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path: root/drivers/mtd/devices/block2mtd.c
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Diffstat (limited to 'drivers/mtd/devices/block2mtd.c')
-rw-r--r--drivers/mtd/devices/block2mtd.c339
1 files changed, 159 insertions, 180 deletions
diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
index 4a7a805e756..66f0405f7e5 100644
--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -1,14 +1,14 @@
/*
- * $Id: block2mtd.c,v 1.28 2005/03/19 22:40:44 gleixner Exp $
- *
* block2mtd.c - create an mtd from a block device
*
* Copyright (C) 2001,2002 Simon Evans <spse@secret.org.uk>
- * Copyright (C) 2004,2005 Jörn Engel <joern@wh.fh-wedel.de>
+ * Copyright (C) 2004-2006 Joern Engel <joern@wh.fh-wedel.de>
*
* Licence: GPL
*/
-#include <linux/config.h>
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/blkdev.h>
@@ -17,21 +17,17 @@
#include <linux/list.h>
#include <linux/init.h>
#include <linux/mtd/mtd.h>
-#include <linux/buffer_head.h>
-
-#define VERSION "$Revision: 1.28 $"
-
-
-#define ERROR(fmt, args...) printk(KERN_ERR "block2mtd: " fmt "\n" , ## args)
-#define INFO(fmt, args...) printk(KERN_INFO "block2mtd: " fmt "\n" , ## args)
-
+#include <linux/mutex.h>
+#include <linux/mount.h>
+#include <linux/slab.h>
+#include <linux/major.h>
/* Info for the block device */
struct block2mtd_dev {
struct list_head list;
struct block_device *blkdev;
struct mtd_info mtd;
- struct semaphore write_mutex;
+ struct mutex write_mutex;
};
@@ -39,60 +35,11 @@ struct block2mtd_dev {
static LIST_HEAD(blkmtd_device_list);
-#define PAGE_READAHEAD 64
-void cache_readahead(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);
-}
-
-
-static struct page* page_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;
- cache_readahead(mapping, index);
- return read_cache_page(mapping, index, filler, NULL);
+ 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)
{
@@ -104,19 +51,18 @@ static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
u_long *max;
while (pages) {
- page = page_readahead(mapping, index);
- if (!page)
- return -ENOMEM;
+ page = page_read(mapping, index);
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);
set_page_dirty(page);
unlock_page(page);
+ balance_dirty_pages_ratelimited(mapping);
break;
}
@@ -134,16 +80,15 @@ static int block2mtd_erase(struct mtd_info *mtd, struct erase_info *instr)
int err;
instr->state = MTD_ERASING;
- down(&dev->write_mutex);
+ mutex_lock(&dev->write_mutex);
err = _block2mtd_erase(dev, from, len);
- up(&dev->write_mutex);
+ mutex_unlock(&dev->write_mutex);
if (err) {
- ERROR("erase failed err = %d", err);
+ pr_err("erase failed err = %d\n", err);
instr->state = MTD_ERASE_FAILED;
} else
instr->state = MTD_ERASE_DONE;
- instr->state = MTD_ERASE_DONE;
mtd_erase_callback(instr);
return err;
}
@@ -158,14 +103,6 @@ static int block2mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
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
@@ -173,10 +110,7 @@ static int block2mtd_read(struct mtd_info *mtd, loff_t from, size_t len,
cpylen = len; // this page
len = len - cpylen;
- // Get page
- page = page_readahead(dev->blkdev->bd_inode->i_mapping, index);
- if (!page)
- return -ENOMEM;
+ page = page_read(dev->blkdev->bd_inode->i_mapping, index);
if (IS_ERR(page))
return PTR_ERR(page);
@@ -203,19 +137,14 @@ static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
int offset = to & ~PAGE_MASK; // page offset
int cpylen;
- if (retlen)
- *retlen = 0;
while (len) {
- if ((offset+len) > PAGE_SIZE)
+ if ((offset+len) > PAGE_SIZE)
cpylen = PAGE_SIZE - offset; // multiple pages
else
cpylen = len; // this page
len = len - cpylen;
- // Get page
- page = page_readahead(mapping, index);
- if (!page)
- return -ENOMEM;
+ page = page_read(mapping, index);
if (IS_ERR(page))
return PTR_ERR(page);
@@ -224,6 +153,7 @@ static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
memcpy(page_address(page) + offset, buf, cpylen);
set_page_dirty(page);
unlock_page(page);
+ balance_dirty_pages_ratelimited(mapping);
}
page_cache_release(page);
@@ -236,22 +166,17 @@ static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
}
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;
-
- down(&dev->write_mutex);
+ mutex_lock(&dev->write_mutex);
err = _block2mtd_write(dev, buf, to, len, retlen);
- up(&dev->write_mutex);
+ mutex_unlock(&dev->write_mutex);
if (err > 0)
err = 0;
return err;
@@ -275,81 +200,107 @@ static void block2mtd_free_device(struct block2mtd_dev *dev)
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);
+ blkdev_put(dev->blkdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
