zram: do not pass rw argument to __zram_make_request()

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 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.senozhatsky@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 12 insertions, 18 deletions

diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index b3e6f072c19b..3f0d6de36f74 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -533,14 +533,18 @@ 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 == 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;
 }
@@ -672,22 +676,13 @@ 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;
@@ -706,16 +701,15 @@ 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);
@@ -745,7 +739,7 @@ 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;