From: Tahsin Erdogan <tahsin@google.com>
Date: Thu, 22 Jun 2017 02:02:06 +0000 (-0400)
Subject: ext4: ext4_xattr_value_same() should return false for external data
X-Git-Tag: MMI-PSA29.97-13-9~5213^2~33
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=0bd454c04f02e7bb101d8ff510b54826eda4a5f0;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git

ext4: ext4_xattr_value_same() should return false for external data

ext4_xattr_value_same() is used as a quick optimization in case the new
xattr value is identical to the previous value. When xattr value is
stored in a xattr inode the check becomes expensive so it is better to
just assume that they are not equal.

Signed-off-by: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 3983bc455d02..13b7fa4cbf16 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1426,6 +1426,9 @@ static int ext4_xattr_value_same(struct ext4_xattr_search *s,
 {
 	void *value;
 
+	/* When e_value_inum is set the value is stored externally. */
+	if (s->here->e_value_inum)
+		return 0;
 	if (le32_to_cpu(s->here->e_value_size) != i->value_len)
 		return 0;
 	value = ((void *)s->base) + le16_to_cpu(s->here->e_value_offs);