/*
* 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>
#define DM_MSG_PREFIX "crypt"
#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;
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;
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;
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;
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:
return -ENOMEM;
}
- sg_set_buf(&sg, cc->key, cc->key_size);
+ sg_init_one(&sg, cc->key, cc->key_size);
desc.tfm = hash_tfm;
desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
err = crypto_hash_digest(&desc, &sg, cc->key_size, salt);
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;
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 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;
+
+ 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++;
+ }
+
+ return crypt_convert_scatterlist(cc, &dmreq.sg_out, &dmreq.sg_in,
+ dmreq.sg_in.length,
+ bio_data_dir(ctx->bio_in) == WRITE,
+ ctx->sector);
+}
+
+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);
}
/*
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);
- sg_in.offset = bv_in->bv_offset + ctx->offset_in;
- sg_in.length = 1 << SECTOR_SHIFT;
-
- sg_init_table(&sg_out, 1);
- sg_set_page(&sg_out, bv_out->bv_page);
- sg_out.offset = bv_out->bv_offset + ctx->offset_out;
- sg_out.length = 1 << SECTOR_SHIFT;
-
- ctx->offset_in += sg_in.length;
- if (ctx->offset_in >= bv_in->bv_len) {
- ctx->offset_in = 0;
- ctx->idx_in++;
- }
-
- 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);
+ r = crypt_convert_block(cc, ctx);
if (r < 0)
break;
ctx->sector++;
}
+ /*
+ * 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;
}
struct bio *clone;
unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
- unsigned int i;
+ unsigned i, len;
+ struct page *page;
clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
if (!clone)
clone_init(io, clone);
for (i = 0; i < nr_iovecs; i++) {
- struct bio_vec *bv = bio_iovec_idx(clone, i);
-
- bv->bv_page = mempool_alloc(cc->page_pool, gfp_mask);
- if (!bv->bv_page)
+ page = mempool_alloc(cc->page_pool, gfp_mask);
+ if (!page)
break;
/*
if (i == (MIN_BIO_PAGES - 1))
gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
- bv->bv_offset = 0;
- if (size > PAGE_SIZE)
- bv->bv_len = PAGE_SIZE;
- else
- bv->bv_len = size;
+ len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
- clone->bi_size += bv->bv_len;
- clone->bi_vcnt++;
- size -= bv->bv_len;
+ if (!bio_add_page(clone, page, len, 0)) {
+ mempool_free(page, cc->page_pool);
+ break;
+ }
+
+ size -= len;
}
if (!clone->bi_size) {
* 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);
}
* 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;
/*
* free the processed pages
*/
- if (!read_io) {
+ if (rw == WRITE)
crypt_free_buffer_pages(cc, clone);
- goto out;
- }
- if (unlikely(!bio_flagged(clone, BIO_UPTODATE))) {
- error = -EIO;
- goto out;
+ bio_put(clone);
+
+ if (rw == READ && !error) {
+ kcryptd_queue_crypt(io);
+ return;
}
- bio_put(clone);
- kcryptd_queue_crypt(io);
- return;
+ if (unlikely(error))
+ 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)
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);
*/
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;
}
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,
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);
- generic_make_request(clone);
+ r = crypt_convert(cc, &io->ctx);
- /* Do not reference clone after this - it
- * may be gone already. */
+ kcryptd_crypt_write_io_submit(io, r, 0);
+ if (unlikely(r < 0))
+ return;
/* 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_dec_pending(io, crypt_convert(cc, &ctx));
+ crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, io->sector);
+ kcryptd_crypt_write_convert_loop(io);
+
+ 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;
+
+ crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
+ io->sector);
+
+ r = crypt_convert(cc, &io->ctx);
+
+ kcryptd_crypt_read_done(io, r);
+}
+
+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);
}
/*
goto bad_slab_pool;
}
+ cc->dmreq_start = sizeof(struct ablkcipher_request);
+ cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment());
+
+ 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";
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)
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);
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);
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