提交 93339070 编写于 作者: D David Woodhouse
......@@ -40,56 +40,9 @@ struct block2mtd_dev {
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);
}
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);
}
......@@ -105,14 +58,14 @@ 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);
......@@ -174,8 +127,7 @@ 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);
page = page_read(dev->blkdev->bd_inode->i_mapping, index);
if (!page)
return -ENOMEM;
if (IS_ERR(page))
......@@ -213,8 +165,7 @@ static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
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))
......@@ -308,9 +259,9 @@ static struct block2mtd_dev *add_device(char *devname, int erase_size)
/* We might not have rootfs mounted at this point. Try
to resolve the device name by other means. */
dev_t dev = name_to_dev_t(devname);
if (dev != 0) {
bdev = open_by_devnum(dev, FMODE_WRITE | FMODE_READ);
dev_t devt = name_to_dev_t(devname);
if (devt) {
bdev = open_by_devnum(devt, FMODE_WRITE | FMODE_READ);
}
}
#endif
......
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