Merge branch 'for-4.4/core' of git://git.kernel.dk/linux-block
Pull core block updates from Jens Axboe:
"This is the core block pull request for 4.4. I've got a few more
topic branches this time around, some of them will layer on top of the
core+drivers changes and will come in a separate round. So not a huge
chunk of changes in this round.
This pull request contains:
- Enable blk-mq page allocation tracking with kmemleak, from Catalin.
- Unused prototype removal in blk-mq from Christoph.
- Cleanup of the q->blk_trace exchange, using cmpxchg instead of two
xchg()'s, from Davidlohr.
- A plug flush fix from Jeff.
- Also from Jeff, a fix that means we don't have to update shared tag
sets at init time unless we do a state change. This cuts down boot
times on thousands of devices a lot with scsi/blk-mq.
- blk-mq waitqueue barrier fix from Kosuke.
- Various fixes from Ming:
- Fixes for segment merging and splitting, and checks, for
the old core and blk-mq.
- Potential blk-mq speedup by marking ctx pending at the end
of a plug insertion batch in blk-mq.
- direct-io no page dirty on kernel direct reads.
- A WRITE_SYNC fix for mpage from Roman"
* 'for-4.4/core' of git://git.kernel.dk/linux-block:
blk-mq: avoid excessive boot delays with large lun counts
blktrace: re-write setting q->blk_trace
blk-mq: mark ctx as pending at batch in flush plug path
blk-mq: fix for trace_block_plug()
block: check bio_mergeable() early before merging
blk-mq: check bio_mergeable() early before merging
block: avoid to merge splitted bio
block: setup bi_phys_segments after splitting
block: fix plug list flushing for nomerge queues
blk-mq: remove unused blk_mq_clone_flush_request prototype
blk-mq: fix waitqueue_active without memory barrier in block/blk-mq-tag.c
fs: direct-io: don't dirtying pages for ITER_BVEC/ITER_KVEC direct read
fs/mpage.c: forgotten WRITE_SYNC in case of data integrity write
block: kmemleak: Track the page allocations for struct request
diff --git a/block/blk-core.c b/block/blk-core.c
index 18e92a6..f888f23 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1594,6 +1594,30 @@
return ret;
}
+unsigned int blk_plug_queued_count(struct request_queue *q)
+{
+ struct blk_plug *plug;
+ struct request *rq;
+ struct list_head *plug_list;
+ unsigned int ret = 0;
+
+ plug = current->plug;
+ if (!plug)
+ goto out;
+
+ if (q->mq_ops)
+ plug_list = &plug->mq_list;
+ else
+ plug_list = &plug->list;
+
+ list_for_each_entry(rq, plug_list, queuelist) {
+ if (rq->q == q)
+ ret++;
+ }
+out:
+ return ret;
+}
+
void init_request_from_bio(struct request *req, struct bio *bio)
{
req->cmd_type = REQ_TYPE_FS;
@@ -1641,9 +1665,11 @@
* Check if we can merge with the plugged list before grabbing
* any locks.
