Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt

Pull fscrypt updates from Eric Biggers:
 "This release contains some implementation changes, but no new
  features:

   - Rework the implementation of the fscrypt filesystem-level keyring
     to not be as tightly coupled to the keyrings subsystem. This
     resolves several issues.

   - Eliminate most direct uses of struct request_queue from fs/crypto/,
     since struct request_queue is considered to be a block layer
     implementation detail.

   - Stop using the PG_error flag to track decryption failures. This is
     a prerequisite for freeing up PG_error for other uses"

* tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt:
  fscrypt: work on block_devices instead of request_queues
  fscrypt: stop holding extra request_queue references
  fscrypt: stop using keyrings subsystem for fscrypt_master_key
  fscrypt: stop using PG_error to track error status
  fscrypt: remove fscrypt_set_test_dummy_encryption()

fs/crypto/bio.c

@@ -25,21 +25,25 @@
  * then this function isn't applicable.  This function may sleep, so it must be
  * called from a workqueue rather than from the bio's bi_end_io callback.
  *
- * This function sets PG_error on any pages that contain any blocks that failed
- * to be decrypted.  The filesystem must not mark such pages uptodate.
+ * Return: %true on success; %false on failure.  On failure, bio->bi_status is
+ *	   also set to an error status.
  */
-void fscrypt_decrypt_bio(struct bio *bio)
+bool fscrypt_decrypt_bio(struct bio *bio)
 {
 	struct bio_vec *bv;
 	struct bvec_iter_all iter_all;
 
 	bio_for_each_segment_all(bv, bio, iter_all) {
 		struct page *page = bv->bv_page;
-		int ret = fscrypt_decrypt_pagecache_blocks(page, bv->bv_len,
+		int err = fscrypt_decrypt_pagecache_blocks(page, bv->bv_len,
 							   bv->bv_offset);
-		if (ret)
-			SetPageError(page);
+
+		if (err) {
+			bio->bi_status = errno_to_blk_status(err);
+			return false;
+		}
 	}
+	return true;
 }
 EXPORT_SYMBOL(fscrypt_decrypt_bio);
 

fs/crypto/fscrypt_private.h

@@ -184,7 +184,7 @@ struct fscrypt_symlink_data {
 struct fscrypt_prepared_key {
 	struct crypto_skcipher *tfm;
 #ifdef CONFIG_FS_ENCRYPTION_INLINE_CRYPT
-	struct fscrypt_blk_crypto_key *blk_key;
+	struct blk_crypto_key *blk_key;
 #endif
 };
 
@@ -225,7 +225,7 @@ struct fscrypt_info {
 	 * will be NULL if the master key was found in a process-subscribed
 	 * keyring rather than in the filesystem-level keyring.
 	 */
-	struct key *ci_master_key;
+	struct fscrypt_master_key *ci_master_key;
 
 	/*
 	 * Link in list of inodes that were unlocked with the master key.
@@ -344,7 +344,8 @@ int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
 				     const u8 *raw_key,
 				     const struct fscrypt_info *ci);
 
-void fscrypt_destroy_inline_crypt_key(struct fscrypt_prepared_key *prep_key);
+void fscrypt_destroy_inline_crypt_key(struct super_block *sb,
+				      struct fscrypt_prepared_key *prep_key);
 
 /*
  * Check whether the crypto transform or blk-crypto key has been allocated in
@@ -390,7 +391,8 @@ fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
 }
 
 static inline void
-fscrypt_destroy_inline_crypt_key(struct fscrypt_prepared_key *prep_key)
+fscrypt_destroy_inline_crypt_key(struct super_block *sb,
+				 struct fscrypt_prepared_key *prep_key)
 {
 }
 
@@ -436,6 +438,40 @@ struct fscrypt_master_key_secret {
  */
 struct fscrypt_master_key {
 
+	/*
+	 * Back-pointer to the super_block of the filesystem to which this
+	 * master key has been added.  Only valid if ->mk_active_refs > 0.
+	 */
+	struct super_block			*mk_sb;
+
+	/*
+	 * Link in ->mk_sb->s_master_keys->key_hashtable.
+	 * Only valid if ->mk_active_refs > 0.
+	 */
+	struct hlist_node			mk_node;
+
+	/* Semaphore that protects ->mk_secret and ->mk_users */
+	struct rw_semaphore			mk_sem;
+
+	/*
+	 * Active and structural reference counts.  An active ref guarantees
+	 * that the struct continues to exist, continues to be in the keyring
+	 * ->mk_sb->s_master_keys, and that any embedded subkeys (e.g.
+	 * ->mk_direct_keys) that have been prepared continue to exist.
+	 * A structural ref only guarantees that the struct continues to exist.
+	 *
+	 * There is one active ref associated with ->mk_secret being present,
+	 * and one active ref for each inode in ->mk_decrypted_inodes.
+	 *
+	 * There is one structural ref associated with the active refcount being
+	 * nonzero.  Finding a key in the keyring also takes a structural ref,
+	 * which is then held temporarily while the key is operated on.
+	 */
+	refcount_t				mk_active_refs;
+	refcount_t				mk_struct_refs;
+
+	struct rcu_head				mk_rcu_head;
+
 	/*
 	 * The secret key material.  After FS_IOC_REMOVE_ENCRYPTION_KEY is
 	 * executed, this is wiped and no new inodes can be unlocked with this
@@ -444,7 +480,10 @@ struct fscrypt_master_key {
 	 * FS_IOC_REMOVE_ENCRYPTION_KEY can be retried, or
 	 * FS_IOC_ADD_ENCRYPTION_KEY can add the secret again.
 	 *
-	 * Locking: protected by this master key's key->sem.
+	 * While ->mk_secret is present, one ref in ->mk_active_refs is held.
+	 *
+	 * Locking: protected by ->mk_sem.  The manipulation of ->mk_active_refs
+	 *	    associated with this field is protected by ->mk_sem as well.
 	 */
 	struct fscrypt_master_key_secret	mk_secret;
 
