Revert "Revert "dm verity: switch to using asynchronous hash crypto API""
authorYoungmin Nam <youngmin.nam@samsung.com>
Tue, 23 Apr 2019 07:54:04 +0000 (16:54 +0900)
committerYoungmin Nam <youngmin.nam@samsung.com>
Tue, 30 Apr 2019 06:50:39 +0000 (15:50 +0900)
This reverts commit 6ae9d6ee589365676e1ff13eed18a9fe07f89994.

Signed-off-by: Youngmin Nam <youngmin.nam@samsung.com>
drivers/md/dm-verity-fec.c
drivers/md/dm-verity-target.c
drivers/md/dm-verity.h

index 7fd90a249219d614f0c8166fe8fa997723717424..776a4f77f76ce6031d54401a23dd39ca89ca6524 100644 (file)
@@ -191,7 +191,7 @@ error:
 static int fec_is_erasure(struct dm_verity *v, struct dm_verity_io *io,
                          u8 *want_digest, u8 *data)
 {
-       if (unlikely(verity_hash(v, verity_io_hash_desc(v, io),
+       if (unlikely(verity_hash(v, verity_io_hash_req(v, io),
                                 data, 1 << v->data_dev_block_bits,
                                 verity_io_real_digest(v, io))))
                return 0;
@@ -389,7 +389,7 @@ static int fec_decode_rsb(struct dm_verity *v, struct dm_verity_io *io,
        }
 
        /* Always re-validate the corrected block against the expected hash */
-       r = verity_hash(v, verity_io_hash_desc(v, io), fio->output,
+       r = verity_hash(v, verity_io_hash_req(v, io), fio->output,
                        1 << v->data_dev_block_bits,
                        verity_io_real_digest(v, io));
        if (unlikely(r < 0))
index 097215f2e869b977bd818cb2996cd095b67f97e4..ecb506b6923d19e3cb17db513d395f431e74b74c 100644 (file)
@@ -94,81 +94,123 @@ static sector_t verity_position_at_level(struct dm_verity *v, sector_t block,
 }
 
 /*
- * Wrapper for crypto_shash_init, which handles verity salting.
+ * Callback function for asynchrnous crypto API completion notification
  */
-static int verity_hash_init(struct dm_verity *v, struct shash_desc *desc)
+static void verity_op_done(struct crypto_async_request *base, int err)
 {
-       int r;
+       struct verity_result *res = (struct verity_result *)base->data;
 
-       desc->tfm = v->tfm;
-       desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+       if (err == -EINPROGRESS)
+               return;
 
-       r = crypto_shash_init(desc);
+       res->err = err;
+       complete(&res->completion);
+}
 
-       if (unlikely(r < 0)) {
-               DMERR("crypto_shash_init failed: %d", r);
-               return r;
-       }
+/*
+ * Wait for async crypto API callback
+ */
+static inline int verity_complete_op(struct verity_result *res, int ret)
+{
+       switch (ret) {
+       case 0:
+               break;
 
-       if (likely(v->version >= 1)) {
-               r = crypto_shash_update(desc, v->salt, v->salt_size);
+       case -EINPROGRESS:
+       case -EBUSY:
+               ret = wait_for_completion_interruptible(&res->completion);
+               if (!ret)
+                       ret = res->err;
+               reinit_completion(&res->completion);
+               break;
 
-               if (unlikely(r < 0)) {
-                       DMERR("crypto_shash_update failed: %d", r);
-                       return r;
-               }
+       default:
+               DMERR("verity_wait_hash: crypto op submission failed: %d", ret);
        }
 
-       return 0;
+       if (unlikely(ret < 0))
+               DMERR("verity_wait_hash: crypto op failed: %d", ret);
+
+       return ret;
 }
 
-static int verity_hash_update(struct dm_verity *v, struct shash_desc *desc,
-                             const u8 *data, size_t len)
+static int verity_hash_update(struct dm_verity *v, struct ahash_request *req,
+                               const u8 *data, size_t len,
+                               struct verity_result *res)
 {
-       int r = crypto_shash_update(desc, data, len);
+       struct scatterlist sg;
 
