1 files changed, 45 insertions, 11 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 682ef9e6acd3..ce26c84af064 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -23,7 +23,7 @@
 #include <asm/page.h>
 #include <asm/unaligned.h>
 
-#include "dm.h"
+#include <linux/device-mapper.h>
 
 #define DM_MSG_PREFIX "crypt"
 #define MESG_STR(x) x, sizeof(x)
@@ -56,6 +56,7 @@ struct dm_crypt_io {
         atomic_t pending;
         int error;
         sector_t sector;
+        struct dm_crypt_io *base_io;
 };
 
 struct dm_crypt_request {
@@ -93,7 +94,6 @@ struct crypt_config {
 
         struct workqueue_struct *io_queue;
         struct workqueue_struct *crypt_queue;
-        wait_queue_head_t writeq;
 
         /*
          * crypto related data
@@ -534,6 +534,7 @@ static struct dm_crypt_io *crypt_io_alloc(struct dm_target *ti,
         io->base_bio = bio;
         io->sector = sector;
         io->error = 0;
+        io->base_io = NULL;
         atomic_set(&io->pending, 0);
 
         return io;
@@ -547,6 +548,7 @@ static void crypt_inc_pending(struct dm_crypt_io *io)
 /*
  * One of the bios was finished. Check for completion of
  * the whole request and correctly clean up the buffer.
+ * If base_io is set, wait for the last fragment to complete.
  */
 static void crypt_dec_pending(struct dm_crypt_io *io)
 {
@@ -555,7 +557,14 @@ static void crypt_dec_pending(struct dm_crypt_io *io)
         if (!atomic_dec_and_test(&io->pending))
                 return;
 
-        bio_endio(io->base_bio, io->error);
+        if (likely(!io->base_io))
+                bio_endio(io->base_bio, io->error);
+        else {
+                if (io->error && !io->base_io->error)
+                        io->base_io->error = io->error;
+                crypt_dec_pending(io->base_io);
+        }
+
         mempool_free(io, cc->io_pool);
 }
 
@@ -646,10 +655,7 @@ static void kcryptd_io_read(struct dm_crypt_io *io)
 static void kcryptd_io_write(struct dm_crypt_io *io)
 {
         struct bio *clone = io->ctx.bio_out;
-        struct crypt_config *cc = io->target->private;
-
         generic_make_request(clone);
-        wake_up(&cc->writeq);
 }
 
 static void kcryptd_io(struct work_struct *work)
@@ -688,7 +694,6 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io,
         BUG_ON(io->ctx.idx_out < clone->bi_vcnt);
 
         clone->bi_sector = cc->start + io->sector;
-        io->sector += bio_sectors(clone);
 
         if (async)
                 kcryptd_queue_io(io);
@@ -700,16 +705,18 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
 {
         struct crypt_config *cc = io->target->private;
         struct bio *clone;
+        struct dm_crypt_io *new_io;
         int crypt_finished;
         unsigned out_of_pages = 0;
         unsigned remaining = io->base_bio->bi_size;
+        sector_t sector = io->sector;
         int r;
 
         /*
          * Prevent io from disappearing until this function completes.
          */
         crypt_inc_pending(io);
-        crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, io->sector);
+        crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
 
         /*
          * The allocated buffers can be smaller than the whole bio,
@@ -726,6 +733,7 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
                 io->ctx.idx_out = 0;
 
                 remaining -= clone->bi_size;
+                sector += bio_sectors(clone);
 
                 crypt_inc_pending(io);
                 r = crypt_convert(cc, &io->ctx);
@@ -741,6 +749,8 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
                          */
                         if (unlikely(r < 0))
                                 break;
+
+                        io->sector = sector;
                 }
 
                 /*
@@ -750,8 +760,33 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
                 if (unlikely(out_of_pages))
                         congestion_wait(WRITE, HZ/100);
 
-                if (unlikely(remaining))
-                        wait_event(cc->writeq, !atomic_read(&io->ctx.pending));
+                /*
+                 * With async crypto it is unsafe to share the crypto context
+                 * 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,
+                                                sector);
+                        crypt_inc_pending(new_io);
+                        crypt_convert_init(cc, &new_io->ctx, NULL,
+                                           io->base_bio, sector);
+                        new_io->ctx.idx_in = io->ctx.idx_in;
+                        new_io->ctx.offset_in = io->ctx.offset_in;
+
+                        /*
+                         * Fragments after the first use the base_io
+                         * pending count.
+                         */
+                        if (!io->base_io)
+                                new_io->base_io = io;
+                        else {
+                                new_io->base_io = io->base_io;
+                                crypt_inc_pending(io->base_io);
+                                crypt_dec_pending(io);
+                        }
+
+                        io = new_io;
+                }
         }
 
         crypt_dec_pending(io);
@@ -1078,7 +1113,6 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                 goto bad_crypt_queue;
         }
 
-        init_waitqueue_head(&cc->writeq);
         ti->private = cc;
         return 0;