diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-16 10:06:39 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-12-16 10:06:39 -0800 |
commit | 9cfc86249f32d984339c6d1f8a1fd1326989b3b8 (patch) | |
tree | 56428d319483f54949de8d9d0a5b3f715287ed91 /Documentation/DocBook | |
parent | f42647acc4eab1befa9e290691ed7a40f9a7d3cc (diff) | |
parent | 243797f59b748f679ab88d456fcc4f92236d724b (diff) |
Merge branch 'akpm'
* akpm: (173 commits)
genalloc: use bitmap_find_next_zero_area
ia64: use bitmap_find_next_zero_area
sparc: use bitmap_find_next_zero_area
mlx4: use bitmap_find_next_zero_area
isp1362-hcd: use bitmap_find_next_zero_area
iommu-helper: use bitmap library
bitmap: introduce bitmap_set, bitmap_clear, bitmap_find_next_zero_area
qnx4: use hweight8
qnx4fs: remove remains of the (defunct) write support
resource: constify arg to resource_size() and resource_type()
gru: send cross partition interrupts using the gru
gru: function to generate chipset IPI values
gru: update driver version number
gru: improve GRU TLB dropin statistics
gru: fix GRU interrupt race at deallocate
gru: add hugepage support
gru: fix bug in allocation of kernel contexts
gru: update GRU structures to match latest hardware spec
gru: check for correct GRU chiplet assignment
gru: remove stray local_irq_enable
...
Diffstat (limited to 'Documentation/DocBook')
-rw-r--r-- | Documentation/DocBook/Makefile | 17 | ||||
-rw-r--r-- | Documentation/DocBook/procfs-guide.tmpl | 626 | ||||
-rw-r--r-- | Documentation/DocBook/procfs_example.c | 201 |
3 files changed, 3 insertions, 841 deletions
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile index ab8300f67182..ee34ceb9ad5f 100644 --- a/Documentation/DocBook/Makefile +++ b/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 diff --git a/Documentation/DocBook/procfs-guide.tmpl b/Documentation/DocBook/procfs-guide.tmpl deleted file mode 100644 index 9eba4b7af73d..000000000000 --- a/Documentation/DocBook/procfs-guide.tmpl +++ /dev/null @@ -1,626 +0,0 @@ -<?xml version="1.0" encoding="UTF-8"?> -<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" - "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" [ -<!ENTITY procfsexample SYSTEM "procfs_example.xml"> -]> - -<book id="LKProcfsGuide"> - <bookinfo> - <title>Linux Kernel Procfs Guide</title> - - <authorgroup> - <author> - <firstname>Erik</firstname> - <othername>(J.A.K.)</othername> - <surname>Mouw</surname> - <affiliation> - <address> - <email>mouw@nl.linux.org</email> - </address> - </affiliation> - </author> - <othercredit> - <contrib> - This software and documentation were written while working on the - LART computing board - (<ulink url="http://www.lartmaker.nl/">http://www.lartmaker.nl/</ulink>), - which was sponsored by the Delt University of Technology projects - Mobile Multi-media Communications and Ubiquitous Communications. - </contrib> - </othercredit> - </authorgroup> - - <revhistory> - <revision> - <revnumber>1.0</revnumber> - <date>May 30, 2001</date> - <revremark>Initial revision posted to linux-kernel</revremark> - </revision> - <revision> - <revnumber>1.1</revnumber> - <date>June 3, 2001</date> - <revremark>Revised after comments from linux-kernel</revremark> - </revision> - </revhistory> - - <copyright> - <year>2001</year> - <holder>Erik Mouw</holder> - </copyright> - - - <legalnotice> - <para> - This documentation 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. - </para> - - <para> - This documentation 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. - </para> - - <para> - 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 - </para> - - <para> - For more details see the file COPYING in the source - distribution of Linux. - </para> - </legalnotice> - </bookinfo> - - - - - <toc> - </toc> - - - - - <preface id="Preface"> - <title>Preface</title> - - <para> - This guide describes the use of the procfs file system from - within the Linux kernel. The idea to write this guide came up on - the #kernelnewbies IRC channel (see <ulink - url="http://www.kernelnewbies.org/">http://www.kernelnewbies.org/</ulink>), - when Jeff Garzik explained the use of procfs and forwarded me a - message Alexander Viro wrote to the linux-kernel mailing list. I - agreed to write it up nicely, so here it is. - </para> - - <para> - I'd like to thank Jeff Garzik - <email>jgarzik@pobox.com</email> and Alexander Viro - <email>viro@parcelfarce.linux.theplanet.co.uk</email> for their input, - Tim Waugh <email>twaugh@redhat.com</email> for his <ulink - url="http://people.redhat.com/twaugh/docbook/selfdocbook/">Selfdocbook</ulink>, - and Marc Joosen <email>marcj@historia.et.tudelft.nl</email> for - proofreading. - </para> - - <para> - Erik - </para> - </preface> - - - - - <chapter id="intro"> - <title>Introduction</title> - - <para> - The <filename class="directory">/proc</filename> file system - (procfs) is a special file system in the linux kernel. It's a - virtual file system: it is not associated with a block device - but exists only in memory. The