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>

1 files changed, 2 insertions, 13 deletions

diff --git a/fs/nfsd/fault_inject.c b/fs/nfsd/fault_inject.c
index d620e7f81429..2ed05c3cd43d 100644
--- 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,