NFSD: Use simple_read_from_buffer for coping data to userspace

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/fault_inject.c b/fs/nfsd/fault_inject.c
index d620e7f..2ed05c3 100644 (file)
--- a/fs/nfsd/fault_inject.c
+++ b/fs/nfsd/fault_inject.c
@@ -97,25 +97,14 @@ static ssize_t fault_inject_read(struct file *file, char __user *buf,
 {
        static u64 val;
        char read_buf[25];
-       size_t size, ret;
+       size_t size;
        loff_t pos = *ppos;
 
        if (!pos)
                nfsd_inject_get(file_inode(file)->i_private, &val);
        size = scnprintf(read_buf, sizeof(read_buf), "%llu\n", val);
 
-       if (pos < 0)
-               return -EINVAL;
-       if (pos >= size || !len)
-               return 0;
-       if (len > size - pos)
-               len = size - pos;
-       ret = copy_to_user(buf, read_buf + pos, len);
-       if (ret == len)
-               return -EFAULT;
-       len -= ret;
-       *ppos = pos + len;
-       return len;
+       return simple_read_from_buffer(buf, len, ppos, read_buf, size);
 }
 
 static ssize_t fault_inject_write(struct file *file, const char __user *buf,