1 files changed, 62 insertions, 78 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index faee4757c03..3302d8068c4 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -19,18 +19,18 @@
 #include <linux/hardirq.h>
 
 #include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_dbg.h>
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_driver.h>
 #include <scsi/scsi_eh.h>
 #include <scsi/scsi_host.h>
-#include <scsi/scsi_request.h>
 
 #include "scsi_priv.h"
 #include "scsi_logging.h"
 
 
-#define SG_MEMPOOL_NR		(sizeof(scsi_sg_pools)/sizeof(struct scsi_host_sg_pool))
+#define SG_MEMPOOL_NR		ARRAY_SIZE(scsi_sg_pools)
 #define SG_MEMPOOL_SIZE		32
 
 struct scsi_host_sg_pool {
@@ -83,7 +83,7 @@ static void scsi_unprep_request(struct request *req)
 	struct scsi_cmnd *cmd = req->special;
 
 	req->flags &= ~REQ_DONTPREP;
-	req->special = (req->flags & REQ_SPECIAL) ? cmd->sc_request : NULL;
+	req->special = NULL;
 
 	scsi_put_command(cmd);
 }
@@ -161,72 +161,6 @@ int scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
 	return 0;
 }
 
-/*
- * Function:    scsi_do_req
- *
- * Purpose:     Queue a SCSI request
- *
- * Arguments:   sreq	  - command descriptor.
- *              cmnd      - actual SCSI command to be performed.
- *              buffer    - data buffer.
- *              bufflen   - size of data buffer.
- *              done      - completion function to be run.
- *              timeout   - how long to let it run before timeout.
- *              retries   - number of retries we allow.
- *
- * Lock status: No locks held upon entry.
- *
- * Returns:     Nothing.
- *
- * Notes:	This function is only used for queueing requests for things
- *		like ioctls and character device requests - this is because
- *		we essentially just inject a request into the queue for the
- *		device.
- *
- *		In order to support the scsi_device_quiesce function, we
- *		now inject requests on the *head* of the device queue
- *		rather than the tail.
- */
-void scsi_do_req(struct scsi_request *sreq, const void *cmnd,
-		 void *buffer, unsigned bufflen,
-		 void (*done)(struct scsi_cmnd *),
-		 int timeout, int retries)
-{
-	/*
-	 * If the upper level driver is reusing these things, then
-	 * we should release the low-level block now.  Another one will
-	 * be allocated later when this request is getting queued.
-	 */
-	__scsi_release_request(sreq);
-
-	/*
-	 * Our own function scsi_done (which marks the host as not busy,
-	 * disables the timeout counter, etc) will be called by us or by the
-	 * scsi_hosts[host].queuecommand() function needs to also call
-	 * the completion function for the high level driver.
-	 */
-	memcpy(sreq->sr_cmnd, cmnd, sizeof(sreq->sr_cmnd));
-	sreq->sr_bufflen = bufflen;
-	sreq->sr_buffer = buffer;
-	sreq->sr_allowed = retries;
-	sreq->sr_done = done;
-	sreq->sr_timeout_per_command = timeout;
-
-	if (sreq->sr_cmd_len == 0)
-		sreq->sr_cmd_len = COMMAND_SIZE(sreq->sr_cmnd[0]);
-
-	/*
-	 * head injection *required* here otherwise quiesce won't work
-	 *
-	 * Because users of this function are apt to reuse requests with no
-	 * modification, we have to sanitise the request flags here
-	 */
-	sreq->sr_request->flags &= ~REQ_DONTPREP;
-	blk_insert_request(sreq->sr_device->request_queue, sreq->sr_request,
-		       	   1, sreq);
-}
-EXPORT_SYMBOL(scsi_do_req);
-
 /**
  * scsi_execute - insert request and wait for the result
  * @sdev:	scsi device
@@ -1300,15 +1234,7 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
 	 * at request->cmd, as this tells us the real story.
 	 */
 	if (req->flags & REQ_SPECIAL && req->special) {
-		struct scsi_request *sreq = req->special;
-
-		if (sreq->sr_magic == SCSI_REQ_MAGIC) {
-			cmd = scsi_get_command(sreq->sr_device, GFP_ATOMIC);
-			if (unlikely(!cmd))
-				goto defer;
-			scsi_init_cmd_from_req(cmd, sreq);
-		} else
-			cmd = req->special;
+		cmd = req->special;
 	} else if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) {
 
 		if(unlikely(specials_only) && !(req->flags & REQ_SPECIAL)) {
@@ -2363,3 +2289,61 @@ scsi_target_unblock(struct device *dev)
 		device_for_each_child(dev, NULL, target_unblock);
 }
 EXPORT_SYMBOL_GPL(scsi_target_unblock);
+
+/**
+ * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
+ * @sg:		scatter-gather list
+ * @sg_count:	number of segments in sg
+ * @offset:	offset in bytes into sg, on return offset into the mapped area
+ * @len:	bytes to map, on return number of bytes mapped
+ *
+ * Returns virtual address of the start of the mapped page
+ */
+void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
+			  size_t *offset, size_t *len)
+{
+	int i;
+	size_t sg_len = 0, len_complete = 0;
+	struct page *page;
+
+	for (i = 0; i < sg_count; i++) {
+		len_complete = sg_len; /* Complete sg-entries */
+		sg_len += sg[i].length;
+		if (sg_len > *offset)
+			break;
+	}
+
+	if (unlikely(i == sg_count)) {
+		printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, "
+			"elements %d\n",
+		       __FUNCTION__, sg_len, *offset, sg_count);
+		WARN_ON(1);
+		return NULL;
+	}
+
+	/* Offset starting from the beginning of first page in this sg-entry */
+	*offset = *offset - len_complete + sg[i].offset;
+
+	/* Assumption: contiguous pages can be accessed as "page + i" */
+	page = nth_page(sg[i].page, (*offset >> PAGE_SHIFT));
+	*offset &= ~PAGE_MASK;
+
+	/* Bytes in this sg-entry from *offset to the end of the page */
+	sg_len = PAGE_SIZE - *offset;
+	if (*len > sg_len)
+		*len = sg_len;
+
+	return kmap_atomic(page, KM_BIO_SRC_IRQ);
+}
+EXPORT_SYMBOL(scsi_kmap_atomic_sg);
+
+/**
+ * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously
+ *			   mapped with scsi_kmap_atomic_sg
+ * @virt:	virtual address to be unmapped
+ */
+void scsi_kunmap_atomic_sg(void *virt)
+{
+	kunmap_atomic(virt, KM_BIO_SRC_IRQ);
+}
+EXPORT_SYMBOL(scsi_kunmap_atomic_sg);