On 01/14/2014 10:37 AM, Sergey Senozhatsky wrote:
> Do not pass rw argument down the __zram_make_request() -> zram_bvec_rw()
> chain, decode it in zram_bvec_rw() instead. Besides, this is the place
> where we distinguish READ (+READ AHEAD) and WRITE bio data directions, so
> account zram RW stats here, instead of __zram_make_request(). This also
> allows to account a real number of zram READ/WRITE operations, not just
> requests (single RW request may cause a number of zram RW ops with separate
> locking, compression/decompression, etc).
>
> Signed-off-by: Sergey Senozhatsky <sergey.senozhat...@gmail.com>
> ---
> drivers/block/zram/zram_drv.c | 33 +++++++++++++++------------------
> 1 file changed, 15 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
> index c323e05..2a7682c 100644
> --- a/drivers/block/zram/zram_drv.c
> +++ b/drivers/block/zram/zram_drv.c
> @@ -533,14 +533,21 @@ out:
> }
>
> static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,
> - int offset, struct bio *bio, int rw)
> + int offset, struct bio *bio)
> {
> int ret;
> + int rw = bio_data_dir(bio);
>
> - if (rw == READ)
> + if (rw == READA)
> + rw = READ;
This could never happen: bio_data_dir() can only return READ or WRITE.
Jerome
> +
> + if (rw == READ) {
> + atomic64_inc(&zram->stats.num_reads);
> ret = zram_bvec_read(zram, bvec, index, offset, bio);
> - else
> + } else {
> + atomic64_inc(&zram->stats.num_writes);
> ret = zram_bvec_write(zram, bvec, index, offset);
> + }
>
> return ret;
> }
> @@ -670,22 +677,13 @@ out:
> return ret;
> }
>
> -static void __zram_make_request(struct zram *zram, struct bio *bio, int rw)
> +static void __zram_make_request(struct zram *zram, struct bio *bio)
> {
> int offset;
> u32 index;
> struct bio_vec bvec;
> struct bvec_iter iter;
>
> - switch (rw) {
> - case READ:
> - atomic64_inc(&zram->stats.num_reads);
> - break;
> - case WRITE:
> - atomic64_inc(&zram->stats.num_writes);
> - break;
> - }
> -
> index = bio->bi_iter.bi_sector >> SECTORS_PER_PAGE_SHIFT;
> offset = (bio->bi_iter.bi_sector &
> (SECTORS_PER_PAGE - 1)) << SECTOR_SHIFT;
> @@ -704,16 +702,15 @@ static void __zram_make_request(struct zram *zram,
> struct bio *bio, int rw)
> bv.bv_len = max_transfer_size;
> bv.bv_offset = bvec.bv_offset;
>
> - if (zram_bvec_rw(zram, &bv, index, offset, bio, rw) < 0)
> + if (zram_bvec_rw(zram, &bv, index, offset, bio) < 0)
> goto out;
>
> bv.bv_len = bvec.bv_len - max_transfer_size;
> bv.bv_offset += max_transfer_size;
> - if (zram_bvec_rw(zram, &bv, index+1, 0, bio, rw) < 0)
> + if (zram_bvec_rw(zram, &bv, index + 1, 0, bio) < 0)
> goto out;
> } else
> - if (zram_bvec_rw(zram, &bvec, index, offset, bio, rw)
> - < 0)
> + if (zram_bvec_rw(zram, &bvec, index, offset, bio) < 0)
> goto out;
>
> update_position(&index, &offset, &bvec);
> @@ -743,7 +740,7 @@ static void zram_make_request(struct request_queue
> *queue, struct bio *bio)
> goto error;
> }
>
> - __zram_make_request(zram, bio, bio_data_dir(bio));
> + __zram_make_request(zram, bio);
> up_read(&zram->init_lock);
>
> return;
>
--
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