X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fmd%2Fdm-crypt.c;h=4c2471ee054aa099a8777de111e7b219fe6c6eb9;hb=ac6d141dc7d1d0eeec850d1b451dca83ce649684;hp=3783cf97885016d8509e69d1ee16dd8a9fe9837f;hpb=8b004457168995f2ae2a35327f885183a9e74141;p=linux-2.6

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 3783cf9788..4c2471ee05 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -16,9 +16,11 @@
 #include <linux/slab.h>
 #include <linux/crypto.h>
 #include <linux/workqueue.h>
+#include <linux/backing-dev.h>
 #include <asm/atomic.h>
 #include <linux/scatterlist.h>
 #include <asm/page.h>
+#include <asm/unaligned.h>
 
 #include "dm.h"
 
@@ -35,6 +37,7 @@ struct crypt_io {
 	struct work_struct work;
 	atomic_t pending;
 	int error;
+	int post_process;
 };
 
 /*
@@ -76,13 +79,17 @@ struct crypt_config {
 	 */
 	mempool_t *io_pool;
 	mempool_t *page_pool;
+	struct bio_set *bs;
 
 	/*
 	 * crypto related data
 	 */
 	struct crypt_iv_operations *iv_gen_ops;
 	char *iv_mode;
-	struct crypto_cipher *iv_gen_private;
+	union {
+		struct crypto_cipher *essiv_tfm;
+		int benbi_shift;
+	} iv_gen_private;
 	sector_t iv_offset;
 	unsigned int iv_size;
 
@@ -94,11 +101,11 @@ struct crypt_config {
 	u8 key[0];
 };
 
-#define MIN_IOS        256
+#define MIN_IOS        16
 #define MIN_POOL_PAGES 32
 #define MIN_BIO_PAGES  8
 
-static kmem_cache_t *_crypt_io_pool;
+static struct kmem_cache *_crypt_io_pool;
 
 /*
  * Different IV generation algorithms:
@@ -110,6 +117,9 @@ static kmem_cache_t *_crypt_io_pool;
  *        encrypted with the bulk cipher using a salt as key. The salt
  *        should be derived from the bulk cipher's key via hashing.
  *
+ * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
+ *        (needed for LRW-32-AES and possible other narrow block modes)
+ *
  * plumb: unimplemented, see:
  * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
  */
@@ -188,21 +198,61 @@ static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
 	}
 	kfree(salt);
 
-	cc->iv_gen_private = essiv_tfm;
+	cc->iv_gen_private.essiv_tfm = essiv_tfm;
 	return 0;
 }
 
 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
 {
-	crypto_free_cipher(cc->iv_gen_private);
-	cc->iv_gen_private = NULL;
+	crypto_free_cipher(cc->iv_gen_private.essiv_tfm);
+	cc->iv_gen_private.essiv_tfm = NULL;
 }
 
 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
 {
 	memset(iv, 0, cc->iv_size);
 	*(u64 *)iv = cpu_to_le64(sector);
-	crypto_cipher_encrypt_one(cc->iv_gen_private, iv, iv);
+	crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv);
+	return 0;
+}
+
+static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
+			      const char *opts)
+{
+	unsigned int bs = crypto_blkcipher_blocksize(cc->tfm);
+	int log = ilog2(bs);
+
+	/* we need to calculate how far we must shift the sector count
+	 * to get the cipher block count, we use this shift in _gen */
+
+	if (1 << log != bs) {
+		ti->error = "cypher blocksize is not a power of 2";
+		return -EINVAL;
+	}
+
+	if (log > 9) {
+		ti->error = "cypher blocksize is > 512";
+		return -EINVAL;
+	}
+
+	cc->iv_gen_private.benbi_shift = 9 - log;
+
+	return 0;
+}
+
+static void crypt_iv_benbi_dtr(struct crypt_config *cc)
+{
+}
+
+static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
+{
+	__be64 val;
+
+	memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
+
+	val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1);
+	put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
+
 	return 0;
 }
 
@@ -216,13 +266,18 @@ static struct crypt_iv_operations crypt_iv_essiv_ops = {
 	.generator = crypt_iv_essiv_gen
 };
 
