[RFC PATCH 05/19] btrfs: add key list

[Mark Harmstone]

Signed-off-by: Mark Harmstone <mark@xxxxxxxxxxxxx>
---
 fs/btrfs/ctree.h      |  5 +++++
 fs/btrfs/disk-io.c    | 18 ++++++++++++++++++
 fs/btrfs/encryption.h | 13 +++++++++++++
 3 files changed, 36 insertions(+)

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 723e9b38e0aa..3f3356a2d145 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1116,6 +1116,9 @@ struct btrfs_fs_info {
 	u32 sectorsize;
 	u32 stripesize;
 
+	struct list_head key_list;
+	struct rw_semaphore key_sem;
+
 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
 	spinlock_t ref_verify_lock;
 	struct rb_root block_tree;
@@ -2413,6 +2416,8 @@ BTRFS_SETGET_FUNCS(file_extent_encryption, struct btrfs_file_extent_item,
 BTRFS_SETGET_FUNCS(file_extent_other_encoding, struct btrfs_file_extent_item,
 		   other_encoding, 16);
 
+#define BTRFS_ENCRYPTION_KEY_ID_LENGTH 64
+
 /*
  * this returns the number of bytes used by the item on disk, minus the
  * size of any extent headers.  If a file is compressed on disk, this is
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index a533c00855be..a1964b768750 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -18,6 +18,7 @@
 #include <linux/error-injection.h>
 #include <linux/crc32c.h>
 #include <asm/unaligned.h>
+#include <crypto/rng.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -38,6 +39,7 @@
 #include "compression.h"
 #include "tree-checker.h"
 #include "ref-verify.h"
+#include "encryption.h"
 
 #ifdef CONFIG_X86
 #include <asm/cpufeature.h>
@@ -2751,6 +2753,9 @@ int open_ctree(struct super_block *sb,
 
 	INIT_LIST_HEAD(&fs_info->pinned_chunks);
 
+	INIT_LIST_HEAD(&fs_info->key_list);
+	init_rwsem(&fs_info->key_sem);
+
 	/* Usable values until the real ones are cached from the superblock */
 	fs_info->nodesize = 4096;
 	fs_info->sectorsize = 4096;
@@ -4013,6 +4018,19 @@ void close_ctree(struct btrfs_fs_info *fs_info)
 		list_del_init(&em->list);
 		free_extent_map(em);
 	}
+
+	while (!list_empty(&fs_info->key_list)) {
+		struct btrfs_enc_key *key;
+
+		key = list_first_entry(&fs_info->key_list,
+				       struct btrfs_enc_key, key_list);
+
+		if (key->loaded)
+			crypto_free_skcipher(key->skcipher);
+
+		list_del_init(&key->key_list);
+		kfree(key);
+	}
 }
 
 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid,
diff --git a/fs/btrfs/encryption.h b/fs/btrfs/encryption.h
index b9a37e76e4a6..77914d7797c6 100644
--- a/fs/btrfs/encryption.h
+++ b/fs/btrfs/encryption.h
@@ -6,6 +6,8 @@
 #ifndef BTRFS_ENCRYPTION_H
 #define BTRFS_ENCRYPTION_H
 
+#include <crypto/skcipher.h>
+
 enum btrfs_encryption_type {
 	BTRFS_ENCRYPTION_NONE       = 0,
 	BTRFS_ENCRYPTION_AES256CTR  = 1,
@@ -17,4 +19,15 @@ struct btrfs_encryption_header {
 	u8 iv[BTRFS_ENCRYPTION_BLOCK_LENGTH];
 };
 
+struct btrfs_enc_key {
+	struct list_head key_list;
+	u8 key_id[BTRFS_ENCRYPTION_KEY_ID_LENGTH];
+	u64 key_number;
+	bool loaded;
+	bool added;
+	bool used;
+	struct crypto_skcipher *skcipher;
+	struct mutex lock;
+};
+
 #endif
-- 
2.19.2