sysfs: prepare path write for unified regular / bin file handling

[platform/adaptation/renesas_rcar/renesas_kernel.git] / fs / sysfs / file.c

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 4921bda..b36473f 100644 (file)
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -54,6 +54,11 @@ struct sysfs_open_file {
        struct list_head        list;
 };
 
+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;
@@ -138,16 +143,16 @@ static int sysfs_seq_show(struct seq_file *sf, void *v)
  * 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 it with @buf.
  */
-static int flush_write_buffer(struct sysfs_open_file *of, char *buf,
+static int flush_write_buffer(struct sysfs_open_file *of, char *buf, loff_t off,
                              size_t count)
 {
        struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
-       const struct sysfs_ops *ops;
        int rc = 0;
 
        /*
@@ -161,8 +166,18 @@ static int flush_write_buffer(struct sysfs_open_file *of, char *buf,
                return -ENODEV;
        }
 
-       ops = sysfs_file_ops(of->sd);
-       rc = ops->store(kobj, of->sd->s_attr.attr, buf, count);
+       if (sysfs_is_bin(of->sd)) {
+               struct bin_attribute *battr = of->sd->s_bin_attr.bin_attr;
+
+               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);
@@ -190,9 +205,17 @@ static ssize_t sysfs_write_file(struct file *file, const char __user *user_buf,
                                size_t count, loff_t *ppos)
 {
        struct sysfs_open_file *of = sysfs_of(file);
-       ssize_t len = min_t(size_t, count, PAGE_SIZE - 1);
+       ssize_t len = min_t(size_t, count, PAGE_SIZE);
        char *buf;
 
+       if (sysfs_is_bin(of->sd)) {
+               loff_t size = file_inode(file)->i_size;
+
+               if (size <= *ppos)
+                       return 0;
+               len = min_t(ssize_t, len, size - *ppos);
+       }
+
        if (!len)
                return 0;
 
@@ -206,7 +229,7 @@ static ssize_t sysfs_write_file(struct file *file, const char __user *user_buf,
        }
        buf[len] = '\0';        /* guarantee string termination */
 
-       len = flush_write_buffer(of, buf, len);
+       len = flush_write_buffer(of, buf, *ppos, len);
        if (len > 0)
                *ppos += len;
 out_free:
@@ -471,6 +494,11 @@ const struct file_operations sysfs_file_operations = {
        .poll           = sysfs_poll,
 };
 
+const struct file_operations sysfs_bin_operations = {
+       .write          = sysfs_write_file,
+       .llseek         = generic_file_llseek,
+};
+
 int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd,
                           const struct attribute *attr, int type,
                           umode_t amode, const void *ns)