Merge tag 'dm-4.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - Fix dm-raid transient device failure processing and other smaller
   tweaks.

 - Add journal support to the DM raid target to close the 'write hole'
   on raid 4/5/6.

 - Fix dm-cache corruption, due to rounding bug, when cache exceeds 2TB.

 - Add 'metadata2' feature to dm-cache to separate the dirty bitset out
   from other cache metadata. This improves speed of shutting down a
   large cache device (which implies writing out dirty bits).

 - Fix a memory leak during dm-stats data structure destruction.

 - Fix a DM multipath round-robin path selector performance regression
   that was caused by less precise balancing across all paths.

 - Lastly, introduce a DM core fix for a long-standing DM snapshot
   deadlock that is rooted in the complexity of the device stack used in
   conjunction with block core maintaining bios on current->bio_list to
   manage recursion in generic_make_request(). A more comprehensive fix
   to block core (and its hook in the cpu scheduler) would be wonderful
   but this DM-specific fix is pragmatic considering how difficult it
   has been to make progress on a generic fix.

* tag 'dm-4.11-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (22 commits)
  dm: flush queued bios when process blocks to avoid deadlock
  dm round robin: revert "use percpu 'repeat_count' and 'current_path'"
  dm stats: fix a leaked s->histogram_boundaries array
  dm space map metadata: constify dm_space_map structures
  dm cache metadata: use cursor api in blocks_are_clean_separate_dirty()
  dm persistent data: add cursor skip functions to the cursor APIs
  dm cache metadata: use dm_bitset_new() to create the dirty bitset in format 2
  dm bitset: add dm_bitset_new()
  dm cache metadata: name the cache block that couldn't be loaded
  dm cache metadata: add "metadata2" feature
  dm cache metadata: use bitset cursor api to load discard bitset
  dm bitset: introduce cursor api
  dm btree: use GFP_NOFS in dm_btree_del()
  dm space map common: memcpy the disk root to ensure it's arch aligned
  dm block manager: add unlikely() annotations on dm_bufio error paths
  dm cache: fix corruption seen when using cache > 2TB
  dm raid: cleanup awkward branching in raid_message() option processing
  dm raid: use mddev rather than rdev->mddev
  dm raid: use read_disk_sb() throughout
  dm raid: add raid4/5/6 journaling support
  ...

1 files changed, 39 insertions, 0 deletions

diff --git a/drivers/md/persistent-data/dm-bitset.h b/drivers/md/persistent-data/dm-bitset.h
index c2287d672ef5..df888da04ee1 100644
--- a/drivers/md/persistent-data/dm-bitset.h
+++ b/drivers/md/persistent-data/dm-bitset.h
@@ -93,6 +93,22 @@ void dm_disk_bitset_init(struct dm_transaction_manager *tm,
 int dm_bitset_empty(struct dm_disk_bitset *info, dm_block_t *new_root);
 
 /*
+ * Creates a new bitset populated with values provided by a callback
+ * function.  This is more efficient than creating an empty bitset,
+ * resizing, and then setting values since that process incurs a lot of
+ * copying.
+ *
+ * info - describes the array
+ * root - the root block of the array on disk
+ * size - the number of entries in the array
+ * fn - the callback
+ * context - passed to the callback
+ */
+typedef int (*bit_value_fn)(uint32_t index, bool *value, void *context);
+int dm_bitset_new(struct dm_disk_bitset *info, dm_block_t *root,
+		  uint32_t size, bit_value_fn fn, void *context);
+
+/*
  * Resize the bitset.
  *
  * info - describes the bitset
@@ -161,6 +177,29 @@ int dm_bitset_test_bit(struct dm_disk_bitset *info, dm_block_t root,
 int dm_bitset_flush(struct dm_disk_bitset *info, dm_block_t root,
 		    dm_block_t *new_root);
 
+struct dm_bitset_cursor {
+	struct dm_disk_bitset *info;
+	struct dm_array_cursor cursor;
+
+	uint32_t entries_remaining;
+	uint32_t array_index;
+	uint32_t bit_index;
+	uint64_t current_bits;
+};
+
+/*
+ * Make sure you've flush any dm_disk_bitset and updated the root before
+ * using this.
+ */
+int dm_bitset_cursor_begin(struct dm_disk_bitset *info,
+			   dm_block_t root, uint32_t nr_entries,
+			   struct dm_bitset_cursor *c);
+void dm_bitset_cursor_end(struct dm_bitset_cursor *c);
+
+int dm_bitset_cursor_next(struct dm_bitset_cursor *c);
+int dm_bitset_cursor_skip(struct dm_bitset_cursor *c, uint32_t count);
+bool dm_bitset_cursor_get_value(struct dm_bitset_cursor *c);
+
 /*----------------------------------------------------------------*/
 
 #endif /* _LINUX_DM_BITSET_H */