*/
- if (!blk_queue_nomerges(q) &&
- blk_attempt_plug_merge(q, bio, &request_count, NULL))
- return;
+ if (!blk_queue_nomerges(q)) {
+ if (blk_attempt_plug_merge(q, bio, &request_count, NULL))
+ return;
+ } else
+ request_count = blk_plug_queued_count(q);
spin_lock_irq(q->queue_lock);
diff --git a/block/blk-merge.c b/block/blk-merge.c
index c4e9c37..de5716d8 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -11,13 +11,16 @@
static struct bio *blk_bio_discard_split(struct request_queue *q,
struct bio *bio,
- struct bio_set *bs)
+ struct bio_set *bs,
+ unsigned *nsegs)
{
unsigned int max_discard_sectors, granularity;
int alignment;
sector_t tmp;
unsigned split_sectors;
+ *nsegs = 1;
+
/* Zero-sector (unknown) and one-sector granularities are the same. */
granularity = max(q->limits.discard_granularity >> 9, 1U);
@@ -51,8 +54,11 @@
static struct bio *blk_bio_write_same_split(struct request_queue *q,
struct bio *bio,
- struct bio_set *bs)
+ struct bio_set *bs,
+ unsigned *nsegs)
{
+ *nsegs = 1;
+
if (!q->limits.max_write_same_sectors)
return NULL;
@@ -64,7 +70,8 @@
static struct bio *blk_bio_segment_split(struct request_queue *q,
struct bio *bio,
- struct bio_set *bs)
+ struct bio_set *bs,
+ unsigned *segs)
{
struct bio_vec bv, bvprv, *bvprvp = NULL;
struct bvec_iter iter;
@@ -106,24 +113,35 @@
sectors += bv.bv_len >> 9;
}
+ *segs = nsegs;
return NULL;
split:
+ *segs = nsegs;
return bio_split(bio, sectors, GFP_NOIO, bs);
}
void blk_queue_split(struct request_queue *q, struct bio **bio,
struct bio_set *bs)
{
- struct bio *split;
+ struct bio *split, *res;
+ unsigned nsegs;
if ((*bio)->bi_rw & REQ_DISCARD)
- split = blk_bio_discard_split(q, *bio, bs);
+ split = blk_bio_discard_split(q, *bio, bs, &nsegs);
else if ((*bio)->bi_rw & REQ_WRITE_SAME)
- split = blk_bio_write_same_split(q, *bio, bs);
+ split = blk_bio_write_same_split(q, *bio, bs, &nsegs);
else
- split = blk_bio_segment_split(q, *bio, q->bio_split);
+ split = blk_bio_segment_split(q, *bio, q->bio_split, &nsegs);
+
+ /* physical segments can be figured out during splitting */
+ res = split ? split : *bio;
+ res->bi_phys_segments = nsegs;
+ bio_set_flag(res, BIO_SEG_VALID);
if (split) {
+ /* there isn't chance to merge the splitted bio */
+ split->bi_rw |= REQ_NOMERGE;
+
bio_chain(split, *bio);
generic_make_request(*bio);
*bio = split;
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index ec2d119..60ac684 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -75,6 +75,10 @@
struct blk_mq_bitmap_tags *bt;
int i, wake_index;
+ /*
+ * Make sure all changes prior to this are visible from other CPUs.
+ */
+ smp_mb();
bt = &tags->bitmap_tags;
wake_index = atomic_read(&bt->wake_index);
for (i = 0; i < BT_WAIT_QUEUES; i++) {
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 85f0143..309e410 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -9,6 +9,7 @@
#include <linux/backing-dev.h>
#include <linux/bio.h>
#include <linux/blkdev.h>
+#include <linux/kmemleak.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/slab.h>
@@ -989,18 +990,25 @@
}
EXPORT_SYMBOL(blk_mq_delay_queue);
-static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
- struct request *rq, bool at_head)
+static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx,
+ struct blk_mq_ctx *ctx,
+ struct request *rq,
+ bool at_head)
{
- struct blk_mq_ctx *ctx = rq->mq_ctx;
-
trace_block_rq_insert(hctx->queue, rq);
if (at_head)
list_add(&rq->queuelist, &ctx->rq_list);
else
list_add_tail(&rq->queuelist, &ctx->rq_list);
+}
+static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
+ struct request *rq, bool at_head)
+{
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
