blk-crypto: don't use struct request_queue for public interfaces

Switch all public blk-crypto interfaces to use struct block_device
arguments to specify the device they operate on instead of th
request_queue, which is a block layer implementation detail.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20221114042944.1009870-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Documentation/block/inline-encryption.rst

@@ -142,7 +142,7 @@ Therefore, we also introduce *blk-crypto-fallback*, which is an implementation
 of inline encryption using the kernel crypto API.  blk-crypto-fallback is built
 into the block layer, so it works on any block device without any special setup.
 Essentially, when a bio with an encryption context is submitted to a
-request_queue that doesn't support that encryption context, the block layer will
+block_device that doesn't support that encryption context, the block layer will
 handle en/decryption of the bio using blk-crypto-fallback.
 
 For encryption, the data cannot be encrypted in-place, as callers usually rely
@@ -187,7 +187,7 @@ API presented to users of the block layer
 
 ``blk_crypto_config_supported()`` allows users to check ahead of time whether
 inline encryption with particular crypto settings will work on a particular
-request_queue -- either via hardware or via blk-crypto-fallback.  This function
+block_device -- either via hardware or via blk-crypto-fallback.  This function
 takes in a ``struct blk_crypto_config`` which is like blk_crypto_key, but omits
 the actual bytes of the key and instead just contains the algorithm, data unit
 size, etc.  This function can be useful if blk-crypto-fallback is disabled.
@@ -195,7 +195,7 @@ size, etc.  This function can be useful if blk-crypto-fallback is disabled.
 ``blk_crypto_init_key()`` allows users to initialize a blk_crypto_key.
 
 Users must call ``blk_crypto_start_using_key()`` before actually starting to use
-a blk_crypto_key on a request_queue (even if ``blk_crypto_config_supported()``
+a blk_crypto_key on a block_device (even if ``blk_crypto_config_supported()``
 was called earlier).  This is needed to initialize blk-crypto-fallback if it
 will be needed.  This must not be called from the data path, as this may have to
 allocate resources, which may deadlock in that case.
@@ -207,7 +207,7 @@ for en/decryption.  Users don't need to worry about freeing the bio_crypt_ctx
 later, as that happens automatically when the bio is freed or reset.
 
 Finally, when done using inline encryption with a blk_crypto_key on a
-request_queue, users must call ``blk_crypto_evict_key()``.  This ensures that
+block_device, users must call ``blk_crypto_evict_key()``.  This ensures that
 the key is evicted from all keyslots it may be programmed into and unlinked from
 any kernel data structures it may be linked into.
 
@@ -221,9 +221,9 @@ as follows:
 5. ``blk_crypto_evict_key()`` (after all I/O has completed)
 6. Zeroize the blk_crypto_key (this has no dedicated function)
 
-If a blk_crypto_key is being used on multiple request_queues, then
+If a blk_crypto_key is being used on multiple block_devices, then
 ``blk_crypto_config_supported()`` (if used), ``blk_crypto_start_using_key()``,
-and ``blk_crypto_evict_key()`` must be called on each request_queue.
+and ``blk_crypto_evict_key()`` must be called on each block_device.
 
 API presented to device drivers
 ===============================

block/blk-crypto.c

@@ -354,20 +354,21 @@ int blk_crypto_init_key(struct blk_crypto_key *blk_key, const u8 *raw_key,
 
 /*
  * Check if bios with @cfg can be en/decrypted by blk-crypto (i.e. either the
- * request queue it's submitted to supports inline crypto, or the
+ * block_device it's submitted to supports inline crypto, or the
  * blk-crypto-fallback is enabled and supports the cfg).
  */
-bool blk_crypto_config_supported(struct request_queue *q,
+bool blk_crypto_config_supported(struct block_device *bdev,
 				 const struct blk_crypto_config *cfg)
 {
 	return IS_ENABLED(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK) ||
-	       __blk_crypto_cfg_supported(q->crypto_profile, cfg);
+	       __blk_crypto_cfg_supported(bdev_get_queue(bdev)->crypto_profile,
+					  cfg);
 }
 
