[linux.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
 */

#define NFS_NEED_XDR_TYPES
#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/slab.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_nolock(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
	13	#define NFS_NEED_XDR_TYPES
	14	#include <linux/time.h>
	15	#include <linux/errno.h>
	16	#include <linux/sunrpc/clnt.h>
	17	#include <linux/nfs.h>
	18	#include <linux/nfs2.h>
	19	#include <linux/nfs_fs.h>
	20	#include <linux/pagemap.h>
	21	#include <linux/stat.h>
	22	#include <linux/mm.h>
	23	#include <linux/slab.h>
	24	#include <linux/string.h>
1da177e4 LT	25	#include <linux/namei.h>
	26
	27	/* Symlink caching in the page cache is even more simplistic
	28	* and straight-forward than readdir caching.
1da177e4 LT	29	*/
1da177e4 LT	30
1da177e4 LT	31	static int nfs_symlink_filler(struct inode inode, struct page page)
1da177e4 LT	32	{
1da177e4 LT	33	int error;
1da177e4 LT	34
cc314eef	35	error = NFS_PROTO(inode)->readlink(inode, page, 0, PAGE_SIZE);
1da177e4 LT	36	if (error < 0)
	37	goto error;
	38	SetPageUptodate(page);
	39	unlock_page(page);
	40	return 0;
	41
	42	error:
	43	SetPageError(page);
	44	unlock_page(page);
	45	return -EIO;
	46	}
	47
cc314eef	48	static void nfs_follow_link(struct dentry dentry, struct nameidata *nd)
1da177e4 LT	49	{
	50	struct inode *inode = dentry->d_inode;
	51	struct page *page;
717d44e8 TM	52	void *err;
	53
	54	err = ERR_PTR(nfs_revalidate_mapping_nolock(inode, inode->i_mapping));
1da177e4 LT	55	if (err)
	56	goto read_failed;
	57	page = read_cache_page(&inode->i_data, 0,
	58	(filler_t *)nfs_symlink_filler, inode);
	59	if (IS_ERR(page)) {
	60	err = page;
	61	goto read_failed;
	62	}
cc314eef LT	63	nd_set_link(nd, kmap(page));
cc314eef LT	64	return page;
1da177e4	65
1da177e4 LT	66	read_failed:
1da177e4 LT	67	nd_set_link(nd, err);
cc314eef	68	return NULL;
1da177e4 LT	69	}
1da177e4 LT	70
1da177e4 LT	71	/*
	72	* symlinks can't do much...
	73	*/
92e1d5be	74	const struct inode_operations nfs_symlink_inode_operations = {
1da177e4 LT	75	.readlink = generic_readlink,
1da177e4 LT	76	.follow_link = nfs_follow_link,
9bf2aa12	77	.put_link = page_put_link,
1da177e4 LT	78	.getattr = nfs_getattr,
	79	.setattr = nfs_setattr,
	80	};