+
+ __blk_mq_insert_req_list(hctx, ctx, rq, at_head);
blk_mq_hctx_mark_pending(hctx, ctx);
}
@@ -1056,8 +1064,9 @@
rq = list_first_entry(list, struct request, queuelist);
list_del_init(&rq->queuelist);
rq->mq_ctx = ctx;
- __blk_mq_insert_request(hctx, rq, false);
+ __blk_mq_insert_req_list(hctx, ctx, rq, false);
}
+ blk_mq_hctx_mark_pending(hctx, ctx);
spin_unlock(&ctx->lock);
blk_mq_run_hw_queue(hctx, from_schedule);
@@ -1139,7 +1148,7 @@
struct blk_mq_ctx *ctx,
struct request *rq, struct bio *bio)
{
- if (!hctx_allow_merges(hctx)) {
+ if (!hctx_allow_merges(hctx) || !bio_mergeable(bio)) {
blk_mq_bio_to_request(rq, bio);
spin_lock(&ctx->lock);
insert_rq:
@@ -1267,9 +1276,12 @@
blk_queue_split(q, &bio, q->bio_split);
- if (!is_flush_fua && !blk_queue_nomerges(q) &&
- blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq))
- return;
+ if (!is_flush_fua && !blk_queue_nomerges(q)) {
+ if (blk_attempt_plug_merge(q, bio, &request_count,
+ &same_queue_rq))
+ return;
+ } else
+ request_count = blk_plug_queued_count(q);
rq = blk_mq_map_request(q, bio, &data);
if (unlikely(!rq))
@@ -1376,7 +1388,7 @@
plug = current->plug;
if (plug) {
blk_mq_bio_to_request(rq, bio);
- if (list_empty(&plug->mq_list))
+ if (!request_count)
trace_block_plug(q);
else if (request_count >= BLK_MAX_REQUEST_COUNT) {
blk_flush_plug_list(plug, false);
@@ -1430,6 +1442,11 @@
while (!list_empty(&tags->page_list)) {
page = list_first_entry(&tags->page_list, struct page, lru);
list_del_init(&page->lru);
+ /*
+ * Remove kmemleak object previously allocated in
+ * blk_mq_init_rq_map().
+ */
+ kmemleak_free(page_address(page));
__free_pages(page, page->private);
}
@@ -1502,6 +1519,11 @@
list_add_tail(&page->lru, &tags->page_list);
p = page_address(page);
+ /*
+ * Allow kmemleak to scan these pages as they contain pointers
+ * to additional allocations like via ops->init_request().
+ */
+ kmemleak_alloc(p, order_to_size(this_order), 1, GFP_KERNEL);
entries_per_page = order_to_size(this_order) / rq_size;
to_do = min(entries_per_page, set->queue_depth - i);
left -= to_do * rq_size;
@@ -1673,7 +1695,7 @@
INIT_LIST_HEAD(&hctx->dispatch);
hctx->queue = q;
hctx->queue_num = hctx_idx;
- hctx->flags = set->flags;
+ hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED;
blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
blk_mq_hctx_notify, hctx);
@@ -1860,27 +1882,26 @@
}
}
-static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set)
+static void queue_set_hctx_shared(struct request_queue *q, bool shared)
{
struct blk_mq_hw_ctx *hctx;
- struct request_queue *q;
- bool shared;
int i;
- if (set->tag_list.next == set->tag_list.prev)
- shared = false;
- else
- shared = true;
+ queue_for_each_hw_ctx(q, hctx, i) {
+ if (shared)
+ hctx->flags |= BLK_MQ_F_TAG_SHARED;
+ else
+ hctx->flags &= ~BLK_MQ_F_TAG_SHARED;
+ }
+}
+
+static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, bool shared)
+{
+ struct request_queue *q;
list_for_each_entry(q, &set->tag_list, tag_set_list) {
blk_mq_freeze_queue(q);
-
- queue_for_each_hw_ctx(q, hctx, i) {
- if (shared)
- hctx->flags |= BLK_MQ_F_TAG_SHARED;
- else
- hctx->flags &= ~BLK_MQ_F_TAG_SHARED;
- }
+ queue_set_hctx_shared(q, shared);
blk_mq_unfreeze_queue(q);
}
}
@@ -1891,7 +1912,12 @@
mutex_lock(&set->tag_list_lock);
list_del_init(&q->tag_set_list);
- blk_mq_update_tag_set_depth(set);
+ if (list_is_singular(&set->tag_list)) {
+ /* just transitioned to unshared */
+ set->flags &= ~BLK_MQ_F_TAG_SHARED;
+ /* update existing queue */
+ blk_mq_update_tag_set_depth(set, false);
+ }
mutex_unlock(&set->tag_list_lock);
}
@@ -1901,8 +1927,17 @@
q->tag_set = set;
mutex_lock(&set->tag_list_lock);
