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Commit e50cf501 authored by Jörn Engel's avatar Jörn Engel Committed by Linus Torvalds
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[PATCH] fixups for block2mtd 

Fixes to block2mtd.c - the previous driver was only compile-tested:
o Corrected copyright statements and some comments.
o Renamed blockmtd to block2mtd.
o Fixed the newline handling, it oopsed the kernel if no erase size
  was passed.
o Replaced some printk() by INFO().
o Tried (but failed) to replace the readahead code.
Signed-off-by: default avatarJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 7c503df2
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Showing with 57 additions and 66 deletions
drivers/mtd/devices/block2mtd.c
View file @ e50cf501
/* /*
* $Id: block2mtd.c,v 1.23 2005/01/05 17:05:46 dwmw2 Exp $ * $Id: block2mtd.c,v 1.23 2005/01/05 17:05:46 dwmw2 Exp $
* *
* blockmtd.c - use a block device as a fake MTD * block2mtd.c - create an mtd from a block device
* *
* Author: Simon Evans <spse@secret.org.uk> * Copyright (C) 2001,2002 Simon Evans <spse@secret.org.uk>
* * Copyright (C) 2004 Gareth Bult <Gareth@Encryptec.net>
* Copyright (C) 2001,2002 Simon Evans * Copyright (C) 2004,2005 Jrn Engel <joern@wh.fh-wedel.de>
* Copyright (C) 2004
* Copyright (C) 2004 Jörn Engel <joern@wh.fh-wedel.de>
* *
* Licence: GPL * Licence: GPL
*
* How it works:
* The driver uses raw/io to read/write the device and the page
* cache to cache access. Writes update the page cache with the
* new data and mark it dirty and add the page into a BIO which
* is then written out.
*
* It can be loaded Read-Only to prevent erases and writes to the
* medium.
*
*/ */
#include <linux/config.h> #include <linux/config.h>
#include <linux/module.h> #include <linux/module.h>
#include <linux/fs.h> #include <linux/fs.h>
...@@ -33,15 +20,15 @@ ...@@ -33,15 +20,15 @@
#include <linux/mtd/mtd.h> #include <linux/mtd/mtd.h>
#include <linux/buffer_head.h> #include <linux/buffer_head.h>
#define ERROR(fmt, args...) printk(KERN_ERR "blockmtd: " fmt "\n" , ## args) #define VERSION "$Revision: 1.23 $"
#define INFO(fmt, args...) printk(KERN_INFO "blockmtd: " fmt "\n" , ## args)
/* Default erase size in K, always make it a multiple of PAGE_SIZE */ #define ERROR(fmt, args...) printk(KERN_ERR "block2mtd: " fmt "\n" , ## args)
#define VERSION "$Revision: 1.23 $" #define INFO(fmt, args...) printk(KERN_INFO "block2mtd: " fmt "\n" , ## args)
/* Info for the block device */ /* Info for the block device */
struct blockmtd_dev { struct block2mtd_dev {
struct list_head list; struct list_head list;
struct block_device *blkdev; struct block_device *blkdev;
struct mtd_info mtd; struct mtd_info mtd;
...@@ -66,7 +53,7 @@ void cache_readahead(struct address_space *mapping, int index) ...@@ -66,7 +53,7 @@ void cache_readahead(struct address_space *mapping, int index)
loff_t isize = i_size_read(inode); loff_t isize = i_size_read(inode);
if (!isize) { if (!isize) {
printk(KERN_INFO "iSize=0 in cache_readahead\n"); INFO("iSize=0 in cache_readahead\n");
return; return;
} }
...@@ -76,7 +63,7 @@ void cache_readahead(struct address_space *mapping, int index) ...@@ -76,7 +63,7 @@ void cache_readahead(struct address_space *mapping, int index)
for (i = 0; i < PAGE_READAHEAD; i++) { for (i = 0; i < PAGE_READAHEAD; i++) {
pagei = index + i; pagei = index + i;
if (pagei > end_index) { if (pagei > end_index) {
printk(KERN_INFO "Overrun end of disk in cache readahead\n"); INFO("Overrun end of disk in cache readahead\n");
break; break;
} }
page = radix_tree_lookup(&mapping->page_tree, pagei); page = radix_tree_lookup(&mapping->page_tree, pagei);
