/*
* gendisk handling
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/genhd.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>
#define MAX_PROBE_HASH 255 /* random */
static struct subsystem block_subsys;
static DECLARE_MUTEX(block_subsys_sem);
/*
* Can be deleted altogether. Later.
*
*/
static struct blk_major_name {
struct blk_major_name *next;
int major;
char name[16];
} *major_names[MAX_PROBE_HASH];
/* index in the above - for now: assume no multimajor ranges */
static inline int major_to_index(int major)
{
return major % MAX_PROBE_HASH;
}
#ifdef CONFIG_PROC_FS
/* get block device names in somewhat random order */
int get_blkdev_list(char *p)
{
struct blk_major_name *n;
int i, len;
len = sprintf(p, "\nBlock devices:\n");
down(&block_subsys_sem);
for (i = 0; i < ARRAY_SIZE(major_names); i++) {
for (n = major_names[i]; n; n = n->next)
len += sprintf(p+len, "%3d %s\n",
n->major, n->name);
}
up(&block_subsys_sem);
return len;
}
#endif
int register_blkdev(unsigned int major, const char *name)
{
struct blk_major_name **n, *p;
int index, ret = 0;
down(&block_subsys_sem);
/* 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:
up(&block_subsys_sem);
return ret;
}
EXPORT_SYMBOL(register_blkdev);
/* todo: make void - error printk here */
int 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);
int ret = 0;
down(&block_subsys_sem);
for (n = &major_names[index]; *n; n = &(*n)->next)
if ((*n)->major == major)
break;
if (!*n || strcmp((*n)->name, name))
ret = -EINVAL;
else {
p = *n;
*n = p->next;
}
up(&block_subsys_sem);
kfree(p);
return ret;
}
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 dev, unsigned long range, struct module *module,
struct kobject *(*probe)(dev_t, int *, void *),
int (*lock)(dev_t, void *), void *data)
{
kobj_map(bdev_map, dev, range, module, probe, lock, data);
}
EXPORT_SYMBOL(blk_register_region);
void blk_unregister_region(dev_t dev, unsigned long range)
{
kobj_unmap(bdev_map, dev, range);
}
EXPORT_SYMBOL(blk_unregister_region);
static struct kobject *exact_match(dev_t dev, int *part, void *data)
{
struct gendisk *p = data;
return &p->kobj;
}
static int exact_lock(dev_t dev, 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)
{
disk->flags |= GENHD_FL_UP;
blk_register_region(MKDEV(disk->major, disk->first_minor),
disk->minors, NULL, exact_match, exact_lock, disk);
register_disk(disk);
blk_register_queue(disk);
}
EXPORT_SYMBOL(add_disk);
EXPORT_SYMBOL(del_gendisk); /* in partitions/check.c */
void unlink_gendisk(struct gendisk *disk)
{
blk_unregister_queue(disk);
blk_unregister_region(MKDEV(disk->major, disk->first_minor),
disk->minors);
}
#define to_disk(obj) container_of(obj,struct gendisk,kobj)
/**
* get_gendisk - get partitioning information for a given device
* @dev: device to get partitioning information for
*
* This function gets the structure containing partitioning
* information for the given device @dev.
