Merge tag 'driver-core-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core / sysfs patches from Greg KH:
 "Here's the big driver core / sysfs update for 3.13-rc1.

  There's lots of dev_groups updates for different subsystems, as they
  all get slowly migrated over to the safe versions of the attribute
  groups (removing userspace races with the creation of the sysfs
  files.) Also in here are some kobject updates, devres expansions, and
  the first round of Tejun's sysfs reworking to enable it to be used by
  other subsystems as a backend for an in-kernel filesystem.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (83 commits)
  sysfs: rename sysfs_assoc_lock and explain what it's about
  sysfs: use generic_file_llseek() for sysfs_file_operations
  sysfs: return correct error code on unimplemented mmap()
  mdio_bus: convert bus code to use dev_groups
  device: Make dev_WARN/dev_WARN_ONCE print device as well as driver name
  sysfs: separate out dup filename warning into a separate function
  sysfs: move sysfs_hash_and_remove() to fs/sysfs/dir.c
  sysfs: remove unused sysfs_get_dentry() prototype
  sysfs: honor bin_attr.attr.ignore_lockdep
  sysfs: merge sysfs_elem_bin_attr into sysfs_elem_attr
  devres: restore zeroing behavior of devres_alloc()
  sysfs: fix sysfs_write_file for bin file
  input: gameport: convert bus code to use dev_groups
  input: serio: remove bus usage of dev_attrs
  input: serio: use DEVICE_ATTR_RO()
  i2o: convert bus code to use dev_groups
  memstick: convert bus code to use dev_groups
  tifm: convert bus code to use dev_groups
  virtio: convert bus code to use dev_groups
  ipack: convert bus code to use dev_groups
  ...

1 files changed, 591 insertions, 281 deletions

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 15ef5eb..79b5da2 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -21,70 +21,114 @@
 #include <linux/mutex.h>
 #include <linux/limits.h>
 #include <linux/uaccess.h>
+#include <linux/seq_file.h>
+#include <linux/mm.h>
 
 #include "sysfs.h"
 
 /*
- * There's one sysfs_buffer for each open file and one
- * sysfs_open_dirent for each sysfs_dirent with one or more open
- * files.
+ * There's one sysfs_open_file for each open file and one sysfs_open_dirent
+ * for each sysfs_dirent with one or more open files.
  *
- * filp->private_data points to sysfs_buffer and
- * sysfs_dirent->s_attr.open points to sysfs_open_dirent.  s_attr.open
- * is protected by sysfs_open_dirent_lock.
+ * sysfs_dirent->s_attr.open points to sysfs_open_dirent.  s_attr.open is
+ * protected by sysfs_open_dirent_lock.
+ *
+ * filp->private_data points to seq_file whose ->private points to
+ * sysfs_open_file.  sysfs_open_files are chained at
+ * sysfs_open_dirent->files, which is protected by sysfs_open_file_mutex.
  */
 static DEFINE_SPINLOCK(sysfs_open_dirent_lock);
+static DEFINE_MUTEX(sysfs_open_file_mutex);
 
 struct sysfs_open_dirent {
 	atomic_t		refcnt;
 	atomic_t		event;
 	wait_queue_head_t	poll;
-	struct list_head	buffers; /* goes through sysfs_buffer.list */
+	struct list_head	files; /* goes through sysfs_open_file.list */
 };
 
-struct sysfs_buffer {
-	size_t			count;
-	loff_t			pos;
-	char			*page;
-	const struct sysfs_ops	*ops;
+struct sysfs_open_file {
+	struct sysfs_dirent	*sd;
+	struct file		*file;
 	struct mutex		mutex;
-	int			needs_read_fill;
 	int			event;
 	struct list_head	list;
+
+	bool			mmapped;
+	const struct vm_operations_struct *vm_ops;
 };
 
-/**
- *	fill_read_buffer - allocate and fill buffer from object.
- *	@dentry:	dentry pointer.
- *	@buffer:	data buffer for file.
- *
- *	Allocate @buffer->page, if it hasn't been already, then call the
- *	kobject's show() method to fill the buffer with this attribute's
- *	data.
- *	This is called only once, on the file's first read unless an error
- *	is returned.
+static bool sysfs_is_bin(struct sysfs_dirent *sd)
+{
+	return sysfs_type(sd) == SYSFS_KOBJ_BIN_ATTR;
+}
+
+static struct sysfs_open_file *sysfs_of(struct file *file)
+{
+	return ((struct seq_file *)file->private_data)->private;
+}
+
+/*
+ * Determine ktype->sysfs_ops for the given sysfs_dirent.  This function
+ * must be called while holding an active reference.
  */
-static int fill_read_buffer(struct dentry *dentry, struct sysfs_buffer *buffer)
+static const struct sysfs_ops *sysfs_file_ops(struct sysfs_dirent *sd)
 {
-	struct sysfs_dirent *attr_sd = dentry->d_fsdata;
-	struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
-	const struct sysfs_ops *ops = buffer->ops;
-	int ret = 0;
+	struct kobject *kobj = sd->s_parent->s_dir.kobj;
+
+	if (!sysfs_ignore_lockdep(sd))
+		lockdep_assert_held(sd);
+	return kobj->ktype ? kobj->ktype->sysfs_ops : NULL;
+}
+
+/*
+ * Reads on sysfs are handled through seq_file, which takes care of hairy
+ * details like buffering and seeking.  The following function pipes
+ * sysfs_ops->show() result through seq_file.
+ */
+static int sysfs_seq_show(struct seq_file *sf, void *v)
+{
+	struct sysfs_open_file *of = sf->private;
+	struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
+	const struct sysfs_ops *ops;
+	char *buf;
 	ssize_t count;
 
