On 1/30/19 2:53 AM, 김찬솔 wrote:
Changes:
1. Function pblk_rw_io to get bio* as a reference
2. In pblk_rw_io bio_put call on read case removed
A fix to address issue where
1. pblk_make_rq calls pblk_rw_io passes bio* pointer as a value (0xA)
2. pblk_rw_io calls blk_queue_split passing bio* pointer as reference
3. In blk_queue_split, when there is a split, the original bio* (0xA)
is passed to generic_make_requests, and the newly allocated bio is
returned
4. If NVM_IO_DONE returned, pblk_make_rq calls bio_endio on the bio*,
that is not the one returned by blk_queue_split
5. As a result bio_endio is not called on the newly allocated bio.
The commit message needs a bit of massaging. The Changes: paragraph is
not needed (that is what the patch is for). Also, please redo the second
paragraph in without the bullets.
Signed-off-by: chansol.kim <chansol.kim@xxxxxxxxxxx>
---
drivers/lightnvm/pblk-init.c | 22 ++++++++--------------
1 file changed, 8 insertions(+), 14 deletions(-)
diff --git a/drivers/lightnvm/pblk-init.c b/drivers/lightnvm/pblk-init.c
index b57f764d..4efc929 100644
--- a/drivers/lightnvm/pblk-init.c
+++ b/drivers/lightnvm/pblk-init.c
@@ -31,30 +31,24 @@ static DECLARE_RWSEM(pblk_lock);
struct bio_set pblk_bio_set;
static int pblk_rw_io(struct request_queue *q, struct pblk *pblk,
- struct bio *bio)
+ struct bio **bio)
I am not sure why the **bio change is needed. Can you elaborate?
{
- int ret;
-
/* Read requests must be <= 256kb due to NVMe's 64 bit completion bitmap
* constraint. Writes can be of arbitrary size.
*/
- if (bio_data_dir(bio) == READ) {
- blk_queue_split(q, &bio);
- ret = pblk_submit_read(pblk, bio);
- if (ret == NVM_IO_DONE && bio_flagged(bio, BIO_CLONED))
- bio_put(bio);
-
- return ret;
+ if (bio_data_dir(*bio) == READ) {
+ blk_queue_split(q, bio);
+ return pblk_submit_read(pblk, *bio);
}
/* Prevent deadlock in the case of a modest LUN configuration and large
* user I/Os. Unless stalled, the rate limiter leaves at least 256KB
* available for user I/O.
*/
- if (pblk_get_secs(bio) > pblk_rl_max_io(&pblk->rl))
- blk_queue_split(q, &bio);
+ if (pblk_get_secs(*bio) > pblk_rl_max_io(&pblk->rl))
+ blk_queue_split(q, bio);
- return pblk_write_to_cache(pblk, bio, PBLK_IOTYPE_USER);
+ return pblk_write_to_cache(pblk, *bio, PBLK_IOTYPE_USER);
}
static blk_qc_t pblk_make_rq(struct request_queue *q, struct bio *bio)
@@ -69,7 +63,7 @@ static blk_qc_t pblk_make_rq(struct request_queue *q, struct bio *bio)
}
}
- switch (pblk_rw_io(q, pblk, bio)) {
+ switch (pblk_rw_io(q, pblk, &bio)) {
case NVM_IO_ERR:
bio_io_error(bio);
break;
