sysfs: fixup merge

fs/sysfs/Makefile

@@ -2,4 +2,4 @@
 # Makefile for the sysfs virtual filesystem
 #
 
-obj-y		:= inode.o
+obj-y		:= inode.o file.o dir.o symlink.o mount.o bin.o

fs/sysfs/bin.c

+/*
+ * bin.c - binary file operations for sysfs.
+ */
+
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/kobject.h>
+
+#include "sysfs.h"
+
+static struct file_operations bin_fops;
+
+static int fill_read(struct file * file, struct sysfs_bin_buffer * buffer)
+{
+	struct bin_attribute * attr = file->f_dentry->d_fsdata;
+	struct kobject * kobj = file->f_dentry->d_parent->d_fsdata;
+
+	if (!buffer->data)
+		attr->read(kobj,buffer);
+	return buffer->size ? 0 : -ENOENT;
+}
+
+static int flush_read(struct file * file, char * userbuf, 
+		      struct sysfs_bin_buffer * buffer)
+{
+	return copy_to_user(userbuf,buffer->data + buffer->offset,buffer->count) ? 
+		-EFAULT : 0;
+}
+
+static ssize_t
+read(struct file * file, char * userbuf, size_t count, loff_t * off)
+{
+	struct sysfs_bin_buffer * buffer = file->private_data;
+	int ret;
+
+	ret = fill_read(file,buffer);
+	if (ret) 
+		goto Done;
+
+	buffer->offset = *off;
+
+	if (count > (buffer->size - *off))
+		count = buffer->size - *off;
+
+	buffer->count = count;
+
+	ret = flush_read(file,userbuf,buffer);
+	if (!ret) {
+		*off += count;
+		ret = count;
+	}
+ Done:
+	return ret;
+}
+
+int alloc_buf_data(struct sysfs_bin_buffer * buffer)
+{
+	buffer->data = kmalloc(buffer->count,GFP_KERNEL);
+	if (buffer->data) {
+		memset(buffer->data,0,buffer->count);
+		return 0;
+	} else
+		return -ENOMEM;
+}
+
+static int fill_write(struct file * file, const char * userbuf, 
+		      struct sysfs_bin_buffer * buffer)
+{
+	return copy_from_user(buffer,userbuf,buffer->count) ?
+		-EFAULT : 0;
+}
+
+static int flush_write(struct file * file, const char * userbuf, 
+		       struct sysfs_bin_buffer * buffer)
+{
+	struct bin_attribute * attr = file->f_dentry->d_fsdata;
+	struct kobject * kobj = file->f_dentry->d_parent->d_fsdata;
+
+	return attr->write(kobj,buffer);
+}
+
+static ssize_t write(struct file * file, const char * userbuf,
+		     size_t count, loff_t * off)
+{
+	struct sysfs_bin_buffer * buffer = file->private_data;
+	int ret;
+
+	if (count > PAGE_SIZE)
+		count = PAGE_SIZE;
+	buffer->count = count;
+
+	ret = alloc_buf_data(buffer);
+	if (ret)
+		goto Done;
+
+	ret = fill_write(file,userbuf,buffer);
+	if (ret)
+		goto Done;
+
+	ret = flush_write(file,userbuf,buffer);
+	if (ret > 0)
+		*off += count;
+ Done:
+	if (buffer->data) {
+		kfree(buffer->data);
+		buffer->data = NULL;
+	}
+	return ret;
+}
+
+static int check_perm(struct inode * inode, struct file * file)
+{
+	struct kobject * kobj = kobject_get(file->f_dentry->d_parent->d_fsdata);
+	struct bin_attribute * attr = file->f_dentry->d_fsdata;
+	struct sysfs_bin_buffer * buffer;
+	int error = 0;
+
+	if (!kobj || !attr)
+		goto Einval;
+
+	/* File needs write support.
+	 * The inode's perms must say it's ok, 
+	 * and we must have a store method.
+	 */
+	if (file->f_mode & FMODE_WRITE) {
+		if (!(inode->i_mode & S_IWUGO) || !attr->write)
+			goto Eaccess;
+	}
+
+	/* File needs read support.
+	 * The inode's perms must say it's ok, and we there
+	 * must be a show method for it.
+	 */
+	if (file->f_mode & FMODE_READ) {
+		if (!(inode->i_mode & S_IRUGO) || !attr->read)
+			goto Eaccess;
+	}
+
+	buffer = kmalloc(sizeof(struct sysfs_bin_buffer),GFP_KERNEL);
+	if (buffer) {
+		memset(buffer,0,sizeof(struct sysfs_bin_buffer));
+		file->private_data = buffer;
+	} else
+		error = -ENOMEM;
+	goto Done;
+
+ Einval:
+	error = -EINVAL;
+	goto Done;
+ Eaccess:
+	error = -EACCES;
+ Done:
+	if (error && kobj)
+		kobject_put(kobj);
+	return error;
+}
+
+static int open(struct inode * inode, struct file * file)
+{
+	return check_perm(inode,file);
+}
+
+static int release(struct inode * inode, struct file * file)
+{
+	struct kobject * kobj = file->f_dentry->d_parent->d_fsdata;
+	u8 * buffer = file->private_data;
+
+	if (kobj) 
+		kobject_put(kobj);
+	if (buffer)
+		kfree(buffer);
+	return 0;
+}
+
+static struct file_operations bin_fops = {
+	.read		= read,
+	.write		= write,
+	.llseek		= generic_file_llseek,
+	.open		= open,
+	.release	= release,
+};
+
+/**
+ *	sysfs_create_bin_file - create binary file for object.
+ *	@kobj:	object.
+ *	@attr:	attribute descriptor.
+ *
+ */
+
+int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr)
+{
+	struct dentry * dentry;
+	struct dentry * parent;
+	int error = 0;
+
+	if (!kobj || !attr)
+		return -EINVAL;
+
+	parent = kobj->dentry;
+
+	down(&parent->d_inode->i_sem);
+	dentry = sysfs_get_dentry(parent,attr->attr.name);
+	if (!IS_ERR(dentry)) {
+		dentry->d_fsdata = (void *)attr;
+		error = sysfs_create(dentry,
+				     (attr->attr.mode & S_IALLUGO) | S_IFREG,
+				     NULL);
+		if (!error) {
+			dentry->d_inode->i_size = attr->size;
+			dentry->d_inode->i_fop = &bin_fops;
+		}
+	} else
+		error = PTR_ERR(dentry);
+	up(&parent->d_inode->i_sem);
+	return error;
+}
+
+
+/**
+ *	sysfs_remove_bin_file - remove binary file for object.
+ *	@kobj:	object.
+ *	@attr:	attribute descriptor.
+ *
+ */
+
+int sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr)
+{
+	sysfs_hash_and_remove(kobj->dentry,attr->attr.name);
+}
+
+EXPORT_SYMBOL(sysfs_create_bin_file);
+EXPORT_SYMBOL(sysfs_remove_bin_file);

