Revert "bcache: inflight prefetch requests block overlapped normal requests"

euleros/rtos inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4LOJ6
CVE: NA

--------------------------------

This patch set introduce many conflicts while backporting mainline
bcache patches, revert it temporarily.

This reverts commit 08a3ac0e.
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

drivers/md/bcache/acache.c

@@ -31,12 +31,6 @@ int acache_prefetch_workers = 1000;
 module_param_named(prefetch_workers, acache_prefetch_workers, int, 0444);
 MODULE_PARM_DESC(prefetch_workers, "num of workers for processing prefetch requests");
 
-struct inflight_list_head {
-	struct list_head entry;
-	spinlock_t io_lock;
-	bool initialized;
-};
-
 struct prefetch_worker {
 	struct acache_info s;
 	struct work_struct work;
@@ -56,8 +50,6 @@ struct acache_device {
 
 	struct acache_circ *acache_info_circ;
 
-	struct inflight_list_head inflight_list;
-
 	struct workqueue_struct *wq;
 	struct prefetch_worker *prefetch_workers;
 	struct list_head prefetch_workers_free;
@@ -303,7 +295,6 @@ int acache_dev_init(void)
 	int major;
 	struct device *dev;
 
-	inflight_list_ops.init();
 	major = alloc_chrdev_region(&adev.devno, 0, ACACHE_NR_DEVS, DEV_NAME);
 	if (major < 0) {
 		pr_err("failed to allocate chrdev region: %d\n", major);
@@ -386,7 +377,6 @@ int acache_dev_init(void)
 fail_class:
 	unregister_chrdev_region(adev.devno, ACACHE_NR_DEVS);
 fail_allocdev:
-	inflight_list_ops.exit();
 	return ret;
 }
 
@@ -405,112 +395,9 @@ void acache_dev_exit(void)
 	kfree(adev.mem_regionp);
 	unregister_chrdev_region(adev.devno, ACACHE_NR_DEVS);
 	class_destroy(adev.class);
-	inflight_list_ops.exit();
 	kfree(adev.prefetch_workers);
 }
 
-static struct search *__inflight_list_lookup_locked(struct search *s)
-{
-	struct search *iter;
-	struct bio *bio, *sbio;
-
-	if (!adev.inflight_list.initialized)
-		return NULL;
-	sbio = &s->bio.bio;
-	list_for_each_entry(iter, &adev.inflight_list.entry, list_node) {
-		bio = &iter->bio.bio;
-		if (sbio->bi_disk == bio->bi_disk &&
-		    sbio->bi_iter.bi_sector < bio_end_sector(bio) &&
-		    bio_end_sector(sbio) > bio->bi_iter.bi_sector) {
-			return iter;
-		}
-	}
-	return NULL;
-}
-
-static void inflight_list_init(void)
-{
-	INIT_LIST_HEAD(&adev.inflight_list.entry);
-	spin_lock_init(&adev.inflight_list.io_lock);
-	adev.inflight_list.initialized = true;
-}
-
-static void inflight_list_exit(void)
-{
-	if (!list_empty(&adev.inflight_list.entry))
-		pr_err("existing with inflight list not empty\n");
-}
-
-static int inflight_list_insert(struct search *s)
-{
-	if (!adev.inflight_list.initialized)
-		return -1;
-
-	init_waitqueue_head(&s->wqh);
-	spin_lock(&adev.inflight_list.io_lock);
-	list_add_tail(&s->list_node, &adev.inflight_list.entry);
-	spin_unlock(&adev.inflight_list.io_lock);
-
-	trace_bcache_inflight_list_insert(s->d, s->orig_bio);
-	return 0;
-}
-
-static int inflight_list_remove(struct search *s)
-{
-	if (!adev.inflight_list.initialized)
-		return -1;
-
-	spin_lock(&adev.inflight_list.io_lock);
-	list_del_init(&s->list_node);
-	spin_unlock(&adev.inflight_list.io_lock);
-
-	wake_up_interruptible_all(&s->wqh);
-
-	trace_bcache_inflight_list_remove(s->d, s->orig_bio);
-	return 0;
-}
-
-static bool inflight_list_wait(struct search *s)
-{
-	struct search *pfs = NULL;
-	struct cached_dev *dc;
-	DEFINE_WAIT(wqe);
-
-	if (!adev.inflight_list.initialized)
-		return false;
-
-	spin_lock(&adev.inflight_list.io_lock);
-	pfs = __inflight_list_lookup_locked(s);
-	if (pfs == NULL) {
-		spin_unlock(&adev.inflight_list.io_lock);
-		return false;
-	}
-
-	dc = container_of(pfs->d, struct cached_dev, disk);
-	if (!dc->inflight_block_enable) {
-		spin_unlock(&adev.inflight_list.io_lock);
-		return true;
-	}
-
-	prepare_to_wait(&pfs->wqh, &wqe, TASK_INTERRUPTIBLE);
-
-	/* unlock here to ensure pfs not changed. */
-	spin_unlock(&adev.inflight_list.io_lock);
-	schedule();
-
-	finish_wait(&pfs->wqh, &wqe);
-
-	return true;
-}
-
-const struct inflight_queue_ops inflight_list_ops = {
-	.init	= inflight_list_init,
-	.exit	= inflight_list_exit,
-	.insert	= inflight_list_insert,
-	.remove	= inflight_list_remove,
-	.wait	= inflight_list_wait,
-};
-
 struct cached_dev *get_cached_device_by_dev(dev_t dev)
 {
 	struct cache_set *c, *tc;

