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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/fs/partitions/check.c

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11 KiB
C
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/*
* fs/partitions/check.c
*
* Code extracted from drivers/block/genhd.c
* Copyright (C) 1991-1998 Linus Torvalds
* Re-organised Feb 1998 Russell King
*
* We now have independent partition support from the
* block drivers, which allows all the partition code to
* be grouped in one location, and it to be mostly self
* contained.
*
* Added needed MAJORS for new pairs, {hdi,hdj}, {hdk,hdl}
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/kmod.h>
#include <linux/ctype.h>
#include <linux/devfs_fs_kernel.h>
#include "check.h"
#include "devfs.h"
#include "acorn.h"
#include "amiga.h"
#include "atari.h"
#include "ldm.h"
#include "mac.h"
#include "msdos.h"
#include "osf.h"
#include "sgi.h"
#include "sun.h"
#include "ibm.h"
#include "ultrix.h"
#include "efi.h"
#ifdef CONFIG_BLK_DEV_MD
extern void md_autodetect_dev(dev_t dev);
#endif
int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/
static int (*check_part[])(struct parsed_partitions *, struct block_device *) = {
/*
* Probe partition formats with tables at disk address 0
* that also have an ADFS boot block at 0xdc0.
*/
#ifdef CONFIG_ACORN_PARTITION_ICS
adfspart_check_ICS,
#endif
#ifdef CONFIG_ACORN_PARTITION_POWERTEC
adfspart_check_POWERTEC,
#endif
#ifdef CONFIG_ACORN_PARTITION_EESOX
adfspart_check_EESOX,
#endif
/*
* Now move on to formats that only have partition info at
* disk address 0xdc0. Since these may also have stale
* PC/BIOS partition tables, they need to come before
* the msdos entry.
*/
#ifdef CONFIG_ACORN_PARTITION_CUMANA
adfspart_check_CUMANA,
#endif
#ifdef CONFIG_ACORN_PARTITION_ADFS
adfspart_check_ADFS,
#endif
#ifdef CONFIG_EFI_PARTITION
efi_partition, /* this must come before msdos */
#endif
#ifdef CONFIG_SGI_PARTITION
sgi_partition,
#endif
#ifdef CONFIG_LDM_PARTITION
ldm_partition, /* this must come before msdos */
#endif
#ifdef CONFIG_NEC98_PARTITION
nec98_partition, /* must be come before `msdos_partition' */
#endif
#ifdef CONFIG_MSDOS_PARTITION
msdos_partition,
#endif
#ifdef CONFIG_OSF_PARTITION
osf_partition,
#endif
#ifdef CONFIG_SUN_PARTITION
sun_partition,
#endif
#ifdef CONFIG_AMIGA_PARTITION
amiga_partition,
#endif
#ifdef CONFIG_ATARI_PARTITION
atari_partition,
#endif
#ifdef CONFIG_MAC_PARTITION
mac_partition,
#endif
#ifdef CONFIG_ULTRIX_PARTITION
ultrix_partition,
#endif
#ifdef CONFIG_IBM_PARTITION
ibm_partition,
#endif
NULL
};
/*
* disk_name() is used by partition check code and the genhd driver.
* It formats the devicename of the indicated disk into
* the supplied buffer (of size at least 32), and returns
* a pointer to that same buffer (for convenience).
*/
char *disk_name(struct gendisk *hd, int part, char *buf)
{
if (!part)
snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, part);
else
snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, part);
return buf;
}
const char *bdevname(struct block_device *bdev, char *buf)
{
int part = MINOR(bdev->bd_dev) - bdev->bd_disk->first_minor;
return disk_name(bdev->bd_disk, part, buf);
}
EXPORT_SYMBOL(bdevname);
/*
* There's very little reason to use this, you should really
* have a struct block_device just about everywhere and use
* bdevname() instead.
