X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;ds=sidebyside;f=fs%2Fsysfs%2Ffile.c;h=a84b734f7b2947c3784b41c34b4f344705a8bd98;hb=8312a8d7c1d19d31027bd4ca127ce671962c23d4;hp=db0413a411d61e57fda9ef39e9b36ac37dd2a6b2;hpb=523ded71de0c5e66973335bf99a80edfda9f401b;p=safe%2Fjmp%2Flinux-2.6

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index db0413a..a84b734 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -13,8 +13,7 @@
 
 #include "sysfs.h"
 
-#define to_subsys(k) container_of(k,struct subsystem,kset.kobj)
-#define to_sattr(a) container_of(a,struct subsys_attribute,attr)
+#define to_sattr(a) container_of(a,struct subsys_attribute, attr)
 
 /*
  * Subsystem file operations.
@@ -24,12 +23,12 @@
 static ssize_t 
 subsys_attr_show(struct kobject * kobj, struct attribute * attr, char * page)
 {
-	struct subsystem * s = to_subsys(kobj);
+	struct kset *kset = to_kset(kobj);
 	struct subsys_attribute * sattr = to_sattr(attr);
 	ssize_t ret = -EIO;
 
 	if (sattr->show)
-		ret = sattr->show(s,page);
+		ret = sattr->show(kset, page);
 	return ret;
 }
 
@@ -37,12 +36,12 @@ static ssize_t
 subsys_attr_store(struct kobject * kobj, struct attribute * attr, 
 		  const char * page, size_t count)
 {
-	struct subsystem * s = to_subsys(kobj);
+	struct kset *kset = to_kset(kobj);
 	struct subsys_attribute * sattr = to_sattr(attr);
 	ssize_t ret = -EIO;
 
 	if (sattr->store)
-		ret = sattr->store(s,page,count);
+		ret = sattr->store(kset, page, count);
 	return ret;
 }
 
@@ -51,29 +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.
@@ -88,9 +73,8 @@ remove_from_collection(struct sysfs_buffer *buffer, struct inode *node)
  */
 static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer)
 {
-	struct sysfs_dirent * sd = dentry->d_fsdata;
-	struct attribute * attr = to_attr(dentry);
-	struct kobject * kobj = to_kobj(dentry->d_parent);
+	struct sysfs_dirent *attr_sd = dentry->d_fsdata;
+	struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
 	struct sysfs_ops * ops = buffer->ops;
 	int ret = 0;
 	ssize_t count;
@@ -100,8 +84,15 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer
 	if (!buffer->page)
 		return -ENOMEM;
 
-	buffer->event = atomic_read(&sd->s_event);
-	count = ops->show(kobj,attr,buffer->page);
+	/* need attr_sd for attr and ops, its parent for kobj */
+	if (!sysfs_get_active_two(attr_sd))
+		return -ENODEV;
+
+	buffer->event = atomic_read(&attr_sd->s_event);
+	count = ops->show(kobj, attr_sd->s_elem.attr.attr, buffer->page);
+
+	sysfs_put_active_two(attr_sd);
+
 	BUG_ON(count > (ssize_t)PAGE_SIZE);
 	if (count >= 0) {
 		buffer->needs_read_fill = 0;
@@ -112,36 +103,6 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer
 	return ret;
 }
 
