bcache: A block layer cache

Does writethrough and writeback caching, handles unclean shutdown, and
has a bunch of other nifty features motivated by real world usage.

See the wiki at http://bcache.evilpiepirate.org for more.

Signed-off-by: Kent Overstreet <koverstreet@google.com>

3 files changed, 281 insertions, 0 deletions

diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
index f204a7a9cf38..6e7ec64b69ab 100644
--- a/include/linux/cgroup_subsys.h
+++ b/include/linux/cgroup_subsys.h
@@ -78,3 +78,9 @@ SUBSYS(hugetlb)
 #endif
 
 /* */
+
+#ifdef CONFIG_CGROUP_BCACHE
+SUBSYS(bcache)
+#endif
+
+/* */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index d35d2b6ddbfb..a8482d063bc3 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1576,6 +1576,10 @@ struct task_struct {
 #ifdef CONFIG_UPROBES
 	struct uprobe_task *utask;
 #endif
+#if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
+	unsigned int	sequential_io;
+	unsigned int	sequential_io_avg;
+#endif
 };
 
 /* Future-safe accessor for struct task_struct's cpus_allowed. */
diff --git a/include/trace/events/bcache.h b/include/trace/events/bcache.h
new file mode 100644
index 000000000000..3cc5a0b278c3
--- /dev/null
+++ b/include/trace/events/bcache.h
@@ -0,0 +1,271 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM bcache
+
+#if !defined(_TRACE_BCACHE_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_BCACHE_H
+
+#include <linux/tracepoint.h>
+
+struct search;
+
+DECLARE_EVENT_CLASS(bcache_request,
+
+	TP_PROTO(struct search *s, struct bio *bio),
+
+	TP_ARGS(s, bio),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev			)
+		__field(unsigned int,	orig_major		)
+		__field(unsigned int,	orig_minor		)
+		__field(sector_t,	sector			)
+		__field(dev_t,		orig_sector		)
+		__field(unsigned int,	nr_sector		)
+		__array(char,		rwbs,	6		)
+		__array(char,		comm,	TASK_COMM_LEN	)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= bio->bi_bdev->bd_dev;
+		__entry->orig_major	= s->d->disk->major;
+		__entry->orig_minor	= s->d->disk->first_minor;
+		__entry->sector		= bio->bi_sector;
+		__entry->orig_sector	= bio->bi_sector - 16;
+		__entry->nr_sector	= bio->bi_size >> 9;
+		blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
+		memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+	),
+
+	TP_printk("%d,%d %s %llu + %u [%s] (from %d,%d @ %llu)",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->rwbs,
+		  (unsigned long long)__entry->sector,
+		  __entry->nr_sector, __entry->comm,
+		  __entry->orig_major, __entry->orig_minor,
+		  (unsigned long long)__entry->orig_sector)
+);
+
+DEFINE_EVENT(bcache_request, bcache_request_start,
+
+	TP_PROTO(struct search *s, struct bio *bio),
+
+	TP_ARGS(s, bio)
+);
+
+DEFINE_EVENT(bcache_request, bcache_request_end,
+
+	TP_PROTO(struct search *s, struct bio *bio),
+
+	TP_ARGS(s, bio)
+);
+
+DECLARE_EVENT_CLASS(bcache_bio,
+
+	TP_PROTO(struct bio *bio),
+
+	TP_ARGS(bio),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev			)
+		__field(sector_t,	sector			)
+		__field(unsigned int,	nr_sector		)
+		__array(char,		rwbs,	6		)
+		__array(char,		comm,	TASK_COMM_LEN	)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= bio->bi_bdev->bd_dev;
+		__entry->sector		= bio->bi_sector;
+		__entry->nr_sector	= bio->bi_size >> 9;
+		blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
+		memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+	),
