[PATCH 08/16] zram: nvdimm: use bio_{start,end}_io_acct and disk_{start,end}_io_acct

From: Christoph Hellwig
Date: Wed May 27 2020 - 01:25:33 EST


Switch zram to use the nicer bio accounting helpers, and as part of that
ensure each bio is counted as a single I/O request.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
---
drivers/block/zram/zram_drv.c | 24 ++++++++++--------------
1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index ebb234f36909c..6e2ad90b17a37 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -1510,13 +1510,8 @@ static void zram_bio_discard(struct zram *zram, u32 index,
static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
int offset, unsigned int op, struct bio *bio)
{
- unsigned long start_time = jiffies;
- struct request_queue *q = zram->disk->queue;
int ret;

- generic_start_io_acct(q, op, bvec->bv_len >> SECTOR_SHIFT,
- &zram->disk->part0);
-
if (!op_is_write(op)) {
atomic64_inc(&zram->stats.num_reads);
ret = zram_bvec_read(zram, bvec, index, offset, bio);
@@ -1526,8 +1521,6 @@ static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
ret = zram_bvec_write(zram, bvec, index, offset, bio);
}

- generic_end_io_acct(q, op, &zram->disk->part0, start_time);
-
zram_slot_lock(zram, index);
zram_accessed(zram, index);
zram_slot_unlock(zram, index);
@@ -1548,6 +1541,7 @@ static void __zram_make_request(struct zram *zram, struct bio *bio)
u32 index;
struct bio_vec bvec;
struct bvec_iter iter;
+ unsigned long start_time;

index = bio->bi_iter.bi_sector >> SECTORS_PER_PAGE_SHIFT;
offset = (bio->bi_iter.bi_sector &
@@ -1563,6 +1557,7 @@ static void __zram_make_request(struct zram *zram, struct bio *bio)
break;
}

+ start_time = bio_start_io_acct(bio);
bio_for_each_segment(bvec, bio, iter) {
struct bio_vec bv = bvec;
unsigned int unwritten = bvec.bv_len;
@@ -1571,8 +1566,10 @@ static void __zram_make_request(struct zram *zram, struct bio *bio)
bv.bv_len = min_t(unsigned int, PAGE_SIZE - offset,
unwritten);
if (zram_bvec_rw(zram, &bv, index, offset,
- bio_op(bio), bio) < 0)
- goto out;
+ bio_op(bio), bio) < 0) {
+ bio->bi_status = BLK_STS_IOERR;
+ break;
+ }

bv.bv_offset += bv.bv_len;
unwritten -= bv.bv_len;
@@ -1580,12 +1577,8 @@ static void __zram_make_request(struct zram *zram, struct bio *bio)
update_position(&index, &offset, &bv);
} while (unwritten);
}
-
+ bio_end_io_acct(bio, start_time);
bio_endio(bio);
- return;
-
-out:
- bio_io_error(bio);
}

/*
@@ -1633,6 +1626,7 @@ static int zram_rw_page(struct block_device *bdev, sector_t sector,
u32 index;
struct zram *zram;
struct bio_vec bv;
+ unsigned long start_time;

if (PageTransHuge(page))
return -ENOTSUPP;
@@ -1651,7 +1645,9 @@ static int zram_rw_page(struct block_device *bdev, sector_t sector,
bv.bv_len = PAGE_SIZE;
bv.bv_offset = 0;

+ start_time = disk_start_io_acct(bdev->bd_disk, SECTORS_PER_PAGE, op);
ret = zram_bvec_rw(zram, &bv, index, offset, op, NULL);
+ disk_end_io_acct(bdev->bd_disk, op, start_time);
out:
/*
* If I/O fails, just return error(ie, non-zero) without
--
2.26.2