1 files changed, 40 insertions, 51 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index d8121234c347..7b0fcfc9eaa5 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -33,7 +33,6 @@
 struct crypt_io {
         struct dm_target *target;
         struct bio *base_bio;
-        struct bio *first_clone;
         struct work_struct work;
         atomic_t pending;
         int error;
@@ -107,6 +106,8 @@ struct crypt_config {
 
 static struct kmem_cache *_crypt_io_pool;
 
+static void clone_init(struct crypt_io *, struct bio *);
+
 /*
  * Different IV generation algorithms:
  *
@@ -120,6 +121,9 @@ static struct kmem_cache *_crypt_io_pool;
  * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
  *        (needed for LRW-32-AES and possible other narrow block modes)
  *
+ * null: the initial vector is always zero.  Provides compatibility with
+ *       obsolete loop_fish2 devices.  Do not use for new devices.
+ *
  * plumb: unimplemented, see:
  * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
  */
@@ -256,6 +260,13 @@ static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
         return 0;
 }
 
+static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
+{
+        memset(iv, 0, cc->iv_size);
+
+        return 0;
+}
+
 static struct crypt_iv_operations crypt_iv_plain_ops = {
         .generator = crypt_iv_plain_gen
 };
@@ -272,6 +283,10 @@ static struct crypt_iv_operations crypt_iv_benbi_ops = {
         .generator = crypt_iv_benbi_gen
 };
 
+static struct crypt_iv_operations crypt_iv_null_ops = {
+        .generator = crypt_iv_null_gen
+};
+
 static int
 crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out,
                           struct scatterlist *in, unsigned int length,
@@ -378,36 +393,21 @@ static int crypt_convert(struct crypt_config *cc,
  * This should never violate the device limitations
  * May return a smaller bio when running out of pages
  */
-static struct bio *
-crypt_alloc_buffer(struct crypt_config *cc, unsigned int size,
-                   struct bio *base_bio, unsigned int *bio_vec_idx)
+static struct bio *crypt_alloc_buffer(struct crypt_io *io, unsigned int size)
 {
+        struct crypt_config *cc = io->target->private;
         struct bio *clone;
         unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
         gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
         unsigned int i;
 
-        if (base_bio) {
-                clone = bio_alloc_bioset(GFP_NOIO, base_bio->bi_max_vecs, cc->bs);
-                __bio_clone(clone, base_bio);
-        } else
-                clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
-
+        clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
         if (!clone)
                 return NULL;
 
-        clone->bi_destructor = dm_crypt_bio_destructor;
-
-        /* if the last bio was not complete, continue where that one ended */
-        clone->bi_idx = *bio_vec_idx;
-        clone->bi_vcnt = *bio_vec_idx;
-        clone->bi_size = 0;
-        clone->bi_flags &= ~(1 << BIO_SEG_VALID);
-
-        /* clone->bi_idx pages have already been allocated */
-        size -= clone->bi_idx * PAGE_SIZE;
+        clone_init(io, clone);
 
-        for (i = clone->bi_idx; i < nr_iovecs; i++) {
+        for (i = 0; i < nr_iovecs; i++) {
                 struct bio_vec *bv = bio_iovec_idx(clone, i);
 
                 bv->bv_page = mempool_alloc(cc->page_pool, gfp_mask);
@@ -419,7 +419,7 @@ 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 - clone->bi_idx) == (MIN_BIO_PAGES - 1))
+                if (i == (MIN_BIO_PAGES - 1))
                         gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
 
                 bv->bv_offset = 0;
@@ -438,12 +438,6 @@ crypt_alloc_buffer(struct crypt_config *cc, unsigned int size,
                 return NULL;
         }
 
-        /*
-         * Remember the last bio_vec allocated to be able
-         * to correctly continue after the splitting.
-         */
-        *bio_vec_idx = clone->bi_vcnt;
-
         return clone;
 }
 
@@ -495,9 +489,6 @@ static void dec_pending(struct crypt_io *io, int error)
         if (!atomic_dec_and_test(&io->pending))
                 return;
 
-        if (io->first_clone)
-                bio_put(io->first_clone);
-
         bio_endio(io->base_bio, io->base_bio->bi_size, io->error);
 
         mempool_free(io, cc->io_pool);
@@ -562,6 +553,7 @@ static void clone_init(struct crypt_io *io, struct bio *clone)
         clone->bi_end_io  = crypt_endio;
         clone->bi_bdev    = cc->dev->bdev;
         clone->bi_rw      = io->base_bio->bi_rw;
+        clone->bi_destructor = dm_crypt_bio_destructor;
 }
 
 static void process_read(struct crypt_io *io)
@@ -585,7 +577,6 @@ static void process_read(struct crypt_io *io)
         }
 
         clone_init(io, clone);
-        clone->bi_destructor = dm_crypt_bio_destructor;
         clone->bi_idx = 0;
         clone->bi_vcnt = bio_segments(base_bio);
         clone->bi_size = base_bio->bi_size;
@@ -604,7 +595,6 @@ static void process_write(struct crypt_io *io)
         struct convert_context ctx;
         unsigned remaining = base_bio->bi_size;
         sector_t sector = base_bio->bi_sector - io->target->begin;
-        unsigned bvec_idx = 0;
 
         atomic_inc(&io->pending);
 
@@ -615,14 +605,14 @@ static void process_write(struct crypt_io *io)
          * 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);
+                clone = crypt_alloc_buffer(io, remaining);
                 if (unlikely(!clone)) {
                         dec_pending(io, -ENOMEM);
                         return;
                 }
 
                 ctx.bio_out = clone;
+                ctx.idx_out = 0;
 
                 if (unlikely(crypt_convert(cc, &ctx) < 0)) {
                         crypt_free_buffer_pages(cc, clone, clone->bi_size);
@@ -631,31 +621,26 @@ static void process_write(struct crypt_io *io)
                         return;
                 }
 
-                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;
-                }
+                /* crypt_convert should have filled the clone bio */
+                BUG_ON(ctx.idx_out < clone->bi_vcnt);
 
+                clone->bi_sector = cc->start + sector;
                 remaining -= clone->bi_size;
                 sector += bio_sectors(clone);
 
-                /* prevent bio_put of first_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(bio_data_dir(clone), HZ/100);
+                        congestion_wait(WRITE, HZ/100);
         }
 }
 
@@ -832,6 +817,8 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                 cc->iv_gen_ops = &crypt_iv_essiv_ops;
         else if (strcmp(ivmode, "benbi") == 0)
                 cc->iv_gen_ops = &crypt_iv_benbi_ops;
+        else if (strcmp(ivmode, "null") == 0)
+                cc->iv_gen_ops = &crypt_iv_null_ops;
         else {
                 ti->error = "Invalid IV mode";
                 goto bad2;
@@ -954,10 +941,12 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
         struct crypt_config *cc = ti->private;
         struct crypt_io *io;
 
+        if (bio_barrier(bio))
+                return -EOPNOTSUPP;
+
         io = mempool_alloc(cc->io_pool, GFP_NOIO);
         io->target = ti;
         io->base_bio = bio;
-        io->first_clone = NULL;
         io->error = io->post_process = 0;
         atomic_set(&io->pending, 0);
         kcryptd_queue_io(io);
@@ -1057,7 +1046,7 @@ error:
 
 static struct target_type crypt_target = {
         .name   = "crypt",
-        .version= {1, 3, 0},
+        .version= {1, 5, 0},
         .module = THIS_MODULE,
         .ctr    = crypt_ctr,
         .dtr    = crypt_dtr,