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>

1 files changed, 15 insertions, 16 deletions

diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 095c7a258d97..cd944a7a99cd 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -995,20 +995,18 @@ void ext4_show_inline_dir(struct inode *dir, struct buffer_head *bh,
  * and -EEXIST if directory entry already exists.
  */
 static int ext4_add_dirent_to_inline(handle_t *handle,
+                                     struct ext4_filename *fname,
                                      struct dentry *dentry,
                                      struct inode *inode,
                                      struct ext4_iloc *iloc,
                                      void *inline_start, int inline_size)
 {
         struct inode    *dir = d_inode(dentry->d_parent);
-        const char      *name = dentry->d_name.name;
-        int             namelen = dentry->d_name.len;
         int             err;
         struct ext4_dir_entry_2 *de;
 
-        err = ext4_find_dest_de(dir, inode, iloc->bh,
-                                inline_start, inline_size,
-                                name, namelen, &de);
+        err = ext4_find_dest_de(dir, inode, iloc->bh, inline_start,
+                                inline_size, fname, &de);
         if (err)
                 return err;
 
@@ -1016,8 +1014,7 @@ static int ext4_add_dirent_to_inline(handle_t *handle,
         err = ext4_journal_get_write_access(handle, iloc->bh);
         if (err)
                 return err;
-        ext4_insert_dentry(dir, inode, de, inline_size, &dentry->d_name,
-                           name, namelen);
+        ext4_insert_dentry(dir, inode, de, inline_size, fname);
 
         ext4_show_inline_dir(dir, iloc->bh, inline_start, inline_size);
 
@@ -1248,8 +1245,8 @@ out:
  * If succeeds, return 0. If not, extended the inline dir and copied data to
  * the new created block.
  */
-int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
-                              struct inode *inode)
+int ext4_try_add_inline_entry(handle_t *handle, struct ext4_filename *fname,
+                              struct dentry *dentry, struct inode *inode)
 {
         int ret, inline_size;
         void *inline_start;
@@ -1268,7 +1265,7 @@ int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
                                                  EXT4_INLINE_DOTDOT_SIZE;
         inline_size = EXT4_MIN_INLINE_DATA_SIZE - EXT4_INLINE_DOTDOT_SIZE;
 
-        ret = ext4_add_dirent_to_inline(handle, dentry, inode, &iloc,
+        ret = ext4_add_dirent_to_inline(handle, fname, dentry, inode, &iloc,
                                         inline_start, inline_size);
         if (ret != -ENOSPC)
                 goto out;
@@ -1289,8 +1286,9 @@ int ext4_try_add_inline_entry(handle_t *handle, struct dentry *dentry,
         if (inline_size) {
                 inline_start = ext4_get_inline_xattr_pos(dir, &iloc);
 
-                ret = ext4_add_dirent_to_inline(handle, dentry, inode, &iloc,
-                                                inline_start, inline_size);
+                ret = ext4_add_dirent_to_inline(handle, fname, dentry,
+                                                inode, &iloc, inline_start,
+                                                inline_size);
 
                 if (ret != -ENOSPC)
                         goto out;
@@ -1611,6 +1609,7 @@ out:
 }
 
 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)
@@ -1632,8 +1631,8 @@ struct buffer_head *ext4_find_inline_entry(struct inode *dir,
         inline_start = (void *)ext4_raw_inode(&iloc)->i_block +
                                                 EXT4_INLINE_DOTDOT_SIZE;
         inline_size = EXT4_MIN_INLINE_DATA_SIZE - EXT4_INLINE_DOTDOT_SIZE;
-        ret = search_dir(iloc.bh, inline_start, inline_size,
-                         dir, d_name, 0, res_dir);
+        ret = ext4_search_dir(iloc.bh, inline_start, inline_size,
+                              dir, fname, d_name, 0, res_dir);
         if (ret == 1)
                 goto out_find;
         if (ret < 0)
@@ -1645,8 +1644,8 @@ struct buffer_head *ext4_find_inline_entry(struct inode *dir,
         inline_start = ext4_get_inline_xattr_pos(dir, &iloc);
         inline_size = ext4_get_inline_size(dir) - EXT4_MIN_INLINE_DATA_SIZE;
 
-        ret = search_dir(iloc.bh, inline_start, inline_size,
-                         dir, d_name, 0, res_dir);
+        ret = ext4_search_dir(iloc.bh, inline_start, inline_size,
+                              dir, fname, d_name, 0, res_dir);
         if (ret == 1)
                 goto out_find;