[PATCH RFC v2 08/24] scsi: add host tagset busy iterator

John Garry
2020-03-10T16:30:46Z

From: Hannes Reinecke <hare@suse.de>

Add an iterator scsi_host_tagset_busy_iter() to easily traverse all
busy commands. No locking is done here; this need to be ensured by
the caller.

Signed-off-by: Hannes Reinecke <hare@suse.com>
---
drivers/scsi/hosts.c | 27 +++++++++++++++++++++++++++
include/scsi/scsi_host.h | 5 +++++
2 files changed, 32 insertions(+)

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 1d669e47b692..97704a630f8e 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -650,3 +650,30 @@ void scsi_flush_work(struct Scsi_Host *shost)
flush_workqueue(shost->work_q);
}
EXPORT_SYMBOL_GPL(scsi_flush_work);
+
+struct scsi_host_tagset_busy_iter_data {
+ scsi_host_busy_iter_fn *fn;
+ void *priv;
+};
+
+static bool scsi_host_tagset_busy_iter_fn(struct request *req, void *priv,
+ bool reserved)
+{
+ struct scsi_host_tagset_busy_iter_data *iter_data = priv;
+ struct scsi_cmnd *sc = blk_mq_rq_to_pdu(req);
+
+ return iter_data->fn(sc, iter_data->priv, reserved);
+}
+
+void scsi_host_tagset_busy_iter(struct Scsi_Host *shost,
+ scsi_host_busy_iter_fn *fn, void *priv)
+{
+ struct scsi_host_tagset_busy_iter_data iter_data = {
+ .fn = fn,
+ .priv = priv,
+ };
+
+ blk_mq_tagset_busy_iter(&shost->tag_set, scsi_host_tagset_busy_iter_fn,
+ &iter_data);
+}
+EXPORT_SYMBOL_GPL(scsi_host_tagset_busy_iter);
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 2258a4f7b4d8..663aef22437a 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -767,6 +767,11 @@ static inline int scsi_host_scan_allowed(struct Scsi_Host *shost)
extern void scsi_unblock_requests(struct Scsi_Host *);
extern void scsi_block_requests(struct Scsi_Host *);

+typedef bool (scsi_host_busy_iter_fn)(struct scsi_cmnd *, void *, bool);
+
+void scsi_host_tagset_busy_iter(struct Scsi_Host *,
+ scsi_host_busy_iter_fn *fn, void *priv);
+
struct class_container;

/*
--
2.17.1