[PATCH 2/5] block: change request end_io handler to pass back a return value

Jens Axboe
2022-09-22T18:28:32Z

Everything is just converted to returning RQ_END_IO_NONE, and there
should be no functional changes with this patch.

In preparation for allowing the end_io handler to pass ownership back
to the block layer, rather than retain ownership of the request.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
block/blk-flush.c | 10 +++++++---
block/blk-mq.c | 14 +++++++++-----
drivers/md/dm-rq.c | 4 +++-
drivers/nvme/host/core.c | 6 ++++--
drivers/nvme/host/ioctl.c | 5 ++++-
drivers/nvme/host/pci.c | 12 ++++++++----
drivers/nvme/target/passthru.c | 5 +++--
drivers/scsi/scsi_error.c | 4 +++-
drivers/scsi/sg.c | 9 +++++----
drivers/scsi/st.c | 4 +++-
drivers/target/target_core_pscsi.c | 6 ++++--
drivers/ufs/core/ufshpb.c | 8 ++++++--
include/linux/blk-mq.h | 7 ++++++-
13 files changed, 65 insertions(+), 29 deletions(-)

diff --git a/block/blk-flush.c b/block/blk-flush.c
index d20a0c6b2c66..ac850f4d9c4c 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -218,7 +218,8 @@ static void blk_flush_complete_seq(struct request *rq,
blk_kick_flush(q, fq, cmd_flags);
}

-static void flush_end_io(struct request *flush_rq, blk_status_t error)
+static enum rq_end_io_ret flush_end_io(struct request *flush_rq,
+ blk_status_t error)
{
struct request_queue *q = flush_rq->q;
struct list_head *running;
@@ -232,7 +233,7 @@ static void flush_end_io(struct request *flush_rq, blk_status_t error)
if (!req_ref_put_and_test(flush_rq)) {
fq->rq_status = error;
spin_unlock_irqrestore(&fq->mq_flush_lock, flags);
- return;
+ return RQ_END_IO_NONE;
}

blk_account_io_flush(flush_rq);
@@ -269,6 +270,7 @@ static void flush_end_io(struct request *flush_rq, blk_status_t error)
}

spin_unlock_irqrestore(&fq->mq_flush_lock, flags);
+ return RQ_END_IO_NONE;
}

bool is_flush_rq(struct request *rq)
@@ -354,7 +356,8 @@ static void blk_kick_flush(struct request_queue *q, struct blk_flush_queue *fq,
blk_flush_queue_rq(flush_rq, false);
}

-static void mq_flush_data_end_io(struct request *rq, blk_status_t error)
+static enum rq_end_io_ret mq_flush_data_end_io(struct request *rq,
+ blk_status_t error)
{
struct request_queue *q = rq->q;
struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
@@ -376,6 +379,7 @@ static void mq_flush_data_end_io(struct request *rq, blk_status_t error)
spin_unlock_irqrestore(&fq->mq_flush_lock, flags);

blk_mq_sched_restart(hctx);
+ return RQ_END_IO_NONE;
}

/**
diff --git a/block/blk-mq.c b/block/blk-mq.c
index d3a9f8b9c7ee..a4e018c82b7c 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1001,7 +1001,8 @@ inline void __blk_mq_end_request(struct request *rq, blk_status_t error)

if (rq->end_io) {
rq_qos_done(rq->q, rq);
- rq->end_io(rq, error);
+ if (rq->end_io(rq, error) == RQ_END_IO_FREE)
+ blk_mq_free_request(rq);
} else {
blk_mq_free_request(rq);
}
@@ -1287,12 +1288,13 @@ struct blk_rq_wait {
blk_status_t ret;
};

