[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 <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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@ -504,12 +504,14 @@ static void clone_init(struct crypt_io *io, struct bio *clone)
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clone->bi_rw = io->base_bio->bi_rw;
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}
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static struct bio *clone_read(struct crypt_io *io,
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sector_t sector)
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static int process_read(struct crypt_io *io)
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{
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struct crypt_config *cc = io->target->private;
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struct bio *base_bio = io->base_bio;
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struct bio *clone;
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sector_t sector = base_bio->bi_sector - io->target->begin;
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atomic_inc(&io->pending);
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/*
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* The block layer might modify the bvec array, so always
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@ -517,47 +519,94 @@ static struct bio *clone_read(struct crypt_io *io,
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* one in order to decrypt the whole bio data *afterwards*.
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*/
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clone = bio_alloc(GFP_NOIO, bio_segments(base_bio));
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if (unlikely(!clone))
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return NULL;
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if (unlikely(!clone)) {
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dec_pending(io, -ENOMEM);
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return 0;
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}
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clone_init(io, clone);
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clone->bi_idx = 0;
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clone->bi_vcnt = bio_segments(base_bio);
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clone->bi_size = base_bio->bi_size;
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clone->bi_sector = cc->start + sector;
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memcpy(clone->bi_io_vec, bio_iovec(base_bio),
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sizeof(struct bio_vec) * clone->bi_vcnt);
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clone->bi_sector = cc->start + sector;
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return clone;
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generic_make_request(clone);
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return 0;
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}
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static struct bio *clone_write(struct crypt_io *io,
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sector_t sector,
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unsigned *bvec_idx,
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struct convert_context *ctx)
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static int process_write(struct crypt_io *io)
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{
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struct crypt_config *cc = io->target->private;
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struct bio *base_bio = io->base_bio;
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struct bio *clone;
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struct convert_context ctx;
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unsigned remaining = base_bio->bi_size;
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sector_t sector = base_bio->bi_sector - io->target->begin;
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unsigned bvec_idx = 0;
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atomic_inc(&io->pending);
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crypt_convert_init(cc, &ctx, NULL, base_bio, sector, 1);
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/*
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* The allocated buffers can be smaller than the whole bio,
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* so repeat the whole process until all the data can be handled.
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*/
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while (remaining) {
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clone = crypt_alloc_buffer(cc, base_bio->bi_size,
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io->first_clone, bvec_idx);
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if (!clone)
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return NULL;
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io->first_clone, &bvec_idx);
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if (unlikely(!clone))
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goto cleanup;
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ctx->bio_out = clone;
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ctx.bio_out = clone;
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if (unlikely(crypt_convert(cc, ctx) < 0)) {
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crypt_free_buffer_pages(cc, clone,
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clone->bi_size);
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if (unlikely(crypt_convert(cc, &ctx) < 0)) {
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crypt_free_buffer_pages(cc, clone, clone->bi_size);
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bio_put(clone);
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return NULL;
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goto cleanup;
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}
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clone_init(io, clone);
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clone->bi_sector = cc->start + sector;
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return clone;
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if (!io->first_clone) {
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/*
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* hold a reference to the first clone, because it
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* holds the bio_vec array and that can't be freed
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* before all other clones are released
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*/
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bio_get(clone);
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io->first_clone = clone;
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}
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atomic_inc(&io->pending);
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remaining -= clone->bi_size;
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sector += bio_sectors(clone);
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generic_make_request(clone);
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/* out of memory -> run queues */
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if (remaining)
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blk_congestion_wait(bio_data_dir(clone), HZ/100);
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}
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/* drop reference, clones could have returned before we reach this */
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dec_pending(io, 0);
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return 0;
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cleanup:
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if (io->first_clone) {
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dec_pending(io, -ENOMEM);
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return 0;
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}
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/* if no bio has been dispatched yet, we can directly return the error */
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mempool_free(io, cc->io_pool);
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return -ENOMEM;
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}
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static void process_read_endio(struct crypt_io *io)
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@ -838,68 +887,19 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
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{
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struct crypt_config *cc = ti->private;
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struct crypt_io *io;
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struct convert_context ctx;
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struct bio *clone;
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unsigned int remaining = bio->bi_size;
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sector_t sector = bio->bi_sector - ti->begin;
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unsigned int bvec_idx = 0;
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io = mempool_alloc(cc->io_pool, GFP_NOIO);
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io->target = ti;
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io->base_bio = bio;
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io->first_clone = NULL;
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io->error = 0;
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atomic_set(&io->pending, 1); /* hold a reference */
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atomic_set(&io->pending, 0);
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if (bio_data_dir(bio) == WRITE)
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crypt_convert_init(cc, &ctx, NULL, bio, sector, 1);
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return process_write(io);
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/*
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* The allocated buffers can be smaller than the whole bio,
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* so repeat the whole process until all the data can be handled.
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*/
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while (remaining) {
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if (bio_data_dir(bio) == WRITE)
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clone = clone_write(io, sector, &bvec_idx, &ctx);
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else
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clone = clone_read(io, sector);
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if (!clone)
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goto cleanup;
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if (!io->first_clone) {
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/*
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* hold a reference to the first clone, because it
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* holds the bio_vec array and that can't be freed
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* before all other clones are released
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*/
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bio_get(clone);
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io->first_clone = clone;
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}
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atomic_inc(&io->pending);
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remaining -= clone->bi_size;
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sector += bio_sectors(clone);
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generic_make_request(clone);
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/* out of memory -> run queues */
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if (remaining)
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blk_congestion_wait(bio_data_dir(clone), HZ/100);
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}
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/* drop reference, clones could have returned before we reach this */
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dec_pending(io, 0);
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return 0;
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cleanup:
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if (io->first_clone) {
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dec_pending(io, -ENOMEM);
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return 0;
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}
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/* if no bio has been dispatched yet, we can directly return the error */
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mempool_free(io, cc->io_pool);
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return -ENOMEM;
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return process_read(io);
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}
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static int crypt_status(struct dm_target *ti, status_type_t type,
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