From 5a646037d9eddcdb9deb6c2175b78860f0cf36d0 Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@redhat.com>
Date: Mon, 2 Aug 2010 17:43:54 -0400
Subject: [PATCH] --- yaml --- r: 206260 b: refs/heads/master c:
 5acfec2502cf60a91dc1959e476b588ecb3a1b8a h: refs/heads/master v: v3

---
 [refs]                |  2 +-
 trunk/fs/cifs/inode.c | 43 +++++++++++++++++++++++++++++++------------
 2 files changed, 32 insertions(+), 13 deletions(-)

diff --git a/[refs] b/[refs]
index 915b0956613d..9bd9759a7a7e 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 67b7626a0512d12e34b38ff45e32c693cf9c79a1
+refs/heads/master: 5acfec2502cf60a91dc1959e476b588ecb3a1b8a
diff --git a/trunk/fs/cifs/inode.c b/trunk/fs/cifs/inode.c
index a15b3a9bbff4..dc4c47ab9588 100644
--- a/trunk/fs/cifs/inode.c
+++ b/trunk/fs/cifs/inode.c
@@ -732,15 +732,9 @@ cifs_find_inode(struct inode *inode, void *opaque)
 	if ((inode->i_mode & S_IFMT) != (fattr->cf_mode & S_IFMT))
 		return 0;
 
-	/*
-	 * uh oh -- it's a directory. We can't use it since hardlinked dirs are
-	 * verboten. Disable serverino and return it as if it were found, the
-	 * caller can discard it, generate a uniqueid and retry the find
-	 */
-	if (S_ISDIR(inode->i_mode) && !list_empty(&inode->i_dentry)) {
+	/* if it's not a directory or has no dentries, then flag it */
+	if (S_ISDIR(inode->i_mode) && !list_empty(&inode->i_dentry))
 		fattr->cf_flags |= CIFS_FATTR_INO_COLLISION;
-		cifs_autodisable_serverino(CIFS_SB(inode->i_sb));
-	}
 
 	return 1;
 }
@@ -754,6 +748,27 @@ cifs_init_inode(struct inode *inode, void *opaque)
 	return 0;
 }
 
+/*
+ * walk dentry list for an inode and report whether it has aliases that
+ * are hashed. We use this to determine if a directory inode can actually
+ * be used.
+ */
+static bool
+inode_has_hashed_dentries(struct inode *inode)
+{
+	struct dentry *dentry;
+
+	spin_lock(&dcache_lock);
+	list_for_each_entry(dentry, &inode->i_dentry, d_alias) {
+		if (!d_unhashed(dentry) || IS_ROOT(dentry)) {
+			spin_unlock(&dcache_lock);
+			return true;
+		}
+	}
+	spin_unlock(&dcache_lock);
+	return false;
+}
+
 /* Given fattrs, get a corresponding inode */
 struct inode *
 cifs_iget(struct super_block *sb, struct cifs_fattr *fattr)
@@ -769,12 +784,16 @@ cifs_iget(struct super_block *sb, struct cifs_fattr *fattr)
 
 	inode = iget5_locked(sb, hash, cifs_find_inode, cifs_init_inode, fattr);
 	if (inode) {
-		/* was there a problematic inode number collision? */
+		/* was there a potentially problematic inode collision? */
 		if (fattr->cf_flags & CIFS_FATTR_INO_COLLISION) {
-			iput(inode);
-			fattr->cf_uniqueid = iunique(sb, ROOT_I);
 			fattr->cf_flags &= ~CIFS_FATTR_INO_COLLISION;
-			goto retry_iget5_locked;
+
+			if (inode_has_hashed_dentries(inode)) {
+				cifs_autodisable_serverino(CIFS_SB(sb));
+				iput(inode);
+				fattr->cf_uniqueid = iunique(sb, ROOT_I);
+				goto retry_iget5_locked;
+			}
 		}
 
 		cifs_fattr_to_inode(inode, fattr);