline, softirq or timer */
|
|
switch (irqmode) {
|
|
case NULL_IRQ_SOFTIRQ:
|
|
switch (queue_mode) {
|
|
case NULL_Q_MQ:
|
|
blk_mq_complete_request(cmd->rq);
|
|
break;
|
|
case NULL_Q_RQ:
|
|
blk_complete_request(cmd->rq);
|
|
break;
|
|
case NULL_Q_BIO:
|
|
/*
|
|
* XXX: no proper submitting cpu information available.
|
|
*/
|
|
end_cmd(cmd);
|
|
break;
|
|
}
|
|
break;
|
|
case NULL_IRQ_NONE:
|
|
end_cmd(cmd);
|
|
break;
|
|
case NULL_IRQ_TIMER:
|
|
null_cmd_end_timer(cmd);
|
|
break;
|
|
}
|
|
}
|
|
|
|
static struct nullb_queue *nullb_to_queue(struct nullb *nullb)
|
|
{
|
|
int index = 0;
|
|
|
|
if (nullb->nr_queues != 1)
|
|
index = raw_smp_processor_id() / ((nr_cpu_ids + nullb->nr_queues - 1) / nullb->nr_queues);
|
|
|
|
return &nullb->queues[index];
|
|
}
|
|
|
|
static void null_queue_bio(struct request_queue *q, struct bio *bio)
|
|
{
|
|
struct nullb *nullb = q->queuedata;
|
|
struct nullb_queue *nq = nullb_to_queue(nullb);
|
|
struct nullb_cmd *cmd;
|
|
|
|
cmd = alloc_cmd(nq, 1);
|
|
cmd->bio = bio;
|
|
|
|
null_handle_cmd(cmd);
|
|
}
|
|
|
|
static int null_rq_prep_fn(struct request_queue *q, struct request *req)
|
|
{
|
|
struct nullb *nullb = q->queuedata;
|
|
struct nullb_queue *nq = nullb_to_queue(nullb);
|
|
struct nullb_cmd *cmd;
|
|
|
|
cmd = alloc_cmd(nq, 0);
|
|
if (cmd) {
|
|
cmd->rq = req;
|
|
req->special = cmd;
|
|
return BLKPREP_OK;
|
|
}
|
|
|
|
return BLKPREP_DEFER;
|
|
}
|
|
|
|
static void null_request_fn(struct request_queue *q)
|
|
{
|
|
struct request *rq;
|
|
|
|
while ((rq = blk_fetch_request(q)) != NULL) {
|
|
struct nullb_cmd *cmd = rq->special;
|
|
|
|
spin_unlock_irq(q->queue_lock);
|
|
null_handle_cmd(cmd);
|
|
spin_lock_irq(q->queue_lock);
|
|
}
|
|
}
|
|
|
|
static int null_queue_rq(struct blk_mq_hw_ctx *hctx,
|
|
const struct blk_mq_queue_data *bd)
|
|
{
|
|
struct nullb_cmd *cmd = blk_mq_rq_to_pdu(bd->rq);
|
|
|
|
cmd->rq = bd->rq;
|
|
cmd->nq = hctx->driver_data;
|
|
|
|
blk_mq_start_request(bd->rq);
|
|
|
|
null_handle_cmd(cmd);
|
|
return BLK_MQ_RQ_QUEUE_OK;
|
|
}
|
|
|
|
static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq)
|
|
{
|
|
BUG_ON(!nullb);
|
|
BUG_ON(!nq);
|
|
|
|
init_waitqueue_head(&nq->wait);
|
|
nq->queue_depth = nullb->queue_depth;
|
|
}
|
|
|
|
static int null_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
|
|
unsigned int index)
|
|
{
|
|
struct nullb *nullb = data;
|
|
struct nullb_queue *nq = &nullb->queues[index];
|
|
|
|
hctx->driver_data = nq;
|
|
null_init_queue(nullb, nq);
|
|
nullb->nr_queues++;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct blk_mq_ops null_mq_ops = {
|
|
.queue_rq = null_queue_rq,
|
|
.map_queue = blk_mq_map_queue,
|
|
.init_hctx = null_init_hctx,
|
|
.complete = null_softirq_done_fn,
|
|
};
|
|
|
|
static void null_del_dev(struct nullb *nullb)
|
|
{
|
|
list_del_init(&nullb->list);
|
|
|
|
del_gendisk(nullb->disk);
|
|
blk_cleanup_queue(nullb->q);
|
|
if (queue_mode == NULL_Q_MQ)
|
|
blk_mq_free_tag_set(&nullb->tag_set);
|
|
put_disk(nullb->disk);
|
|
kfree(nullb);
|
|
}
|
|
|
|
static int null_open(struct block_device *bdev, fmode_t mode)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static void null_release(struct gendisk *disk, fmode_t mode)
|
|
{
|
|
}
|
|
|
|
