Merge tag 'dm-3.20-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper changes from Mike Snitzer:

 - The most significant change this cycle is request-based DM now
   supports stacking ontop of blk-mq devices.  This blk-mq support
   changes the model request-based DM uses for cloning a request to
   relying on calling blk_get_request() directly from the underlying
   blk-mq device.

   An early consumer of this code is Intel's emerging NVMe hardware;
   thanks to Keith Busch for working on, and pushing for, these changes.

 - A few other small fixes and cleanups across other DM targets.

* tag 'dm-3.20-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm: inherit QUEUE_FLAG_SG_GAPS flags from underlying queues
  dm snapshot: remove unnecessary NULL checks before vfree() calls
  dm mpath: simplify failure path of dm_multipath_init()
  dm thin metadata: remove unused dm_pool_get_data_block_size()
  dm ioctl: fix stale comment above dm_get_inactive_table()
  dm crypt: update url in CONFIG_DM_CRYPT help text
  dm bufio: fix time comparison to use time_after_eq()
  dm: use time_in_range() and time_after()
  dm raid: fix a couple integer overflows
  dm table: train hybrid target type detection to select blk-mq if appropriate
  dm: allocate requests in target when stacking on blk-mq devices
  dm: prepare for allocating blk-mq clone requests in target
  dm: submit stacked requests in irq enabled context
  dm: split request structure out from dm_rq_target_io structure
  dm: remove exports for request-based interfaces without external callers

17 files changed, 416 insertions, 198 deletions

diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index c355a226a024..c39644478aa4 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -231,9 +231,8 @@ config DM_CRYPT
           transparently encrypts the data on it. You'll need to activate
           the ciphers you're going to use in the cryptoapi configuration.
 
-          Information on how to use dm-crypt can be found on
-
-          <http://www.saout.de/misc/dm-crypt/>
+          For further information on dm-crypt and userspace tools see:
+          <http://code.google.com/p/cryptsetup/wiki/DMCrypt>
 
           To compile this code as a module, choose M here: the module will
           be called dm-crypt.
diff --git a/drivers/md/dm-bufio.c b/drivers/md/dm-bufio.c
index c33b49792b87..86dbbc737402 100644
--- a/drivers/md/dm-bufio.c
+++ b/drivers/md/dm-bufio.c
@@ -11,6 +11,7 @@
 #include <linux/device-mapper.h>
 #include <linux/dm-io.h>
 #include <linux/slab.h>
+#include <linux/jiffies.h>
 #include <linux/vmalloc.h>
 #include <linux/shrinker.h>
 #include <linux/module.h>
@@ -1739,7 +1740,7 @@ static unsigned get_max_age_hz(void)
 
 static bool older_than(struct dm_buffer *b, unsigned long age_hz)
 {
-        return (jiffies - b->last_accessed) >= age_hz;
+        return time_after_eq(jiffies, b->last_accessed + age_hz);
 }
 
 static void __evict_old_buffers(struct dm_bufio_client *c, unsigned long age_hz)
diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index e1650539cc2f..7755af351867 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -11,6 +11,7 @@
 
 #include <linux/dm-io.h>
 #include <linux/dm-kcopyd.h>
+#include <linux/jiffies.h>
 #include <linux/init.h>
 #include <linux/mempool.h>
 #include <linux/module.h>
@@ -1562,8 +1563,8 @@ static void process_bio(struct cache *cache, struct prealloc *structs,
 
 static int need_commit_due_to_time(struct cache *cache)
 {
-        return jiffies < cache->last_commit_jiffies ||
-               jiffies > cache->last_commit_jiffies + COMMIT_PERIOD;
+        return !time_in_range(jiffies, cache->last_commit_jiffies,
+                              cache->last_commit_jiffies + COMMIT_PERIOD);
 }
 
 static int commit_if_needed(struct cache *cache)
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index 73f791bb9ea4..c8a18e4ee9dc 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -639,8 +639,8 @@ static int check_name(const char *name)
 
 /*
  * On successful return, the caller must not attempt to acquire
- * _hash_lock without first calling dm_table_put, because dm_table_destroy
- * waits for this dm_table_put and could be called under this lock.
+ * _hash_lock without first calling dm_put_live_table, because dm_table_destroy
+ * waits for this dm_put_live_table and could be called under this lock.
  */
 static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx)
 {
diff --git a/drivers/md/dm-log-userspace-base.c b/drivers/md/dm-log-userspace-base.c
index b953db6cc229..03177ca0b009 100644
--- a/drivers/md/dm-log-userspace-base.c
+++ b/drivers/md/dm-log-userspace-base.c
@@ -6,6 +6,7 @@
 
 #include <linux/bio.h>
 #include <linux/slab.h>
+#include <linux/jiffies.h>
 #include <linux/dm-dirty-log.h>
 #include <linux/device-mapper.h>
 #include <linux/dm-log-userspace.h>
@@ -829,7 +830,7 @@ static int userspace_is_remote_recovering(struct dm_dirty_log *log,
         int r;
         uint64_t region64 = region;
         struct log_c *lc = log->context;
-        static unsigned long long limit;
+        static unsigned long limit;
         struct {
                 int64_t is_recovering;
                 uint64_t in_sync_hint;
@@ -845,7 +846,7 @@ static int userspace_is_remote_recovering(struct dm_dirty_log *log,
          */
         if (region < lc->in_sync_hint)
                 return 0;
-        else if (jiffies < limit)
+        else if (time_after(limit, jiffies))
                 return 1;
 
         limit = jiffies + (HZ / 4);
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 7b6b0f0f831a..d376dc87716e 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -11,6 +11,7 @@
 #include "dm-path-selector.h"
 #include "dm-uevent.h"
 
+#include <linux/blkdev.h>
 #include <linux/ctype.h>
 #include <linux/init.h>
 #include <linux/mempool.h>
@@ -378,18 +379,18 @@ static int __must_push_back(struct multipath *m)
 /*
  * Map cloned requests
  */
-static int multipath_map(struct dm_target *ti, struct request *clone,
-                         union map_info *map_context)
+static int __multipath_map(struct dm_target *ti, struct request *clone,
+                           union map_info *map_context,
+                           struct request *rq, struct request **__clone)
 {
         struct multipath *m = (struct multipath *) ti->private;
         int r = DM_MAPIO_REQUEUE;
-        size_t nr_bytes = blk_rq_bytes(clone);
-        unsigned long flags;
+        size_t nr_bytes = clone ? blk_rq_bytes(clone) : blk_rq_bytes(rq);
         struct pgpath *pgpath;
         struct block_device *bdev;
         struct dm_mpath_io *mpio;
 
-        spin_lock_irqsave(&m->lock, flags);
+        spin_lock_irq(&m->lock);
 
         /* Do we need to select a new pgpath? */
         if (!m->current_pgpath ||
@@ -411,25 +412,61 @@ static int multipath_map(struct dm_target *ti, struct request *clone,
                 /* ENOMEM, requeue */
                 goto out_unlock;