Driver core: Constify struct sysfs_ops in struct kobj_type

Constify struct sysfs_ops.

This is part of the ops structure constification
effort started by Arjan van de Ven et al.

Benefits of this constification:

 * prevents modification of data that is shared
   (referenced) by many other structure instances
   at runtime

 * detects/prevents accidental (but not intentional)
   modification attempts on archs that enforce
   read-only kernel data at runtime

 * potentially better optimized code as the compiler
   can assume that the const data cannot be changed

 * the compiler/linker move const data into .rodata
   and therefore exclude them from false sharing

Signed-off-by: Emese Revfy <re.emese@gmail.com>
Acked-by: David Teigland <teigland@redhat.com>
Acked-by: Matt Domsch <Matt_Domsch@dell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Acked-by: Hans J. Koch <hjk@linutronix.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 4 insertions, 4 deletions

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 50b725bcc3f3..ced2299f1c9a 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -53,7 +53,7 @@ struct sysfs_buffer {
 	size_t			count;
 	loff_t			pos;
 	char			* page;
-	struct sysfs_ops	* ops;
+	const struct sysfs_ops	* ops;
 	struct mutex		mutex;
 	int			needs_read_fill;
 	int			event;
@@ -75,7 +75,7 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer
 {
 	struct sysfs_dirent *attr_sd = dentry->d_fsdata;
 	struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
-	struct sysfs_ops * ops = buffer->ops;
+	const struct sysfs_ops * ops = buffer->ops;
 	int ret = 0;
 	ssize_t count;
 
@@ -199,7 +199,7 @@ flush_write_buffer(struct dentry * dentry, struct sysfs_buffer * buffer, size_t
 {
 	struct sysfs_dirent *attr_sd = dentry->d_fsdata;
 	struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
-	struct sysfs_ops * ops = buffer->ops;
+	const struct sysfs_ops * ops = buffer->ops;
 	int rc;
 
 	/* need attr_sd for attr and ops, its parent for kobj */
@@ -335,7 +335,7 @@ 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;
-	struct sysfs_ops *ops;
+	const struct sysfs_ops *ops;
 	int error = -EACCES;
 	char *p;