+
+ /* Check to see if we're transitioning to shared (from 1 to 2 queues). */
+ if (!list_empty(&set->tag_list) && !(set->flags & BLK_MQ_F_TAG_SHARED)) {
+ set->flags |= BLK_MQ_F_TAG_SHARED;
+ /* update existing queue */
+ blk_mq_update_tag_set_depth(set, true);
+ }
+ if (set->flags & BLK_MQ_F_TAG_SHARED)
+ queue_set_hctx_shared(q, true);
list_add_tail(&q->tag_set_list, &set->tag_list);
- blk_mq_update_tag_set_depth(set);
+
mutex_unlock(&set->tag_list_lock);
}
diff --git a/block/blk-mq.h b/block/blk-mq.h
index f4fea79..b44dce1 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -29,8 +29,6 @@
void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
void blk_mq_freeze_queue(struct request_queue *q);
void blk_mq_free_queue(struct request_queue *q);
-void blk_mq_clone_flush_request(struct request *flush_rq,
- struct request *orig_rq);
int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr);
void blk_mq_wake_waiters(struct request_queue *q);
diff --git a/block/blk.h b/block/blk.h
index 98614ad..aa27d02 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -86,6 +86,7 @@
bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
unsigned int *request_count,
struct request **same_queue_rq);
+unsigned int blk_plug_queued_count(struct request_queue *q);
void blk_account_io_start(struct request *req, bool new_io);
void blk_account_io_completion(struct request *req, unsigned int bytes);
diff --git a/block/elevator.c b/block/elevator.c
index 84d6394..c3555c9 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -420,7 +420,7 @@
* noxmerges: Only simple one-hit cache try
* merges: All merge tries attempted
*/
- if (blk_queue_nomerges(q))
+ if (blk_queue_nomerges(q) || !bio_mergeable(bio))
return ELEVATOR_NO_MERGE;
/*
diff --git a/fs/direct-io.c b/fs/direct-io.c
index 1125629..3ae0e04 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -120,6 +120,7 @@
int page_errors; /* errno from get_user_pages() */
int is_async; /* is IO async ? */
bool defer_completion; /* defer AIO completion to workqueue? */
+ bool should_dirty; /* if pages should be dirtied */
int io_error; /* IO error in completion path */
unsigned long refcount; /* direct_io_worker() and bios */
struct bio *bio_list; /* singly linked via bi_private */
@@ -393,7 +394,7 @@
dio->refcount++;
spin_unlock_irqrestore(&dio->bio_lock, flags);
- if (dio->is_async && dio->rw == READ)
+ if (dio->is_async && dio->rw == READ && dio->should_dirty)
bio_set_pages_dirty(bio);
if (sdio->submit_io)
@@ -464,14 +465,15 @@
if (bio->bi_error)
dio->io_error = -EIO;
- if (dio->is_async && dio->rw == READ) {
+ if (dio->is_async && dio->rw == READ && dio->should_dirty) {
bio_check_pages_dirty(bio); /* transfers ownership */
err = bio->bi_error;
} else {
bio_for_each_segment_all(bvec, bio, i) {
struct page *page = bvec->bv_page;
- if (dio->rw == READ && !PageCompound(page))
+ if (dio->rw == READ && !PageCompound(page) &&
+ dio->should_dirty)
set_page_dirty_lock(page);
page_cache_release(page);
}
@@ -1219,6 +1221,7 @@
spin_lock_init(&dio->bio_lock);
dio->refcount = 1;
+ dio->should_dirty = (iter->type == ITER_IOVEC);
sdio.iter = iter;
sdio.final_block_in_request =
(offset + iov_iter_count(iter)) >> blkbits;
diff --git a/fs/mpage.c b/fs/mpage.c
index a7c3427..09abba7 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -485,6 +485,7 @@
struct buffer_head map_bh;
loff_t i_size = i_size_read(inode);
int ret = 0;
+ int wr = (wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC : WRITE);
if (page_has_buffers(page)) {
struct buffer_head *head = page_buffers(page);
@@ -593,7 +594,7 @@
* This page will go to BIO. Do we need to send this BIO off first?
