patch-2.3.27 linux/fs/proc/link.c

• Lines: 206
• Date: Wed Dec 31 16:00:00 1969
• Orig file: v2.3.26/linux/fs/proc/link.c
• Orig date: Wed Jul 28 10:45:39 1999

diff -u --recursive --new-file v2.3.26/linux/fs/proc/link.c linux/fs/proc/link.c
@@ -1,205 +0,0 @@
-/*
- *  linux/fs/proc/link.c
- *
- *  Copyright (C) 1991, 1992  Linus Torvalds
- *
- *  /proc link-file handling code
- */
-
-#include <asm/uaccess.h>
-
-#include <linux/errno.h>
-#include <linux/sched.h>
-#include <linux/mm.h>
-#include <linux/fs.h>
-#include <linux/file.h>
-#include <linux/proc_fs.h>
-#include <linux/stat.h>
-
-static int proc_readlink(struct dentry *, char *, int);
-static struct dentry * proc_follow_link(struct dentry *, struct dentry *, unsigned int);
-
-/*
- * links can't do much...
- */
-static struct file_operations proc_fd_link_operations = {
-	NULL,			/* lseek - default */
-	NULL,			/* read - bad */
-	NULL,			/* write - bad */
-	NULL,			/* readdir - bad */
-	NULL,			/* poll - default */
-	NULL,			/* ioctl - default */
-	NULL,			/* mmap */
-	NULL,			/* very special open code */
-	NULL,			/* flush */
-	NULL,			/* no special release code */
-	NULL			/* can't fsync */
-};
-
-struct inode_operations proc_link_inode_operations = {
-	&proc_fd_link_operations,/* file-operations */
-	NULL,			/* create */
-	NULL,			/* lookup */
-	NULL,			/* link */
-	NULL,			/* unlink */
-	NULL,			/* symlink */
-	NULL,			/* mkdir */
-	NULL,			/* rmdir */
-	NULL,			/* mknod */
-	NULL,			/* rename */
-	proc_readlink,		/* readlink */
-	proc_follow_link,	/* follow_link */
-	NULL,			/* get_block */
-	NULL,			/* readpage */
-	NULL,			/* writepage */
-	NULL,			/* flushpage */
-	NULL,			/* truncate */
-	proc_permission,	/* permission */
-	NULL,			/* smap */
-	NULL			/* revalidate */
-};
-
-static struct dentry * proc_follow_link(struct dentry *dentry,
-					struct dentry *base,
-					unsigned int follow)
-{
-	struct inode *inode = dentry->d_inode;
-	struct task_struct *p;
-	struct dentry * result;
-	int ino, pid;
-	int error;
-
-	/* We don't need a base pointer in the /proc filesystem */
-	dput(base);
-
-	error = permission(inode, MAY_EXEC);
-	result = ERR_PTR(error);
-	if (error)
-		goto out;
-
-	ino = inode->i_ino;
-	pid = ino >> 16;
-	ino &= 0x0000ffff;
-
-	result = ERR_PTR(-ENOENT);
-
-	switch (ino) {
-		case PROC_PID_CWD:
-			read_lock(&tasklist_lock);
-			p = find_task_by_pid(pid);
-			if (p && p->fs && p->fs->pwd)
-				result = dget(p->fs->pwd);
-			read_unlock(&tasklist_lock);
-			break;
-
-		case PROC_PID_ROOT:
-			read_lock(&tasklist_lock);
-			p = find_task_by_pid(pid);
-			if (p && p->fs && p->fs->root)
-				result = dget(p->fs->root);
-			read_unlock(&tasklist_lock);
-			break;
-
-		case PROC_PID_EXE: {
-			struct mm_struct *mm = NULL;
-			struct vm_area_struct * vma;
-			read_lock(&tasklist_lock);
-			p = find_task_by_pid(pid);
-			if (p)
-				mm = p->mm;
-			if (mm)
-				atomic_inc(&mm->mm_users);
-			read_unlock(&tasklist_lock);
-			if (!mm)
-				break;
-			down(&mm->mmap_sem);
-			vma = mm->mmap;
-			while (vma) {
-				if ((vma->vm_flags & VM_EXECUTABLE) && 
-				    vma->vm_file) {
-					result = dget(vma->vm_file->f_dentry);
-					break;
-				}
-				vma = vma->vm_next;
-			}
-			up(&mm->mmap_sem);
-			mmput(mm);
-			break;
-		}
-		default:
-			if (ino & PROC_PID_FD_DIR) {
-				struct file * file;
-				struct files_struct *files = NULL;
-				read_lock(&tasklist_lock);
-				p = find_task_by_pid(pid);
-				if (p)
-					files = p->files;
-				read_unlock(&tasklist_lock);
-				if (!files)
-					break;
-				ino &= 0x7fff;
-				read_lock(&files->file_lock);
-				/* XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX */
-				if (ino < files->max_fds &&
-				    (file = files->fd[ino]) && file->f_dentry)
-					result = dget(file->f_dentry);
-				read_unlock(&p->files->file_lock);
-			}
-	}
-out:
-	return result;
-}
-
-/*
- * This pretty-prints the pathname of a dentry,
- * clarifying sockets etc.
- */
-static int do_proc_readlink(struct dentry *dentry, char * buffer, int buflen)
-{
-	struct inode * inode;
-	char * tmp = (char*)__get_free_page(GFP_KERNEL), *path, *pattern;
-	int len;
-
-	if(tmp==NULL)
-		return -ENOMEM;
-		
-	/* Check for special dentries.. */
-	pattern = NULL;
-	inode = dentry->d_inode;
-	if (inode && IS_ROOT(dentry)) {
-		if (S_ISSOCK(inode->i_mode))
-			pattern = "socket:[%lu]";
-		if (S_ISFIFO(inode->i_mode))
-			pattern = "pipe:[%lu]";
-	}
-	
-	if (pattern) {
-		len = sprintf(tmp, pattern, inode->i_ino);
-		path = tmp;
-	} else {
-		path = d_path(dentry, tmp, PAGE_SIZE);
-		len = tmp + PAGE_SIZE - 1 - path;
-	}
-
-	if (len < buflen)
-		buflen = len;
-	dput(dentry);
-	copy_to_user(buffer, path, buflen);
-	free_page((unsigned long)tmp);
-	return buflen;
-}
-
-static int proc_readlink(struct dentry * dentry, char * buffer, int buflen)
-{
-	int error;
-
-	dentry = proc_follow_link(dentry, NULL, 1);
-	error = PTR_ERR(dentry);
-	if (!IS_ERR(dentry)) {
-		error = -ENOENT;
-		if (dentry) {
-			error = do_proc_readlink(dentry, buffer, buflen);
-		}
-	}
-	return error;
-}