-       if (unlikely(r < 0))
-               DMERR("crypto_shash_update failed: %d", r);
+       sg_init_one(&sg, data, len);
+       ahash_request_set_crypt(req, &sg, NULL, len);
+
+       return verity_complete_op(res, crypto_ahash_update(req));
+}
+
+/*
+ * Wrapper for crypto_ahash_init, which handles verity salting.
+ */
+static int verity_hash_init(struct dm_verity *v, struct ahash_request *req,
+                               struct verity_result *res)
+{
+       int r;
+
+       ahash_request_set_tfm(req, v->tfm);
+       ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP |
+                                       CRYPTO_TFM_REQ_MAY_BACKLOG,
+                                       verity_op_done, (void *)res);
+       init_completion(&res->completion);
+
+       r = verity_complete_op(res, crypto_ahash_init(req));
+
+       if (unlikely(r < 0)) {
+               DMERR("crypto_ahash_init failed: %d", r);
+               return r;
+       }
+
+       if (likely(v->salt_size && (v->version >= 1)))
+               r = verity_hash_update(v, req, v->salt, v->salt_size, res);
 
        return r;
 }
 
-static int verity_hash_final(struct dm_verity *v, struct shash_desc *desc,
-                            u8 *digest)
+static int verity_hash_final(struct dm_verity *v, struct ahash_request *req,
+                            u8 *digest, struct verity_result *res)
 {
        int r;
 
-       if (unlikely(!v->version)) {
-               r = crypto_shash_update(desc, v->salt, v->salt_size);
+       if (unlikely(v->salt_size && (!v->version))) {
+               r = verity_hash_update(v, req, v->salt, v->salt_size, res);
 
                if (r < 0) {
-                       DMERR("crypto_shash_update failed: %d", r);
-                       return r;
+                       DMERR("verity_hash_final failed updating salt: %d", r);
+                       goto out;
                }
        }
 
-       r = crypto_shash_final(desc, digest);
-
-       if (unlikely(r < 0))
-               DMERR("crypto_shash_final failed: %d", r);
-
+       ahash_request_set_crypt(req, NULL, digest, 0);
+       r = verity_complete_op(res, crypto_ahash_final(req));
+out:
        return r;
 }
 
-int verity_hash(struct dm_verity *v, struct shash_desc *desc,
+int verity_hash(struct dm_verity *v, struct ahash_request *req,
                const u8 *data, size_t len, u8 *digest)
 {
        int r;
+       struct verity_result res;
 
-       r = verity_hash_init(v, desc);
+       r = verity_hash_init(v, req, &res);
        if (unlikely(r < 0))
-               return r;
+               goto out;
 
-       r = verity_hash_update(v, desc, data, len);
+       r = verity_hash_update(v, req, data, len, &res);
        if (unlikely(r < 0))
-               return r;
+               goto out;
+
+       r = verity_hash_final(v, req, digest, &res);
 
-       return verity_hash_final(v, desc, digest);
+out:
+       return r;
 }
 
 static void verity_hash_at_level(struct dm_verity *v, sector_t block, int level,
@@ -276,7 +318,7 @@ static int verity_verify_level(struct dm_verity *v, struct dm_verity_io *io,
                        goto release_ret_r;
                }
 
-               r = verity_hash(v, verity_io_hash_desc(v, io),
+               r = verity_hash(v, verity_io_hash_req(v, io),
                                data, 1 << v->hash_dev_block_bits,
                                verity_io_real_digest(v, io));
                if (unlikely(r < 0))
@@ -344,6 +386,49 @@ out:
        return r;
 }
 
+/*
+ * Calculates the digest for the given bio
+ */
+int verity_for_io_block(struct dm_verity *v, struct dm_verity_io *io,
+                       struct bvec_iter *iter, struct verity_result *res)
+{
+       unsigned int todo = 1 << v->data_dev_block_bits;
+       struct bio *bio = dm_bio_from_per_bio_data(io, v->ti->per_io_data_size);
+       struct scatterlist sg;
+       struct ahash_request *req = verity_io_hash_req(v, io);
+
+       do {
+               int r;
+               unsigned int len;
+               struct bio_vec bv = bio_iter_iovec(bio, *iter);
+
+               sg_init_table(&sg, 1);
+
+               len = bv.bv_len;
+
+               if (likely(len >= todo))
+                       len = todo;
+               /*
+                * Operating on a single page at a time looks suboptimal
+                * until you consider the typical block size is 4,096B.
+                * Going through this loops twice should be very rare.
+                */
+               sg_set_page(&sg, bv.bv_page, len, bv.bv_offset);
+               ahash_request_set_crypt(req, &sg, NULL, len);
+               r = verity_complete_op(res, crypto_ahash_update(req));
+
+               if (unlikely(r < 0)) {
+                       DMERR("verity_for_io_block crypto op failed: %d", r);
+                       return r;
+               }
+
+               bio_advance_iter(bio, iter, len);
+               todo -= len;
+       } while (todo);
+
+       return 0;
+}
+
 /*
  * Calls function process for 1 << v->data_dev_block_bits bytes in the bio_vec
  * starting from iter.
@@ -382,12 +467,6 @@ int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io,
        return 0;
 }
 