-	if (!buffer->page)
-		buffer->page = (char *) get_zeroed_page(GFP_KERNEL);
-	if (!buffer->page)
-		return -ENOMEM;
+	/* acquire buffer and ensure that it's >= PAGE_SIZE */
+	count = seq_get_buf(sf, &buf);
+	if (count < PAGE_SIZE) {
+		seq_commit(sf, -1);
+		return 0;
+	}
 
-	/* need attr_sd for attr and ops, its parent for kobj */
-	if (!sysfs_get_active(attr_sd))
+	/*
+	 * Need @of->sd for attr and ops, its parent for kobj.  @of->mutex
+	 * nests outside active ref and is just to ensure that the ops
+	 * aren't called concurrently for the same open file.
+	 */
+	mutex_lock(&of->mutex);
+	if (!sysfs_get_active(of->sd)) {
+		mutex_unlock(&of->mutex);
 		return -ENODEV;
+	}
 
-	buffer->event = atomic_read(&attr_sd->s_attr.open->event);
-	count = ops->show(kobj, attr_sd->s_attr.attr, buffer->page);
+	of->event = atomic_read(&of->sd->s_attr.open->event);
 
-	sysfs_put_active(attr_sd);
+	/*
+	 * Lookup @ops and invoke show().  Control may reach here via seq
+	 * file lseek even if @ops->show() isn't implemented.
+	 */
+	ops = sysfs_file_ops(of->sd);
+	if (ops->show)
+		count = ops->show(kobj, of->sd->s_attr.attr, buf);
+	else
+		count = 0;
+
+	sysfs_put_active(of->sd);
+	mutex_unlock(&of->mutex);
+
+	if (count < 0)
+		return count;
 
 	/*
 	 * The code works fine with PAGE_SIZE return but it's likely to
@@ -96,155 +140,389 @@ static int fill_read_buffer(struct dentry *dentry, struct sysfs_buffer *buffer)
 		/* Try to struggle along */
 		count = PAGE_SIZE - 1;
 	}
-	if (count >= 0) {
-		buffer->needs_read_fill = 0;
-		buffer->count = count;
-	} else {
-		ret = count;
-	}
-	return ret;
+	seq_commit(sf, count);
+	return 0;
 }
 
-/**
- *	sysfs_read_file - read an attribute.
- *	@file:	file pointer.
- *	@buf:	buffer to fill.
- *	@count:	number of bytes to read.
- *	@ppos:	starting offset in file.
- *
- *	Userspace wants to read an attribute file. The attribute descriptor
- *	is in the file's ->d_fsdata. The target object is in the directory's
- *	->d_fsdata.
- *
- *	We call fill_read_buffer() to allocate and fill the buffer from the
- *	object's show() method exactly once (if the read is happening from
- *	the beginning of the file). That should fill the entire buffer with
- *	all the data the object has to offer for that attribute.
- *	We then call flush_read_buffer() to copy the buffer to userspace
- *	in the increments specified.
+/*
+ * Read method for bin files.  As reading a bin file can have side-effects,
+ * the exact offset and bytes specified in read(2) call should be passed to
+ * the read callback making it difficult to use seq_file.  Implement
+ * simplistic custom buffering for bin files.
  */
-
-static ssize_t
-sysfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+static ssize_t sysfs_bin_read(struct file *file, char __user *userbuf,
+			      size_t bytes, loff_t *off)
 {
-	struct sysfs_buffer *buffer = file->private_data;
-	ssize_t retval = 0;
+	struct sysfs_open_file *of = sysfs_of(file);
+	struct bin_attribute *battr = of->sd->s_attr.bin_attr;
+	struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
+	loff_t size = file_inode(file)->i_size;
+	int count = min_t(size_t, bytes, PAGE_SIZE);
+	loff_t offs = *off;
+	char *buf;
+
+	if (!bytes)
+		return 0;
 
-	mutex_lock(&buffer->mutex);
-	if (buffer->needs_read_fill || *ppos == 0) {
-		retval = fill_read_buffer(file->f_path.dentry, buffer);
-		if (retval)
-			goto out;
+	if (size) {
+		if (offs > size)
+			return 0;
+		if (offs + count > size)
+			count = size - offs;
 	}
-	pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n",
-		 __func__, count, *ppos, buffer->page);
-	retval = simple_read_from_buffer(buf, count, ppos, buffer->page,
-					 buffer->count);
-out:
-	mutex_unlock(&buffer->mutex);
-	return retval;
-}
 
-/**
- *	fill_write_buffer - copy buffer from userspace.
- *	@buffer:	data buffer for file.
- *	@buf:		data from user.
- *	@count:		number of bytes in @userbuf.
- *
- *	Allocate @buffer->page if it hasn't been already, then
- *	copy the user-supplied buffer into it.
- */
-static int fill_write_buffer(struct sysfs_buffer *buffer,
-			     const char __user *buf, size_t count)
-{
-	int error;
-
-	if (!buffer->page)
-		buffer->page = (char *)get_zeroed_page(GFP_KERNEL);
-	if (!buffer->page)
+	buf = kmalloc(count, GFP_KERNEL);
+	if (!buf)
 		return -ENOMEM;
 