@@ -465,22 +504,12 @@ struct fscrypt_master_key {
 	 *
 	 * This is NULL for v1 policy keys; those can only be added by root.
 	 *
-	 * Locking: in addition to this keyring's own semaphore, this is
-	 * protected by this master key's key->sem, so we can do atomic
-	 * search+insert.  It can also be searched without taking any locks, but
-	 * in that case the returned key may have already been removed.
+	 * Locking: protected by ->mk_sem.  (We don't just rely on the keyrings
+	 * subsystem semaphore ->mk_users->sem, as we need support for atomic
+	 * search+insert along with proper synchronization with ->mk_secret.)
 	 */
 	struct key		*mk_users;
 
-	/*
-	 * Length of ->mk_decrypted_inodes, plus one if mk_secret is present.
-	 * Once this goes to 0, the master key is removed from ->s_master_keys.
-	 * The 'struct fscrypt_master_key' will continue to live as long as the
-	 * 'struct key' whose payload it is, but we won't let this reference
-	 * count rise again.
-	 */
-	refcount_t		mk_refcount;
-
 	/*
 	 * List of inodes that were unlocked using this key.  This allows the
 	 * inodes to be evicted efficiently if the key is removed.
@@ -506,10 +535,10 @@ static inline bool
 is_master_key_secret_present(const struct fscrypt_master_key_secret *secret)
 {
 	/*
-	 * The READ_ONCE() is only necessary for fscrypt_drop_inode() and
-	 * fscrypt_key_describe().  These run in atomic context, so they can't
-	 * take the key semaphore and thus 'secret' can change concurrently
-	 * which would be a data race.  But they only need to know whether the
+	 * The READ_ONCE() is only necessary for fscrypt_drop_inode().
+	 * fscrypt_drop_inode() runs in atomic context, so it can't take the key
+	 * semaphore and thus 'secret' can change concurrently which would be a
+	 * data race.  But fscrypt_drop_inode() only need to know whether the
 	 * secret *was* present at the time of check, so READ_ONCE() suffices.
 	 */
 	return READ_ONCE(secret->size) != 0;
@@ -538,7 +567,11 @@ static inline int master_key_spec_len(const struct fscrypt_key_specifier *spec)
 	return 0;
 }
 
-struct key *
+void fscrypt_put_master_key(struct fscrypt_master_key *mk);
+
+void fscrypt_put_master_key_activeref(struct fscrypt_master_key *mk);
+
+struct fscrypt_master_key *
 fscrypt_find_master_key(struct super_block *sb,
 			const struct fscrypt_key_specifier *mk_spec);
 
@@ -569,7 +602,8 @@ extern struct fscrypt_mode fscrypt_modes[];
 int fscrypt_prepare_key(struct fscrypt_prepared_key *prep_key,
 			const u8 *raw_key, const struct fscrypt_info *ci);
 
-void fscrypt_destroy_prepared_key(struct fscrypt_prepared_key *prep_key);
+void fscrypt_destroy_prepared_key(struct super_block *sb,
+				  struct fscrypt_prepared_key *prep_key);
 
 int fscrypt_set_per_file_enc_key(struct fscrypt_info *ci, const u8 *raw_key);
 

fs/crypto/hooks.c

@@ -5,8 +5,6 @@
  * Encryption hooks for higher-level filesystem operations.
  */
 
-#include <linux/key.h>
-
 #include "fscrypt_private.h"
 
 /**
@@ -142,7 +140,6 @@ int fscrypt_prepare_setflags(struct inode *inode,
 			     unsigned int oldflags, unsigned int flags)
 {
 	struct fscrypt_info *ci;
-	struct key *key;
 	struct fscrypt_master_key *mk;
 	int err;
 
@@ -158,14 +155,13 @@ int fscrypt_prepare_setflags(struct inode *inode,
 		ci = inode->i_crypt_info;
 		if (ci->ci_policy.version != FSCRYPT_POLICY_V2)
 			return -EINVAL;
-		key = ci->ci_master_key;
-		mk = key->payload.data[0];
-		down_read(&key->sem);
+		mk = ci->ci_master_key;
+		down_read(&mk->mk_sem);
 		if (is_master_key_secret_present(&mk->mk_secret))
 			err = fscrypt_derive_dirhash_key(ci, mk);
 		else
 			err = -ENOKEY;
-		up_read(&key->sem);
+		up_read(&mk->mk_sem);
 		return err;
 	}
 	return 0;

fs/crypto/inline_crypt.c

@@ -21,26 +21,22 @@
 
 #include "fscrypt_private.h"
 