-static void blk_end_sync_rq(struct request *rq, blk_status_t ret)
+static enum rq_end_io_ret blk_end_sync_rq(struct request *rq, blk_status_t ret)
{
struct blk_rq_wait *wait = rq->end_io_data;

wait->ret = ret;
complete(&wait->done);
+ return RQ_END_IO_NONE;
}

bool blk_rq_is_poll(struct request *rq)
@@ -1526,10 +1528,12 @@ static bool blk_mq_req_expired(struct request *rq, unsigned long *next)

void blk_mq_put_rq_ref(struct request *rq)
{
- if (is_flush_rq(rq))
- rq->end_io(rq, 0);
- else if (req_ref_put_and_test(rq))
+ if (is_flush_rq(rq)) {
+ if (rq->end_io(rq, 0) == RQ_END_IO_FREE)
+ blk_mq_free_request(rq);
+ } else if (req_ref_put_and_test(rq)) {
__blk_mq_free_request(rq);
+ }
}

static bool blk_mq_check_expired(struct request *rq, void *priv)
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 4f49bbcce4f1..3001b10a3fbf 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -292,11 +292,13 @@ static void dm_kill_unmapped_request(struct request *rq, blk_status_t error)
dm_complete_request(rq, error);
}

-static void end_clone_request(struct request *clone, blk_status_t error)
+static enum rq_end_io_ret end_clone_request(struct request *clone,
+ blk_status_t error)
{
struct dm_rq_target_io *tio = clone->end_io_data;

dm_complete_request(tio->orig, error);
+ return RQ_END_IO_NONE;
}

static int dm_rq_bio_constructor(struct bio *bio, struct bio *bio_orig,
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 13080a017ecf..f946f85e7a66 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1177,7 +1177,8 @@ static void nvme_queue_keep_alive_work(struct nvme_ctrl *ctrl)
queue_delayed_work(nvme_wq, &ctrl->ka_work, ctrl->kato * HZ / 2);
}

-static void nvme_keep_alive_end_io(struct request *rq, blk_status_t status)
+static enum rq_end_io_ret nvme_keep_alive_end_io(struct request *rq,
+ blk_status_t status)
{
struct nvme_ctrl *ctrl = rq->end_io_data;
unsigned long flags;
@@ -1189,7 +1190,7 @@ static void nvme_keep_alive_end_io(struct request *rq, blk_status_t status)
dev_err(ctrl->device,
"failed nvme_keep_alive_end_io error=%d\n",
status);
- return;
+ return RQ_END_IO_NONE;
}

ctrl->comp_seen = false;
@@ -1200,6 +1201,7 @@ static void nvme_keep_alive_end_io(struct request *rq, blk_status_t status)
spin_unlock_irqrestore(&ctrl->lock, flags);
if (startka)
nvme_queue_keep_alive_work(ctrl);
+ return RQ_END_IO_NONE;
}

static void nvme_keep_alive_work(struct work_struct *work)
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index 548aca8b5b9f..c80b3ecca5c8 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -385,7 +385,8 @@ static void nvme_uring_task_cb(struct io_uring_cmd *ioucmd)
io_uring_cmd_done(ioucmd, status, result);
}

-static void nvme_uring_cmd_end_io(struct request *req, blk_status_t err)
+static enum rq_end_io_ret nvme_uring_cmd_end_io(struct request *req,
+ blk_status_t err)
{
struct io_uring_cmd *ioucmd = req->end_io_data;
struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
@@ -404,6 +405,8 @@ static void nvme_uring_cmd_end_io(struct request *req, blk_status_t err)
nvme_uring_task_cb(ioucmd);
else
io_uring_cmd_complete_in_task(ioucmd, nvme_uring_task_cb);
+
+ return RQ_END_IO_NONE;
}

static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 09b5d62f342b..361f09f23648 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -1268,7 +1268,7 @@ static int adapter_delete_sq(struct nvme_dev *dev, u16 sqid)
return adapter_delete_queue(dev, nvme_admin_delete_sq, sqid);
}

-static void abort_endio(struct request *req, blk_status_t error)
+static enum rq_end_io_ret abort_endio(struct request *req, blk_status_t error)
{
struct nvme_queue *nvmeq = req->mq_hctx->driver_data;

@@ -1276,6 +1276,7 @@ static void abort_endio(struct request *req, blk_status_t error)
"Abort status: 0x%x", nvme_req(req)->status);
atomic_inc(&nvmeq->dev->ctrl.abort_limit);
blk_mq_free_request(req);
+ return RQ_END_IO_NONE;
}

static bool nvme_should_reset(struct nvme_dev *dev, u32 csts)
@@ -2447,22 +2448,25 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
return result;
}

