From 0c7bb9d00f00061d7c4edde4b164256b6bb91a60 Mon Sep 17 00:00:00 2001
From: Thomas Schoebel-Theuer <tst@1und1.de>
Date: Fri, 19 Apr 2013 09:07:32 +0200
Subject: [PATCH] if: fix bio flags for newer kernels

The old code was just bullshit.
---
 kernel/mars_bio.c | 21 ++++++++++++++++-----
 kernel/mars_if.c  | 18 +++++++++++-------
 2 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/kernel/mars_bio.c b/kernel/mars_bio.c
index 40e8de4e..9eaf34db 100644
--- a/kernel/mars_bio.c
+++ b/kernel/mars_bio.c
@@ -353,21 +353,32 @@ void _bio_ref_io(struct bio_output *output, struct mref_object *mref, bool cork)
 	bio_get(bio);
 
 	rw = mref->ref_rw & 1;
-#ifdef BIO_RW_NOIDLE
 	if (brick->do_noidle && !cork) {
+// adapt to different kernel versions (TBD: improve)
+#if defined(BIO_RW_RQ_MASK) || defined(BIO_FLUSH)
 		rw |= (1 << BIO_RW_NOIDLE);
+#elif defined(REQ_NOIDLE)
+		rw |= REQ_NOIDLE;
+#else
+#warning Cannot control the NOIDLE flag
+#endif
 	}
-#endif
 	if (!mref->ref_skip_sync) {
-#ifdef BIO_RW_SYNCIO
 		if (brick->do_sync) {
+#if defined(BIO_RW_RQ_MASK) || defined(BIO_FLUSH)
 			rw |= (1 << BIO_RW_SYNCIO);
-		}
+#elif defined(REQ_SYNC)
+			rw |= REQ_SYNC;
+#else
+#warning Cannot control the SYNC flag
 #endif
-#ifdef BIO_RW_UNPLUG
+		}
+#if defined(BIO_RW_RQ_MASK) || defined(BIO_FLUSH)
 		if (brick->do_unplug && !cork) {
 			rw |= (1 << BIO_RW_UNPLUG);
 		}
+#else
+		// there is no substitute, but the above NOIDLE should do the job (CHECK!)
 #endif
 	}
 
diff --git a/kernel/mars_if.c b/kernel/mars_if.c
index d75d6859..0b4a7bec 100644
--- a/kernel/mars_if.c
+++ b/kernel/mars_if.c
@@ -246,6 +246,7 @@ if_make_request(struct request_queue *q, struct bio *bio)
 	 */
 	const int  rw      = bio_data_dir(bio);
 	const int  sectors = bio_sectors(bio);
+// adapt to different kernel versions (TBD: improve)
 #if defined(BIO_RW_RQ_MASK) || defined(BIO_FLUSH)
 	const bool ahead   = bio_rw_flagged(bio, BIO_RW_AHEAD) && rw == READ;
 	const bool barrier = bio_rw_flagged(bio, BIO_RW_BARRIER);
@@ -254,14 +255,17 @@ if_make_request(struct request_queue *q, struct bio *bio)
 	const bool meta    = bio_rw_flagged(bio, BIO_RW_META);
 	const bool discard = bio_rw_flagged(bio, BIO_RW_DISCARD);
 	const bool noidle  = bio_rw_flagged(bio, BIO_RW_NOIDLE);
-#else
-	const bool ahead   = bio_flagged(bio, __REQ_RAHEAD) && rw == READ;
-	const bool barrier = bio_flagged(bio, __REQ_FLUSH);
-	const bool syncio  = bio_flagged(bio, __REQ_SYNC);
+#elif defined(REQ_FLUSH) && defined(REQ_SYNC)
+#define _flagged(x) (bio->bi_rw & (x))
+	const bool ahead   = _flagged(REQ_RAHEAD) && rw == READ;
+	const bool barrier = _flagged(REQ_FLUSH);
+	const bool syncio  = _flagged(REQ_SYNC);
 	const bool unplug  = false;
-	const bool meta    = bio_flagged(bio, __REQ_META);
-	const bool discard = bio_flagged(bio, __REQ_DISCARD);
-	const bool noidle  = bio_flagged(bio, __REQ_THROTTLED);
+	const bool meta    = _flagged(REQ_META);
+	const bool discard = _flagged(REQ_DISCARD);
+	const bool noidle  = _flagged(REQ_THROTTLED);
+#else
+#error Cannot decode the bio flags
 #endif
 	const int  prio    = bio_prio(bio);