-static int verity_bv_hash_update(struct dm_verity *v, struct dm_verity_io *io,
-                                u8 *data, size_t len)
-{
-       return verity_hash_update(v, verity_io_hash_desc(v, io), data, len);
-}
-
 static int verity_bv_zero(struct dm_verity *v, struct dm_verity_io *io,
                          u8 *data, size_t len)
 {
@@ -416,11 +495,12 @@ static int verity_verify_io(struct dm_verity_io *io)
        struct dm_verity *v = io->v;
        struct bvec_iter start;
        unsigned b;
+       struct verity_result res;
 
        for (b = 0; b < io->n_blocks; b++) {
                int r;
-               struct shash_desc *desc = verity_io_hash_desc(v, io);
                sector_t cur_block = io->block + b;
+               struct ahash_request *req = verity_io_hash_req(v, io);
 
                if (v->validated_blocks &&
                    likely(test_bit(cur_block, v->validated_blocks))) {
@@ -447,16 +527,17 @@ static int verity_verify_io(struct dm_verity_io *io)
                        continue;
                }
 
-               r = verity_hash_init(v, desc);
+               r = verity_hash_init(v, req, &res);
                if (unlikely(r < 0))
                        return r;
 
                start = io->iter;
-               r = verity_for_bv_block(v, io, &io->iter, verity_bv_hash_update);
+               r = verity_for_io_block(v, io, &io->iter, &res);
                if (unlikely(r < 0))
                        return r;
 
-               r = verity_hash_final(v, desc, verity_io_real_digest(v, io));
+               r = verity_hash_final(v, req, verity_io_real_digest(v, io),
+                                       &res);
                if (unlikely(r < 0))
                        return r;
 
@@ -740,7 +821,7 @@ void verity_dtr(struct dm_target *ti)
        kfree(v->zero_digest);
 
        if (v->tfm)
-               crypto_free_shash(v->tfm);
+               crypto_free_ahash(v->tfm);
 
        kfree(v->alg_name);
 
@@ -778,7 +859,7 @@ static int verity_alloc_most_once(struct dm_verity *v)
 static int verity_alloc_zero_digest(struct dm_verity *v)
 {
        int r = -ENOMEM;
-       struct shash_desc *desc;
+       struct ahash_request *req;
        u8 *zero_data;
 
        v->zero_digest = kmalloc(v->digest_size, GFP_KERNEL);
@@ -786,9 +867,9 @@ static int verity_alloc_zero_digest(struct dm_verity *v)
        if (!v->zero_digest)
                return r;
 
-       desc = kmalloc(v->shash_descsize, GFP_KERNEL);
+       req = kmalloc(v->ahash_reqsize, GFP_KERNEL);
 
-       if (!desc)
+       if (!req)
                return r; /* verity_dtr will free zero_digest */
 
        zero_data = kzalloc(1 << v->data_dev_block_bits, GFP_KERNEL);
@@ -796,11 +877,11 @@ static int verity_alloc_zero_digest(struct dm_verity *v)
        if (!zero_data)
                goto out;
 
-       r = verity_hash(v, desc, zero_data, 1 << v->data_dev_block_bits,
+       r = verity_hash(v, req, zero_data, 1 << v->data_dev_block_bits,
                        v->zero_digest);
 
 out:
-       kfree(desc);
+       kfree(req);
        kfree(zero_data);
 
        return r;
@@ -984,21 +1065,21 @@ int verity_ctr(struct dm_target *ti, unsigned argc, char **argv)
                goto bad;
        }
 