-static void nvme_del_queue_end(struct request *req, blk_status_t error)
+static enum rq_end_io_ret nvme_del_queue_end(struct request *req,
+ blk_status_t error)
{
struct nvme_queue *nvmeq = req->end_io_data;

blk_mq_free_request(req);
complete(&nvmeq->delete_done);
+ return RQ_END_IO_NONE;
}

-static void nvme_del_cq_end(struct request *req, blk_status_t error)
+static enum rq_end_io_ret nvme_del_cq_end(struct request *req,
+ blk_status_t error)
{
struct nvme_queue *nvmeq = req->end_io_data;

if (error)
set_bit(NVMEQ_DELETE_ERROR, &nvmeq->flags);

- nvme_del_queue_end(req, error);
+ return nvme_del_queue_end(req, error);
}

static int nvme_delete_queue(struct nvme_queue *nvmeq, u8 opcode)
diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c
index 6f39a29828b1..4876ccaac55b 100644
--- a/drivers/nvme/target/passthru.c
+++ b/drivers/nvme/target/passthru.c
@@ -240,14 +240,15 @@ static void nvmet_passthru_execute_cmd_work(struct work_struct *w)
blk_mq_free_request(rq);
}

-static void nvmet_passthru_req_done(struct request *rq,
- blk_status_t blk_status)
+static enum rq_end_io_ret nvmet_passthru_req_done(struct request *rq,
+ blk_status_t blk_status)
{
struct nvmet_req *req = rq->end_io_data;

req->cqe->result = nvme_req(rq)->result;
nvmet_req_complete(req, nvme_req(rq)->status);
blk_mq_free_request(rq);
+ return RQ_END_IO_NONE;
}

static int nvmet_passthru_map_sg(struct nvmet_req *req, struct request *rq)
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 448748e3fba5..786fb963cf3f 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -2004,9 +2004,11 @@ enum scsi_disposition scsi_decide_disposition(struct scsi_cmnd *scmd)
}
}

-static void eh_lock_door_done(struct request *req, blk_status_t status)
+static enum rq_end_io_ret eh_lock_door_done(struct request *req,
+ blk_status_t status)
{
blk_mq_free_request(req);
+ return RQ_END_IO_NONE;
}

/**
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 340b050ad28d..94c5e9a9309c 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -177,7 +177,7 @@ typedef struct sg_device { /* holds the state of each scsi generic device */
} Sg_device;

/* tasklet or soft irq callback */
-static void sg_rq_end_io(struct request *rq, blk_status_t status);
+static enum rq_end_io_ret sg_rq_end_io(struct request *rq, blk_status_t status);
static int sg_start_req(Sg_request *srp, unsigned char *cmd);
static int sg_finish_rem_req(Sg_request * srp);
static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
@@ -1311,7 +1311,7 @@ sg_rq_end_io_usercontext(struct work_struct *work)
* This function is a "bottom half" handler that is called by the mid
* level when a command is completed (or has failed).
*/
-static void
+static enum rq_end_io_ret
sg_rq_end_io(struct request *rq, blk_status_t status)
{
struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
@@ -1324,11 +1324,11 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
int result, resid, done = 1;

if (WARN_ON(srp->done != 0))
- return;
+ return RQ_END_IO_NONE;

sfp = srp->parentfp;
if (WARN_ON(sfp == NULL))
- return;
+ return RQ_END_IO_NONE;

sdp = sfp->parentdp;
if (unlikely(atomic_read(&sdp->detaching)))
@@ -1406,6 +1406,7 @@ sg_rq_end_io(struct request *rq, blk_status_t status)
INIT_WORK(&srp->ew.work, sg_rq_end_io_usercontext);
schedule_work(&srp->ew.work);
}
+ return RQ_END_IO_NONE;
}

static const struct file_operations sg_fops = {
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 850172a2b8f1..55e7c07ebe4c 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -512,7 +512,8 @@ static void st_do_stats(struct scsi_tape *STp, struct request *req)
atomic64_dec(&STp->stats->in_flight);
}