*/
const char *__bdevname(dev_t dev, char *buffer)
{
scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
MAJOR(dev), MINOR(dev));
return buffer;
}
EXPORT_SYMBOL(__bdevname);
static struct parsed_partitions *
check_partition(struct gendisk *hd, struct block_device *bdev)
{
struct parsed_partitions *state;
int i, res;
state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
if (!state)
return NULL;
#ifdef CONFIG_DEVFS_FS
if (hd->devfs_name[0] != '\0') {
printk(KERN_INFO " /dev/%s:", hd->devfs_name);
sprintf(state->name, "p");
}
#endif
else {
disk_name(hd, 0, state->name);
printk(KERN_INFO " %s:", state->name);
if (isdigit(state->name[strlen(state->name)-1]))
sprintf(state->name, "p");
}
state->limit = hd->minors;
i = res = 0;
while (!res && check_part[i]) {
memset(&state->parts, 0, sizeof(state->parts));
res = check_part[i++](state, bdev);
}
if (res > 0)
return state;
if (!res)
printk(" unknown partition table\n");
else if (warn_no_part)
printk(" unable to read partition table\n");
kfree(state);
return NULL;
}
/*
* sysfs bindings for partitions
*/
struct part_attribute {
struct attribute attr;
ssize_t (*show)(struct hd_struct *,char *);
};
static ssize_t
part_attr_show(struct kobject * kobj, struct attribute * attr, char * page)
{
struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
struct part_attribute * part_attr = container_of(attr,struct part_attribute,attr);
ssize_t ret = 0;
if (part_attr->show)
ret = part_attr->show(p,page);
return ret;
}
static struct sysfs_ops part_sysfs_ops = {
.show = part_attr_show,
};
static ssize_t part_dev_read(struct hd_struct * p, char *page)
{
struct gendisk *disk = container_of(p->kobj.parent,struct gendisk,kobj);
dev_t dev = MKDEV(disk->major, disk->first_minor + p->partno);
return print_dev_t(page, dev);
}
static ssize_t part_start_read(struct hd_struct * p, char *page)
{
return sprintf(page, "%llu\n",(unsigned long long)p->start_sect);
}
static ssize_t part_size_read(struct hd_struct * p, char *page)
{
return sprintf(page, "%llu\n",(unsigned long long)p->nr_sects);
}
static ssize_t part_stat_read(struct hd_struct * p, char *page)
{
return sprintf(page, "%8u %8llu %8u %8llu\n",
p->reads, (unsigned long long)p->read_sectors,
p->writes, (unsigned long long)p->write_sectors);
}
static struct part_attribute part_attr_dev = {
.attr = {.name = "dev", .mode = S_IRUGO },
.show = part_dev_read
};
static struct part_attribute part_attr_start = {
.attr = {.name = "start", .mode = S_IRUGO },
.show = part_start_read
};
static struct part_attribute part_attr_size = {
.attr = {.name = "size", .mode = S_IRUGO },
.show = part_size_read
};
static struct part_attribute part_attr_stat = {
.attr = {.name = "stat", .mode = S_IRUGO },
.show = part_stat_read
};
static struct attribute * default_attrs[] = {
&part_attr_dev.attr,
&part_attr_start.attr,
&part_attr_size.attr,
&part_attr_stat.attr,
NULL,
};
extern struct subsystem block_subsys;
static void part_release(struct kobject *kobj)
{
struct hd_struct * p = container_of(kobj,struct hd_struct,kobj);
kfree(p);
}
struct kobj_type ktype_part = {
.release = part_release,
.default_attrs = default_attrs,
.sysfs_ops = &part_sysfs_ops,
};
void delete_partition(struct gendisk *disk, int part)
{
struct hd_struct *p = disk->part[part-1];
if (!p)
return;
if (!p->nr_sects)
return;
disk->part[part-1] = NULL;
p->start_sect = 0;
p->nr_sects = 0;
p->reads = p->writes = p->read_sectors = p->write_sectors = 0;
devfs_remove("%s/part%d", disk->devfs_name, part);
kobject_unregister(&p->kobj);
}
void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len)
