add scsi helpers

PATCH New Mike Christie 1 participant 1 message Nov 11, 2005

Subsystems (3)

VFS SCSI Block layer

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Mike Christie

author

2005-11-11 11:31 UTC #0 lore raw

PATCH 2/5 add scsi helpers

Add scsi helpers to create really-large-requests and convert scsi-ml to scsi_execute_async().

Per Jens's previous comments, I placed this function in scsi_lib.c. I made it follow all the queue's limits - I think I did at least :), so I removed the warning on the function header.

I think the scsi_execute_* functions should envtually take a request_queue and be placed some place where the dm-multipath hw_handler can use them if that failover code is going to stay in the kernel. That conversion patch will be sent in another mail though.

Signed-off-by Mike Christie <[email protected]>

drivers/scsi/scsi_error.c +9 ~~-38~~

index 18c5d25..53ea62d 100644
@@ -1315,23 +1315,6 @@ int scsi_decide_disposition(struct scsi_
 }
 
 /**
- * scsi_eh_lock_done - done function for eh door lock request
- * @scmd:	SCSI command block for the door lock request
- *
- * Notes:
- * 	We completed the asynchronous door lock request, and it has either
- * 	locked the door or failed.  We must free the command structures
- * 	associated with this request.
- **/
-static void scsi_eh_lock_done(struct scsi_cmnd *scmd)
-{
-	struct scsi_request *sreq = scmd->sc_request;
-
-	scsi_release_request(sreq);
-}
-
-
-/**
  * scsi_eh_lock_door - Prevent medium removal for the specified device
  * @sdev:	SCSI device to prevent medium removal
  *

@@ -1353,29 +1336,17 @@ static void scsi_eh_lock_done(struct scs
  **/
 static void scsi_eh_lock_door(struct scsi_device *sdev)
 {
-	struct scsi_request *sreq = scsi_allocate_request(sdev, GFP_KERNEL);
-
-	if (unlikely(!sreq)) {
-		printk(KERN_ERR "%s: request allocate failed,"
-		       "prevent media removal cmd not sent\n", __FUNCTION__);
-		return;
-	}
+	unsigned char cmnd[MAX_COMMAND_SIZE];
 
-	sreq->sr_cmnd[0] = ALLOW_MEDIUM_REMOVAL;
-	sreq->sr_cmnd[1] = 0;
-	sreq->sr_cmnd[2] = 0;
-	sreq->sr_cmnd[3] = 0;
-	sreq->sr_cmnd[4] = SCSI_REMOVAL_PREVENT;
-	sreq->sr_cmnd[5] = 0;
-	sreq->sr_data_direction = DMA_NONE;
-	sreq->sr_bufflen = 0;
-	sreq->sr_buffer = NULL;
-	sreq->sr_allowed = 5;
-	sreq->sr_done = scsi_eh_lock_done;
-	sreq->sr_timeout_per_command = 10 * HZ;
-	sreq->sr_cmd_len = COMMAND_SIZE(sreq->sr_cmnd[0]);
+	cmnd[0] = ALLOW_MEDIUM_REMOVAL;
+	cmnd[1] = 0;
+	cmnd[2] = 0;
+	cmnd[3] = 0;
+	cmnd[4] = SCSI_REMOVAL_PREVENT;
+	cmnd[5] = 0;
 
-	scsi_insert_special_req(sreq, 1);
+	scsi_execute_async(sdev, cmnd, DMA_NONE, NULL, 0, 0, 10 * HZ,
+			   5, NULL, NULL, GFP_KERNEL);
 }

drivers/scsi/scsi_lib.c +196 ~~-34~~

249 lines not on this page · raw message

drivers/scsi/scsi_priv.h +0 -1

index d632d9e..647aa62 100644
@@ -40,7 +40,6 @@ extern void scsi_exit_hosts(void);
 extern int scsi_dispatch_cmd(struct scsi_cmnd *cmd);
 extern int scsi_setup_command_freelist(struct Scsi_Host *shost);
 extern void scsi_destroy_command_freelist(struct Scsi_Host *shost);
-extern int scsi_insert_special_req(struct scsi_request *sreq, int);
 extern void scsi_init_cmd_from_req(struct scsi_cmnd *cmd,
 		struct scsi_request *sreq);
 extern void __scsi_release_request(struct scsi_request *sreq);

fs/bio.c +20 -0

index 460554b..4d21ee3 100644
@@ -386,6 +386,25 @@ static int __bio_add_page(request_queue_
 }
 
 /**
+ *	bio_add_pc_page	-	attempt to add page to bio
+ *	@bio: destination bio
+ *	@page: page to add
+ *	@len: vec entry length
+ *	@offset: vec entry offset
+ *
+ *	Attempt to add a page to the bio_vec maplist. This can fail for a
+ *	number of reasons, such as the bio being full or target block
+ *	device limitations. The target block device must allow bio's
+ *      smaller than PAGE_SIZE, so it is always possible to add a single
+ *      page to an empty bio. This should only be used by REQ_PC bios.
+ */
+int bio_add_pc_page(request_queue_t *q, struct bio *bio, struct page *page,
+		    unsigned int len, unsigned int offset)
+{
+	return __bio_add_page(q, bio, page, len, offset);
+}
+
+/**
  *	bio_add_page	-	attempt to add page to bio
  *	@bio: destination bio
  *	@page: page to add

@@ -1228,6 +1247,7 @@ EXPORT_SYMBOL(bio_clone);
 EXPORT_SYMBOL(bio_phys_segments);
 EXPORT_SYMBOL(bio_hw_segments);
 EXPORT_SYMBOL(bio_add_page);
+EXPORT_SYMBOL(bio_add_pc_page);
 EXPORT_SYMBOL(bio_get_nr_vecs);
 EXPORT_SYMBOL(bio_map_user);
 EXPORT_SYMBOL(bio_unmap_user);

include/linux/bio.h +2 -0

index 685fd37..b60ffe3 100644
@@ -292,6 +292,8 @@ extern struct bio *bio_clone(struct bio 
 extern void bio_init(struct bio *);
 
 extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
+extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
+			   unsigned int, unsigned int);
 extern int bio_get_nr_vecs(struct block_device *);
 extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
 				unsigned long, unsigned int, int);

include/scsi/scsi_device.h +6 -0

index 85cfd88..ce35cf0 100644
@@ -274,6 +274,12 @@ extern int scsi_execute(struct scsi_devi
 extern int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd,
 			    int data_direction, void *buffer, unsigned bufflen,
 			    struct scsi_sense_hdr *, int timeout, int retries);
+extern int scsi_execute_async(struct scsi_device *sdev,
+			      const unsigned char *cmd, int data_direction,
+			      void *buffer, unsigned bufflen, int use_sg,
+			      int timeout, int retries, void *privdata,
+			      void (*done)(void *, char *, int, int),
+			      gfp_t gfp);
 
 static inline unsigned int sdev_channel(struct scsi_device *sdev)
 {