blk: introduce generic io stat accounting help function

Many block drivers accounting io stat based on bio (e.g. NVMe...),
the blk_account_io_start/end() which is based on request
does not make sense to them, so here we introduce the similar help
function named generic_start/end_io_acct base on raw sectors, and it can
simplify some driver's open io accounting code.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

2 files changed, 33 insertions, 0 deletions

diff --git a/block/bio.c b/block/bio.c
index 3e6e1986a5b2..3d4a072375ef 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1739,6 +1739,34 @@ void bio_check_pages_dirty(struct bio *bio)
         }
 }
 
+void generic_start_io_acct(int rw, unsigned long sectors,
+                           struct hd_struct *part)
+{
+        int cpu = part_stat_lock();
+
+        part_round_stats(cpu, part);
+        part_stat_inc(cpu, part, ios[rw]);
+        part_stat_add(cpu, part, sectors[rw], sectors);
+        part_inc_in_flight(part, rw);
+
+        part_stat_unlock();
+}
+EXPORT_SYMBOL(generic_start_io_acct);
+
+void generic_end_io_acct(int rw, struct hd_struct *part,
+                         unsigned long start_time)
+{
+        unsigned long duration = jiffies - start_time;
+        int cpu = part_stat_lock();
+
+        part_stat_add(cpu, part, ticks[rw], duration);
+        part_round_stats(cpu, part);
+        part_dec_in_flight(part, rw);
+
+        part_stat_unlock();
+}
+EXPORT_SYMBOL(generic_end_io_acct);
+
 #if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 void bio_flush_dcache_pages(struct bio *bi)
 {
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 7347f486ceca..efead0b532c4 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -443,6 +443,11 @@ extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
 extern void bio_set_pages_dirty(struct bio *bio);
 extern void bio_check_pages_dirty(struct bio *bio);
 
+void generic_start_io_acct(int rw, unsigned long sectors,
+                           struct hd_struct *part);
+void generic_end_io_acct(int rw, struct hd_struct *part,
+                         unsigned long start_time);
+
 #ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
 # error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
 #endif