mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-29 15:43:59 +08:00
21fc61c73c
kmap() in page_follow_link_light() needed to go - allowing to hold an arbitrary number of kmaps for long is a great way to deadlocking the system. new helper (inode_nohighmem(inode)) needs to be used for pagecache symlinks inodes; done for all in-tree cases. page_follow_link_light() instrumented to yell about anything missed. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
53 lines
1.1 KiB
C
53 lines
1.1 KiB
C
/*
|
|
* symlink.c
|
|
*
|
|
* Copyright (c) 1999 Al Smith
|
|
*
|
|
* Portions derived from work (c) 1995,1996 Christian Vogelgsang.
|
|
*/
|
|
|
|
#include <linux/string.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/buffer_head.h>
|
|
#include "efs.h"
|
|
|
|
static int efs_symlink_readpage(struct file *file, struct page *page)
|
|
{
|
|
char *link = page_address(page);
|
|
struct buffer_head * bh;
|
|
struct inode * inode = page->mapping->host;
|
|
efs_block_t size = inode->i_size;
|
|
int err;
|
|
|
|
err = -ENAMETOOLONG;
|
|
if (size > 2 * EFS_BLOCKSIZE)
|
|
goto fail;
|
|
|
|
/* read first 512 bytes of link target */
|
|
err = -EIO;
|
|
bh = sb_bread(inode->i_sb, efs_bmap(inode, 0));
|
|
if (!bh)
|
|
goto fail;
|
|
memcpy(link, bh->b_data, (size > EFS_BLOCKSIZE) ? EFS_BLOCKSIZE : size);
|
|
brelse(bh);
|
|
if (size > EFS_BLOCKSIZE) {
|
|
bh = sb_bread(inode->i_sb, efs_bmap(inode, 1));
|
|
if (!bh)
|
|
goto fail;
|
|
memcpy(link + EFS_BLOCKSIZE, bh->b_data, size - EFS_BLOCKSIZE);
|
|
brelse(bh);
|
|
}
|
|
link[size] = '\0';
|
|
SetPageUptodate(page);
|
|
unlock_page(page);
|
|
return 0;
|
|
fail:
|
|
SetPageError(page);
|
|
unlock_page(page);
|
|
return err;
|
|
}
|
|
|
|
const struct address_space_operations efs_symlink_aops = {
|
|
.readpage = efs_symlink_readpage
|
|
};
|