-	if (count >= PAGE_SIZE)
-		count = PAGE_SIZE - 1;
-	error = copy_from_user(buffer->page, buf, count);
-	buffer->needs_read_fill = 1;
-	/* if buf is assumed to contain a string, terminate it by \0,
-	   so e.g. sscanf() can scan the string easily */
-	buffer->page[count] = 0;
-	return error ? -EFAULT : count;
-}
+	/* need of->sd for battr, its parent for kobj */
+	mutex_lock(&of->mutex);
+	if (!sysfs_get_active(of->sd)) {
+		count = -ENODEV;
+		mutex_unlock(&of->mutex);
+		goto out_free;
+	}
+
+	if (battr->read)
+		count = battr->read(file, kobj, battr, buf, offs, count);
+	else
+		count = -EIO;
 
+	sysfs_put_active(of->sd);
+	mutex_unlock(&of->mutex);
+
+	if (count < 0)
+		goto out_free;
+
+	if (copy_to_user(userbuf, buf, count)) {
+		count = -EFAULT;
+		goto out_free;
+	}
+
+	pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count);
+
+	*off = offs + count;
+
+ out_free:
+	kfree(buf);
+	return count;
+}
 
 /**
- *	flush_write_buffer - push buffer to kobject.
- *	@dentry:	dentry to the attribute
- *	@buffer:	data buffer for file.
- *	@count:		number of bytes
+ * flush_write_buffer - push buffer to kobject
+ * @of: open file
+ * @buf: data buffer for file
+ * @off: file offset to write to
+ * @count: number of bytes
  *
- *	Get the correct pointers for the kobject and the attribute we're
- *	dealing with, then call the store() method for the attribute,
- *	passing the buffer that we acquired in fill_write_buffer().
+ * Get the correct pointers for the kobject and the attribute we're dealing
+ * with, then call the store() method for it with @buf.
  */
-static int flush_write_buffer(struct dentry *dentry,
-			      struct sysfs_buffer *buffer, size_t count)
+static int flush_write_buffer(struct sysfs_open_file *of, char *buf, loff_t off,
+			      size_t count)
 {
-	struct sysfs_dirent *attr_sd = dentry->d_fsdata;
-	struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
-	const struct sysfs_ops *ops = buffer->ops;
-	int rc;
+	struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
+	int rc = 0;
 
-	/* need attr_sd for attr and ops, its parent for kobj */
-	if (!sysfs_get_active(attr_sd))
+	/*
+	 * Need @of->sd for attr and ops, its parent for kobj.  @of->mutex
+	 * nests outside active ref and is just to ensure that the ops
+	 * aren't called concurrently for the same open file.
+	 */
+	mutex_lock(&of->mutex);
+	if (!sysfs_get_active(of->sd)) {
+		mutex_unlock(&of->mutex);
 		return -ENODEV;
+	}
 
-	rc = ops->store(kobj, attr_sd->s_attr.attr, buffer->page, count);
+	if (sysfs_is_bin(of->sd)) {
+		struct bin_attribute *battr = of->sd->s_attr.bin_attr;
 
-	sysfs_put_active(attr_sd);
+		rc = -EIO;
+		if (battr->write)
+			rc = battr->write(of->file, kobj, battr, buf, off,
+					  count);
+	} else {
+		const struct sysfs_ops *ops = sysfs_file_ops(of->sd);
+
+		rc = ops->store(kobj, of->sd->s_attr.attr, buf, count);
+	}
+
+	sysfs_put_active(of->sd);
+	mutex_unlock(&of->mutex);
 
 	return rc;
 }
 
-
 /**
- *	sysfs_write_file - write an attribute.
- *	@file:	file pointer
- *	@buf:	data to write
- *	@count:	number of bytes
- *	@ppos:	starting offset
+ * sysfs_write_file - write an attribute
+ * @file: file pointer
+ * @user_buf: data to write
+ * @count: number of bytes
+ * @ppos: starting offset
+ *
+ * Copy data in from userland and pass it to the matching
+ * sysfs_ops->store() by invoking flush_write_buffer().
  *
- *	Similar to sysfs_read_file(), though working in the opposite direction.
- *	We allocate and fill the data from the user in fill_write_buffer(),
- *	then push it to the kobject in flush_write_buffer().
- *	There is no easy way for us to know if userspace is only doing a partial
- *	write, so we don't support them. We expect the entire buffer to come
- *	on the first write.
- *	Hint: if you're writing a value, first read the file, modify only the
- *	the value you're changing, then write entire buffer back.
+ * There is no easy way for us to know if userspace is only doing a partial
+ * write, so we don't support them. We expect the entire buffer to come on
+ * the first write.  Hint: if you're writing a value, first read the file,
+ * modify only the the value you're changing, then write entire buffer
+ * back.
  */
-static ssize_t sysfs_write_file(struct file *file, const char __user *buf,
+static ssize_t sysfs_write_file(struct file *file, const char __user *user_buf,
 				size_t count, loff_t *ppos)
 {
-	struct sysfs_buffer *buffer = file->private_data;
-	ssize_t len;
+	struct sysfs_open_file *of = sysfs_of(file);
+	ssize_t len = min_t(size_t, count, PAGE_SIZE);
+	loff_t size = file_inode(file)->i_size;
+	char *buf;
+
+	if (sysfs_is_bin(of->sd) && size) {
+		if (size <= *ppos)
+			return 0;
+		len = min_t(ssize_t, len, size - *ppos);
+	}
 
