Merge tag 'block-5.12-2021-02-27' of git://git.kernel.dk/linux-block

Pull more block updates from Jens Axboe:
 "A few stragglers (and one due to me missing it originally), and fixes
  for changes in this merge window mostly. In particular:

   - blktrace cleanups (Chaitanya, Greg)

   - Kill dead blk_pm_* functions (Bart)

   - Fixes for the bio alloc changes (Christoph)

   - Fix for the partition changes (Christoph, Ming)

   - Fix for turning off iopoll with polled IO inflight (Jeffle)

   - nbd disconnect fix (Josef)

   - loop fsync error fix (Mauricio)

   - kyber update depth fix (Yang)

   - max_sectors alignment fix (Mikulas)

   - Add bio_max_segs helper (Matthew)"

* tag 'block-5.12-2021-02-27' of git://git.kernel.dk/linux-block: (21 commits)
  block: Add bio_max_segs
  blktrace: fix documentation for blk_fill_rw()
  block: memory allocations in bounce_clone_bio must not fail
  block: remove the gfp_mask argument to bounce_clone_bio
  block: fix bounce_clone_bio for passthrough bios
  block-crypto-fallback: use a bio_set for splitting bios
  block: fix logging on capacity change
  blk-settings: align max_sectors on "logical_block_size" boundary
  block: reopen the device in blkdev_reread_part
  block: don't skip empty device in in disk_uevent
  blktrace: remove debugfs file dentries from struct blk_trace
  nbd: handle device refs for DESTROY_ON_DISCONNECT properly
  kyber: introduce kyber_depth_updated()
  loop: fix I/O error on fsync() in detached loop devices
  block: fix potential IO hang when turning off io_poll
  block: get rid of the trace rq insert wrapper
  blktrace: fix blk_rq_merge documentation
  blktrace: fix blk_rq_issue documentation
  blktrace: add blk_fill_rwbs documentation comment
  block: remove superfluous param in blk_fill_rwbs()
  ...

3 files changed, 23 insertions, 16 deletions

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index a06b99473ca0..a370cde3ddd4 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1212,6 +1212,9 @@ static int __loop_clr_fd(struct loop_device *lo, bool release)
 		goto out_unlock;
 	}
 
+	if (test_bit(QUEUE_FLAG_WC, &lo->lo_queue->queue_flags))
+		blk_queue_write_cache(lo->lo_queue, false, false);
+
 	/* freeze request queue during the transition */
 	blk_mq_freeze_queue(lo->lo_queue);
 
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 8b9622eb0a21..4ff71b579cfc 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -78,8 +78,7 @@ struct link_dead_args {
 #define NBD_RT_HAS_PID_FILE		3
 #define NBD_RT_HAS_CONFIG_REF		4
 #define NBD_RT_BOUND			5
-#define NBD_RT_DESTROY_ON_DISCONNECT	6
-#define NBD_RT_DISCONNECT_ON_CLOSE	7
+#define NBD_RT_DISCONNECT_ON_CLOSE	6
 
 #define NBD_DESTROY_ON_DISCONNECT	0
 #define NBD_DISCONNECT_REQUESTED	1
@@ -1904,12 +1903,21 @@ again:
 	if (info->attrs[NBD_ATTR_CLIENT_FLAGS]) {
 		u64 flags = nla_get_u64(info->attrs[NBD_ATTR_CLIENT_FLAGS]);
 		if (flags & NBD_CFLAG_DESTROY_ON_DISCONNECT) {
-			set_bit(NBD_RT_DESTROY_ON_DISCONNECT,
-				&config->runtime_flags);
-			set_bit(NBD_DESTROY_ON_DISCONNECT, &nbd->flags);
-			put_dev = true;
+			/*
+			 * We have 1 ref to keep the device around, and then 1
+			 * ref for our current operation here, which will be
+			 * inherited by the config.  If we already have
+			 * DESTROY_ON_DISCONNECT set then we know we don't have
+			 * that extra ref already held so we don't need the
+			 * put_dev.
+			 */
+			if (!test_and_set_bit(NBD_DESTROY_ON_DISCONNECT,
+					      &nbd->flags))
+				put_dev = true;
 		} else {
-			clear_bit(NBD_DESTROY_ON_DISCONNECT, &nbd->flags);
+			if (test_and_clear_bit(NBD_DESTROY_ON_DISCONNECT,
+					       &nbd->flags))
+				refcount_inc(&nbd->refs);
 		}
 		if (flags & NBD_CFLAG_DISCONNECT_ON_CLOSE) {
 			set_bit(NBD_RT_DISCONNECT_ON_CLOSE,
@@ -2080,15 +2088,13 @@ static int nbd_genl_reconfigure(struct sk_buff *skb, struct genl_info *info)
 	if (info->attrs[NBD_ATTR_CLIENT_FLAGS]) {
 		u64 flags = nla_get_u64(info->attrs[NBD_ATTR_CLIENT_FLAGS]);
 		if (flags & NBD_CFLAG_DESTROY_ON_DISCONNECT) {
-			if (!test_and_set_bit(NBD_RT_DESTROY_ON_DISCONNECT,
-					      &config->runtime_flags))
+			if (!test_and_set_bit(NBD_DESTROY_ON_DISCONNECT,
+					      &nbd->flags))
 				put_dev = true;
-			set_bit(NBD_DESTROY_ON_DISCONNECT, &nbd->flags);
 		} else {
-			if (test_and_clear_bit(NBD_RT_DESTROY_ON_DISCONNECT,
-					       &config->runtime_flags))
+			if (test_and_clear_bit(NBD_DESTROY_ON_DISCONNECT,
+					       &nbd->flags))
 				refcount_inc(&nbd->refs);
-			clear_bit(NBD_DESTROY_ON_DISCONNECT, &nbd->flags);
 		}
 
 		if (flags & NBD_CFLAG_DISCONNECT_ON_CLOSE) {
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index da16121140ca..1cdf09ff67b6 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -1326,9 +1326,7 @@ static int dispatch_rw_block_io(struct xen_blkif_ring *ring,
 				     pages[i]->page,
 				     seg[i].nsec << 9,
 				     seg[i].offset) == 0)) {
-
-			int nr_iovecs = min_t(int, (nseg-i), BIO_MAX_PAGES);
-			bio = bio_alloc(GFP_KERNEL, nr_iovecs);
+			bio = bio_alloc(GFP_KERNEL, bio_max_segs(nseg - i));
 			if (unlikely(bio == NULL))
 				goto fail_put_bio;