From: Milan Broz Date: Tue, 3 Oct 2006 08:15:38 +0000 (-0700) Subject: [PATCH] dm crypt: restructure write processing X-Git-Tag: v2.6.19-rc1~259 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=93e605c237a61f5a0ea37b12353392f01d596628;p=linux-2.6-omap-h63xx.git [PATCH] dm crypt: restructure write processing Restructure the dm-crypt write processing in preparation for workqueue changes in the next patches. Signed-off-by: Milan Broz Signed-off-by: Alasdair G Kergon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 3783cf97885..946a9ebc89d 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -504,12 +504,14 @@ 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 int 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 @@ -517,47 +519,94 @@ static struct bio *clone_read(struct crypt_io *io, * one in order to decrypt the whole bio data *afterwards*. */ clone = bio_alloc(GFP_NOIO, bio_segments(base_bio)); - if (unlikely(!clone)) - return NULL; + if (unlikely(!clone)) { + dec_pending(io, -ENOMEM); + return 0; + } clone_init(io, clone); 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); + + return 0; } -static struct bio *clone_write(struct crypt_io *io, - sector_t sector, - unsigned *bvec_idx, - struct convert_context *ctx) +static int 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)) + goto cleanup; + + ctx.bio_out = clone; + + if (unlikely(crypt_convert(cc, &ctx) < 0)) { + crypt_free_buffer_pages(cc, clone, clone->bi_size); + bio_put(clone); + goto cleanup; + } + + 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; + } + + 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); } - clone_init(io, clone); - clone->bi_sector = cc->start + sector; + /* drop reference, clones could have returned before we reach this */ + dec_pending(io, 0); + return 0; - return clone; +cleanup: + if (io->first_clone) { + dec_pending(io, -ENOMEM); + return 0; + } + + /* if no bio has been dispatched yet, we can directly return the error */ + mempool_free(io, cc->io_pool); + return -ENOMEM; } static void process_read_endio(struct crypt_io *io) @@ -838,68 +887,19 @@ 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 */ + atomic_set(&io->pending, 0); 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); - } + return process_write(io); - /* 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; - } - - /* if no bio has been dispatched yet, we can directly return the error */ - mempool_free(io, cc->io_pool); - return -ENOMEM; + return process_read(io); } static int crypt_status(struct dm_target *ti, status_type_t type,