+static struct crypt_iv_operations crypt_iv_benbi_ops = {
+	.ctr	   = crypt_iv_benbi_ctr,
+	.dtr	   = crypt_iv_benbi_dtr,
+	.generator = crypt_iv_benbi_gen
+};
 
 static int
 crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out,
                           struct scatterlist *in, unsigned int length,
                           int write, sector_t sector)
 {
-	u8 iv[cc->iv_size];
+	u8 iv[cc->iv_size] __attribute__ ((aligned(__alignof__(u64))));
 	struct blkcipher_desc desc = {
 		.tfm = cc->tfm,
 		.info = iv,
@@ -310,6 +365,14 @@ static int crypt_convert(struct crypt_config *cc,
 	return r;
 }
 
+ static void dm_crypt_bio_destructor(struct bio *bio)
+ {
+	struct crypt_io *io = bio->bi_private;
+	struct crypt_config *cc = io->target->private;
+
+	bio_free(bio, cc->bs);
+ }
+
 /*
  * Generate a new unfragmented bio with the given size
  * This should never violate the device limitations
@@ -324,18 +387,17 @@ crypt_alloc_buffer(struct crypt_config *cc, unsigned int size,
 	gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
 	unsigned int i;
 
-	/*
-	 * Use __GFP_NOMEMALLOC to tell the VM to act less aggressively and
-	 * to fail earlier.  This is not necessary but increases throughput.
-	 * FIXME: Is this really intelligent?
-	 */
-	if (base_bio)
-		clone = bio_clone(base_bio, GFP_NOIO|__GFP_NOMEMALLOC);
-	else
-		clone = bio_alloc(GFP_NOIO|__GFP_NOMEMALLOC, nr_iovecs);
+	if (base_bio) {
+		clone = bio_alloc_bioset(GFP_NOIO, base_bio->bi_max_vecs, cc->bs);
+		__bio_clone(clone, base_bio);
+	} else
+		clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
+
 	if (!clone)
 		return NULL;
 
+	clone->bi_destructor = dm_crypt_bio_destructor;
+
 	/* if the last bio was not complete, continue where that one ended */
 	clone->bi_idx = *bio_vec_idx;
 	clone->bi_vcnt = *bio_vec_idx;
@@ -445,15 +507,14 @@ static void dec_pending(struct crypt_io *io, int error)
  * kcryptd:
  *
  * Needed because it would be very unwise to do decryption in an
- * interrupt context, so bios returning from read requests get
- * queued here.
+ * interrupt context.
  */
 static struct workqueue_struct *_kcryptd_workqueue;
-static void kcryptd_do_work(void *data);
+static void kcryptd_do_work(struct work_struct *work);
 
 static void kcryptd_queue_io(struct crypt_io *io)
 {
-	INIT_WORK(&io->work, kcryptd_do_work, io);
+	INIT_WORK(&io->work, kcryptd_do_work);
 	queue_work(_kcryptd_workqueue, &io->work);
 }
 
@@ -470,12 +531,10 @@ static int crypt_endio(struct bio *clone, unsigned int done, int error)
 	if (!read_io)
 		crypt_free_buffer_pages(cc, clone, done);
 
+	/* keep going - not finished yet */
 	if (unlikely(clone->bi_size))
 		return 1;
 
-	/*
-	 * successful reads are decrypted by the worker thread
-	 */
 	if (!read_io)
 		goto out;
 
@@ -485,6 +544,7 @@ static int crypt_endio(struct bio *clone, unsigned int done, int error)
 	}
 
 	bio_put(clone);
+	io->post_process = 1;
 	kcryptd_queue_io(io);
 	return 0;
 
@@ -504,60 +564,99 @@ static void clone_init(struct crypt_io *io, struct bio *clone)
 	clone->bi_rw      = io->base_bio->bi_rw;
 }
 
-static struct bio *clone_read(struct crypt_io *io,
-			      sector_t sector)
+static void process_read(struct crypt_io *io)
 {
 	struct crypt_config *cc = io->target->private;
 	struct bio *base_bio = io->base_bio;
 	struct bio *clone;
+	sector_t sector = base_bio->bi_sector - io->target->begin;
+
+	atomic_inc(&io->pending);
 
 	/*
 	 * The block layer might modify the bvec array, so always
 	 * copy the required bvecs because we need the original
 	 * one in order to decrypt the whole bio data *afterwards*.
 	 */
-	clone = bio_alloc(GFP_NOIO, bio_segments(base_bio));
-	if (unlikely(!clone))
-		return NULL;
+	clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
+	if (unlikely(!clone)) {
+		dec_pending(io, -ENOMEM);
+		return;
+	}
 
 	clone_init(io, clone);
+	clone->bi_destructor = dm_crypt_bio_destructor;
 	clone->bi_idx = 0;
 	clone->bi_vcnt = bio_segments(base_bio);
 	clone->bi_size = base_bio->bi_size;
+	clone->bi_sector = cc->start + sector;
 	memcpy(clone->bi_io_vec, bio_iovec(base_bio),
 	       sizeof(struct bio_vec) * clone->bi_vcnt);
-	clone->bi_sector = cc->start + sector;
 
