1 files changed, 246 insertions, 13 deletions

diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
index 66f6e58a7e4..07703d3ff4a 100644
--- a/fs/sysfs/bin.c
+++ b/fs/sysfs/bin.c
@@ -21,15 +21,28 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/mutex.h>
+#include <linux/mm.h>
 
 #include <asm/uaccess.h>
 
 #include "sysfs.h"
 
+/*
+ * There's one bin_buffer for each open file.
+ *
+ * filp->private_data points to bin_buffer and
+ * sysfs_dirent->s_bin_attr.buffers points to a the bin_buffer s
+ * sysfs_dirent->s_bin_attr.buffers is protected by sysfs_bin_lock
+ */
+static DEFINE_MUTEX(sysfs_bin_lock);
+
 struct bin_buffer {
-	struct mutex	mutex;
-	void		*buffer;
-	int		mmapped;
+	struct mutex			mutex;
+	void				*buffer;
+	int				mmapped;
+	struct vm_operations_struct 	*vm_ops;
+	struct file			*file;
+	struct hlist_node		list;
 };
 
 static int
@@ -63,6 +76,9 @@ read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off)
 	int count = min_t(size_t, bytes, PAGE_SIZE);
 	char *temp;
 
+	if (!bytes)
+		return 0;
+
 	if (size) {
 		if (offs > size)
 			return 0;
@@ -131,6 +147,9 @@ static ssize_t write(struct file *file, const char __user *userbuf,
 	int count = min_t(size_t, bytes, PAGE_SIZE);
 	char *temp;
 
+	if (!bytes)
+		return 0;
+
 	if (size) {
 		if (offs > size)
 			return 0;
@@ -162,6 +181,175 @@ out_free:
 	return count;
 }
 
+static void bin_vma_open(struct vm_area_struct *vma)
+{
+	struct file *file = vma->vm_file;
+	struct bin_buffer *bb = file->private_data;
+	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+
+	if (!bb->vm_ops || !bb->vm_ops->open)
+		return;
+
+	if (!sysfs_get_active_two(attr_sd))
+		return;
+
+	bb->vm_ops->open(vma);
+
+	sysfs_put_active_two(attr_sd);
+}
+
+static void bin_vma_close(struct vm_area_struct *vma)
+{
+	struct file *file = vma->vm_file;
+	struct bin_buffer *bb = file->private_data;
+	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+
+	if (!bb->vm_ops || !bb->vm_ops->close)
+		return;
+
+	if (!sysfs_get_active_two(attr_sd))
+		return;
+
+	bb->vm_ops->close(vma);
+
+	sysfs_put_active_two(attr_sd);
+}
+
+static int bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct file *file = vma->vm_file;
+	struct bin_buffer *bb = file->private_data;
+	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+	int ret;
+
+	if (!bb->vm_ops || !bb->vm_ops->fault)
+		return VM_FAULT_SIGBUS;
+
+	if (!sysfs_get_active_two(attr_sd))
+		return VM_FAULT_SIGBUS;
+
+	ret = bb->vm_ops->fault(vma, vmf);
+
+	sysfs_put_active_two(attr_sd);
+	return ret;
+}
+
+static int bin_page_mkwrite(struct vm_area_struct *vma, struct page *page)
+{
+	struct file *file = vma->vm_file;
+	struct bin_buffer *bb = file->private_data;
+	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+	int ret;
+
+	if (!bb->vm_ops)
+		return -EINVAL;
+
+	if (!bb->vm_ops->page_mkwrite)
+		return 0;
+
+	if (!sysfs_get_active_two(attr_sd))
+		return -EINVAL;
+
+	ret = bb->vm_ops->page_mkwrite(vma, page);
+
+	sysfs_put_active_two(attr_sd);
+	return ret;
+}
+
+static int bin_access(struct vm_area_struct *vma, unsigned long addr,
+		  void *buf, int len, int write)
+{
+	struct file *file = vma->vm_file;
+	struct bin_buffer *bb = file->private_data;
+	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+	int ret;
+
+	if (!bb->vm_ops || !bb->vm_ops->access)
+		return -EINVAL;
+
+	if (!sysfs_get_active_two(attr_sd))
+		return -EINVAL;
+
+	ret = bb->vm_ops->access(vma, addr, buf, len, write);
+
+	sysfs_put_active_two(attr_sd);
+	return ret;
+}
+
+#ifdef CONFIG_NUMA
+static int bin_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
+{
+	struct file *file = vma->vm_file;
+	struct bin_buffer *bb = file->private_data;
+	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+	int ret;
+
+	if (!bb->vm_ops || !bb->vm_ops->set_policy)
+		return 0;
+
+	if (!sysfs_get_active_two(attr_sd))
+		return -EINVAL;
+
+	ret = bb->vm_ops->set_policy(vma, new);
+
+	sysfs_put_active_two(attr_sd);
+	return ret;
+}
+
+static struct mempolicy *bin_get_policy(struct vm_area_struct *vma,
+					unsigned long addr)
+{
+	struct file *file = vma->vm_file;
+	struct bin_buffer *bb = file->private_data;
+	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+	struct mempolicy *pol;
+
+	if (!bb->vm_ops || !bb->vm_ops->get_policy)
+		return vma->vm_policy;
+
+	if (!sysfs_get_active_two(attr_sd))
+		return vma->vm_policy;
+
+	pol = bb->vm_ops->get_policy(vma, addr);
+
+	sysfs_put_active_two(attr_sd);
+	return pol;
+}
+
+static int bin_migrate(struct vm_area_struct *vma, const nodemask_t *from,
+			const nodemask_t *to, unsigned long flags)
+{
+	struct file *file = vma->vm_file;
+	struct bin_buffer *bb = file->private_data;
+	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
+	int ret;
+
+	if (!bb->vm_ops || !bb->vm_ops->migrate)
+		return 0;
+
+	if (!sysfs_get_active_two(attr_sd))
+		return 0;
+
+	ret = bb->vm_ops->migrate(vma, from, to, flags);
+
+	sysfs_put_active_two(attr_sd);
+	return ret;
+}
+#endif
+
+static struct vm_operations_struct bin_vm_ops = {
+	.open		= bin_vma_open,
+	.close		= bin_vma_close,
+	.fault		= bin_fault,
+	.page_mkwrite	= bin_page_mkwrite,
+	.access		= bin_access,
+#ifdef CONFIG_NUMA
+	.set_policy	= bin_set_policy,
+	.get_policy	= bin_get_policy,
+	.migrate	= bin_migrate,
+#endif
+};
+
 static int mmap(struct file *file, struct vm_area_struct *vma)
 {
 	struct bin_buffer *bb = file->private_data;
@@ -173,18 +361,37 @@ static int mmap(struct file *file, struct vm_area_struct *vma)
 	mutex_lock(&bb->mutex);
 
