[PATCH 1/11] eCryptfs: Remove header_extent_size
From: Michael Halcrow
Date: Mon Sep 17 2007 - 17:50:18 EST
There is no point to keeping a separate header_extent_size and an
extent_size. The total size of the header can always be represented as
some multiple of the regular data extent size.
Signed-off-by: Michael Halcrow <mhalcrow@xxxxxxxxxx>
---
fs/ecryptfs/crypto.c | 40 ++++++++++++++++++++--------------------
fs/ecryptfs/ecryptfs_kernel.h | 39 +++++++++++++++++++++++++++------------
fs/ecryptfs/inode.c | 7 ++++---
fs/ecryptfs/mmap.c | 2 +-
4 files changed, 52 insertions(+), 36 deletions(-)
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 8e9b36d..3dbb21a 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -366,8 +366,8 @@ ecryptfs_extent_to_lwr_pg_idx_and_offset(unsigned long *lower_page_idx,
int extents_per_page;
bytes_occupied_by_headers_at_front =
- ( crypt_stat->header_extent_size
- * crypt_stat->num_header_extents_at_front );
+ (crypt_stat->extent_size
+ * crypt_stat->num_header_extents_at_front);
extents_occupied_by_headers_at_front =
( bytes_occupied_by_headers_at_front
/ crypt_stat->extent_size );
@@ -376,8 +376,8 @@ ecryptfs_extent_to_lwr_pg_idx_and_offset(unsigned long *lower_page_idx,
(*lower_page_idx) = lower_extent_num / extents_per_page;
extent_offset = lower_extent_num % extents_per_page;
(*byte_offset) = extent_offset * crypt_stat->extent_size;
- ecryptfs_printk(KERN_DEBUG, " * crypt_stat->header_extent_size = "
- "[%d]\n", crypt_stat->header_extent_size);
+ ecryptfs_printk(KERN_DEBUG, " * crypt_stat->extent_size = "
+ "[%d]\n", crypt_stat->extent_size);
ecryptfs_printk(KERN_DEBUG, " * crypt_stat->"
"num_header_extents_at_front = [%d]\n",
crypt_stat->num_header_extents_at_front);
@@ -899,15 +899,17 @@ void ecryptfs_set_default_sizes(struct ecryptfs_crypt_stat *crypt_stat)
crypt_stat->extent_size = ECRYPTFS_DEFAULT_EXTENT_SIZE;
set_extent_mask_and_shift(crypt_stat);
crypt_stat->iv_bytes = ECRYPTFS_DEFAULT_IV_BYTES;
- if (PAGE_CACHE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE) {
- crypt_stat->header_extent_size =
- ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
- } else
- crypt_stat->header_extent_size = PAGE_CACHE_SIZE;
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
crypt_stat->num_header_extents_at_front = 0;
- else
- crypt_stat->num_header_extents_at_front = 1;
+ else {
+ if (PAGE_CACHE_SIZE <= ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)
+ crypt_stat->num_header_extents_at_front =
+ (ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE
+ / crypt_stat->extent_size);
+ else
+ crypt_stat->num_header_extents_at_front =
+ (PAGE_CACHE_SIZE / crypt_stat->extent_size);
+ }
}
/**
@@ -1319,7 +1321,7 @@ ecryptfs_write_header_metadata(char *virt,
u32 header_extent_size;
u16 num_header_extents_at_front;
- header_extent_size = (u32)crypt_stat->header_extent_size;
+ header_extent_size = (u32)crypt_stat->extent_size;
num_header_extents_at_front =
(u16)crypt_stat->num_header_extents_at_front;
header_extent_size = cpu_to_be32(header_extent_size);
@@ -1415,7 +1417,7 @@ ecryptfs_write_metadata_to_contents(struct ecryptfs_crypt_stat *crypt_stat,
set_fs(oldfs);
goto out;
}
- header_pages = ((crypt_stat->header_extent_size
+ header_pages = ((crypt_stat->extent_size
* crypt_stat->num_header_extents_at_front)
/ PAGE_CACHE_SIZE);
memset(page_virt, 0, PAGE_CACHE_SIZE);
@@ -1532,17 +1534,16 @@ static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat,
virt += 4;
memcpy(&num_header_extents_at_front, virt, 2);
num_header_extents_at_front = be16_to_cpu(num_header_extents_at_front);
- crypt_stat->header_extent_size = (int)header_extent_size;
crypt_stat->num_header_extents_at_front =
(int)num_header_extents_at_front;
- (*bytes_read) = 6;
+ (*bytes_read) = (sizeof(u32) + sizeof(u16));
if ((validate_header_size == ECRYPTFS_VALIDATE_HEADER_SIZE)
- && ((crypt_stat->header_extent_size
+ && ((crypt_stat->extent_size
* crypt_stat->num_header_extents_at_front)
< ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE)) {
rc = -EINVAL;
- ecryptfs_printk(KERN_WARNING, "Invalid header extent size: "
- "[%d]\n", crypt_stat->header_extent_size);
+ printk(KERN_WARNING "Invalid number of header extents: [%d]\n",
+ crypt_stat->num_header_extents_at_front);
}
return rc;
}
@@ -1557,8 +1558,7 @@ static int parse_header_metadata(struct ecryptfs_crypt_stat *crypt_stat,
*/
static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat)
{
- crypt_stat->header_extent_size = 4096;
- crypt_stat->num_header_extents_at_front = 1;
+ crypt_stat->num_header_extents_at_front = 2;
}
/**
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 78761e4..a618ab7 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -38,7 +38,7 @@
/* Version verification for shared data structures w/ userspace */
#define ECRYPTFS_VERSION_MAJOR 0x00
#define ECRYPTFS_VERSION_MINOR 0x04
-#define ECRYPTFS_SUPPORTED_FILE_VERSION 0x02
+#define ECRYPTFS_SUPPORTED_FILE_VERSION 0x03
