Merge tag 'for-5.1/block-post-20190315' of git://git.kernel.dk/linux-block

Pull more block layer changes from Jens Axboe:
 "This is a collection of both stragglers, and fixes that came in after
  I finalized the initial pull. This contains:

   - An MD pull request from Song, with a few minor fixes

   - Set of NVMe patches via Christoph

   - Pull request from Konrad, with a few fixes for xen/blkback

   - pblk fix IO calculation fix (Javier)

   - Segment calculation fix for pass-through (Ming)

   - Fallthrough annotation for blkcg (Mathieu)"

* tag 'for-5.1/block-post-20190315' of git://git.kernel.dk/linux-block: (25 commits)
  blkcg: annotate implicit fall through
  nvme-tcp: support C2HData with SUCCESS flag
  nvmet: ignore EOPNOTSUPP for discard
  nvme: add proper write zeroes setup for the multipath device
  nvme: add proper discard setup for the multipath device
  nvme: remove nvme_ns_config_oncs
  nvme: disable Write Zeroes for qemu controllers
  nvmet-fc: bring Disconnect into compliance with FC-NVME spec
  nvmet-fc: fix issues with targetport assoc_list list walking
  nvme-fc: reject reconnect if io queue count is reduced to zero
  nvme-fc: fix numa_node when dev is null
  nvme-fc: use nr_phys_segments to determine existence of sgl
  nvme-loop: init nvmet_ctrl fatal_err_work when allocate
  nvme: update comment to make the code easier to read
  nvme: put ns_head ref if namespace fails allocation
  nvme-trace: fix cdw10 buffer overrun
  nvme: don't warn on block content change effects
  nvme: add get-feature to admin cmds tracer
  md: Fix failed allocation of md_register_thread
  It's wrong to add len to sector_nr in raid10 reshape twice
  ...

drivers/md/raid5-ppl.c

@@ -20,6 +20,7 @@
 #include <linux/raid/md_p.h>
 #include "md.h"
 #include "raid5.h"
+#include "raid5-log.h"
 
 /*
  * PPL consists of a 4KB header (struct ppl_header) and at least 128KB for
@@ -115,6 +116,8 @@ struct ppl_conf {
 	/* stripes to retry if failed to allocate io_unit */
 	struct list_head no_mem_stripes;
 	spinlock_t no_mem_stripes_lock;
+
+	unsigned short write_hint;
 };
 
 struct ppl_log {
@@ -474,6 +477,7 @@ static void ppl_submit_iounit(struct ppl_io_unit *io)
 	bio_set_dev(bio, log->rdev->bdev);
 	bio->bi_iter.bi_sector = log->next_io_sector;
 	bio_add_page(bio, io->header_page, PAGE_SIZE, 0);
+	bio->bi_write_hint = ppl_conf->write_hint;
 
 	pr_debug("%s: log->current_io_sector: %llu\n", __func__,
 	    (unsigned long long)log->next_io_sector);
@@ -503,6 +507,7 @@ static void ppl_submit_iounit(struct ppl_io_unit *io)
 			bio = bio_alloc_bioset(GFP_NOIO, BIO_MAX_PAGES,
 					       &ppl_conf->bs);
 			bio->bi_opf = prev->bi_opf;
+			bio->bi_write_hint = prev->bi_write_hint;
 			bio_copy_dev(bio, prev);
 			bio->bi_iter.bi_sector = bio_end_sector(prev);
 			bio_add_page(bio, sh->ppl_page, PAGE_SIZE, 0);
@@ -1407,6 +1412,7 @@ int ppl_init_log(struct r5conf *conf)
 	atomic64_set(&ppl_conf->seq, 0);
 	INIT_LIST_HEAD(&ppl_conf->no_mem_stripes);
 	spin_lock_init(&ppl_conf->no_mem_stripes_lock);
+	ppl_conf->write_hint = RWF_WRITE_LIFE_NOT_SET;
 
 	if (!mddev->external) {
 		ppl_conf->signature = ~crc32c_le(~0, mddev->uuid, sizeof(mddev->uuid));
@@ -1501,3 +1507,60 @@ int ppl_modify_log(struct r5conf *conf, struct md_rdev *rdev, bool add)
 
 	return ret;
 }
+
+static ssize_t
+ppl_write_hint_show(struct mddev *mddev, char *buf)
+{
+	size_t ret = 0;
+	struct r5conf *conf;
+	struct ppl_conf *ppl_conf = NULL;
+
+	spin_lock(&mddev->lock);
+	conf = mddev->private;
+	if (conf && raid5_has_ppl(conf))
+		ppl_conf = conf->log_private;
+	ret = sprintf(buf, "%d\n", ppl_conf ? ppl_conf->write_hint : 0);
+	spin_unlock(&mddev->lock);
+
+	return ret;
+}
+
+static ssize_t
+ppl_write_hint_store(struct mddev *mddev, const char *page, size_t len)
+{
+	struct r5conf *conf;
+	struct ppl_conf *ppl_conf;
+	int err = 0;
+	unsigned short new;
+
+	if (len >= PAGE_SIZE)
+		return -EINVAL;
+	if (kstrtou16(page, 10, &new))
+		return -EINVAL;
+
+	err = mddev_lock(mddev);
+	if (err)
+		return err;
+
+	conf = mddev->private;
+	if (!conf) {
+		err = -ENODEV;
+	} else if (raid5_has_ppl(conf)) {
+		ppl_conf = conf->log_private;
+		if (!ppl_conf)
+			err = -EINVAL;
+		else
+			ppl_conf->write_hint = new;
+	} else {
+		err = -EINVAL;
+	}
+
+	mddev_unlock(mddev);
+
+	return err ?: len;
+}
+
+struct md_sysfs_entry
+ppl_write_hint = __ATTR(ppl_write_hint, S_IRUGO | S_IWUSR,
+			ppl_write_hint_show,
+			ppl_write_hint_store);