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Commit 8b004457 authored by Milan Broz's avatar Milan Broz Committed by Linus Torvalds
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[PATCH] dm crypt: restructure for workqueue change 



Restructure part of the dm-crypt code in preparation for workqueue changes.

Use 'base_bio' or 'clone' variable names consistently throughout.  No
functional changes are included in this patch.

Signed-off-by: default avatarMilan Broz <mbroz@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent e48d4bbf

drivers/md/dm-crypt.c

+156 −123
Original line number Diff line number Diff line
@@ -30,7 +30,7 @@ 
 */

struct crypt_io {

	struct dm_target *target;

	struct bio *bio;

	struct bio *base_bio;

	struct bio *first_clone;

	struct work_struct work;

	atomic_t pending;
@@ -319,7 +319,7 @@ static struct bio * 
crypt_alloc_buffer(struct crypt_config *cc, unsigned int size,

                   struct bio *base_bio, unsigned int *bio_vec_idx)

{

	struct bio *bio;

	struct bio *clone;

	unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;

	gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;

	unsigned int i;
@@ -330,23 +330,23 @@ crypt_alloc_buffer(struct crypt_config *cc, unsigned int size, 
	 * FIXME: Is this really intelligent?

	 */

	if (base_bio)

		bio = bio_clone(base_bio, GFP_NOIO|__GFP_NOMEMALLOC);

		clone = bio_clone(base_bio, GFP_NOIO|__GFP_NOMEMALLOC);

	else

		bio = bio_alloc(GFP_NOIO|__GFP_NOMEMALLOC, nr_iovecs);

	if (!bio)

		clone = bio_alloc(GFP_NOIO|__GFP_NOMEMALLOC, nr_iovecs);

	if (!clone)

		return NULL;



	/* if the last bio was not complete, continue where that one ended */

	bio->bi_idx = *bio_vec_idx;

	bio->bi_vcnt = *bio_vec_idx;

	bio->bi_size = 0;

	bio->bi_flags &= ~(1 << BIO_SEG_VALID);

	clone->bi_idx = *bio_vec_idx;

	clone->bi_vcnt = *bio_vec_idx;

	clone->bi_size = 0;

	clone->bi_flags &= ~(1 << BIO_SEG_VALID);



	/* bio->bi_idx pages have already been allocated */

	size -= bio->bi_idx * PAGE_SIZE;

	/* clone->bi_idx pages have already been allocated */

	size -= clone->bi_idx * PAGE_SIZE;



	for(i = bio->bi_idx; i < nr_iovecs; i++) {

		struct bio_vec *bv = bio_iovec_idx(bio, i);

	for (i = clone->bi_idx; 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)
@@ -357,7 +357,7 @@ crypt_alloc_buffer(struct crypt_config *cc, unsigned int size, 
		 * return a partially allocated bio, the caller will then try

		 * to allocate additional bios while submitting this partial bio

		 */

		if ((i - bio->bi_idx) == (MIN_BIO_PAGES - 1))

		if ((i - clone->bi_idx) == (MIN_BIO_PAGES - 1))

			gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;



		bv->bv_offset = 0;
@@ -366,13 +366,13 @@ crypt_alloc_buffer(struct crypt_config *cc, unsigned int size, 
		else

			bv->bv_len = size;



		bio->bi_size += bv->bv_len;

		bio->bi_vcnt++;

		clone->bi_size += bv->bv_len;

		clone->bi_vcnt++;

		size -= bv->bv_len;

	}



	if (!bio->bi_size) {

		bio_put(bio);

	if (!clone->bi_size) {

		bio_put(clone);

		return NULL;

	}
@@ -380,13 +380,13 @@ crypt_alloc_buffer(struct crypt_config *cc, unsigned int size, 
	 * Remember the last bio_vec allocated to be able

	 * to correctly continue after the splitting.

	 */

	*bio_vec_idx = bio->bi_vcnt;

	*bio_vec_idx = clone->bi_vcnt;



	return bio;

	return clone;

}



static void crypt_free_buffer_pages(struct crypt_config *cc,

                                    struct bio *bio, unsigned int bytes)

                                    struct bio *clone, unsigned int bytes)

{

	unsigned int i, start, end;

	struct bio_vec *bv;
@@ -400,19 +400,19 @@ static void crypt_free_buffer_pages(struct crypt_config *cc, 
	 * A fix to the bi_idx issue in the kernel is in the works, so

	 * we will hopefully be able to revert to the cleaner solution soon.

