Merge branch 'for-linus' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "Here's a set of block fixes for the current 4.8-rc release.  This
  contains:

   - a fix for a secure erase regression, from Adrian.

   - a fix for an mmc use-after-free bug regression, also from Adrian.

   - potential zero pointer deference in bdev freezing, from Andrey.

   - a race fix for blk_set_queue_dying() from Bart.

   - a set of xen blkfront fixes from Bob Liu.

   - three small fixes for bcache, from Eric and Kent.

   - a fix for a potential invalid NVMe state transition, from Gabriel.

   - blk-mq CPU offline fix, preventing us from issuing and completing a
     request on the wrong queue.  From me.

   - revert two previous floppy changes, since they caused a user
     visibile regression.  A better fix is in the works.

   - ensure that we don't send down bios that have more than 256
     elements in them.  Fixes a crash with bcache, for example.  From
     Ming.

   - a fix for deferencing an error pointer with cgroup writeback.
     Fixes a regression.  From Vegard"

* 'for-linus' of git://git.kernel.dk/linux-block:
  mmc: fix use-after-free of struct request
  Revert "floppy: refactor open() flags handling"
  Revert "floppy: fix open(O_ACCMODE) for ioctl-only open"
  fs/block_dev: fix potential NULL ptr deref in freeze_bdev()
  blk-mq: improve warning for running a queue on the wrong CPU
  blk-mq: don't overwrite rq->mq_ctx
  block: make sure a big bio is split into at most 256 bvecs
  nvme: Fix nvme_get/set_features() with a NULL result pointer
  bdev: fix NULL pointer dereference
  xen-blkfront: free resources if xlvbd_alloc_gendisk fails
  xen-blkfront: introduce blkif_set_queue_limits()
  xen-blkfront: fix places not updated after introducing 64KB page granularity
  bcache: pr_err: more meaningful error message when nr_stripes is invalid
  bcache: RESERVE_PRIO is too small by one when prio_buckets() is a power of two.
  bcache: register_bcache(): call blkdev_put() when cache_alloc() fails
  block: Fix race triggered by blk_set_queue_dying()
  block: Fix secure erase
  nvme: Prevent controller state invalid transition

1 files changed, 10 insertions, 4 deletions

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 95a4ca6ce6ff..849ad441cd76 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -760,7 +760,8 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size,
 	if (!d->nr_stripes ||
 	    d->nr_stripes > INT_MAX ||
 	    d->nr_stripes > SIZE_MAX / sizeof(atomic_t)) {
-		pr_err("nr_stripes too large");
+		pr_err("nr_stripes too large or invalid: %u (start sector beyond end of disk?)",
+			(unsigned)d->nr_stripes);
 		return -ENOMEM;
 	}
 
@@ -1820,7 +1821,7 @@ static int cache_alloc(struct cache *ca)
 	free = roundup_pow_of_two(ca->sb.nbuckets) >> 10;
 
 	if (!init_fifo(&ca->free[RESERVE_BTREE], 8, GFP_KERNEL) ||
-	    !init_fifo(&ca->free[RESERVE_PRIO], prio_buckets(ca), GFP_KERNEL) ||
+	    !init_fifo_exact(&ca->free[RESERVE_PRIO], prio_buckets(ca), GFP_KERNEL) ||
 	    !init_fifo(&ca->free[RESERVE_MOVINGGC], free, GFP_KERNEL) ||
 	    !init_fifo(&ca->free[RESERVE_NONE], free, GFP_KERNEL) ||
 	    !init_fifo(&ca->free_inc,	free << 2, GFP_KERNEL) ||
@@ -1844,7 +1845,7 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page,
 				struct block_device *bdev, struct cache *ca)
 {
 	char name[BDEVNAME_SIZE];
-	const char *err = NULL;
+	const char *err = NULL; /* must be set for any error case */
 	int ret = 0;
 
 	memcpy(&ca->sb, sb, sizeof(struct cache_sb));
@@ -1861,8 +1862,13 @@ static int register_cache(struct cache_sb *sb, struct page *sb_page,
 		ca->discard = CACHE_DISCARD(&ca->sb);
 
 	ret = cache_alloc(ca);
-	if (ret != 0)
+	if (ret != 0) {
+		if (ret == -ENOMEM)
+			err = "cache_alloc(): -ENOMEM";
+		else
+			err = "cache_alloc(): unknown error";
 		goto err;
+	}
 
 	if (kobject_add(&ca->kobj, &part_to_dev(bdev->bd_part)->kobj, "bcache")) {
 		err = "error calling kobject_add";