static const struct block_device_operations null_fops = {
|
|
.owner = THIS_MODULE,
|
|
.open = null_open,
|
|
.release = null_release,
|
|
};
|
|
|
|
static int setup_commands(struct nullb_queue *nq)
|
|
{
|
|
struct nullb_cmd *cmd;
|
|
int i, tag_size;
|
|
|
|
nq->cmds = kzalloc(nq->queue_depth * sizeof(*cmd), GFP_KERNEL);
|
|
if (!nq->cmds)
|
|
return -ENOMEM;
|
|
|
|
tag_size = ALIGN(nq->queue_depth, BITS_PER_LONG) / BITS_PER_LONG;
|
|
nq->tag_map = kzalloc(tag_size * sizeof(unsigned long), GFP_KERNEL);
|
|
if (!nq->tag_map) {
|
|
kfree(nq->cmds);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
for (i = 0; i < nq->queue_depth; i++) {
|
|
cmd = &nq->cmds[i];
|
|
INIT_LIST_HEAD(&cmd->list);
|
|
cmd->ll_list.next = NULL;
|
|
cmd->tag = -1U;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void cleanup_queue(struct nullb_queue *nq)
|
|
{
|
|
kfree(nq->tag_map);
|
|
kfree(nq->cmds);
|
|
}
|
|
|
|
static void cleanup_queues(struct nullb *nullb)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < nullb->nr_queues; i++)
|
|
cleanup_queue(&nullb->queues[i]);
|
|
|
|
kfree(nullb->queues);
|
|
}
|
|
|
|
static int setup_queues(struct nullb *nullb)
|
|
{
|
|
nullb->queues = kzalloc(submit_queues * sizeof(struct nullb_queue),
|
|
GFP_KERNEL);
|
|
if (!nullb->queues)
|
|
return -ENOMEM;
|
|
|
|
nullb->nr_queues = 0;
|
|
nullb->queue_depth = hw_queue_depth;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int init_driver_queues(struct nullb *nullb)
|
|
{
|
|
struct nullb_queue *nq;
|
|
int i, ret = 0;
|
|
|
|
for (i = 0; i < submit_queues; i++) {
|
|
nq = &nullb->queues[i];
|
|
|
|
null_init_queue(nullb, nq);
|
|
|
|
ret = setup_commands(nq);
|
|
if (ret)
|
|
return ret;
|
|
nullb->nr_queues++;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int null_add_dev(void)
|
|
{
|
|
struct gendisk *disk;
|
|
struct nullb *nullb;
|
|
sector_t size;
|
|
int rv;
|
|
|
|
nullb = kzalloc_node(sizeof(*nullb), GFP_KERNEL, home_node);
|
|
if (!nullb) {
|
|
rv = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
spin_lock_init(&nullb->lock);
|
|
|
|
if (queue_mode == NULL_Q_MQ && use_per_node_hctx)
|
|
submit_queues = nr_online_nodes;
|
|
|
|
rv = setup_queues(nullb);
|
|
if (rv)
|
|
goto out_free_nullb;
|
|
|
|
if (queue_mode == NULL_Q_MQ) {
|
|
nullb->tag_set.ops = &null_mq_ops;
|
|
nullb->tag_set.nr_hw_queues = submit_queues;
|
|
nullb->tag_set.queue_depth = hw_queue_depth;
|
|
nullb->tag_set.numa_node = home_node;
|
|
nullb->tag_set.cmd_size = sizeof(struct nullb_cmd);
|
|
nullb->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
|
|
nullb->tag_set.driver_data = nullb;
|
|
|
|
rv = blk_mq_alloc_tag_set(&nullb->tag_set);
|
|
if (rv)
|
|
goto out_cleanup_queues;
|
|
|
|
nullb->q = blk_mq_init_queue(&nullb->tag_set);
|
|
if (!nullb->q) {
|
|
rv = -ENOMEM;
|
|
goto out_cleanup_tags;
|
|
}
|
|
} else if (queue_mode == NULL_Q_BIO) {
|
|
nullb->q = blk_alloc_queue_node(GFP_KERNEL, home_node);
|
|
if (!nullb->q) {
|
|
rv = -ENOMEM;
|
|
goto out_cleanup_queues;
|
|
}
|
|
blk_queue_make_request(nullb->q, null_queue_bio);
|
|
rv = init_driver_queues(nullb);
|
|
if (rv)
|
|
goto out_cleanup_blk_queue;
|
|
} else {
|
|
nullb->q = blk_init_queue_node(null_request_fn, &nullb->lock, home_node);
|
|
if (!nullb->q) {
