Merge tag 'dm-4.8-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:

 - a stable fix in both DM crypt and DM log-writes for too large bios
   (as generated by bcache)

 - two other stable fixes for DM log-writes

 - a stable fix for a DM crypt bug that could result in freeing pointers
   from uninitialized memory in the tfm allocation error path

 - a DM bufio cleanup to discontinue using create_singlethread_workqueue()

* tag 'dm-4.8-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm bufio: remove use of deprecated create_singlethread_workqueue()
  dm crypt: fix free of bad values after tfm allocation failure
  dm crypt: fix error with too large bios
  dm log writes: fix check of kthread_run() return value
  dm log writes: fix bug with too large bios
  dm log writes: move IO accounting earlier to fix error path

3 files changed, 14 insertions, 7 deletions

diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index 6571c81465e1..8625040bae92 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -1879,7 +1879,7 @@ static int __init dm_bufio_init(void)
         __cache_size_refresh();
         mutex_unlock(&dm_bufio_clients_lock);
 
-        dm_bufio_wq = create_singlethread_workqueue("dm_bufio_cache");
+        dm_bufio_wq = alloc_workqueue("dm_bufio_cache", WQ_MEM_RECLAIM, 0);
         if (!dm_bufio_wq)
                 return -ENOMEM;
 
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index eedba67b0e3e..874295757caa 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1453,7 +1453,7 @@ static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
         unsigned i;
         int err;
 
-        cc->tfms = kmalloc(cc->tfms_count * sizeof(struct crypto_skcipher *),
+        cc->tfms = kzalloc(cc->tfms_count * sizeof(struct crypto_skcipher *),
                            GFP_KERNEL);
         if (!cc->tfms)
                 return -ENOMEM;
@@ -1924,6 +1924,13 @@ static int crypt_map(struct dm_target *ti, struct bio *bio)
                 return DM_MAPIO_REMAPPED;
         }
 
+        /*
+         * Check if bio is too large, split as needed.
+         */
+        if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) &&
+            bio_data_dir(bio) == WRITE)
+                dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT));
+
         io = dm_per_bio_data(bio, cc->per_bio_data_size);
         crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
         io->ctx.req = (struct skcipher_request *)(io + 1);
diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c
index 4ab68033f9d1..49e4d8d4558f 100644
--- a/drivers/md/dm-log-writes.c
+++ b/drivers/md/dm-log-writes.c
@@ -259,12 +259,12 @@ static int log_one_block(struct log_writes_c *lc,
                 goto out;
         sector++;
 
-        bio = bio_alloc(GFP_KERNEL, block->vec_cnt);
+        atomic_inc(&lc->io_blocks);
+        bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt, BIO_MAX_PAGES));
         if (!bio) {
                 DMERR("Couldn't alloc log bio");
                 goto error;
         }
-        atomic_inc(&lc->io_blocks);
         bio->bi_iter.bi_size = 0;
         bio->bi_iter.bi_sector = sector;
         bio->bi_bdev = lc->logdev->bdev;
@@ -282,7 +282,7 @@ static int log_one_block(struct log_writes_c *lc,
                 if (ret != block->vecs[i].bv_len) {
                         atomic_inc(&lc->io_blocks);
                         submit_bio(bio);
-                        bio = bio_alloc(GFP_KERNEL, block->vec_cnt - i);
+                        bio = bio_alloc(GFP_KERNEL, min(block->vec_cnt - i, BIO_MAX_PAGES));
                         if (!bio) {
                                 DMERR("Couldn't alloc log bio");
                                 goto error;
@@ -459,9 +459,9 @@ static int log_writes_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                 goto bad;
         }
 
-        ret = -EINVAL;
         lc->log_kthread = kthread_run(log_writes_kthread, lc, "log-write");
-        if (!lc->log_kthread) {
+        if (IS_ERR(lc->log_kthread)) {
+                ret = PTR_ERR(lc->log_kthread);
                 ti->error = "Couldn't alloc kthread";
                 dm_put_device(ti, lc->dev);
                 dm_put_device(ti, lc->logdev);