1 files changed, 115 insertions, 153 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 764a8b375ead..08af9aae7df3 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
@@ -367,7 +301,7 @@ static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl,
 			   int nsegs, unsigned bufflen, gfp_t gfp)
 {
 	struct request_queue *q = rq->q;
-	int nr_pages = (bufflen + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
 	unsigned int data_len = 0, len, bytes, off;
 	struct page *page;
 	struct bio *bio = NULL;
@@ -566,7 +500,7 @@ void scsi_device_unbusy(struct scsi_device *sdev)
 	spin_lock_irqsave(shost->host_lock, flags);
 	shost->host_busy--;
 	if (unlikely(scsi_host_in_recovery(shost) &&
-		     shost->host_failed))
+		     (shost->host_failed || shost->host_eh_scheduled)))
 		scsi_eh_wakeup(shost);
 	spin_unlock(shost->host_lock);
 	spin_lock(sdev->request_queue->queue_lock);
@@ -921,8 +855,7 @@ static void scsi_release_buffers(struct scsi_cmnd *cmd)
  *		b) We can just use scsi_requeue_command() here.  This would
  *		   be used if we just wanted to retry, for example.
  */
-void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes,
-			unsigned int block_bytes)
+void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 {
 	int result = cmd->result;
 	int this_count = cmd->bufflen;
@@ -987,87 +920,70 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes,
 	 * Next deal with any sectors which we were able to correctly
 	 * handle.
 	 */
-	if (good_bytes >= 0) {
-		SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, %d bytes done.\n",
-					      req->nr_sectors, good_bytes));
-		SCSI_LOG_HLCOMPLETE(1, printk("use_sg is %d\n", cmd->use_sg));
+	SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, "
+				      "%d bytes done.\n",
+				      req->nr_sectors, good_bytes));
+	SCSI_LOG_HLCOMPLETE(1, printk("use_sg is %d\n", cmd->use_sg));
 
-		if (clear_errors)
-			req->errors = 0;
-		/*
-		 * If multiple sectors are requested in one buffer, then
-		 * they will have been finished off by the first command.
-		 * If not, then we have a multi-buffer command.
-		 *
-		 * If block_bytes != 0, it means we had a medium error
-		 * of some sort, and that we want to mark some number of
-		 * sectors as not uptodate.  Thus we want to inhibit
-		 * requeueing right here - we will requeue down below
-		 * when we handle the bad sectors.
-		 */
+	if (clear_errors)
+		req->errors = 0;
 