drivers/md/bcache/acache.h

@@ -66,14 +66,4 @@ void acache_dev_exit(void);
 struct acache_info *fetch_circ_item(struct acache_circ *circ);
 void save_circ_item(struct acache_info *data);
 
-struct inflight_queue_ops {
-	void (*init)(void);
-	void (*exit)(void);
-
-	int (*insert)(struct search *s);
-	int (*remove)(struct search *s);
-	bool (*wait)(struct search *s);
-};
-extern const struct inflight_queue_ops inflight_list_ops;
-
 #endif

drivers/md/bcache/bcache.h

@@ -376,7 +376,6 @@ struct cached_dev {
 	unsigned char		writeback_percent;
 	unsigned int		writeback_delay;
 
-	unsigned int		inflight_block_enable;
 	unsigned int		read_bypass;
 
 	uint64_t		writeback_rate_target;

drivers/md/bcache/request.c

@@ -706,9 +706,6 @@ void search_free(struct closure *cl)
 	if (s->iop.bio)
 		bio_put(s->iop.bio);
 
-	if (s->prefetch)
-		inflight_list_ops.remove(s);
-
 	bio_complete(s);
 	closure_debug_destroy(cl);
 	mempool_free(s, &s->iop.c->search);
@@ -977,11 +974,6 @@ void cached_dev_read(struct cached_dev *dc, struct search *s)
 {
 	struct closure *cl = &s->cl;
 
-	if (s->prefetch)
-		inflight_list_ops.insert(s);
-	else if (inflight_list_ops.wait(s))
-		bch_mark_cache_prefetch_fake_hit(s->iop.c, s->d);
-
 	closure_call(&s->iop.cl, cache_lookup, NULL, cl);
 	continue_at(cl, cached_dev_read_done_bh, NULL);
 }

drivers/md/bcache/stats.c

@@ -48,7 +48,6 @@ read_attribute(cache_bypass_misses);
 read_attribute(cache_hit_ratio);
 read_attribute(cache_readaheads);
 read_attribute(cache_miss_collisions);
-read_attribute(cache_prefetch_fake_hits);
 read_attribute(bypassed);
 
 SHOW(bch_stats)
@@ -67,7 +66,6 @@ SHOW(bch_stats)
 
 	var_print(cache_readaheads);
 	var_print(cache_miss_collisions);
-	var_print(cache_prefetch_fake_hits);
 	sysfs_hprint(bypassed,	var(sectors_bypassed) << 9);
 #undef var
 	return 0;
@@ -90,7 +88,6 @@ static struct attribute *bch_stats_files[] = {
 	&sysfs_cache_hit_ratio,
 	&sysfs_cache_readaheads,
 	&sysfs_cache_miss_collisions,
-	&sysfs_cache_prefetch_fake_hits,
 	&sysfs_bypassed,
 	NULL
 };
@@ -150,7 +147,6 @@ static void scale_stats(struct cache_stats *stats, unsigned long rescale_at)
 		scale_stat(&stats->cache_bypass_misses);
 		scale_stat(&stats->cache_readaheads);
 		scale_stat(&stats->cache_miss_collisions);
-		scale_stat(&stats->cache_prefetch_fake_hits);
 		scale_stat(&stats->sectors_bypassed);
 	}
 }
@@ -174,7 +170,6 @@ static void scale_accounting(struct timer_list *t)
 	move_stat(cache_bypass_misses);
 	move_stat(cache_readaheads);
 	move_stat(cache_miss_collisions);
-	move_stat(cache_prefetch_fake_hits);
 	move_stat(sectors_bypassed);
 
 	scale_stats(&acc->total, 0);
@@ -230,14 +225,6 @@ void bch_mark_cache_miss_collision(struct cache_set *c, struct bcache_device *d)
 	atomic_inc(&c->accounting.collector.cache_miss_collisions);
 }
 
