[PATCH] eCryptfs: Reduce stack usage in ecryptfs_generate_key_packet_set()

eCryptfs is gobbling a lot of stack in ecryptfs_generate_key_packet_set()
because it allocates a temporary memory-hungry ecryptfs_key_record struct.
This patch introduces a new kmem_cache for that struct and converts
ecryptfs_generate_key_packet_set() to use it.

Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 26fe405..80044d1 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -651,6 +651,11 @@
 		.name = "ecryptfs_lower_page_cache",
 		.size = PAGE_CACHE_SIZE,
 	},
+	{
+		.cache = &ecryptfs_key_record_cache,
+		.name = "ecryptfs_key_record_cache",
+		.size = sizeof(struct ecryptfs_key_record),
+	},
 };
 
 static void ecryptfs_free_kmem_caches(void)