[linux-2.6-block.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>

/* 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_follow_link(struct dentry *dentry, void **cookie)
{
	struct inode *inode = d_inode(dentry);
	struct page *page;
	void *err;

	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);
	*cookie = page;
	return kmap(page);
}

/*
 * 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
	24	/* Symlink caching in the page cache is even more simplistic
	25	* and straight-forward than readdir caching.
1da177e4 LT	26	*/
1da177e4 LT	27
1da177e4 LT	28	static int nfs_symlink_filler(struct inode inode, struct page page)
1da177e4 LT	29	{
1da177e4 LT	30	int error;
1da177e4 LT	31
cc314eef	32	error = NFS_PROTO(inode)->readlink(inode, page, 0, PAGE_SIZE);
1da177e4 LT	33	if (error < 0)
	34	goto error;
	35	SetPageUptodate(page);
	36	unlock_page(page);
	37	return 0;
	38
	39	error:
	40	SetPageError(page);
	41	unlock_page(page);
	42	return -EIO;
	43	}
	44
6e77137b	45	static const char nfs_follow_link(struct dentry dentry, void **cookie)
1da177e4	46	{
2b0143b5	47	struct inode *inode = d_inode(dentry);
1da177e4	48	struct page *page;
717d44e8 TM	49	void *err;
717d44e8 TM	50
1cda707d	51	err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping));
1da177e4	52	if (err)
680baacb	53	return err;
1da177e4 LT	54	page = read_cache_page(&inode->i_data, 0,
1da177e4 LT	55	(filler_t *)nfs_symlink_filler, inode);
680baacb AV	56	if (IS_ERR(page))
	57	return ERR_CAST(page);
	58	*cookie = page;
	59	return kmap(page);
1da177e4 LT	60	}
1da177e4 LT	61
1da177e4 LT	62	/*
	63	* symlinks can't do much...
	64	*/
92e1d5be	65	const struct inode_operations nfs_symlink_inode_operations = {
1da177e4 LT	66	.readlink = generic_readlink,
1da177e4 LT	67	.follow_link = nfs_follow_link,
9bf2aa12	68	.put_link = page_put_link,
1da177e4 LT	69	.getattr = nfs_getattr,
	70	.setattr = nfs_setattr,
	71	};