Now I just know I'm going to regret this somehow...
Anyway, here's yet-another-ramfs-based filesystem, ndevfs. It's a very
tiny:
$ size fs/ndevfs/inode.o
text data bss dec hex filename
1571 200 8 1779 6f3 fs/ndevfs/inode.o
replacement for devfs for those embedded users who just can't live
without the damm thing. It doesn't allow subdirectories, and only uses
LSB compliant names. But it works, and should be enough for people to
use, if they just can't wean themselves off of the idea of an in-kernel
fs to provide device nodes.
Now, with this, is there still anyone out there who just can't live
without devfs in their kernel?
Damm, the depths I've sunk to these days, I'm such a people pleaser...
Comments? Questions? Criticisms?
I need sleep.
greg k-h
---------------
ndevfs - a "nano" devfs
For embedded people to use since they seem to hate userspace.
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/base/class.c | 3
fs/Kconfig | 3
fs/Makefile | 1
fs/ndevfs/Makefile | 4
fs/ndevfs/inode.c | 249 +++++++++++++++++++++++++++++++++++++++++++++++++
fs/partitions/check.c | 6 +
include/linux/ndevfs.h | 13 ++
7 files changed, 279 insertions(+)
--- gregkh-2.6.orig/fs/Kconfig 2005-06-24 01:05:59.000000000 -0700
+++ gregkh-2.6/fs/Kconfig 2005-06-24 01:06:02.000000000 -0700
@@ -1700,6 +1700,9 @@
config RXRPC
tristate
+config NDEV_FS
+ bool "Nano Device File System"
+
endmenu
menu "Partition Types"
--- gregkh-2.6.orig/fs/Makefile 2005-06-24 01:05:59.000000000 -0700
+++ gregkh-2.6/fs/Makefile 2005-06-24 01:06:02.000000000 -0700
@@ -95,3 +95,4 @@
obj-$(CONFIG_HOSTFS) += hostfs/
obj-$(CONFIG_HPPFS) += hppfs/
obj-$(CONFIG_DEBUG_FS) += debugfs/
+obj-$(CONFIG_NDEV_FS) += ndevfs/
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gregkh-2.6/include/linux/ndevfs.h 2005-06-24 01:06:02.000000000 -0700
@@ -0,0 +1,13 @@
+#ifndef _NDEVFS_H_
+#define _NDEVFS_H_
+
+#if defined(CONFIG_NDEV_FS)
+extern void ndevfs_create(const char *name, dev_t dev, int is_char);
+extern void ndevfs_remove(const char *name);
+#else
+static inline void ndevfs_create(const char *name, dev_t dev, int is_char) {}
+static inline void ndevfs_remove(const char *name) {}
+#endif
+
+#endif
+
--- gregkh-2.6.orig/drivers/base/class.c 2005-06-24 01:05:59.000000000 -0700
+++ gregkh-2.6/drivers/base/class.c 2005-06-24 01:06:02.000000000 -0700
@@ -17,6 +17,7 @@
#include <linux/string.h>
#include <linux/kdev_t.h>
#include <linux/err.h>
+#include <linux/ndevfs.h>
#include "base.h"
#define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
@@ -492,6 +493,7 @@
attr->store = NULL;
class_device_create_file(class_dev, attr);
class_dev->devt_attr = attr;
+ ndevfs_create(class_dev->class_id, class_dev->devt, 1);
}
class_device_add_attrs(class_dev);
@@ -595,6 +597,7 @@
class_device_remove_file(class_dev, class_dev->devt_attr);
kfree(class_dev->devt_attr);
class_dev->devt_attr = NULL;
+ ndevfs_remove(class_dev->class_id);
}
class_device_remove_attrs(class_dev);
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gregkh-2.6/fs/ndevfs/Makefile 2005-06-24 01:06:02.000000000 -0700
@@ -0,0 +1,4 @@
+ndevfs-objs := inode.o
+
+obj-$(CONFIG_NDEV_FS) += ndevfs.o
+
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gregkh-2.6/fs/ndevfs/inode.c 2005-06-24 01:06:02.000000000 -0700
@@ -0,0 +1,249 @@
+/*
+ * inode.c - part of ndevfs, a tiny little device file system
+ *
+ * Copyright (C) 2004,2005 Greg Kroah-Hartman <[email protected]>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * Written for all of the people out there who just hate userspace solutions.
