diff options
Diffstat (limited to 'block/blk-crypto-profile.c')
| -rw-r--r-- | block/blk-crypto-profile.c | 60 |
1 files changed, 25 insertions, 35 deletions
diff --git a/block/blk-crypto-profile.c b/block/blk-crypto-profile.c index 0307fb0d95d3..2a67d3fb63e5 100644 --- a/block/blk-crypto-profile.c +++ b/block/blk-crypto-profile.c @@ -227,14 +227,13 @@ EXPORT_SYMBOL_GPL(blk_crypto_keyslot_index); * @profile: the crypto profile of the device the key will be used on * @key: the key that will be used * @slot_ptr: If a keyslot is allocated, an opaque pointer to the keyslot struct - * will be stored here; otherwise NULL will be stored here. + * will be stored here. blk_crypto_put_keyslot() must be called + * later to release it. Otherwise, NULL will be stored here. * * If the device has keyslots, this gets a keyslot that's been programmed with * the specified key. If the key is already in a slot, this reuses it; * otherwise this waits for a slot to become idle and programs the key into it. * - * This must be paired with a call to blk_crypto_put_keyslot(). - * * Context: Process context. Takes and releases profile->lock. * Return: BLK_STS_OK on success, meaning that either a keyslot was allocated or * one wasn't needed; or a blk_status_t error on failure. @@ -312,20 +311,15 @@ success: /** * blk_crypto_put_keyslot() - Release a reference to a keyslot - * @slot: The keyslot to release the reference of (may be NULL). + * @slot: The keyslot to release the reference of * * Context: Any context. */ void blk_crypto_put_keyslot(struct blk_crypto_keyslot *slot) { - struct blk_crypto_profile *profile; + struct blk_crypto_profile *profile = slot->profile; unsigned long flags; - if (!slot) - return; - - profile = slot->profile; - if (atomic_dec_and_lock_irqsave(&slot->slot_refs, &profile->idle_slots_lock, flags)) { list_add_tail(&slot->idle_slot_node, &profile->idle_slots); @@ -354,28 +348,16 @@ bool __blk_crypto_cfg_supported(struct blk_crypto_profile *profile, return true; } -/** - * __blk_crypto_evict_key() - Evict a key from a device. - * @profile: the crypto profile of the device - * @key: the key to evict. It must not still be used in any I/O. - * - * If the device has keyslots, this finds the keyslot (if any) that contains the - * specified key and calls the driver's keyslot_evict function to evict it. - * - * Otherwise, this just calls the driver's keyslot_evict function if it is - * implemented, passing just the key (without any particular keyslot). This - * allows layered devices to evict the key from their underlying devices. - * - * Context: Process context. Takes and releases profile->lock. - * Return: 0 on success or if there's no keyslot with the specified key, -EBUSY - * if the keyslot is still in use, or another -errno value on other - * error. +/* + * This is an internal function that evicts a key from an inline encryption + * device that can be either a real device or the blk-crypto-fallback "device". + * It is used only by blk_crypto_evict_key(); see that function for details. */ int __blk_crypto_evict_key(struct blk_crypto_profile *profile, const struct blk_crypto_key *key) { struct blk_crypto_keyslot *slot; - int err = 0; + int err; if (profile->num_slots == 0) { if (profile->ll_ops.keyslot_evict) { @@ -389,22 +371,30 @@ int __blk_crypto_evict_key(struct blk_crypto_profile *profile, blk_crypto_hw_enter(profile); slot = blk_crypto_find_keyslot(profile, key); - if (!slot) - goto out_unlock; + if (!slot) { + /* + * Not an error, since a key not in use by I/O is not guaranteed + * to be in a keyslot. There can be more keys than keyslots. + */ + err = 0; + goto out; + } if (WARN_ON_ONCE(atomic_read(&slot->slot_refs) != 0)) { + /* BUG: key is still in use by I/O */ err = -EBUSY; - goto out_unlock; + goto out_remove; } err = profile->ll_ops.keyslot_evict(profile, key, blk_crypto_keyslot_index(slot)); - if (err) - goto out_unlock; - +out_remove: + /* + * Callers free the key even on error, so unlink the key from the hash + * table and clear slot->key even on error. + */ hlist_del(&slot->hash_node); slot->key = NULL; - err = 0; -out_unlock: +out: blk_crypto_hw_exit(profile); return err; } |