-	return clone;
+	generic_make_request(clone);
 }
 
-static struct bio *clone_write(struct crypt_io *io,
-			       sector_t sector,
-			       unsigned *bvec_idx,
-			       struct convert_context *ctx)
+static void process_write(struct crypt_io *io)
 {
 	struct crypt_config *cc = io->target->private;
 	struct bio *base_bio = io->base_bio;
 	struct bio *clone;
+	struct convert_context ctx;
+	unsigned remaining = base_bio->bi_size;
+	sector_t sector = base_bio->bi_sector - io->target->begin;
+	unsigned bvec_idx = 0;
 
-	clone = crypt_alloc_buffer(cc, base_bio->bi_size,
-				   io->first_clone, bvec_idx);
-	if (!clone)
-		return NULL;
+	atomic_inc(&io->pending);
 
-	ctx->bio_out = clone;
+	crypt_convert_init(cc, &ctx, NULL, base_bio, sector, 1);
 
-	if (unlikely(crypt_convert(cc, ctx) < 0)) {
-		crypt_free_buffer_pages(cc, clone,
-		                        clone->bi_size);
-		bio_put(clone);
-		return NULL;
-	}
+	/*
+	 * The allocated buffers can be smaller than the whole bio,
+	 * so repeat the whole process until all the data can be handled.
+	 */
+	while (remaining) {
+		clone = crypt_alloc_buffer(cc, base_bio->bi_size,
+					   io->first_clone, &bvec_idx);
+		if (unlikely(!clone)) {
+			dec_pending(io, -ENOMEM);
+			return;
+		}
 
-	clone_init(io, clone);
-	clone->bi_sector = cc->start + sector;
+		ctx.bio_out = clone;
 
-	return clone;
+		if (unlikely(crypt_convert(cc, &ctx) < 0)) {
+			crypt_free_buffer_pages(cc, clone, clone->bi_size);
+			bio_put(clone);
+			dec_pending(io, -EIO);
+			return;
+		}
+
+		clone_init(io, clone);
+		clone->bi_sector = cc->start + sector;
+
+		if (!io->first_clone) {
+			/*
+			 * hold a reference to the first clone, because it
+			 * holds the bio_vec array and that can't be freed
+			 * before all other clones are released
+			 */
+			bio_get(clone);
+			io->first_clone = clone;
+		}
+
+		remaining -= clone->bi_size;
+		sector += bio_sectors(clone);
+
+		/* prevent bio_put of first_clone */
+		if (remaining)
+			atomic_inc(&io->pending);
+
+		generic_make_request(clone);
+
+		/* out of memory -> run queues */
+		if (remaining)
+			congestion_wait(bio_data_dir(clone), HZ/100);
+	}
 }
 
 static void process_read_endio(struct crypt_io *io)
@@ -571,11 +670,16 @@ static void process_read_endio(struct crypt_io *io)
 	dec_pending(io, crypt_convert(cc, &ctx));
 }
 
-static void kcryptd_do_work(void *data)
+static void kcryptd_do_work(struct work_struct *work)
 {
-	struct crypt_io *io = data;
+	struct crypt_io *io = container_of(work, struct crypt_io, work);
 
-	process_read_endio(io);
+	if (io->post_process)
+		process_read_endio(io);
+	else if (bio_data_dir(io->base_bio) == READ)
+		process_read(io);
+	else
+		process_write(io);
 }
 
 /*
@@ -716,7 +820,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	cc->tfm = tfm;
 
 	/*
-	 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>".
+	 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
 	 * See comments at iv code
 	 */
 
@@ -726,6 +830,8 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		cc->iv_gen_ops = &crypt_iv_plain_ops;
 	else if (strcmp(ivmode, "essiv") == 0)
 		cc->iv_gen_ops = &crypt_iv_essiv_ops;
+	else if (strcmp(ivmode, "benbi") == 0)
+		cc->iv_gen_ops = &crypt_iv_benbi_ops;
 	else {
 		ti->error = "Invalid IV mode";
 		goto bad2;
@@ -761,6 +867,12 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		goto bad4;
 	}
 
