From: Herbert Xu Subject: [PATCH 2/3] [DM] dm-crypt: Add async infrastructure Date: Wed, 11 Jul 2007 11:05:41 +0800 Message-ID: References: <20070711030303.GA6730@gondor.apana.org.au> Reply-To: device-mapper development To: Alasdair G Kergon , dm-devel@redhat.com, Christophe Saout , Linux Crypto Mailing List Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com List-Id: linux-crypto.vger.kernel.org [DM] dm-crypt: Add async infrastructure This patch breaks up the read/write processing so that the crypto operations can complete asynchronously. Signed-off-by: Herbert Xu --- drivers/md/dm-crypt.c | 170 ++++++++++++++++++++++++++++++++++---------------- 1 files changed, 117 insertions(+), 53 deletions(-) diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -28,17 +28,6 @@ #define MESG_STR(x) x, sizeof(x) /* - * per bio private data - */ -struct 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 { @@ -50,6 +39,23 @@ struct convert_context { unsigned int idx_out; sector_t sector; int write; + int err; +}; + +/* + * per bio private data + */ +struct crypt_io { + struct dm_target *target; + struct bio *base_bio; + struct work_struct work; + + struct convert_context ctx; + + atomic_t pending; + int error; + unsigned remaining; + sector_t sector; }; struct crypt_config; @@ -318,6 +324,17 @@ crypt_convert_scatterlist(struct crypt_c return r; } +static void dec_pending(struct crypt_io *io, int error); + +static inline void crypt_read_done(struct convert_context *ctx, int async) +{ + struct crypt_io *io = container_of(ctx, struct crypt_io, ctx); + + dec_pending(io, ctx->err); +} + +static void crypt_write_done(struct convert_context *ctx, int async); + static void crypt_convert_init(struct crypt_config *cc, struct convert_context *ctx, struct bio *bio_out, struct bio *bio_in, @@ -370,13 +387,19 @@ static int crypt_convert(struct crypt_co r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length, ctx->write, ctx->sector); + ctx->err = r; if (r < 0) break; ctx->sector++; } - return r; + if (ctx->write) + crypt_write_done(ctx, 0); + else + crypt_read_done(ctx, 0); + + return ctx->err; } static void dm_crypt_bio_destructor(struct bio *bio) @@ -601,72 +624,111 @@ static void process_read(struct crypt_io generic_make_request(clone); } -static void process_write(struct crypt_io *io) +static void crypt_write_loop(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; - - atomic_inc(&io->pending); - - crypt_convert_init(cc, &ctx, NULL, base_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) { - clone = crypt_alloc_buffer(io, remaining); + do { + struct bio *clone; + + clone = crypt_alloc_buffer(io, io->remaining); if (unlikely(!clone)) { dec_pending(io, -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, clone->bi_size); - bio_put(clone); - dec_pending(io, -EIO); + if (crypt_convert(cc, &io->ctx)) return; - } + } while (io->remaining); +} + +static void process_write_endio(struct crypt_io *io, int async) +{ + struct bio *clone = io->ctx.bio_out; + unsigned remaining = io->remaining; + + /* Grab another reference to the io struct + * before we kick off the request */ + if (remaining) + atomic_inc(&io->pending); + + generic_make_request(clone); + + /* Do not reference clone after this - it + * may be gone already. */ + + if (likely(!remaining)) + return; + + /* out of memory -> run queues */ + if (remaining) + congestion_wait(WRITE, HZ / 100); + + if (!async) + return; + + crypt_write_loop(io); +} + +static void crypt_write_done(struct convert_context *ctx, int async) +{ + struct bio *clone = ctx->bio_out; + struct crypt_io *io = container_of(ctx, struct crypt_io, ctx); + struct crypt_config *cc = io->target->private; - /* crypt_convert should have filled the clone bio */ - BUG_ON(ctx.idx_out < clone->bi_vcnt); + if (ctx->err) { + crypt_free_buffer_pages(cc, clone, clone->bi_size); + bio_put(clone); + dec_pending(io, -EIO); + return; + } - 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); - - /* Do not reference clone after this - it - * may be gone already. */ - - /* out of memory -> run queues */ - if (remaining) - congestion_wait(WRITE, HZ/100); + /* crypt_convert should have filled the clone bio */ + BUG_ON(ctx->idx_out < clone->bi_vcnt); + + clone->bi_sector = cc->start + io->sector; + io->remaining -= clone->bi_size; + io->sector += bio_sectors(clone); + + if (async) { + kcryptd_queue_io(io); + return; } + + process_write_endio(io, 0); +} + +static void process_write(struct crypt_io *io) +{ + struct crypt_config *cc = io->target->private; + struct bio *base_bio = io->base_bio; + + io->remaining = base_bio->bi_size; + io->sector = base_bio->bi_sector - io->target->begin; + + atomic_inc(&io->pending); + + crypt_convert_init(cc, &io->ctx, NULL, base_bio, io->sector, 1); + + if (likely(io->remaining)) + crypt_write_loop(io); } static void process_read_endio(struct 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, + crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio, io->base_bio->bi_sector - io->target->begin, 0); - dec_pending(io, crypt_convert(cc, &ctx)); + crypt_convert(cc, &io->ctx); } static void kcryptd_do_work(struct work_struct *work) @@ -675,6 +737,8 @@ static void kcryptd_do_work(struct work_ if (bio_data_dir(io->base_bio) == READ) process_read(io); + else + process_write_endio(io, 1); } static void kcryptd_do_crypt(struct work_struct *work)