1 files changed, 124 insertions, 76 deletions

diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
index d3b9f5f07db1..5afe2a26f5d8 100644
--- a/fs/sysfs/bin.c
+++ b/fs/sysfs/bin.c
@@ -20,29 +20,41 @@
 
 #include "sysfs.h"
 
+struct bin_buffer {
+	struct mutex	mutex;
+	void		*buffer;
+	int		mmapped;
+};
+
 static int
 fill_read(struct dentry *dentry, char *buffer, loff_t off, size_t count)
 {
-	struct bin_attribute * attr = to_bin_attr(dentry);
-	struct kobject * kobj = to_kobj(dentry->d_parent);
+	struct sysfs_dirent *attr_sd = dentry->d_fsdata;
+	struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
+	struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
+	int rc;
+
+	/* need attr_sd for attr, its parent for kobj */
+	if (!sysfs_get_active_two(attr_sd))
+		return -ENODEV;
+
+	rc = -EIO;
+	if (attr->read)
+		rc = attr->read(kobj, attr, buffer, off, count);
 
-	if (!attr->read)
-		return -EIO;
+	sysfs_put_active_two(attr_sd);
 
-	return attr->read(kobj, buffer, off, count);
+	return rc;
 }
 
 static ssize_t
-read(struct file * file, char __user * userbuf, size_t count, loff_t * off)
+read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off)
 {
-	char *buffer = file->private_data;
+	struct bin_buffer *bb = file->private_data;
 	struct dentry *dentry = file->f_path.dentry;
 	int size = dentry->d_inode->i_size;
 	loff_t offs = *off;
-	int ret;
-
-	if (count > PAGE_SIZE)
-		count = PAGE_SIZE;
+	int count = min_t(size_t, bytes, PAGE_SIZE);
 
 	if (size) {
 		if (offs > size)
@@ -51,43 +63,56 @@ read(struct file * file, char __user * userbuf, size_t count, loff_t * off)
 			count = size - offs;
 	}
 
-	ret = fill_read(dentry, buffer, offs, count);
-	if (ret < 0) 
-		return ret;
-	count = ret;
+	mutex_lock(&bb->mutex);
+
+	count = fill_read(dentry, bb->buffer, offs, count);
+	if (count < 0)
+		goto out_unlock;
 
-	if (copy_to_user(userbuf, buffer, count))
-		return -EFAULT;
+	if (copy_to_user(userbuf, bb->buffer, count)) {
+		count = -EFAULT;
+		goto out_unlock;
+	}
 
-	pr_debug("offs = %lld, *off = %lld, count = %zd\n", offs, *off, count);
+	pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count);
 
 	*off = offs + count;
 
+ out_unlock:
+	mutex_unlock(&bb->mutex);
 	return count;
 }
 
 static int
 flush_write(struct dentry *dentry, char *buffer, loff_t offset, size_t count)
 {
-	struct bin_attribute *attr = to_bin_attr(dentry);
-	struct kobject *kobj = to_kobj(dentry->d_parent);
+	struct sysfs_dirent *attr_sd = dentry->d_fsdata;
+	struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
+	struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
+	int rc;
 
-	if (!attr->write)
-		return -EIO;
+	/* need attr_sd for attr, its parent for kobj */
+	if (!sysfs_get_active_two(attr_sd))
+		return -ENODEV;
 
-	return attr->write(kobj, buffer, offset, count);
+	rc = -EIO;
+	if (attr->write)
+		rc = attr->write(kobj, attr, buffer, offset, count);
+
+	sysfs_put_active_two(attr_sd);
+
+	return rc;
 }
 
-static ssize_t write(struct file * file, const char __user * userbuf,
-		     size_t count, loff_t * off)
+static ssize_t write(struct file *file, const char __user *userbuf,
+		     size_t bytes, loff_t *off)
 {
-	char *buffer = file->private_data;
+	struct bin_buffer *bb = file->private_data;
 	struct dentry *dentry = file->f_path.dentry;
 	int size = dentry->d_inode->i_size;
 	loff_t offs = *off;
+	int count = min_t(size_t, bytes, PAGE_SIZE);
 
-	if (count > PAGE_SIZE)
-		count = PAGE_SIZE;
 	if (size) {
 		if (offs > size)
 			return 0;
@@ -95,72 +120,100 @@ static ssize_t write(struct file * file, const char __user * userbuf,
 			count = size - offs;
 	}
 
-	if (copy_from_user(buffer, userbuf, count))
-		return -EFAULT;
+	mutex_lock(&bb->mutex);
+
+	if (copy_from_user(bb->buffer, userbuf, count)) {
+		count = -EFAULT;
+		goto out_unlock;
+	}
 
