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authorLinus Torvalds <torvalds@linux-foundation.org>2019-07-09 10:45:06 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-07-09 10:45:06 -0700
commit3b99107f0e0298e6fe0787f75b8f3d8306dfb230 (patch)
tree30536dbc9ca176470a2ae2938f952381e33f5deb /block
parent0415052db4f92b7e272fc15802ad8b8be672deea (diff)
parentc9b3007feca018d3f7061f5d5a14cb00766ffe9b (diff)
downloadlinux-3b99107f0e0298e6fe0787f75b8f3d8306dfb230.tar.bz2
Merge tag 'for-5.3/block-20190708' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe: "This is the main block updates for 5.3. Nothing earth shattering or major in here, just fixes, additions, and improvements all over the map. This contains: - Series of documentation fixes (Bart) - Optimization of the blk-mq ctx get/put (Bart) - null_blk removal race condition fix (Bob) - req/bio_op() cleanups (Chaitanya) - Series cleaning up the segment accounting, and request/bio mapping (Christoph) - Series cleaning up the page getting/putting for bios (Christoph) - block cgroup cleanups and moving it to where it is used (Christoph) - block cgroup fixes (Tejun) - Series of fixes and improvements to bcache, most notably a write deadlock fix (Coly) - blk-iolatency STS_AGAIN and accounting fixes (Dennis) - Series of improvements and fixes to BFQ (Douglas, Paolo) - debugfs_create() return value check removal for drbd (Greg) - Use struct_size(), where appropriate (Gustavo) - Two lighnvm fixes (Heiner, Geert) - MD fixes, including a read balance and corruption fix (Guoqing, Marcos, Xiao, Yufen) - block opal shadow mbr additions (Jonas, Revanth) - sbitmap compare-and-exhange improvemnts (Pavel) - Fix for potential bio->bi_size overflow (Ming) - NVMe pull requests: - improved PCIe suspent support (Keith Busch) - error injection support for the admin queue (Akinobu Mita) - Fibre Channel discovery improvements (James Smart) - tracing improvements including nvmetc tracing support (Minwoo Im) - misc fixes and cleanups (Anton Eidelman, Minwoo Im, Chaitanya Kulkarni)" - Various little fixes and improvements to drivers and core" * tag 'for-5.3/block-20190708' of git://git.kernel.dk/linux-block: (153 commits) blk-iolatency: fix STS_AGAIN handling block: nr_phys_segments needs to be zero for REQ_OP_WRITE_ZEROES blk-mq: simplify blk_mq_make_request() blk-mq: remove blk_mq_put_ctx() sbitmap: Replace cmpxchg with xchg block: fix .bi_size overflow block: sed-opal: check size of shadow mbr block: sed-opal: ioctl for writing to shadow mbr block: sed-opal: add ioctl for done-mark of shadow mbr block: never take page references for ITER_BVEC direct-io: use bio_release_pages in dio_bio_complete block_dev: use bio_release_pages in bio_unmap_user block_dev: use bio_release_pages in blkdev_bio_end_io iomap: use bio_release_pages in iomap_dio_bio_end_io block: use bio_release_pages in bio_map_user_iov block: use bio_release_pages in bio_unmap_user block: optionally mark pages dirty in bio_release_pages block: move the BIO_NO_PAGE_REF check into bio_release_pages block: skd_main.c: Remove call to memset after dma_alloc_coherent block: mtip32xx: Remove call to memset after dma_alloc_coherent ...
Diffstat (limited to 'block')
-rw-r--r--block/Kconfig.iosched7
-rw-r--r--block/bfq-cgroup.c212
-rw-r--r--block/bfq-iosched.c967
-rw-r--r--block/bfq-iosched.h48
-rw-r--r--block/bio.c96
-rw-r--r--block/blk-cgroup.c139
-rw-r--r--block/blk-core.c111
-rw-r--r--block/blk-iolatency.c51
-rw-r--r--block/blk-map.c10
-rw-r--r--block/blk-merge.c112
-rw-r--r--block/blk-mq-debugfs.c42
-rw-r--r--block/blk-mq-sched.c31
-rw-r--r--block/blk-mq-sched.h10
-rw-r--r--block/blk-mq-tag.c8
-rw-r--r--block/blk-mq.c44
-rw-r--r--block/blk-mq.h7
-rw-r--r--block/blk.h36
-rw-r--r--block/genhd.c5
-rw-r--r--block/kyber-iosched.c6
-rw-r--r--block/mq-deadline.c5
-rw-r--r--block/opal_proto.h16
-rw-r--r--block/sed-opal.c197
22 files changed, 1342 insertions, 818 deletions
diff --git a/block/Kconfig.iosched b/block/Kconfig.iosched
index 4626b88b2d5a..7a6b2f29a582 100644
--- a/block/Kconfig.iosched
+++ b/block/Kconfig.iosched
@@ -36,6 +36,13 @@ config BFQ_GROUP_IOSCHED
Enable hierarchical scheduling in BFQ, using the blkio
(cgroups-v1) or io (cgroups-v2) controller.
+config BFQ_CGROUP_DEBUG
+ bool "BFQ IO controller debugging"
+ depends on BFQ_GROUP_IOSCHED
+ ---help---
+ Enable some debugging help. Currently it exports additional stat
+ files in a cgroup which can be useful for debugging.
+
endmenu
endif
diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index b3796a40a61a..0f6cd688924f 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -15,7 +15,83 @@
#include "bfq-iosched.h"
-#if defined(CONFIG_BFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP)
+#ifdef CONFIG_BFQ_CGROUP_DEBUG
+static int bfq_stat_init(struct bfq_stat *stat, gfp_t gfp)
+{
+ int ret;
+
+ ret = percpu_counter_init(&stat->cpu_cnt, 0, gfp);
+ if (ret)
+ return ret;
+
+ atomic64_set(&stat->aux_cnt, 0);
+ return 0;
+}
+
+static void bfq_stat_exit(struct bfq_stat *stat)
+{
+ percpu_counter_destroy(&stat->cpu_cnt);
+}
+
+/**
+ * bfq_stat_add - add a value to a bfq_stat
+ * @stat: target bfq_stat
+ * @val: value to add
+ *
+ * Add @val to @stat. The caller must ensure that IRQ on the same CPU
+ * don't re-enter this function for the same counter.
+ */
+static inline void bfq_stat_add(struct bfq_stat *stat, uint64_t val)
+{
+ percpu_counter_add_batch(&stat->cpu_cnt, val, BLKG_STAT_CPU_BATCH);
+}
+
+/**
+ * bfq_stat_read - read the current value of a bfq_stat
+ * @stat: bfq_stat to read
+ */
+static inline uint64_t bfq_stat_read(struct bfq_stat *stat)
+{
+ return percpu_counter_sum_positive(&stat->cpu_cnt);
+}
+
+/**
+ * bfq_stat_reset - reset a bfq_stat
+ * @stat: bfq_stat to reset
+ */
+static inline void bfq_stat_reset(struct bfq_stat *stat)
+{
+ percpu_counter_set(&stat->cpu_cnt, 0);
+ atomic64_set(&stat->aux_cnt, 0);
+}
+
+/**
+ * bfq_stat_add_aux - add a bfq_stat into another's aux count
+ * @to: the destination bfq_stat
+ * @from: the source
+ *
+ * Add @from's count including the aux one to @to's aux count.
+ */
+static inline void bfq_stat_add_aux(struct bfq_stat *to,
+ struct bfq_stat *from)
+{
+ atomic64_add(bfq_stat_read(from) + atomic64_read(&from->aux_cnt),
+ &to->aux_cnt);
+}
+
+/**
+ * blkg_prfill_stat - prfill callback for bfq_stat
+ * @sf: seq_file to print to
+ * @pd: policy private data of interest
+ * @off: offset to the bfq_stat in @pd
+ *
+ * prfill callback for printing a bfq_stat.
+ */
+static u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd,
+ int off)
+{
+ return __blkg_prfill_u64(sf, pd, bfq_stat_read((void *)pd + off));
+}
/* bfqg stats flags */
enum bfqg_stats_flags {
@@ -53,7 +129,7 @@ static void bfqg_stats_update_group_wait_time(struct bfqg_stats *stats)
now = ktime_get_ns();
if (now > stats->start_group_wait_time)
- blkg_stat_add(&stats->group_wait_time,
+ bfq_stat_add(&stats->group_wait_time,
now - stats->start_group_wait_time);
bfqg_stats_clear_waiting(stats);
}
@@ -82,14 +158,14 @@ static void bfqg_stats_end_empty_time(struct bfqg_stats *stats)
now = ktime_get_ns();
if (now > stats->start_empty_time)
- blkg_stat_add(&stats->empty_time,
+ bfq_stat_add(&stats->empty_time,
now - stats->start_empty_time);
bfqg_stats_clear_empty(stats);
}
void bfqg_stats_update_dequeue(struct bfq_group *bfqg)
{
- blkg_stat_add(&bfqg->stats.dequeue, 1);
+ bfq_stat_add(&bfqg->stats.dequeue, 1);
}
void bfqg_stats_set_start_empty_time(struct bfq_group *bfqg)
@@ -119,7 +195,7 @@ void bfqg_stats_update_idle_time(struct bfq_group *bfqg)
u64 now = ktime_get_ns();
if (now > stats->start_idle_time)
- blkg_stat_add(&stats->idle_time,
+ bfq_stat_add(&stats->idle_time,
now - stats->start_idle_time);
bfqg_stats_clear_idling(stats);
}
@@ -137,9 +213,9 @@ void bfqg_stats_update_avg_queue_size(struct bfq_group *bfqg)
{
struct bfqg_stats *stats = &bfqg->stats;
- blkg_stat_add(&stats->avg_queue_size_sum,
+ bfq_stat_add(&stats->avg_queue_size_sum,
blkg_rwstat_total(&stats->queued));
- blkg_stat_add(&stats->avg_queue_size_samples, 1);
+ bfq_stat_add(&stats->avg_queue_size_samples, 1);
bfqg_stats_update_group_wait_time(stats);
}
@@ -176,7 +252,7 @@ void bfqg_stats_update_completion(struct bfq_group *bfqg, u64 start_time_ns,
io_start_time_ns - start_time_ns);
}
-#else /* CONFIG_BFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */
+#else /* CONFIG_BFQ_CGROUP_DEBUG */
void bfqg_stats_update_io_add(struct bfq_group *bfqg, struct bfq_queue *bfqq,
unsigned int op) { }
@@ -190,7 +266,7 @@ void bfqg_stats_update_idle_time(struct bfq_group *bfqg) { }
void bfqg_stats_set_start_idle_time(struct bfq_group *bfqg) { }
void bfqg_stats_update_avg_queue_size(struct bfq_group *bfqg) { }
-#endif /* CONFIG_BFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */
+#endif /* CONFIG_BFQ_CGROUP_DEBUG */
#ifdef CONFIG_BFQ_GROUP_IOSCHED
@@ -274,18 +350,18 @@ void bfqg_and_blkg_put(struct bfq_group *bfqg)
/* @stats = 0 */
static void bfqg_stats_reset(struct bfqg_stats *stats)
{
-#ifdef CONFIG_DEBUG_BLK_CGROUP
+#ifdef CONFIG_BFQ_CGROUP_DEBUG
/* queued stats shouldn't be cleared */
blkg_rwstat_reset(&stats->merged);
blkg_rwstat_reset(&stats->service_time);
blkg_rwstat_reset(&stats->wait_time);
- blkg_stat_reset(&stats->time);
- blkg_stat_reset(&stats->avg_queue_size_sum);
- blkg_stat_reset(&stats->avg_queue_size_samples);
- blkg_stat_reset(&stats->dequeue);
- blkg_stat_reset(&stats->group_wait_time);
- blkg_stat_reset(&stats->idle_time);
- blkg_stat_reset(&stats->empty_time);
+ bfq_stat_reset(&stats->time);
+ bfq_stat_reset(&stats->avg_queue_size_sum);
+ bfq_stat_reset(&stats->avg_queue_size_samples);
+ bfq_stat_reset(&stats->dequeue);
+ bfq_stat_reset(&stats->group_wait_time);
+ bfq_stat_reset(&stats->idle_time);
+ bfq_stat_reset(&stats->empty_time);
#endif
}
@@ -295,19 +371,19 @@ static void bfqg_stats_add_aux(struct bfqg_stats *to, struct bfqg_stats *from)
if (!to || !from)
return;
-#ifdef CONFIG_DEBUG_BLK_CGROUP
+#ifdef CONFIG_BFQ_CGROUP_DEBUG
/* queued stats shouldn't be cleared */
blkg_rwstat_add_aux(&to->merged, &from->merged);
blkg_rwstat_add_aux(&to->service_time, &from->service_time);
blkg_rwstat_add_aux(&to->wait_time, &from->wait_time);
- blkg_stat_add_aux(&from->time, &from->time);
- blkg_stat_add_aux(&to->avg_queue_size_sum, &from->avg_queue_size_sum);
- blkg_stat_add_aux(&to->avg_queue_size_samples,
+ bfq_stat_add_aux(&from->time, &from->time);
+ bfq_stat_add_aux(&to->avg_queue_size_sum, &from->avg_queue_size_sum);
+ bfq_stat_add_aux(&to->avg_queue_size_samples,
&from->avg_queue_size_samples);
- blkg_stat_add_aux(&to->dequeue, &from->dequeue);
- blkg_stat_add_aux(&to->group_wait_time, &from->group_wait_time);
- blkg_stat_add_aux(&to->idle_time, &from->idle_time);
- blkg_stat_add_aux(&to->empty_time, &from->empty_time);
+ bfq_stat_add_aux(&to->dequeue, &from->dequeue);
+ bfq_stat_add_aux(&to->group_wait_time, &from->group_wait_time);
+ bfq_stat_add_aux(&to->idle_time, &from->idle_time);
+ bfq_stat_add_aux(&to->empty_time, &from->empty_time);
#endif
}
@@ -355,35 +431,35 @@ void bfq_init_entity(struct bfq_entity *entity, struct bfq_group *bfqg)
static void bfqg_stats_exit(struct bfqg_stats *stats)
{
-#ifdef CONFIG_DEBUG_BLK_CGROUP
+#ifdef CONFIG_BFQ_CGROUP_DEBUG
blkg_rwstat_exit(&stats->merged);
blkg_rwstat_exit(&stats->service_time);
blkg_rwstat_exit(&stats->wait_time);
blkg_rwstat_exit(&stats->queued);
- blkg_stat_exit(&stats->time);
- blkg_stat_exit(&stats->avg_queue_size_sum);
- blkg_stat_exit(&stats->avg_queue_size_samples);
- blkg_stat_exit(&stats->dequeue);
- blkg_stat_exit(&stats->group_wait_time);
- blkg_stat_exit(&stats->idle_time);
- blkg_stat_exit(&stats->empty_time);
+ bfq_stat_exit(&stats->time);
+ bfq_stat_exit(&stats->avg_queue_size_sum);
+ bfq_stat_exit(&stats->avg_queue_size_samples);
+ bfq_stat_exit(&stats->dequeue);
+ bfq_stat_exit(&stats->group_wait_time);
+ bfq_stat_exit(&stats->idle_time);
+ bfq_stat_exit(&stats->empty_time);
#endif
}
static int bfqg_stats_init(struct bfqg_stats *stats, gfp_t gfp)
{
-#ifdef CONFIG_DEBUG_BLK_CGROUP
+#ifdef CONFIG_BFQ_CGROUP_DEBUG
if (blkg_rwstat_init(&stats->merged, gfp) ||
blkg_rwstat_init(&stats->service_time, gfp) ||
blkg_rwstat_init(&stats->wait_time, gfp) ||
blkg_rwstat_init(&stats->queued, gfp) ||
- blkg_stat_init(&stats->time, gfp) ||
- blkg_stat_init(&stats->avg_queue_size_sum, gfp) ||
- blkg_stat_init(&stats->avg_queue_size_samples, gfp) ||
- blkg_stat_init(&stats->dequeue, gfp) ||
- blkg_stat_init(&stats->group_wait_time, gfp) ||
- blkg_stat_init(&stats->idle_time, gfp) ||
- blkg_stat_init(&stats->empty_time, gfp)) {
+ bfq_stat_init(&stats->time, gfp) ||
+ bfq_stat_init(&stats->avg_queue_size_sum, gfp) ||
+ bfq_stat_init(&stats->avg_queue_size_samples, gfp) ||
+ bfq_stat_init(&stats->dequeue, gfp) ||
+ bfq_stat_init(&stats->group_wait_time, gfp) ||
+ bfq_stat_init(&stats->idle_time, gfp) ||
+ bfq_stat_init(&stats->empty_time, gfp)) {
bfqg_stats_exit(stats);
return -ENOMEM;
}
@@ -909,7 +985,7 @@ static ssize_t bfq_io_set_weight(struct kernfs_open_file *of,
return ret ?: nbytes;
}
-#ifdef CONFIG_DEBUG_BLK_CGROUP
+#ifdef CONFIG_BFQ_CGROUP_DEBUG
static int bfqg_print_stat(struct seq_file *sf, void *v)
{
blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_stat,
@@ -927,17 +1003,34 @@ static int bfqg_print_rwstat(struct seq_file *sf, void *v)
static u64 bfqg_prfill_stat_recursive(struct seq_file *sf,
struct blkg_policy_data *pd, int off)
{
- u64 sum = blkg_stat_recursive_sum(pd_to_blkg(pd),
- &blkcg_policy_bfq, off);
+ struct blkcg_gq *blkg = pd_to_blkg(pd);
+ struct blkcg_gq *pos_blkg;
+ struct cgroup_subsys_state *pos_css;
+ u64 sum = 0;
+
+ lockdep_assert_held(&blkg->q->queue_lock);
+
+ rcu_read_lock();
+ blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
+ struct bfq_stat *stat;
+
+ if (!pos_blkg->online)
+ continue;
+
+ stat = (void *)blkg_to_pd(pos_blkg, &blkcg_policy_bfq) + off;
+ sum += bfq_stat_read(stat) + atomic64_read(&stat->aux_cnt);
+ }
+ rcu_read_unlock();
+
return __blkg_prfill_u64(sf, pd, sum);
}
static u64 bfqg_prfill_rwstat_recursive(struct seq_file *sf,
struct blkg_policy_data *pd, int off)
{
- struct blkg_rwstat sum = blkg_rwstat_recursive_sum(pd_to_blkg(pd),
- &blkcg_policy_bfq,
- off);
+ struct blkg_rwstat_sample sum;
+
+ blkg_rwstat_recursive_sum(pd_to_blkg(pd), &blkcg_policy_bfq, off, &sum);
return __blkg_prfill_rwstat(sf, pd, &sum);
}
@@ -975,12 +1068,13 @@ static int bfqg_print_stat_sectors(struct seq_file *sf, void *v)
static u64 bfqg_prfill_sectors_recursive(struct seq_file *sf,
struct blkg_policy_data *pd, int off)
{
- struct blkg_rwstat tmp = blkg_rwstat_recursive_sum(pd->blkg, NULL,
- offsetof(struct blkcg_gq, stat_bytes));
- u64 sum = atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_READ]) +
- atomic64_read(&tmp.aux_cnt[BLKG_RWSTAT_WRITE]);
+ struct blkg_rwstat_sample tmp;
- return __blkg_prfill_u64(sf, pd, sum >> 9);
+ blkg_rwstat_recursive_sum(pd->blkg, NULL,
+ offsetof(struct blkcg_gq, stat_bytes), &tmp);
+
+ return __blkg_prfill_u64(sf, pd,
+ (tmp.cnt[BLKG_RWSTAT_READ] + tmp.cnt[BLKG_RWSTAT_WRITE]) >> 9);
}
static int bfqg_print_stat_sectors_recursive(struct seq_file *sf, void *v)
@@ -995,11 +1089,11 @@ static u64 bfqg_prfill_avg_queue_size(struct seq_file *sf,
struct blkg_policy_data *pd, int off)
{
struct bfq_group *bfqg = pd_to_bfqg(pd);
- u64 samples = blkg_stat_read(&bfqg->stats.avg_queue_size_samples);
+ u64 samples = bfq_stat_read(&bfqg->stats.avg_queue_size_samples);
u64 v = 0;
if (samples) {
- v = blkg_stat_read(&bfqg->stats.avg_queue_size_sum);
+ v = bfq_stat_read(&bfqg->stats.avg_queue_size_sum);
v = div64_u64(v, samples);
}
__blkg_prfill_u64(sf, pd, v);
@@ -1014,7 +1108,7 @@ static int bfqg_print_avg_queue_size(struct seq_file *sf, void *v)
0, false);
return 0;
}
-#endif /* CONFIG_DEBUG_BLK_CGROUP */
+#endif /* CONFIG_BFQ_CGROUP_DEBUG */
struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node)
{
@@ -1062,7 +1156,7 @@ struct cftype bfq_blkcg_legacy_files[] = {
.private = (unsigned long)&blkcg_policy_bfq,
.seq_show = blkg_print_stat_ios,
},
-#ifdef CONFIG_DEBUG_BLK_CGROUP
+#ifdef CONFIG_BFQ_CGROUP_DEBUG
{
.name = "bfq.time",
.private = offsetof(struct bfq_group, stats.time),
@@ -1092,7 +1186,7 @@ struct cftype bfq_blkcg_legacy_files[] = {
.private = offsetof(struct bfq_group, stats.queued),
.seq_show = bfqg_print_rwstat,
},
-#endif /* CONFIG_DEBUG_BLK_CGROUP */
+#endif /* CONFIG_BFQ_CGROUP_DEBUG */
/* the same statistics which cover the bfqg and its descendants */
{
@@ -1105,7 +1199,7 @@ struct cftype bfq_blkcg_legacy_files[] = {
.private = (unsigned long)&blkcg_policy_bfq,
.seq_show = blkg_print_stat_ios_recursive,
},
-#ifdef CONFIG_DEBUG_BLK_CGROUP
+#ifdef CONFIG_BFQ_CGROUP_DEBUG
{
.name = "bfq.time_recursive",
.private = offsetof(struct bfq_group, stats.time),
@@ -1159,7 +1253,7 @@ struct cftype bfq_blkcg_legacy_files[] = {
.private = offsetof(struct bfq_group, stats.dequeue),
.seq_show = bfqg_print_stat,
},
-#endif /* CONFIG_DEBUG_BLK_CGROUP */
+#endif /* CONFIG_BFQ_CGROUP_DEBUG */
{ } /* terminate */
};
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index f9269ae6da9c..50c9d2598500 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -157,6 +157,7 @@ BFQ_BFQQ_FNS(in_large_burst);
BFQ_BFQQ_FNS(coop);
BFQ_BFQQ_FNS(split_coop);
BFQ_BFQQ_FNS(softrt_update);
+BFQ_BFQQ_FNS(has_waker);
#undef BFQ_BFQQ_FNS \
/* Expiration time of sync (0) and async (1) requests, in ns. */
@@ -1427,17 +1428,19 @@ static int bfq_min_budget(struct bfq_data *bfqd)
* mechanism may be re-designed in such a way to make it possible to
* know whether preemption is needed without needing to update service
* trees). In addition, queue preemptions almost always cause random
- * I/O, and thus loss of throughput. Because of these facts, the next
- * function adopts the following simple scheme to avoid both costly
- * operations and too frequent preemptions: it requests the expiration
- * of the in-service queue (unconditionally) only for queues that need
- * to recover a hole, or that either are weight-raised or deserve to
- * be weight-raised.
