Merge tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-block

Pull block layer updates from Jens Axboe:
 "Not a huge amount of changes in this round, the biggest one is that we
  finally have Mings multi-page bvec support merged. Apart from that,
  this pull request contains:

   - Small series that avoids quiescing the queue for sysfs changes that
     match what we currently have (Aleksei)

   - Series of bcache fixes (via Coly)

   - Series of lightnvm fixes (via Mathias)

   - NVMe pull request from Christoph. Nothing major, just SPDX/license
     cleanups, RR mp policy (Hannes), and little fixes (Bart,
     Chaitanya).

   - BFQ series (Paolo)

   - Save blk-mq cpu -> hw queue mapping, removing a pointer indirection
     for the fast path (Jianchao)

   - fops->iopoll() added for async IO polling, this is a feature that
     the upcoming io_uring interface will use (Christoph, me)

   - Partition scan loop fixes (Dongli)

   - mtip32xx conversion from managed resource API (Christoph)

   - cdrom registration race fix (Guenter)

   - MD pull from Song, two minor fixes.

   - Various documentation fixes (Marcos)

   - Multi-page bvec feature. This brings a lot of nice improvements
     with it, like more efficient splitting, larger IOs can be supported
     without growing the bvec table size, and so on. (Ming)

   - Various little fixes to core and drivers"

* tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-block: (117 commits)
  block: fix updating bio's front segment size
  block: Replace function name in string with __func__
  nbd: propagate genlmsg_reply return code
  floppy: remove set but not used variable 'q'
  null_blk: fix checking for REQ_FUA
  block: fix NULL pointer dereference in register_disk
  fs: fix guard_bio_eod to check for real EOD errors
  blk-mq: use HCTX_TYPE_DEFAULT but not 0 to index blk_mq_tag_set->map
  block: optimize bvec iteration in bvec_iter_advance
  block: introduce mp_bvec_for_each_page() for iterating over page
  block: optimize blk_bio_segment_split for single-page bvec
  block: optimize __blk_segment_map_sg() for single-page bvec
  block: introduce bvec_nth_page()
  iomap: wire up the iopoll method
  block: add bio_set_polled() helper
  block: wire up block device iopoll method
  fs: add an iopoll method to struct file_operations
  loop: set GENHD_FL_NO_PART_SCAN after blkdev_reread_part()
  loop: do not print warn message if partition scan is successful
  block: bounce: make sure that bvec table is updated
  ...

1 files changed, 43 insertions, 21 deletions

diff --git a/drivers/lightnvm/pblk-recovery.c b/drivers/lightnvm/pblk-recovery.c
index 5ee20da7bdb3..d86f580036d3 100644
--- a/drivers/lightnvm/pblk-recovery.c
+++ b/drivers/lightnvm/pblk-recovery.c
@@ -302,35 +302,55 @@ static int pblk_pad_distance(struct pblk *pblk, struct pblk_line *line)
 	return (distance > line->left_msecs) ? line->left_msecs : distance;
 }
 
-static int pblk_line_wp_is_unbalanced(struct pblk *pblk,
-				      struct pblk_line *line)
+/* Return a chunk belonging to a line by stripe(write order) index */
+static struct nvm_chk_meta *pblk_get_stripe_chunk(struct pblk *pblk,
+						  struct pblk_line *line,
+						  int index)
 {
 	struct nvm_tgt_dev *dev = pblk->dev;
 	struct nvm_geo *geo = &dev->geo;
-	struct pblk_line_meta *lm = &pblk->lm;
 	struct pblk_lun *rlun;
-	struct nvm_chk_meta *chunk;
 	struct ppa_addr ppa;
-	u64 line_wp;
-	int pos, i;
+	int pos;
 
-	rlun = &pblk->luns[0];
+	rlun = &pblk->luns[index];
 	ppa = rlun->bppa;
 	pos = pblk_ppa_to_pos(geo, ppa);
-	chunk = &line->chks[pos];
 
-	line_wp = chunk->wp;
+	return &line->chks[pos];
+}
 
-	for (i = 1; i < lm->blk_per_line; i++) {
-		rlun = &pblk->luns[i];
-		ppa = rlun->bppa;
-		pos = pblk_ppa_to_pos(geo, ppa);
-		chunk = &line->chks[pos];
+static int pblk_line_wps_are_unbalanced(struct pblk *pblk,
+				      struct pblk_line *line)
+{
+	struct pblk_line_meta *lm = &pblk->lm;
+	int blk_in_line = lm->blk_per_line;
+	struct nvm_chk_meta *chunk;
+	u64 max_wp, min_wp;
+	int i;
+
+	i = find_first_zero_bit(line->blk_bitmap, blk_in_line);
 
-		if (chunk->wp > line_wp)
+	/* If there is one or zero good chunks in the line,
+	 * the write pointers can't be unbalanced.
+	 */
+	if (i >= (blk_in_line - 1))
+		return 0;
+
+	chunk = pblk_get_stripe_chunk(pblk, line, i);
+	max_wp = chunk->wp;
+	if (max_wp > pblk->max_write_pgs)
+		min_wp = max_wp - pblk->max_write_pgs;
+	else
+		min_wp = 0;
+
+	i = find_next_zero_bit(line->blk_bitmap, blk_in_line, i + 1);
+	while (i < blk_in_line) {
+		chunk = pblk_get_stripe_chunk(pblk, line, i);
+		if (chunk->wp > max_wp || chunk->wp < min_wp)
 			return 1;
-		else if (chunk->wp < line_wp)
-			line_wp = chunk->wp;
+
+		i = find_next_zero_bit(line->blk_bitmap, blk_in_line, i + 1);
 	}
 
 	return 0;
@@ -356,7 +376,7 @@ static int pblk_recov_scan_oob(struct pblk *pblk, struct pblk_line *line,
 	int ret;
 	u64 left_ppas = pblk_sec_in_open_line(pblk, line) - lm->smeta_sec;
 
-	if (pblk_line_wp_is_unbalanced(pblk, line))
+	if (pblk_line_wps_are_unbalanced(pblk, line))
 		pblk_warn(pblk, "recovering unbalanced line (%d)\n", line->id);
 
 	ppa_list = p.ppa_list;
@@ -703,11 +723,13 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk)
 
 		/* The first valid instance uuid is used for initialization */
 		if (!valid_uuid) {
-			memcpy(pblk->instance_uuid, smeta_buf->header.uuid, 16);
+			guid_copy(&pblk->instance_uuid,
+				  (guid_t *)&smeta_buf->header.uuid);
 			valid_uuid = 1;
 		}
 
-		if (memcmp(pblk->instance_uuid, smeta_buf->header.uuid, 16)) {
+		if (!guid_equal(&pblk->instance_uuid,
+				(guid_t *)&smeta_buf->header.uuid)) {
 			pblk_debug(pblk, "ignore line %u due to uuid mismatch\n",
 					i);
 			continue;
@@ -737,7 +759,7 @@ struct pblk_line *pblk_recov_l2p(struct pblk *pblk)
 	}
 
 	if (!found_lines) {
-		pblk_setup_uuid(pblk);
+		guid_gen(&pblk->instance_uuid);
 
 		spin_lock(&l_mg->free_lock);
 		WARN_ON_ONCE(!test_and_clear_bit(meta_line,