From 984907f29e6efe3283e255209aa0081fbf0c3849 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Tue, 21 Sep 2010 11:49:01 +0200
Subject: [PATCH] --- yaml --- r: 210895 b: refs/heads/master c:
 371d217ee1ff8b418b8f73fb2a34990f951ec2d4 h: refs/heads/master i:   210893:
 39bc6042e5a55285fa0640ee6981691febd5563f   210891:
 123f0c07844258ec480557bd8eb3dcb4f4e92855   210887:
 8c3f10e51f025d1066cb15f2167cf1b0bb5754bf   210879:
 b04e3610bc61b88d425e8fa7084e50919621f578 v: v3

---
 [refs]                   | 2 +-
 trunk/drivers/char/mem.c | 3 ++-
 trunk/fs/char_dev.c      | 4 +++-
 3 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index 091c29787611..54a81ab6a3f6 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 976e48f8a5b02fc33f3e5cad87fb3fcea041a49c
+refs/heads/master: 371d217ee1ff8b418b8f73fb2a34990f951ec2d4
diff --git a/trunk/drivers/char/mem.c b/trunk/drivers/char/mem.c
index a398ecdbd758..1f528fad3516 100644
--- a/trunk/drivers/char/mem.c
+++ b/trunk/drivers/char/mem.c
@@ -788,10 +788,11 @@ static const struct file_operations zero_fops = {
 /*
  * capabilities for /dev/zero
  * - permits private mappings, "copies" are taken of the source of zeros
+ * - no writeback happens
  */
 static struct backing_dev_info zero_bdi = {
 	.name		= "char/mem",
-	.capabilities	= BDI_CAP_MAP_COPY,
+	.capabilities	= BDI_CAP_MAP_COPY | BDI_CAP_NO_ACCT_AND_WRITEBACK,
 };
 
 static const struct file_operations full_fops = {
diff --git a/trunk/fs/char_dev.c b/trunk/fs/char_dev.c
index f80a4f25123c..143d393881cb 100644
--- a/trunk/fs/char_dev.c
+++ b/trunk/fs/char_dev.c
@@ -40,7 +40,9 @@ struct backing_dev_info directly_mappable_cdev_bdi = {
 #endif
 		/* permit direct mmap, for read, write or exec */
 		BDI_CAP_MAP_DIRECT |
-		BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP),
+		BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP |
+		/* no writeback happens */
+		BDI_CAP_NO_ACCT_AND_WRITEBACK),
 };
 
 static struct kobj_map *cdev_map;