+ * I/O, which may in turn cause loss of throughput. Finally, there may
+ * even be no in-service queue when the next function is invoked (so,
+ * no queue to compare timestamps with). Because of these facts, the
+ * next function adopts the following simple scheme to avoid costly
+ * operations, too frequent preemptions and too many dependencies on
+ * the state of the scheduler: it requests the expiration of the
+ * in-service queue (unconditionally) only for queues that need to
+ * recover a hole. Then it delegates to other parts of the code the
+ * responsibility of handling the above case 2.
*/
static bool bfq_bfqq_update_budg_for_activation(struct bfq_data *bfqd,
struct bfq_queue *bfqq,
- bool arrived_in_time,
- bool wr_or_deserves_wr)
+ bool arrived_in_time)
{
struct bfq_entity *entity = &bfqq->entity;
@@ -1492,7 +1495,7 @@ static bool bfq_bfqq_update_budg_for_activation(struct bfq_data *bfqd,
entity->budget = max_t(unsigned long, bfqq->max_budget,
bfq_serv_to_charge(bfqq->next_rq, bfqq));
bfq_clear_bfqq_non_blocking_wait_rq(bfqq);
- return wr_or_deserves_wr;
+ return false;
}
/*
@@ -1610,6 +1613,36 @@ static bool bfq_bfqq_idle_for_long_time(struct bfq_data *bfqd,
bfqd->bfq_wr_min_idle_time);
}
+
+/*
+ * Return true if bfqq is in a higher priority class, or has a higher
+ * weight than the in-service queue.
+ */
+static bool bfq_bfqq_higher_class_or_weight(struct bfq_queue *bfqq,
+ struct bfq_queue *in_serv_bfqq)
+{
+ int bfqq_weight, in_serv_weight;
+
+ if (bfqq->ioprio_class < in_serv_bfqq->ioprio_class)
+ return true;
+
+ if (in_serv_bfqq->entity.parent == bfqq->entity.parent) {
+ bfqq_weight = bfqq->entity.weight;
+ in_serv_weight = in_serv_bfqq->entity.weight;
+ } else {
+ if (bfqq->entity.parent)
+ bfqq_weight = bfqq->entity.parent->weight;
+ else
+ bfqq_weight = bfqq->entity.weight;
+ if (in_serv_bfqq->entity.parent)
+ in_serv_weight = in_serv_bfqq->entity.parent->weight;
+ else
+ in_serv_weight = in_serv_bfqq->entity.weight;
+ }
+
+ return bfqq_weight > in_serv_weight;
+}
+
static void bfq_bfqq_handle_idle_busy_switch(struct bfq_data *bfqd,
struct bfq_queue *bfqq,
int old_wr_coeff,
@@ -1654,8 +1687,7 @@ static void bfq_bfqq_handle_idle_busy_switch(struct bfq_data *bfqd,
*/
bfqq_wants_to_preempt =
bfq_bfqq_update_budg_for_activation(bfqd, bfqq,
- arrived_in_time,
- wr_or_deserves_wr);
+ arrived_in_time);
/*
* If bfqq happened to be activated in a burst, but has been
@@ -1720,21 +1752,111 @@ static void bfq_bfqq_handle_idle_busy_switch(struct bfq_data *bfqd,
/*
* Expire in-service queue only if preemption may be needed
- * for guarantees. In this respect, the function
- * next_queue_may_preempt just checks a simple, necessary
- * condition, and not a sufficient condition based on
- * timestamps. In fact, for the latter condition to be
- * evaluated, timestamps would need first to be updated, and
- * this operation is quite costly (see the comments on the
- * function bfq_bfqq_update_budg_for_activation).
+ * for guarantees. In particular, we care only about two
+ * cases. The first is that bfqq has to recover a service
+ * hole, as explained in the comments on
+ * bfq_bfqq_update_budg_for_activation(), i.e., that
+ * bfqq_wants_to_preempt is true. However, if bfqq does not
+ * carry time-critical I/O, then bfqq's bandwidth is less
+ * important than that of queues that carry time-critical I/O.
+ * So, as a further constraint, we consider this case only if
+ * bfqq is at least as weight-raised, i.e., at least as time
+ * critical, as the in-service queue.
+ *
+ * The second case is that bfqq is in a higher priority class,
+ * or has a higher weight than the in-service queue. If this
+ * condition does not hold, we don't care because, even if
+ * bfqq does not start to be served immediately, the resulting
+ * delay for bfqq's I/O is however lower or much lower than
+ * the ideal completion time to be guaranteed to bfqq's I/O.
+ *
+ * In both cases, preemption is needed only if, according to
+ * the timestamps of both bfqq and of the in-service queue,
+ * bfqq actually is the next queue to serve. So, to reduce
+ * useless preemptions, the return value of
+ * next_queue_may_preempt() is considered in the next compound
+ * condition too. Yet next_queue_may_preempt() just checks a
+ * simple, necessary condition for bfqq to be the next queue
+ * to serve. In fact, to evaluate a sufficient condition, the
+ * timestamps of the in-service queue would need to be
+ * updated, and this operation is quite costly (see the
+ * comments on bfq_bfqq_update_budg_for_activation()).
*/
- if (bfqd->in_service_queue && bfqq_wants_to_preempt &&
- bfqd->in_service_queue->wr_coeff < bfqq->wr_coeff &&
+ if (bfqd->in_service_queue &&
+ ((bfqq_wants_to_preempt &&
+ bfqq->wr_coeff >= bfqd->in_service_queue->wr_coeff) ||
+ bfq_bfqq_higher_class_or_weight(bfqq, bfqd->in_service_queue)) &&
next_queue_may_preempt(bfqd))
bfq_bfqq_expire(bfqd, bfqd->in_service_queue,
false, BFQQE_PREEMPTED);
}
+static void bfq_reset_inject_limit(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq)
+{
+ /* invalidate baseline total service time */
+ bfqq->last_serv_time_ns = 0;
+
+ /*
+ * Reset pointer in case we are waiting for
+ * some request completion.
+ */
+ bfqd->waited_rq = NULL;
+
+ /*
+ * If bfqq has a short think time, then start by setting the
+ * inject limit to 0 prudentially, because the service time of
+ * an injected I/O request may be higher than the think time
+ * of bfqq, and therefore, if one request was injected when
+ * bfqq remains empty, this injected request might delay the
+ * service of the next I/O request for bfqq significantly. In
+ * case bfqq can actually tolerate some injection, then the
+ * adaptive update will however raise the limit soon. This
+ * lucky circumstance holds exactly because bfqq has a short
+ * think time, and thus, after remaining empty, is likely to
+ * get new I/O enqueued---and then completed---before being
+ * expired. This is the very pattern that gives the
+ * limit-update algorithm the chance to measure the effect of
+ * injection on request service times, and then to update the
+ * limit accordingly.
+ *
+ * However, in the following special case, the inject limit is
+ * left to 1 even if the think time is short: bfqq's I/O is
+ * synchronized with that of some other queue, i.e., bfqq may
+ * receive new I/O only after the I/O of the other queue is
+ * completed. Keeping the inject limit to 1 allows the
+ * blocking I/O to be served while bfqq is in service. And
+ * this is very convenient both for bfqq and for overall
+ * throughput, as explained in detail in the comments in
+ * bfq_update_has_short_ttime().
+ *
+ * On the opposite end, if bfqq has a long think time, then
+ * start directly by 1, because:
+ * a) on the bright side, keeping at most one request in
+ * service in the drive is unlikely to cause any harm to the
+ * latency of bfqq's requests, as the service time of a single
+ * request is likely to be lower than the think time of bfqq;
+ * b) on the downside, after becoming empty, bfqq is likely to
+ * expire before getting its next request. With this request
+ * arrival pattern, it is very hard to sample total service
+ * times and update the inject limit accordingly (see comments
+ * on bfq_update_inject_limit()). So the limit is likely to be
+ * never, or at least seldom, updated. As a consequence, by
+ * setting the limit to 1, we avoid that no injection ever
+ * occurs with bfqq. On the downside, this proactive step
+ * further reduces chances to actually compute the baseline
+ * total service time. Thus it reduces chances to execute the
+ * limit-update algorithm and possibly raise the limit to more
+ * than 1.
+ */
+ if (bfq_bfqq_has_short_ttime(bfqq))
+ bfqq->inject_limit = 0;
+ else
+ bfqq->inject_limit = 1;
+
+ bfqq->decrease_time_jif = jiffies;
+}
+
static void bfq_add_request(struct request *rq)
{
struct bfq_queue *bfqq = RQ_BFQQ(rq);
@@ -1749,77 +1871,119 @@ static void bfq_add_request(struct request *rq)
if (RB_EMPTY_ROOT(&bfqq->sort_list) && bfq_bfqq_sync(bfqq)) {
/*
+ * Detect whether bfqq's I/O seems synchronized with
+ * that of some other queue, i.e., whether bfqq, after
+ * remaining empty, happens to receive new I/O only
+ * right after some I/O request of the other queue has
+ * been completed. We call waker queue the other
+ * queue, and we assume, for simplicity, that bfqq may
+ * have at most one waker queue.
+ *
+ * A remarkable throughput boost can be reached by
+ * unconditionally injecting the I/O of the waker
+ * queue, every time a new bfq_dispatch_request
+ * happens to be invoked while I/O is being plugged
+ * for bfqq. In addition to boosting throughput, this
+ * unblocks bfqq's I/O, thereby improving bandwidth
+ * and latency for bfqq. Note that these same results
+ * may be achieved with the general injection
+ * mechanism, but less effectively. For details on
+ * this aspect, see the comments on the choice of the
+ * queue for injection in bfq_select_queue().
+ *
+ * Turning back to the detection of a waker queue, a
+ * queue Q is deemed as a waker queue for bfqq if, for
+ * two consecutive times, bfqq happens to become non
+ * empty right after a request of Q has been
+ * completed. In particular, on the first time, Q is
+ * tentatively set as a candidate waker queue, while
+ * on the second time, the flag
+ * bfq_bfqq_has_waker(bfqq) is set to confirm that Q
+ * is a waker queue for bfqq. These detection steps
+ * are performed only if bfqq has a long think time,
+ * so as to make it more likely that bfqq's I/O is
+ * actually being blocked by a synchronization. This
+ * last filter, plus the above two-times requirement,
+ * make false positives less likely.
+ *
+ * NOTE
+ *
+ * The sooner a waker queue is detected, the sooner
+ * throughput can be boosted by injecting I/O from the
+ * waker queue. Fortunately, detection is likely to be
+ * actually fast, for the following reasons. While
+ * blocked by synchronization, bfqq has a long think
+ * time. This implies that bfqq's inject limit is at
+ * least equal to 1 (see the comments in
+ * bfq_update_inject_limit()). So, thanks to
+ * injection, the waker queue is likely to be served
+ * during the very first I/O-plugging time interval
+ * for bfqq. This triggers the first step of the
+ * detection mechanism. Thanks again to injection, the
+ * candidate waker queue is then likely to be
+ * confirmed no later than during the next
+ * I/O-plugging interval for bfqq.
+ */
+ if (!bfq_bfqq_has_short_ttime(bfqq) &&
+ ktime_get_ns() - bfqd->last_completion <
+ 200 * NSEC_PER_USEC) {
+ if (bfqd->last_completed_rq_bfqq != bfqq &&
+ bfqd->last_completed_rq_bfqq !=
+ bfqq->waker_bfqq) {
+ /*
+ * First synchronization detected with
+ * a candidate waker queue, or with a
+ * different candidate waker queue
+ * from the current one.
+ */
+ bfqq->waker_bfqq = bfqd->last_completed_rq_bfqq;
+
+ /*
+ * If the waker queue disappears, then
+ * bfqq->waker_bfqq must be reset. To
+ * this goal, we maintain in each
+ * waker queue a list, woken_list, of
+ * all the queues that reference the
+ * waker queue through their
+ * waker_bfqq pointer. When the waker
+ * queue exits, the waker_bfqq pointer
+ * of all the queues in the woken_list
+ * is reset.
+ *
+ * In addition, if bfqq is already in
+ * the woken_list of a waker queue,
+ * then, before being inserted into
+ * the woken_list of a new waker
+ * queue, bfqq must be removed from
+ * the woken_list of the old waker
+ * queue.
+ */
+ if (!hlist_unhashed(&bfqq->woken_list_node))
+ hlist_del_init(&bfqq->woken_list_node);
+ hlist_add_head(&bfqq->woken_list_node,
+ &bfqd->last_completed_rq_bfqq->woken_list);
+
+ bfq_clear_bfqq_has_waker(bfqq);
+ } else if (bfqd->last_completed_rq_bfqq ==
+ bfqq->waker_bfqq &&
+ !bfq_bfqq_has_waker(bfqq)) {
+ /*
+ * synchronization with waker_bfqq
+ * seen for the second time
+ */
+ bfq_mark_bfqq_has_waker(bfqq);
+ }
+ }
+
+ /*
* Periodically reset inject limit, to make sure that
* the latter eventually drops in case workload
* changes, see step (3) in the comments on
* bfq_update_inject_limit().
*/
if (time_is_before_eq_jiffies(bfqq->decrease_time_jif +
- msecs_to_jiffies(1000))) {
- /* invalidate baseline total service time */
- bfqq->last_serv_time_ns = 0;
-
- /*
- * Reset pointer in case we are waiting for
- * some request completion.
- */
- bfqd->waited_rq = NULL;
-
- /*
- * If bfqq has a short think time, then start
- * by setting the inject limit to 0
- * prudentially, because the service time of
- * an injected I/O request may be higher than
- * the think time of bfqq, and therefore, if
- * one request was injected when bfqq remains
- * empty, this injected request might delay
- * the service of the next I/O request for
- * bfqq significantly. In case bfqq can
- * actually tolerate some injection, then the
- * adaptive update will however raise the
- * limit soon. This lucky circumstance holds
- * exactly because bfqq has a short think
- * time, and thus, after remaining empty, is
- * likely to get new I/O enqueued---and then
- * completed---before being expired. This is
- * the very pattern that gives the
- * limit-update algorithm the chance to
- * measure the effect of injection on request
- * service times, and then to update the limit
- * accordingly.
- *
- * On the opposite end, if bfqq has a long
- * think time, then start directly by 1,
- * because:
- * a) on the bright side, keeping at most one
- * request in service in the drive is unlikely
- * to cause any harm to the latency of bfqq's
- * requests, as the service time of a single
- * request is likely to be lower than the
- * think time of bfqq;
- * b) on the downside, after becoming empty,
- * bfqq is likely to expire before getting its
- * next request. With this request arrival
- * pattern, it is very hard to sample total
- * service times and update the inject limit
- * accordingly (see comments on
- * bfq_update_inject_limit()). So the limit is
- * likely to be never, or at least seldom,
- * updated. As a consequence, by setting the
- * limit to 1, we avoid that no injection ever
- * occurs with bfqq. On the downside, this
- * proactive step further reduces chances to
- * actually compute the baseline total service
- * time. Thus it reduces chances to execute the
- * limit-update algorithm and possibly raise the
- * limit to more than 1.
