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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/fs/partitions/check.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 "check.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"
#include "karma.h"
#include "sysv68.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_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
#ifdef CONFIG_KARMA_PARTITION
karma_partition,
#endif
#ifdef CONFIG_SYSV68_PARTITION
sysv68_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, err;
state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
if (!state)
return NULL;
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 = err = 0;
while (!res && check_part[i]) {
memset(&state->parts, 0, sizeof(state->parts));
res = check_part[i++](state, bdev);
if (res < 0) {
/* We have hit an I/O error which we don't report now.
* But record it, and let the others do their job.
*/
err = res;
res = 0;
}
}
if (res > 0)
return state;
if (err)
/* The partition is unrecognized. So report I/O errors if there were any */
res = err;
if (!res)
printk(" unknown partition table\n");
else if (warn_no_part)
printk(" unable to read partition table\n");
kfree(state);
return ERR_PTR(res);
}
/*
* sysfs bindings for partitions
*/
struct part_attribute {
struct attribute attr;
ssize_t (*show)(struct hd_struct *,char *);
ssize_t (*store)(struct hd_struct *,const char *, size_t);
};
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 ssize_t
part_attr_store(struct kobject * kobj, struct attribute * attr,
const char *page, size_t count)
{
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->store)
ret = part_attr->store(p, page, count);
return ret;
}
static struct sysfs_ops part_sysfs_ops = {
.show = part_attr_show,
.store = part_attr_store,
};
static ssize_t part_uevent_store(struct hd_struct * p,
const char *page, size_t count)
{
kobject_uevent(&p->kobj, KOBJ_ADD);
return count;
}
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->ios[0], (unsigned long long)p->sectors[0],
p->ios[1], (unsigned long long)p->sectors[1]);
}
static struct part_attribute part_attr_uevent = {
.attr = {.name = "uevent", .mode = S_IWUSR },
.store = part_uevent_store
};
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
};
#ifdef CONFIG_FAIL_MAKE_REQUEST
static ssize_t part_fail_store(struct hd_struct * p,
const char *buf, size_t count)
{
int i;
if (count > 0 && sscanf(buf, "%d", &i) > 0)
p->make_it_fail = (i == 0) ? 0 : 1;
return count;
}
static ssize_t part_fail_read(struct hd_struct * p, char *page)
{
return sprintf(page, "%d\n", p->make_it_fail);
}
static struct part_attribute part_attr_fail = {
.attr = {.name = "make-it-fail", .mode = S_IRUGO | S_IWUSR },
.store = part_fail_store,
.show = part_fail_read
};
#endif
static struct attribute * default_attrs[] = {
&part_attr_uevent.attr,
&part_attr_dev.attr,
&part_attr_start.attr,
&part_attr_size.attr,
&part_attr_stat.attr,
#ifdef CONFIG_FAIL_MAKE_REQUEST
&part_attr_fail.attr,
#endif
NULL,
};
extern struct kset 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,
};
static inline void partition_sysfs_add_subdir(struct hd_struct *p)
{
struct kobject *k;
k = kobject_get(&p->kobj);
p->holder_dir = kobject_add_dir(k, "holders");
kobject_put(k);
}
static inline void disk_sysfs_add_subdirs(struct gendisk *disk)
{
struct kobject *k;
k = kobject_get(&disk->kobj);
disk->holder_dir = kobject_add_dir(k, "holders");
disk->slave_dir = kobject_add_dir(k, "slaves");
kobject_put(k);
}
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->ios[0] = p->ios[1] = 0;
p->sectors[0] = p->sectors[1] = 0;
sysfs_remove_link(&p->kobj, "subsystem");
kobject_unregister(p->holder_dir);
kobject_uevent(&p->kobj, KOBJ_REMOVE);
kobject_del(&p->kobj);
kobject_put(&p->kobj);
}
void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len, int flags)
{
struct hd_struct *p;
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p)
return;
p->start_sect = start;
p->nr_sects = len;
p->partno = part;
p->policy = disk->policy;
if (isdigit(disk->kobj.k_name[strlen(disk->kobj.k_name)-1]))
kobject_set_name(&p->kobj, "%sp%d",
kobject_name(&disk->kobj), part);
