proc: remove docbook and example

Example is outdated, it still uses old ->read_proc interfaces and "fb"
example is plain racy.  There are better examples all over the tree.

Docbook itself says almost nothing about /proc and contain quite a number
of simply wrong facts, e.g.  device nodes support.  What it does is
describing at great length interface which are going to be removed.

There are Documentation/filesystems/seq_file.txt in exchange.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Erik Mouw <mouw@nl.linux.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/DocBook/Makefile

@@ -8,7 +8,7 @@
 
 DOCBOOKS := z8530book.xml mcabook.xml device-drivers.xml \
 	    kernel-hacking.xml kernel-locking.xml deviceiobook.xml \
-	    procfs-guide.xml writing_usb_driver.xml networking.xml \
+	    writing_usb_driver.xml networking.xml \
 	    kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \
 	    gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \
 	    genericirq.xml s390-drivers.xml uio-howto.xml scsi.xml \
@@ -65,7 +65,7 @@ KERNELDOC = $(srctree)/scripts/kernel-doc
 DOCPROC   = $(objtree)/scripts/basic/docproc
 
 XMLTOFLAGS = -m $(srctree)/Documentation/DocBook/stylesheet.xsl
-#XMLTOFLAGS += --skip-validation
+XMLTOFLAGS += --skip-validation
 
 ###
 # DOCPROC is used for two purposes:
@@ -101,17 +101,6 @@ endif
 # Changes in kernel-doc force a rebuild of all documentation
 $(BOOKS): $(KERNELDOC)
 
-###
-# procfs guide uses a .c file as example code.
-# This requires an explicit dependency
-C-procfs-example = procfs_example.xml
-C-procfs-example2 = $(addprefix $(obj)/,$(C-procfs-example))
-$(obj)/procfs-guide.xml: $(C-procfs-example2)
-
-# List of programs to build
-##oops, this is a kernel module::hostprogs-y := procfs_example
-obj-m += procfs_example.o
-
 # Tell kbuild to always build the programs
 always := $(hostprogs-y)
 
@@ -238,7 +227,7 @@ clean-files := $(DOCBOOKS) \
 	$(patsubst %.xml, %.pdf,  $(DOCBOOKS)) \
 	$(patsubst %.xml, %.html, $(DOCBOOKS)) \
 	$(patsubst %.xml, %.9,    $(DOCBOOKS)) \
-	$(C-procfs-example) $(index)
+	$(index)
 