- */
- if (bfq_bfqq_has_short_ttime(bfqq))
- bfqq->inject_limit = 0;
- else
- bfqq->inject_limit = 1;
- bfqq->decrease_time_jif = jiffies;
- }
+ msecs_to_jiffies(1000)))
+ bfq_reset_inject_limit(bfqd, bfqq);
/*
* The following conditions must hold to setup a new
@@ -2027,7 +2191,8 @@ static void bfq_remove_request(struct request_queue *q,
}
-static bool bfq_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio)
+static bool bfq_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio,
+ unsigned int nr_segs)
{
struct request_queue *q = hctx->queue;
struct bfq_data *bfqd = q->elevator->elevator_data;
@@ -2050,7 +2215,7 @@ static bool bfq_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio)
bfqd->bio_bfqq = NULL;
bfqd->bio_bic = bic;
- ret = blk_mq_sched_try_merge(q, bio, &free);
+ ret = blk_mq_sched_try_merge(q, bio, nr_segs, &free);
if (free)
blk_mq_free_request(free);
@@ -2513,6 +2678,7 @@ static void bfq_bfqq_save_state(struct bfq_queue *bfqq)
* to enjoy weight raising if split soon.
*/
bic->saved_wr_coeff = bfqq->bfqd->bfq_wr_coeff;
+ bic->saved_wr_start_at_switch_to_srt = bfq_smallest_from_now();
bic->saved_wr_cur_max_time = bfq_wr_duration(bfqq->bfqd);
bic->saved_last_wr_start_finish = jiffies;
} else {
@@ -3045,7 +3211,186 @@ static void bfq_dispatch_remove(struct request_queue *q, struct request *rq)
bfq_remove_request(q, rq);
}
-static bool __bfq_bfqq_expire(struct bfq_data *bfqd, struct bfq_queue *bfqq)
+/*
+ * There is a case where idling does not have to be performed for
+ * throughput concerns, but to preserve the throughput share of
+ * the process associated with bfqq.
+ *
+ * To introduce this case, we can note that allowing the drive
+ * to enqueue more than one request at a time, and hence
+ * delegating de facto final scheduling decisions to the
+ * drive's internal scheduler, entails loss of control on the
+ * actual request service order. In particular, the critical
+ * situation is when requests from different processes happen
+ * to be present, at the same time, in the internal queue(s)
+ * of the drive. In such a situation, the drive, by deciding
+ * the service order of the internally-queued requests, does
+ * determine also the actual throughput distribution among
+ * these processes. But the drive typically has no notion or
+ * concern about per-process throughput distribution, and
+ * makes its decisions only on a per-request basis. Therefore,
+ * the service distribution enforced by the drive's internal
+ * scheduler is likely to coincide with the desired throughput
+ * distribution only in a completely symmetric, or favorably
+ * skewed scenario where:
+ * (i-a) each of these processes must get the same throughput as
+ * the others,
+ * (i-b) in case (i-a) does not hold, it holds that the process
+ * associated with bfqq must receive a lower or equal
+ * throughput than any of the other processes;
+ * (ii) the I/O of each process has the same properties, in
+ * terms of locality (sequential or random), direction
+ * (reads or writes), request sizes, greediness
+ * (from I/O-bound to sporadic), and so on;
+
+ * In fact, in such a scenario, the drive tends to treat the requests
+ * of each process in about the same way as the requests of the
+ * others, and thus to provide each of these processes with about the
+ * same throughput. This is exactly the desired throughput
+ * distribution if (i-a) holds, or, if (i-b) holds instead, this is an
+ * even more convenient distribution for (the process associated with)
+ * bfqq.
+ *
+ * In contrast, in any asymmetric or unfavorable scenario, device
+ * idling (I/O-dispatch plugging) is certainly needed to guarantee
+ * that bfqq receives its assigned fraction of the device throughput
+ * (see [1] for details).
+ *
+ * The problem is that idling may significantly reduce throughput with
+ * certain combinations of types of I/O and devices. An important
+ * example is sync random I/O on flash storage with command
+ * queueing. So, unless bfqq falls in cases where idling also boosts
+ * throughput, it is important to check conditions (i-a), i(-b) and
+ * (ii) accurately, so as to avoid idling when not strictly needed for
+ * service guarantees.
+ *
+ * Unfortunately, it is extremely difficult to thoroughly check
+ * condition (ii). And, in case there are active groups, it becomes
+ * very difficult to check conditions (i-a) and (i-b) too. In fact,
+ * if there are active groups, then, for conditions (i-a) or (i-b) to
+ * become false 'indirectly', it is enough that an active group
+ * contains more active processes or sub-groups than some other active
+ * group. More precisely, for conditions (i-a) or (i-b) to become
+ * false because of such a group, it is not even necessary that the
+ * group is (still) active: it is sufficient that, even if the group
+ * has become inactive, some of its descendant processes still have
+ * some request already dispatched but still waiting for
+ * completion. In fact, requests have still to be guaranteed their
+ * share of the throughput even after being dispatched. In this
+ * respect, it is easy to show that, if a group frequently becomes
+ * inactive while still having in-flight requests, and if, when this
+ * happens, the group is not considered in the calculation of whether
+ * the scenario is asymmetric, then the group may fail to be
+ * guaranteed its fair share of the throughput (basically because
+ * idling may not be performed for the descendant processes of the
+ * group, but it had to be). We address this issue with the following
+ * bi-modal behavior, implemented in the function
+ * bfq_asymmetric_scenario().
+ *
+ * If there are groups with requests waiting for completion
+ * (as commented above, some of these groups may even be
+ * already inactive), then the scenario is tagged as
+ * asymmetric, conservatively, without checking any of the
+ * conditions (i-a), (i-b) or (ii). So the device is idled for bfqq.
+ * This behavior matches also the fact that groups are created
+ * exactly if controlling I/O is a primary concern (to
+ * preserve bandwidth and latency guarantees).
+ *
+ * On the opposite end, if there are no groups with requests waiting
+ * for completion, then only conditions (i-a) and (i-b) are actually
+ * controlled, i.e., provided that conditions (i-a) or (i-b) holds,
+ * idling is not performed, regardless of whether condition (ii)
+ * holds. In other words, only if conditions (i-a) and (i-b) do not
+ * hold, then idling is allowed, and the device tends to be prevented
+ * from queueing many requests, possibly of several processes. Since
+ * there are no groups with requests waiting for completion, then, to
+ * control conditions (i-a) and (i-b) it is enough to check just
+ * whether all the queues with requests waiting for completion also
+ * have the same weight.
+ *
+ * Not checking condition (ii) evidently exposes bfqq to the
+ * risk of getting less throughput than its fair share.
+ * However, for queues with the same weight, a further
+ * mechanism, preemption, mitigates or even eliminates this
+ * problem. And it does so without consequences on overall
+ * throughput. This mechanism and its benefits are explained
+ * in the next three paragraphs.
+ *
+ * Even if a queue, say Q, is expired when it remains idle, Q
+ * can still preempt the new in-service queue if the next
+ * request of Q arrives soon (see the comments on
+ * bfq_bfqq_update_budg_for_activation). If all queues and
+ * groups have the same weight, this form of preemption,
+ * combined with the hole-recovery heuristic described in the
+ * comments on function bfq_bfqq_update_budg_for_activation,
+ * are enough to preserve a correct bandwidth distribution in
+ * the mid term, even without idling. In fact, even if not
+ * idling allows the internal queues of the device to contain
+ * many requests, and thus to reorder requests, we can rather
+ * safely assume that the internal scheduler still preserves a
+ * minimum of mid-term fairness.
+ *
+ * More precisely, this preemption-based, idleless approach
+ * provides fairness in terms of IOPS, and not sectors per
+ * second. This can be seen with a simple example. Suppose
+ * that there are two queues with the same weight, but that
+ * the first queue receives requests of 8 sectors, while the
+ * second queue receives requests of 1024 sectors. In
+ * addition, suppose that each of the two queues contains at
+ * most one request at a time, which implies that each queue
+ * always remains idle after it is served. Finally, after
+ * remaining idle, each queue receives very quickly a new
+ * request. It follows that the two queues are served
+ * alternatively, preempting each other if needed. This
+ * implies that, although both queues have the same weight,
+ * the queue with large requests receives a service that is
+ * 1024/8 times as high as the service received by the other
+ * queue.
+ *
+ * The motivation for using preemption instead of idling (for
+ * queues with the same weight) is that, by not idling,
+ * service guarantees are preserved (completely or at least in
+ * part) without minimally sacrificing throughput. And, if
+ * there is no active group, then the primary expectation for
+ * this device is probably a high throughput.
+ *
+ * We are now left only with explaining the additional
+ * compound condition that is checked below for deciding
+ * whether the scenario is asymmetric. To explain this
+ * compound condition, we need to add that the function
+ * bfq_asymmetric_scenario checks the weights of only
+ * non-weight-raised queues, for efficiency reasons (see
+ * comments on bfq_weights_tree_add()). Then the fact that
+ * bfqq is weight-raised is checked explicitly here. More
+ * precisely, the compound condition below takes into account
+ * also the fact that, even if bfqq is being weight-raised,
+ * the scenario is still symmetric if all queues with requests
+ * waiting for completion happen to be
+ * weight-raised. Actually, we should be even more precise
+ * here, and differentiate between interactive weight raising
+ * and soft real-time weight raising.
+ *
+ * As a side note, it is worth considering that the above
+ * device-idling countermeasures may however fail in the
+ * following unlucky scenario: if idling is (correctly)
+ * disabled in a time period during which all symmetry
+ * sub-conditions hold, and hence the device is allowed to
+ * enqueue many requests, but at some later point in time some
+ * sub-condition stops to hold, then it may become impossible
+ * to let requests be served in the desired order until all
+ * the requests already queued in the device have been served.
+ */
+static bool idling_needed_for_service_guarantees(struct bfq_data *bfqd,
+ struct bfq_queue *bfqq)
+{
+ return (bfqq->wr_coeff > 1 &&
+ bfqd->wr_busy_queues <
+ bfq_tot_busy_queues(bfqd)) ||
+ bfq_asymmetric_scenario(bfqd, bfqq);
+}
+
+static bool __bfq_bfqq_expire(struct bfq_data *bfqd, struct bfq_queue *bfqq,
+ enum bfqq_expiration reason)
{
/*
* If this bfqq is shared between multiple processes, check
@@ -3056,7 +3401,22 @@ static bool __bfq_bfqq_expire(struct bfq_data *bfqd, struct bfq_queue *bfqq)
if (bfq_bfqq_coop(bfqq) && BFQQ_SEEKY(bfqq))
bfq_mark_bfqq_split_coop(bfqq);
- if (RB_EMPTY_ROOT(&bfqq->sort_list)) {
+ /*
+ * Consider queues with a higher finish virtual time than
+ * bfqq. If idling_needed_for_service_guarantees(bfqq) returns
+ * true, then bfqq's bandwidth would be violated if an
+ * uncontrolled amount of I/O from these queues were
+ * dispatched while bfqq is waiting for its new I/O to
+ * arrive. This is exactly what may happen if this is a forced
+ * expiration caused by a preemption attempt, and if bfqq is
+ * not re-scheduled. To prevent this from happening, re-queue
+ * bfqq if it needs I/O-dispatch plugging, even if it is
+ * empty. By doing so, bfqq is granted to be served before the
+ * above queues (provided that bfqq is of course eligible).
+ */
+ if (RB_EMPTY_ROOT(&bfqq->sort_list) &&
+ !(reason == BFQQE_PREEMPTED &&
+ idling_needed_for_service_guarantees(bfqd, bfqq))) {
if (bfqq->dispatched == 0)
/*
* Overloading budget_timeout field to store
@@ -3073,7 +3433,8 @@ static bool __bfq_bfqq_expire(struct bfq_data *bfqd, struct bfq_queue *bfqq)
* Resort priority tree of potential close cooperators.
* See comments on bfq_pos_tree_add_move() for the unlikely().
*/
- if (unlikely(!bfqd->nonrot_with_queueing))
+ if (unlikely(!bfqd->nonrot_with_queueing &&
+ !RB_EMPTY_ROOT(&bfqq->sort_list)))
bfq_pos_tree_add_move(bfqd, bfqq);
}
@@ -3574,7 +3935,7 @@ void bfq_bfqq_expire(struct bfq_data *bfqd,
* reason.
*/
__bfq_bfqq_recalc_budget(bfqd, bfqq, reason);
- if (__bfq_bfqq_expire(bfqd, bfqq))
+ if (__bfq_bfqq_expire(bfqd, bfqq, reason))
/* bfqq is gone, no more actions on it */
return;
@@ -3721,184 +4082,6 @@ static bool idling_boosts_thr_without_issues(struct bfq_data *bfqd,
}
/*
- * There is a case where idling does not have to be performed for
- * throughput concerns, but to preserve the throughput share of
- * the process associated with bfqq.
- *
- * To introduce this case, we can note that allowing the drive
- * to enqueue more than one request at a time, and hence
- * delegating de facto final scheduling decisions to the
- * drive's internal scheduler, entails loss of control on the
- * actual request service order. In particular, the critical
- * situation is when requests from different processes happen
- * to be present, at the same time, in the internal queue(s)
- * of the drive. In such a situation, the drive, by deciding
- * the service order of the internally-queued requests, does
- * determine also the actual throughput distribution among
- * these processes. But the drive typically has no notion or
- * concern about per-process throughput distribution, and
- * makes its decisions only on a per-request basis. Therefore,
- * the service distribution enforced by the drive's internal
- * scheduler is likely to coincide with the desired throughput
- * distribution only in a completely symmetric, or favorably
- * skewed scenario where:
- * (i-a) each of these processes must get the same throughput as
- * the others,
- * (i-b) in case (i-a) does not hold, it holds that the process
- * associated with bfqq must receive a lower or equal
- * throughput than any of the other processes;
- * (ii) the I/O of each process has the same properties, in
- * terms of locality (sequential or random), direction
- * (reads or writes), request sizes, greediness
- * (from I/O-bound to sporadic), and so on;
-
- * In fact, in such a scenario, the drive tends to treat the requests
- * of each process in about the same way as the requests of the
- * others, and thus to provide each of these processes with about the
- * same throughput. This is exactly the desired throughput
- * distribution if (i-a) holds, or, if (i-b) holds instead, this is an
- * even more convenient distribution for (the process associated with)
- * bfqq.
- *
- * In contrast, in any asymmetric or unfavorable scenario, device
- * idling (I/O-dispatch plugging) is certainly needed to guarantee
- * that bfqq receives its assigned fraction of the device throughput
- * (see [1] for details).
- *
- * The problem is that idling may significantly reduce throughput with
- * certain combinations of types of I/O and devices. An important
- * example is sync random I/O on flash storage with command
- * queueing. So, unless bfqq falls in cases where idling also boosts
- * throughput, it is important to check conditions (i-a), i(-b) and
- * (ii) accurately, so as to avoid idling when not strictly needed for
- * service guarantees.
- *
- * Unfortunately, it is extremely difficult to thoroughly check
- * condition (ii). And, in case there are active groups, it becomes
- * very difficult to check conditions (i-a) and (i-b) too. In fact,
- * if there are active groups, then, for conditions (i-a) or (i-b) to
- * become false 'indirectly', it is enough that an active group
- * contains more active processes or sub-groups than some other active
- * group. More precisely, for conditions (i-a) or (i-b) to become
- * false because of such a group, it is not even necessary that the
- * group is (still) active: it is sufficient that, even if the group
- * has become inactive, some of its descendant processes still have
- * some request already dispatched but still waiting for
- * completion. In fact, requests have still to be guaranteed their
- * share of the throughput even after being dispatched. In this
- * respect, it is easy to show that, if a group frequently becomes
- * inactive while still having in-flight requests, and if, when this
- * happens, the group is not considered in the calculation of whether
- * the scenario is asymmetric, then the group may fail to be
- * guaranteed its fair share of the throughput (basically because
- * idling may not be performed for the descendant processes of the
- * group, but it had to be). We address this issue with the following
- * bi-modal behavior, implemented in the function
- * bfq_asymmetric_scenario().
- *
- * If there are groups with requests waiting for completion
- * (as commented above, some of these groups may even be
- * already inactive), then the scenario is tagged as
- * asymmetric, conservatively, without checking any of the
- * conditions (i-a), (i-b) or (ii). So the device is idled for bfqq.
- * This behavior matches also the fact that groups are created
- * exactly if controlling I/O is a primary concern (to
- * preserve bandwidth and latency guarantees).
- *
- * On the opposite end, if there are no groups with requests waiting
- * for completion, then only conditions (i-a) and (i-b) are actually
- * controlled, i.e., provided that conditions (i-a) or (i-b) holds,
- * idling is not performed, regardless of whether condition (ii)
- * holds. In other words, only if conditions (i-a) and (i-b) do not
- * hold, then idling is allowed, and the device tends to be prevented
- * from queueing many requests, possibly of several processes. Since
- * there are no groups with requests waiting for completion, then, to
- * control conditions (i-a) and (i-b) it is enough to check just
- * whether all the queues with requests waiting for completion also
- * have the same weight.
- *
- * Not checking condition (ii) evidently exposes bfqq to the
- * risk of getting less throughput than its fair share.
- * However, for queues with the same weight, a further
- * mechanism, preemption, mitigates or even eliminates this
- * problem. And it does so without consequences on overall
- * throughput. This mechanism and its benefits are explained
- * in the next three paragraphs.
- *
- * Even if a queue, say Q, is expired when it remains idle, Q
- * can still preempt the new in-service queue if the next
- * request of Q arrives soon (see the comments on
- * bfq_bfqq_update_budg_for_activation). If all queues and
- * groups have the same weight, this form of preemption,
- * combined with the hole-recovery heuristic described in the
- * comments on function bfq_bfqq_update_budg_for_activation,
- * are enough to preserve a correct bandwidth distribution in
- * the mid term, even without idling. In fact, even if not
- * idling allows the internal queues of the device to contain
- * many requests, and thus to reorder requests, we can rather
- * safely assume that the internal scheduler still preserves a
- * minimum of mid-term fairness.
- *
- * More precisely, this preemption-based, idleless approach
- * provides fairness in terms of IOPS, and not sectors per
- * second. This can be seen with a simple example. Suppose
- * that there are two queues with the same weight, but that
- * the first queue receives requests of 8 sectors, while the
- * second queue receives requests of 1024 sectors. In
- * addition, suppose that each of the two queues contains at
- * most one request at a time, which implies that each queue
- * always remains idle after it is served. Finally, after
- * remaining idle, each queue receives very quickly a new
- * request. It follows that the two queues are served
- * alternatively, preempting each other if needed. This
- * implies that, although both queues have the same weight,
- * the queue with large requests receives a service that is
- * 1024/8 times as high as the service received by the other
- * queue.
- *
- * The motivation for using preemption instead of idling (for
- * queues with the same weight) is that, by not idling,
- * service guarantees are preserved (completely or at least in
- * part) without minimally sacrificing throughput. And, if
- * there is no active group, then the primary expectation for
- * this device is probably a high throughput.