files in the procfs are there to - allow userland programs access to certain information from the - kernel (like process information in <filename - class="directory">/proc/[0-9]+/</filename>), but also for debug - purposes (like <filename>/proc/ksyms</filename>). - </para> - - <para> - This guide describes the use of the procfs file system from - within the Linux kernel. It starts by introducing all relevant - functions to manage the files within the file system. After that - it shows how to communicate with userland, and some tips and - tricks will be pointed out. Finally a complete example will be - shown. - </para> - - <para> - Note that the files in <filename - class="directory">/proc/sys</filename> are sysctl files: they - don't belong to procfs and are governed by a completely - different API described in the Kernel API book. - </para> - </chapter> - - - - - <chapter id="managing"> - <title>Managing procfs entries</title> - - <para> - This chapter describes the functions that various kernel - components use to populate the procfs with files, symlinks, - device nodes, and directories. - </para> - - <para> - A minor note before we start: if you want to use any of the - procfs functions, be sure to include the correct header file! - This should be one of the first lines in your code: - </para> - - <programlisting> -#include <linux/proc_fs.h> - </programlisting> - - - - - <sect1 id="regularfile"> - <title>Creating a regular file</title> - - <funcsynopsis> - <funcprototype> - <funcdef>struct proc_dir_entry* <function>create_proc_entry</function></funcdef> - <paramdef>const char* <parameter>name</parameter></paramdef> - <paramdef>mode_t <parameter>mode</parameter></paramdef> - <paramdef>struct proc_dir_entry* <parameter>parent</parameter></paramdef> - </funcprototype> - </funcsynopsis> - - <para> - This function creates a regular file with the name - <parameter>name</parameter>, file mode - <parameter>mode</parameter> in the directory - <parameter>parent</parameter>. To create a file in the root of - the procfs, use <constant>NULL</constant> as - <parameter>parent</parameter> parameter. When successful, the - function will return a pointer to the freshly created - <structname>struct proc_dir_entry</structname>; otherwise it - will return <constant>NULL</constant>. <xref - linkend="userland"/> describes how to do something useful with - regular files. - </para> - - <para> - Note that it is specifically supported that you can pass a - path that spans multiple directories. For example - <function>create_proc_entry</function>(<parameter>"drivers/via0/info"</parameter>) - will create the <filename class="directory">via0</filename> - directory if necessary, with standard - <constant>0755</constant> permissions. - </para> - - <para> - If you only want to be able to read the file, the function - <function>create_proc_read_entry</function> described in <xref - linkend="convenience"/> may be used to create and initialise - the procfs entry in one single call. - </para> - </sect1> - - - - - <sect1 id="Creating_a_symlink"> - <title>Creating a symlink</title> - - <funcsynopsis> - <funcprototype> - <funcdef>struct proc_dir_entry* - <function>proc_symlink</function></funcdef> <paramdef>const - char* <parameter>name</parameter></paramdef> - <paramdef>struct proc_dir_entry* - <parameter>parent</parameter></paramdef> <paramdef>const - char* <parameter>dest</parameter></paramdef> - </funcprototype> - </funcsynopsis> - - <para> - This creates a symlink in the procfs directory - <parameter>parent</parameter> that points from - <parameter>name</parameter> to - <parameter>dest</parameter>. This translates in userland to - <literal>ln -s</literal> <parameter>dest</parameter> - <parameter>name</parameter>. - </para> - </sect1> - - <sect1 id="Creating_a_directory"> - <title>Creating a directory</title> - - <funcsynopsis> - <funcprototype> - <funcdef>struct proc_dir_entry* <function>proc_mkdir</function></funcdef> - <paramdef>const char* <parameter>name</parameter></paramdef> - <paramdef>struct proc_dir_entry* <parameter>parent</parameter></paramdef> - </funcprototype> - </funcsynopsis> - - <para> - Create a directory <parameter>name</parameter> in the procfs - directory <parameter>parent</parameter>. - </para> - </sect1> - - - - - <sect1 id="Removing_an_entry"> - <title>Removing an entry</title> - - <funcsynopsis> - <funcprototype> - <funcdef>void <function>remove_proc_entry</function></funcdef> - <paramdef>const char* <parameter>name</parameter></paramdef> - <paramdef>struct proc_dir_entry* <parameter>parent</parameter></paramdef> - </funcprototype> - </funcsynopsis> - - <para> - Removes the entry <parameter>name</parameter> in the directory - <parameter>parent</parameter> from the procfs. Entries are - removed by their <emphasis>name</emphasis>, not by the - <structname>struct proc_dir_entry</structname> returned by the - various create functions. Note that this function doesn't - recursively remove entries. - </para> - - <para> - Be sure to