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 init_dir(struct inode * inode)
+{
+	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++;
+	return 0;
+}
+
+/**
+ *	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_create(dentry,(S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO),
+				     init_dir);
+		if (!error)
+			parent->d_inode->i_nlink++;
+	} 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.
+ */
+
+#define DEBUG 
+
+#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;
+struct super_block * sysfs_sb = NULL;
+
+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;
+	sysfs_sb = sb;
+
+	inode = sysfs_new_inode(S_IFDIR | S_IRUGO | S_IWUSR);
+	if (inode) {
+		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++;	
+	} else {
+		pr_debug("sysfs: could not get root inode\n");
+		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 init_symlink(struct inode * inode)
+{
+	inode->i_op = &page_symlink_inode_operations;
+	return 0;
+}
+
+static int sysfs_symlink(struct inode * dir, struct dentry *dentry, const char * symname)
+{
+	int error;
+
+	error = sysfs_create(dentry, S_IFLNK|S_IRWXUGO, init_symlink);
+	if (!error) {
+		int l = strlen(symname)+1;
+		error = page_symlink(dentry->d_inode, symname, l);
+		if (error)
+			iput(dentry->d_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_new_inode(mode_t mode);
+extern int sysfs_create(struct dentry *, int mode, int (*init)(struct inode *));
+
+extern struct dentry * sysfs_get_dentry(struct dentry *, char *);
+
+extern void sysfs_hash_and_remove(struct dentry * dir, const char * name);
+

include/linux/sysfs.h

@@ -16,6 +16,20 @@ struct attribute {
 	mode_t			mode;
 };
 
+struct sysfs_bin_buffer {
+	u8 * 	data;
+	size_t	size;
+	size_t	count;
+	loff_t	offset;
+};
+
+struct bin_attribute {
+	struct attribute	attr;
+	size_t			size;
+	ssize_t (*read)(struct kobject *, struct sysfs_bin_buffer *);
+	ssize_t (*write)(struct kobject *, struct sysfs_bin_buffer *);
+};
+
 struct sysfs_ops {
 	ssize_t	(*show)(struct kobject *, struct attribute *,char *);
 	ssize_t	(*store)(struct kobject *,struct attribute *,const char *, size_t);