+ *
+ */
+
+/* uncomment to get debug messages */
+#define DEBUG
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/pagemap.h>
+#include <linux/init.h>
+#include <linux/namei.h>
+#include <linux/device.h>
+#include <linux/ndevfs.h>
+
+#define MAGIC 0x64756d62
+
+struct entry {
+ struct list_head node;
+ struct dentry *dentry;
+ char name[BUS_ID_SIZE];
+};
+static LIST_HEAD(entries);
+
+static struct vfsmount *mount;
+static int mount_count;
+
+static struct file_operations stupid_file_ops = {
+ .read = generic_file_read,
+ .write = generic_file_write,
+ .mmap = generic_file_mmap,
+ .fsync = simple_sync_file,
+ .llseek = generic_file_llseek,
+};
+
+static struct inode *get_inode(struct super_block *sb, int mode, dev_t dev)
+{
+ struct inode *inode = new_inode(sb);
+
+ if (inode) {
+ inode->i_mode = mode;
+ inode->i_uid = 0;
+ inode->i_gid = 0;
+ inode->i_blksize = PAGE_CACHE_SIZE;
+ inode->i_blocks = 0;
+ inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ switch (mode & S_IFMT) {
+ default:
+ init_special_inode(inode, mode, dev);
+ break;
+ case S_IFREG:
+ inode->i_fop = &stupid_file_ops;
+ break;
+ case S_IFDIR:
+ inode->i_op = &simple_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+
+ /* directory inodes start off with i_nlink == 2 (for "." entry) */
+ inode->i_nlink++;
+ break;
+ }
+ }
+ return inode;
+}
+
+/* SMP-safe */
+static int mknod(struct inode *dir, struct dentry *dentry,
+ int mode, dev_t dev)
+{
+ struct inode *inode = get_inode(dir->i_sb, mode, dev);
+ int error = -EPERM;
+
+ if (dentry->d_inode)
+ return -EEXIST;
+
+ if (inode) {
+ d_instantiate(dentry, inode);
+ dget(dentry);
+ error = 0;
+ }
+ return error;
+}
+
+static inline int positive(struct dentry *dentry)
+{
+ return dentry->d_inode && !d_unhashed(dentry);
+}
+
+static int fill_super(struct super_block *sb, void *data, int silent)
+{
+ static struct tree_descr files[] = {{""}};
+
+ return simple_fill_super(sb, MAGIC, files);
+}
+
+static struct super_block *get_sb(struct file_system_type *fs_type,
+ int flags, const char *dev_name,
+ void *data)
+{
+ return get_sb_single(fs_type, flags, data, fill_super);
+}
+
+static void remove(struct dentry *dentry)
+{
+ struct dentry *parent;
+
+ if (!dentry)
+ return;
+
+ parent = dentry->d_parent;
+ if (!parent || !parent->d_inode)
+ return;
+
+ down(&parent->d_inode->i_sem);
+ if (positive(dentry)) {
+ if (dentry->d_inode) {
+ if (S_ISDIR(dentry->d_inode->i_mode))
+ simple_rmdir(parent->d_inode, dentry);
+ else
+ simple_unlink(parent->d_inode, dentry);
+ dput(dentry);
+ }
+ }
+ up(&parent->d_inode->i_sem);
+ simple_release_fs(&mount, &mount_count);
+}
+
+/**
+ * ndevfs_create - create a device node in ndevfs
+ *
+ * @name: the name to create
+ * @dev: the dev_t of the node
+ * @is_char: if the node is a char device or not
+ */
+void ndevfs_create(const char *name, dev_t dev, int is_char)
+{
+ struct dentry *parent;
+ struct dentry *dentry;
+ struct entry *entry;
+ int err;
+ int mode = S_IRUSR | S_IWUSR;
+
+ pr_debug("ndevfs: creating file '%s' with major %d and minor %d\n",
+ name, MAJOR(dev), MINOR(dev));
+
+ if (is_char)
+ mode |= S_IFCHR;