-
-/**
- *	flush_read_buffer - push buffer to userspace.
- *	@buffer:	data buffer for file.
- *	@buf:		user-passed buffer.
- *	@count:		number of bytes requested.
- *	@ppos:		file position.
- *
- *	Copy the buffer we filled in fill_read_buffer() to userspace.
- *	This is done at the reader's leisure, copying and advancing 
- *	the amount they specify each time.
- *	This may be called continuously until the buffer is empty.
- */
-static int flush_read_buffer(struct sysfs_buffer * buffer, char __user * buf,
-			     size_t count, loff_t * ppos)
-{
-	int error;
-
-	if (*ppos > buffer->count)
-		return 0;
-
-	if (count > (buffer->count - *ppos))
-		count = buffer->count - *ppos;
-
-	error = copy_to_user(buf,buffer->page + *ppos,count);
-	if (!error)
-		*ppos += count;
-	return error ? -EFAULT : count;
-}
-
 /**
  *	sysfs_read_file - read an attribute. 
  *	@file:	file pointer.
@@ -169,16 +130,14 @@ 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;
 	}
 	pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n",
 		 __FUNCTION__, count, *ppos, buffer->page);
-	retval = flush_read_buffer(buffer,buf,count,ppos);
+	retval = simple_read_from_buffer(buf, count, ppos, buffer->page,
+					 buffer->count);
 out:
 	up(&buffer->sem);
 	return retval;
@@ -226,14 +185,23 @@ fill_write_buffer(struct sysfs_buffer * buffer, const char __user * buf, size_t
  *	passing the buffer that we acquired in fill_write_buffer().
  */
 
-static int 
+static int
 flush_write_buffer(struct dentry * dentry, struct sysfs_buffer * buffer, size_t count)
 {
-	struct attribute * attr = to_attr(dentry);
-	struct kobject * kobj = to_kobj(dentry->d_parent);
+	struct sysfs_dirent *attr_sd = dentry->d_fsdata;
+	struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
 	struct sysfs_ops * ops = buffer->ops;
+	int rc;
+
+	/* need attr_sd for attr and ops, its parent for kobj */
+	if (!sysfs_get_active_two(attr_sd))
+		return -ENODEV;
 
-	return ops->store(kobj,attr,buffer->page,count);
+	rc = ops->store(kobj, attr_sd->s_elem.attr.attr, buffer->page, count);
+
+	sysfs_put_active_two(attr_sd);
+
+	return rc;
 }
 
 
@@ -261,37 +229,26 @@ 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;
 }
 
 static int sysfs_open_file(struct inode *inode, struct file *file)
 {
-	struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent);
-	struct attribute * attr = to_attr(file->f_path.dentry);
-	struct sysfs_buffer_collection *set;
+	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+	struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
 	struct sysfs_buffer * buffer;
 	struct sysfs_ops * ops = NULL;
-	int error = 0;
-
-	if (!kobj || !attr)
-		goto Einval;
+	int error;
 
-	/* Grab the module reference for this attribute if we have one */
-	if (!try_module_get(attr->owner)) {
-		error = -ENODEV;
-		goto Done;
-	}
+	/* need attr_sd for attr and ops, its parent for kobj */
+	if (!sysfs_get_active_two(attr_sd))
+		return -ENODEV;
 
 	/* if the kobject has no ktype, then we assume that it is a subsystem
 	 * itself, and use ops for it.
@@ -303,33 +260,21 @@ 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.
 	 */
 	if (!ops)
-		goto Eaccess;
-
-	/* make sure we have a collection to add our buffers to */
-	mutex_lock(&inode->i_mutex);
-	if (!(set = inode->i_private)) {
-		if (!(set = inode->i_private = kmalloc(sizeof(struct sysfs_buffer_collection), GFP_KERNEL))) {
-			error = -ENOMEM;
-			goto Done;
-		} else {
-			INIT_LIST_HEAD(&set->associates);
-		}
-	}
-	mutex_unlock(&inode->i_mutex);
+		goto err_out;
 
 	/* 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) || !ops->store)
-			goto Eaccess;
-
+			goto err_out;
 	}
 
 	/* File needs read support.
@@ -338,48 +283,38 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
 	 */
 	if (file->f_mode & FMODE_READ) {
 		if (!(inode->i_mode & S_IRUGO) || !ops->show)
-			goto Eaccess;
+			goto err_out;
 	}
 
 	/* No error? Great, allocate a buffer for the file, and store it
 	 * it in file->private_data for easy access.
 	 */
+	error = -ENOMEM;
 	buffer = kzalloc(sizeof(struct sysfs_buffer), GFP_KERNEL);
-	if (buffer) {
-		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;
-	} else
-		error = -ENOMEM;
-	goto Done;
+	if (!buffer)
+		goto err_out;
 