...@@ -102,13 +89,14 @@ void cache_readahead(struct address_space *mapping, int index) ...@@ -102,13 +89,14 @@ void cache_readahead(struct address_space *mapping, int index)
static struct page* page_readahead(struct address_space *mapping, int index) static struct page* page_readahead(struct address_space *mapping, int index)
{ {
filler_t *filler = (filler_t*)mapping->a_ops->readpage; filler_t *filler = (filler_t*)mapping->a_ops->readpage;
//do_page_cache_readahead(mapping, index, XXX, 64);
cache_readahead(mapping, index); cache_readahead(mapping, index);
return read_cache_page(mapping, index, filler, NULL); return read_cache_page(mapping, index, filler, NULL);
} }
/* erase a specified part of the device */ /* erase a specified part of the device */
static int _blockmtd_erase(struct blockmtd_dev *dev, loff_t to, size_t len) 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 address_space *mapping = dev->blkdev->bd_inode->i_mapping;
struct page *page; struct page *page;
...@@ -140,16 +128,16 @@ static int _blockmtd_erase(struct blockmtd_dev *dev, loff_t to, size_t len) ...@@ -140,16 +128,16 @@ static int _blockmtd_erase(struct blockmtd_dev *dev, loff_t to, size_t len)
} }
return 0; return 0;
} }
static int blockmtd_erase(struct mtd_info *mtd, struct erase_info *instr) static int block2mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
{ {
struct blockmtd_dev *dev = mtd->priv; struct block2mtd_dev *dev = mtd->priv;
size_t from = instr->addr; size_t from = instr->addr;
size_t len = instr->len; size_t len = instr->len;
int err; int err;
instr->state = MTD_ERASING; instr->state = MTD_ERASING;
down(&dev->write_mutex); down(&dev->write_mutex);
err = _blockmtd_erase(dev, from, len); err = _block2mtd_erase(dev, from, len);
up(&dev->write_mutex); up(&dev->write_mutex);
if (err) { if (err) {
ERROR("erase failed err = %d", err); ERROR("erase failed err = %d", err);
...@@ -163,10 +151,10 @@ static int blockmtd_erase(struct mtd_info *mtd, struct erase_info *instr) ...@@ -163,10 +151,10 @@ static int blockmtd_erase(struct mtd_info *mtd, struct erase_info *instr)
} }
static int blockmtd_read(struct mtd_info *mtd, loff_t from, size_t len, static int block2mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf) size_t *retlen, u_char *buf)
{ {
struct blockmtd_dev *dev = mtd->priv; struct block2mtd_dev *dev = mtd->priv;
struct page *page; struct page *page;
int index = from >> PAGE_SHIFT; int index = from >> PAGE_SHIFT;
int offset = from & (PAGE_SHIFT-1); int offset = from & (PAGE_SHIFT-1);
...@@ -208,7 +196,7 @@ static int blockmtd_read(struct mtd_info *mtd, loff_t from, size_t len, ...@@ -208,7 +196,7 @@ static int blockmtd_read(struct mtd_info *mtd, loff_t from, size_t len,
/* write data to the underlying device */ /* write data to the underlying device */
static int _blockmtd_write(struct blockmtd_dev *dev, const u_char *buf, static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
loff_t to, size_t len, size_t *retlen) loff_t to, size_t len, size_t *retlen)
{ {
struct page *page; struct page *page;
...@@ -250,10 +238,10 @@ static int _blockmtd_write(struct blockmtd_dev *dev, const u_char *buf, ...@@ -250,10 +238,10 @@ static int _blockmtd_write(struct blockmtd_dev *dev, const u_char *buf,
} }
return 0; return 0;
} }
static int blockmtd_write(struct mtd_info *mtd, loff_t to, size_t len, static int block2mtd_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf) size_t *retlen, const u_char *buf)
{ {
struct blockmtd_dev *dev = mtd->priv; struct block2mtd_dev *dev = mtd->priv;
int err; int err;
if (!len) if (!len)
