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authorJames Bottomley <James.Bottomley@steeleye.com>2007-08-04 10:06:25 -0500
committerJames Bottomley <jejb@mulgrave.localdomain>2007-10-12 14:49:30 -0400
commit7f9a6bc4e9d59e7fcf03ed23f60cd81ca5d80b65 (patch)
treef2cceb87e2b6c9a66c66a8c8ceeb20bad09bb6fa /drivers/scsi/scsi_lib.c
parentd3849d512fb0ca1e369e3efcaec910a949f55f62 (diff)
[SCSI] move ULD attachment into the prep function
One of the intents of the block prep function was to allow ULDs to use it for preprocessing. The original SCSI model was to have a single prep function and add a pointer indirect filter to build the necessary commands. This patch reverses that, does away with the init_command field of the scsi_driver structure and makes ULDs attach directly to the prep function instead. The value is really that it allows us to begin to separate the ULDs from the SCSI mid layer (as long as they don't use any core functions---which is hard at the moment---a ULD doesn't even need SCSI to bind). Acked-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
-rw-r--r--drivers/scsi/scsi_lib.c84
1 files changed, 37 insertions, 47 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 47d3cdd6ddf..94d82cb9662 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1039,9 +1039,6 @@ static int scsi_init_io(struct scsi_cmnd *cmd)
printk(KERN_ERR "req nr_sec %lu, cur_nr_sec %u\n", req->nr_sectors,
req->current_nr_sectors);
- /* release the command and kill it */
- scsi_release_buffers(cmd);
- scsi_put_command(cmd);
return BLKPREP_KILL;
}
@@ -1078,9 +1075,13 @@ static void scsi_blk_pc_done(struct scsi_cmnd *cmd)
scsi_io_completion(cmd, cmd->request_bufflen);
}
-static int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
+int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
{
struct scsi_cmnd *cmd;
+ int ret = scsi_prep_state_check(sdev, req);
+
+ if (ret != BLKPREP_OK)
+ return ret;
cmd = scsi_get_cmd_from_req(sdev, req);
if (unlikely(!cmd))
@@ -1126,18 +1127,20 @@ static int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
cmd->done = scsi_blk_pc_done;
return BLKPREP_OK;
}
+EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd);
/*
* Setup a REQ_TYPE_FS command. These are simple read/write request
* from filesystems that still need to be translated to SCSI CDBs from
* the ULD.
*/
-static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
+int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
{
struct scsi_cmnd *cmd;
- struct scsi_driver *drv;
- int ret;
+ int ret = scsi_prep_state_check(sdev, req);
+ if (ret != BLKPREP_OK)
+ return ret;
/*
* Filesystem requests must transfer data.
*/
@@ -1147,26 +1150,12 @@ static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
if (unlikely(!cmd))
return BLKPREP_DEFER;
- ret = scsi_init_io(cmd);
- if (unlikely(ret))
- return ret;
-
- /*
- * Initialize the actual SCSI command for this request.
- */
- drv = *(struct scsi_driver **)req->rq_disk->private_data;
- if (unlikely(!drv->init_command(cmd))) {
- scsi_release_buffers(cmd);
- scsi_put_command(cmd);
- return BLKPREP_KILL;
- }
-
- return BLKPREP_OK;
+ return scsi_init_io(cmd);
}
+EXPORT_SYMBOL(scsi_setup_fs_cmnd);
-static int scsi_prep_fn(struct request_queue *q, struct request *req)
+int scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
{
- struct scsi_device *sdev = q->queuedata;
int ret = BLKPREP_OK;
/*
@@ -1212,35 +1201,25 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
ret = BLKPREP_KILL;
break;
}
-
- if (ret != BLKPREP_OK)
- goto out;
}
+ return ret;
+}
+EXPORT_SYMBOL(scsi_prep_state_check);
- switch (req->cmd_type) {
- case REQ_TYPE_BLOCK_PC:
- ret = scsi_setup_blk_pc_cmnd(sdev, req);
- break;
- case REQ_TYPE_FS:
- ret = scsi_setup_fs_cmnd(sdev, req);
- break;
- default:
- /*
- * All other command types are not supported.
- *
- * Note that these days the SCSI subsystem does not use
- * REQ_TYPE_SPECIAL requests anymore. These are only used
- * (directly or via blk_insert_request) by non-SCSI drivers.
- */
- blk_dump_rq_flags(req, "SCSI bad req");
- ret = BLKPREP_KILL;
- break;
- }
+int scsi_prep_return(struct request_queue *q, struct request *req, int ret)
+{
+ struct scsi_device *sdev = q->queuedata;
- out:
switch (ret) {
case BLKPREP_KILL:
req->errors = DID_NO_CONNECT << 16;
+ /* release the command and kill it */
+ if (req->special) {
+ struct scsi_cmnd *cmd = req->special;
+ scsi_release_buffers(cmd);
+ scsi_put_command(cmd);
+ req->special = NULL;
+ }
break;
case BLKPREP_DEFER:
/*
@@ -1257,6 +1236,17 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
return ret;
}
+EXPORT_SYMBOL(scsi_prep_return);
+
+static int scsi_prep_fn(struct request_queue *q, struct request *req)
+{
+ struct scsi_device *sdev = q->queuedata;
+ int ret = BLKPREP_KILL;
+
+ if (req->cmd_type == REQ_TYPE_BLOCK_PC)
+ ret = scsi_setup_blk_pc_cmnd(sdev, req);
+ return scsi_prep_return(q, req, ret);
+}
/*
* scsi_dev_queue_ready: if we can send requests to sdev, return 1 else