-		/*
-		 * If the command completed without error, then either
-		 * finish off the rest of the command, or start a new one.
-		 */
-		if (scsi_end_request(cmd, 1, good_bytes, result == 0) == NULL)
-			return;
-	}
-	/*
-	 * Now, if we were good little boys and girls, Santa left us a request
-	 * sense buffer.  We can extract information from this, so we
-	 * can choose a block to remap, etc.
+	/* A number of bytes were successfully read.  If there
+	 * are leftovers and there is some kind of error
+	 * (result != 0), retry the rest.
+	 */
+	if (scsi_end_request(cmd, 1, good_bytes, result == 0) == NULL)
+		return;
+
+	/* good_bytes = 0, or (inclusive) there were leftovers and
+	 * result = 0, so scsi_end_request couldn't retry.
 	 */
 	if (sense_valid && !sense_deferred) {
 		switch (sshdr.sense_key) {
 		case UNIT_ATTENTION:
 			if (cmd->device->removable) {
-				/* detected disc change.  set a bit 
+				/* Detected disc change.  Set a bit
 				 * and quietly refuse further access.
 				 */
 				cmd->device->changed = 1;
-				scsi_end_request(cmd, 0,
-						this_count, 1);
+				scsi_end_request(cmd, 0, this_count, 1);
 				return;
 			} else {
-				/*
-				* Must have been a power glitch, or a
-				* bus reset.  Could not have been a
-				* media change, so we just retry the
-				* request and see what happens.  
-				*/
+				/* Must have been a power glitch, or a
+				 * bus reset.  Could not have been a
+				 * media change, so we just retry the
+				 * request and see what happens.
+				 */
 				scsi_requeue_command(q, cmd);
 				return;
 			}
 			break;
 		case ILLEGAL_REQUEST:
-			/*
-		 	* If we had an ILLEGAL REQUEST returned, then we may
-		 	* have performed an unsupported command.  The only
-		 	* thing this should be would be a ten byte read where
-			* only a six byte read was supported.  Also, on a
-			* system where READ CAPACITY failed, we may have read
-			* past the end of the disk.
-		 	*/
+			/* If we had an ILLEGAL REQUEST returned, then
+			 * we may have performed an unsupported
+			 * command.  The only thing this should be
+			 * would be a ten byte read where only a six
+			 * byte read was supported.  Also, on a system
+			 * where READ CAPACITY failed, we may have
+			 * read past the end of the disk.
+			 */
 			if ((cmd->device->use_10_for_rw &&
 			    sshdr.asc == 0x20 && sshdr.ascq == 0x00) &&
 			    (cmd->cmnd[0] == READ_10 ||
 			     cmd->cmnd[0] == WRITE_10)) {
 				cmd->device->use_10_for_rw = 0;
-				/*
-				 * This will cause a retry with a 6-byte
-				 * command.
+				/* This will cause a retry with a
+				 * 6-byte command.
 				 */
 				scsi_requeue_command(q, cmd);
-				result = 0;
+				return;
 			} else {
 				scsi_end_request(cmd, 0, this_count, 1);
 				return;
 			}
 			break;
 		case NOT_READY:
-			/*
-			 * If the device is in the process of becoming
+			/* If the device is in the process of becoming
 			 * ready, or has a temporary blockage, retry.
 			 */
 			if (sshdr.asc == 0x04) {
@@ -1087,7 +1003,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes,
 			}
 			if (!(req->flags & REQ_QUIET)) {
 				scmd_printk(KERN_INFO, cmd,
-					   "Device not ready: ");
+					    "Device not ready: ");
 				scsi_print_sense_hdr("", &sshdr);
 			}
 			scsi_end_request(cmd, 0, this_count, 1);
@@ -1095,21 +1011,21 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes,
 		case VOLUME_OVERFLOW:
 			if (!(req->flags & REQ_QUIET)) {
 				scmd_printk(KERN_INFO, cmd,
-					   "Volume overflow, CDB: ");
+					    "Volume overflow, CDB: ");
 				__scsi_print_command(cmd->data_cmnd);
 				scsi_print_sense("", cmd);
 			}
-			scsi_end_request(cmd, 0, block_bytes, 1);
+			/* See SSC3rXX or current. */
+			scsi_end_request(cmd, 0, this_count, 1);
 			return;
 		default:
 			break;
 		}
-	}			/* driver byte != 0 */
+	}
 	if (host_byte(result) == DID_RESET) {
-		/*
-		 * Third party bus reset or reset for error
-		 * recovery reasons.  Just retry the request
-		 * and see what happens.  
+		/* Third party bus reset or reset for error recovery
+		 * reasons.  Just retry the request and see what
+		 * happens.
 		 */
 		scsi_requeue_command(q, cmd);
 		return;
@@ -1117,21 +1033,13 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes,
 	if (result) {
 		if (!(req->flags & REQ_QUIET)) {
 			scmd_printk(KERN_INFO, cmd,
-				   "SCSI error: return code = 0x%x\n", result);
-
+				    "SCSI error: return code = 0x%08x\n",
+				    result);
 			if (driver_byte(result) & DRIVER_SENSE)
 				scsi_print_sense("", cmd);
 		}
-		/*
-		 * Mark a single buffer as not uptodate.  Queue the remainder.
-		 * We sometimes get this cruft in the event that a medium error
-		 * isn't properly reported.
-		 */
-		block_bytes = req->hard_cur_sectors << 9;
-		if (!block_bytes)
-			block_bytes = req->data_len;
-		scsi_end_request(cmd, 0, block_bytes, 1);
 	}
+	scsi_end_request(cmd, 0, this_count, !result);
 }
 EXPORT_SYMBOL(scsi_io_completion);
 
@@ -1235,7 +1143,7 @@ static void scsi_blk_pc_done(struct scsi_cmnd *cmd)
 	 * successfully. Since this is a REQ_BLOCK_PC command the
 	 * caller should check the request's errors value
 	 */
-	scsi_io_completion(cmd, cmd->bufflen, 0);
+	scsi_io_completion(cmd, cmd->bufflen);
 }
 
 static void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd)
@@ -1300,15 +1208,7 @@ 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)) {
@@ -2124,6 +2024,7 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
 		switch (oldstate) {
 		case SDEV_CREATED:
 		case SDEV_RUNNING:
+		case SDEV_QUIESCE:
 		case SDEV_OFFLINE:
 		case SDEV_BLOCK:
 			break;
@@ -2134,6 +2035,9 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state)
 
 	case SDEV_DEL:
 		switch (oldstate) {
+		case SDEV_CREATED:
+		case SDEV_RUNNING:
+		case SDEV_OFFLINE:
 		case SDEV_CANCEL:
 			break;
 		default:
@@ -2363,3 +2267,61 @@ 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);