-struct fscrypt_blk_crypto_key {
-	struct blk_crypto_key base;
-	int num_devs;
-	struct request_queue *devs[];
-};
-
-static int fscrypt_get_num_devices(struct super_block *sb)
+static struct block_device **fscrypt_get_devices(struct super_block *sb,
+						 unsigned int *num_devs)
 {
-	if (sb->s_cop->get_num_devices)
-		return sb->s_cop->get_num_devices(sb);
-	return 1;
-}
+	struct block_device **devs;
 
-static void fscrypt_get_devices(struct super_block *sb, int num_devs,
-				struct request_queue **devs)
-{
-	if (num_devs == 1)
-		devs[0] = bdev_get_queue(sb->s_bdev);
-	else
-		sb->s_cop->get_devices(sb, devs);
+	if (sb->s_cop->get_devices) {
+		devs = sb->s_cop->get_devices(sb, num_devs);
+		if (devs)
+			return devs;
+	}
+	devs = kmalloc(sizeof(*devs), GFP_KERNEL);
+	if (!devs)
+		return ERR_PTR(-ENOMEM);
+	devs[0] = sb->s_bdev;
+	*num_devs = 1;
+	return devs;
 }
 
 static unsigned int fscrypt_get_dun_bytes(const struct fscrypt_info *ci)
@@ -74,15 +70,17 @@ static unsigned int fscrypt_get_dun_bytes(const struct fscrypt_info *ci)
  * helpful for debugging problems where the "wrong" implementation is used.
  */
 static void fscrypt_log_blk_crypto_impl(struct fscrypt_mode *mode,
-					struct request_queue **devs,
-					int num_devs,
+					struct block_device **devs,
+					unsigned int num_devs,
 					const struct blk_crypto_config *cfg)
 {
-	int i;
+	unsigned int i;
 
 	for (i = 0; i < num_devs; i++) {
+		struct request_queue *q = bdev_get_queue(devs[i]);
+
 		if (!IS_ENABLED(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK) ||
-		    __blk_crypto_cfg_supported(devs[i]->crypto_profile, cfg)) {
+		    __blk_crypto_cfg_supported(q->crypto_profile, cfg)) {
 			if (!xchg(&mode->logged_blk_crypto_native, 1))
 				pr_info("fscrypt: %s using blk-crypto (native)\n",
 					mode->friendly_name);
@@ -99,9 +97,9 @@ int fscrypt_select_encryption_impl(struct fscrypt_info *ci)
 	const struct inode *inode = ci->ci_inode;
 	struct super_block *sb = inode->i_sb;
 	struct blk_crypto_config crypto_cfg;
-	int num_devs;
-	struct request_queue **devs;
-	int i;
+	struct block_device **devs;
+	unsigned int num_devs;
+	unsigned int i;
 
 	/* The file must need contents encryption, not filenames encryption */
 	if (!S_ISREG(inode->i_mode))
@@ -129,20 +127,20 @@ int fscrypt_select_encryption_impl(struct fscrypt_info *ci)
 		return 0;
 
 	/*
-	 * On all the filesystem's devices, blk-crypto must support the crypto
-	 * configuration that the file would use.
+	 * On all the filesystem's block devices, blk-crypto must support the
+	 * crypto configuration that the file would use.
 	 */
 	crypto_cfg.crypto_mode = ci->ci_mode->blk_crypto_mode;
 	crypto_cfg.data_unit_size = sb->s_blocksize;
 	crypto_cfg.dun_bytes = fscrypt_get_dun_bytes(ci);
-	num_devs = fscrypt_get_num_devices(sb);
-	devs = kmalloc_array(num_devs, sizeof(*devs), GFP_KERNEL);
-	if (!devs)
-		return -ENOMEM;
-	fscrypt_get_devices(sb, num_devs, devs);
+
+	devs = fscrypt_get_devices(sb, &num_devs);
+	if (IS_ERR(devs))
+		return PTR_ERR(devs);
 
 	for (i = 0; i < num_devs; i++) {
-		if (!blk_crypto_config_supported(devs[i], &crypto_cfg))
+		if (!blk_crypto_config_supported(bdev_get_queue(devs[i]),
+						 &crypto_cfg))
 			goto out_free_devs;
 	}
 
@@ -162,49 +160,41 @@ int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
 	const struct inode *inode = ci->ci_inode;
 	struct super_block *sb = inode->i_sb;
 	enum blk_crypto_mode_num crypto_mode = ci->ci_mode->blk_crypto_mode;
-	int num_devs = fscrypt_get_num_devices(sb);
-	int queue_refs = 0;
-	struct fscrypt_blk_crypto_key *blk_key;
+	struct blk_crypto_key *blk_key;
+	struct block_device **devs;
+	unsigned int num_devs;
+	unsigned int i;
 	int err;
-	int i;
 
-	blk_key = kzalloc(struct_size(blk_key, devs, num_devs), GFP_KERNEL);
+	blk_key = kmalloc(sizeof(*blk_key), GFP_KERNEL);
 	if (!blk_key)
 		return -ENOMEM;
 
-	blk_key->num_devs = num_devs;
-	fscrypt_get_devices(sb, num_devs, blk_key->devs);
-
-	err = blk_crypto_init_key(&blk_key->base, raw_key, crypto_mode,
+	err = blk_crypto_init_key(blk_key, raw_key, crypto_mode,
 				  fscrypt_get_dun_bytes(ci), sb->s_blocksize);
 	if (err) {
 		fscrypt_err(inode, "error %d initializing blk-crypto key", err);
 		goto fail;
 	}
 
