---

yaml --- r: 176557 b: refs/heads/master c: 12fc0f4 h: refs/heads/master i: 176555: 04c3d14 v: v3
git-mirror · Dec 10, 2009 · fb80eeb · fb80eeb
1 parent b5cb256
commit fb80eeb
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Showing 2 changed files with 8 additions and 4 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 67a46dad25ccc8910995d8671f7ec17a6bc823cb
+refs/heads/master: 12fc0f49dc994d8d90dcf3df13f5b1ee5441288d
diff --git a/trunk/drivers/md/dm-io.c b/trunk/drivers/md/dm-io.c
@@ -309,7 +309,11 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
 	unsigned num_bvecs;
 	sector_t remaining = where->count;
 
-	while (remaining) {
+	/*
+	 * where->count may be zero if rw holds a write barrier and we
+	 * need to send a zero-sized barrier.
+	 */
+	do {
 		/*
 		 * Allocate a suitably sized-bio.
 		 */
@@ -339,7 +343,7 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where,
 
 		atomic_inc(&io->count);
 		submit_bio(rw, bio);
-	}
+	} while (remaining);
 }
 
 static void dispatch_io(int rw, unsigned int num_regions,
@@ -360,7 +364,7 @@ static void dispatch_io(int rw, unsigned int num_regions,
 	 */
 	for (i = 0; i < num_regions; i++) {
 		*dp = old_pages;
-		if (where[i].count)
+		if (where[i].count || (rw & (1 << BIO_RW_BARRIER)))
 			do_region(rw, i, where + i, dp, io);
 	}