-	count = flush_write(dentry, buffer, offs, count);
+	count = flush_write(dentry, bb->buffer, offs, count);
 	if (count > 0)
 		*off = offs + count;
+
+ out_unlock:
+	mutex_unlock(&bb->mutex);
 	return count;
 }
 
 static int mmap(struct file *file, struct vm_area_struct *vma)
 {
-	struct dentry *dentry = file->f_path.dentry;
-	struct bin_attribute *attr = to_bin_attr(dentry);
-	struct kobject *kobj = to_kobj(dentry->d_parent);
+	struct bin_buffer *bb = file->private_data;
+	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+	struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
+	struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
+	int rc;
 
-	if (!attr->mmap)
-		return -EINVAL;
+	mutex_lock(&bb->mutex);
 
-	return attr->mmap(kobj, attr, vma);
+	/* need attr_sd for attr, its parent for kobj */
+	if (!sysfs_get_active_two(attr_sd))
+		return -ENODEV;
+
+	rc = -EINVAL;
+	if (attr->mmap)
+		rc = attr->mmap(kobj, attr, vma);
+
+	if (rc == 0 && !bb->mmapped)
+		bb->mmapped = 1;
+	else
+		sysfs_put_active_two(attr_sd);
+
+	mutex_unlock(&bb->mutex);
+
+	return rc;
 }
 
 static int open(struct inode * inode, struct file * file)
 {
-	struct kobject *kobj = sysfs_get_kobject(file->f_path.dentry->d_parent);
-	struct bin_attribute * attr = to_bin_attr(file->f_path.dentry);
-	int error = -EINVAL;
-
-	if (!kobj || !attr)
-		goto Done;
+	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+	struct bin_attribute *attr = attr_sd->s_elem.bin_attr.bin_attr;
+	struct bin_buffer *bb = NULL;
+	int error;
 
-	/* Grab the module reference for this attribute if we have one */
-	error = -ENODEV;
-	if (!try_module_get(attr->attr.owner)) 
-		goto Done;
+	/* need attr_sd for attr */
+	if (!sysfs_get_active(attr_sd))
+		return -ENODEV;
 
 	error = -EACCES;
 	if ((file->f_mode & FMODE_WRITE) && !(attr->write || attr->mmap))
-		goto Error;
+		goto err_out;
 	if ((file->f_mode & FMODE_READ) && !(attr->read || attr->mmap))
-		goto Error;
+		goto err_out;
 
 	error = -ENOMEM;
-	file->private_data = kmalloc(PAGE_SIZE, GFP_KERNEL);
-	if (!file->private_data)
-		goto Error;
-
-	error = 0;
-    goto Done;
-
- Error:
-	module_put(attr->attr.owner);
- Done:
-	if (error)
-		kobject_put(kobj);
+	bb = kzalloc(sizeof(*bb), GFP_KERNEL);
+	if (!bb)
+		goto err_out;
+
+	bb->buffer = kmalloc(PAGE_SIZE, GFP_KERNEL);
+	if (!bb->buffer)
+		goto err_out;
+
+	mutex_init(&bb->mutex);
+	file->private_data = bb;
+
+	/* open succeeded, put active reference and pin attr_sd */
+	sysfs_put_active(attr_sd);
+	sysfs_get(attr_sd);
+	return 0;
+
+ err_out:
+	sysfs_put_active(attr_sd);
+	kfree(bb);
 	return error;
 }
 
 static int release(struct inode * inode, struct file * file)
 {
-	struct kobject * kobj = to_kobj(file->f_path.dentry->d_parent);
-	struct bin_attribute * attr = to_bin_attr(file->f_path.dentry);
-	u8 * buffer = file->private_data;
-
-	kobject_put(kobj);
-	module_put(attr->attr.owner);
-	kfree(buffer);
+	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+	struct bin_buffer *bb = file->private_data;
+
+	if (bb->mmapped)
+		sysfs_put_active_two(attr_sd);
+	sysfs_put(attr_sd);
+	kfree(bb->buffer);
+	kfree(bb);
 	return 0;
 }
 
@@ -181,9 +234,9 @@ const struct file_operations bin_fops = {
 
 int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr)
 {
-	BUG_ON(!kobj || !kobj->dentry || !attr);
+	BUG_ON(!kobj || !kobj->sd || !attr);
 
-	return sysfs_add_file(kobj->dentry, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
+	return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
 }
 
 
@@ -195,12 +248,7 @@ int sysfs_create_bin_file(struct kobject * kobj, struct bin_attribute * attr)
 
 void sysfs_remove_bin_file(struct kobject * kobj, struct bin_attribute * attr)
 {
-	if (sysfs_hash_and_remove(kobj->dentry, attr->attr.name) < 0) {
-		printk(KERN_ERR "%s: "
-			"bad dentry or inode or no such file: \"%s\"\n",
-			__FUNCTION__, attr->attr.name);
-		dump_stack();
-	}
+	sysfs_hash_and_remove(kobj->sd, attr->attr.name);
 }
 
 EXPORT_SYMBOL_GPL(sysfs_create_bin_file);