[v3,01/16] fscrypt: factor helper for locking master key

Commit Message

Sweet Tea Dorminy Aug. 8, 2023, 5:08 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(-)

Comments

Josef Bacik Aug. 9, 2023, 5:53 p.m. UTC | #1

On Tue, Aug 08, 2023 at 01:08:18PM -0400, Sweet Tea Dorminy wrote:
> 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]>

You factor this out, but I went and checked your tree with all of your patches
and this is only ever used in this one case, so do you actually need this patch
anymore?  Thanks,

Josef

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;