-	mutex_lock(&buffer->mutex);
-	len = fill_write_buffer(buffer, buf, count);
-	if (len > 0)
-		len = flush_write_buffer(file->f_path.dentry, buffer, len);
+	if (!len)
+		return 0;
+
+	buf = kmalloc(len + 1, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	if (copy_from_user(buf, user_buf, len)) {
+		len = -EFAULT;
+		goto out_free;
+	}
+	buf[len] = '\0';	/* guarantee string termination */
+
+	len = flush_write_buffer(of, buf, *ppos, len);
 	if (len > 0)
 		*ppos += len;
-	mutex_unlock(&buffer->mutex);
+out_free:
+	kfree(buf);
 	return len;
 }
 
+static void sysfs_bin_vma_open(struct vm_area_struct *vma)
+{
+	struct file *file = vma->vm_file;
+	struct sysfs_open_file *of = sysfs_of(file);
+
+	if (!of->vm_ops)
+		return;
+
+	if (!sysfs_get_active(of->sd))
+		return;
+
+	if (of->vm_ops->open)
+		of->vm_ops->open(vma);
+
+	sysfs_put_active(of->sd);
+}
+
+static int sysfs_bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+	struct file *file = vma->vm_file;
+	struct sysfs_open_file *of = sysfs_of(file);
+	int ret;
+
+	if (!of->vm_ops)
+		return VM_FAULT_SIGBUS;
+
+	if (!sysfs_get_active(of->sd))
+		return VM_FAULT_SIGBUS;
+
+	ret = VM_FAULT_SIGBUS;
+	if (of->vm_ops->fault)
+		ret = of->vm_ops->fault(vma, vmf);
+
+	sysfs_put_active(of->sd);
+	return ret;
+}
+
+static int sysfs_bin_page_mkwrite(struct vm_area_struct *vma,
+				  struct vm_fault *vmf)
+{
+	struct file *file = vma->vm_file;
+	struct sysfs_open_file *of = sysfs_of(file);
+	int ret;
+
+	if (!of->vm_ops)
+		return VM_FAULT_SIGBUS;
+
+	if (!sysfs_get_active(of->sd))
+		return VM_FAULT_SIGBUS;
+
+	ret = 0;
+	if (of->vm_ops->page_mkwrite)
+		ret = of->vm_ops->page_mkwrite(vma, vmf);
+	else
+		file_update_time(file);
+
+	sysfs_put_active(of->sd);
+	return ret;
+}
+
+static int sysfs_bin_access(struct vm_area_struct *vma, unsigned long addr,
+			    void *buf, int len, int write)
+{
+	struct file *file = vma->vm_file;
+	struct sysfs_open_file *of = sysfs_of(file);
+	int ret;
+
+	if (!of->vm_ops)
+		return -EINVAL;
+
+	if (!sysfs_get_active(of->sd))
+		return -EINVAL;
+
+	ret = -EINVAL;
+	if (of->vm_ops->access)
+		ret = of->vm_ops->access(vma, addr, buf, len, write);
+
+	sysfs_put_active(of->sd);
+	return ret;
+}
+
+#ifdef CONFIG_NUMA
+static int sysfs_bin_set_policy(struct vm_area_struct *vma,
+				struct mempolicy *new)
+{
+	struct file *file = vma->vm_file;
+	struct sysfs_open_file *of = sysfs_of(file);
+	int ret;
+
+	if (!of->vm_ops)
+		return 0;
+
+	if (!sysfs_get_active(of->sd))
+		return -EINVAL;
+
+	ret = 0;
+	if (of->vm_ops->set_policy)
+		ret = of->vm_ops->set_policy(vma, new);
+
+	sysfs_put_active(of->sd);
+	return ret;
+}
+
+static struct mempolicy *sysfs_bin_get_policy(struct vm_area_struct *vma,
+					      unsigned long addr)
+{
+	struct file *file = vma->vm_file;
+	struct sysfs_open_file *of = sysfs_of(file);
+	struct mempolicy *pol;
+
+	if (!of->vm_ops)
+		return vma->vm_policy;
+
+	if (!sysfs_get_active(of->sd))
+		return vma->vm_policy;
+
+	pol = vma->vm_policy;
+	if (of->vm_ops->get_policy)
+		pol = of->vm_ops->get_policy(vma, addr);
+
+	sysfs_put_active(of->sd);
+	return pol;
+}
+
+static int sysfs_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 sysfs_open_file *of = sysfs_of(file);
+	int ret;
+
+	if (!of->vm_ops)
+		return 0;
+
+	if (!sysfs_get_active(of->sd))
+		return 0;
+
+	ret = 0;
+	if (of->vm_ops->migrate)
+		ret = of->vm_ops->migrate(vma, from, to, flags);
+
+	sysfs_put_active(of->sd);
+	return ret;
+}
+#endif
+
+static const struct vm_operations_struct sysfs_bin_vm_ops = {
+	.open		= sysfs_bin_vma_open,
+	.fault		= sysfs_bin_fault,
+	.page_mkwrite	= sysfs_bin_page_mkwrite,
+	.access		= sysfs_bin_access,
+#ifdef CONFIG_NUMA
+	.set_policy	= sysfs_bin_set_policy,
+	.get_policy	= sysfs_bin_get_policy,
+	.migrate	= sysfs_bin_migrate,
+#endif
+};
+
+static int sysfs_bin_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct sysfs_open_file *of = sysfs_of(file);
+	struct bin_attribute *battr = of->sd->s_attr.bin_attr;
+	struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
+	int rc;
+
+	mutex_lock(&of->mutex);
+
+	/* need of->sd for battr, its parent for kobj */
+	rc = -ENODEV;
+	if (!sysfs_get_active(of->sd))
+		goto out_unlock;
+
+	if (!battr->mmap)
+		goto out_put;
+
+	rc = battr->mmap(file, kobj, battr, vma);
+	if (rc)
+		goto out_put;
+
+	/*
+	 * 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 (of->mmapped && of->vm_ops != vma->vm_ops)
+		goto out_put;
+
+	/*
+	 * It is not possible to successfully wrap close.
+	 * So error if someone is trying to use close.
+	 */
+	rc = -EINVAL;
+	if (vma->vm_ops && vma->vm_ops->close)
+		goto out_put;
+
+	rc = 0;
+	of->mmapped = 1;
+	of->vm_ops = vma->vm_ops;
+	vma->vm_ops = &sysfs_bin_vm_ops;
+out_put:
+	sysfs_put_active(of->sd);
+out_unlock:
+	mutex_unlock(&of->mutex);
+
+	return rc;
+}
+
 /**
  *	sysfs_get_open_dirent - get or create sysfs_open_dirent
  *	@sd: target sysfs_dirent
- *	@buffer: sysfs_buffer for this instance of open
+ *	@of: sysfs_open_file for this instance of open
  *
  *	If @sd->s_attr.open exists, increment its reference count;
- *	otherwise, create one.  @buffer is chained to the buffers
- *	list.
+ *	otherwise, create one.  @of is chained to the files list.
  *
  *	LOCKING:
  *	Kernel thread context (may sleep).
@@ -253,11 +531,12 @@ static ssize_t sysfs_write_file(struct file *file, const char __user *buf,
  *	0 on success, -errno on failure.
  */
 static int sysfs_get_open_dirent(struct sysfs_dirent *sd,
-				 struct sysfs_buffer *buffer)
+				 struct sysfs_open_file *of)
 {
 	struct sysfs_open_dirent *od, *new_od = NULL;
 
