[PATCH 24/25] lightnvm: pblk: add iostat support

From: Matias BjÃrling
Date: Wed Dec 20 2017 - 12:23:16 EST


From: Javier GonzÃlez <javier@xxxxxxxxxxxx>

Since pblk registers its own block device, the iostat accounting is
not automatically done for us. Therefore, add the necessary
accounting logic to satisfy the iostat interface.

Signed-off-by: Javier GonzÃlez <javier@xxxxxxxxxxxx>
Signed-off-by: Matias BjÃrling <m@xxxxxxxxxxx>
---
drivers/lightnvm/pblk-cache.c | 5 +++++
drivers/lightnvm/pblk-read.c | 31 +++++++++++++++++++------------
drivers/lightnvm/pblk.h | 1 +
3 files changed, 25 insertions(+), 12 deletions(-)

diff --git a/drivers/lightnvm/pblk-cache.c b/drivers/lightnvm/pblk-cache.c
index 0d227ef..000fcad 100644
--- a/drivers/lightnvm/pblk-cache.c
+++ b/drivers/lightnvm/pblk-cache.c
@@ -19,12 +19,16 @@

int pblk_write_to_cache(struct pblk *pblk, struct bio *bio, unsigned long flags)
{
+ struct request_queue *q = pblk->dev->q;
struct pblk_w_ctx w_ctx;
sector_t lba = pblk_get_lba(bio);
+ unsigned long start_time = jiffies;
unsigned int bpos, pos;
int nr_entries = pblk_get_secs(bio);
int i, ret;

+ generic_start_io_acct(q, WRITE, bio_sectors(bio), &pblk->disk->part0);
+
/* Update the write buffer head (mem) with the entries that we can
* write. The write in itself cannot fail, so there is no need to
* rollback from here on.
@@ -67,6 +71,7 @@ int pblk_write_to_cache(struct pblk *pblk, struct bio *bio, unsigned long flags)
pblk_rl_inserted(&pblk->rl, nr_entries);

out:
+ generic_end_io_acct(q, WRITE, &pblk->disk->part0, start_time);
pblk_write_should_kick(pblk);
return ret;
}
diff --git a/drivers/lightnvm/pblk-read.c b/drivers/lightnvm/pblk-read.c
index 0fe0c04..2f76128 100644
--- a/drivers/lightnvm/pblk-read.c
+++ b/drivers/lightnvm/pblk-read.c
@@ -158,8 +158,12 @@ static void pblk_end_user_read(struct bio *bio)
static void __pblk_end_io_read(struct pblk *pblk, struct nvm_rq *rqd,
bool put_line)
{
+ struct nvm_tgt_dev *dev = pblk->dev;
struct pblk_g_ctx *r_ctx = nvm_rq_to_pdu(rqd);
struct bio *bio = rqd->bio;
+ unsigned long start_time = r_ctx->start_time;
+
+ generic_end_io_acct(dev->q, READ, &pblk->disk->part0, start_time);

if (rqd->error)
pblk_log_read_err(pblk, rqd);
@@ -193,9 +197,9 @@ static void pblk_end_io_read(struct nvm_rq *rqd)
__pblk_end_io_read(pblk, rqd, true);
}

-static int pblk_fill_partial_read_bio(struct pblk *pblk, struct nvm_rq *rqd,
- unsigned int bio_init_idx,
- unsigned long *read_bitmap)
+static int pblk_partial_read_bio(struct pblk *pblk, struct nvm_rq *rqd,
+ unsigned int bio_init_idx,
+ unsigned long *read_bitmap)
{
struct bio *new_bio, *bio = rqd->bio;
struct pblk_sec_meta *meta_list = rqd->meta_list;
@@ -306,6 +310,8 @@ static int pblk_fill_partial_read_bio(struct pblk *pblk, struct nvm_rq *rqd,
return NVM_IO_OK;

err:
+ pr_err("pblk: failed to perform partial read\n");
+
/* Free allocated pages in new bio */
pblk_bio_free_pages(pblk, bio, 0, new_bio->bi_vcnt);
__pblk_end_io_read(pblk, rqd, false);
@@ -357,6 +363,7 @@ static void pblk_read_rq(struct pblk *pblk, struct nvm_rq *rqd,
int pblk_submit_read(struct pblk *pblk, struct bio *bio)
{
struct nvm_tgt_dev *dev = pblk->dev;
+ struct request_queue *q = dev->q;
sector_t blba = pblk_get_lba(bio);
unsigned int nr_secs = pblk_get_secs(bio);
struct pblk_g_ctx *r_ctx;
@@ -372,6 +379,8 @@ int pblk_submit_read(struct pblk *pblk, struct bio *bio)
return NVM_IO_ERR;
}

+ generic_start_io_acct(q, READ, bio_sectors(bio), &pblk->disk->part0);
+
bitmap_zero(&read_bitmap, nr_secs);

rqd = pblk_alloc_rqd(pblk, PBLK_READ);
@@ -383,6 +392,7 @@ int pblk_submit_read(struct pblk *pblk, struct bio *bio)
rqd->end_io = pblk_end_io_read;

r_ctx = nvm_rq_to_pdu(rqd);
+ r_ctx->start_time = jiffies;
r_ctx->lba = blba;

/* Save the index for this bio's start. This is needed in case
@@ -422,7 +432,7 @@ int pblk_submit_read(struct pblk *pblk, struct bio *bio)
int_bio = bio_clone_fast(bio, GFP_KERNEL, pblk_bio_set);
if (!int_bio) {
pr_err("pblk: could not clone read bio\n");
- return NVM_IO_ERR;
+ goto fail_end_io;
}

rqd->bio = int_bio;
@@ -433,7 +443,7 @@ int pblk_submit_read(struct pblk *pblk, struct bio *bio)
pr_err("pblk: read IO submission failed\n");
if (int_bio)
bio_put(int_bio);
- return ret;
+ goto fail_end_io;
}

return NVM_IO_OK;
@@ -442,17 +452,14 @@ int pblk_submit_read(struct pblk *pblk, struct bio *bio)
/* The read bio request could be partially filled by the write buffer,
* but there are some holes that need to be read from the drive.
*/
- ret = pblk_fill_partial_read_bio(pblk, rqd, bio_init_idx, &read_bitmap);
- if (ret) {
- pr_err("pblk: failed to perform partial read\n");
- return ret;
- }
-
- return NVM_IO_OK;
+ return pblk_partial_read_bio(pblk, rqd, bio_init_idx, &read_bitmap);

fail_rqd_free:
pblk_free_rqd(pblk, rqd, PBLK_READ);
return ret;
+fail_end_io:
+ __pblk_end_io_read(pblk, rqd, false);
+ return ret;
}

static int read_ppalist_rq_gc(struct pblk *pblk, struct nvm_rq *rqd,
diff --git a/drivers/lightnvm/pblk.h b/drivers/lightnvm/pblk.h
index cb38990..1e9eafd 100644
--- a/drivers/lightnvm/pblk.h
+++ b/drivers/lightnvm/pblk.h
@@ -113,6 +113,7 @@ struct pblk_c_ctx {
/* read context */
struct pblk_g_ctx {
void *private;
+ unsigned long start_time;
u64 lba;
};

--
2.9.3