*/
struct gendisk *get_gendisk(dev_t dev, int *part)
{
struct kobject *kobj = kobj_lookup(bdev_map, dev, part);
return kobj ? to_disk(kobj) : NULL;
}
#ifdef CONFIG_PROC_FS
/* iterator */
static void *part_start(struct seq_file *part, loff_t *pos)
{
struct list_head *p;
loff_t l = *pos;
down(&block_subsys_sem);
list_for_each(p, &block_subsys.kset.list)
if (!l--)
return list_entry(p, struct gendisk, kobj.entry);
return NULL;
}
static void *part_next(struct seq_file *part, void *v, loff_t *pos)
{
struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
++*pos;
return p==&block_subsys.kset.list ? NULL :
list_entry(p, struct gendisk, kobj.entry);
}
static void part_stop(struct seq_file *part, void *v)
{
up(&block_subsys_sem);
}
static int show_partition(struct seq_file *part, void *v)
{
struct gendisk *sgp = v;
int n;
char buf[BDEVNAME_SIZE];
if (&sgp->kobj.entry == block_subsys.kset.list.next)
seq_puts(part, "major minor #blocks name\n\n");
/* Don't show non-partitionable removeable devices or empty devices */
if (!get_capacity(sgp) ||
(sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
return 0;
if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
return 0;
/* show the full disk and all non-0 size partitions of it */
seq_printf(part, "%4d %4d %10llu %s\n",
sgp->major, sgp->first_minor,
(unsigned long long)get_capacity(sgp) >> 1,
disk_name(sgp, 0, buf));
for (n = 0; n < sgp->minors - 1; n++) {
if (!sgp->part[n])
continue;
if (sgp->part[n]->nr_sects == 0)
continue;
seq_printf(part, "%4d %4d %10llu %s\n",
sgp->major, n + 1 + sgp->first_minor,
(unsigned long long)sgp->part[n]->nr_sects >> 1 ,
disk_name(sgp, n + 1, buf));
}
return 0;
}
struct seq_operations partitions_op = {
.start =part_start,
.next = part_next,
.stop = part_stop,
.show = show_partition
};
#endif
extern int blk_dev_init(void);
static struct kobject *base_probe(dev_t dev, int *part, void *data)
{
if (request_module("block-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0)
/* Make old-style 2.4 aliases work */
request_module("block-major-%d", MAJOR(dev));
return NULL;
}
static int __init genhd_device_init(void)
{
bdev_map = kobj_map_init(base_probe, &block_subsys_sem);
blk_dev_init();
subsystem_register(&block_subsys);
return 0;
}
subsys_initcall(genhd_device_init);
/*
* kobject & sysfs bindings for block devices
*/
static ssize_t disk_attr_show(struct kobject *kobj, struct attribute *attr,
char *page)
{
struct gendisk *disk = to_disk(kobj);
struct disk_attribute *disk_attr =
container_of(attr,struct disk_attribute,attr);
ssize_t ret = 0;
if (disk_attr->show)
ret = disk_attr->show(disk,page);
return ret;
}
static struct sysfs_ops disk_sysfs_ops = {
.show = &disk_attr_show,
};
static ssize_t disk_dev_read(struct gendisk * disk, char *page)
{
dev_t base = MKDEV(disk->major, disk->first_minor);
return print_dev_t(page, base);
}
static ssize_t disk_range_read(struct gendisk * disk, char *page)
{
return sprintf(page, "%d\n", disk->minors);
}
static ssize_t disk_removable_read(struct gendisk * disk, char *page)
{
return sprintf(page, "%d\n",
(disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
}
static ssize_t disk_size_read(struct gendisk * disk, char *page)
{
return sprintf(page, "%llu\n", (unsigned long long)get_capacity(disk));
}
static ssize_t disk_stats_read(struct gendisk * disk, char *page)
{
preempt_disable();
disk_round_stats(disk);
preempt_enable();
return sprintf(page,
"%8u %8u %8llu %8u "
"%8u %8u %8llu %8u "
"%8u %8u %8u"
"\n",
disk_stat_read(disk, reads), disk_stat_read(disk, read_merges),
(unsigned long long)disk_stat_read(disk, read_sectors),
