sysfs: split up inode.c into different files for different purposes.

- new files file.c, dir.c, symlink.c, mount.c.

- Purely cosmetic (for now). Should make it easier to add new filetypes.

fs/sysfs/Makefile

@@ -2,6 +2,6 @@
 # Makefile for the sysfs virtual filesystem
 #
 
-export-objs	:= inode.o
+export-objs	:= file.o dir.o symlink.o
 
-obj-y		:= inode.o
+obj-y		:= inode.o file.o dir.o symlink.o mount.o

fs/sysfs/dir.c

+/*
+ * dir.c - Operations for sysfs directories.
+ */
+
+#undef DEBUG
+
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/module.h>
+#include <linux/kobject.h>
+#include "sysfs.h"
+
+static int sysfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+	int res;
+	mode = (mode & (S_IRWXUGO|S_ISVTX)) | S_IFDIR;
+ 	res = sysfs_mknod(dir, dentry, mode, 0);
+ 	if (!res)
+ 		dir->i_nlink++;
+	return res;
+}
+
+
+/**
+ *	sysfs_create_dir - create a directory for an object.
+ *	@parent:	parent parent object.
+ *	@kobj:		object we're creating directory for. 
+ */
+
+int sysfs_create_dir(struct kobject * kobj)
+{
+	struct dentry * dentry = NULL;
+	struct dentry * parent;
+	int error = 0;
+
+	if (!kobj)
+		return -EINVAL;
+
+	if (kobj->parent)
+		parent = kobj->parent->dentry;
+	else if (sysfs_mount && sysfs_mount->mnt_sb)
+		parent = sysfs_mount->mnt_sb->s_root;
+	else
+		return -EFAULT;
+
+	down(&parent->d_inode->i_sem);
+	dentry = sysfs_get_dentry(parent,kobj->name);
+	if (!IS_ERR(dentry)) {
+		dentry->d_fsdata = (void *)kobj;
+		kobj->dentry = dentry;
+		error = sysfs_mkdir(parent->d_inode,dentry,
+				    (S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO));
+	} else
+		error = PTR_ERR(dentry);
+	up(&parent->d_inode->i_sem);
+
+	return error;
+}
+
+
+
+/**
+ *	sysfs_remove_dir - remove an object's directory.
+ *	@kobj:	object. 
+ *
+ *	The only thing special about this is that we remove any files in 
+ *	the directory before we remove the directory, and we've inlined
+ *	what used to be sysfs_rmdir() below, instead of calling separately.
+ */
+
+void sysfs_remove_dir(struct kobject * kobj)
+{
+	struct list_head * node, * next;
+	struct dentry * dentry = dget(kobj->dentry);
+	struct dentry * parent;
+
+	if (!dentry)
+		return;
+
+	pr_debug("sysfs %s: removing dir\n",dentry->d_name.name);
+	parent = dget(dentry->d_parent);
+	down(&parent->d_inode->i_sem);
+	down(&dentry->d_inode->i_sem);
+
+	list_for_each_safe(node,next,&dentry->d_subdirs) {
+		struct dentry * d = dget(list_entry(node,struct dentry,d_child));
+		/** 
+		 * Make sure dentry is still there 
+		 */
+		pr_debug(" o %s: ",d->d_name.name);
+		if (d->d_inode) {
+
+			pr_debug("removing");
+			/**
+			 * Unlink and unhash.
+			 */
+			simple_unlink(dentry->d_inode,d);
+			d_delete(d);
+
+			/**
+			 * Drop reference from initial sysfs_get_dentry().
+			 */
+			dput(d);
+		}
+		pr_debug(" done (%d)\n",atomic_read(&d->d_count));
+		/**
+		 * drop reference from dget() above.
+		 */
+		dput(d);
+	}
+
+	up(&dentry->d_inode->i_sem);
+	d_invalidate(dentry);
+	simple_rmdir(parent->d_inode,dentry);
+	d_delete(dentry);
+
+	pr_debug(" o %s removing done (%d)\n",dentry->d_name.name,
+		 atomic_read(&dentry->d_count));
+	/**
+	 * Drop reference from initial sysfs_get_dentry().
+	 */
+	dput(dentry);
+
+	/**
+	 * Drop reference from dget() on entrance.
+	 */
+	dput(dentry);
+	up(&parent->d_inode->i_sem);
+	dput(parent);
+}
+
+
+EXPORT_SYMBOL(sysfs_create_dir);
+EXPORT_SYMBOL(sysfs_remove_dir);
+

