Merge tag 'for-4.21/block-20190102' of git://git.kernel.dk/linux-block

Pull more block updates from Jens Axboe:

 - Dead code removal for loop/sunvdc (Chengguang)

 - Mark BIDI support for bsg as deprecated, logging a single dmesg
   warning if anyone is actually using it (Christoph)

 - blkcg cleanup, killing a dead function and making the tryget_closest
   variant easier to read (Dennis)

 - Floppy fixes, one fixing a regression in swim3 (Finn)

 - lightnvm use-after-free fix (Gustavo)

 - gdrom leak fix (Wenwen)

 - a set of drbd updates (Lars, Luc, Nathan, Roland)

* tag 'for-4.21/block-20190102' of git://git.kernel.dk/linux-block: (28 commits)
  block/swim3: Fix regression on PowerBook G3
  block/swim3: Fix -EBUSY error when re-opening device after unmount
  block/swim3: Remove dead return statement
  block/amiflop: Don't log error message on invalid ioctl
  gdrom: fix a memory leak bug
  lightnvm: pblk: fix use-after-free bug
  block: sunvdc: remove redundant code
  block: loop: remove redundant code
  bsg: deprecate BIDI support in bsg
  blkcg: remove unused __blkg_release_rcu()
  blkcg: clean up blkg_tryget_closest()
  drbd: Change drbd_request_detach_interruptible's return type to int
  drbd: Avoid Clang warning about pointless switch statment
  drbd: introduce P_ZEROES (REQ_OP_WRITE_ZEROES on the "wire")
  drbd: skip spurious timeout (ping-timeo) when failing promote
  drbd: don't retry connection if peers do not agree on "authentication" settings
  drbd: fix print_st_err()'s prototype to match the definition
  drbd: avoid spurious self-outdating with concurrent disconnect / down
  drbd: do not block when adjusting "disk-options" while IO is frozen
  drbd: fix comment typos
  ...

3 files changed, 8 insertions, 23 deletions

diff --git a/block/bio.c b/block/bio.c
index 8281bfcbc265..4db1008309ed 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -2097,8 +2097,12 @@ EXPORT_SYMBOL_GPL(bio_associate_blkg);
  */
 void bio_clone_blkg_association(struct bio *dst, struct bio *src)
 {
+	rcu_read_lock();
+
 	if (src->bi_blkg)
 		__bio_associate_blkg(dst, src->bi_blkg);
+
+	rcu_read_unlock();
 }
 EXPORT_SYMBOL_GPL(bio_clone_blkg_association);
 #endif /* CONFIG_BLK_CGROUP */
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index c8cc1cbb6370..2bed5725aa03 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -438,29 +438,6 @@ static void blkg_destroy_all(struct request_queue *q)
 	spin_unlock_irq(&q->queue_lock);
 }
 
-/*
- * A group is RCU protected, but having an rcu lock does not mean that one
- * can access all the fields of blkg and assume these are valid.  For
- * example, don't try to follow throtl_data and request queue links.
- *
- * Having a reference to blkg under an rcu allows accesses to only values
- * local to groups like group stats and group rate limits.
- */
-void __blkg_release_rcu(struct rcu_head *rcu_head)
-{
-	struct blkcg_gq *blkg = container_of(rcu_head, struct blkcg_gq, rcu_head);
-
-	/* release the blkcg and parent blkg refs this blkg has been holding */
-	css_put(&blkg->blkcg->css);
-	if (blkg->parent)
-		blkg_put(blkg->parent);
-
-	wb_congested_put(blkg->wb_congested);
-
-	blkg_free(blkg);
-}
-EXPORT_SYMBOL_GPL(__blkg_release_rcu);
-
 static int blkcg_reset_stats(struct cgroup_subsys_state *css,
 			     struct cftype *cftype, u64 val)
 {
diff --git a/block/bsg.c b/block/bsg.c
index 44f6028b9567..50e5f8f666f2 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -177,6 +177,10 @@ bsg_map_hdr(struct request_queue *q, struct sg_io_v4 *hdr, fmode_t mode)
 			goto out;
 		}
 
+		pr_warn_once(
+			"BIDI support in bsg has been deprecated and might be removed. "
+			"Please report your use case to linux-scsi@vger.kernel.org\n");
+
 		next_rq = blk_get_request(q, REQ_OP_SCSI_IN, 0);
 		if (IS_ERR(next_rq)) {
 			ret = PTR_ERR(next_rq);