+	cc->bs = bioset_create(MIN_IOS, MIN_IOS, 4);
+	if (!cc->bs) {
+		ti->error = "Cannot allocate crypt bioset";
+		goto bad_bs;
+	}
+
 	if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
 		ti->error = "Error setting key";
 		goto bad5;
@@ -800,6 +912,8 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	return 0;
 
 bad5:
+	bioset_free(cc->bs);
+bad_bs:
 	mempool_destroy(cc->page_pool);
 bad4:
 	mempool_destroy(cc->io_pool);
@@ -819,6 +933,7 @@ static void crypt_dtr(struct dm_target *ti)
 {
 	struct crypt_config *cc = (struct crypt_config *) ti->private;
 
+	bioset_free(cc->bs);
 	mempool_destroy(cc->page_pool);
 	mempool_destroy(cc->io_pool);
 
@@ -838,76 +953,22 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
 {
 	struct crypt_config *cc = ti->private;
 	struct crypt_io *io;
-	struct convert_context ctx;
-	struct bio *clone;
-	unsigned int remaining = bio->bi_size;
-	sector_t sector = bio->bi_sector - ti->begin;
-	unsigned int bvec_idx = 0;
 
 	io = mempool_alloc(cc->io_pool, GFP_NOIO);
 	io->target = ti;
 	io->base_bio = bio;
 	io->first_clone = NULL;
-	io->error = 0;
-	atomic_set(&io->pending, 1); /* hold a reference */
-
-	if (bio_data_dir(bio) == WRITE)
-		crypt_convert_init(cc, &ctx, NULL, bio, sector, 1);
-
-	/*
-	 * The allocated buffers can be smaller than the whole bio,
-	 * so repeat the whole process until all the data can be handled.
-	 */
-	while (remaining) {
-		if (bio_data_dir(bio) == WRITE)
-			clone = clone_write(io, sector, &bvec_idx, &ctx);
-		else
-			clone = clone_read(io, sector);
-		if (!clone)
-			goto cleanup;
-
-		if (!io->first_clone) {
-			/*
-			 * hold a reference to the first clone, because it
-			 * holds the bio_vec array and that can't be freed
-			 * before all other clones are released
-			 */
-			bio_get(clone);
-			io->first_clone = clone;
-		}
-		atomic_inc(&io->pending);
-
-		remaining -= clone->bi_size;
-		sector += bio_sectors(clone);
-
-		generic_make_request(clone);
-
-		/* out of memory -> run queues */
-		if (remaining)
-			blk_congestion_wait(bio_data_dir(clone), HZ/100);
-	}
-
-	/* drop reference, clones could have returned before we reach this */
-	dec_pending(io, 0);
-	return 0;
-
-cleanup:
-	if (io->first_clone) {
-		dec_pending(io, -ENOMEM);
-		return 0;
-	}
+	io->error = io->post_process = 0;
+	atomic_set(&io->pending, 0);
+	kcryptd_queue_io(io);
 
-	/* if no bio has been dispatched yet, we can directly return the error */
-	mempool_free(io, cc->io_pool);
-	return -ENOMEM;
+	return DM_MAPIO_SUBMITTED;
 }
 
 static int crypt_status(struct dm_target *ti, status_type_t type,
 			char *result, unsigned int maxlen)
 {
 	struct crypt_config *cc = (struct crypt_config *) ti->private;
-	const char *cipher;
-	const char *chainmode = NULL;
 	unsigned int sz = 0;
 
 	switch (type) {
@@ -916,14 +977,11 @@ static int crypt_status(struct dm_target *ti, status_type_t type,
 		break;
 
 	case STATUSTYPE_TABLE:
-		cipher = crypto_blkcipher_name(cc->tfm);
-
-		chainmode = cc->chainmode;
-
 		if (cc->iv_mode)
-			DMEMIT("%s-%s-%s ", cipher, chainmode, cc->iv_mode);
+			DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode,
+			       cc->iv_mode);
 		else
-			DMEMIT("%s-%s ", cipher, chainmode);
+			DMEMIT("%s-%s ", cc->cipher, cc->chainmode);
 
 		if (cc->key_size > 0) {
 			if ((maxlen - sz) < ((cc->key_size << 1) + 1))
@@ -999,7 +1057,7 @@ error:
 
 static struct target_type crypt_target = {
 	.name   = "crypt",
-	.version= {1, 2, 0},
+	.version= {1, 3, 0},
 	.module = THIS_MODULE,
 	.ctr    = crypt_ctr,
 	.dtr    = crypt_dtr,