[PATCH] helper function for retrieving scsi_cmd given host based block layer tag

This was necessitated by the need for a function to get back
to a scsi_cmnd, when an hba the posts its (corresponding) completion
interrupt with a block layer tag as its reference.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: David Somayajulu <david.somayajulu@qlogic.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
David C Somayajulu
2006-10-04 08:27:25 +02:00
committed by Jens Axboe
parent 4a61f17378
commit f583f4924d
3 changed files with 29 additions and 6 deletions

View File

@ -144,5 +144,25 @@ static inline int scsi_init_shared_tag_map(struct Scsi_Host *shost, int depth)
return shost->bqt ? 0 : -ENOMEM;
}
/**
* scsi_host_find_tag - find the tagged command by host
* @shost: pointer to scsi_host
* @tag: tag of the scsi_cmnd
*
* Notes:
* Only works with tags allocated by the generic blk layer.
**/
static inline struct scsi_cmnd *scsi_host_find_tag(struct Scsi_Host *shost,
int tag)
{
struct request *req;
if (tag != SCSI_NO_TAG) {
req = blk_map_queue_find_tag(shost->bqt, tag);
return req ? (struct scsi_cmnd *)req->special : NULL;
}
return NULL;
}
#endif /* CONFIG_BLOCK */
#endif /* _SCSI_SCSI_TCQ_H */