-void bch_mark_cache_prefetch_fake_hit(struct cache_set *c, struct bcache_device *d)
-{
-	struct cached_dev *dc = container_of(d, struct cached_dev, disk);
-
-	atomic_inc(&dc->accounting.collector.cache_prefetch_fake_hits);
-	atomic_inc(&c->accounting.collector.cache_prefetch_fake_hits);
-}
-
 void bch_mark_sectors_bypassed(struct cache_set *c, struct cached_dev *dc,
 			       int sectors)
 {

drivers/md/bcache/stats.h

@@ -9,7 +9,6 @@ struct cache_stat_collector {
 	atomic_t cache_bypass_misses;
 	atomic_t cache_readaheads;
 	atomic_t cache_miss_collisions;
-	atomic_t cache_prefetch_fake_hits;
 	atomic_t sectors_bypassed;
 };
 
@@ -22,7 +21,6 @@ struct cache_stats {
 	unsigned long cache_bypass_misses;
 	unsigned long cache_readaheads;
 	unsigned long cache_miss_collisions;
-	unsigned long cache_prefetch_fake_hits;
 	unsigned long sectors_bypassed;
 
 	unsigned int		rescale;
@@ -60,7 +58,6 @@ void bch_mark_cache_accounting(struct cache_set *c, struct bcache_device *d,
 void bch_mark_cache_readahead(struct cache_set *c, struct bcache_device *d);
 void bch_mark_cache_miss_collision(struct cache_set *c,
 				   struct bcache_device *d);
-void bch_mark_cache_prefetch_fake_hit(struct cache_set *c, struct bcache_device *d);
 void bch_mark_sectors_bypassed(struct cache_set *c,
 			       struct cached_dev *dc,
 			       int sectors);

drivers/md/bcache/super.c

@@ -1439,7 +1439,6 @@ static int cached_dev_init(struct cached_dev *dc, unsigned int block_size)
 	bch_cache_accounting_init(&dc->accounting, &dc->disk.cl);
 
 	dc->sequential_cutoff		= 4 << 20;
-	dc->inflight_block_enable	= 1;
 	dc->read_bypass			= 0;
 
 	for (io = dc->io; io < dc->io + RECENT_IO; io++) {

drivers/md/bcache/sysfs.c

@@ -109,7 +109,6 @@ rw_attribute(congested_write_threshold_us);
 
 rw_attribute(sequential_cutoff);
 rw_attribute(read_bypass);
-rw_attribute(inflight_block_enable);
 rw_attribute(data_csum);
 rw_attribute(cache_mode);
 rw_attribute(readahead_cache_policy);
@@ -254,7 +253,6 @@ SHOW(__bch_cached_dev)
 	var_printf(partial_stripes_expensive,	"%u");
 
 	var_hprint(sequential_cutoff);
-	var_print(inflight_block_enable);
 	var_print(read_bypass);
 	var_hprint(readahead);
 
@@ -353,9 +351,6 @@ STORE(__cached_dev)
 	sysfs_strtoul_clamp(read_bypass,
 			    dc->read_bypass,
 			    0, 1);
-	sysfs_strtoul_clamp(inflight_block_enable,
-			    dc->inflight_block_enable,
-			    0, 1);
 	d_strtoi_h(readahead);
 
 	if (attr == &sysfs_clear_stats)
@@ -522,7 +517,6 @@ static struct attribute *bch_cached_dev_files[] = {
 	&sysfs_partial_stripes_expensive,
 	&sysfs_sequential_cutoff,
 	&sysfs_read_bypass,
-	&sysfs_inflight_block_enable,
 	&sysfs_clear_stats,
 	&sysfs_running,
 	&sysfs_state,

include/trace/events/bcache.h

@@ -81,17 +81,6 @@ DEFINE_EVENT(bcache_request, bcache_prefetch_request,
 	TP_ARGS(d, bio)
 );
 
-/* interface.c */
-DEFINE_EVENT(bcache_request, bcache_inflight_list_insert,
-	TP_PROTO(struct bcache_device *d, struct bio *bio),
-	TP_ARGS(d, bio)
-);
-
-DEFINE_EVENT(bcache_request, bcache_inflight_list_remove,
-	TP_PROTO(struct bcache_device *d, struct bio *bio),
-	TP_ARGS(d, bio)
-);
-
 /* request.c */
 
 DEFINE_EVENT(bcache_request, bcache_request_start,