diff options
Diffstat (limited to 'drivers/md/dm-crypt.c')
-rw-r--r-- | drivers/md/dm-crypt.c | 486 |
1 files changed, 320 insertions, 166 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 6b66ee46b87..b04f98df94e 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1,11 +1,12 @@ /* * Copyright (C) 2003 Christophe Saout <christophe@saout.de> * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> - * Copyright (C) 2006 Red Hat, Inc. All rights reserved. + * Copyright (C) 2006-2007 Red Hat, Inc. All rights reserved. * * This file is released under the GPL. */ +#include <linux/completion.h> #include <linux/err.h> #include <linux/module.h> #include <linux/init.h> @@ -28,20 +29,10 @@ #define MESG_STR(x) x, sizeof(x) /* - * per bio private data - */ -struct dm_crypt_io { - struct dm_target *target; - struct bio *base_bio; - struct work_struct work; - atomic_t pending; - int error; -}; - -/* * context holding the current state of a multi-part conversion */ struct convert_context { + struct completion restart; struct bio *bio_in; struct bio *bio_out; unsigned int offset_in; @@ -49,7 +40,27 @@ struct convert_context { unsigned int idx_in; unsigned int idx_out; sector_t sector; - int write; + atomic_t pending; +}; + +/* + * per bio private data + */ +struct dm_crypt_io { + struct dm_target *target; + struct bio *base_bio; + struct work_struct work; + + struct convert_context ctx; + + atomic_t pending; + int error; + sector_t sector; +}; + +struct dm_crypt_request { + struct scatterlist sg_in; + struct scatterlist sg_out; }; struct crypt_config; @@ -72,10 +83,11 @@ struct crypt_config { sector_t start; /* - * pool for per bio private data and - * for encryption buffer pages + * pool for per bio private data, crypto requests and + * encryption requeusts/buffer pages */ mempool_t *io_pool; + mempool_t *req_pool; mempool_t *page_pool; struct bio_set *bs; @@ -93,9 +105,25 @@ struct crypt_config { sector_t iv_offset; unsigned int iv_size; + /* + * Layout of each crypto request: + * + * struct ablkcipher_request + * context + * padding + * struct dm_crypt_request + * padding + * IV + * + * The padding is added so that dm_crypt_request and the IV are + * correctly aligned. + */ + unsigned int dmreq_start; + struct ablkcipher_request *req; + char cipher[CRYPTO_MAX_ALG_NAME]; char chainmode[CRYPTO_MAX_ALG_NAME]; - struct crypto_blkcipher *tfm; + struct crypto_ablkcipher *tfm; unsigned long flags; unsigned int key_size; u8 key[0]; @@ -108,6 +136,7 @@ struct crypt_config { static struct kmem_cache *_crypt_io_pool; static void clone_init(struct dm_crypt_io *, struct bio *); +static void kcryptd_queue_crypt(struct dm_crypt_io *io); /* * Different IV generation algorithms: @@ -188,7 +217,7 @@ static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, return PTR_ERR(essiv_tfm); } if (crypto_cipher_blocksize(essiv_tfm) != - crypto_blkcipher_ivsize(cc->tfm)) { + crypto_ablkcipher_ivsize(cc->tfm)) { ti->error = "Block size of ESSIV cipher does " "not match IV size of block cipher"; crypto_free_cipher(essiv_tfm); @@ -225,7 +254,7 @@ static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector) 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); + unsigned bs = crypto_ablkcipher_blocksize(cc->tfm); int log = ilog2(bs); /* we need to calculate how far we must shift the sector count @@ -289,42 +318,10 @@ static struct crypt_iv_operations crypt_iv_null_ops = { .generator = crypt_iv_null_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] __attribute__ ((aligned(__alignof__(u64)))); - struct blkcipher_desc desc = { - .tfm = cc->tfm, - .info = iv, - .flags = CRYPTO_TFM_REQ_MAY_SLEEP, - }; - int r; - - if (cc->iv_gen_ops) { - r = cc->iv_gen_ops->generator(cc, iv, sector); - if (r < 0) - return r; - - if (write) - r = crypto_blkcipher_encrypt_iv(&desc, out, in, length); - else - r = crypto_blkcipher_decrypt_iv(&desc, out, in, length); - } else { - if (write) - r = crypto_blkcipher_encrypt(&desc, out, in, length); - else - r = crypto_blkcipher_decrypt(&desc, out, in, length); - } - - return r; -} - static void crypt_convert_init(struct crypt_config *cc, struct convert_context *ctx, struct bio *bio_out, struct bio *bio_in, - sector_t sector, int write) + sector_t sector) { ctx->bio_in = bio_in; ctx->bio_out = bio_out; @@ -333,7 +330,79 @@ static void crypt_convert_init(struct crypt_config *cc, ctx->idx_in = bio_in ? bio_in->bi_idx : 0; ctx->idx_out = bio_out ? bio_out->bi_idx : 0; ctx->sector = sector + cc->iv_offset; - ctx->write = write; + init_completion(&ctx->restart); + /* + * Crypto operation can be asynchronous, + * ctx->pending is increased after request submission. + * We need to ensure that we don't call the crypt finish + * operation before pending got incremented + * (dependent on crypt submission return code). + */ + atomic_set(&ctx->pending, 2); +} + +static int crypt_convert_block(struct crypt_config *cc, + struct convert_context *ctx, + struct ablkcipher_request *req) +{ + struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in); + struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out); + struct dm_crypt_request *dmreq; + u8 *iv; + int r = 0; + + dmreq = (struct dm_crypt_request *)((char *)req + cc->dmreq_start); + iv = (u8 *)ALIGN((unsigned long)(dmreq + 1), + crypto_ablkcipher_alignmask(cc->tfm) + 1); + + sg_init_table(&dmreq->sg_in, 1); + sg_set_page(&dmreq->sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT, + bv_in->bv_offset + ctx->offset_in); + + sg_init_table(&dmreq->sg_out, 1); + sg_set_page(&dmreq->sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT, + bv_out->bv_offset + ctx->offset_out); + + ctx->offset_in += 1 << SECTOR_SHIFT; + if (ctx->offset_in >= bv_in->bv_len) { + ctx->offset_in = 0; + ctx->idx_in++; + } + + ctx->offset_out += 1 << SECTOR_SHIFT; + if (ctx->offset_out >= bv_out->bv_len) { + ctx->offset_out = 0; + ctx->idx_out++; + } + + if (cc->iv_gen_ops) { + r = cc->iv_gen_ops->generator(cc, iv, ctx->sector); + if (r < 0) + return r; + } + + ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out, + 1 << SECTOR_SHIFT, iv); + + if (bio_data_dir(ctx->bio_in) == WRITE) + r = crypto_ablkcipher_encrypt(req); + else + r = crypto_ablkcipher_decrypt(req); + + return r; +} + +static void kcryptd_async_done(struct crypto_async_request *async_req, + int error); +static void crypt_alloc_req(struct crypt_config *cc, + struct convert_context *ctx) +{ + if (!cc->req) + cc->req = mempool_alloc(cc->req_pool, GFP_NOIO); + ablkcipher_request_set_tfm(cc->req, cc->tfm); + ablkcipher_request_set_callback(cc->req, CRYPTO_TFM_REQ_MAY_BACKLOG | + CRYPTO_TFM_REQ_MAY_SLEEP, + kcryptd_async_done, ctx); } /* @@ -346,36 +415,38 @@ static int crypt_convert(struct crypt_config *cc, while(ctx->idx_in < ctx->bio_in->bi_vcnt && ctx->idx_out < ctx->bio_out->bi_vcnt) { - struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in); - struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out); - struct scatterlist sg_in, sg_out; - - sg_init_table(&sg_in, 1); - sg_set_page(&sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT, bv_in->bv_offset + ctx->offset_in); - - sg_init_table(&sg_out, 1); - sg_set_page(&sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT, bv_out->bv_offset + ctx->offset_out); - ctx->offset_in += sg_in.length; - if (ctx->offset_in >= bv_in->bv_len) { - ctx->offset_in = 0; - ctx->idx_in++; + crypt_alloc_req(cc, ctx); + + r = crypt_convert_block(cc, ctx, cc->req); + + switch (r) { + case -EBUSY: + wait_for_completion(&ctx->restart); + INIT_COMPLETION(ctx->restart); + /* fall through*/ + case -EINPROGRESS: + atomic_inc(&ctx->pending); + cc->req = NULL; + r = 0; + /* fall through*/ + case 0: + ctx->sector++; + continue; } - ctx->offset_out += sg_out.length; - if (ctx->offset_out >= bv_out->bv_len) { - ctx->offset_out = 0; - ctx->idx_out++; - } - - r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length, - ctx->write, ctx->sector); - if (r < 0) - break; - - ctx->sector++; + break; } + /* + * If there are pending crypto operation run async + * code. Otherwise process return code synchronously. + * The step of 2 ensures that async finish doesn't + * call crypto finish too early. + */ + if (atomic_sub_return(2, &ctx->pending)) + return -EINPROGRESS; + return r; } @@ -455,18 +526,14 @@ static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) * One of the bios was finished. Check for completion of * the whole request and correctly clean up the buffer. */ -static void crypt_dec_pending(struct dm_crypt_io *io, int error) +static void crypt_dec_pending(struct dm_crypt_io *io) { - struct crypt_config *cc = (struct crypt_config *) io->target->private; - - if (error < 0) - io->error = error; + struct crypt_config *cc = io->target->private; if (!atomic_dec_and_test(&io->pending)) return; bio_endio(io->base_bio, io->error); - mempool_free(io, cc->io_pool); } @@ -484,30 +551,11 @@ static void crypt_dec_pending(struct dm_crypt_io *io, int error) * starved by new requests which can block in the first stages due * to memory allocation. */ -static void kcryptd_do_work(struct work_struct *work); -static void kcryptd_do_crypt(struct work_struct *work); - -static void kcryptd_queue_io(struct dm_crypt_io *io) -{ - struct crypt_config *cc = io->target->private; - - INIT_WORK(&io->work, kcryptd_do_work); - queue_work(cc->io_queue, &io->work); -} - -static void kcryptd_queue_crypt(struct dm_crypt_io *io) -{ - struct crypt_config *cc = io->target->private; - - INIT_WORK(&io->work, kcryptd_do_crypt); - queue_work(cc->crypt_queue, &io->work); -} - static void crypt_endio(struct bio *clone, int error) { struct dm_crypt_io *io = clone->bi_private; struct crypt_config *cc = io->target->private; - unsigned read_io = bio_data_dir(clone) == READ; + unsigned rw = bio_data_dir(clone); if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error)) error = -EIO; @@ -515,21 +563,20 @@ static void crypt_endio(struct bio *clone, int error) /* * free the processed pages */ - if (!read_io) { + if (rw == WRITE) crypt_free_buffer_pages(cc, clone); - goto out; + + bio_put(clone); + + if (rw == READ && !error) { + kcryptd_queue_crypt(io); + return; } if (unlikely(error)) - goto out; - - bio_put(clone); - kcryptd_queue_crypt(io); - return; + io->error = error; -out: - bio_put(clone); - crypt_dec_pending(io, error); + crypt_dec_pending(io); } static void clone_init(struct dm_crypt_io *io, struct bio *clone) @@ -543,12 +590,11 @@ static void clone_init(struct dm_crypt_io *io, struct bio *clone) clone->bi_destructor = dm_crypt_bio_destructor; } -static void process_read(struct dm_crypt_io *io) +static void kcryptd_io_read(struct dm_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); @@ -559,7 +605,8 @@ static void process_read(struct dm_crypt_io *io) */ clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs); if (unlikely(!clone)) { - crypt_dec_pending(io, -ENOMEM); + io->error = -ENOMEM; + crypt_dec_pending(io); return; } @@ -567,25 +614,71 @@ static void process_read(struct dm_crypt_io *io) clone->bi_idx = 0; clone->bi_vcnt = bio_segments(base_bio); clone->bi_size = base_bio->bi_size; - clone->bi_sector = cc->start + sector; + clone->bi_sector = cc->start + io->sector; memcpy(clone->bi_io_vec, bio_iovec(base_bio), sizeof(struct bio_vec) * clone->bi_vcnt); generic_make_request(clone); } -static void process_write(struct dm_crypt_io *io) +static void kcryptd_io_write(struct dm_crypt_io *io) +{ + struct bio *clone = io->ctx.bio_out; + + generic_make_request(clone); +} + +static void kcryptd_io(struct work_struct *work) +{ + struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); + + if (bio_data_dir(io->base_bio) == READ) + kcryptd_io_read(io); + else + kcryptd_io_write(io); +} + +static void kcryptd_queue_io(struct dm_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; - atomic_inc(&io->pending); + INIT_WORK(&io->work, kcryptd_io); + queue_work(cc->io_queue, &io->work); +} - crypt_convert_init(cc, &ctx, NULL, base_bio, sector, 1); +static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, + int error, int async) +{ + struct bio *clone = io->ctx.bio_out; + struct crypt_config *cc = io->target->private; + + if (unlikely(error < 0)) { + crypt_free_buffer_pages(cc, clone); + bio_put(clone); + io->error = -EIO; + return; + } + + /* crypt_convert should have filled the clone bio */ + BUG_ON(io->ctx.idx_out < clone->bi_vcnt); + + clone->bi_sector = cc->start + io->sector; + io->sector += bio_sectors(clone); + + if (async) + kcryptd_queue_io(io); + else { + atomic_inc(&io->pending); + generic_make_request(clone); + } +} + +static void kcryptd_crypt_write_convert_loop(struct dm_crypt_io *io) +{ + struct crypt_config *cc = io->target->private; + struct bio *clone; + unsigned remaining = io->base_bio->bi_size; + int r; /* * The allocated buffers can be smaller than the whole bio, @@ -594,70 +687,110 @@ static void process_write(struct dm_crypt_io *io) while (remaining) { clone = crypt_alloc_buffer(io, remaining); if (unlikely(!clone)) { - crypt_dec_pending(io, -ENOMEM); + io->error = -ENOMEM; return; } - ctx.bio_out = clone; - ctx.idx_out = 0; + io->ctx.bio_out = clone; + io->ctx.idx_out = 0; - if (unlikely(crypt_convert(cc, &ctx) < 0)) { - crypt_free_buffer_pages(cc, clone); - bio_put(clone); - crypt_dec_pending(io, -EIO); - return; - } - - /* crypt_convert should have filled the clone bio */ - BUG_ON(ctx.idx_out < clone->bi_vcnt); - - clone->bi_sector = cc->start + sector; remaining -= clone->bi_size; - sector += bio_sectors(clone); - /* Grab another reference to the io struct - * before we kick off the request */ - if (remaining) - atomic_inc(&io->pending); + r = crypt_convert(cc, &io->ctx); - generic_make_request(clone); - - /* Do not reference clone after this - it - * may be gone already. */ + if (r != -EINPROGRESS) { + kcryptd_crypt_write_io_submit(io, r, 0); + if (unlikely(r < 0)) + return; + } else + atomic_inc(&io->pending); /* out of memory -> run queues */ - if (remaining) + if (unlikely(remaining)) congestion_wait(WRITE, HZ/100); } } -static void process_read_endio(struct dm_crypt_io *io) +static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) { struct crypt_config *cc = io->target->private; - struct convert_context ctx; - crypt_convert_init(cc, &ctx, io->base_bio, io->base_bio, - io->base_bio->bi_sector - io->target->begin, 0); + /* + * Prevent io from disappearing until this function completes. + */ + atomic_inc(&io->pending); + + crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, io->sector); + kcryptd_crypt_write_convert_loop(io); - crypt_dec_pending(io, crypt_convert(cc, &ctx)); + crypt_dec_pending(io); } -static void kcryptd_do_work(struct work_struct *work) +static void kcryptd_crypt_read_done(struct dm_crypt_io *io, int error) { - struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); + if (unlikely(error < 0)) + io->error = -EIO; + + crypt_dec_pending(io); +} + +static void kcryptd_crypt_read_convert(struct dm_crypt_io *io) +{ + struct crypt_config *cc = io->target->private; + int r = 0; + + atomic_inc(&io->pending); + + crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio, + io->sector); + + r = crypt_convert(cc, &io->ctx); + + if (r != -EINPROGRESS) + kcryptd_crypt_read_done(io, r); + + crypt_dec_pending(io); +} + +static void kcryptd_async_done(struct crypto_async_request *async_req, + int error) +{ + struct convert_context *ctx = async_req->data; + struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); + struct crypt_config *cc = io->target->private; + + if (error == -EINPROGRESS) { + complete(&ctx->restart); + return; + } + + mempool_free(ablkcipher_request_cast(async_req), cc->req_pool); + + if (!atomic_dec_and_test(&ctx->pending)) + return; if (bio_data_dir(io->base_bio) == READ) - process_read(io); + kcryptd_crypt_read_done(io, error); + else + kcryptd_crypt_write_io_submit(io, error, 1); } -static void kcryptd_do_crypt(struct work_struct *work) +static void kcryptd_crypt(struct work_struct *work) { struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); if (bio_data_dir(io->base_bio) == READ) - process_read_endio(io); + kcryptd_crypt_read_convert(io); else - process_write(io); + kcryptd_crypt_write_convert(io); +} + +static void kcryptd_queue_crypt(struct dm_crypt_io *io) +{ + struct crypt_config *cc = io->target->private; + + INIT_WORK(&io->work, kcryptd_crypt); + queue_work(cc->crypt_queue, &io->work); } /* @@ -733,7 +866,7 @@ static int crypt_wipe_key(struct crypt_config *cc) static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) { struct crypt_config *cc; - struct crypto_blkcipher *tfm; + struct crypto_ablkcipher *tfm; char *tmp; char *cipher; char *chainmode; @@ -787,7 +920,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) goto bad_cipher; } - tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); + tfm = crypto_alloc_ablkcipher(cc->cipher, 0, 0); if (IS_ERR(tfm)) { ti->error = "Error allocating crypto tfm"; goto bad_cipher; @@ -821,7 +954,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0) goto bad_ivmode; - cc->iv_size = crypto_blkcipher_ivsize(tfm); + cc->iv_size = crypto_ablkcipher_ivsize(tfm); if (cc->iv_size) /* at least a 64 bit sector number should fit in our buffer */ cc->iv_size = max(cc->iv_size, @@ -841,6 +974,20 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) goto bad_slab_pool; } + cc->dmreq_start = sizeof(struct ablkcipher_request); + cc->dmreq_start += crypto_ablkcipher_reqsize(tfm); + cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment()); + cc->dmreq_start += crypto_ablkcipher_alignmask(tfm) & + ~(crypto_tfm_ctx_alignment() - 1); + + cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start + + sizeof(struct dm_crypt_request) + cc->iv_size); + if (!cc->req_pool) { + ti->error = "Cannot allocate crypt request mempool"; + goto bad_req_pool; + } + cc->req = NULL; + cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0); if (!cc->page_pool) { ti->error = "Cannot allocate page mempool"; @@ -853,7 +1000,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) goto bad_bs; } - if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) { + if (crypto_ablkcipher_setkey(tfm, cc->key, key_size) < 0) { ti->error = "Error setting key"; goto bad_device; } @@ -914,12 +1061,14 @@ bad_device: bad_bs: mempool_destroy(cc->page_pool); bad_page_pool: + mempool_destroy(cc->req_pool); +bad_req_pool: mempool_destroy(cc->io_pool); bad_slab_pool: if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) cc->iv_gen_ops->dtr(cc); bad_ivmode: - crypto_free_blkcipher(tfm); + crypto_free_ablkcipher(tfm); bad_cipher: /* Must zero key material before freeing */ memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8)); @@ -934,14 +1083,18 @@ static void crypt_dtr(struct dm_target *ti) destroy_workqueue(cc->io_queue); destroy_workqueue(cc->crypt_queue); + if (cc->req) + mempool_free(cc->req, cc->req_pool); + bioset_free(cc->bs); mempool_destroy(cc->page_pool); + mempool_destroy(cc->req_pool); mempool_destroy(cc->io_pool); kfree(cc->iv_mode); if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) cc->iv_gen_ops->dtr(cc); - crypto_free_blkcipher(cc->tfm); + crypto_free_ablkcipher(cc->tfm); dm_put_device(ti, cc->dev); /* Must zero key material before freeing */ @@ -958,6 +1111,7 @@ static int crypt_map(struct dm_target *ti, struct bio *bio, io = mempool_alloc(cc->io_pool, GFP_NOIO); io->target = ti; io->base_bio = bio; + io->sector = bio->bi_sector - ti->begin; io->error = 0; atomic_set(&io->pending, 0); |