- *
- * We are now left only with explaining the additional
- * compound condition that is checked below for deciding
- * whether the scenario is asymmetric. To explain this
- * compound condition, we need to add that the function
- * bfq_asymmetric_scenario checks the weights of only
- * non-weight-raised queues, for efficiency reasons (see
- * comments on bfq_weights_tree_add()). Then the fact that
- * bfqq is weight-raised is checked explicitly here. More
- * precisely, the compound condition below takes into account
- * also the fact that, even if bfqq is being weight-raised,
- * the scenario is still symmetric if all queues with requests
- * waiting for completion happen to be
- * weight-raised. Actually, we should be even more precise
- * here, and differentiate between interactive weight raising
- * and soft real-time weight raising.
- *
- * As a side note, it is worth considering that the above
- * device-idling countermeasures may however fail in the
- * following unlucky scenario: if idling is (correctly)
- * disabled in a time period during which all symmetry
- * sub-conditions hold, and hence the device is allowed to
- * enqueue many requests, but at some later point in time some
- * sub-condition stops to hold, then it may become impossible
- * to let requests be served in the desired order until all
- * the requests already queued in the device have been served.
- */
-static bool idling_needed_for_service_guarantees(struct bfq_data *bfqd,
- struct bfq_queue *bfqq)
-{
- return (bfqq->wr_coeff > 1 &&
- bfqd->wr_busy_queues <
- bfq_tot_busy_queues(bfqd)) ||
- bfq_asymmetric_scenario(bfqd, bfqq);
-}
-
-/*
* For a queue that becomes empty, device idling is allowed only if
* this function returns true for that queue. As a consequence, since
* device idling plays a critical role for both throughput boosting
@@ -4156,22 +4339,95 @@ check_queue:
(bfqq->dispatched != 0 && bfq_better_to_idle(bfqq))) {
struct bfq_queue *async_bfqq =
bfqq->bic && bfqq->bic->bfqq[0] &&
- bfq_bfqq_busy(bfqq->bic->bfqq[0]) ?
+ bfq_bfqq_busy(bfqq->bic->bfqq[0]) &&
+ bfqq->bic->bfqq[0]->next_rq ?
bfqq->bic->bfqq[0] : NULL;
/*
- * If the process associated with bfqq has also async
- * I/O pending, then inject it
- * unconditionally. Injecting I/O from the same
- * process can cause no harm to the process. On the
- * contrary, it can only increase bandwidth and reduce
- * latency for the process.
+ * The next three mutually-exclusive ifs decide
+ * whether to try injection, and choose the queue to
+ * pick an I/O request from.
+ *
+ * The first if checks whether the process associated
+ * with bfqq has also async I/O pending. If so, it
+ * injects such I/O unconditionally. Injecting async
+ * I/O from the same process can cause no harm to the
+ * process. On the contrary, it can only increase
+ * bandwidth and reduce latency for the process.
+ *
+ * The second if checks whether there happens to be a
+ * non-empty waker queue for bfqq, i.e., a queue whose
+ * I/O needs to be completed for bfqq to receive new
+ * I/O. This happens, e.g., if bfqq is associated with
+ * a process that does some sync. A sync generates
+ * extra blocking I/O, which must be completed before
+ * the process associated with bfqq can go on with its
+ * I/O. If the I/O of the waker queue is not served,
+ * then bfqq remains empty, and no I/O is dispatched,
+ * until the idle timeout fires for bfqq. This is
+ * likely to result in lower bandwidth and higher
+ * latencies for bfqq, and in a severe loss of total
+ * throughput. The best action to take is therefore to
+ * serve the waker queue as soon as possible. So do it
+ * (without relying on the third alternative below for
+ * eventually serving waker_bfqq's I/O; see the last
+ * paragraph for further details). This systematic
+ * injection of I/O from the waker queue does not
+ * cause any delay to bfqq's I/O. On the contrary,
+ * next bfqq's I/O is brought forward dramatically,
+ * for it is not blocked for milliseconds.
+ *
+ * The third if checks whether bfqq is a queue for
+ * which it is better to avoid injection. It is so if
+ * bfqq delivers more throughput when served without
+ * any further I/O from other queues in the middle, or
+ * if the service times of bfqq's I/O requests both
+ * count more than overall throughput, and may be
+ * easily increased by injection (this happens if bfqq
+ * has a short think time). If none of these
+ * conditions holds, then a candidate queue for
+ * injection is looked for through
+ * bfq_choose_bfqq_for_injection(). Note that the
+ * latter may return NULL (for example if the inject
+ * limit for bfqq is currently 0).
+ *
+ * NOTE: motivation for the second alternative
+ *
+ * Thanks to the way the inject limit is updated in
+ * bfq_update_has_short_ttime(), it is rather likely
+ * that, if I/O is being plugged for bfqq and the
+ * waker queue has pending I/O requests that are
+ * blocking bfqq's I/O, then the third alternative
+ * above lets the waker queue get served before the
+ * I/O-plugging timeout fires. So one may deem the
+ * second alternative superfluous. It is not, because
+ * the third alternative may be way less effective in
+ * case of a synchronization. For two main
+ * reasons. First, throughput may be low because the
+ * inject limit may be too low to guarantee the same
+ * amount of injected I/O, from the waker queue or
+ * other queues, that the second alternative
+ * guarantees (the second alternative unconditionally
+ * injects a pending I/O request of the waker queue
+ * for each bfq_dispatch_request()). Second, with the
+ * third alternative, the duration of the plugging,
+ * i.e., the time before bfqq finally receives new I/O,
+ * may not be minimized, because the waker queue may
+ * happen to be served only after other queues.
*/
if (async_bfqq &&
icq_to_bic(async_bfqq->next_rq->elv.icq) == bfqq->bic &&
bfq_serv_to_charge(async_bfqq->next_rq, async_bfqq) <=
bfq_bfqq_budget_left(async_bfqq))
bfqq = bfqq->bic->bfqq[0];
+ else if (bfq_bfqq_has_waker(bfqq) &&
+ bfq_bfqq_busy(bfqq->waker_bfqq) &&
+ bfqq->next_rq &&
+ bfq_serv_to_charge(bfqq->waker_bfqq->next_rq,
+ bfqq->waker_bfqq) <=
+ bfq_bfqq_budget_left(bfqq->waker_bfqq)
+ )
+ bfqq = bfqq->waker_bfqq;
else if (!idling_boosts_thr_without_issues(bfqd, bfqq) &&
(bfqq->wr_coeff == 1 || bfqd->wr_busy_queues > 1 ||
!bfq_bfqq_has_short_ttime(bfqq)))
@@ -4403,7 +4659,7 @@ exit:
return rq;
}
-#if defined(CONFIG_BFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP)
+#ifdef CONFIG_BFQ_CGROUP_DEBUG
static void bfq_update_dispatch_stats(struct request_queue *q,
struct request *rq,
struct bfq_queue *in_serv_queue,
@@ -4453,7 +4709,7 @@ static inline void bfq_update_dispatch_stats(struct request_queue *q,
struct request *rq,
struct bfq_queue *in_serv_queue,
bool idle_timer_disabled) {}
-#endif
+#endif /* CONFIG_BFQ_CGROUP_DEBUG */
static struct request *bfq_dispatch_request(struct blk_mq_hw_ctx *hctx)
{
@@ -4560,8 +4816,11 @@ static void bfq_put_cooperator(struct bfq_queue *bfqq)
static void bfq_exit_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq)
{
+ struct bfq_queue *item;
+ struct hlist_node *n;
+
if (bfqq == bfqd->in_service_queue) {
- __bfq_bfqq_expire(bfqd, bfqq);
+ __bfq_bfqq_expire(bfqd, bfqq, BFQQE_BUDGET_TIMEOUT);
bfq_schedule_dispatch(bfqd);
}
@@ -4569,6 +4828,18 @@ static void bfq_exit_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq)
bfq_put_cooperator(bfqq);
+ /* remove bfqq from woken list */
+ if (!hlist_unhashed(&bfqq->woken_list_node))
+ hlist_del_init(&bfqq->woken_list_node);
+
+ /* reset waker for all queues in woken list */
+ hlist_for_each_entry_safe(item, n, &bfqq->woken_list,
+ woken_list_node) {
+ item->waker_bfqq = NULL;
+ bfq_clear_bfqq_has_waker(item);
+ hlist_del_init(&item->woken_list_node);
+ }
+
bfq_put_queue(bfqq); /* release process reference */
}
@@ -4584,6 +4855,7 @@ static void bfq_exit_icq_bfqq(struct bfq_io_cq *bic, bool is_sync)
unsigned long flags;
spin_lock_irqsave(&bfqd->lock, flags);
+ bfqq->bic = NULL;
bfq_exit_bfqq(bfqd, bfqq);
bic_set_bfqq(bic, NULL, is_sync);
spin_unlock_irqrestore(&bfqd->lock, flags);
@@ -4687,6 +4959,8 @@ static void bfq_init_bfqq(struct bfq_data *bfqd, struct bfq_queue *bfqq,
RB_CLEAR_NODE(&bfqq->entity.rb_node);
INIT_LIST_HEAD(&bfqq->fifo);
INIT_HLIST_NODE(&bfqq->burst_list_node);
+ INIT_HLIST_NODE(&bfqq->woken_list_node);
+ INIT_HLIST_HEAD(&bfqq->woken_list);
bfqq->ref = 0;
bfqq->bfqd = bfqd;
@@ -4854,7 +5128,7 @@ static void bfq_update_has_short_ttime(struct bfq_data *bfqd,
struct bfq_queue *bfqq,
struct bfq_io_cq *bic)
{
- bool has_short_ttime = true;
+ bool has_short_ttime = true, state_changed;
/*
* No need to update has_short_ttime if bfqq is async or in
@@ -4879,13 +5153,102 @@ static void bfq_update_has_short_ttime(struct bfq_data *bfqd,
bfqq->ttime.ttime_mean > bfqd->bfq_slice_idle))
has_short_ttime = false;
- bfq_log_bfqq(bfqd, bfqq, "update_has_short_ttime: has_short_ttime %d",
- has_short_ttime);
+ state_changed = has_short_ttime != bfq_bfqq_has_short_ttime(bfqq);
if (has_short_ttime)
bfq_mark_bfqq_has_short_ttime(bfqq);
else
bfq_clear_bfqq_has_short_ttime(bfqq);
+
+ /*
+ * Until the base value for the total service time gets
+ * finally computed for bfqq, the inject limit does depend on
+ * the think-time state (short|long). In particular, the limit
+ * is 0 or 1 if the think time is deemed, respectively, as
+ * short or long (details in the comments in
+ * bfq_update_inject_limit()). Accordingly, the next
+ * instructions reset the inject limit if the think-time state
+ * has changed and the above base value is still to be
+ * computed.
+ *
+ * However, the reset is performed only if more than 100 ms
+ * have elapsed since the last update of the inject limit, or
+ * (inclusive) if the change is from short to long think
+ * time. The reason for this waiting is as follows.
+ *
+ * bfqq may have a long think time because of a
+ * synchronization with some other queue, i.e., because the
+ * I/O of some other queue may need to be completed for bfqq
+ * to receive new I/O. Details in the comments on the choice
+ * of the queue for injection in bfq_select_queue().
+ *
+ * As stressed in those comments, if such a synchronization is
+ * actually in place, then, without injection on bfqq, the
+ * blocking I/O cannot happen to served while bfqq is in
+ * service. As a consequence, if bfqq is granted
+ * I/O-dispatch-plugging, then bfqq remains empty, and no I/O
+ * is dispatched, until the idle timeout fires. This is likely
+ * to result in lower bandwidth and higher latencies for bfqq,
+ * and in a severe loss of total throughput.
+ *
+ * On the opposite end, a non-zero inject limit may allow the
+ * I/O that blocks bfqq to be executed soon, and therefore
+ * bfqq to receive new I/O soon.
+ *
+ * But, if the blocking gets actually eliminated, then the
+ * next think-time sample for bfqq may be very low. This in
+ * turn may cause bfqq's think time to be deemed
+ * short. Without the 100 ms barrier, this new state change
+ * would cause the body of the next if to be executed
+ * immediately. But this would set to 0 the inject
+ * limit. Without injection, the blocking I/O would cause the
+ * think time of bfqq to become long again, and therefore the
+ * inject limit to be raised again, and so on. The only effect
+ * of such a steady oscillation between the two think-time
+ * states would be to prevent effective injection on bfqq.
+ *
+ * In contrast, if the inject limit is not reset during such a
+ * long time interval as 100 ms, then the number of short
+ * think time samples can grow significantly before the reset
+ * is performed. As a consequence, the think time state can
+ * become stable before the reset. Therefore there will be no
+ * state change when the 100 ms elapse, and no reset of the
+ * inject limit. The inject limit remains steadily equal to 1
+ * both during and after the 100 ms. So injection can be
+ * performed at all times, and throughput gets boosted.
+ *
+ * An inject limit equal to 1 is however in conflict, in
+ * general, with the fact that the think time of bfqq is
+ * short, because injection may be likely to delay bfqq's I/O
+ * (as explained in the comments in
+ * bfq_update_inject_limit()). But this does not happen in
+ * this special case, because bfqq's low think time is due to
+ * an effective handling of a synchronization, through
+ * injection. In this special case, bfqq's I/O does not get
+ * delayed by injection; on the contrary, bfqq's I/O is
+ * brought forward, because it is not blocked for
+ * milliseconds.
+ *
+ * In addition, serving the blocking I/O much sooner, and much
+ * more frequently than once per I/O-plugging timeout, makes
+ * it much quicker to detect a waker queue (the concept of
+ * waker queue is defined in the comments in
+ * bfq_add_request()). This makes it possible to start sooner
+ * to boost throughput more effectively, by injecting the I/O
+ * of the waker queue unconditionally on every
+ * bfq_dispatch_request().
+ *
+ * One last, important benefit of not resetting the inject
+ * limit before 100 ms is that, during this time interval, the
+ * base value for the total service time is likely to get
+ * finally computed for bfqq, freeing the inject limit from
+ * its relation with the think time.
+ */
+ if (state_changed && bfqq->last_serv_time_ns == 0 &&
+ (time_is_before_eq_jiffies(bfqq->decrease_time_jif +
+ msecs_to_jiffies(100)) ||
+ !has_short_ttime))
+ bfq_reset_inject_limit(bfqd, bfqq);
}
/*
@@ -4895,19 +5258,9 @@ static void bfq_update_has_short_ttime(struct bfq_data *bfqd,
static void bfq_rq_enqueued(struct bfq_data *bfqd, struct bfq_queue *bfqq,
struct request *rq)
{
- struct bfq_io_cq *bic = RQ_BIC(rq);
-
if (rq->cmd_flags & REQ_META)
bfqq->meta_pending++;
- bfq_update_io_thinktime(bfqd, bfqq);
- bfq_update_has_short_ttime(bfqd, bfqq, bic);
- bfq_update_io_seektime(bfqd, bfqq, rq);
-
- bfq_log_bfqq(bfqd, bfqq,
- "rq_enqueued: has_short_ttime=%d (seeky %d)",
- bfq_bfqq_has_short_ttime(bfqq), BFQQ_SEEKY(bfqq));
-
bfqq->last_request_pos = blk_rq_pos(rq) + blk_rq_sectors(rq);
if (bfqq == bfqd->in_service_queue && bfq_bfqq_wait_request(bfqq)) {
@@ -4995,6 +5348,10 @@ static bool __bfq_insert_request(struct bfq_data *bfqd, struct request *rq)
bfqq = new_bfqq;
}
+ bfq_update_io_thinktime(bfqd, bfqq);
+ bfq_update_has_short_ttime(bfqd, bfqq, RQ_BIC(rq));
+ bfq_update_io_seektime(bfqd, bfqq, rq);
+
waiting = bfqq && bfq_bfqq_wait_request(bfqq);
bfq_add_request(rq);
idle_timer_disabled = waiting && !bfq_bfqq_wait_request(bfqq);
@@ -5007,7 +5364,7 @@ static bool __bfq_insert_request(struct bfq_data *bfqd, struct request *rq)
return idle_timer_disabled;
}
-#if defined(CONFIG_BFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP)
+#ifdef CONFIG_BFQ_CGROUP_DEBUG
static void bfq_update_insert_stats(struct request_queue *q,
struct bfq_queue *bfqq,
bool idle_timer_disabled,
@@ -5037,7 +5394,7 @@ static inline void bfq_update_insert_stats(struct request_queue *q,
struct bfq_queue *bfqq,
bool idle_timer_disabled,
unsigned int cmd_flags) {}
-#endif
+#endif /* CONFIG_BFQ_CGROUP_DEBUG */
static void bfq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
bool at_head)
@@ -5200,6 +5557,7 @@ static void bfq_completed_request(struct bfq_queue *bfqq, struct bfq_data *bfqd)
1UL<<(BFQ_RATE_SHIFT - 10))
bfq_update_rate_reset(bfqd, NULL);
bfqd->last_completion = now_ns;
+ bfqd->last_completed_rq_bfqq = bfqq;
/*
* If we are waiting to discover whether the request pattern
@@ -5397,8 +5755,14 @@ static void bfq_update_inject_limit(struct bfq_data *bfqd,
* total service time, and there seem to be the right
* conditions to do it, or we can lower the last base value
* computed.
+ *
+ * NOTE: (bfqd->rq_in_driver == 1) means that there is no I/O
+ * request in flight, because this function is in the code
+ * path that handles the completion of a request of bfqq, and,
+ * in particular, this function is executed before
+ * bfqd->rq_in_driver is decremented in such a code path.
*/
- if ((bfqq->last_serv_time_ns == 0 && bfqd->rq_in_driver == 0) ||
+ if ((bfqq->last_serv_time_ns == 0 && bfqd->rq_in_driver == 1) ||
tot_time_ns < bfqq->last_serv_time_ns) {
bfqq->last_serv_time_ns = tot_time_ns;
/*
@@ -5406,7 +5770,18 @@ static void bfq_update_inject_limit(struct bfq_data *bfqd,
* start trying injection.
*/
bfqq->inject_limit = max_t(unsigned int, 1, old_limit);
- }
+ } else if (!bfqd->rqs_injected && bfqd->rq_in_driver == 1)
+ /*
+ * No I/O injected and no request still in service in
+ * the drive: these are the exact conditions for
+ * computing the base value of the total service time
+ * for bfqq. So let's update this value, because it is
+ * rather variable. For example, it varies if the size
+ * or the spatial locality of the I/O requests in bfqq
+ * change.
+ */
+ bfqq->last_serv_time_ns = tot_time_ns;
+
/* update complete, not waiting for any request completion any longer */
bfqd->waited_rq = NULL;
diff --git a/block/bfq-iosched.h b/block/bfq-iosched.h
index c2faa77824f8..e80adf822bbe 100644
--- a/block/bfq-iosched.h
+++ b/block/bfq-iosched.h
@@ -357,6 +357,24 @@ struct bfq_queue {
/* max service rate measured so far */
u32 max_service_rate;
+
+ /*
+ * Pointer to the waker queue for this queue, i.e., to the
+ * queue Q such that this queue happens to get new I/O right
+ * after some I/O request of Q is completed. For details, see
+ * the comments on the choice of the queue for injection in
+ * bfq_select_queue().
+ */
+ struct bfq_queue *waker_bfqq;
+ /* node for woken_list, see below */
+ struct hlist_node woken_list_node;
+ /*
+ * Head of the list of the woken queues for this queue, i.e.,
+ * of the list of the queues for which this queue is a waker
+ * queue. This list is used to reset the waker_bfqq pointer in
+ * the woken queues when this queue exits.
