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Kernel v2.6.25 /block/blk-exec.c

Filename:/block/blk-exec.c
Lines Added:104
Lines Deleted:0
Also changed in: (Previous) 2.6.25-rc9  2.6.25-rc8  2.6.25-rc7  2.6.25-rc6  2.6.25-rc5  2.6.25-rc4 
(Following) 2.6.26-git2  2.6.26-git3  2.6.26-git4  2.6.26-git5  2.6.26-git6  2.6.26-git7 

Location
[  2.6.25
  [  block
     o  blk-exec.c

Patch

diff --git a/block/blk-exec.c b/block/blk-exec.c
new file mode 100644
index 0000000..391dd62
--- /dev/null
+++ b/block/blk-exec.c
@@ -0,0 +1,104 @@
+/*
+ * Functions related to setting various queue properties from drivers
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+
+#include "blk.h"
+
+/*
+ * for max sense size
+ */
+#include <scsi/scsi_cmnd.h>
+
+/**
+ * blk_end_sync_rq - executes a completion event on a request
+ * @rq: request to complete
+ * @error: end io status of the request
+ */
+void blk_end_sync_rq(struct request *rq, int error)
+{
+   struct completion *waiting = rq->end_io_data;
+
+   rq->end_io_data = NULL;
+   __blk_put_request(rq->q, rq);
+
+   /*
+    * complete last, if this is a stack request the process (and thus
+    * the rq pointer) could be invalid right after this complete()
+    */
+   complete(waiting);
+}
+EXPORT_SYMBOL(blk_end_sync_rq);
+
+/**
+ * blk_execute_rq_nowait - insert a request into queue for execution
+ * @q:      queue to insert the request in
+ * @bd_disk:   matching gendisk
+ * @rq:      request to insert
+ * @at_head:    insert request at head or tail of queue
+ * @done:   I/O completion handler
+ *
+ * Description:
+ *    Insert a fully prepared request at the back of the io scheduler queue
+ *    for execution.  Don't wait for completion.
+ */
+void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
+            struct request *rq, int at_head,
+            rq_end_io_fn *done)
+{
+   int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
+
+   rq->rq_disk = bd_disk;
+   rq->cmd_flags |= REQ_NOMERGE;
+   rq->end_io = done;
+   WARN_ON(irqs_disabled());
+   spin_lock_irq(q->queue_lock);
+   __elv_add_request(q, rq, where, 1);
+   __generic_unplug_device(q);
+   spin_unlock_irq(q->queue_lock);
+}
+EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
+
+/**
+ * blk_execute_rq - insert a request into queue for execution
+ * @q:      queue to insert the request in
+ * @bd_disk:   matching gendisk
+ * @rq:      request to insert
+ * @at_head:    insert request at head or tail of queue
+ *
+ * Description:
+ *    Insert a fully prepared request at the back of the io scheduler queue
+ *    for execution and wait for completion.
+ */
+int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
+         struct request *rq, int at_head)
+{
+   DECLARE_COMPLETION_ONSTACK(wait);
+   char sense[SCSI_SENSE_BUFFERSIZE];
+   int err = 0;
+
+   /*
+    * we need an extra reference to the request, so we can look at
+    * it after io completion
+    */
+   rq->ref_count++;
+
+   if (!rq->sense) {
+      memset(sense, 0, sizeof(sense));
+      rq->sense = sense;
+      rq->sense_len = 0;
+   }
+
+   rq->end_io_data = &wait;
+   blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq);
+   wait_for_completion(&wait);
+
+   if (rq->errors)
+      err = -EIO;
+
+   return err;
+}
+EXPORT_SYMBOL(blk_execute_rq);


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