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authorLinus Torvalds <torvalds@linux-foundation.org>2018-12-29 00:19:59 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-12-29 00:19:59 +0300
commit0e9da3fbf7d81f0f913b491c8de1ba7883d4f217 (patch)
tree2b3d25e3be60bf4ee40b4690c7bb9d6fa499ae69 /block/bio.c
parentb12a9124eeb71d766a3e3eb594ebbb3fefc66902 (diff)
parent00203ba40d40d7f33857416adfb18adaf0e40123 (diff)
downloadlinux-0e9da3fbf7d81f0f913b491c8de1ba7883d4f217.tar.xz
Merge tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe: "This is the main pull request for block/storage for 4.21. Larger than usual, it was a busy round with lots of goodies queued up. Most notable is the removal of the old IO stack, which has been a long time coming. No new features for a while, everything coming in this week has all been fixes for things that were previously merged. This contains: - Use atomic counters instead of semaphores for mtip32xx (Arnd) - Cleanup of the mtip32xx request setup (Christoph) - Fix for circular locking dependency in loop (Jan, Tetsuo) - bcache (Coly, Guoju, Shenghui) * Optimizations for writeback caching * Various fixes and improvements - nvme (Chaitanya, Christoph, Sagi, Jay, me, Keith) * host and target support for NVMe over TCP * Error log page support * Support for separate read/write/poll queues * Much improved polling * discard OOM fallback * Tracepoint improvements - lightnvm (Hans, Hua, Igor, Matias, Javier) * Igor added packed metadata to pblk. Now drives without metadata per LBA can be used as well. * Fix from Geert on uninitialized value on chunk metadata reads. * Fixes from Hans and Javier to pblk recovery and write path. * Fix from Hua Su to fix a race condition in the pblk recovery code. * Scan optimization added to pblk recovery from Zhoujie. * Small geometry cleanup from me. - Conversion of the last few drivers that used the legacy path to blk-mq (me) - Removal of legacy IO path in SCSI (me, Christoph) - Removal of legacy IO stack and schedulers (me) - Support for much better polling, now without interrupts at all. blk-mq adds support for multiple queue maps, which enables us to have a map per type. This in turn enables nvme to have separate completion queues for polling, which can then be interrupt-less. Also means we're ready for async polled IO, which is hopefully coming in the next release. - Killing of (now) unused block exports (Christoph) - Unification of the blk-rq-qos and blk-wbt wait handling (Josef) - Support for zoned testing with null_blk (Masato) - sx8 conversion to per-host tag sets (Christoph) - IO priority improvements (Damien) - mq-deadline zoned fix (Damien) - Ref count blkcg series (Dennis) - Lots of blk-mq improvements and speedups (me) - sbitmap scalability improvements (me) - Make core inflight IO accounting per-cpu (Mikulas) - Export timeout setting in sysfs (Weiping) - Cleanup the direct issue path (Jianchao) - Export blk-wbt internals in block debugfs for easier debugging (Ming) - Lots of other fixes and improvements" * tag 'for-4.21/block-20181221' of git://git.kernel.dk/linux-block: (364 commits) kyber: use sbitmap add_wait_queue/list_del wait helpers sbitmap: add helpers for add/del wait queue handling block: save irq state in blkg_lookup_create() dm: don't reuse bio for flushes nvme-pci: trace SQ status on completions nvme-rdma: implement polling queue map nvme-fabrics: allow user to pass in nr_poll_queues nvme-fabrics: allow nvmf_connect_io_queue to poll nvme-core: optionally poll sync commands block: make request_to_qc_t public nvme-tcp: fix spelling mistake "attepmpt" -> "attempt" nvme-tcp: fix endianess annotations nvmet-tcp: fix endianess annotations nvme-pci: refactor nvme_poll_irqdisable to make sparse happy nvme-pci: only set nr_maps to 2 if poll queues are supported nvmet: use a macro for default error location nvmet: fix comparison of a u16 with -1 blk-mq: enable IO poll if .nr_queues of type poll > 0 blk-mq: change blk_mq_queue_busy() to blk_mq_queue_inflight() blk-mq: skip zero-queue maps in blk_mq_map_swqueue ...