-	/*
-	 * We have to start using blk-crypto on all the filesystem's devices.
-	 * We also have to save all the request_queue's for later so that the
-	 * key can be evicted from them.  This is needed because some keys
-	 * aren't destroyed until after the filesystem was already unmounted
-	 * (namely, the per-mode keys in struct fscrypt_master_key).
-	 */
+	/* Start using blk-crypto on all the filesystem's block devices. */
+	devs = fscrypt_get_devices(sb, &num_devs);
+	if (IS_ERR(devs)) {
+		err = PTR_ERR(devs);
+		goto fail;
+	}
 	for (i = 0; i < num_devs; i++) {
-		if (!blk_get_queue(blk_key->devs[i])) {
-			fscrypt_err(inode, "couldn't get request_queue");
-			err = -EAGAIN;
-			goto fail;
-		}
-		queue_refs++;
-
-		err = blk_crypto_start_using_key(&blk_key->base,
-						 blk_key->devs[i]);
-		if (err) {
-			fscrypt_err(inode,
-				    "error %d starting to use blk-crypto", err);
-			goto fail;
-		}
+		err = blk_crypto_start_using_key(blk_key,
+						 bdev_get_queue(devs[i]));
+		if (err)
+			break;
+	}
+	kfree(devs);
+	if (err) {
+		fscrypt_err(inode, "error %d starting to use blk-crypto", err);
+		goto fail;
 	}
+
 	/*
 	 * Pairs with the smp_load_acquire() in fscrypt_is_key_prepared().
 	 * I.e., here we publish ->blk_key with a RELEASE barrier so that
@@ -215,24 +205,29 @@ int fscrypt_prepare_inline_crypt_key(struct fscrypt_prepared_key *prep_key,
 	return 0;
 
 fail:
-	for (i = 0; i < queue_refs; i++)
-		blk_put_queue(blk_key->devs[i]);
 	kfree_sensitive(blk_key);
 	return err;
 }
 
-void fscrypt_destroy_inline_crypt_key(struct fscrypt_prepared_key *prep_key)
+void fscrypt_destroy_inline_crypt_key(struct super_block *sb,
+				      struct fscrypt_prepared_key *prep_key)
 {
-	struct fscrypt_blk_crypto_key *blk_key = prep_key->blk_key;
-	int i;
+	struct blk_crypto_key *blk_key = prep_key->blk_key;
+	struct block_device **devs;
+	unsigned int num_devs;
+	unsigned int i;
 
-	if (blk_key) {
-		for (i = 0; i < blk_key->num_devs; i++) {
-			blk_crypto_evict_key(blk_key->devs[i], &blk_key->base);
-			blk_put_queue(blk_key->devs[i]);
-		}
-		kfree_sensitive(blk_key);
+	if (!blk_key)
+		return;
+
+	/* Evict the key from all the filesystem's block devices. */
+	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);
+		kfree(devs);
 	}
+	kfree_sensitive(blk_key);
 }
 
 bool __fscrypt_inode_uses_inline_crypto(const struct inode *inode)
@@ -282,7 +277,7 @@ void fscrypt_set_bio_crypt_ctx(struct bio *bio, const struct inode *inode,
 	ci = inode->i_crypt_info;
 
 	fscrypt_generate_dun(ci, first_lblk, dun);
-	bio_crypt_set_ctx(bio, &ci->ci_enc_key.blk_key->base, dun, gfp_mask);
+	bio_crypt_set_ctx(bio, ci->ci_enc_key.blk_key, dun, gfp_mask);
 }
 EXPORT_SYMBOL_GPL(fscrypt_set_bio_crypt_ctx);
 
@@ -369,7 +364,7 @@ bool fscrypt_mergeable_bio(struct bio *bio, const struct inode *inode,
 	 * uses the same pointer.  I.e., there's currently no need to support
 	 * merging requests where the keys are the same but the pointers differ.
 	 */
-	if (bc->bc_key != &inode->i_crypt_info->ci_enc_key.blk_key->base)
+	if (bc->bc_key != inode->i_crypt_info->ci_enc_key.blk_key)
 		return false;
 
 	fscrypt_generate_dun(inode->i_crypt_info, next_lblk, next_dun);

fs/crypto/keysetup.c

@@ -9,7 +9,6 @@
  */
 
 #include <crypto/skcipher.h>
-#include <linux/key.h>
 #include <linux/random.h>
 
 #include "fscrypt_private.h"
@@ -155,10 +154,12 @@ int fscrypt_prepare_key(struct fscrypt_prepared_key *prep_key,
 }
 
 /* Destroy a crypto transform object and/or blk-crypto key. */
-void fscrypt_destroy_prepared_key(struct fscrypt_prepared_key *prep_key)
+void fscrypt_destroy_prepared_key(struct super_block *sb,
+				  struct fscrypt_prepared_key *prep_key)
 {
 	crypto_free_skcipher(prep_key->tfm);
-	fscrypt_destroy_inline_crypt_key(prep_key);
+	fscrypt_destroy_inline_crypt_key(sb, prep_key);
+	memzero_explicit(prep_key, sizeof(*prep_key));
 }
 