 	/* need attr_sd for attr, its parent for kobj */
+	rc = -ENODEV;
 	if (!sysfs_get_active_two(attr_sd))
-		return -ENODEV;
+		goto out_unlock;
 
 	rc = -EINVAL;
-	if (attr->mmap)
-		rc = attr->mmap(kobj, attr, vma);
+	if (!attr->mmap)
+		goto out_put;
+
+	rc = attr->mmap(kobj, attr, vma);
+	if (rc)
+		goto out_put;
 
-	if (rc == 0 && !bb->mmapped)
-		bb->mmapped = 1;
-	else
-		sysfs_put_active_two(attr_sd);
+	/*
+	 * PowerPC's pci_mmap of legacy_mem uses shmem_zero_setup()
+	 * to satisfy versions of X which crash if the mmap fails: that
+	 * substitutes a new vm_file, and we don't then want bin_vm_ops.
+	 */
+	if (vma->vm_file != file)
+		goto out_put;
 
+	rc = -EINVAL;
+	if (bb->mmapped && bb->vm_ops != vma->vm_ops)
+		goto out_put;
+
+	rc = 0;
+	bb->mmapped = 1;
+	bb->vm_ops = vma->vm_ops;
+	vma->vm_ops = &bin_vm_ops;
+out_put:
+	sysfs_put_active_two(attr_sd);
+out_unlock:
 	mutex_unlock(&bb->mutex);
 
 	return rc;
@@ -217,8 +424,13 @@ static int open(struct inode * inode, struct file * file)
 		goto err_out;
 
 	mutex_init(&bb->mutex);
+	bb->file = file;
 	file->private_data = bb;
 
+	mutex_lock(&sysfs_bin_lock);
+	hlist_add_head(&bb->list, &attr_sd->s_bin_attr.buffers);
+	mutex_unlock(&sysfs_bin_lock);
+
 	/* open succeeded, put active references */
 	sysfs_put_active_two(attr_sd);
 	return 0;
@@ -231,11 +443,12 @@ static int open(struct inode * inode, struct file * file)
 
 static int release(struct inode * inode, struct file * file)
 {
-	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);
+	mutex_lock(&sysfs_bin_lock);
+	hlist_del(&bb->list);
+	mutex_unlock(&sysfs_bin_lock);
+
 	kfree(bb->buffer);
 	kfree(bb);
 	return 0;
@@ -250,6 +463,26 @@ const struct file_operations bin_fops = {
 	.release	= release,
 };
 
+
+void unmap_bin_file(struct sysfs_dirent *attr_sd)
+{
+	struct bin_buffer *bb;
+	struct hlist_node *tmp;
+
+	if (sysfs_type(attr_sd) != SYSFS_KOBJ_BIN_ATTR)
+		return;
+
+	mutex_lock(&sysfs_bin_lock);
+
+	hlist_for_each_entry(bb, tmp, &attr_sd->s_bin_attr.buffers, list) {
+		struct inode *inode = bb->file->f_path.dentry->d_inode;
+
+		unmap_mapping_range(inode->i_mapping, 0, 0, 1);
+	}
+
+	mutex_unlock(&sysfs_bin_lock);
+}
+
 /**
  *	sysfs_create_bin_file - create binary file for object.
  *	@kobj:	object.