From 26dd4e799e75381c681a711bf9fb960eb342cbea Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Wed, 27 Apr 2011 11:49:09 -0400 Subject: [PATCH] nfs: don't lose MS_SYNCHRONOUS on remount of noac mount commit 26c4c170731f00008f4317a2888a0a07ac99d90d upstream. On a remount, the VFS layer will clear the MS_SYNCHRONOUS bit on the assumption that the flags on the mount syscall will have it set if the remounted fs is supposed to keep it. In the case of "noac" though, MS_SYNCHRONOUS is implied. A remount of such a mount will lose the MS_SYNCHRONOUS flag since "sync" isn't part of the mount options. Reported-by: Max Matveev Signed-off-by: Jeff Layton Signed-off-by: Trond Myklebust Signed-off-by: Paul Gortmaker --- fs/nfs/super.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/fs/nfs/super.c b/fs/nfs/super.c index ae570b0360da6..85958a1d0433e 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -1989,6 +1989,15 @@ nfs_remount(struct super_block *sb, int *flags, char *raw_data) if (error < 0) goto out; + /* + * noac is a special case. It implies -o sync, but that's not + * necessarily reflected in the mtab options. do_remount_sb + * will clear MS_SYNCHRONOUS if -o sync wasn't specified in the + * remount options, so we have to explicitly reset it. + */ + if (data->flags & NFS_MOUNT_NOAC) + *flags |= MS_SYNCHRONOUS; + /* compare new mount options with old ones */ error = nfs_compare_remount_data(nfss, data); out: -- 2.47.3