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| author | David C Somayajulu <david.somayajulu@qlogic.com> | 2006-10-04 08:27:25 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@nelson.home.kernel.dk> | 2006-10-04 19:32:09 +0200 |
| commit | f583f4924d669d36de677e0cc2422ee95203d444 (patch) | |
| tree | 08efeac804151bbaef8cf0ca7effaa4e30e037f9 /include | |
| parent | 4a61f17378c2cdd9bd8f34ef8bd7422861d0c1f1 (diff) | |
| download | op-kernel-dev-f583f4924d669d36de677e0cc2422ee95203d444.zip op-kernel-dev-f583f4924d669d36de677e0cc2422ee95203d444.tar.gz | |
[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>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/blkdev.h | 8 | ||||
| -rw-r--r-- | include/scsi/scsi_tcq.h | 20 |
2 files changed, 28 insertions, 0 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 1d79b8d..26f7856 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -769,6 +769,14 @@ extern struct blk_queue_tag *blk_init_tags(int); extern void blk_free_tags(struct blk_queue_tag *); extern void blk_congestion_end(int rw); +static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt, + int tag) +{ + if (unlikely(bqt == NULL || tag >= bqt->real_max_depth)) + return NULL; + return bqt->tag_index[tag]; +} + extern void blk_rq_bio_prep(request_queue_t *, struct request *, struct bio *); extern int blkdev_issue_flush(struct block_device *, sector_t *); diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h index c247a282..cf4c219 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 */ |