else
kobject_set_name(&p->kobj, "%s%d",
kobject_name(&disk->kobj),part);
p->kobj.parent = &disk->kobj;
p->kobj.ktype = &ktype_part;
kobject_init(&p->kobj);
kobject_add(&p->kobj);
if (!disk->part_uevent_suppress)
kobject_uevent(&p->kobj, KOBJ_ADD);
sysfs_create_link(&p->kobj, &block_subsys.kobj, "subsystem");
if (flags & ADDPART_FLAG_WHOLEDISK) {
static struct attribute addpartattr = {
.name = "whole_disk",
.mode = S_IRUSR | S_IRGRP | S_IROTH,
};
sysfs_create_file(&p->kobj, &addpartattr);
}
partition_sysfs_add_subdir(p);
disk->part[part-1] = p;
}
static char *make_block_name(struct gendisk *disk)
{
char *name;
static char *block_str = "block:";
int size;
char *s;
size = strlen(block_str) + strlen(disk->disk_name) + 1;
name = kmalloc(size, GFP_KERNEL);
if (!name)
return NULL;
strcpy(name, block_str);
strcat(name, disk->disk_name);
/* ewww... some of these buggers have / in name... */
s = strchr(name, '/');
if (s)
*s = '!';
return name;
}
static int disk_sysfs_symlinks(struct gendisk *disk)
{
struct device *target = get_device(disk->driverfs_dev);
int err;
char *disk_name = NULL;
if (target) {
disk_name = make_block_name(disk);
if (!disk_name) {
err = -ENOMEM;
goto err_out;
}
err = sysfs_create_link(&disk->kobj, &target->kobj, "device");
if (err)
goto err_out_disk_name;
err = sysfs_create_link(&target->kobj, &disk->kobj, disk_name);
if (err)
goto err_out_dev_link;
}
err = sysfs_create_link(&disk->kobj, &block_subsys.kobj,
"subsystem");
if (err)
goto err_out_disk_name_lnk;
kfree(disk_name);
return 0;
err_out_disk_name_lnk:
if (target) {
sysfs_remove_link(&target->kobj, disk_name);
err_out_dev_link:
sysfs_remove_link(&disk->kobj, "device");
err_out_disk_name:
kfree(disk_name);
err_out:
put_device(target);
}
return err;
}
/* Not exported, helper to add_disk(). */
void register_disk(struct gendisk *disk)
{
struct block_device *bdev;
char *s;
int i;
struct hd_struct *p;
int err;
kobject_set_name(&disk->kobj, "%s", disk->disk_name);
/* ewww... some of these buggers have / in name... */
s = strchr(disk->kobj.k_name, '/');
if (s)
*s = '!';
if ((err = kobject_add(&disk->kobj)))
return;
err = disk_sysfs_symlinks(disk);
if (err) {
kobject_del(&disk->kobj);
return;
}
disk_sysfs_add_subdirs(disk);
/* No minors to use for partitions */
if (disk->minors == 1)
goto exit;
/* No such device (e.g., media were just removed) */
if (!get_capacity(disk))
goto exit;
bdev = bdget_disk(disk, 0);
if (!bdev)
goto exit;
/* scan partition table, but suppress uevents */
bdev->bd_invalidated = 1;
disk->part_uevent_suppress = 1;
err = blkdev_get(bdev, FMODE_READ, 0);
disk->part_uevent_suppress = 0;
if (err < 0)
goto exit;
blkdev_put(bdev);
exit:
/* announce disk after possible partitions are already created */
kobject_uevent(&disk->kobj, KOBJ_ADD);
/* announce possible partitions */
for (i = 1; i < disk->minors; i++) {
p = disk->part[i-1];
if (!p || !p->nr_sects)
continue;
kobject_uevent(&p->kobj, KOBJ_ADD);
}
}
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;
if (IS_ERR(state)) /* I/O error reading the partition table */
return -EIO;
for (p = 1; p < state->limit; p++) {
sector_t size = state->parts[p].size;
sector_t from = state->parts[p].from;
if (!size)
continue;
if (from + size > get_capacity(disk)) {
printk(" %s: p%d exceeds device capacity\n",
disk->disk_name, p);
}
add_partition(disk, p, from, size, state->parts[p].flags);
#ifdef CONFIG_BLK_DEV_MD
if (state->parts[p].flags & ADDPART_FLAG_RAID)
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_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
NULL);
if (!IS_ERR(page)) {
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 = 0;
kobject_uevent(&disk->kobj, KOBJ_REMOVE);
kobject_unregister(disk->holder_dir);
kobject_unregister(disk->slave_dir);
if (disk->driverfs_dev) {
char *disk_name = make_block_name(disk);
sysfs_remove_link(&disk->kobj, "device");
if (disk_name) {
sysfs_remove_link(&disk->driverfs_dev->kobj, disk_name);
kfree(disk_name);
}
put_device(disk->driverfs_dev);
disk->driverfs_dev = NULL;
}
sysfs_remove_link(&disk->kobj, "subsystem");
kobject_del(&disk->kobj);
}
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