|
|
rv = -ENOMEM;
|
|
goto out_cleanup_queues;
|
|
}
|
|
blk_queue_prep_rq(nullb->q, null_rq_prep_fn);
|
|
blk_queue_softirq_done(nullb->q, null_softirq_done_fn);
|
|
rv = init_driver_queues(nullb);
|
|
if (rv)
|
|
goto out_cleanup_blk_queue;
|
|
}
|
|
|
|
nullb->q->queuedata = nullb;
|
|
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, nullb->q);
|
|
queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, nullb->q);
|
|
|
|
disk = nullb->disk = alloc_disk_node(1, home_node);
|
|
if (!disk) {
|
|
rv = -ENOMEM;
|
|
goto out_cleanup_blk_queue;
|
|
}
|
|
|
|
mutex_lock(&lock);
|
|
list_add_tail(&nullb->list, &nullb_list);
|
|
nullb->index = nullb_indexes++;
|
|
mutex_unlock(&lock);
|
|
|
|
blk_queue_logical_block_size(nullb->q, bs);
|
|
blk_queue_physical_block_size(nullb->q, bs);
|
|
|
|
size = gb * 1024 * 1024 * 1024ULL;
|
|
sector_div(size, bs);
|
|
set_capacity(disk, size);
|
|
|
|
disk->flags |= GENHD_FL_EXT_DEVT;
|
|
disk->major = null_major;
|
|
disk->first_minor = nullb->index;
|
|
disk->fops = &null_fops;
|
|
disk->private_data = nullb;
|
|
disk->queue = nullb->q;
|
|
sprintf(disk->disk_name, "nullb%d", nullb->index);
|
|
add_disk(disk);
|
|
return 0;
|
|
|
|
out_cleanup_blk_queue:
|
|
blk_cleanup_queue(nullb->q);
|
|
out_cleanup_tags:
|
|
if (queue_mode == NULL_Q_MQ)
|
|
blk_mq_free_tag_set(&nullb->tag_set);
|
|
out_cleanup_queues:
|
|
cleanup_queues(nullb);
|
|
out_free_nullb:
|
|
kfree(nullb);
|
|
out:
|
|
return rv;
|
|
}
|
|
|
|
static int __init null_init(void)
|
|
{
|
|
unsigned int i;
|
|
|
|
if (bs > PAGE_SIZE) {
|
|
pr_warn("null_blk: invalid block size\n");
|
|
pr_warn("null_blk: defaults block size to %lu\n", PAGE_SIZE);
|
|
bs = PAGE_SIZE;
|
|
}
|
|
|
|
if (queue_mode == NULL_Q_MQ && use_per_node_hctx) {
|
|
if (submit_queues < nr_online_nodes) {
|
|
pr_warn("null_blk: submit_queues param is set to %u.",
|
|
nr_online_nodes);
|
|
submit_queues = nr_online_nodes;
|
|
}
|
|
} else if (submit_queues > nr_cpu_ids)
|
|
submit_queues = nr_cpu_ids;
|
|
else if (!submit_queues)
|
|
submit_queues = 1;
|
|
|
|
mutex_init(&lock);
|
|
|
|
/* Initialize a separate list for each CPU for issuing softirqs */
|
|
for_each_possible_cpu(i) {
|
|
struct completion_queue *cq = &per_cpu(completion_queues, i);
|
|
|
|
init_llist_head(&cq->list);
|
|
|
|
if (irqmode != NULL_IRQ_TIMER)
|
|
continue;
|
|
|
|
hrtimer_init(&cq->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
|
|
cq->timer.function = null_cmd_timer_expired;
|
|
}
|
|
|
|
null_major = register_blkdev(0, "nullb");
|
|
if (null_major < 0)
|
|
return null_major;
|
|
|
|
for (i = 0; i < nr_devices; i++) {
|
|
if (null_add_dev()) {
|
|
unregister_blkdev(null_major, "nullb");
|
|
return -EINVAL;
|
|
}
|
|
}
|
|
|
|
pr_info("null: module loaded\n");
|
|
return 0;
|
|
}
|
|
|
|
static void __exit null_exit(void)
|
|
{
|
|
struct nullb *nullb;
|
|
|
|
unregister_blkdev(null_major, "nullb");
|
|
|
|
mutex_lock(&lock);
|
|
while (!list_empty(&nullb_list)) {
|
|
nullb = list_entry(nullb_list.next, struct nullb, list);
|
|
null_del_dev(nullb);
|
|
}
|
|
mutex_unlock(&lock);
|
|
}
|
|
|
|
module_init(null_init);
|
|
module_exit(null_exit);
|
|
|
|
MODULE_AUTHOR("Jens Axboe <jaxboe@fusionio.com>");
|
|
MODULE_LICENSE("GPL");
|