{
struct hd_struct *p;
p = kmalloc(sizeof(*p), GFP_KERNEL);
if (!p)
return;
memset(p, 0, sizeof(*p));
p->start_sect = start;
p->nr_sects = len;
p->partno = part;
devfs_mk_bdev(MKDEV(disk->major, disk->first_minor + part),
S_IFBLK|S_IRUSR|S_IWUSR,
"%s/part%d", disk->devfs_name, part);
if (isdigit(disk->kobj.name[strlen(disk->kobj.name)-1]))
snprintf(p->kobj.name,KOBJ_NAME_LEN,"%sp%d",disk->kobj.name,part);
else
snprintf(p->kobj.name,KOBJ_NAME_LEN,"%s%d",disk->kobj.name,part);
p->kobj.parent = &disk->kobj;
p->kobj.ktype = &ktype_part;
kobject_register(&p->kobj);
disk->part[part-1] = p;
}
static void disk_sysfs_symlinks(struct gendisk *disk)
{
struct device *target = get_device(disk->driverfs_dev);
if (target) {
sysfs_create_link(&disk->kobj,&target->kobj,"device");
sysfs_create_link(&target->kobj,&disk->kobj,"block");
}
}
/* Not exported, helper to add_disk(). */
void register_disk(struct gendisk *disk)
{
struct block_device *bdev;
char *s;
int err;
strlcpy(disk->kobj.name,disk->disk_name,KOBJ_NAME_LEN);
/* ewww... some of these buggers have / in name... */
s = strchr(disk->kobj.name, '/');
if (s)
*s = '!';
if ((err = kobject_add(&disk->kobj)))
return;
disk_sysfs_symlinks(disk);
/* No minors to use for partitions */
if (disk->minors == 1) {
if (disk->devfs_name[0] != '\0')
devfs_add_disk(disk);
return;
}
/* always add handle for the whole disk */
devfs_add_partitioned(disk);
/* No such device (e.g., media were just removed) */
if (!get_capacity(disk))
return;
bdev = bdget_disk(disk, 0);
if (!bdev)
return;
bdev->bd_invalidated = 1;
if (blkdev_get(bdev, FMODE_READ, 0) < 0)
return;
blkdev_put(bdev);
}
int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
{
struct parsed_partitions *state;
int p, res;
if (bdev->bd_part_count)
return -EBUSY;
res = invalidate_partition(disk, 0);
if (res)
return res;
bdev->bd_invalidated = 0;
for (p = 1; p < disk->minors; p++)
delete_partition(disk, p);
if (disk->fops->revalidate_disk)
disk->fops->revalidate_disk(disk);
if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
return 0;
for (p = 1; p < state->limit; p++) {
sector_t size = state->parts[p].size;
sector_t from = state->parts[p].from;
if (!size)
continue;
add_partition(disk, p, from, size);
#ifdef CONFIG_BLK_DEV_MD
if (state->parts[p].flags)
md_autodetect_dev(bdev->bd_dev+p);
#endif
}
kfree(state);
return 0;
}
unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
{
struct address_space *mapping = bdev->bd_inode->i_mapping;
struct page *page;
page = read_cache_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
(filler_t *)mapping->a_ops->readpage, NULL);
if (!IS_ERR(page)) {
wait_on_page_locked(page);
if (!PageUptodate(page))
goto fail;
if (PageError(page))
goto fail;
p->v = page;
return (unsigned char *)page_address(page) + ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
fail:
page_cache_release(page);
}
p->v = NULL;
return NULL;
}
EXPORT_SYMBOL(read_dev_sector);
void del_gendisk(struct gendisk *disk)
{
int p;
/* invalidate stuff */
for (p = disk->minors - 1; p > 0; p--) {
invalidate_partition(disk, p);
delete_partition(disk, p);
}
invalidate_partition(disk, 0);
disk->capacity = 0;
disk->flags &= ~GENHD_FL_UP;
unlink_gendisk(disk);
disk_stat_set_all(disk, 0);
disk->stamp = disk->stamp_idle = 0;
devfs_remove_disk(disk);
if (disk->driverfs_dev) {
sysfs_remove_link(&disk->kobj, "device");
sysfs_remove_link(&disk->driverfs_dev->kobj, "block");
put_device(disk->driverfs_dev);
}
kobject_del(&disk->kobj);
}
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