From 73107cb3ad3963c0f929ae681c05081eafb1c079 Mon Sep 17 00:00:00 2001
From: Tejun Heo <htejun@gmail.com>
Date: Thu, 14 Jun 2007 03:45:16 +0900
Subject: sysfs: kill attribute file orphaning

Now that sysfs_dirent can be disconnected from kobject on deletion,
there is no need to orphan each attribute files.  All [bin_]attribute
nodes are automatically orphaned when the parent node is deleted.
Kill attribute file orphaning.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 fs/sysfs/file.c | 65 ++++++++++++---------------------------------------------
 1 file changed, 13 insertions(+), 52 deletions(-)

(limited to 'fs/sysfs/file.c')

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 310430baf57..d673d9b5d33 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -50,29 +50,15 @@ static struct sysfs_ops subsys_sysfs_ops = {
 	.store	= subsys_attr_store,
 };
 
-/**
- *	add_to_collection - add buffer to a collection
- *	@buffer:	buffer to be added
- *	@node:		inode of set to add to
- */
-
-static inline void
-add_to_collection(struct sysfs_buffer *buffer, struct inode *node)
-{
-	struct sysfs_buffer_collection *set = node->i_private;
-
-	mutex_lock(&node->i_mutex);
-	list_add(&buffer->associates, &set->associates);
-	mutex_unlock(&node->i_mutex);
-}
-
-static inline void
-remove_from_collection(struct sysfs_buffer *buffer, struct inode *node)
-{
-	mutex_lock(&node->i_mutex);
-	list_del(&buffer->associates);
-	mutex_unlock(&node->i_mutex);
-}
+struct sysfs_buffer {
+	size_t			count;
+	loff_t			pos;
+	char			* page;
+	struct sysfs_ops	* ops;
+	struct semaphore	sem;
+	int			needs_read_fill;
+	int			event;
+};
 
 /**
  *	fill_read_buffer - allocate and fill buffer from object.
@@ -144,10 +130,7 @@ sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos)
 
 	down(&buffer->sem);
 	if (buffer->needs_read_fill) {
-		if (buffer->orphaned)
-			retval = -ENODEV;
-		else
-			retval = fill_read_buffer(file->f_path.dentry,buffer);
+		retval = fill_read_buffer(file->f_path.dentry,buffer);
 		if (retval)
 			goto out;
 	}
@@ -246,16 +229,11 @@ sysfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t
 	ssize_t len;
 
 	down(&buffer->sem);
-	if (buffer->orphaned) {
-		len = -ENODEV;
-		goto out;
-	}
 	len = fill_write_buffer(buffer, buf, count);
 	if (len > 0)
 		len = flush_write_buffer(file->f_path.dentry, buffer, len);
 	if (len > 0)
 		*ppos += len;
-out:
 	up(&buffer->sem);
 	return len;
 }
@@ -265,7 +243,6 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
 	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
 	struct attribute *attr = attr_sd->s_elem.attr.attr;
 	struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
-	struct sysfs_buffer_collection *set;
 	struct sysfs_buffer * buffer;
 	struct sysfs_ops * ops = NULL;
 	int error;
@@ -289,26 +266,14 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
 	else
 		ops = &subsys_sysfs_ops;
 
+	error = -EACCES;
+
 	/* No sysfs operations, either from having no subsystem,
 	 * or the subsystem have no operations.
 	 */
-	error = -EACCES;
 	if (!ops)
 		goto err_mput;
 
-	/* make sure we have a collection to add our buffers to */
-	mutex_lock(&inode->i_mutex);
-	if (!(set = inode->i_private)) {
-		error = -ENOMEM;
-		if (!(set = inode->i_private = kmalloc(sizeof(struct sysfs_buffer_collection), GFP_KERNEL)))
-			goto err_mput;
-		else
-			INIT_LIST_HEAD(&set->associates);
-	}
-	mutex_unlock(&inode->i_mutex);
-
-	error = -EACCES;
-
 	/* File needs write support.
 	 * The inode's perms must say it's ok, 
 	 * and we must have a store method.
@@ -335,11 +300,9 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
 	if (!buffer)
 		goto err_mput;
 
-	INIT_LIST_HEAD(&buffer->associates);
 	init_MUTEX(&buffer->sem);
 	buffer->needs_read_fill = 1;
 	buffer->ops = ops;
-	add_to_collection(buffer, inode);
 	file->private_data = buffer;
 
 	/* open succeeded, put active references and pin attr_sd */
@@ -358,10 +321,8 @@ static int sysfs_release(struct inode * inode, struct file * filp)
 {
 	struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata;
 	struct attribute *attr = attr_sd->s_elem.attr.attr;
-	struct sysfs_buffer * buffer = filp->private_data;
+	struct sysfs_buffer *buffer = filp->private_data;
 
-	if (buffer)
-		remove_from_collection(buffer, inode);
 	sysfs_put(attr_sd);
 	/* After this point, attr should not be accessed. */
 	module_put(attr->owner);
-- 
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