From 02b9984d640873b7b3809e63f81a0d7e13496886 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Thu, 13 Mar 2014 10:14:33 -0400 Subject: fs: push sync_filesystem() down to the file system's remount_fs() Previously, the no-op "mount -o mount /dev/xxx" operation when the file system is already mounted read-write causes an implied, unconditional syncfs(). This seems pretty stupid, and it's certainly documented or guaraunteed to do this, nor is it particularly useful, except in the case where the file system was mounted rw and is getting remounted read-only. However, it's possible that there might be some file systems that are actually depending on this behavior. In most file systems, it's probably fine to only call sync_filesystem() when transitioning from read-write to read-only, and there are some file systems where this is not needed at all (for example, for a pseudo-filesystem or something like romfs). Signed-off-by: "Theodore Ts'o" Cc: linux-fsdevel@vger.kernel.org Cc: Christoph Hellwig Cc: Artem Bityutskiy Cc: Adrian Hunter Cc: Evgeniy Dushistov Cc: Jan Kara Cc: OGAWA Hirofumi Cc: Anders Larsen Cc: Phillip Lougher Cc: Kees Cook Cc: Mikulas Patocka Cc: Petr Vandrovec Cc: xfs@oss.sgi.com Cc: linux-btrfs@vger.kernel.org Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Cc: codalist@coda.cs.cmu.edu Cc: linux-ext4@vger.kernel.org Cc: linux-f2fs-devel@lists.sourceforge.net Cc: fuse-devel@lists.sourceforge.net Cc: cluster-devel@redhat.com Cc: linux-mtd@lists.infradead.org Cc: jfs-discussion@lists.sourceforge.net Cc: linux-nfs@vger.kernel.org Cc: linux-nilfs@vger.kernel.org Cc: linux-ntfs-dev@lists.sourceforge.net Cc: ocfs2-devel@oss.oracle.com Cc: reiserfs-devel@vger.kernel.org --- fs/proc/root.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/proc') diff --git a/fs/proc/root.c b/fs/proc/root.c index 87dbcbef7fe4..ac823a85cf6e 100644 --- a/fs/proc/root.c +++ b/fs/proc/root.c @@ -92,6 +92,8 @@ static int proc_parse_options(char *options, struct pid_namespace *pid) int proc_remount(struct super_block *sb, int *flags, char *data) { struct pid_namespace *pid = sb->s_fs_info; + + sync_filesystem(sb); return !proc_parse_options(data, pid); } -- cgit v1.2.3-58-ga151