  retry:
+	mutex_lock(&sysfs_open_file_mutex);
 	spin_lock_irq(&sysfs_open_dirent_lock);
 
 	if (!sd->s_attr.open && new_od) {
@@ -268,10 +547,11 @@ static int sysfs_get_open_dirent(struct sysfs_dirent *sd,
 	od = sd->s_attr.open;
 	if (od) {
 		atomic_inc(&od->refcnt);
-		list_add_tail(&buffer->list, &od->buffers);
+		list_add_tail(&of->list, &od->files);
 	}
 
 	spin_unlock_irq(&sysfs_open_dirent_lock);
+	mutex_unlock(&sysfs_open_file_mutex);
 
 	if (od) {
 		kfree(new_od);
@@ -286,36 +566,40 @@ static int sysfs_get_open_dirent(struct sysfs_dirent *sd,
 	atomic_set(&new_od->refcnt, 0);
 	atomic_set(&new_od->event, 1);
 	init_waitqueue_head(&new_od->poll);
-	INIT_LIST_HEAD(&new_od->buffers);
+	INIT_LIST_HEAD(&new_od->files);
 	goto retry;
 }
 
 /**
  *	sysfs_put_open_dirent - put sysfs_open_dirent
  *	@sd: target sysfs_dirent
- *	@buffer: associated sysfs_buffer
+ *	@of: associated sysfs_open_file
  *
- *	Put @sd->s_attr.open and unlink @buffer from the buffers list.
- *	If reference count reaches zero, disassociate and free it.
+ *	Put @sd->s_attr.open and unlink @of from the files list.  If
+ *	reference count reaches zero, disassociate and free it.
  *
  *	LOCKING:
  *	None.
  */
 static void sysfs_put_open_dirent(struct sysfs_dirent *sd,
-				  struct sysfs_buffer *buffer)
+				  struct sysfs_open_file *of)
 {
 	struct sysfs_open_dirent *od = sd->s_attr.open;
 	unsigned long flags;
 
+	mutex_lock(&sysfs_open_file_mutex);
 	spin_lock_irqsave(&sysfs_open_dirent_lock, flags);
 
-	list_del(&buffer->list);
+	if (of)
+		list_del(&of->list);
+
 	if (atomic_dec_and_test(&od->refcnt))
 		sd->s_attr.open = NULL;
 	else
 		od = NULL;
 
 	spin_unlock_irqrestore(&sysfs_open_dirent_lock, flags);
+	mutex_unlock(&sysfs_open_file_mutex);
 
 	kfree(od);
 }
@@ -324,67 +608,81 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
 {
 	struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
 	struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
-	struct sysfs_buffer *buffer;
-	const struct sysfs_ops *ops;
+	struct sysfs_open_file *of;
+	bool has_read, has_write;
 	int error = -EACCES;
 
