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>
This commit is contained in:
Hannes Reinecke 2020-02-28 08:53:15 +01:00 committed by Martin K. Petersen
parent 3d3ca53b16
commit dcece99e86
2 changed files with 40 additions and 0 deletions

View File

@ -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);

View File

@ -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;
/*