ext4: add inline encryption support
Wire up ext4 to support inline encryption via the helper functions which
fs/crypto/ now provides. This includes:
- Adding a mount option 'inlinecrypt' which enables inline encryption
on encrypted files where it can be used.
- Setting the bio_crypt_ctx on bios that will be submitted to an
inline-encrypted file.
Note: submit_bh_wbc() in fs/buffer.c also needed to be patched for
this part, since ext4 sometimes uses ll_rw_block() on file data.
- Not adding logically discontiguous data to bios that will be submitted
to an inline-encrypted file.
- Not doing filesystem-layer crypto on inline-encrypted files.
Co-developed-by: Satya Tangirala <satyat@google.com>
Signed-off-by: Satya Tangirala <satyat@google.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Link: https://lore.kernel.org/r/20200702015607.1215430-5-satyat@google.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 330957e..0907f90 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1508,6 +1508,7 @@ enum {
Opt_journal_path, Opt_journal_checksum, Opt_journal_async_commit,
Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
Opt_data_err_abort, Opt_data_err_ignore, Opt_test_dummy_encryption,
+ Opt_inlinecrypt,
Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
Opt_noquota, Opt_barrier, Opt_nobarrier, Opt_err,
@@ -1610,6 +1611,7 @@ static const match_table_t tokens = {
{Opt_max_dir_size_kb, "max_dir_size_kb=%u"},
{Opt_test_dummy_encryption, "test_dummy_encryption=%s"},
{Opt_test_dummy_encryption, "test_dummy_encryption"},
+ {Opt_inlinecrypt, "inlinecrypt"},
{Opt_nombcache, "nombcache"},
{Opt_nombcache, "no_mbcache"}, /* for backward compatibility */
{Opt_removed, "check=none"}, /* mount option from ext2/3 */
@@ -1946,6 +1948,13 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
case Opt_nolazytime:
sb->s_flags &= ~SB_LAZYTIME;
return 1;
+ case Opt_inlinecrypt:
+#ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
+ sb->s_flags |= SB_INLINECRYPT;
+#else
+ ext4_msg(sb, KERN_ERR, "inline encryption not supported");
+#endif
+ return 1;
}
for (m = ext4_mount_opts; m->token != Opt_err; m++)
@@ -2404,6 +2413,9 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
fscrypt_show_test_dummy_encryption(seq, sep, sb);
+ if (sb->s_flags & SB_INLINECRYPT)
+ SEQ_OPTS_PUTS("inlinecrypt");
+
if (test_opt(sb, DAX_ALWAYS)) {
if (IS_EXT2_SB(sb))
SEQ_OPTS_PUTS("dax");