block: Add and use op_stat_group() for indexing disk_stat fields.

Add and use a new op_stat_group() function for indexing partition stat
fields rather than indexing them by rq_data_dir() or bio_data_dir().
This function works similarly to op_is_sync() in that it takes the
request::cmd_flags or bio::bi_opf flags and determines which stats
should et updated.

In addition, the second parameter to generic_start_io_acct() and
generic_end_io_acct() is now a REQ_OP rather than simply a read or
write bit and it uses op_stat_group() on the parameter to determine
the stat group.

Note that the partition in_flight counts are not part of the per-cpu
statistics and as such are not indexed via this function.  It's now
indexed by op_is_write().

tj: Refreshed on top of v4.17.  Updated to pass around REQ_OP.

Signed-off-by: Michael Callahan <michaelcallahan@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Joshua Morris <josh.h.morris@us.ibm.com>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Matias Bjorling <mb@lightnvm.io>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Alasdair Kergon <agk@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 5 insertions, 8 deletions

diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index ae67f5fa8047..97707b0c54ce 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -667,8 +667,7 @@ static void backing_request_endio(struct bio *bio)
 static void bio_complete(struct search *s)
 {
         if (s->orig_bio) {
-                generic_end_io_acct(s->d->disk->queue,
-                                    bio_data_dir(s->orig_bio),
+                generic_end_io_acct(s->d->disk->queue, bio_op(s->orig_bio),
                                     &s->d->disk->part0, s->start_time);
 
                 trace_bcache_request_end(s->d, s->orig_bio);
@@ -1062,8 +1061,7 @@ static void detached_dev_end_io(struct bio *bio)
         bio->bi_end_io = ddip->bi_end_io;
         bio->bi_private = ddip->bi_private;
 
-        generic_end_io_acct(ddip->d->disk->queue,
-                            bio_data_dir(bio),
+        generic_end_io_acct(ddip->d->disk->queue, bio_op(bio),
                             &ddip->d->disk->part0, ddip->start_time);
 
         if (bio->bi_status) {
@@ -1120,7 +1118,7 @@ static blk_qc_t cached_dev_make_request(struct request_queue *q,
         }
 
         atomic_set(&dc->backing_idle, 0);
-        generic_start_io_acct(q, rw, bio_sectors(bio), &d->disk->part0);
+        generic_start_io_acct(q, bio_op(bio), bio_sectors(bio), &d->disk->part0);
 
         bio_set_dev(bio, dc->bdev);
         bio->bi_iter.bi_sector += dc->sb.data_offset;
@@ -1229,7 +1227,6 @@ static blk_qc_t flash_dev_make_request(struct request_queue *q,
         struct search *s;
         struct closure *cl;
         struct bcache_device *d = bio->bi_disk->private_data;
-        int rw = bio_data_dir(bio);
 
         if (unlikely(d->c && test_bit(CACHE_SET_IO_DISABLE, &d->c->flags))) {
                 bio->bi_status = BLK_STS_IOERR;
@@ -1237,7 +1234,7 @@ static blk_qc_t flash_dev_make_request(struct request_queue *q,
                 return BLK_QC_T_NONE;
         }
 
-        generic_start_io_acct(q, rw, bio_sectors(bio), &d->disk->part0);
+        generic_start_io_acct(q, bio_op(bio), bio_sectors(bio), &d->disk->part0);
 
         s = search_alloc(bio, d);
         cl = &s->cl;
@@ -1254,7 +1251,7 @@ static blk_qc_t flash_dev_make_request(struct request_queue *q,
                                       flash_dev_nodata,
                                       bcache_wq);
                 return BLK_QC_T_NONE;
-        } else if (rw) {
+        } else if (bio_data_dir(bio)) {
                 bch_keybuf_check_overlapping(&s->iop.c->moving_gc_keys,
                                         &KEY(d->id, bio->bi_iter.bi_sector, 0),
                                         &KEY(d->id, bio_end_sector(bio), 0));