 clean-dirs := $(patsubst %.xml,%,$(DOCBOOKS)) man
 

Documentation/DocBook/procfs_example.c

-/*
- * procfs_example.c: an example proc interface
- *
- * Copyright (C) 2001, Erik Mouw (mouw@nl.linux.org)
- *
- * This file accompanies the procfs-guide in the Linux kernel
- * source. Its main use is to demonstrate the concepts and
- * functions described in the guide.
- *
- * This software has been developed while working on the LART
- * computing board (http://www.lartmaker.nl), which was sponsored
- * by the Delt University of Technology projects Mobile Multi-media
- * Communications and Ubiquitous Communications.
- *
- * 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.  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., 59 Temple Place,
- * Suite 330, Boston, MA  02111-1307  USA
- *
- */
-
-#include <linux/module.h>
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/proc_fs.h>
-#include <linux/jiffies.h>
-#include <asm/uaccess.h>
-
-
-#define MODULE_VERS "1.0"
-#define MODULE_NAME "procfs_example"
-
-#define FOOBAR_LEN 8
-
-struct fb_data_t {
-	char name[FOOBAR_LEN + 1];
-	char value[FOOBAR_LEN + 1];
-};
-
-
-static struct proc_dir_entry *example_dir, *foo_file,
-	*bar_file, *jiffies_file, *symlink;
-
-
-struct fb_data_t foo_data, bar_data;
-
-
-static int proc_read_jiffies(char *page, char **start,
-			     off_t off, int count,
-			     int *eof, void *data)
-{
-	int len;
-
-	len = sprintf(page, "jiffies = %ld\n",
-                      jiffies);
-
-	return len;
-}
-
-
-static int proc_read_foobar(char *page, char **start,
-			    off_t off, int count, 
-			    int *eof, void *data)
-{
-	int len;
-	struct fb_data_t *fb_data = (struct fb_data_t *)data;
-
-	/* DON'T DO THAT - buffer overruns are bad */
-	len = sprintf(page, "%s = '%s'\n", 
-		      fb_data->name, fb_data->value);
-
-	return len;
-}
-
-
-static int proc_write_foobar(struct file *file,
-			     const char *buffer,
-			     unsigned long count, 
-			     void *data)
-{
-	int len;
-	struct fb_data_t *fb_data = (struct fb_data_t *)data;
-
-	if(count > FOOBAR_LEN)
-		len = FOOBAR_LEN;
-	else
-		len = count;
-
-	if(copy_from_user(fb_data->value, buffer, len))
-		return -EFAULT;
-
-	fb_data->value[len] = '\0';
-
-	return len;
-}
-
-
-static int __init init_procfs_example(void)
-{
-	int rv = 0;
-
-	/* create directory */
-	example_dir = proc_mkdir(MODULE_NAME, NULL);
-	if(example_dir == NULL) {
-		rv = -ENOMEM;
-		goto out;
-	}
-	/* create jiffies using convenience function */
-	jiffies_file = create_proc_read_entry("jiffies", 
-					      0444, example_dir, 
-					      proc_read_jiffies,
-					      NULL);
-	if(jiffies_file == NULL) {
-		rv  = -ENOMEM;
-		goto no_jiffies;
-	}
-
-	/* create foo and bar files using same callback
-	 * functions 
-	 */
-	foo_file = create_proc_entry("foo", 0644, example_dir);
-	if(foo_file == NULL) {
-		rv = -ENOMEM;
-		goto no_foo;
-	}
-
-	strcpy(foo_data.name, "foo");
-	strcpy(foo_data.value, "foo");
-	foo_file->data = &foo_data;
-	foo_file->read_proc = proc_read_foobar;
-	foo_file->write_proc = proc_write_foobar;
-		
-	bar_file = create_proc_entry("bar", 0644, example_dir);
-	if(bar_file == NULL) {
-		rv = -ENOMEM;
-		goto no_bar;
-	}
-
-	strcpy(bar_data.name, "bar");
-	strcpy(bar_data.value, "bar");
-	bar_file->data = &bar_data;
-	bar_file->read_proc = proc_read_foobar;
-	bar_file->write_proc = proc_write_foobar;
-		
-	/* create symlink */
-	symlink = proc_symlink("jiffies_too", example_dir, 
-			       "jiffies");
-	if(symlink == NULL) {
-		rv = -ENOMEM;
-		goto no_symlink;
-	}
-
-	/* everything OK */
-	printk(KERN_INFO "%s %s initialised\n",
-	       MODULE_NAME, MODULE_VERS);
-	return 0;
-
-no_symlink:
-	remove_proc_entry("bar", example_dir);
-no_bar:
-	remove_proc_entry("foo", example_dir);
-no_foo:
-	remove_proc_entry("jiffies", example_dir);
-no_jiffies:			      
-	remove_proc_entry(MODULE_NAME, NULL);
-out:
-	return rv;
-}
-
-
-static void __exit cleanup_procfs_example(void)
-{
-	remove_proc_entry("jiffies_too", example_dir);
-	remove_proc_entry("bar", example_dir);
-	remove_proc_entry("foo", example_dir);
-	remove_proc_entry("jiffies", example_dir);
-	remove_proc_entry(MODULE_NAME, NULL);
-
-	printk(KERN_INFO "%s %s removed\n",
-	       MODULE_NAME, MODULE_VERS);
-}
-
-
-module_init(init_procfs_example);
-module_exit(cleanup_procfs_example);
-
-MODULE_AUTHOR("Erik Mouw");
-MODULE_DESCRIPTION("procfs examples");
-MODULE_LICENSE("GPL");