 /* Given a per-file encryption key, set up the file's crypto transform object */
@@ -412,20 +413,18 @@ static bool fscrypt_valid_master_key_size(const struct fscrypt_master_key *mk,
 /*
  * Find the master key, then set up the inode's actual encryption key.
  *
- * If the master key is found in the filesystem-level keyring, then the
- * corresponding 'struct key' is returned in *master_key_ret with its semaphore
- * read-locked.  This is needed to ensure that only one task links the
- * fscrypt_info into ->mk_decrypted_inodes (as multiple tasks may race to create
- * an fscrypt_info for the same inode), and to synchronize the master key being
- * removed with a new inode starting to use it.
+ * If the master key is found in the filesystem-level keyring, then it is
+ * returned in *mk_ret with its semaphore read-locked.  This is needed to ensure
+ * that only one task links the fscrypt_info into ->mk_decrypted_inodes (as
+ * multiple tasks may race to create an fscrypt_info for the same inode), and to
+ * synchronize the master key being removed with a new inode starting to use it.
  */
 static int setup_file_encryption_key(struct fscrypt_info *ci,
 				     bool need_dirhash_key,
-				     struct key **master_key_ret)
+				     struct fscrypt_master_key **mk_ret)
 {
-	struct key *key;
-	struct fscrypt_master_key *mk = NULL;
 	struct fscrypt_key_specifier mk_spec;
+	struct fscrypt_master_key *mk;
 	int err;
 
 	err = fscrypt_select_encryption_impl(ci);
@@ -436,11 +435,10 @@ static int setup_file_encryption_key(struct fscrypt_info *ci,
 	if (err)
 		return err;
 
-	key = fscrypt_find_master_key(ci->ci_inode->i_sb, &mk_spec);
-	if (IS_ERR(key)) {
-		if (key != ERR_PTR(-ENOKEY) ||
-		    ci->ci_policy.version != FSCRYPT_POLICY_V1)
-			return PTR_ERR(key);
+	mk = fscrypt_find_master_key(ci->ci_inode->i_sb, &mk_spec);
+	if (!mk) {
+		if (ci->ci_policy.version != FSCRYPT_POLICY_V1)
+			return -ENOKEY;
 
 		/*
 		 * As a legacy fallback for v1 policies, search for the key in
@@ -450,9 +448,7 @@ static int setup_file_encryption_key(struct fscrypt_info *ci,
 		 */
 		return fscrypt_setup_v1_file_key_via_subscribed_keyrings(ci);
 	}
-
-	mk = key->payload.data[0];
-	down_read(&key->sem);
+	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)) {
@@ -480,18 +476,18 @@ static int setup_file_encryption_key(struct fscrypt_info *ci,
 	if (err)
 		goto out_release_key;
 
-	*master_key_ret = key;
+	*mk_ret = mk;
 	return 0;
 
 out_release_key:
-	up_read(&key->sem);
-	key_put(key);
+	up_read(&mk->mk_sem);
+	fscrypt_put_master_key(mk);
 	return err;
 }
 
 static void put_crypt_info(struct fscrypt_info *ci)
 {
-	struct key *key;
+	struct fscrypt_master_key *mk;
 
 	if (!ci)
 		return;
@@ -499,26 +495,21 @@ static void put_crypt_info(struct fscrypt_info *ci)
 	if (ci->ci_direct_key)
 		fscrypt_put_direct_key(ci->ci_direct_key);
 	else if (ci->ci_owns_key)
-		fscrypt_destroy_prepared_key(&ci->ci_enc_key);
-
-	key = ci->ci_master_key;
-	if (key) {
-		struct fscrypt_master_key *mk = key->payload.data[0];
+		fscrypt_destroy_prepared_key(ci->ci_inode->i_sb,
+					     &ci->ci_enc_key);
 
+	mk = ci->ci_master_key;
+	if (mk) {
 		/*
 		 * Remove this inode from the list of inodes that were unlocked
-		 * with the master key.
-		 *
-		 * In addition, if we're removing the last inode from a key that
-		 * already had its secret removed, invalidate the key so that it
-		 * gets removed from ->s_master_keys.
+		 * with the master key.  In addition, if we're removing the last
+		 * inode from a master key struct that already had its secret
+		 * removed, then complete the full removal of the struct.
 		 */
 		spin_lock(&mk->mk_decrypted_inodes_lock);
 		list_del(&ci->ci_master_key_link);
 		spin_unlock(&mk->mk_decrypted_inodes_lock);
-		if (refcount_dec_and_test(&mk->mk_refcount))
-			key_invalidate(key);
-		key_put(key);
+		fscrypt_put_master_key_activeref(mk);
 	}
 	memzero_explicit(ci, sizeof(*ci));
 	kmem_cache_free(fscrypt_info_cachep, ci);
@@ -532,7 +523,7 @@ fscrypt_setup_encryption_info(struct inode *inode,
 {
 	struct fscrypt_info *crypt_info;
 	struct fscrypt_mode *mode;
-	struct key *master_key = NULL;
+	struct fscrypt_master_key *mk = NULL;
 	int res;
 
 	res = fscrypt_initialize(inode->i_sb->s_cop->flags);
@@ -555,8 +546,7 @@ fscrypt_setup_encryption_info(struct inode *inode,
 	WARN_ON(mode->ivsize > FSCRYPT_MAX_IV_SIZE);
 	crypt_info->ci_mode = mode;
 