jiffies_to_msecs(disk_stat_read(disk, read_ticks)),
disk_stat_read(disk, writes),
disk_stat_read(disk, write_merges),
(unsigned long long)disk_stat_read(disk, write_sectors),
jiffies_to_msecs(disk_stat_read(disk, write_ticks)),
disk->in_flight,
jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
}
static struct disk_attribute disk_attr_dev = {
.attr = {.name = "dev", .mode = S_IRUGO },
.show = disk_dev_read
};
static struct disk_attribute disk_attr_range = {
.attr = {.name = "range", .mode = S_IRUGO },
.show = disk_range_read
};
static struct disk_attribute disk_attr_removable = {
.attr = {.name = "removable", .mode = S_IRUGO },
.show = disk_removable_read
};
static struct disk_attribute disk_attr_size = {
.attr = {.name = "size", .mode = S_IRUGO },
.show = disk_size_read
};
static struct disk_attribute disk_attr_stat = {
.attr = {.name = "stat", .mode = S_IRUGO },
.show = disk_stats_read
};
static struct attribute * default_attrs[] = {
&disk_attr_dev.attr,
&disk_attr_range.attr,
&disk_attr_removable.attr,
&disk_attr_size.attr,
&disk_attr_stat.attr,
NULL,
};
static void disk_release(struct kobject * kobj)
{
struct gendisk *disk = to_disk(kobj);
kfree(disk->random);
kfree(disk->part);
free_disk_stats(disk);
kfree(disk);
}
static struct kobj_type ktype_block = {
.release = disk_release,
.sysfs_ops = &disk_sysfs_ops,
.default_attrs = default_attrs,
};
extern struct kobj_type ktype_part;
static int block_hotplug_filter(struct kset *kset, struct kobject *kobj)
{
struct kobj_type *ktype = get_ktype(kobj);
return ((ktype == &ktype_block) || (ktype == &ktype_part));
}
static int block_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
int num_envp, char *buffer, int buffer_size)
{
struct kobj_type *ktype = get_ktype(kobj);
struct device *physdev;
struct gendisk *disk;
struct hd_struct *part;
int length = 0;
int i = 0;
if (ktype == &ktype_block) {
disk = container_of(kobj, struct gendisk, kobj);
add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
&length, "MINOR=%u", disk->first_minor);
} else if (ktype == &ktype_part) {
disk = container_of(kobj->parent, struct gendisk, kobj);
part = container_of(kobj, struct hd_struct, kobj);
add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
&length, "MINOR=%u",
disk->first_minor + part->partno);
} else
return 0;
add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size, &length,
"MAJOR=%u", disk->major);
/* add physical device, backing this device */
physdev = disk->driverfs_dev;
if (physdev) {
char *path = kobject_get_path(&physdev->kobj, GFP_KERNEL);
add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
&length, "PHYSDEVPATH=%s", path);
kfree(path);
if (physdev->bus)
add_hotplug_env_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"PHYSDEVBUS=%s",
physdev->bus->name);
if (physdev->driver)
add_hotplug_env_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"PHYSDEVDRIVER=%s",
physdev->driver->name);
}
/* terminate, set to next free slot, shrink available space */
envp[i] = NULL;
envp = &envp[i];
num_envp -= i;
buffer = &buffer[length];
buffer_size -= length;
return 0;
}
static struct kset_hotplug_ops block_hotplug_ops = {
.filter = block_hotplug_filter,
.hotplug = block_hotplug,
};
/* declare block_subsys. */
static decl_subsys(block, &ktype_block, &block_hotplug_ops);
/*
* aggregate disk stat collector. Uses the same stats that the sysfs
* entries do, above, but makes them available through one seq_file.
* Watching a few disks may be efficient through sysfs, but watching
* all of them will be more efficient through this interface.
*
* The output looks suspiciously like /proc/partitions with a bunch of
* extra fields.