 /**
  * blk_crypto_start_using_key() - Start using a blk_crypto_key on a device
+ * @bdev: block device to operate on
  * @key: A key to use on the device
- * @q: the request queue for the device
  *
  * Upper layers must call this function to ensure that either the hardware
  * supports the key's crypto settings, or the crypto API fallback has transforms
@@ -379,10 +380,11 @@ bool blk_crypto_config_supported(struct request_queue *q,
  *	   blk-crypto-fallback is either disabled or the needed algorithm
  *	   is disabled in the crypto API; or another -errno code.
  */
-int blk_crypto_start_using_key(const struct blk_crypto_key *key,
-			       struct request_queue *q)
+int blk_crypto_start_using_key(struct block_device *bdev,
+			       const struct blk_crypto_key *key)
 {
-	if (__blk_crypto_cfg_supported(q->crypto_profile, &key->crypto_cfg))
+	if (__blk_crypto_cfg_supported(bdev_get_queue(bdev)->crypto_profile,
+			&key->crypto_cfg))
 		return 0;
 	return blk_crypto_fallback_start_using_mode(key->crypto_cfg.crypto_mode);
 }
@@ -390,7 +392,7 @@ int blk_crypto_start_using_key(const struct blk_crypto_key *key,
 /**
  * blk_crypto_evict_key() - Evict a key from any inline encryption hardware
  *			    it may have been programmed into
- * @q: The request queue who's associated inline encryption hardware this key
+ * @bdev: The block_device who's associated inline encryption hardware this key
  *     might have been programmed into
  * @key: The key to evict
  *
@@ -400,14 +402,16 @@ int blk_crypto_start_using_key(const struct blk_crypto_key *key,
  *
  * Return: 0 on success or if the key wasn't in any keyslot; -errno on error.
  */
-int blk_crypto_evict_key(struct request_queue *q,
+int blk_crypto_evict_key(struct block_device *bdev,
 			 const struct blk_crypto_key *key)
 {
+	struct request_queue *q = bdev_get_queue(bdev);
+
 	if (__blk_crypto_cfg_supported(q->crypto_profile, &key->crypto_cfg))
 		return __blk_crypto_evict_key(q->crypto_profile, key);
 
 	/*
-	 * If the request_queue didn't support the key, then blk-crypto-fallback
+	 * If the block_device didn't support the key, then blk-crypto-fallback
 	 * may have been used, so try to evict the key from blk-crypto-fallback.
 	 */
 	return blk_crypto_fallback_evict_key(key);

drivers/md/dm-table.c

@@ -1215,7 +1215,7 @@ static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
 	struct dm_keyslot_evict_args *args = data;
 	int err;
 
-	err = blk_crypto_evict_key(bdev_get_queue(dev->bdev), args->key);
+	err = blk_crypto_evict_key(dev->bdev, args->key);
 	if (!args->err)
 		args->err = err;
 	/* Always try to evict the key from all devices. */

fs/crypto/inline_crypt.c

@@ -139,8 +139,7 @@ int fscrypt_select_encryption_impl(struct fscrypt_info *ci)
 		return PTR_ERR(devs);
 
 	for (i = 0; i < num_devs; i++) {
-		if (!blk_crypto_config_supported(bdev_get_queue(devs[i]),
-						 &crypto_cfg))
+		if (!blk_crypto_config_supported(devs[i], &crypto_cfg))
 			goto out_free_devs;
 	}
 
@@ -184,8 +183,7 @@ int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
 		goto fail;
 	}
 	for (i = 0; i < num_devs; i++) {
-		err = blk_crypto_start_using_key(blk_key,
-						 bdev_get_queue(devs[i]));
+		err = blk_crypto_start_using_key(devs[i], blk_key);
 		if (err)
 			break;
 	}
@@ -224,7 +222,7 @@ void fscrypt_destroy_inline_crypt_key(struct super_block *sb,
 	devs = fscrypt_get_devices(sb, &num_devs);
 	if (!IS_ERR(devs)) {
 		for (i = 0; i < num_devs; i++)
-			blk_crypto_evict_key(bdev_get_queue(devs[i]), blk_key);
+			blk_crypto_evict_key(devs[i], blk_key);
 		kfree(devs);
 	}
 	kfree_sensitive(blk_key);

include/linux/blk-crypto.h

@@ -71,9 +71,6 @@ struct bio_crypt_ctx {
 #include <linux/blk_types.h>
 #include <linux/blkdev.h>
 
-struct request;
-struct request_queue;
-
 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
 
 static inline bool bio_has_crypt_ctx(struct bio *bio)
@@ -94,13 +91,13 @@ int blk_crypto_init_key(struct blk_crypto_key *blk_key, const u8 *raw_key,
 			unsigned int dun_bytes,
 			unsigned int data_unit_size);
 
-int blk_crypto_start_using_key(const struct blk_crypto_key *key,
-			       struct request_queue *q);
+int blk_crypto_start_using_key(struct block_device *bdev,
+			       const struct blk_crypto_key *key);
 
-int blk_crypto_evict_key(struct request_queue *q,
+int blk_crypto_evict_key(struct block_device *bdev,
 			 const struct blk_crypto_key *key);
 
-bool blk_crypto_config_supported(struct request_queue *q,
+bool blk_crypto_config_supported(struct block_device *bdev,
 				 const struct blk_crypto_config *cfg);
 
 #else /* CONFIG_BLK_INLINE_ENCRYPTION */