sysfs: add sysfs_open_file->sd and ->file

sysfs will be converted to use seq_file for read path, which will make
it difficult to pass around multiple pointers directly.  This patch
adds sysfs_open_file->sd and ->file so that we can reach all the
necessary data structures from sysfs_open_file.

flush_write_buffer() is updated to drop @dentry which was used to
discover the sysfs_dirent as it's now available through
sysfs_open_file->sd.

This patch doesn't cause any behavior difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 12 insertions, 11 deletions

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 4b55bcf4422e..af6e9092a679 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -45,6 +45,8 @@ struct sysfs_open_dirent {
 };
 
 struct sysfs_open_file {
+        struct sysfs_dirent     *sd;
+        struct file             *file;
         size_t                  count;
         char                    *page;
         struct mutex            mutex;
@@ -192,7 +194,6 @@ static int fill_write_buffer(struct sysfs_open_file *of,
 
 /**
  *      flush_write_buffer - push buffer to kobject.
- *      @dentry:        dentry to the attribute
  *      @of:            open file
  *      @count:         number of bytes
  *
@@ -200,22 +201,20 @@ static int fill_write_buffer(struct sysfs_open_file *of,
  *      dealing with, then call the store() method for the attribute,
  *      passing the buffer that we acquired in fill_write_buffer().
  */
-static int flush_write_buffer(struct dentry *dentry,
-                              struct sysfs_open_file *of, size_t count)
+static int flush_write_buffer(struct sysfs_open_file *of, size_t count)
 {
-        struct sysfs_dirent *attr_sd = dentry->d_fsdata;
-        struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
+        struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
         const struct sysfs_ops *ops;
         int rc;
 
-        /* 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 */
+        if (!sysfs_get_active(of->sd))
                 return -ENODEV;
 
-        ops = sysfs_file_ops(attr_sd);
-        rc = ops->store(kobj, attr_sd->s_attr.attr, of->page, count);
+        ops = sysfs_file_ops(of->sd);
+        rc = ops->store(kobj, of->sd->s_attr.attr, of->page, count);
 
-        sysfs_put_active(attr_sd);
+        sysfs_put_active(of->sd);
 
         return rc;
 }
@@ -245,7 +244,7 @@ static ssize_t sysfs_write_file(struct file *file, const char __user *buf,
         mutex_lock(&of->mutex);
         len = fill_write_buffer(of, buf, count);
         if (len > 0)
-                len = flush_write_buffer(file->f_path.dentry, of, len);
+                len = flush_write_buffer(of, len);
         if (len > 0)
                 *ppos += len;
         mutex_unlock(&of->mutex);
@@ -385,6 +384,8 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
                 goto err_out;
 
         mutex_init(&of->mutex);
+        of->sd = attr_sd;
+        of->file = file;
         file->private_data = of;
 
         /* make sure we have open dirent struct */