108 lines
2.2 KiB
C
108 lines
2.2 KiB
C
/*
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* linux/fs/nfs/symlink.c
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*
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* Copyright (C) 1992 Rick Sladkey
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*
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* nfs symlink handling code
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*/
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#include <asm/segment.h>
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#include <linux/sched.h>
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#include <linux/errno.h>
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#include <linux/nfs_fs.h>
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#include <linux/stat.h>
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#include <linux/mm.h>
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#include <linux/malloc.h>
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static int nfs_readlink(struct inode *, char *, int);
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static int nfs_follow_link(struct inode *, struct inode *, int, int,
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struct inode **);
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/*
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* symlinks can't do much...
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*/
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struct inode_operations nfs_symlink_inode_operations = {
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NULL, /* no file-operations */
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NULL, /* create */
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NULL, /* lookup */
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NULL, /* link */
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NULL, /* unlink */
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NULL, /* symlink */
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NULL, /* mkdir */
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NULL, /* rmdir */
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NULL, /* mknod */
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NULL, /* rename */
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nfs_readlink, /* readlink */
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nfs_follow_link, /* follow_link */
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NULL, /* bmap */
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NULL, /* truncate */
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NULL /* permission */
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};
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static int nfs_follow_link(struct inode *dir, struct inode *inode,
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int flag, int mode, struct inode **res_inode)
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{
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int error;
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char *res;
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*res_inode = NULL;
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if (!dir) {
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dir = current->root;
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dir->i_count++;
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}
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if (!inode) {
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iput(dir);
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return -ENOENT;
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}
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if (!S_ISLNK(inode->i_mode)) {
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iput(dir);
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*res_inode = inode;
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return 0;
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}
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if (current->link_count > 5) {
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iput(inode);
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iput(dir);
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return -ELOOP;
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}
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res = (char *) kmalloc(NFS_MAXPATHLEN + 1, GFP_KERNEL);
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error = nfs_proc_readlink(NFS_SERVER(inode), NFS_FH(inode), res);
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if (error) {
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iput(inode);
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iput(dir);
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kfree_s(res, NFS_MAXPATHLEN + 1);
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return error;
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}
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iput(inode);
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current->link_count++;
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error = open_namei(res, flag, mode, res_inode, dir);
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current->link_count--;
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kfree_s(res, NFS_MAXPATHLEN + 1);
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return error;
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}
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static int nfs_readlink(struct inode *inode, char *buffer, int buflen)
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{
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int i;
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char c;
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int error;
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char *res;
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if (!S_ISLNK(inode->i_mode)) {
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iput(inode);
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return -EINVAL;
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}
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if (buflen > NFS_MAXPATHLEN)
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buflen = NFS_MAXPATHLEN;
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res = (char *) kmalloc(buflen + 1, GFP_KERNEL);
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error = nfs_proc_readlink(NFS_SERVER(inode), NFS_FH(inode), res);
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iput(inode);
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if (error) {
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kfree_s(res, buflen + 1);
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return error;
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}
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for (i = 0; i < buflen && (c = res[i]); i++)
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put_fs_byte(c,buffer++);
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kfree_s(res, buflen + 1);
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return i;
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}
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