Merge tag 'for-5.2/dm-changes-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - Improve DM snapshot target's scalability by using finer grained
   locking. Requires some list_bl interface improvements.

 - Add ability for DM integrity to use a bitmap mode, that tracks
   regions where data and metadata are out of sync, instead of using a
   journal.

 - Improve DM thin provisioning target to not write metadata changes to
   disk if the thin-pool and associated thin devices are merely
   activated but not used. This avoids metadata corruption due to
   concurrent activation of thin devices across different OS instances
   (e.g. split brain scenarios, which ultimately would be avoided if
   proper device filters were used -- but not having proper filtering
   has proven a very common configuration mistake)

 - Fix missing call to path selector type->end_io in DM multipath. This
   fixes reported performance problems due to inaccurate path selector
   IO accounting causing an imbalance of IO (e.g. avoiding issuing IO to
   particular path due to it seemingly being heavily used).

 - Fix bug in DM cache metadata's loading of its discard bitset that
   could lead to all cache blocks being discarded if the very first
   cache block was discarded (thankfully in practice the first cache
   block is generally in use; be it FS superblock, partition table, disk
   label, etc).

 - Add testing-only DM dust target which simulates a device that has
   failing sectors and/or read failures.

 - Fix a DM init error path reference count hang that caused boot hangs
   if user supplied malformed input on kernel commandline.

 - Fix a couple issues with DM crypt target's logging being overly
   verbose or lacking context.

 - Various other small fixes to DM init, DM multipath, DM zoned, and DM
   crypt.

* tag 'for-5.2/dm-changes-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (42 commits)
  dm: fix a couple brace coding style issues
  dm crypt: print device name in integrity error message
  dm crypt: move detailed message into debug level
  dm ioctl: fix hang in early create error condition
  dm integrity: whitespace, coding style and dead code cleanup
  dm integrity: implement synchronous mode for reboot handling
  dm integrity: handle machine reboot in bitmap mode
  dm integrity: add a bitmap mode
  dm integrity: introduce a function add_new_range_and_wait()
  dm integrity: allow large ranges to be described
  dm ingerity: pass size to dm_integrity_alloc_page_list()
  dm integrity: introduce rw_journal_sectors()
  dm integrity: update documentation
  dm integrity: don't report unused options
  dm integrity: don't check null pointer before kvfree and vfree
  dm integrity: correctly calculate the size of metadata area
  dm dust: Make dm_dust_init and dm_dust_exit static
  dm dust: remove redundant unsigned comparison to less than zero
  dm mpath: always free attached_handler_name in parse_path()
  dm init: fix max devices/targets checks
  ...

3 files changed, 29 insertions, 2 deletions

diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index b0672756d056..e1f51d607cc5 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -62,7 +62,8 @@ typedef int (*dm_clone_and_map_request_fn) (struct dm_target *ti,
 					    struct request *rq,
 					    union map_info *map_context,
 					    struct request **clone);
-typedef void (*dm_release_clone_request_fn) (struct request *clone);
+typedef void (*dm_release_clone_request_fn) (struct request *clone,
+					     union map_info *map_context);
 
 /*
  * Returns:
diff --git a/include/linux/list.h b/include/linux/list.h
index d3b4db895340..e951228db4b2 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -789,7 +789,7 @@ static inline void hlist_add_behind(struct hlist_node *n,
 				    struct hlist_node *prev)
 {
 	n->next = prev->next;
-	WRITE_ONCE(prev->next, n);
+	prev->next = n;
 	n->pprev = &prev->next;
 
 	if (n->next)
diff --git a/include/linux/list_bl.h b/include/linux/list_bl.h
index 3fc2cc57ba1b..ae1b541446c9 100644
--- a/include/linux/list_bl.h
+++ b/include/linux/list_bl.h
@@ -86,6 +86,32 @@ static inline void hlist_bl_add_head(struct hlist_bl_node *n,
 	hlist_bl_set_first(h, n);
 }
 
+static inline void hlist_bl_add_before(struct hlist_bl_node *n,
+				       struct hlist_bl_node *next)
+{
+	struct hlist_bl_node **pprev = next->pprev;
+
+	n->pprev = pprev;
+	n->next = next;
+	next->pprev = &n->next;
+
+	/* pprev may be `first`, so be careful not to lose the lock bit */
+	WRITE_ONCE(*pprev,
+		   (struct hlist_bl_node *)
+			((uintptr_t)n | ((uintptr_t)*pprev & LIST_BL_LOCKMASK)));
+}
+
+static inline void hlist_bl_add_behind(struct hlist_bl_node *n,
+				       struct hlist_bl_node *prev)
+{
+	n->next = prev->next;
+	n->pprev = &prev->next;
+	prev->next = n;
+
+	if (n->next)
+		n->next->pprev = &n->next;
+}
+
 static inline void __hlist_bl_del(struct hlist_bl_node *n)
 {
 	struct hlist_bl_node *next = n->next;