+ else
+ mode |= S_IFBLK;
+
+ err = simple_pin_fs("ndevfs", &mount, &mount_count);
+ if (err)
+ return;
+
+ /* everything is at the root fs, no directories allowed */
+ if (mount && mount->mnt_sb) {
+ parent = mount->mnt_sb->s_root;
+ } else {
+ pr_debug("%s: no parent?\n", __FUNCTION__);
+ goto error;
+ }
+
+ down(&parent->d_inode->i_sem);
+ dentry = lookup_one_len(name, parent, strlen(name));
+ if (!IS_ERR(dentry))
+ err = mknod(parent->d_inode, dentry, mode, dev);
+ else
+ err = PTR_ERR(dentry);
+ up(&parent->d_inode->i_sem);
+
+ if (err)
+ goto error;
+
+ entry = kmalloc(sizeof(struct entry), GFP_KERNEL);
+ if (!entry) {
+ remove(dentry);
+ err = -ENOMEM;
+ goto error;
+ }
+ entry->dentry = dentry;
+ strcpy(&entry->name[0], name);
+ list_add(&entry->node, &entries);
+ return;
+
+error:
+ pr_debug("%s failed with error %d\n", __FUNCTION__, err);
+ simple_release_fs(&mount, &mount_count);
+}
+EXPORT_SYMBOL_GPL(ndevfs_create);
+
+/**
+ * ndevfs_remove - removes the node from the fs
+ *
+ * @name: the name to remove.
+ */
+void ndevfs_remove(const char *name)
+{
+ struct entry *entry;
+ struct dentry *dentry = NULL;
+
+ pr_debug("ndevfs: removing file '%s'\n", name);
+
+ list_for_each_entry(entry, &entries, node) {
+ if (strcmp(name, &entry->name[0]) == 0) {
+ dentry = entry->dentry;
+ break;
+ }
+ }
+ if (!dentry) {
+ pr_debug("%s: can't find %s\n", __FUNCTION__, name);
+ return;
+ }
+ remove (dentry);
+}
+EXPORT_SYMBOL_GPL(ndevfs_remove);
+
+static struct file_system_type fs_type = {
+ .owner = THIS_MODULE,
+ .name = "ndevfs",
+ .get_sb = get_sb,
+ .kill_sb = kill_litter_super,
+};
+
+static int __init ndevfs_init(void)
+{
+ return register_filesystem(&fs_type);
+}
+
+static void __exit ndevfs_exit(void)
+{
+ simple_release_fs(&mount, &mount_count);
+ unregister_filesystem(&fs_type);
+}
+
+core_initcall(ndevfs_init);
+module_exit(ndevfs_exit);
+MODULE_LICENSE("GPL");
+
--- gregkh-2.6.orig/fs/partitions/check.c 2005-06-24 01:05:59.000000000 -0700
+++ gregkh-2.6/fs/partitions/check.c 2005-06-24 01:06:02.000000000 -0700
@@ -18,6 +18,7 @@
#include <linux/fs.h>
#include <linux/kmod.h>
#include <linux/ctype.h>
+#include <linux/ndevfs.h>
#include "check.h"
@@ -273,6 +274,7 @@
p->start_sect = 0;
p->nr_sects = 0;
p->reads = p->writes = p->read_sectors = p->write_sectors = 0;
+ ndevfs_remove(kobject_name(&p->kobj));
kobject_unregister(&p->kobj);
}
@@ -296,6 +298,7 @@
p->kobj.parent = &disk->kobj;
p->kobj.ktype = &ktype_part;
kobject_register(&p->kobj);
+ ndevfs_create(kobject_name(&p->kobj), MKDEV(disk->major, p->partno), 0);
disk->part[part-1] = p;
}
@@ -323,6 +326,8 @@
if ((err = kobject_add(&disk->kobj)))
return;
disk_sysfs_symlinks(disk);
+ ndevfs_create(kobject_name(&disk->kobj),
+ MKDEV(disk->major, disk->first_minor), 0);
kobject_hotplug(&disk->kobj, KOBJ_ADD);
/* No minors to use for partitions */
@@ -420,6 +425,7 @@
sysfs_remove_link(&disk->driverfs_dev->kobj, "block");
put_device(disk->driverfs_dev);
}
+ ndevfs_remove(kobject_name(&disk->kobj));
kobject_hotplug(&disk->kobj, KOBJ_REMOVE);
kobject_del(&disk->kobj);
}
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