+
+	TP_printk("%d,%d  %s %llu + %u [%s]",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->rwbs,
+		  (unsigned long long)__entry->sector,
+		  __entry->nr_sector, __entry->comm)
+);
+
+
+DEFINE_EVENT(bcache_bio, bcache_passthrough,
+
+	TP_PROTO(struct bio *bio),
+
+	TP_ARGS(bio)
+);
+
+DEFINE_EVENT(bcache_bio, bcache_cache_hit,
+
+	TP_PROTO(struct bio *bio),
+
+	TP_ARGS(bio)
+);
+
+DEFINE_EVENT(bcache_bio, bcache_cache_miss,
+
+	TP_PROTO(struct bio *bio),
+
+	TP_ARGS(bio)
+);
+
+DEFINE_EVENT(bcache_bio, bcache_read_retry,
+
+	TP_PROTO(struct bio *bio),
+
+	TP_ARGS(bio)
+);
+
+DEFINE_EVENT(bcache_bio, bcache_writethrough,
+
+	TP_PROTO(struct bio *bio),
+
+	TP_ARGS(bio)
+);
+
+DEFINE_EVENT(bcache_bio, bcache_writeback,
+
+	TP_PROTO(struct bio *bio),
+
+	TP_ARGS(bio)
+);
+
+DEFINE_EVENT(bcache_bio, bcache_write_skip,
+
+	TP_PROTO(struct bio *bio),
+
+	TP_ARGS(bio)
+);
+
+DEFINE_EVENT(bcache_bio, bcache_btree_read,
+
+	TP_PROTO(struct bio *bio),
+
+	TP_ARGS(bio)
+);
+
+DEFINE_EVENT(bcache_bio, bcache_btree_write,
+
+	TP_PROTO(struct bio *bio),
+
+	TP_ARGS(bio)
+);
+
+DEFINE_EVENT(bcache_bio, bcache_write_dirty,
+
+	TP_PROTO(struct bio *bio),
+
+	TP_ARGS(bio)
+);
+
+DEFINE_EVENT(bcache_bio, bcache_read_dirty,
+
+	TP_PROTO(struct bio *bio),
+
+	TP_ARGS(bio)
+);
+
+DEFINE_EVENT(bcache_bio, bcache_write_moving,
+
+	TP_PROTO(struct bio *bio),
+
+	TP_ARGS(bio)
+);
+
+DEFINE_EVENT(bcache_bio, bcache_read_moving,
+
+	TP_PROTO(struct bio *bio),
+
+	TP_ARGS(bio)
+);
+
+DEFINE_EVENT(bcache_bio, bcache_journal_write,
+
+	TP_PROTO(struct bio *bio),
+
+	TP_ARGS(bio)
+);
+
+DECLARE_EVENT_CLASS(bcache_cache_bio,
+
+	TP_PROTO(struct bio *bio,
+		 sector_t orig_sector,
+		 struct block_device* orig_bdev),
+
+	TP_ARGS(bio, orig_sector, orig_bdev),
+
+	TP_STRUCT__entry(
+		__field(dev_t,		dev			)
+		__field(dev_t,		orig_dev		)
+		__field(sector_t,	sector			)
+		__field(sector_t,	orig_sector		)
+		__field(unsigned int,	nr_sector		)
+		__array(char,		rwbs,	6		)
+		__array(char,		comm,	TASK_COMM_LEN	)
+	),
+
+	TP_fast_assign(
+		__entry->dev		= bio->bi_bdev->bd_dev;
+		__entry->orig_dev	= orig_bdev->bd_dev;
+		__entry->sector		= bio->bi_sector;
+		__entry->orig_sector	= orig_sector;
+		__entry->nr_sector	= bio->bi_size >> 9;
+		blk_fill_rwbs(__entry->rwbs, bio->bi_rw, bio->bi_size);
+		memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
+	),
+
+	TP_printk("%d,%d  %s %llu + %u [%s] (from %d,%d %llu)",
+		  MAJOR(__entry->dev), MINOR(__entry->dev),
+		  __entry->rwbs,
+		  (unsigned long long)__entry->sector,
+		  __entry->nr_sector, __entry->comm,
+		  MAJOR(__entry->orig_dev), MINOR(__entry->orig_dev),
+		  (unsigned long long)__entry->orig_sector)
+);
+
+DEFINE_EVENT(bcache_cache_bio, bcache_cache_insert,
+
+	TP_PROTO(struct bio *bio,
+		 sector_t orig_sector,
+		 struct block_device *orig_bdev),
+
+	TP_ARGS(bio, orig_sector, orig_bdev)
+);
+
+DECLARE_EVENT_CLASS(bcache_gc,
+
+	TP_PROTO(uint8_t *uuid),
+
+	TP_ARGS(uuid),
+
+	TP_STRUCT__entry(
+		__field(uint8_t *,	uuid)
+	),
+
+	TP_fast_assign(
+		__entry->uuid		= uuid;
+	),
+
+	TP_printk("%pU", __entry->uuid)
+);
+
+
+DEFINE_EVENT(bcache_gc, bcache_gc_start,
+
+	     TP_PROTO(uint8_t *uuid),
+
+	     TP_ARGS(uuid)
+);
+
+DEFINE_EVENT(bcache_gc, bcache_gc_end,
+
+	     TP_PROTO(uint8_t *uuid),
+
+	     TP_ARGS(uuid)
+);
+
+#endif /* _TRACE_BCACHE_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>