From f583f4924d669d36de677e0cc2422ee95203d444 Mon Sep 17 00:00:00 2001 From: David C Somayajulu Date: Wed, 4 Oct 2006 08:27:25 +0200 Subject: [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 Signed-off-by: David Somayajulu Signed-off-by: Jens Axboe --- include/scsi/scsi_tcq.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'include/scsi/scsi_tcq.h') diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h index c247a28259bc..cf4c219c0b5c 100644 --- a/include/scsi/scsi_tcq.h +++ b/include/scsi/scsi_tcq.h @@ -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 */ -- cgit v1.2.3-59-g8ed1b