Diffstat (limited to 'block/bio.c')
-rw-r--r--block/bio.c202
1 files changed, 125 insertions, 77 deletions
diff --git a/block/bio.c b/block/bio.c
index 4d86e90654b2..8281bfcbc265 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -244,7 +244,7 @@ fallback:
void bio_uninit(struct bio *bio)
{
- bio_disassociate_task(bio);
+ bio_disassociate_blkg(bio);
}
EXPORT_SYMBOL(bio_uninit);
@@ -571,14 +571,13 @@ void bio_put(struct bio *bio)
}
EXPORT_SYMBOL(bio_put);
-inline int bio_phys_segments(struct request_queue *q, struct bio *bio)
+int bio_phys_segments(struct request_queue *q, struct bio *bio)
{
if (unlikely(!bio_flagged(bio, BIO_SEG_VALID)))
blk_recount_segments(q, bio);
return bio->bi_phys_segments;
}
-EXPORT_SYMBOL(bio_phys_segments);
/**
* __bio_clone_fast - clone a bio that shares the original bio's biovec
@@ -610,7 +609,8 @@ void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
bio->bi_iter = bio_src->bi_iter;
bio->bi_io_vec = bio_src->bi_io_vec;
- bio_clone_blkcg_association(bio, bio_src);
+ bio_clone_blkg_association(bio, bio_src);
+ blkcg_bio_issue_init(bio);
}
EXPORT_SYMBOL(__bio_clone_fast);
@@ -901,7 +901,6 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
return 0;
}
-EXPORT_SYMBOL_GPL(bio_iov_iter_get_pages);
static void submit_bio_wait_endio(struct bio *bio)
{
@@ -1592,7 +1591,6 @@ void bio_set_pages_dirty(struct bio *bio)
set_page_dirty_lock(bvec->bv_page);
}
}
-EXPORT_SYMBOL_GPL(bio_set_pages_dirty);
static void bio_release_pages(struct bio *bio)
{
@@ -1662,17 +1660,33 @@ defer:
spin_unlock_irqrestore(&bio_dirty_lock, flags);
schedule_work(&bio_dirty_work);
}
-EXPORT_SYMBOL_GPL(bio_check_pages_dirty);
+
+void update_io_ticks(struct hd_struct *part, unsigned long now)
+{
+ unsigned long stamp;
+again:
+ stamp = READ_ONCE(part->stamp);
+ if (unlikely(stamp != now)) {
+ if (likely(cmpxchg(&part->stamp, stamp, now) == stamp)) {
+ __part_stat_add(part, io_ticks, 1);
+ }
+ }
+ if (part->partno) {
+ part = &part_to_disk(part)->part0;
+ goto again;
+ }
+}
void generic_start_io_acct(struct request_queue *q, int op,
unsigned long sectors, struct hd_struct *part)
{
const int sgrp = op_stat_group(op);
- int cpu = part_stat_lock();
- part_round_stats(q, cpu, part);
- part_stat_inc(cpu, part, ios[sgrp]);
- part_stat_add(cpu, part, sectors[sgrp], sectors);
+ part_stat_lock();
+
+ update_io_ticks(part, jiffies);
+ part_stat_inc(part, ios[sgrp]);
+ part_stat_add(part, sectors[sgrp], sectors);
part_inc_in_flight(q, part, op_is_write(op));
part_stat_unlock();
@@ -1682,12 +1696,15 @@ EXPORT_SYMBOL(generic_start_io_acct);
void generic_end_io_acct(struct request_queue *q, int req_op,
struct hd_struct *part, unsigned long start_time)
{
- unsigned long duration = jiffies - start_time;
+ unsigned long now = jiffies;
+ unsigned long duration = now - start_time;
const int sgrp = op_stat_group(req_op);
- int cpu = part_stat_lock();
- part_stat_add(cpu, part, nsecs[sgrp], jiffies_to_nsecs(duration));
- part_round_stats(q, cpu, part);
+ part_stat_lock();
+
+ update_io_ticks(part, now);