-	res = setup_file_encryption_key(crypt_info, need_dirhash_key,
-					&master_key);
+	res = setup_file_encryption_key(crypt_info, need_dirhash_key, &mk);
 	if (res)
 		goto out;
 
@@ -571,12 +561,9 @@ fscrypt_setup_encryption_info(struct inode *inode,
 		 * We won the race and set ->i_crypt_info to our crypt_info.
 		 * Now link it into the master key's inode list.
 		 */
-		if (master_key) {
-			struct fscrypt_master_key *mk =
-				master_key->payload.data[0];
-
-			refcount_inc(&mk->mk_refcount);
-			crypt_info->ci_master_key = key_get(master_key);
+		if (mk) {
+			crypt_info->ci_master_key = mk;
+			refcount_inc(&mk->mk_active_refs);
 			spin_lock(&mk->mk_decrypted_inodes_lock);
 			list_add(&crypt_info->ci_master_key_link,
 				 &mk->mk_decrypted_inodes);
@@ -586,9 +573,9 @@ fscrypt_setup_encryption_info(struct inode *inode,
 	}
 	res = 0;
 out:
-	if (master_key) {
-		up_read(&master_key->sem);
-		key_put(master_key);
+	if (mk) {
+		up_read(&mk->mk_sem);
+		fscrypt_put_master_key(mk);
 	}
 	put_crypt_info(crypt_info);
 	return res;
@@ -753,7 +740,6 @@ EXPORT_SYMBOL(fscrypt_free_inode);
 int fscrypt_drop_inode(struct inode *inode)
 {
 	const struct fscrypt_info *ci = fscrypt_get_info(inode);
-	const struct fscrypt_master_key *mk;
 
 	/*
 	 * If ci is NULL, then the inode doesn't have an encryption key set up
@@ -763,7 +749,6 @@ int fscrypt_drop_inode(struct inode *inode)
 	 */
 	if (!ci || !ci->ci_master_key)
 		return 0;
-	mk = ci->ci_master_key->payload.data[0];
 
 	/*
 	 * With proper, non-racy use of FS_IOC_REMOVE_ENCRYPTION_KEY, all inodes
@@ -782,6 +767,6 @@ int fscrypt_drop_inode(struct inode *inode)
 	 * then the thread removing the key will either evict the inode itself
 	 * or will correctly detect that it wasn't evicted due to the race.
 	 */
-	return !is_master_key_secret_present(&mk->mk_secret);
+	return !is_master_key_secret_present(&ci->ci_master_key->mk_secret);
 }
 EXPORT_SYMBOL_GPL(fscrypt_drop_inode);

fs/crypto/keysetup_v1.c

@@ -143,6 +143,7 @@ find_and_lock_process_key(const char *prefix,
 
 /* Master key referenced by DIRECT_KEY policy */
 struct fscrypt_direct_key {
+	struct super_block		*dk_sb;
 	struct hlist_node		dk_node;
 	refcount_t			dk_refcount;
 	const struct fscrypt_mode	*dk_mode;
@@ -154,7 +155,7 @@ struct fscrypt_direct_key {
 static void free_direct_key(struct fscrypt_direct_key *dk)
 {
 	if (dk) {
-		fscrypt_destroy_prepared_key(&dk->dk_key);
+		fscrypt_destroy_prepared_key(dk->dk_sb, &dk->dk_key);
 		kfree_sensitive(dk);
 	}
 }
@@ -231,6 +232,7 @@ fscrypt_get_direct_key(const struct fscrypt_info *ci, const u8 *raw_key)
 	dk = kzalloc(sizeof(*dk), GFP_KERNEL);
 	if (!dk)
 		return ERR_PTR(-ENOMEM);
+	dk->dk_sb = ci->ci_inode->i_sb;
 	refcount_set(&dk->dk_refcount, 1);
 	dk->dk_mode = ci->ci_mode;
 	err = fscrypt_prepare_key(&dk->dk_key, raw_key, ci);

fs/crypto/policy.c

@@ -744,12 +744,8 @@ int fscrypt_set_context(struct inode *inode, void *fs_data)
 	 * delayed key setup that requires the inode number.
 	 */
 	if (ci->ci_policy.version == FSCRYPT_POLICY_V2 &&
-	    (ci->ci_policy.v2.flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32)) {
-		const struct fscrypt_master_key *mk =
-			ci->ci_master_key->payload.data[0];
-
-		fscrypt_hash_inode_number(ci, mk);
-	}
+	    (ci->ci_policy.v2.flags & FSCRYPT_POLICY_FLAG_IV_INO_LBLK_32))
+		fscrypt_hash_inode_number(ci, ci->ci_master_key);
 
 	return inode->i_sb->s_cop->set_context(inode, &ctx, ctxsize, fs_data);
 }
@@ -833,19 +829,6 @@ bool fscrypt_dummy_policies_equal(const struct fscrypt_dummy_policy *p1,
 }
 EXPORT_SYMBOL_GPL(fscrypt_dummy_policies_equal);
 