 	/* need attr_sd for attr and ops, its parent for kobj */
 	if (!sysfs_get_active(attr_sd))
 		return -ENODEV;
 
-	/* every kobject with an attribute needs a ktype assigned */
-	if (kobj->ktype && kobj->ktype->sysfs_ops)
-		ops = kobj->ktype->sysfs_ops;
-	else {
-		WARN(1, KERN_ERR
-		     "missing sysfs attribute operations for kobject: %s\n",
-		     kobject_name(kobj));
-		goto err_out;
-	}
+	if (sysfs_is_bin(attr_sd)) {
+		struct bin_attribute *battr = attr_sd->s_attr.bin_attr;
 
-	/* 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 err_out;
-	}
+		has_read = battr->read || battr->mmap;
+		has_write = battr->write || battr->mmap;
+	} else {
+		const struct sysfs_ops *ops = sysfs_file_ops(attr_sd);
 
-	/* 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) || !ops->show)
+		/* every kobject with an attribute needs a ktype assigned */
+		if (WARN(!ops, KERN_ERR
+			 "missing sysfs attribute operations for kobject: %s\n",
+			 kobject_name(kobj)))
 			goto err_out;
+
+		has_read = ops->show;
+		has_write = ops->store;
 	}
 
-	/* No error? Great, allocate a buffer for the file, and store it
-	 * it in file->private_data for easy access.
-	 */
+	/* check perms and supported operations */
+	if ((file->f_mode & FMODE_WRITE) &&
+	    (!(inode->i_mode & S_IWUGO) || !has_write))
+		goto err_out;
+
+	if ((file->f_mode & FMODE_READ) &&
+	    (!(inode->i_mode & S_IRUGO) || !has_read))
+		goto err_out;
+
+	/* allocate a sysfs_open_file for the file */
 	error = -ENOMEM;
-	buffer = kzalloc(sizeof(struct sysfs_buffer), GFP_KERNEL);
-	if (!buffer)
+	of = kzalloc(sizeof(struct sysfs_open_file), GFP_KERNEL);
+	if (!of)
 		goto err_out;
 
-	mutex_init(&buffer->mutex);
-	buffer->needs_read_fill = 1;
-	buffer->ops = ops;
-	file->private_data = buffer;
+	mutex_init(&of->mutex);
+	of->sd = attr_sd;
+	of->file = file;
 
-	/* make sure we have open dirent struct */
-	error = sysfs_get_open_dirent(attr_sd, buffer);
+	/*
+	 * Always instantiate seq_file even if read access doesn't use
+	 * seq_file or is not requested.  This unifies private data access
+	 * and readable regular files are the vast majority anyway.
+	 */
+	if (sysfs_is_bin(attr_sd))
+		error = single_open(file, NULL, of);
+	else
+		error = single_open(file, sysfs_seq_show, of);
 	if (error)
 		goto err_free;
 
+	/* seq_file clears PWRITE unconditionally, restore it if WRITE */
+	if (file->f_mode & FMODE_WRITE)
+		file->f_mode |= FMODE_PWRITE;
+
+	/* make sure we have open dirent struct */
+	error = sysfs_get_open_dirent(attr_sd, of);
+	if (error)
+		goto err_close;
+
 	/* open succeeded, put active references */
 	sysfs_put_active(attr_sd);
 	return 0;
 
- err_free:
-	kfree(buffer);
- err_out:
+err_close:
+	single_release(inode, file);
+err_free:
+	kfree(of);
+err_out:
 	sysfs_put_active(attr_sd);
 	return error;
 }
@@ -392,17 +690,41 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
 static int sysfs_release(struct inode *inode, struct file *filp)
 {
 	struct sysfs_dirent *sd = filp->f_path.dentry->d_fsdata;
-	struct sysfs_buffer *buffer = filp->private_data;
+	struct sysfs_open_file *of = sysfs_of(filp);
 
-	sysfs_put_open_dirent(sd, buffer);
-
-	if (buffer->page)
-		free_page((unsigned long)buffer->page);
-	kfree(buffer);
+	sysfs_put_open_dirent(sd, of);
+	single_release(inode, filp);
+	kfree(of);
 
 	return 0;
 }
 
+void sysfs_unmap_bin_file(struct sysfs_dirent *sd)
+{
+	struct sysfs_open_dirent *od;
+	struct sysfs_open_file *of;
+
+	if (!sysfs_is_bin(sd))
+		return;
+
+	spin_lock_irq(&sysfs_open_dirent_lock);
+	od = sd->s_attr.open;
+	if (od)
+		atomic_inc(&od->refcnt);
+	spin_unlock_irq(&sysfs_open_dirent_lock);
+	if (!od)
+		return;
+
+	mutex_lock(&sysfs_open_file_mutex);
+	list_for_each_entry(of, &od->files, list) {
+		struct inode *inode = file_inode(of->file);
+		unmap_mapping_range(inode->i_mapping, 0, 0, 1);
+	}
+	mutex_unlock(&sysfs_open_file_mutex);
+
+	sysfs_put_open_dirent(sd, NULL);
+}
+
 /* Sysfs attribute files are pollable.  The idea is that you read
  * the content and then you use 'poll' or 'select' to wait for
  * the content to change.  When the content changes (assuming the
@@ -418,7 +740,7 @@ 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 sysfs_open_file *of = sysfs_of(filp);
 	struct sysfs_dirent *attr_sd = filp->f_path.dentry->d_fsdata;
 	struct sysfs_open_dirent *od = attr_sd->s_attr.open;
 
