From 1b7af065769fa2341f8b28520eca9f2ec0971c52 Mon Sep 17 00:00:00 2001
From: Boaz Harrosh <bharrosh@panasas.com>
Date: Sun, 17 May 2009 18:57:15 +0300
Subject: [PATCH] --- yaml --- r: 147049 b: refs/heads/master c:
 79eb63e9e5875b84341a3a05f8e6ae9cdb4bb6f6 h: refs/heads/master i:   147047:
 382333b44cc0f977f258d60a249d9fe9b32c29bb v: v3

---
 [refs]                       |  2 +-
 trunk/block/blk-core.c       | 45 ++++++++++++++++++++++++++++++++++++
 trunk/include/linux/blkdev.h |  2 ++
 3 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 8be63a1c0c60..0a97efacb7df 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: bc38bf106c967389a465d926be22c7371abba69d
+refs/heads/master: 79eb63e9e5875b84341a3a05f8e6ae9cdb4bb6f6
diff --git a/trunk/block/blk-core.c b/trunk/block/blk-core.c
index e3f7e6a3a095..bec1d69952d0 100644
--- a/trunk/block/blk-core.c
+++ b/trunk/block/blk-core.c
@@ -890,6 +890,51 @@ struct request *blk_get_request(struct request_queue *q, int rw, gfp_t gfp_mask)
 }
 EXPORT_SYMBOL(blk_get_request);
 
+/**
+ * blk_make_request - given a bio, allocate a corresponding struct request.
+ *
+ * @bio:  The bio describing the memory mappings that will be submitted for IO.
+ *        It may be a chained-bio properly constructed by block/bio layer.
+ *
+ * blk_make_request is the parallel of generic_make_request for BLOCK_PC
+ * type commands. Where the struct request needs to be farther initialized by
+ * the caller. It is passed a &struct bio, which describes the memory info of
+ * the I/O transfer.
+ *
+ * The caller of blk_make_request must make sure that bi_io_vec
+ * are set to describe the memory buffers. That bio_data_dir() will return
+ * the needed direction of the request. (And all bio's in the passed bio-chain
+ * are properly set accordingly)
+ *
+ * If called under none-sleepable conditions, mapped bio buffers must not
+ * need bouncing, by calling the appropriate masked or flagged allocator,
+ * suitable for the target device. Otherwise the call to blk_queue_bounce will
+ * BUG.
+ */
+struct request *blk_make_request(struct request_queue *q, struct bio *bio,
+				 gfp_t gfp_mask)
+{
+	struct request *rq = blk_get_request(q, bio_data_dir(bio), gfp_mask);
+
+	if (unlikely(!rq))
+		return ERR_PTR(-ENOMEM);
+
+	for_each_bio(bio) {
+		struct bio *bounce_bio = bio;
+		int ret;
+
+		blk_queue_bounce(q, &bounce_bio);
+		ret = blk_rq_append_bio(q, rq, bounce_bio);
+		if (unlikely(ret)) {
+			blk_put_request(rq);
+			return ERR_PTR(ret);
+		}
+	}
+
+	return rq;
+}
+EXPORT_SYMBOL(blk_make_request);
+
 /**
  * blk_requeue_request - put a request back on queue
  * @q:		request queue where request should be inserted
diff --git a/trunk/include/linux/blkdev.h b/trunk/include/linux/blkdev.h
index f9d60a78c08a..88a83e112c95 100644
--- a/trunk/include/linux/blkdev.h
+++ b/trunk/include/linux/blkdev.h
@@ -740,6 +740,8 @@ extern void blk_rq_init(struct request_queue *q, struct request *rq);
 extern void blk_put_request(struct request *);
 extern void __blk_put_request(struct request_queue *, struct request *);
 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
+extern struct request *blk_make_request(struct request_queue *, struct bio *,
+					gfp_t);
 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
 extern void blk_requeue_request(struct request_queue *, struct request *);
 extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);