+ */
+ struct hlist_head woken_list;
};
/**
@@ -533,6 +551,9 @@ struct bfq_data {
/* time of last request completion (ns) */
u64 last_completion;
+ /* bfqq owning the last completed rq */
+ struct bfq_queue *last_completed_rq_bfqq;
+
/* time of last transition from empty to non-empty (ns) */
u64 last_empty_occupied_ns;
@@ -743,7 +764,8 @@ enum bfqq_state_flags {
* update
*/
BFQQF_coop, /* bfqq is shared */
- BFQQF_split_coop /* shared bfqq will be split */
+ BFQQF_split_coop, /* shared bfqq will be split */
+ BFQQF_has_waker /* bfqq has a waker queue */
};
#define BFQ_BFQQ_FNS(name) \
@@ -763,6 +785,7 @@ BFQ_BFQQ_FNS(in_large_burst);
BFQ_BFQQ_FNS(coop);
BFQ_BFQQ_FNS(split_coop);
BFQ_BFQQ_FNS(softrt_update);
+BFQ_BFQQ_FNS(has_waker);
#undef BFQ_BFQQ_FNS
/* Expiration reasons. */
@@ -777,8 +800,13 @@ enum bfqq_expiration {
BFQQE_PREEMPTED /* preemption in progress */
};
+struct bfq_stat {
+ struct percpu_counter cpu_cnt;
+ atomic64_t aux_cnt;
+};
+
struct bfqg_stats {
-#if defined(CONFIG_BFQ_GROUP_IOSCHED) && defined(CONFIG_DEBUG_BLK_CGROUP)
+#ifdef CONFIG_BFQ_CGROUP_DEBUG
/* number of ios merged */
struct blkg_rwstat merged;
/* total time spent on device in ns, may not be accurate w/ queueing */
@@ -788,25 +816,25 @@ struct bfqg_stats {
/* number of IOs queued up */
struct blkg_rwstat queued;
/* total disk time and nr sectors dispatched by this group */
- struct blkg_stat time;
+ struct bfq_stat time;
/* sum of number of ios queued across all samples */
- struct blkg_stat avg_queue_size_sum;
+ struct bfq_stat avg_queue_size_sum;
/* count of samples taken for average */
- struct blkg_stat avg_queue_size_samples;
+ struct bfq_stat avg_queue_size_samples;
/* how many times this group has been removed from service tree */
- struct blkg_stat dequeue;
+ struct bfq_stat dequeue;
/* total time spent waiting for it to be assigned a timeslice. */
- struct blkg_stat group_wait_time;
+ struct bfq_stat group_wait_time;
/* time spent idling for this blkcg_gq */
- struct blkg_stat idle_time;
+ struct bfq_stat idle_time;
/* total time with empty current active q with other requests queued */
- struct blkg_stat empty_time;
+ struct bfq_stat empty_time;
/* fields after this shouldn't be cleared on stat reset */
u64 start_group_wait_time;
u64 start_idle_time;
u64 start_empty_time;
uint16_t flags;
-#endif /* CONFIG_BFQ_GROUP_IOSCHED && CONFIG_DEBUG_BLK_CGROUP */
+#endif /* CONFIG_BFQ_CGROUP_DEBUG */
};
#ifdef CONFIG_BFQ_GROUP_IOSCHED
diff --git a/block/bio.c b/block/bio.c
index ce797d73bb43..29cd6cf4da51 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -558,14 +558,6 @@ void bio_put(struct bio *bio)
}
EXPORT_SYMBOL(bio_put);
-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;
-}
-
/**
* __bio_clone_fast - clone a bio that shares the original bio's biovec
* @bio: destination bio
@@ -731,10 +723,10 @@ static int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
}
}
- if (bio_full(bio))
+ if (bio_full(bio, len))
return 0;
- if (bio->bi_phys_segments >= queue_max_segments(q))
+ if (bio->bi_vcnt >= queue_max_segments(q))
return 0;
bvec = &bio->bi_io_vec[bio->bi_vcnt];
@@ -744,8 +736,6 @@ static int __bio_add_pc_page(struct request_queue *q, struct bio *bio,
bio->bi_vcnt++;
done:
bio->bi_iter.bi_size += len;
- bio->bi_phys_segments = bio->bi_vcnt;
- bio_set_flag(bio, BIO_SEG_VALID);
return len;
}
@@ -807,7 +797,7 @@ void __bio_add_page(struct bio *bio, struct page *page,
struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt];
WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
- WARN_ON_ONCE(bio_full(bio));
+ WARN_ON_ONCE(bio_full(bio, len));
bv->bv_page = page;
bv->bv_offset = off;
@@ -834,7 +824,7 @@ int bio_add_page(struct bio *bio, struct page *page,
bool same_page = false;
if (!__bio_try_merge_page(bio, page, len, offset, &same_page)) {
- if (bio_full(bio))
+ if (bio_full(bio, len))
return 0;
__bio_add_page(bio, page, len, offset);
}
@@ -842,22 +832,19 @@ int bio_add_page(struct bio *bio, struct page *page,
}
EXPORT_SYMBOL(bio_add_page);
-static void bio_get_pages(struct bio *bio)
+void bio_release_pages(struct bio *bio, bool mark_dirty)
{
struct bvec_iter_all iter_all;
struct bio_vec *bvec;
- bio_for_each_segment_all(bvec, bio, iter_all)
- get_page(bvec->bv_page);
-}
-
-static void bio_release_pages(struct bio *bio)
-{
- struct bvec_iter_all iter_all;
- struct bio_vec *bvec;
+ if (bio_flagged(bio, BIO_NO_PAGE_REF))
+ return;
- bio_for_each_segment_all(bvec, bio, iter_all)
+ bio_for_each_segment_all(bvec, bio, iter_all) {
+ if (mark_dirty && !PageCompound(bvec->bv_page))
+ set_page_dirty_lock(bvec->bv_page);
put_page(bvec->bv_page);
+ }
}
static int __bio_iov_bvec_add_pages(struct bio *bio, struct iov_iter *iter)
@@ -922,7 +909,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
if (same_page)
put_page(page);
} else {
- if (WARN_ON_ONCE(bio_full(bio)))
+ if (WARN_ON_ONCE(bio_full(bio, len)))
return -EINVAL;
__bio_add_page(bio, page, len, offset);
}
@@ -966,13 +953,10 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
ret = __bio_iov_bvec_add_pages(bio, iter);
else
ret = __bio_iov_iter_get_pages(bio, iter);
- } while (!ret && iov_iter_count(iter) && !bio_full(bio));
+ } while (!ret && iov_iter_count(iter) && !bio_full(bio, 0));
- if (iov_iter_bvec_no_ref(iter))
+ if (is_bvec)
bio_set_flag(bio, BIO_NO_PAGE_REF);
- else if (is_bvec)
- bio_get_pages(bio);
-
return bio->bi_vcnt ? 0 : ret;
}
@@ -1124,8 +1108,7 @@ static struct bio_map_data *bio_alloc_map_data(struct iov_iter *data,
if (data->nr_segs > UIO_MAXIOV)
return NULL;
- bmd = kmalloc(sizeof(struct bio_map_data) +
- sizeof(struct iovec) * data->nr_segs, gfp_mask);
+ bmd = kmalloc(struct_size(bmd, iov, data->nr_segs), gfp_mask);
if (!bmd)
return NULL;
memcpy(bmd->iov, data->iov, sizeof(struct iovec) * data->nr_segs);
@@ -1371,8 +1354,6 @@ struct bio *bio_map_user_iov(struct request_queue *q,
int j;
struct bio *bio;
int ret;
- struct bio_vec *bvec;
- struct bvec_iter_all iter_all;
if (!iov_iter_count(iter))
return ERR_PTR(-EINVAL);
@@ -1439,31 +1420,11 @@ struct bio *bio_map_user_iov(struct request_queue *q,
return bio;
out_unmap:
- bio_for_each_segment_all(bvec, bio, iter_all) {
- put_page(bvec->bv_page);
- }
+ bio_release_pages(bio, false);
bio_put(bio);
return ERR_PTR(ret);
}
-static void __bio_unmap_user(struct bio *bio)
-{
- struct bio_vec *bvec;
- struct bvec_iter_all iter_all;
-
- /*
- * make sure we dirty pages we wrote to
- */
- bio_for_each_segment_all(bvec, bio, iter_all) {
- if (bio_data_dir(bio) == READ)
- set_page_dirty_lock(bvec->bv_page);
-
- put_page(bvec->bv_page);
- }
-
- bio_put(bio);
-}
-
/**
* bio_unmap_user - unmap a bio
* @bio: the bio being unmapped
@@ -1475,7 +1436,8 @@ static void __bio_unmap_user(struct bio *bio)
*/
void bio_unmap_user(struct bio *bio)
{
- __bio_unmap_user(bio);
+ bio_release_pages(bio, bio_data_dir(bio) == READ);
+ bio_put(bio);
bio_put(bio);
}
@@ -1695,9 +1657,7 @@ static void bio_dirty_fn(struct work_struct *work)
while ((bio = next) != NULL) {
next = bio->bi_private;
- bio_set_pages_dirty(bio);
- if (!bio_flagged(bio, BIO_NO_PAGE_REF))
- bio_release_pages(bio);
+ bio_release_pages(bio, true);
bio_put(bio);
}
}
@@ -1713,8 +1673,7 @@ void bio_check_pages_dirty(struct bio *bio)
goto defer;
}
- if (!bio_flagged(bio, BIO_NO_PAGE_REF))
- bio_release_pages(bio);
+ bio_release_pages(bio, false);
bio_put(bio);
return;
defer:
@@ -1775,18 +1734,6 @@ void generic_end_io_acct(struct request_queue *q, int req_op,
}
EXPORT_SYMBOL(generic_end_io_acct);
-#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
-void bio_flush_dcache_pages(struct bio *bi)
-{
- struct bio_vec bvec;
- struct bvec_iter iter;
-
- bio_for_each_segment(bvec, bi, iter)
- flush_dcache_page(bvec.bv_page);
-}
-EXPORT_SYMBOL(bio_flush_dcache_pages);
-#endif
-
static inline bool bio_remaining_done(struct bio *bio)
{
/*
@@ -1914,10 +1861,7 @@ void bio_trim(struct bio *bio, int offset, int size)
if (offset == 0 && size == bio->bi_iter.bi_size)
return;
- bio_clear_flag(bio, BIO_SEG_VALID);
-
bio_advance(bio, offset << 9);
-
bio->bi_iter.bi_size = size;
if (bio_integrity(bio))
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 1f7127b03490..53b7bd4c7000 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -79,6 +79,7 @@ static void blkg_free(struct blkcg_gq *blkg)
blkg_rwstat_exit(&blkg->stat_ios);
blkg_rwstat_exit(&blkg->stat_bytes);
+ percpu_ref_exit(&blkg->refcnt);
kfree(blkg);
}
@@ -86,8 +87,6 @@ static void __blkg_release(struct rcu_head *rcu)
{
struct blkcg_gq *blkg = container_of(rcu, struct blkcg_gq, rcu_head);
- percpu_ref_exit(&blkg->refcnt);
-
/* release the blkcg and parent blkg refs this blkg has been holding */
css_put(&blkg->blkcg->css);
if (blkg->parent)
@@ -132,6 +131,9 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct request_queue *q,
if (!blkg)
return NULL;
+ if (percpu_ref_init(&blkg->refcnt, blkg_release, 0, gfp_mask))
+ goto err_free;
+
if (blkg_rwstat_init(&blkg->stat_bytes, gfp_mask) ||
blkg_rwstat_init(&blkg->stat_ios, gfp_mask))
goto err_free;
@@ -244,11 +246,6 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg,
blkg_get(blkg->parent);
}
- ret = percpu_ref_init(&blkg->refcnt, blkg_release, 0,
- GFP_NOWAIT | __GFP_NOWARN);
- if (ret)
- goto err_cancel_ref;
-
/* invoke per-policy init */
for (i = 0; i < BLKCG_MAX_POLS; i++) {
struct blkcg_policy *pol = blkcg_policy[i];
@@ -281,8 +278,6 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg,
blkg_put(blkg);
return ERR_PTR(ret);
-err_cancel_ref:
- percpu_ref_exit(&blkg->refcnt);
err_put_congested:
wb_congested_put(wb_congested);
err_put_css:
@@ -549,7 +544,7 @@ EXPORT_SYMBOL_GPL(__blkg_prfill_u64);
* Print @rwstat to @sf for the device assocaited with @pd.
*/
u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
- const struct blkg_rwstat *rwstat)
+ const struct blkg_rwstat_sample *rwstat)
{
static const char *rwstr[] = {
[BLKG_RWSTAT_READ] = "Read",
@@ -567,31 +562,17 @@ u64 __blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
for (i = 0; i < BLKG_RWSTAT_NR; i++)
seq_printf(sf, "%s %s %llu\n", dname, rwstr[i],
- (unsigned long long)atomic64_read(&rwstat->aux_cnt[i]));
+ rwstat->cnt[i]);
- v = atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_READ]) +
- atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_WRITE]) +
- atomic64_read(&rwstat->aux_cnt[BLKG_RWSTAT_DISCARD]);
- seq_printf(sf, "%s Total %llu\n", dname, (unsigned long long)v);
+ v = rwstat->cnt[BLKG_RWSTAT_READ] +
+ rwstat->cnt[BLKG_RWSTAT_WRITE] +
+ rwstat->cnt[BLKG_RWSTAT_DISCARD];
+ seq_printf(sf, "%s Total %llu\n", dname, v);
return v;
}
EXPORT_SYMBOL_GPL(__blkg_prfill_rwstat);
/**
- * blkg_prfill_stat - prfill callback for blkg_stat
- * @sf: seq_file to print to
- * @pd: policy private data of interest
- * @off: offset to the blkg_stat in @pd
- *
- * prfill callback for printing a blkg_stat.
- */
-u64 blkg_prfill_stat(struct seq_file *sf, struct blkg_policy_data *pd, int off)
-{
- return __blkg_prfill_u64(sf, pd, blkg_stat_read((void *)pd + off));
-}
-EXPORT_SYMBOL_GPL(blkg_prfill_stat);
-
-/**
* blkg_prfill_rwstat - prfill callback for blkg_rwstat
* @sf: seq_file to print to
* @pd: policy private data of interest
@@ -602,8 +583,9 @@ EXPORT_SYMBOL_GPL(blkg_prfill_stat);
u64 blkg_prfill_rwstat(struct seq_file *sf, struct blkg_policy_data *pd,
int off)
{
- struct blkg_rwstat rwstat = blkg_rwstat_read((void *)pd + off);
+ struct blkg_rwstat_sample rwstat = { };
+ blkg_rwstat_read((void *)pd + off, &rwstat);
return __blkg_prfill_rwstat(sf, pd, &rwstat);
}
EXPORT_SYMBOL_GPL(blkg_prfill_rwstat);
@@ -611,8 +593,9 @@ EXPORT_SYMBOL_GPL(blkg_prfill_rwstat);
static u64 blkg_prfill_rwstat_field(struct seq_file *sf,
struct blkg_policy_data *pd, int off)
{
- struct blkg_rwstat rwstat = blkg_rwstat_read((void *)pd->blkg + off);
+ struct blkg_rwstat_sample rwstat = { };
+ blkg_rwstat_read((void *)pd->blkg + off, &rwstat);
return __blkg_prfill_rwstat(sf, pd, &rwstat);
}
@@ -654,8 +637,9 @@ static u64 blkg_prfill_rwstat_field_recursive(struct seq_file *sf,
struct blkg_policy_data *pd,
int off)
{
- struct blkg_rwstat rwstat = blkg_rwstat_recursive_sum(pd->blkg,
- NULL, off);
+ struct blkg_rwstat_sample rwstat;
+
+ blkg_rwstat_recursive_sum(pd->blkg, NULL, off, &rwstat);
return __blkg_prfill_rwstat(sf, pd, &rwstat);
}
@@ -690,52 +674,11 @@ int blkg_print_stat_ios_recursive(struct seq_file *sf, void *v)
EXPORT_SYMBOL_GPL(blkg_print_stat_ios_recursive);
/**
- * blkg_stat_recursive_sum - collect hierarchical blkg_stat
- * @blkg: blkg of interest
- * @pol: blkcg_policy which contains the blkg_stat
- * @off: offset to the blkg_stat in blkg_policy_data or @blkg
- *
- * Collect the blkg_stat specified by @blkg, @pol and @off and all its
- * online descendants and their aux counts. The caller must be holding the
- * queue lock for online tests.
- *
- * If @pol is NULL, blkg_stat is at @off bytes into @blkg; otherwise, it is
- * at @off bytes into @blkg's blkg_policy_data of the policy.
- */
-u64 blkg_stat_recursive_sum(struct blkcg_gq *blkg,
- struct blkcg_policy *pol, int off)
-{
- struct blkcg_gq *pos_blkg;
- struct cgroup_subsys_state *pos_css;
- u64 sum = 0;
-
- lockdep_assert_held(&blkg->q->queue_lock);
-
- rcu_read_lock();
- blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
- struct blkg_stat *stat;
-
- if (!pos_blkg->online)
- continue;
-
- if (pol)
- stat = (void *)blkg_to_pd(pos_blkg, pol) + off;
- else
- stat = (void *)blkg + off;
-
- sum += blkg_stat_read(stat) + atomic64_read(&stat->aux_cnt);
- }
- rcu_read_unlock();
-
- return sum;
-}
-EXPORT_SYMBOL_GPL(blkg_stat_recursive_sum);
-
-/**
* blkg_rwstat_recursive_sum - collect hierarchical blkg_rwstat
* @blkg: blkg of interest
* @pol: blkcg_policy which contains the blkg_rwstat
* @off: offset to the blkg_rwstat in blkg_policy_data or @blkg
+ * @sum: blkg_rwstat_sample structure containing the results
*
* Collect the blkg_rwstat specified by @blkg, @pol and @off and all its
* online descendants and their aux counts. The caller must be holding the
@@ -744,13 +687,12 @@ EXPORT_SYMBOL_GPL(blkg_stat_recursive_sum);
* If @pol is NULL, blkg_rwstat is at @off bytes into @blkg; otherwise, it
* is at @off bytes into @blkg's blkg_policy_data of the policy.
