Merge branch 'for-4.16/block' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:
 "This is the main pull request for block IO related changes for the
  4.16 kernel. Nothing major in this pull request, but a good amount of
  improvements and fixes all over the map. This contains:

   - BFQ improvements, fixes, and cleanups from Angelo, Chiara, and
     Paolo.

   - Support for SMR zones for deadline and mq-deadline from Damien and
     Christoph.

   - Set of fixes for bcache by way of Michael Lyle, including fixes
     from himself, Kent, Rui, Tang, and Coly.

   - Series from Matias for lightnvm with fixes from Hans Holmberg,
     Javier, and Matias. Mostly centered around pblk, and the removing
     rrpc 1.2 in preparation for supporting 2.0.

   - A couple of NVMe pull requests from Christoph. Nothing major in
     here, just fixes and cleanups, and support for command tracing from
     Johannes.

   - Support for blk-throttle for tracking reads and writes separately.
     From Joseph Qi. A few cleanups/fixes also for blk-throttle from
     Weiping.

   - Series from Mike Snitzer that enables dm to register its queue more
     logically, something that's alwways been problematic on dm since
     it's a stacked device.

   - Series from Ming cleaning up some of the bio accessor use, in
     preparation for supporting multipage bvecs.

   - Various fixes from Ming closing up holes around queue mapping and
     quiescing.

   - BSD partition fix from Richard Narron, fixing a problem where we
     can't mount newer (10/11) FreeBSD partitions.

   - Series from Tejun reworking blk-mq timeout handling. The previous
     scheme relied on atomic bits, but it had races where we would think
     a request had timed out if it to reused at the wrong time.

   - null_blk now supports faking timeouts, to enable us to better
     exercise and test that functionality separately. From me.

   - Kill the separate atomic poll bit in the request struct. After
     this, we don't use the atomic bits on blk-mq anymore at all. From
     me.

   - sgl_alloc/free helpers from Bart.

   - Heavily contended tag case scalability improvement from me.

   - Various little fixes and cleanups from Arnd, Bart, Corentin,
     Douglas, Eryu, Goldwyn, and myself"

* 'for-4.16/block' of git://git.kernel.dk/linux-block: (186 commits)
  block: remove smart1,2.h
  nvme: add tracepoint for nvme_complete_rq
  nvme: add tracepoint for nvme_setup_cmd
  nvme-pci: introduce RECONNECTING state to mark initializing procedure
  nvme-rdma: remove redundant boolean for inline_data
  nvme: don't free uuid pointer before printing it
  nvme-pci: Suspend queues after deleting them
  bsg: use pr_debug instead of hand crafted macros
  blk-mq-debugfs: don't allow write on attributes with seq_operations set
  nvme-pci: Fix queue double allocations
  block: Set BIO_TRACE_COMPLETION on new bio during split
  blk-throttle: use queue_is_rq_based
  block: Remove kblockd_schedule_delayed_work{,_on}()
  blk-mq: Avoid that blk_mq_delay_run_hw_queue() introduces unintended delays
  blk-mq: Rename blk_mq_request_direct_issue() into blk_mq_request_issue_directly()
  lib/scatterlist: Fix chaining support in sgl_alloc_order()
  blk-throttle: track read and write request individually
  block: add bdev_read_only() checks to common helpers
  block: fail op_is_write() requests to read-only partitions
  blk-throttle: export io_serviced_recursive, io_service_bytes_recursive
  ...

drivers/target/Kconfig

@@ -5,6 +5,7 @@ menuconfig TARGET_CORE
 	select CONFIGFS_FS
 	select CRC_T10DIF
 	select BLK_SCSI_REQUEST # only for scsi_command_size_tbl..
+	select SGL_ALLOC
 	default n
 	help
 	Say Y or M here to enable the TCM Storage Engine and ConfigFS enabled

drivers/target/target_core_transport.c

@@ -2300,13 +2300,7 @@ queue_full:
 
 void target_free_sgl(struct scatterlist *sgl, int nents)
 {
-	struct scatterlist *sg;
-	int count;
-
-	for_each_sg(sgl, sg, nents, count)
-		__free_page(sg_page(sg));
-
-	kfree(sgl);
+	sgl_free_n_order(sgl, nents, 0);
 }
 EXPORT_SYMBOL(target_free_sgl);
 
@@ -2414,42 +2408,10 @@ int
 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
 		 bool zero_page, bool chainable)
 {
-	struct scatterlist *sg;
-	struct page *page;
-	gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
-	unsigned int nalloc, nent;
-	int i = 0;
+	gfp_t gfp = GFP_KERNEL | (zero_page ? __GFP_ZERO : 0);
 
-	nalloc = nent = DIV_ROUND_UP(length, PAGE_SIZE);
-	if (chainable)
-		nalloc++;
-	sg = kmalloc_array(nalloc, sizeof(struct scatterlist), GFP_KERNEL);
-	if (!sg)
-		return -ENOMEM;
-
-	sg_init_table(sg, nalloc);
-
-	while (length) {
-		u32 page_len = min_t(u32, length, PAGE_SIZE);
-		page = alloc_page(GFP_KERNEL | zero_flag);
-		if (!page)
-			goto out;
-
-		sg_set_page(&sg[i], page, page_len, 0);
-		length -= page_len;
-		i++;
-	}
-	*sgl = sg;
-	*nents = nent;
-	return 0;
-
-out:
-	while (i > 0) {
-		i--;
-		__free_page(sg_page(&sg[i]));
-	}
-	kfree(sg);
-	return -ENOMEM;
+	*sgl = sgl_alloc_order(length, 0, chainable, gfp, nents);
+	return *sgl ? 0 : -ENOMEM;
 }
 EXPORT_SYMBOL(target_alloc_sgl);