-static void st_scsi_execute_end(struct request *req, blk_status_t status)
+static enum rq_end_io_ret st_scsi_execute_end(struct request *req,
+ blk_status_t status)
{
struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(req);
struct st_request *SRpnt = req->end_io_data;
@@ -532,6 +533,7 @@ static void st_scsi_execute_end(struct request *req, blk_status_t status)

blk_rq_unmap_user(tmp);
blk_mq_free_request(req);
+ return RQ_END_IO_NONE;
}

static int st_scsi_execute(struct st_request *SRpnt, const unsigned char *cmd,
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index e6a967ddc08c..8a7306e5e133 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -39,7 +39,7 @@ static inline struct pscsi_dev_virt *PSCSI_DEV(struct se_device *dev)
}

static sense_reason_t pscsi_execute_cmd(struct se_cmd *cmd);
-static void pscsi_req_done(struct request *, blk_status_t);
+static enum rq_end_io_ret pscsi_req_done(struct request *, blk_status_t);

/* pscsi_attach_hba():
*
@@ -1002,7 +1002,8 @@ static sector_t pscsi_get_blocks(struct se_device *dev)
return 0;
}

-static void pscsi_req_done(struct request *req, blk_status_t status)
+static enum rq_end_io_ret pscsi_req_done(struct request *req,
+ blk_status_t status)
{
struct se_cmd *cmd = req->end_io_data;
struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(req);
@@ -1029,6 +1030,7 @@ static void pscsi_req_done(struct request *req, blk_status_t status)
}

blk_mq_free_request(req);
+ return RQ_END_IO_NONE;
}

static const struct target_backend_ops pscsi_ops = {
diff --git a/drivers/ufs/core/ufshpb.c b/drivers/ufs/core/ufshpb.c
index a1a7a1175a5a..3d69a81c5b17 100644
--- a/drivers/ufs/core/ufshpb.c
+++ b/drivers/ufs/core/ufshpb.c
@@ -613,14 +613,17 @@ static void ufshpb_activate_subregion(struct ufshpb_lu *hpb,
srgn->srgn_state = HPB_SRGN_VALID;
}

-static void ufshpb_umap_req_compl_fn(struct request *req, blk_status_t error)
+static enum rq_end_io_ret ufshpb_umap_req_compl_fn(struct request *req,
+ blk_status_t error)
{
struct ufshpb_req *umap_req = (struct ufshpb_req *)req->end_io_data;

ufshpb_put_req(umap_req->hpb, umap_req);
+ return RQ_END_IO_NONE;
}

-static void ufshpb_map_req_compl_fn(struct request *req, blk_status_t error)
+static enum rq_end_io_ret ufshpb_map_req_compl_fn(struct request *req,
+ blk_status_t error)
{
struct ufshpb_req *map_req = (struct ufshpb_req *) req->end_io_data;
struct ufshpb_lu *hpb = map_req->hpb;
@@ -636,6 +639,7 @@ static void ufshpb_map_req_compl_fn(struct request *req, blk_status_t error)
spin_unlock_irqrestore(&hpb->rgn_state_lock, flags);

ufshpb_put_map_req(map_req->hpb, map_req);
+ return RQ_END_IO_NONE;
}

static void ufshpb_set_unmap_cmd(unsigned char *cdb, struct ufshpb_region *rgn)
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 00a15808c137..e6fa49dd6196 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -14,7 +14,12 @@ struct blk_flush_queue;
#define BLKDEV_MIN_RQ 4
#define BLKDEV_DEFAULT_RQ 128

-typedef void (rq_end_io_fn)(struct request *, blk_status_t);
+enum rq_end_io_ret {
+ RQ_END_IO_NONE,
+ RQ_END_IO_FREE,
+};
+
+typedef enum rq_end_io_ret (rq_end_io_fn)(struct request *, blk_status_t);

/*
* request flags */
--
2.35.1