linux/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 <linux/genhd.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 partno, char *buf)
{
if (!partno)
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, partno);
else
snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
return buf;
}
const char *bdevname(struct block_device *bdev, char *buf)
{
int partno = 0;
if (bdev->bd_part)
partno = bdev->bd_part->partno;
return disk_name(bdev->bd_disk, partno, 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 = disk_max_parts(hd) + 1;
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);
}
static ssize_t part_start_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hd_struct *p = dev_to_part(dev);
return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
}
static ssize_t part_size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hd_struct *p = dev_to_part(dev);
return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects);
}
static ssize_t part_stat_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hd_struct *p = dev_to_part(dev);
int cpu;
cpu = disk_stat_lock();
part_round_stats(cpu, p);
disk_stat_unlock();
return sprintf(buf,
"%8lu %8lu %8llu %8u "
"%8lu %8lu %8llu %8u "
"%8u %8u %8u"
"\n",
part_stat_read(p, ios[READ]),
part_stat_read(p, merges[READ]),
(unsigned long long)part_stat_read(p, sectors[READ]),
jiffies_to_msecs(part_stat_read(p, ticks[READ])),
part_stat_read(p, ios[WRITE]),
part_stat_read(p, merges[WRITE]),
(unsigned long long)part_stat_read(p, sectors[WRITE]),
jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
p->in_flight,
jiffies_to_msecs(part_stat_read(p, io_ticks)),
jiffies_to_msecs(part_stat_read(p, time_in_queue)));
}
#ifdef CONFIG_FAIL_MAKE_REQUEST
static ssize_t part_fail_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct hd_struct *p = dev_to_part(dev);
return sprintf(buf, "%d\n", p->make_it_fail);
}
static ssize_t part_fail_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct hd_struct *p = dev_to_part(dev);
int i;
if (count > 0 && sscanf(buf, "%d", &i) > 0)
p->make_it_fail = (i == 0) ? 0 : 1;
return count;
}
#endif
static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
#ifdef CONFIG_FAIL_MAKE_REQUEST
static struct device_attribute dev_attr_fail =
__ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
#endif
static struct attribute *part_attrs[] = {
&dev_attr_start.attr,
&dev_attr_size.attr,
&dev_attr_stat.attr,
#ifdef CONFIG_FAIL_MAKE_REQUEST
&dev_attr_fail.attr,
#endif
NULL
};
static struct attribute_group part_attr_group = {
.attrs = part_attrs,
};
static struct attribute_group *part_attr_groups[] = {
&part_attr_group,
NULL
};
static void part_release(struct device *dev)
{
struct hd_struct *p = dev_to_part(dev);
free_part_stats(p);
kfree(p);
}
struct device_type part_type = {
.name = "partition",
.groups = part_attr_groups,
.release = part_release,
};
static inline void disk_sysfs_add_subdirs(struct gendisk *disk)
{
struct kobject *k;
k = kobject_get(&disk->dev.kobj);
disk->holder_dir = kobject_create_and_add("holders", k);
disk->slave_dir = kobject_create_and_add("slaves", k);
kobject_put(k);
}
static void delete_partition_rcu_cb(struct rcu_head *head)
{
struct hd_struct *part = container_of(head, struct hd_struct, rcu_head);
part->start_sect = 0;
part->nr_sects = 0;
part_stat_set_all(part, 0);
put_device(&part->dev);
}
void delete_partition(struct gendisk *disk, int partno)
{
struct hd_struct *part;
part = disk->__part[partno-1];
if (!part)
return;
blk_free_devt(part_devt(part));
rcu_assign_pointer(disk->__part[partno-1], NULL);
kobject_put(part->holder_dir);
device_del(&part->dev);
call_rcu(&part->rcu_head, delete_partition_rcu_cb);
}
static ssize_t whole_disk_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return 0;
}
static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
whole_disk_show, NULL);
int add_partition(struct gendisk *disk, int partno,
sector_t start, sector_t len, int flags)
{
struct hd_struct *p;
dev_t devt = MKDEV(0, 0);
int err;
if (disk->__part[partno - 1])
return -EBUSY;
2007-07-19 08:49:03 +00:00
