[net-next-2.6.git] / fs / nfs / symlink.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>
#include <linux/namei.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 void *nfs_follow_link(struct dentry *dentry, struct nameidata *nd)
{
	struct inode *inode = dentry->d_inode;
	struct page *page;
	void *err;

	err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping));
	if (err)
		goto read_failed;
	page = read_cache_page(&inode->i_data, 0,
				(filler_t *)nfs_symlink_filler, inode);
	if (IS_ERR(page)) {
		err = page;
		goto read_failed;
	}
	nd_set_link(nd, kmap(page));
	return page;

read_failed:
	nd_set_link(nd, err);
	return NULL;
}

/*
 * symlinks can't do much...
 */
const struct inode_operations nfs_symlink_inode_operations = {
	.readlink	= generic_readlink,
	.follow_link	= nfs_follow_link,
	.put_link	= page_put_link,
	.getattr	= nfs_getattr,
	.setattr	= nfs_setattr,
};
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/nfs/symlink.c
	3	*
	4	* Copyright (C) 1992 Rick Sladkey
	5	*
	6	* Optimization changes Copyright (C) 1994 Florian La Roche
	7	*
	8	* Jun 7 1999, cache symlink lookups in the page cache. -DaveM
	9	*
	10	* nfs symlink handling code
	11	*/
	12
1da177e4 LT	13	#include <linux/time.h>
	14	#include <linux/errno.h>
	15	#include <linux/sunrpc/clnt.h>
	16	#include <linux/nfs.h>
	17	#include <linux/nfs2.h>
	18	#include <linux/nfs_fs.h>
	19	#include <linux/pagemap.h>
	20	#include <linux/stat.h>
	21	#include <linux/mm.h>
1da177e4	22	#include <linux/string.h>
1da177e4 LT	23	#include <linux/namei.h>
	24
	25	/* Symlink caching in the page cache is even more simplistic
	26	* and straight-forward than readdir caching.
1da177e4 LT	27	*/
1da177e4 LT	28
1da177e4 LT	29	static int nfs_symlink_filler(struct inode inode, struct page page)
1da177e4 LT	30	{
1da177e4 LT	31	int error;
1da177e4 LT	32
cc314eef	33	error = NFS_PROTO(inode)->readlink(inode, page, 0, PAGE_SIZE);
1da177e4 LT	34	if (error < 0)
	35	goto error;
	36	SetPageUptodate(page);
	37	unlock_page(page);
	38	return 0;
	39
	40	error:
	41	SetPageError(page);
	42	unlock_page(page);
	43	return -EIO;
	44	}
	45
cc314eef	46	static void nfs_follow_link(struct dentry dentry, struct nameidata *nd)
1da177e4 LT	47	{
	48	struct inode *inode = dentry->d_inode;
	49	struct page *page;
717d44e8 TM	50	void *err;
717d44e8 TM	51
1cda707d	52	err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping));
1da177e4 LT	53	if (err)
	54	goto read_failed;
	55	page = read_cache_page(&inode->i_data, 0,
	56	(filler_t *)nfs_symlink_filler, inode);
	57	if (IS_ERR(page)) {
	58	err = page;
	59	goto read_failed;
	60	}
cc314eef LT	61	nd_set_link(nd, kmap(page));
cc314eef LT	62	return page;
1da177e4	63
1da177e4 LT	64	read_failed:
1da177e4 LT	65	nd_set_link(nd, err);
cc314eef	66	return NULL;
1da177e4 LT	67	}
1da177e4 LT	68
1da177e4 LT	69	/*
	70	* symlinks can't do much...
	71	*/
92e1d5be	72	const struct inode_operations nfs_symlink_inode_operations = {
1da177e4 LT	73	.readlink = generic_readlink,
1da177e4 LT	74	.follow_link = nfs_follow_link,
9bf2aa12	75	.put_link = page_put_link,
1da177e4 LT	76	.getattr = nfs_getattr,
	77	.setattr = nfs_setattr,
	78	};