	 */

	i = bio->bi_vcnt - 1;

	bv = bio_iovec_idx(bio, i);

	end = (i << PAGE_SHIFT) + (bv->bv_offset + bv->bv_len) - bio->bi_size;

	i = clone->bi_vcnt - 1;

	bv = bio_iovec_idx(clone, i);

	end = (i << PAGE_SHIFT) + (bv->bv_offset + bv->bv_len) - clone->bi_size;

	start = end - bytes;



	start >>= PAGE_SHIFT;

	if (!bio->bi_size)

		end = bio->bi_vcnt;

	if (!clone->bi_size)

		end = clone->bi_vcnt;

	else

		end >>= PAGE_SHIFT;



	for (i = start; i < end; i++) {

		bv = bio_iovec_idx(bio, i);

		bv = bio_iovec_idx(clone, i);

		BUG_ON(!bv->bv_page);

		mempool_free(bv->bv_page, cc->page_pool);

		bv->bv_page = NULL;
@@ -436,7 +436,7 @@ static void dec_pending(struct crypt_io *io, int error) 
	if (io->first_clone)

		bio_put(io->first_clone);



	bio_endio(io->bio, io->bio->bi_size, io->error);

	bio_endio(io->base_bio, io->base_bio->bi_size, io->error);



	mempool_free(io, cc->io_pool);

}
@@ -449,25 +449,133 @@ static void dec_pending(struct crypt_io *io, int error) 
 * queued here.

 */

static struct workqueue_struct *_kcryptd_workqueue;

static void kcryptd_do_work(void *data);



static void kcryptd_do_work(void *data)

static void kcryptd_queue_io(struct crypt_io *io)

{

	struct crypt_io *io = (struct crypt_io *) data;

	struct crypt_config *cc = (struct crypt_config *) io->target->private;

	INIT_WORK(&io->work, kcryptd_do_work, io);

	queue_work(_kcryptd_workqueue, &io->work);

}



static int crypt_endio(struct bio *clone, unsigned int done, int error)

{

	struct crypt_io *io = clone->bi_private;

	struct crypt_config *cc = io->target->private;

	unsigned read_io = bio_data_dir(clone) == READ;



	/*

	 * free the processed pages, even if

	 * it's only a partially completed write

	 */

	if (!read_io)

		crypt_free_buffer_pages(cc, clone, done);



	if (unlikely(clone->bi_size))

		return 1;



	/*

	 * successful reads are decrypted by the worker thread

	 */

	if (!read_io)

		goto out;



	if (unlikely(!bio_flagged(clone, BIO_UPTODATE))) {

		error = -EIO;

		goto out;

	}



	bio_put(clone);

	kcryptd_queue_io(io);

	return 0;



out:

	bio_put(clone);

	dec_pending(io, error);

	return error;

}



static void clone_init(struct crypt_io *io, struct bio *clone)

{

	struct crypt_config *cc = io->target->private;



	clone->bi_private = io;

	clone->bi_end_io  = crypt_endio;

	clone->bi_bdev    = cc->dev->bdev;

	clone->bi_rw      = io->base_bio->bi_rw;

}



static struct bio *clone_read(struct crypt_io *io,

			      sector_t sector)

{

	struct crypt_config *cc = io->target->private;

	struct bio *base_bio = io->base_bio;

	struct bio *clone;



	/*

	 * The block layer might modify the bvec array, so always

	 * copy the required bvecs because we need the original

	 * one in order to decrypt the whole bio data *afterwards*.

	 */

	clone = bio_alloc(GFP_NOIO, bio_segments(base_bio));

	if (unlikely(!clone))

		return NULL;



	clone_init(io, clone);

	clone->bi_idx = 0;

	clone->bi_vcnt = bio_segments(base_bio);

	clone->bi_size = base_bio->bi_size;

	memcpy(clone->bi_io_vec, bio_iovec(base_bio),

	       sizeof(struct bio_vec) * clone->bi_vcnt);

	clone->bi_sector = cc->start + sector;



	return clone;

}



static struct bio *clone_write(struct crypt_io *io,

			       sector_t sector,

			       unsigned *bvec_idx,

			       struct convert_context *ctx)

{

	struct crypt_config *cc = io->target->private;

	struct bio *base_bio = io->base_bio;

	struct bio *clone;



	clone = crypt_alloc_buffer(cc, base_bio->bi_size,

				   io->first_clone, bvec_idx);

	if (!clone)

		return NULL;



	ctx->bio_out = clone;



	if (unlikely(crypt_convert(cc, ctx) < 0)) {

		crypt_free_buffer_pages(cc, clone,

		                        clone->bi_size);

		bio_put(clone);

		return NULL;