- Einval:
-	error = -EINVAL;
-	goto Done;
- Eaccess:
-	error = -EACCES;
-	module_put(attr->owner);
- Done:
-	if (error)
-		kobject_put(kobj);
+	init_MUTEX(&buffer->sem);
+	buffer->needs_read_fill = 1;
+	buffer->ops = ops;
+	file->private_data = buffer;
+
+	/* open succeeded, put active references and pin attr_sd */
+	sysfs_put_active_two(attr_sd);
+	sysfs_get(attr_sd);
+	return 0;
+
+ err_out:
+	sysfs_put_active_two(attr_sd);
 	return error;
 }
 
 static int sysfs_release(struct inode * inode, struct file * filp)
 {
-	struct kobject * kobj = to_kobj(filp->f_path.dentry->d_parent);
-	struct attribute * attr = to_attr(filp->f_path.dentry);
-	struct module * owner = attr->owner;
-	struct sysfs_buffer * buffer = filp->private_data;
+	struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata;
+	struct sysfs_buffer *buffer = filp->private_data;
 
-	if (buffer)
-		remove_from_collection(buffer, inode);
-	kobject_put(kobj);
-	/* After this point, attr should not be accessed. */
-	module_put(owner);
+	sysfs_put(attr_sd);
 
 	if (buffer) {
 		if (buffer->page)
@@ -406,18 +341,25 @@ static int sysfs_release(struct inode * inode, struct file * filp)
 static unsigned int sysfs_poll(struct file *filp, poll_table *wait)
 {
 	struct sysfs_buffer * buffer = filp->private_data;
-	struct kobject * kobj = to_kobj(filp->f_path.dentry->d_parent);
-	struct sysfs_dirent * sd = filp->f_path.dentry->d_fsdata;
-	int res = 0;
+	struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata;
+	struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
+
+	/* need parent for the kobj, grab both */
+	if (!sysfs_get_active_two(attr_sd))
+		goto trigger;
 
 	poll_wait(filp, &kobj->poll, wait);
 
-	if (buffer->event != atomic_read(&sd->s_event)) {
-		res = POLLERR|POLLPRI;
-		buffer->needs_read_fill = 1;
-	}
+	sysfs_put_active_two(attr_sd);
 
-	return res;
+	if (buffer->event != atomic_read(&attr_sd->s_event))
+		goto trigger;
+
+	return 0;
+
+ trigger:
+	buffer->needs_read_fill = 1;
+	return POLLERR|POLLPRI;
 }
 
 
@@ -474,14 +416,26 @@ int sysfs_add_file(struct dentry * dir, const struct attribute * attr, int type)
 {
 	struct sysfs_dirent * parent_sd = dir->d_fsdata;
 	umode_t mode = (attr->mode & S_IALLUGO) | S_IFREG;
-	int error = -EEXIST;
+	struct sysfs_dirent *sd;
+	int error = 0;
 
 	mutex_lock(&dir->d_inode->i_mutex);
-	if (!sysfs_dirent_exist(parent_sd, attr->name))
-		error = sysfs_make_dirent(parent_sd, NULL, (void *)attr,
-					  mode, type);
-	mutex_unlock(&dir->d_inode->i_mutex);
 
+	if (sysfs_dirent_exist(parent_sd, attr->name)) {
+		error = -EEXIST;
+		goto out_unlock;
+	}
+
+	sd = sysfs_new_dirent(attr->name, mode, type);
+	if (!sd) {
+		error = -ENOMEM;
+		goto out_unlock;
+	}
+	sd->s_elem.attr.attr = (void *)attr;
+	sysfs_attach_dirent(sd, parent_sd, NULL);
+
+ out_unlock:
+	mutex_unlock(&dir->d_inode->i_mutex);
 	return error;
 }