-       v->tfm = crypto_alloc_shash(v->alg_name, 0, 0);
+       v->tfm = crypto_alloc_ahash(v->alg_name, 0, 0);
        if (IS_ERR(v->tfm)) {
                ti->error = "Cannot initialize hash function";
                r = PTR_ERR(v->tfm);
                v->tfm = NULL;
                goto bad;
        }
-       v->digest_size = crypto_shash_digestsize(v->tfm);
+       v->digest_size = crypto_ahash_digestsize(v->tfm);
        if ((1 << v->hash_dev_block_bits) < v->digest_size * 2) {
                ti->error = "Digest size too big";
                r = -EINVAL;
                goto bad;
        }
-       v->shash_descsize =
-               sizeof(struct shash_desc) + crypto_shash_descsize(v->tfm);
+       v->ahash_reqsize = sizeof(struct ahash_request) +
+               crypto_ahash_reqsize(v->tfm);
 
        v->root_digest = kmalloc(v->digest_size, GFP_KERNEL);
        if (!v->root_digest) {
@@ -1106,7 +1187,7 @@ int verity_ctr(struct dm_target *ti, unsigned argc, char **argv)
        }
 
        ti->per_io_data_size = sizeof(struct dm_verity_io) +
-                               v->shash_descsize + v->digest_size * 2;
+                               v->ahash_reqsize + v->digest_size * 2;
 
        r = verity_fec_ctr(v);
        if (r)
index 6d6d8df5b58c1988b3600edc15197f1e0e8bfe47..e80e06aa5ec6876f8dd2596c4a485157b97cd111 100644 (file)
@@ -37,7 +37,7 @@ struct dm_verity {
        struct dm_target *ti;
        struct dm_bufio_client *bufio;
        char *alg_name;
-       struct crypto_shash *tfm;
+       struct crypto_ahash *tfm;
        u8 *root_digest;        /* digest of the root block */
        u8 *salt;               /* salt: its size is salt_size */
        u8 *zero_digest;        /* digest for a zero block */
@@ -52,7 +52,7 @@ struct dm_verity {
        unsigned char levels;   /* the number of tree levels */
        unsigned char version;
        unsigned digest_size;   /* digest size for the current hash algorithm */
-       unsigned shash_descsize;/* the size of temporary space for crypto */
+       unsigned int ahash_reqsize;/* the size of temporary space for crypto */
        int hash_failed;        /* set to 1 if hash of any block failed */
        enum verity_mode mode;  /* mode for handling verification errors */
        unsigned corrupted_errs;/* Number of errors for corrupted blocks */
@@ -82,31 +82,36 @@ struct dm_verity_io {
        /*
         * Three variably-size fields follow this struct:
         *
-        * u8 hash_desc[v->shash_descsize];
+        * u8 hash_req[v->ahash_reqsize];
         * u8 real_digest[v->digest_size];
         * u8 want_digest[v->digest_size];
         *
-        * To access them use: verity_io_hash_desc(), verity_io_real_digest()
+        * To access them use: verity_io_hash_req(), verity_io_real_digest()
         * and verity_io_want_digest().
         */
 };
 
-static inline struct shash_desc *verity_io_hash_desc(struct dm_verity *v,
+struct verity_result {
+       struct completion completion;
+       int err;
+};
+
+static inline struct ahash_request *verity_io_hash_req(struct dm_verity *v,
                                                     struct dm_verity_io *io)
 {
-       return (struct shash_desc *)(io + 1);
+       return (struct ahash_request *)(io + 1);
 }
 
 static inline u8 *verity_io_real_digest(struct dm_verity *v,
                                        struct dm_verity_io *io)
 {
-       return (u8 *)(io + 1) + v->shash_descsize;
+       return (u8 *)(io + 1) + v->ahash_reqsize;
 }
 
 static inline u8 *verity_io_want_digest(struct dm_verity *v,
                                        struct dm_verity_io *io)
 {
-       return (u8 *)(io + 1) + v->shash_descsize + v->digest_size;
+       return (u8 *)(io + 1) + v->ahash_reqsize + v->digest_size;
 }
 
 static inline u8 *verity_io_digest_end(struct dm_verity *v,
@@ -121,7 +126,7 @@ extern int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io,
                                              struct dm_verity_io *io,
                                              u8 *data, size_t len));
 
-extern int verity_hash(struct dm_verity *v, struct shash_desc *desc,
+extern int verity_hash(struct dm_verity *v, struct ahash_request *req,
                       const u8 *data, size_t len, u8 *digest);
 
 extern int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io,