85 lines
1.8 KiB
C
85 lines
1.8 KiB
C
|
/*
|
||
|
|
* linux/fs/nfs/symlink.c
|
||
|
|
*
|
||
|
|
* Copyright (C) 1992 Rick Sladkey
|
||
|
|
*
|
||
|
|
* Optimization changes Copyright (C) 1994 Florian La Roche
|
||
|
|
*
|
||
|
|
* Jun 7 1999, cache symlink lookups in the page cache. -DaveM
|
||
|
|
*
|
||
|
|
* nfs symlink handling code
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/time.h>
|
||
|
|
#include <linux/errno.h>
|
||
|
|
#include <linux/sunrpc/clnt.h>
|
||
|
|
#include <linux/nfs.h>
|
||
|
|
#include <linux/nfs2.h>
|
||
|
|
#include <linux/nfs_fs.h>
|
||
|
|
#include <linux/pagemap.h>
|
||
|
|
#include <linux/stat.h>
|
||
|
|
#include <linux/mm.h>
|
||
|
|
#include <linux/string.h>
|
||
|
|
|
||
|
|
/* Symlink caching in the page cache is even more simplistic
|
||
|
|
* and straight-forward than readdir caching.
|
||
|
|
*/
|
||
|
|
|
||
|
|
static int nfs_symlink_filler(struct inode *inode, struct page *page)
|
||
|
|
{
|
||
|
|
int error;
|
||
|
|
|
||
|
|
error = NFS_PROTO(inode)->readlink(inode, page, 0, PAGE_SIZE);
|
||
|
|
if (error < 0)
|
||
|
|
goto error;
|
||
|
|
SetPageUptodate(page);
|
||
|
|
unlock_page(page);
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
error:
|
||
|
|
SetPageError(page);
|
||
|
|
unlock_page(page);
|
||
|
|
return -EIO;
|
||
|
|
}
|
||
|
|
|
||
|
|
static const char *nfs_get_link(struct dentry *dentry,
|
||
|
|
struct inode *inode,
|
||
|
|
struct delayed_call *done)
|
||
|
|
{
|
||
|
|
struct page *page;
|
||
|
|
void *err;
|
||
|
|
|
||
|
|
if (!dentry) {
|
||
|
|
err = ERR_PTR(nfs_revalidate_mapping_rcu(inode));
|
||
|
|
if (err)
|
||
|
|
return err;
|
||
|
|
page = find_get_page(inode->i_mapping, 0);
|
||
|
|
if (!page)
|
||
|
|
return ERR_PTR(-ECHILD);
|
||
|
|
if (!PageUptodate(page)) {
|
||
|
|
put_page(page);
|
||
|
|
return ERR_PTR(-ECHILD);
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping));
|
||
|
|
if (err)
|
||
|
|
return err;
|
||
|
|
page = read_cache_page(&inode->i_data, 0,
|
||
|
|
(filler_t *)nfs_symlink_filler, inode);
|
||
|
|
if (IS_ERR(page))
|
||
|
|
return ERR_CAST(page);
|
||
|
|
}
|
||
|
|
set_delayed_call(done, page_put_link, page);
|
||
|
|
return page_address(page);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* symlinks can't do much...
|
||
|
|
*/
|
||
|
|
const struct inode_operations nfs_symlink_inode_operations = {
|
||
|
|
.readlink = generic_readlink,
|
||
|
|
.get_link = nfs_get_link,
|
||
|
|
.getattr = nfs_getattr,
|
||
|
|
.setattr = nfs_setattr,
|
||
|
|
};
|