	}



	clone_init(io, clone);

	clone->bi_sector = cc->start + sector;



	return clone;

}



static void process_read_endio(struct crypt_io *io)

{

	struct crypt_config *cc = io->target->private;

	struct convert_context ctx;

	int r;



	crypt_convert_init(cc, &ctx, io->bio, io->bio,

	                   io->bio->bi_sector - io->target->begin, 0);

	r = crypt_convert(cc, &ctx);

	crypt_convert_init(cc, &ctx, io->base_bio, io->base_bio,

			   io->base_bio->bi_sector - io->target->begin, 0);



	dec_pending(io, r);

	dec_pending(io, crypt_convert(cc, &ctx));

}



static void kcryptd_queue_io(struct crypt_io *io)

static void kcryptd_do_work(void *data)

{

	INIT_WORK(&io->work, kcryptd_do_work, io);

	queue_work(_kcryptd_workqueue, &io->work);

	struct crypt_io *io = data;



	process_read_endio(io);

}



/*
@@ -725,88 +833,10 @@ static void crypt_dtr(struct dm_target *ti) 
	kfree(cc);

}



static int crypt_endio(struct bio *bio, unsigned int done, int error)

{

	struct crypt_io *io = (struct crypt_io *) bio->bi_private;

	struct crypt_config *cc = (struct crypt_config *) io->target->private;



	if (bio_data_dir(bio) == WRITE) {

		/*

		 * free the processed pages, even if

		 * it's only a partially completed write

		 */

		crypt_free_buffer_pages(cc, bio, done);

	}



	if (bio->bi_size)

		return 1;



	bio_put(bio);



	/*

	 * successful reads are decrypted by the worker thread

	 */

	if ((bio_data_dir(bio) == READ)

	    && bio_flagged(bio, BIO_UPTODATE)) {

		kcryptd_queue_io(io);

		return 0;

	}



	dec_pending(io, error);

	return error;

}



static inline struct bio *

crypt_clone(struct crypt_config *cc, struct crypt_io *io, struct bio *bio,

            sector_t sector, unsigned int *bvec_idx,

            struct convert_context *ctx)

{

	struct bio *clone;



	if (bio_data_dir(bio) == WRITE) {

		clone = crypt_alloc_buffer(cc, bio->bi_size,

                                 io->first_clone, bvec_idx);

		if (clone) {

			ctx->bio_out = clone;

			if (crypt_convert(cc, ctx) < 0) {

				crypt_free_buffer_pages(cc, clone,

				                        clone->bi_size);

				bio_put(clone);

				return NULL;

			}

		}

	} else {

		/*

		 * The block layer might modify the bvec array, so always

		 * copy the required bvecs because we need the original

		 * one in order to decrypt the whole bio data *afterwards*.

		 */

		clone = bio_alloc(GFP_NOIO, bio_segments(bio));

		if (clone) {

			clone->bi_idx = 0;

			clone->bi_vcnt = bio_segments(bio);

			clone->bi_size = bio->bi_size;

			memcpy(clone->bi_io_vec, bio_iovec(bio),

			       sizeof(struct bio_vec) * clone->bi_vcnt);

		}

	}



	if (!clone)

		return NULL;



	clone->bi_private = io;

	clone->bi_end_io = crypt_endio;

	clone->bi_bdev = cc->dev->bdev;

	clone->bi_sector = cc->start + sector;

	clone->bi_rw = bio->bi_rw;



	return clone;

}



static int crypt_map(struct dm_target *ti, struct bio *bio,

		     union map_info *map_context)

{

	struct crypt_config *cc = (struct crypt_config *) ti->private;

	struct crypt_config *cc = ti->private;

	struct crypt_io *io;

	struct convert_context ctx;

	struct bio *clone;
@@ -816,7 +846,7 @@ static int crypt_map(struct dm_target *ti, struct bio *bio, 


	io = mempool_alloc(cc->io_pool, GFP_NOIO);

	io->target = ti;

	io->bio = bio;

	io->base_bio = bio;

	io->first_clone = NULL;

	io->error = 0;

	atomic_set(&io->pending, 1); /* hold a reference */
@@ -829,7 +859,10 @@ static int crypt_map(struct dm_target *ti, struct bio *bio, 
	 * so repeat the whole process until all the data can be handled.

	 */

	while (remaining) {

		clone = crypt_clone(cc, io, bio, sector, &bvec_idx, &ctx);

		if (bio_data_dir(bio) == WRITE)

			clone = clone_write(io, sector, &bvec_idx, &ctx);

		else

			clone = clone_read(io, sector);

		if (!clone)

			goto cleanup;