dm crypt: store crypt_config instead of dm_target struct

Store the crypt_config struct pointer directly in struct dm_crypt_io
instead of the dm_target struct pointer.

Target information is never used - only target->private is referenced,
thus we can change it to point directly to struct crypt_config.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 18 insertions, 20 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 711e0ac58665..8298eaee2c5a 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -50,7 +50,7 @@ struct convert_context {
  * per bio private data
  */
 struct dm_crypt_io {
-        struct dm_target *target;
+        struct crypt_config *cc;
         struct bio *base_bio;
         struct work_struct work;
 
@@ -801,7 +801,7 @@ static int crypt_convert(struct crypt_config *cc,
 static void dm_crypt_bio_destructor(struct bio *bio)
 {
         struct dm_crypt_io *io = bio->bi_private;
-        struct crypt_config *cc = io->target->private;
+        struct crypt_config *cc = io->cc;
 
         bio_free(bio, cc->bs);
 }
@@ -815,7 +815,7 @@ static void dm_crypt_bio_destructor(struct bio *bio)
 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size,
                                       unsigned *out_of_pages)
 {
-        struct crypt_config *cc = io->target->private;
+        struct crypt_config *cc = io->cc;
         struct bio *clone;
         unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
         gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
@@ -874,14 +874,13 @@ static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
         }
 }
 
-static struct dm_crypt_io *crypt_io_alloc(struct dm_target *ti,
+static struct dm_crypt_io *crypt_io_alloc(struct crypt_config *cc,
                                           struct bio *bio, sector_t sector)
 {
-        struct crypt_config *cc = ti->private;
         struct dm_crypt_io *io;
 
         io = mempool_alloc(cc->io_pool, GFP_NOIO);
-        io->target = ti;
+        io->cc = cc;
         io->base_bio = bio;
         io->sector = sector;
         io->error = 0;
@@ -903,7 +902,7 @@ static void crypt_inc_pending(struct dm_crypt_io *io)
  */
 static void crypt_dec_pending(struct dm_crypt_io *io)
 {
-        struct crypt_config *cc = io->target->private;
+        struct crypt_config *cc = io->cc;
         struct bio *base_bio = io->base_bio;
         struct dm_crypt_io *base_io = io->base_io;
         int error = io->error;
@@ -942,7 +941,7 @@ static void crypt_dec_pending(struct dm_crypt_io *io)
 static void crypt_endio(struct bio *clone, int error)
 {
         struct dm_crypt_io *io = clone->bi_private;
-        struct crypt_config *cc = io->target->private;
+        struct crypt_config *cc = io->cc;
         unsigned rw = bio_data_dir(clone);
 
         if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error))
@@ -969,7 +968,7 @@ static void crypt_endio(struct bio *clone, int error)
 
 static void clone_init(struct dm_crypt_io *io, struct bio *clone)
 {
-        struct crypt_config *cc = io->target->private;
+        struct crypt_config *cc = io->cc;
 
         clone->bi_private = io;
         clone->bi_end_io  = crypt_endio;
@@ -980,7 +979,7 @@ static void clone_init(struct dm_crypt_io *io, struct bio *clone)
 
 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
 {
-        struct crypt_config *cc = io->target->private;
+        struct crypt_config *cc = io->cc;
         struct bio *base_bio = io->base_bio;
         struct bio *clone;
 
@@ -1028,7 +1027,7 @@ static void kcryptd_io(struct work_struct *work)
 
 static void kcryptd_queue_io(struct dm_crypt_io *io)
 {
-        struct crypt_config *cc = io->target->private;
+        struct crypt_config *cc = io->cc;
 
         INIT_WORK(&io->work, kcryptd_io);
         queue_work(cc->io_queue, &io->work);
@@ -1037,7 +1036,7 @@ static void kcryptd_queue_io(struct dm_crypt_io *io)
 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
 {
         struct bio *clone = io->ctx.bio_out;
-        struct crypt_config *cc = io->target->private;
+        struct crypt_config *cc = io->cc;
 
         if (unlikely(io->error < 0)) {
                 crypt_free_buffer_pages(cc, clone);
@@ -1059,7 +1058,7 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
 
 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
 {
-        struct crypt_config *cc = io->target->private;
+        struct crypt_config *cc = io->cc;
         struct bio *clone;
         struct dm_crypt_io *new_io;
         int crypt_finished;
@@ -1125,7 +1124,7 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
                  * between fragments, so switch to a new dm_crypt_io structure.
                  */
                 if (unlikely(!crypt_finished && remaining)) {
-                        new_io = crypt_io_alloc(io->target, io->base_bio,
+                        new_io = crypt_io_alloc(io->cc, io->base_bio,
                                                 sector);
                         crypt_inc_pending(new_io);
                         crypt_convert_init(cc, &new_io->ctx, NULL,
@@ -1159,7 +1158,7 @@ static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
 
 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
 {
-        struct crypt_config *cc = io->target->private;
+        struct crypt_config *cc = io->cc;
         int r = 0;
 
         crypt_inc_pending(io);
@@ -1183,7 +1182,7 @@ static void kcryptd_async_done(struct crypto_async_request *async_req,
         struct dm_crypt_request *dmreq = async_req->data;
         struct convert_context *ctx = dmreq->ctx;
         struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
-        struct crypt_config *cc = io->target->private;
+        struct crypt_config *cc = io->cc;
 
         if (error == -EINPROGRESS) {
                 complete(&ctx->restart);
@@ -1219,7 +1218,7 @@ static void kcryptd_crypt(struct work_struct *work)
 
 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
 {
-        struct crypt_config *cc = io->target->private;
+        struct crypt_config *cc = io->cc;
 
         INIT_WORK(&io->work, kcryptd_crypt);
         queue_work(cc->crypt_queue, &io->work);
@@ -1708,7 +1707,7 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
                      union map_info *map_context)
 {
         struct dm_crypt_io *io;
-        struct crypt_config *cc;
+        struct crypt_config *cc = ti->private;
 
         /*
          * If bio is REQ_FLUSH or REQ_DISCARD, just bypass crypt queues.
@@ -1716,14 +1715,13 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
          * - for REQ_DISCARD caller must use flush if IO ordering matters
          */
         if (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) {
-                cc = ti->private;
                 bio->bi_bdev = cc->dev->bdev;
                 if (bio_sectors(bio))
                         bio->bi_sector = cc->start + dm_target_offset(ti, bio->bi_sector);
                 return DM_MAPIO_REMAPPED;
         }
 
-        io = crypt_io_alloc(ti, bio, dm_target_offset(ti, bio->bi_sector));
+        io = crypt_io_alloc(cc, bio, dm_target_offset(ti, bio->bi_sector));
 
         if (bio_data_dir(io->base_bio) == READ) {
                 if (kcryptd_io_read(io, GFP_NOWAIT))