@@ -430,13 +752,12 @@ static unsigned int sysfs_poll(struct file *filp, poll_table *wait)
 
 	sysfs_put_active(attr_sd);
 
-	if (buffer->event != atomic_read(&od->event))
+	if (of->event != atomic_read(&od->event))
 		goto trigger;
 
 	return DEFAULT_POLLMASK;
 
  trigger:
-	buffer->needs_read_fill = 1;
 	return DEFAULT_POLLMASK|POLLERR|POLLPRI;
 }
 
@@ -466,9 +787,9 @@ void sysfs_notify(struct kobject *k, const char *dir, const char *attr)
 	mutex_lock(&sysfs_mutex);
 
 	if (sd && dir)
-		sd = sysfs_find_dirent(sd, NULL, dir);
+		sd = sysfs_find_dirent(sd, dir, NULL);
 	if (sd && attr)
-		sd = sysfs_find_dirent(sd, NULL, attr);
+		sd = sysfs_find_dirent(sd, attr, NULL);
 	if (sd)
 		sysfs_notify_dirent(sd);
 
@@ -477,7 +798,7 @@ void sysfs_notify(struct kobject *k, const char *dir, const char *attr)
 EXPORT_SYMBOL_GPL(sysfs_notify);
 
 const struct file_operations sysfs_file_operations = {
-	.read		= sysfs_read_file,
+	.read		= seq_read,
 	.write		= sysfs_write_file,
 	.llseek		= generic_file_llseek,
 	.open		= sysfs_open_file,
@@ -485,58 +806,25 @@ const struct file_operations sysfs_file_operations = {
 	.poll		= sysfs_poll,
 };
 
-static int sysfs_attr_ns(struct kobject *kobj, const struct attribute *attr,
-			 const void **pns)
-{
-	struct sysfs_dirent *dir_sd = kobj->sd;
-	const struct sysfs_ops *ops;
-	const void *ns = NULL;
-	int err;
-
-	if (!dir_sd) {
-		WARN(1, KERN_ERR "sysfs: kobject %s without dirent\n",
-			kobject_name(kobj));
-		return -ENOENT;
-	}
-
-	err = 0;
-	if (!sysfs_ns_type(dir_sd))
-		goto out;
-
-	err = -EINVAL;
-	if (!kobj->ktype)
-		goto out;
-	ops = kobj->ktype->sysfs_ops;
-	if (!ops)
-		goto out;
-	if (!ops->namespace)
-		goto out;
-
-	err = 0;
-	ns = ops->namespace(kobj, attr);
-out:
-	if (err) {
-		WARN(1, KERN_ERR
-		     "missing sysfs namespace attribute operation for kobject: %s\n",
-		     kobject_name(kobj));
-	}
-	*pns = ns;
-	return err;
-}
+const struct file_operations sysfs_bin_operations = {
+	.read		= sysfs_bin_read,
+	.write		= sysfs_write_file,
+	.llseek		= generic_file_llseek,
+	.mmap		= sysfs_bin_mmap,
+	.open		= sysfs_open_file,
+	.release	= sysfs_release,
+	.poll		= sysfs_poll,
+};
 
-int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
-			const struct attribute *attr, int type, umode_t amode)
+int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd,
+			   const struct attribute *attr, int type,
+			   umode_t amode, const void *ns)
 {
 	umode_t mode = (amode & S_IALLUGO) | S_IFREG;
 	struct sysfs_addrm_cxt acxt;
 	struct sysfs_dirent *sd;
-	const void *ns;
 	int rc;
 
-	rc = sysfs_attr_ns(dir_sd->s_dir.kobj, attr, &ns);
-	if (rc)
-		return rc;
-
 	sd = sysfs_new_dirent(attr->name, mode, type);
 	if (!sd)
 		return -ENOMEM;
@@ -545,8 +833,8 @@ int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
 	sd->s_attr.attr = (void *)attr;
 	sysfs_dirent_init_lockdep(sd);
 
-	sysfs_addrm_start(&acxt, dir_sd);
-	rc = sysfs_add_one(&acxt, sd);
+	sysfs_addrm_start(&acxt);
+	rc = sysfs_add_one(&acxt, sd, dir_sd);
 	sysfs_addrm_finish(&acxt);
 
 	if (rc)
@@ -559,23 +847,25 @@ int sysfs_add_file_mode(struct sysfs_dirent *dir_sd,
 int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr,
 		   int type)
 {
-	return sysfs_add_file_mode(dir_sd, attr, type, attr->mode);
+	return sysfs_add_file_mode_ns(dir_sd, attr, type, attr->mode, NULL);
 }
 
