| From 26c4c170731f00008f4317a2888a0a07ac99d90d Mon Sep 17 00:00:00 2001 |
| From: Jeff Layton <jlayton@redhat.com> |
| Date: Wed, 27 Apr 2011 11:49:09 -0400 |
| Subject: nfs: don't lose MS_SYNCHRONOUS on remount of noac mount |
| |
| From: Jeff Layton <jlayton@redhat.com> |
| |
| 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 <makc@redhat.com> |
| Signed-off-by: Jeff Layton <jlayton@redhat.com> |
| Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| fs/nfs/super.c | 9 +++++++++ |
| 1 file changed, 9 insertions(+) |
| |
| --- a/fs/nfs/super.c |
| +++ b/fs/nfs/super.c |
| @@ -1981,6 +1981,15 @@ nfs_remount(struct super_block *sb, int |
| 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: |