This patch changes dm-crypt so that it uses auxiliary data allocated with
the bio.
Dm-crypt requires two allocations per request - struct dm_crypt_io and
struct ablkcipher_request (with other data appended to it). It used
mempool for the allocation.
Some requests may require more dm_crypt_ios and ablkcipher_requests,
however most requests need just one of each of these two structures to
complete.
This patch changes it so that the first dm_crypt_io and ablkcipher_request
and allocated with the bio (using target per_bio_data_size option). If the
request needs additional values, they are allocated from the mempool.
Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
---
drivers/md/dm-crypt.c | 40 ++++++++++++++++++++++++++--------------
1 file changed, 26 insertions(+), 14 deletions(-)
Index: linux-3.14-rc4/drivers/md/dm-crypt.c
===================================================================
--- linux-3.14-rc4.orig/drivers/md/dm-crypt.c 2014-02-27 17:48:31.000000000 +0100
+++ linux-3.14-rc4/drivers/md/dm-crypt.c 2014-02-27 17:48:31.000000000 +0100
@@ -59,7 +59,7 @@ struct dm_crypt_io {
int error;
sector_t sector;
struct dm_crypt_io *base_io;
-};
+} CRYPTO_MINALIGN_ATTR;
struct dm_crypt_request {
struct convert_context *ctx;
@@ -162,6 +162,8 @@ struct crypt_config {
*/
unsigned int dmreq_start;
+ unsigned int per_bio_data_size;
+
unsigned long flags;
unsigned int key_size;
unsigned int key_parts; /* independent parts in key buffer */
@@ -895,6 +897,14 @@ static void crypt_alloc_req(struct crypt
kcryptd_async_done, dmreq_of_req(cc, ctx->req));
}
+static void crypt_free_req(struct crypt_config *cc,
+ struct ablkcipher_request *req, struct bio *base_bio)
+{
+ struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
+ if ((struct ablkcipher_request *)(io + 1) != req)
+ mempool_free(req, cc->req_pool);
+}
+
/*
* Encrypt / decrypt data from one bio to another one (can be the same one)
*/
@@ -1008,12 +1018,9 @@ static void crypt_free_buffer_pages(stru
}
}
-static struct dm_crypt_io *crypt_io_alloc(struct crypt_config *cc,
- struct bio *bio, sector_t sector)
+static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
+ struct bio *bio, sector_t sector)
{
- struct dm_crypt_io *io;
-
- io = mempool_alloc(cc->io_pool, GFP_NOIO);
io->cc = cc;
io->base_bio = bio;
io->sector = sector;
@@ -1021,8 +1028,6 @@ static struct dm_crypt_io *crypt_io_allo
io->base_io = NULL;
io->ctx.req = NULL;
atomic_set(&io->io_pending, 0);
-
- return io;
}
static void crypt_inc_pending(struct dm_crypt_io *io)
@@ -1046,8 +1051,9 @@ static void crypt_dec_pending(struct dm_
return;
if (io->ctx.req)
- mempool_free(io->ctx.req, cc->req_pool);
- mempool_free(io, cc->io_pool);
+ crypt_free_req(cc, io->ctx.req, base_bio);
+ if (io != dm_per_bio_data(base_bio, cc->per_bio_data_size))
+ mempool_free(io, cc->io_pool);
if (likely(!base_io))
bio_endio(base_bio, error);
@@ -1255,8 +1261,8 @@ static void kcryptd_crypt_write_convert(
* between fragments, so switch to a new dm_crypt_io structure.
*/
if (unlikely(!crypt_finished && remaining)) {
- new_io = crypt_io_alloc(io->cc, io->base_bio,
- sector);
+ new_io = mempool_alloc(cc->io_pool, GFP_NOIO);
+ crypt_io_init(new_io, io->cc, io->base_bio, sector);
crypt_inc_pending(new_io);
crypt_convert_init(cc, &new_io->ctx, NULL,
io->base_bio, sector);
@@ -1325,7 +1331,7 @@ static void kcryptd_async_done(struct cr
if (error < 0)
io->error = -EIO;
- mempool_free(req_of_dmreq(cc, dmreq), cc->req_pool);
+ crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
if (!atomic_dec_and_test(&ctx->cc_pending))
return;
@@ -1728,6 +1734,10 @@ static int crypt_ctr(struct dm_target *t
goto bad;
}
+ cc->per_bio_data_size = ti->per_bio_data_size =
+ sizeof(struct dm_crypt_io) + cc->dmreq_start +
+ sizeof(struct dm_crypt_request) + cc->iv_size;
+
cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
if (!cc->page_pool) {
ti->error = "Cannot allocate page mempool";
@@ -1824,7 +1834,9 @@ static int crypt_map(struct dm_target *t
return DM_MAPIO_REMAPPED;
}
- io = crypt_io_alloc(cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
+ io = dm_per_bio_data(bio, cc->per_bio_data_size);
+ crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
+ io->ctx.req = (struct ablkcipher_request *)(io + 1);
if (bio_data_dir(io->base_bio) == READ) {
if (kcryptd_io_read(io, GFP_NOWAIT))
--
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