android_kernel_xiaomi_sm8350/fs/partitions/check.c
Linus Torvalds 032ebf2620 Alternative fix for MMC oops on unmount after removal
Make sure to clear the driverfs_dev pointer when we do del_gendisk() (on
disk removal), so that other users that may still have a ref to the disk
won't try to use the stale pointer.

Also move the KOBJ_REMOVE uevent handler up, so that the uevent still
has access to the driverfs_dev data.

This all should hopefully fix the problems with MMC umounts after device
removals that caused commit 56cf6504fc and
its reversal (1a2acc9e92).

Original problem reported by Todd Blumer and others.

Acked-by: Greg KH <gregkh@suse.de>
Cc: Russell King <rmk+lkml@arm.linux.org.uk>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Cc: Erik Mouw <erik@harddisk-recovery.com>
Cc: Andrew Vasquez <andrew.vasquez@qlogic.com>
Cc: Todd Blumer <todd@sdgsystems.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-05-12 18:42:09 -07:00

553 lines
13 KiB
C

/*
* 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"
#include "karma.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
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 *);
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
};
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,
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,
};
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;
devfs_remove("%s/part%d", disk->devfs_name, part);
if (p->holder_dir)
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)
{
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_init(&p->kobj);
kobject_add(&p->kobj);
if (!disk->part_uevent_suppress)
kobject_uevent(&p->kobj, KOBJ_ADD);
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 void disk_sysfs_symlinks(struct gendisk *disk)
{
struct device *target = get_device(disk->driverfs_dev);
if (target) {
char *disk_name = make_block_name(disk);
sysfs_create_link(&disk->kobj,&target->kobj,"device");
if (disk_name) {
sysfs_create_link(&target->kobj,&disk->kobj,disk_name);
kfree(disk_name);
}
}
}
/* 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;
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);
disk_sysfs_add_subdirs(disk);
/* No minors to use for partitions */
if (disk->minors == 1) {
if (disk->devfs_name[0] != '\0')
devfs_add_disk(disk);
goto exit;
}
/* always add handle for the whole disk */
devfs_add_partitioned(disk);
/* 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;
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 = 0;
devfs_remove_disk(disk);
kobject_uevent(&disk->kobj, KOBJ_REMOVE);
if (disk->holder_dir)
kobject_unregister(disk->holder_dir);
if (disk->slave_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;
}
kobject_del(&disk->kobj);
}