-
 /**
- *	sysfs_create_file - create an attribute file for an object.
- *	@kobj:	object we're creating for.
- *	@attr:	attribute descriptor.
+ * sysfs_create_file_ns - create an attribute file for an object with custom ns
+ * @kobj: object we're creating for
+ * @attr: attribute descriptor
+ * @ns: namespace the new file should belong to
  */
-int sysfs_create_file(struct kobject *kobj, const struct attribute *attr)
+int sysfs_create_file_ns(struct kobject *kobj, const struct attribute *attr,
+			 const void *ns)
 {
 	BUG_ON(!kobj || !kobj->sd || !attr);
 
-	return sysfs_add_file(kobj->sd, attr, SYSFS_KOBJ_ATTR);
+	return sysfs_add_file_mode_ns(kobj->sd, attr, SYSFS_KOBJ_ATTR,
+				      attr->mode, ns);
 
 }
-EXPORT_SYMBOL_GPL(sysfs_create_file);
+EXPORT_SYMBOL_GPL(sysfs_create_file_ns);
 
 int sysfs_create_files(struct kobject *kobj, const struct attribute **ptr)
 {
@@ -604,7 +894,7 @@ int sysfs_add_file_to_group(struct kobject *kobj,
 	int error;
 
 	if (group)
-		dir_sd = sysfs_get_dirent(kobj->sd, NULL, group);
+		dir_sd = sysfs_get_dirent(kobj->sd, group);
 	else
 		dir_sd = sysfs_get(kobj->sd);
 
@@ -630,17 +920,12 @@ int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr,
 {
 	struct sysfs_dirent *sd;
 	struct iattr newattrs;
-	const void *ns;
 	int rc;
 
-	rc = sysfs_attr_ns(kobj, attr, &ns);
-	if (rc)
-		return rc;
-
 	mutex_lock(&sysfs_mutex);
 
 	rc = -ENOENT;
-	sd = sysfs_find_dirent(kobj->sd, ns, attr->name);
+	sd = sysfs_find_dirent(kobj->sd, attr->name, NULL);
 	if (!sd)
 		goto out;
 
@@ -655,22 +940,21 @@ int sysfs_chmod_file(struct kobject *kobj, const struct attribute *attr,
 EXPORT_SYMBOL_GPL(sysfs_chmod_file);
 
 /**
- *	sysfs_remove_file - remove an object attribute.
- *	@kobj:	object we're acting for.
- *	@attr:	attribute descriptor.
+ * sysfs_remove_file_ns - remove an object attribute with a custom ns tag
+ * @kobj: object we're acting for
+ * @attr: attribute descriptor
+ * @ns: namespace tag of the file to remove
  *
- *	Hash the attribute name and kill the victim.
+ * Hash the attribute name and namespace tag and kill the victim.
  */
-void sysfs_remove_file(struct kobject *kobj, const struct attribute *attr)
+void sysfs_remove_file_ns(struct kobject *kobj, const struct attribute *attr,
+			  const void *ns)
 {
-	const void *ns;
-
-	if (sysfs_attr_ns(kobj, attr, &ns))
-		return;
+	struct sysfs_dirent *dir_sd = kobj->sd;
 
-	sysfs_hash_and_remove(kobj->sd, ns, attr->name);
+	sysfs_hash_and_remove(dir_sd, attr->name, ns);
 }
-EXPORT_SYMBOL_GPL(sysfs_remove_file);
+EXPORT_SYMBOL_GPL(sysfs_remove_file_ns);
 
 void sysfs_remove_files(struct kobject *kobj, const struct attribute **ptr)
 {
@@ -692,16 +976,42 @@ void sysfs_remove_file_from_group(struct kobject *kobj,
 	struct sysfs_dirent *dir_sd;
 
 	if (group)
-		dir_sd = sysfs_get_dirent(kobj->sd, NULL, group);
+		dir_sd = sysfs_get_dirent(kobj->sd, group);
 	else
 		dir_sd = sysfs_get(kobj->sd);
 	if (dir_sd) {
-		sysfs_hash_and_remove(dir_sd, NULL, attr->name);
+		sysfs_hash_and_remove(dir_sd, attr->name, NULL);
 		sysfs_put(dir_sd);
 	}
 }
 EXPORT_SYMBOL_GPL(sysfs_remove_file_from_group);
 
+/**
+ *	sysfs_create_bin_file - create binary file for object.
+ *	@kobj:	object.
+ *	@attr:	attribute descriptor.
+ */
+int sysfs_create_bin_file(struct kobject *kobj,
+			  const struct bin_attribute *attr)
+{
+	BUG_ON(!kobj || !kobj->sd || !attr);
+
+	return sysfs_add_file(kobj->sd, &attr->attr, SYSFS_KOBJ_BIN_ATTR);
+}
+EXPORT_SYMBOL_GPL(sysfs_create_bin_file);
+
+/**
+ *	sysfs_remove_bin_file - remove binary file for object.
+ *	@kobj:	object.
+ *	@attr:	attribute descriptor.
+ */
+void sysfs_remove_bin_file(struct kobject *kobj,
+			   const struct bin_attribute *attr)
+{
+	sysfs_hash_and_remove(kobj->sd, attr->attr.name, NULL);
+}
+EXPORT_SYMBOL_GPL(sysfs_remove_bin_file);
+
 struct sysfs_schedule_callback_struct {
 	struct list_head	workq_list;
 	struct kobject		*kobj;