Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2:
  [PATCH] ocfs2: fix oops in mmap_truncate testing
  configfs: call drop_link() to cleanup after create_link() failure
  configfs: Allow ->make_item() and ->make_group() to return detailed errors.
  configfs: Fix failing mkdir() making racing rmdir() fail
  configfs: Fix deadlock with racing rmdir() and rename()
  configfs: Make configfs_new_dirent() return error code instead of NULL
  configfs: Protect configfs_dirent s_links list mutations
  configfs: Introduce configfs_dirent_lock
  ocfs2: Don't snprintf() without a format.
  ocfs2: Fix CONFIG_OCFS2_DEBUG_FS #ifdefs
  ocfs2/net: Silence build warnings on sparc64
  ocfs2: Handle error during journal load
  ocfs2: Silence an error message in ocfs2_file_aio_read()
  ocfs2: use simple_read_from_buffer()
  ocfs2: fix printk format warnings with OCFS2_FS_STATS=n
  [PATCH 2/2] ocfs2: Instrument fs cluster locks
  [PATCH 1/2] ocfs2: Add CONFIG_OCFS2_FS_STATS config option

1 files changed, 5 insertions, 14 deletions

diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c
index bd7e0f3..353fc35 100644
--- a/fs/ocfs2/stack_user.c
+++ b/fs/ocfs2/stack_user.c
@@ -550,26 +550,17 @@ static ssize_t ocfs2_control_read(struct file *file,
 				  size_t count,
 				  loff_t *ppos)
 {
-	char *proto_string = OCFS2_CONTROL_PROTO;
-	size_t to_write = 0;
-
-	if (*ppos >= OCFS2_CONTROL_PROTO_LEN)
-		return 0;
-
-	to_write = OCFS2_CONTROL_PROTO_LEN - *ppos;
-	if (to_write > count)
-		to_write = count;
-	if (copy_to_user(buf, proto_string + *ppos, to_write))
-		return -EFAULT;
+	ssize_t ret;
 
-	*ppos += to_write;
+	ret = simple_read_from_buffer(buf, count, ppos,
+			OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN);
 
 	/* Have we read the whole protocol list? */
-	if (*ppos >= OCFS2_CONTROL_PROTO_LEN)
+	if (ret > 0 && *ppos >= OCFS2_CONTROL_PROTO_LEN)
 		ocfs2_control_set_handshake_state(file,
 						  OCFS2_CONTROL_HANDSHAKE_READ);
 
-	return to_write;
+	return ret;
 }
 
 static int ocfs2_control_release(struct inode *inode, struct file *file)