From ba4c5863d1e1024de81ed1616fe1b6e3bb60e4b5 Mon Sep 17 00:00:00 2001
From: Daniel Rosenberg <drosen@google.com>
Date: Wed, 19 Jul 2017 17:16:43 -0700
Subject: [PATCH] ANDROID: sdcardfs: Remove unnecessary lock

The mmap_sem lock does not appear to be protecting
anything, and has been removed in Samsung's more
recent versions of sdcardfs.

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Change-Id: I76ff3e33002716b8384fc8be368028ed63dffe4e
Bug: 63785372
---
 fs/sdcardfs/inode.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/fs/sdcardfs/inode.c b/fs/sdcardfs/inode.c
index 39b8b2b9af87..179725c5bd24 100644
--- a/fs/sdcardfs/inode.c
+++ b/fs/sdcardfs/inode.c
@@ -768,13 +768,9 @@ static int sdcardfs_setattr(struct vfsmount *mnt, struct dentry *dentry, struct
 	 * afterwards in the other cases: we fsstack_copy_inode_size from
 	 * the lower level.
 	 */
-	if (current->mm)
-		down_write(&current->mm->mmap_sem);
 	if (ia->ia_valid & ATTR_SIZE) {
 		err = inode_newsize_ok(&tmp, ia->ia_size);
 		if (err) {
-			if (current->mm)
-				up_write(&current->mm->mmap_sem);
 			goto out;
 		}
 		truncate_setsize(inode, ia->ia_size);
@@ -797,8 +793,6 @@ static int sdcardfs_setattr(struct vfsmount *mnt, struct dentry *dentry, struct
 	err = notify_change2(lower_mnt, lower_dentry, &lower_ia, /* note: lower_ia */
 			NULL);
 	mutex_unlock(&lower_dentry->d_inode->i_mutex);
-	if (current->mm)
-		up_write(&current->mm->mmap_sem);
 	if (err)
 		goto out;
 
-- 
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