*/
-struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg,
- struct blkcg_policy *pol, int off)
+void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol,
+ int off, struct blkg_rwstat_sample *sum)
{
struct blkcg_gq *pos_blkg;
struct cgroup_subsys_state *pos_css;
- struct blkg_rwstat sum = { };
- int i;
+ unsigned int i;
lockdep_assert_held(&blkg->q->queue_lock);
@@ -767,13 +709,9 @@ struct blkg_rwstat blkg_rwstat_recursive_sum(struct blkcg_gq *blkg,
rwstat = (void *)pos_blkg + off;
for (i = 0; i < BLKG_RWSTAT_NR; i++)
- atomic64_add(atomic64_read(&rwstat->aux_cnt[i]) +
- percpu_counter_sum_positive(&rwstat->cpu_cnt[i]),
- &sum.aux_cnt[i]);
+ sum->cnt[i] = blkg_rwstat_read_counter(rwstat, i);
}
rcu_read_unlock();
-
- return sum;
}
EXPORT_SYMBOL_GPL(blkg_rwstat_recursive_sum);
@@ -939,7 +877,7 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
const char *dname;
char *buf;
- struct blkg_rwstat rwstat;
+ struct blkg_rwstat_sample rwstat;
u64 rbytes, wbytes, rios, wios, dbytes, dios;
size_t size = seq_get_buf(sf, &buf), off = 0;
int i;
@@ -959,17 +897,17 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
spin_lock_irq(&blkg->q->queue_lock);
- rwstat = blkg_rwstat_recursive_sum(blkg, NULL,
- offsetof(struct blkcg_gq, stat_bytes));
- rbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]);
- wbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]);
- dbytes = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_DISCARD]);
+ blkg_rwstat_recursive_sum(blkg, NULL,
+ offsetof(struct blkcg_gq, stat_bytes), &rwstat);
+ rbytes = rwstat.cnt[BLKG_RWSTAT_READ];
+ wbytes = rwstat.cnt[BLKG_RWSTAT_WRITE];
+ dbytes = rwstat.cnt[BLKG_RWSTAT_DISCARD];
- rwstat = blkg_rwstat_recursive_sum(blkg, NULL,
- offsetof(struct blkcg_gq, stat_ios));
- rios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_READ]);
- wios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_WRITE]);
- dios = atomic64_read(&rwstat.aux_cnt[BLKG_RWSTAT_DISCARD]);
+ blkg_rwstat_recursive_sum(blkg, NULL,
+ offsetof(struct blkcg_gq, stat_ios), &rwstat);
+ rios = rwstat.cnt[BLKG_RWSTAT_READ];
+ wios = rwstat.cnt[BLKG_RWSTAT_WRITE];
+ dios = rwstat.cnt[BLKG_RWSTAT_DISCARD];
spin_unlock_irq(&blkg->q->queue_lock);
@@ -1006,8 +944,12 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
}
next:
if (has_stats) {
- off += scnprintf(buf+off, size-off, "\n");
- seq_commit(sf, off);
+ if (off < size - 1) {
+ off += scnprintf(buf+off, size-off, "\n");
+ seq_commit(sf, off);
+ } else {
+ seq_commit(sf, -1);
+ }
}
}
@@ -1391,7 +1333,8 @@ pd_prealloc:
spin_lock_irq(&q->queue_lock);
- list_for_each_entry(blkg, &q->blkg_list, q_node) {
+ /* blkg_list is pushed at the head, reverse walk to init parents first */
+ list_for_each_entry_reverse(blkg, &q->blkg_list, q_node) {
struct blkg_policy_data *pd;
if (blkg->pd[pol->plid])
diff --git a/block/blk-core.c b/block/blk-core.c
index 8340f69670d8..5d1fc8e17dd1 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -120,6 +120,42 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
}
EXPORT_SYMBOL(blk_rq_init);
+#define REQ_OP_NAME(name) [REQ_OP_##name] = #name
+static const char *const blk_op_name[] = {
+ REQ_OP_NAME(READ),
+ REQ_OP_NAME(WRITE),
+ REQ_OP_NAME(FLUSH),
+ REQ_OP_NAME(DISCARD),
+ REQ_OP_NAME(SECURE_ERASE),
+ REQ_OP_NAME(ZONE_RESET),
+ REQ_OP_NAME(WRITE_SAME),
+ REQ_OP_NAME(WRITE_ZEROES),
+ REQ_OP_NAME(SCSI_IN),
+ REQ_OP_NAME(SCSI_OUT),
+ REQ_OP_NAME(DRV_IN),
+ REQ_OP_NAME(DRV_OUT),
+};
+#undef REQ_OP_NAME
+
+/**
+ * blk_op_str - Return string XXX in the REQ_OP_XXX.
+ * @op: REQ_OP_XXX.
+ *
+ * Description: Centralize block layer function to convert REQ_OP_XXX into
+ * string format. Useful in the debugging and tracing bio or request. For
+ * invalid REQ_OP_XXX it returns string "UNKNOWN".
+ */
+inline const char *blk_op_str(unsigned int op)
+{
+ const char *op_str = "UNKNOWN";
+
+ if (op < ARRAY_SIZE(blk_op_name) && blk_op_name[op])
+ op_str = blk_op_name[op];
+
+ return op_str;
+}
+EXPORT_SYMBOL_GPL(blk_op_str);
+
static const struct {
int errno;
const char *name;
@@ -167,18 +203,23 @@ int blk_status_to_errno(blk_status_t status)
}
EXPORT_SYMBOL_GPL(blk_status_to_errno);
-static void print_req_error(struct request *req, blk_status_t status)
+static void print_req_error(struct request *req, blk_status_t status,
+ const char *caller)
{
int idx = (__force int)status;
if (WARN_ON_ONCE(idx >= ARRAY_SIZE(blk_errors)))
return;
- printk_ratelimited(KERN_ERR "%s: %s error, dev %s, sector %llu flags %x\n",
- __func__, blk_errors[idx].name,
- req->rq_disk ? req->rq_disk->disk_name : "?",
- (unsigned long long)blk_rq_pos(req),
- req->cmd_flags);
+ printk_ratelimited(KERN_ERR
+ "%s: %s error, dev %s, sector %llu op 0x%x:(%s) flags 0x%x "
+ "phys_seg %u prio class %u\n",
+ caller, blk_errors[idx].name,
+ req->rq_disk ? req->rq_disk->disk_name : "?",
+ blk_rq_pos(req), req_op(req), blk_op_str(req_op(req)),
+ req->cmd_flags & ~REQ_OP_MASK,
+ req->nr_phys_segments,
+ IOPRIO_PRIO_CLASS(req->ioprio));
}
static void req_bio_endio(struct request *rq, struct bio *bio,
@@ -550,15 +591,15 @@ void blk_put_request(struct request *req)
}
EXPORT_SYMBOL(blk_put_request);
-bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
- struct bio *bio)
+bool bio_attempt_back_merge(struct request *req, struct bio *bio,
+ unsigned int nr_segs)
{
const int ff = bio->bi_opf & REQ_FAILFAST_MASK;
- if (!ll_back_merge_fn(q, req, bio))
+ if (!ll_back_merge_fn(req, bio, nr_segs))
return false;
- trace_block_bio_backmerge(q, req, bio);
+ trace_block_bio_backmerge(req->q, req, bio);
if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
blk_rq_set_mixed_merge(req);
@@ -571,15 +612,15 @@ bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
return true;
}
-bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
- struct bio *bio)
+bool bio_attempt_front_merge(struct request *req, struct bio *bio,
+ unsigned int nr_segs)
{
const int ff = bio->bi_opf & REQ_FAILFAST_MASK;
- if (!ll_front_merge_fn(q, req, bio))
+ if (!ll_front_merge_fn(req, bio, nr_segs))
return false;
- trace_block_bio_frontmerge(q, req, bio);
+ trace_block_bio_frontmerge(req->q, req, bio);
if ((req->cmd_flags & REQ_FAILFAST_MASK) != ff)
blk_rq_set_mixed_merge(req);
@@ -621,6 +662,7 @@ no_merge:
* blk_attempt_plug_merge - try to merge with %current's plugged list
* @q: request_queue new bio is being queued at
* @bio: new bio being queued
+ * @nr_segs: number of segments in @bio
* @same_queue_rq: pointer to &struct request that gets filled in when
* another request associated with @q is found on the plug list
* (optional, may be %NULL)
@@ -639,7 +681,7 @@ no_merge:
* Caller must ensure !blk_queue_nomerges(q) beforehand.
*/
bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
- struct request **same_queue_rq)
+ unsigned int nr_segs, struct request **same_queue_rq)
{
struct blk_plug *plug;
struct request *rq;
@@ -668,10 +710,10 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
switch (blk_try_merge(rq, bio)) {
case ELEVATOR_BACK_MERGE:
- merged = bio_attempt_back_merge(q, rq, bio);
+ merged = bio_attempt_back_merge(rq, bio, nr_segs);
break;
case ELEVATOR_FRONT_MERGE:
- merged = bio_attempt_front_merge(q, rq, bio);
+ merged = bio_attempt_front_merge(rq, bio, nr_segs);
break;
case ELEVATOR_DISCARD_MERGE:
merged = bio_attempt_discard_merge(q, rq, bio);
@@ -687,18 +729,6 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
return false;
}
-void blk_init_request_from_bio(struct request *req, struct bio *bio)
-{
- if (bio->bi_opf & REQ_RAHEAD)
- req->cmd_flags |= REQ_FAILFAST_MASK;
-
- req->__sector = bio->bi_iter.bi_sector;
- req->ioprio = bio_prio(bio);
- req->write_hint = bio->bi_write_hint;
- blk_rq_bio_prep(req->q, req, bio);
-}
-EXPORT_SYMBOL_GPL(blk_init_request_from_bio);
-
static void handle_bad_sector(struct bio *bio, sector_t maxsector)
{
char b[BDEVNAME_SIZE];
@@ -1163,7 +1193,7 @@ static int blk_cloned_rq_check_limits(struct request_queue *q,
* Recalculate it to check the request correctly on this queue's
* limitation.
*/
- blk_recalc_rq_segments(rq);
+ rq->nr_phys_segments = blk_recalc_rq_segments(rq);
if (rq->nr_phys_segments > queue_max_segments(q)) {
printk(KERN_ERR "%s: over max segments limit. (%hu > %hu)\n",
__func__, rq->nr_phys_segments, queue_max_segments(q));
@@ -1348,7 +1378,7 @@ EXPORT_SYMBOL_GPL(blk_steal_bios);
*
* This special helper function is only for request stacking drivers
* (e.g. request-based dm) so that they can handle partial completion.
- * Actual device drivers should use blk_end_request instead.
+ * Actual device drivers should use blk_mq_end_request instead.
*
* Passing the result of blk_rq_bytes() as @nr_bytes guarantees
* %false return from this function.
@@ -1373,7 +1403,7 @@ bool blk_update_request(struct request *req, blk_status_t error,
if (unlikely(error && !blk_rq_is_passthrough(req) &&
!(req->rq_flags & RQF_QUIET)))
- print_req_error(req, error);
+ print_req_error(req, error, __func__);
blk_account_io_completion(req, nr_bytes);
@@ -1432,28 +1462,13 @@ bool blk_update_request(struct request *req, blk_status_t error,
}
/* recalculate the number of segments */
- blk_recalc_rq_segments(req);
+ req->nr_phys_segments = blk_recalc_rq_segments(req);
}
return true;
}
EXPORT_SYMBOL_GPL(blk_update_request);
-void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
- struct bio *bio)
-{
- if (bio_has_data(bio))
- rq->nr_phys_segments = bio_phys_segments(q, bio);
- else if (bio_op(bio) == REQ_OP_DISCARD)
- rq->nr_phys_segments = 1;
-
- rq->__data_len = bio->bi_iter.bi_size;
- rq->bio = rq->biotail = bio;
-
- if (bio->bi_disk)
- rq->rq_disk = bio->bi_disk;
-}
-
#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
/**
* rq_flush_dcache_pages - Helper function to flush all pages in a request
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index d22e61bced86..d973c38ee4fd 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -618,44 +618,26 @@ static void blkcg_iolatency_done_bio(struct rq_qos *rqos, struct bio *bio)
inflight = atomic_dec_return(&rqw->inflight);
WARN_ON_ONCE(inflight < 0);
- if (iolat->min_lat_nsec == 0)
- goto next;
- iolatency_record_time(iolat, &bio->bi_issue, now,
- issue_as_root);
- window_start = atomic64_read(&iolat->window_start);
- if (now > window_start &&
- (now - window_start) >= iolat->cur_win_nsec) {
- if (atomic64_cmpxchg(&iolat->window_start,
- window_start, now) == window_start)
- iolatency_check_latencies(iolat, now);
+ /*
+ * If bi_status is BLK_STS_AGAIN, the bio wasn't actually
+ * submitted, so do not account for it.
+ */
+ if (iolat->min_lat_nsec && bio->bi_status != BLK_STS_AGAIN) {
+ iolatency_record_time(iolat, &bio->bi_issue, now,
+ issue_as_root);
+ window_start = atomic64_read(&iolat->window_start);
+ if (now > window_start &&
+ (now - window_start) >= iolat->cur_win_nsec) {
+ if (atomic64_cmpxchg(&iolat->window_start,
+ window_start, now) == window_start)
+ iolatency_check_latencies(iolat, now);
+ }
}
-next:
wake_up(&rqw->wait);
blkg = blkg->parent;
}
}
-static void blkcg_iolatency_cleanup(struct rq_qos *rqos, struct bio *bio)
-{
- struct blkcg_gq *blkg;
-
- blkg = bio->bi_blkg;
- while (blkg && blkg->parent) {
- struct rq_wait *rqw;
- struct iolatency_grp *iolat;
-
- iolat = blkg_to_lat(blkg);
- if (!iolat)
- goto next;
-
- rqw = &iolat->rq_wait;
- atomic_dec(&rqw->inflight);
- wake_up(&rqw->wait);
-next:
- blkg = blkg->parent;
- }
-}
-
static void blkcg_iolatency_exit(struct rq_qos *rqos)
{
struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos);
@@ -667,7 +649,6 @@ static void blkcg_iolatency_exit(struct rq_qos *rqos)
static struct rq_qos_ops blkcg_iolatency_ops = {
.throttle = blkcg_iolatency_throttle,
- .cleanup = blkcg_iolatency_cleanup,
.done_bio = blkcg_iolatency_done_bio,
.exit = blkcg_iolatency_exit,
};
@@ -778,8 +759,10 @@ static int iolatency_set_min_lat_nsec(struct blkcg_gq *blkg, u64 val)
if (!oldval && val)
return 1;
- if (oldval && !val)
+ if (oldval && !val) {
+ blkcg_clear_delay(blkg);
return -1;
+ }
return 0;
}
diff --git a/block/blk-map.c b/block/blk-map.c
index db9373bd31ac..3a62e471d81b 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -18,13 +18,19 @@
int blk_rq_append_bio(struct request *rq, struct bio **bio)
{
struct bio *orig_bio = *bio;
+ struct bvec_iter iter;
+ struct bio_vec bv;
+ unsigned int nr_segs = 0;
blk_queue_bounce(rq->q, bio);
+ bio_for_each_bvec(bv, *bio, iter)
+ nr_segs++;
+
if (!rq->bio) {
- blk_rq_bio_prep(rq->q, rq, *bio);
+ blk_rq_bio_prep(rq, *bio, nr_segs);
} else {
- if (!ll_back_merge_fn(rq->q, rq, *bio)) {
+ if (!ll_back_merge_fn(rq, *bio, nr_segs)) {
if (orig_bio != *bio) {
bio_put(*bio);
*bio = orig_bio;
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 17713d7d98d5..57f7990b342d 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -105,7 +105,7 @@ static struct bio *blk_bio_discard_split(struct request_queue *q,
static struct bio *blk_bio_write_zeroes_split(struct request_queue *q,
struct bio *bio, struct bio_set *bs, unsigned *nsegs)
{
- *nsegs = 1;
+ *nsegs = 0;
if (!q->limits.max_write_zeroes_sectors)
return NULL;
@@ -202,8 +202,6 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
struct bio_vec bv, bvprv, *bvprvp = NULL;
struct bvec_iter iter;
unsigned nsegs = 0, sectors = 0;
- bool do_split = true;
- struct bio *new = NULL;
const unsigned max_sectors = get_max_io_size(q, bio);
const unsigned max_segs = queue_max_segments(q);
@@ -245,45 +243,36 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
}
}
- do_split = false;
+ *segs = nsegs;
+ return NULL;
split:
*segs = nsegs;
-
- if (do_split) {
- new = bio_split(bio, sectors, GFP_NOIO, bs);
- if (new)
- bio = new;
- }
-
- return do_split ? new : NULL;
+ return bio_split(bio, sectors, GFP_NOIO, bs);
}
-void blk_queue_split(struct request_queue *q, struct bio **bio)
+void __blk_queue_split(struct request_queue *q, struct bio **bio,
+ unsigned int *nr_segs)
{
- struct bio *split, *res;
- unsigned nsegs;
+ struct bio *split;
switch (bio_op(*bio)) {
case REQ_OP_DISCARD:
case REQ_OP_SECURE_ERASE:
- split = blk_bio_discard_split(q, *bio, &q->bio_split, &nsegs);
+ split = blk_bio_discard_split(q, *bio, &q->bio_split, nr_segs);
break;
case REQ_OP_WRITE_ZEROES:
- split = blk_bio_write_zeroes_split(q, *bio, &q->bio_split, &nsegs);
+ split = blk_bio_write_zeroes_split(q, *bio, &q->bio_split,
+ nr_segs);
break;
case REQ_OP_WRITE_SAME:
- split = blk_bio_write_same_split(q, *bio, &q->bio_split, &nsegs);
+ split = blk_bio_write_same_split(q, *bio, &q->bio_split,
+ nr_segs);
break;
default:
- split = blk_bio_segment_split(q, *bio, &q->bio_split, &nsegs);
+ split = blk_bio_segment_split(q, *bio, &q->bio_split, nr_segs);
break;
}
- /* 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_opf |= REQ_NOMERGE;
@@ -304,19 +293,25 @@ void blk_queue_split(struct request_queue *q, struct bio **bio)
*bio = split;
}
}
+
+void blk_queue_split(struct request_queue *q, struct bio **bio)
+{
+ unsigned int nr_segs;
+
+ __blk_queue_split(q, bio, &nr_segs);
+}
EXPORT_SYMBOL(blk_queue_split);
-static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
- struct bio *bio)
