From dcece99e86b1191d2789fb5b5caa4c5b7fc2bfef Mon Sep 17 00:00:00 2001
From: Hannes Reinecke <hare@suse.de>
Date: Fri, 28 Feb 2020 08:53:15 +0100
Subject: [PATCH] scsi: core: add scsi_host_busy_iter()
Add an iterator scsi_host_busy_iter() to traverse all busy commands. If
locking against concurrent command completions is required, it has to be
provided by the caller.
Link: https://lore.kernel.org/r/20200228075318.91255-11-hare@suse.de
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---
drivers/scsi/hosts.c | 37 +++++++++++++++++++++++++++++++++++++
include/scsi/scsi_host.h | 3 +++
2 files changed, 40 insertions(+)
diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 00ae9d43ce9f5..7ec91c3a66cad 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -678,3 +678,40 @@ void scsi_host_complete_all_commands(struct Scsi_Host *shost, int status)
&status);
}
EXPORT_SYMBOL_GPL(scsi_host_complete_all_commands);
+
+struct scsi_host_busy_iter_data {
+ bool (*fn)(struct scsi_cmnd *, void *, bool);
+ void *priv;
+};
+
+static bool __scsi_host_busy_iter_fn(struct request *req, void *priv,
+ bool reserved)
+{
+ struct scsi_host_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);
+}
+
+/**
+ * scsi_host_busy_iter - Iterate over all busy commands
+ * @shost: Pointer to Scsi_Host.
+ * @fn: Function to call on each busy command
+ * @priv: Data pointer passed to @fn
+ *
+ * If locking against concurrent command completions is required
+ * ithas to be provided by the caller
+ **/
+void scsi_host_busy_iter(struct Scsi_Host *shost,
+ bool (*fn)(struct scsi_cmnd *, void *, bool),
+ void *priv)
+{
+ struct scsi_host_busy_iter_data iter_data = {
+ .fn = fn,
+ .priv = priv,
+ };
+
+ blk_mq_tagset_busy_iter(&shost->tag_set, __scsi_host_busy_iter_fn,
+ &iter_data);
+}
+EXPORT_SYMBOL_GPL(scsi_host_busy_iter);
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 613c3820028ea..eff12445b8239 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -761,6 +761,9 @@ extern void scsi_block_requests(struct Scsi_Host *);
extern int scsi_host_block(struct Scsi_Host *shost);
extern int scsi_host_unblock(struct Scsi_Host *shost, int new_state);
+void scsi_host_busy_iter(struct Scsi_Host *,
+ bool (*fn)(struct scsi_cmnd *, void *, bool), void *priv);
+
struct class_container;
/*
--
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