-/* Deprecated, do not use */
-int fscrypt_set_test_dummy_encryption(struct super_block *sb, const char *arg,
-				      struct fscrypt_dummy_policy *dummy_policy)
-{
-	struct fs_parameter param = {
-		.type = fs_value_is_string,
-		.string = arg ? (char *)arg : "",
-	};
-	return fscrypt_parse_test_dummy_encryption(&param, dummy_policy) ?:
-		fscrypt_add_test_dummy_key(sb, dummy_policy);
-}
-EXPORT_SYMBOL_GPL(fscrypt_set_test_dummy_encryption);
-
 /**
  * fscrypt_show_test_dummy_encryption() - show '-o test_dummy_encryption'
  * @seq: the seq_file to print the option to

fs/ext4/readpage.c

@@ -75,7 +75,7 @@ static void __read_end_io(struct bio *bio)
 	bio_for_each_segment_all(bv, bio, iter_all) {
 		page = bv->bv_page;
 
-		/* PG_error was set if any post_read step failed */
+		/* PG_error was set if verity failed. */
 		if (bio->bi_status || PageError(page)) {
 			ClearPageUptodate(page);
 			/* will re-read again later */
@@ -96,10 +96,12 @@ static void decrypt_work(struct work_struct *work)
 {
 	struct bio_post_read_ctx *ctx =
 		container_of(work, struct bio_post_read_ctx, work);
+	struct bio *bio = ctx->bio;
 
-	fscrypt_decrypt_bio(ctx->bio);
-
-	bio_post_read_processing(ctx);
+	if (fscrypt_decrypt_bio(bio))
+		bio_post_read_processing(ctx);
+	else
+		__read_end_io(bio);
 }
 
 static void verity_work(struct work_struct *work)

fs/f2fs/data.c

@@ -139,7 +139,7 @@ static void f2fs_finish_read_bio(struct bio *bio, bool in_task)
 			continue;
 		}
 
-		/* PG_error was set if decryption or verity failed. */
+		/* PG_error was set if verity failed. */
 		if (bio->bi_status || PageError(page)) {
 			ClearPageUptodate(page);
 			/* will re-read again later */
@@ -185,7 +185,7 @@ static void f2fs_verify_bio(struct work_struct *work)
 			struct page *page = bv->bv_page;
 
 			if (!f2fs_is_compressed_page(page) &&
-			    !PageError(page) && !fsverity_verify_page(page))
+			    !fsverity_verify_page(page))
 				SetPageError(page);
 		}
 	} else {
@@ -236,10 +236,9 @@ static void f2fs_handle_step_decompress(struct bio_post_read_ctx *ctx,
 	bio_for_each_segment_all(bv, ctx->bio, iter_all) {
 		struct page *page = bv->bv_page;
 
-		/* PG_error was set if decryption failed. */
 		if (f2fs_is_compressed_page(page))
-			f2fs_end_read_compressed_page(page, PageError(page),
-						blkaddr, in_task);
+			f2fs_end_read_compressed_page(page, false, blkaddr,
+						      in_task);
 		else
 			all_compressed = false;
 
@@ -259,14 +258,17 @@ static void f2fs_post_read_work(struct work_struct *work)
 {
 	struct bio_post_read_ctx *ctx =
 		container_of(work, struct bio_post_read_ctx, work);
+	struct bio *bio = ctx->bio;
 
-	if (ctx->enabled_steps & STEP_DECRYPT)
-		fscrypt_decrypt_bio(ctx->bio);
+	if ((ctx->enabled_steps & STEP_DECRYPT) && !fscrypt_decrypt_bio(bio)) {
+		f2fs_finish_read_bio(bio, true);
+		return;
+	}
 
 	if (ctx->enabled_steps & STEP_DECOMPRESS)
 		f2fs_handle_step_decompress(ctx, true);
 
-	f2fs_verify_and_finish_bio(ctx->bio, true);
+	f2fs_verify_and_finish_bio(bio, true);
 }
 
 static void f2fs_read_end_io(struct bio *bio)

fs/f2fs/super.c

@@ -3039,23 +3039,24 @@ static void f2fs_get_ino_and_lblk_bits(struct super_block *sb,
 	*lblk_bits_ret = 8 * sizeof(block_t);
 }
 
-static int f2fs_get_num_devices(struct super_block *sb)
+static struct block_device **f2fs_get_devices(struct super_block *sb,
+					      unsigned int *num_devs)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(sb);
+	struct block_device **devs;
+	int i;
 
-	if (f2fs_is_multi_device(sbi))
-		return sbi->s_ndevs;
-	return 1;
-}
+	if (!f2fs_is_multi_device(sbi))
+		return NULL;
 
-static void f2fs_get_devices(struct super_block *sb,
-			     struct request_queue **devs)
-{
-	struct f2fs_sb_info *sbi = F2FS_SB(sb);
-	int i;
+	devs = kmalloc_array(sbi->s_ndevs, sizeof(*devs), GFP_KERNEL);
+	if (!devs)
+		return ERR_PTR(-ENOMEM);
 
 	for (i = 0; i < sbi->s_ndevs; i++)
-		devs[i] = bdev_get_queue(FDEV(i).bdev);
+		devs[i] = FDEV(i).bdev;
+	*num_devs = sbi->s_ndevs;
+	return devs;
 }
 
