From: Daniel Rosenberg <drosen@google.com>
Date: Fri, 21 Apr 2017 01:05:02 +0000 (-0700)
Subject: ANDROID: sdcardfs: Use filesystem specific hash
X-Git-Tag: release-20171130_firefly~4^2~100^2~130
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=9b2a5cdae059228e8039c0a779c4b77006b79438;p=firefly-linux-kernel-4.4.55.git

ANDROID: sdcardfs: Use filesystem specific hash

We weren't accounting for FS specific hash functions,
causing us to miss negative dentries for any FS that
had one.

Similar to a patch from esdfs
commit 75bd25a9476d ("esdfs: support lower's own hash")

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Change-Id: I32d1ba304d728e0ca2648cacfb4c2e441ae63608
---

diff --git a/fs/sdcardfs/lookup.c b/fs/sdcardfs/lookup.c
index a0f221501b4c..446ef4027ebc 100644
--- a/fs/sdcardfs/lookup.c
+++ b/fs/sdcardfs/lookup.c
@@ -366,8 +366,13 @@ put_name:
 	/* instatiate a new negative dentry */
 	dname.name = name->name;
 	dname.len = name->len;
-	dname.hash = full_name_hash(dname.name, dname.len);
-	lower_dentry = d_lookup(lower_dir_dentry, &dname);
+
+	/* See if the low-level filesystem might want
+	 * to use its own hash
+	 */
+	lower_dentry = d_hash_and_lookup(lower_dir_dentry, &dname);
+	if (IS_ERR(lower_dentry))
+		return lower_dentry;
 	if (lower_dentry)
 		goto setup_lower;