+ part_stat_add(part, nsecs[sgrp], jiffies_to_nsecs(duration));
+ part_stat_add(part, time_in_queue, duration);
part_dec_in_flight(q, part, op_is_write(req_op));
part_stat_unlock();
@@ -1957,102 +1974,133 @@ EXPORT_SYMBOL(bioset_init_from_src);
#ifdef CONFIG_BLK_CGROUP
-#ifdef CONFIG_MEMCG
/**
- * bio_associate_blkcg_from_page - associate a bio with the page's blkcg
+ * bio_disassociate_blkg - puts back the blkg reference if associated
* @bio: target bio
- * @page: the page to lookup the blkcg from
*
- * Associate @bio with the blkcg from @page's owning memcg. This works like
- * every other associate function wrt references.
+ * Helper to disassociate the blkg from @bio if a blkg is associated.
*/
-int bio_associate_blkcg_from_page(struct bio *bio, struct page *page)
+void bio_disassociate_blkg(struct bio *bio)
{
- struct cgroup_subsys_state *blkcg_css;
-
- if (unlikely(bio->bi_css))
- return -EBUSY;
- if (!page->mem_cgroup)
- return 0;
- blkcg_css = cgroup_get_e_css(page->mem_cgroup->css.cgroup,
- &io_cgrp_subsys);
- bio->bi_css = blkcg_css;
- return 0;
+ if (bio->bi_blkg) {
+ blkg_put(bio->bi_blkg);
+ bio->bi_blkg = NULL;
+ }
}
-#endif /* CONFIG_MEMCG */
+EXPORT_SYMBOL_GPL(bio_disassociate_blkg);
/**
- * bio_associate_blkcg - associate a bio with the specified blkcg
+ * __bio_associate_blkg - associate a bio with the a blkg
* @bio: target bio
- * @blkcg_css: css of the blkcg to associate
+ * @blkg: the blkg to associate
*
- * Associate @bio with the blkcg specified by @blkcg_css. Block layer will
- * treat @bio as if it were issued by a task which belongs to the blkcg.
+ * This tries to associate @bio with the specified @blkg. Association failure
+ * is handled by walking up the blkg tree. Therefore, the blkg associated can
+ * be anything between @blkg and the root_blkg. This situation only happens
+ * when a cgroup is dying and then the remaining bios will spill to the closest
+ * alive blkg.
*
- * This function takes an extra reference of @blkcg_css which will be put
- * when @bio is released. The caller must own @bio and is responsible for
- * synchronizing calls to this function.
+ * A reference will be taken on the @blkg and will be released when @bio is
+ * freed.
*/
-int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css)
+static void __bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg)
{
- if (unlikely(bio->bi_css))
- return -EBUSY;
- css_get(blkcg_css);
- bio->bi_css = blkcg_css;
- return 0;
+ bio_disassociate_blkg(bio);
+
+ bio->bi_blkg = blkg_tryget_closest(blkg);
}
-EXPORT_SYMBOL_GPL(bio_associate_blkcg);
/**
- * bio_associate_blkg - associate a bio with the specified blkg
+ * bio_associate_blkg_from_css - associate a bio with a specified css
* @bio: target bio
- * @blkg: the blkg to associate
+ * @css: target css
*
- * Associate @bio with the blkg specified by @blkg. This is the queue specific
- * blkcg information associated with the @bio, a reference will be taken on the
- * @blkg and will be freed when the bio is freed.
