2006-10-20 06:28:16 +00:00
|
|
|
|
|
|
|
#include <linux/wait.h>
|
|
|
|
#include <linux/backing-dev.h>
|
|
|
|
#include <linux/fs.h>
|
|
|
|
#include <linux/sched.h>
|
|
|
|
#include <linux/module.h>
|
2008-04-30 07:54:32 +00:00
|
|
|
#include <linux/writeback.h>
|
|
|
|
#include <linux/device.h>
|
|
|
|
|
|
|
|
|
|
|
|
static struct class *bdi_class;
|
|
|
|
|
|
|
|
static ssize_t read_ahead_kb_store(struct device *dev,
|
|
|
|
struct device_attribute *attr,
|
|
|
|
const char *buf, size_t count)
|
|
|
|
{
|
|
|
|
struct backing_dev_info *bdi = dev_get_drvdata(dev);
|
|
|
|
char *end;
|
|
|
|
unsigned long read_ahead_kb;
|
|
|
|
ssize_t ret = -EINVAL;
|
|
|
|
|
|
|
|
read_ahead_kb = simple_strtoul(buf, &end, 10);
|
|
|
|
if (*buf && (end[0] == '\0' || (end[0] == '\n' && end[1] == '\0'))) {
|
|
|
|
bdi->ra_pages = read_ahead_kb >> (PAGE_SHIFT - 10);
|
|
|
|
ret = count;
|
|
|
|
}
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
|
|
|
|
#define K(pages) ((pages) << (PAGE_SHIFT - 10))
|
|
|
|
|
|
|
|
#define BDI_SHOW(name, expr) \
|
|
|
|
static ssize_t name##_show(struct device *dev, \
|
|
|
|
struct device_attribute *attr, char *page) \
|
|
|
|
{ \
|
|
|
|
struct backing_dev_info *bdi = dev_get_drvdata(dev); \
|
|
|
|
\
|
|
|
|
return snprintf(page, PAGE_SIZE-1, "%lld\n", (long long)expr); \
|
|
|
|
}
|
|
|
|
|
|
|
|
BDI_SHOW(read_ahead_kb, K(bdi->ra_pages))
|
|
|
|
|
|
|
|
BDI_SHOW(reclaimable_kb, K(bdi_stat(bdi, BDI_RECLAIMABLE)))
|
|
|
|
BDI_SHOW(writeback_kb, K(bdi_stat(bdi, BDI_WRITEBACK)))
|
|
|
|
|
|
|
|
static inline unsigned long get_dirty(struct backing_dev_info *bdi, int i)
|
|
|
|
{
|
|
|
|
unsigned long thresh[3];
|
|
|
|
|
|
|
|
get_dirty_limits(&thresh[0], &thresh[1], &thresh[2], bdi);
|
|
|
|
|
|
|
|
return thresh[i];
|
|
|
|
}
|
|
|
|
|
|
|
|
BDI_SHOW(dirty_kb, K(get_dirty(bdi, 1)))
|
|
|
|
BDI_SHOW(bdi_dirty_kb, K(get_dirty(bdi, 2)))
|
|
|
|
|
|
|
|
#define __ATTR_RW(attr) __ATTR(attr, 0644, attr##_show, attr##_store)
|
|
|
|
|
|
|
|
static struct device_attribute bdi_dev_attrs[] = {
|
|
|
|
__ATTR_RW(read_ahead_kb),
|
|
|
|
__ATTR_RO(reclaimable_kb),
|
|
|
|
__ATTR_RO(writeback_kb),
|
|
|
|
__ATTR_RO(dirty_kb),
|
|
|
|
__ATTR_RO(bdi_dirty_kb),
|
|
|
|
__ATTR_NULL,
|
|
|
|
};
|
|
|
|
|
|
|
|
static __init int bdi_class_init(void)
|
|
|
|
{
|
|
|
|
bdi_class = class_create(THIS_MODULE, "bdi");
|
|
|
|
bdi_class->dev_attrs = bdi_dev_attrs;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
core_initcall(bdi_class_init);
|
|
|
|
|
|
|
|
int bdi_register(struct backing_dev_info *bdi, struct device *parent,
|
|
|
|
const char *fmt, ...)
