eCryptfs: Invalidate dcache entries when lower i_nlink is zero

Consider eCryptfs dcache entries to be stale when the corresponding lower inode's i_nlink count is zero. This solves a problem caused by the lower inode being directly modified, without going through the eCryptfs mount, leaving stale eCryptfs dentries cached and the eCryptfs inode's i_nlink count not being cleared. Signed-off-by: Tyler Hicks <[email protected]> Reported-by: Richard Weinberger <[email protected]> Cc: [email protected]
CamonZ · Aug 18, 2015 · 5556e7e · 5556e7e
1 parent 4469942
commit 5556e7e
Showing 1 changed file with 8 additions and 8 deletions.
diff --git a/fs/ecryptfs/dentry.c b/fs/ecryptfs/dentry.c
@@ -45,20 +45,20 @@
 static int ecryptfs_d_revalidate(struct dentry *dentry, unsigned int flags)
 {
 	struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
-	int rc;
-
-	if (!(lower_dentry->d_flags & DCACHE_OP_REVALIDATE))
-		return 1;
+	int rc = 1;
 
 	if (flags & LOOKUP_RCU)
 		return -ECHILD;
 
-	rc = lower_dentry->d_op->d_revalidate(lower_dentry, flags);
+	if (lower_dentry->d_flags & DCACHE_OP_REVALIDATE)
+		rc = lower_dentry->d_op->d_revalidate(lower_dentry, flags);
+
 	if (d_really_is_positive(dentry)) {
-		struct inode *lower_inode =
-			ecryptfs_inode_to_lower(d_inode(dentry));
+		struct inode *inode = d_inode(dentry);
 
-		fsstack_copy_attr_all(d_inode(dentry), lower_inode);
+		fsstack_copy_attr_all(inode, ecryptfs_inode_to_lower(inode));
+		if (!inode->i_nlink)
+			return 0;
 	}
 	return rc;
 }