...@@ -264,7 +252,7 @@ static int blockmtd_write(struct mtd_info *mtd, loff_t to, size_t len, ...@@ -264,7 +252,7 @@ static int blockmtd_write(struct mtd_info *mtd, loff_t to, size_t len,
len = mtd->size - to; len = mtd->size - to;
down(&dev->write_mutex); down(&dev->write_mutex);
err = _blockmtd_write(dev, buf, to, len, retlen); err = _block2mtd_write(dev, buf, to, len, retlen);
up(&dev->write_mutex); up(&dev->write_mutex);
if (err > 0) if (err > 0)
err = 0; err = 0;
...@@ -273,15 +261,15 @@ static int blockmtd_write(struct mtd_info *mtd, loff_t to, size_t len, ...@@ -273,15 +261,15 @@ static int blockmtd_write(struct mtd_info *mtd, loff_t to, size_t len,
/* sync the device - wait until the write queue is empty */ /* sync the device - wait until the write queue is empty */
static void blockmtd_sync(struct mtd_info *mtd) static void block2mtd_sync(struct mtd_info *mtd)
{ {
struct blockmtd_dev *dev = mtd->priv; struct block2mtd_dev *dev = mtd->priv;
sync_blockdev(dev->blkdev); sync_blockdev(dev->blkdev);
return; return;
} }
static void blockmtd_free_device(struct blockmtd_dev *dev) static void block2mtd_free_device(struct block2mtd_dev *dev)
{ {
if (!dev) if (!dev)
return; return;
...@@ -298,15 +286,15 @@ static void blockmtd_free_device(struct blockmtd_dev *dev) ...@@ -298,15 +286,15 @@ static void blockmtd_free_device(struct blockmtd_dev *dev)
/* FIXME: ensure that mtd->size % erase_size == 0 */ /* FIXME: ensure that mtd->size % erase_size == 0 */
static struct blockmtd_dev *add_device(char *devname, int erase_size) static struct block2mtd_dev *add_device(char *devname, int erase_size)
{ {
struct block_device *bdev; struct block_device *bdev;
struct blockmtd_dev *dev; struct block2mtd_dev *dev;
if (!devname) if (!devname)
return NULL; return NULL;
dev = kmalloc(sizeof(struct blockmtd_dev), GFP_KERNEL); dev = kmalloc(sizeof(struct block2mtd_dev), GFP_KERNEL);
if (!dev) if (!dev)
return NULL; return NULL;
memset(dev, 0, sizeof(*dev)); memset(dev, 0, sizeof(*dev));
...@@ -328,22 +316,22 @@ static struct blockmtd_dev *add_device(char *devname, int erase_size) ...@@ -328,22 +316,22 @@ static struct blockmtd_dev *add_device(char *devname, int erase_size)
/* Setup the MTD structure */ /* Setup the MTD structure */
/* make the name contain the block device in */ /* make the name contain the block device in */
dev->mtd.name = kmalloc(sizeof("blockmtd: ") + strlen(devname), dev->mtd.name = kmalloc(sizeof("block2mtd: ") + strlen(devname),
GFP_KERNEL); GFP_KERNEL);
if (!dev->mtd.name) if (!dev->mtd.name)
goto devinit_err; goto devinit_err;
sprintf(dev->mtd.name, "blockmtd: %s", devname); sprintf(dev->mtd.name, "block2mtd: %s", devname);
dev->mtd.size = dev->blkdev->bd_inode->i_size & PAGE_MASK; dev->mtd.size = dev->blkdev->bd_inode->i_size & PAGE_MASK;
dev->mtd.erasesize = erase_size; dev->mtd.erasesize = erase_size;
dev->mtd.type = MTD_RAM; dev->mtd.type = MTD_RAM;
dev->mtd.flags = MTD_CAP_RAM; dev->mtd.flags = MTD_CAP_RAM;
dev->mtd.erase = blockmtd_erase; dev->mtd.erase = block2mtd_erase;
dev->mtd.write = blockmtd_write; dev->mtd.write = block2mtd_write;
dev->mtd.writev = default_mtd_writev; dev->mtd.writev = default_mtd_writev;
dev->mtd.sync = blockmtd_sync; dev->mtd.sync = block2mtd_sync;
dev->mtd.read = blockmtd_read; dev->mtd.read = block2mtd_read;
dev->mtd.readv = default_mtd_readv; dev->mtd.readv = default_mtd_readv;
dev->mtd.priv = dev; dev->mtd.priv = dev;
dev->mtd.owner = THIS_MODULE; dev->mtd.owner = THIS_MODULE;
...@@ -353,13 +341,13 @@ static struct blockmtd_dev *add_device(char *devname, int erase_size) ...@@ -353,13 +341,13 @@ static struct blockmtd_dev *add_device(char *devname, int erase_size)
goto devinit_err; goto devinit_err;
} }
