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Commit caf292ae authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-3.19/core' of git://git.kernel.dk/linux-block 

Pull block driver core update from Jens Axboe:
 "This is the pull request for the core block IO changes for 3.19.  Not
  a huge round this time, mostly lots of little good fixes:

   - Fix a bug in sysfs blktrace interface causing a NULL pointer
     dereference, when enabled/disabled through that API.  From Arianna
     Avanzini.

   - Various updates/fixes/improvements for blk-mq:

        - A set of updates from Bart, mostly fixing buts in the tag
          handling.

        - Cleanup/code consolidation from Christoph.

        - Extend queue_rq API to be able to handle batching issues of IO
          requests. NVMe will utilize this shortly. From me.

        - A few tag and request handling updates from me.

        - Cleanup of the preempt handling for running queues from Paolo.

        - Prevent running of unmapped hardware queues from Ming Lei.

        - Move the kdump memory limiting check to be in the correct
          location, from Shaohua.

        - Initialize all software queues at init time from Takashi. This
          prevents a kobject warning when CPUs are brought online that
          weren't online when a queue was registered.

   - Single writeback fix for I_DIRTY clearing from Tejun.  Queued with
     the core IO changes, since it's just a single fix.

   - Version X of the __bio_add_page() segment addition retry from
     Maurizio.  Hope the Xth time is the charm.

   - Documentation fixup for IO scheduler merging from Jan.

   - Introduce (and use) generic IO stat accounting helpers for non-rq
     drivers, from Gu Zheng.

   - Kill off artificial limiting of max sectors in a request from
     Christoph"

* 'for-3.19/core' of git://git.kernel.dk/linux-block: (26 commits)
  bio: modify __bio_add_page() to accept pages that don't start a new segment
  blk-mq: Fix uninitialized kobject at CPU hotplugging
  blktrace: don't let the sysfs interface remove trace from running list
  blk-mq: Use all available hardware queues
  blk-mq: Micro-optimize bt_get()
  blk-mq: Fix a race between bt_clear_tag() and bt_get()
  blk-mq: Avoid that __bt_get_word() wraps multiple times
  blk-mq: Fix a use-after-free
  blk-mq: prevent unmapped hw queue from being scheduled
  blk-mq: re-check for available tags after running the hardware queue
  blk-mq: fix hang in bt_get()
  blk-mq: move the kdump check to blk_mq_alloc_tag_set
  blk-mq: cleanup tag free handling
  blk-mq: use 'nr_cpu_ids' as highest CPU ID count for hwq <-> cpu map
  blk: introduce generic io stat accounting help function
  blk-mq: handle the single queue case in blk_mq_hctx_next_cpu
  genhd: check for int overflow in disk_expand_part_tbl()
  blk-mq: add blk_mq_free_hctx_request()
  blk-mq: export blk_mq_free_request()
  blk-mq: use get_cpu/put_cpu instead of preempt_disable/preempt_enable
  ...
parents 8f4385d5 fcbf6a08

Documentation/block/biodoc.txt

+5 −1
Original line number Diff line number Diff line
@@ -942,7 +942,11 @@ elevator_allow_merge_fn called whenever the block layer determines 
				request safely. The io scheduler may still

				want to stop a merge at this point if it

				results in some sort of conflict internally,

				this hook allows it to do that.

				this hook allows it to do that. Note however

				that two *requests* can still be merged at later

				time. Currently the io scheduler has no way to

				prevent that. It can only learn about the fact

				from elevator_merge_req_fn callback.



elevator_dispatch_fn*		fills the dispatch queue with ready requests.

				I/O schedulers are free to postpone requests by

block/bio.c

+58 −24
Original line number Diff line number Diff line
@@ -748,6 +748,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page 
				}

			}



			bio->bi_iter.bi_size += len;

			goto done;

		}
@@ -764,28 +765,31 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page 
		return 0;



	/*

	 * we might lose a segment or two here, but rather that than

	 * make this too complex.

	 * setup the new entry, we might clear it again later if we

	 * cannot add the page

	 */

	bvec = &bio->bi_io_vec[bio->bi_vcnt];

	bvec->bv_page = page;

	bvec->bv_len = len;

	bvec->bv_offset = offset;

	bio->bi_vcnt++;

	bio->bi_phys_segments++;

	bio->bi_iter.bi_size += len;



	/*

	 * Perform a recount if the number of segments is greater

	 * than queue_max_segments(q).