 static const struct fscrypt_operations f2fs_cryptops = {
@@ -3066,7 +3067,6 @@ static const struct fscrypt_operations f2fs_cryptops = {
 	.empty_dir		= f2fs_empty_dir,
 	.has_stable_inodes	= f2fs_has_stable_inodes,
 	.get_ino_and_lblk_bits	= f2fs_get_ino_and_lblk_bits,
-	.get_num_devices	= f2fs_get_num_devices,
 	.get_devices		= f2fs_get_devices,
 };
 #endif

fs/super.c

@@ -291,7 +291,6 @@ static void __put_super(struct super_block *s)
 		WARN_ON(s->s_inode_lru.node);
 		WARN_ON(!list_empty(&s->s_mounts));
 		security_sb_free(s);
-		fscrypt_sb_free(s);
 		put_user_ns(s->s_user_ns);
 		kfree(s->s_subtype);
 		call_rcu(&s->rcu, destroy_super_rcu);
@@ -480,6 +479,7 @@ void generic_shutdown_super(struct super_block *sb)
 		evict_inodes(sb);
 		/* only nonzero refcount inodes can have marks */
 		fsnotify_sb_delete(sb);
+		fscrypt_sb_delete(sb);
 		security_sb_delete(sb);
 
 		if (sb->s_dio_done_wq) {

include/linux/fs.h

@@ -1472,7 +1472,7 @@ struct super_block {
 	const struct xattr_handler **s_xattr;
 #ifdef CONFIG_FS_ENCRYPTION
 	const struct fscrypt_operations	*s_cop;
-	struct key		*s_master_keys; /* master crypto keys in use */
+	struct fscrypt_keyring	*s_master_keys; /* master crypto keys in use */
 #endif
 #ifdef CONFIG_FS_VERITY
 	const struct fsverity_operations *s_vop;

include/linux/fscrypt.h

@@ -161,24 +161,21 @@ struct fscrypt_operations {
 				      int *ino_bits_ret, int *lblk_bits_ret);
 
 	/*
-	 * Return the number of block devices to which the filesystem may write
-	 * encrypted file contents.
+	 * Return an array of pointers to the block devices to which the
+	 * filesystem may write encrypted file contents, NULL if the filesystem
+	 * only has a single such block device, or an ERR_PTR() on error.
+	 *
+	 * On successful non-NULL return, *num_devs is set to the number of
+	 * devices in the returned array.  The caller must free the returned
+	 * array using kfree().
 	 *
 	 * If the filesystem can use multiple block devices (other than block
 	 * devices that aren't used for encrypted file contents, such as
 	 * external journal devices), and wants to support inline encryption,
 	 * then it must implement this function.  Otherwise it's not needed.
 	 */
-	int (*get_num_devices)(struct super_block *sb);
-
-	/*
-	 * If ->get_num_devices() returns a value greater than 1, then this
-	 * function is called to get the array of request_queues that the
-	 * filesystem is using -- one per block device.  (There may be duplicate
-	 * entries in this array, as block devices can share a request_queue.)
-	 */
-	void (*get_devices)(struct super_block *sb,
-			    struct request_queue **devs);
+	struct block_device **(*get_devices)(struct super_block *sb,
+					     unsigned int *num_devs);
 };
 
 static inline struct fscrypt_info *fscrypt_get_info(const struct inode *inode)
@@ -295,8 +292,6 @@ int fscrypt_parse_test_dummy_encryption(const struct fs_parameter *param,
 				    struct fscrypt_dummy_policy *dummy_policy);
 bool fscrypt_dummy_policies_equal(const struct fscrypt_dummy_policy *p1,
 				  const struct fscrypt_dummy_policy *p2);
-int fscrypt_set_test_dummy_encryption(struct super_block *sb, const char *arg,
-				struct fscrypt_dummy_policy *dummy_policy);
 void fscrypt_show_test_dummy_encryption(struct seq_file *seq, char sep,
 					struct super_block *sb);
 static inline bool
@@ -312,7 +307,7 @@ fscrypt_free_dummy_policy(struct fscrypt_dummy_policy *dummy_policy)
 }
 
 /* keyring.c */
-void fscrypt_sb_free(struct super_block *sb);
+void fscrypt_sb_delete(struct super_block *sb);
 int fscrypt_ioctl_add_key(struct file *filp, void __user *arg);
 int fscrypt_add_test_dummy_key(struct super_block *sb,
 			       const struct fscrypt_dummy_policy *dummy_policy);
@@ -353,7 +348,7 @@ u64 fscrypt_fname_siphash(const struct inode *dir, const struct qstr *name);
 int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags);
 
 /* bio.c */
-void fscrypt_decrypt_bio(struct bio *bio);
+bool fscrypt_decrypt_bio(struct bio *bio);
 int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,
 			  sector_t pblk, unsigned int len);
 
@@ -526,7 +521,7 @@ fscrypt_free_dummy_policy(struct fscrypt_dummy_policy *dummy_policy)
 }
 
 /* keyring.c */
-static inline void fscrypt_sb_free(struct super_block *sb)
+static inline void fscrypt_sb_delete(struct super_block *sb)
 {
 }
 
@@ -646,8 +641,9 @@ static inline int fscrypt_d_revalidate(struct dentry *dentry,
 }
 
 /* bio.c */
-static inline void fscrypt_decrypt_bio(struct bio *bio)
+static inline bool fscrypt_decrypt_bio(struct bio *bio)
 {
+	return true;
 }
 
 static inline int fscrypt_zeroout_range(const struct inode *inode, pgoff_t lblk,