+ * Associate @bio with the blkg found by combining the css's blkg and the
+ * request_queue of the @bio. This falls back to the queue's root_blkg if
+ * the association fails with the css.
*/
-int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg)
+void bio_associate_blkg_from_css(struct bio *bio,
+ struct cgroup_subsys_state *css)
{
- if (unlikely(bio->bi_blkg))
- return -EBUSY;
- if (!blkg_try_get(blkg))
- return -ENODEV;
- bio->bi_blkg = blkg;
- return 0;
+ struct request_queue *q = bio->bi_disk->queue;
+ struct blkcg_gq *blkg;
+
+ rcu_read_lock();
+
+ if (!css || !css->parent)
+ blkg = q->root_blkg;
+ else
+ blkg = blkg_lookup_create(css_to_blkcg(css), q);
+
+ __bio_associate_blkg(bio, blkg);
+
+ rcu_read_unlock();
}
+EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css);
+#ifdef CONFIG_MEMCG
/**
- * bio_disassociate_task - undo bio_associate_current()
+ * bio_associate_blkg_from_page - associate a bio with the page's blkg
* @bio: target bio
+ * @page: the page to lookup the blkcg from
+ *
+ * Associate @bio with the blkg from @page's owning memcg and the respective
+ * request_queue. If cgroup_e_css returns %NULL, fall back to the queue's
+ * root_blkg.
*/
-void bio_disassociate_task(struct bio *bio)
+void bio_associate_blkg_from_page(struct bio *bio, struct page *page)
{
- if (bio->bi_ioc) {
- put_io_context(bio->bi_ioc);
- bio->bi_ioc = NULL;
- }
- if (bio->bi_css) {
- css_put(bio->bi_css);
- bio->bi_css = NULL;
- }
- if (bio->bi_blkg) {
- blkg_put(bio->bi_blkg);
- bio->bi_blkg = NULL;
- }
+ struct cgroup_subsys_state *css;
+
+ if (!page->mem_cgroup)
+ return;
+
+ rcu_read_lock();
+
+ css = cgroup_e_css(page->mem_cgroup->css.cgroup, &io_cgrp_subsys);
+ bio_associate_blkg_from_css(bio, css);
+
+ rcu_read_unlock();
+}
+#endif /* CONFIG_MEMCG */
+
+/**
+ * bio_associate_blkg - associate a bio with a blkg
+ * @bio: target bio
+ *
+ * Associate @bio with the blkg found from the bio's css and request_queue.
+ * If one is not found, bio_lookup_blkg() creates the blkg. If a blkg is
+ * already associated, the css is reused and association redone as the
+ * request_queue may have changed.
+ */
+void bio_associate_blkg(struct bio *bio)
+{
+ struct cgroup_subsys_state *css;
+
+ rcu_read_lock();
+
+ if (bio->bi_blkg)
+ css = &bio_blkcg(bio)->css;
+ else
+ css = blkcg_css();
+
+ bio_associate_blkg_from_css(bio, css);
+
+ rcu_read_unlock();
}
+EXPORT_SYMBOL_GPL(bio_associate_blkg);
/**
- * bio_clone_blkcg_association - clone blkcg association from src to dst bio
+ * bio_clone_blkg_association - clone blkg association from src to dst bio
* @dst: destination bio
* @src: source bio
*/
-void bio_clone_blkcg_association(struct bio *dst, struct bio *src)
+void bio_clone_blkg_association(struct bio *dst, struct bio *src)
{
- if (src->bi_css)
- WARN_ON(bio_associate_blkcg(dst, src->bi_css));
+ if (src->bi_blkg)
+ __bio_associate_blkg(dst, src->bi_blkg);
}
-EXPORT_SYMBOL_GPL(bio_clone_blkcg_association);
+EXPORT_SYMBOL_GPL(bio_clone_blkg_association);
#endif /* CONFIG_BLK_CGROUP */
static void __init biovec_init_slabs(void)