	 */



	while (bio->bi_phys_segments >= queue_max_segments(q)) {

	while (bio->bi_phys_segments > queue_max_segments(q)) {



		if (retried_segments)

			return 0;

			goto failed;



		retried_segments = 1;

		blk_recount_segments(q, bio);

	}



	/*

	 * setup the new entry, we might clear it again later if we

	 * cannot add the page

	 */

	bvec = &bio->bi_io_vec[bio->bi_vcnt];

	bvec->bv_page = page;

	bvec->bv_len = len;

	bvec->bv_offset = offset;



	/*

	 * if queue has other restrictions (eg varying max sector size

	 * depending on offset), it can specify a merge_bvec_fn in the
@@ -795,7 +799,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page 
		struct bvec_merge_data bvm = {

			.bi_bdev = bio->bi_bdev,

			.bi_sector = bio->bi_iter.bi_sector,

			.bi_size = bio->bi_iter.bi_size,

			.bi_size = bio->bi_iter.bi_size - len,

			.bi_rw = bio->bi_rw,

		};
@@ -803,23 +807,25 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page 
		 * merge_bvec_fn() returns number of bytes it can accept

		 * at this offset

		 */

		if (q->merge_bvec_fn(q, &bvm, bvec) < bvec->bv_len) {

			bvec->bv_page = NULL;

			bvec->bv_len = 0;

			bvec->bv_offset = 0;

			return 0;

		}

		if (q->merge_bvec_fn(q, &bvm, bvec) < bvec->bv_len)

			goto failed;

	}



	/* If we may be able to merge these biovecs, force a recount */

	if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))

	if (bio->bi_vcnt > 1 && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))

		bio->bi_flags &= ~(1 << BIO_SEG_VALID);



	bio->bi_vcnt++;

	bio->bi_phys_segments++;

 done:

	bio->bi_iter.bi_size += len;

	return len;



 failed:

	bvec->bv_page = NULL;

	bvec->bv_len = 0;

	bvec->bv_offset = 0;

	bio->bi_vcnt--;

	bio->bi_iter.bi_size -= len;

	blk_recount_segments(q, bio);

	return 0;

}



/**
@@ -1739,6 +1745,34 @@ void bio_check_pages_dirty(struct bio *bio) 
	}

}



void generic_start_io_acct(int rw, unsigned long sectors,

			   struct hd_struct *part)

{

	int cpu = part_stat_lock();



	part_round_stats(cpu, part);

	part_stat_inc(cpu, part, ios[rw]);

	part_stat_add(cpu, part, sectors[rw], sectors);

	part_inc_in_flight(part, rw);



	part_stat_unlock();

}

EXPORT_SYMBOL(generic_start_io_acct);



void generic_end_io_acct(int rw, struct hd_struct *part,

			 unsigned long start_time)

{

	unsigned long duration = jiffies - start_time;

	int cpu = part_stat_lock();



	part_stat_add(cpu, part, ticks[rw], duration);

	part_round_stats(cpu, part);

	part_dec_in_flight(part, rw);



	part_stat_unlock();

}

EXPORT_SYMBOL(generic_end_io_acct);



#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE

void bio_flush_dcache_pages(struct bio *bi)

{

block/blk-core.c

+3 −0
Original line number Diff line number Diff line
@@ -525,6 +525,9 @@ void blk_cleanup_queue(struct request_queue *q) 
	del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer);

	blk_sync_queue(q);



	if (q->mq_ops)

		blk_mq_free_queue(q);



	spin_lock_irq(lock);

	if (q->queue_lock != &q->__queue_lock)

		q->queue_lock = &q->__queue_lock;

block/blk-mq-cpumap.c

+2 −2
Original line number Diff line number Diff line
@@ -17,7 +17,7 @@ 
static int cpu_to_queue_index(unsigned int nr_cpus, unsigned int nr_queues,

			      const int cpu)

{

	return cpu / ((nr_cpus + nr_queues - 1) / nr_queues);

	return cpu * nr_queues / nr_cpus;

}



static int get_first_sibling(unsigned int cpu)
@@ -90,7 +90,7 @@ unsigned int *blk_mq_make_queue_map(struct blk_mq_tag_set *set) 
	unsigned int *map;



	/* If cpus are offline, map them to first hctx */

	map = kzalloc_node(sizeof(*map) * num_possible_cpus(), GFP_KERNEL,

	map = kzalloc_node(sizeof(*map) * nr_cpu_ids, GFP_KERNEL,

				set->numa_node);

	if (!map)

		return NULL;

block/blk-mq-sysfs.c

+4 −5
Original line number Diff line number Diff line
@@ -390,17 +390,16 @@ static void blk_mq_sysfs_init(struct request_queue *q) 
{

	struct blk_mq_hw_ctx *hctx;

	struct blk_mq_ctx *ctx;

	int i, j;

	int i;



	kobject_init(&q->mq_kobj, &blk_mq_ktype);



	queue_for_each_hw_ctx(q, hctx, i) {

	queue_for_each_hw_ctx(q, hctx, i)

		kobject_init(&hctx->kobj, &blk_mq_hw_ktype);



		hctx_for_each_ctx(hctx, ctx, j)

	queue_for_each_ctx(q, ctx, i)

		kobject_init(&ctx->kobj, &blk_mq_ctx_ktype);

}

}



/* see blk_register_queue() */

void blk_mq_finish_init(struct request_queue *q)