free the <structfield>data</structfield> entry from - the <structname>struct proc_dir_entry</structname> before - <function>remove_proc_entry</function> is called (that is: if - there was some <structfield>data</structfield> allocated, of - course). See <xref linkend="usingdata"/> for more information - on using the <structfield>data</structfield> entry. - </para> - </sect1> - </chapter> - - - - - <chapter id="userland"> - <title>Communicating with userland</title> - - <para> - Instead of reading (or writing) information directly from - kernel memory, procfs works with <emphasis>call back - functions</emphasis> for files: functions that are called when - a specific file is being read or written. Such functions have - to be initialised after the procfs file is created by setting - the <structfield>read_proc</structfield> and/or - <structfield>write_proc</structfield> fields in the - <structname>struct proc_dir_entry*</structname> that the - function <function>create_proc_entry</function> returned: - </para> - - <programlisting> -struct proc_dir_entry* entry; - -entry->read_proc = read_proc_foo; -entry->write_proc = write_proc_foo; - </programlisting> - - <para> - If you only want to use a the - <structfield>read_proc</structfield>, the function - <function>create_proc_read_entry</function> described in <xref - linkend="convenience"/> may be used to create and initialise the - procfs entry in one single call. - </para> - - - - <sect1 id="Reading_data"> - <title>Reading data</title> - - <para> - The read function is a call back function that allows userland - processes to read data from the kernel. The read function - should have the following format: - </para> - - <funcsynopsis> - <funcprototype> - <funcdef>int <function>read_func</function></funcdef> - <paramdef>char* <parameter>buffer</parameter></paramdef> - <paramdef>char** <parameter>start</parameter></paramdef> - <paramdef>off_t <parameter>off</parameter></paramdef> - <paramdef>int <parameter>count</parameter></paramdef> - <paramdef>int* <parameter>peof</parameter></paramdef> - <paramdef>void* <parameter>data</parameter></paramdef> - </funcprototype> - </funcsynopsis> - - <para> - The read function should write its information into the - <parameter>buffer</parameter>, which will be exactly - <literal>PAGE_SIZE</literal> bytes long. - </para> - - <para> - The parameter - <parameter>peof</parameter> should be used to signal that the - end of the file has been reached by writing - <literal>1</literal> to the memory location - <parameter>peof</parameter> points to. - </para> - - <para> - The <parameter>data</parameter> - parameter can be used to create a single call back function for - several files, see <xref linkend="usingdata"/>. - </para> - - <para> - The rest of the parameters and the return value are described - by a comment in <filename>fs/proc/generic.c</filename> as follows: - </para> - - <blockquote> - <para> - You have three ways to return data: - </para> - <orderedlist> - <listitem> - <para> - Leave <literal>*start = NULL</literal>. (This is the default.) - Put the data of the requested offset at that - offset within the buffer. Return the number (<literal>n</literal>) - of bytes there are from the beginning of the - buffer up to the last byte of data. If the - number of supplied bytes (<literal>= n - offset</literal>) is - greater than zero and you didn't signal eof - and the reader is prepared to take more data - you will be called again with the requested - offset advanced by the number of bytes - absorbed. This interface is useful for files - no larger than the buffer. - </para> - </listitem> - <listitem> - <para> - Set <literal>*start</literal> to an unsigned long value less than - the buffer address but greater than zero. - Put the data of the requested offset at the - beginning of the buffer. Return the number of - bytes of data placed there. If this number is - greater than zero and you didn't signal eof - and the reader is prepared to take more data - you will be called again with the requested - offset advanced by <literal>*start</literal>. This interface is - useful when you have a large file consisting - of a series of blocks which you want to count - and return as wholes. - (Hack by Paul.Russell@rustcorp.com.au) - </para> - </listitem> - <listitem> - <para> - Set <literal>*start</literal> to an address within the buffer. - Put the data of the requested offset at <literal>*start</literal>. - Return the number of bytes of data placed there. - If this number is greater than zero and you - didn't signal eof and the reader is prepared to - take more data you will be called again with the - requested offset advanced by the number of bytes - absorbed. - </para> - </listitem> - </orderedlist> - </blockquote> - - <para> - <xref linkend="example"/> shows how to use a read call back - function. - </para> - </sect1> - - - - - <sect1 id="Writing_data"> - <title>Writing data</title> - - <para> - The write call back function allows a userland process to write - data to the kernel, so it has some kind of control over the - kernel. The write function should have the following format: - </para> - - <funcsynopsis> - <funcprototype> - <funcdef>int <function>write_func</function></funcdef> - <paramdef>struct file* <parameter>file</parameter></paramdef> - <paramdef>const char* <parameter>buffer</parameter></paramdef> - <paramdef>unsigned long <parameter>count</parameter></paramdef> - <paramdef>void* <parameter>data</parameter></paramdef> - </funcprototype> - </funcsynopsis> - - <para> - The write function should read <parameter>count</parameter> - bytes at maximum from the <parameter>buffer</parameter>. Note - that the <parameter>buffer</parameter> doesn't live in the - kernel's memory space, so it should first be copied to kernel - space with <function>copy_from_user</function>. The - <parameter>file</parameter> parameter is usually - ignored. <xref linkend="usingdata"/> shows how to use the - <parameter>data</parameter> parameter. - </para> - - <para> - Again, <xref linkend="example"/> shows how to use this call back - function. - </para> - </sect1> - - - - - <sect1 id="usingdata"> - <title>A single call back for many files</title> - - <para> - When a large number of almost identical files is used, it's - quite inconvenient to use a separate call back function for - each file. A better approach is to have a single call back - function that distinguishes between the files by using the - <structfield>data</structfield> field in <structname>struct - proc_dir_entry</structname>. First of all, the - <structfield>data</structfield> field has to be initialised: - </para> - - <programlisting> -struct proc_dir_entry* entry; -struct my_file_data *file_data; - -file_data = kmalloc(sizeof(struct my_file_data), GFP_KERNEL); -entry->data = file_data; - </programlisting> - - <para> - The <structfield>data</structfield> field is a <type>void - *</type>, so it can be initialised with anything. - </para> - - <para> - Now that the <structfield>data</structfield> field is set, the - <function>read_proc</function> and - <function>write_proc</function> can use it to distinguish - between files because they get it passed into their - <parameter>data</parameter> parameter: - </para> - - <programlisting> -int foo_read_func(char *page, char **start, off_t off, - int count, int *eof, void *data) -{ - int len; - - if(data == file_data) { - /* special case for this file */ - } else { - /* normal processing */ - } - - return len; -} - </programlisting> - - <para> - Be sure to free the <structfield>data</structfield> data field - when removing the procfs entry. - </para> - </sect1> - </chapter> - - - - - <chapter id="tips"> - <title>Tips and tricks</title> - - - - - <sect1 id="convenience"> - <title>Convenience functions</title> - - <funcsynopsis> - <funcprototype> - <funcdef>struct proc_dir_entry* <function>create_proc_read_entry</function></funcdef> - <paramdef>const char* <parameter>name</parameter></paramdef> - <paramdef>mode_t <parameter>mode</parameter></paramdef> - <paramdef>struct proc_dir_entry* <parameter>parent</parameter></paramdef> - <paramdef>read_proc_t* <parameter>read_proc</parameter></paramdef> - <paramdef>void* <parameter>data</parameter></paramdef> - </funcprototype> - </funcsynopsis> - - <para> - This function creates a regular file in exactly the same way - as <function>create_proc_entry</function> from <xref - linkend="regularfile"/> does, but also allows to set the read - function <parameter>read_proc</parameter> in one call. This - function can set the <parameter>data</parameter> as well, like - explained in <xref linkend="usingdata"/>. - </para> - </sect1> - - - - <sect1 id="Modules"> - <title>Modules</title> - - <para> - If procfs is being used from within a module, be sure to set - the <structfield>owner</structfield> field in the - <structname>struct proc_dir_entry</structname> to - <constant>THIS_MODULE</constant>. - </para> - - <programlisting> -struct proc_dir_entry* entry; - -entry->owner = THIS_MODULE; - </programlisting> - </sect1> - - - - - <sect1 id="Mode_and_ownership"> - <title>Mode and ownership</title> - - <para> - Sometimes it is useful to change the mode and/or ownership of - a procfs entry. Here is an example that shows how to achieve - that: - </para> - - <programlisting> -struct proc_dir_entry* entry; - -entry->mode = S_IWUSR |S_IRUSR | S_IRGRP | S_IROTH; -entry->uid = 0; -entry->gid = 100; - </programlisting> - - </sect1> - </chapter> - - - - - <chapter id="example"> - <title>Example</title> - - <!-- be careful with the example code: it shouldn't be wider than - approx. 60 columns, or otherwise it won't fit properly on a page - --> - -&procfsexample; - - </chapter> -</book> diff --git a/Documentation/DocBook/procfs_example.c b/Documentation/DocBook/procfs_example.c deleted file mode 100644 index a5b11793b1e0..000000000000 --- a/Documentation/DocBook/procfs_example.c +++ /dev/null @@ -1,201 +0,0 @@ -/* - * 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"); |