/*
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/*
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* linux/fs/ext2/symlink.c
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* linux/fs/ext2/symlink.c
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*
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*
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* Copyright (C) 1992, 1993, 1994, 1995
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* Copyright (C) 1992, 1993, 1994, 1995
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* Remy Card (card@masi.ibp.fr)
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* Remy Card (card@masi.ibp.fr)
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* Laboratoire MASI - Institut Blaise Pascal
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* Laboratoire MASI - Institut Blaise Pascal
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* Universite Pierre et Marie Curie (Paris VI)
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* Universite Pierre et Marie Curie (Paris VI)
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*
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*
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* from
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* from
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*
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*
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* linux/fs/minix/symlink.c
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* linux/fs/minix/symlink.c
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*
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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*
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* ext2 symlink handling code
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* ext2 symlink handling code
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*/
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*/
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#include <asm/segment.h>
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#include <asm/segment.h>
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#include <linux/errno.h>
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#include <linux/errno.h>
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#include <linux/fs.h>
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#include <linux/fs.h>
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#include <linux/ext2_fs.h>
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#include <linux/ext2_fs.h>
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#include <linux/sched.h>
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#include <linux/sched.h>
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#include <linux/stat.h>
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#include <linux/stat.h>
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static int ext2_readlink (struct inode *, char *, int);
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static int ext2_readlink (struct inode *, char *, int);
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static int ext2_follow_link (struct inode *, struct inode *, int, int,
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static int ext2_follow_link (struct inode *, struct inode *, int, int,
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struct inode **);
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struct inode **);
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/*
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/*
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* symlinks can't do much...
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* symlinks can't do much...
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*/
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*/
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struct inode_operations ext2_symlink_inode_operations = {
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struct inode_operations ext2_symlink_inode_operations = {
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NULL, /* no file-operations */
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NULL, /* no 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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ext2_readlink, /* readlink */
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ext2_readlink, /* readlink */
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ext2_follow_link, /* follow_link */
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ext2_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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static int ext2_follow_link(struct inode * dir, struct inode * inode,
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static int ext2_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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int error;
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int error;
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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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*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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if (!(bh = ext2_bread (inode, 0, 0, &error))) {
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if (!(bh = ext2_bread (inode, 0, 0, &error))) {
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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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link = (char *) inode->u.ext2_i.i_data;
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link = (char *) inode->u.ext2_i.i_data;
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UPDATE_ATIME(inode);
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UPDATE_ATIME(inode);
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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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return error;
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return error;
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}
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}
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static int ext2_readlink (struct inode * inode, char * buffer, int buflen)
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static int ext2_readlink (struct inode * inode, char * buffer, int buflen)
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{
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{
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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, err;
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int i, err;
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char c;
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char c;
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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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bh = ext2_bread (inode, 0, 0, &err);
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bh = ext2_bread (inode, 0, 0, &err);
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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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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.ext2_i.i_data;
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link = (char *) inode->u.ext2_i.i_data;
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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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UPDATE_ATIME(inode);
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UPDATE_ATIME(inode);
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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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