android_kernel_xiaomi_sm8350/drivers/mtd/devices/block2mtd.c
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00

486 lines
10 KiB
C

/*
* block2mtd.c - create an mtd from a block device
*
* Copyright (C) 2001,2002 Simon Evans <spse@secret.org.uk>
* Copyright (C) 2004-2006 Joern Engel <joern@wh.fh-wedel.de>
*
* Licence: GPL
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/bio.h>
#include <linux/pagemap.h>
#include <linux/list.h>
#include <linux/init.h>
#include <linux/mtd/mtd.h>
#include <linux/buffer_head.h>
#include <linux/mutex.h>
#include <linux/mount.h>
#include <linux/slab.h>
#define ERROR(fmt, args...) printk(KERN_ERR "block2mtd: " fmt "\n" , ## args)
#define INFO(fmt, args...) printk(KERN_INFO "block2mtd: " fmt "\n" , ## args)
/* Info for the block device */
struct block2mtd_dev {
struct list_head list;
struct block_device *blkdev;
struct mtd_info mtd;
struct mutex write_mutex;
};
/* Static info about the MTD, used in cleanup_module */
static LIST_HEAD(blkmtd_device_list);
static struct page *page_read(struct address_space *mapping, int index)
{
return read_mapping_page(mapping, index, NULL);
}
/* erase a specified part of the device */
static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
{
struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
struct page *page;
int index = to >> PAGE_SHIFT; // page index
int pages = len >> PAGE_SHIFT;
u_long *p;
u_long *max;
while (pages) {
page = page_read(mapping, index);
if (!page)
return -ENOMEM;
if (IS_ERR(page))
return PTR_ERR(page);
max = page_address(page) + PAGE_SIZE;
for (p=page_address(page); p<max; p++)
if (*p != -1UL) {
lock_page(page);
memset(page_address(page), 0xff, PAGE_SIZE);
set_page_dirty(page);
unlock_page(page);
break;
}
page_cache_release(page);
pages--;
index++;
}
return 0;
}
static int block2mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
{
struct block2mtd_dev *dev = mtd->priv;
size_t from = instr->addr;
size_t len = instr->len;
int err;
instr->state = MTD_ERASING;
mutex_lock(&dev->write_mutex);
err = _block2mtd_erase(dev, from, len);
mutex_unlock(&dev->write_mutex);
if (err) {
ERROR("erase failed err = %d", err);
instr->state = MTD_ERASE_FAILED;
} else
instr->state = MTD_ERASE_DONE;
instr->state = MTD_ERASE_DONE;
mtd_erase_callback(instr);
return err;
}
static int block2mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf)
{
struct block2mtd_dev *dev = mtd->priv;
struct page *page;
int index = from >> PAGE_SHIFT;
int offset = from & (PAGE_SIZE-1);
int cpylen;
if (from > mtd->size)
return -EINVAL;
if (from + len > mtd->size)
len = mtd->size - from;
if (retlen)
*retlen = 0;
while (len) {
if ((offset + len) > PAGE_SIZE)
cpylen = PAGE_SIZE - offset; // multiple pages
else
cpylen = len; // this page
len = len - cpylen;
page = page_read(dev->blkdev->bd_inode->i_mapping, index);
if (!page)
return -ENOMEM;
if (IS_ERR(page))
return PTR_ERR(page);
memcpy(buf, page_address(page) + offset, cpylen);
page_cache_release(page);
if (retlen)
*retlen += cpylen;
buf += cpylen;
offset = 0;
index++;
}
return 0;
}
/* write data to the underlying device */
static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
loff_t to, size_t len, size_t *retlen)
{
struct page *page;
struct address_space *mapping = dev->blkdev->bd_inode->i_mapping;
int index = to >> PAGE_SHIFT; // page index
int offset = to & ~PAGE_MASK; // page offset
int cpylen;
if (retlen)
