/*
- * $Id: block2mtd.c,v 1.30 2005/11/29 14:48:32 gleixner Exp $
- *
* block2mtd.c - create an mtd from a block device
*
* Copyright (C) 2001,2002 Simon Evans <spse@secret.org.uk>
- * Copyright (C) 2004-2006 Jรถrn Engel <joern@wh.fh-wedel.de>
+ * Copyright (C) 2004-2006 Joern Engel <joern@wh.fh-wedel.de>
*
* Licence: GPL
*/
-#include <linux/config.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
#include <linux/mtd/mtd.h>
#include <linux/buffer_head.h>
#include <linux/mutex.h>
-
-#define VERSION "$Revision: 1.30 $"
-
+#include <linux/mount.h>
#define ERROR(fmt, args...) printk(KERN_ERR "block2mtd: " fmt "\n" , ## args)
#define INFO(fmt, args...) printk(KERN_INFO "block2mtd: " fmt "\n" , ## args)
static LIST_HEAD(blkmtd_device_list);
-#define PAGE_READAHEAD 64
-static void cache_readahead(struct address_space *mapping, int index)
+static struct page *page_read(struct address_space *mapping, int index)
{
- filler_t *filler = (filler_t*)mapping->a_ops->readpage;
- int i, pagei;
- unsigned ret = 0;
- unsigned long end_index;
- struct page *page;
- LIST_HEAD(page_pool);
- struct inode *inode = mapping->host;
- loff_t isize = i_size_read(inode);
-
- if (!isize) {
- INFO("iSize=0 in cache_readahead\n");
- return;
- }
-
- end_index = ((isize - 1) >> PAGE_CACHE_SHIFT);
-
- read_lock_irq(&mapping->tree_lock);
- for (i = 0; i < PAGE_READAHEAD; i++) {
- pagei = index + i;
- if (pagei > end_index) {
- INFO("Overrun end of disk in cache readahead\n");
- break;
- }
- page = radix_tree_lookup(&mapping->page_tree, pagei);
- if (page && (!i))
- break;
- if (page)
- continue;
- read_unlock_irq(&mapping->tree_lock);
- page = page_cache_alloc_cold(mapping);
- read_lock_irq(&mapping->tree_lock);
- if (!page)
- break;
- page->index = pagei;
- list_add(&page->lru, &page_pool);
- ret++;
- }
- read_unlock_irq(&mapping->tree_lock);
- if (ret)
- read_cache_pages(mapping, &page_pool, filler, NULL);
+ return read_mapping_page(mapping, index, NULL);
}
-
-static struct page* page_readahead(struct address_space *mapping, int index)
-{
- filler_t *filler = (filler_t*)mapping->a_ops->readpage;
- cache_readahead(mapping, index);
- return read_cache_page(mapping, index, filler, NULL);
-}
-
-
/* erase a specified part of the device */
static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
{
u_long *max;
while (pages) {
- page = page_readahead(mapping, index);
+ page = page_read(mapping, index);
if (!page)
return -ENOMEM;
if (IS_ERR(page))
return PTR_ERR(page);
- max = (u_long*)page_address(page) + PAGE_SIZE;
- for (p=(u_long*)page_address(page); p<max; p++)
+ 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);
cpylen = len; // this page
len = len - cpylen;
- // Get page
- page = page_readahead(dev->blkdev->bd_inode->i_mapping, index);
+ page = page_read(dev->blkdev->bd_inode->i_mapping, index);
if (!page)
return -ENOMEM;
if (IS_ERR(page))
cpylen = len; // this page
len = len - cpylen;
- // Get page
- page = page_readahead(mapping, index);
+ page = page_read(mapping, index);
if (!page)
return -ENOMEM;
if (IS_ERR(page))
}
return 0;
}
+
+
static int block2mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf)
{
kfree(dev->mtd.name);
if (dev->blkdev) {
- invalidate_inode_pages(dev->blkdev->bd_inode->i_mapping);
- close_bdev_excl(dev->blkdev);
+ invalidate_mapping_pages(dev->blkdev->bd_inode->i_mapping,
+ 0, -1);
+ close_bdev_exclusive(dev->blkdev, FMODE_READ|FMODE_WRITE);
}
kfree(dev);
{
struct block_device *bdev;
struct block2mtd_dev *dev;
+ char *name;
if (!devname)
return NULL;
- dev = kmalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
+ dev = kzalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
if (!dev)
return NULL;
- memset(dev, 0, sizeof(*dev));
/* Get a handle on the device */
- bdev = open_bdev_excl(devname, O_RDWR, NULL);
+ 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;
/* Setup the MTD structure */
/* make the name contain the block device in */
- dev->mtd.name = kmalloc(sizeof("block2mtd: ") + strlen(devname),
+ name = kmalloc(sizeof("block2mtd: ") + strlen(devname) + 1,
GFP_KERNEL);
- if (!dev->mtd.name)
+ if (!name)
goto devinit_err;
- sprintf(dev->mtd.name, "block2mtd: %s", devname);
+ 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;
}
list_add(&dev->list, &blkmtd_device_list);
INFO("mtd%d: [%s] erase_size = %dKiB [%d]", dev->mtd.index,
- dev->mtd.name + strlen("blkmtd: "),
+ dev->mtd.name + strlen("block2mtd: "),
dev->mtd.erasesize >> 10, dev->mtd.erasesize);
return dev;
}
-static int parse_name(char **pname, const char *token, size_t limit)
-{
- size_t len;
- char *name;
-
- len = strlen(token) + 1;
- if (len > limit)
- return -ENOSPC;
-
- name = kmalloc(len, GFP_KERNEL);
- if (!name)
- return -ENOMEM;
-
- strcpy(name, token);
-
- *pname = name;
- return 0;
-}
-
-
static inline void kill_final_newline(char *str)
{
char *newline = strrchr(str, '\n');
}
-#define parse_err(fmt, args...) do { \
- ERROR("block2mtd: " fmt "\n", ## args); \
- return 0; \
+#define parse_err(fmt, args...) do { \
+ ERROR(fmt, ## args); \
+ return 0; \
} while (0)
-static int block2mtd_setup(const char *val, struct kernel_param *kp)
+#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 buf[80 + 12]; /* 80 for device, 12 for erase size */
char *str = buf;
char *token[2];
char *name;
if (!token[0])
parse_err("no argument");
- ret = parse_name(&name, token[0], 80);
- if (ret == -ENOMEM)
- parse_err("out of memory");
- if (ret == -ENOSPC)
- parse_err("name too long");
- if (ret)
- return 0;
+ 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) {
- kfree(name);
parse_err("illegal erase size");
}
}
}
+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)
{
- INFO("version " VERSION);
- return 0;
+ int ret = 0;
+
+#ifndef MODULE
+ if (strlen(block2mtd_paramline))
+ ret = block2mtd_setup2(block2mtd_paramline);
+ block2mtd_init_called = 1;
+#endif
+
+ return ret;
}
block2mtd_sync(&dev->mtd);
del_mtd_device(&dev->mtd);
INFO("mtd%d: [%s] removed", dev->mtd.index,
- dev->mtd.name + strlen("blkmtd: "));
+ dev->mtd.name + strlen("block2mtd: "));
list_del(&dev->list);
block2mtd_free_device(dev);
}
module_exit(block2mtd_exit);
MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Simon Evans <spse@secret.org.uk> and others");
+MODULE_AUTHOR("Joern Engel <joern@lazybastard.org>");
MODULE_DESCRIPTION("Emulate an MTD using a block device");
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff