[v2,01/14] fscrypt: factor helper for locking master key

Commit Message

Sweet Tea Dorminy July 9, 2023, 6:53 p.m. UTC

When we are making extent infos, we'll need to lock the master key in
more places, so go on and factor out a helper.

Signed-off-by: Sweet Tea Dorminy <[e-mail]>
---
 fs/crypto/keysetup.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

Patch

diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c
index a19650f954e2..c3d3da5da449 100644
--- a/fs/crypto/keysetup.c
+++ b/fs/crypto/keysetup.c
@@ -106,7 +106,18 @@  select_encryption_mode(const union fscrypt_policy *policy,
 	return ERR_PTR(-EINVAL);
 }
 
-/* Create a symmetric cipher object for the given encryption mode and key */
+static int lock_master_key(struct fscrypt_master_key *mk)
+{
+	down_read(&mk->mk_sem);
+
+	/* Has the secret been removed (via FS_IOC_REMOVE_ENCRYPTION_KEY)? */
+	if (!is_master_key_secret_present(&mk->mk_secret))
+		return -ENOKEY;
+
+	return 0;
+}
+
+/* Create a symmetric cipher object for the given encryption mode */
 static struct crypto_skcipher *
 fscrypt_allocate_skcipher(struct fscrypt_mode *mode, const u8 *raw_key,
 			  const struct inode *inode)
@@ -556,13 +567,10 @@  static int find_and_lock_master_key(const struct fscrypt_info *ci,
 		*mk_ret = NULL;
 		return 0;
 	}
-	down_read(&mk->mk_sem);
 
-	/* Has the secret been removed (via FS_IOC_REMOVE_ENCRYPTION_KEY)? */
-	if (!is_master_key_secret_present(&mk->mk_secret)) {
-		err = -ENOKEY;
+	err = lock_master_key(mk);
+	if (err)
 		goto out_release_key;
-	}
 
 	if (!fscrypt_valid_master_key_size(mk, ci)) {
 		err = -ENOKEY;