/*
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/*
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* linux/fs/ufs/ufs_symlink.c
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* linux/fs/ufs/ufs_symlink.c
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*
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*
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* Copyright (C) 1996
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* Copyright (C) 1996
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* Adrian Rodriguez (adrian@franklins-tower.rutgers.edu)
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* Adrian Rodriguez (adrian@franklins-tower.rutgers.edu)
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* Laboratory for Computer Science Research Computing Facility
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* Laboratory for Computer Science Research Computing Facility
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* Rutgers, The State University of New Jersey
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* Rutgers, The State University of New Jersey
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*
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*
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* $Id: ufs_symlink.c,v 1.1.1.1 2001-09-10 07:44:40 simons Exp $
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* $Id: ufs_symlink.c,v 1.1.1.1 2001-09-10 07:44:40 simons Exp $
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*
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*
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*/
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*/
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#include <linux/fs.h>
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#include <linux/fs.h>
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#include <linux/sched.h>
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#include <linux/sched.h>
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#include <asm/segment.h>
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#include <asm/segment.h>
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extern int ufs_bmap (struct inode *, int);
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extern int ufs_bmap (struct inode *, int);
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static int
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static int
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ufs_readlink(struct inode * inode, char * buffer, int buflen)
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ufs_readlink(struct inode * inode, char * buffer, int buflen)
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{
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{
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unsigned long int block;
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unsigned long int block;
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struct buffer_head * bh = NULL;
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struct buffer_head * bh = NULL;
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char * link;
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char * link;
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int i;
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int i;
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char c;
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char c;
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if (inode->i_sb->u.ufs_sb.s_flags & (UFS_DEBUG|UFS_DEBUG_LINKS)) {
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if (inode->i_sb->u.ufs_sb.s_flags & (UFS_DEBUG|UFS_DEBUG_LINKS)) {
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printk("ufs_readlink: called on ino %lu dev %u/%u\n",
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printk("ufs_readlink: called on ino %lu dev %u/%u\n",
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inode->i_ino, MAJOR(inode->i_dev), MINOR(inode->i_dev));
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inode->i_ino, MAJOR(inode->i_dev), MINOR(inode->i_dev));
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}
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}
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if (!S_ISLNK(inode->i_mode)) {
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if (!S_ISLNK(inode->i_mode)) {
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iput (inode);
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iput (inode);
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return -EINVAL;
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return -EINVAL;
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}
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}
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if (buflen > inode->i_sb->s_blocksize - 1)
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if (buflen > inode->i_sb->s_blocksize - 1)
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buflen = inode->i_sb->s_blocksize - 1;
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buflen = inode->i_sb->s_blocksize - 1;
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if (inode->i_blocks) {
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if (inode->i_blocks) {
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/* XXX - error checking */
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/* XXX - error checking */
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block = ufs_bmap(inode, 0);
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block = ufs_bmap(inode, 0);
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if (inode->i_sb->u.ufs_sb.s_flags &(UFS_DEBUG|UFS_DEBUG_LINKS)) {
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if (inode->i_sb->u.ufs_sb.s_flags &(UFS_DEBUG|UFS_DEBUG_LINKS)) {
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printk("ufs_readlink: bmap got %lu for ino %lu\n",
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printk("ufs_readlink: bmap got %lu for ino %lu\n",
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block, inode->i_ino);
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block, inode->i_ino);
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}
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}
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bh = bread(inode->i_dev, block, BLOCK_SIZE);
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bh = bread(inode->i_dev, block, BLOCK_SIZE);
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if (!bh) {
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if (!bh) {
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iput (inode);
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iput (inode);
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printk("ufs_readlink: can't read block 0 for ino %lu on dev %u/%u\n",
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printk("ufs_readlink: can't read block 0 for ino %lu on dev %u/%u\n",
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inode->i_ino, MAJOR(inode->i_dev),
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inode->i_ino, MAJOR(inode->i_dev),
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MINOR(inode->i_dev));
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MINOR(inode->i_dev));
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return 0;
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return 0;
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}
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}
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link = bh->b_data;
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link = bh->b_data;
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}
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}
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else {
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else {
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link = (char *)&(inode->u.ufs_i.ui_db[0]);
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link = (char *)&(inode->u.ufs_i.ui_db[0]);
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}
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}
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i = 0;
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i = 0;
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while (i < buflen && (c = link[i])) {
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while (i < buflen && (c = link[i])) {
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i++;
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i++;
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put_user (c, buffer++);
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put_user (c, buffer++);
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}
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}
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iput (inode);
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iput (inode);
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if (bh)
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if (bh)
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brelse (bh);
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brelse (bh);
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return i;
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return i;
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}
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}
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/*
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/*
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* XXX - blatantly stolen from ext2fs
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* XXX - blatantly stolen from ext2fs
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*/
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*/
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static int
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static int
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ufs_follow_link(struct inode * dir, struct inode * inode,
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ufs_follow_link(struct inode * dir, struct inode * inode,
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int flag, int mode, struct inode ** res_inode)
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int flag, int mode, struct inode ** res_inode)
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{
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{
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unsigned long int block;
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unsigned long int block;
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int error;
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int error;
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struct buffer_head * bh;
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struct buffer_head * bh;
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char * link;
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char * link;
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bh = NULL;
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bh = NULL;
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if (inode->i_sb->u.ufs_sb.s_flags & (UFS_DEBUG|UFS_DEBUG_LINKS)) {
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if (inode->i_sb->u.ufs_sb.s_flags & (UFS_DEBUG|UFS_DEBUG_LINKS)) {
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printk("ufs_follow_link: called on ino %lu dev %u/%u\n",
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printk("ufs_follow_link: called on ino %lu dev %u/%u\n",
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dir->i_ino, MAJOR(dir->i_dev), MINOR(dir->i_dev));
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dir->i_ino, MAJOR(dir->i_dev), MINOR(dir->i_dev));
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}
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}
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*res_inode = NULL;
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*res_inode = NULL;
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if (!dir) {
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if (!dir) {
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dir = current->fs->root;
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dir = current->fs->root;
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dir->i_count++;
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dir->i_count++;