*/
/* iterator */
static void *diskstats_start(struct seq_file *part, loff_t *pos)
{
loff_t k = *pos;
struct list_head *p;
down(&block_subsys_sem);
list_for_each(p, &block_subsys.kset.list)
if (!k--)
return list_entry(p, struct gendisk, kobj.entry);
return NULL;
}
static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
{
struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
++*pos;
return p==&block_subsys.kset.list ? NULL :
list_entry(p, struct gendisk, kobj.entry);
}
static void diskstats_stop(struct seq_file *part, void *v)
{
up(&block_subsys_sem);
}
static int diskstats_show(struct seq_file *s, void *v)
{
struct gendisk *gp = v;
char buf[BDEVNAME_SIZE];
int n = 0;
/*
if (&sgp->kobj.entry == block_subsys.kset.list.next)
seq_puts(s, "major minor name"
" rio rmerge rsect ruse wio wmerge "
"wsect wuse running use aveq"
"\n\n");
*/
preempt_disable();
disk_round_stats(gp);
preempt_enable();
seq_printf(s, "%4d %4d %s %u %u %llu %u %u %u %llu %u %u %u %u\n",
gp->major, n + gp->first_minor, disk_name(gp, n, buf),
disk_stat_read(gp, reads), disk_stat_read(gp, read_merges),
(unsigned long long)disk_stat_read(gp, read_sectors),
jiffies_to_msecs(disk_stat_read(gp, read_ticks)),
disk_stat_read(gp, writes), disk_stat_read(gp, write_merges),
(unsigned long long)disk_stat_read(gp, write_sectors),
jiffies_to_msecs(disk_stat_read(gp, write_ticks)),
gp->in_flight,
jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
/* now show all non-0 size partitions of it */
for (n = 0; n < gp->minors - 1; n++) {
struct hd_struct *hd = gp->part[n];
if (hd && hd->nr_sects)
seq_printf(s, "%4d %4d %s %u %u %u %u\n",
gp->major, n + gp->first_minor + 1,
disk_name(gp, n + 1, buf),
hd->reads, hd->read_sectors,
hd->writes, hd->write_sectors);
}
return 0;
}
struct seq_operations diskstats_op = {
.start = diskstats_start,
.next = diskstats_next,
.stop = diskstats_stop,
.show = diskstats_show
};
struct gendisk *alloc_disk(int minors)
{
struct gendisk *disk = kmalloc(sizeof(struct gendisk), GFP_KERNEL);
if (disk) {
memset(disk, 0, sizeof(struct gendisk));
if (!init_disk_stats(disk)) {
kfree(disk);
return NULL;
}
if (minors > 1) {
int size = (minors - 1) * sizeof(struct hd_struct *);
disk->part = kmalloc(size, GFP_KERNEL);
if (!disk->part) {
kfree(disk);
return NULL;
}
memset(disk->part, 0, size);
}
disk->minors = minors;
kobj_set_kset_s(disk,block_subsys);
kobject_init(&disk->kobj);
rand_initialize_disk(disk);
}
return disk;
}
EXPORT_SYMBOL(alloc_disk);
struct kobject *get_disk(struct gendisk *disk)
{
struct module *owner;
struct kobject *kobj;
if (!disk->fops)
return NULL;
owner = disk->fops->owner;
if (owner && !try_module_get(owner))
return NULL;
kobj = kobject_get(&disk->kobj);
if (kobj == NULL) {
module_put(owner);
return NULL;
}
return kobj;
}
EXPORT_SYMBOL(get_disk);
void put_disk(struct gendisk *disk)
{
if (disk)
kobject_put(&disk->kobj);
}
EXPORT_SYMBOL(put_disk);
void set_device_ro(struct block_device *bdev, int flag)
{
if (bdev->bd_contains != bdev)
bdev->bd_part->policy = flag;
else
bdev->bd_disk->policy = flag;
}
EXPORT_SYMBOL(set_device_ro);
void set_disk_ro(struct gendisk *disk, int flag)
{
int i;
disk->policy = flag;
for (i = 0; i < disk->minors - 1; i++)
if (disk->part[i]) disk->part[i]->policy = flag;
}
EXPORT_SYMBOL(set_disk_ro);
int bdev_read_only(struct block_device *bdev)
{
if (!bdev)
return 0;
else if (bdev->bd_contains != bdev)
return bdev->bd_part->policy;
else
return bdev->bd_disk->policy;
}
EXPORT_SYMBOL(bdev_read_only);
int invalidate_partition(struct gendisk *disk, int index)
{
int res = 0;
struct block_device *bdev = bdget_disk(disk, index);
if (bdev) {
res = __invalidate_device(bdev, 1);
bdput(bdev);
}
return res;
}
EXPORT_SYMBOL(invalidate_partition);
