/* -*- mode: c; c-basic-offset: 8; -*- * vim: noexpandtab sw=8 ts=8 sts=0: * * linux/cluster/ssi/cfs/symlink.c * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE * or NON INFRINGEMENT. See the GNU General Public License for more * details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * * Questions/Comments/Bugfixes to ssic-linux-devel@lists.sourceforge.net * * Copyright (C) 1992 Rick Sladkey * * Optimization changes Copyright (C) 1994 Florian La Roche * * Jun 7 1999, cache symlink lookups in the page cache. -DaveM * * Portions Copyright (C) 2001 Compaq Computer Corporation * * ocfs2 symlink handling code. * * Copyright (C) 2004, 2005 Oracle. * */ #include <linux/fs.h> #include <linux/types.h> #include <linux/slab.h> #include <linux/pagemap.h> #include <linux/utsname.h> #define MLOG_MASK_PREFIX ML_NAMEI #include <cluster/masklog.h> #include "ocfs2.h" #include "alloc.h" #include "file.h" #include "inode.h" #include "journal.h" #include "symlink.h" #include "buffer_head_io.h" static char *ocfs2_page_getlink(struct dentry * dentry, struct page **ppage); static char *ocfs2_fast_symlink_getlink(struct inode *inode, struct buffer_head **bh); /* get the link contents into pagecache */ static char *ocfs2_page_getlink(struct dentry * dentry, struct page **ppage) { struct page * page; struct address_space *mapping = dentry->d_inode->i_mapping; page = read_mapping_page(mapping, 0, NULL); if (IS_ERR(page)) goto sync_fail; wait_on_page_locked(page); if (!PageUptodate(page)) goto async_fail; *ppage = page; return kmap(page); async_fail: page_cache_release(page); return ERR_PTR(-EIO); sync_fail: return (char*)page; } static char *ocfs2_fast_symlink_getlink(struct inode *inode, struct buffer_head **bh) { int status; char *link = NULL; struct ocfs2_dinode *fe; mlog_entry_void(); status = ocfs2_read_block(OCFS2_SB(inode->i_sb), OCFS2_I(inode)->ip_blkno, bh, OCFS2_BH_CACHED, inode); if (status < 0) { mlog_errno(status); link = ERR_PTR(status); goto bail; } fe = (struct ocfs2_dinode *) (*bh)->b_data; link = (char *) fe->id2.i_symlink; bail: mlog_exit(status); return link; } static int ocfs2_readlink(struct dentry *dentry, char __user *buffer, int buflen) { int ret; char *link; struct buffer_head *bh = NULL; struct inode *inode = dentry->d_inode; mlog_entry_void(); link = ocfs2_fast_symlink_getlink(inode, &bh); if (IS_ERR(link)) { ret = PTR_ERR(link); goto out; } /* * Without vfsmount we can't update atime now, * but we will update atime here ultimately. */ ret = vfs_readlink(dentry, buffer, buflen, link); brelse(bh); out: mlog_exit(ret); return ret; } static void *ocfs2_follow_link(struct dentry *dentry, struct nameidata *nd) { int status; char *link; struct inode *inode = dentry->d_inode; struct page *page = NULL; struct buffer_head *bh = NULL; if (ocfs2_inode_is_fast_symlink(inode)) link = ocfs2_fast_symlink_getlink(inode, &bh); else link = ocfs2_page_getlink(dentry, &page); if (IS_ERR(link)) { status = PTR_ERR(link); mlog_errno(status); goto bail; } status = vfs_follow_link(nd, link); bail: if (page) { kunmap(page); page_cache_release(page); } if (bh) brelse(bh); return ERR_PTR(status); } const struct inode_operations ocfs2_symlink_inode_operations = { .readlink = page_readlink, .follow_link = ocfs2_follow_link, .getattr = ocfs2_getattr, }; const struct inode_operations ocfs2_fast_symlink_inode_operations = { .readlink = ocfs2_readlink, .follow_link = ocfs2_follow_link, .getattr = ocfs2_getattr, };