Merge branch 'for-3.8/core' of git://git.kernel.dk/linux-block

Pull block layer core updates from Jens Axboe:
 "Here are the core block IO bits for 3.8.  The branch contains:

   - The final version of the surprise device removal fixups from Bart.

   - Don't hide EFI partitions under advanced partition types.  It's
     fairly wide spread these days.  This is especially dangerous for
     systems that have both msdos and efi partition tables, where you
     want to keep them in sync.

   - Cleanup of using -1 instead of the proper NUMA_NO_NODE

   - Export control of bdi flusher thread CPU mask and default to using
     the home node (if known) from Jeff.

   - Export unplug tracepoint for MD.

   - Core improvements from Shaohua.  Reinstate the recursive merge, as
     the original bug has been fixed.  Add plugging for discard and also
     fix a problem handling non pow-of-2 discard limits.

  There's a trivial merge in block/blk-exec.c due to a fix that went
  into 3.7-rc at a later point than -rc4 where this is based."

* 'for-3.8/core' of git://git.kernel.dk/linux-block:
  block: export block_unplug tracepoint
  block: add plug for blkdev_issue_discard
  block: discard granularity might not be power of 2
  deadline: Allow 0ms deadline latency, increase the read speed
  partitions: enable EFI/GPT support by default
  bsg: Remove unused function bsg_goose_queue()
  block: Make blk_cleanup_queue() wait until request_fn finished
  block: Avoid scheduling delayed work on a dead queue
  block: Avoid that request_fn is invoked on a dead queue
  block: Let blk_drain_queue() caller obtain the queue lock
  block: Rename queue dead flag
  bdi: add a user-tunable cpu_list for the bdi flusher threads
  block: use NUMA_NO_NODE instead of -1
  block: recursive merge requests
  block CFQ: avoid moving request to different queue

1 files changed, 16 insertions, 10 deletions

diff --git a/block/blk-lib.c b/block/blk-lib.c
index 9373b58dfab1..b3a1f2b70b31 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -43,11 +43,12 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	DECLARE_COMPLETION_ONSTACK(wait);
 	struct request_queue *q = bdev_get_queue(bdev);
 	int type = REQ_WRITE | REQ_DISCARD;
-	unsigned int max_discard_sectors;
-	unsigned int granularity, alignment, mask;
+	sector_t max_discard_sectors;
+	sector_t granularity, alignment;
 	struct bio_batch bb;
 	struct bio *bio;
 	int ret = 0;
+	struct blk_plug plug;
 
 	if (!q)
 		return -ENXIO;
@@ -57,15 +58,16 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
-	mask = granularity - 1;
-	alignment = (bdev_discard_alignment(bdev) >> 9) & mask;
+	alignment = bdev_discard_alignment(bdev) >> 9;
+	alignment = sector_div(alignment, granularity);
 
 	/*
 	 * Ensure that max_discard_sectors is of the proper
 	 * granularity, so that requests stay aligned after a split.
 	 */
 	max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9);
-	max_discard_sectors = round_down(max_discard_sectors, granularity);
+	sector_div(max_discard_sectors, granularity);
+	max_discard_sectors *= granularity;
 	if (unlikely(!max_discard_sectors)) {
 		/* Avoid infinite loop below. Being cautious never hurts. */
 		return -EOPNOTSUPP;
@@ -81,9 +83,10 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	bb.flags = 1 << BIO_UPTODATE;
 	bb.wait = &wait;
 
+	blk_start_plug(&plug);
 	while (nr_sects) {
 		unsigned int req_sects;
-		sector_t end_sect;
+		sector_t end_sect, tmp;
 
 		bio = bio_alloc(gfp_mask, 1);
 		if (!bio) {
@@ -98,10 +101,12 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		 * misaligned, stop the discard at the previous aligned sector.
 		 */
 		end_sect = sector + req_sects;
-		if (req_sects < nr_sects && (end_sect & mask) != alignment) {
-			end_sect =
-				round_down(end_sect - alignment, granularity)
-				+ alignment;
+		tmp = end_sect;
+		if (req_sects < nr_sects &&
+		    sector_div(tmp, granularity) != alignment) {
+			end_sect = end_sect - alignment;
+			sector_div(end_sect, granularity);
+			end_sect = end_sect * granularity + alignment;
 			req_sects = end_sect - sector;
 		}
 
@@ -117,6 +122,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		atomic_inc(&bb.done);
 		submit_bio(type, bio);
 	}
+	blk_finish_plug(&plug);
 
 	/* Wait for bios in-flight */
 	if (!atomic_dec_and_test(&bb.done))