From 374f37aca99226ac0385566d343ae3367d2b3f8f Mon Sep 17 00:00:00 2001
From: Thomas Schoebel-Theuer <schoebel@bell.site>
Date: Fri, 5 Aug 2011 10:26:24 +0100
Subject: [PATCH] import mars-121.tgz

---
 mars_bio.c        |  2 ++
 mars_if.c         | 14 ++++++++++++--
 mars_if.h         |  1 +
 userspace/marsadm | 23 +++++++++++++++++++++++
 4 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/mars_bio.c b/mars_bio.c
index bf9aeeae..8c8dff46 100644
--- a/mars_bio.c
+++ b/mars_bio.c
@@ -490,8 +490,10 @@ static int bio_switch(struct bio_brick *brick)
 			q = bdev_get_queue(inode->i_bdev);
 			CHECK_PTR(q, done);
 
+#if 1
 			MARS_INF("ra_pages OLD=%lu NEW=%d\n", q->backing_dev_info.ra_pages, brick->ra_pages);
 			q->backing_dev_info.ra_pages = brick->ra_pages;
+#endif
 			brick->bvec_max = queue_max_hw_sectors(q) >> (PAGE_SHIFT - 9);
 			brick->total_size = inode->i_size;
 			brick->thread = kthread_create(bio_thread, brick, "mars_bio%d", index++);
diff --git a/mars_if.c b/mars_if.c
index 52ea1061..346c9986 100644
--- a/mars_if.c
+++ b/mars_if.c
@@ -209,7 +209,6 @@ static int if_make_request(struct request_queue *q, struct bio *bio)
                 goto err;
 	
 	if (unlikely(!bio_sectors(bio))) {
-		atomic_inc(&input->total_empty_count);
 		_if_unplug(input);
 		/* THINK: usually this happens only at write barriers.
 		 * We have no "barrier" operation in MARS, since
@@ -222,6 +221,13 @@ static int if_make_request(struct request_queue *q, struct bio *bio)
 		return 0;
 	}
 
+#if 1 // provisinary -- we should introduce an equivalent of READA also to the MARS infrastructure
+	if (bio_rw(bio) == READA) {
+		atomic_inc(&input->total_reada_count);
+		bio_endio(bio, -EWOULDBLOCK);
+		return 0;
+	}
+#endif
 	if (rw) {
 		atomic_inc(&input->total_write_count);
 	} else {
@@ -623,8 +629,10 @@ static int if_switch(struct if_brick *brick)
 		/* we have no partitions. we contain only ourselves. */
 		input->bdev->bd_contains = input->bdev;
 
+#if 1
 		MARS_INF("ra_pages OLD = %lu NEW = %d\n", q->backing_dev_info.ra_pages, brick->readahead);
 		q->backing_dev_info.ra_pages = brick->readahead;
+#endif
 #ifdef USE_CONGESTED_FN
 		q->backing_dev_info.congested_fn = mars_congested;
 		q->backing_dev_info.congested_data = input;
@@ -675,13 +683,15 @@ char *if_statistics(struct if_brick *brick, int verbose)
 {
 	struct if_input *input = brick->inputs[0];
 	char *res = kmalloc(512, GFP_MARS);
+	int tmp0 = atomic_read(&input->total_reada_count); 
 	int tmp1 = atomic_read(&input->total_read_count); 
 	int tmp2 = atomic_read(&input->total_mref_read_count);
 	int tmp3 = atomic_read(&input->total_write_count); 
 	int tmp4 = atomic_read(&input->total_mref_write_count);
 	if (!res)
 		return NULL;
-	snprintf(res, 512, "total reads = %d mref_reads = %d (%d%%) writes = %d mref_writes = %d (%d%%) empty = %d | plugged = %d flying = %d (reads = %d writes = %d)\n",
+	snprintf(res, 512, "total reada = %d reads = %d mref_reads = %d (%d%%) writes = %d mref_writes = %d (%d%%) empty = %d | plugged = %d flying = %d (reads = %d writes = %d)\n",
+		tmp0,
 		tmp1,
 		tmp2,
 		tmp1 ? tmp2 * 100 / tmp1 : 0,
diff --git a/mars_if.h b/mars_if.h
index 9c6007df..fd7adbda 100644
--- a/mars_if.h
+++ b/mars_if.h
@@ -45,6 +45,7 @@ struct if_input {
 	// only for statistics
 	atomic_t read_flying_count;
 	atomic_t write_flying_count;
+	atomic_t total_reada_count;
 	atomic_t total_read_count;
 	atomic_t total_write_count;
 	atomic_t total_empty_count;
diff --git a/userspace/marsadm b/userspace/marsadm
index d4b3f23d..6cd5c455 100644
--- a/userspace/marsadm
+++ b/userspace/marsadm
@@ -94,6 +94,17 @@ sub check_primary_gone {
   }
 }
 
+sub check_status {
+  my ($res, $key, $val) = @_;
+  for(;;) {
+    my $path = "$mars/resource-$res/actual-$host/$key";
+    my $link = readlink($path) or die "cannot read symlink '$path'\n";
+    last if $link == $val;
+    print "waiting until $key reaches the value $val....\n";
+    sleep(5);
+  }
+}
+
 sub check_splitbrain {
   my ($res, $host) = @_;
   my @links = glob("$mars/resource-$res/version-[0-9]*-$host");
@@ -403,6 +414,17 @@ sub up_res {
   }
 }
 
+sub fake_local_res {
+  my ($cmd, $res) = @_;
+  my $path = "$mars/resource-$res/switch-$host/sync";
+  _switch($cmd, $res, $path, 0);
+  #check_status($res, "copy-syncstatus-$host", 0);
+  my $size = readlink("$mars/resource-$res/size") or die "cannot read size\n";
+  my $target = "$mars/resource-$res/syncstatus-$host";
+  symlink($size, "$target.tmp") or die "cannot create faked syncstatus\n";
+  rename("$target.tmp", $target) or die "cannot reaname symlink\n";
+}
+
 sub _primary_res {
   my ($res, $host, $pri, $old) = @_;
   my $tmp = "$mars/resource-$res/.tmp.primary";
@@ -468,6 +490,7 @@ my %cmd_table =
    "create-resource"   => \&create_res,
    "join-resource"     => \&create_res,
    "logrotate"         => \&logrotate_res,
+   "fake-sync"         => \&fake_local_res,
 
    # compatible keywords
    "attach"            => \&attach_res,