*retlen = 0;
while (len) {
if ((offset+len) > PAGE_SIZE)
cpylen = PAGE_SIZE - offset; // multiple pages
else
cpylen = len; // this page
len = len - cpylen;
page = page_read(mapping, index);
if (!page)
return -ENOMEM;
if (IS_ERR(page))
return PTR_ERR(page);
if (memcmp(page_address(page)+offset, buf, cpylen)) {
lock_page(page);
memcpy(page_address(page) + offset, buf, cpylen);
set_page_dirty(page);
unlock_page(page);
}
page_cache_release(page);
if (retlen)
*retlen += cpylen;
buf += cpylen;
offset = 0;
index++;
}
return 0;
}
static int block2mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf)
{
struct block2mtd_dev *dev = mtd->priv;
int err;
if (!len)
return 0;
if (to >= mtd->size)
return -ENOSPC;
if (to + len > mtd->size)
len = mtd->size - to;
mutex_lock(&dev->write_mutex);
err = _block2mtd_write(dev, buf, to, len, retlen);
mutex_unlock(&dev->write_mutex);
if (err > 0)
err = 0;
return err;
}
/* sync the device - wait until the write queue is empty */
static void block2mtd_sync(struct mtd_info *mtd)
{
struct block2mtd_dev *dev = mtd->priv;
sync_blockdev(dev->blkdev);
return;
}
static void block2mtd_free_device(struct block2mtd_dev *dev)
{
if (!dev)
return;
kfree(dev->mtd.name);
if (dev->blkdev) {
invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
0, -1);
close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
}
kfree(dev);
}
/* FIXME: ensure that mtd->size % erase_size == 0 */
static struct block2mtd_dev *add_device(char *devname, int erase_size)
{
struct block_device *bdev;
struct block2mtd_dev *dev;
char *name;
if (!devname)
return NULL;
dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
if (!dev)
return NULL;
/* Get a handle on the device */
bdev = open_bdev_exclusive(devname, FMODE_READ|FMODE_WRITE, NULL);
#ifndef MODULE
if (IS_ERR(bdev)) {
/* We might not have rootfs mounted at this point. Try
to resolve the device name by other means. */
dev_t devt = name_to_dev_t(devname);
if (devt) {
bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
}
}
#endif
if (IS_ERR(bdev)) {
ERROR("error: cannot open device %s", devname);
goto devinit_err;
}
dev->blkdev = bdev;
if (MAJOR(bdev->bd_dev) == MTD_BLOCK_MAJOR) {
ERROR("attempting to use an MTD device as a block device");
goto devinit_err;
}
mutex_init(&dev->write_mutex);
/* Setup the MTD structure */
/* make the name contain the block device in */
name = kmalloc(sizeof("block2mtd: ") + strlen(devname) + 1,
GFP_KERNEL);
if (!name)
goto devinit_err;
sprintf(name, "block2mtd: %s", devname);
dev->mtd.name = name;
dev->mtd.size = dev->blkdev->bd_inode->i_size & PAGE_MASK;
dev->mtd.erasesize = erase_size;
dev->mtd.writesize = 1;
dev->mtd.type = MTD_RAM;
dev->mtd.flags = MTD_CAP_RAM;
dev->mtd.erase = block2mtd_erase;
dev->mtd.write = block2mtd_write;
dev->mtd.writev = default_mtd_writev;
dev->mtd.sync = block2mtd_sync;
dev->mtd.read = block2mtd_read;
dev->mtd.priv = dev;
dev->mtd.owner = THIS_MODULE;
if (add_mtd_device(&dev->mtd)) {
/* Device didnt get added, so free the entry */
goto devinit_err;
}
list_add(&dev->list, &blkmtd_device_list);
INFO("mtd%d: [%s] erase_size = %dKiB [%d]", dev->mtd.index,
dev->mtd.name + strlen("block2mtd: "),
dev->mtd.erasesize >> 10, dev->mtd.erasesize);
return dev;
devinit_err:
block2mtd_free_device(dev);
return NULL;
}
/* This function works similar to reguler strtoul. In addition, it
* allows some suffixes for a more human-readable number format:
* ki, Ki, kiB, KiB - multiply result with 1024
* Mi, MiB - multiply result with 1024^2
* Gi, GiB - multiply result with 1024^3
*/
static int ustrtoul(const char *cp, char **endp, unsigned int base)
{
unsigned long result = simple_strtoul(cp, endp, base);
switch (**endp) {
case 'G' :
result *= 1024;
case 'M':
result *= 1024;
case 'K':
case 'k':
result *= 1024;
/* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */
if ((*endp)[1] == 'i') {
if ((*endp)[2] == 'B')
(*endp) += 3;
else
(*endp) += 2;
}
}
return result;
}
static int parse_num(size_t *num, const char *token)
{
char *endp;
size_t n;
n = (size_t) ustrtoul(token, &endp, 0);
if (*endp)
return -EINVAL;
*num = n;
return 0;
}
static inline void kill_final_newline(char *str)
{
char *newline = strrchr(str, '\n');
if (newline && !newline[1])
*newline = 0;
}
#define parse_err(fmt, args...) do { \
ERROR(fmt, ## args); \
return 0; \
} while (0)
#ifndef MODULE
static int block2mtd_init_called = 0;
static char block2mtd_paramline[80 + 12]; /* 80 for device, 12 for erase size */
#endif
static int block2mtd_setup2(const char *val)
{
char buf[80 + 12]; /* 80 for device, 12 for erase size */
char *str = buf;
char *token[2];
char *name;
size_t erase_size = PAGE_SIZE;
int i, ret;
if (strnlen(val, sizeof(buf)) >= sizeof(buf))
parse_err("parameter too long");
strcpy(str, val);
kill_final_newline(str);
for (i = 0; i < 2; i++)
token[i] = strsep(&str, ",");
if (str)
parse_err("too many arguments");
if (!token[0])
parse_err("no argument");
name = token[0];
if (strlen(name) + 1 > 80)
parse_err("device name too long");
if (token[1]) {
ret = parse_num(&erase_size, token[1]);
if (ret) {
parse_err("illegal erase size");
}
}
add_device(name, erase_size);
return 0;
}
static int block2mtd_setup(const char *val, struct kernel_param *kp)
{
#ifdef MODULE
return block2mtd_setup2(val);
#else
/* If more parameters are later passed in via
/sys/module/block2mtd/parameters/block2mtd
and block2mtd_init() has already been called,
we can parse the argument now. */
if (block2mtd_init_called)
return block2mtd_setup2(val);
/* During early boot stage, we only save the parameters
here. We must parse them later: if the param passed
from kernel boot command line, block2mtd_setup() is
called so early that it is not possible to resolve
the device (even kmalloc() fails). Deter that work to
block2mtd_setup2(). */
strlcpy(block2mtd_paramline, val, sizeof(block2mtd_paramline));
return 0;
#endif
}
module_param_call(block2mtd, block2mtd_setup, NULL, NULL, 0200);
MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,<erasesize>]\"");
static int __init block2mtd_init(void)
{
int ret = 0;
#ifndef MODULE
if (strlen(block2mtd_paramline))
ret = block2mtd_setup2(block2mtd_paramline);
block2mtd_init_called = 1;
#endif
return ret;
}
static void __devexit block2mtd_exit(void)
{
struct list_head *pos, *next;
/* Remove the MTD devices */
list_for_each_safe(pos, next, &blkmtd_device_list) {
struct block2mtd_dev *dev = list_entry(pos, typeof(*dev), list);
block2mtd_sync(&dev->mtd);
del_mtd_device(&dev->mtd);
INFO("mtd%d: [%s] removed", dev->mtd.index,
dev->mtd.name + strlen("block2mtd: "));
list_del(&dev->list);
block2mtd_free_device(dev);
}
}
module_init(block2mtd_init);
module_exit(block2mtd_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Joern Engel <joern@lazybastard.org>");
MODULE_DESCRIPTION("Emulate an MTD using a block device");