+unsigned int blk_recalc_rq_segments(struct request *rq)
{
unsigned int nr_phys_segs = 0;
- struct bvec_iter iter;
+ struct req_iterator iter;
struct bio_vec bv;
- if (!bio)
+ if (!rq->bio)
return 0;
- switch (bio_op(bio)) {
+ switch (bio_op(rq->bio)) {
case REQ_OP_DISCARD:
case REQ_OP_SECURE_ERASE:
case REQ_OP_WRITE_ZEROES:
@@ -325,30 +320,11 @@ static unsigned int __blk_recalc_rq_segments(struct request_queue *q,
return 1;
}
- for_each_bio(bio) {
- bio_for_each_bvec(bv, bio, iter)
- bvec_split_segs(q, &bv, &nr_phys_segs, NULL, UINT_MAX);
- }
-
+ rq_for_each_bvec(bv, rq, iter)
+ bvec_split_segs(rq->q, &bv, &nr_phys_segs, NULL, UINT_MAX);
return nr_phys_segs;
}
-void blk_recalc_rq_segments(struct request *rq)
-{
- rq->nr_phys_segments = __blk_recalc_rq_segments(rq->q, rq->bio);
-}
-
-void blk_recount_segments(struct request_queue *q, struct bio *bio)
-{
- struct bio *nxt = bio->bi_next;
-
- bio->bi_next = NULL;
- bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio);
- bio->bi_next = nxt;
-
- bio_set_flag(bio, BIO_SEG_VALID);
-}
-
static inline struct scatterlist *blk_next_sg(struct scatterlist **sg,
struct scatterlist *sglist)
{
@@ -519,16 +495,13 @@ int blk_rq_map_sg(struct request_queue *q, struct request *rq,
}
EXPORT_SYMBOL(blk_rq_map_sg);
-static inline int ll_new_hw_segment(struct request_queue *q,
- struct request *req,
- struct bio *bio)
+static inline int ll_new_hw_segment(struct request *req, struct bio *bio,
+ unsigned int nr_phys_segs)
{
- int nr_phys_segs = bio_phys_segments(q, bio);
-
- if (req->nr_phys_segments + nr_phys_segs > queue_max_segments(q))
+ if (req->nr_phys_segments + nr_phys_segs > queue_max_segments(req->q))
goto no_merge;
- if (blk_integrity_merge_bio(q, req, bio) == false)
+ if (blk_integrity_merge_bio(req->q, req, bio) == false)
goto no_merge;
/*
@@ -539,12 +512,11 @@ static inline int ll_new_hw_segment(struct request_queue *q,
return 1;
no_merge:
- req_set_nomerge(q, req);
+ req_set_nomerge(req->q, req);
return 0;
}
-int ll_back_merge_fn(struct request_queue *q, struct request *req,
- struct bio *bio)
+int ll_back_merge_fn(struct request *req, struct bio *bio, unsigned int nr_segs)
{
if (req_gap_back_merge(req, bio))
return 0;
@@ -553,21 +525,15 @@ int ll_back_merge_fn(struct request_queue *q, struct request *req,
return 0;
if (blk_rq_sectors(req) + bio_sectors(bio) >
blk_rq_get_max_sectors(req, blk_rq_pos(req))) {
- req_set_nomerge(q, req);
+ req_set_nomerge(req->q, req);
return 0;
}
- if (!bio_flagged(req->biotail, BIO_SEG_VALID))
- blk_recount_segments(q, req->biotail);
- if (!bio_flagged(bio, BIO_SEG_VALID))
- blk_recount_segments(q, bio);
- return ll_new_hw_segment(q, req, bio);
+ return ll_new_hw_segment(req, bio, nr_segs);
}
-int ll_front_merge_fn(struct request_queue *q, struct request *req,
- struct bio *bio)
+int ll_front_merge_fn(struct request *req, struct bio *bio, unsigned int nr_segs)
{
-
if (req_gap_front_merge(req, bio))
return 0;
if (blk_integrity_rq(req) &&
@@ -575,15 +541,11 @@ int ll_front_merge_fn(struct request_queue *q, struct request *req,
return 0;
if (blk_rq_sectors(req) + bio_sectors(bio) >
blk_rq_get_max_sectors(req, bio->bi_iter.bi_sector)) {
- req_set_nomerge(q, req);
+ req_set_nomerge(req->q, req);
return 0;
}
- if (!bio_flagged(bio, BIO_SEG_VALID))
- blk_recount_segments(q, bio);
- if (!bio_flagged(req->bio, BIO_SEG_VALID))
- blk_recount_segments(q, req->bio);
- return ll_new_hw_segment(q, req, bio);
+ return ll_new_hw_segment(req, bio, nr_segs);
}
static bool req_attempt_discard_merge(struct request_queue *q, struct request *req,
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 3afe327f816f..b3f2ba483992 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -17,7 +17,7 @@
static void print_stat(struct seq_file *m, struct blk_rq_stat *stat)
{
if (stat->nr_samples) {
- seq_printf(m, "samples=%d, mean=%lld, min=%llu, max=%llu",
+ seq_printf(m, "samples=%d, mean=%llu, min=%llu, max=%llu",
stat->nr_samples, stat->mean, stat->min, stat->max);
} else {
seq_puts(m, "samples=0");
@@ -29,13 +29,13 @@ static int queue_poll_stat_show(void *data, struct seq_file *m)
struct request_queue *q = data;
int bucket;
- for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS/2; bucket++) {
- seq_printf(m, "read (%d Bytes): ", 1 << (9+bucket));
- print_stat(m, &q->poll_stat[2*bucket]);
+ for (bucket = 0; bucket < (BLK_MQ_POLL_STATS_BKTS / 2); bucket++) {
+ seq_printf(m, "read (%d Bytes): ", 1 << (9 + bucket));
+ print_stat(m, &q->poll_stat[2 * bucket]);
seq_puts(m, "\n");
- seq_printf(m, "write (%d Bytes): ", 1 << (9+bucket));
- print_stat(m, &q->poll_stat[2*bucket+1]);
+ seq_printf(m, "write (%d Bytes): ", 1 << (9 + bucket));
+ print_stat(m, &q->poll_stat[2 * bucket + 1]);
seq_puts(m, "\n");
}
return 0;
@@ -261,23 +261,6 @@ static int hctx_flags_show(void *data, struct seq_file *m)
return 0;
}
-#define REQ_OP_NAME(name) [REQ_OP_##name] = #name
-static const char *const op_name[] = {
- REQ_OP_NAME(READ),
- REQ_OP_NAME(WRITE),
- REQ_OP_NAME(FLUSH),
- REQ_OP_NAME(DISCARD),
- REQ_OP_NAME(SECURE_ERASE),
- REQ_OP_NAME(ZONE_RESET),
- REQ_OP_NAME(WRITE_SAME),
- REQ_OP_NAME(WRITE_ZEROES),
- REQ_OP_NAME(SCSI_IN),
- REQ_OP_NAME(SCSI_OUT),
- REQ_OP_NAME(DRV_IN),
- REQ_OP_NAME(DRV_OUT),
-};
-#undef REQ_OP_NAME
-
#define CMD_FLAG_NAME(name) [__REQ_##name] = #name
static const char *const cmd_flag_name[] = {
CMD_FLAG_NAME(FAILFAST_DEV),
@@ -341,13 +324,14 @@ static const char *blk_mq_rq_state_name(enum mq_rq_state rq_state)
int __blk_mq_debugfs_rq_show(struct seq_file *m, struct request *rq)
{
const struct blk_mq_ops *const mq_ops = rq->q->mq_ops;
- const unsigned int op = rq->cmd_flags & REQ_OP_MASK;
+ const unsigned int op = req_op(rq);
+ const char *op_str = blk_op_str(op);
seq_printf(m, "%p {.op=", rq);
- if (op < ARRAY_SIZE(op_name) && op_name[op])
- seq_printf(m, "%s", op_name[op]);
+ if (strcmp(op_str, "UNKNOWN") == 0)
+ seq_printf(m, "%u", op);
else
- seq_printf(m, "%d", op);
+ seq_printf(m, "%s", op_str);
seq_puts(m, ", .cmd_flags=");
blk_flags_show(m, rq->cmd_flags & ~REQ_OP_MASK, cmd_flag_name,
ARRAY_SIZE(cmd_flag_name));
@@ -779,8 +763,8 @@ static int blk_mq_debugfs_release(struct inode *inode, struct file *file)
if (attr->show)
return single_release(inode, file);
- else
- return seq_release(inode, file);
+
+ return seq_release(inode, file);
}
static const struct file_operations blk_mq_debugfs_fops = {
diff --git a/block/blk-mq-sched.c b/block/blk-mq-sched.c
index 2766066a15db..c9d183d6c499 100644
--- a/block/blk-mq-sched.c
+++ b/block/blk-mq-sched.c
@@ -224,7 +224,7 @@ void blk_mq_sched_dispatch_requests(struct blk_mq_hw_ctx *hctx)
}
bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio,
- struct request **merged_request)
+ unsigned int nr_segs, struct request **merged_request)
{
struct request *rq;
@@ -232,7 +232,7 @@ bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio,
case ELEVATOR_BACK_MERGE:
if (!blk_mq_sched_allow_merge(q, rq, bio))
return false;
- if (!bio_attempt_back_merge(q, rq, bio))
+ if (!bio_attempt_back_merge(rq, bio, nr_segs))
return false;
*merged_request = attempt_back_merge(q, rq);
if (!*merged_request)
@@ -241,7 +241,7 @@ bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio,
case ELEVATOR_FRONT_MERGE:
if (!blk_mq_sched_allow_merge(q, rq, bio))
return false;
- if (!bio_attempt_front_merge(q, rq, bio))
+ if (!bio_attempt_front_merge(rq, bio, nr_segs))
return false;
*merged_request = attempt_front_merge(q, rq);
if (!*merged_request)
@@ -260,7 +260,7 @@ EXPORT_SYMBOL_GPL(blk_mq_sched_try_merge);
* of them.
*/
bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list,
- struct bio *bio)
+ struct bio *bio, unsigned int nr_segs)
{
struct request *rq;
int checked = 8;
@@ -277,11 +277,13 @@ bool blk_mq_bio_list_merge(struct request_queue *q, struct list_head *list,
switch (blk_try_merge(rq, bio)) {
case ELEVATOR_BACK_MERGE:
if (blk_mq_sched_allow_merge(q, rq, bio))
- merged = bio_attempt_back_merge(q, rq, bio);
+ merged = bio_attempt_back_merge(rq, bio,
+ nr_segs);
break;
case ELEVATOR_FRONT_MERGE:
if (blk_mq_sched_allow_merge(q, rq, bio))
- merged = bio_attempt_front_merge(q, rq, bio);
+ merged = bio_attempt_front_merge(rq, bio,
+ nr_segs);
break;
case ELEVATOR_DISCARD_MERGE:
merged = bio_attempt_discard_merge(q, rq, bio);
@@ -304,13 +306,14 @@ EXPORT_SYMBOL_GPL(blk_mq_bio_list_merge);
*/
static bool blk_mq_attempt_merge(struct request_queue *q,
struct blk_mq_hw_ctx *hctx,
- struct blk_mq_ctx *ctx, struct bio *bio)
+ struct blk_mq_ctx *ctx, struct bio *bio,
+ unsigned int nr_segs)
{
enum hctx_type type = hctx->type;
lockdep_assert_held(&ctx->lock);
- if (blk_mq_bio_list_merge(q, &ctx->rq_lists[type], bio)) {
+ if (blk_mq_bio_list_merge(q, &ctx->rq_lists[type], bio, nr_segs)) {
ctx->rq_merged++;
return true;
}
@@ -318,7 +321,8 @@ static bool blk_mq_attempt_merge(struct request_queue *q,
return false;
}
-bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio)
+bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio,
+ unsigned int nr_segs)
{
struct elevator_queue *e = q->elevator;
struct blk_mq_ctx *ctx = blk_mq_get_ctx(q);
@@ -326,21 +330,18 @@ bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio)
bool ret = false;
enum hctx_type type;
- if (e && e->type->ops.bio_merge) {
- blk_mq_put_ctx(ctx);
- return e->type->ops.bio_merge(hctx, bio);
- }
+ if (e && e->type->ops.bio_merge)
+ return e->type->ops.bio_merge(hctx, bio, nr_segs);
type = hctx->type;
if ((hctx->flags & BLK_MQ_F_SHOULD_MERGE) &&
!list_empty_careful(&ctx->rq_lists[type])) {
/* default per sw-queue merge */
spin_lock(&ctx->lock);
- ret = blk_mq_attempt_merge(q, hctx, ctx, bio);
+ ret = blk_mq_attempt_merge(q, hctx, ctx, bio, nr_segs);
spin_unlock(&ctx->lock);
}
- blk_mq_put_ctx(ctx);
return ret;
}
diff --git a/block/blk-mq-sched.h b/block/blk-mq-sched.h
index 3cf92cbbd8ac..cf22ab00fefb 100644
--- a/block/blk-mq-sched.h
+++ b/block/blk-mq-sched.h
@@ -12,8 +12,9 @@ void blk_mq_sched_assign_ioc(struct request *rq);
void blk_mq_sched_request_inserted(struct request *rq);
bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio,
- struct request **merged_request);
-bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio);
+ unsigned int nr_segs, struct request **merged_request);
+bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio,
+ unsigned int nr_segs);
bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq);
void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx);
void blk_mq_sched_restart(struct blk_mq_hw_ctx *hctx);
@@ -31,12 +32,13 @@ void blk_mq_exit_sched(struct request_queue *q, struct elevator_queue *e);
void blk_mq_sched_free_requests(struct request_queue *q);
static inline bool
-blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio)
+blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio,
+ unsigned int nr_segs)
{
if (blk_queue_nomerges(q) || !bio_mergeable(bio))
return false;
- return __blk_mq_sched_bio_merge(q, bio);
+ return __blk_mq_sched_bio_merge(q, bio, nr_segs);
}
static inline bool
diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index 7513c8eaabee..da19f0bc8876 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -113,7 +113,6 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
struct sbq_wait_state *ws;
DEFINE_SBQ_WAIT(wait);
unsigned int tag_offset;
- bool drop_ctx;
int tag;
if (data->flags & BLK_MQ_REQ_RESERVED) {
@@ -136,7 +135,6 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
return BLK_MQ_TAG_FAIL;
ws = bt_wait_ptr(bt, data->hctx);
- drop_ctx = data->ctx == NULL;
do {
struct sbitmap_queue *bt_prev;
@@ -161,9 +159,6 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
if (tag != -1)
break;
- if (data->ctx)
- blk_mq_put_ctx(data->ctx);
-
bt_prev = bt;
io_schedule();
@@ -189,9 +184,6 @@ unsigned int blk_mq_get_tag(struct blk_mq_alloc_data *data)
ws = bt_wait_ptr(bt, data->hctx);
} while (1);
- if (drop_ctx && data->ctx)
- blk_mq_put_ctx(data->ctx);
-
sbitmap_finish_wait(bt, ws, &wait);
found_tag:
diff --git a/block/blk-mq.c b/block/blk-mq.c
index ce0f5f4ede70..e5ef40c603ca 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -355,13 +355,13 @@ static struct request *blk_mq_get_request(struct request_queue *q,
struct elevator_queue *e = q->elevator;
struct request *rq;
unsigned int tag;
- bool put_ctx_on_error = false;
+ bool clear_ctx_on_error = false;
blk_queue_enter_live(q);
data->q = q;
if (likely(!data->ctx)) {
data->ctx = blk_mq_get_ctx(q);
- put_ctx_on_error = true;
+ clear_ctx_on_error = true;
}
if (likely(!data->hctx))
data->hctx = blk_mq_map_queue(q, data->cmd_flags,
@@ -387,10 +387,8 @@ static struct request *blk_mq_get_request(struct request_queue *q,
tag = blk_mq_get_tag(data);
if (tag == BLK_MQ_TAG_FAIL) {
- if (put_ctx_on_error) {
- blk_mq_put_ctx(data->ctx);
+ if (clear_ctx_on_error)
data->ctx = NULL;
- }
blk_queue_exit(q);
return NULL;
}
@@ -427,8 +425,6 @@ struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
if (!rq)
return ERR_PTR(-EWOULDBLOCK);
- blk_mq_put_ctx(alloc_data.ctx);
-
rq->__data_len = 0;
rq->__sector = (sector_t) -1;
rq->bio = rq->biotail = NULL;
@@ -1764,9 +1760,15 @@ void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
}
}
-static void blk_mq_bio_to_request(struct request *rq, struct bio *bio)
+static void blk_mq_bio_to_request(struct request *rq, struct bio *bio,
+ unsigned int nr_segs)
{
- blk_init_request_from_bio(rq, bio);
+ if (bio->bi_opf & REQ_RAHEAD)
+ rq->cmd_flags |= REQ_FAILFAST_MASK;
+
+ rq->__sector = bio->bi_iter.bi_sector;
+ rq->write_hint = bio->bi_write_hint;
+ blk_rq_bio_prep(rq, bio, nr_segs);
blk_account_io_start(rq, true);
}
@@ -1936,20 +1938,20 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
struct request *rq;
struct blk_plug *plug;
struct request *same_queue_rq = NULL;
+ unsigned int nr_segs;
blk_qc_t cookie;
blk_queue_bounce(q, &bio);
-
- blk_queue_split(q, &bio);
+ __blk_queue_split(q, &bio, &nr_segs);
if (!bio_integrity_prep(bio))
return BLK_QC_T_NONE;
if (!is_flush_fua && !blk_queue_nomerges(q) &&
- blk_attempt_plug_merge(q, bio, &same_queue_rq))
+ blk_attempt_plug_merge(q, bio, nr_segs, &same_queue_rq))
return BLK_QC_T_NONE;
- if (blk_mq_sched_bio_merge(q, bio))
+ if (blk_mq_sched_bio_merge(q, bio, nr_segs))
return BLK_QC_T_NONE;
rq_qos_throttle(q, bio);
@@ -1969,11 +1971,10 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
cookie = request_to_qc_t(data.hctx, rq);
+ blk_mq_bio_to_request(rq, bio, nr_segs);
+
plug = current->plug;
if (unlikely(is_flush_fua)) {
- blk_mq_put_ctx(data.ctx);
- blk_mq_bio_to_request(rq, bio);
-
/* bypass scheduler for flush rq */
blk_insert_flush(rq);
blk_mq_run_hw_queue(data.hctx, true);
@@ -1985,9 +1986,6 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
unsigned int request_count = plug->rq_count;
struct request *last = NULL;
- blk_mq_put_ctx(data.ctx);
- blk_mq_bio_to_request(rq, bio);
-
if (!request_count)
trace_block_plug(q);
else
@@ -2001,8 +1999,6 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
blk_add_rq_to_plug(plug, rq);
} else if (plug && !blk_queue_nomerges(q)) {
- blk_mq_bio_to_request(rq, bio);
-
/*
* We do limited plugging. If the bio can be merged, do that.
