From: Theodore Ts'o <tytso@mit.edu>
Date: Sun, 22 May 2011 20:12:35 +0000 (-0400)
Subject: ext4: don't show mount options in /proc/mounts if there is no journal
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=373cd5c53d5ea6622c319ecd84e29e2737d488bd;p=linux-beck.git

ext4: don't show mount options in /proc/mounts if there is no journal

After creating an ext4 file system without a journal:

  # mke2fs -t ext4 -O ^has_journal /dev/sda
  # mount -t ext4 /dev/sda /test

the /proc/mounts will show:
"/dev/sda /test ext4 rw,relatime,user_xattr,acl,barrier=1,data=writeback 0 0"
which can fool users into thinking that the fs is using writeback mode.

So don't set the writeback option when the journal has not been
enabled; we don't depend on the writeback option being set, since
ext4_should_writeback_data() in ext4_jbd2.h tests to see if the
journal is not present before returning true.

Reported-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index ed5e80ef48c4..fdce4eebce0c 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3485,7 +3485,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		goto failed_mount_wq;
 	} else {
 		clear_opt(sb, DATA_FLAGS);
-		set_opt(sb, WRITEBACK_DATA);
 		sbi->s_journal = NULL;
 		needs_recovery = 0;
 		goto no_journal;