ext4 crypto: optimize filename encryption
Encrypt the filename as soon it is passed in by the user. This avoids
our needing to encrypt the filename 2 or 3 times while in the process
of creating a filename.
Similarly, when looking up a directory entry, encrypt the filename
early, or if the encryption key is not available, base-64 decode the
file syystem so that the hash value and the last 16 bytes of the
encrypted filename is available in the new struct ext4_filename data
structure.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 9a83f14..866831e 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1838,6 +1838,17 @@
*/
#define HASH_NB_ALWAYS 1
+struct ext4_filename {
+ const struct qstr *usr_fname;
+ struct ext4_str disk_name;
+ struct dx_hash_info hinfo;
+#ifdef CONFIG_EXT4_FS_ENCRYPTION
+ struct ext4_str crypto_buf;
+#endif
+};
+
+#define fname_name(p) ((p)->disk_name.name)
+#define fname_len(p) ((p)->disk_name.len)
/*
* Describe an inode's exact location on disk and in memory
@@ -2098,21 +2109,16 @@
int ext4_fname_usr_to_disk(struct ext4_fname_crypto_ctx *ctx,
const struct qstr *iname,
struct ext4_str *oname);
-int ext4_fname_usr_to_hash(struct ext4_fname_crypto_ctx *ctx,
- const struct qstr *iname,
- struct dx_hash_info *hinfo);
int ext4_fname_crypto_namelen_on_disk(struct ext4_fname_crypto_ctx *ctx,
u32 namelen);
-int ext4_fname_match(struct ext4_fname_crypto_ctx *ctx, struct ext4_str *cstr,
- int len, const char * const name,
- struct ext4_dir_entry_2 *de);
-
-
#ifdef CONFIG_EXT4_FS_ENCRYPTION
void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx);
struct ext4_fname_crypto_ctx *ext4_get_fname_crypto_ctx(struct inode *inode,
u32 max_len);
void ext4_fname_crypto_free_buffer(struct ext4_str *crypto_str);
+int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
+ int lookup, struct ext4_filename *fname);
+void ext4_fname_free_filename(struct ext4_filename *fname);
#else
static inline
void ext4_put_fname_crypto_ctx(struct ext4_fname_crypto_ctx **ctx) { }
@@ -2123,6 +2129,16 @@
return NULL;
}
static inline void ext4_fname_crypto_free_buffer(struct ext4_str *p) { }
+static inline int ext4_fname_setup_filename(struct inode *dir,
+ const struct qstr *iname,
+ int lookup, struct ext4_filename *fname)
+{
+ fname->usr_fname = iname;
+ fname->disk_name.name = (unsigned char *) iname->name;
+ fname->disk_name.len = iname->len;
+ return 0;
+}
+static inline void ext4_fname_free_filename(struct ext4_filename *fname) { }
#endif
@@ -2156,14 +2172,13 @@
extern int ext4_find_dest_de(struct inode *dir, struct inode *inode,
struct buffer_head *bh,
void *buf, int buf_size,
- const char *name, int namelen,
+ struct ext4_filename *fname,
struct ext4_dir_entry_2 **dest_de);
int ext4_insert_dentry(struct inode *dir,
- struct inode *inode,
- struct ext4_dir_entry_2 *de,
- int buf_size,
- const struct qstr *iname,
- const char *name, int namelen);
+ struct inode *inode,
+ struct ext4_dir_entry_2 *de,
+ int buf_size,
+ struct ext4_filename *fname);
static inline void ext4_update_dx_flag(struct inode *inode)
{
if (!EXT4_HAS_COMPAT_FEATURE(inode->i_sb,
@@ -2317,13 +2332,14 @@
extern int ext4_orphan_del(handle_t *, struct inode *);
extern int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
__u32 start_minor_hash, __u32 *next_hash);
-extern int search_dir(struct buffer_head *bh,
- char *search_buf,
- int buf_size,
- struct inode *dir,
- const struct qstr *d_name,
- unsigned int offset,
- struct ext4_dir_entry_2 **res_dir);
+extern int ext4_search_dir(struct buffer_head *bh,
+ char *search_buf,
+ int buf_size,
+ struct inode *dir,
+ struct ext4_filename *fname,
+ const struct qstr *d_name,
+ unsigned int offset,
+ struct ext4_dir_entry_2 **res_dir);
extern int ext4_generic_delete_entry(handle_t *handle,
struct inode *dir,
struct ext4_dir_entry_2 *de_del,
@@ -2768,7 +2784,9 @@
extern int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos,
unsigned len, unsigned copied,
struct page *page);
-extern int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
+extern int ext4_try_add_inline_entry(handle_t *handle,
+ struct ext4_filename *fname,
+ struct dentry *dentry,
struct inode *inode);
extern int ext4_try_create_inline_dir(handle_t *handle,
struct inode *parent,
@@ -2782,6 +2800,7 @@
__u32 start_hash, __u32 start_minor_hash,
int *has_inline_data);
extern struct buffer_head *ext4_find_inline_entry(struct inode *dir,
+ struct ext4_filename *fname,
const struct qstr *d_name,
struct ext4_dir_entry_2 **res_dir,
int *has_inline_data);