}
kfree(dev);
}
-/* FIXME: ensure that mtd->size % erase_size == 0 */
static struct block2mtd_dev *add_device(char *devname, int erase_size)
{
+ const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;
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 = blkdev_get_by_path(devname, mode, dev);
+#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 = blkdev_get_by_dev(devt, mode, dev);
+ }
+#endif
+
if (IS_ERR(bdev)) {
- ERROR("error: cannot open device %s", devname);
- goto devinit_err;
+ pr_err("error: cannot open device %s\n", devname);
+ goto err_free_block2mtd;
}
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;
+ pr_err("attempting to use an MTD device as a block device\n");
+ goto err_free_block2mtd;
+ }
+
+ if ((long)dev->blkdev->bd_inode->i_size % erase_size) {
+ pr_err("erasesize must be a divisor of device size\n");
+ goto err_free_block2mtd;
}
- init_MUTEX(&dev->write_mutex);
+ mutex_init(&dev->write_mutex);
/* Setup the MTD structure */
/* make the name contain the block device in */
- dev->mtd.name = kmalloc(sizeof("block2mtd: ") + strlen(devname),
- GFP_KERNEL);
- if (!dev->mtd.name)
- goto devinit_err;
+ name = kasprintf(GFP_KERNEL, "block2mtd: %s", devname);
+ if (!name)
+ goto err_destroy_mutex;
- sprintf(dev->mtd.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.writebufsize = PAGE_SIZE;
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.readv = default_mtd_readv;
+ dev->mtd._erase = block2mtd_erase;
+ dev->mtd._write = block2mtd_write;
+ 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;
+ if (mtd_device_register(&dev->mtd, NULL, 0)) {
+ /* Device didn't get added, so free the entry */
+ goto err_destroy_mutex;
}
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.erasesize >> 10, dev->mtd.erasesize);
+ pr_info("mtd%d: [%s] erase_size = %dKiB [%d]\n",
+ dev->mtd.index,
+ dev->mtd.name + strlen("block2mtd: "),
+ dev->mtd.erasesize >> 10, dev->mtd.erasesize);
return dev;
-devinit_err:
+err_destroy_mutex:
+ mutex_destroy(&dev->write_mutex);
+err_free_block2mtd:
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);
@@ -358,11 +309,16 @@ static int ustrtoul(const char *cp, char **endp, unsigned int base)
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')
- (*endp) += 2;
+ if ((*endp)[1] == 'i') {
+ if ((*endp)[2] == 'B')
+ (*endp) += 3;
+ else
+ (*endp) += 2;
+ }
}
return result;
}
@@ -382,26 +338,6 @@ static int parse_num(size_t *num, const char *token)
}
-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');
@@ -410,46 +346,53 @@ static inline void kill_final_newline(char *str)
}
-#define parse_err(fmt, args...) do { \
- ERROR("block2mtd: " fmt "\n", ## 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_setup(const char *val, struct kernel_param *kp)
+static int block2mtd_setup2(const char *val)
{
- char buf[80+12], *str=buf; /* 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;
size_t erase_size = PAGE_SIZE;
int i, ret;
- if (strnlen(val, sizeof(buf)) >= sizeof(buf))
- parse_err("parameter too long");
+ if (strnlen(val, sizeof(buf)) >= sizeof(buf)) {
+ pr_err("parameter too long\n");
+ return 0;
+ }
strcpy(str, val);
kill_final_newline(str);
- for (i=0; i<2; i++)
+ for (i = 0; i < 2; i++)
token[i] = strsep(&str, ",");
- if (str)
- parse_err("too many arguments");
+ if (str) {
+ pr_err("too many arguments\n");
+ return 0;
+ }
- if (!token[0])
- parse_err("no argument");
+ if (!token[0]) {
+ pr_err("no argument\n");
+ return 0;
+ }
- 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)
+ name = token[0];
+ if (strlen(name) + 1 > 80) {
+ pr_err("device name too long\n");
return 0;
+ }
if (token[1]) {
ret = parse_num(&erase_size, token[1]);
- if (ret)
- parse_err("illegal erase size");
+ if (ret) {
+ pr_err("illegal erase size\n");
+ return 0;
+ }
}
add_device(name, erase_size);
@@ -458,17 +401,51 @@ static int block2mtd_setup(const char *val, struct kernel_param *kp)
}
+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;
}
-static void __devexit block2mtd_exit(void)
+static void block2mtd_exit(void)
{
struct list_head *pos, *next;
@@ -476,9 +453,11 @@ static void __devexit block2mtd_exit(void)
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("blkmtd: "));
+ mtd_device_unregister(&dev->mtd);
+ mutex_destroy(&dev->write_mutex);
+ pr_info("mtd%d: [%s] removed\n",
+ dev->mtd.index,
+ dev->mtd.name + strlen("block2mtd: "));
list_del(&dev->list);
block2mtd_free_device(dev);
}
@@ -489,5 +468,5 @@ module_init(block2mtd_init);
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");
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-12-13 20:20:56 +0000