aboutsummaryrefslogtreecommitdiffstats
path: root/block/blk-exec.c
diff options
context:
space:
mode:
authorJens Axboe <jens.axboe@oracle.com>2008-01-29 13:53:40 (GMT)
committerJens Axboe <jens.axboe@oracle.com>2008-01-29 20:55:08 (GMT)
commit86db1e29772372155db08ff48a9ceb76e11a2ad1 (patch)
tree312f38eb3245873c476c50f816b85610fef9615a /block/blk-exec.c
parent8324aa91d1e11a1fc25f209687a0b2e6c2ed47d0 (diff)
block: continue ll_rw_blk.c splitup
Adds files for barrier handling, rq execution, io context handling, mapping data to requests, and queue settings. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'block/blk-exec.c')
-rw-r--r--block/blk-exec.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/block/blk-exec.c b/block/blk-exec.c
new file mode 100644
index 0000000..ebfb44e
--- /dev/null
+++ b/block/blk-exec.c
@@ -0,0 +1,105 @@
+/*
+ * 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);

Privacy Policy