list_add(&dev->list, &blkmtd_device_list); list_add(&dev->list, &blkmtd_device_list);
INFO("mtd%d: [%s] erase_size = %dKiB [%ld]", dev->mtd.index, INFO("mtd%d: [%s] erase_size = %dKiB [%d]", dev->mtd.index,
dev->mtd.name + strlen("blkmtd: "), dev->mtd.name + strlen("blkmtd: "),
dev->mtd.erasesize >> 10, PAGE_SIZE); dev->mtd.erasesize >> 10, dev->mtd.erasesize);
return dev; return dev;
devinit_err: devinit_err:
blockmtd_free_device(dev); block2mtd_free_device(dev);
return NULL; return NULL;
} }
...@@ -416,12 +404,20 @@ static int parse_name(char **pname, const char *token, size_t limit) ...@@ -416,12 +404,20 @@ static int parse_name(char **pname, const char *token, size_t limit)
} }
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 { \ #define parse_err(fmt, args...) do { \
ERROR("blockmtd: " fmt "\n", ## args); \ ERROR("block2mtd: " fmt "\n", ## args); \
return 0; \ return 0; \
} while (0) } while (0)
static int blockmtd_setup(const char *val, struct kernel_param *kp) static int block2mtd_setup(const char *val, struct kernel_param *kp)
{ {
char buf[80+12], *str=buf; /* 80 for device, 12 for erase size */ char buf[80+12], *str=buf; /* 80 for device, 12 for erase size */
char *token[2]; char *token[2];
...@@ -433,16 +429,11 @@ static int blockmtd_setup(const char *val, struct kernel_param *kp) ...@@ -433,16 +429,11 @@ static int blockmtd_setup(const char *val, struct kernel_param *kp)
parse_err("parameter too long"); parse_err("parameter too long");
strcpy(str, val); strcpy(str, val);
kill_final_newline(str);
for (i=0; i<2; i++) for (i=0; i<2; i++)
token[i] = strsep(&str, ","); token[i] = strsep(&str, ",");
{ /* people dislike typing "echo -n". and it's simple enough */
char *newline = strrchr(token[1], '\n');
if (newline && !newline[1])
*newline = 0;
}
if (str) if (str)
parse_err("too many arguments"); parse_err("too many arguments");
...@@ -469,35 +460,35 @@ static int blockmtd_setup(const char *val, struct kernel_param *kp) ...@@ -469,35 +460,35 @@ static int blockmtd_setup(const char *val, struct kernel_param *kp)
} }
module_param_call(blockmtd, blockmtd_setup, NULL, NULL, 0200); module_param_call(block2mtd, block2mtd_setup, NULL, NULL, 0200);
MODULE_PARM_DESC(blockmtd, "Device to use. \"blockmtd=<dev>[,<erasesize>]\""); MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,<erasesize>]\"");
static int __init blockmtd_init(void) static int __init block2mtd_init(void)
{ {
INFO("version " VERSION); INFO("version " VERSION);
return 0; return 0;
} }
static void __devexit blockmtd_exit(void) static void __devexit block2mtd_exit(void)
{ {
struct list_head *pos, *next; struct list_head *pos, *next;
/* Remove the MTD devices */ /* Remove the MTD devices */
list_for_each_safe(pos, next, &blkmtd_device_list) { list_for_each_safe(pos, next, &blkmtd_device_list) {
struct blockmtd_dev *dev = list_entry(pos, typeof(*dev), list); struct block2mtd_dev *dev = list_entry(pos, typeof(*dev), list);
blockmtd_sync(&dev->mtd); block2mtd_sync(&dev->mtd);
del_mtd_device(&dev->mtd); del_mtd_device(&dev->mtd);
INFO("mtd%d: [%s] removed", dev->mtd.index, INFO("mtd%d: [%s] removed", dev->mtd.index,
dev->mtd.name + strlen("blkmtd: ")); dev->mtd.name + strlen("blkmtd: "));
list_del(&dev->list); list_del(&dev->list);
blockmtd_free_device(dev); block2mtd_free_device(dev);
} }
} }
module_init(blockmtd_init); module_init(block2mtd_init);
module_exit(blockmtd_exit); module_exit(block2mtd_exit);
MODULE_LICENSE("GPL"); MODULE_LICENSE("GPL");
MODULE_AUTHOR("Simon Evans <spse@secret.org.uk> and others"); MODULE_AUTHOR("Simon Evans <spse@secret.org.uk> and others");
......
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