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p)
return -ENOMEM;
if (!init_part_stats(p)) {
err = -ENOMEM;
goto out_free;
}
p->start_sect = start;
p->nr_sects = len;
p->partno = partno;
p->policy = disk->policy;
if (isdigit(disk->dev.bus_id[strlen(disk->dev.bus_id)-1]))
snprintf(p->dev.bus_id, BUS_ID_SIZE,
"%sp%d", disk->dev.bus_id, partno);
else
snprintf(p->dev.bus_id, BUS_ID_SIZE,
"%s%d", disk->dev.bus_id, partno);
device_initialize(&p->dev);
p->dev.class = &block_class;
p->dev.type = &part_type;
p->dev.parent = &disk->dev;
err = blk_alloc_devt(p, &devt);
if (err)
goto out_put;
p->dev.devt = devt;
/* delay uevent until 'holders' subdir is created */
p->dev.uevent_suppress = 1;
err = device_add(&p->dev);
if (err)
goto out_put;
err = -ENOMEM;
p->holder_dir = kobject_create_and_add("holders", &p->dev.kobj);
if (!p->holder_dir)
goto out_del;
p->dev.uevent_suppress = 0;
if (flags & ADDPART_FLAG_WHOLEDISK) {
err = device_create_file(&p->dev, &dev_attr_whole_disk);
if (err)
goto out_del;
}
/* everything is up and running, commence */
INIT_RCU_HEAD(&p->rcu_head);
rcu_assign_pointer(disk->__part[partno - 1], p);
/* suppress uevent if the disk supresses it */
if (!disk->dev.uevent_suppress)
kobject_uevent(&p->dev.kobj, KOBJ_ADD);
return 0;
out_free:
kfree(p);
return err;
out_del:
kobject_put(p->holder_dir);
device_del(&p->dev);
out_put:
put_device(&p->dev);
blk_free_devt(devt);
return err;
}
/* Not exported, helper to add_disk(). */
void register_disk(struct gendisk *disk)
{
struct block_device *bdev;
struct disk_part_iter piter;
struct hd_struct *part;
char *s;
int err;
disk->dev.parent = disk->driverfs_dev;
strlcpy(disk->dev.bus_id, disk->disk_name, BUS_ID_SIZE);
/* ewww... some of these buggers have / in the name... */
s = strchr(disk->dev.bus_id, '/');
if (s)
*s = '!';
/* delay uevents, until we scanned partition table */
disk->dev.uevent_suppress = 1;
if (device_add(&disk->dev))
return;
#ifndef CONFIG_SYSFS_DEPRECATED
err = sysfs_create_link(block_depr, &disk->dev.kobj,
kobject_name(&disk->dev.kobj));
if (err) {
device_del(&disk->dev);
return;
}
#endif
disk_sysfs_add_subdirs(disk);
/* No minors to use for partitions */
if (!disk_max_parts(disk))
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;
bdev->bd_invalidated = 1;
err = blkdev_get(bdev, FMODE_READ, 0);
if (err < 0)
goto exit;
blkdev_put(bdev);
exit:
/* announce disk after possible partitions are created */
disk->dev.uevent_suppress = 0;
kobject_uevent(&disk->dev.kobj, KOBJ_ADD);
/* announce possible partitions */
disk_part_iter_init(&piter, disk, 0);
while ((part = disk_part_iter_next(&piter)))
kobject_uevent(&part->dev.kobj, KOBJ_ADD);
disk_part_iter_exit(&piter);
}
int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
{
struct disk_part_iter piter;
struct hd_struct *part;
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;
disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
while ((part = disk_part_iter_next(&piter)))
delete_partition(disk, part->partno);
disk_part_iter_exit(&piter);
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;
/* tell userspace that the media / partition table may have changed */
kobject_uevent(&disk->dev.kobj, KOBJ_CHANGE);
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(KERN_WARNING
"%s: p%d exceeds device capacity\n",
disk->disk_name, p);
}
res = add_partition(disk, p, from, size, state->parts[p].flags);
if (res) {
printk(KERN_ERR " %s: p%d could not be added: %d\n",
disk->disk_name, p, -res);
continue;
}
#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)
{
struct disk_part_iter piter;
struct hd_struct *part;
/* invalidate stuff */
disk_part_iter_init(&piter, disk,
DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
while ((part = disk_part_iter_next(&piter))) {
invalidate_partition(disk, part->partno);
delete_partition(disk, part->partno);
}
disk_part_iter_exit(&piter);
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_put(disk->holder_dir);
kobject_put(disk->slave_dir);
disk->driverfs_dev = NULL;
#ifndef CONFIG_SYSFS_DEPRECATED
sysfs_remove_link(block_depr, disk->dev.bus_id);
#endif
device_del(&disk->dev);
}