include/linux/backing-dev.h

Source file repositories/reference/linux-study-clean/include/linux/backing-dev.h

File Facts

System
Linux kernel
Corpus path
include/linux/backing-dev.h
Extension
.h
Size
10735 bytes
Lines
378
Domain
Core OS
Bucket
Core Kernel Interface
Inferred role
Core OS: implementation source
Status
source implementation candidate

Why This File Exists

Core operating-system implementation surface: boot, tasks, memory, VFS, syscall-facing interfaces, synchronization, credentials, and isolation.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef _LINUX_BACKING_DEV_H
#define _LINUX_BACKING_DEV_H

#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/device.h>
#include <linux/writeback.h>
#include <linux/backing-dev-defs.h>
#include <linux/slab.h>

static inline struct backing_dev_info *bdi_get(struct backing_dev_info *bdi)
{
	kref_get(&bdi->refcnt);
	return bdi;
}

struct backing_dev_info *bdi_get_by_id(u64 id);
void bdi_put(struct backing_dev_info *bdi);

__printf(2, 3)
int bdi_register(struct backing_dev_info *bdi, const char *fmt, ...);
__printf(2, 0)
int bdi_register_va(struct backing_dev_info *bdi, const char *fmt,
		    va_list args);
void bdi_set_owner(struct backing_dev_info *bdi, struct device *owner);
void bdi_unregister(struct backing_dev_info *bdi);

struct backing_dev_info *bdi_alloc(int node_id);

void wb_start_background_writeback(struct bdi_writeback *wb);
void wb_workfn(struct work_struct *work);

void wb_wait_for_completion(struct wb_completion *done);

extern spinlock_t bdi_lock;
extern struct list_head bdi_list;

extern struct workqueue_struct *bdi_wq;

static inline bool wb_has_dirty_io(struct bdi_writeback *wb)
{
	return test_bit(WB_has_dirty_io, &wb->state);
}

static inline bool bdi_has_dirty_io(struct backing_dev_info *bdi)
{
	/*
	 * @bdi->tot_write_bandwidth is guaranteed to be > 0 if there are
	 * any dirty wbs.  See wb_update_write_bandwidth().
	 */
	return atomic_long_read(&bdi->tot_write_bandwidth);
}

static inline void wb_stat_mod(struct bdi_writeback *wb,
				 enum wb_stat_item item, s64 amount)
{
	percpu_counter_add_batch(&wb->stat[item], amount, WB_STAT_BATCH);
}

static inline s64 wb_stat(struct bdi_writeback *wb, enum wb_stat_item item)
{
	return percpu_counter_read_positive(&wb->stat[item]);
}

static inline s64 wb_stat_sum(struct bdi_writeback *wb, enum wb_stat_item item)
{
	return percpu_counter_sum_positive(&wb->stat[item]);
}

extern void wb_writeout_inc(struct bdi_writeback *wb);

/*
 * maximal error of a stat counter.
 */
static inline unsigned long wb_stat_error(void)
{
#ifdef CONFIG_SMP
	return nr_cpu_ids * WB_STAT_BATCH;
#else
	return 1;
#endif
}

/* BDI ratio is expressed as part per 1000000 for finer granularity. */
#define BDI_RATIO_SCALE 10000

u64 bdi_get_min_bytes(struct backing_dev_info *bdi);
u64 bdi_get_max_bytes(struct backing_dev_info *bdi);
int bdi_set_min_ratio(struct backing_dev_info *bdi, unsigned int min_ratio);

Annotation

Implementation Notes