/*
* gendisk handling
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/genhd.h>
#include <linux/kdev_t.h>
#include <linux/kernel.h>
#include <linux/blkdev.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/kmod.h>
#include <linux/kobj_map.h>
#include <linux/buffer_head.h>
#include <linux/mutex.h>
#include "blk.h"
static DEFINE_MUTEX(block_class_lock);
#ifndef CONFIG_SYSFS_DEPRECATED
struct kobject *block_depr;
#endif
static struct device_type disk_type;
/*
* Can be deleted altogether. Later.
*
*/
static struct blk_major_name {
struct blk_major_name *next;
int major;
char name[16];
} *major_names[BLKDEV_MAJOR_HASH_SIZE];
/* index in the above - for now: assume no multimajor ranges */
static inline int major_to_index(int major)
{
return major % BLKDEV_MAJOR_HASH_SIZE;
}
#ifdef CONFIG_PROC_FS
void blkdev_show(struct seq_file *f, off_t offset)
{
struct blk_major_name *dp;
if (offset < BLKDEV_MAJOR_HASH_SIZE) {
mutex_lock(&block_class_lock);
for (dp = major_names[offset]; dp; dp = dp->next)
seq_printf(f, "%3d %s\n", dp->major, dp->name);
mutex_unlock(&block_class_lock);
}
}
#endif /* CONFIG_PROC_FS */
int register_blkdev(unsigned int major, const char *name)
{
struct blk_major_name **n, *p;
int index, ret = 0;
mutex_lock(&block_class_lock);
/* temporary */
if (major == 0) {
for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
if (major_names[index] == NULL)
break;
}
if (index == 0) {
printk("register_blkdev: failed to get major for %s\n",
name);
ret = -EBUSY;
goto out;
}
major = index;
ret = major;
}
p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
if (p == NULL) {
ret = -ENOMEM;
goto out;
}
p->major = major;
strlcpy(p->name, name, sizeof(p->name));
p->next = NULL;
index = major_to_index(major);
for (n = &major_names[index]; *n; n = &(*n)->next) {
if ((*n)->major == major)
break;
}
if (!*n)
*n = p;
else
ret = -EBUSY;
if (ret < 0) {
printk("register_blkdev: cannot get major %d for %s\n",
major, name);
kfree(p);
}
out:
mutex_unlock(&block_class_lock);
return ret;
}
EXPORT_SYMBOL(register_blkdev);
void unregister_blkdev(unsigned int major, const char *name)
{
struct blk_major_name **n;
struct blk_major_name *p = NULL;
int index = major_to_index(major);
mutex_lock(&block_class_lock);
for (n = &major_names[index]; *n; n = &(*n)->next)
if ((*n)->major == major)
break;
if (!*n || strcmp((*n)->name, name)) {
WARN_ON(1);
} else {
p = *n;
*n = p->next;
}
mutex_unlock(&block_class_lock);
kfree(p);
}
EXPORT_SYMBOL(unregister_blkdev);
static struct kobj_map *bdev_map;
/*
* Register device numbers dev..(dev+range-1)
* range must be nonzero
* The hash chain is sorted on range, so that subranges can override.
*/
void blk_register_region(dev_t devt, unsigned long range, struct module *module,
struct kobject *(*probe)(dev_t, int *, void *),
int (*lock)(dev_t, void *), void *data)
{
kobj_map(bdev_map, devt, range, module, probe, lock, data);
}
EXPORT_SYMBOL(blk_register_region);
void blk_unregister_region(dev_t devt, unsigned long range)
{
kobj_unmap(bdev_map, devt, range);
}
EXPORT_SYMBOL(blk_unregister_region);
static struct kobject *exact_match(dev_t devt, int *part, void *data)
{
struct gendisk *p = data;
return &p->dev.kobj;
}
static int exact_lock(dev_t devt, void *data)
{
struct gendisk *p = data;
if (!get_disk(p))
return -1;
return 0;
}
/**
* add_disk - add partitioning information to kernel list
* @disk: per-device partitioning information
*
* This function registers the partitioning information in @disk
* with the kernel.
*/
void add_disk(struct gendisk *disk)
{
struct backing_dev_info *bdi;
int retval;
disk->flags |= GENHD_FL_UP;
blk_register_region(MKDEV(disk->major