1 files changed, 23 insertions, 14 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 50ae6ef83738..dc4403bcc6a0 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -787,26 +787,30 @@ static void clone_init(struct dm_crypt_io *io, struct bio *clone)
         clone->bi_destructor = dm_crypt_bio_destructor;
 }
 
-static void kcryptd_io_read(struct dm_crypt_io *io)
+static void kcryptd_unplug(struct crypt_config *cc)
+{
+        blk_unplug(bdev_get_queue(cc->dev->bdev));
+}
+
+static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
 {
         struct crypt_config *cc = io->target->private;
         struct bio *base_bio = io->base_bio;
         struct bio *clone;
 
-        crypt_inc_pending(io);
-
         /*
          * 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_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
-        if (unlikely(!clone)) {
-                io->error = -ENOMEM;
-                crypt_dec_pending(io);
-                return;
+        clone = bio_alloc_bioset(gfp, bio_segments(base_bio), cc->bs);
+        if (!clone) {
+                kcryptd_unplug(cc);
+                return 1;
         }
 
+        crypt_inc_pending(io);
+
         clone_init(io, clone);
         clone->bi_idx = 0;
         clone->bi_vcnt = bio_segments(base_bio);
@@ -816,6 +820,7 @@ static void kcryptd_io_read(struct dm_crypt_io *io)
                sizeof(struct bio_vec) * clone->bi_vcnt);
 
         generic_make_request(clone);
+        return 0;
 }
 
 static void kcryptd_io_write(struct dm_crypt_io *io)
@@ -828,9 +833,12 @@ static void kcryptd_io(struct work_struct *work)
 {
         struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
 
-        if (bio_data_dir(io->base_bio) == READ)
-                kcryptd_io_read(io);
-        else
+        if (bio_data_dir(io->base_bio) == READ) {
+                crypt_inc_pending(io);
+                if (kcryptd_io_read(io, GFP_NOIO))
+                        io->error = -ENOMEM;
+                crypt_dec_pending(io);
+        } else
                 kcryptd_io_write(io);
 }
 
@@ -1424,9 +1432,10 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
 
         io = crypt_io_alloc(ti, bio, dm_target_offset(ti, bio->bi_sector));
 
-        if (bio_data_dir(io->base_bio) == READ)
-                kcryptd_queue_io(io);
-        else
+        if (bio_data_dir(io->base_bio) == READ) {
+                if (kcryptd_io_read(io, GFP_NOWAIT))
+                        kcryptd_queue_io(io);
+        } else
                 kcryptd_queue_crypt(io);
 
         return DM_MAPIO_SUBMITTED;