*/
if (bio && mpd->last_block_in_bio != blocks[0] - 1)
- bio = mpage_bio_submit(WRITE, bio);
+ bio = mpage_bio_submit(wr, bio);
alloc_new:
if (bio == NULL) {
@@ -620,7 +621,7 @@
wbc_account_io(wbc, page, PAGE_SIZE);
length = first_unmapped << blkbits;
if (bio_add_page(bio, page, length, 0) < length) {
- bio = mpage_bio_submit(WRITE, bio);
+ bio = mpage_bio_submit(wr, bio);
goto alloc_new;
}
@@ -630,7 +631,7 @@
set_page_writeback(page);
unlock_page(page);
if (boundary || (first_unmapped != blocks_per_page)) {
- bio = mpage_bio_submit(WRITE, bio);
+ bio = mpage_bio_submit(wr, bio);
if (boundary_block) {
write_boundary_block(boundary_bdev,
boundary_block, 1 << blkbits);
@@ -642,7 +643,7 @@
confused:
if (bio)
- bio = mpage_bio_submit(WRITE, bio);
+ bio = mpage_bio_submit(wr, bio);
if (mpd->use_writepage) {
ret = mapping->a_ops->writepage(page, wbc);
@@ -698,8 +699,11 @@
};
ret = write_cache_pages(mapping, wbc, __mpage_writepage, &mpd);
- if (mpd.bio)
- mpage_bio_submit(WRITE, mpd.bio);
+ if (mpd.bio) {
+ int wr = (wbc->sync_mode == WB_SYNC_ALL ?
+ WRITE_SYNC : WRITE);
+ mpage_bio_submit(wr, mpd.bio);
+ }
}
blk_finish_plug(&plug);
return ret;
@@ -716,8 +720,11 @@
.use_writepage = 0,
};
int ret = __mpage_writepage(page, wbc, &mpd);
- if (mpd.bio)
- mpage_bio_submit(WRITE, mpd.bio);
+ if (mpd.bio) {
+ int wr = (wbc->sync_mode == WB_SYNC_ALL ?
+ WRITE_SYNC : WRITE);
+ mpage_bio_submit(wr, mpd.bio);
+ }
return ret;
}
EXPORT_SYMBOL(mpage_writepage);
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 90e72a0..e3a2618 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -437,7 +437,7 @@
struct block_device *bdev,
struct blk_user_trace_setup *buts)
{
- struct blk_trace *old_bt, *bt = NULL;
+ struct blk_trace *bt = NULL;
struct dentry *dir = NULL;
int ret;
@@ -519,11 +519,8 @@
bt->trace_state = Blktrace_setup;
ret = -EBUSY;
- old_bt = xchg(&q->blk_trace, bt);
- if (old_bt) {
- (void) xchg(&q->blk_trace, old_bt);
+ if (cmpxchg(&q->blk_trace, NULL, bt))
goto err;
- }
if (atomic_inc_return(&blk_probes_ref) == 1)
blk_register_tracepoints();
@@ -1481,7 +1478,7 @@
static int blk_trace_setup_queue(struct request_queue *q,
struct block_device *bdev)
{
- struct blk_trace *old_bt, *bt = NULL;
+ struct blk_trace *bt = NULL;
int ret = -ENOMEM;
bt = kzalloc(sizeof(*bt), GFP_KERNEL);
@@ -1497,12 +1494,9 @@
blk_trace_setup_lba(bt, bdev);
- old_bt = xchg(&q->blk_trace, bt);
- if (old_bt != NULL) {
- (void)xchg(&q->blk_trace, old_bt);
- ret = -EBUSY;
+ ret = -EBUSY;
+ if (cmpxchg(&q->blk_trace, NULL, bt))
goto free_bt;
- }
if (atomic_inc_return(&blk_probes_ref) == 1)
blk_register_tracepoints();