Merge branch 'for-linus' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "A small collection of fixes/changes for the current series.  This
  contains:

   - Removal of dead code from Gu Zheng.

   - Revert of two bad fixes that went in earlier in this round, marking
     things as __init that were not purely used from init.

   - A fix for blk_mq_start_hw_queue() using the __blk_mq_run_hw_queue(),
     which could place us wrongly.  Make it use the non __ variant,
     which handles cases where we are called from the wrong CPU set.
     From me.

   - A fix for drbd, which allocates discard requests without room for
     the SCSI payload.  From Lars Ellenberg.

   - A fix for user-after-free in the blkcg code from Tejun.

   - Addition of limiting gaps in SG lists, if the hardware needs it.
     This is the last pre-req patch for blk-mq to enable the full NVMe
     conversion.  Could wait until 3.17, but it's simple enough so would
     be nice to have everything we need for the NVMe port in the 3.17
     release.  From me"

* 'for-linus' of git://git.kernel.dk/linux-block:
  drbd: fix NULL pointer deref in blk_add_request_payload
  blk-mq: blk_mq_start_hw_queue() should use blk_mq_run_hw_queue()
  block: add support for limiting gaps in SG lists
  bio: remove unused macro bip_vec_idx()
  Revert "block: add __init to elv_register"
  Revert "block: add __init to blkcg_policy_register"
  blkcg: fix use-after-free in __blkg_release_rcu() by making blkcg_gq refcnt an atomic_t
  floppy: format block0 read error message properly

3 files changed, 11 insertions, 5 deletions

diff --git a/include/linux/bio.h b/include/linux/bio.h
index 5a645769f02..d2633ee099d 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -186,6 +186,15 @@ static inline void *bio_data(struct bio *bio)
 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
 	__BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
 
+/*
+ * Check if adding a bio_vec after bprv with offset would create a gap in
+ * the SG list. Most drivers don't care about this, but some do.
+ */
+static inline bool bvec_gap_to_prev(struct bio_vec *bprv, unsigned int offset)
+{
+	return offset || ((bprv->bv_offset + bprv->bv_len) & (PAGE_SIZE - 1));
+}
+
 #define bio_io_error(bio) bio_endio((bio), -EIO)
 
 /*
@@ -644,10 +653,6 @@ struct biovec_slab {
 
 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 
-
-
-#define bip_vec_idx(bip, idx)	(&(bip->bip_vec[(idx)]))
-
 #define bip_for_each_vec(bvl, bip, iter)				\
 	for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
 
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 713f8b62b43..8699bcf5f09 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -512,6 +512,7 @@ struct request_queue {
 #define QUEUE_FLAG_DEAD        19	/* queue tear-down finished */
 #define QUEUE_FLAG_INIT_DONE   20	/* queue is initialized */
 #define QUEUE_FLAG_NO_SG_MERGE 21	/* don't attempt to merge SG segments*/
+#define QUEUE_FLAG_SG_GAPS     22	/* queue doesn't support SG gaps */
 
 #define QUEUE_FLAG_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
 				 (1 << QUEUE_FLAG_STACKABLE)	|	\
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index e2a6bd7fb13..45a91474487 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -143,7 +143,7 @@ extern void elv_drain_elevator(struct request_queue *);
  * io scheduler registration
  */
 extern void __init load_default_elevator_module(void);
-extern int __init elv_register(struct elevator_type *);
+extern int elv_register(struct elevator_type *);
 extern void elv_unregister(struct elevator_type *);
 
 /*