|
|
|
|
{
|
|
|
|
char *name;
|
|
|
|
va_list args;
|
|
|
|
int ret = 0;
|
|
|
|
struct device *dev;
|
|
|
|
|
|
|
|
va_start(args, fmt);
|
|
|
|
name = kvasprintf(GFP_KERNEL, fmt, args);
|
|
|
|
va_end(args);
|
|
|
|
|
|
|
|
if (!name)
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
dev = device_create(bdi_class, parent, MKDEV(0, 0), name);
|
|
|
|
if (IS_ERR(dev)) {
|
|
|
|
ret = PTR_ERR(dev);
|
|
|
|
goto exit;
|
|
|
|
}
|
|
|
|
|
|
|
|
bdi->dev = dev;
|
|
|
|
dev_set_drvdata(bdi->dev, bdi);
|
|
|
|
|
|
|
|
exit:
|
|
|
|
kfree(name);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(bdi_register);
|
|
|
|
|
|
|
|
int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev)
|
|
|
|
{
|
|
|
|
return bdi_register(bdi, NULL, "%u:%u", MAJOR(dev), MINOR(dev));
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(bdi_register_dev);
|
|
|
|
|
|
|
|
void bdi_unregister(struct backing_dev_info *bdi)
|
|
|
|
{
|
|
|
|
if (bdi->dev) {
|
|
|
|
device_unregister(bdi->dev);
|
|
|
|
bdi->dev = NULL;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(bdi_unregister);
|
2006-10-20 06:28:16 +00:00
|
|
|
|
2007-10-17 06:25:47 +00:00
|
|
|
int bdi_init(struct backing_dev_info *bdi)
|
|
|
|
{
|
2007-12-05 07:45:07 +00:00
|
|
|
int i;
|
2007-10-17 06:25:47 +00:00
|
|
|
int err;
|
|
|
|
|
2008-04-30 07:54:32 +00:00
|
|
|
bdi->dev = NULL;
|
|
|
|
|
2007-10-17 06:25:47 +00:00
|
|
|
for (i = 0; i < NR_BDI_STAT_ITEMS; i++) {
|
|
|
|
err = percpu_counter_init_irq(&bdi->bdi_stat[i], 0);
|
2007-10-17 06:25:50 +00:00
|
|
|
if (err)
|
|
|
|
goto err;
|
|
|
|
}
|
|
|
|
|
|
|
|
bdi->dirty_exceeded = 0;
|
|
|
|
err = prop_local_init_percpu(&bdi->completions);
|
|
|
|
|
|
|
|
if (err) {
|
|
|
|
err:
|
2007-12-05 07:45:07 +00:00
|
|
|
while (i--)
|
2007-10-17 06:25:50 +00:00
|
|
|
percpu_counter_destroy(&bdi->bdi_stat[i]);
|
2007-10-17 06:25:47 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
return err;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(bdi_init);
|
|
|
|
|
|
|
|
void bdi_destroy(struct backing_dev_info *bdi)
|
|
|
|
{
|
|
|
|
int i;
|
|
|
|
|
2008-04-30 07:54:32 +00:00
|
|
|
bdi_unregister(bdi);
|
|
|
|
|
2007-10-17 06:25:47 +00:00
|
|
|
for (i = 0; i < NR_BDI_STAT_ITEMS; i++)
|
|
|
|
percpu_counter_destroy(&bdi->bdi_stat[i]);
|
2007-10-17 06:25:50 +00:00
|
|
|
|
|
|
|
prop_local_destroy_percpu(&bdi->completions);
|
2007-10-17 06:25:47 +00:00
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(bdi_destroy);
|
|
|
|
|
2006-10-20 06:28:16 +00:00
|
|
|
static wait_queue_head_t congestion_wqh[2] = {
|
|
|
|
__WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]),
|
|
|
|
__WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1])
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
|
|
void clear_bdi_congested(struct backing_dev_info *bdi, int rw)
|
|
|
|
{
|
|
|
|
enum bdi_state bit;
|
|
|
|
wait_queue_head_t *wqh = &congestion_wqh[rw];
|
|
|
|
|
|
|
|
bit = (rw == WRITE) ? BDI_write_congested : BDI_read_congested;
|
|
|
|
clear_bit(bit, &bdi->state);
|
|
|
|
smp_mb__after_clear_bit();
|
|
|
|
if (waitqueue_active(wqh))
|
|
|
|
wake_up(wqh);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(clear_bdi_congested);
|
|
|
|
|
|
|
|
void set_bdi_congested(struct backing_dev_info *bdi, int rw)
|
|
|
|
{
|
|
|
|
enum bdi_state bit;
|
|
|
|
|
|
|
|
bit = (rw == WRITE) ? BDI_write_congested : BDI_read_congested;
|
|
|
|
set_bit(bit, &bdi->state);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(set_bdi_congested);
|
|
|
|
|
|
|
|
/**
|
|
|
|
* congestion_wait - wait for a backing_dev to become uncongested
|
|
|
|
* @rw: READ or WRITE
|
|
|
|
* @timeout: timeout in jiffies
|
|
|
|
*
|
|
|
|
* Waits for up to @timeout jiffies for a backing_dev (any backing_dev) to exit
|
|
|
|
* write congestion. If no backing_devs are congested then just wait for the
|
|
|
|
* next write to be completed.
|
|
|
|
*/
|
|
|
|
long congestion_wait(int rw, long timeout)
|
|
|
|
{
|
|
|
|
long ret;
|
|
|
|
DEFINE_WAIT(wait);
|
|
|
|
wait_queue_head_t *wqh = &congestion_wqh[rw];
|
|
|
|
|
|
|
|
prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE);
|
|
|
|
ret = io_schedule_timeout(timeout);
|
|
|
|
finish_wait(wqh, &wait);
|
|
|
|
return ret;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(congestion_wait);
|
2007-10-17 06:25:50 +00:00
|
|
|
|