fs/sysfs/mount.c

+/*
+ * mount.c - operations for initializing and mounting sysfs.
+ */
+
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/pagemap.h>
+
+#include "sysfs.h"
+
+/* Random magic number */
+#define SYSFS_MAGIC 0x62656572
+
+struct vfsmount *sysfs_mount;
+
+static struct super_operations sysfs_ops = {
+	.statfs		= simple_statfs,
+	.drop_inode	= generic_delete_inode,
+};
+
+static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
+{
+	struct inode *inode;
+	struct dentry *root;
+
+	sb->s_blocksize = PAGE_CACHE_SIZE;
+	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+	sb->s_magic = SYSFS_MAGIC;
+	sb->s_op = &sysfs_ops;
+	inode = sysfs_get_inode(sb, S_IFDIR | 0755, 0);
+
+	if (!inode) {
+		pr_debug("%s: could not get inode!\n",__FUNCTION__);
+		return -ENOMEM;
+	}
+
+	root = d_alloc_root(inode);
+	if (!root) {
+		pr_debug("%s: could not get root dentry!\n",__FUNCTION__);
+		iput(inode);
+		return -ENOMEM;
+	}
+	sb->s_root = root;
+	return 0;
+}
+
+static struct super_block *sysfs_get_sb(struct file_system_type *fs_type,
+	int flags, char *dev_name, void *data)
+{
+	return get_sb_single(fs_type, flags, data, sysfs_fill_super);
+}
+
+static struct file_system_type sysfs_fs_type = {
+	.name		= "sysfs",
+	.get_sb		= sysfs_get_sb,
+	.kill_sb	= kill_litter_super,
+};
+
+static int __init sysfs_init(void)
+{
+	int err;
+
+	err = register_filesystem(&sysfs_fs_type);
+	if (!err) {
+		sysfs_mount = kern_mount(&sysfs_fs_type);
+		if (IS_ERR(sysfs_mount)) {
+			printk(KERN_ERR "sysfs: could not mount!\n");
+			err = PTR_ERR(sysfs_mount);
+			sysfs_mount = NULL;
+		}
+	}
+	return err;
+}
+
+core_initcall(sysfs_init);

fs/sysfs/symlink.c

+/*
+ * symlink.c - operations for sysfs symlinks.
+ */
+
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/kobject.h>
+
+#include "sysfs.h"
+
+
+static int sysfs_symlink(struct inode * dir, struct dentry *dentry, const char * symname)
+{
+	struct inode *inode;
+	int error = -ENOSPC;
+
+	if (dentry->d_inode)
+		return -EEXIST;
+
+	inode = sysfs_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0);
+	if (inode) {
+		int l = strlen(symname)+1;
+		error = page_symlink(inode, symname, l);
+		if (!error) {
+			d_instantiate(dentry, inode);
+			dget(dentry);
+		} else
+			iput(inode);
+	}
+	return error;
+}
+
+static int object_depth(struct kobject * kobj)
+{
+	struct kobject * p = kobj;
+	int depth = 0;
+	do { depth++; } while ((p = p->parent));
+	return depth;
+}
+
+static int object_path_length(struct kobject * kobj)
+{
+	struct kobject * p = kobj;
+	int length = 1;
+	do {
+		length += strlen(p->name) + 1;
+		p = p->parent;
+	} while (p);
+	return length;
+}
+
+static void fill_object_path(struct kobject * kobj, char * buffer, int length)
+{
+	struct kobject * p;
+
+	--length;
+	for (p = kobj; p; p = p->parent) {
+		int cur = strlen(p->name);
+
+		/* back up enough to print this bus id with '/' */
+		length -= cur;
+		strncpy(buffer + length,p->name,cur);
+		*(buffer + --length) = '/';
+	}
+}
+
+/**
+ *	sysfs_create_link - create symlink between two objects.
+ *	@kobj:	object whose directory we're creating the link in.
+ *	@target:	object we're pointing to.
+ *	@name:		name of the symlink.
+ */
+int sysfs_create_link(struct kobject * kobj, struct kobject * target, char * name)
+{
+	struct dentry * dentry = kobj->dentry;
+	struct dentry * d;
+	int error = 0;
+	int size;
+	int depth;
+	char * path;
+	char * s;
+
+	depth = object_depth(kobj);
+	size = object_path_length(target) + depth * 3 - 1;
+	if (size > PATH_MAX)
+		return -ENAMETOOLONG;
+	pr_debug("%s: depth = %d, size = %d\n",__FUNCTION__,depth,size);
+
+	path = kmalloc(size,GFP_KERNEL);
+	if (!path)
+		return -ENOMEM;
+	memset(path,0,size);
+
+	for (s = path; depth--; s += 3)
+		strcpy(s,"../");
+
+	fill_object_path(target,path,size);
+	pr_debug("%s: path = '%s'\n",__FUNCTION__,path);
+
+	down(&dentry->d_inode->i_sem);
+	d = sysfs_get_dentry(dentry,name);
+	if (!IS_ERR(d))
+		error = sysfs_symlink(dentry->d_inode,d,path);
+	else
+		error = PTR_ERR(d);
+	up(&dentry->d_inode->i_sem);
+	kfree(path);
+	return error;
+}
+
+
+/**
+ *	sysfs_remove_link - remove symlink in object's directory.
+ *	@kobj:	object we're acting for.
+ *	@name:	name of the symlink to remove.
+ */
+
+void sysfs_remove_link(struct kobject * kobj, char * name)
+{
+	sysfs_hash_and_remove(kobj->dentry,name);
+}
+
+
+EXPORT_SYMBOL(sysfs_create_link);
+EXPORT_SYMBOL(sysfs_remove_link);
+

fs/sysfs/sysfs.h

+
+extern struct vfsmount * sysfs_mount;
+
+extern struct inode *sysfs_get_inode(struct super_block *sb, int mode, int dev);
+
+extern int sysfs_mknod(struct inode *, struct dentry *, int, dev_t);
+
+extern struct dentry * sysfs_get_dentry(struct dentry *, char *);
+
+extern void sysfs_hash_and_remove(struct dentry * dir, const char * name);
+