* Otherwise the existing request in the plug list will be
@@ -2019,8 +2015,6 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
blk_add_rq_to_plug(plug, rq);
trace_block_plug(q);
- blk_mq_put_ctx(data.ctx);
-
if (same_queue_rq) {
data.hctx = same_queue_rq->mq_hctx;
trace_block_unplug(q, 1, true);
@@ -2029,12 +2023,8 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
}
} else if ((q->nr_hw_queues > 1 && is_sync) || (!q->elevator &&
!data.hctx->dispatch_busy)) {
- blk_mq_put_ctx(data.ctx);
- blk_mq_bio_to_request(rq, bio);
blk_mq_try_issue_directly(data.hctx, rq, &cookie);
} else {
- blk_mq_put_ctx(data.ctx);
- blk_mq_bio_to_request(rq, bio);
blk_mq_sched_insert_request(rq, false, true, true);
}
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 633a5a77ee8b..f4bf5161333e 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -151,12 +151,7 @@ static inline struct blk_mq_ctx *__blk_mq_get_ctx(struct request_queue *q,
*/
static inline struct blk_mq_ctx *blk_mq_get_ctx(struct request_queue *q)
{
- return __blk_mq_get_ctx(q, get_cpu());
-}
-
-static inline void blk_mq_put_ctx(struct blk_mq_ctx *ctx)
-{
- put_cpu();
+ return __blk_mq_get_ctx(q, raw_smp_processor_id());
}
struct blk_mq_alloc_data {
diff --git a/block/blk.h b/block/blk.h
index 7814aa207153..de6b2e146d6e 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -51,8 +51,6 @@ struct blk_flush_queue *blk_alloc_flush_queue(struct request_queue *q,
int node, int cmd_size, gfp_t flags);
void blk_free_flush_queue(struct blk_flush_queue *q);
-void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
- struct bio *bio);
void blk_freeze_queue(struct request_queue *q);
static inline void blk_queue_enter_live(struct request_queue *q)
@@ -101,6 +99,18 @@ static inline bool bvec_gap_to_prev(struct request_queue *q,
return __bvec_gap_to_prev(q, bprv, offset);
}
+static inline void blk_rq_bio_prep(struct request *rq, struct bio *bio,
+ unsigned int nr_segs)
+{
+ rq->nr_phys_segments = nr_segs;
+ rq->__data_len = bio->bi_iter.bi_size;
+ rq->bio = rq->biotail = bio;
+ rq->ioprio = bio_prio(bio);
+
+ if (bio->bi_disk)
+ rq->rq_disk = bio->bi_disk;
+}
+
#ifdef CONFIG_BLK_DEV_INTEGRITY
void blk_flush_integrity(void);
bool __bio_integrity_endio(struct bio *);
@@ -154,14 +164,14 @@ static inline bool bio_integrity_endio(struct bio *bio)
unsigned long blk_rq_timeout(unsigned long timeout);
void blk_add_timer(struct request *req);
-bool bio_attempt_front_merge(struct request_queue *q, struct request *req,
- struct bio *bio);
-bool bio_attempt_back_merge(struct request_queue *q, struct request *req,
- struct bio *bio);
+bool bio_attempt_front_merge(struct request *req, struct bio *bio,
+ unsigned int nr_segs);
+bool bio_attempt_back_merge(struct request *req, struct bio *bio,
+ unsigned int nr_segs);
bool bio_attempt_discard_merge(struct request_queue *q, struct request *req,
struct bio *bio);
bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
- struct request **same_queue_rq);
+ unsigned int nr_segs, struct request **same_queue_rq);
void blk_account_io_start(struct request *req, bool new_io);
void blk_account_io_completion(struct request *req, unsigned int bytes);
@@ -202,15 +212,17 @@ static inline int blk_should_fake_timeout(struct request_queue *q)
}
#endif
-int ll_back_merge_fn(struct request_queue *q, struct request *req,
- struct bio *bio);
-int ll_front_merge_fn(struct request_queue *q, struct request *req,
- struct bio *bio);
+void __blk_queue_split(struct request_queue *q, struct bio **bio,
+ unsigned int *nr_segs);
+int ll_back_merge_fn(struct request *req, struct bio *bio,
+ unsigned int nr_segs);
+int ll_front_merge_fn(struct request *req, struct bio *bio,
+ unsigned int nr_segs);
struct request *attempt_back_merge(struct request_queue *q, struct request *rq);
struct request *attempt_front_merge(struct request_queue *q, struct request *rq);
int blk_attempt_req_merge(struct request_queue *q, struct request *rq,
struct request *next);
-void blk_recalc_rq_segments(struct request *rq);
+unsigned int blk_recalc_rq_segments(struct request *rq);
void blk_rq_set_mixed_merge(struct request *rq);
bool blk_rq_merge_ok(struct request *rq, struct bio *bio);
enum elv_merge blk_try_merge(struct request *rq, struct bio *bio);
diff --git a/block/genhd.c b/block/genhd.c
index 24654e1d83e6..97887e59f3b2 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1281,7 +1281,6 @@ int disk_expand_part_tbl(struct gendisk *disk, int partno)
struct disk_part_tbl *new_ptbl;
int len = old_ptbl ? old_ptbl->len : 0;
int i, target;
- size_t size;
/*
* check for int overflow, since we can get here from blkpg_ioctl()
@@ -1298,8 +1297,8 @@ int disk_expand_part_tbl(struct gendisk *disk, int partno)
if (target <= len)
return 0;
- size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]);
- new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id);
+ new_ptbl = kzalloc_node(struct_size(new_ptbl, part, target), GFP_KERNEL,
+ disk->node_id);
if (!new_ptbl)
return -ENOMEM;
diff --git a/block/kyber-iosched.c b/block/kyber-iosched.c
index c3b05119cebd..34dcea0ef637 100644
--- a/block/kyber-iosched.c
+++ b/block/kyber-iosched.c
@@ -562,7 +562,8 @@ static void kyber_limit_depth(unsigned int op, struct blk_mq_alloc_data *data)
}
}
-static bool kyber_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio)
+static bool kyber_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio,
+ unsigned int nr_segs)
{
struct kyber_hctx_data *khd = hctx->sched_data;
struct blk_mq_ctx *ctx = blk_mq_get_ctx(hctx->queue);
@@ -572,9 +573,8 @@ static bool kyber_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio)
bool merged;
spin_lock(&kcq->lock);
- merged = blk_mq_bio_list_merge(hctx->queue, rq_list, bio);
+ merged = blk_mq_bio_list_merge(hctx->queue, rq_list, bio, nr_segs);
spin_unlock(&kcq->lock);
- blk_mq_put_ctx(ctx);
return merged;
}
diff --git a/block/mq-deadline.c b/block/mq-deadline.c
index 1876f5712bfd..b8a682b5a1bb 100644
--- a/block/mq-deadline.c
+++ b/block/mq-deadline.c
@@ -469,7 +469,8 @@ static int dd_request_merge(struct request_queue *q, struct request **rq,
return ELEVATOR_NO_MERGE;
}
-static bool dd_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio)
+static bool dd_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio,
+ unsigned int nr_segs)
{
struct request_queue *q = hctx->queue;
struct deadline_data *dd = q->elevator->elevator_data;
@@ -477,7 +478,7 @@ static bool dd_bio_merge(struct blk_mq_hw_ctx *hctx, struct bio *bio)
bool ret;
spin_lock(&dd->lock);
- ret = blk_mq_sched_try_merge(q, bio, &free);
+ ret = blk_mq_sched_try_merge(q, bio, nr_segs, &free);
spin_unlock(&dd->lock);
if (free)
diff --git a/block/opal_proto.h b/block/opal_proto.h
index d9a05ad02eb5..466ec7be16ef 100644
--- a/block/opal_proto.h
+++ b/block/opal_proto.h
@@ -98,6 +98,7 @@ enum opal_uid {
OPAL_ENTERPRISE_BANDMASTER0_UID,
OPAL_ENTERPRISE_ERASEMASTER_UID,
/* tables */
+ OPAL_TABLE_TABLE,
OPAL_LOCKINGRANGE_GLOBAL,
OPAL_LOCKINGRANGE_ACE_RDLOCKED,
OPAL_LOCKINGRANGE_ACE_WRLOCKED,
@@ -152,6 +153,21 @@ enum opal_token {
OPAL_STARTCOLUMN = 0x03,
OPAL_ENDCOLUMN = 0x04,
OPAL_VALUES = 0x01,
+ /* table table */
+ OPAL_TABLE_UID = 0x00,
+ OPAL_TABLE_NAME = 0x01,
+ OPAL_TABLE_COMMON = 0x02,
+ OPAL_TABLE_TEMPLATE = 0x03,
+ OPAL_TABLE_KIND = 0x04,
+ OPAL_TABLE_COLUMN = 0x05,
+ OPAL_TABLE_COLUMNS = 0x06,
+ OPAL_TABLE_ROWS = 0x07,
+ OPAL_TABLE_ROWS_FREE = 0x08,
+ OPAL_TABLE_ROW_BYTES = 0x09,
+ OPAL_TABLE_LASTID = 0x0A,
+ OPAL_TABLE_MIN = 0x0B,
+ OPAL_TABLE_MAX = 0x0C,
+
/* authority table */
OPAL_PIN = 0x03,
/* locking tokens */
diff --git a/block/sed-opal.c b/block/sed-opal.c
index a46e8d13e16d..7e1a444a25b2 100644
--- a/block/sed-opal.c
+++ b/block/sed-opal.c
@@ -26,6 +26,9 @@
#define IO_BUFFER_LENGTH 2048
#define MAX_TOKS 64
+/* Number of bytes needed by cmd_finalize. */
+#define CMD_FINALIZE_BYTES_NEEDED 7
+
struct opal_step {
int (*fn)(struct opal_dev *dev, void *data);
void *data;
@@ -127,6 +130,8 @@ static const u8 opaluid[][OPAL_UID_LENGTH] = {
/* tables */
+ [OPAL_TABLE_TABLE]
+ { 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01 },
[OPAL_LOCKINGRANGE_GLOBAL] =
{ 0x00, 0x00, 0x08, 0x02, 0x00, 0x00, 0x00, 0x01 },
[OPAL_LOCKINGRANGE_ACE_RDLOCKED] =
@@ -523,12 +528,17 @@ static int opal_discovery0_step(struct opal_dev *dev)
return execute_step(dev, &discovery0_step, 0);
}
+static size_t remaining_size(struct opal_dev *cmd)
+{
+ return IO_BUFFER_LENGTH - cmd->pos;
+}
+
static bool can_add(int *err, struct opal_dev *cmd, size_t len)
{
if (*err)
return false;
- if (len > IO_BUFFER_LENGTH || cmd->pos > IO_BUFFER_LENGTH - len) {
+ if (remaining_size(cmd) < len) {
pr_debug("Error adding %zu bytes: end of buffer.\n", len);
*err = -ERANGE;
return false;
@@ -674,7 +684,11 @@ static int cmd_finalize(struct opal_dev *cmd, u32 hsn, u32 tsn)
struct opal_header *hdr;
int err = 0;
- /* close the parameter list opened from cmd_start */
+ /*
+ * Close the parameter list opened from cmd_start.
+ * The number of bytes added must be equal to
+ * CMD_FINALIZE_BYTES_NEEDED.
+ */
add_token_u8(&err, cmd, OPAL_ENDLIST);
add_token_u8(&err, cmd, OPAL_ENDOFDATA);
@@ -1119,6 +1133,29 @@ static int generic_get_column(struct opal_dev *dev, const u8 *table,
return finalize_and_send(dev, parse_and_check_status);
}
+/*
+ * see TCG SAS 5.3.2.3 for a description of the available columns
+ *
+ * the result is provided in dev->resp->tok[4]
+ */
+static int generic_get_table_info(struct opal_dev *dev, enum opal_uid table,
+ u64 column)
+{
+ u8 uid[OPAL_UID_LENGTH];
+ const unsigned int half = OPAL_UID_LENGTH/2;
+
+ /* sed-opal UIDs can be split in two halves:
+ * first: actual table index
+ * second: relative index in the table
+ * so we have to get the first half of the OPAL_TABLE_TABLE and use the
+ * first part of the target table as relative index into that table
+ */
+ memcpy(uid, opaluid[OPAL_TABLE_TABLE], half);
+ memcpy(uid+half, opaluid[table], half);
+
+ return generic_get_column(dev, uid, column);
+}
+
static int gen_key(struct opal_dev *dev, void *data)
{
u8 uid[OPAL_UID_LENGTH];
@@ -1307,6 +1344,7 @@ static int start_generic_opal_session(struct opal_dev *dev,
break;
case OPAL_ADMIN1_UID:
case OPAL_SID_UID:
+ case OPAL_PSID_UID:
add_token_u8(&err, dev, OPAL_STARTNAME);
add_token_u8(&err, dev, 0); /* HostChallenge */
add_token_bytestring(&err, dev, key, key_len);
@@ -1367,6 +1405,16 @@ static int start_admin1LSP_opal_session(struct opal_dev *dev, void *data)
key->key, key->key_len);
}
+static int start_PSID_opal_session(struct opal_dev *dev, void *data)
+{
+ const struct opal_key *okey = data;
+
+ return start_generic_opal_session(dev, OPAL_PSID_UID,
+ OPAL_ADMINSP_UID,
+ okey->key,
+ okey->key_len);
+}
+
static int start_auth_opal_session(struct opal_dev *dev, void *data)
{
struct opal_session_info *session = data;
@@ -1525,6 +1573,72 @@ static int set_mbr_enable_disable(struct opal_dev *dev, void *data)
return finalize_and_send(dev, parse_and_check_status);
}
+static int write_shadow_mbr(struct opal_dev *dev, void *data)
+{
+ struct opal_shadow_mbr *shadow = data;
+ const u8 __user *src;
+ u8 *dst;
+ size_t off = 0;
+ u64 len;
+ int err = 0;
+
+ /* do we fit in the available shadow mbr space? */
+ err = generic_get_table_info(dev, OPAL_MBR, OPAL_TABLE_ROWS);
+ if (err) {
+ pr_debug("MBR: could not get shadow size\n");
+ return err;
+ }
+
+ len = response_get_u64(&dev->parsed, 4);
+ if (shadow->size > len || shadow->offset > len - shadow->size) {
+ pr_debug("MBR: does not fit in shadow (%llu vs. %llu)\n",
+ shadow->offset + shadow->size, len);
+ return -ENOSPC;
+ }
+
+ /* do the actual transmission(s) */
+ src = (u8 __user *)(uintptr_t)shadow->data;
+ while (off < shadow->size) {
+ err = cmd_start(dev, opaluid[OPAL_MBR], opalmethod[OPAL_SET]);
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, OPAL_WHERE);
+ add_token_u64(&err, dev, shadow->offset + off);
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+
+ add_token_u8(&err, dev, OPAL_STARTNAME);
+ add_token_u8(&err, dev, OPAL_VALUES);
+
+ /*
+ * The bytestring header is either 1 or 2 bytes, so assume 2.
+ * There also needs to be enough space to accommodate the
+ * trailing OPAL_ENDNAME (1 byte) and tokens added by
+ * cmd_finalize.
+ */
+ len = min(remaining_size(dev) - (2+1+CMD_FINALIZE_BYTES_NEEDED),
+ (size_t)(shadow->size - off));
+ pr_debug("MBR: write bytes %zu+%llu/%llu\n",
+ off, len, shadow->size);
+
+ dst = add_bytestring_header(&err, dev, len);
+ if (!dst)
+ break;
+ if (copy_from_user(dst, src + off, len))
+ err = -EFAULT;
+ dev->pos += len;
+
+ add_token_u8(&err, dev, OPAL_ENDNAME);
+ if (err)
+ break;
+
+ err = finalize_and_send(dev, parse_and_check_status);
+ if (err)
+ break;
+
+ off += len;
+ }
+ return err;
+}
+
static int generic_pw_cmd(u8 *key, size_t key_len, u8 *cpin_uid,
struct opal_dev *dev)
{
@@ -1978,6 +2092,50 @@ static int opal_enable_disable_shadow_mbr(struct opal_dev *dev,
return ret;
}
+static int opal_set_mbr_done(struct opal_dev *dev,
+ struct opal_mbr_done *mbr_done)
+{
+ u8 mbr_done_tf = mbr_done->done_flag == OPAL_MBR_DONE ?
+ OPAL_TRUE : OPAL_FALSE;
+
+ const struct opal_step mbr_steps[] = {
+ { start_admin1LSP_opal_session, &mbr_done->key },
+ { set_mbr_done, &mbr_done_tf },
+ { end_opal_session, }
+ };
+ int ret;
+
+ if (mbr_done->done_flag != OPAL_MBR_DONE &&
+ mbr_done->done_flag != OPAL_MBR_NOT_DONE)
+ return -EINVAL;
+
+ mutex_lock(&dev->dev_lock);
+ setup_opal_dev(dev);
+ ret = execute_steps(dev, mbr_steps, ARRAY_SIZE(mbr_steps));
+ mutex_unlock(&dev->dev_lock);
+ return ret;
+}
+
+static int opal_write_shadow_mbr(struct opal_dev *dev,
+ struct opal_shadow_mbr *info)
+{
+ const struct opal_step mbr_steps[] = {
+ { start_admin1LSP_opal_session, &info->key },
+ { write_shadow_mbr, info },
+ { end_opal_session, }
+ };
+ int ret;
+
+ if (info->size == 0)
+ return 0;
+
+ mutex_lock(&dev->dev_lock);
+ setup_opal_dev(dev);
+ ret = execute_steps(dev, mbr_steps, ARRAY_SIZE(mbr_steps));
+ mutex_unlock(&dev->dev_lock);
+ return ret;
+}
+
static int opal_save(struct opal_dev *dev, struct opal_lock_unlock *lk_unlk)
{
struct opal_suspend_data *suspend;
@@ -2030,17 +2188,28 @@ static int opal_add_user_to_lr(struct opal_dev *dev,
return ret;
}
-static int opal_reverttper(struct opal_dev *dev, struct opal_key *opal)
+static int opal_reverttper(struct opal_dev *dev, struct opal_key *opal, bool psid)
{
+ /* controller will terminate session */
const struct opal_step revert_steps[] = {
{ start_SIDASP_opal_session, opal },
- { revert_tper, } /* controller will terminate session */
+ { revert_tper, }
+ };
+ const struct opal_step psid_revert_steps[] = {
+ { start_PSID_opal_session, opal },
+ { revert_tper, }
};
+
int ret;
mutex_lock(&dev->dev_lock);
setup_opal_dev(dev);
- ret = execute_steps(dev, revert_steps, ARRAY_SIZE(revert_steps));
+ if (psid)
+ ret = execute_steps(dev, psid_revert_steps,
+ ARRAY_SIZE(psid_revert_steps));
+ else
+ ret = execute_steps(dev, revert_steps,
+ ARRAY_SIZE(revert_steps));
mutex_unlock(&dev->dev_lock);
/*
@@ -2092,8 +2261,7 @@ static int opal_lock_unlock(struct opal_dev *dev,
{
int ret;
- if (lk_unlk->session.who < OPAL_ADMIN1 ||
- lk_unlk->session.who > OPAL_USER9)
+ if (lk_unlk->session.who > OPAL_USER9)
return -EINVAL;
mutex_lock(&dev->dev_lock);
@@ -2171,9 +2339,7 @@ static int opal_set_new_pw(struct opal_dev *dev, struct opal_new_pw *opal_pw)
};
int ret;
- if (opal_pw->session.who < OPAL_ADMIN1 ||
- opal_pw->session.who > OPAL_USER9 ||
- opal_pw->new_user_pw.who < OPAL_ADMIN1 ||
+ if (opal_pw->session.who > OPAL_USER9 ||
opal_pw->new_user_pw.who > OPAL_USER9)
return -EINVAL;
@@ -2280,7 +2446,7 @@ int sed_ioctl(struct opal_dev *dev, unsigned int cmd, void __user *arg)
ret = opal_activate_user(dev, p);
break;
case IOC_OPAL_REVERT_TPR:
- ret = opal_reverttper(dev, p);
+ ret = opal_reverttper(dev, p, false);
break;
case IOC_OPAL_LR_SETUP:
ret = opal_setup_locking_range(dev, p);
@@ -2291,12 +2457,21 @@ int sed_ioctl(struct opal_dev *dev, unsigned int cmd, void __user *arg)
case IOC_OPAL_ENABLE_DISABLE_MBR:
ret = opal_enable_disable_shadow_mbr(dev, p);
break;
+ case IOC_OPAL_MBR_DONE:
+ ret = opal_set_mbr_done(dev, p);
+ break;
+ case IOC_OPAL_WRITE_SHADOW_MBR:
+ ret = opal_write_shadow_mbr(dev, p);
+ break;
case IOC_OPAL_ERASE_LR:
ret = opal_erase_locking_range(dev, p);
break;
case IOC_OPAL_SECURE_ERASE_LR:
ret = opal_secure_erase_locking_range(dev, p);
break;
+ case IOC_OPAL_PSID_REVERT_TPR:
+ ret = opal_reverttper(dev, p, true);
+ break;
default:
break;
}