/* These flags indicate which features are supported by the kernel
* module; userspace tools such as the mount helper read
* ECRYPTFS_VERSIONING_MASK from a sysfs handle in order to determine
@@ -67,8 +67,7 @@
#define ECRYPTFS_MAX_KEY_BYTES 64
#define ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES 512
#define ECRYPTFS_DEFAULT_IV_BYTES 16
-#define ECRYPTFS_FILE_VERSION 0x02
-#define ECRYPTFS_DEFAULT_HEADER_EXTENT_SIZE 8192
+#define ECRYPTFS_FILE_VERSION 0x03
#define ECRYPTFS_DEFAULT_EXTENT_SIZE 4096
#define ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE 8192
#define ECRYPTFS_DEFAULT_MSG_CTX_ELEMS 32
@@ -201,7 +200,7 @@ ecryptfs_get_key_payload_data(struct key *key)
#define ECRYPTFS_SALT_BYTES 2
#define MAGIC_ECRYPTFS_MARKER 0x3c81b7f5
#define MAGIC_ECRYPTFS_MARKER_SIZE_BYTES 8 /* 4*2 */
-#define ECRYPTFS_FILE_SIZE_BYTES 8
+#define ECRYPTFS_FILE_SIZE_BYTES (sizeof(u64))
#define ECRYPTFS_DEFAULT_CIPHER "aes"
#define ECRYPTFS_DEFAULT_KEY_BYTES 16
#define ECRYPTFS_DEFAULT_HASH "md5"
@@ -238,7 +237,6 @@ struct ecryptfs_crypt_stat {
u32 flags;
unsigned int file_version;
size_t iv_bytes;
- size_t header_extent_size;
size_t num_header_extents_at_front;
size_t extent_size; /* Data extent size; default is 4096 */
size_t key_size;
@@ -273,6 +271,17 @@ struct ecryptfs_dentry_info {
};
/**
+ * ecryptfs_global_auth_tok - A key used to encrypt all new files under the mountpoint
+ * @flags: Status flags
+ * @mount_crypt_stat_list: These auth_toks hang off the mount-wide
+ * cryptographic context. Every time a new
+ * inode comes into existence, eCryptfs copies
+ * the auth_toks on that list to the set of
+ * auth_toks on the inode's crypt_stat
+ * @global_auth_tok_key: The key from the user's keyring for the sig
+ * @global_auth_tok: The key contents
+ * @sig: The key identifier
+ *
* ecryptfs_global_auth_tok structs refer to authentication token keys
* in the user keyring that apply to newly created files. A list of
* these objects hangs off of the mount_crypt_stat struct for any
@@ -283,15 +292,21 @@ struct ecryptfs_dentry_info {
struct ecryptfs_global_auth_tok {
#define ECRYPTFS_AUTH_TOK_INVALID 0x00000001
u32 flags;
- struct list_head mount_crypt_stat_list; /* Default auth_tok list for
- * the mount_crypt_stat */
- struct key *global_auth_tok_key; /* The key from the user's keyring for
- * the sig */
- struct ecryptfs_auth_tok *global_auth_tok; /* The key contents */
- unsigned char sig[ECRYPTFS_SIG_SIZE_HEX + 1]; /* The key identifier */
+ struct list_head mount_crypt_stat_list;
+ struct key *global_auth_tok_key;
+ struct ecryptfs_auth_tok *global_auth_tok;
+ unsigned char sig[ECRYPTFS_SIG_SIZE_HEX + 1];
};
/**
+ * ecryptfs_key_tfm - Persistent key tfm
+ * @key_tfm: crypto API handle to the key
+ * @key_size: Key size in bytes
+ * @key_tfm_mutex: Mutex to ensure only one operation in eCryptfs is
+ * using the persistent TFM at any point in time
+ * @key_tfm_list: Handle to hang this off the module-wide TFM list
+ * @cipher_name: String name for the cipher for this TFM
+ *
* Typically, eCryptfs will use the same ciphers repeatedly throughout
* the course of its operations. In order to avoid unnecessarily
* destroying and initializing the same cipher repeatedly, eCryptfs
@@ -301,7 +316,7 @@ struct ecryptfs_key_tfm {
struct crypto_blkcipher *key_tfm;
size_t key_size;
struct mutex key_tfm_mutex;
- struct list_head key_tfm_list; /* The module's tfm list */
+ struct list_head key_tfm_list;
unsigned char cipher_name[ECRYPTFS_MAX_CIPHER_NAME_SIZE + 1];
};
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 131954b..abac91c 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -392,7 +392,8 @@ static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
dentry->d_sb)->mount_crypt_stat;
if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
- file_size = (crypt_stat->header_extent_size
+ file_size = ((crypt_stat->extent_size
+ * crypt_stat->num_header_extents_at_front)
+ i_size_read(lower_dentry->d_inode));
else
file_size = i_size_read(lower_dentry->d_inode);
@@ -722,8 +723,8 @@ upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
{
loff_t lower_size;
- lower_size = ( crypt_stat->header_extent_size
- * crypt_stat->num_header_extents_at_front );
+ lower_size = (crypt_stat->extent_size
+ * crypt_stat->num_header_extents_at_front);
if (upper_size != 0) {
loff_t num_extents;
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index aaea55a..89dbbbb 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -301,7 +301,7 @@ static int ecryptfs_readpage(struct file *file, struct page *page)
} else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) {
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
int num_pages_in_header_region =
- (crypt_stat->header_extent_size
+ (crypt_stat->extent_size
/ PAGE_CACHE_SIZE);
if (page->index < num_pages_in_header_region) {
--
1.5.1.6
-
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