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}
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}
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if (!inode) {
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if (!inode) {
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iput (dir);
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iput (dir);
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return -ENOENT;
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return -ENOENT;
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}
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}
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if (!S_ISLNK(inode->i_mode)) {
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if (!S_ISLNK(inode->i_mode)) {
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iput (dir);
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iput (dir);
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*res_inode = inode;
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*res_inode = inode;
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return 0;
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return 0;
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}
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}
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if (current->link_count > 5) {
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if (current->link_count > 5) {
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iput (dir);
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iput (dir);
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iput (inode);
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iput (inode);
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return -ELOOP;
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return -ELOOP;
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}
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}
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if (inode->i_blocks) {
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if (inode->i_blocks) {
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/* read the link from disk */
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/* read the link from disk */
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/* XXX - error checking */
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/* XXX - error checking */
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block = ufs_bmap(inode, 0);
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block = ufs_bmap(inode, 0);
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bh = bread(inode->i_dev, block, BLOCK_SIZE);
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bh = bread(inode->i_dev, block, BLOCK_SIZE);
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if (bh == NULL) {
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if (bh == NULL) {
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printk("ufs_follow_link: can't read block 0 for ino %lu on dev %u/%u\n",
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printk("ufs_follow_link: can't read block 0 for ino %lu on dev %u/%u\n",
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inode->i_ino, MAJOR(inode->i_dev),
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inode->i_ino, MAJOR(inode->i_dev),
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MINOR(inode->i_dev));
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MINOR(inode->i_dev));
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iput(dir);
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iput(dir);
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iput(inode);
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iput(inode);
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return(-EIO);
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return(-EIO);
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}
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}
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link = bh->b_data;
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link = bh->b_data;
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} else {
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} else {
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/* fast symlink */
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/* fast symlink */
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link = (char *)&(inode->u.ufs_i.ui_db[0]);
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link = (char *)&(inode->u.ufs_i.ui_db[0]);
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}
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}
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current->link_count++;
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current->link_count++;
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error = open_namei (link, flag, mode, res_inode, dir);
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error = open_namei (link, flag, mode, res_inode, dir);
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current->link_count--;
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current->link_count--;
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iput (inode);
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iput (inode);
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if (bh) {
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if (bh) {
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brelse (bh);
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brelse (bh);
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}
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}
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return(error);
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return(error);
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}
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}
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static struct file_operations ufs_symlink_operations = {
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static struct file_operations ufs_symlink_operations = {
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NULL, /* lseek */
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NULL, /* lseek */
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NULL, /* read */
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NULL, /* read */
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NULL, /* write */
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NULL, /* write */
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NULL, /* readdir */
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NULL, /* readdir */
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NULL, /* select */
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NULL, /* select */
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NULL, /* ioctl */
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NULL, /* ioctl */
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NULL, /* mmap */
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NULL, /* mmap */
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NULL, /* open */
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NULL, /* open */
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NULL, /* release */
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NULL, /* release */
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NULL, /* fsync */ /* XXX - is this ok? */
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NULL, /* fsync */ /* XXX - is this ok? */
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NULL, /* fasync */
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NULL, /* fasync */
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NULL, /* check_media_change */
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NULL, /* check_media_change */
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NULL, /* revalidate */
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NULL, /* revalidate */
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};
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};
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struct inode_operations ufs_symlink_inode_operations = {
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struct inode_operations ufs_symlink_inode_operations = {
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&ufs_symlink_operations, /* default directory file operations */
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&ufs_symlink_operations, /* default directory file operations */
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NULL, /* create */
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NULL, /* create */
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NULL, /* lookup */
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NULL, /* lookup */
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NULL, /* link */
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NULL, /* link */
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NULL, /* unlink */
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NULL, /* unlink */
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NULL, /* symlink */
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NULL, /* symlink */
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NULL, /* mkdir */
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NULL, /* mkdir */
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NULL, /* rmdir */
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NULL, /* rmdir */
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NULL, /* mknod */
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NULL, /* mknod */
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NULL, /* rename */
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NULL, /* rename */
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&ufs_readlink, /* readlink */
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&ufs_readlink, /* readlink */
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&ufs_follow_link, /* follow_link */
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&ufs_follow_link, /* follow_link */
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NULL, /* readpage */
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NULL, /* readpage */
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NULL, /* writepage */
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NULL, /* writepage */
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NULL, /* bmap */
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NULL, /* bmap */
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NULL, /* truncate */
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NULL, /* truncate */
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NULL, /* permission */
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NULL, /* permission */
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NULL, /* smap */
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NULL, /* smap */
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};
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};
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/*
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/*
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* Local Variables: ***
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* Local Variables: ***
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* c-indent-level: 8 ***
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* c-indent-level: 8 ***
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* c-continued-statement-offset: 8 ***
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* c-continued-statement-offset: 8 ***
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* c-brace-offset: -8 ***
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* c-brace-offset: -8 ***
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* c-argdecl-indent: 0 ***
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* c-argdecl-indent: 0 ***
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* c-label-offset: -8 ***
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* c-label-offset: -8 ***
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* End: ***
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* End: ***
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*/
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*/
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